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Patent Searching and Data


Title:
SYSTEM AND METHOD FOR CONTROLLING A GRINDER
Document Type and Number:
WIPO Patent Application WO/2019/191443
Kind Code:
A1
Abstract:
A tool is provided and includes a tool frame. The tool frame includes a spindle and an abrasive article is mounted to the spindle. Further, a spark-invariant sensor is coupled to the frame and is configured to measure the rotation rate of the abrasive article.

Inventors:
SINGH VIVEK (US)
GOULET REMI (US)
RAGHU GOWDA BELAGUMBA VENKATACHALAIAH (US)
ARCONA CHRISTOPHER (US)
WRIGHT ROBERT (US)
VINCENTELLI GUILLERMO (US)
SAHLIN KATHERINE (US)
GEBB II DAVID (US)
HOWARD MILO (US)
MILLOT PATRICK (US)
Application Number:
PCT/US2019/024602
Publication Date:
October 03, 2019
Filing Date:
March 28, 2019
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
SAINT GOBAIN ABRASIVES INC (US)
SAINT GOBAIN ABRASIFS SA (FR)
International Classes:
B24B23/02; B24B49/10; B24B49/12; B24B55/05
Foreign References:
US20080032601A12008-02-07
US20140216735A12014-08-07
US20150263592A12015-09-17
US5827111A1998-10-27
US20150148937A12015-05-28
Attorney, Agent or Firm:
CHURILLA, J., Eric et al. (US)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1. A tool comprising:

a tool frame including a spindle;

an abrasive article mounted to the spindle; and

a spark-invariant sensor coupled to the frame and configured to measure the rotation rate of the abrasive article.

2. A sensor for mounting to a tool comprising:

a sensor arm;

a spark-invariant sensor coupled to the sensor arm; and

a spacing mechanism coupled to the sensor arm and configured to move between a plurality of positions and control the placement of the spark-invariant sensor relative to a sensing target.

3. A sensor for mounting to a tool comprising:

a sensor arm;

a spark-invariant sensor coupled to the sensor arm; and

a shield coupled to the sensor arm and disposed adjacent to the spark-invariant sensor.

4. A tool system comprising:

a tool frame;

a spark-invariant sensor mounted to the tool frame, wherein the spark-invariant sensor is configured to detect one or more sensing targets and generate a sensing signal; a logic element configured to receive the sensing signal and generate one or more instructions in response to the sensing signal; and

a controller in communication with the logic element and configured to receive the instruction and adjust a condition of the tool or provide a diagnostic condition of the tool.

5. The tool, sensor, or tool system according to any of claims 1, 2, 3, or 4, wherein the spark- invariant sensor comprises an inductive sensor.

6. The tool, sensor, or tool system according to any of claims 1, 2, 3, or 4, wherein the spark- invariant sensor comprises a fiber optic sensor.

7. The tool, sensor, or tool system according to any of claims 1, 2, 3, or 4, wherein the spark- invariant sensor is configured to interact with at least one sensing target.

8. The tool, sensor, or tool system according to claim 7, wherein the at least one sensing target is coupled to the tool.

9. The tool, sensor, or tool system according to claim 7, wherein the at least one sensing target is coupled to the spindle and configured to rotate with the abrasive article.

10. The tool, sensor, or tool system according to claim 7, wherein the at least one sensing target is configured to move relative to the spark-invariant sensor.

11. The tool, sensor, or tool system according to claim 7, wherein the at least one sensing target is configured to rotate with the abrasive article during use.

12. The tool, sensor, or tool system according to any of claims 1, 2, 3, or 4, further comprising a shield disposed adjacent to the spark-invariant sensor.

13. The tool, sensor, or tool system according to claim 12, wherein the shield is disposed between the spark-invariant sensor and at least a portion of the tool frame.

14. The tool system according to claim 4, wherein the logic element is configured to analyze a plurality of operation data and generate RPM data.

15. The tool system according to claim 4, wherein the controller is coupled to a valve configured to control a pressure of fluid to the tool.

Description:
SYSTEM AND METHOD FOR CONTROLLING A GRINDER

TECHNICAL FIELD

The present invention relates, in general, to grinders and pneumatic grinders.

BACKGROUND ART

Grinders can be used to smooth and contour the edges of certain metallic materials, e.g., sheets of steel, for safety and cosmetic reasons. Such grinders may utilize abrasive grinding wheels that may further include diamond-containing abrasive wheels and may be used to shape the edges of materials for various industries, including but not limited to automotive, architectural, furniture, and appliance industries. Further, grinders can be used for cutting operations, grinding operations, or a combination thereof.

The industry continues to demand improved grinders, particularly for pneumatic grinders.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings.

FIG. 1 includes an illustration of a control system for a grinder in accordance with an embodiment.

FIG. 2 includes an illustration of a perspective view of a grinder head for a grinder in accordance with an embodiment.

FIG. 3 includes an illustration of another perspective view of a grinder head for a grinder in accordance with an embodiment.

FIG. 4 includes an illustration of a side plan view of a grinder head for a grinder in accordance with an embodiment.

FIG. 5 includes an illustration of another side plan view of a grinder head for a grinder in accordance with an embodiment.

FIG. 6 includes an illustration of a top plan view of a locking flange for a grinder in accordance with an embodiment.

FIG. 7 includes an illustration of a side plan view of a locking flange for a grinder in accordance with an embodiment.

FIG. 8 includes an illustration of a top plan view of another locking flange for a grinder in accordance with an embodiment. FIG. 9 includes an illustration of a side plan view of another locking flange for a grinder in accordance with an embodiment.

FIG. 10 includes an illustration of a top plan view of yet another locking flange for a grinder in accordance with an embodiment.

FIG. 11 includes an illustration of a side plan view of yet another locking flange for a grinder in accordance with an embodiment.

FIG. 12 includes an illustration of a top plan view of still another locking flange for a grinder in accordance with an embodiment.

FIG. 13 includes an illustration of a side plan view of still another locking flange for a grinder in accordance with an embodiment.

FIG. 14 includes an illustration of a perspective view of another grinder head for a grinder in accordance with an embodiment.

FIG. 15 includes an illustration of a front plan view of another grinder head for a grinder in accordance with an embodiment.

FIG. 16 includes an illustration of a top plan view of another grinder head for a grinder in accordance with an embodiment.

FIG. 17 includes an illustration of a side plan view of another grinder head for a grinder in accordance with an embodiment.

FIG. 18 includes an illustration of a perspective view of a sensor assembly for a tool in accordance with an embodiment.

FIG. 19 includes an illustration of a front plan view of a sensor assembly for a tool in accordance with an embodiment.

FIG. 20 includes an illustration of a top plan view of a sensor assembly for a tool in accordance with an embodiment.

FIG. 21 includes an illustration of a side plan view of a sensor assembly for a tool in accordance with an embodiment.

FIG. 22 includes an illustration of a flow chart of a method of controlling a grinder in accordance with an embodiment.

FIG. 23 includes an illustration of a perspective view of an inner protective shield for a sensor assembly for a tool in accordance with an embodiment.

FIG. 24 includes an illustration of a side plan view of an inner protective shield for a sensor assembly for a tool in accordance with an embodiment.

FIG. 25 includes an illustration of a front plan view of an inner protective shield for a sensor assembly for a tool in accordance with an embodiment. FIG. 26 includes an illustration of a top plan view of an inner protective shield for a sensor assembly for a tool in accordance with an embodiment.

FIG. 27 includes an illustration of a perspective view of an inner protective shield for a sensor assembly for a tool in accordance with an embodiment.

FIG. 28 includes an illustration of a side plan view of an inner protective shield for a sensor assembly for a tool in accordance with an embodiment.

FIG. 29 includes an illustration of a front plan view of an inner protective shield for a sensor assembly for a tool in accordance with an embodiment.

FIG. 30 includes an illustration of a top plan view of an inner protective shield for a sensor assembly for a tool in accordance with an embodiment.

FIG. 31 includes an illustration of a perspective view of another grinder head for a grinder in accordance with an embodiment.

FIG. 32 includes an illustration of a front plan view of another grinder head for a grinder in accordance with an embodiment.

FIG. 33 includes an illustration of a top plan view of another grinder head for a grinder in accordance with an embodiment.

FIG. 34 includes an illustration of a side plan view of another grinder head for a grinder in accordance with an embodiment.

FIG. 35 includes an illustration of a side plan view of another grinder head for a grinder in accordance with an embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMB ODIMENT (S )

The following is generally directed to a grinder and a method of controlling a grinder.

Embodiments are directed to a system for controlling a tool such as a grinder. The grinder includes a sensing target and a spark-invariant sensor. As the sensing target moves past the spark-invariant sensor, a signal is generated. A logic element coupled to the spark- invariant sensor utilizes the signals from the sensor to diagnose the tool, adjust the speed of the tool, and warn the user if there are issues with the tool.

SYSTEM FOR CONTROLLING A GRINDER

Referring initially to FIG. 1 a system for controlling a tool, e.g., a grinder, is illustrated and is generally designated 100. As shown, the system can include a tool, e.g., a grinder 102. In a particular aspect, the grinder 102 is a fluid controlled grinder, e.g., a pneumatic grinder, and the grinder 102 can be connected to a fluid valve, e.g., an air valve 104, via a first air line 106. The air valve 104 can be connected to an air compressor 108 via a second air line 110. It can be appreciated that the air lines may be considered fluid lines. In a particular aspect, the grinder 102 can include a logic element 112 and a spark- invariant sensor 114 connected to the logic element 112 via line 116. The logic element 112 can include a processing device, e.g., a microprocessor. Further, the spark-invariant sensor 114 can include an inductive sensor.

As shown in FIG. 1, the logic element 112 can be connected to the air valve 104 via line 118. In another aspect, the logic element 112 can communicate with the air valve 104 wirelessly, e.g., via a wireless fidelity (Wi-Fi) connection, a Bluetooth connection, a light fidelity (Li-Fi) connection, an infrared connection, a near field communication (NFC) connection, or some other wireless connection. Regardless, the air valve 104 is a smart valve that may be opened and closed in response to one or more signals received from the logic element 112.

FIG. 1 further shows that the grinder 102 can include a tool frame, e.g., a body 120, having a handle 122. Moreover, the grinder 102 can include a grinding head assembly 124 coupled to the body 120. In a particular aspect, and described in greater detail below, the grinding head assembly 124 can include the spark-invariant sensor 114. The spark-invariant sensor 114 can be coupled to the body 120, i.e., the tool frame.

As illustrated in FIG. 1, the system 100 can further include a downstream air pressure sensor 130 between the air valve 104 and the grinder 102 and an upstream air pressure sensor 132 between the air valve 104 and the air compressor 108. These sensors may also be connected to the logic element 112 via wireless connections or wired connections 134, 136. The logic element 112 may use air pressure data fore and aft of the air valve 104 in conjunction with RPM data from the grinder 102 to determine whether there are issues with the grinder 102 or with the air supply from the air compressor 108 during operation of the grinder 102. This information may be further used to provide a diagnostic condition of the tool, e.g., the grinder 102.

GRINDING HEAD ASSEMBLY

Referring now to FIG. 2 through FIG. 5, details concerning the grinding head assembly 124 are depicted. As shown, the grinding head assembly 124 can include a spindle 200 around which an abrasive article 202 is mounted or installed. The spindle 200 can include a plurality of external threads 204 extending at least partially along the length of the spindle 200. In a particular aspect, the abrasive article 202 can be a grinding wheel, a cut-off wheel, or some other abrasive wheel.

FIG. 2 through FIG. 5 further indicate that the grinding head assembly 124 can include a locking flange 206 that fits around the spindle 200 adjacent to the abrasive article 202. The locking flange 206 can include internal threads that are sized and shaped to threadably engage the external threads 204 formed on the spindle 200. In a particular aspect, the locking flange 206 can be tightened onto the spindle 200 using a spanner wrench (not shown). In a particular aspect, the spindle 200 and the locking flange 206 are formed with left-hand threads so that the locking flange 206 will not spin of off the spindle 200 during use of the grinder 102 on which the grinding head assembly 124 is installed.

The locking flange 206 is described in greater detail below in conjunction with FIG. 6 and FIG. 7 and the locking flange 206 can include at least one sensing target 208 formed in the locking flange 206 or extending from the locking flange 206. It can be appreciated that the locking flange 206 can be coupled to the tool, e.g., the grinder 102, via the spindle 200. Further, the locking flange 206 can be configured to be coupled to the spindle 200 as shown and further, the locking flange 206 can be configured to rotate with the abrasive article 202 as the spindle 200 rotates. The at least one sensing target 208 is configured to move relative to a spark-invariant sensor, described in greater detail below. In particular, the at least one sensing target 208 is configured to rotate with the abrasive article 202 during use. Moreover, the at least one sensing target 208 is configured to rotate relative to the spark-invariant sensor.

As illustrated, the grinding head assembly 124 may include an outer protective shield 210 that can extend at least partially around the abrasive article 202. In particular aspect, the outer protective shield 210 can extend around at least 50% of the abrasive article 202. FIG. 2 through FIG. 5 further indicate that the grinding head assembly 124 can further include a retractable sensor assembly 220 that this affixed to the outer protective shield 210.

In particular, the retractable sensor assembly 220 can include an articulating element, e.g., a hinge 222. In lieu of a hinge 222, the articulating element may include a ball joint. Further, the articulating element may provide rotational movement, translational movement, or a combination thereof. Moreover, the articulating element can provide three degrees of movement.

As illustrated, the hinge 222 can include a static leaf 224 and a rotatable leaf 226.

The static leaf 224 and the rotating leaf 226 of the hinge 222 can be rotatably connected to each other via a hinge pin 228 having a proximal end 230 and a distal end 232. The proximal end 230 of the hinge pin 228 can include a handle 234 fitted over the proximal end 230 and held in place via a screw 236. The distal end 232 of the hinge pin 228 can be threaded and can extend through a first knuckle 238 and a second knuckle 240 of the static leaf 224, through a first knuckle 242 of the rotatable leaf 226, and threadably engage a second knuckle 244 of the rotatable leaf 226. Accordingly, the second knuckle 244 of the rotatable leaf 226 is threaded. In a particular aspect, the hinge pin 228 can be made from a material that can withstand high temperatures, e.g., the high temperatures associated with cutting and grinding operations typically associated with a grinder. For example, the hinge pin 228 can be made from metal such as stainless steel. Further, the hinge pin 228 can be made from a high temperature polymer. In another aspect, the hinge pin 228 can be made from a ceramic material. Moreover, the hinge pin 228 can be a composite material made from metals, high temperature polymers, ceramics, or any combination thereof.

During use, the retractable sensor assembly 220 can be loosened by rotating the hinge pin 228 in a counter-clockwise direction using the handle 234. Conversely, the retractable sensor assembly 220 can be tightened by rotating the hinge pin 228 in a clockwise direction using the handle 234. Tightening the hinge pin 228 will allow the retractable sensor assembly 220 to be locked in a sensing position or in an abrasive wheel removal position, described in greater detail below.

As illustrated, the static leaf 224 of the hinge 222 can be attached to the outer protective shield 210 using two or more threaded fasteners 246, e.g., machine screws.

Further, the retractable sensor assembly 220 can include a sensor arm 250. The sensor arm 250 can be a generally flat, rectangular plate having a proximal end 252 and a distal end 254. The proximal end 252 of the sensor arm 250 can be connected to the rotating leaf 226 of the hinge 222 via a pair of threaded fasteners 256, e.g., machine screws.

The distal end 254 of the sensor arm 250 can be formed with a bore 258. The bore 258 can extend through the sensor arm 250 in a direction perpendicular to a longitudinal axis of the sensor arm 250 between a first face and a second face of the sensor arm 250.

Moreover, as illustrated in FIG. 2 through FIG. 5, a spark-invariant sensor 114 can be installed within the bore 258 formed in the distal end 254 of the sensor arm 250. In a particular aspect, the spark-invariant sensor 114 can include an inductive sensor. In another aspect, the spark-invariant sensor 114 can include an inductive proximity switch. Moreover, the spark- invariant sensor 114 can include a switching frequency that is higher than the maximum rotational speed, i.e., revolutions per minute (RPM), of the grinding head assembly 124. In another aspect, the spark- invariant sensor 114 can include a fiber optic sensor.

The spark-invariant sensor 114 can be a high temperature resistant sensor and can be used with temperatures greater than or equal to 150° Celsius (C). Further, the spark-invariant sensor 114 can be used with temperatures greater than or equal to 160° C, such as greater than or equal to 170° C, or greater than or equal to 180° C. In another aspect, spark-invariant sensor 114 can be used with temperatures less than or equal to 220° C, such as less than or equal to 210° C, less than or equal to 200° C, or less than or equal to 190° C.

In a particular aspect, the spark- invariant sensor 114 is generally cylindrical, but other types of shapes may be used. It can be appreciated that in the case of a generally cylindrical shape, the spark- invariant sensor 114 can be formed with external threads and can be held in place on the sensor arm 250 using a first nut 262 and a second nut 264. Further, the spark- invariant sensor 114 can include a proximal end 266 and a distal end 268. The nuts 262, 264 and external threads of the spark- invariant sensor 114 can act as a spacing mechanism that includes a plurality of positions and by manipulating the nuts 262, 264, the spacing mechanism, and the spark-invariant sensor 114, can be moved between the plurality of positions. Accordingly, the spacing mechanism is configured to move between the plurality of positions and control the placement of the spark-invariant sensor 114 relative to the at least one sensing target 208. Further, the spacing mechanism is configured to move between the plurality of positions and control the placement of the spark-invariant sensor 114 relative to the tool frame, e.g., the body 120 of the grinder 102.

The spark-invariant sensor 114 can be configured to work in conjunction with the at least one sensing target 208 that is part of the locking flange 206. Further, the spark- invariant sensor 114 can be spaced apart from the locking flange 206 such that a sensing distance, Ds, between an upper face of the at least one sensing target 208 when it passes beneath a lower face of the distal end 268 is less than or equal to 5 millimeters (mm). Further, Ds can be less than or equal to 4.5 mm, such as less than or equal to 4.0 mm, less than or equal to 3.5 mm, less than or equal to 3.0 mm, less than or equal to 2.5 mm, or less than or equal to 2.0 mm. In another aspect, Ds, can be greater than or equal to 0.25 mm, such as greater than or equal to 0.5 mm, greater than or equal to 0.75 mm, greater than or equal to 1.0 mm, greater than or equal to 1.25 mm, greater than or equal to 1.5 mm, or greater than or equal to 1.75 mm. It is to be understood that Ds can be within a range between and including any of the maximum and minimum values of Ds described herein. It can be appreciate that Ds can be adjusted via the spacing mechanism described above.

During use, the distal end 268 of the spark-invariant sensor 114 can be placed near the locking flange 206 in order to sense rotational movement of the sensing target 208 as the locking flange 206 rotates in conjunction with the spindle 200 and the abrasive article 202. The proximal end 266 of the spark-invariant sensor 114 can include a connector 272 that can be connected to a processing device (not shown in FIG. 2). As described in greater detail below, the spark-invariant sensor 114 can operate in conjunction with the processing device and the sensing target 208 on the locking flange 206 in order to determine the speed of the abrasive article 202 as it rotates during operation of the grinder 120 or, more specifically, during operation of the grinding head assembly 124.

FIG. 2 through FIG. 5 further indicate that the retractable sensor assembly 220 can include an inner protective shield 280 placed adjacent to the spark- invariant sensor 114. In one aspect, the inner protective shield 280 can be disposed between the spark-invariant sensor 114 and at least a portion of the tool frame, e.g., between the spark-invariant sensor 114 and the outer protective shield 210. Further, the inner protective shield 280 can be disposed between the spark-invariant sensor 114 and at least a portion of the abrasive article 202. As illustrated, the inner protective shield 280 that can extend at least partially around a portion, or all, of the spark-invariant sensor 114. For example, the inner protective shield 280 can be generally partially cylindrically- shaped and the inner protective shield 280 can at least partially envelope the spark-invariant sensor 114.

In a particular aspect, the partially cylindrically-shaped inner protective shield 280 can include a central angle, a, that can be greater than or equal to 120°. Further, a can be greater than or equal to 130°, such as greater than or equal to 140°, greater than or equal to 150°, greater than or equal to 160°, greater than or equal to 170°, or greater than or equal to 180°. Further, a can be less than or equal to 240°, such as less than or equal to 230°, less than or equal to 220°, less than or equal to 210°, less than or equal to 200°, or less than or equal to 190°. In a particular aspect, a, can be within a range between and including any of the minimum and maximum values of a described herein. In still another embodiment, the inner protective shield 280 can be cylindrical and can completely surround the spark-invariant sensor 114. In such a case, a can be 360°.

In another aspect, the spark-invariant sensor 114 can have a radius, Rsis, and the inner protective shield 280 can also have a radius, R IPS , and a ratio of R IPS to Rsis can be greater than or equal to 2.0. In another aspect, the ratio of R IPS to Rsis can be greater than or equal to 2.5, such as greater than or equal to 3.0, greater than or equal to 3.5, greater than or equal to 4.0, greater than or equal to 4.5, greater than or equal to 5.0, or greater than or equal to 5.5.

In another aspect, the ratio of R IPS to Rsis can be less than or equal to 10.0, such as less than or equal to 9.5, less than or equal to 9.0, less than or equal to 8.5, less than or equal to 8.0, less than or equal to 7.5, less than or equal to 7.0, less than or equal to 6.5, or less than or equal to 6.0. In another aspect, the ratio of R IPS to Rsis can be within a range between an including any of the minimum and maximum values of R iP s to Rsis described above. Further, as best illustrated in FIG. 5, the inner protective shield 280 is off-centered from the spark-invariant sensor 114. In other words, the center of the inner protective shield 280 is offset from the center of the invariant sensor 114 by an offset distance, Do- It is to be understood that this offset distance, Do, is a lateral offset between the center of inner protective shield 280 and the center of the invariant sensor 114. In a particular aspect, a ratio of Do to R IPS can be less or equal to 95%. Further, the ratio of Do to Rn > s can be less than or equal to 90%, such as less than or equal to 85%, less than or equal to 80%, or less than or equal to 75%. In another aspect, the ratio of Do to R IPS can be greater than or equal to 50%, such as greater than or equal to 55%, greater than or equal to 60%, or greater than or equal to 65%. In another aspect, the ratio of Do to R iP s can be within a range between and including any of the minimum and maximum values of Do to R IPS described above.

In a particular aspect, the inner protective shield 280 can be connected to the distal end 254 of the sensor arm 250 via an L bracket 282 that is held in place by a threaded fastener 284. In a particular aspect, the threaded fastener 284 can act as a stop mechanism and can be used to level the spark-invariant sensor 114 with respect to the outer protective shield 210. In other words, the threaded fastener 284 (as a stop mechanism) can be used to ensure that a long axis of the spark- invariant sensor 114 is perpendicular to an upper surface of the outer protective shield 210. The L bracket 282 can include a slot (not shown) that can allow the L bracket 282 and the inner protective shield 280 to move linearly along the sensor arm 250, e.g., along the longitudinal axis of the sensor arm 250. The inner protective shield 280 can be made from a metal. For example, the inner protective shield 280 can be made from copper. In another aspect, the inner protective shield 280 can be made from iron, or an iron alloy such as steel. Further, the inner protective shield 280 can include a coating over the entire inner protective shield 280, such as a ceramic coating or an amorphous inorganic coating. In another aspect, the inner protective shield 280 can include a plated coating, e.g., a chrome plated coating. The various coatings may provide improved wear resistance, may reduce friction, and/or may facilitate the dispersal of sparks away from the spark-invariant sensor 114. For example, to reduce friction, the coating can include molybdenum sulfide (MoS2), tungsten sulfide (WS2), or Teflon (PTFE). Further, to reduce wear, the coating can include tungsten carbide (WC) or chrome carbide (Cr3C2). The low-friction may prevent sparks from sticking and it may slowly erode. The wear-resistant coating may not prevent sparks from sticking, but it may protect the underlying metal surface longer than the low- friction coating. The articulating element, e.g., the hinge 222, allows the sensor arm 250 and the spark- invariant sensor 114 to move between a disengaged position and an engaged position. In the disengaged position, the sensor arm 250 and the spark-invariant sensor 114 is rotated away from the abrasive article 202 to allow removal of the locking flange 206, e.g., using a spanner wrench (not shown), in order to remove and replace the abrasive article 202. In the engaged position, the sensor arm 250 and the spark-invariant sensor 114 is rotated toward the abrasive article 202 so that the spark-invariant sensor 114 is in position to sense the sensing target 208 on the locking flange 206 as the abrasive article 202 and locking flange 206 rotate in conjunction with the spindle 200.

It can be appreciated that when the grinder 102 is energized and the abrasive article 202 rotates on the spindle 200, the locking flange 206 and the sensing target 208 will also rotate. As the sensing target 208 moves past the spark-invariant sensor 114 it will cause the spark-invariant sensor 114 to pulse and send a signal to the logic element 112. In other words, the spark-invariant sensor 114 is configured to detect the one or more sensing targets 208 and generate a sensing signal when the one or more sensing target 208 is detected. The logic element 112 is configured to receive the sensing signal and store the sensing signal as operation data. Further, the logic element 112 is configured to analyze a plurality of operation data and generate speed, or RPM, data. The logic element 112 is further configured to compare the RPM data to stored data, e.g., in a data table, and generate an instruction that can be transmitted to a controller within the air valve 104. The controller within the air valve 104 is configured to receive the instruction from the logic element and adjust a pressure to the tool, e.g., the grinder 102. In particular, the controller is coupled to, or disposed within, the air valve 104, which, in turn, is configured to control a pressure of fluid, e.g., air, to the tool, e.g., the grinder 102. The logic element 112 can use data from the spark-invariant sensor 114 to diagnose the tool, e.g., the grinder 102 and the abrasive article 202, and warn the user. For example, using the spark-invariant sensor 114 and the pressure sensors 130, 132, the system 100 is able to determine the actual speed of the abrasive article 202 and compare the speed to a table of operational speeds for various abrasive articles 202 (e.g., based on size). The system 100 can prevent over spinning of the abrasive article 202 prior to engagement of the abrasive article 202 with a workpiece, e.g., for a cutting operation, a grinding operation, or a combination thereof. It can be appreciated that in lieu of a sensing target 208, a fiber optic spark-invariant sensor 114 may utilize another feature or characteristic of the grinder 102 as a target. For example, the spindles 200 of certain grinders 102 may be formed with a vertical notch. The fiber optic spark-invariant sensor 114 can use this notch as a target in order to determine the rotational speed of the grinder 102 during use. In other words, each time the vertical notch passes the fiber optic spark- invariant sensor 114 it can be detected by the fiber optic spark-invariant 114 causing the fiber optic spark-invariant sensor 114 to produce a pulse or signal.

LOCKING FLANGE

Referring now to FIG. 6 and FIG. 7, details concerning the locking flange 206 are shown. As illustrated, the locking flange 206 can include a generally ring-shaped body 600. The body 600 of the locking flange 206 includes a central bore 602 that extends through the entire body 600 and that is sized and shaped to fit over the spindle 200 of the grinding head assembly 124. The body 600 of the locking flange 206 is also formed with at least one sensing target bore 604 formed in the body 600 of the locking flange 206 between the central bore 602 and the outer periphery of the locking flange 206. It can be appreciated that the sensing target bore 604 may be detected by the spark-invariant sensor 114 to generate a signal as the sensing target bore 604 moves past the end of the spark-invariant sensor 114.

The difference between the detectable metal locking flange 206 and the lack of sensing material provided by the sensing target bore 604 provides a detectable pulse that can be used to determine the speed of the locking flange 206 and an abrasive article engaged therewith.

It can be appreciated that in another aspect the at least one sensing target 208 can be disposed within the at least one sensing target bore 604 formed in the body 600 of the locking flange 206. In a particular aspect, the at least one sensing target 208 can be press fitted into the at least one sensing target bore 604. Further, the at least one sensing target 208 can be flush with the upper surface of the body 600 of the locking flange 206.

In a particular aspect, the sensing target 208 can be made from a metal or a metal alloy. For example, the sensing target 208 can be made from iron or mild steel. Further, the sensing target 208 can be made from 4340 steel or 4140 steel. In a particular aspect, the sensing target 208 can be made from a metal having a tensile strength greater than or equal to 60,000 psi.

It is to be understood that the sensing target 208 can be made from a non-detectable material, a material that is more detectable than the locking flange 206, or a material that is less detectable than the locking flange 206. Regardless, to create a signal with a flush mounted sensing target 208, a difference in detectability between the sensing target 208 and the locking flange 206 will create a signal pulse that can be used to determine the speed of the locking flange 206. In an alternative embodiment of a locking flange 800, illustrated in FIG. 8 and FIG. 9, the sensing target 802 may not be flush with an upper surface of the locking flange 804 and the sensing target 802 can extend beyond the upper surface of the body 804 of the locking flange 800. In this embodiment, the sensing target 802 and the body 804 of the locking flange 800 may be constructed from the same material or from different materials.

Further, in another embodiment of a locking flange 1000, depicted in FIG. 10 and FIG. 11, the sensing target 1002 can be affixed to, or otherwise disposed on, an upper surface of the body 1004 of the locking flange 1000. In this embodiment, the sensing target 1002 and the body 1004 of the locking flange 1000 may be constructed from the same material or from different materials.

Finally, in yet another embodiment of a locking flange 1200, shown in FIG. 12 and FIG. 13, the sensing target 1202 can be threadably engaged with a threaded bore 1204 formed in the body 1206 of the locking flange 1200. In this embodiment, the sensing target 1202 and the body 1204 of the locking flange 1200 may be constructed from the same material or from different materials.

Each of the embodiments of the locking flange 206, 800, 1000, 1200 show four sensing targets 208, 802, 1002 ,1202, but it can be appreciated that any number of sensing targets 208, 802, 1002, 1202 may be incorporated into, affixed to, or engaged with the locking flange 206, 800, 1000, 1200 (e.g., one, two, three, four, five, six, seven, eight, nine, ten, etc.)

ADDITIONAL GRINDING HEAD ASSEMBLY

Referring now to FIG. 14, another grinding head assembly is shown and is generally designated 1400. As illustrated, the grinding head assembly 1400 is substantially identical to the grinding head assembly 124 described above. However, in lieu of an inner protective shield, the grinding head assembly 124 can include a protective sleeve 1402 that can fit around the spark-invariant sensor 1404. The protective sleeve 1402 may be constructed from a polymer material. For example, the protective sleeve 1402 may be made from

polyetherimide (PEI) or poly ether ether ketone (PEEK). In another aspect, the protective sleeve 1402 can be made from a thermoset polymer capable of withstanding relatively high operating temperatures without melting. For example, the protective sleeve 1402 can be made from a thermoset polymer such as polyimide.

In a particular aspect, the protective sleeve 1402 includes an average wall thickness,

T, and the spark-invariant sensor 1404 has an average diameter, D. In a particular aspect, T can be greater than or equal to 0.5 mm. Further, T can be greater than or equal to 0.75 mm, such as greater than or equal to 1.0 mm, greater than or equal to 1.25 mm, or greater than or equal to 1.5 mm. In another aspect, T can be less than or equal to 2.5 mm, such as less than or equal to 2.25 mm, less than or equal to 2.0 mm, or less than or equal to 1.75 mm. It is to be understood that T can be within a range between, and including, any of the minimum and maximum values for T described herein.

In another aspect, D can be greater than or equal to 5.0 mm. Moreover, D can be greater than or equal to 5.5 mm, such as greater than or equal to 6.0 mm, greater than or equal to 6.5 mm, greater than or equal to 7.0 mm, greater than or equal to 7.5 mm, or greater than or equal to 8.0 mm. In yet another aspect, D can be less than or equal to 10.0 mm, such as less than or equal to 9.5 mm, less than or equal to 9.0 mm, or less than or equal to 8.5 mm. It is to be understood that D can be within a range between, and including, any of the minimum and maximum values for T described herein.

In another aspect, a ratio of T:D can be greater than or equal to 0.05. Further, T:D can be greater than or equal to 0.10, such as greater than or equal to 0.15, or greater than or equal to 0.20. In another aspect, T:D can be less than or equal to 3.5, such as less than or equal to 3.0, or less than or equal to 0.25. It can be appreciated that T:D can be within a range between, and including, any of the values of T:D described herein.

The protective sleeve 1402 can be formed with internal threads and the protective sleeve 1402 can be threadably engaged with external threads on the spark-invariant sensor 1404. A lateral set screw (not shown) can extend through the side wall of the protective sleeve 1402 and can be tightened in order to prevent the protective sleeve 1402 from rotating and disengaging from the spark-invariant sensor 1404. In another aspect, the protective sleeve 1402 can be sized so that it may be press fitted over the spark-invariant sensor 1404.

FIG. 17 further shows that the grinding head assembly 1400 can include a stop mechanism 1406, e.g., a threaded bolt that extends through the sensing arm 1408 of the grinding head assembly 1400. The stop mechanism 1406 can be used to level the spark- invariant sensor 1404 with respect to the outer protective shield 1410. In other words, the stop mechanism 1406 can be used to ensure that a long axis of the spark-invariant sensor 1404 is perpendicular to an upper surface of the outer protective shield 1410.

SENSOR ASSEMBLY

Referring now to FIG. 18 through FIG. 21, a sensor assembly is shown and is generally designated 1800. As illustrated, the sensor assembly 1800 can include a sensor arm 1802 having a proximal end 1804 and a distal end 1806. A fixed bracket 1814 can be attached to the proximal end 1804 of the sensor arm 1802. A movable bracket 1816 can be installed over the sensor arm 1802 between the fixed bracket 1814 and the distal end 1806 of the sensor arm 1802. The fixed bracket 1814 can be affixed to the sensor arm 1802 via a weld, a screw, a rivet, or other fastener. The movable bracket 1816 can be slid to a position selected by the user and then, a fastener (not shown), e.g., a thumb screw, a hand knob, or some other type of threaded fastener, can be used to secure the movable bracket 1816 in the selected position along the sensor arm 1802.

As most clearly illustrated in FIG. 18 and FIG. 20, the sensor arm 1802 can be formed with a slot 1820 that extends at least partially along a length of the sensor arm 1802. In a particular aspect, the slot 1820 has a length, Ls, and the sensor arm 1802 has a length L SA · In one aspect, a ratio L S :L SA can be greater than or equal to 0.15. Further, L S :L SA can be greater than or equal to 0.20, such as greater than or equal to 0.225, greater than or equal to 0.25, greater than or equal to 0.275, greater than or equal to 0.30, or greater than or equal to 0.325. In another aspect, L S :L SA can be less than or equal to 0.50, such as less than or equal to 0.475, less than or equal to 0.45, less than or equal to 0.425, less than or equal to 0.40, less than or equal to 0.375, or less than or equal to 0.35. It is to be understood that L S :L SA can be within a range between, and including, any of the minimum and maximum values described herein.

In another aspect, L SA can be greater than or equal to 4 inches. Further, L SA can be greater than or equal to 4.5 inches, such as greater than or equal to 5.0 inches, greater than or equal to 5.5 inches, greater than or equal to 6.0 inches, greater than or equal to 6.5 inches, greater than or equal to 7.0, greater than or equal to 7.5 inches, or greater than or equal to 8.0 inches. Further, L SA can be less than or equal to 15 inches. Further, L SA can be less than or equal to 14.5 inches, such as less than or equal to 14.0 inches, less than or equal to 13.5 inches, less than or equal to 13.0 inches, less than or equal to 12.5 inches, less than or equal to 12.0, less than or equal to 11.5 inches, less than or equal to 11.0 inches, less than or equal to 10.5 inches, or less than or equal to 10.0 inches. It is to be understood that L SA can be within a range between, and including, any of the minimum and maximum values described herein.

As depicted in FIG. 18 through FIG. 21, a spark-invariant sensor 1822 can be installed within the slot 1820. The spark-invariant sensor 1822 can be substantially identical to the spark-invariant sensor 114 described herein. The spark- invariant sensor 1822 can be formed with external threads and the spark-invariant sensor 1822 can be held in place within the slot 1820 by a pair of threaded nuts (not shown) placed above and below the sensor arm 1802. The sensor assembly 1800 can further include an inner protective shield (not shown) configured in a manner substantially identical the inner protective shield 280 described above. Alternatively, the sensor assembly 1800 can include a protective sleeve (not shown) that is fitted over the spark- invariant sensor 1822, e.g., near the sensing end of the spark- invariant sensor 1822. The protective sleeve (not shown) can be substantially identical to the protective sleeve 1402 described above. In another aspect, the protective sleeve can include internal and external threads and the spark- invariant sensor 1822 can be threaded into the protective sleeve and the threaded nuts can hold the spark-invariant sensor 1822 in place on the sensor arm 1802.

FIG. 18 through FIG. 21 further show that the fixed bracket 1806 includes a first lateral threaded fastener 1830. Moreover, the movable bracket 1806 can also include a second lateral threaded fastener 1832. When the sensor assembly 1800 is fitted over an outer protective shield 1840 of a grinding head assembly (not shown), the lateral threaded fasteners 1830, 1832 can be used to hold the sensor assembly 1800 in place on the outer protective shield 1840. Thereafter, the spark-invariant sensor 1822 can be moved into position to sense a sensing target (not shown) on a locking flange (not shown) installed on the grinding head assembly (not shown).

The configuration of the sensor assembly 1800 allows it to be fitted over grinding head assemblies of varying sizes. Specifically, the sensor assembly 1800 can be attached, or otherwise clamped, to the outer protective shields of most grinding head assemblies of most grinders. It can be appreciated that the sensor arm 1802 can be configured to allow the spark- invariant sensor 1822 to be slid in multiple directions to fine-tune the final position of the spark-invariant sensor 1822.

OPERATIONAL LOGIC

Referring now to FIG. 22, a method of controlling a grinder is shown and is generally designated 2200. Beginning at step 2202, when a tool, e.g., a grinder is activated, a do loop can be entered and the following steps can be performed. At step, 2204, a logic element, e.g., a microprocessor, can receive signals from a spark-invariant sensor. Moving to step 2206, the speed of the grinder in RPMs can be determined. Thereafter, at step 2208, the RPM speed can be compared to speed table for a particular workpiece material, a particular abrasive wheel, or a combination thereof.

Continuing to step 2210, it can be determined whether the speed is within a safe, or productive, operating range for the particular workpiece material, the particular abrasive wheel, or a combination thereof. If not, the method 2200 can proceed to step 2212 and the logic element can provide a warning to the operator of the grinder. For example, the logic element can provide a signal or instruction to energize a warning light near the operator or on the tool. Moving to step 2214, the logic element can transmit a signal to a fluid control valve, e.g., an air valve, to adjust the speed of the grinder. Thereafter, the method 2200 can return to step 2210 and continue as described.

At step 2210, if the speed is within the safe, or productive, operating range, the method 2200 may proceed to step 2216 and the operation of the grinder can continue.

Thereafter, the method 2200 can proceed to step 2218 and it can be determined whether the grinder, or tool, is de-activated. If so, the method 2200 may proceed to step 2220 and end. Returning to step 2218, if the grinder is not de-activated, i.e., the grinder remains in operation, method 2200 may return to step 2204 and continue as described herein.

ADDITIONAL INNER PROTECTIVE SHIELDS

Referring now to FIG. 23 through FIG. 26 another embodiment of an inner protective shield is shown and is generally designated 2300. As shown, the inner protective shield 2300 includes a generally cylindrical body 2302 having a first end 2304 and a second end 2306. The cylindrical body 2302 of the inner protective shield 2300 can include an inner surface 2308 and an outer surface 2310. Further, the cylindrical body 2302 of the inner protective shield 2300 can include an outer radial inset 2312 formed in the outer surface 2310 near the first end 2304 of the body 2302. The outer radial inset 2312 can extend radially inward from the outer surface 2310 of the body 2302. Further, the outer radial inset 2312 can extend axially from the first end 2304 of the body 2302 toward the second end 2306 of the body 2302 at least partially along a length of the body 2302.

FIG. 23 through 26 further illustrate that the cylindrical body 2302 of the inner protective shield 2300 can include an inner radial inset 2314 formed in the inner surface 2308 near the first end 2304 of the body 2302. The inner radial inset 2314 can extend radially outward from the inner surface 2310 of the body 2302. Moreover, the inner radial inset 2314 can extend axially from the first end 2304 of the body 2302 toward the second end 2306 of the body 2302 at least partially along a length of the body 2302. The inner radial inset 2314 can be substantially the same size and shape as the outer radial inset 2312. Further, the inner radial inset 2314 and the outer radial inset 2312 can form a mounting plate to facilitate mounting the inner protective shield 2300 to a sensor arm, e.g., the sensor arm 250 illustrated in FIG. 5. The body 2302 of the inner protective shield 2300 can include at least two radial bores 2316, or holes, formed in the mounting plate and extending from the inner radial inset 2314 to the outer radial inset 2312.

In a particular aspect, the body 2302 of the inner protective shield 2300 can be made from a metal, a metal alloy, or a combination thereof. Moreover, the inner protective shield 2300 can be made from copper, a copper alloy, aluminum, an aluminum alloy, tin, a tin alloy, iron, an iron alloy, nickel, a nickel alloy, titanium, a titanium alloy, or a combination thereof. In another aspect, the body 2302 of the inner protective shield 2300 can have a thickness, T, measured from the outer surface 2310 to the inner surface 2308, and T can be greater than or equal to 2 millimeters (mm). In another aspect, T can be greater than or equal to 2.5 mm, such as greater than or equal to 3.0 mm, greater than or equal to 3.5 mm, or greater than or equal to 4.0 mm. In still another aspect, T can be less than or equal to 6.5 mm, such as less than or equal to 6.0 mm, less than or equal to 5.5 mm, less than or equal to 5.0 mm, or less than or equal to 4.5 mm. It can is to be understood that T can be within a range between, and including, any of the minimum and maximum values of T described herein. It can be appreciated that the inner protective shield 2300 can protect a spark-invariant sensor installed therein from sparks created during a grinding operation performed adjacent to the spark- invariant sensor.

Referring to FIG. 27 through FIG. 30 another embodiment of an inner protective shield is shown and is generally designated 2700. As shown, the inner protective shield 2700 includes a generally cylindrical body 2702 having a first end 2704 and a second end 2706. The cylindrical body 2702 of the inner protective shield 2700 can include an inner surface 2708 and an outer surface 2710. Further, the cylindrical body 2702 of the inner protective shield 2700 can include an outer radial inset 2712 formed in the outer surface 2710 near the first end 2704 of the body 2702. The outer radial inset 2712 can extend radially inward from the outer surface 2710 of the body 2702. Further, the outer radial inset 2712 can extend axially from the first end 2704 of the body 2702 toward the second end 2706 of the body 2702 at least partially along a length of the body 2702.

FIG. 27 through 26 further illustrate that the cylindrical body 2702 of the inner protective shield 2700 can include an inner radial inset 2714 formed in the inner surface 2708 near the first end 2704 of the body 2702. The inner radial inset 2714 can extend radially outward from the inner surface 2710 of the body 2702. Moreover, the inner radial inset 2714 can extend axially from the first end 2704 of the body 2702 toward the second end 2706 of the body 2702 at least partially along a length of the body 2702. The inner radial inset 2714 can be substantially the same size and shape as the outer radial inset 2712. Further, the inner radial inset 2714 and the outer radial inset 2712 can form a mounting plate to facilitate mounting the inner protective shield 2700 to a sensor arm, e.g., the sensor arm 250 illustrated in FIG. 5. The body 2702 of the inner protective shield 2700 can include at least two radial bores 2716, or holes, formed in the mounting plate and extending from the inner radial inset 2714 to the outer radial inset 2712.

FIG. 27 through FIG. 30 further indicate that the inner protective shield 2700 can include an axial inset 2720 formed in the body 2702. The axial inset 2720 can extend from the first end 2704 of the body 2702 toward the second end 2706 of the body 2702 at least partially along a length of the body 2702. The axial inset 2720 can include a cover plate 2722 that can extend at least partially over an inner bore 2724 bound by the inner surface 2708 of the body 2702 of the inner protective shield 2700. In a particular aspect, the inner bore 2724 can have an area, A ro , and the cover plate 2722 can have an area Acp and Acp can be greater than or equal to 25% A IB . Further, Acp can be greater than or equal to 30% A ro , such as greater than or equal to 35% A IB , or greater than or equal to 40% A IB . In another aspect, Acp can be less than or equal to 60% A IB , such as less than or equal to 55% A IB , less than or equal to 50% A ro , or less than or equal to 45% A |B .

In a particular aspect, the body 2702 of the inner protective shield 2700 can be made from a metal, a metal alloy, or a combination thereof. Moreover, the inner protective shield 2700 can be made from copper, a copper alloy, aluminum, an aluminum alloy, tin, a tin alloy, iron, an iron alloy, nickel, a nickel alloy, titanium, a titanium alloy, or a combination thereof. In another aspect, the body 2702 of the inner protective shield 2700 can have a thickness, T, measured from the outer surface 2710 to the inner surface 2708, and T can be greater than or equal to 2 millimeters (mm). In another aspect, T can be greater than or equal to 2.5 mm, such as greater than or equal to 3.0 mm, greater than or equal to 3.5 mm, or greater than or equal to 4.0 mm. In still another aspect, T can be less than or equal to 6.5 mm, such as less than or equal to 6.0 mm, less than or equal to 5.5 mm, less than or equal to 5.0 mm, or less than or equal to 4.5 mm. It can is to be understood that T can be within a range between, and including, any of the minimum and maximum values of T described herein. It can be appreciated that the inner protective shield 2700 can protect a spark-invariant sensor installed therein from sparks created during a grinding operation performed adjacent to the spark- invariant sensor.

ADDITIONAL GRINDING HEAD ASSEMBLY

Referring now to FIG. 31 through FIG. 35, details concerning another grinding head assembly 3100 are depicted. As shown, the grinding head assembly 3100 can include a spindle 3102 around which an abrasive article 3104 is mounted or installed. The spindle 3102 can include a plurality of external threads 3106 extending at least partially along the length of the spindle 3102. In a particular aspect, the abrasive article 3104 can be a grinding wheel, a cut-off wheel, or some other abrasive wheel.

FIG. 31 through FIG. 35 further indicate that the grinding head assembly 3100 can include a locking flange 3108 that fits around the spindle 3102 adjacent to the abrasive article 3104. The locking flange 3108 can include at least one sensing target 3110 formed in the locking flange 3108 or extending from the locking flange 3108. The locking flange 3108 can be configured to be coupled to the spindle 3102 as shown and further, the locking flange 3108 can be configured to rotate with the abrasive article 3104 as the spindle 3102 rotates. The at least one sensing target 3110 is configured to move relative to a spark-invariant sensor, described in greater detail below. In particular, the at least one sensing target 3110 is configured to rotate with the abrasive article 3104 during use. Moreover, the at least one sensing target 3110 is configured to rotate relative to the spark-invariant sensor.

As illustrated, the grinding head assembly 3100 may include an outer protective shield 3112 that can extend at least partially around the abrasive article 3104. FIG. 31 through FIG. 35 further indicate that the grinding head assembly 3100 can further include a retractable sensor assembly 3120 that this affixed to the outer protective shield 3112.

In particular, the retractable sensor assembly 3120 can include a first hinge 3122 and a second hinge 3124 installed along a sensor arm 3126. The first hinge 3122 can be similar to the hinge 222 described above. The sensor arm 3126 can include a first portion 3130 having a proximal end 3132 and a distal end 3134. The proximal end 3132 of the first portion 3130 can be engaged with, or coupled to, the first hinge 3122. The distal end 3134 of the first portion 3130 can be engaged with, or coupled to, the second hinge 3124. The sensor arm 3126 can also include a second portion 3140 having a proximal end 3142 and a distal end 3144. The proximal end 3142 of the second portion 3140 can be engaged with, or coupled to, the second hinge 3124 so that the second portion 3140 of the sensor arm 3126 can rotate relative to the first portion 3130 of the sensor arm 3216 about the second hinge 3124 as depicted in FIG. 34 and FIG. 35. The entire sensor arm 3126, including the first portion 3130 and the second portion 3140 can rotate relative about the first hinge 3122.

As shown in FIG. 31, the distal end 3144 of the second portion 3140 of the sensor arm 3126 can be formed with a slotted bore 3146. The slotted bore 3146 can extend through the second portion 3140 of the sensor arm 3126 in a direction perpendicular to a longitudinal axis of the second portion 3140 of the sensor arm 3126 between a first face and a second face of the second portion 3140 of the sensor arm 3126. Further, the slotted bore 3146 can extend at least partially along the length of the second portion 3140 of the sensor arm 3126. Moreover, as illustrated in FIG. 31 through FIG. 35, a spark-invariant sensor 3150 can be installed within the bore 3158 formed in the distal end 3154 of the sensor arm 3150. In a particular aspect, the spark-invariant sensor 3150 can include an inductive sensor. In another aspect, the spark- invariant sensor 3150 can include an inductive proximity switch. Moreover, the spark-invariant sensor 3150 can include a switching frequency that is higher than the maximum rotational speed, i.e., revolutions per minute (RPM), of the grinding head assembly 3100. In another aspect, the spark-invariant sensor 3150 can include a fiber optic sensor.

In a particular aspect, the spark-invariant sensor 3150 can have a generally cylindrical housing 3152 formed with external threads 3154. The spark-invariant sensor 3150 can be held in place on the sensor arm 3126 using a first nut 3156 and a second nut 3158. Further, the spark- invariant sensor 3150 can include a proximal end 3160 and a distal end 3162. The nuts 3156, 3158 and external threads 3154 of the spark-invariant sensor 3150 can act as a spacing mechanism that includes a plurality of positions and by manipulating the nuts 3156, 3158, the spacing mechanism, and the spark-invariant sensor 3150, can be moved between the plurality of positions. Accordingly, the spacing mechanism is configured to move between the plurality of positions and control the placement of the spark-invariant sensor 3150 relative to the at least one sensing target 3110. Further, the spacing mechanism is configured to move between the plurality of positions and control the placement of the spark- invariant sensor 3150 relative to the tool frame, e.g., the body 120 of the grinder 102. In another aspect, rotating the second portion 3140 of the sensor arm 3126 relative to the first portion 3130 can allow the spark- invariant sensor 3150 to be positioned at an angle relative to the sensing target 3110. A sensor wire 3164 can extend from the proximal end 3160 of spark-invariant sensor 3150. The sensor wire 3164 can be an electrical conductor or a fiber optic cable.

During use, the distal end 3162 of the spark-invariant sensor 3150 can be placed near the locking flange 3108 in order to sense rotational movement of the sensing target 3110 as the locking flange 3108 rotates in conjunction with the spindle 3102 and the abrasive article 3104. The spark-invariant sensor 3150 can operate in conjunction with the processing device and the sensing target 3110 on the locking flange 3108 in order to determine the speed of the abrasive article 3104 as it rotates during operation of the grinder 120 or, more specifically, during operation of the grinding head assembly 3100.

FIG. 31 through FIG. 35 further indicate that the retractable sensor assembly 3120 can include an inner protective shield 3180 placed around to the spark-invariant sensor 3150.

The inner protective shield 3180 can be any of the inner protective shields described herein. In particular, the inner protective shield 3180 can extend around a portion of the spark- invariant sensor 3150 that extends beyond the second nut 3158.

In a particular aspect, the inner protective shield 3180 can be connected to the distal end 3134 of the first portion 3130 of the sensor arm 3126 via an L bracket 3182. The L bracket 3182 can be coupled to the distal end 3134 of the first portion 3130 of the sensor arm 3126 using one or more threaded fasteners 3184. Additionally, one or more threaded fastener 3186 can connect the inner protective shield 3180 to the L bracket 3182. The retractable sensor assembly 3120 can further include a threaded adjuster 3188 that can extend through the first portion 3130 of the sensor arm 3126 between the proximal end 3132 of the first portion 3130 of the sensor arm 3126 (and the first hinge 3122) and the distal end 3134 of the first portion 3130 of the sensor arm 3126. The threaded adjuster 3188 can allow for fine adjustment of the retractable sensor assembly 3120 during use of the retractable sensor assembly 3120.

In a particular aspect, the housing 3152 of the spark-invariant sensor 3150 and the threaded nuts 3156, 3158 can be made from a thermoset polymer capable of withstanding relatively high operating temperatures without melting. For example, the housing 3152 of the spark-invariant sensor 3150 and the threaded nuts 3156, 3158 can be made from a thermoset polymer such as polyimide. This can protect the spark-invariant sensor 3150 from potential damage caused by high operating temperatures associated with grinding operations. Further, with a relatively low thermal conductivity, the sensor wire 3164 can also be protected since the material of the housing 3152 of the spark- invariant sensor 3150 can minimize heat transmission from the distal end 3162 of the housing 3152 to the proximal end 3160 of the housing 3152.

In a particular aspect, the thermoset polymer of the housing 3152 of the spark- invariant sensor 3150 and the threaded nuts 3156, 3158 can have a thermal conductivity that is less than or equal to 0.5 W/mk. In another aspect, the thermal conductivity can be less than or equal to 0.45 W/mk, such as less than or equal to 0.40 W/mk, or less than or equal to 0.35 W/mk. Further, the thermal conductivity can be greater than or equal to 0.10 W/mk, such as greater than or equal to 0.15 W/mk, greater than or equal to 0.20 W/mk, greater than or equal to 0.25 W/mk, or greater than or equal to 0.30 W/mk. It is to be understood that the thermal conductivity can be within a range between, and including, any of the maximum or minimum values described herein.

In a particular aspect, the thermoset polymer of the housing 3152 of the spark- invariant sensor 3150 and the threaded nuts 3156, 3158 can have an operating temperature that is greater than or equal to 275°C. In another aspect, the operating temperature can be greater than or equal to 300°C, such as greater than or equal to 305°C, greater than or equal to 3 lO°C, or greater than or equal to 3 l5°C. Further, the operating temperature can be less than or equal to 350°C, such as less than or equal to 330°C, less than or equal to 325°C, or less than or equal to 320°C. It is to be understood that the operating temperature can be within a range between, and including, any of the minimum or maximum values described herein.

In another particular aspect, the thermoset polymer of the housing 3152 of the spark- invariant sensor 3150 and the threaded nuts 3156, 3158 can have a coefficient of thermal expansion that is less than or equal to 10.0 mm/mm/C 0 . In another aspect, the coefficient of thermal expansion can be less than or equal to 7.5 mm/mm/C 0 , such as less than or equal to 7.0 mm/mm/C 0 , less than or equal to 6.5 mm/mm/C 0 , less than or equal to 6.0 mm/mm/C 0 , less than or equal to 5.5 mm/mm/C 0 , or less than or equal to 5.0 mm/mm/C 0 . Further, the coefficient of thermal expansion can be greater than or equal to 2.5 mm/mm/C 0 , such as greater than or equal to 3.0 mm/mm/C 0 , greater than or equal to 3.5 mm/mm/C 0 , greater than or equal to 4.0 mm/mm/C 0 , or greater than or equal to 4.5 mm/mm/C 0 . It is to be understood that the coefficient of thermal expansion can be within a range between, and including, any of the maximum or minimum values described herein.

Many different aspects and embodiments are possible. Some of those aspects and embodiments are described herein. After reading this specification, skilled artisans will appreciate that those aspects and embodiments are only illustrative and do not limit the scope of the present invention. Embodiments may be in accordance with any one or more of the items as listed below.

Embodiments.

Embodiment 1. A tool comprising:

a tool frame including a spindle;

an abrasive article mounted to the spindle; and

a spark-invariant sensor coupled to the frame and configured to measure the rotation rate of the abrasive article.

Embodiment 2. The tool of embodiment 1, wherein the spark-invariant sensor comprises an inductive sensor.

Embodiment 3. The tool of embodiment 1, wherein the spark-invariant sensor comprises an inductive proximity switch. Embodiment 4. The tool of embodiment 1, wherein the spark-invariant sensor is configured to interact with at least one sensing target.

Embodiment 5. The tool of embodiment 4, wherein the at least one sensing target is coupled to the tool.

Embodiment 6. The tool of embodiment 4, wherein the at least one sensing target is coupled to the spindle and configured to rotate with the abrasive article.

Embodiment 7. The tool of embodiment 4, wherein the at least one sensing target is configured to move relative to the spark-invariant sensor.

Embodiment 8. The tool of embodiment 4, wherein the at least one sensing target is configured to rotate with the abrasive article during use.

Embodiment 9. The tool of embodiment 4, wherein the at least one sensing target comprises a metal or metal alloy.

Embodiment 10. The tool of embodiment 4, wherein the at least one sensing target comprises at least one bore formed in a locking flange.

Embodiment 11. The tool of embodiment 1, further comprising a sensor arm connected to the tool frame, wherein the spark-invariant sensor is coupled to the sensor arm.

Embodiment 12. The tool of embodiment 11, wherein the sensor arm comprises an articulating element configured to move the sensor arm from a disengaged position to an engaged position.

Embodiment 13. The tool of embodiment 12, wherein the articulating element includes at least one of a hinge, a slide, a ball joint, or any combination thereof.

Embodiment 14. The tool of embodiment 11, further comprising a spacing mechanism having a plurality of positions and configured to move between the plurality of positions.

Embodiment 15. The tool of embodiment 14, wherein the spacing mechanism is configured to move between the plurality of positions and control the placement of the spark- invariant sensor relative to a sensing target.

Embodiment 16. The tool of embodiment 14, wherein the spacing mechanism is configured to move between the plurality of positions and control the placement of the spark- invariant sensor relative to the tool frame.

Embodiment 17. The tool of embodiment 14, wherein the spacing mechanism is coupled to a sensor arm and the spark-invariant sensor is coupled to the sensor arm, and wherein the spacing mechanism is configured to control the placement of the sensor arm and the spark-invariant sensor relative to the tool frame. Embodiment 18. The tool of embodiment 14, wherein the spacing mechanism is coupled to a sensor arm and the spark-invariant sensor is coupled to the sensor arm, and wherein the spacing mechanism is configured to control the height of the sensor arm and the spark-invariant sensor relative to a sensing target.

Embodiment 19. The tool of embodiment 1, further comprising a shield disposed adjacent to the spark-invariant sensor.

Embodiment 20. The tool of embodiment 19, wherein the shield is disposed between the spark-invariant sensor and at least a portion of the tool frame.

Embodiment 21. The tool of embodiment 19, wherein the shield comprises a sleeve around the spark-invariant sensor.

Embodiment 22. The tool of embodiment 19, wherein the shield comprises a metal, a high-temperature polymer, or a combination thereof.

Embodiment 23. The tool of embodiment 19, wherein the shield further comprises a coating thereon.

Embodiment 24. The tool of embodiment 19, wherein the shield extends around at least a portion of the spark-invariant sensor.

Embodiment 25. The tool of embodiment 19, wherein the shield has a concave shape and partially envelops the spark-invariant sensor.

Embodiment 26. The tool of embodiment 1, wherein the spark-invariant sensor is configured to detect one or more sensing targets and generate a sensing signal.

Embodiment 27. The tool of embodiment 26, further comprising a logic element configured to receive the sensing signal and store the sensing signal as operation data.

Embodiment 28. The tool of embodiment 27, wherein the logic element is configured to analyze a plurality of operation data and generate RPM data.

Embodiment 29. The tool of embodiment 28, wherein the logic element is configured to compare RPM data to stored data and generate an instruction.

Embodiment 30. The tool of embodiment 29, further comprising a controller in communication with the logic element and configured to receive the instruction and adjust a pressure to the tool.

Embodiment 31. The tool of embodiment 30, wherein the controller is coupled to a valve configured to control a pressure of fluid to the tool.

Embodiment 32. A sensor for mounting to a tool comprising:

a sensor arm;

a spark-invariant sensor coupled to the sensor arm; and a spacing mechanism coupled to the sensor arm and configured to move between a plurality of positions and control the placement of the spark-invariant sensor relative to a sensing target.

Embodiment 33. The sensor of embodiment 32, further comprising a tool frame including a spindle, wherein the sensor arm is coupled to the tool frame.

Embodiment 34. The sensor of embodiment 33, further comprising an abrasive article mounted to the spindle.

Embodiment 35. The sensor of embodiment 32, wherein the spark-invariant sensor comprises an inductive sensor.

Embodiment 36. The sensor of embodiment 32, wherein the spark-invariant sensor comprises an inductive proximity switch.

Embodiment 37. The sensor of embodiment 32, wherein the spark-invariant sensor is configured to interact with at least one sensing target.

Embodiment 38. The sensor of embodiment 32, wherein the at least one sensing target is coupled to the tool.

Embodiment 39. The sensor of embodiment 32, wherein the at least one sensing target is coupled to the spindle and configured to rotate with the abrasive article.

Embodiment 40. The sensor of embodiment 32, wherein the at least one sensing target is configured to move relative to the spark-invariant sensor.

Embodiment 41. The sensor of embodiment 32, wherein the at least one sensing target is configured to rotate with the abrasive article during use.

Embodiment 42. The sensor of embodiment 32, wherein the at least one sensing target comprises a metal or metal alloy.

Embodiment 43. The sensor of embodiment 32, wherein the at least one sensing target comprises at least one bore formed in a locking flange.

Embodiment 44. The sensor of embodiment 32, wherein the sensor arm comprises an articulating element configured to move the sensor arm from a disengaged position to an engaged position.

Embodiment 45. The sensor of embodiment 32, wherein the articulating element includes at least one of a hinge, a slide, a ball joint, or a combination thereof.

Embodiment 46. The sensor of embodiment 32, wherein the spacing mechanism is configured to move between the plurality of positions and control the placement of the spark- invariant sensor relative to the tool frame. Embodiment 47. The sensor of embodiment 32, wherein the spacing mechanism is configured to control the height of the sensor arm and the spark- invariant sensor relative to the tool frame, the sensing target, or a combination thereof.

Embodiment 48. The sensor of embodiment 32, wherein the spark-invariant sensor is slidably engaged with the sensor arm.

Embodiment 49. The sensor of embodiment 32, further comprising a shield disposed adjacent to the spark-invariant sensor.

Embodiment 50. The sensor of embodiment 49, wherein the shield is disposed between the spark-invariant sensor and at least a portion of the tool frame.

Embodiment 51. The sensor of embodiment 49, wherein the shield is disposed between the spark-invariant sensor and at least a portion of the abrasive article.

Embodiment 52. The sensor of embodiment 49, wherein the shield comprises a metal.

Embodiment 53. The sensor of embodiment 49, wherein the shield comprises copper.

Embodiment 54. The sensor of embodiment 49, wherein the shield extends around at least a portion of the spark-invariant sensor.

Embodiment 55. The sensor of embodiment 49, wherein the shield has a concave shape and partially envelops the spark-invariant sensor.

Embodiment 56. The sensor of embodiment 32, wherein the spark-invariant sensor is configured to detect one or more sensing targets and generate a sensing signal.

Embodiment 57. The sensor of embodiment 56, further comprising a logic element configured to receive the sensing signal and store the sensing signal as operation data.

Embodiment 58. The sensor of embodiment 57, wherein the logic element is configured to analyze a plurality of operation data and generate RPM data.

Embodiment 59. The sensor of embodiment 57, wherein the logic element is configured to compare RPM data to stored data and generate an instruction.

Embodiment 60. The sensor of embodiment 59, further comprising a controller in communication with the logic element and configured to receive the instruction and adjust a pressure to the tool.

Embodiment 61. The sensor of embodiment 60, wherein the controller is coupled to a valve configured to control a pressure of fluid to the tool.

Embodiment 62. A sensor for mounting to a tool comprising:

a sensor arm;

a spark-invariant sensor coupled to the sensor arm; and a shield coupled to the sensor arm and disposed adjacent to the spark-invariant sensor.

Embodiment 63. The sensor of embodiment 62, further comprising a tool frame including a spindle, wherein the sensor arm is coupled to the tool frame.

Embodiment 64. The sensor of embodiment 63, further comprising an abrasive article mounted to the spindle.

Embodiment 65. The sensor of embodiment 62, wherein the spark-invariant sensor comprises an inductive sensor.

Embodiment 66. The sensor of embodiment 62, wherein the spark-invariant sensor comprises an inductive proximity switch.

Embodiment 67. The sensor of embodiment 62, wherein the spark-invariant sensor is configured to interact with at least one sensing target.

Embodiment 68. The sensor of embodiment 67, wherein the at least one sensing target is coupled to the tool.

Embodiment 69. The sensor of embodiment 67, wherein the at least one sensing target is coupled to the spindle and configured to rotate with the abrasive article.

Embodiment 70. The sensor of embodiment 67, wherein the at least one sensing target is configured to move relative to the spark-invariant sensor.

Embodiment 71. The sensor of embodiment 67, wherein the at least one sensing target is configured to rotate with the abrasive article during use.

Embodiment 72. The sensor of embodiment 67, wherein the at least one sensing target comprises a metal or metal alloy.

Embodiment 73. The sensor of embodiment 67, wherein the at least one sensing target comprises a metal selected from the group consisting of mild steel, 4340 steel, or 4140 steel.

Embodiment 74. The sensor of embodiment 62, wherein the sensor arm comprises an articulating element configured to move the sensor arm from a disengaged position to an engaged position.

Embodiment 75. The sensor of embodiment 74, wherein the articulating element includes at least one of a hinge, a slide, or a combination thereof.

Embodiment 76. The sensor of embodiment 62, further comprising a spacing mechanism coupled to the sensor arm and configured to move between the plurality of positions and control the placement of the spark-invariant sensor relative to the tool frame. Embodiment 77. The sensor of embodiment 76, wherein the spacing mechanism is configured to control the height of the sensor arm and the spark- invariant sensor relative to the tool frame.

Embodiment 78. The sensor of embodiment 76, wherein the spacing mechanism is configured to control the height of the sensor arm and the spark- invariant sensor relative to a sensing target.

Embodiment 79. The sensor of embodiment 62, wherein the shield is disposed between the spark-invariant sensor and at least a portion of the tool frame.

Embodiment 80. The sensor of embodiment 62, wherein the shield is disposed between the spark-invariant sensor and at least a portion of the abrasive article.

Embodiment 81. The sensor of embodiment 62, wherein the shield comprises a metal.

Embodiment 82. The sensor of embodiment 62, wherein the shield comprises copper.

Embodiment 83. The sensor of embodiment 62, wherein the shield extends around at least a portion of the spark-invariant sensor.

Embodiment 84. The sensor of embodiment 62, wherein the shield has a concave shape and partially envelops the spark-invariant sensor.

Embodiment 85. The sensor of embodiment 62, wherein the spark-invariant sensor is configured to detect one or more sensing targets and generate a sensing signal.

Embodiment 86. The sensor of embodiment 85, further comprising a logic element configured to receive the sensing signal and store the sensing signal as operation data.

Embodiment 87. The sensor of embodiment 86, wherein the logic element is configured to analyze a plurality of operation data and generate RPM data.

Embodiment 88. The sensor of embodiment 86, wherein the logic element is configured to compare RPM data to stored data and generate an instruction.

Embodiment 89. The sensor of embodiment 86, further comprising a controller in communication with the logic element and configured to receive the instruction and adjust a pressure to the tool.

Embodiment 90. The sensor of embodiment 89, wherein the controller is coupled to a valve configured to control a pressure of fluid to the tool.

Embodiment 91. A tool system comprising:

a tool frame;

a spark-invariant sensor mounted to the tool frame, wherein the spark-invariant sensor is configured to detect one or more sensing targets and generate a sensing signal; a logic element configured to receive the sensing signal and generate one or more instructions in response to the sensing signal; and

a controller in communication with the logic element and configured to receive the instruction and adjust a condition of the tool or provide a diagnostic condition of the tool.

Embodiment 92. The tool system of embodiment 91, wherein the logic element is configured to analyze a plurality of operation data and generate RPM data.

Embodiment 93. The tool system of embodiment 91, wherein the logic element is configured to compare RPM data to stored data and generate an instruction.

Embodiment 94. The tool system of embodiment 91, wherein the controller is coupled to a valve configured to control a pressure of fluid to the tool.

Embodiment 95. A tool comprising:

a tool frame including a spindle;

an abrasive article mounted to the spindle; and

a spark-invariant sensor coupled to the frame and configured to measure the rotation rate of the abrasive article.

Embodiment 96. A sensor for mounting to a tool comprising:

a sensor arm;

a spark-invariant sensor coupled to the sensor arm; and

a spacing mechanism coupled to the sensor arm and configured to move between a plurality of positions and control the placement of the spark-invariant sensor relative to a sensing target.

Embodiment 97. A sensor for mounting to a tool comprising:

a sensor arm;

a spark-invariant sensor coupled to the sensor arm; and

a shield coupled to the sensor arm and disposed adjacent to the spark-invariant sensor. Embodiment 98. A tool system comprising:

a tool frame;

a spark-invariant sensor mounted to the tool frame, wherein the spark-invariant sensor is configured to detect one or more sensing targets and generate a sensing signal;

a logic element configured to receive the sensing signal and generate one or more instructions in response to the sensing signal; and

a controller in communication with the logic element and configured to receive the instruction and adjust a condition of the tool or provide a diagnostic condition of the tool. Embodiment 99. The tool, sensor, or tool system according to any of embodiments 95, 96, 97, or 98, wherein the spark-invariant sensor comprises an inductive sensor.

Embodiment 100. The tool, sensor, or tool system according to any of embodiments 95, 96, 97, or 98, wherein the spark-invariant sensor comprises a fiber optic sensor.

Embodiment 101. The tool, sensor, or tool system according to any of embodiments 95, 96, 97, or 98, wherein the spark-invariant sensor is configured to interact with at least one sensing target.

Embodiment 102. The tool, sensor, or tool system according to embodiment 101, wherein the at least one sensing target is coupled to the tool.

Embodiment 103. The tool, sensor, or tool system according to embodiment 101, wherein the at least one sensing target is coupled to the spindle and configured to rotate with the abrasive article.

Embodiment 104. The tool, sensor, or tool system according to embodiment 101, wherein the at least one sensing target is configured to move relative to the spark-invariant sensor.

Embodiment 105. The tool, sensor, or tool system according to embodiment 101, wherein the at least one sensing target is configured to rotate with the abrasive article during use.

Embodiment 106. The tool, sensor, or tool system according to any of embodiments 95, 96, 97, or 98, further comprising a shield disposed adjacent to the spark-invariant sensor.

Embodiment 107. The tool, sensor, or tool system according to embodiment 106, wherein the shield is disposed between the spark-invariant sensor and at least a portion of the tool frame.

Embodiment 108. The tool system according to embodiment 98, wherein the logic element is configured to analyze a plurality of operation data and generate RPM data.

Embodiment 109. The tool system according to embodiment 98, wherein the controller is coupled to a valve configured to control a pressure of fluid to the tool.

The specification and illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The specification and illustrations are not intended to serve as an exhaustive and comprehensive description of all of the elements and features of apparatus and systems that use the structures or methods described herein. Separate embodiments may also be provided in combination in a single embodiment, and conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Further, reference to values stated in ranges includes each and every value within that range. Many other embodiments may be apparent to skilled artisans only after reading this specification. Other embodiments may be used and derived from the disclosure, such that a structural substitution, logical substitution, or another change may be made without departing from the scope of the disclosure. Accordingly, the disclosure is to be regarded as illustrative rather than restrictive. Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.

The description in combination with the figures is provided to assist in understanding the teachings disclosed herein. The following discussion will focus on specific

implementations and embodiments of the teachings. This focus is provided to assist in describing the teachings and should not be interpreted as a limitation on the scope or applicability of the teachings. However, other teachings can certainly be used in this application.

As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

Also, the use of "a" or "an" is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural, or vice versa, unless it is clear that it is meant otherwise.

For example, when a single item is described herein, more than one item may be used in place of a single item. Similarly, where more than one item is described herein, a single item may be substituted for that more than one item.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent not described herein, many details regarding specific materials and processing acts are conventional and may be found in reference books and other sources within the structural arts and corresponding manufacturing arts.

The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.