Background Art Many products made on assembly lines, such as cars and trucks, are processed through a series of production steps. In many instances, it is necessary to clean a surface prior to performing a step such as the application of adhesively secured trim pieces or pin- stripes. Problems are presented when the article has complex contours that are not continuous along the length of the vehicle.

Fixtures for cleaning contoured surfaces have been developed that include a rigid urethane foam applicator that is cut to the contour of a portion of a particular vehicle. A towel fed between two spools passes between the vehicle and the applicator. The applicator has a defined contour which cannot change as the contours along the length of the vehicle change.

This may result in portions of the body being missed by the applicator. Also, the applicator may contact the surface with excessive force when the contour changes along the length of the vehicle. With a rigid applica- tor, the applicator must be replaced relatively fre- quently due to wear.

Prior art surface preparation fixtures are also affected by misalignment of the vehicle or if the vehicle pitches or yaws as it moves down an assembly line. The known prior art fixtures are difficult to adjust and cannot conform to changing contours.

Other applications require a tool that is capable of engaging complex contours with substantially uniform pressure being applied to the contoured surface to which the present invention can be applied are many and varied. For example, a sanding block used for sanding contoured surfaces such as wood furniture surfaces or plaster covings have utilized contoured blocks of fixed configurations and are generally made of solid pieces of wood, plastic, or rubber. These types of devices are not well suited to three-dimensionally varying surfaces and require dedicated blocks for each different surface to be sanded.

Label applicator pads are used to wipe labels or other sheet form products onto the surface of a bottle or of an article. If the bottle or article has a three-dimensional contour or are presented to the labeling applicator pad in a skew orientation, a fixed contour label applicator pad may provide uneven applica- tion pressure. There is believed to be a need for a label applicator pad that is capable of following the contours of complexly contoured bottles and other arti- cles and providing substantially equal overall pressure across the surface of a label, regardless of the contour to which the label is applied.

Clamp blocks or part nesting blocks made according to prior art techniques are generally machined

blocks that are specially shaped to accept a particular part in, for example, an assembly operation. If the part being operated upon undergoes a design change requiring modification of its shape or the orientation that the part is held, it is necessary to remachine or replace the clamping block or nesting block resulting in added expense and lost production time.

Assembly tools used to press electronic components onto circuit boards or for insertion of parts on a supporting structure frequently require assembly of parts by pressing the parts onto the supporting struc- ture. In many applications, parts of different shapes and sizes must be assembled in the same step. Assembly specifications may require substantially uniform pres- sure for optimum quality in the assembly operation.

Contour gauges are used for measuring the contours of parts and other surfaces. Prior art ap- proaches to contour gauging include solid gauges and contour measurement machines (CMM) that are typically utilized offline. Solid gauges are usually only usable for inspecting batch samples. Laser measurement heads may be used online. CMM and laser heads are complex devices that can provide a computer model of a surface for gauging that is amenable to digital analysis but are extremely costly.

These and other problems associated with prior art methods and apparatus for preparing contoured surfaces are addressed by this invention as summarized below.

Summary Of The Invention

It is an object of the present invention to provide a contour following tool for preparing the surface of a vehicle moving on an assembly line prior to application of adhesively applied trim or pinstripes.

It is another object of the present invention to provide a contour conforming tool for other process- es.

According to another object of the invention, a contour conforming tool is provided which applies controlled pressure to a plurality of pins which are biased into engagement with the workpiece but which are partially retracted upon contact with a contoured surface.

Another object of the present invention is to provide a contour following tool which applies uniform pressure through a plurality of pins with the quantity of pressure applied being adjustable overall.

It is still another object of the present invention is to provide a self-equalizing contour following tool.

It is a further object of the invention to provide a contour following tool having a plurality of pins which are biased by means of pneumatic, hydraulic, mechanical, or electromechanical systems.

It is yet another object of the present invention to provide a contour following tool for preparing the surface of a vehicle on an assembly line which includes an integral cleaning fluid dispensing

mechanism which dispenses cleaning fluid through one or more of a plurality of pins that follow the contour of the surface to be prepared. Another pin, preferably on the bottom of the tool, can be provided with a suction- ing port similar to the fluid dispersing mechanism.

Still further, it is another object of the present invention to provide a resilient, elastomeric cap for one or more pins of a contour following tool.

It is a further object of the invention to provide a contour following tool which works in conjunc- tion with a cloth web that is moved across the contour following tool.

According to another aspect of the invention, a contour following tool is provided which includes a housing and a plurality of pins partially disposed within the housing. Each of the plurality of pins has a longitudinal axis and is axially shiftable. A biasing system is operative to apply a biasing force to each of the pins to shift the pins to an extended position. The pins are axially shiftable against the biasing force to follow a contoured surface. The biasing system may be either a pneumatic pressure system, a hydraulic system, a mechanical spring, or an electromechanical force applying mechanism.

According to another aspect of the invention, a contour following tool as described above is provided which also includes a fluid port for supplying cleaning fluid which passes through one or more of the pins.

Another aspect of the present invention to provide a resilient or elastomer cap which is attached to a distal end of one or more of the pins. The resil- ient cap may be made of felt, foam polyurethane, polyurethane, cloth, or a foam elastomer.

According to another aspect of the invention, a cleaning fluid may be applied by means of a spray or drip dispenser external of the contour following tool.

According to another aspect of the invention, a fixture having an arm is provided for cleaning a contoured surface. A tool attached to the distal end of the arm has a plurality of axially movable pins which are biased to extend from the tool and are axially shiftable toward a retracted position against the biasing force. The fixture also preferably includes a wiping medium disposed to be backed up by the pins as the wiping medium is placed in contact with the con- toured surface to be cleaned. The fixture may be a robot having six axes of motion or may be a fixture of less sophisticated design.

According to another aspect of the invention, a method of cleaning a contoured workpiece is disclosed in which a robot or fixture having an arm supports a housing. A plurality of pins are partially disposed within the housing and are axially shiftable to extend from the housing. The method includes the step of biasing the pins into an extended position. The method also includes the step of providing a fluid retaining member between a distal end of the plurality of pins and the contoured workpiece to be cleaned with the pins serving to back up the fluid retaining member. The

method includes the step of wiping the contoured workpiece with the fluid retaining member as the workpiece and arm move relative to each other. The pins are shifted axially in response to changes in the contours of the workpiece as the workpiece moves rela- tive to the arm.

Other aspects of the method of the present invention include dispensing the cleaning fluid onto the fluid retaining member.

Further, the method includes the step of biasing the pins into an extended position by providing pneumatic pressure to a chamber which acts upon the pins.

According to another aspect of the invention, the step of providing a fluid retaining member further comprises advancing a web across the distal end of the pins to provide a fresh surface for wiping the work- piece.

According to another embodiment of the inven- tion, a tool for assembling component parts to an assembly is provided. The tool includes a housing in which a plurality of pins are partially disposed. The pins have a longitudinal axis and are axially shiftable along the longitudinal axis. A system is provided to apply a biasing force to each of the pins to shift the pins to a position in which the pins are extended from the housing. The pins are axially shiftable against the biasing force. The pins are adapted to engage a compo- nent part and apply pressure to the component parts to assemble the components parts to the assembly.

According to another embodiment of the inven- tion, a gauge is provided wherein a plurality of pins are partially disposed within a housing. The pins have a longitudinal axis and are axially shiftable. A system is operative to apply a biasing force to each of the pins to shift the pins to the position in which the pins are extended from the housing. The pins are axially shiftable against the biasing force to engage a con- toured surface. A plurality of sensors are operatively associated with the plurality of pins to sense axial displacement of the pins relative to the housing. The sensors provide an electrical signal that is representa- tive of the axial displacement of the pins.

These and other objects, features, and advan- tages of the present invention will be readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.

Brief Description Of The Drawings FIGURE 1 is a side elevation view of an automobile assembly line showing vehicles being cleaned by a fixture utilizing a contour following tool to prepare the surface of the vehicle; FIGURE 2 is a front elevation view partially fragmented away showing a contour following tool at- tached to the arm of a fixture or robot; FIGURE 3 is a magnified view taken of the area within the circle 3 in Figure 2 showing a portion of the contour following tool;

FIGURE 4 is a front elevation view partially fragmented away of a contour following tool having a fluid dispensing port within a pin of the contour following tool; FIGURE 5 is a magnified view taken of the area within the circle 5 in Figure 4 showing the fluid dispensing port; FIGURE 6 is a side elevation view of an alternative embodiment of the contour following tool of the present invention wherein springs are the mechanical biasing mechanism used to bias the pins into an extended position; FIGURE 7 is a perspective view of a pin of the contour following tool of the present invention showing the pins in conjunction with a cap; FIGURE 8 is a top plan view of the contour following tool attached to the arm of a fixture or robot; FIGURE 9 is a front elevation view of the contour following tool; FIGURE 10 is a diagrammatic perspective view of an alternative embodiment of a contour following tool made according to the present invention; FIGURE 11 is an exploded perspective view of the embodiment of the contour following tool shown in Figure 10;

FIGURE 12 is a diagrammatic perspective view of a clamp block/nest block made according to the present invention; FIGURE 13 is a diagrammatic perspective view of a clamp block/nest block of Figure 12 shown in engagement with an object; FIGURE 14 is a front elevation view of a tool for assembling component parts made in accordance with the present invention; and FIGURE 15 is a diagrammatic perspective view of a gauge made in accordance with the present inven- tion.

Detailed Description of the Preferred Embodiment Referring now to Figure 1, an automotive assembly line 10 is shown which includes a fixture 12, or robot, for preparing contoured surfaces of a vehicle 13 for adhesive application of trim pieces or pinstrip- es.

As shown in Figures 2 and 8, a contour follow- ing tool 14 is held by the fixture 12 for engaging the portion of the vehicle 13 to be cleaned by an alcohol wipe preparation step.

The structure of the tool 14 is shown in Figures 2-9 to include a housing 16 which is formed from a block 18 of steel or other suitable material by drilling a plurality of bores 20 through the block 18 from a rear side 22 to a front side 24 in a substantial-

ly parallel array. The block 18 may be formed as a unitary body or in several parts. An end cap 26 is secured by appropriate fasteners to the front side 24.

The end cap 26 has holes 28 formed at locations corre- sponding to the bores 20. The holes 28 are slightly smaller than the bores 18. A cover 30 is secured by appropriate fasteners to the rear side 22 of the block 18.

A plurality of pins 32 having a longitudinal axis are retained partially within the housing 16 and are disposed in the bores 20 and extend through the holes 28 in the end cap 26. The pins 32 each have a shoulder 34 formed intermediate their length. The shoulders 34 form a step at the juncture of a front portion 36 of the pin having a diameter corresponding to but slightly less than the holes 28 and a rear portion 38 of the pin having a diameter corresponding to but slightly less than the bores 20. The pins 32 are axially shiftable and the fit between the rear portion 38 of the pins 32 and the bores 20 is a close tolerance fit to substantially establish a seal in the pneumatic or hydraulic embodiments as will be more fully described below. The pins 32 may also have a further reduced diameter section 40 at their distal end 42 or other structure to facilitate securing a resilient cap 44 to one or more of the pins 32.

The resilient cap 44 is used to provide a soft element for engaging a contoured surface 46 of a vehicle or other object to be processed by the tool 14. The cap 44 may be formed from any number of different materials, including but not limited to felt, foam polyurethane, poly urethane, cloth or elastomeric material. As shown

in Figures 2, 4, 6, 7 and 8 the cap 44 may be attached to one pin, a subset of pins, or all of the pins 32.

Referring to Figure 8, the use of the tool 14 is shown in conjunction with a cloth 48 covering the cap 44. The cloth 48 may be advanced from a dispensing roll 50 and collected by a take up roll 52. In this way dirt and foreign materials may be removed from the contoured surface 46 and collected on the cloth 48.

Referring to Figures 2 through 5, the embod- iment of the invention in which the pins 32 are biased by fluid pressure toward a fully extended position wherein the shoulder 34 is in engagement with the end cap 26 and the caps 44 are biased toward the contoured surface 46 is shown. The fluid pressure may be provided by a pneumatic pressure source or a hydraulic pressure source. Alternatively, it is anticipated that a modifi- cation of the design could be made wherein a vacuum source could provide the fluid pressure. The fluid pressure causes the pins 32 to be axially shifted within the bores 20 to a first position in which the pins are extended to a maximum extent from the housing 16. This is the position shown in Figure 8 in which the tool 14 is out of engagement with the contoured surface 46. As shown in Figures 2, 4 and 6, upon engagement with the contoured surface 46 the pins are shifted against the biasing force back into the housing 16 to accommodate changes in the contour of the object to be processed as it moves relative to the tool 14.

The cover 30 has a fitting 54 through which the fluid pressure is supplied which is adapted to be connected to a hose 56 that is connected to a source of

fluid pressure. A seal 58 is provided between the cover and the block 18 to form a seal therebetween. The space between the cover on one hand and the block 18 and pins 32 on the other hand acts as a plenum 60 through which fluid pressure may be communicated to the pins 32. The plenum 60 may be small in volume.

In the alternative embodiment shown in Figures 6, 7 and 9, the biasing force is provided by helical springs 62. It is anticipated that other equivalent mechanical elements such as magnets or solenoids could be substituted for the spring 62. In this alternative embodiment the housing 64 may be of an open construction since it in not necessary to provide a pressure seal with a mechanical biasing force applying member. The pins 66, end cap 68 and cap 70 all perform in a manner similar to the fluid pressure biasing embodiment previ- ously described and will not be repeated for brevity.

In some applications, effective cleaning requires application of a cleaning fluid 72 on the cloth 48 or cap 44. An appropriate cleaning fluid for automo- tive assembly line surface preparation may be alcohol or an alcohol solution. The method of applying the clean- ing fluid may include a drip or spray applicator 74 as shown in Figure 2. According to another aspect of the invention the cleaning fluid may be supplied through one or more fluid dispensing pins 78 as shown in Figures 4 and 5.

Each fluid dispensing pin 78 has a small bore 80 extending axially from a distal end 82 of the pin 78 to a location 84 within the pin 78 proximate the oppo- site end 86. A radial bore 88 extends from the bore 80

near the location 84 to the outside of the pin 78. A multiple position fluid transfer fitting 90 is formed about the pin 78 by providing an annular space 92 with seals 94 at opposite ends of the annular space 92.

Cleaning fluid is supplied through a port 96 formed in the block 18. A fitting 98 is connected to the port 96 to facilitate connection to a hose 100 which supplies cleaning fluid from a reservoir 101 or other convention- al source. Cleaning fluid 72 is supplied through the pin 78 regardless of the position of the pin 78 because fluid can flow through the port 96 into the annular space 92 throughout the full range of pin displacement.

Fluid in the annular space is then provided through the radial bore 88 to the bore 80 and to the distal end 82.

If the cap 44 is porous the fluid may pass through the cap 44 or if the cap is formed of a nonporous material, such as an elastomer, one or more holes may be provided to allow the fluid to be supplied to the cloth 48.

In some applications the spacing between the fixture 12 supporting the tool 14 and the contoured surface 46 may vary significantly. To assure proper location of the tool a self-equalizing slide 102 of conventional design, as shown in Figures 2 and 8, may be secured between the fixture 12 and the tool 14. On automotive assembly lines 10 after vehicles 13 have been fully assembled and are supported on their wheels variation in positioning and pitching of the vehicle caused by external forces may require 2 inches or more of tolerance. Since the pin displacement is anticipated to be designed for 1 to 1.5 inches, the use of a self- equalizing slide 102 may be required for some applica- tions.

A positioning roller 104, as shown in Figures 2, 4 and 8 may also be required to aid in positioning the tool 14. The roller 104 preferably has bearings to improve tool life and reduce the possibility of scratch- ing the surface of a vehicle. The perimeter of the roller 104 preferably extends partially over the pins when they are in their fully extended position. The roller 104 allows the tool 14 to ride over transitions in body panels.

Referring now to Figures 10 and 11, an alter- native embodiment of a contour following tool 120 is shown. A body 122 has a plurality of bores 124 extend- ing therethrough in a parallel matrix array. A cover 126 is assembled to the body 122 at one end and an end cap 128 is assembled to the body 122 at the opposite end. A plurality of pins 130 are received, one in each of the bores 124. The pins 130 preferably have ends 132 that are partially spherical in shape. A resilient cap 134 has a plurality of pockets 136 that are preferably partially spherical in shape and adapted to receive the ends 132 of each of the pins 130. The cover 126 is provided with a fluid or air inlet 138 that allows pressurized air to be supplied to a plenum 140 that is formed by the cover that is also defined by the body 122. Air provided under pressure to the inlet 138 is supplied to the plenum 140 which is open to the bores 124. Air pressure in the plenum 140 acts upon the pins 130 to urge them outwardly with a desired level of force appropriate for the application. The resilient cap 134 engages an object and is sufficient resilient to follow the surface of the object. The resilient cap 134 is permitted to bend but is supported uniformly by the pressure applied by the pins 130. End cap 128 restrains

the pins 130 so that they are not expelled from the body 122. A lip 142 is provided intermediate the length of the pins that is sized to engage the holes 144 in the end cap 128 so that the pins can be partially extended through the end cap 128 but are stopped upon the lip 142 being extended to the end cap 128. This embodiment and the embodiments previously described can be used for a variety of applications including use as a sanding block or as a label applicator pad. Many other potential applications for the contour following tool will be apparent to one of ordinary skill in the art to which this invention relates.

Referring now to Figures 12 and 13, a clamp block or nest tool 150 is disclosed that comprises a body 152 having a cavity 154 into which a plurality of square pins 156 are received. Square pins 156 prefera- bly have partially spherical tips 158 on their distal end which the end that extends outwardly from the cavity 154. The pins 156 may alternatively be round pins and may either be solid or hollow. At inlet 160 is provided in the body 152 to permit air or another fluid pressure transmission medium to be provided to the cavity 154.

The cavity 154 defines a plenum 162 in conjunction with the pins 156. The plenum 162 is pressurized by the fluid admitted through the inlet 160 so that an equal pressure is applied to each of the pins 156.

The pins 156 include a rib 164 that is defined intermediate the length of the pin 156. The rear portion of the pin 156 is of greater cross-section than the portion of the pin 156 that extends outwardly from the body 152 to the tips 158. A pressure plate 166 is provided on one side of the cavity 154 for locking the

pins 156 in place after they have been positioned in the desired orientation. Fasteners 168 are received in threaded bores 168 formed in the body 152. The fasten- ers 168 may be tightened to exert pressure upon the pressure plate 166 sufficient to lock the pins 156 in place.

An end cap 172 is formed at one end of the body 152 and secured to the body by fasteners, welding, or other means. The end cap 172 has holes 174 that are sized to receive the forward end of the pins 156 but restrict movement of the pins when the ribs 164 engage the holes 174. An object 176 that is to be supported or engaged by the nest tool 150 is placed into engagement with the spherical tips 158 of the pins 156 while fluid pressure is supplied through the inlet 160 to the plenum 162. The pins 156 are pressured to extend outwardly from the cavity 154 until the tips 158 either contact the object or the rib 164 contacts the holes 174 in the end cap 172. Once the pins 156 have been extended sufficiently to follow the contour of the object 176, the pins can be locked in place by tightening the fasteners 168 to force pressure plate 166 into locking engagement with the sides of the pins 156.

Referring now to Figure 14, an assembly tool 180 is shown in conjunction with a tool fixture 182.

The assembly tool 180 has a body 184 that defines bores 186 in which pins 188 are received. Individual air inlets 190 are provided in a cover 192. Air supplied through the inlets 190 is provided under pressure through the cover 192 to the bores 186. Air pressure in the bores 186 exerts pressure against the pins 188, causing the pins to be driven outwardly through an end

cap 194. Fasteners 196 and 198 secure the cover 192 and end cap 194 to opposite ends of the body 184. The assembly tool 180 is used to form an assembly 200 by pressing component parts 202 into the assembly 200. The pins 188 are located to be aligned with component parts 202 as they are assembled to the assembly 200. Assembly 200 is carried by a part support fixture 204 that supports the assembly 200 while the component parts 202 are pressed into the assembly 200 by the pins 188. In this application, the assembly tool and part support fixture 204 are preferably moved together and apart relatively by moving either the tool fixture 182 or part support fixture 204. The pins 188 preferably have ends 206 that receive tip covers 208. The tip covers are preferably elastomeric members having pockets 210 that are adapted to receive the ends 206 of the pins 188.

This embodiment can be used to assemble parts such as electrical relays and to an assembly such as a power distribution box for wiring harnesses. Alterna- tively, this embodiment can be used to assemble electri- cal components on circuit boards or assemble plastic parts to a supporting structure. The assembly tool 180 can be provided with different air pressure in each of the inlets 190 to provide varying amounts of pressure to different components being assembled to the same assem- bly. A primary advantage of the embodiment is that either a constant load can be applied to each component part or different but controlled pressures can be provided to each pin 188 and therefore apply the desired pressure on each component part 202.

Referring now to Figure 15, a contour gauge 220 is shown for measuring the contour of an object 222

and providing a digital or analog signal that can be interpreted electronically to provide an indication of the surface contour of the object 222. The contour gauge 220 includes a body 224 having bores 226 in which pins 228 are received. Pins 228 have a first portion 230 and a second portion 232. First portion 230 is of lesser cross-section than second portion 232 so that a lip 234 is defined intermediate the length of the pin 228 where the first and second portions 230 and 232 meet. An inlet 236 is provided to allow air or other fluid under pressure to be supplied to a plenum 238 formed by a cover 240 that is secured to one end of the body 224. A plurality of holes 242 are formed in the cover 240 through which rods 244 of linear feedback sensors 246 are received. Linear feedback sensors 246 may be either analog or digital sensors that provide either an analog or digital signal that can be inter- preted by a computer (not shown) . Linear feedback sensors 246 are aligned with and associated with indi- vidual pins 228. A support 248 is provided for retain- ing the linear feedback sensors 246 in alignment with the pins 228. Electrical wires 250 extend from the linear feedback sensors 246 to a computer or other electronic device that utilizes the signal received from the linear feedback sensors 246. Tips 252 are provided on each of the pins 228 to engage the object 222. The tips are preferably partially spherical and directly engage the object 222 without requiring elastomeric covers or tips unless it is necessary to protect the surface of the object 222. The pins 228 extend through holes 254 in an end cap 256 which is secured to the opposite end of the body 224 from the cover 240.

While several alternative embodiments of the invention have been disclosed above, it should be understood that other applications may be developed for the invention and other improvements may be made by persons of skill in the art. The above description of several embodiments should not be read to limit the scope of the invention to that which is disclosed. The broad scope of the invention should be interpreted by reference to the following claims.