2. Background Art Hand tools for cutting various forms of cable have been known in the art for many years. In particular, many of these tools have been small, hand held models specifically designed to cut a particular type of cable. Many of these tools have employed either a blade-to-blade flush cut, or a shearing action. These hand held tools, particularly the hand held cable cutters, have worked well in the past for most cable applications as most standard cable may be cut with force amply generated by a single hand.

However, certain types of cable require larger amounts of force for a complete, substantially clean cut. In particular, to effectively cut cable that is reinforced with steel or other strengthing material, heavier duty cable cutters which generate more cutting force are often required. For instance, to cut aluminum cable with a reinforced steel core (ACSR), a common conductor in both commercial and home electrical installations, a specialized tool is required with not only the versatility to cut through varying materials, but also with the force to cut the reinforced steel core. While aluminum is soft and generally regarded as easy to cut with a sharp pair of blades, the steel core

is much harder, and difficult to cut with typical flush cut or shearing hand-held cable cutters. Steel conventionally requires a blunt edge and substantial force for a proper cut. However, the blunt edge needed to cut steel is largely ineffective in cutting aluminum, as aluminum requires a sharp edge. Thus, the blunt edge necessary to cut steel requires more force when cutting through aluminum substantially simultaneously. Accordingly, much heavier duty cutters, such as the one shown at page 31 in the 1995 catalog for Klein Tools, are necessary to generate additional force. As can be seen, the Klein cutting tool, specified as serviceable for use in cutting ACSR, employs long lever arms and a ratcheting mechanism to generate enough cutting force to achieve the desired task.

While this and other heavier duty ratcheting cutting tools for specialized applications such as ACSR have worked well, the amount of force mandated by these specialized applications has required cutting tools which are large, bulky and expensive. In particular, the force generation potential of ratcheting mechanisms designed for a hand tools are limited by physical and mechanical considerations. As such, these ratcheting-type hand tools can only generate and store so much power, and are thus limited in the amount of potential force generation by their size, shape and materials.

Indeed, the more force and power that is needed, generally the larger the ratcheting tool. These large and bulky tools are not only more expensive because of material requirements, but also inconvenient in a work site setting. Many workers prefer to holster their cable cutters, including those

used for ACSR, on their belt to avoid inefficiencies inherent in having to search for and retrieve a tool in either a nearby or remote location.

Thus, there remains a need for a cable cutter of the type which is suitable for cutting ACSR and other heavy duty cable applications, and which can generate substantial cutting force in a hand held model. There also remains a need for a hand tool which, at the same time, is suitable for other tooling operations. There likewise remains a need for a substantially hydraulic powered hand tool which can generate the substantial force required in specialized ACSR and other heavy duty cutting and tooling applications.

These and other desirable characteristics of the present invention will become apparent in light of the present specification (including claims) and drawings.

SUMMARY OF THE INVENTION The present application is directed to a hydraulic hand tool for performing mechanical work on an object comprising a main body, an actuation member, a substantially stationary tooling implement, a 8 tooling implement and a closed-circuit fluid forcing system. The substantially stationary tooling implement is preferably operably affixed to the main body, while the moving tooling implement is preferably mounted on the main body for reciprocating movement relative to the body and relative to the substantially stationary tooling implement, between a nonworking position and a working position. The substantially stationary tooling implement is further preferably pivotally attached to the main body to enable placement of an object to be worked between the tooling implements.

The closed circuit fluid forcing system includes a driving member, and is disposed within the main body such that it is associated with the actuation member and the moving tooling implement. The actuation member incrementally propels the moving tooling implement from the nonworking position to the working position, thus performing work on the object placed between the tooling implements.

The hydraulic hand tool is capable of generating substantial mechanical force for performing work on various objects, and is particularly adapted for heavy duty or specialized cutting or other tooling applications, as will be described in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side elevation of one embodiment of a hydraulic hand tool according to the present invention; Fig. 2 is a side elevation in cross-section of the hydraulic hand tool shown in Fig. 1, with the trigger arm and cam assembly in a pre-actuated orientation; Fig. 3 is a side elevation in cross-section of the hydraulic hand tool shown in Fig. 1, with the trigger arm and cam assembly in an actuated orientation; Fig. 4 is a fragmentary side elevation in partial cross-section of the hydraulic hand tool shown in Fig. 1; Fig. 5 is a top plan view of the hydraulic hand tool taken along the lines 5-5 of Fig. 1; Fig. 6 is a top plan view in cross-section of the hydraulic hand tool taken along the lines 6-6 of Fig. 1; Fig. 7 is a top plan view in cross-section of a portion of the cam assembly taken along the lines 7-7 of Fig. 1; Fig. 8 is a top plan view in cross-section of the release valve assembly taken along the lines 8-8 of Fig. 4; Fig. 9 is a side elevation in cross-section of another embodiment of the working head according to the present invention; Fig. 10 is a top plan view in cross-section of the locking assembly according to one embodiment of the invention taken along the lines 10-10 of Fig. 1;

Fig. 11 is a fragmentary side elevation of another embodiment of the locking assembly according to the present invention; Fig. 12 is a side elevation in cross-section of the push rod according to another embodiment of the present invention; Fig. 13 is a side elevation in cross-section of the cam assembly and push rod according to another embodiment of the present invention; Fig. 14 is a side elevation of the cam assembly and push rod according to another embodiment of the present invention; Fig. 15 is a fragmentary side elevation in cross-section of the cam assembly and push rod shown in Fig. 14; and Fig. 16 is a rear elevation in partial cross-section of the cam assembly and push rod shown in Fig. 15.

DETAILED DESCRIPTION OF THE INVENTION While this invention is susceptible of embodiment in many different forms, there are shown in the drawings and will herein be described in detail, several specific embodiments with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated.

Hydraulic hand tool 20 is shown in Fig. 1-8 as including main body 22, handle 24, closed-circuit fluid forcing system 26 and working head 28.

Main body 22 is preferably constructed of a light weight material such as plastic, to make the hand tool easier to carry on a work belt and/or in a toolbox. However, it is likewise contemplated that main body 22 may be formed of other light weight materials, such as light weight metals or composites. Alternatively, the main body may be constructed from still other materials which are both stronger and/or heavier. Moreover, while main body 22 is shown as a one-piece construction, it is likewise contemplated that it may be formed from two pieces, particularly two half-pieces which are secured together. Furthermore, while shown in Figs. 1,3 and 6 as separate and attachable to main body 22, working head 28 may likewise be directly integrated into main body 22, as is shown in Fig. 9. Both constructions will be discussed in more detail below. At the outset, it is also noted that like reference numerals will be used to designate like parts throughout this detailed description.

Closed-circuit fluid forcing system 26, shown in Figs. 1-4 and 6-8, is housed within main body 22 and handle 24, and includes cam assembly 30, fluid reservoir assembly 50, first check valve assembly 90, push rod assembly 110, fluid entry assembly 170, second check valve assembly 190, working head driving piston assembly 220 and fluid release assembly 250.

At the outset, fluid forcing system may comprise any hydraulic system for forcing substantially non-compressible fluids in a closed circuit manner.

Moreover, while fluid forcing system will be described as including each of these assemblies, it is likewise contemplated that the fluid forcing system may also include additional components, or in the alternative, substitute components, as would be recognized by those of ordinary skill in the art, having the present disclosure before them.

Cam assembly 30, shown in Figs. 1-4 and 7, includes trigger arm 32, cam head 33, elongated rods 38 and 39, stopping pin 42, pivot pin 44, and rod guides 46 and 47. Trigger arm 32 is pivotably attached to main body 22 by pivot pin 44. As can be seen from Figs. 2 and 3, trigger arm 32 has a substantially c-shaped cross section that fits directly over handle 24, for reciprocating movement relative to the handle. Trigger arm 32 terminates in cam head 33 at its upper end, proximate pivot pin 44. In particular, cam head 33 can be seen in Fig. 7 as preferably comprising two separate cam head segments 34 and 35, each having a respective cam surface 36 and 37.

The cam heads 34 and 35 each include a central aperture for insertion of pivot pin 44. A unitary cam head with a single cam surface could be used in the present invention.

Elongated rods 38 and 39, shown in Figs. 1,4 and 7, are preferably supported in main body 22 by rod guides 46 and 47. Rod guides 46 and 47 permit rods 38 and 39 to slide freely through the main body upon both prompting and release of trigger arm 32. While the inner diameter of rod guides 46 and 47 is shown in the drawings as substantially uniform, it is likewise contemplated that the inner diameter may vary, such as in a more conical design with a larger inner diameter proximate push rod assembly 110, according to the desired construction of the cam and push rod assemblies. Elongated rods 38 and 39 are preferably constructed from steel, although other suitable materials may be used as would be recognized by those with ordinary skill in the art with the present disclosure before them.

Each elongated rod includes two ends, one end of which is in contact with a respective cam surface 36 and 37, the other end of which is in contact with lever 112, as will be described below. Furthermore, as shown in Fig. 7, elongated rods 38 and 39 further include sleeves 40 and 41 for limiting movement of the rods toward cam surfaces 36 and 37. Sleeves 40 and 41 also assist in maintaining proper alignment of elongated rods 38 and 39 in rod guides 46 and 47, while ensuring proper engagement of the elongated rods with cam surfaces 36 and 37 and lever 112.

As is further shown in Fig. 7, cam heads 34 and 35 straddle upper handle portion 45 of main body 22. Upper handle portion 45 of main body 22 preferably further includes an aperture with a bushing 48 positioned therein to permit insertion and rotation of pivot pin 44, which allows rotation of cam head 33 and trigger arm 32 thereabout.

Stopping pin 42, shown in Figs. 1,4 and 7, extends from upper handle portion 45 of main body 22. Stopping pin 42 limits the range of movement of trigger arm 32, thus limiting the maximum distance between the trigger arm and handle 34--to ensure that a users hand is fully capable of spanning the distance between the trigger arm and the handle. This helps a user establish leverage for pulling the trigger arm, actuating the cam assembly and completing each stroke of the push rod, described below.

Fluid reservoir assembly 50 is shown in Figs. 2 and 3 as including sleeve 52, fluid reservoir 54, inner body 56, piston 58 and spring 60. Fluid reservoir assembly 50 is preferably positioned in handle 24 of the hydraulic hand tool. Sleeve 52 includes top end 61, bottom end 62, top wall 64 and sidewall 66. Sleeve 52 is preferably substantially cylindrical with an open bottom end, and is securably retained in handle 24 with a threaded connection between threads 67 on the upper portion of sleeve sidewall 66, and receiving threads on the inside of handle 24. Top wall 64 of the sleeve further includes a fluid exit port 68, from which fluid may be transferred from inside fluid reservoir 54 into fluid introduction channel 92, as will be described below. Likewise, sidewall 66 further includes fluid entry port 70 from which fluid may enter fluid reservoir 54 from fluid return channel 258. Sleeve 54 further includes an inner threaded region 72, which accepts inner body 56.

Inner body 56 includes head 74, threaded region 76, shoulder 80 and cap 84. Threaded region 76 mates with inner threaded region 72 of sleeve 52 to secure the inner body within the sleeve in a fluid-tight manner. Further, a lower 0-ring 78 is positioned on the outside of the inner body to maintain

the fluid-tight fit between the inner body and the sleeve. Shoulder 80 is designed to receive spring 60, while cap 84 closes off the bottom end of inner body 56.

Piston 58 includes stem 86, retaining ring 88 and piston head O-ring 89. The stem fits through inner body head 74 and continues into the inner region of the inner body. Moreover, an upper O-ring 82 is positioned between stem 86 and the inside surface of inner body head 74 to maintain a fluid tight seal between the inner body and the stem. Retaining ring 88 slidably anchors the lower portion of the stem as the piston moves up and down the fluid reservoir, maintaining the stem within the inner body. The retaining ring also acts to stop the piston upon full extension of the piston toward the top of the fluid reservoir. 0-ring 89 is positioned between the piston and the interior wall of the sleeve 52 to maintain a fluid tight seat therebetween.

Spring 60 is placed between the shoulder portion 80 of inner body 56 and the bottom surface of piston 58. The spring biases the piston 58 upwards towards the top of fluid reservoir 54, thus forcing fluid contained inside the fluid reservoir toward and through the fluid exit port 68. Fig. 2 illustrates the piston in its initial position wherein the fluid reservoir is full, while Fig. 3 shows the piston in an extended position in which fluid has been forced through the fluid forcing system and into second fluid chamber 234.

First check valve assembly 90, shown in Figs. 2 and 3, includes fluid introduction channel 92, sleeve 94, plunger 96, T-cylinder 98 and spring 100.

Fluid introduction channel 92 connects fluid exit port 68 of fluid reservoir 54

with first fluid chamber 180. Sleeve 94 is positioned in the bottom portion of fluid introduction channel 92, while T-cylinder 98 is positioned proximate the top of the fluid introduction channel. Plunger 96 includes seat 102, which accepts spring 100. T-cylinder 98 includes channel 104, through which fluid flows into fluid entry assembly 170.

Notably, first check valve assembly 90 is preferably a one-way valve, which allows flow in one direction, but prevents back flow in the other direction. As can be seen, fluid which flows through sleeve 94 forces plunger 96 upwards, thus allowing fluid to enter fluid introduction channel 92. That fluid is subsequently forced through T-cylinder channel 104 and into fluid entry assembly 170. However, fluid is precluded from flowing downward back through fluid introduction channel 92 and into fluid reservoir. Those of ordinary skill in the art with the present disclosure before them will readily recognize that various different one-way valve assemblies may be used in association with the described fluid forcing system in particular, and the present invention in general.

Push rod assembly 110 is shown in Figs. 1-6 as including lever 112, push rod 114, seat 116, bushing 118, spring 120, spacer 122 and fluid pusher rod 124. Lever 112 includes both top end 126 and bottom end 128.

Lever 112 is attached to main body 22 with pivot pin 130, which extends through opposing rear wing sections of the main body 131 and 133, and through lever 112. Bottom end 128 of lever 112 is preferably in contact with one end of elongated rods 38 and 39, while top end 126 of lever 112 has a face which is preferably in contact with push rod 114.

As can be seen from Figs. 2,3 and 6, push rod 114 is preferably a cylindrical, at least partially hollow rod with a wall 134 and a drill hole 132.

While drill hole 132 reduces the overall weight of push rod, and thus the weight of the hydraulic hand tool, it is likewise contemplated that push rod 114 may be constructed without the drill hole. Seat 116 sits inside of push rod 114 in the hollow cylindrical opening, and includes slot 136 and shoulder 138. Slot 136 is designed to accept the head of fluid pusher rod 124 for easy assembly and disassembly. Shoulder 138 provides, in combination with cylindrical wall 134 of the push rod, a housing for spring 120.

Bushing 118, likewise shown in Figs. 3,4, and 6, includes shoulder 140, which receives the other end of spring 120. Bushing 118 acts as a stop for the push rod in its fully compressed orientation. Spacer 122 is positioned on the other side of bushing 118, between the bushing and the bore hole in main body 22, and further includes aperture 142. The aperture is of a size selected to permit slidable movement of fluid pusher rod 124, including head 144, stop 146 and rod portion 148, therein. However, spacer also serves to prevent movement of fluid pusher rod 124 out of first fluid chamber 180, as stop 146 abuts spacer 122. Fluid pusher rod 124 is shown in its initial, unforced state in Fig. 2, while Fig. 3 displays full compression of the push rod into first fluid chamber 180 during a stroke.

In an alternative embodiment, shown in Fig. 12, the push rod assembly is configured differently. In particular, push rod assembly 150 includes push rod 152, fluid pusher rod 154 and spring 155. While push rod 152 is somewhat similar to push rod 114 shown in Figs. 1,2,3 and 6, push

rod 152 includes a drill hole 156 with threads to house fluid pusher rod 154, and cylindrical walls 158 to house spring 155. Instead of a seat, fluid pusher rod 154 fits directly into push rod 152 as the fluid pusher rod includes a first threaded end 160 which mates with the threaded region in the push rod drill hole. Those of ordinary skill in the art with the present disclosure before them will likewise appreciate that push rod assembly can be constructed in a number of ways to achieve the same result of forcing fluid through the first fluid chamber.

In yet another embodiment shown in Fig. 13, the hydraulic hand tool includes push rod assembly 450. In particular, while the cam assembly remains substantially the same, elongated rods 451 are attached to a driving pinion 452, which drives a rack 454 positioned on the bottom of push rod 455. Pinion 452 comprises rod pivot attachment 456, teeth 458 and pin 462 for rotation. Pin 462 extends through pinion 452 and secures pinion to main body 22'. Elongated rods 451 are preferably attached to either side of pinion 452 with rod pivot attachment 456, which preferably comprises a pin extending through each of the rods and the pinion. Rack 454 includes teeth 466 for mating with teeth 458 on pinion 452, to drive push rod 455 by a conventional rack and pinion mechanism. The spacing between teeth 458 on pinion 452 and teeth 466 on rack 454 may be altered to accommodate the length of the push rod, the size and inner diameter of the first fluid chamber, the size and inner diameter of the second fluid chamber, the force required in a specified tooling application and the required hand-generated cam actuation force or other variable which affects the specific hand tool design.

Moreover, as touched upon above, the elongated rod guides may likewise be modified, for instance their inner diameter widened proximate pinion 452, to accommodate the pivoting of elongated rods 451 as they move with pinion 452.

In still another embodiment, shown in Figs. 14-16, the hydraulic hand tool includes handle 470, cam assembly 472 and push rod 474. Handle 470 is preferably attached to the rear portion of main body 22", and includes shaped trigger accepting region 476 and rear wing portions 478 and 480.

Each rear wing portion 478 and 480 includes proximal and distal apertures, shown as frontal aperture 482 and distal aperture 484 on rear wing 478.

While handle 470 still houses the fluid reservoir assembly, handle 470 is configured with shaped trigger accepting region 476 to receive trigger arm 490 on its rear-most side, not its front-most side as is shown in Figs. 1-13.

Push rod 474 includes opposing rear walls 506 and 508 and pin 510.

As is shown in Fig. 16, pin 510 extends between rear walls 506 and 508. Pin 510 accepts slot 504 of pivoting connection member 494, discussed below.

Notably, aside from the rear portion of push rod 474, namely rear walls 506 and 508 and pin 510, push rod 474 is substantially similar to push rod 114 described above.

Cam assembly 472 includes trigger arm 490, cam head 492, pivoting connection member 494, cam pin 496 and pivoting connection member pin 498. Cam head 492 is pivotably attached to rear wing portions 478 and 480 of handle 470 with cam pin 496. Attachment of cam head 492 to the rear portion of handle 470 positions trigger arm 490 behind handle 470, and

forces a user to push trigger arm 490 toward handle 470 with the palm of his or her hand, instead of pulling trigger arm toward the handle as is required in the embodiments illustrated in Figs. 1-13. Such an orientation can be quite ergonomically friendly to a user who is conducting multiple tooling operations in a single day, or who is generating the kinds of force required to cut cable such as ASCR, or perform other relatively heavy duty tooling operations. As can be seen in Fig. 14, the hydraulic hand tool may also be equipped with connecting member 512, which extends between main body 22"and handle 470. Connecting member 512 preferably acts as a housing for a portion of the fluid return channel, including release valve 290'shown in phantom in Fig. 14. Of course, it is likewise contemplated that the fluid return channel may be routed from the second fluid channel to the fluid reservoir in a manner different than that specifically shown in the drawings, so as to either change the dimensions and/or structure of connecting member 512, or to obviate the need for connecting member 512 altogether.

Cam head 492 further includes gear face 500. Gear face 500 may be constructed of gears of various sizes and shapes, to mate with gear face 502 on pivoting connection member 494. One with ordinary skill in the art with the present disclosure will recognize that gears 500 and 502 may likewise be replaced by other driving or ratcheting mechanisms to achieve the same result of propelling push rod 474 forward to a fluid forcing orientation.

Pivoting connection member 494 further includes slot 504. At one end, pivoting connection member 494 is pivotably secured between rear wing portions 478 and 480 of handle 470 with pivoting connection member pin

498. At the other end, slot 504 is preferably of a configuration to permit slidable movement of pivoting connection member 494 relative to push rod pin 510. Gear face 502 mates with gear face 500 on cam head 492, such that compression of trigger arm toward handle 470 rotates cam head 492 and gear face 500, which, in turn, drives gear face 502 and thus pivoting connection member 494. As can be seen from Fig. 14, showing the trigger arm compressed, and Fig. 15, showing the trigger arm in an initial state, pivoting connection member 494, and slot 504 contained therein, are of sufficient lengths and/or dimensions to facilitate reciprocating movement of pivoting connection member 494 and thus push rod 474 between forward fluid forcing (Fig. 15) and rearward fluid refilling (Fig. 14) positions. Of course, those lengths and/or dimensions can be varied depending on the desired size of the hand tool, the desired length of the push rod stroke, the gear ratio of the cam head to the pivoting connection member, the size of the fluid chambers, the amount of force required for various tooling operations and other system variables as would be recognized by those of ordinary skill in the art with the present disclosure before them.

As shown in Figs. 2,3 and 6, fluid entry assembly 170 includes fluid channel 172, cylinder body 174, first fluid chamber 180, first check valve assembly connector 176 and filler cap 178. Cylinder body 174 includes threaded portion 179 which secures the cylinder body within main body 22.

Cylinder body 174 further includes fluid filling port 182 and fluid entry channel 184, while also defining first fluid chamber 180. First fluid chamber 180 has an inner diameter, which, as will be described in more detail below, is smaller

than the inner diameter of second fluid chamber 234. The relationship between the inner diameters of the first and second fluid chambers, as well as the volume of the first fluid chamber, are primary factors in determining the amount of force and mechanical work that can be generated by the hand tool.

Fluid filling port 182 is positioned in the top of cylinder body 174, such that first fluid chamber 180 may be filled with fluid. Filler cap 178 is preferably threaded to mate with the main body portion immediately above cylinder body 174 to form a fluid-tight seal. First check valve assembly connector 176 permits fluid to enter first fluid chamber 180 from fluid reservoir 54 and through fluid introduction channel 92, fluid channel 172, and finally through fluid entry channel 184. As can be seen from Fig. 3, fluid pusher rod 124 extends past fluid entry channel 184 during a stroke when in a compressed orientation, thus precluding any flow of fluid from fluid reservoir 54 through first check valve assembly 90 and fluid entry channel 184, and into first fluid chamber 180. However, upon retraction of fluid pusher rod 124, the volume of first fluid chamber 180 expands, thus leaving fluid entry channel 184 open, and allowing fluid to enter the first fluid chamber.

Second check valve assembly 190, shown in Figs. 2,3 and 6, is positioned in fluid forcing channel 192 and includes sleeve 194, plunger 196, T-cylinder 198, spring 200 and jacket 202. Second check valve assembly 190 functions in much the same one-way manner as first check valve assembly 90, wherein sleeve 194 includes channel 204 for fluid flow, plunger

196 includes seat 206 to house spring 200, and T-cylinder 198 includes channel 208 to permit fluid flow therethrough. While jacket 202 is shown preferably threadably secured to main body 22, jacket 202 may likewise be secured only to sleeve 194. Jacket 202 includes fluid passageway 214 to allow fluid to pass into second fluid chamber 234.

Working head driving piston assembly 220 is shown in Figs. 2,3 and 6, as including sleeve 222, jacket 224, piston 226, seat 228 and spring 230.

Sleeve 222 defines second fluid chamber 234, which has an inner diameter that is preferably larger than that of first fluid chamber 180, to gain the mechanical advantage of forcing a specific volume of fluid from a chamber having a smaller inner diameter to a chamber having a larger inner diameter.

As will be described below as well, this mechanical advantage, in turn, transforms the force required for multiple, fluid forcing strokes of trigger arm 32 and associated pusher rod 114 into a substantially lager driving force generated by incremental movement of piston 226 in second fluid chamber 234. Of course, inasmuch as piston 226 is preferably attached to the moving tooling implement, for instance a cutting blade, the substantially larger force is translated into work performed by the moving tooling implement on an object during a specific tooling application.

Sleeve further includes fluid entry port 232, through which fluid forcing channel 192 is in fluid communication with second fluid chamber 234. Sleeve 222 also includes fluid exit port 240, which maintains second fluid chamber 234 in fluid communication with fluid return channel 258, described below.

Sleeve 222 is preferably secured in hydraulic hand tool main body 22 by

threaded portion 236. Sleeve, 222 further preferably includes receiving threads on a portion of its outer surface proximate working head 28, for receiving jacket 224. As can be seen, jacket 224 includes a threaded portion which mates with sleeve 222. Moreover, while jacket 224 is shown as a component separate from working head 28, it is likewise contemplated that the jacket may be integrated into working head 28 and used to secure working head 28 to main body 22. However, the hydraulic hand tool of the present invention may also be constructed without the jacket, with slight modifications to the main body and/or sleeve 222, that may readily be accomplished by one of ordinary skill in the art having the present disclosure before them.

Piston 226 is positioned within second fluid chamber 234 and includes O-ring seals 242 and 243, base 244 and head 246.0-rings 242 and 243 provide a fluid-tight seal between piston base 244 and the inner walls of sleeve 222. Piston head 246 is preferably attached to moving tooling implement 322, as described below. That attachment preferably comprises a threaded attachment, to allow piston head 246 to be interchangeably attached to any one of a number of tooling implements, including various blades, crimping dies, punching dies, stamping dies, etc. However, it is likewise contemplated that piston head 246 is attached to moving tooling implement 322 by any attachment mechanism that allows a user to interchange moving tooling implements, as would be accomplished by those with ordinary skill in the art with the present disclosure before them.

Seat 228 is positioned on the inside of sleeve 222, and is preferably secured thereto. However, seat 228 may likewise be a separate component maintained in second fluid chamber 234 by sleeve 222 in combination with spring 230. Seat 228, in combination with base 244 of piston 226, provides a housing for spring 230, which resists entry of fluid into second fluid chamber 234, or, stated differently, resists movement of piston 226 away from fluid entry port 232. Of course, any entry of fluid into second fluid chamber 234 drives piston 226 forward, thus incrementally forcing moving tooling implement 322 from a nonworking position distal from substantially stationary tooling implement 324, toward substantially stationary tooling implement 324 and to a working position proximate substantially stationary tooling implement 324 to perform a cutting or other tooling operation. Inasmuch as moving tooling implement 322 preferably moves toward substantially stationary tooling implement 324 in an incremental fashion, the working position will be understood to mean any number moving tooling implement orientations or positions closer to substantially stationary tooling implement than the initial nonworking position.

Fluid release assembly 250 is shown in Figs. 2-5 and 8 as including release lever 252, detent subassembly 254, release subassembly 256 and fluid return channel 258. Release lever 252 includes gripping end 260 and pivot end 262. Gripping end 260 preferably includes a dimple 264 or a depression on its inside face to cooperate with detent subassembly 254, to maintain release lever 252 in a closed orientation. Pivot end 262 includes aperture 266, which allows for pivotable attachment of release lever 252 to

the main body. Release lever 252 pivots about pivot pin 292 between closed and open orientations, which either open or close the fluid release valve.

Detent subassembly 254 includes bore hole 268, detent 270, screw 272 and spring 274. Detent further includes a rounded head 276 and a shoulder portion 278, which houses spring 274. Rounded head 276 facilitates manipulation of the release lever between open, unlocked and closed, locked orientations shown in Fig. 4. Screw 272, preferably a socket head set screw, includes seat 280 to likewise seat spring 274. Notably, while a specific detent subassembly has been described, those of ordinary skill in the art with the present disclosure before them will recognize that release lever 252 may be releasably locked in a closed orientation in a number of ways in keeping with the spirit of the present invention. For instance, a simple spring-loaded plunger may be used in place of the sub-assembly shown in Fig. 8.

Release valve sub-assembly is shown best in Fig. 8 and includes release valve 290, pivot pin 292, resistance spring 294, screw 296 and release valve housing 298. Release valve 290 further includes fluid flow aperture 300. Fluid flow aperture 300 permits fluid to flow from second fluid chamber 234, through fluid return channel 258, and into fluid reservoir 54 when aligned with the fluid return channel in an open orientation. An open release valve orientation preferably corresponds to an open release lever orientation shown in phantom in Fig. 4. Resistance spring 294 is positioned relative to pivot pin 292 and release lever 252 to resist movement of the release lever into a valve opening orientation. Thus, resistance spring 294,

in combination with the detent sub-assembly, prevents inadvertent opening of the release lever, and premature fluid return from second fluid chamber 234 to fluid reservoir 54. Screw 296 preferably includes a small groove that houses an O-ring 304, to create a fluid-tight seal for release valve housing 298. This prevents fluid from leaking out of the hydraulic hand tool.

Fluid return channel 258 includes top end 306 and bottom end 308.

Top end 306 extends directly from fluid exit port 240 of second fluid chamber 234, while bottom end 304 leads into entry port 70 in fluid reservoir 54.

Notably, a cap, such as that shown in Figs. 2 and 3, may be necessary to plug a portion of the channel which extends above second fluid chamber.

While the portion of the channel above the second fluid chamber preferably has no involvement in the operation of the present invention, the bore hole may result from manufacturing of the present hand tool. Moreover, main body 22 of the hydraulic hand tool preferably further includes recess 312 in the side thereof, as shown in Figs. 5 and 8. This recess preferably matches the size and shape of release lever 252, and may further include a small shelf defining a bottom boundary for the release lever.

Main body 22 of the hydraulic tool is further shown in Figs. 5 and 6 as including guides 314 and 318 to accept working head 28. Guides 314 and 318 may comprise simple tracks on the front end of the main body which permit working head 28 to slide thereon, and to be interchangeably removed therefrom. However, it is likewise contemplated that working head 28 may be attached to the main body in any number of ways as might be readily perceived by those of ordinary skill in the art with the present disclosure

before them. Moreover, it is likewise contemplated that guides 314 and 318 further include a locking structure to cooperate with the working head to releasably lock the working head onto the main body. Such a locking structure prevents inadvertent release of the working head from the main body during use, while allowing use of interchangeable working heads which may perform different tooling operations, or different variations on the same tooling operation. Of course, in the embodiment of the invention shown in Fig. 9 in which the hydraulic hand tool is a single piece, those guides are unnecessary.

Working head 28 is shown in Figs. 1-3,5 and 6 as including attachment portion 320, moving tooling implement 322, substantially stationary tooling implement 324, moving tooling implement track 326, substantially stationary tooling implement pivot pin 328 and locking subassembly 330. At the outset and as touched upon above, while working head 28 is shown in Figs. 1-3,5 and 6 as releasably securable to main body 22, it is likewise contemplated that working head is integrated directly into the main body of the hydraulic hand tool as shown in Fig. 9, described hereinbelow.

Attachment portion 320, shown best in Figs. 5 and 6 includes arms 332 and 333. Each arm includes a track 334 and 335, respectively, which cooperates with main body guides 314 and 318 to allow securable sliding of working head 28 onto main body 22. As is shown in Figs. 1-3, attachment portion 320 may be secured to main body 22 with socket head cap screws 340. However, as discussed above relative to the main body, it is likewise

contemplated that each arm includes a locking mechanism for cooperation with a mating locking structure on main body 22, which secures working head 28 into position. For instance, the working head may include a protruding threaded portion which mates with a receiving threaded portion on main body to ensure a secured fit. Alternatively, each arm may also include a detent, aperture, or a set of teeth which mates with a similar receiving structure on the main body guides. Certainly, one of ordinary skill in the art with the present disclosure before them will appreciate the variety of ways working head 28 may be securely locked onto main body 22. Furthermore, and as is shown in Fig. 1, arms 332 and 333 may further include holes in the sides thereof. These holes further lighten the working head, and thus the overall hydraulic hand tool, to facilitate carrying and use.

Moving tooling implement 322 is shown in Figs. 2,3 and 6 as including piston head receiving socket 342 and tooling edge 344. Piston head receiving socket 342 may be threaded to receive piston head, so as to allow different moving tooling implements to be interchanged for use with the same piston. Likewise, piston head 246 may be secured in piston head receiving socket 342 frictionally, with a retaining ring to maintain a secure fit.

Alternatively, moving tooling implement 322 may be directly integrated into the structure of driving piston 246. Notably, while moving tooling implement 322 is shown in the figures as including a blade specifically designed for cable cutting applications, it is likewise contemplated that moving tooling implement 322, as well as substantially stationary tooling implement 324, are designed for other tooling operations such as crimping, stamping, punching,

etc. Given the construction of the hydraulic hand tool, different driving and stationary implements may be substituted into the working head, depending on a desired tooling operation. Thus, the hydraulic hand tool is flexible for use in many different applications. Notably, for purposes of the present description, tooling implements 322 and 324 will be described specifically in relation to a cutting operation.

Tooling edge 344 includes a blunted portion 346 and a tapered portion 348. As is known to those with ordinary skill in the art, steel reinforced aluminum cable requires a blade having a sufficiently blunted tip portion for cutting through the steel core, yet a blade which is still sharp enough to cut through the softer aluminum portion. The blade may be designed as shown in Fig. 1, Fig. 9 or in any other configuration as would be desired, depending on the type of cutting operation and/or the type of cable to be cut.

Substantially stationary tooling implement 324, shown in Figs. 1-3,5 and 6, includes tooling edge 350, aperture 352 and locking facilitation end 354. Like moving tooling implement 322, substantially stationary tooling implement 324 is specifically shown in the drawings as a cutting instrument, with a blade having a blunted portion 356 and a tapered portion 358. Of course, as explained above, the actual tooling operation may vary, and accordingly, the tooling edge and/or design of the stationary implement may be readily changed to accommodate such an operation. Moreover, while substantially stationary tooling implement 324 is shown in the drawings as substantially stationary during a working or tooling operation, it is likewise

contemplated that the stationary tooling implement likewise move toward the moving tooling implement during a tooling operation.

Aperture 352 receives stationary pivot pin 328, which locks substantially stationary tooling implement 324 to working head 28 and allows rotation of substantially stationary tooling implement 324 about that pivot point. Such rotation expands the region between moving tooling implement 322 and substantially stationary tooling implement 324, and permits a desired object, such as a cable, to be placed therebetween for subsequent cutting or other tooling operations. Locking facilitation end 354 is shown in detail in Figs. 2 and 10 as comprising an opening 356 for receiving a plunger and a tab 358 for easy access to substantially stationary tooling implement 324.

However, as will be described below, locking facilitation end 354 may vary according to the design of locking sub-assembly 330.

As is shown in Fig. 2, moving tooling implement track 326 includes both an upper guide 360 and a lower guide 362. The moving tooling dJ ^ ,.,. implement fits within the upper and lower guides, which permit reciprocating slidable movement of moving tooling implement 322 in the track. Of course, reciprocal movement of moving tooling implement 322 is dictated by reciprocaing movement of driving piston 226 in second fluid chamber 234.

In one embodiment, shown in Fig. 10, locking sub-assembly 330 comprises a locking plunger sub-assembly 370. Locking plunger assembly 370 comprises plunger 372, housing 374 and spring 376. Plunger 372 includes shoulder 380, head 382 and gripping nut 384. Housing 374 includes open cylinder 386, which houses spring 376. Open cylinder likewise houses

plunger 372 and is of an inner diameter sufficient to permit shoulder portion 380, and therefore plunger 372, to slide therein. Shoulder 380 likewise provides a resistance surface for spring 376, to controllably resist any motion of plunger 372 outwardly, such as by pulling on gripping end 384, to release substantially stationary tooling implement 324. Of course, plunger 372 may be pulled outwardly against the spring resistance to release substantially stationary tooling implement 324 for rotational pivoting and insertion of a cable or other item to be worked.

In another embodiment, shown in Fig. 9, the locking sub-assembly comprises a locking lever sub-assembly 390, which includes locking lever 392, pivot pin 394 and spring 396, associated with working head 28'. The locking lever includes manipulable end 398, locking end 400 and pivot portion 402. Pivot portion 402 has an opening to receive pivot pin 394.

Locking end 400 includes a cavity 404 designed to engage mating region 403 of working head 28'. As is shown in Fig. 9, mating cavity 404 may simply comprise a groove designed to accept a sloped ridge 403 on working head 28'. However, it is likewise contemplated that locking lever 392 may be held into place relative to working head 28'by any number of locking mechanisms as would be recognized by those of ordinary skill in the art with the present disclosure before them.

Also shown in Fig. 9, working head 28'is directly integrated into the main body of the hydraulic hand tool. In this embodiment, stationary tooling implement 412 separately houses the tooling edge, again shown as a cutting blade. Moreover, stationary tooling implement 412 further includes pin 414 to

hold the blade in place, pivot housing 416 for locking lever and moving tooling implement housing 418. Pin 414 securably locks the stationary blade into place inside the stationary tooling implement 412, while at the same time permitting any blade or tooling edge to interchanged or replaced for other cutting or tooling operations.

Pivot housing 416 for the locking lever extends downwardly from stationary implement 412. Pivot housing includes two wing portions which straddle locking lever 392, and permit insertion of the pivot pin therethrough.

Moving tooling implement housing 418 is much the same as described above in relation to the portion of working head 28 which houses the moving tooling implement in Figs. 1-3,5 and 6. In particular, moving tooling implement housing 418 preferably includes guides or tracks to permit reciprocal, slidable movement of the driving implement therein.

In yet another embodiment, shown in Fig. 11, the locking subassembly comprises a slide lock sub-assembly 430. The slide lock sub-assembly comprises slide 432, track 434, bore hole 436 and spring 438. Slide further includes pin 440 and knob portion 442. Spring is housed partially in a bore hole 436, and encompasses pin 440, while abutting knob 442. Track 434 is positioned in the inside of the working head, so as to slidably accept slide 432. In this particular embodiment, the substantially stationary tooling implement further includes a contoured accepting region 444 for mating with slide 432. In this locking sub-assembly, slide 432 contours into contoured accepting region 444 to lock substantially stationary tooling implement in place. However, upon forcing the slide against the spring bias away from the

substantially stationary tooling implement, slide 432 freely travels in track 434 relative to the working head, thus releasing the substantially stationary tooling implement. The substantially stationary tooling implement may then be rotated about its pivotal attachment to the working head for subsequent insertion of a cable or other item for tooling.

In operation of the hydraulic hand tool 22, fluid is first introduced into fluid reservoir 54, and may likewise also be introduced into first fluid chamber 180. Preferably, the fluid is a substantially non-compressible liquid such as oil, although other substantially non-compressible liquids are likewise contemplated. Fluid non-compressibility ensures that the fluid moves within the fluid forcing system in a uniform manner without compression, which detracts from the mechanical advantage achieved through the present hydraulic system.

From the fluid reservoir, spring biased piston 58 forces the fluid through first check valve assembly 90 and into first fluid chamber 180. As seen from Fig. 2 showing the hand tool pre-tooling or nonworking orientation, moving tooling implement 322 has not been moved toward substantially stationary tooling implement 324 in a working orientation, and second fluid chamber 234 remains completely unfilled. In this initial pre-working state, lever 112 is in its retracted orientation, as is push rod assembly 110.

Notably, fluid does not move from first fluid chamber 180, through the fluid forcing channel and past second check valve assembly 190 without the assistance of push rod 114.

To initiate a tooling operation, the fluid forcing system is actuated by pulling trigger arm 32 against handle 24, thus actuating cam assembly 30. In particular, each cam head 34 and 35 forces a corresponding elongated rod 39 and 38, respectively, toward the rear end of main body 22. Inasmuch as each elongated rod is also in contact with lever 112, actuation of the cam assembly forces the elongated rods to activate the lever, thus, pushing the top end of the lever against push rod 114. The push rod, in turn, is forced in a forward stroke against the bias of spring 120, forcing fluid pusher rod 124 into first fluid chamber 180. This forward stroke of the fluid pusher rod forces the fluid through fluid forcing channel 192, through second check valve assembly 190 and into second fluid chamber 234. Entry of fluid into second fluid chamber 234, in turn, forces piston 226 forward in the second fluid chamber. Forward movement of the piston forces the attached moving tooling implement 322 incrementally forward from a nonworking position toward substantially stationary tooling implement 324 and into a working position.

Fig. 3 illustrates the fluid forcing system after the piston and attached moving tooling implement have been forced into a working position during a cutting or other tooling operation. Notably, Fig. 3 illustrates the system after the trigger arm and cam assembly have been actuated multiple times, thus inducing the incremental movement of the piston and moving tooling implement that is shown. Complete forward movement of the moving tooling implement into a working position relative to the substantially stationary tooling implement requires multiple actuations of the cam assembly to

generate the requisite amount of working force for a desired tooling operation.

Upon release of the trigger arm, spring 120 in the push rod assembly forces push rod 114 backward, thus withdrawing fluid pusher rod 148 from its position deep within first fluid chamber 180. This spring forced movement of the push rod returns lever 112 to its original position, thus forcing the elongated rods back against the cam surface and back to their original position. Inasmuch as the fluid pusher rod preferably extends beyond the fluid entry channel 184 in the first fluid chamber in a fully forced orientation, retraction of the fluid pusher rod once again places the fluid entry channel into fluid communication with the first fluid chamber. In so doing, retraction of the fluid pusher rod creates a vacuum in the first fluid chamber, which, in combination with the spring-forced fluid reservoir piston, again forces fluid through the fluid introduction channel, through the first check valve assembly and back into the first fluid chamber.

Upon completion of a desired tooling operation, such as complete severing of cable placed between the driving implement and the stationary implement, release lever 252 is manipulated from its closed orientation to an open orientation. In so doing, release valve 290 is opened, thus allowing the fluid in the second fluid chamber to travel through fluid exit port 240 and into fluid return channel 258. Fluid reenters fluid reservoir 54 through fluid entry port 70. Inasmuch as spring 230, which resists forward motion of piston 226 in the second fluid chamber, is preferably stronger than spring 60, which drives piston 58 in the fluid reservoir, fluid is forced through the fluid return

channel and back into the fluid reservoir. Thus, piston 58 is forced back into its original orientation allowing the fluid reservoir to again be filled with fluid to initiate a subsequent tooling operation.

If the push rod assembly shown in Fig. 13 is used in association with the hydraulic hand tool, actuation of the cam assembly simply drives the pinion, which, in turn, drives the rack and associated push rod assembly. In particular, actuation of the cam assembly forces the elongated rods toward the rear of the main body, thus driving pinion 452. The pinion, in turn, propels rack 454 and push rod 455 against the spring bias toward the first fluid chamber 180, thus forcing fluid pusher rod 148 into first fluid chamber 180. As been described in reference to the figures above, fluid is forced from the first fluid chamber through the fluid forcing channel and into the second fluid chamber. Upon retraction of the trigger arm, the spring forces the push rod back, in turn driving the pinion in a reverse direction and forcing the elongated rods back to their original resting posture. The subsequent forcing of fluid through the fluid system and refilling of fluid through the fluid introduction channel and back into the first fluid chamber are substantially the same as described above.

Of course, if cam assembly 472 and push rod 474 of Figs. 14-16 are used in association with the hydraulic hand tool, actuation of the cam assembly drives the pivoting connection member. The pivoting connection member, in turn, drives push rod 474, which forces fluid from the first fluid chamber into the second fluid chamber, as described above in reference to Figs. 1-13. Upon return of the trigger arm to its initial uncompressed

orientation, the push rod is retracted to its initial rearward orientation, thus permitting the fluid forcing system to recharge fluid into the first fluid chamber.

Also, upon completing a desired tooling operation, locking subassembly 330 on working head 28 may likewise be released, thus freeing substantially stationary tooling implement 324 for full rotation about pivot 328.

Thus, another cable and/or item may be inserted between the moving tooling implement and the substantially stationary tooling implement for subsequent tooling. Of course, if a different tooling operation is desired, the cable cutting blades shown in the figures may easily be replaced by other desired tooling implements.

As touched upon above, inasmuch as the present hydraulic hand tool makes use of a hydraulic-based fluid forcing system, a mechanical advantage is achieved. In particular, the first fluid chamber has an inner diameter which is smaller than that of the second fluid chamber. Each stroke of the trigger arm and the push rod forces fluid from the smaller inner diameter first fluid chamber to the larger inner diameter second fluid chamber, realizing the advantage of generating substantial force based upon the principles of hydraulics. Those collective strokes generate a total amount of tooling force which is greater than that of any individual stroke, or the sum thereof, and a total work output superior to that found in hand tools which employ ratcheting mechanisms. Thus, while the trigger arm must be pumped a number of times to complete a cutting and/or tooling operation, each stroke requires a force which is well within a hand tool user's capability. The

collective force generated by the fluid forcing system of the present hand tool is of the magnitude required for cutting steel reinforced aluminum cable, such as ACSR.

The foregoing description and drawings merely explain and illustrate the invention and the invention is not limited thereto except insofar as the appended claims are so limited as those skilled in the art who have the present disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.