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Publication numberUS2688231 A
Publication typeGrant
Publication dateSep 7, 1954
Filing dateJun 20, 1951
Priority dateJun 20, 1951
Publication numberUS 2688231 A, US 2688231A, US-A-2688231, US2688231 A, US2688231A
InventorsNorthcutt Walter E
Original AssigneeManco Mfg Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Piston actuated hydraulic pressure tool
US 2688231 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

@Rpt 7@ M54 w. E. Nom'HcUT-n RIsToN ACTUATED HYDRAULIC PRESSURE Toor.

Filed June 20, 1951 3 Sheets-Sheet 1 Nm wm .5MM Q\ ATTORNEYS Set 7 5 W. E. Nom'-HTT E PISTON CTUATED HYDRAULIC PRESSURE TOOL Filed June 20, 1951 3 Sheets-Sheet 3 @NVENTDR Y @UQT- E Nmr'h EMU ATTORNEYS,

Patented Sept. 7, 1954 PISTON ACTUATED HYDRAULIC PRESSURE TOOL Walter E. Northcutt, Kankakee, Ill., assigner to Manco Mfg. Co., Bradley, Ill., a, corporation of Illinois Application June 20, 1951, Serial No. 232,563

9 Claims. l

The present invention relates to manually operated hydraulic tools, such as crimping and cutting tools actuated by hydraulic ram, and in particular to the hydraulic actuating mechanism.

An object of the present invention is to provide a hand operated tool having relatively movable dies, cutters, or the like, movable toward one another with substantial force to effect bending, forming, crimping, cutting or the like, of hard materials, particularly metals, with the eX- penditure of little physical effort.

Another object. of the present invention is to provide a tool including a manually operated hydraulic pump adapted to reciprocate a ram or piston for eiiecting a work stroke or movement of a die, cutter, or the like, wherein the manual veffort required is slight and the application of force to the work piece is great.

Another object of the invention is the provision of a tool including a manually operated two-stage or compound pump for rapidly moving a die or the like into engagement with the work piece and thereafter slowly moving said die or the like with respect to the work piece with application of ccnsid'erable force to do Work on the work piece. Y

./-i further object ofv the invention is the provision of a completely self-contained tool, comprising a fluid reservoir, a. iiuid pump and a ram movable to effect work, the pump being manually operated and providing a large mechanical adi" vantage between the operating lever of the pump .andthe ram.

A still further object oi the invention is to provide a tool of the character dened in the preceding paragraph having a compound pump ini l cluding a high volume-low pressure unit and a low volumeehigh pressure unit, the tWo units cooperating toprovide rapid. movement of the ram 4 to bring a die or the like carried thereby into engagement with the work piece, the low volumehigh pressure unit thereafter effecting movement of' the ram to apply force to the work piece and perform work thereon.

In addition to the foregoing, it is an object of the 'present invention to provide a tool of the character described having automatic valve means for oy-passing the output of the low pressure pump unit back to the duid reservoir after the die or the like has been moved into engagement with the work piece and while the high pressure pump unit effects the performance of work.

Another object of the invention is to provide in a tool of the character described, automatic safety valve means for relieving hydraulic pressure 2 acting on the ram when the pressure rises to a predetermined maximum.

It is also an object of the present invention to provide a manually operated hydraulic ram for actuating dies, cutters, or the like for performing Work on a work piece, the pump being of a compound nature and having a by-pass valve for one stage of the pump when the ram actuating pressure exceeds a predetermined value. The hydraulic ram of the present invention also includes a relief valve for Venting the ram pressure chamber to the reservoir when the pressure in the ram chamber exceeds a predetermined maximum, a manually operable valve for venting the ram chamber to the reservoir and a pair of handles, one handle being manually oscillatable to operate the compound pump and the other being adapted to eiiect actuation of the last named valve for relieving the pressure in the ram chamber.

Y Another object of the invention is to provide a hydraulic tool having a pair of handles, one oscillatable to operate a pump to actuate a ram in its working stroke and the other rotatable to operate a valve for venting the ram pressure chamber to a fluid reservoir to accommodate the return stroke of the ram.

A still further obj ect of the invention is the provision of a hydraulic tool that is compact, operated with a minimum of physical effort, economical of manufacture and maintenance, sturdy and of long life.

Other objects and advantages of the invention Will become apparent in the following detailed description of a preferred embodiment of the invention, wherein reference is made to the accompanying drawings, in which:

Figure l is a plan View of the tool, a portion of the pump body being cut away to show the low pressure pump by-pass valve and latch means for that valve;

Figure 2 is a side View, partly in section and partly in elevation, taken substantially along the line 2-2 of Figure 4;

Figure 3 is a vertical sectional View of the pump mechanism, with the ram, the material working members, and the members defining the fluid reservoir, removed, taken substantially along the line 3 3 of Figure 4;

Figure 4 is an enlarged end elevation of the body of the tool, the view being taken from the right hand side of Figures 2 and 3, but showing only the body;

Figure 5 is a plan view, partly in section, on an enlarged scale, the cross sectioned portion being taken substantially along the line 5-5 of Figure 4; and

Figure 6 is a partial sectional view of the automatic relief valve taken substantially along the line 6 6 of Figure 4.

Referring to the drawings, the hydraulic tool of the present invention comprises a body I0 dening a pump chamber and a ram chamber, a tool head I2 upon which dies, cutters, or the like are mounted for actuation by the ram, a pump actuating handle I4, a supporting and valve actuating handle I6 and a fluid reservoir I8.

Referring to Figure 2, the body IIIY is preferably an integral steel forging having a main portion that is generally cylindrical and provided at one end with an enlarged cylindrical extension having a bore 2| therein forming a ram pressure chamber or cylinder. The cylindrical extension 26 is provided with an external thread 22 for the reception of the tool head I2. At its opposite end, the body I0 is provided with an enlarged cylindrical portion 23 for the reception of the members defining the fluid reservoir I8 and is provided with an internal thread 24 for securement of those members to the body I0. A cylindrical bore 25 is formed in the body along the longitudinal axis thereof, the bore 25 being provided at either end with counterbores 26 and 21 communicating with the ram chamber 2| and the uid reservoir I8, respectively.

Referring now to Figures 1 and 3, the body I0 is provided, at one side of the axis of the bore 25, with a cylindrical portion 28 extending perpendicular to, but laterally spaced from, the axis of the bore 25. The cylindrical portion 28 is provided with a stepped bore 29 defining a pair of pump chambers 3U and 3|. A pair of spaced parallel bores 32 and 33 are provided in the body In and extend normally to but in vertical alignment with the stepped bore 28 and intersect the pump chambers 30 and 3| respectively. Both bores 32 and 33 extend through the body IIJ and communicate with the bore 2| and the cylindrical portion 23. The bores 32 and 33 are provided at each end with counterbores and tapped portions for the reception of valve mechanisms to be described hereinafter. Vertically aligned with, but spaced from the bores 32 and 33, is a valve chamber 34 defined by a counterbore of a bore 35. The bore 35 is open at the reservoir side of the body I6 and is provided with a second enlarged counterbore 36 provided with an internal thread 31 for the reception of the handle I6. Communicating with the chamber 34 is an inclined bore 38 which extends upwardly and toward the center of the body I Il from the chamber 34, the bore 33 opening into the cylindrical portion 23, as shown in Figure 4. Communicating with the bore 35 is an inclined bore 39, which extends upwardly and toward the center of the body I0 from the bore 35 and opens into the bore 2|.

Immediately below the chamber` 34, as shown in the drawings, the body Ill is provided with a boss 4G within which a tapped hole 4| is formed, the hole serving as a filling opening for the iiuid reservoir and being normally closed by a plug 42 threaded into the bore 4|.

As shown in Figures l and 5, a transverse bore 43 extends from one side of the body I0 into communication with the bore 32 and thus with the pump chamber 38. Bore 43 is provided at its outer end with a counterbore 44 for the reception of a valve to be described in detail hereinafter. A longitudinal bore 45, spaced from,

but generally parallel to the bore 32, establishes communication between the reservoir and the counterbore 44. The bore 45 opens along its bottom edge into the counterbore 21. A second and smaller bore 46, co-extensive with an opening along one edge into the bore 45, see Figures 4 and 5, serves to provide a fluid by-pass of a latch member, to be described hereinafter, normally positioned in the bore 45. Referring to Figures 4 and 6, a longitudinal bore 41 extends/ through the body IU from the bore 2| to the cylindrical portion 23 and is provided at each end with a counterbore. The bore 41 serves as a relief passage for fluid from the ram chamber 2| when pressure therein exceeds a predetermined maximum. At its upper end, the body I0 is provided with an upwardly extending portion 48 having a transverse bore 49 therein forming a fulcrum for the handle I4.

In the preceding description, the body I0 has been described with little reference to the members to be associated therewith for the purpose of defining the structure and formation of the body I0. The parts and members to be associated with the body and their association therewith will now be described.

Slidably mounted in the bore 25 is a piston rod 50 threadedly connected at one end to a ram 5| deiined by a radial flange having a diameter slightly less than the diameter of the bore 2| defining the ram pressure chamber or cylinder. The flange is slidably received in the bore 2| and forms the head of the ram or piston. Immediately inward from the flange, the ram 5| is provided with a cylindrical portion 52 about which is positioned an annular sealing ring 53. The sealing ring 53 is generally of the block-V type and is confined between the cylindrical Wall of the cylinder 2| and the cylindrical part 52. An annular washer 54 is slidably received on the rod 5U and is held against the surface of the ring 53 by means of a lock nut 55. The lock nut 55 is slidable within counterbore 26 of the bore 25 and a seal 56 is positioned in the bottom of the counterbore 26 around the rod 5B to seal off the ram pressure chamber defined between the ram or piston 5| and the bottom of the bore 2| and the counterbore 26.

At its opposite end, the rod 5U is provided with a reduced extension and a washer 51 is presstted to a knurled portion of the rod at the inner end of the reduced extension, the Washer 51 being received in the counterbore 21 of the bore 25. The washer 51 serves as a latch actuator as will be described hereinafter. At its outer end, the reduced extension is provided with a threaded portion upon which a fianged nut 58 is received. A compression spring 59 is confined between the flanged nut 58 and a flanged annulus 60 surrounding the rod 50 and seated against the endwall of the body I0. The spring 59 constitutes a return spring for the hydraulic ram and serves to bias the ram 5| toward the bottom of the pressure chamber dened by the bore 2|.

Referring now to Figure 3, a spring 6| and a ball valve 62 are positioned in the counterbore on the reservoir side of each of the bores 32 and 33. A seat deiining tubular stem 63 is threaded into each counterbore and forms at its inner end a valve seat for the ball 62. Each stem 63 is closed at its outer end and is provided with a circumferential groove 64 adjacent its outer end Within which a cylindrical screen 65 is positioned. Radial holes 66 establish communication between the circumferential groove 64 and the central' boreI or holein` the stem. 63. The spring 6| normallyr holdsv theI bali valve 62 to itsi seat on the inner` end of the stem. 63. In the counterbore` on: the ram pressure chamber side of. each of the bores 32 and 313,v a. ball valve 91' normally sealingly engages a seat` formed by the counterboreandv isf urged thereagainst by a? compression. spring 69 compressed between the ball and` a tubular stem 69 threaded into the counterbore; Ball valves lf2.- and 61 serve as inlet and outlet check. valves respectively for each of the pump chambers 30"l and 3|.

A pump s1eeve10is threaded intoy the stepped bore 29? and. extends downwardly to provide ad,- jacent its lower end a high: volume-low pressure pump chamber in. the chamber 30'. The bore in the sleeve 10 is stepped-1,` and. ports 1|. are pro.- vided in the sleeve to establish communication between the chamber 39 and the lower end of the bore in the sleeve. Adjacent its upper end, the sleeve 10. is provided,r withA a circumferential groove within which a Neoprene 0- ring seal 12 is received? to prevent leakage past the sleeve. At. its upper end, the sleeve 1011s provided with a counterbore 13. within which a Neoprene O ring seal 1:4 is received.. Neoprene is the preferred material for the O ring seals12 and. 14, since Neoprene is not. subject to deterioration due tov contact with hydraulic fluids. It is apparent that other materials may be utilized for the formation of the O rings and' other seals as: desired.

A lock nut 15 is threaded into the bore' 29 to lock the sleeve in place and retain the seal 14 within the counterbore 19. A pump plunger piston 16. is-slidably mounted in the sleeve 1.0 and is provided with an enlarged portion slidably mounted in the bore of the sleeve 10 andi a reduced end portion extending into the reduced lower end of the bore 291 The slioulder on the plunger 116 betweeny the enlarged and reduced portions thereof provides a pump piston.` re.- ciprocable within the bore of the sleeve 10 to comprise a high volume-low pressure pump.

The lower end of the plunger 1t` is reciprocable Y within the reduced lowerI end of the bore 29 to comprise a high pressure-low volume pump. The 0 ring seal 14 sealingl'y gripsthe piston 16 to prevent leakage past the piston.A

At its upper end, the plunger. 16- is provided with an enlarged head 11 provided with aslot.'|=8 therein for the lose reception of an.` actuating pin 19 connected tothe handle |41 The handle |4- comprises a head member 90 and. a tubular shank 8|.. The head 80'; consists oi agenerally arcuate forging having parallel but olset end portions joined by -an arcuate portion'. Handle head 80 is bifurcated, at 82, for the reception oi the upwardly projecting. portion 4B of the body |0. The biiurcated portion 82 of the handle |4 is pivotally securedy to the. opstanding portion 481 by a pin 89 extending through aligned bores in each leg of the bircurcatedv portion 82"v and of the bore 49 in the bodyl portion. 48?. The pin 83 is preferably` provided atone endl' with an integral head 94 and at its' other end with a circumferential. groove within whichL a C washer or clip 851 is received to holdE the pin in position.

The head 11' of the plunger 16 is alsoy received in the bifurcated portion 82 of' the' handle I4 and is secured therein in a manner similar to the connection of the bifurcated portion 82 and the body portion 48, bythe pin' 19 which has a head 01 and a circumferential groove within which a Cwasher ori clip: 88 is received. The pin 1:9.:isfloosely'received'. in the slot 18 to`4 accominodate the horizontal component. of the oscillation'v ot the handle |'4 in an arcuate path about the pin4 93. When the handle |4 is manually oscillated, the vertical component of the movement will beV imparted' to the plunger 11 and eiiect vertical reciprocation thereof in a pump.- ingv action. The shank 8| of the handle I44 is encased' in a twoepiece tube 90 of insulating material, one piece of which forms a hand grip. 9|.

rZChe handle |16 comprises a iirst tubular por'- tionl 92*` threaded into the counterbore 36 ot bore 35;.with theforward portion of the tube 92A being encased in a tube. 93 of insulating'material. Just beyond the endof the tube 193, the tubular portion 92 is provided,.intermediate its length, with a circumferentiat groove 94. Rotatably mounted on the outer end of the tubular portion 92 is a second metallic tube 95- which is provided atv its forward edge with an inturned iiange 96v loosely received within the groove 94 to. preventdissociation of theA tubular portions 92` and 95. The tubes 92 and 99y are provided with mating threaded portions 91. The tube 95 is encased in a handle: grip 99 of insulating material and is. secured to. a rod' 99 extending coaxially through the tubes 92 and 95 by means of a pin |00 and a. block |0|.. The rody 99: extends through the tubes 92. and 95 and into the counterbore of the bore 35l forming the chamber 34. Adjacent. its forward edge, therod 99 is provided with a circumferential: groove |02 within which an O ring seal |93 is` received to prevent leakage: of fluid past the rod 99 from chamber 94. The rod 99 has a reduced? and rounded forward end arranged to. engage a ball valve |94 positioned in the chamber 34. The ball |04 is adapted to be moved to a conical. seatrv |05 formed at the. end of thev chamber 94 to close the port or bore 35. The groovev 94l in the. tubular handle portion 92 is of a width to accommodate relative linear movement between the tubes 92 and 95. The threaded portions 91 of the tubes' have a large pitch angle so'that the threaded portions 91 form a fast thread for moving the rod 99 forwardly and` rearwardly a relatively great distance upon slight rotary movement of' the hand grip 98 to seat and" unseat the ball valve |04;

A- ccnical by-pass valve member |06 is slidably positioned inthe ccunterbore 44 of the transverse bore 491 and is arrangedl to1 close the bore 49. The valve |09 is' held againstconical' seat 91' formed at the inner end ofthe counterbore 44 by a spring |09 coniined. between the valve and a plug |99 threaded into the counterbore 44. Thev spring |208 exerts a predetermined force on thevalve |96 sothat the valveV |06 will be automatically opened upon attainment of a predetermined pressure in the pump chamber 90. The conical portion of the valve 09 terminates in a cylindrical surface H9 whichI is aligned with the axis of the bore 45 when' the1valve is closed, as shown in Figure 5. A bypass latchis slidably mounted in the bore 45v and comprises a cylindrical portion H2 sldably received in. the bore 45 and ar reduced noseportion. H3 having a rounded end. The end of the nose I |'3 normally engages the cylindrical surface H0 of thev valve |96` (see Fig. 5) and is urged thereagainst by a spring |'|4 confined between the cylindrical portion I I2 of the latch and the flanged annulus or collar 69. The nose |'|3 of the" latch is adapted 'tov cooperate'with the conical portion' of the valve |06V to cam the valve to full open position under the urge of the spring |I4 after the valve |06 has been cracked or partially opened by iluid pressure in the pump chamber 30. The conical surface of the valve and the nose of the latch constitute cooperating cam surfaces effective to fully open the valve |06 after the cylindrical surface has been moved out of engagement with the nose I I3 of the latch. The latch holds the valve in open position to establish communication between the chamber 30 and the fluid reservoir through the bores 43 and 45. The cylindrical portion |I2 of the latch III extends into the counterbore 21 of the bore 25 along one edge and is arranged to be engaged by the latch actuator washer 51 on the piston rod 50 on the return stroke of the piston.

Referring now to Figures 4 and 6, a ball valve I |5 is positioned in the bottom of the counterbore of the bore 41 on the fluid reservoir side thereof. The ball I5 is held against a seat in the bottom of the counterbore by a plug I I6 and a spring I I 1 conned between the plug IIB and a plug I I8 threaded into the counterbore. The valve I I5 serves as a pressure relief valve for the ram pressure chamber when the pressure therein exceeds a predetermined maximum.

The fluid reservoir is deiined by a resilient sack or bag I I9, preferably formed of Neoprene, having a cylindrical open end. A similarly shaped metalli-c dome |20 having a depth slightly greater than the normal depth of the sack I I9 surrounds the sack and protects it against damage and in addition restricts the amount of expansion of the sack I I9. The metallic dome |20 is provided with a plurality of vent holes to accommodate free expansion and contraction of the resilient sack ||9. Both the sack IIS and the dome |20 are provided with a radial flange |2| and |22, respectively, at their open ends and the flange |2| ofI the sack |I9 is conned between the end wall of the body I0 and the flange |22 of the dome |20 within the cylindrical portion 23 of the body I0. An annular nut |23 is threadably engaged with the thread 24 on the cylindrical portion 23 and is screwed down against the flange |22 of the dome |20 to tightly secure the dome |20 and the sack ||9 to the body I0 and to effect a seal, by means of the ilange |2| of the sack I I9, between the body I0, the sack ||9 and the dome |20. When mounted on the body I0, the sack ||9 encloses the piston rod 50, the nut 58, the spring 59, the inlet valves 62 and the inlet valve stems 63.

The foregoing description has been directed to the formation, construction and assembly of the various parts and elements of the hydraulic ram and pump. Assuming now that the fluid reservoir is filled by removing the plug 42 and pouring fluid into the reservoir through the bore 4|, the chamber 34 and the bore 38, and that the ram is arranged to engage a work piece, the operation of the hydraulic tool is as follows: The handle grip 99 of the handle i6 is rotated in a clockwise direction, as viewed from the right hand side of Figures 1 to 3, to move the rod 99 toward the body I0 to force the valve |04 against its seat |05 to close the port 35 and bore 39 communicating with the ram pressure chamber 2|. The handle I4 is then oscillated to effect reciprocation of the plunger 16. As the plunger 16 is moved in an up stroke, a vacuum is created within the pump chambers 30 and 3| causing the inlet ball valves 62 to be unseated. As the valves 62 are unseated, a quantity of fluid is sucked into the chambers 30 and 3| from the reservoir defined by the sack |I9. 'Ihe screens 65 on the stems 63 serve to prevent the entry of solid particles or extraneous material into the pump chambers. As the handle I4 is moved in its down stroke, the hydraulic fluid in the chambers 30 and 3| is put under pressure until the outlet check valves 61 are opened and the fluid is forced into the ram chamber 2 I. Both pistons are utilized in forcing fluid into the ram chamber 2| and due to the volume of fluid forced into the chamber, the piston or ram 5| will be rapidly moved to the left, as viewed in the drawings, against the urge of the spring 59. Upon continued reciprocation, the pressure in the chamber 2| will increase until it is sufficient to effect unseating of the valve |06 on a downstroke of the plunger 16. As soon as the valve I 06 is unseated, the rounded nose I3 of the latch I I will engage the conical surface of the valve |06 and cause same to be moved or cammed away from the valve seat |01, thus opening the port or bore 43 establishing communication between the pump chamber 30 and the fluid reservoir through the bores 43 and 46. Upon continued reciprocation of the plunger 16, the chamber 30 will be bypassed to the iiuid reservoir so that the pump defined by the enlarged portion of the plunger 16 and the chamber 30 will be ineffectual. Thereafter, pressure will be built up in the ram chamber 2| solely by the pump defined by the reduced end portion of the plunger 16 and the chamber 3|. This pump is effective to force a relatively small quantity of iiuid into the ram chamber 2| under high pressure. Upon continued oscillation of the handle |4, pressure is further built up in the ram chamber 2| by means of the fluids forced therein by the reduced lower end of the plunger 16. It is during this last defined pumping cycle that the hydraulic ram is adapted to perform its designated work.

Should the pressure in the chamber 2| exceed a predetermined safe maximum pressure for the material utilized in the construction of the apparatus, the pressure relief valve I5 will be automatically opened against the urge of the spring ||1 to vent the ram chamber 2| to the fluid reservoir. The relief valve ||5 will be effective only to reduce the pressure in the chamber 2| to the aforesaid predetermined maximum. In actuality, however, the valve I I5 after being unseated by uid pressure has a greater area thereof exposed to the fluid and due to this increased area and the velocity of flow through the bore 41, the valve |I5 will remain unseated until the pressure is somewhat below the predetermined maximum, at which time the spring ||1 will return the ball I I5 to its seat to close the relief port 41.

In normal operation, or after the relief valve has been automatically actuated, the ram cylinder 2| is Vented to the fluid reservoir to allow or accommodate the return stroke of the piston or ram 5| under the force of the spring 59. Venting of the ram cylinder 2| is accomplished by imparting a slight rotary twist to the handle grip 98 of the handle I6 in a counterclockwise direction, as viewed from the right hand end of the Figures 1 to 3. Due to the fast thread formed by the threaded portions 91, the rod 99 is moved a suflicient distance rearwardly by a slight twist of the handle grip 98 to permit unseating of the ball valve |04 to accommodate venting of the ram pressure chamber 2| through the bores 39 and 35, the chamber 34 and the bore 38 to the fluid pressure reservoir. As the piston 5| is moved in its return stroke by the spring 59, the latch actuator or annulus 51 engages the cylindrical portion 1| I2, yor the shoulder defined between the reduced nose portion I|3 `and. `the cylindrical portion II2, of the ,latch 1|-|,| itc move the latch rearwardly out of engagement with the valve |06, whereupon the valve |06 is urged by .the spring |08' into vengagement with its seat |01 to again render the pump :chamber 30 operative. When the pressure chamber has been completely vented and the piston 5| has been returned to its normal yposition by the Spring 59, the handle grip ,98 isrotated in the opposite direction, clockwise as viewed from the right hand of the Figures 1 `to 3, to again seat the ball |04 whereupon the apparatus is in readiness for repetition of the cycle just described.

The ram I is adapted to carry or be operatively associated with a material working mem- .ber which is preferably associated with a work supporting member or tool head. The tool head may take any one of a plurality of forms, but is preferably in the form of a C-clamp. The C- clamp comprises a generally C-shaped body |24 having at one end thereof an integral cylindrical portion |25 provided with an internally threaded bore |26 adapted to be threadedly connected with the thread 22 of Athe cylindrical portion 20 of the body |0. The threaded connection between the body I0 and the C-clamp I2 is particularly or purposely arranged to be a semipermanent connection in which the clamp |'2 is not readily removed from the body I0 but is capable of slight relative rotary movement with respect to the body I0. As shown in Figures 2 and 3, cam slots |21 are formed in the end face of the cylindrical portion and a number of slots may be provided las desired, but according to the present invention, it is preferred that two cam slots be provided, spaced 180 apart. Each slot is identical `having van inclined -surface leading into the slot from the bottom, .as shown in Figure 3. A spring pressed plunger |28 is mounted in a stepped bore `|29 (see Figure 2) in the cylindrical portion of the clamp I2 and is urged into the slots |21. A straight wall of the slot, at the upper edge thereof as shown in Figure 3, prevents rotation in one direction but the inclined surface acts to cam the plunger |28 out of the slot to accommodate relative rotation in the opposite direction until the plunger |28 slides into the other slot on the inclined wall thereof and engages the straight wall of .that slot to prevent further relative rotation in that direction. It is therefore kseen that the C-clamp |2 is oscillatable in a 180" arc with respect to the body I0.

The G-clamp may be removed from the body I 0 by reaching into the bore |29 andcatching the spring therein and compressing same with a wire hook or the :like to relieve the pressure on the plunger |28 and thus accommodate a free rotational movement between the C-clamp I2 and the body l0 to permit removal of the C-clamp |2. Preferably, the `plunger |28 is provided with a threaded bore (not shown) into which a screw may be threaded to provide a handle for retracting the plunger from the end face of the portion 20 of the body |0.

The c-clamp |2 is provided with a `bore |30 aligned `with the bore 2| of the cylindrical portion 20. An end 'extension |3| of the ram 5| extends through the bore `|30 and is adapted to carry a die, a cutter, or `the like at its free end.

The C-clamp I2 provides a flat-sided groove |32 for the reception of dies, cutters, or the like material `working members. Within the upper wall of the Vgroove |32, as viewed in Figure 2,

the C-shaped body portion |24 is provided with a bore |33 for the reception of a pin |315. on one of the material working members |35. A retainer plate |36 is positioned adjacent the free end of the clamp `I2 at the outer side of the groove |32. The plate |36 is provided with a pin |31 arranged to 'be received in a bore |38 in the body |24. Intermediate its end, the plate |38 is provided with a hole |39 through which a thumb Screw |40 extends for threaded engagement in a tapped hole |4| in the ybody |24. The pin |31 and the thumb screw |40 serve to retain the ,plate |33 on the body |24 and to prevent relative rotation ybetween the plate and the body. The plate |33 has a free end portion extending over the groove |32 and serving to hold the material working member |35 in the groove in cooperation with the pin |34. If desired, a pin may be provided in the free end of the plate |36 for engagement in a recess in the member |35. The material working member |35 is preferably substantially square or rectangular in cross section so as to be firmly `retained against relative rotational Vmovement due to engagement of its flat or planar sides with the vflat or planar .sides of the groove |32.

To remove the member |35 from the groove |32, the thumb screw |40 `is loosened to such degree that the pin |31 is freed from the bore |33 to accommodate rotation of the plate |36 about the screw |40. If desired, a spring washer ymay be :interposed between the plate and the body to move the plate away from the body when the screw is loosened. By turning the plate |35 sideways, the member |35 can be slidably removed from the groove |32. As is apparent, the member .|35 is stationary and lpresents a working face adapted to cooperate with the `juxtaposed Vface of a movable material working member..

The member |35 cooperates with a movable member `|42 which iS also rectangular or square in Vcross section and is arranged to have one hat side Vthereof engaging the flat upper side, as viewed .in Figure 2, of the groove |32 to prevent relative rotation between the member |42 and the C-clamp I2. At the end opposite its work piece engaging face, the member |42 is provided with a bore |43 having a circumferential groove |44 therein. The bore |43 is of such size as to slidably receive the end portion |3| of the ram 5 I.

The reduced end portion |3| of the ram 5I is provided with a diametral bore |45 within which a spring |46 and a pair of balls |41 are received. As the member |42 is slid onto the end |:3I of the ram 5|, the balls |41 are cammed inwardly by the edge of the member |42 adjacent the bore `|43 against the urge ofthe spring |46l until the balls are aligned with the groove |44 inthe ybore |43, at which time the balls |41 are forced into the groove by the spring .|46 to form a ball-type-detent ,for retaining the member |42 on the end 13| of the ram. If desired, the balls |41 may be welded vor otherwise secured to the spring |46 to prevent disassociation of the members when the material working member |42 `is removed from the end |3| of the ram. Preferably, however, the Vmaterial surrounding the bore |45 at each end thereof is swaged to reduce the .diameter of the bore |45 `after insertion of the spring |46 and the balls |41 to prevent removal of the balls, but to allow the balls to project slightly from the surface of the ram portion |3I for engagement in the groove |44.

Due -to the fact that balls |41 engage in a groove -in ythe material working member, the

member is rotatable with respect to the ram 5I. It is apparent, therefore, that when the clamp I2 is oscillated with respect to the body I0, the member |42 will be moved with the clamp I2, and both will rotate with respect to the body I and the ram To provide means for readily storing or transporting the tool of the present invention, a resilient ring or loop |48 is secured in a known manner to the C-clamp I2.

In operation, a work piece is positioned in the groove |32 of the C-clamp I2 in engagement with the working face of the stationary material working member |35. Thereafter, the hydraulic ram and pump are operated, as described here inbefore, to bring the working face of the material working member |42 into engagement with the work piece. The member |42 is rapidly moved into engagement with the work piece due to the rapid movement of the ram 5| under the urge of the fluid discharge of the two pumps. As the material working member |42 engages the work piece and commences the performance of work on the work piece, the pressure in the ram chamber 2| necessarily rises to accomplish the performance of Work. As the pressure rises, the large volume pump (chamber 30) is automatically cut out of operation by the by-pass valve |06, as described hereinbefore, and the high pressure pump independently effects the buildup of pressure in the ram chamber 2| to perform work on the work piece. When the desired Work has been performed, the pumping action is ceased and the hand grip 98 on the handle I6 is given a twist to accommodate opening of the valve |04 to vent the ram pressure chamber to the fluid reservoir. As the ram or piston 5| is returned to its original position under the urge of the spring 59, the washer 51 on the piston rod 50 engages the latch I I to move same out of the path of the valve |06 and the valve |06 is closed by the spring |08 to return the entire mechanism to its original position. The material working member |42 is returned to its original position together with the piston 5| and the work piece is released and the material working members are cleared for the reception of another work piece.

In the preferred embodiment of my invention, the tool is adapted for utilization in crimping metallic sleeves about metallic Wires or the like and in such application, the high volume-low pressure Dump is designed for use up to a pressure of 400 pounds per square inch in the ram pressure chamber. Upon the attainment of 400 pounds per square inch, the by-pass valve |06 is opened to accommodate relief of the low pressure pump. Thereafter, the low volume-high pressure pump is designed to build the pressure in the ram pressure chamber up to 10,000 pounds with an approximate manual effort of 40 pounds. Upon the attainment of 10,000 pounds per square inch in the ram pressure chamber 2 I, the relief valve |I5 is actuated to vent the chamber 2| to the lluid reservoir until the pressure in the ram chamber 2| is below the maximum pressure of 10,000 pounds per square inch. The handles I4 and I6 are provided with insulation as described hereinbefore, to render the tool particularly adapted for crimping sleeves or connectors to live or hot electrical conductors.

A particular use for which the tool of the present invention is adapted, is the crimping of connectors to high voltage electric power lines. Many power lines are run through tunnels, and

Cil

in such tunnels, working space is very limited. To render the tool more readily usable in situations wherein working space is limited, the provision for oscillation of the tool head I 2 with respect to the pump body I0 is made. Such provision renders the tool more conveniently usable in many situations.

Due to the detailed nature of the construction and operation of the tool of the present invention, the foregoing description has been directed in detail to the exact constructional features of a preferred embodiment of the invention. It will be apparent to those skilled in the art that various modifications, changes, and rearrangements can be made in the apparatus Without departing from the spirit and scope of the present invention and withoutchanging the end result or function of the tool. For example, in the preferred embodiment, threaded connections are utilized throughout to render the apparatus capable of ready assembly and disassembly. It will be apparent that other types of connections, such as press-nts, can be substituted for the threaded connections referred to. In addition, the various valve members have been specifically referred to as balls, or conical members, or Whatever preferred construction they take in the preferred embodiment of the invention. It will be apparent that the exact type of the valve may be varied or changed as desired, without departing from the spirit and scope of the invention. Therefore, while references has been made to specific parts, elements and details of construction, the terminology utilized in the foregoing description and appended claims is to be construed as including within the scope thereof all equivalent structures, parts or elements.

While I have described a preferred embodiment of my invention, it is apparent that various changes, modifications and rearrangements can be made therein without departing from the spirit and scope of the invention, as defined by the appended claims.

I claim l. In a hydraulic tool, a pump body having a plurality of pump chambers, a fluid reservoir, a ram cylinder, said body having inlet and outlet passages for establishing communication between said reservoir and pump chambers and between said pump chambers and said cylinder, check valves controlling said passages, means for venting one of the pump chambers to the reservoir in response to fluid pressure in said one chamber, comprising fluid passageway means including two passages in said pump establishing communication between said one pump chamber and the fluid reservoir, a by-pass valve reciprocably mounted in one of said passages, a latch reciprocably mounted in a second of said passages, spring means urging said latch into engagement with said valve, said valve and said latch presenting cooperating cam surfaces, spring means normally urging said valve to closed position, said last named spring means exerting a predetermined force on said valve, said valve being adapted to be opened by fluid pressure in said one pump chamber in excess of the pressure exertion of said last named spring means, said latch under the urge of said first named spring means camming said valve to full open position and retaining said valve in full open position after said valve has been opened by fluid pressure in said one pump chamber, and means for moving upon relief of pressure in said cylinder.

' 2. In a `hydraulic tool, a body having two pump chambers, a fluid reservoir, a ram cylinder, said body having inlet and outlet passages for establishing communication between said reservoir and pump chambers and between said pump chambers and said cylinder, check valves controlling said passages, pump plungers operable in said chambers, means for operating said plungers in unison, a piston operable in said cylinder, said body being provided with a pair of angularly related by-pass passages establishing communication between one of said pump chambers and said uid reservoir, a'by-pass valve slidably mounted in one of said passages, spring means urging said valve to closed position, a latch slidably mounted in the other of said passages, spring means urging said latch into engagement with said valve, said valve and said latch presenting cooperating cam surfaces, said valve being arranged to be opened by fluid pressure in said one pump chamber when the pressure therein is Sullicient to overcome said rst named spring means, said latch under the urge of said second named spring means camming said valve to full open position and retaining said valve in full open position after said valve has been opened by iiuid pressure in said one pump chamber, and a latch actuator operatively associated with said piston and arranged to engage said latch to move said latch out of engagement with said valve when fluid pressure in said cylinder is relieved and said piston is returned to its original position, whereby said valve is urged to `closed position by said iirst named spring means.

3. in a hydraulic tool, a body having two pump chambers, ,a fluid reservoir, a ram cylinder, a piston operable in said cylinder, said body having inlet and outlet passages for establishing communication between said reservoir and pump chambers and between said pump chambers and said cylinder, check valves controlling said passages, said body having a by-pass for venting one of said pump chambers to said reservoir, two pump plungers operable in said pump chambers, means for operating said plungers in unison, a normally closed valve controlling said by-pass yieldingly urged in closing direction and opened responsive to a predetermined high pressure in said one pump chamber, means for returning said piston to its retracted inward position, means for retaining said by-pass valve open independently of piston operating hydraulic pressure in said cylinder, and means for releasing said bypass valve for closing responsive to retraction of said piston to its inward position.

4. In a hydraulic tool, a body having two pump chambers of materially different diameters, a hydraulic liquid reservoir, a ram cylinder, said body having inlet and outlet passages for establishing communication between said reservoir and pump chambers and between said pump chambers and said cylinder, check valves controlling said passages, a piston operable in said cylinder yieldingly urged inward thereof, two pump plungers operable in said pump chambers, means for operating said plungers in unison, said body having a by-pass for venting the pump chamber of greater diameter to said reservoir and a vent passage for venting said cylinder to said reservoir, a vent valve normally closing said vent passage, means for releasing said vent valve for opening and thereby elfecting venting of said cylinder to said reservoir and return of said piston from an outer position inwardly of said cylinder, a by-pass valve controlling said by-pass normally yieldingly held closed and opened responsive to a predetermined high pressure in said pump .chamber of greater diameter, latch means effective for retaining said by-pass valve open independently of piston operating hydraulic pressure in said cylinder after it has been opened and during continued operation of said pump plungers, and means for disengaging said latch means and thereby releasing said by-pass valve for closing responsive to venting of said cylinder to said reservoir and return of said piston inwardly of said cylinder.

5. In a hydraulic tool, a body having two pump chambers of materially different diameters, a hydraulic liquid reservoir, a ram cylinder, said body having inlet and outlet passages for establishing communication between said reservoir and pump chambers and between said pump chambers and said cylinder, check valves controlling said 'passages, a piston operable in said cylinder yieldingly urged inward thereof, two pump plungers operable in sa-id pump chambers, means for operating said `plungers in unison, said body having a by-pass for Venting the pump chamber of greater diameter to said reservoir and a vent passage for venting said cylinder to said reservoir, a vent valve normally closing said vent passage, means for releasing said vent valve for opening and thereby effecting venting of said cylinder to said reservoir and return of said piston from an outer position inwardly of said cylinder, a bypass valve controlling said by-pass normally yieldingly held closed and opened responsive to a predetermined high pressure in said pump chamber of greater diameter, latch means effective for retaining said by-pass valve open independently of piston operating hydraulic pressure in said cylinder, and means actuated by said piston effective forreleasing said by-'pass valve from said latch means responsive to return of said piston inwardly of said cylinder.

6. In a hydraulic tool, a body having two pump chambers, a liquid reservoir, a ram cylinder, a piston operable in said cylinder yieldingly urged inward thereof, a piston rod slidable in said body and attached to and movable with said piston, said body having inlet and outlet passages for establishing communication between said reservoir and pump chambers and between said pump chambers and cylinder, check valves controlling said passages, two pump plungers operable in said chambers, means for operating said plungers in unison, means for venting one of said pump chambers to said reservoir comprising a normally closed by-pass valve yieldingly urged in closing direction and opened responsive to a predetermined high pressure in said one pump chamber, latch means eifective for retaining said bypass valve open independently of the piston operating pressure in said cylinder, means for optionally venting said cylinder to said reservoir, and cooperating means carried by said rod and latch means effective for releasing said by-pass valve for closing responsive to inward movement of said rod with said piston.

'7. In a hydraulic tool, a body having two pump chambers, a liquid reservoir, a ram cylinder, a piston operable in said cylinder yieldingly urged inward thereof, a piston rod slidable in said body and attached to and movable with said piston, said body having inlet and outlet passages for establishing communication between said reservoir and pump chambers and between said pump chambers and cylinder, check valves controlling said passages, two pump plungers operable in said chambers, means for operating said plungers in unison, means for venting one of said pump chambers to said reservoir comprising a normally closed by-pass valve yieldingly urged in closing direction and opened responsive to a predetermined high pressure in said one pump chamber, a latch member yieldingly urged toward said by-pass valve engageable therewith for holding it open when said by-pass valve opens responsive to pressure in said one pump chamber, means for optionally venting said cylinder to said reservoir, and a member carried by said rod engageable with said latch member for moving the latter out of engagement with said by-pass valve in the inward movement of said rod with said piston.

8. In a hydraulic tool, a body having two pump chambers, a liquid reservoir, a ram cylinder, a piston operable in said cylinder yieldingly urged inward thereof, a piston rod slidable in said body and attached to and movable with said piston, said body having inlet and outlet passages for establishing communication between said reservoir and pump chambers and between said pump chambers and cylinder, check valves controlling said passages, two pump plungers operable in said chambers, means for operating said plungers in unison, means for venting one of said pump chambers to said reservoir comprising a normally closed by-pass valve yieldingly urged in closing direction and opened responsive to a predetermined high pressure in said one 'pump chamber, a latch member adjacent and substantially parallel with said rod yieldingly urged toward said by-pass valve engageable therewith for holding it open when said by-pass valve opens responsive to pressure in said one pump chamber, means for optionally venting said cylinder to said reservoir, and a member carried by said rod engageable with said latch member for moving the latter out of engagement with said by-pass valve in the inward movement of said rod with said piston.

9. In a hydraulic tool, a body having two pump chambers, a liquid reservoir, a ram cylinder, a piston operable in said cylinder yieldingly urged inward thereof, a piston rod slidable in said body and attached to and movable with said piston, said body having inlet and outlet passages for establishing communication between said reservoir and pump chambers and between said pump chambers and cylinder, check Valves controlling said passages, two pump plungers operable in said chambers, means for operating said plungers in unison, means for venting one of said pump chambers to said reservoir comprising a normally closed bypass valve yieldingly urged in closing direction and opened responsive to a predetermined high pressure in said one pump chamber, said by-pass valve comprising an inner tapered portion and an outer straight portion, a latch member adjacent and substantially parallel with said rod yieldingly urged toward said by-pass valve, said latch member comprising a body portion and a reduced nose portion disposed to contact said outer portion of said by-pass valve when the latter is closed and to contact the tapered portion of said by-pass valve when it is opened by pressure in said one pump chamber, said nose of said latch member cooperating with said tapered portion of said by-pass valve for moving the latter to full open position and retaining it in that position, and a member carried by said rod engageable with the body portion of said latch member for moving the latter out of engagement with said by-pass valve in the inward movement of said rod with said piston.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,044,857 Pfauser June 23, 1936 2,096,574 Denny Oct. 19, 1937 2,134,773 Arp Nov. 1, 1938 2,165,504 Pfauser July 11, 1939 2,250,551 Pfauser July 29, 1941 2,311,468 Pfauser Feb. 16, 1943 2,417,956 Strom Mar. 25, 1947 2,555,421 Ronan June 5, 1951 FOREIGN PATENTS Number Country Date 432,823 Germany Apr. 19, 1925

Patent Citations
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2729063 *May 14, 1954Jan 3, 1956Manco Mfg CoHydraulic tool
US2869407 *Oct 15, 1954Jan 20, 1959Greenlee Bros & CoPortable metal working tool
US2979032 *Apr 30, 1959Apr 11, 1961Bahco AbHydraulically operable hand tools
US3155041 *May 16, 1963Nov 3, 1964Mansfield Green IncPressure apparatus
US3359636 *Aug 6, 1965Dec 26, 1967Fleix SonnbergerCutting implements for cables
US3372570 *May 31, 1963Mar 12, 1968Henry J. MansellHydraulic tool
US3475946 *Mar 22, 1965Nov 4, 1969Laux Friedrich GPressing tool,specifically hand press
US4492106 *Dec 27, 1982Jan 8, 1985Mario AmighiniManually actuated hydraulic jack for compressively applying terminals on electric cables and conductors in general
US4543789 *Jan 18, 1985Oct 1, 1985Peter NortonMultiple displacement hydraulic pump system with automatic displacement control for brake boosters and the like
US5113679 *Jun 27, 1990May 19, 1992Burndy CorporationApparatus for crimping articles
US5152162 *Jun 27, 1990Oct 6, 1992Burndy CorporationSystem and method for crimping articles
US5195042 *Jun 27, 1990Mar 16, 1993Burndy CorporationApparatus and method for controlling crimping of articles
US7533556Mar 15, 2006May 19, 2009Fci Americas Technology, Inc.Hydraulic tool release system
DE19743747B4 *Oct 2, 1997Jul 18, 2013Gustav Klauke GmbhKolbenpumpe
WO1999004165A1Apr 25, 1998Jan 28, 1999Frenken EgbertPiston pump
WO2007108915A2 *Mar 2, 2007Sep 27, 2007Fci Americas Technology IncHydraulic tool release system
Classifications
U.S. Classification60/430, 417/287, 92/130.00C, 81/301, 92/130.00R, 72/409.1, 91/29
International ClassificationH01R43/04, H01R43/042
Cooperative ClassificationH01R43/0427
European ClassificationH01R43/042E