US3919877A

US3919877A - Tool

Info

Publication number: US3919877A
Application number: US413341A
Authority: US
Inventors: Louis A Netta
Original assignee: Thomas and Betts Corp
Current assignee: ABB Installation Products Inc
Priority date: 1973-11-06
Filing date: 1973-11-06
Publication date: 1975-11-18
Anticipated expiration: 1992-11-18
Also published as: SE7413871L; BE821918A; DE2451779A1; FR2249766A1; NL7414499A; AU7451874A; AU466544B2; JPS5074083A; IT1023089B; FR2249766B3

Abstract

A reciprocating piston of a fluid operated tool has key means slidably engagable with preferably selectively formed grooved portions in longitudinally extending frame members flanking the piston to maintain accurate angular orientation of the piston means with respect to the frame members along its path of travel. The key means also serves at least partially as a load bearing means for a die member which may be removably coupled to the head portion of the piston. One of the flanking frame members may be pivotally or otherwise movably connected to the tool frame to permit its disengagement from the key means to allow the die member to be slidably detached from the piston head portion while a portion of the key means is still cooperatively engaged to the other frame member to maintain the desired orientation of the piston with respect to the frame members.

Description

United States Patent [191 Netta 1 TOOL [75] Inventor: Louis A. Netta, North Brunswick,

[73] Assignee: Thomas & Betts Corporation,

Elizabeth, NJ.

22 Filed: Nov. 6, 1973 21 Appl. No.: 413,341

[56] References Cited UNITED STATES PATENTS 671,835 4/1901 MCTighe 72/446 X 676,292 6/1901 Wigtel 72/416 2,722,859 11/1955 Stoltz 72/409 2,940,497 6/1960 Herrstrum.. 72/453 X 3,008,234 ll/l96l Mattera 72/453 X 3,031,903 5/1962 Billen et a1. 72/413 X 3,070,144 12/1962 Evans..... 72/418 X 3,135,146 6/1964 Loucks.. 72/415 3,204,445 9/1965 Filia 72/410 Nov. 18, 1975 6/1967 Porter 72/453 X 1/1973 Thode 72/456 X [57] ABSTRACT A reciprocating piston of a fluid operated tool has key means slidably engagable with preferably selectively formed grooved portions in longitudinally extending frame members flanking the piston to maintain accurate angular orientation of the piston means with respect to the frame members along its path of travel. The key means also serves at least partially as a load bearing means for a die member which may be removably coupled to the head portion of the piston. One of the flanking frame members may be pivotally or otherwise movably connected to the tool frame to permit its disengagement from the key means to allow the die member to be slidably detached from the piston head portion while a portion of the key means is still cooperatively engaged to the other frame member to maintain the desired orientation of the piston with respect to the frame members.

4 Claims, 11 Drawing Figures US. Patent N0v. 18, 1975 Sheet10f4 3,919,877

FIG. 1

Sheet 2 of4 3,919,877

I U.S. Patent Nov. 18, 1975 FIG. 2

FIG. 3

US. Patent Nov. 18,1975 Sheet40f4 3,919,877

TOOL

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention is directed to the field of fluid operated tools and principally to piston orientation means therefor.

2. Description of the Prior Art In fluid operated tools, according to the prior art, a hydraulically or pneumatically operated piston is disposed within a cylinder comprising at least part of the frame of the tool and is reciprocatingly movable towards and away from the item upon which work is to be done. In many cases, the piston is fabricated with an intergral head portion shaped to form the movable die member of the die set whereby upon advancement of the piston the movable die member is advanced towards the mating die member and then retracted after the work has been performed. To provide for a fixed range of operative die configurations, both the movable and mating die members may be arranged to accommodate a series of removable inserts each proportioned to provide a specific die contour. Many tools of this nature are generally employed as terminal crimping or cable cutter devices requiring relatively accurate alignment between the movable and fixed die members of the die set. An example of such a tool is disclosed in US. Pat. No. 3,267,717, issued Aug. 23, 1966 to W. Reischer, such tool being representative of a large variety of tools employed for such purposes. To maintain the movable die member in alignment with respect to the fixed die member the piston head is complexedly contoured to providea shoulder portion engageable with a cooperating recess in a fixedly mounted supporting shaft attached to the tool body. Accordingly, replacement of the movable die member due to damage or the like entails a cumbersome, expensive, and time consuming operation requiring removal and replacement of the entire piston assembly with the attendant loss of orientation of the piston with respect to the supporting shaft so that, upon replacement of the piston and die member assembly, the piston must be manipulated against the counter-acting force of a restraining spring or like member to reestablish proper orientation and alignment of the assembly, a procedure which may be quite difficult, time consuming, and cumbersome. This factor, coupled with the expense of providing a complex integral piston and die support required to effect the necessary orientation and alignment during operation, presents additional problems in field replacement and maintenance.

SUMMARY OF THE INVENTION The invention overcomes the limitations and difficulties noted above with respect to prior art devices by providing an improved fluid operated tool having removable key means cooperatively associated with the piston and frame members of such tool to align, guide, and at least partially support the piston and associated die member in a manner more efficient, reliable, verstile and economical than such prior art devices. The piston comprises, in one embodiment, a reduced diameter head portion adapted to receive key means having extending shoulder portions each engaging associated grooves in flanking frame members extending parallel to the path of travel of the piston. The head portion of the piston is further provided with means for releasably 2 coupling the die member to the piston in a predetermined orientation, said die member being additionally provided with extensions for engaging preferably the same grooves engaged by the shoulder portions of the key means, thus providing a dual support and guide for both the piston and die member during operation. Upon removal of the die member, orientation and alignment of the piston with respect to the frame members is advantageously maintained by engagement of at least one of the shoulder portions of the key means with the groove of an-associated frame member. One of the flanking frame members may be pivotably or otherwise displaceable from its operating position to a release position to permit the die member to be detached from the piston head portion while the remaining shoulder of the key means is engaged with the groove in the other frame member so that orientation is maintained throughout the replacement operation. The key means may be coupled to the piston head portion by a split ring or the like which may be readily removed to permit convenient and rapid replacement of either the key means or the piston. The piston head portion is further provided with means arranged to releasably couple the die member thereto which means may comprise a slotted shoulder providing axial restraint while permitting transverse movement of the die member for slidable release from the head portion. It is thus an object of this invention to provide an improved fluid operated tool.

It is another object of this invention to provide means for maintaining a specific angular orientation between the piston and frame member of a fluid operated tool.

It is a further object of this invention to provide means for supporting and guiding a piston during its reciprocating movement within the frame of a fluid operated tool.

It is another object of this invention to provide an improved fluid operated tool having means for keying the piston of the tool to the tool frame to prevent rotational displacement of the piston along its path of travel.

It is yet another object of this invention to provide an improved fluid operated tool having a piston head portion selectively contoured to accept both a keying means and die member both removably coupled thereto.

Other objects and features will be pointed out in the following description and claims and illustrated in the accompanying drawings which disclose, by way of example, the principle of the invention and the best mode contemplated for carrying it out.

BRIEF DESCRIPTION OF THE DRAWINGS In the Drawings FIG. 1 is a fragmentary front elevational view, partly cut away and partly in section, of an improved fluid operated tool constructed in accordance with the concepts of the invention.

FIG. 2 is a cross sectional view of the device of FIG. 1 taken along the line 22 of FIG. 1.

FIG. 3 is a cross sectional view of the device of FIG. 1 taken along the line 33 of FIG. 1.

FIG. 4 is a fragmentary perspective view of the head portion of the piston of the device of FIG. 1.

FIG. 5 is a persepctive view showing a keying means for an improved fluid operated tool constructed in accordance with the concepts of the invention.

FIG. 6 is an exploded frangmentary perspective view .of the piston head portion, keying means, and means for coupling the keying means to the piston head por- 3 tion of the device of FIG. 1.

FIG. 7 is a fragmentary front elevational view, partly cut away, showing an assembly of the piston head portion, keying means, and die member of the device of FIG. 1.

FIG. 8 is a fragmentary side elevational view, of the assembly of FIG. 7.

FIG. 9 is a fragmentary front elevational view, partly cut away, showing the device of FIG. 1 preparatory to the removal of the die member therefrom.

FIG. 10 is a top plan view of a further embodiment of a keying means for an improved fluid operated tool constructed in accordance with the concepts of the invention.

FIG. 1 l is a fragmentary top plan view, partly in section, showing a further embodiment of a keying means for an improved fluid operated tool constructed in accordance with the concepts of the invention.

Similar elements are given similar reference characters in each of the respective drawings:

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to FIGS. 1 through 6 there is shown an improved fluid operated tool constructed in accordance with the concepts of the invention. The tool 20 comprises a frame 22 having a pair of

members

24, 26 extending generally longitudinally from the frame member body 28 in generally spaced parallel relationship and flanking a piston 30 reciprocatingly movable between the

members

24, 26. The piston 30 is activated by fluid pressure in a manner well known in the art, such fluid pressure comprising either hydraulic or pneumatic fluid suitably valved into and out of a cylinder 32 encompassing the piston 30. Attached to an upper or head portion 34 of the piston 30 is a key 36 having downturned

shoulder portions

38, 38. Each of the

shoulder portions

38, 38 are suitably dimensioned to be slidingly received within key receiving

recesses

40, 40 in the

members

24, 26 respectively. As shown in greater detail in FIGS. 4 and 5, the piston head portion 34 protrudes from the top of the piston 30 and is provided with a first flatted element 42 having a contour adapted to receive a mating aperture 44 extending transversely through the thickness of the key 36. The key 36 is thus rotationally locked in a given position with respect to the longitudinal axis of the piston 30 and is secured thereto by a split ring 46 (FIG. 6) adapated to seat atop the key 36 and engage a groove 48 extending about the periphery of the flatted element 42. Extending above the flatted element 42 of the head portion 34 is a slotted overhanging portion 50 adapted to lockingly receive a die member 52 therein. The overhanging portion 50 is designed to engage a recess 54 (FIG. 1) in the die member 52 so that the die member 52 will be locked against longitudinal displacement with respect to the piston 30 but may be removed therefrom by sliding said die member 52 tranversely either to the right or left of the piston 30. The sides of the die member 52 extend into the

recess

40, 40 of

members

24, 26, as shown in detail in the cut away section of FIG. 1, so that the recesses 40, 40' may provide both a guide and support for the die member 52 in conjunction with the key means shoulder portions 38, 38', during the reciprocatting movement of the piston 30. The manner of attachment of the die member 52 to the piston head portion 34 is shown in greater detail in FIGS. 7 and 8. As illustrated therein, the overhanging portion 50 of head portion 34 is provided with a slot 56 adapted to slidably mate with a foot portion 58 of the die member 52, thus providing a self-aligning feature whereby the die member 52 will align itself with the

frame member grooves

40, 40 irrespective of the alignment of the piston 30 therewith. The head portion 34 thus provides a track or guide for the die member 52 which may thus slide reciprocatingly between the

members

24 and 26 but is securely retained against rotation with respect thereto both by its engagement with the

recesses

40, 40 and its additional engagement with the head portion 34. The assembly of the key 36 to the head portion 34 of the piston 30 is shown in the exploded view of FIG. 6. As illustrated therein, the key 36 is placed over the flatted element 42 so that the flatted portion of the aperture 44 of the key 36 is aligned with the mating surface of the flatted element 42 of head portion 34. The retaining ring 46 is then disposed over the key 36 and engaged with the slot 48 in the flatted element 42 to securely couple the key 36 to the head portion 34; whereby the piston 30 is accurately maintained in a fixed angular orientation with respect to the shoulder portions 38, 38' of the key 36. Accordingly, upon the engagement of the

shoulder portions

38, 38 of the key 36 with the recesses 40, 40' of the

members

24, 26, the piston 30 is thus accurately aligned in a specific angular orientation with respect to

such members

24, 26, independently of the location of the die member 52 with respect thereto. It should also be noted that the employment of a D-shaped aperture such as 44 in the key 36 confines the angular orientation thereof with respect to the piston 30 to a single predetermined position. This may be modified, however, as shown for example in FIG. 11, wherein the D-shaped aperture 44 is replaced by a double flatted aperture 60 arranged to mate with a corresponding double flatted piston head portion element (not shown) so that the key may be disposed over the head portion of the piston in either one of two positions angularly displaced from one another. However, in the embodiment illustrated in FIG. 11, the key may be provided with the non-symetrically formed shoulder portions 62, 62', each adapted to engage a complimentarily formed mating recess 64, 64' respectively, in the frame member extending portions, thus insuring that the key is coupled to the piston in the desired orientation. As illustrated in FIG. 10, the key may be provided with a slotted aperture 66 wherein the key may be pressed onto the flatted element 42 of the head portion 34 in a self-locking arrangement wherein a pair of inwardly turned protrusions 68, 68' adjacent the open end of the aperture 66 are adapted to lockingly engage complimentary bores or recesses (not shown) in the flatted element 42 of the head portion 34, to secure the key to the piston in the desired orientation. Other means may, of course be employed to attach the key to the piston, which may include threaded fasteners or like removable coupling means. A further embodiment (not shown) may include one or more pins protruding upwardly from the piston 30 adapted to engage corresponding receiving apertures in the key, such pins having annular recesses for receiving a retaining ring thereabout too securely maintain the key in position atop the piston 30.

Referring now to FIG. 9 there is illustrated a means for removing the die member 52 from the head portion 34 of the piston 30 while maintaining the desired angular alignment and orientation between the piston 30 and frame member 26. The member 24 is pivotally displaced from its original position towards the left of FIG. 9 in a direction indicated by the arrow 67, the member 24 being pivoted about a pin 68 coupling the member 24 to the frame 22. Although the shoulder 38 of key 36 has now been disengaged from the recess 40 of frame member 24, the opposite shoulder 38 of key 36 is still in engagement with the recess 40 of frame member 26 to maintain the original alignment and orientation of the piston 30. The die member 52 may now be released from the head portion 34 of the piston 30 simply by sliding it to the left of FIG. 9 in a direction indicated by the arrow 70. The replacement or substitution of the die member 52 may, accordingly, be rapidly and simply accomplished by reversing the above procedure. Thus, although the die member 52 has been disengaged from the piston 30 and the sides of die member 52 released from engagement with the recesses 40, 40' of

members

24 and 26, respectively, the piston 30 is still keyed in the desired position with respect to the

frame members

24 and 26 by the engagement of the shoulder portion 38' of key 36 with the recess 40' of member 26 throughout the above described operation. It therefore becomes unnecessary to realign the piston 30 upon the removal or replacement of the die member 52 from atop the piston 30 during this operation. It should, of course, be appreciated that either or both of the

members

24 or 26 may be pivotally attached to the frame 22, if necessary or desirable. It should be further understood that although the die member 52 is shown attached to the head portion 34 of the piston 30 in sliding relationship, other variations including, for example, a twist lock arrangement (not shown) or threaded fasteners or the like may be similarly employed to secure the die member 52 to the head portion 34 of piston 30. An upper die member 72 cooperative with die member 52 may be pivotally attached to the frame member 26, as at 74, so that the removal of the die member 52 may be facilitated by pivoting the upper die member 72 towards the right of FIG. 9 in a clockwise direction as indicated by the arrow 76. It should be further understood that the member 24 may be coupled to the frame 22 in other than the pivoting arrangement hereinabove described and may be attached thereto either by a threaded fastener (not shown) replacing the pivot pin 68 or by the employment of a slotted aperture in the frame 22 (not shown) adapted to permit the member 24 to be retracted sufficiently to permit the removal of the die member 52 from the head portion 34 of piston 30.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a fluid operated tool of the type having frame means, piston means reciprocatingly movable within said frame means, and a die member releasably connected to said piston means for reciprocating movement within said frame means, the improvement comprising: said frame means including first and second members extending generally parallel to the path of travel of said piston means, and having key receiving means comprising a grooved portion extending along the length of the interior of each of said first and second members; key means including opposingly disposed downturned shoulder portions each slidably engaging a respective one of said first and second member grooved portions said piston means having a head portion of reduced diameter integral therewith and protruding longitudinally from the free end thereof, said head portion having an asymmetrically formed key means engaging portion located adjacent the junction between said piston means and said head portion, said key means having an asymmetrically formed transverse aperture conforming to said key means engaging portion and within which said key means engaging portion is seated to prevent the rotation of said key means about the longitudinal axis of said piston means; said die member having a foot portion disposed generally normal to the plane thereof, said piston means head portion having a slotted portion extending generally transverse to the longtiudinal axis of said piston means and located adjacent said key means engaging portion, said die member foot portion being engaged within said head portion slotted portion for corresponding movement therewith, said die member foot portion being transversely slidable within said head portion slotted portion; and pivot means coupling one of said frame means first and second members to said frame means and arranged to permit said one of said first and second members to be pivoted away from an associated one of said key means shoulder portions and to permit free access to said die member while the other of said key means shoulder portions is engaged within said grooved portion of the other of said frame means first and second members to prevent loss of orientation between said piston means and said frame means upon removal of said die member.

2. The improvement as defined in claim 1 wherein said key means asymmetrically formed transverse aperture is generally D-shaped and said key means engaging portion has a mating D-shape for intimate engagement with said key means aperture.

3. The improvement as defined in claim 1 further comprising av locking ring disposed about said key means engaging portion to prevent longitudinal displacement of said key means relative to said piston means head portion.

4. The improvement as defined in claim 3 wherein said key means engaging portions has a circumferential groove for receiving said locking ring.

Claims

3. The improvement as defined in claim 1 further comprising a locking ring disposed about said key means engaging portion to prevent longitudinal displacement of said key means relative to said piston means head portion.