US3059334A - Power operated shear - Google Patents

Description

Oct. 23, 1962 w. F. JOERS POWER OPERATED SHEAR Filed April 5, 1961 INVENTOR.

Osfforn e ys ing member.

United States Patent 3,059,334 POWER OPERATED SHEAR William F. J'oers, Milwaukee, Wis., assignor to Applied Power Industries, Inc., a corporation of Wisconsin Filed Apr. 3, 1961, Ser. No. 100,035 11 Claims. (Cl. 30-228) The present invention relates generally to improvements in the art of cutting metallic cables, and relates more particularly to the provision of an improved power operated shear.

A primary object of the invention is to provide an improved portable cable cutting device operable by fluid pressure and which is extremely simple and compact in construction as well as highly eflicient and flexible in use.

Mechanically and fluid actuated cutting tools in the nature of shears for operating on diverse materials have heretofore been proposed as shown in United States Patents No. 239,817, No. 335,796, No. 492,931, No. 693,231, No. 1,467,262, No. 1,623,201, No. 2,526,955, No. 2,699,- 756, and No. 2,716,812 amongst others. While some of these prior cutters were intended for use on metal, most of them were necessarily restricted in use by reason of their construction to much softer and more readily severable materials. In addition to these limitations as to use, many of the cutting shears heretofore proposed have lacked the desired compactness and portability and the resultant flexibility of operation in the field and in confined working areas. In addition, these prior devices are lacking in the desired simplicity of construction which enable quick dismantling of the tool for replacement or repair of parts and easy reassembly thereof without special complicated instructions.

It is therefore another important object of this invention to provide an improved power operated cable cutter or shear which obviates all of the aforesaid objections and disadvantages of prior devices of this general t e.

ZA further important object of the present invention is to provide an improved fluid actuated power shear which embodies novel manually operable means for quickly articulating the cutting blades to or from a partially closed working position, thus shortening the required length of stroke or travel of the ram for performance of the work.

Still another object of the invention is to provide an improved cable cutter or shear embodying novel means for maintaining the cutting blades under resilient tension throughout their complete operating range so as to cause the same to automatically return or tend to return to open position with the activating rear edges of the blades constantly urged into engagement with the blade actuat- These and other objects and advantages of the invention will become apparent from the following detailed description.

A clear conception of the several features constituting the present improvement and of the mode of constructing and of utilizing of a typical cable cutter embodying the invention may be 'had by referring to the drawing accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

FIG. 1 is a side elevation of a typical cable cutter embodying the invention and showing the blades in completely open or expanded condition, the blade actuating member and a portion of the main return spring being broken away for the sake of clarity;

FIG. 2 is a somewhat reduced fragmentary side elevational view showing the blades actuated to partially closed Working condition by the manually operable stepped slide, the actuating member being again broken used with equal effect, and the shaft 12 may be secured 3,059,334- Patented Oct. 23, 1962 ice away and with the main spring as well as the blade carrier and secondary spring housing being shown in section;

a FIG. 3 is another fragmentary side view of the blade end of the device taken from the right side of FIG. 2 and with a part of the blade actuating member again being broken away for clarity;

FIG. 4 is an end view of the power shear with the blades partially closed as in FIGS. 2 and 3; and FIG. 5 is a transverse section taken along the line 55 of FIG. 2. While the invention has been shown herein as being especially adapted for use in a cable cutter and as being operable by a hydraulic ram of a particular type, it is not intended to thereby unnecessarily restrict or limit the use or operability since the novel features may be used to advantage in any type of shear with the blades being adapted for power actuation by various types of fluid motors. It is also intended that the broadest possible interpretation shall be given to descriptive terms used herein.

Referring to the drawing, the cable cutter shown thereing as embodying the invention comprises, in general, a pair of cooperable cutting blades 7, 8 secured as by means of a pivot pin 9 between the spaced arms 11 of a blade carrying block 10 having a shaft 12 extending axially from the opposite side thereof, a blade actuating member 13 shown as being generally cup-shaped and having a central aperture 14 formed in its base 15 for freely slidably receiving the shaft 12 with the spaced actuating edges 16 of the member 13 hearing directly against rear cam surfaces 17, 18 of the blades 7, 8 respectively on the opposite sides of the pivot pins 9, means such as a compression spring 19 surrounding the shaft 12 within the confines of the member 13 and seated at one end against the base 15 of the member 13 and at the other end against an annular shoulder 20 formed on the blade carrying block 10 to constantly resiliently urge the block 10 outwardly, and power actuating means shown generally herein as a fluid motor 21 acting against the base 15 of the cup-shaped member 13 in opposition to the spring 19 to thereby move the member 13 axially relative to the blade carrying block 10 as movement of the shaft 12 is restrained, thus causing the blades 7, 8 to swing upwardly about their pivot 9 in the performance of a cutting operation due to the coa ction of the lip 16 of the member 13 with the cam surfaces 17, 18 of the blades 7, 8 respectively.

The. fluid motor 21 shown herein for purposes of illustration is of the type disclosed more fully in United States Patent No. 2,955,578 and comprising a cylinder 23 having a pressure fluid supply conduit 24 communicating with one side of the work performing plunger or ram 25 to move the same outwardly, the ram 25 being returned to its initial starting or inactive position as by means of a spring, not shown, and having a bore extending axially therethrough for receiving the shaft or rod 12 which has a nut 26 threaded thereon and bearing against the end of the cylinder 23 remote from the extending work perconduit 24, the ram 25 is caused to move outwardly carrying with it the cup-shaped member 13, and since the shaft 12 is restrained from axial movement by the nut 26 .bearing .against the cylinder end head 27, the blade carrya ing block 10 remains stationary and the blades 7, 8 are articulated about their pivot 9 by the coaction of the lip 16 of the member 13 with the curved cam surfaces 17, 18 of the blades. It should however be understood that other types of fluid motors or power actuators may be directly to the piston of a reversely acting ram device 3 with a suitable spacer being provided between the base of the cup-shaped member 13 and the adjacent end of the power cylinder.

As shown, the blades 7, 8 of the present power shear are each generally semi-circular with the cooperating cutting edges 29, 30 respectively being conveniently formed by a grinding wheel or disc, and with the curved rear cam edges 17, 18 being relatively wide and flat to afford an effective bearing and blade actuating surface. Also, to maintain the blades 7, 8 closely together during their working strokes to render the same more efficient, one leg of a generally U-shaped guide 31 is secured as by means of machine screws 32 to one of the blades with the other leg thereof being slidably cooperable with the other blade as the blades are articulated about the pivot 9. While the shaft or draw rod 12 may be secured to the bifurcated blade carrying block in any suitable manner, this shaft may be conveniently threaded within a socket 33 formed as an integral part of the block 10.

While the spring 19 which is compressed between the blade carrying block 1t and the base of the cup-shaped blade actuating member 13 effectively acts in opposition to the ram of the fluid motor to constantly urge the block to its outermost position to enable the lip 16 of the member 13 to effectively act on the edges 17, 18 of the blades, means should also be provided for resiliently urging the blades 7, 8 outwardly about the pivot 9 and into constant effective bearing contact with the lip =16. For this purpose, a pair of simple but effective combined coil and leaf springs designated generally by the numerals 35, 36 are provided by the present invention as shown most clearly in FIGS. 2 and 3, each of the composite springs cooperating with one of the blades to constantly urge the same outwardly about the common pivot 9, and since these springs are identical, reference will only be made herein to the spring 36 which coacts with the blade 8. This composite spring 36 consists simply of a coil spring 37 seated within a bore or cavity 38 formed in the blade carrying block 10 and opening between the spaced arms 11 thereof laterally of the pivot 9, and a T-shaped leaf spring 39 carried by the coil spring 37 with the crosshead thereof seated within a notch or groove 40 formed in a portion 41 of the blade 8 which extends rearwardly beyond the pivot pin 9. The coil spring 37 is thus retained in position within the bore 38 by the leg of the T-shaped leaf spring 39 which it embraces and is compressed between the bottom of the bore 38 and the crosshead of the leaf spring 39 to constantly seat the same within the notch 40 of the extending portion 41 of the blade, thus urging the blade into seating engagement with the lip 16 of the member 13 at all times, and it is to be understood that the spring 35 has similar coaction with the blade 7.

To quickly articulate the blades from extreme open condition to a partly closed position as when operating on work of smaller diameters, a laterally movable lever cam or slide 43 is provided between the base 15 of the cup-shaped member 13 and the work engaging end of the ram 25. This cam member 43 is slotted longitudinally as at 44 and has stepped surfaces 45, 46 and a gripping portion 47. Thus, when the slide 43 is in the position shown in FIG. 1 wherein the base of the cup-shaped member 13 is seated on the surface of the slide 43, the blades 7, 8 are permitted to open to their fullest extent. To activate the blades initially to a partially closed position and thus reduce the amount of ram stroke necessary to perform the work, the cam member 43 may be used as a lever or fulcrum, as shown by means of dot-and-dash lines in FIG. 2, to lift and manually move the cup-shaped member 13 axially toward the cutting blades, thereby compressing the spring 19 and permitting the member 43 to be moved laterally with the aid of its gripping portion 47 from the dot-and-dash line position to the full line position as shown. In this position, the blades 7, 8 are partially closed and a shorter piston stroke is required to perform the work.

From the foregoing detailed description, it is believed apparent that the present invention contemplates the provision of a portable power actuated shear or cable cutter which is extremely compact and versatile in its operation as well as highly flexible in its uses. The blades 7, 8 are effectively actuated by the fluid motor 21 through coaction of the cup-shaped member 13 directly with the cam surfaces 17, 18, and these blades are constantly maintained in contact with the lip 16 of the cup-shaped member 13 by means of the novel composite coal- leaf springs 35, 36. In addition, the blades may be quickly and readily manually manipulated to partially closed work engaging position by means of the novel cam member 43 having stepped cam surfaces and which is also adapted to be used as a lever for conveniently manually lifting the cupshaped member 13 to thus permit lateral movement of the member 43.

Various modes of carrying out the invention are contemplate as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. A cutting tool comprising, a pair of blades pivotally interconnected for relative swinging movement, said blades each having a rearwardly facing inwardly and forwardly directed cam surface located rearwardly and laterally of the pivotal connection, blade actuator having spaced edges cooperable with said inwardly and forwardly directed cam surfaces of said blades rearwardly of their pivotal connection, power means for effecting relative movement of said blade actuator and said blades to thereby cause said blades to swing about their pivotal connection, means housed within said blade actuator for constantly resiliently opposing relative movement of said actuator and said blades by said power means, and other means independently cooperable with each of said blades for constantly resiliently urging the same apart to maintain the cam surfaces thereof in contact with the lip of said actuator.

2. A cutting tool comprising, a pair of blades pivotally interconnected on a carrying member for relative swinging movement, said blades each having a rearwardly facing inwardly and forwardly directed cam surface located rearwardly and laterally of the pivotal connection, a cupshaped blade actuator having its peripheral lip cooperable with said inwardly and forwardly directed cam surfaces of said blades and provided with an opening extending axially through the base thereof, an elongated element secured at one end to said blade carrying member and having the other end thereof extending outwardly through the base opening of said blade actuator, power means carried by said elongated element for effecting relative movement of said blade actuator and said blades to thereby cause said blades to swing about their pivotal connection, means housed within said blade actuator for constantly resiliently urging said actuator and said blade carrying member apart, and other means independently cooperable with each of said blades for constantly resiliently urging the same to open condition with the cam surfaces thereof in contact with the lip of said actuator.

3. A cutting tool comprising, a pair of blades pivotally connected to a carrying member for relative swinging movement, said blades each having a rearwardly facing cam surface located on One side of the pivotal connection and each of said blades also having a rear portion extending laterally of the opposite side of the pivotal connection, a cup-shaped blade actuator having its peripheral lip cooperable with the cam surfaces of said blades and provided with an opening extending axially through the base thereof, an elongated element secured at one end to said blade carrying member and having the other end thereof extending outwardly through the base opening of said blade actuator, power means carried by the outwardly extending end of said elongated element and cooperable with said blade actuator to move the same relative to said blade carrying member and thereby cause said blades to swing about their pivotal connection, spring means housed within said blade actuator and compressed between the base thereof and said blade carrying member for constantly resiliently urging said actuator and said member apart, and other spring means compressed between said blade carrying member and the laterally extending rear portions of said blades for constantly resiliently urging the same to open condition.

4. A cutting tool comprising, a pair of blades pivotally interconnected for relative swinging movement, said blades each having a rearwardly facing cam surface located laterally of the pivotal connection, a cup-shaped blade actuator having its peripheral lip cooperable with the cam surfaces of said blades, power means for effecting relative axial movement between said blade actuator and said blades to thereby cause said blades to swing about their pivotal connection, cam means interposed between said power means and said blade actuator and movable to selected positions to vary the amount of axial movement required to swing the blades in their working stroke, means housed within said blade actuator for constantly resiliently opposing relative movement of said actuator and said blades, and other means cooperable with said blades for constantly resiliently urging the same apart to maintain the cam surfaces thereof in contact with the lip of said actuator.

5. A cutting tool comprising, a pair of blades pivotally interconnected for relative swinging movement, said blades each having a rearwardly facing cam surface laterally of the pivotal connection, a cup-shaped blade actuator having its peripheral lip cooperable with the cam surfaces of said blades, power means for effecting relative axial movement between said blade actuator and said blades to thereby cause said blades to swing about their pivotal connection, a cam lever interposed between said power means and said blade actuator and pivotally and laterally movable to selected positions to vary the relative positions of the blades and the amount of axial movement required by said power means to swing said blades in their working stroke, means housed within said blade actuator for constantly resiliently opposing relative movement of said actuator and said blades, and other means cooperable with said blades for constantly resiliently urging the same. apart to maintain the cam surfaces thereof in contact with the lip of said actuator.

6. A cutting tool comprising, a pair of blades pivotally interconnected for relative swinging movement, said blades each having a rearwardly facing cam surface cated laterally of the pivotal connection, a cup-shaped blade actuator having its peripheral lip cooperable with the cam surfaces of said blades, a fluid motor having a force applying ram cooperable with said blade actuator for effecting relative axial movement between said blade actuator and said blades to thereby cause said blades to swing about their pivotal connection, a cam lever interposed between and spacing said ram from said blade actuator, said cam lever being movable to selected positions to vary the spacing between said ram and said blade actuator and consequently the amount of ram travel required to swing the blades in their working stroke, means housed within said blade actuator for constantly resiliently opposing relative movement of said actuator and said blades, and other means cooperable with said blades for constantly resiliently urging the same apart to maintain the cam surfaces thereof in contact with the lip of said actuator.

7. A cutting tool comprising, a pair of blades pivotally interconnected [for relative swinging movement, said blades each having a rearwardly facing cam surface located laterally of the pivotal connection, a cup-shaped blade actuator havingits peripheral lip cooperable with the cam surfaces of said blades and provided with an opening extending axially through the base thereof, an elongated element secured at one end to said blade carrying member and having the other end thereof extending outwardly through the base opening of said blade actuator, a fluid motor carried by the extending end of said elongated element and having a force transmitting ram for eifecting relative axial movement of said blade actu-' ator and said blades to thereby cause said blades to swing about their pivotal connection, a cam embracing said elongated member between said ram and said blade actuator and movable to selected positions to vary the spacing between said ram and said actuator and thus vary the length of ram travel required to swing said blades, means housed within said blade actuator for constantly resiliently urging said actuator and said member apart, and other means cooperable with said blades for constantly resiliently urging the same to open condition with the cam surfaces thereof in contact with the lip of said actuator.

8. A cutting tool comprising, a pair of blades pivotally interconnected tfor melative swinging movement, said blades each having a rearwardly facing cam surf-ace located on one side and rearwardly of the pivotal con nection and each blade also having a portion extending laterally across to the opposite side of and in proximity to the pivot connection, a cup shaped blade actuator having its peripheral lip cooperable with said cam surtaces of said blades, power means for effecting relative movement between said blade actuator and said blades to thereby cause said blades to swing about their pivotal connection, means housed within said blade actuator for constantly resiliently opposing movement of said actuator by said power means, and a spring cooperable with the laterally extending portion of each of said blades for constantly resiliently urging the same to open condition.

9. A cutting tool comprising, a pair of blades pivotally connected to a carrying member for relative swinging movement, said blades each having a rearwardly (facing cam surface located on one side of the pivotal connection and each blade also having a portion extending laterally across to the opposite side of the pivotal connection, a cup-shaped blade actuator having its peripheral lip cooperable with the cam surfaces of said blades, power means for eifecting relative movement between said blade actuator and said blades to thereby cause said blades to swing about their pivotal connection, means housed within said blade actuator for constantly resiliently opposing movement of said actuator by said power means, and a spring compressed between the laterally extending portion of each of said blades and said blade carrying member for constantly resilient urging said blades to open condition.

10. A cutting tool comprising, a pair of blades pivotally connected to a carrying member for relative swingng movement, said blades each having a rearwardly facmg cam surface located on one side of the pivotal connection and each blade also having a rearwardly notched portion extending laterally across to the opposite side of the pivotal connection, a cup-shaped blade actuator having its peripheral lip cooperable with the cam surfaces of said blades, power means for effecting relative movement between said blade actuator and said blades to thereby cause said blades to swing about their pivotal connection, means housed within said blade actuator for constantly relisiently opposing movement of said actuator by said power means, and a pair of composr-te springs each having a coil portion bearing against said blade carrier and a leaf portion extending from one end of the coil portion and seated in the notch in the laterally extending portion of one of said blades for constantly resiliently urging said blades to open condition.

11. A cutting tool comprising, a pair of blades pivotally interconnected for relative swing movement, said blades each having a rearwardly 'facing cam surface located laterally of the pivotal connection, a blade actuating member having spaced edges co-operable with the cam surfaces of said blades, power means for moving 3,059,334 7 8 said blade actuating member relative to said blades to References Cited in the file of this patent thereby cause said blades to swing about their pivotal UNITED STATES PATENTS connection, 0am means interposed between said power means and said blade actuating member and movable 239,817 McCarty P 1 81 to vary the amount of axial movement required to swing r 335,796 Cullen 1886 the blades in their Working stroke, means housed within 7701270 Dehn p 1904 said blade acuating member for constantly resiliently 2,836,888 Hargrove June 3, 95

opposing movement of said member by said power means, and other means cooperable with said blades for constantly resiliently urging the same to open condition. 10

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