US3787970A

US3787970A - Bevelling tool

Info

Publication number: US3787970A
Authority: US
Inventors: A Krieg
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-02-18
Filing date: 1972-02-18
Publication date: 1974-01-29
Anticipated expiration: 1991-01-29
Also published as: CA988761A

Abstract

A tool for bevelling an edge of an elongated metal workpiece is provided comprising a head, a stirrup, depending from the head and a cutting member pivotally mounted within the stirrup. The stirrup defines an opening for receiving the workpiece. A hydraulic linear moving motor is mounted in the head and connected to the cutting element to swing it in an arcuate path through a corner of the opening to cut a curved groove or bevel in the workpiece.

Description

United States Patent [191 Krieg Jan. 29, 1974 I BEVELLING TOOL [76] Inventor: Adrian H. Krieg, 2627 Dunning Dr.,

Yorktown, NY. 10598 [22] Filed: Feb. 18, 1972 [21] .Appl. No.: 227,449

[52] US. Cl 30/272 R, 30/283, 30/293,

90/31, 83/3 [51] Int. Cl B26d 3/02 [581 ie $959911; 232 2 2 55.2723 2. 2.7.9.223 30/293,2s9; 83/581, 3,491,585,597; 90/31,

[56] References Cited UNITED STATES PATENTS 3,192,835 7/1965 Leibinger 83/581 X FOREIGN PATENTS OR APPLICATIONS Germany 30/272 R Primary Examiner-0thell M. Simpson Assistant Examiner-Harold P. Smith, Jr. Attorney, Agent, or FirmMurray Schaffer [5 7 ABSTRACT A tool for bevelling an edge of an elongated metal workpiece is provided comprising a head, a stirrup, depending from the head and a cutting member pivotally mounted within the stirrup. The stirrup defines an opening for receiving the workpiece. A hydraulic linear moving motor is mounted in the head and connected to the cutting element to swing it in an arcuate path through a corner of the opening to cut a curved groove or bevel in the workpiece.

15 Claims, 4 Drawing Figures PAIENIEB JAN 2 9 I974 sum 1 or 3 BEVELLING TOOL BACKGROUND OF INVENTION The present invention relates to apparatus for cutting the edges of elongated me'tal workpieces and in particular, to a portable tool therefor.

In my copending application, Ser. No. 194,284, filed Nov. 1, 1971, there is shown a portable electrical tool for forming bevels along the edges of metal strips. This tool is a considerably improvement over conventional devices, in that it drives the cutting element in an arcuate path so that the metal-is sheared. In the conventional device the cutting element is reciprocated along a straight path and consequently punches or tears at the workpiece. Nevertheless, the motive power of the tool in the aforementioned application is conventional in that an electric rotary motor is provided which is connected, by gear transmission to an arm linked to the cutting element. The motor is housed and rotates about an axis perpendicular to the plane in which the cutting element moves. Thus, considerable power is lost in connecting the rotary motion of the motor into the generally linear motion of the linking arm and then into the arcuate motion of the cutting element. Further, the rotary motor is large and heavy making the tool somewhat cumbersome for its intended purpose.

It is the object of the present invention to improve on the prior device by providing a cutting tool not dependent upon rotary motive power.

It is the specific object to provide a cutting tool in which a linear source of motive power is used, thereby rendering the tool more compact, and its driving power directed within the plane of the cutting element.

Specifically, it is an object of the present invention to provide a cutting tool of the type disclosed in which a hydraulic motive means (piston and cylinder) are employed. With such mechanisms the source of fluid power may be separately maintained and fed to the device by a light conduit. Thus, the device can be made more compact and of less weight.

It is a further object of the present invention to provide an improved cutting element and an improved arrangement for mounting the cutting element. This lat ter object is essential as it is not possible to merely substitute one power source for another and obtain the beneficial results desired. Specifically, it is the object of the present invention to provide a cutting element and its arrangement for mounting which insures an arcuate shearing cut of the workpiece even though actuated by a linear source of power.

It is still another object of the present invention to provide an improved arrangement for locating and fixns h utting ni wi h n t cutting 9 it to provide an improved arrangement for supporting the workpiece during the cutting operation.

These objects and advantages, as-well as numerous others, will be apparent from the following disclosure.

SUMMARY OF THE INVENTION According to the present invention a tool for bevelling an edge of an elongated metal workpiece is provided comprising a head, a stirrup, depending from the head and a cutting member pivotally mounted within the stirrup. The stirrup defines an opening for receiving the workpiece. A hydraulic linear moving motor is mounted in the head and connected to the cutting element to swing it in an arcuate path through a corner of the opening to cut a curved groove or bevel in the workpiece.

The hydraulic motor is linearly reciprocating piston and cylinder, actuated by the flow of fluid to the cylinder via suitable valve and flow control means.

The cutting member is pivoted to the stirrup so as to be fulcrumed about a central point remote from the connection with the motor thus providing the arcuate path. The cutting member includes a replacable blade element, which may also be formed with more than one cutting edge. The blade, edges can also be sequentially presented for use prior to the replacement of the entire blade.

Full details of the present invention will be seen in the attached drawings and from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. I is an end view of a bevelling machine embodying the present invention,

FIG. 2 is aside view partially in section of the machine shown in FIG. 1,

FIG. 3 is the view of the cutting element carrier seen in dotted lines in FIG. 1, and

FIG. 4 is a sectional view along lines 4-4 of FIG. 3.

DESCRIPTION OF THE INVENTION mounted within the head on the frame 10. Depending from the frame 10, below the hydraulic assembly, is a stirrup assembly 16 in which a carrier 18 holding a cutting element 20 is mounted. The stirrup assembly 16 is open at its lower end (defined by the numeral 22) and carries a pair of spaced work holders and guides cylinder 28 and leads to a source of fluid under pres-- sure. The conduit is provided with one or more remotely controlled valves (solenoid operation is suitableyrwhile the housing has mounted on it operational switches for controlling the valve operation. Pressure and flow regulating means are also employed in conventional manner. The hydraulic power assembly has a number of advantages, other than the in-line operational stroke of the piston. A hydraulic unit has very little resiliency, bounce, or residual compressibility as for example, is inherent in a pneumatic unit. Small volumes of fluid are needed to obtain the desired stroke at the desired pressure or force, and the unit, as a whole, may be compact.

The stirrup assembly 16 is formed of a pair of spaced opposed

parallel plates

34 and 36 which are substan tially mirror images of each other. Each plate has an inwardly directed peripheral lip 38 and an enlarged boss 40 at its upper end. The boss 40 is adapted to en circle the outer surface of the cylinder 28 of the hydraulic assembly, while the peripheral lips 38 define a hollow interior space 42 in which the cutting assembly carrier 18 is located. The forward portion of each of the

stirrup plates

34 and 36, which as viewed in FIG. ,1 are to the left, has a generally circular configuration with an' inner edge 44 substantially circumscribed about a center which itself is coaxial with a line perpendicular to the plane of the interior space 42.

The opening 22 for the workpieces lies generally along a diametrical line d-d passing through the center 0. The rearward portion of the

stirrup plates

34 and 36 lying to the right in FIG. I has a curved arcuate surface 46 with respect to the center 0 but is not circumscribed thereabout. The surface 46 is furthermore,

farther removed from the center 0, than the surface 44 of the forward portion. The center line L-L of the bosses 40 (e.g. also of the hydraulic cylinder 28) is parallel to line d-d but is offset from the center 0 by a distance mm.

The

stirrup plates

34 and 36 are joined to the frame by bolts 48 and to each other by a plurality of bolts 49 spaced about their outer periphery. Spacers 50, through which bolts 49 pass, are used to maintain the stirrup plates34 and 36 in parallel relationship.

The peripheral lips 38 and

plates

34 and 36 define a substantial flat disk like planar outline. The bosses 40 hold the hydraulic cylinder 28 co-planar with the outline of the space 42 and the opening 22 is likewise defined co-planar with the space 42.

The cutting element assembly (FIG. 3) comprises the carrier 18 which has a disk like teardrop shape, conforming generally, to the space 42. The carrier 18 is pivoted to rotate about an axle pin 52 at the geometric center 0, which pin 52 is retained within bearing holes 54 formed in the

opposed stirrup plates

34 and 36 along the center axis 0 and fixedly secured by C-clamp or Seager clips 56 at each of its ends.

The node or enlarged portion of the carrier 18 is undercut on both surfaces to form a flanged car 58 in which an eccentric hole 60 offset from the center 0 by the distance m-m is provided. The car 58 enters between the spaced portions of a bifurcated yoke 62 which is threaded or otherwise secured to the end of the piston 30. A pin 64 pivotally secures the yoke 62 to the ear 58. As will be obvious, the pin 64 forms an offset fulcrum point for the carrier 18, which on linear movement of the piston 30, causes the carrier 18 to rotate about the central axle 52 fixed at the center 0.

The knife is arranged at the circular peripheral portion of the carrier 18 in a circumferential sector recess 66 and is offset from the fulcrum point of piston 30 (i.e. the axle 60) by an angle somewhat greater than 90 relative to the center 0. Thus, a small reciprocal linear movement of the piston will swing the kinfe 20 arcuately past the opening 22, shearing the edge of the workpiece in the desired manner. The shearing action is clockwise in movement about the center 0 while the deburring and stripping of the workpiece will be effected by the counter clockwise or retracted movement of the knife. p

As seen in FIGS. 3 and 4, the knife 20, which is formed of any suitable metal, has a frontal face curved about an axis parallel to the axis of the center 0 so as to have a sharpened point P at each end. The back of the knife is also curved, but along its length about an axis perpendicular to the face. The curved back of the knife 20 sits in a hardened triangular wedge 68 which is also curved to conform to it. The wedge 68 acts as a back stop for the knife and abuts against the back edge wall of the sector recess 66. The wedge 68 is provided with a small diameter shear pin 70 extending cess 66, consequently, wedging the knife 20 securely against the back stop wedge 68. The front'end of the retaining member 74 is curved to conform to the knife surface, and the retaining member is secured to the carrier 18 by a suitable bolt 78 threaded into the carrier. It will be seen that the knife 20 is held securely in place only by the wedgingaction of the retaining member 74, which itself is held by only one bolt 78. Thus, the knife may be easily and conveniently replaced without disassembly of the carrier 18..F urther, since the knife is provided with two points P and P symmetrically formed on it, the knife has two usable surfaces, allowing longer operation without the need for change. I

A further advantage is obvious from the construction. The back stop wedge 68 is preferably, made of hardened steel or other strong material since it absorbs the greatest portion of the shock and stress of the knife impact on the workpiece. The single shear pin 70 sitting in its hole, however, enables a uniquesafety feature to be obtained, namely, should the shock on the knife be so great the impact will create a torque on the wedge 68 via the knife 20 which wouldrotate the wedge 68 counter clockwise. The shear pin 70 will snap or break causing the knife 20 to fall out before any damage could occur to its cutting edgesLReplacement of the shear pin 70 is an easy task, and resumption of the cutting operationcan be resumed as quickly as possible.

The apparatus is also provided with bottom work holding and guide means 24 and 26 respectively, which are formed somewhat to those shown in the aforementioned application. The bottom work holding device 24 comprises a saddle having a straight surface 80 extending with a slight. inward taper radially from the center 0. The work holding device is provided with a hook 82 which fits into grooves 84 in

stirrup plates

34 and 36. A screw fastener extends through the holder 24 upwardly into a nut 86 secured between the

stirrup plates

34 and 36. Various sizes and angles of saddle surfaces can be provided to cooperate with the selected workpiece. Adjustable height bed plates, such as those shown in the aformentioned application may be used. The upper holder or guide 26 is triangular in shape having three edges of different angular relationship. The holder 26 is provided with a groove 88 parallel to at least two of its edges into which ledges 90 formed on the interior of the bottom edge of the stirrup plates fit. A thumb screw 92 extends laterally into stirrup plate 36 and-is turnable to secure the holder 26 in selected position. Thus, the holder may be arranged with any one of its sides, at any height or space from the saddle surface 80, to hold the workpiece.

Unlike other devices the present apparatus functions in a unique manner in placing the workpiece in position and defining the depth of the cut or bevel to be made. As seen in FIG. 1, the workpiece W is inserted between the bottom holder 24 andthe guide 26. The generally flat back of the workpiece is set to abut flush against the surface 80. In this manner the edge E, which is to be cut is shoved upwardly to contact the surface of the knife retaining member 74. When cutting occurs the depth of the bevel will, therefore, correspond to the distance between the point P of the knife and the surface of the retaining member 74. Even after an indefinite number of cuts this distance will remain constant. The depth of the out can be varied as desired by merely exchanging one retainer 74 for another of a different size relative to the knife edge P,. If desired, the tool may be provided initially with a set of exchangeable holders or knife retainers 74 of different depth. It will also be observed that with the present device neither the bottom holder 24 and guide 26 need be adjusted at any time to vary the depth of the bevel cut.

The frame, housing or stirrup plates may be provided with suitable handles and other operating mechanism, as required.

The operation of the present apparatus is, of course, simple and very much the same as that of the aforementioned application. "After placement of the workpiece between the bed plate and the guide the hydraulic motor is actuated. It is to be appreciated that because of the direct connection between the piston 30, the yoke 62 and the carrier 18 a smooth power is transmitted. The usual hammer and clatter of moving linkages is absent from the present device. The arrangement furthermore, provides a smooth crank action and the knife passes arcuately in a clockwise direction through the workpiece to make the desired bevel cut. The knife is retracted by return of the piston, which may if desired, be positive under fluid pressure or may be spring actuated, depending on the type of hydraulic motore used. Retraction tends to clean or strip the cut edge of the workpiece.

It will thus be seen that the present invention provides a simplified cutting tool, employing hydraulic motive power and in-line action,'resulting in improved operability, greater reliability and lower cost, in addition to the numerous advantages enumerated earlier. Various changes and modifications are possible and the present disclosure is intended to be illutrative only and not limiting of the scope of the invention.

What is claimed is:

1. A portable tool for bevelling an edge of an elongated workpiece comprising a head, a stirrup depend- .ing from said head, an opening defined in said stirrup for receiving said workpiece transverse to the plane thereof, a carrier mounted on said stirrup to move in plane parallel to that of said stirrup, a cutting element mounted on said carrier, a hydraulic motor located in said head, Said motor having means lying in the plane of said carrier interconnecting said motor and said carrier to move said carrier in an arcuate path casuing said cutting element to intersect a corner of said opening.

2. The tool according to claim 1 wherein said hydraulic motorcomprises a cylinder and a piston and said stirrup comprises a pair of spaced plates secured to said head, said piston depending between said plates and pivotally connected to said carrier, said carrier being pivotally journaled about a pin fixed to said plates at the geometrical center of said carrier to be rotatable thereabout.

3. The tool according to claim 2 wherein said carrier is 'a generallyflattened-member having a first portion in which its peripheral edge is circumscribed about the geometric center and a second portion which is arcuate to the geometric center and offset radially therefrom, the piston being connected to the offset portion of said carrier.

4. The tool according to claim 2 wherein said cutting element comprises a blade, and fastening means for removably clamping said blade to said carrier whereby the same may be removed and replaced.

5. The tool according to claim 4 wherein said blade is radially offset from the connection between said piston and said carrier by an amount greater than 6. The tool according to claim 4 wherein the-center line of said piston extends in a direction parallel to a line drawn between the geometric center of said carrier and the opening in said stirrup.

7. The tool according to claim 4 wherein said fastening means includes a shear member wedging said knife in position and adapted to be dislodged on an impact exceeding a predetermined force.

8. The tool according to claim 2 including guide means slidably mounted on said stirrup adjacent said opening and movable into and out of the opening to limit the upper extent of said opening and to position said workpiece therein.

9. The tool according to claim 8 wherein said guide means comprises a triangularplate slidably mounted along one edge between the plates of said stirrup, the

remaining edges of said guide extending at different angles with respect to said one edge, said guide being adapted to selectively present one of the remaining edges toward said opening thereby varying the angle of the edge limiting the upper extent of said opening.

10. The tool according to claim 9, wherein said guide and said cutting element are aligned in the same plane between the plates of said stirrup and cooperate to stabilice the workpiece during cutting.

11. The tool according to claim 1 wherein said carrier is provided with a cut out recess in a sector of its periphery, and including means for securing said cutting element within said sector recess.

12. The tool according to claim 11 wherein said cutting element is a knife'forcibly held between a first member and a second member conforming in dimension to said recess, one of said members being fastened by screw means to said carrier.

13. The tool according to claim 12 wherein the other of the members holding said knife is held by a shear pin, said shear pin being adapted to snap on impact of said knife in excess of a predetermined force.

14. The tool according to claim 12 including means engaging the surface of and supporting said workpiece located adjacent said means for securing said knife.

15. The tool according to claim 14 wherein said means for securing said knife is replaceable.

Claims

1. A portable tool for bevelling an edge of an elongated workpiece comprising a head, a stirrup depending from said head, an opening defined in said stirrup for receiving said workpiece transverse to the plane thereof, a carrier mounted on said stirrup to move in plane parallel to that of said stirrup, a cutting element mounted on said carrier, a hydraulic motor located in said head, said motor having means lying in the plane of said carrier interconnecting said motor and said carrier to move said carrier in an arcuate path casuing said cutting element to intersect a corner of said opening.

2. The tool according to claim 1 wherein said hydraulic motor comprises a cylinder and a piston and said stirrup comprises a pair of spaced plates secured to said head, said piston depending between said plates and pivotally connected to said carrier, said carrier being pivotally journaled about a pin fixed to said plates at the geometrical center of said carrier to be rotatable thereabout.

3. The tool according to claim 2 wherein said carrier is a generally flattened member having a first portion in which its peripheral edge is circumscribed about the geometric center and a second portion which is arcuate to the geometric center and offset radially therefrom, the piston being connected to the offset portion of said carrier.

5. The tool according to claim 4 wherein said blade is radially offset from the connection between said piston and said carrier by an amount greater than 90*.

6. The tool according to claim 4 wherein the center line of said piston extends in a direction parallel to a line drawn between the geometric center of said carrier and the opening in said stirrup.

9. The tool according to claim 8 wherein said guide means comprises a triangular plate slidably mounted along one edge between the plates of said stirrup, the remaining edges of said guide extending at different angles with respect to said one edge, said guide being adapted to selectively present one of the remaining edges toward said opening thereby varying the angle of the edge limiting the upper extent of said opening.

12. The tool according to claim 11 wherein said cutting element is a knife forcibly held between a first member and a second member conforming in dimension to said recess, one of said members being fastened by screw means to said carrier.