US3891201A

US3891201A - Compression hold-down elements

Info

Publication number: US3891201A
Application number: US433898A
Authority: US
Inventors: Robert G Clugage
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-07-21
Filing date: 1974-01-16
Publication date: 1975-06-24
Anticipated expiration: 1992-06-24

Abstract

Workpiece hold-down elements for holding the workpiece between the jaws of a machine vise, said jaws being shaped to prevent the hold-down elements from slipping. The hold-down elements are of channel shape with top and bottom portions thereof connected by a web that is slightly curved. These top and bottom portions are engaged by a face of the vise jaw so that when pressure is exerted on the elements by the vise the work engaging front of each element is pressed against the workpiece. The face of each jaw is provided with a groove for receiving the rear portion of each of the top parts of the hold-down elements to prevent these from slipping with respect to the vise jaws. Accidental displacing the hold-down elements with respect to the workpiece is prevented. The top parts of the hold-down elements are also provided with hardened steel or other metal shoes. The forward parts of the hardened shoes engage the workpiece and these are sufficiently hard to resist wear. The bodies of the elements may be made of softer material such as extruded aluminum or alloys thereof.

Description

United States Patent 1 1 Clugage 1 1 COMPRESSION HOLD-DOWN ELEMENTS Robert G. Clugage, P.O. Box 5021, Incline Village, Nev. 89450 [76] Inventor:

[ Notice: The portion of the term of this patent subsequent to Feb. 12. 1991. has been disclaimed.

[22] Filed: Jan. 16, 1974 211 App]. No.: 433,898

Related US. Application Data [63] Continuation-impart of Scr. No. 273.971, July 21,

1972, Pat. N0. 3.791.640.

Primary Examiner-Roy Lake Assistant Examiner-Mark S. Bicks Attorney, Agent, or Firm-Ben .l. Chromy; Gerald L.

Moore 1*June 24, 1975 5 7 ABSTRACT Workpiece hold-down elements for holding the workpiece between the jaws of a machine vise, said jaws being shaped to prevent the hold-down elements from slipping. The hold-down elements are of channel shape with top and bottom portions thereof connected by a web that is slightly curved. These top and bottom portions are engaged by a face of the vise jaw so that when pressure is exerted on the elements by the vise the work engaging front of each element is pressed against the workpiece. The face of each jaw is provided with a groove for receiving the rear portion of each of the top parts of the hold-down elements to prevent these from slipping with respect to the vise jaws. Accidental displacing the hold-down elements with respect to the workpiece is prevented. The top parts of the hold-down elements are also provided with hardened steel or other metal shoes. The forward parts of the hardened shoes engage the workpiece and these are sufficiently hard to resist wear. The bodies of the elements may be made of softer material such as extruded aluminum or alloys thereof.

2 Claims, 3 Drawing Figures COMPRESSION HOLD-DOWN ELEMENTS DESCRIPTION OF THE INVENTION This application is a continuation-in-part of my Application Ser. No. 273,971 filed July 21, 1972 now US. Pat. No. 3,791,640.

This invention relates to compression hold-down cle ments for use with machine vise jaws shaped to prevent accidental displacement of the hold-down elements when pressure is applied thereto during the gripping of a workpiece therebetween.

An object of this invention is to provide an improved combination of hold-down elements and machine vise for holding a workpiece firmly therebetween.

Another object of this invention is to provide improved workpiece hold-down elements which may be made of extruded aluminum or aluminum alloys and which are provided with hardened workpiece-engaging members or shoes.

Another object of this invention is to provide an improved arrangement of workpiece hold-down elements and machine vise jaws provided with recesses to prevent the hold-down elements from accidentally slipping or being dislodged when pressure is applied to the elements by the vise. Said elements are of channel shape and each of them is provided with a web between the vise engaging top portion and lower portion thereof. Said web is adapted to flex slightly so that the holddown elements press the workpiece downward firmly. The faces of the jaws of the vise are grooved or recessed to receive a rear part of each of the hold-down elements so that the elements can not be accidentally dislodged from the faces of the jaws when pressure is applied thereto.

Other and further objects of this invention will be apparent to those skilled in the art to which it relates from the following specification, claims and drawing.

In accordance with this invention I have provided an improved arrangement for holding a workpiece in a machine vise so that the workpiece will be held with precision during milling. grinding or other operations being performed thereon. In this invention the workpiece is positioned between a pair of hold-down elements, each of which is of a channel shape and each of which is also provided with a top portion and a bottom portion which are connected by a web of arcuate shape. The top portion of each hold-down element is provided with a hardened work-engaging shoe which extends between the workpiece and the jaw of the vise. Providing the hold'down element with such a hardened shoe permits making the balance of the hold-down element of softer material such as aluminum or aluminum alloys by the extrusion process. The hardened shoe is attached to the hold-down element by means of rivets, screws or the like. The rounded front portion of the hardened shoe extends forward of the body of the element so that it engages the workpiece. The angular rear part of the hardened shoe or member extends into a horizontal groove or recess provided to the vise jaw so that when pressure is applied to the element by the vise the element can not accidentally slip or become dislodged from the vise. Thus, the hold-down elements can not accidentally release the workpiece or allow the workpiece to shift during the grinding, milling or other operations being performed thereon.

Further details and features of this invention will be set forth in the following specification, claims and drawing in which briefly:

FIG. I is a view in side elevation showing the holddown elements and vise arrangement of this invention holding a workpiece;

FIG. 2 is a perspective view of the arrangement shown in FIG. 1; and

FIG. 3 is an end view of one of the hold-down elements.

Referring to the drawing in detail, reference numeral 10 designates a flat plate which may be the base of a conventional vise or it may be the table of a metal working machine such as a milling machine. Base 10 is provided with a stationary jaw 11 and an adjustable jaw 12. The metal workpiece l3 and the hold-down

elements

14 and 15 are held firmly between the jaws 11 and 12. Thus, opposite sides of the workpiece 13 are engaged by the hold-down

elements

14 and 15, respectively.

Hold-down element 14 is provided with a shoe or member 14a of hardened steel or the like which is firmly attached to the top portion 14b by several rivets 140. The rounded forward part of the shoe 14a engages a side of the workpiece 13 while the angular rear part of this shoe engages the vise jaw 11 in the upper part of the recess 11a which is provided to the face of the vise jaw and extends horizontally across this face. The lower part 14d of the hold-down element 14 is provided with a rear flat face that engages the front face of the jaw 11. The forward part of the member 1411 is connected to the upper part 1417 by the web which is adapted to flex slightly when the workpiece 13 is clamped.

Hold-down element 15 is the same as hold down element l4 and it is provided with a shoe 15a of hardened steel that is attached to the upper part 15b by several rivets 15:- so that the parts 15a and 15b are firmly at tached to each other. The hardened shoe 15a is provided with a rounded front that engages the workpiece 13. The angular rear part of the shoe engages the jaw 12 of the vise in the recess 12a which extends horizontally across the face of the jaw. The bottom part 15a of the hold-down element is provided with a flat rear surface that engages the lower part of the vise jaw. Part 15d is attached to the upper part 15b by the web l5e which is adapted to flex slightly when the workpiece 15 is clamped. The

parts

15b, 15d and l5e of hold-down element 15 are made of extruded aluminum or alloys thereof the same as corresponding parts of the holddown element 14.

The workpiece 13 is supported by the

parallel members

16 and 17. Thus when pressure is applied to

holddown elements

14 and 15 by the jaws 11 and 12 of the vise, the hardened members 14a and 15a of the

holddown

14 and 15, respectively, apply downward pressure on the workpiece l3 pressing this workpiece firmly against the parallel supports 16 and 17. This downward pressure results from the fact that the hardened members 14a and 15a are tilted at slight angles D with respect to the horizontal and the pressure of the vise on the hold-down elements tends to increase this angle. Thus there is a tendency for the angular rear parts of the hardened members 14a and 15a to slip with respect to the vise jaws 11 and 12, respectively. However. this tendency to slip is prevented by the recesses lla and 12a provided in the jaws 11 and 12, respectively. These recesses therefore prevent the accidental slippage and release of the hold-down elements. Also providing the recesses 11a and 12a to the vise jaws re duces the likelihood of the

webs

14c and 150 of the hold-down elements being deformed if these webs are made'of extruded aluminum and if considerable pres sure is applied to the hold-down elements by the vise. The hardened members 14a and 15a form the parts of the hold-down elements receiving the greatest wear and since these members are of hardened steel the life of the hold-down elements is greatly prolonged.

While I have shown and described a preferred form of the invention it will be apparent that the invention is capable of variation and modification from the form shown so that the scope thereof should be limited only by the proper scope of the claims appended thereto.

What i claim is:

l. A compression hold-down and clamping device for holding a work-piece down upon supporting means interposed between the jaws of the clamping device, the combination comprising a hold-down element having an elongated top member, said top member having a rounded forward surface for engaging the workpiece, an elongated bottom member the forward parts of said members being joined by a web. a clamping device comprising a pair of jaws and means to move one jaw toward the other to effect a clamping action. the jaws of the clamping device each having a horizontally extending recess for receiving the rear part of said top member to prevent said top member from slipping when pressure is applied thereto, said bottom member engaging said jaw of the clamping device near the bottom of said jaw, said top member being tilted at a predetermined angle with respect to the side of the workpiece engaged thereby. said predetermined angle is slightly reduced when pressure is applied to said top member and said rear parts of said top member and said bottom member are moved away from each other as said web if flexed whereby the workpiece is pressed down on the supporting means.

2. A compression hold-down and clamping device as set forth in claim 1, further characterized in that said top member comprises two parts, means fastening said two parts together so that one of said parts is on top of the other, said top part being of hardened metal and being provided with said rounded forward surface for engaging said workpiece and the rear end of said top part engaging said jaw in said recess.

Claims

1. A compression hold-down and clamping device for holding a work-piece down upon supporting means interposed between the jaws of the clamping device, the combination comprising a hold-down element having an elongated top member, said top member having a rounded forward surface for engaging the workpiece, an elongated bottom member, the forward parts of said members being joined by a web, a clamping device comprising a pair of jaws and means to move one jaw toward the other to effect a clamping action, the jaws of the clamping device each having a horizontally extending recess for receiving the rear part of said top member to prevent said top member from slipping when pressure is applied thereto, said bottom member engaging said jaw of the clamping device near the bottom of said jaw, said top member being tilted at a predetermined angle with respect to the side of the workpiece engaged thereby, said predetermined angle is slightly reduced when pressure is applied to said top member and said rear parts of said top member and said bottom member are moved away from each other as said web is flexed whereby the workpipece is pressed down on the supporting means.