US3687441A

US3687441A - Machine tools

Info

Publication number: US3687441A
Application number: US77980A
Authority: US
Inventors: Robert F Anderson
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-10-05
Filing date: 1970-10-05
Publication date: 1972-08-29
Anticipated expiration: 1989-08-29
Also published as: DE2149358A1; FR2110223B3; IT939926B; BE773497A; FR2110223A3; NL7113585A

Abstract

Machine tools comprising new and useful clamping components and in combination of a set-up and hold-down assembly of a T-nut, stud, strap clamp and leveling unit are disclosed. The set-up and hold-down tools are designed to provide ready assembly and disassembly from a T-slotted work table and for universal adjustment with regards to leveling.

Description

United States Patent Anderson 1 Aug. 29, 1972 [54] MACHINE TOOLS [72] Inventor: Robert F. Anderson, 3613 13th St.,

Menominee, Mich. 49858 22 Filed: Oct. 5, 1970 21 Appl. No.: 77,980

[52] US. Cl. ..269/47, 269/91, 269/223, 269/239, 269/245 [51] Int. Cl. ..B23q 3/02, B23q 3/ 10, B251) 5/ 10 [58] Field of Search ..269/47, 91-94, 269/223, 239, 245

[56] References Cited UNITED STATES PATENTS Zwick ..269/93 Carver ..269/94 X Dittman ..269/91 X Nelson ..269/91 Cadwallader ..269/93 Pettavel ..269/92 1,072,363 9/1913 Roberts ..269/203 1,401,444 12/ l 921 Roberts ..269/92 2,349,087 5/1944 Fraser ..269/92 2,560,525 7/1951 Nyl ..287/20 3,512,769 5/1970 Pendry ..269/94 FOREIGN PATENTS OR APPLICATIONS 1,222,770 6/ 1960 France ..269/94 Primary Examiner-Wayne A. Morse, Jr. AttorneyC. Kenneth Bjork [57] ABSTRACT Machine tools comprising new and useful clamping components and in combination of a set-up and holddown assembly of a T-nut, stud, strap clamp and leveling unit are disclosed. The set-up and hold-down tools are designed to provide ready assembly and disassembly from a T-slotted work table and for universal adjustment with regards to leveling.

5 Claims, 13 Drawing Figures Patented Aug. 29, 1972 3,687,441

2 Sheets-Sheet l INVENTOK Robert F. 9/?08/250/9 AGE/VT Patented Aug. 29, 1972 s 3,687,441

2 Sheets-Sheet 2 INVENTOR.

& i U BY 124 1 419412 5 :2 W

flGENT R0 er/ E Hack/var I MACHINE TOOLS BACKGROUND OF THE INVENTION The present invention relates to machine tools and more particularly is concerned with new and useful tools for securing a work piece to a T-slotted table or machine bed.

A variety of supporting and holding devices are used to set up and securely hold a metal work piece to a T- slotted table of a cutting, boring, shaping or the like forming machine. These tools commonly are known in the machine art as set-up and hold-down tools. Conventionally, these tools as used on the job comprise in combination a T-nut into which is screwed a stud, or a T-headed bolt, which T-head slips into a slot of the T- slotted table on which a work piece rests. An elongated strap-like clamp, such as a finger clamp, U-clamp, screw heel clamp, gooseneck clamp or plain clamp fits over the end of the bolt and is held in place by a conventional nut and washer assembly. The work piece is maintained relatively level and at a predetermined height by means of adjustable step blocks, adjustable vertical jacks or planer jacks. Representative examples of such conventional set-up and hold-down tools are described in Catalog 700A, Armstrong Bros. Tool Co., Chicago, Ill.

These tools are widely used but have certain inherent problems associated therewith. For example, the conventional T-nut or T-bolt units can be inserted into a T- slotted table only from the end. This means that any chips, machine dust or other debris must be carefully removed therefrom before sliding the conventional T- headed member therein. Sometimes with complex work pieces this entails lengthy periods of time to get the T slot cleaned out in order to add additional clamps to a particular set-up. Also additional nuts and bolts cannot be inserted between existing assemblies in a given slot without taking the assembly apart. Further, in conventional set-up and hold-down tool assemblies the shank of the stud screwed into a T-nut, or the shank of the T-bolt, if such is used, generally extends an undesirably high distance above the strap clamp. To tighten the clamp by use of a conventional nut and washer takes time. Further, there is great opportunity for dirt, dust and grime to get into the threads of the stud thereby necessitating cleaning these before attempting to screw the nut thereon.

One big problem with such conventional set-up and hold-down assemblies is that there often is no means for providing an infinite number of positions for leveling and height adjustment of the strap clamp member. The conventional assemblies of the type mentioned hereinbefore usually have stepped adjustments and leveling blocks, for example.

It is a principal advantage of the present invention to provide new, improved set-up and hold-down machine tools for use with a T-slotted work table.

It is also an object of the present invention to provide set-up and hold-down tools which provide both rapid and easy assembly and disassembly when used in a machining operation to hold a work piece.

It is another object of the present invention to provide such new tools which in themselves offer an infinite number of holding positions thereby assuring secure fastening and level positioning of the strap clamp holding a work piece.

It is a further object of the present invention to provide new and useful set-up and hold-down tools of which various components themselves alone or in combination have been unknown before my invention thereof.

These and other objects and advantages readily will become apparent from the detailed description presented hereinafter when read in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a vertical elevation of a T-nut of the present invention.

FIG. 2 is a top view of the T-nut depicted in FIG. 1.

FIG. 3 is a vertical elevation of a stud member employed in the tool set-up and hold-down assembly of the present invention.

FIG. 4 is a top elevation of one embodiment of a strap clamp of the present invention.

FIG. 5 is a cross-sectional view taken along line 55 of the clamp of FIG. 4.

FIG. 6 is one embodiment of a leveling post suitable for use in the tool assembly of the present invention.

FIG. 7 is one embodiment of a leveling pad for use with the leveling post depicted in FIG. 6.

FIG. 8 is a vertical elevation of one end of a strap clamp of the present invention.

FIG. 9 is a fragmentary top plan view of the clamp depicted in FIG. 8.

FIG. 10 is a fragmentary top plan view of a clamp of the present invention for use with another embodiment of leveling means.

FIG. 11 is a vertical elevation of the leveling assembly used with the clamp shown in FIG. 10.

FIG. 12 is a fragmentary side sectional view of a clamp showing an alternate type of leveling means.

FIG. 13 is a side plan view of a leveling post unit for use with the clamp of FIG. 12.

GENERAL SUMMARY OF THE INVENTION In general, the set-up and hold-down tools of the present invention comprise in combination a T-nut, stud, strap clamp and leveling unit.

Certain of the individual components employed in this combination are new and useful in themselves as will be shown hereinafter.

More particularly these tools consist of a T-nut having a stepped head so as to be held by the T-slot of a conventional slotted machine or worktable, but having one dimension such that the nut can be slipped into a T-slot anywhere along its length without having to be slipped in from the end. The top portion of the nut extends above the surface of the table top such that it can readily be gripped by the fingers and freely moved along the slot.

The upper portion of the nut contains a threaded opening designed to mate with the threaded portion of a stud member which in operation holds a strap clamp. The shaft of the stud contains a series of parallel, spaced apart grooves positioned circumferentially around said stud along most of its length. The stud can be of any of a variety of predetermined lengths. Usually it has an integral nut in its top which mates with the threaded portion of a second stud thereby providing for ready extension of this stud to a desired height without requiring the need for maintaining an extensive inventory of different stud lengths.

The strap clamp of the present invention has an opening which permits its placement within predetermined grooves in a shaft of the stud. It is held in this position by shoulders and grooves in a passage connected to said opening and mating with those of the shaft. The strap clamp is further secured by a holding, leveling means which also provides for ready adjustment to any of an infinite number of positions and quick assembly and disassembly.

DESCRIPTION OF PREFERRED EMBODIMENTS One embodiment of the T-nut of the present invention as shown in FIGS. 1 and 2 consists of an elongated member 10. The bottom portion is a substantially rectangular stepped section 12 having a length sufficient such that in use it is held within a T-slot of a machine or table bed. It is of a width such that this section of the nut can be slipped into a T-slot of the table anywhere along its length without having to be slipped in from the end.

The upper portion of section 12 consists of a vertical wall shoulder 14. The vertical walls 16 of shoulder 14 are indented a distance from the ends of section 12 such that when the T-nut is positioned in a T-slot these slidably but snugly fit between the walls of such a slot in the expected manner of a T-nut and T-slot assembly.

The bottom surface 18 of section 12 is fitted, usually about at its midpoint, with a spring-tensioned pin 19. This pin 19 is of a length such that when compressed as the nut 10 is pushed into a T-slot it permits free rotation of the T-nut 10 within the slot below the walls of the slot. As the T-nut 10 is rotated in an arc of about 90 and the walls 16 become aligned with the walls of a T-slot, the pressure on the nut is released thereby permitting the spring 20 to exert tension on the pin 19. This pin 19 extends downwardly pushing the shoulder 14 of T-nut 10 upwardly against the bottom of the T- slot thereby holding the T-nut 10 in a predetermined position in the slot and preventing it from turning within the slot.

Above section 12, T-nut 10 consists of an elongated shank 22 usually cylindrical in shape and of a height such that the top of this shank 22 extends above the upper surface of a T-slotted table top and provides for easy gripping. Conveniently, as shown, the top of shank 22 is formed into a knurled extension 24 usually of a size, i.e., diameter in the case of a circular cross-section shank, larger than the width of the T-slot in a bed or table. This assures that the T-nut 10 cannot fall down into a T-slot of the table in case it is dropped or tilted. This also provides for easy gripping of the T-nut 10 by the fingers for movement and positioning.

The shank 22 has a threaded bore 26 extending down from its top. This bore 26 usually is centrally located and ordinarily extends to near the bottom of shank 22.

As shown in the depicted embodiment the shank 22 and its cap or extension 24 are circular in cross-section. This shape is not critical as any convenient cross-sectional shape canbe employed. It is essential only that the T-nut 10 has dimensional characteristics as set forth hereinbefore to obtain the improved operation of installation and positioning unique with the T-nut 10 of the present invention.

FIG. 3 shows a stud 28 to be employed with the T-nut 10. This stud 28 has a lower threaded portion 30 which mates with bore 26 in T-nut 10 or with a nut 32 in another stud 28. Between nut 32 and threaded portion 30 is a cylindrical section 34 made up of a series of parallel grooves 36. The grooves 36 and intermediate shoulders 38 are of equal height. Ordinarily these range from about 1/16 to about V1 inch, usually from about 4; to about 3/16 inch, in height. If they are much thinner than the size indicated they may not provide the necessary strength when used in a clamp assembly. If they are much thicker, the strap clamp which fits thereon will become unnecessarily thick and cumbersome. Further, unduly thick grooves will increase the incremental height between each change in position.

The top of stud 28 terminates in an integral nut 32 having a threaded bore 40 which, as indicated herein before, can hold a second stud 28. This design provides for ready interchange and connection of studs one to another to easily complete an assembly for accommodating work pieces of different heights.

The studs 28 themselves generally are fabricated in from 3 to 8 inch lengths. Conveniently, they are made in 1 inch incremental differences. Because of the versatility of operation, it is unnecessary to have a large number of different sizes as a support stud 28 of a given height can readily be fashioned by connecting two or more of the studs 28 together.

A principal advantage of this stud 28 is that once a strap clamp is positioned thereon, as will be described more fully hereinafter, the threaded shank 30 can be screwed down into T-nut 10 to tighten the clamp providing a universal number of height adjustments. Further, by proper height selection, the stud 28 does not stick up an undesirable distance above the top of the work piece.

Because of the integral nut 32, a stud 28 can be readily removed from a T-nut 10 or two or more studs 28 can be separated from each other. In conventional set-up and hold-down tools as discussed hereinbefore, the nut must be completely removed from a stud to remove or put on a strap clamp.

The strap clamps 42 for use with the stud 28 as exemplified by the embodiment of FIGS. 4 and 5 consist of a clamp of conventional external shape as commonly employed for holding a work piece. It is to be understood that this clamp 42 can be plain, gooseneck-shaped or other shape as commonly used. It is essential with any configuration that the strap clamp 42 contain an internal through passage 44. This passage 44 mustbe large enough in one section, usually at one end, to freely pass over the nut 32 and shoulder 38 of a stud 28. Adjacent the enlarged portion are shoulders 46 having a groove 48 therebetween which mate with shoulders 38 and grooves 36 in stud 28. These are of such tolerance that the clamp 42 can freely slide back and forth along the stud 28. This provides for a variety of positions to facilitate ready ease of securing a work piece. For the optimum in versatility, the passage 44 usually extends over a major portion along the long dimension of clamp 42. Except for the enlarged portion, the remainder of the passage 44 contains the groove 48 and shoulders 46 along its length.

As indicated hereinbefore the enlarged section of passage 44 in the illustrative embodiment is at one end of this strap member 42', however, it can be placed at any position along this passage 44, if desired.

A variety of leveling assemblies can be used to secure and level the clamp 42. One embodiment of such an assembly as shown in FIGS. 4 and 5 has a cut-out section 50in one end of the clamp 42. This section 50 is fitted with a groove and shoulders 52 similar to those in passage 44. These mate with those in a leveling post 54 having universally positioning ability; these replace conventional step blocks as now used in the art and have only a limited number of positions for height adjustment.

Additionally, as shown in FIGS. 4 and 5 the other end of clamp 42 has a through passage 56 extending from the end 58 to the shoulder 46 and groove 48 containing internal cut-out section 44. This passage 56 accommodates a pin 60 having a circumferential friction engaging member 62, such as a rubber or flexible plastic O-ring which permits the pin 60 to be slid in and out along the passage 56. Pin 60 is used in certain operations to aid in holding down a workpiece by fitting said pin into a hold in the side of a workpiece when machining the top of such a piece. The pin 60 merely is alternative securing means to add to the versatility of the present tools. It is to be understood that the clamp 42 may be fabricated without this additional securing member.

The leveling post 54, as shown in FIG. 6, comprises a series of shoulders 64 and grooves 66 intermediate its length. These, as indicated hereinbefore, usually are of the same size as in stud 28 so as to mate with those in cut-out section 50 of the clamp 42. (It is not essential that the two separate assemblies of grooves and shoulders be the same size in the stud 28 and passage 44 and in the second assembly of cut-out section 50 and leveling post 54. However, to aid in their fabrication, these usually are made the same to cut down in the number of different machining operational changes required.) The bottom section 68 of post 54 is convex at its lower end and mates with a concave depression 82 in the top 84 of a leveling pad 74 shown in FIG. 7. The top 76 of post 54 has a concave surface so as to accommodate the convex surface 68 of a second post 54 for securing work pieces of different heights if two or more posts are desired or required. The bottom section 68 has a rubber, plastic or other type flexible O-ring or other configuration frictional engaging member 78a above its convex end. The post 54 also contains a similar frictional engaging member 78b near its top. These frictional engaging members 78a and 78b provide for ready connection of one post 54 to another when these are placed in stacked array in an assembly. In such as operation the convex end 68 of a first post 54 is placed in the concave section of the top 76 of a second post 54 and a tubular collar 79 which provides frictional engagement with the members 78a-78b when slipped over these members 78a-78b is used to secure the two posts 54 together. The cross-sectional diameter of the top 76 and bottom section 68 containing the frictional engaging members 78a-78b is less than that of shoulder 64. This assures that the collar coupling 79 cannot slip down over shoulder 64 but is stopped by a step 81a in the shoulder 64 next to the top section 76 of one post 54 and step 81b in the shoulder 64 adjacent the bottom section 68 of a second post 54.

The leveling pad 74 consists of a top member 80 having a concave indentation 82 in its upper surface 84 and a threaded lower shank 86. The bottom 88 of pad 74 has a threaded bore 90 which mates with threaded shank 86 of top member 80. As shown, this member 88 contains a ridge 92 around its periphery. This is not critical to the operation of the tool but serves to make it easier to grip the base 88 during a leveling operation.

In using the set-up and hold down tool assembly depicted in FIGS. 1-7, a T-nut 10 is slipped into the T-slot of a table top or machine bed. Once in the slot at a predetermined position it is turned to have its side walls 16 mate with the walls of the slot and pressure released whereupon tension pin 19 pushes the walls 16 of the nut 10 up against those of the slot. A stud 28 of appropriate length is partially screwed into T-nut 10 and a strap clamp 42 slid over stud 28 and positioned at an appropriate groove-shoulder height such that it rests loosely on top of a work piece. Leveling post 54 is placed on pad 74 and fitted into appropriate grooves of section 50 in clamp 42. The height is such that the clamp is substantially horizontal across the work piece. The stud 28 is screwed down so that clamp 42 exerts a firm hold on the work piece. The top section of pad 74 also is adjusted by screwing it up or down, if necessary, to provide for the maximum in holding power of the clamp 42 and level positioning of the clamp 42 on a work piece.

In an alternative leveling means for use with clamp 42 as shown in FIGS. 8 and 9, clamp 42 has a cut out portion 94 in one end. This portion 94 is fitted with threads 96 which accommodate a threaded leveling post (not shown). This post is generally of the same configuration as post 54 except that it has a continuous spiral thread forming the grooves and shoulders rather than the parallel grooves and shoulders of post 54. In the leveling embodiment of FIGS. 8 and 9 the spiral threads provide for universal leveling of the assembly although for additional adjustment the pad 74 also can be used.

Still another embodiment of leveling post assembly is shown in FIGS. 10 and 11. In this embodiment, the clamp 42 has a second internal through passage 98 adjacent end 100. This passage 98 is generally circular but elongated at two opposite portions. Threads 102 fill the circular portion, the elongated sections 104a-104b being non-threaded. Leveling post 106 is a threaded stud having cut down sections 108 extending its length on both sides corresponding to the threads 102 of passage 98. The sections 108 are generally just cut down to the body of the post 106 and permit the post 106 to be freely slid up and down within passage 98 when the sections 108 are adjacent threads 102 of the passage 98. In operation, at a predetermined level or height, the shaft 106 is turned, usually about to obtain maximum gripping of threads 110 of shaft 106 and threads 102 of passage 98 thereby securing the clamp in a fixed position. For convenience in turning the shaft 106, it is fitted with a head 112, usually knurled for easy gripping and cut down in the same manner as the shaft so that a clamp 42 can easily be slid onto a single shaft 106 or a plurality of these in stacked array, This head 112 also contains a depression 114 which can accommodate the post 116 in the bottom of a second shaft 106 if these are employed in stacked array. A foundation plate 118, with passage 120 accommodating post 116 provides support for this assembly.

If desired, the threaded shaft employed with the clamp configuration shown in FIGS. 8 and 9 also can be fitted with a post to fit within a foundation pad as shown in the embodiment of FIGS. 10 and 11. In this alternative design there is no need to use the leveling pad 74.

In use of the leveling assembly shown in FIGS. 10 and 11 the strap clamp 42 is placed on top of the work piece to be secured. The T-nut 10 is slipped into the T- slot of a machine bed and positioned therein. Stud 28 is slid through the strap until it engages T-nut 10 and slid along passage 44 to a desired position. The post 106 is passed down through passage 98 in clamp 42; its lower post 116 fitted into support pad 118 placed on the machine table top. Post 106 is turned about 90 to lock the strap clamp 42 and correspondingly the work piece at the proper height.

A further illustrative embodiment of a leveling and securing assembly is shown in FIGS. 12 and 13. In this embodiment a strap clamp 42 has a through passage 122 near one end. This consists of a collared section 124 in the bottom of the clamp and a conically tapered bore 126 extending from shoulder 124 up through the body of the clamp 42. The support post for use with this embodiment is a threaded stud 128 having a nonthreaded smooth cylindrical lower portion 130 which fits into a foundation pad 132 positioned on a worktable in much the same manner as described for the embodiment of FIG. 11. In this latter configuration the post 116 is shown as extending through the foundation pad 118 while in the embodiment of FIG. 13 the post 130 is shown as being positioned in a pocket 133 in the foundation pad 132. It is to be understood that either of The top of post 128 contains a conical depression I 135 to hold a post 130 of a second shaft 128 if these are used in stacked array in an assembly.

Two hemi-conical members, i.e., half-nuts, l34a-134b, each have a threaded internal bore to mate with the threads of post 128 when these are placed around a post 128 to form a complete nut. The external shape of members 134a134b is such that these conform with passage 122 of the clamp 42.

In using this leveling assembly, the post 128 is positioned near a work piece to be clamped and a half nut 134a placed on top of the work piece. The half nut 134a is slid into mating threads on the post 128 and the assembly moved away from the work piece. Placing the half nut 134a on top of the work piece is not critical but serves to give an easy measure of the height needed for level clamping. The other half nut 134b is fitted to post 128 to give a complete nut. The post 128 with half nuts 134a-134b positioned thereon is placed in passage 122 of strap clamp 42. The bottom 130 of post 128 is fit into a foundation pad 132 on the top of the worktable. Stud 28 in T-nut 10 is slid into passage 44 of clamp 42 and the assembly screwed to provide a secure holding of the work piece.

It is to be understood that the various supporting assemblies and connecting means for holding the studs and/or leveling posts at their lower ends or for securing a series of these in stacked array can be used with any of the embodiments depicted herein.

The various components of the present invention are made from materials ordinarily employed for such tools. Tool steel commonly is used. However, for some operations where extreme high strength is not required, aluminum alloys and magnesium alloys provide a desirably high strength to weight ratio and are suitable for many operations. Other metals as used in tooling and clamping operations can be used.

It is expected that the various components will be sold in sets. However, because of the versatility and interchangeability of the various components as has been disclosed in the present specification it is also to be understood that the various novel individual components are to be made available.

I claim:

1. A set-up and hold-down tool for securing a work piece to a T-slotted machine table which comprises in combination:

a. a T-nut, said T-nut consisting of an elongated member, the bottom portion of said member being a substantially rectangular stepped section so as to be held by the T-slot of a T-slotted machine table. said stepped section having a length sufficient such that when positioned in said T-slot it is held therein but having a width such that said rectangular section can be slipped into the T-slot of said table anywhere along its length, the upper portion of the stepped section of said T-nut being a vertical walled shoulder indented a distance from its end such that when said T-nut is positioned in said T- slot the walls slidably but snugly fit between the walls of said T-slot, the bottom surface of said stepped section being fitted with a spring tensioned member, said spring tensioned member being of a length such that when compressed it permits free rotation of said T-nut within a T-slot and when released it pushes said T-nut upwardly against the bottom of said T-slot, the walls of said shoulder being aligned with the walls of said T-slot thereby holding said T-nut in a predetermined position within said slot, an elongated shank above said stepped section, said shank being of a height such that the top of said shank extends above the upper surface of the T-slotted table, and the upper portion of said nut containing athreaded opening,

. a stud, said stud having a threaded portion at one end which mates with the threaded portion of said T-nut and having a series of parallel, spaced apart shoulders and grooves along its length above said threaded portion, said shoulders and grooves extending circumferentially around said stud,

c. a strap clamp for holding a work piece, said strap clamp having a first internal through passage extending substantially along its length, said through passage having an enlarged portion in one section to freely pass over said stud and adjacent said enlarged portion shoulders and grooves in the wall of said internal through passage, said shoulders and grooves being substantially parallel to the long dimension of said clamp and mating with the shoulders and grooves in said stud with a tolerance such that the clamp can freely slide back and forth along said stud when placed thereover, said strap clamp having a second internal through passage adjacent one end, said second through passage being generally circular in shape but being elongated at two opposite portions, the circular portion of said passage being fitted with threads and the elongated portions being non-threaded, and

. a leveling means for use with said strap clamp and providing for universal adjustment of said clamp, said leveling means consisting of a threaded stud having cut down sections extending along its length on both sides corresponding to the threaded portions of said second internal through passage, said cut down sections permitting said post to be freely slid up and down within said second passage in said strap clamp when said out down sections of said post are adjacent the threaded sections of said second passage in said clamp, and the threads in said post mating with the threads in said passage when said post is turned, the bottom of said stud defining a post fitting into a foundation plate which provides support for said leveling means.

2. The tool asdefined in claim 1 wherein the top of the shank of said T-nut contains a knurled extension of a size larger than the width of the T-slot in said table.

3. The tool as defined in claim 1 wherein the shoulder and groove containing stud has an integral nut in the end opposite that containing said threaded portion, said nut having a threaded bore the threads of which mate with the threaded portion of a second of said stud members and wherein the threaded stud of said leveling means has a head containing a depression which can accommodate the post of a second of said threaded studs.

4. The tool as defined in claim 1 wherein the strap clamp has a third through passage extending from the end of said clamp opposite said second through passage and communicating with said internal through passage, a pin fitted in said third passage, said pin having a circumferential fn'ction engaging member which provides for holding said pin in said third passage and permits sliding of said pin in and out along said third passage.

5. The tool as defined in claim 1 wherein the spring tensioned member of the T-nut is a spring tensioned pin.

Claims

1. A set-up and hold-down tool for securing a work piece to a Tslotted machine table which comprises in combination: a. a T-nut, said T-nut consisting of an elongated member, the bottom portion of said member being a substantially rectangular stepped section so as to be held by the T-slot of a T-slotted machine table, said stepped section having a length sufficient such that when positioned in said T-slot it is held therein but having a width such that said rectangular section can be slipped into the T-slot of said table anywhere along its length, the upper portion of the stepped section of said T-nut being a vertical walled shoulder indented a distance from its end such that when said T-nut is positioned in said T-slot the walls slidably but snugly fit between the walls of said T-slot, the bottom surface of said stepped section being fitted with a spring tensioned member, said spring tensioned member being of a length such that when compressed it permits free rotation of said T-nut within a T-slot and when released it pushes said Tnut upwardly against the bottom of said T-slot, the walls of said shoulder being aligned with the walls of said T-slot thereby holding said T-nut in a predetermined position within said slot, an elongated shank above said stepped section, said shank being of a height such that the top of said shank extends above the upper surface of the T-slotted table, and the upper portion of said nut containing a threaded opening, b. a stud, said stud having a threaded portion at one end which mates with the threaded portion of said T-nut and having a series of parallel, spaced apart shoulders and grooves along its length above said threaded portion, said shoulders and grooves extending circumferentially around said stud, c. a strap clamp for holding a work piece, said strap clamp having a first internal through passage extending substantially along its length, said through passage having an enlarged portion in one section to freely pass over said stud and adjacent said enlarged portion shoulders and grooves in the wall of said internal through passage, said shoulders and grooves being substantially parallel to the long dimension of said clamp and mating with the shoulders and grooves in said stud with a tolerance such that the clamp can freely slide back and forth along said stud when placed thereover, said strap clamp having a second internal through passage adjacent one end, said second through passage being generally circular in shape but being elongated at two opposite poRtions, the circular portion of said passage being fitted with threads and the elongated portions being non-threaded, and d. a leveling means for use with said strap clamp and providing for universal adjustment of said clamp, said leveling means consisting of a threaded stud having cut down sections extending along its length on both sides corresponding to the threaded portions of said second internal through passage, said cut down sections permitting said post to be freely slid up and down within said second passage in said strap clamp when said cut down sections of said post are adjacent the threaded sections of said second passage in said clamp, and the threads in said post mating with the threads in said passage when said post is turned, the bottom of said stud defining a post fitting into a foundation plate which provides support for said leveling means.

2. The tool as defined in claim 1 wherein the top of the shank of said T-nut contains a knurled extension of a size larger than the width of the T-slot in said table.

4. The tool as defined in claim 1 wherein the strap clamp has a third through passage extending from the end of said clamp opposite said second through passage and communicating with said internal through passage, a pin fitted in said third passage, said pin having a circumferential friction engaging member which provides for holding said pin in said third passage and permits sliding of said pin in and out along said third passage.