US2428111A - Work clamping unit - Google Patents

Description

Spt.`30,`1947. N. ELDRUPI 2,428,111

WORK CLAMPING UNIT Filed May 5, 194s 1NVENToR Patented Sept. 30, `1947 2,428,1111' f WORK CLAMINQUNIfT f NielsiEldrupg'Chicago, Ill. j^l a Application May 5, 19u-,serial No. 485.699

(CL en -59) i '4, v 2 `Claims.

f The principal object of this'inventionis to provide an .improved'work clamping-'unit forvAuse in connection with drill presses, x'n'illirlg machines, and the like. i The-devices heretofore `employed forthis purpose vhave ordinarily consisted of a flat metal strap which is slotted near its front end to receive a boltl and is fulcrumed at its rear end on a --wooden block of the proper height. While such an arrangement provides an eiective clamp it usually takes quite a bit of time to set up because unless a block of the proper height happens to be at hand material for one must iirst be located and then cut to size. Furthermore, a loose block is somewhat difcult to handle because it must be held in correct position with respect to both the strap and the work until after the bolt has been at least partially tightened.

Many special clamping devices have been suggested for the purpose of overcoming these dimculties--as evidenced by numerous prior patents-but very few have been found sufficiently satisfactory to warrant their continued use, either because of the complicated nature of their construction or the fact that when set up they tend in some measure to obstruct the work. As a result of this the practice has been conned almost entirely to the use of makeshift blocks.

The new work clamping unit is extremely simple and inexpensive in construction, is assembled from graduated parts into a temporarily unified arrangement, can be assembled in but a moments time, will t any size work and will hold the work .securely with minimum obstruction to the same.

While the foregoing statements are indicative in a general way of the nature of the invention, other more specic objects and advantages will be apparent to those skilled in the art upon a full understanding of the new unit.

A preferred embodiment of the invention is presented herein for the purpose of exemplication, but it will of course be appreciated that the invention is capable of being incorporated in other structurally modified forms coming equally within the scope of the appended claims.

In the accompanying drawing:

Fig. 1 is a fragmentary perspective view of the bed of a machine, showing a piece of work clamped to the bed by a, pair of the units;

Fig. 2 is a perspective view of one of the units;

Fig. 3 is a vertical section through the unit;

Fig. 4 is a perspective view of the upright block which forms one part of the unit;

Fig. 5 is a bottom planview of the horizontal Astrap which forms the complementary part ofthe unitjandl 1 f Fig. 6 shows several graduated sets of blocks. C f The work clamping unitshownin the drawing is 'a two-piece L-shaped assembly consisting ofa horizontal strap I0 and an upright block II. The strap IIl is made of metal and is provided intermediate its ends with a longitudinally extending slot I2 for the reception of the upper end of a bolt I3. The under side of the front end I4 of the strap serves as a clamping jaw for engagement with the work I5, while the under side of the rear end I6 of the strap is provided with a transversely extending dovetail groove I1 for temporarily interlocked association with the upper end of the upright block II. The block IIl like the strap Il), is made of metal and is provided at its upper end I8 with a. dovetail rib I9 for edgewise insertion in the groove I1. The lower end 2U of the block is provided with a convex bearing edge 2I parallel to the rib I9. A spring projected indexing ball 22 is mounted in the bottom of the groove I1 intermediate the ends of the latter for resiliently yieldable engagement within an indentation 23 in the top of the rib I9.

In securing the work I5 to the bed 24 of the drill press or other machine tool two or more of the clamping units are ordinarily used. Straps I0 and blocks II of the required lengths are selected from a graduated assortment of such parts. The ribs I9 on the blocks are slid edgewise into the grooves Il in the straps, producing temporarily unified L-shaped clamps. After the clamps have been assembled they are placed properly with respect to the work and bolts I3 of the required length are passed through the slots I2 in the straps into holes 25 in the bed and tightened 11p.

Instead of employing a graduated assortment By employing a work clamping unit of the above described construction, both parts of the junit are firmly held together while the Work is being clamped in place. Either of the parts can be instantaneously replaced by parts of larger or smaller size, whereby to provide a clamp of any desired character. In the use of the unit the ilat design of the top of the same, with the block l set in under the rear end of the strap i0, leaves the work practically free from obstruction by the clamp, enabling the operator to get at the Work from al1 directions without diculty.

I claim:

1. A work clamping unit for use in connection with machine tools of the type having a bolt receiving bed against which a piece of Work is adapted i0 be clnmpedfomprisieg :i horizontal at topped-strap :which is provideii intermediate its ends with a longitudinally extending bolt refceiving slot and is provided on the under sur- 4` face of its rear end with a transverse doyetal groove and a resiliently projected indexingmember Within said groove, and an upright @ook which is provided at its upper .end 'withv a dove-v tail rib for insertion in said groove and-anilmdentation intermediate the ends of the ribfiorftk'ie reception of said indexing member.

.e werk demping .unit for use.ir1..e0eeeeti9i1 with machine 'tools `ofthe typeY havingallqlt gremii/ ing` leed against .which e piece .of work "1S adapted ltobe Qiarnped "comprising "a'jliorizgntal a oppe ra 'hi'ch'is r'ovidediinterniediate io euettosaidrib.

NIELS 'ELDRUR REFERENCES CITED u `VIV1`h'eiol1owing references are of record in the Number STATES PATENTS

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