US1639561A - Clamp - Google Patents

Description

Aug. 16,1927. Y 39,56l

. J. M. HARGRAVE CLAMP Filed A112. 9. 1926 mnnfoz damn.

Patented Aug. 16, 1927.

UNITED STATES JOHN M. HARGRAVE, 0F" cm'ci'NNArI, OHIO.

CLAMP.

Application filed August 9, 1926.- Sam No. 129,302.

This invention relates to a type of clamps known as joiners employing a longitudir nal bar having afiXed clamping jaw at one end of the bar and a second jaw slidable upon the bar, and carrying a screw parallel to the bar to cooperate with the stationarybar. The invention: is particularly directed to the mechanism for bindin'gly holding the jaw in its adjusted positionon the bar; Thebinding mechanism comprises serrated facedblocks carried by the movable jaw relatively offset and at opposite sides or edges ofthe bar, to grip the edges of the bar with a slight writing of the. jaw. The block -isrecessed respectively within holders or inserts mounted with the j'aws;

Theretore an object ofthis invention is to 7 provide; in a work: clamping jaw adjustable on: a longitudinal bar, a pair of toothed blocks rockingly mounted and diagonally located'within opposite sides of the bar engaging bore of the adjustable jaw, the blocks adapted to move toward the-bar when: the jaw. is; canrtecli due to its outer end being torceduagai'nst the work and-the' teeth inclined after the manner of: saw teethin the:

direction in which the jawte'nds' to move ber ins-engagement; with thebar so that the aw is normally sustained in any position on thebar but so balanced as to be-easilv mov able: when desired.

Another object isvto provide amounting forzthe 'grippingf elements in the aw bore;

thusflbeing in the nature of blocks secured 1 at each side of the:bore, eachblockgrooved to houseit'hose gripping elements in the same: side ofthe bore namel y a-spl 'ing and a toothed member, and the blocks removable from the: bore of the jaw wi'thou'tremoval of the" jaw fromtheabar, "this-construction beings ofYimporttmcein theLa'ssembly of the:

various small elements which would other wise be extremely difficult-to place in: the jawbore.

Another object is to provide a curved base to the grooves which: contain the toothed membersgso that theseim-embersare allowed to rock thereon and adjust themselves, as the jaw is canted,- for permitting all the teeth of the members to engage the bar with equal effect.

Further objects and certain advantages will be more tully set'forth in the accompanying drawings; forming a part of this specification, in which:

Figure 1 is a sideview of a clamp.

FigureQ, is atop view of the clamp illustrating the relation of the mounting blocks to the bar. I

Figure 3 is an enlarged sectional view taken: on line 3-3 of F igure 2, detailing the arrangement and construction of the variousgrlppin-g elements in the clamp jaw.

Figure 4' isa perspective view of a: mounting block removed from the jaw.

Figure 5' is a perspective view of a toothed element removedfrom the mounting block. 1 7

Referring to the drawings the clamp comprises a longitudinal rectangular bar 1 having a fixed jaw 2 secured at one end and an adjustable jaw 3 slidable longitudinally of th'eba-r inrelation to the fixed jaw; The fixed jaw 2 is riveted to the bar land has it faced portion 4- on the side toward the adjustable jaw and 'aga'ins't which the work is The axljustablejaw 3- carries a screw 5- :threaded through: a projecting end 6 of the jaw 3, the screw being" arallel-with the longitudinalr bar. A- wing shaped handle 7 is provided at one end of the screw and a hat headS is pivoted to the other end of the: screw as a work engaging member. The fiat-head 8: is secured to the screwend by a balland socket-joint so that the headmay adjust itself to anyirregularities in the work when the work is clamped between said head and the lower jaw.

The longitudinal bar I is madein any lengthand lias a rivet 9 in itsoute'rend for preventing the removal of the adjustable clampgjaw.-

The rectangular bore 10 of] the jaw through w'hich the bar" extends is made ofgrea'ter" width than the bar and mounting blocks'l l ar-e secured within this bore at each sidejthereo fl These blocks 1'1 carry the V bar engaging elements,- engaging the oppo-1 'siie'edges of the rectangular bar. ,7

Pinsl2- pass through the jaw and mounting blocks and serve to maintain the blocks in the j aw'bore-whileat the same time they the blocks are permitted to rock.

are easily driven out and the blocks removed for replacing any worn out parts in blocks.

Each mounting block has two crosswise grooves as at 13, let, each serving to house respectively springs 15 and a toothed block 16. The two mounting blocks although formed identical are put in the bore in opposite directions so that the toothed blocks 16 are diagonally related and the springs are positioned in the same way (see Figure The bore of the jaw is of sufficient width that when the mounting blocks are inserted and the bar aligned in the bore there is a slight clearance at each side of the bar between the bar edge and mounting blocks.

A toothed block 16, described in detail, is rectangular and has one side toothed as at 17 after the fashion of saw teeth. Shoulders 18 are formed at each end of the toothed surface and these shoulders are overhung by projections 19 on the outer end edges of the grooves 14 for loosely maintaining the toothed members in the mounting blocks.

The springs used, are formed of fiat metal turned upon itself and as placed in the groove they act outwardly from the base of the groove containing them against the bar edge. The mounting blocks are of the same thickness as the bar and the same is true of the various elements, so that the entire bar edge thickness is engaged.

Bringing the screw down upon the work cants the adjustable jaw slightly and as a result the toothed members may be said to swing in a circle. This action causes the toothed members to be forced against the bar edge with the result that they dig in slightly and thereby positively grip the bar. The gripping action of the toothed members is aided by the outward curvature of the toothed block groove base 20. Due to this bulging curvature being engaged by the flat base of the toothed blocks and to the fact that the blocks are loose in the groove They automatically adjust themselves to the movement of the jaw and all the teeth engage the bar with equal effect. The teeth are inclined-in the direction in which they tend to move on the bar under load so that they bite into the bar.

It is readily apparent that this positive jaw grip produced by the pivotal movement of the toothed blocks in their grooves is important since the tendency of the aw is not only 'to cant under load but to slide down the bar. lVhen the jawis not in clamping service, the springs tend to align the jaw bore in is a spring opposite each'toothed member the jaw is balanced and the toothed members are held against the bar edge sufficiently to hold the jaw in set position. However. the easy movement of the jaw, when not in service, is not interfered with since relation to the bar, and since there.

the spring tension is the factor governing the movement of the jaw and they are made to resist only the movement of the jaw re sulting from its own weight or other light forces. Movement of the jaw is further eased by canting the bar in an opposite direction to the cant created by pressure in the work, this disengaging the toothed members from the bar edge.

The mounting blocks aid in assembly since it is not necessary to remove the-jaw from the bar to replace the various members. The members are placed in the mounting blocks and the unit is then slid into the bore at the side of the bar and the pin set in place. These adjustable jaw features are for use on any style bar and where it is inconvenient or impossible to remove the jaws from the bar due to the shape or position of the bar, the feature of assembly is of especial importance,

In the smaller size clamps it is only necessary to have the gripping elements at one side of the bar, so that only one insert is used, that is, a mounting block carrying a toothed block and spring. Also it is to be noted that the invention relates to the features for positively engaging the jaw on the bar so that it is of no importance whether the jaw moves in relation to a fixed jaw or another adjustable jaw. 7

Having described my invention, I claim:

1. In a clamp, a longitudinal bar, an adjustable work engaging jaw having an aperture therein through which said bar extends, mounting blocks secured in said aperture at opposite edges of said bar, toothed elements and springs mounted in recesses formed by grooves in said blocks and the side walls of the jaw, the toothed elements diagonally located so as to gri the bar when the jaw is canted due to pressure against the work andv the springs located opposite each toothed member so as to normally maintain the teeth. against the bar when the jaw is in set position and not engaging the work.

2. In a clamp, a longitudinal bar, an adjustable work engaging jaw having an aperture therein through which said bar loosely extends, toothed members and springs, mounting blocks carrying said toothed members and springs. in respective grooves, each block with its variouselemen'tsbeing identical in, structurev but secured within the aperture at each edge. of the bar in reverse manner so that the toothed members are diagonally related, and a spring opposite each toothedv member for normally" maintaining the teeth against the bar edge.

3. In combinationwitha longitudinal bar and an adjustable jaw a'pertured to receive secured within the aperture at one edge of.

the bar a toothed member loosely seated in said mounting block and having its teeth disposed against the .bar edge, a spring mounted within the mounting block and normally maintaining the toothed member in engagement with the bar, and said teeth so positioned as to be positively enga ed against the bar when the jaw is canted ue to pressure at its outer or work engaging end.

4. In a clamp, a longitudinal .bar, an adjustable jaw apertured to receive said bar and slidable thereon, mounting blocks secured within the aperture at opposite edges of the bar, toothed members loosely seated in slots in said mounting block at each edge of said bar, the base of said slots being out wardly curved to allow the toothed members to pivot thereon whereby all the teeth of r the members positively engage the bar edge when the jaw is canted due to pressure against the work.

within each mounting block and diagonally related, whereby when thej aw is canted due to work engaging pressures on its outer end the friction elements are drawn against and grip the respective bar edges.

In witness whereof, I hereunto subscribe my name.

JOHN M. HARGRAVE.

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