US 401553 A
Description (OCR text may contain errors)
B. P. GODFREY.
WOOD WORKING CLAMP.
No. 401,553. Patented Apr. '16, 1889.
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ERNEST F. GODFREY, OF SOUTHINGTON, CONNECTICUT.
SPECIFICATION forming part of Letters Patent No. 401,553, dated April 16, 1889.
Application filed August 15, 1888- Serial No. 282,766. (No model.) i
To all whom itmag concern.-
Be it known that I, ERNEST F. GODFREY, a citizen of the United States, residing at Southington, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in WVood Working Clamps; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.
This invention has relation to improvements in wood-workers clamps,which maybe better known as beam-clamps.
' An important desideratum in this class of devices has been to provide a cheap and durable means for securing the movable clamping jaw or arm on the beam at any desired point without the employment of the objectionable keys or shoes which have been interposed between the sliding yoke and the beam. This object is accomplished by the device illustrated in the accompanying drawings, in which-- Figure 1 is a side elevation, partly in section and partly broken away, of awood-workers clamp constructed according to my improvements. Fig. 2 is a side view of the clamping arm or jaw removed from its slide or yoke, and Fig. 3 is an edge view of the slide or yoke removed from the beam.
Referring by letter to the said drawings, A indicates the beam, which may be of any or dinary or approved construction, having the plain upper and lower longitudinal sides and provided at one end with a vertical arm, a, which latter is provided with an internallythreaded aperture, 1), to receive the usual clamping-screw, B.
C indicates a sliding yoke or frame, which has its upwardly-directed arms (I perforated near their upper ends for the purpose of receiving a pivot rod or pin which passes through a pivoted clamping arm or jaw, which will be presently explained. This clamping arm or jaw D is of a peculiar construction, and is of a height about equal to that of the fixed arm a on the beam. lhis arm or jaw D is perforated, as shown at e, for the reception of the pivotpin g, whereby the said jaw or arm may be pivoted to the sliding ypke or frame C. The
said jaw or arm has its lower end out straight for the greater portion of its width, as shown at 7L, and its forward lower end rounded, as shown at It will thus be seen that the said arm may be allowed a forward movement upon the beam, but will be prevented from any backward movement when the stock is held, and that the greater the strain that is brought upon the upper end of this jaw in the act of clamping the stock the firmer the engagement will be between the lower end and the upper side of the beam. To this feature of construction I attach considerable importance, and I also attach importance to the fact that such means as screws and the like for fastening the sliding frame or yoke or the movable jaw to the beam have been dispensed with.
I have found by experience that by forming the lower end of the pivoted jaw in the manner shown and pivoting it to the yoke when the said arm approximates a position at right angles to the beam the frictional contact caused by the stock being clamped will be sufficiently great between the lower end of the said jaw and the upper side of the beam to prevent any liability of slipping.
By reference to Fig. 1 of the drawings itwill be observed that the inner side of the transverse portion 5 of the yoke or sliding frame is inclined forwardly, the object of which is to allow the said frame a slight rocking movement upon the beam A. It will be seen from this construction that when the said yoke has been pushed squarely up against the under side of the beam it, together with the jaw, may be slid along the beam after the pressure has been released from the jaw C.
The movable jaw or arm is provided at its upper end with the usual pivoted bearingdisk, F, so that it may clamp stock of any form.
I am aware of the English Patent No.1,246 of 1862, in which a sliding jaw is employed on a bar and carries a clamping-screw, the jaw being made of a single piece. I am also aware of German Patent No. 18,833, of 1882, in which a bar is provided with a rectangular arm at one end and ayoke employed with a pivoted arm in which a clamping-screw is arranged, and is more particularly adapted for clamping articles in a parallel position.
I attach importance to the fact that the yoke or clamping-arm pivoted thereto is allowed a rocking bearing on the bar, and thatI have a bearing-disk, F, pivoted to the upper end of the sliding arm instead of a threaded bearing or a clamping-screw.
It will be observed by reference to Fig. 1 of the drawings that the flat portion h of the foot of the jaw D presents an extended gripping portion, which, when a backward pressure on the upper arm of said jaw is eX- erted, will firmly bear upon the upper plain edge of the bar A. At the same time the lower edge of this bar is caught and rigidly held by the bite of the angle 8' of the transverse upper beveled portion 8 of the yokeframe 0. By this construction it will be seen that there is a downward force and an upward force, both forces co-operatin g to firmly clamp the jaw D to the bar A, the same being efiected without the interposition of supplemental wedges or the like. The jaw D is, in fact, a
1 gripping eccentric, while the yoke O, with its beveled transverse portion 3, operates as a pawl.
Having described my invention, what I claim is- 1. The combination, in a wood working clamp having a straight smootl1-edged bar, A, terminating on one end in an arm having a clamping-screw, of the yoke 0, provided with parallel arms (1 cl, and a transverse connecting portion beveled to afford a biting angle, 8, and a pivotal jaw, D,provided at its lower end with a front rounded portion and a rear flat gripping portion, substantially as specified.
2. The combination, with the bar A, having an arm at one end provided with a clampingscrew, of an adjustable arm consisting of the yoke 0, having an acute angular biting portion,
' 8, formed on it, and a grippingjaw pivoted to said yoke and adapted to'impinge directly upon the upper edge of said bar A, as specified.
In testimony whereof I affix my signature in presence of two witnesses.
ERNEST F. GODFREY.
EDWIN G. LEWIS, A. C. ROBBINS.