US2299294A

US2299294A - Work holding device

Info

Publication number: US2299294A
Application number: US305587A
Authority: US
Inventors: Barnes Edwin
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-11-22
Filing date: 1939-11-22
Publication date: 1942-10-20
Anticipated expiration: 1959-10-20

Description

Get. 20, 1942.

E. BARNES WORK HOLDING DEVICE Filed NOV. 22, 1939 fnwcntor j Gum-neg Patented Oct. 20, 1942 UNITED STATES PATENT OFFICE WORK HOLDING DEVICE Edwin Barnes, Marshall, Tex.

Application November 22, 1939, Serial No. 305,587

3 Claims.

My invention relates generally to clamping devices, and more particularly to a clamping device for holding several pieces of work at the same time.

An object of my invention is to provide a clamp for clamping a single piece of work, or several pieces of work, in line upon the bed of a planing mill or similar machine.

Other objects and advantages of my invention will become apparent from a reading of the detailed description of the invention in connection with the drawing illustrating a preferred form of my invention.

In the drawing:

Fig. 1 is an elevation view of my work holding device showing a number of pieces of work held clamped in line with one another and clamped down on the bed of a machine.

Fig. 2 is an enlarged perspective view showing more details of the center clamping member of my work holding device in holding position.

Fig. 3 is an end elevation view of the center clamp member.

Fig. 4 is a side elevation view of the center clamp member, and

Fig. 5 is an enlarged broken perspective view of an end clamping member of my work holding device.

In the drawing B designates the work bed of a machine carrying my work holding device. The

letter W designates pieces of work held by my work holding device. The spacing strips designated by letter S serve to hold the work off the base of the working plate of the machine. While these spacing strips S cooperate with my work holding device, they are not to be considered as an essential part of the combination of elements making up my work holding device. The special function of the strips S is to elevate the work such as an unlevel casting or the like, above the working surface of the machine to prevent any tendency of the casting, or the like, from rocking after it is clamped.

The end clamp I consists in a rectangular steel slab which is provided with longitudinal biting edges along one of its longest faces.

The end clamp I is urged up against the work W by means of a screw and pressure bar combination comprising a set screw 2 threaded through a pressure bar 3 to contact the clamp I. The pressure bar is prevented from backing up due to the reaction of the screw 2 on the clamp I by means of the spacer pins 4 shown in Fig. 1

mounted in a pair of spacer pin holes 5 shown 55 by the dotted lines through the base B of the machine.

The center clamps designated generally by numeral 6 are provided with long biting edges I on both of their longer sides so that they bite into opposing pieces of work when pressure is applied to the end clamps I.

The center clamps 6 are slidably held to the base B of the machine by means of flat headed clamping bolts 8 whose heads 9 slide in T shaped grooves in the bed B below its working surface.

The vertical position of the center clamp is controlled by the clamping nuts II] on the clamping bolts 8. The center clamp is provided with a recess II into which the nut I0 fits. This recess is important in that it prevents the nuts from extending above the clamp 6 itself to interfere with the cutting of the work W. When very thin work is being handled the upper face of the clamp sometimes must be set close to the face of the work being out.

My invention, broadly speaking, is the combination of two end clamps and one or more center clamps slidably mounted in a machines work bed B on a line connecting the end clamps. The work W, held in my work holding device, may be machined on its upper face and both side faces with one setting. The number of pieces of work to be machined is limited only by the length and width of the bed B of the machine and the number of tool heads or milling cutters employed. Fig. 1 of the drawing illustrates a set up of three pieces of work W being held by the use of two center clamps 6. Obviously additional center clamps would be used if more than the three pieces of work W were set up.

In practice, the work is placed over the longitudinal slots of the bed of the machine with center clamps 6 in place between the pieces of work W. Suitable parallel strips S are used to elevate the work W to provide clearance. At; each extremity of the series of pieces of work W there is placed an end clamp I backed up by a: pressure bar 4, set screw 2, and spacer pins 4, as described above for the purpose of tightening the work W. While my Work holding device would operate with a single pressure applying device of the style described above, or some other type of pressure applying device, the use of the two pressure applying devices have been found to be of advantage. I have illustrated my invention showing the use of the two pressure applying devices, but it must be understood that I am not limiting my invention to the style shown employing two pressure applying devices.

Usually when a series of pieces of work are clamped in line with one another, using my work holding device, the pieces of work W buckle slightly. This buckling may be deliberately brought about if desired when extreme pressure on the work W is needed. After the end pressure has been applied on the series of end and center clamp and pieces of work W, the center clamp 6 may be pulled down to the bed B of the machine by means of the bolts 8 and the nuts II]. This movement of the center clamps takes out all of the slack in the assembled work W and causes the biting edges on the clamp to bite still further into work W. This extreme clamping pressure is peculiar to my invention. As

ing threaded engagement with the said pressure bars and having contact with the said work far as applicant is aware of it, such high pressure cannot be obtained by any of the prior artwork holding means.

of construction or arrangement of parts'making up my work holding device as herein illustrated and described, for it is apparent that various changes in size and arrangement of parts maybe resorted to without departing from my invention.

My clamping device may be constructed out of hard steel or other suitable materials.

Having thus described my invention, I claim:

1. A work holder of the class described comprising a pair of opposing longitudinally adjustable pressure applying end clamps, each of said end clamps being provided with an anchoring means for anchoring the same to a machine bed or the like, said anchoring means including a pressure bar which extends across a pair of spacer pins extended up from the machine bed each of said end clamps being provided' with clamping jaws including horizontally extending knife edges adapted to bite into a piece of work, and a work separating and holding clamp provided with a vertically adjustable attaching means for attaching it to a machine bed or the like, said attaching means comprising a clamping bolt including a head adapted to slide in a T slot in a machine bed, said separating and holding clamp being positioned in line with and between the said end clamps and being provided with parallel faces each of which is provided with knife edges adapted to bite into pieces of work.

2. A work holder of the class described comprising a pair of opposing longitudinally adjustclamping jaws and a work separating and hold- 7 ing clamp provided with a vertically adjustable attaching means for attaching it to a machine bed or the like, said attaching means including a clamping bolt having a head which is adapted to slide in a T slot in a machine bed or the like, said separating and holding clamp being positioned in line with and between the said end clamps, said separating clamp being provided with parallel jaws each of which is provided'with horizontally extending knife edges adapted to bite into pieces of work.

3. A work holder of the class described comprising a longitudinally'adjustable pressure applying end clamp, an anchoring means for anchoring the adjustable end clamp to a machine bed, said anchoring means including a bar suspended across a pair of anchoring pins extending up from the machine bed, the saidend clamp including a jaw provided with longitudinally extending knife edges adapted to bite'into a piece of work, a separating clamp including a pair of parallel work engaging faces, each of which is provided with a series of longitudinally extending knife edges adapted to bite into pieces of work separated by the said separating clamp, a vertically adjustable fastening means for holding the said separating clamp to the machine bed or the like and an end clamp provided with a work contacting face provided with a series of parallel horizontally extending knife edges adapted to bite into a piece of work, said end clamp being provided with an anchoring means for anchoring it to the machine bed, or the like.

EDWIN BARNES.