US2639744A - Adjustable cam actuated hold-down clamp - Google Patents

Description

May 26, 1953 w. B. HERBERT ADJUSTABLE CAM ACTUATED HOLD-DOWN CLAMP 2 Sheets-Sheet 1 Filed March 7, 195

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ADJUSTABLE CAM ACTUATED HOLD-DOWN CLAMP Filed March 7, 1951 2 Sheets-Sheet 2 INVENTOR He rZ'arZ' LBY ATTORNEY5 Patented May 26, 1953 UNITED STATE PATENT OFFICE William B. Herbert, Ridgewood, N. J. i

Application March 7, 1951, Serial No.-214,395

Thisinvention relates to jig nuts and is an improvement over the construction embodied in my prior Patent 2,464,133, issued March 8, 1949, for Jig Nuts.

An object of this invention is to provide a jig nut construction embodying a pressure or clamping body with adjustable means whereby the clamping body may be placed under suitable clamping pressure to hold a work piece on a table or other suitable surface.

Another object of this invention is to provide a device of this kind which is so constructed and arranged that the degree of pressure to be applied to the work may be closely adjusted so that the same clamping pressure may be applied to similar work pieces as where mass production is being performed.

A further object of this invention is to provide a device of this kind which is simple in construction and canbe applied to machine tool beds or other surfaces without changing the construction of the tool bed or surface.

A further object of this invention is to provide a device of this kind wherein the clamping body is formed with a socket or recess within which a pressure regulating washer engages, the socket holding the washer against shifting action caused by application of pressure to the work.

With the above and other objects in view, my invention consists in the arrangement, combination and details of construction disclosed in the drawings and specification, and then more particularly pointed out in the appended claims.

In the drawings,

Figure 1 is a detailed side elevation, partly broken away and in section, of a jig nut constructed according to an embodiment of this invention, showing the device in released position,

Figure 2 is a fragmentary sectional view taken on the line 22 of Figure 1,

Figure 3 is a fragmentary sectional view taken on the line 33 of Figure 2,

Figure 4 is a fragmentary sectiona1 view taken on the line 4-4 of Figure 1,

Figure 5 is a fragmentary sectional view taken on the line 5-5 of either Figure 1 or Figure 4,

Figure 6 is a fragmentary sectional view taken on the line 6-6 of Figure 4,

Figure 7 is a fragmentary sectional view similar to Figure 3, but showing the device in clamping or operative position,

Figure 8 is a fragmentary sectional view of a modified form of this invention.

Referring to the drawings, the numeral I0 designates generally a machine tool bed which 2 Claiins.- (01. 144-290) has mounted on the upper side thereof a Work piece I I. .The bed I0 in the present instance is formed with an inverted T.-shaped slot I3. The slotI 3 has disposed thereina headedupstan-ding bolt I2, and a second bolt I4 is threaded into the bed or table IO'and is provided withan upper head'I5,

A clamping body lii engages on the upper end of the bolt I5 and bears at. the opposite end against the upper side of the work piece II. The clamping body I6 is formed with an opening I! through which the bolt I2 loosely engages, and a nut I8 is threaded on the bolt I2 and provides a means for initially exerting clamping pressure on the clamping body I6. V t

The upper side'of the body I6 is formed with a recess 0r socket I9 within which a washer 20 is adapted to loosely engage. A pair of cam studs 2| are rotatablymounted in openings 22 formed in the body I6, and the studs 2| are disposed in alignment and are's'ecured to a lever 23. openings 22 communicate with the socket I9 and each cam stud 2| is formed with a fiat side 24 which is adapted to be disposed flush with the bottom of the socket I9 when the studs 2| are in released position.

In order to provide a means whereby the washer 20 may be adjusted Within the socket I9 so that a selected clamping pressure may be applied to the clamping body I6, I have provided a pair of washer adjusting pins 25 which are disposed in sockets 26 formed in the body It and communicate with the socket I9. The pins 25 are constantly urged upwardly by means of springs 21, and the pins 25 are locked in adjusted position by means of set screws 28 which are threaded into the body I6. When the maximum clamping pressure is to be applied to the body It, the upper ends of the pins 25 will be disposed flush with the bottom of the socket I9. In Figure 5 the pins 25 are disclosed in upwardly adjusted position so as to thereby hold the ring 20 above the bottom of the socket I9.

Referring now to Figure 8, the Washer or ring 20a is adjusted within the socket I9a by means of one or more set screws 29 which are threaded vertically through the clamping bar I6.

In the use and operation of this device the headed bolt I2 is inserted in the T-slot I3 and the outer end of the body I6 is engaged on the fulcrum bolt I5. The inner end of the body I6 engages the upper side of the work piece II and the nut I8 is threaded downwardly on the bolt I2. The initial adjustment of the nut I8 may be made by the hand of the operator and at this The time the lever 23 will be disposed in a vertical released position so that the flat sides 24 of the cam members 2| will be flush with the bottom of the socket [9. After initial hand adjustment of the nut l8, lever 23 may then be swung downwardly to a substantially horizontal position, thereby increasing the clamping pressure on body I6. In the event it is desired to place the work under less than maximum clampingypressure, the Washer orring lii imay-lbe raised upwardly in the socket l9 by loosening the set screws 28 so that the spring-pressed pins 25 may move upwardly for the desired distance. When the Pin 25 project upwardly into the socket 19, "the cam studs or members 2| will apply a pressure to the body [6 which is less than the maximumnclampr ing pressure.

I do not mean to confine myself to th-eexact details of construction herein disclosed -but claim all variations falling within the purview of the appended claims.

What I claim is:

1. A work c'lampingmeans comprising a, tool bed having a T-slot thereinla clamping body for engaging a workpiece on said tool fbed,' said.b.ody having a vertical bore .between'the ends thereof saidbore terminating "in an enlarged socket opening in the uppersurface of said .clampingbody, an upright bolt looselylengaging through said bore, ahead on said bolt ,len-gaged in saidT-slot, a nut threaded on said bo'lt'for adjusting said clamping body relative to said workpiece, a washer interposed between said nut and said bodyfand locatedwithin-each socket, a pair of aligned substantially cylindrical scam members rotatably carried :by said-body and le ctending inwardly into saidbore just below the ,bottommf d 9k 3 am fill lb l' ha g a-fla ifl adapted to be disposed uppermostand con'frontins sa Washer whe said an em e s. ar i released .position, a lever-fixed to saidcam meme bers, and spring biased pin means carried by said body for adjusting said washer relative to said cam members.

2. A work clamping means comprising a tool bed having a T-slot therein a clamping body for engaging a. work piece on said tool bed, said body having a vertical bore between the ends thereof, said bore terminating in an enlarged socket opening I in the aupper 'surfacegofgsaid clamping body,

an upright boltfllooselyeengaging through said bore, a head on said bolt engaged in said T-slot,

-;-a,.nut threaded on said bolt for adjusting said clamping body relative to said workpiece, a washer interposed between said nut and said body and located within each socket, a pair of aligned substantially cylindrical cam members rotatably carried by said body and extending inwardly into said bore just below the bottom of said socket, each cam member having a flat face adapted to be disposed uppermost and confrontingsaid washer whensaid cam'membersare i n released ,position, a 'lever fixed lto saidscam members, atleast one spring pressed washer 3 d? justing pin slidably carried'by said bodyfinconfronting position with respect to said washer, and threaded locking means carried by saidbody for locking said pin in adjusted position.

WILLIAM B. vI-IERIBER'I'.

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