US2269381A

US2269381A - Work-holding vise

Info

Publication number: US2269381A
Application number: US372465A
Authority: US
Inventors: Robertson John Watson
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-01-09
Filing date: 1940-12-30
Publication date: 1942-01-06
Anticipated expiration: 1959-01-06

Description

Jam 6 1942 J. W. ROBERTSON 2,269,381

WORK-HOLDING VI SE WE/V702 JWKOBERTSON Jan. 6, 1942 l J. w. ROBERTSON 2,269,381

WORK-HOLDING vIsE v Jan. 6, 1942 J. WROBERTSON WORK-HOLDING vIs'E 4 sheets-sheet 5 Lik* Filed Dec. 30, 1940 vAftrap/viens Jan. 6; 1942 J. w. ROBERTSON 2,269,381

` WORK-HOLDING vIsE Filed Dec. so, 1940" 4 sheets-sheet 4 l .1w/@Ww Waning,

Patented Jan. 6, 1942 AUNITED Isifn'lflsslearnNr OFFICE `Worm-Honnlncf vIsE John Watson Robertson. London, England ApplicationDecemhen 30, 19.40. Serial No. 372,465 In Great Britain January 9, 1940 7 claims. del. 812-36) This invention relates'y to Workholding. visesY of the kind in which the screw co-operates witha half-nut capable of being moved into and ont. of

engagement withvthe screw by means` of a.. cam v or other device operating to displace the halfnut positively in both directions. The invention provides improved means wherebyk theA half-nut isy actuated as a consequence of the rotation of the screw.

According to this invention an additional screwthread is formedV on a partr of theI screw spindle which is normally unthreaded and this additional screwthread co-operates with a nut which is operatively connected to the half-nutso that rotation of the screw spindle causes the nut to move lengthwise of the spindle tov engage or disengage the half-nut according to the direction of rotation of the spindle.

Preferably, the device whichactuates. the halfnut consists of a cam movable lengthwisey ofthe screw spindle and directly connected to the nut so that the cam is pushed by the nut. in one direction or the'other according to the direction of rotation of the spindle.

Referring to they accompanying drawings, Figure 1 is a vertical sectional View of one'embodiment of the invention,

Figure 2 is a view similar to Figure l showing the parts in a different position.

Figure 3 is a horizontal sectional view on; line III-III in'Figure 1,

Figure 4 is a transverse sectional view on, the line IV-IV in Figure 3, and f Figure 5 is a view similar'to Figure 1 showing a modification.

Referring to Figures l to 4, the movable jawv II) ofthe vise has a longitudinal extension I 2 which slides within the body I4 of the vise having the xed jaw I 6 cast integral with it. The screw .y

ends of which are bent as at 26, 2B to constitute t cams, the bent portions sliding in inclined holes the

I

30, 32 respectively in the end walls of the extenc sion I2. Figure 1 shows the half-nut 20 engaged with the screw spindle I8, the

cam bar

24, 26, 28 having been moved to the left, and Figure 2 shows the halinut disengaged from the screw spindle in consequence of the cam bar having been moved to the right.

The normally unthreaded part of the screw spindle IS at the left-hand end as viewed in Figures 1l to 3 isj formed with a multi-start screw-l. thread 34 of lquick pitch, flanked on both` sides by

unthreaded portions

36, 38, the diameter of which is not greater than the core rdiameter of the thread 34. Co-operating with the thread 34 is a nut 40 having a downward extension42engaging` ina slot 44 in the bar 24, the length vof the slot being such as to provide lost motion between the nut 40, and the bar 24. A light coil spring 46 is. interposed betweenthe nut 40 and a shoulder ,48. at' they left of the Unthreaded portion 36 and a similar spring 5.0 is vprovided which abuts against a collar 52'xed to the spindle I8 at the right of the. unthreaded portion 38.`

Assuming that the parts are in the position 'shown in` Figure l with the jaws gripping a workpiece 54, if the screw is turned counterclockwise as seen from the left to loosen the grip of the jaws, the screwthread 34 will engage the ,screwthread within the nut 40, the nut being urged to the right by the spring 46, and will drive the nutY to the, right, the nut of courser being held against rotation by the engagement of the extension 42 in the slot 44. This motion continues until the extension 42` encounters the right-hand endof the slot 4,4. whereupon the bar will be pushed to the right. and owing to the slopeof Athe cam,

portions

26, 28 the bar will move downwards as well as to the right, thereby disengaging the half-nul'l 20.4from the screw spindle I8 as-shown in Figure 2.

Normally the operator would cease turning the screw after thisv has happened because he can then moye the movable jaw to any position mere,-y ly by sliding itin or out. If, however,v he should continue to turn the screw the nut 40. will move still further to the right until it is clear of the screwthread 34. and rides freely upon the` unthreaded portion 38 of the spindle. Thus, it is impossible for the parts to be jammed or damaged by unnecessary turnlng of the screw spindle v in the counterclockwise direction.

It will be appreciated 4that when the spindle is turned in the clockwise direction the converse will take place; the nut, being urged to the left by the spring 50, will at once engage the screwthread 34 and will be driven to the left thereby pushing the bar 24 to the left and re-engaging the half-nut 20 with the screw spindle I8. Here again, owing to the fact that the nut 40 has moved clear of the screwthread 34 and rides freely upon the unthreaded portion 36, the screw spindle can be turned further to tighten the jaws upon the workpiece without having any further effect upon the nut 4B or the bar 24, while at the ment with the screw spindle I8, and to the left y to disengage it.

It may be desired to put the disengaging mechanism out of action so that the half-nut 20 is always in engagement with the screw spindle I8."

For this purpose a slide 56 is provided which ,is

guided in slots 58 in the sides of the extension I2`Y and is formed with a hook 60 which engages with the extension 42 of theI nut 4l) when the slide in moved to the right as seen in Figure 4. This hook then maintains the nut 40 out of engagement with the screwthread 34 and also prevents the bar 24 from moving to the right. Thus', the half-nut 20 remains in engagement with the screw spindle I8.

I claim:

l. The combination with a work-holding vise having a half-nut mounted in guides to move into or out of engagement with the screw spindle, of means for automatically engaging Vor disengaging the half-nut as a consequence of the rotation of the screw spindle comprising an additional screwthread formed on a part of the screw spindle which is normally unthreaded, a nut cooperating with said additional screwthread and an operative connection between the said nut and the said half-nut.

2. The combination with a work-holding vise having a half-nut mounted in guides to move into or out of engagement with the screw spindle, of means for automatically engaging or disengaging the half-nut as a consequence of the rotation of the screw spindle comprising an additional screwthread formed on a part of the screw spindle which is normally unthreaded, a nut co-operating with said additional screwthread and an operative connection between the said nut and the said half-nut, a portion of the spindle adjacent said additional screwthread being left unthreaded and of a diameter not greater than the core diameter of the threaded portion, to receive the nut after the screw spindle has been rotated by a certain amount in the tightening direction, whereby further rotation oi the spindle in that direction has no further action on the nut.

3. The combination with a work-holding vise having a half-nut mounted in guides to move into or out of engagement with the screw spindle, of means for automatically engaging or disengaging the half-nut as a consequence of rotation of the screw spindle comprising an additional screwthread formed on a part of the screw spindle which is normally unthreaded, said spindle having an unthreaded portion adjacent the ed to be slightly compressed by the nut after it has become disengaged from the additional screwthread. '4. The combination with a work-holding vise l.having a half-nut mounted in guides to move vinto or .out ofl engagement with the screw spindle, of means for automatically engaging or disengaging the half-nut as a consequence of the rotation of the screw spindle comprising an additional screwthread formed on a part of the screw spindle which is normally unthreaded, a nut cooperating with said additional screwthread and an operative connection between the said nut and the said half-nut, portions of the spindle adjacent said additional screwthread at either end thereof being left unthreaded and of a diameter not greater than the core diameter of the threaded portion, to receive the nut after the screw spindle has been rotated by a certain amount in either direction, whereby further rotation of the spindle has no further action on the nut.

5. A work-holding vise according to claim 4 wherein two coil springs, one on each of the unthreaded portions of the screw spindle, are adapted to be slightly compressed by the nut after it has become disengaged from the additional screwthread at either end.

6. The combination with a work-holding vise having a half-nut mounted in guides to move into and out of engagement with the screw spindle, of a cam device movable in a direction lengthwise of the screw and adapted to displace the half-nut positively in both directions, and means for automatically engaging or disengaging the half-nut asa consequence of the rotation of the screw spindle comprising an additional screwthread formed on a part of the screw spindle which is normally unthreaded, a nut (3o-operating with said additional screwthread and an operative connection between the said nut and the said cam device.

7. A work-holding vise according to claim 6, wherein the cam device comprises a bar having a straight middle portion parallel to the screw spindle and extending through a bore in the halfnut and having end portions bent to form cams sliding in inclined apertures in the movable part of the vise.

JOHN WATSON ROBERTSON.