US1382793A - Machine-tool fixture - Google Patents

Description

'E. C) LEWIS. MACHINE TooL FIXTURE.

AfPLlATION FILED DEC. 22, 1919.'

Patented im 2s, 1921.

E. C. LEWISl MACHINE TOOL FIXTURE'. A-PPUCATION EILED D'ECLZ'Z. 1919.

.Patented June 28, 1921.

2 swans-SHEET 2.

"Providence, in the county of etres eruit orifice.

EVERETT C. LEW'IS, 0F PROVL'DENCE, RHODE ISLAND.

Application led December 22. 1919.

To all iii/0m :it may concern:

.lie it known that l, Evnnn'rr C. LEWIS, a citizen oi the United States, residing at Providence, State ot Rhode lsland, have invented certain new and useful linprovements in Machine-Tool Fixtures, of which the following is a specilication.

My invention is an improved fixture for holding worlr to be operated upon in milling machines, grinding machines 01 other niachine-tools.

@ne object of my improvement is to provide a i .ture which will hold the worlr with greater iirniness and rigidity to resist the thrust ot the tool acting against it.

another object of the improvement is to provide for greater facility and convenience in applying the work to the fixture and for a quicker action in clamping the jaws of the lixture against the work.

A further object ot the improvement is to render the lixture more easily and quickly adjustable for pieces of work of varying sizes and shapes.

.another object of the improvement is to provide a iixture of more rugged and stanch striflcturc, capable of resisting strain and wear on its operating parts and having greater durability under hard usage.

Still further objects of the improvement will appear from the following specification comprising a detailed description of one embodiinent et the invention as illustrated by lthc accompanying drawings, in which like reference characters designate like parts. ln the drawings:

Figure l is a plan view ot my improved fixture;v

Fig. 2, a longitudinal, sectional elevation ot the device, taken in a median plane on the line iii-nl.. of Fig. l;

lfig. 3, a detailed View of a portion oi the device in cross-section, taken on the line lil B of Fig. 2;

Fig. it, an elevation of the forward end of he device;

YWig. 5, a side elevation of the device showing a modification in the arri' ngement oi its movable jaw-member which adapts it for liol ng tapered pieces; and

`G, an end view ot' this type et device.

lle'lierring to the dra-wings, 2 designates the main frame or base of the iixture which constructed with a relatively broad T- head il at its `forward end, and a narrower Specification of Letters Eatent.

Patented June 28, 151,21.

Serial No. 346.530.

tail-piece l extending rearwardly therefrom. Reaching out from thesides of the base 2 at the rear of its head 3 are ears 5, see Figs. 1 and 4l, to which are attached tongues 6 for locating the xture on the table T ot the milling-machine or other tool with which it is used. The tongues 6 may consist of cylindrical plugs set into counterbores 7 on the under side oi" the ears 5 and secured in place by screws 8. The tongues 6 are adapted to enter a T-slot t on the top of the table T, see lFigs. l and Ll, to hold the ixture square therewith. The tongues may also be inserted in other counterbores 9 at the forward and rearward ends of the base 2, see Fig. 2, to adapt the fixture to be set parallel with the slot t in the table T. it the center of the base 2 is a fastening-bolt 11 having a head 12 at its lower end adapted to underlie the sides of the T-slot t in the table T, as shown in Figs. 1 and 2. The bolt l1 carries a nut 13 at its upper end arranged in a cut-out recess 1iin the base 2, so that `it may be turned by a wrench to draw the head 12 of the bolt against the overhanging sides of the slot t to clamp the ixture down against the table T.

The top of the base 2 is formed with a rectangular slot 15 extending throughout its length, longitudinally of the tail-piece 4l. Fitted to slide in the slot 15 is a square bar 16 which serves as a. movable support for the outer jawcarrying member 17 of the fixture. A cap i8, conforming to outline of the base 2, .is litted its top across the slot 15 to hold lthe bar 16 in place therein, the cap being secured to the base by screws i9 and dowel-pins 20. i-ibutting the torward end ot the cap 18 is the fixed jaw 21 which is secured thereto by screws 22 reaching through from the rear. rllhe movable jaw support 17, before mentioned, is iitted to a stud 23 projecting from the forward end of the sliding bar 16 and is formed with lugs or ribs 24 abutting the sides of the square end of the bar to prevent it from turning thereon. rPhe jaw-support 17 is held against a shoulder 25 on the bar 16 by means o a nut 27 screwed onto the tl'ireaded end 28 of the stud 23 against washer 29. @n the jaw-support t7 is the movable aw 30 oit' hardened steel, similar to the lined jaw 21, and held in place by the screws 31.

The movable jaw is adapted to be drawn toward the xed jaw 21,'to clamp the work W therebetween, by the sliding -nut 58 formed thereon.

movement of the bar 16. rllhe bar 16 is slid rearwardly through the slot 15 of the base 2 under the action of a cam 35 operated from a handled lever 36. The cani 35 is rotatable on a stud 37 with its curved edge 38 bearing against a hardened thrust-plate 39. The plate 39 is set in a slot 40 at the rear of the cap 18, which, as will be noted by reference to Figs. 1 and 2, does not extend clear to the end of the tail-piece 4 of the base 2. rlhe plate 39 is held in place by a suitable means, such as the pins 41, and serves as a wearresisting element to taire the thrust of the cam 35. The handle or lever 36 has a hub 42 rotatably mounted on the stud 37 and held in place by the countersunlr head of a screw 43 screwed down into the stud. Biveted through the lever 36 is a pin 44 which projects downwardly to adapt it to enter any one of a series of holes 45 spaced around the cam 35. By removing the screw 43 the lever 36 may be lifted and turned in relation to the cam 35, its pin 44 being then set in any one of the holes 45 to provide for the most convenient position of the handle in accordance with the location of the fixture on the tool.

Referring particularly to Fig. 2, the stud 37 is held in a rectangular slide or block 56 fitted to the slot 15 in the base 2 in which the bar 16 slides. Reaching forward from the slide 56 is a threaded rod or bolt 51 which is screwed into the aXial, threaded bore 52 of a stud 53. rThe stud 53 is fitted to a longitudinal bore 54 in the sliding bar 16 and is provided with a head 55 abutting the rearward end thereof. The forward end 56 of the stud 53 is reduced in diameter and projects through the stud 23 at the front end of the bar 16. Its protruding end is screwthreaded at 57 and terminates in a square Screwed onto the threads 57 is anut 59 acting against the washer 60 which abuts the end of the stud 23 on the bar 16. The nut 59 coperates with the head 55 on the stud 53 toi hold the latter longitudinally of the bar 16, while allowing it to turn therein. By turning the stud 53 through the means of a wrench applied to its squared end 53 the movable 30 may be adjusted in relation to the fixed jaw 21 in the manner and for the purpose as hereinafter more fully explained.

0n the top of the black 50 is a cover-plate 61 which is held in place by the cam 35 and slides in the slot 15 in the base 2. 1t will be observed from Figs. 3 and 5 that the sides ofthe slot 15 extend above the top of the bar 16 along the tail-piece 4, the cap 18 being cut away at 62 on its under side to provide a space for the plate 61 as shown in Fig. 2. The plate 61 slides in under the cap 18 and covers the slot 15 at the rear of the cap to prevent dirt or chips from working down into the slot.

The stud 37 is held in the bloclr 50 by means of a set-screw 63, see Fig. 2, screwed in from the rear of the block with its end engaging a slot 64 on the side of the stud. The thread-ed hole 65 for the set-screw 63 also receives the end of a bolt 66 which fastens a guide-member 67 to the rear face of the block. The member 67 consists of a vertical plate 68 provided with a cylindrical sleeve 69 projecting forwardly from its lower end. rilhe sleeve 69 enters a horizontal bore 76 in the base 2 and slides therein under the movement of the block 50; thereby acting as a guide and brace for the block to prevent it from raising up out of the slot 15 in the base. The sleeve 69 also serves as a housing for a coiled spring 71 which acts to draw the bloclr or slide 50 forward in the fixture to force its jaws apart and maintain the cam 35 bearing against its thrust-plate 39. One end of the spring 71 is anchored to a pin 72 extending across the bore of the sleeve 69; while its opposite end is fastened to a cross-pin 73 at the end of the bore 70.

ln the modified form of the device illustrated in Figs. 5 and 6 l provide a rockable support 75 for the movable `iaw 30 which is pivoted to rock` on a horizontal axis on the sliding bar 16. As shown more particularly in Fig. 6, the support 75 is formed with lateral bearings 76 abutting the sides of the bar 16 and pivoted thereto by screws 77. T he screws 77 are screwed through the sides of the support 75 and provided with reduced extensions 78 engaging bores 79 in the op- `iosite sides of the bar 16. rlhe support 75 carries the jaw 30 secured at its top by the screws 31, and below its bearings 76 is a triangular extension 8O carrying an adjustingscrew 61 at the bottom with a check-nut 82 on its outer end. rEhe screw 81 is rounded off on its inner end and bears against a hardened block 83 set into the front of the base 2. By releasing the check-nut 82 the screw 81 may be 'adjusted through its bearing in the support 75 to rock the latter on its pivots 7 6, whereby to vary the angularity of the working face of the jaw 36 to adapt it to the taper of an angular piece W held .in the fixture. he construction and arrangement of the parts of my improved device having now been described in detail, its method of operation will next be explained.

My improved fixture is attached to the table 'll of the milling machine or other machine-tool by setting the tongues 6 in the appropriate counierbores 7 or 9 and engaging them in the T-slot t in accordance with the position in which the device is to set. rllhe holding screw 11 at the center of the base 2 is also slid into the slot t, `with its head 12 underlying the sides thereof, and when its nut 13 is tightened it will clamp the fixture firmly in place on the table T. T he device is most generally used where it is required to machine or finish pieces of uniform dimensions in quantity lots, although it is equally well adapted for individual work, as in toolmalring. lhere the work is uniform only one adjustment of the jaws of the fixture is necessary and this is accomplished in the following manner: The handle or lever 36 is swung around to turn the cam 35 into the position illustrated by the dash-lines in Fig. 1 with its straight side against the thrust-plate 39. This action allows the spring 71, acting through the guide-member 67, to slide the block 50 forward in the slot 15, and the bolt 51 on the block pushes the slide-bar 16 forward to move theA jaw 30 away from the fixed jaw 2l. The piece WT to be operated upon is next placed in position between the jaws, and the outer janY 30 adjusted on the stud 23 of' the bar 16 to leave a slight space between it and the side of the piece. The jaw 30 is adjusted in relation to the fixed jaw 21 by turning the stud 53 with a wrench applied to its squared end 58, whereby to either slierten or lengthen the telescoping connection 51-56 between the slide 50 and bar 16. Now when the operating handle 36 is turned back in the direction indicated by the arrow 0J, Fig. l, the rounded face 38 o'f the cam will be brought against the thrust-plate 39 to cause the slide or block 50 and its connected bar 16 to be withdrawn through the base 2, whereby to draw the movable, jaw 30 toward the fixed jaw 21 to clamp the work WV therebetween. This action causes the jaws to bind iirmly against the sides of the piece lll, thus holding it with a firm grip until the handle is thrown back again to release the wedging action of the cam. It will be noted from Fig. l that the curved face 38 of the cam 35 is formed eccentric to the axis of the stud 37 on which the cam turns so that a more extended movement oit the jaw 3() may be ettected by turning the handle 56 beyond the point shown in the drawing. lThis provides for a considerable range of action of the jaws to accommodate pieces of different thickness, and where a greater movement is required the outer jaw 30 may be further adjusted on the slide-bar 16.

ln the modified form of device shown in Figs. 5 and 6 the outer jaw 3() may be adjusted at an inclination to the vertical to accommodate angular-sided pieces and, when necessary, the working tace of the jaw 21 may be beveled or inclined to accommodate dilierent shapes in the work.

My improved device provides for a quick action of the jaws both in gripping and releasing the work, and their clamping effect is particularly powerful and secure. it is to be observed that the work W is held against the iixed jaw of the device in such manner that the thrust of the tool on the piece will be taken on the solid base oi the fixture, whereby to provide greater rigidity and to prevent chattering or vibration of' the tool on the work. it is also to be noted that the operating handle or lever 36 may be adjusted on the cam 35 through an angle of one hundred and eighty degrees so that it may be set in whatever relation is most convenient for the operator in accordance with the different positions in which the fixture is set on the machine.

Particular attention is called to the stanchness of the device as provided by the structure of its base 2 and the arrangement of the operating parts within the base. it

will also be noted that this self-contained feature ot the mechanism protects the working parts from dirt and chips, while making for improvement in the general appearance and neatness of the device. My improved fixture is lighter and more compact than the usual devices employed for like purposes, yet is particularly stanch and rugged and proof against wear or deterioration under hard usage.

Various modifications might be made in the design and structure of. the device without departing from the spirit or scope of the invention; therefore, without limiting myself to the exact embodiment herein shown and described, what I claim and desire to secure by Letters iBatent is:

1. ln a fixture for machine-tools, the combination with a base, of a fixed jaw on said base, a movable jaw, a support for the movable aw slidable on the base, automaticallyoperated means for sliding the support to open the jaws7 a cam for sliding the support to close the j aws7 and a variable connection between the cam and support for adjusting the operative relation between the movable jaw and fixed jaw.

2.' ln a fixture for machine-tools, the combination with a base, of a fixed jaw on said base, a movable jaw arranged opposite the fixed jaw, resilient means for sliding the movable jaw away from the fixed jaw, means to slide the movable jaw toward the fixed jaw, a cam for operating said means, and means for adjusting the position of the sliding means to vary the operative relation between the movable aw and fixed jaw.

3. .in a fixture for machine-tools, the combination with a base, of fixed jaw on said base, a member slidable on the base, a movable aw carried by said member, means connected to slide the jaw-carrying member, means for manually operating the slidingmeans to close the jaws, means for automatically operating the sliding` means to open the j aws, and means for adjusting the connection between said sliding-means and the jaw-carrying member to vary the width of the opening between the jaws.

4. In a machine-tool fixture, the combination with a base, of a lixed jaw on said base,

a movable jaw, a slidable support tor the movable jaw, a spring for sliding the support to move the movable jaw away from the fixed jaw, a rotatable cam for sliding said support to move the movable jawl toward the `iixed jaw, a lever for operating the cam, and means for connecting the lever with the cam in diiierent positions of angular adjustment whereby to provide Jfor the most convenient position of operation oi the lever.

5. In a machine-tool fixture, the combination with a base, of a fixed jaw on said base, a movable jaw, a slidable support for the movable jaw, a rotatable cam for sliding said support, said cam provided with a ser-ies of holes arranged circumierentially of its axis, a lever pivoted on the axis of the cam, and a pin carried by the lever and adapted 'for engagement with the holes in the cam to connect the lever therewith while providing for its adjustment in angular relation thereto.

G. In a machine-tool lixture, the combination with a base, oi a lixed jaw on said base, a support slidable on the base, a movable jaw carried by said support, a slide for sliding the support, manually-operable means forsliding the slide, and means extending through the base to connect the slide with the support, said connecting-means being longitudinally-adjustable to vary the operative relation between the movable jaw and fixed jaw.

7. In a machine-tool fixture, the combination with a base, oi a fixed jaw on said base, a support slidable on the base, a movable jaw carried by said support, a slide for sliding the support, manually-operable means for sliding the slide, a screw-threaded telescopie connection extending through thebase between the slide and support, and means for adjusting said connection longitudinally to vary the operative relation between the movable jaw and {ixed j aw.y

8. ln a machine-tool fixture, the combination with a base, of a fixed jaw on said base, a movable jaw, a slidable support tor the movable jaw, a slide for sliding the support, manually-operable means for sliding the slide, a screw-threaded telescopic connection on the slide extending through the base, and adjustable means on the support engaging the threads of the connection to vary the longitudinal relation between the slide and support to regula-te the operative relation between the movable jaw and fixed jaw.

9. ln a machine-tool fixture, the combination with a base, of a fixed jaw on said base, a movable jaw, a slidable support for the "movable jaw, a slide for sliding the support, manually-operable means Jfor sliding the slide, a screw projecting from the slide, and a rotatable stud held longitudinally of the support and provided with an internallythreaded bore engaging the end oi the screw, said stud having means at its end whereby it may be turned to adjust the longitudinal relation between the slide and support to regulate the operative relation of the jaws.

l0. in machine-tool ixture, the combination with a base, oi a jaw on said base, a bar slidable in the base, a movable jaw carried by said bar, a slide for sliding the bar, manually-operable means for sliding the slide, a stud rotatable in the support and projecting therefrom with a nut at its end, and a screw on the slide engaging a threaded bore in the stud.

1l. in a machine-tool fixture, the combination with a base, of a iixed jaw on said base, a bar slidable in the base, a movable jaw at the end oi' the bar, a slide slidable on the base, a cam rotatable on the slide to act against the base, and an adjustable screwthreaded telescopic connection between the slide and bar for varying the operative relation between the jaws.

l2. in a machine-tool fixture, the Combination with a base, ot a bar slidable in a slot in the base, a cap for holding the bar in its slot in the base, a iixed jaw on said cap, a movable jaw on the end of the bar, a slide slidable in the slot in the base, an adjustable telescopic connection between the slide and the bar, and a cam rotatable on the slide to adapt it to act against the cap to slide the bar to open and close the jaws.

13. in a machine-tool fixture, the combination with a base, of a bar slidable in a slot in the base, a cap 'for holding the bar in the slot, a fixed aw on the cap, a movable aw on the bar, a slide slidable in the slot in the base, a longitudinally-adjustable connection between the slide and bar, a cam ior sliding the slide to move the bar to draw the movable jaw toward the fixed jaw, anda spring acting on the slide to move the bar to open the jaws. Y

In a machine-tool fixture, the combination with a base, oi a rectangular bar slidable in a slot in the base, a lixed jaw on the base, a movable jaw, a support for the movable jaw fitted to the end ot the slidable bar, a nut 'for securing the support on the bar, an elongated stud extending through a bore in the bar and projecting forwardly tnerefrom with nut at its end, means tor holding the stud longitudinally oi the bar while allowing it to turn therein, a slide, a screw on the slide threaded into the stud in the bar, and a cam for sliding` the slide to move the bar to open and close the jaws.

l5. ln a machine-tool fixture, the combination with a base, ot a bar sli dable in a slot in the base, a cap for holding the bar in the slot, a iixed jaw on the cap, a movable jaw on the bar, a slide slidable in the slot in the base, a Cam ."'of sliding the Slide, a longitudinally-adjustable connection between the slide and bar., and a Guide projecting rlownwaidly iom the slide and slidable iii a bore in the base to Steady the movement of the slide.

1G. ln a maoliiiie-tool ixtule7 the eombination with a base, of a bai' slidable in a Slot in ltbe base, a Cap for holding the bai' in the slot, a .fixed jaw on the cap, a movable jaw on tbe bar, a slide slidable in the slot in the base1 a Cam for sliding; the slide, a longitudinally-adj ustable connection between tlie Slide and bar, a guide on the slideliaviugahollow stud slidable in a bote in the base, and a s iiiiig housed in Said Stud and bote and aetinge; on tlie ,guide to slide the slide against the action o't the cam.

17, lin machine-tool Fixture, the combination with a base, of a fixed jaw on the base, a support Slidable on the base, a movable jaw carried by said support, means extending between the movable jaw and the base for adjusting` tbe jaw in angular position on the support, a slide for sliding the support to move the movable jaw toward and away from the fixed j aw, a longitudinally-adjustable connection between the slide and suppo't, and a Cam for operating the slide to open and close the jaws.

18. In a machine-tool lixture, the Combination with a base, of a fixed jaw on the base, a Support slidable on the base, a movable jaw pivotally mounted on the support to adapt it to rock in relation to the fixed jaw, an adjusting-screw oaried'by the jaw and adapted to engage the base for rocking the jaw on its support, and manually-operable means for sliding the support to move the movable jaw toward and away from the fixed Jaw.

ln testimony whereof l aliix my signature.

EVERETT U. LEWIS,

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