US2377594A - Cushioning holder for lathes and the like - Google Patents

Description

June 5, 1945. w. J WEBERG 2,377,594

CUSHIONING HOLDER FOR LATHES AND THE LIKE Filed April 20. 1944 a Sheets-Sheet 1 I I N VEN TOR.

June 5, 1945. w. J. WEBERG 2,377,594

CUSHIONING HOLD ER FOR LATHES AND THE LIKE Filed April 20, 1944 3 Sheets-Sheet 2 INVENTOR. *wmmvawe Jazzy June 1945. w. J. WEBERG. 2,377,594

CUSHIONING HOLDER FOR LATHES AND THE LIKE FiledrApril 20, 1944 3 Sheets-Sheet 3 IN V EN TOR.

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aawsf M Patented June 5, 1945 um'rsp surf-:5 PATENT osrics William J. Weber-g, Chicago, Ill. Application April 20; 1944, Serial No. 831,889 5 Claims. (01. ice-sis) This invention relates to I improvements in cushioning holders for use in lathes and other rotary cutting machines.

The principal object of the invention is to provide a simple and eflieient construction of cushioning devices of the character described, having normally loaded spring means for aflording limited endwlse yielding movement, together with manually adjustable means for providing additional spring cushioning means at will in accordance with varying requirements.

My invention is adapted for use inilathe centers. either of the live, or rotary type, or oi the dead, or non-rotary type, and may also be 9.1 plied to cushioning tool holders of the type disclosed and claimed in my prior patent, No. 2,327,685, issued August 24, 1943, which are especially adapted to produce limited feeding movement or the tool at the end of a normal feeding stroke oi the tool holder.

The invention may best be. understood by ref-- erence to the accompanying drawings illustrating certain embodiments thereof as applied to lathe centers; In the drawings:

Figure l is a longitudinal section of a lathe center holder of the dead or non-rotary type, embodying the principles of my invention.

Figure 2 is a fragmentary front endview oi the holder shown in Fig. 1.

Figure 3 is a section taken on line 3-4 of Fig. 1.

Flsureiisasectiontakenonlinel-lotFis. 1. Figure 5 is a longitudinal section of a lathe center holder of the live or rotary type, embod lngthe principles oi my invention.

Figure 6 is asection taken on line H or Fig- Figure 7 is a section taken on line 1-1 of Fig- Figure 9 is a front face view oi the holder shown in Figure 8.

Referring now to details or the embodiment of my invention illustrated in Figures 1 to 4 inclusive. the holding device consists of a tapered shank ll adaptedtobeinserted asusual inthe tail stock cl a lathe, and a head indicated generelly at ll, adapted to receive a lathe center point I! in non-rotative relation therein. The head I I has an endwise yieldable holding member is therein. consisting oi an annular end plate it formed integral with a spindle I 5 extending into the'hollow portion oi the shank I I. The end plate It has a close sliding flt axially of a cylinmounted in bored recesses ll. iormed in the inner,

duced end portion i I or the spindle It has sliding engagement in the rear end of the shank ill, so as to maintain the holding member I! in precise axial alignment within the head ii and its shank II as said holding member slides longitudlnally relative thereto. The center point I! may, as usual, have a tapered lit in the front end of the holding member II, as shown.

Spring tension adjustment means for controlling the yielding or cushioning movement of the holding movement it relative to the head II, includes a plurality oi bored recesses 25 and 26 formed adjacent the periphery oi ,the end. plate it or said holding member, which recesses open inwardly toward the end wall 10 of the hollow 'head II, and on axes parallel with the longitudinal axis-oi the latter. In the form shown, three recesses 25. and an equal number of recesses it are shown, disposed alternately on the same diameters. but it will be understood that the number and relationship oi these recesses may be varied,

ii desired.

The recesses ll each have concentric cap screws 2'! extending therethrough from the front face of the end plate It, in the form shown. the heads ll of said screws being countersunk in said front face. The threaded inner end portions it of the cap screws are engaged in the end wall II of the head. A coil spring 3| is mounted on each oi said cap screws within its recesses 28, and with its inner end abutting the end wall 2|. In practice the coil springs are preloaded under a predetermined compression by their respective cap screws 21 so as to tend to urge the end plate It away from the end wall 20 of thehead ll. 1

The recesses 2| each have other coil springs therein interposed between the end place I 4 and the end wall 20. A single adjusting device is provided for varying the compression of the springs 32. In the improved iorm oi adjusting means shown herein, each oi the coil springs 32 has a plunger 84 associated therewith, said plunger having an outer end is inserted through its respective coil spring, and also having an intermediate collar It which forms an abutment for the inner end of said spring. The outer end ill! of said plunger is guided for sliding movement in a bore I'l formed in the end plate concentric with its recess 2!.

The collars I. of said plungers It are slldably face of the end wall 20. Said plungers also have inner ,end portions II, which extend through dricalrcccss ll iormcdinthe ed -i Arell lllgnedboresll, ltintheendwallll, and project a substantial distance therebeyond, as shown in Figure 1.

The projecting ends 99 of plunger 34 are in knurled cylindrical portion 43 threaded on the] periphery of the head II. A plurality of spaced holes 43 may be provided about the knurled portion 43 for the insertion of a suitable spanner wrench or the like, when desired.

The end plate l4 of the holding member i3 is secured in the head I! by a retaining ring 44, threaded in the front end of the recess IS, with a centrally disposed portion 45 of said end plate extending through said ring, as shown. A felt or fibre washer 46 may surround the central opening of the retaining ring 44 on its inner face, to keep dirt and dust from the interior of the head.

It will now be understood from the foregoing description that the springs 3| are preloaded to a predetermined compression by the cap screws 21 s as to yield only under excessive end thrusts which may be encountered in the kind of operations for which the device is intended to be employed. Thus, when used as a lathe center, the springs 3| may be pre-loaded so the center will not yield under normal free-turning setting of the tail-stock for the lengths and sizes of work usually to be handled, but will yield automatically if such work should become elongated due to heat produced by cutting. In instances where additional spring resistance against yielding movement is desired,an increased amount of such resistance can be readily provided by manual adjustment of the cap 4|, which controls the compression of all of the springs 32 simultaneously. It will be noted that this adjustment can beeifected without dismounting the device from the lathe, and preferably while mounted on the lathe.

In the form of my invention illustrated in Figures to 7 inclusive, the same principles of a yielding holder under preloaded compression, together with a singl manually adjustable device for increasing the effective compression, is shown as applied to a live center for lathes.

In this alternative form of my invention the device consists generally of a hollow head 50 and shank 5| integral therewith, in which is rotatably mounted an end plate 52 with an integral spindle 53 extending into said shank.

The end plate 52 is mounted in suitable antifriction bearings including a roller bearing member 54 of the needle type disposed within the forward end of the head, and a ball thrust bearing member 55 rearwardly of said roller bearing member. The ball thrust member includes an outer race 56 seated in a rabbeted portion 51 adjacent the inner face of the end plate 52, and an inner race 58 having its outer periphery fitting within the head, in abutting relation with the outer end of a compression spring member 59. The inner end of the spring member 59 engages the end wall 60 of the head. In the form shown herein, the spring member 69 consists of two oppositely-dished discs of spring metal. Said spring member forms part of the auxiliary compression adjusting means, as will presently appear.

The preloaded spring compression, to resist yielding movement of the rotary end plate, is provided by a coil spring 6|, mounted in a hollow nut 62 having threaded adjustment in the rear as'r'assa end of the shank iii. The front end of the spring 6| abuts a ball thrust bearing member 63 which in turn abuts against the rear end of the rotating spindle 53. The arrangement is such, that the front end of the hollow adjusting nut 62 is normally spaced from the ball thrust bearing 69, so as to provide a substantial range of adjustment of the spring compression, but when the nut 62 is screwed home against the said ball thrust member, the cushioning or yielding movement of the holding member 19 is temporarily eliminated.

Forwardly of the thrust bearing member 63 is a roller bearing 64 to rotatably support the rear end of the spindle 53 in the hollow shank 5|.

The amount of compression by spring member 59 is adjustable under manual control of the threaded cap 65 on the head 50, through a plurality of plungers 66 having enlarged heads 61 slidably mounted in recesses 68 formed on the inner face of the end wall 60. The heads 6'! are adapted to be moved into abutting-engagement with the spring member 59 so as to control the degree of the compression of the latter. The

rear ends of said plungers 66 extend through said end wall and project a substantial distance therefrom, so as to be simultaneously engaged by the end wall 69 of the adjusting cap 65.

The front end of the end plate is secured in the head 50 by a threaded retaining ring 10 which forms a stop for said end plate.

The rotary type of lathe center holder is especially adapted for use in the tail stock of a lathe, but can also be used in the head stock, if desired.

Among further advantages of the manually adjustable cushioning devices above described is that they can be quickly adjusted while the work is in the lathe to accommodate themselves to variable cutting pressures-especially those which may be temporarily eifective in an axial direction toward the cushioning center holder.

Figures 8 and 9 show how the same structural features and principles of operation above described as applied to lathe center; holders, can be advantageously applied to cutting tool holders, wherein a cutting tool is suitably mounted on the cushioned end plate in place of the center, so as to constitute a tool holding device of the type disclosed in my Patent No. 2,327,685 hereinabove referred to. In the modified form of device shown in Figures 8 and 9 all of the parts are substantially identical with those shown in the type of holder illustrated in Figures 1 to 4 excepting that the end plate l4 of the holding member I3 is extended to provide a pair of exposed ribs Ma, Ma. disposed transversely thereof, having undercut inner faces I511, I511 forming a slot of the kind shown in my aforesaid prior patent for receiving a cutting tool holder block for slidable adjustment therealong. When so employed, the amount of limited feeding movement of the cutting tool at the end of the normal feeding stroke of the tool holder can be quickly adjusted by manipulation of the single adjusting cap, in accordance with varying needs.

Although I have shown and described certain embodiments of my invention, it will be understood that I do not wish to be limited to the exact constructions shown and described, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. In a holder of the character described, a

hollow casing member, a tool supporting member mounted for endwise sliding movement in said casing member, a plurality of compression spring devices interposed between said members, said spring devices having independently adjustable means for varying their respective degrees of compression, the adjusting means for one 01 said spring devices including a plurality oi circumferentially spaced, axially-movable plungers extending through an upright wall portion or said casing member, with their forward ends in abutting engagement with their respective spring devices, and a cap-shaped control member threaded on the exterior. of said casing member with a flanged portion thereof in operative engagement with said plungers.

2. In a holder of the character described. an enlarged hollow head having a rear wall and an axially disposed shank of reduced diameter extending rearwardly therefrom, a supporting member including an end plate slidably mounted in said head, yieldable cushioning means in said head rearwardly of said end plate, and means for controlling the compression of said cushioning means effective on said end plate, including a cap member having threaded adjustment on the exterior oi said head. and a plurality of circumierentially spaced plungers passing through the rear wall of said head with their forward ends operatively connected with said cushioning means and their rear ends operatively engaged by said cap member.

3. In a holder of the character described, an enlarged hollow head having an axially disposed shank of reduced diameter extending rearwardly therefrom. a supporting member includlngan' end late and a spindle slidably and rotatably 'mounted in said head and shank respectively,

yieldable cushioning means in said head rearwardly of said end plate, and means for controlling the. compression oi' said cushioning means eflective on said end plate, adjustable from the exterior or said head, including a cap member threaded on said head, and axially movable abutment means engaging said cushioning means and operatively engaged by said cap memher.

4. In a holder or the character described, an enlarged hollow head having an axially disposed shank of reduced diameter extending rearwardly therefrom, a supporting member including an end plate and a spindle slidably and rotatably mounted in said head and shank respectively, yieldable cushioning means in said head rearwardly 01 said end plate, and means for controlling the compression of said cushioning means efiective on said end plate, adjustable from the exterior or said head, including a ca member threaded on said head, and axially movable abutment means engaging said cushioning means and operatively engaged by said cap member, and a second cushioning means adjacent the rear end of said shank, and means for controlling the compression of said second cushioning means eiiective on said shank including a nut threaded in the end of said shank, and forming a movable abutment for said second cushioning means.

5. In a holder of the character described, an enlarged hollow head,.a supporting member telescopically mounted for axial movementin said head. a plurality of springs interposed between said head and supporting member, a plurality of connecting devices maintaining said springs under compression and limiting the relative axial movement between said head and said member, a plurality of other springs interposed between said head and said member, and means for adlusting the compression of said last named spring said cap member.

WILLIAM J. WEBERG.

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