US248263A - sellers - Google Patents

Description

(Model.) 7 I 3 Sheets'.8heet I.

W. SELLERS 8; J. S. BANGROI'T, r TURNING LATHE Patented Oct. 11, 1881.

't n'esses Inbemtors 1 i (ModeL) v 3 Sheets-Sheet 2 W. SELLERS & J. S. BANORO'IT.

' TURNING LATHE.

No; 248,263. Patented Oct. '11, 1881.

- lhz'e n tars N. PETERS. PlmloJJlhogmphsr. Wcuslunglon. 11c.

UNITED STATES PATENT OFFICE.

WVILLIAM SELLERSAND JOHN SELLERS BANGBOFT, OF PHILADELPHIA, PA.;

SAID BANOROFT ASSIGNOR TO SAID SELLERS. 4

TURNlNG-LATH E.

SEEGIFIGATIO N forming part of Letters Patent No. 248,263, dated October 11, 1881.

' Application filed July 19,1880. (ModeL) T 0 all whom it may concern Be it known that we, WILLIAM SELLERs and JOHN SELLERs BANOROFT, of the city and county of Philadelphia an d State of Pennsylvania, have jointly invented certain new and useful Improvements in Turning-Lathes for Metal; and we hereby declare the followin g to be a full and accurate description thereof, reference being had to the accompanying drawings, which form part of this specification.

One portion ,of our improvements is applicable to all kinds of turning-lathes which employ a revolving and a dead-spindle; another portion is applicable to all forms of the slidelathe, and still another is applicable to that class of slide-lathes in which the tool slide or saddle rests upon the flat top surfaces of a shear or bed, and is held down and guided in its sliding movements by gibs under theedges of the shear but as all are applicable to this class, the drawin gs represent this form of shear.

In a patent granted to Win. Sellers, December 28,1869, for improvements in this class of lathes, a method was shown and described,

whereby the parallelismof the axes of the revolving and the dead spindles could be maintaiued, so that the line of centers and accuracy of the work should not be dependent upon the lateral fit of the movable head between the two sides of the shear, as theretofore, whereby the wear of these fitting parts was greatly diminished and the alignment of the spindles was'not affected by such wear. That improvement, however, provided only a means for maintaining the spindles in a true axial line. It is equally important that the traverse of the saddle should be maintained in planes parallel to that line; butas the saddle of that lathe was guided by gibs under beveled edges of the shear, the wear, which is almost exclusively vertical, permitted the saddle to move laterally and parallel to a plane that is perpendicular to the surface uponwhich the tool is cutting, which movement very seriously affected the accuracy of the work-that is to say, a vertical reduction of the upper surface of the shear would lower the beveled guiding-surface on the saddle and carry it away from its corresponding surface on the shear, thereby permitting the saddle to move laterally upon the flat top of the shear. This wear of the shear necessarily occurred where the I saddle was most frequently used, and if the gibs were adjusted to fit these surfaces the saddle could not be moved upon thoseplaces on theshear where no such wear had occurred. Moreover, whatever the condition of these beveled guiding-surfaces, they will increase the friction between the saddle and the top surface of the shear, unless the power to move the saddle is so applied as to produce no lateral strain, which, practically, is rarely attainable. That the spindles of a lathe should be in a true axial line and that the traverse of the saddle should be parallel to a horizontal as well as to a vertical plane'which intersect each other on this axial line will not be disputed, When the lathe is new andin perfect order any degree of accuracy that may be demanded as to the alignment of the spindles and the traverse of the saddle can be produced with comparative ease; but, as heretofore constructed, the parts which affect this alignment or this traverse must wear with use, and such wear soon produces derangement, so that the perfectalignmentandparalleltraverserequired to produce good work are lost by degrees, until finally it becomes necessary to restore them by extensive repairs, to be again and again subjected to the same process of deterioration. The importance, therefore, of adopting a system of construction which shall maintain these conditions in all their integrity, or so that they will not be materially affected within limits of wear much more extensive than has been heretofore admissible can scarcely be overstated.

Prior to 1869 slide-latheshadbeen described with a flat top shear or bed and with vertical guiding-surfaces for the saddle, in which case the wear of the saddle would not alfect its traverse parallel to a vertical plane but no provision was made for maintaining the alignment of the spindles parallel to the same vertical plane. In 1869 Wm. Sellers, in,his abovementioned patent, described certain means for:- maintaining the alignment of the spindles parallel to a vertical plane, but retaining the beveled guiding-surfaces for the saddle then com monly used, so that in this case the traverse of the saddle could not be maintained parallel to the same vertical plane, and thus prior to our present invention the accuracy of all slide lathes with flat top shears was impaired by wear, either as to the alignment of the spindles or as to the traverse ofthe saddle, none of them being exempt from one or the other of these defects. 7

The dead-spindle in the movable or puppet head of lathes is usually made cylindrical, and is fitted with great nicety into a carefully-prepared hole in the main casting of the puppethead, and as this spindle has frequently to project a long distance from the head, it is necessary that the fit should be very exact, as any play or lost motion in the bearing is greatly exaggerated at the center point.

The importance of holding the spindle firmly in position has long been recognized, and numerous devices have been employed for the purpose. Nearly all of them, however, have been so arranged as to force the spindle against one side of the bearing, thus destroying the axial alignment of the dead-spindle with the live-spindle; or in other cases where care has been taken to hold the spindle centrally on the front end no provision has been made for holding the back end, which has been left free to move to the extent of any lost motion due to defective workmanship or to wear in the bearings.

To remedy these imperfections it is one object of our invention to construct a flat top shear which shall maintain the axes of the spindles in one line and the traverse of the saddle in planes parallel thereto.

A further object of our invention is to support the dead-spindle in the puppethead so that different spindles of the same size of lathes may be interchangeable therein, while obviating the necessity for the accurate fitting of the spindle to the puppethcad heretofore required; and to these ends our invention consists in providing a slide-lathe shear with a flat top surface, a vertical guiding-surface, and a beveled clamping-surface for guiding and clamping the puppet-head, and with two vertical surfaces for guiding the saddle on the flat top, all as hereinafter more particularly set forth; and it further consists in clamping the dead-spindle at two separate places in the puppet-head by coned wedges drawn together or released, as may be required to hold or to release the spindle.

In the accompanying drawings, which form part of this specification, Figure 1, Sheet 1, represents an elevation of part of a lathe embodying our present invention. Fig. 2, Sheet 2, represents asection on thelinesS 99 through the saddle shown in Fig. 1. Fig. 3 represents a plan, partly in section, on the line 10 11, Fig. 1, of the feed-motion in the saddle. Fig. 4 showsamodification of the clutch-motion when used for one feed only-1 0., either longitudinal or lateral. Fig. 5, Sheet 3, shows a longitudinal section through thepuppet-head. Figs. 6 and 7 are cross-sections through Fig. 5 on the lines 12, 13, and 14, respectively.

In all the figures similar letters refer to similar parts.

A, Figs. 1 and 2, represents the bed or shear of a lathe. B is a saddle, which slides freely upon the flat upper surface, a a, of the bed. This face a a guides the saddle in a horizontal plane; but itis necessary that the saddle should be guided in a straight line in this plane, and for this purpose we form the edges I) b of the bed verticaland at right angles with the bearingsurface a. a the front guiding-edge of the saddle B (marked 0 in the figure) fits against the vertical surface I), and the shoe or gib d on the other side of the saddle is made adjustable to regulate the fit, and bears against the otherverticalsurface,b,ofthebed A. Theshoe d is provided with a projection which fits underneath the overhanging part of the shear, as shown, to prevent the saddle from being lifted by any kind of eat. It will be evident that with this construction the wear upon the upper surface, a a, of the bed will only vary the point of the cutting-tool verticallythat is, in a line tangential to the surface under the cutting-point of the tool-while. wear upon the surfaces a a, or upon the corresponding surface of the saddle B, cannot affect the condition and fit of the side guides, b b, for the saddle, by such wear, will be lowered in a vertical line only and parallel to these side guides. The pressure upon the sliding surfaces from the cut is almost entirely vertical to the shear, as shown by the condition of these surfaces after long use. A small proportion'of this pressure comes upon the guiding-surface I). A lateral strain rarely comes upon the guiding-surface b, but will always be produced, to a slight extent, in moving the saddle by hand; hence the surface I) on the back of the bed becomes the most important in maintaining the movement of the saddleparallel with the axis of the spindles, and is made larger accordingly.

In Figs. 1 and 2, sis a splined shaft, which V receives motion from the live-head and transmits it to the feed-gcarin the front of the saddle by means of the sliding clutch 1', which is keyed to the shaft 8, so as to turn with it, and is at the same time arranged to slide freely along it. This clutch 1' has serrated teeth radial to its axis at each end fitted to engage with similar teeth on the two bevel-pinions t t, which are carried by and revolve freely on the shaft 8. The sliding clutch 1' is recessed or grooved to receive the yoke u, by which it is moved so as to engage with either pinion. The

yoke a is secured by the set-screw z to the rod 10, which slides freely in bearings 02 o. The weighted lever E is pivoted to the front of the saddle at F, and carries one end of the lost-motion link G at H. The other end of the link has a slot, J, through which the set-screw zpasses. The object of this slot is to allow the weighted lever E to move through such an angle that the weight upon its upper end shall have sufficient power to hold the clutch r in gear with one of the bcvel-pinions t t, when the saddle is moved along the bed of the lathe by hand. The shaft 8 revolves continually in the same spur-wheel will be tangential to the curved direction, and it is evident that by moving the wedges, and that if the handle be pushed weighted lever E to the right the clutch 1" will engage with the bevel-pinion tand turn the bevel-wheeljin one direction, while, if the weighted lever E be thrown to the left the .clutch 1 will be withdrawn from the pinion t consequently reversing the movement of the saddle. The bevel-wheelj is firmly secured to the shaft K, to which is also secured the spiral pinion L, which engages with and drives the sliding spur-wheel M. The shaftK turns freely in its bearings in the front of the saddle, and is placed at such an angle that the teeth in the teeth in the spiral pinion, and hence the spurgear may be moved in the line of its axis without causing it to rotate.

Asthe details comprising the remainder of this feed-gearing are the subject-matter of another specification, no further description thereot'is deemed necessary in connection with this, as the improvements hercinbefore described may be operated with any of the systems offeed-gearing heretofore in common use.

0, Fig, 5, represents the main casting of a puppet-head. D is the spindle, which is traversedin the usual manner by a screw and hand-wheel. e is a split sleeve-bearing for the spindle D, and is formed at one end as a conical wedge, f, which fits in a conical recess in the front end of the head 0. This sleeve e is divided longitudinally by a slot, to allow for contraction, and has upon its rear end a screwthread, 9, with which a screw-thread in the nut it engages, for a purpose to be hereinafter described. The main casting O is bored out conically at the point It to receive the conical wedge-bushing l, which is bored out somewhat larger than the outside of the sleeve 6 and bears upon three equally spaced packingblocks, M, fitted to the spindle D and in the bushing 1. These blocks pass freely through slots a, formed in the sleeve 6, which are made longer than the blocks m to insure clearance. The blocks m are maintained in position as to the wedge-bushing Z by projections 0, which enter a groove turned in the inside of the bushing 1., The operation of the arrangement is as follows: When the nut his turned, by pulling the handlep toward the operator, the nut bears against the back end of the wedge-bushing 1, while the screw-thread draws the split sleeve 0 backward, thus forcing the conical wedgef and the wedge-bushing l into the conical seats prepared for them with equal force. The wedge f contracts upon the spindle equally in all directions, holding it perfectly central and rigid as to its front end, and at the same time the wedge-bushing l holds the rear end in the same manner by the blocks m. It is evident that back the rear end of the nut h, pressing against the plug Q, will force the sleeve eforward, thus releasing the wedge f, and at the same the wedge-bushing Z, being released from pressure, will spring open by its own elasticity, thus releasing the spindle entirely and leaving it perfectly free to move.

If it is desired to use the spindle'as a sliderest to carry a cutting-tool, the handle 12 may be drawn forward gently to give any desired pressure against the spindle and eliminate any lateral motion.

The packing-blocks m may be omitted, if desired, and the wedge-bushing Z made to fit upon the outside of the split sleeve 6, which it will then force against the spindle; but in this case it is evident that the sleeve 6 must be drawn back while pinched between the Iwedge-bushing l and the spindle D, and hence the spindle will not be held so firmly as in the arrangement shown and described.

The puppet-head U is firmly clamped to the shear A by means of the transverse clampingpiece D which is provided with a beveled clamping-surface, B and a vertical clampingsurface, 01 which operate against corresponding surfaces on the shear and the puppet-head. It will be seen that by tightening the clamp D the puppet-head will be firmly locked between the vertical surface d on the clamp D and the beveled clamping-surface C on the shear, and atthe same time the head will be firmly held upon the flat top of the shear, all as more fully setforth in the before-mentioned former patent granted to William Sellers, December 28, 1869.

The method described of grasping and holding the dead-spindle'in two places in a true axial line is important, not only because it ali'ords a means of securing this spindle in the puppet-head more firmly than it has been possible to do heretofore, but because the means by which it is held are adjustable within a sniall compass, whereby the minute variation of diameter which must exist in the spindles of lathes of the same size becomes unimportant as a factor in determining the fit of the spindle in the puppet-head, so that now such spindles can be made interchangeable at less cost than has heretofore been required to fit each one to its proper puppet-head.

We have hereinbefore referred to a form of construction for fiat-top lathe-shears, whereby the alignment of the spindles could be maintained, and we are aware that flat-top latheshears have heretofore been constructed with two vertical guiding-surfaces for the saddle, and that the saddle has been provided with correspondingguiding-surfaces; buttheseprd visions for maintaining the alignment of the spindles andfor maintaining the traverse of the saddle in planes parallel to the axial line of such spindles have never heretofore been combined in one and the same lathe, so that in all this tool deteriorates with use, either from the wear which renders the alignmentof the spindles defective or the traverse of the saddle imperfect, or from both causes; but defective alignment ot'its spindles or imperfect guidance ofits saddle in planes parallel to the axial line of its work are equally conducive to a bad result, so that this form of lathe, notwithstanding its advantages in other directions, has heretofore been regarded withsotne dist'avor. These objectionable features are obviated entirely by our present invention, so that the advantages of this form ofslide-lathc shearare not now neutralized by any defects from which other forms are exempt.

Having now described our invention, what we claim as new, and desire to secure by Letters Patent, is-

1. In aslide-lathe, the fiat-top shear having a vertical guiding-surface and a beveled clamping-surface for maintaining the alignment of the spindles, combined with the saddle having vertical guiding-surfaces for maintaining the parallelism ofits traverse, substantially as described.

2. In a turning-lathe, the combination, with a puppet-head, of a dead-spindle and coned wedges which inclose, clamp, and release the spindle at two separate places in the puppethead, substantially as and for the purposes set forth.

3. In a turning-lathe, the combination, with a puppet-head, of a dead-spindle, a clampingscrew, and coned wedges which inclose, clamp, and release the spindle at two separate places in the puppet-head, substantially as and for the purposes set forth.

4. In a turning-lathe, the combination, with a dead-spindle, of a coned wedge, a clampingscrew, and packing-blocks, substantially as shown and described.

WM. SELLERS. J. SELLERS BANOROFT.

Witnesses:

J 0s. H. Sonaacma, JAS. O. BROOKS.

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