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Publication numberUS76363 A
Publication typeGrant
Publication dateApr 7, 1868
Publication numberUS 76363 A, US 76363A, US-A-76363, US76363 A, US76363A
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 76363 A
Abstract  available in
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Description  (OCR text may contain errors)


Letters Patent No. 76,363, lated April 7, 1868.


@te dgituic ninna in in tlgcse tttirrs @anni mit mating gmt ni tige same.


Be it known that I, WILLIAM J. WATSON, of Benton Oentre,in the county of Yates, and State ot' New York, have invented anew and useful Improvement in 'Tail-Block for Turning-Lathes; and I do hereby declare that the following is a full, clear, and exact description thereof', which will ,enable those skilled in the art to make and use the same, referencebeing had to the accompanying drawings, forming part of this specification, in which- Figure l is a central vertical longitudinal section of my invention, and

Figure?I is a vertical cross-section o'fthe same, taken in the line :c :i: in iig. 1.

Similar letters of reference indicate Corresponding parts.

This invention consists in a new and improved construction of tail-block .for turning-lathes, whereby the block and centre are secured in place or released with greater facility than heretofore, as hereinafter explained.

In the accompanying drawing, A A is the frame of the lathe, the inner faces ot'` which are provided with grooves, bi, which hold 'a sliding block, c. (lis a second sliding block, whichis mounted on top -of the framepieces ,nnd this block supports two movable jaws, e e, which-hold the centre-j'. The lower ends of jaws e have tenons, which engage with mortises in the supporting-blockd in such manner that the upper ends of thel jaws are free to move laterally, or open and close slightly, while their lower ends are held stationary. The uprights or sliding standards, G G, are held in a vertical position', by passing through holes in the blocks 'd o', but are free to move vertically under pressure, although they are supported by spiral springs i- 7L. The stand-dnrds G have each a pair of links, at their upper ends, which connect with the upper parts of the jaws e e, as shown in iig. 2.- c is a two-armed lever, which is pivoted at its centre to a rod, Z, and one arm of this lever pivoted to the standard G', while the opposite end isconnected to the-elbow hand-lever m, by means of link n, fig. l. The rod Z is held at its lower end by a nut, 1.

Its operation is as follows: After the block and centre have been adjusted. to the work, the leve!` m is pressed down, and both the' centre and block are thereby simultaneously and firmly secured in position. By pressing down the hand-lever, its short arm and the link 1i are brought into line, by which the lever c forces down the standard G', and the pressure upon the hand-lever 'Fulcrum S forces down the other standard, Gr, and all this downward pressure on the standards G and Glis brought upon the links 2', excepting a small item of i'orce which is employed in compressing the spiral springsi i, which act as knee-,joints to press the jaws e eupon the centre, f, withA great force, and thus the centre is very rigidly secured by a single movement on the part ot' the operator. The tail-block is secured by the upward strain on rod Z pressing the block e upward in the grooves I), while the block d is forced down upon the frame A by the downward strain on jaws e e', so that theblocks OZ c grasp the frame A. The short arm ot' the hand-lever and the link n also form another knee-j0int,-so that the clamping-power rapidly increases as the hand-lever is moved down, and gives theparts avery powerful gripe. And also, the strength ofthe bite is easily regulated at any time, or wear taken up, by means of a nut, 7, which allows the fnlcrum-rod Z to be lcngthened out or taken up, as'desired. When the clamping-pressure on' the `iaws is removed, the springs i L press upward on the standards Gr suiiiciently to open the jaws e e slightly, so that the cent1-ef is quite free to be moved.

By this method of securing the centre, it is adjusted toits work and secured much more expeditiously than can be done with ascrew and tightener, as usual; and'as both centre and tail-block are secured or loosened by the same movement ,of the lever, the tail-block is always'frec to be moved at the only time when occasion can arise for its being moved.

' V, tig. 2, is a guide to aid in steadying the tail-block, and is held in areeess of the tail-block, and travels in a groove in the upper side of the frame A. The ends of this guide are bevelled ci? to a sharp point, so as to clear its way in the groove of chips which may lodge in said groove.

rIhe parts may be madeof any suitable material, and may be used-for a wood or metalworking lathe;

By these means these parts ot' a turninglathe are opratedwith much more rapidity and facility than heretofore.

Having thus described my invention, what I claim s new, and desire to secure by Letters Patent, is

A tail-block having a, pair of movable centre-holding jaws, e, when the securing-devices for the tailblock and the opertingsdeviees forthe said jaws act in conjunction, substantially as and for the purpose set forth.




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