GB721744A - An improved work supporting device for machine tools - Google Patents

Abstract

721,744. Lathe and like centres. JONES, C. H. March 3, 1952 [March 13, 1951], No. 6999/51. Class 83 (3). An adjustable worksupport for a machinetool comprises an eccentrically - bored member engaged on the relatively eccentric surfaces by a member which carries or is formed as a work-support and by a further member supported by the machine-tool. Tailstocks.-As applied to lateral adjustment of a tailstock spindle 11, the spindle is mounted in the eccentric bore of a sleeve 13 which is clamped, to secure the spindle in the tailstock casing 10, by pads 15 and a toggle-lever 18, beam 17 and set-screws 16. The clamping pressure may be varied by adjusting the leverpivot 19 or the screws 16 in the beam 17, a screw 20 forming a stop for the lever 18. The spindle 11 has an eccentric Morse-tapered bore 12 for a centre and longitudinal serrations 27, Fig. 2, co-operating with a spring-pressed peg 26 to guide the spindle 11 as it is fed by turning a handle 21 on a screw-threaded shaft 22 engaging the spindle through a nut 24. Centres.-For producing lateral adjustment of the point 31 of a dead-centre, Fig. 3, relatively to the shank 33, the point is formed eccentrically on a cylindrical body 30 having a concentric bore to receive a flanged sleeve 32 with an eccentric bore to engage a spigot on the shank 33. Adjustment of the point 31 is by rotating the sleeve 32 relatively to the shank and the body 30, according to graduations 34, and securing the sleeve to the spigot and the body by at least one grub-screw 35. In a modification, a live-centre. Fig. 5, that may be locked by a grub screw 46 to function as a deadcentre, comprises a casing 47 rotatable in bearings 36 on a sleeve 37 bored eccentrically to receive a further sleeve 38 also having an eccentric bore to receive a spigot on the shank 39. Lateral adjustment of the point is by rotating the sleeve 38 and locking it to the spigot with a grub-screw 40 in the sleeve 37. Chucks.-The chuck 42, Fig. 6, is centred on its carrier 41 by rings 44, 45 having an eccentric spigot-and-socket engagement with one another, the spigots on the chuck and the carrier being concentric with the axes of these members. Screws 43 clamp the parts after adjustment. The Provisional Specification discloses also a dead-centre similar to that of Fig. 3, but having no intermediate sleeve, the eccentric adjustment being facilitated by forming the spindle eccentric to its tapered shank and an eccentric bore in the outer casing in which the spindle bears. The casing is looked to the spindle by a bolt which clamps the split casing against the spindle, the bolt also engaging a groove in the spindle.