| 摘要 |
912,538. Lubricators &c. GAMET PRODUCTS Ltd., and PRATT PRECISION HYDRAULICS Ltd. Feb. 12, 1960 [Feb. 12, 1959; Dec. 31, 1959], No. 5042/60. Class 12 (3). [Also in Group XXII] Rotary - spindle headstock assembly comprises an outer stationary annular member having spaced internal rollerbearing surfaces and three inner rotary members fixed in relation to the spindle, two of the inner members having external roller bearing surfaces between which the third inner member is arranged to co-operate with a central part of the outer member to form a rotary distributer for pressure oil. The rotatable spindle 1 has a driving gear 50 keyed thereto at one end and a chuck 26 secured to a flange 1a at the other end by screws 27. The chuck has radial jaws 40 operated by bell-crank levers 38 which are pivoted by axial movement of a sleeve forming part of a double-acting piston 30 moved by oil pressure in a cylindrical bore of the chuck body. The spindle 1 is supported by two sets of tapered roller bearings 3a, 3b, the outer bearing for which consists in a sleeve 3 forming a stationary part of a distributer for oil pressure operating the chuck. A corresponding sleeve 6 secured to the spindle forms the other part of the distributer, there being a small clearance of the order of one to twohundredths of a millimeter between the rotating and non-rotating surfaces. Oil is fed, either to passage 14 or passage 15, according to whether the chuck is to be clamped or unclamped respectively. Lubrication. This may be effected by the leakage of oil through the clearance, or, separate provision may be made through passages 54, 55, from a relief valve 59. Specification 761,157 is referred to. |
