GB764883A - Machine tools - Google Patents

Abstract

764,883. Lathe details. KOPEZYNSKI, J. F. Feb. 1, 1955, No. 3008/55. Class 83 (3). [Also in. Group XXIII] A centreless machine-tool comprises a pair of peripherally-grooved wheels 50, 52 rotatable about parallel axes, a third wheel 72 rotatable and movable in a plane perpendicular to the axes of the wheels 50, 52 to enter the grooves 54 in the wheels and confine an object 73 in the nip between the wheels, means 60, 59 for moving the wheel 72 and holding it advanced under selected pressure, means 46 for rotating at least one of the wheels, and a tool 75 for machining the object 73 rotated by the wheels. The wheels 50, 52, 72 and the motor 46 and speed-reduction gear 47 for driving the wheels 50, 52 are mounted on a bracket 27 carried by a base-plate 21 which is clamped in adjusted position on the bed 10 of the machine by bolts 23. For taper-turning, the bracket 27 is pivoted at 32 on the base-plate and secured thereto by a stud 30. The wheel 72, which is driven by frictional contact with the work, is mounted on a shaft set at an angle to the axes of the grooved wheels, so that the work is pressed endwise by the wheel 72 against a rotatable centre 74 adjustable axially in a vertically-adjustable pillar 76. The shaft of the wheel 72 is supported in a block 57 traversed along guide-bars 55 by the compressed-air jack 59, 60 which is controlled by a reversing valve 64 and a reducing valve 67. Grinding or cutting-tools 15 are held in an indexable toolpost 14 on a carriage 11, and a tube 80, Fig. 6, discharges cooling fluid. The tool may be inverted and the work rotated in the opposite direction to enable swarf to fall away from the tool.