GB825294A - Improvements in or relating to polishing machines - Google Patents

Abstract

825,294. Polishing. WALL Ltd., H. Aug. 19,1957 [Oct. 3, 1956], No. 30202 /56. Class 60. Apparatus for the application of a polishing composition to the surface of a polishing disc comprises a reciprocating carriage 1, Fig. 1, adapted to hold an elongated cake of polishing composition and to bring one end of it into contact with the disc at the end of each stroke, and an intermittent feed device for advancing the cake towards the disc relative to the carriage by a variable amount, comprising a pair of rollers which grip the cake. The cake of polishing composition (not shown) is held in the reciprocating carriage 1 between rollers 2 and 3. The roller 2 is carried by a spring-loaded cover 4 hinged at 5 to the carriage 1, whilst the roller 3 is mounted on the carriage 1 and driven intermittently, by the reciprocation of the carriage, through gearing actuated by a ratchet-wheel 17 ; a pawl 19 engaging the ratchet-wheel 17 is carried by a bell-crank to which is connected a lost-motion rod 23. The roller 2 may also be driven or, as shown, freely rotatable. An electric motor 12 drives an eccentric 10 through reduction gearing in the casing 11, bearing faces 9, 91 attached to the carriage transmitting the reciprocating motion thereto, but the carriage 1 may be reciprocated by electrical, hydraulic or pneumatic means. The upward motion of the carriage causes the angled portion 23<SP>1</SP> of the lost-motion rod 23 to slide, together with a block 24 to which it is attached, in a slot 241 in the fixed part of the apparatus, until such movement of the block 24 is prevented by an adjustable stop 25 held by a clamping screw 26. Further upward motion of the carriage 1 causes the rod 23 to move the bell-crank 21, 22 clockwise and thus to advance the cake of polishing material from the carriage towards the polishing disc. After the predetermined amount of angular movement has been imparted to the ratchet-wheel 17 the latter is held by a pawl 26<SP>1</SP> whilst the bellcrank 21, 22 and pawl 19 are caused to move anti-clockwise during part of the down stroke of the carriage. The motor is adapted to be switched off automatically when the polishing cake is almost wholly consumed by providing a pivoted member 27, Fig. 4, which is normally depressed by the cake to pull a spring-urged rod 28 downward and, as the end of the cake is fed past the member 27, releases the rod 28 to open a motor control switch. The Provisional Specification describes apparatus for the intermittent distribution of a flowable composition to the polishing disc incorporating a plunger which forces the compound through an orifice, or, alternatively, rollers may be actuated intermittently to squeeze the compound from a collapsible container.