Patent GB-941855-A (GB)
Title: Surface finishing machine
IPC: B24B7/12
Filed: 1961-03-13
Abstract: 941,855. Buffing machines. CLAIR MANUFACTURING CO. Inc. March 13, 1961 [Feb. 7, 1961], No. 9025/61. Heading B3D. [Also in Division F2] An apparatus for finishing surfaces by an abrading, buffing, brushing or polishing roll comprises work-receiving pinch rolls 68, 69, Fig. 3, which deliver the work to a back-up roll 35, Fig. 4, a finishing roll 30 for operating on the work when supported by the back-up roll, and a control system for regulating the movements of the roll 30 towards and away from the roll 35 including automatic control means whereby the passage of the trailing edge of the work relative to the roll 30 causes movement of this roll from its work-contacting position coincident with the completion of the finishing operation on the work up to its trailing edge. The upper pinch roll 68 rotates freely on its shaft 18 which is itself journalled in bearings carried by pedestals 12, 14, from which the shaftends project and have mounted thereon arms 24, 25, Fig. 7, between which the finishing roll 30 is removably supported. A third arm 26 supports the out-board end of a push-pull rod 112, Fig. 9, whereby the support 32 at one end of the finishing roll 30 may be reciprocated by fluid pressure supplied to a piston 120 movable within a cylinder 122; the other support 31 is belt driven by a motor 28 and pulleys 29 concentric with shaft 18 and freely rotatable on the end thereof. At the other side of the machine a motor 66 drives, through a speed reducer 65 and a chain 62, sprockets 72 and 60, the lower pinch roll 69, and the back-up roll 35 respectively. The driving chain and the belt are each tensioned by a jockey member mounted at the end of an arm 78 of a bell-crank operated by fluid-pressure means 80, provided at each side of the machine. Adjustment of the roll 35 is effected by a manually-operated screw 43 through bellcrank arms 37, 45 whereby the roll may be swung forward or rearward of the axis of the finishing roll 30. An arm 55 rigidly secured to a cross-member 16 carries at its outer end a trunnion-mounted nut through which the positioning of the finishing roll 35 may be manually adjusted by a hand wheel on the end of a screwed shaft 53, arms 26 and 52 being rocked about the axis of the shaft 18 during this adjustment. The working pressure on the roll 30 is effected by a pneumatically-operated piston-and-cylinder control unit 57, whilst pressure is applied to the work by the upper pinch roll by manually operated screws 23 and bearing blocks 133 and 15, the latter being slidably mounted in the pedestals 12, 14. Rigidity is afforded the roll-shaft 18 by the cross-member 16, to which it is secured by the blocks 133. The control system of the machine, Fig. 13, provides, through a switch 170, for alternative hand or automatic control. For manual control the buff and feed motor switches 171 and 172 are closed, the work is fed into engagement with the pinch-rolls and the switch 173 controlling the lowering of the roll 30 is closed, any number of workpieces being passed through the machine until the " buff-raise " switch 174 is actuated or when a safety device is operated. When the switch 170 is set for automatic working the finishing roll does not lower because of an air blast from a nozzle 157, Fig. 11, impinges on a cup 154 operating a tiltable mercury-switch 150 which is held thereby in an open position until the advancing edge of the workpiece cuts off the blast and the switch closes and the roll is lowered through a time-delay relay system. As the trailing edge uncovers the nozzle 157 and the switch 150 is actuated to raise the roll 30 the reciprocatory motion of the roll 30 is effected automatically by a cam 125, Fig. 9, operating a switch 130 to control the valve 130a admitting pressure alternately to the opposite ends of the cylinder 122. The feed-in side of the machine is provided with a safety device to prevent damage to the operator's hands. A hinged panel 134, Fig. 11, hangs from a bracket 137 so that the panel if pressed inwards towards the pinch-rolls, moves an arm 140 connected to a micro-switch 142 and thus interrupts the power supply to the machine.