Patent GB-744516-A (GB)
Title: Improvements in machines for use in repairing the valve seat faces of parallel slide valves
Inventor: SPENCE CHARLES ALBERT
IPC: B24B15/02
Filed: 1953-11-09
Abstract: 744,516. Grinding valve seats. DEWRANCE & CO., Ltd. Nov. 9, 1954 [Nov. 9, 1953] No. 30928/53. Class 60 A machine for repairing the seat faces 6 7, Fig. 1. of parallel slide valves comprises a tool 185 rotatably mounted on a rotatable member 142. Fig. 2, rotatably mounted on an abutment member 152 which is located by clamping means 249 arranged to engage the bore 4 of the valve, means being provided to vary the relative positioning of the abutment member 152 and the tool 185 in the direction of the axis of rotation thereof. The tool 185 is a cup-type grinding wheel which is provided with a soft metal bush 186 and secured to a holder 180 by a fibre grip washer 191 and retaining plate 189 having a central boss 190 screwthreaded into a boss 187 on the holder 180. A pulley 179 mounted on the rotatable member 142 is connected by a belt 184 to a pulley 108 rotated by a flexible shaft 119 from an electric motor and serves to rotate the tool which is also caused to planetate by rotation of the member 142 on an axle 140 forming part of the abutment member 152. This latter rotation is produced bv a hand crank 92 connected to the member 142 by a shaft 90, Fig. 3. two sprocket wheels 96, 145 and a chain drive 148 and is usually at the rate of one revolution per second. To maintain the distance between the two pulleys constant, the pulley 108 is mounted on an eccentric pin 98 so that it planetates in step with the pulley 179. The means to produce axial feed of the tool 185 consists of a handheel 76 connected by a sleeve 49, a pair of sprocket wheels 81, 146 and a chain drive 163 to a rotatable feed ring 151 in screw-threaded engagement with the abutment member 152. To maintain the sprocket wheels 81, 146 in alignment, the sleeve 49 is arranged to move axially in step with the feed ring 151 due to screw-threaded engagement with a bush 55. A screw 71 enables the feed mechanism to be locked and a calibrated sleeve 62 indicates the amount of feed applied. The clamping means 249 consists of three wedges mounted about the periphery of a housing 200 and arranged to be initially adjusted against the resistance of a colled helical spring 260 by a screw threaded ring 246. The housing 200 contains a piston 240 which is connected by a spring-loaded piston rod 202 to a ring 137 adapted to be detachablv connected to an undercut slot 136 of T-shaped transverse cross section extending from a central region of the abutment member 152 to one edge thereof. When the machine is due to be assembled on a valve body, the ring 137 is detached from the abutment member and the housing 200 inserted in the valve bore until a metal clip' 244 engages the valve face whereupon the ring 246 is rotated to bring the clamping means 249 into engagement with the valve bore. The ring 137 is connected to the abutment member 152, and the upper part of the machine, which is mounted on a base plate 24, is connected by nuts 26 to four studs 20 on the valve body, the belt and chain drives being placed in position and tensioned by adjustment of nuts 28. Finally, oil under pressure is introduced into the housing 200 through a pipe 231 to displace the piston until the abutment, member 152 engages the valve face whereafter the housing 200 moves axially to tighten the clamping means 249 and the machine is ready for use. Specification 653,828 is referred to.