Patent GB-625808-A (GB)
Title: Improvements in copying planing machines
IPC: B23Q35/00
Filed: 1945-11-19
Abstract: 625,808. Copy-planing. TURCHAN, M., and WALKER, C. Nov. 19, 1945, No. 31105. Convention date, March 29, 1943. [Class 83 (iii)] A hydraulic copying-attachment for a vertically-adjustable, horizontally-reciprocable planing head 16 has a valve housing 52 movable with said head, a tracer housing 36 pivotally mounted on, and beneath, the valve housing, shearable locking means 77 interposed between the tracer and valve housings, and a valve in the housing 52 for controlling the vertical adjustment of the head during reciprocation and for actuation by a vertical tracer spindle 35 having a pattern-engaging roller 33. The planing head 16 is reciprocated horizontally by a ram secured at 16<SP>1</SP>, and has a slide on which a member 15 carrying the tool holder 14 and tracer assembly is vertically reciprocable by means of a movable cylinder 19 having a stationary piston secured to the head 16 by a rod 21; the tracer assembly is adjustable relative to the member 15 in three mutually-perpendicular directions by dove-tail slides operated by screws. Supply of pressure fluid to one or other end of the cylinder 19 is controlled by a tracer valve 48 fitted in the housing 52 and operated by the tracer spindle 35 which slides in the housing 36. A bolt 74 is secured to the housing 36 and is pivotally carried by a plate 72 depending from the valve housing, a shear pin 77 between the plate and the tracer housing normally preventing pivoting of the housing. The tracer spindle can slide in its housing on ball races and is prevented from rotating by rollers 43 carried on a spindle 44 passing through the tracer spindle and engaging guide plates 42. The upper end of the spindle has an adjusting screw 46 locked by a nut 45 and engaging a depending stem 47 on the valve 48. The valve is pressed down by a spring 66, whose compression may be adjusted by a nut 65, but, when the tracer spindle engages the pattern, the valve is raised and fluid entering at a pressure inlet 29 from a hydraulic unit is directed to a pipe 25 connected to the upper end of the cylinder 19 so that the cylinder and planer head are raised : the fluid expelled from the cylinder through the pipe 24 is directed to a pipe 30 leading to a sump in the hydraulic unit. If the tracer spindle meets a depression in the pattern, the valve is forced down by the spring 66 and reverses the flow to and from the cylinder, thus lowering the planing head. If this spindle meets an obstruction causing shearing of the pin 77, the housing and bolt 74 pivot and one of the cam surfaces 84, 85 secured to the housing raises the valve, thus withdrawing the planing head from the work. If required, the valve may also be raised by a handle having a cam engaging a disc 70 secured to a rod 67 on the valve. Oil seepage from the valve drains to a trough 60 and is withdrawn through a vacuum connection 32 from the hydraulic unit. The work 11 and pattern 12 may be directly supported on the table 10 or may be mounted on a shaft indexed by a gear 22. In a modification, the planing head has only a horizontal reciprocating motion and the work table is raised and lowered by two hydraulic cylinders controlled by the tracer.