Patent GB-625895-A (GB)
Title: Improvements in or relating to tracer controlled metal cutting or like machines for copying
IPC: B23D3/04
Filed: 1946-02-20
Abstract: 625,895. Copy-planing; planing screw propeller blades. TURCHAN, M., and WALKER, C. Feb. 20, 1946, No. 5384. Convention date, July 26, 1941. [Class 83 (iii)] A hydraulic duplicating attachment for a cylinder-actuated reciprocable planer head comprises a pattern-engaging tracer, tracer-actuated fluid control means joined to the head for controlling the flow of fluid from a pressure source to the cylinder, means pivotally mounting the tracer to the control means, and a shearable locking means interposed therebetween. The tracer head 27 is adjustably secured to the planer head, and the tracer housing 24 is pivotally mounted on a bolt 28 threaded into the tracer head and secured by a locking screw 29, rotation of the tracer housing being prevented by shearable pin 30 made of relatively soft metal and housed in bushings 301. The tracer spindle 23, which is mounted in bearings 25 and carries a roller 26 in contact with the pattern, deflects a lever 41 pivoted on a bracket 40 to actuate a piston 37 which is slidably disposed in a cylinder 31 and has a piston-rod 41<SP>1</SP> in contact with an adjustable bolt 42<SP>1</SP> carried by the lever. The tracer spindle is prevented from rotating in its housing by guide plates 63 longitudinally disposed within the top portion of the tracer housing 24, with roller guides 64 oppositely disposed therebetween and connected to the spindle by a transversely disposed bolt 641. The upper and lower ends of the cylinder 31 are sealed by a nut 41<SP>11</SP> and a cap member 36, respectively, the latter having a bolt 47 centrally threaded therethrough to adjust a spring 48 interposed between the under surface of the piston and the bolt. Annular recesses 351, 341, 3511, Fig. 8, in the cylinder are governed by annular recesses 80, 81, 82 in the piston, respectively, and a hydraulic unit 32, Fig. 7, supplies fluid under pressure through a conduit 34 to the cylinder recess 34<SP>1</SP>, the recesses 351 and 35<SP>11</SP> being exhaust openings connected by a conduit 35 to the exhaust side of the hydraulic unit. Oil seepage inside the cylinder 31 is scavenged through a conduit 68. Flexible conduits 21 and 22 connect annular openings 211 and 221 in the cylinder to the upper and lower ends, respectively, of a reciprocable cylinder 19 enclosing a stationary piston and connected by a bracket 70 to the planer head. The cylinder may, alternatively, be made stationary with a reciprocable piston. Upward movement of the tracer spindle deflects the lever, producing a downward displacement of the piston valve 37 and allowing fluid to flow under pressure through conduit 34, openings 34<SP>1</SP>, 81, 22<SP>1</SP> and conduit 22 into the lower end of cylinder 19 so as to cause the planer head to ascend. The fluid in the upper end of the cylinder is expelled through the conduit 21, openings 21<SP>1</SP>, 82, 35<SP>11</SP> and conduit 35. Downward displacement of the tracer spindle will, in a similar manner, cause the planer head to descend. If the tracer encounters an obstruction, the locking pin 30 will shear, and the housing 24 will rotate in one direction or the other, causing one of two cam surfaces 60 disposed on opposite sides of the spindle housing to engage and deflect the lever; the piston valve is then displaced downwardly and raises the tool clear of the work-piece. The piston valve may be operated by a manual control consisting of a bracket 43 secured to the tracer head and having a handle 44 pivotally mounted for rotating a cam 45 engaging an adjustable bolt 46. The tracer head is adjustable in three mutually perpendicular directions relative to a bracket 56 on the planer head by bolts 59 and dovetailed slides actuated by screw mechanism. Bolts are provided to lock the tracer head in any desired position relative to the planer head. Two vertical guides disposed one at each side of the work-table contain interconnected screwed rods engaging a horizontal guide transversely disposed with respect to the work-table and along which the planer head and its attachment, which are counterbalanced by springs, may be traversed by a screwed rod engaging the planer head guide.