Patent GB-190728332-A (GB)
Title: Improvements in Machines for Copying Sculpture and Ornamental Devices, in Marble, Stone, and other Substances.
Inventor: DENNY FRANK
Filed: 1907-12-24
Granted: 1908-12-24
Abstract: 28,332. Denny, F. Dec. 24. Carving and shaping by cutting.-In a copying and carving machine which works automatically, the electric circuits that control the operation of the machine are governed by the tracer. As shown in Figs. 1 and 2, a frame A pivoted at B on a stand C is fitted with slides D1, D2 carrying the cutter and tracer rods E, F. These rods carry a rotary and percussive tool G and the tracer H respectively. By means of a proportional controller, pivoted on the rod B and secured to the rods E, F, these rods are caused to move along the frame A in true proportion, the power for this movement being supplied by a plunger O. working on a fixed piston-rod N and moving the slide D1 through rack Q, pinions R, R<1>, and rack S. Proportional backward and forward movement is controlled by a collapsible rhombus I, J, K, L, the members I, J being pivoted on the rod B, and the members K, L on a sliding sleeve M. The power for this movement is supplied by a plunger under the slide D1. Electrically - controlled valve boxes as shown at O1, O2 control the operation of the plungers. The frame A is oscillated on the pivot B by means of a pulley X, which is driven through a flexible shaft and rotates one of a pair of plates Z1, Z2 which in turn actuates a nut W working on a screw V. When the circuit C', Fig. 14, is closed, a magnet operates to move a lever X<1> over, whereupon the pulley X drives the other of the pair of disks Z1, Z2, and the motion of the frame A is reversed. The tracer, Fig. 6, consists of an outside barrel A carrying a ball-jointed tip D, the movement of which causes the spindle B of insulating-material to actuate spring-held levers F', F<2>, F<3>, F<4> and close a circuit from the barrel A to the spindle H. This operates the circuit C<5>, Fig. 14. Circuits C', C<4>, Fig. 14, are closed through the tip D of the tracer. Fig. 14 shows the wiring for the electric circuits, controlled by switches 1, 6, 7, 5, 2, 8. Strips of metal A1, A2, A3, A4 are placed round the model to be copied and are insulated from each other. When the movement of the frame on its pivot causes the tip of the tracer to touch one of the strips A1, A2, the circuit C' is closed and the motion of the frame is reversed. At the same time, the circuit C<2> is closed, and the solenoid E causes the lever D to release the disk F and to close the circuit C<3> at B. This causes the release of a band brake K, fitted on a spindle R<2>, Fig. 2, to steady the machine, and also operates one of a pair of solenoids J1, J2 which operates one of the valve boxes O1, O2, Fig. 1, causing a movement of the cutter slide. This movement is communicated to the disk F, through a rack I and pinion G, and the circuit C<3> is thus kept closed till the cutter has moved the required distance, the circuit being then broken by the engagement of a projection on the lever D with one of the slots in the disk F. When the tracer touches one of the strips A3, A4, the circuit C4 is closed and operates the commutator N through a solenoid O and pawl P, the solenoid J1 or J2 that was previously in action being cut out and the other being put in circuit.. When the circuit C<3> is next closed, the cutter moves in the opposite direction. The circuit C<6 >is normally closed, a solenoid R actuating a valve box supplying pressure to the plunger which presses the tracer towards the model. When the tracer touches the model, the circuit C‹ is closed, and the magnet Q breaks the circuit C<6> and completes the circuit C<7>, a solenoid S actuating a valve box to bring the cntter away from the work. For undercutting, the tool and tracer are set at any angle to their respective rods, and the rods are rotated by means of plungers carrying racks acting on pinions on the rods. The plungers are both fed from the same valve box, a two-way tap being provided to admit pressure to either end of the plungers. The circuit C<8> con. trols this valve box and also controls solenoids T, T' which actuates pawls and ratchets to ensure equal rotation of the cutter and tracer rods. This circuit is controlled by a Morse key.