Patent GB-842989-A (GB)
Title: A machine for drilling small stones
IPC: G04D3/00
Filed: 1956-10-26
Abstract: 842,989. Drilling jewels. SOC. MO. NA. COR, and LEFEVRE, G. Oct. 26, 1956 [Nov. 2, 1955], No. 32679/56. Class 83 (3). A machine for drilling small hard stones for industrial purposes, e.g. jewels for clocks and watches or draw plates for wire-drawing, comprises a circular turret 5 mounted to be rotated about a vertical axis by a motor, and carrying a series of vertical spindles 6, under each of which is positioned one of a corresponding series of rocking members 12 adjusted to hold a stone to be perforated in contact with the drill, each rocking member closing, upon completion of the perforating of the stone, a switch for energizing the motor controlling the turret, which switch actuates, when the spindle carrying the drilled stone arrives into register with the point of loading of the stones into the machine, a second circuit which stops the motor and transiently locks the turret. Each spindle is driven at 30,000-100,000 R.P.M. by a blade wheel 7, to which fluid is pumped through pipes 45, 46. The speed of the spindles may be varied by a valve; above each blade wheel 7 is a deflector 52 operable by a handle 53 to stop the rotation. The pump also supplies fluid through a pipe 47, a chamber 48 and pipes 49 to the bearings for the spindles 6. Each spindle 6 carries a steel wire drill 8. A ring 10 carries, in register with each spindle, a sleeve 11 to guide a carrier 26 on which is glued a workpiece. Each carrier 26 is urged upwardly by a rocker member 12 carried by a support 36 secured to the turret. One end of the rocker member carries a counterweight 38, and the other end carries a contact 39 co-operating with a contact 40; a damping spring blade 42 acts on the tail piece 43 of the rocker member when the latter is near its horizontal position. The turret has teeth 27 by which it can be rotated through a slipping drive by an electric motor 29. The turret also has notches 17 in register with the spindles 6. A bolt is urged by a spring to enter simultaneously a single notch in the base and one of the notches 17, being withdrawn by an electromagnet 20. To the turret are secured a ring 13 entirely of conductive material, and a ring 14 comprising conductive portions in register with the spindles 6, and separated by insulating sections. On the base plate 1 are mounted thirty insulating carriers 16 having the same angular spacing as the spindles 6. Twenty-nine of these carriers 16 each carry a conductive shoe 16a connecting the ring 13 with the registering conductive portion of the ring 14; the thirtieth carrier 31 is located at the loading and unloading station and carries two insulated contact pieces 32, 33, the former contacting the registering conductive portion of the ring 14 and the latter contacting the ring 13. When the drill has completely perforated the workpiece, the rocker member 12 is brought suddenly into its horizontal position, closing contacts 39, 40 to energize the motor 29. The turret is thus rotated, being unlocked by the electromagnet 20, until the rocker member 12 reaches the loading and unloading station. The corresponding conductive portion of the ring 14 then contacts the contact piece 32, causing the motor 29 to stop and the electromagnet 20 to cause locking of the turret. A feed channel comprises a removable arcuate section 60, and a fixed straight section 61. Loaded carriers 26 are placed vertically in the channel, and are acted on by a pin 62 on a spring-loaded pivoted arm 63. A motor 64 under the control of the relay rotates two cams 65, 66. A carriage 68 guided on the frame is moved horizontally by the cam 65, and a plate 71 guided on the carriage 68 is moved vertically by the cam 66. The plate 71 has, opposite the turret, two horizontal noses 74 separated by a gap, within which works a clamping jaw 76 urged in the clamping direction by a blade spring 77, but normally prevented from clamping by a rocking control member 79. Initially, the noses 74 are in register with the delivery end of the feed channel, and an element 26 has engaged the gap between the noses. It is supported by a spring-loaded pivoted flap 82. As the carriage 68 moves towards the turret, the jaw 76 clamps the element 26. Movement continues until the element 26 has been brought into register with the axis of the sleeve 11. At this time the rocker 12 is held inoperative. The plate 71 then rises, during which the jaw 76 moves to free the work, and the rocker moves into position to support the element 26. Unloading of an element carrying a perforated stone is effected by movement of the parts in the reverse sequence, the element being delivered into a discharge channel. As the elements 26 travel along the channel 61, the stones pick up abrasive paste from a container. A group of five machines may be arranged arcuately for control by one operator.