Patent GB-330419-A (GB)
Title: Improvements relating to apparatus for automatically drilling holes in jacquard cylinders or other articles
IPC: B23B41/00
Filed: 1929-06-26
Abstract: 330,419. Ross, H. R., and Cunning- ham, R. June 26, 1929. Drilling machines, especially for boring holes in jacquard cylinders, comprise mechanism whereby the drilling of a series of parallel rows of holes is carried out automatically, with the omission of predetermined holes, and means for varying the pitch of the holes. The cylinder G, Fig. 5, is clamped between a plate 100 and a movable plate by adjusting screws 103 on a plate 108, and rests on a horizontal plate 101, Fig. 1. The drill F, continuously rotated from a motor A through a belt 70, a pulley 71, shaft 72 and friction wheels 73, 74, is held on a carriage 43, Fig. 2, slidable on guides 44, 45, and may be traversed by rotation of a screw H. The drill is raised and lowered by rotation of shaft 28 having a rack and pinion engagement with sleeve of the drill spindle. A lever 14 receives vertical reciprocation about a pivot 15 from the motor A through gearing 10 and a cam 13, which motion is imparted to a rod 17, guided in its motion by a rod 17, guided in its motion by a fixed cam 22, Fig. 4, passing through a forked portion of the rod carrying rollers 18, 19, 20. At the bottom of its motion the top of the rod moves under the end of an arm 24, so that on upward movement of the rod 17 the arm is raised, partial rotation is given to the shaft 28 and the drill is lowered, and is raised again when the arm 24 falls. A member 29 on guides 29<a> is reciprocated by the lever 14 and carries a horizontally slidable plate 30, Fig. 6, carrying pawls 36 and 37 either of which may engage with a chain 30 and hence rotate a pinion 40 and the screw H on downward movement of the member 29, thereby imparting intermittent feed to the drill. A frame 41, moves a small distance against spring pressure when stops 46 or 47 on the carriage 43 strike it at the end of a row of holes, and abuts in a notch of a horizontally pivoted member 42 which by a cam like action, tilts a U-shaped member 40a, 40b whose lower end is bent around the spindle of pinion 39. A catch on the limb 40 engages a notch 33 on a head 32 carried by the spindle 31 thus operating a cam 34 which moves the plate 30 and disengages the pawl. The next reciprocation brings the other pawl into action, and the feed is reversed. A similar mechanism, operated by a lever 53, effects lateral movement at the end of each row of holes, by a screw M, but the cam is so formed that the pawl is normally inoperative, and the same. pawl is brought into action to preserve unidirectional feed. The direction may be reversed, if desired, by adjustment of the relative tensions of springs 49 and 51, to bring the other pawl into operation. In each case springs assist the downward movement, and precise movement is ensured by a spring gripper 66 and a cam 67. When one side is bored, the machine is stopped by a projection 60 striking the starting handle 61. In order to omit holes towards the centre, a stop 77 on the carriage 43 engages a projection 78 on a lever 79 pivoted at 80. This raises a member 81, Fig. 4, which tilts a lever 82 clockwise, so that it comes under the roller 17, thus preventing the rod 17 from coming beneath the lever 24. The size of the projection 71 determines the number of holes to be omitted. To omit a hole at the end of a row, a pin 84 on the frame 41 tilts, by a link 84<a>, a rod 85 clockwise about the point 86, causing a lever 87 to hinge about 88, thus putting a projection 90 on the lever 87 in the path of a stop 91 on the reciprocating rod 16. Hence the lever 87 tilts about the point 92, causing a lever 93 to pivot about 95, this lever carrying a cam which lifts the lever 82 as before. The pitch of the holes may be varied by shrouding the chains. A fan 75 operated by the shaft 72 blows air through a tube 76 on to the drill.