GB558210A - Keyboard perforator - Google Patents

Abstract

558,210. Punching telegraph tapes. TELETYPE CORPORATION. July 10, 1942, No. 9609. Convention date, July 5, 1941. [Class 31 (ii)] Relates to a keyboard perforator, which is especially applicable for perforating telegraph tapes in accordance with a code, and which is of the kind described in Specification 358,737 and comprises a number of punches 29 adapted to perforate a tape 34 by the selective operatior of interponent bars 38 between the punches and electromagnetically operated hammers 37, the bars 38 being controlled by a keyboard mech anism as described in the above Specification wherein keys 15 control permutation bars 28 controlling by links 41 levers 39 connected to the interponent bars 38. According to the invention means are provided to ensure a complete opera tion of the punches when a key is depressed, and to prevent the electrical contacts being prematurely opened, and also to prevent re operation of the key-levers until one operation is complete. Each actuation of a key-lever actuates also a universal bar which oscillates a lever 67 provided with an insulated member 72 adapted to press on an electrical contact 73 adapted to engage a second contact to complete the energizing circuit of the electromagnet 43. Before the circuit is completed a spring-controlled latch member 63 engages a pin 71 on lever 67 and so prevents this lever from moving backwards prematurely. On depression of the armature an anti-chatter device 79 is permitted to move counterclockwise under action of a spring, and a spring arm 83 of this device acts upon the contact 85 to keep the magnet energized by taking control of the contacts 73, 85. The armature also releases a catch or curb member 64 which moves counterclockwise to engage the underside of the projection 71 in order to prevent premature return of the lever 67 after it has been released by raising of the catch 63 by a striker member 75 carried by the armature upon contact of the armature with the poles of magnet 43. The curb member 64 is returned clockwise by a member 77 carried by the armature, and is thus moved to permit a further operation. The tape 34 is advanced by a ratchet 56 engaged by a spring-controlled pawl 55 carried by the hammer 45. The ratchet shaft 56 is provided with pins which engage holes punched in the tape. The punches 29 may pierce the tape so as to leave uncut portions which serve as hinged lids adapted to yield to the sensing pins of a transmitter, as described in Specification 540, 612. To facilitate the back spacing of such tape a tearing-knife 91 by which the tape can be severed when desired is provided with a bevel to cam down the lids when the tape is reversed. To move the tape backwards. a lever 92, Fig. 7, is operated clockwise and acts by means of an arm 97 to trip the pawl 55, and by means of a pawl 98 to rotate a starwheel 104 clockwise. The starwheel is on the shaft 56 and is controlled by a spring detent 105 to limit the rotation to one tooth. The ejectors 51 are provided with wing portions 49 having inclined lower edges so as to cam down the lids when back spacing takes place.