Patent GB-113184-A (GB)
Title: Improvements in or relating to Telegraphic Receiving and Tape Perforating Apparatus.
IPC: H04L15/32
Filed: 1917-04-10
Abstract: 113,184. Muirhead, A. L., Huskinson, A.C., and Muirhead & Co. April 10, 1917. Receiving systems; strip-perforating receivers. -The strip-perforating receiver of a code telegraph system, in which the code elements are differentiated by strength of current, is so arranged that, when a dash or strong current impulse is received, the dot perforator controlled by a weaker current impulse is not operated. The invention is described with reference to a method of signalling in which the code elements and the spaces are differentiated by half waves of alternating-current of different amplitudes. The receiving impulses are amplified by a relay described in Specification 17555/09 associated with a local source of alternating current and a relay described in Specifications 10856/11 and 5950/12. The dot and dash perforators are operated by relatively interposing a member in the path of projections on the operating slide of the perforator of the central or spacing holes of the strip. Receiving system. The circuit C, Fig. 1, of a Heurtley hot-wire relay B described in Specification 17555/09 contains a Kramer relay D described in Specification 10856/11 and 5950/12; while the circuit C' contains the secondary winding e of a transformer E the primary winding e<1> of which is in a circuit controlled by a tuning fork f. The relay D controls through contacts g, g<1>, g<2> relays G, G<1>, G<2> which in turn control the spacing magnet H, the dot magnet H<1> and the dash magnet H<2>. The energization of the dash magnet H<2> opens the circuit of the dot magnet H' at the contact h<5>. Strip-perforator. A cam sleeve K, Figs. 2, 3, and 7, is loosely mounted on a constantly rotating shaft J and is adapted to be clutched to the shaft by means of pawl k and a ratchet-wheel j. The pawl k is normally held out of engagement with the wheel j by the armature h<1> of the spacing magnet H. The sleeve K carries a. cam L provided with a recessed portion l and two concentric portions l<1>, l<2>. The cam L engages a roller m<1> mounted in the head m of a spring-controlled slide M: while the head m is adapted to operate the dot and dash slides M<1>, M<2> by interposing rollers O, O<1>, Figs. 2, 3, and 6, between the head m and the slides M<1>, M<2> respectively. The rollers O, O<1> are mounted in the armatures o, o<1> of the dot and dash magnets H<1>, H<2>. and the armatures o, o<1> are normally retracted by springs o<2>. The armatures o, o<1> are held in their operative positions by catches Q. Q' mounted on shafts q<1>, q<2>. The positions of the catches Q. Q<1> are controlled by a single spring and two arms q<4> which rest upon a lever m<4>. the position of which is controlled by a stud m<3> carried by the slide M. Operation. When a current impulse of a. value corresponding to a space is received by the relay b, Fig. 1. the relay B is operated to send an alterrating current from the transformer E to the relay D, this current being of such. a value that the contacts g are opened to de-energize the relay G. The relay G operates to energize, the spacing magnet H, Figs. 1, 2, and 3. The attraction of the armature h<4> of the magnet H allows the pawl k and ratchet-wheel j to clutch the cam-sleeve K to the rotating-shaft J. In the normal position of the cam L. the roller m<1> engages the recessed portion l and. at the commencement of its rotation, the portion l<1> engages the roller m<1> to advance the slide M a short distance. During this movement, the stud m<3> engages the lever m<4> to raise the arms g<4> and consequently the catches Q, Q<1>. Since the magnets H<1>, H<2> are not energized, their armatures o, o<1> are not attracted and the rollers 0, O<1> are not interposed between the head m and the slides M<1>, M<2>. A further movement of the cam L causes the part l<2> to engage the roller m' thereby advancing the slide M to engage the central space-perforating rod. The cam L is further rotated until its recess l engages the roller m<1> when the released armature h<4> operates to release the pawl k from the wheel i. When a stronger current impulse, corresponding to a dot, is received, the relay D is supplied with a stronger current to open the contacts g, g<1> thereby de-energizing the relays G, G'. The relay G operates through the medium of the magnet H to control the rotation of the cam L as previously described, while the relay G' operates to energize the magnet H<1>. The armature o of the magnet H<1> is attracted to interpose its roller O between the head m and the slide M<1> while the catches Q, Q<1> are lifted in the manner previously described so that, when these catches are lowered by the action of the spring q, the catch Q falls behind the armature o to retain it in its attracted position after the magnet H' is de-energized. The continued rotation of the cam L operates the slides M, M' to operate the space and dot perforating rods. The further rotation of the cam L allows the apparatus to return to its normal condition. When the strongest current impulse, corresponding to the dash, is received, the relay D is supplied with a corresponding current to open the contacts g, g<1>, g<2> thereby deenergizing the relays G, G<1>, G<2>. The relay G operates as previously described to control the rotation of the cam L, while the relays G<1>, G<2> operate to energize. the magnets H<1>, H<2>. The armatures o, o<1> of the magnets H<1>, H<2> are attracted to interpose the rollers O, O<1> between the head m and the slides M<1>, M<2> while the catches Q, Q<1> are lifted and lowered as previously described to fall behind the armatures o, o'. The attraction of the dash armature o<1> causes a projection o<3> mounted upon it to engage a lever q<3> thereby lifting the latch Q to release the armature o which returns to its normal position since the circuit of the magnet H<1> is opened at the contact h<5> of the magnet H<2>. The roller O<1> only is therefore interposed between the head m and the slide M<2> when the operating part l<2> of the cam L engages the roller m<1> thereby operating the space and dash perforating rods.