Patent GB-262561-A (GB)
Title: Improvements in type printing telegraph receivers
IPC: H04L17/22
Filed: 1925-10-26
Abstract: 262,561. McKay, F. Oct. 26, 1925. Type-printing telegraphs.-In a type-printing receiver employing selector devices carried by a rotatable head on a spring - actuated startstop shaft, an electromagnet receiving the impulses acts to release the shaft prior to the receipt of each group of selecting impulses, and, while the shaft is rotating, to move a selection of the devices to actuated position in which, while the shaft is rotating, they cooperate with other devices which select the type. Type selecting mechanism. As applied to a system employing a five-unit code, the rotatable head, in the form of a spur-wheel disc 24, Figs. 1 and 2, on a shaft 23, Figs. 4 and 5, carries groups of pins, the pins of each group being arranged along an involute curve and comprising a spring- projected stop pin 33 and five slidable selector pins 26. Each pin 26 is locked in actuated or unactuated position by a spring 29 engaging one or other of two notches 28 in the pin as shown in Fig. 9. Rotation of the shaft 23 by the wound driving spring 76, Fig. 6, is prevented by the engagement of one of the pins 33 with a fixed stop 35, Fig. 1, until the pin is pushed inwards by an extension 40 of the pivoted armature 38 of the receiving magnet 36 upon energization of this magnet by a starting impulse, whereupon the shaft rotates under the control of an escapement 79, Fig. 1, or of a brake. The succeeding signal impulses energize or fail to energize the magnet, and the extension 40 moves a corresponding selection of the pins 26 to actuated position, whereafter the shaft is arrested by the engagement of the pin 33 of the succeeding group' with the stop 35. The head 24 rotates the inner end of each actuated pin 26, engages the inclined end of a latch 18, Fig. 1, pivoted to a corresponding notched selector bar 12, and moves the latch against the action of a spring 22. Fig. 2, to disengage it from a frame 20, whereupon the bar 12 is moved longitudinally by a spring 16. Notches in the bars 12 are thus aligned to select one of a series of pivoted fingers 9. each corresponding to a type character, projecting through guide slots 5 in a fixed frame 4. The pins 26 are subsequently returned to normal position by a fixed cam plate 107, Fig. 2. Printing. The fingers 9 are normally held clear of the bars 12 by a cross-bar 43. Fig. 4, connecting arms 42 secured to a rock-shaft 41, one arm 42 being connected by a link 45 to a lever 46, forming a toggle which holds the parts rigid. The toggle is locked by the engagement of a shoulder 48 on the lever 46 with a shoulder on a lever 49 connected by a link 50 to an arm 51 on a rockshaft 52 controlled by a spring 53, and is periodically released by the engagement with an arm 54. Fig. 5. on the shaft 52 of successive bevelled fingers 56 projecting from a wheel 55 on the shaft 23. Upon release of the toggle the selected finger 9 is moved by a spring 10 into the aligned notches and lifts a rod 6 connected to a corresponding type-bar 7, thus causing the hooked end 13 of the rod to engage the forward edge of a bail 14 on a rock-shaft 15. The bail is connected by a link 59 to the enlarged upper end of a lever 57 pivoted to the base of the apparatus, and is operated to effect printing by movement to the right of a bar 62 pivoted at 61 to the lever 57. Driving arrangements. The bar 62 is controlled by the engagement of a roller 67 thereon with a spiral cam 68 on a shaft 69 adapted to be alternately clutched to and declutched from a motordriven wheel 99. The clutch comprises a bolt slidable in a radial slot in a disc 98 secured to the shaft 69 and engaging the slotted rim of the wheel 99. With the clutch in operation the bar 62 is moved to the left to restore the printing mechanism, and a spring 65 is stressed through a lever. A link 93 carried by the bar engages a crank 94 on a rock-shaft 95 carrying a bevelled arm 96 which, when the shaft is free to be rocked by a spring 101<a>, engages a pin 100 on the clutch bolt to disengage the bolt from the wheel 99. The roller 67 being then in engagement with the axial portion of the cam 68, the bar 62 is moved to the right by the spring 65 and the cycle of operations is repeated. During the movement to the right a pawl 71. pivoted to the lever 57 and engaging a ratchet wheel 72 secured to a sleeve 74 loose on the shaft 23, rotates the wheel one step and the wheel is again held by its locking pawl 73. This rotation serves to wind the driving spring 76 secured at one end to its housing formed by a flange 78 on the wheel 55, and at the other end to the sleeve 74. At the same time a cam bar 81 pivoted to the lever 57 acts on a roller 84 carried by a lever 83 secured to the shaft 41 and rocks this shaft in a direction to cause the bar 43 to disengage the selected finger 9 from the bars 12 whereupon a roller 103, Fig. 7, carried by the bar 62 acts on a pivoted arm 104 to operate a link 106 for returning the bars 12 to normal position. The rocking of the shaft 41 straightens and re-locks the toggle, and in this locked position the top of a latch 87, Figs. 5 and 7, pivoted to an arm 86 secured to the shaft 41 and controlled by a spring 88, supports a lateral extension 91 of a pivoted arm 90 held by a spring against a cam 89 on the bar 62. The rocking of the shaft 41 upon release of the toggle moves the latch 87 clear of the extension 91 and enables the bar 62 to move to the right to effect printing.