GB235136A - Improvements in impulse transmitters for use in telephone or like systems - Google Patents

Abstract

235,136. Automatic Telephone Manufacturing Co., Ltd., (Assignees of Blessing, J. G.). June 7, 1924, [Convention date]. Impulse transmitters.-A transmitter of the dial type used for numbers which are called very frequently is so constructed that only a single setting operation is required to set up the complete connection. The impulse cam 39 always generates the same number of impulses, and the variable setting of the dial 12 causes the selection of one of a number of cam discs 30 which cooperate with springs 60, 61 to split up the impulses into trains, one cam disc being provided for each subscriber. Two movable finger stops 11, 11<1> are provided on a bar 56, which always moves through the same angle (156‹) to prepare for the rotation of the impulse cam. Gear wheel 13 is fixed to the bar 56, and tensions the usual driving spring during the setting movement, shafts 58, 74 remaining at rest. When the finger stop moves from normal a pin 51 on the bar 56 releases an arm 50 on a shaft 97, so that the latter is rotated slightly by a spring to unlock shaft 58 by means of an arm 46, Fig. 7, and to bring a detent 47 into engagement with a ratchet 26 on the shaft 22 of the dial. When the dial has rotated through the angle of movement of the finger stop (156‹), the lowest point of an inclined wall on ratchet 26 engages a roller 34 on an arm 25, and the roller then rises on the inclined wall so that a bracket 44 with springs 60, 61, 80 is lifted by arm 25 opposite the appropriate cam disc 30. The setting operation is completed when a pin 43 or 43<1> on the bar 56 engages a stop 108 on the mounting plate 8. During the return movement of the bar 56, the shaft 58 of the impulse cam is rotated from gear wheel 13 through a ratchet 18, while the shaft 74 carrying the cam discs 30 is rotated through a ratchet 32 and pawl 33, so that trains of impulses are sent out under control of a governor 21 in a manner subsequently described. When pin 51 again strikes arm 50, shaft 97 returns to normal position, locking shaft 58 and removing detent 47, so that ratchet 26 and the dial return to normal under the action of a spiral spring 22, when a pin 15 engages projections on the finger stop 11<1>, while arm 25 and bracket 44 are restored by a spring 38. The impulse springs 66, 67, Fig. 4, are normally short-circuited by springs 60, 61, which are operated by cams 113, 114, 115 on the disc 30 to remove the short.-circuit and enable three trains of impulses to be sent out. The disc 30 makes a complete revolution at each operation. The engagement of a brush 59 with the cam disc shortcircuits the substation instruments while impulses are being sent out. The framework of the apparatus comprises mounting plates 7, 8 with posts 5, each having a cut-away portion and a screw 6. When the framework is placed in the tubular housing, the screws 6 are screwed outwardly into register with corresponding holes to lock the framework in position. Specification 4179/12 is referred to.