Patent GB-245207-A (GB)
Title: Improved operating means for electric signalling devices
IPC: G10K1/064
Filed: 1924-10-04
Abstract: 245,207. Clark, J. W. Oct. 4, 1924. Bell and audible signalling systems; lamp indicators.-In electromagnetic operating mechanism for signalling devices such as bells, buzzers, annunciators lamps, &c. a pivoted armature which co-operates with electromagnets is controlled so that it may (1) move positively in both directions, (2) vibrate in both directions, or (3) move positively in one direction and vibrate in the other direction or vice versa. As shown in Fig. 1, the armature is adapted to vibrate to the right or left to function as a bell or buzzer respectively depending upon which one of the switches 33, 34 is operated. The armature 16 is pivotally mounted at one end of a permanent magnet 5 which supports at its other end a T-shaped yoke 9 carrying electromagnets 11, 12 disposed at each side of the free extremity of the armature. The armature carries resilient members 22, 23, 24 which cooperate with adjustable screws 27, 28, 30. The screws 27, 28 form electric contacts and may be adjusted to cause the armature to partake of any one of the above mentioned movements. The electromagnets 11, 12 are connected to the operating switches 33, 34 which are so connected to the mains 31, 32 that the switch 33 sends a current through the magnets in a direction opposite to that which results from operation of the switch 34. When the screws 27, 28, 30 are in the positions shown and the switch 34 is operated a circuit is closed from the main 31, lead 41, contacts 36, 35, leads 52, contact screws 28, resilient member 23, armature, lead 56, electromagnets 11, 12, lead 53, contacts 37, 38 to the main 32 and the armature is swung to the left. When the armature is swung to the left, the electromagnets 11, 12 are short-circuited by the screw 27 and resilient member 22 and the armature resumes its central position. Thus, so long as the switch 34 is maintained operated the armature will vibrate to the left and function as a buzzer. When the switch 23 is operated, current flows through the electromagnets 12. 11 in the opposite direction, and a vibratory movement of the armature to the right is produced, intermittent contact being made between the screw 28 and spring 23. When it is desired to operate the armature positivelv to the left. or right, the contact screw is adjusted so as to permanently engage the spring 23 and the screw 27 is adjusted so that the spring 22 cannot engage it in any position of the armature. In order that the armature mav move to the left and vibrate to the right, the contact 27 is adjusted so that the spring 22 cannot co-operate therewith and the contact 28 is adjusted so that contact with the spring 23 is broken when the armature is moved to the right. When vibratory movement to the left and positive movement to the right is required the contact 28 is adjusted so that connection is maintained in all positions of the armature and the contact 27 is adjusted so that the spring 22 engages the contact when the armature moves to the left. The rod 18 carried by the armature may be employed to operate annunciators, switches, &c. Each operating switch 33. 34 consists of a top pair of spring contacts 35, 36 and a bottom pair of spring contacts 37, 38, the pairs being separated by a strip 39 of insulating material.