Patent GB-190721176-A (GB)
Title: Improvements in Electric Signal Systems.
Inventor: SOHM ALFRED LOUID
Filed: 1907-09-24
Granted: 1908-09-24
Abstract: 21,176. Sohm, A. L. Sept. 24. Indicators or annunciators ; indicating ringing of bells to operators.-Relates to electric signalling systems for use in connexion with call bells or annunciators, burglar and fire-alarms, telephone calls, &c. The invention is described as applied to an annunciator system having ninety-nine signal stations and two dials at the central station to indicate the station calling, one dial denoting the tens digit of the calling-station, and the other dial the units digit. All stations having the same tens digit are connected by a single wire with a corresponding stop-coil in the tens indicator, and in the same way all stations having the same units digit are connected to the corresponding stop-coil in the units indicator. When a station calls, a circuit is completed through the corresponding stop coils of both indicators and through the motor-magnets which rotate the indicating dials until stopped by armatures of the energized stop-coils. Local circuits are then closed through magnets which raise shutters to display the number of the calling-station. Figs. 2 and 3 are sections of the units indicator, the tens indicator being similar but having one less stop-coil. The numeral-bearing flanged dial 9 is carried by the spindle 17 of the pinion 18, which gears with the sector 18<11> and is rotated by the motor-magnets 49, 50. The common armature 51 of these magnets has an elastic extension 55 playing between projections 56, 57 on the arm 58 which is pivoted at 59 and rigidly connected with the arm 62 carrying the sector 18<11>. The armatures 24 of the stop-coils 8 arranged round the spindle 17, are provided with lugs 28, Fig. 6, adapted, when the coil is energized, to engage the spring 33, Fig. 6, and arrest the rotating dial, at the same time causing the spring 33 to close the contacts 47, 48, Figs. 3 and 6, the function of which will appear later. A stud 30 on the armature-extension 29 also presses the spring- finger 37 (formed integral with the ring 39), Figs. 3 and 6, against an insulated spring 38 when the stop-coil is energized. The armature 64 of the shutter-magnet 63, Fig. 2, is formed with a spring-extension 67 having an inwardly-extending projection adapted to rock the shaft 70 when the magnet 63 is energized, thus moving the shutter 73 from behind the sight-aperture 34. Fig. 10 shows the construction of the push-button used at the calling-stations. When the springs 107, 108 are brought into contact by depressing the push 106 the catch 105 engages the extension 103 of the armature of the magnet 101. At the same time the lever 110 is rocked on its pivot so as to bring a busy indicator 112 behind an aperture in the casing 100. If the central-station indicator is not in use when the push 106 is pressed, a circuit is completed through the magnet 101 and the catch 105 is at once released. If, however, the indicator is in use, the catch 105 remains engaged by the extension 103 and is released only. when the magnet 101 is energized from the central station. Fig. 12 shows the circuit-connexions for ninety-nine call stations and the tens and units indicators at the central station. The stop-coils in the figure are indicated by the numerals they are adapted to display, associated with the letter C. If a signal is sent from station X 48 by closing the contacts 107, 108, current flows the wires 130, 131, 132, stop-coil C<4> in the tens indicator, wires 133, 134, motor-magnet 49, contacts 79, 78 (closed when the shutter-magnet 63 is not energized), battery B, wires 137, 138, metal ring 139, wire 139, contacts 82, 83 (closed when the sector 18<11> is in its zero position), contacts 83<1>, 82<1>, in the units indicator wires 141, 142, battery B<1>, contacts 79<1>, 78<1>, magnet 49', wire 146, stop-coil C<8>, wire 147, back to the contact 108. The stop-coils C', C<8> are thus energized and close contacts 37, 38, Figs. 3, 12. The motor-magnets 49, 49<1> start the rotation of the dial, but, as soon as the sector 18<11> moves, the contacts 82, 83 and 821, 831 in the circuit just described are opened, but the closing of the contacts 37, 38 completes separate local circuits in the two indicators, each circuit comprising the motor-magnet and the stop-coil previously energized. The rotation of the two dials thus continues until the springs 33, Fig. 6, in the two dials engage the lugs 28 of the attracted armatures of the stop-coils C<4>, C<8>, thus closing a contact between the springs 47, 48 and completing a momentary circuit through the shutter-magnet 63 The attraction of the armature of the shutter-magget completes a holding-on circuit through the contacts 76, 77, 78. A bell or lamp may be arranged in the circuit. The indicators may be returned to their zero positions by operating a switch 121 which first closes the line circuit through all outlying stations exhibiting the busy' sign, energizing the magnets 101 at these stations and releasing the depressed pushes. The switch 121 also closes a local circuit through the motor-magnets 50, 50<1> of the tens and units indicators, which are thus returned to their zero positions.