Patent GB-454158-A (GB)
Title: Improvements in stands or supports for microphones and other devices
IPC: H04R1/08
Filed: 1935-03-22
Abstract: 454,158. Supporting telephone instruments. LEWIS, J. J., and POLSON, A. G., 12, Dartmouth Street, Westminster. March 22, 1935, No. 9017. [Class 40 (iv)] [See also Group XL] A support for a microphone, loud-speaker, television apparatus or like sound or vision apparatus comprises a stand supported below a floor and adapted to carry the microphone or the like and means is provided for raising and lowering the stand in a substantially vertical direction whereby the microphone and stand may normally be arranged below the floor level and be raised when desired into the position for use. The microphone 24 is carried on a rod 25 sliding in guide members 26, 27 secured to angle iron members 28 extending below the floor 11 in which an aperture is formed by blocks 10 carried on arms 12 which move upwardly simultaneously when driven from an electric motor 16. The microphone is raised and lowered by a rope 32 passing over a pulley 31 and wrapping round a drum 33 driven by a second electric motor 34. Fig. 6 shows the control circuits for the electric motors 16, 34. On actuation of the " up button," relay SB operates, locks up over its contact SB1 and closes an energizing circuit for relay B which closes a locking circuit for itself over contact B5 independent of contacts SB2, 3, and by closing contacts B1, B4 completes the circuit of the motor 16 which operates to open the flaps. These immediately close contacts E and on reaching the open position close contacts 2, 4 over which relays A, SA are energized. Relay SA locks up and opens the circuit of the flap opening relay B, whilst relay A, by closing the contacts A1 A4 completes the circuit of the motor 34 which raises the stand. Contacts 3, 5 are opened and the " down-limit " contacts are closed. When the stand has reached a predetermined height, for example, with the microphone eighteen inches above the floor, contacts 6 and 7 are opened and closed respectively, the latter energizing a relay C which through contacts C1, C4 closes the circuit of the motor 16 so that it operates in the reverse direction to close the flaps 10. The flaps open contacts 2, 4 but do not break the circuit of relays A, SA, and on closing, open contacts E by which the motor 16 is stopped. When the stand reaches its upper limit, the " up-limit " contacts are opened and break the circuit through the relays A, SA, SB. This operation may also be effected by pressing the " stop button." To lower the stand, the " down button " is pressed energizing relays D and SD, the latter locking up over contacts SD1. Relay D closes contacts D1, D4 by which the motor 34 is operated in the reverse direction to lower the stand. When a predetermined height has been reached by the microphone, contacts 6 are again closed completing a circuit for relay B which operates the motor 16 to open the flaps. When the flaps are fully opened, contacts 2, 4 are closed, relay SA operates and at SA2 opens the circuit of relay B. The microphone stand continues its downward movement until it opens the " downlimit " contact, breaking the circuit of the relay D and also closing contacts 5 over which relay C is energized to operate the motor 16 to close the flaps. When these close, contacts E are opened and the motor is stopped. If the " stop " button is pressed whilst the flaps are open, the system operates so that the flaps are closed when the button is released. Instead of the hinged flap 10, a single closure member moved transversely may be employed or the closure member may be carried by the stand and arranged above the microphone 24.