GB104967A - An Improved Visible Signalling Device applicable to the Mechanical Signalling Apparatus used in Mines and other Places. - Google Patents

Abstract

104,967. Bell, W., and Briggs, R. May 23, 1916. Mechanical telegraphs; bell signals.- Relates to visible signalling-devices of the type comprising a marked dial over which moves a pointer operated by a toothed wheel which is rotated in a forward direction by a pawl actuated simultaneously with the audible signalling- apparatus, a second or retaining pawl controlled by a dash-pot or other timelag device being provided to prevent return of the toothed wheel when there is only a brief interval between two consecutive raps, but allowing return when the interval exceeds a certain amount. Both the pawl f actuating the wheel e of the pointer c, and the lever v actuating the dash-pot u are directly connected to a tail-piece or like member h on the pivot pin j of the usual rapper a. A " men " signal is provided, comprising a slide 6 adapted to register with an opening 7 in the dial b when three raps are given, the actuation being by an arm 10, on the pointer shaft d, which contacts with a lever 9 connected with the slide by a link 8. A spring- pressed catch 11 holds the lever 9 and slide 6 in the raised position till withdrawn by a contact arrangement as the cage passes certain points.