Improvements in or relating to street box apparatus for fire-alarm systems

摘要

410,433. Man traps. BOHN, H., 7, Zeppelinstrasse, Heilbronn-on-Neckar, Wurtemberg, Germany. Dec. 12, 1933, No. 34964. Convention date, Dec. 13, 1932. [Class 5 (i).] ln a street box apparatus for fire alarm systems, a device is provided which automatically detains the person who operates the alarm. As shown, a heavy shackle 6 is mounted for vertical movement in a frame 4 and is normally maintained in a raised position by the engagement of spring-pressed balls 11, 13 with holes, e.g. 9, in the frame. The alarm is transmitted by operation of the press-button 35 and in order to operate it, the hand, which is inserted through an opening 2, firstly encounters a pivoted plate 16 which has arms 17 adapted to depress the shackle on to the operator's wrist so as to prevent withdrawal of the hand. The shackle is locked in its depressed position by a pawl 27 which engages a notch in a member 20 pivoted at one end to the shackle and connected at the other end through linkwork to the plate 16. The pawl 27 is operated by a member 29 which engages an arm 34 on the plate 16. A guard 37 is provided to prevent operation of the switch 35 by unauthorized implements. A roller provided in an incline 39 is adapted to further prevent withdrawal if the hand is pulled. A push button 40 is operated by the shackle when unobstructed by the hand in order to give an alarm and operate a lamp mounted in the street box. The pawl 27 and shackle 6 are reset by strings 44, 45 which are accessible through a locked lid 48.