Manual call point

#The present invention relates to a manual call point with a housing base, a cover and an alarm insert comprising a fragile panel, a printed-circuit board, a switching element and an actuating mechanism for the latter.

#Manual call points are used, for example, in fire alarm equipment or emergency telephones and are conventionally produced in two designs for direct and indirect actuation. In the alarm type with indirect actuation, the panel is to be smashed and a push button pressed. In the alarm type with direct actuation, which is substantially more common nowadays, when the panel is smashed a spring button jumps out as a result of spring pressure and in the process actuates a switch button of the switching element.

#In a known manual call point of the latter type with a bevelled switching gate, the spring button is extended by a resilient rod which rests on the glass panel and holds the spring button in the pressed-down position, so the switch button is held in the ready position. To sound the alarm when the panel is smashed, the spring button is pressed out by the compression spring and the switch button is released to trigger the alarm signal. This embodiment is very expensive from a mechanical point of view, in particular due to the configuration of the spring button with the resilient rod. Moreover, relatively narrow tolerances must be adhered to, and therefore this embodiment is costly to produce.

#The present invention is described in detail below in connection with FIG. 1 which shows a schematic perspective view from the front of a manual call point according to the invention.

#According to the present invention, the manual call point consists of a housing base 1, a cover (not shown) and an alarm insert comprising a side wall 2, a printed-circuit board 3, a fragile panel 4 held at a distance from the printed-circuit board 3 and having a printed protective film 5, a switch element 6 comprising a sprung-end switch and an actuating mechanism for the switch which serves to actuate the switching element 6 and trigger an alarm when the panel 4 is smashed.

#The actuating mechanism is formed by a two-armed pivoting lever 7 which rests at one end on a lateral edge of the panel 4, with the other end pressing the end of the switching element 6, so that when the panel 4 is intact the switch formed by the switching element 6 is closed. The cover, which is not shown, is placed on the housing base 1 and fixed thereto and contains an edge surrounding the panel 4 and an aperture defined thereby, so that the panel 4 is freely accessible. The panel 4 rests on edge strips provided in the alarm insert and is fixed by two holding digits to the alarm insert. This has the advantage that when an alarm system is installed, the alarm housing and alarm insert can be delivered separately with the alarm insert being fitted into the already installed housing. One of the two holding digits 8 may be designed to pivot in order to facilitate insertion of the panel 4.

#When the panel 4 is smashed, it splits along a line of arrows printed on the film 5 and is pressed inward in this region. The upper end of the pivoting lever 7 is thus released by the lateral edge resting on it when the panel 4 has not been destroyed. The pivoting lever therefore performs a pivoting movement in the clockwise direction and releases the sprung end-switch of the switching element 6, thereby the alarm triggering.