LOCKING DEVICE

Abstract: The present invention relates to a locking device with movable indicator (4, 5) for sensing the "door closed" or "door open" position of a dead-bolt, provided with a pivotably journalled rotating cam (2) (securing plate) intended to be moved between open and locked position by the released dead-bolt (8). The invention is characterized in that the rotating cam (2) and the indicator are mutually connected by means of a spring, e.g. a tension spring (1) arranged in closed, locking position to produce a force component in the closing direction of the rotating cam, and upon removal of the dead-bolt (8) from the rotating cam, i.e. when the door is opened by means of the indicator, to be displaced in relation to the centre (3) of rotation of the rotating cam so that a force component is obtained in opening direction and the rotating cam is turned to opening position by a snap action of the spring.

Description: L O C K I N G D E V I CE Technical field: The present invention relates to a locking device with movable indicator for sensing the "door closed" or "door open" position of a dead-bolt, provided with a pivotably journalled rotating cam (securing plate) intended to be moved between open and locked position by the released dead-bolt. Background art: A known lock comprises a lock case and a rotating cam (securing plate) with U-shaped recess for a protruding dead-bolt. The rotating cam is pivotable about a shaft. A distinct movement is desirable for the rotating cam between locked and open position and it may be difficult to achieve this movement in certain positions of the axis of rotation of the rotating cam. See US patent specification 3861727, for instance. Description of the invention: The object of the invention is to provide a solution to these and other associated problems of obtaining a secure and distinct locking action. The locking device according to the invention is characterized in that the rotating cam and the indicator are mutually connected by means of a spring, e.g. a tension spring, arranged in closed, locking position to produce a force component in the closing direction of the rotating cam, and upon removal of the dead-bolt from the rotating cam, i.e. when the door is opened by means of the indicator, to be displaced in relation to the centre of rotation of the rotating cam so that a force component is obtained in opening direction and the rotating cam is turned to opening position by a snap action of the spring. This device gives a secure and distinct locking and opening action and a clear indication of whether the device is in locked or open position. Another advantage is that this lock requires only a small amount of space for fitting and placing. Brief description of the drawings: The invention is described by way of example in the accompanying drawings, in which Figure 1 shows a locking device seen from the side and Figure 2 the same, seen from above. Figure 3 shows the lock in locked position, Figure 4 in a temporarily passed intermediate position and Figure 5 in open position. Description of embodiment: Figures 1 and 2 show a locking device according to the invention, provided with a rotating cam (2) with an extended shaft (3), an indicator (3, 4, 5), and an electromagnet (6) for operation of a ratchet (7). (8) is a dead-bolt (see Figures 3 and 5) and (5) is a stop. (10) is the actual microswitch included in the indicator. Figure 3 shows the rotating cam (2) locked in position by the dead-bolt (8). (3) is the shaft of the rotating cam and (1) is a tension spring connecting the indicator (4) with the rotating cam (2, 3) (see also Figure 1). In locked position (Figure 3) the spring (1) is arranged so that a force component acts in locking direction of the rotating cam. If the dead-bolt is removed, the spring is moved with the indicator so that the centre of rotation of the rotating cam is passed (see Figure 4). A force component is now obtained in opening direction on the rotating cam (2) from the spring (1) and the rotating cam snaps to the open position shown in Figure 5. See the coupling between the shaft (3) of the rotating cam and the shaft of the indicator (4) in Figure 1. In a locking action the dead-bolt is moved in towards the rotating cam, said equilibrium is passed and a locking force component is obtained. This movement also takes place with a snap action. (See Figure 5.) (10) is a microswitch pertaining to the indicator, which senses the position (locked or open) of the dead-bolt (8). The electromagnet (single or double-acting) controls a ratchet device (7), see Figures 1 and 2, and a space for this can be obtained as shown in Figure 3. The device described above can be varied in many ways within the scope of the following claims.

Claims: CLAIMS 1. A locking device with movable indicator (4, 5) for sensing the "door closed" or "door open" position of a dead-bolt, provided with a pivotably journalled rotating cam (2) (securing plate) intended to be moved between open and locked position by the released dead-bolt (8), characterized in that the rotating cam (2) and the indicator are mutually connected by means of a spring, e.g. a tension spring (1) arranged in closed, locking position to produce a force component in the closing direction of the rotating cam, and upon removal of the dead-bolt (8) from the rotating cam, i.e. when the door is opened by means of the indicator, to be displaced in relation to the centre (3) of rotation of the rotating cam so that a force component is obtained in opening direction and the rotating cam is turned to opening position by a snap action of the spring. 2. A locking device as claimed in claim 1, characterized in that in unlocked position of the dead-bolt a force component is always obtained in opening direction. 3. A locking device as claimed in claims 1-2, characterized in that the spring (1) is attached between a shaft pertaining to the rotating cam (2), and a shaft (4) pertaining to the indicator (5). 4. A locking device as claimed in any of the preceding claims, characterized in that the lock is provided with a ratchet device (7) designed to be operated by means of a single or double-acting electromagnet (6).

Inventors: STENDAL JAN, STENDAL, JAN
Applicants: STENDAL JAN, STENDALS ELEKTRISKA AB, STENDAL, JAN
Application year: 1998
Main classification: E05B41
IPC codes: E05B15, E05B41, E05B45, E05B47