DE9421454U1 - Keys for door locks - Google Patents

Description

2. DESCRIPTION

The invention relates to the design and construction of keys for door locks. The purpose of the invention is to prevent keys of previous designs from frequently falling out of the keyhole.

Locks for doors (Figure 2) are usually equipped with a latch and a bolt, whereby the latch is operated by means of a door handle and the bolt by means of a key. For doors that are not kept permanently locked, opening and closing by means of a door handle and latch is the most common method; the key remains stuck unused. The vibrations generated by this opening and closing cause the key to rotate independently around its axis until the bit, pointing downwards, coincides with the keyhole in the lock and door plate. The next vibration then causes the key to fall out and possibly be lost.

The reason for the independent rotation of the key when shaken is the torque ^U ₈ which the mass of the bit generates under the influence of gravity around the key tube as an axis (Figure 1). The sign of the rotation vector depends on the position of the bit, ie on ψ . The key therefore always turns by the shortest path to the stable rest position Ißt-^ - 0 and then falls out.

One way to avoid this effect would be to rotate the keyhole of the lock and door plate away from the vertical. Apart from the resulting structural problems, this would require changes to the DIN standards for locks and building fittings.

In contrast, the invention proposes a very simple and cost-effective approach:

The decisive factor for the rotation of the key is the sum -391: of all the torques acting, which, in the previously usual symmetrical design of the tube and ring, is essentially identical to the torque of the beard ?3t _B . By introducing additional torques, the stable rest position -33fc= 0 can be achieved for any desired angle φ against the vertical. It is advisable to lay the ring perpendicular to the tube in the opposite direction of the beard (cC =180°) and make \1S8tn\>\10L-i\. The resulting larger additional torque Wb? acting against Ufa* creates a total torque TflC that is also directed against TMt-^ . The stable rest position is

and thus moved upwards by 180°. In the event of vibrations, the bit now rotates upwards from any position against the locking mechanism by the shortest possible path and remains there. A shift in the stable rest position can also be generated by additional moments el < 180, eg 90°. The disadvantage, however, is that the bit must pass through the vertical and thus the direction of the hole from one side on its rotation to the stable rest position and can fall out in the process.

Claims (3)

-i- Key for door locks Inventor: Hans-Karsten Meier 1. PROTECTION CLAIMS Key for door locks consisting of a bit, tube and ring, the masses of which, under the influence of gravity, generate partial moments around the key axis and, as a result, a total moment, characterized in that 1. the stable rest position of the total moment deviates so far from the vertical that the key cannot fall out of the hole in this position. Key according to claim 1, in which 2. the total moment is always opposite to the partial moment of the beard. Key according to claim 2, in which 3. the additional moment counteracting the partial moment of the beard is achieved by appropriate mass arrangement of the ring.