Lock device

Abstract

 A lock device comprises a lock cylinder (1) having a cylinder housing (10) and a cylinder core (20) which is mounted for rotation in an opening in the cylinder housing. The cylinder housing includes a first magnet (14) and the cylinder core includes a second magnet (24). The first and the second magnets are adapted to exert therebetween a force that causes the cylinder core to rotate to a pre-determined position of rotation. This provides a simple and inexpensive way of returning the cylinder core to a starting position.

Description

Technical field

[0001] The present invention relates generally to lock devices and more specifically to a lock device that includes magnets for the positional control of the plug or core of a cylinder lock.

Background of the invention

[0002] Lock cylinders have a wide application and are available in many different forms. Perhaps the most common form of a lock cylinder is one that includes a cylinder house and a cylinder core or plug that is mounted for rotation in an opening in the cylinder house. This core may also include latching means, such as code tumblers, which are manoeuvred by means of a key inserted in the core. One variant is a core that lacks latching means and which is manoeuvred by means of a thumb turn or the like. This latter type of cylinder lock is, for instance, used together with a motor operated lock, in which case the motor operated locking function is housed in a lock case. A key operated lock cylinder is coupled to the lock case on the outside of the door and a thumb-turn manoeuvred lock cylinder is coupled to the lock case on the inside of the door.

[0003] One problem with the use of a thumb-turn-manoeuvred lock cylinder together with a motor operated lock is that the motor lock function can become blocked if the thumb-turn-manoeuvred cylinder core is in a position other than a starting position. This may occur when a user has used the thumb-turn to open door and has left the thumb-turn in a position other than its starting position.

Summary of the invention

[0004] One object of the present invention is to provide a lock device that includes a lock cylinder which includes a function for returning the cylinder core to a starting position.

[0005] The invention is based on the insight that a cylinder core can be caused to rotate to a starting position with the aid of magnets.

[0006] Accordingly, there is provided in accordance with the invention a lock device as defined in the accompanying claim 1.

[0007] Further preferred embodiments of the invention are defined in the dependent claims.

[0008] The use of magnets for returning the cylinder core to its starting position affords many advantages. Firstly, magnets are relatively inexpensive and simple to mount and consequently do not contribute significantly to the total cost of the lock cylinder. Moreover, contact between the magnets is friction free and consequently rotation of the cylinder core is not influenced negatively.

Brief description of the drawings

[0009] The invention will now be described in more detail by way of example and with reference to the accompanying drawing, in which

Fig. 1 is an exploded view of a lock cylinder included in an inventive lock device;

Fig. 2a is a cross-sectional view of the lock cylinder shown in figure 1 on a level with magnets included in said lock cylinder, said lock cylinder being shown in a starting position; and

Fig. 2b and 2c are respective corresponding cross-sectional views of the figure 2a illustration although showing rotational positions of the cylinder core.

Description of a preferred embodiment

[0010] There will now be described a preferred embodiment of a lock device according to the invention.

[0011] The lock device comprises a lock cylinder, generally referenced 1, which includes a cylinder housing 10 and a cylinder core or plug 20 which is mounted for rotation in the cylinder housing. The cylinder housing includes a radial bore 12 to the bottom of which there is firmly affixed a permanent magnet 14 in some suitable way, such as by means of a press fitting or a glue joint.

[0012] A thumb turn 22 is mounted on the outer end part of the cylinder core 20. A permanent magnet 24 is also affixed in a bore in the cylinder core in a manner which will be apparent from the cross-sectional view of figure 2a. The polarity of the magnets 14 and 24 will also be evident from figure 2a. The lock cylinder 1 is designed to be housed in a lock case (not shown) in a typical fashion.

[0013] Referring back to figure 2a it will be seen that a starting position of the cylinder core 20 corresponds to the position of the thumb-turn 22 shown in figure 1. Coupling of the cylinder core to the-lock mechanics housed in the lock case is such that the lock mechanics will not be negatively affected by the illustrated position, said lock mechanics possibly having a motor lock function. It will be seen that the south pole of the magnet 14 is directed towards the north pole of the magnet 24, which provides a mutual attraction force between the magnets. The cylinder core 20 will thus strive to adopt this position of rotation as a result of the attractive force achieved between the magnet 14 in the cylinder housing 10 and the magnet 24 in the cylinder core 20.

[0014] It is highly probable that a user will leave the cylinder core in a position other than that shown in figure 2a after having used the thumb-turn function. Examples of other such rotational positions are shown in figures 2b and 2c. It will be seen from these figures that the south pole of the magnet 14 is directed towards the south pole of the magnet 24, resulting in a mutual repelling force between the magnets. It will be seen that this repelling force generated by the magnet 14 in the cylinder housing 10 and the magnet 24 in the cylinder core 20 in the positions shown in figures 2a and 2b will strive to cause the cylinder core to rotate in the direction of respective arrows to the starting position shown in figure 2a. When the magnet 24 in the cylinder core has a position in which it is perpendicular to the position of the magnet 14 in the cylinder housing, an attraction force will be generated between the south pole of the magnet 14 and the north pole of the magnet 24, therewith amplifying the force that strives to rotate the cylinder core to the starting position shown in figure 2a. This results in a simple, inexpensive and reliable function for returning the cylinder core to a starting position, which is also favourable to the function of the lock device.

[0015] Although a preferred embodiment of a lock device according to the present invention has been described, the person of normal skill in this particular technical field will understand that variations can be made within the scope of the accompanying claims. For example, although the illustrated lock cylinder 1 lacks a tumbler mechanism it will be understood that the inventive concept can also be applied to a lock device whose lock cylinder includes a tumbler mechanism.

[0016] Although the magnets 14 and 24 have been illustrated as permanent magnets, it will be understood that other types of magnets can be used, such a solenoids.

Claims

1. A lock device comprising a lock cylinder (1) having a cylinder housing (10) and a cylinder core (20) which is mounted for rotation in an opening in the cylinder housing, characterized in that the cylinder housing includes a first magnet (14); in that the cylinder core includes a second magnet (24); wherein the first and the second magnets are adapted to exert there between a force that will cause the cylinder core to rotate to a pre-determined position of rotation.

2. A lock device according to claim 1, characterized in that at least one of the magnets is a permanent magnet.

3. A lock device according to claim 1 or 2, characterized in that the first magnet (14) is disposed in the bottom of a radial bore provided in the cylinder housing (10).

4. A lock device according to any one of claims 1-3, characterized in that the second magnet (24) is disposed in a bore provided in the cylinder core (20).

5. A lock device according to any one of claims 1-4, characterized by a thumb-turn (22) which is affixed to the outer end part of the cylinder core (20).

6. A lock device according to any one of claims 1-5, characterized by a lock case that houses lock mechanics having a motor lock function, wherewith the lock cylinder (1) is coupled mechanically to the lock mechanics.

Drawing