GB2123078A

GB2123078A - Electrically lockable fastening

Info

Publication number: GB2123078A
Application number: GB08317664A
Authority: GB
Inventors: Tor Sornes
Original assignee: Elkem ASA
Current assignee: Elkem ASA
Priority date: 1982-07-01
Filing date: 1983-06-29
Publication date: 1984-01-25
Also published as: FR2529605A1; GB8317664D0; NO152058B; NO822305L; NO152058C; SE8303715D0; DE3322197A1; JPS5921879A; SE8303715L

Abstract

The fastening comprises a bolt 11 movable between a locked and an unlocked position through movement of a follower 1 by an operating member, and a locking member 2 and electromagnetic means 3, 8, actuation of the electromagnetic means causing movement of the locking member 2 into or out of engagement with the follower 1, to secure or release the latter. The electromagnetic means consists of a pair of electromagnets or motors 3, 8 and a pivoted shaft 4 whose free end engages a slot 16 in the locking member 8. <IMAGE>

Description

SPECIFICATION Electrically operated lock The present invention relates to a lock where a follower arranged in the lock is acted on by and cooperates with an operating member as for instance a lever handle, the follower acting on a lock means as for instance a dead bolt.

With locks of this type it is often a requirement that the opening and/or locking of the lock should be effected by means of electrical impulses, so that the lock can be controlled, often remotely, by means for example of current carrying conductors. It can also be necessary to effect remote control of such locks by means of wireless impulse transmission. In places where there is only limited access or possibility for supply of electric power for control of such locks, it is necessary to use battery voltage to operate the lock. With such a battery based solution, it is desirable that the lock should consume as little electrical energy as possible so that the battery will last as long as possible.

Several types of electrically operated locks are known. The best known type is the one which is operated by means of a so-called electrical striker plate. The striker plate is usually mounted in the door frame and comprises an electromagnet which releases or blocks a flap which in the blocked position retains the dead locking member of the lock.

These types of locks have the disadvantage that they are not very secure against burglars as the electrical striker plate is easily manipulated or broken apart.

There are also known other types of electrically operated locks where the dead locking member of the lock constitutes an elongation of the core in an electromagnet and which is moved into or out of locking position by current. The core must in this case have a large length of motion. This type of lock demands much electrical energy.

US-PS 3,926,021 describes an electrically operated lock which uses a motor for opening of the door. This type of lock is dependent on very large amounts of energy, as the motor must be operated in several seconds by each unlocking operation.

DE-OS No. 2,851,396 describes an electrically operated lock which is controlled by means of an electromagnet. Also this type of lock demands much energy as the magnet uses power from the moment when the key is removed until the door is opened.

Generally, solutions of this type require much electrical energy so that the batteries will have a too short life. It is not unusual that the batteries have to be exchanged after as little as two to three months, which results in great disadvantages and increased costs with use of such systems.

If electronic electrical locks are to be oper sted by batteries there is a necessity that the batteries are not only that they have as long life as possible, preferably at least one year, but also that they are as small as possible.

The present invention seeks to overcome these and other disadvantages and problems.

According to an aspect of the present invention a lock comprises lock means movable between a locked and an unlocked position through movement of a follower by an operating member, and further comprises a locking member and electromagnetic means, actuation of the electromagnetic means causing movement of the locking member into or out of engagement with the follower, engagement of the follower and the locking member preventing movement of the follower and of the locking means. The invention may however reside in any of the features herein described or any combination thereof. The follower is preferably equipped with a recess, slot or projecting member intended to cooperate with a movable locking plate or bolt which cari be moved radially in relation to the follower, the plate or bolt being movably arranged in a guide in a lock case.The locking plate or bolt is brought into or out of locking engagement with the follower by means of electromagnetic means which can with advantage comprise two magnets or motors (drivers) between which is arranged a shaft which is supported at one end while the opposite end is in engagement with the locking plate or bolt for actuating same. The shaft, which is preferably supported in the middle between the two said magnets or motors, can with advantage have a width which decreases in the direction of the free or distal end so that the distance between the arm and that magnet or motor with which the shaft is not in contact will increase in direction towards the free end of the shaft.

The shaft can be so slanted on either side of its longitudinal axis and can be so positioned in relation to the magnets or motors that that side of the shaft which at any time is in contact with the magnet is parallel with the end surface of the magnet or motor with which it is in contact.

The cores of the magnets used can with advantage have an oval cross section where the larger diameter of the oval is orientated in same direction as the longitudinal direction of the shaft. In operation of the present invention only that magnet which is to attract the shaft is supplied with current, the current being supplied only so long as is required to bring the shaft into the desired position whereupon the current is disconnected. The locking plate or bolt is with advantage equipped with guiding members which cooperate with corresponding guides in the lock case in order to conduct and guide the plate in relation to the lock case. A mechanical bistable, e.g. a spring, is preferably provided to hold the shaft against or closely adjacent to one or the other magnet or motor.

The lock according to the present invention is designed in order to relieve those disadvantages which are mentioned in connection with existing locks and to obtain a security against burglars, using very little energy. It has by testing of the lock been shown that charging for 40 milli seconds may be enough for unlocking and successive locking, a 20 milli seconds charge duration being sufficient for either operation. This is only a fraction of those charging durations which are normally necessary by operation of the known locks.

Thus by operating the electromagnetic means the movement of the follower can be blocked so that the operating member will not be able to act on the lock means. The present invention is especially but not exclusively suitable for use in connection with electronic/ electrical locks which are especially used in connection with guest rooms in hotels etc.

The invention may be carried out in various ways and an embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which; Figure 1 shows an elevation of the interior of the lock in the open position, and Figure 2 shows a perspective of the interior of the lock in the locked position.

Referring to the drawings the lock comprises a lock case 6, a lock front 10 and a locking unit as for instance a cylinder lock (not shown). In the lock case 6 there is arranged a follower 1 which is provided with a square opening 17 into which a lever or handle (not shown) is mounted. The follower 1 is in known way (not shown) connected to the dead locking bolt 11 so that the door can only be opened if the follower 1 can be rotated or turned. A locking plate or bolt 2 is utilized for locking the follower 1 so that it cannot be rotated. The locking plate 2 runs in the guides 12 arranged in the lock case 6 and can be moved radially in relation to the follower 1 from open position where the locking plate 2 does not prevent the follower 1 from being rotated, into locked position in which the plate 2 is in engagement with a slot or recess 1 3 in the follower.In a further form (not shown) the slot 1 3 may be replaced by a projecting bulb or similar arrangement. Fig. 1 shows the locking plate 2 in retracted open position in which the follower 1 can be rotated for opening of the door. In order to bring the lock plate 2 into this position the electromagnet or motor 8 has been activated so that a shaft 4 which is connected to the lock case by means of a pivot 5 has been rotated to a position in which the shaft 4 is in contact with the core 14 of the electric magnet or motor 8 which core may be magnetized. It shall in this connection be pointed out that the electricity is only supplied to the electromagnet or motor 8 in that fraction of a second which is necessary for attracting the shaft 4 to that position.Actuation of the magnet or motor 3 has the reverse effect and brings the shaft 4 into contact with the core 1 5 as shown in Fig. 2. The plate 2 either way moves in its guides with the shaft 4.

Thus' by activation of the electromagnet or motor 8 the shaft 4 will rotate around the pivot 5 and bear against the core 14 of the electromagnet or motor 8 whereby the lock plate 2 will be moved out of a locking position i.e. out of the slot 1 3 of the follower.

Movement of the plate 2 into the recess 1 3 by actuation of magnet or motor 3 leads to a situation in which the follower 1 is then prevented from rotation.

In order to make movement of the locking plate 2 possible it is equipped with an opening 16, such as a slot, upwardly projecting rib or similar arrangement, which cooperates with the lower end 7 of the shaft 4. The locking plate 2 is suspended by guides 12 and guides (not shown) in the side walls of the lock case 6. The lock plate 2 is equipped with projecting parts 9 (see Fig. 2). This means that the lock plate 2, in a possible burglary attempt, will have to be cut off if the door is to be opened. The lower end 7 of the shaft 4 is also contacting a resilient member 18 which acts as a mechanical bistable to hold the shaft 4 against one or other magnet or motor 3, 8.

It is obvious that locking and releasing of the locking can be effected instantly by supplying electrical energy to the electromagnets or motors 3, 8. Experiments have shown that 20 micro seconds is sufficient to move the locking plate 2 from the one position to the other. In this way the lock is current saving in relation to other known locks and will therefore be operable longer by means of a battery before exchange of battery is required.

The cores 14 and 1 5 of the magnets 3, 8 have oblong or oval cross sections, their longer dimensions being disposed substantially parallel to the longitudinal axis of the shaft 4.

Another not unimportant advantage of the solution according to the present invention is that it is adjusted to the dimensions of standarized lock cases.

Claims

1. A lock comprising lock means movable between a locked and an unlocked position through movement of a follower by an operating member, and further comprising a locking member and electromagnetic means, actuation of the electromagnetic means causing movement of the locking member into or out of engagement with the follower, engagement of the follower and the locking member preventing movement of the follower and of the locking means.

2. A lock as claimed in Claim 1 wherein the locking member has a recess therein or a formation thereon adapted to cooperate with a formation or recess of the follower.

3. A lock as claimed in Claim 1 or Claim 2 wherein the locking member is a locking plate movable radially of the follower by the electromagnetic means.

4. A lock as claimed in any of Claims 1, 2 or 3 wherein the electromagnetic means comprises two electromagnets or motors between which is arranged a shaft movement of which moves the locking member.

5. A lock as claimed in Claim 4 in which a shaft is suspended between the said two magnets or motors and has a width which increases from its free end so that the distance between the shaft and that magnet or motor with which the shaft has no contact increases in from the free end of the shaft.

6. A lock as claimed in Claim 4 or Claim 5 in which the shaft is slanting on either side of its longitudinal axis and is so situated in relation to the said magnets or motors that that side which at any time is in contact with a magnet is parallel with the end surface of the magnet or motor and in contact with the core of the magnet or motor.

7. A lock as claimed in Claim 5 or Claim 6 in which the cores of the electromagnet i.e.

means are of oval cross-section, the larger diameter of the oval being orientated in the same direction as the longitudinal axis of the shaft.

8. A lock as claimed in any of Claims 5 to 7 in which current is only supplied to that magnet or motor which is to attract the shaft, the current being only supplied for such an interval that the shaft has arrived into desired position whereupon the current supply is cut off.

9. A lock as in any of the preceding claims in which the locking member is a plate equipped with members which cooperate with corresponding guides in the lock case for conducting and guiding the plate.

10. A lock as claimed in any of Claims 5 to 7 in which a mechanical bistable is provided to retain the shaft in contact or closely adjacent to one or other electromagnet or motor.

11. A lock substantially as described herein with reference to the accompanying drawings.