Magnetically Operated Locking Mechanism

Abstract

A locking device comprises two members having meeting faces in substantial engagement with each other and a plurality of bores extending normally from each meeting face. The members are relatively movable to place each bore in one member in axial alignment with a bore in the other member. A tumbler is slidably mounted in each bore of one member and a plunger is slidably mounted in each bore of the other member. Resilient means urges the tumbler in one direction of movement. Either the tumbler or the plunger or both has magnetic characteristics. One of the members has a recess for reception of a key with magnetic sections which serve to impart locking or unlocking movement to the tumblers and plungers.

Description

This invention relates to a tumbler arrangement for a magnetically operated locking mechanism, and in particular to locking mechanisms having a plurality of tumblers selectively operated, for example by a key member, such as for door locks and similar locks.

There exist many locking devices for either preventing unauthorized, or unwanted movement between two members, as in door locks, except at certain determined occasions; or for permitting free movement between two members except at certain determined occasions when the two members are locked together either immovably or for movement together.

Typical of such devices are door and other locks having a series of spring-loaded tumblers sliding in bores in one member and, in locked condition, extending across a common joint face with another member. The tumblers enter partly into bores or openings in the other member and prevent rotation or other movement of one member relative to the other. Insertion of a key lifts the tumblers to permit relative movement. Generally the tumblers require lifting to different levels requiring a key of particular and unique pattern to operate the lock. This requires that the mating or common joint face has a profile other than a straight line and the manufacture of the parts is somewhat complex. Also, although each lock has its own unique key, the keys are readily copied and unauthorized copies can be obtained by persons not entitled to have such keys.

The present invention provides a tumbler arrangement in which a magnetic force is used to move the tumbler to the desired position. The invention also provides a lock mechanism having a series of tumbler arrangements, and which is operated by a key member having a predetermined magnetic coding system for moving the tumblers. There is no profile which can be readily copied. It is necessary to determine the magnetic coding at each of a series of operative positions on the key, and to reproduce these codings, before a copy can be made.

Thus, in accordance with one feature of the invention there is provided a tumbler arrangement for a locking device, comprising; first and second housings arranged for relative movement on a joint surface; a bore in each of the housings, the bores opposed and in substantial alignment; a member in one of the bores, axially slidable therein between a first position, in which the member extends across the joint surface and partly into the other bore, and a second position in which the tumbler is entirely within said one bore; means resiliently urging the tumbler to one of the two positions and magnetic means for urging the tumbler from said one position to the other of the two positions.

In accordance with another feature of the invention there is provided a lock mechanism having two cooperating members or housings arranged for relative movement on a joint surface; a plurality of bores in each member, the bores opposed in pairs, with the bores of a pair in substantial alignment; a tumbler arrangement in each bore and including a member axially slidable therein from a first position entirely within a bore in one member to a second position extending across the joint surface partly into the opposed bore, means resiliently urging the members to one of said positions; and means for magnetically urging the members each against the resilient means whereby all the members are moved to one of said first and second positions.

The invention will be understood by the following description of certain embodiments, by way of example in conjunction with the accompanying drawings, in which;

FIG. 1 is a longitudinal cross-section through a lock; and

FIGS. 2 to 6 are cross-sections through alternate forms of tumbler arrangements.

As illustrated in FIG. 1, a lock mechanism comprises an outer member, housing or barrel 10, having an axial cylindrical bore 11. An inner member or cylinder 12 is rotatably mounted in the bore 11. One end of the outer member 10 is closed by an end wall 13 having a relatively small central bore 14. The inner member 12 has a flange 15 at its outer end remote from the end wall 13 of the outer member 10, and an inwardly extending flange 16 on the outer member 10 extends over flange 15 and retains the inner member in the axial bore 11. An axial shaft or extension 17 on the end of the inner member 12 extends through the central bore 14 of the outer member end wall 13. Two O-ring seals 18 are provided between the inner member 12 and outer member 10, a seal at each end of the assembly. The seals are positioned in grooves 19 formed in the inner member 12 and outer housing 10. The inner member 12 and the outer member 10 are thus mounted for relative movement on meeting faces which are in substantial engagement and constitute a joint surface 20, and in the present example the outer housing 10 is normally stationary and the inner member 12 rotates.

Formed in the outer housing 10 is a plurality of radial bores 25, the bores extending from the axial bore 11 and in alignment on a longitudinal axis. Formed in the inner member 12 is a plurality of radial bores 26, the bores extending from the periphery of the inner member. The bores 25 and 26 are aligned in opposed pairs and in each pair of bores is located a tumbler device or arrangement indicated generally at 27 and described in more detail later.

A slot or recess 30 is formed in the inner member 12, extending axially from the end thereof having flange 15. The slot extends through the inner member for almost the full length thereof. Slidable axially in the slot 30 is a key 31. Spaced along the key 31 is a plurality of positions or sections 32, a section in radial alignment with each pair of opposed bores 25 and 26. The sections 32 have magnetic characteristics which cooperate with magnetic characteristics of the tumbler arrangements 27 to actuate the tumblers in a desired manner. These magnetic characteristics and tumble actuation will be described in more detail later. In the present example, the inner member 12 is held against rotation in the outer housing 10 by the tumbler arrangements 27, until the key 31 is inserted fully into the slot 30. On insertion, the tumbler arrangements 27 are actuated to release the inner member 12 which is then rotated in the housing 10 by turning the key 31. Rotation of the inner member 12 rotates the shaft 17 to actuate a lock member or other device.

As stated previously, the tumblers are actuated magnetically. There are several ways of such actuation and five of these are illustrated in FIGS. 2 to 6. It will be seen that in each of the arrangements illustrated in FIGS. 2 to 6, there is a spring 35, a tumbler 36 and a plunger 37.

Considering first the arrangement of FIG. 2, spring 35 is a compression spring and urges the tumbler 36 to a position in which it extends across or spans the joint surface 20 thus preventing relative movement between outer housing 10 and inner member 12. Plunger 37 is against the end of bore 26. The plunger is a magnet with, for example, its end 38 remote from tumbler 36, a North pole, the other end 39 a South pole. The tumbler is of magnetic or non-magnetic material. To actuate the tumbler arrangement, the plunger must be moved upward in FIG. 2, and this is done by positioning a north pole magnet in slot 30 of the complete mechanism, at the correct position by the key 31. This repels the plunger and lifts the tumbler. A shoulder 40 is formed in each bore 25 to provide a limit to upward movement of the tumblers 36. The plunger 37 can have the polarity reversed, if desired, and then a South pole is used on the key 31.

In FIG. 3, spring 35 is again a compression spring but the plunger 37 is of a length which positions the tumbler just entirely within bore 25, the plunger just being entirely within bore 26. Thus in this arrangement, as shown, the inner member 12 can move relative to outer housing 10. The tumbler 36 is of magnetic or non-magnetic material and the plunger 37 is a magnet; one end, 41, being a North pole and the other end 42 a South pole. Again, with this arrangement, a North pole is provided on the key 31 at the correct position and repulsion lifts the plunger 37, and tumbler 36, and locks the outer housing 10 and inner member 12 together. The polarity of the plunger can be reversed, with reversal of the pole on the key also.

FIG. 4 illustrates an arrangement in which spring 35 is a tension spring urging the tumbler into contact with the shoulder 40. The tumbler 36 is of magnetic material, for example, soft iron, and the plunger 37 is a magnet. The plunger is held in contact with the tumbler 36 by magnetic forces. The opposite ends 43 and 44 of the plunger can be of North-South polarity, or South-North polarity. However, actuation is by attraction in this arrangement and, therefore, a magnetic pole of opposite polarity to that of end 44 is provided on the key 31. Normally, the inner member 12 is held against rotation by the plunger 37 extending across the joint surface 20, but insertion of the key 31, with the correct polarity at the related zone, pulls the plunger 37 down to free the inner member 12.

The arrangement of FIG. 5 is the reverse of that of FIG. 4 in that the inner member 12 is normally free to rotate in the outer housing 10, and is locked to the outer housing on insertion of the key 31. Thus, spring 35 is a tension spring and tumbler 36 is held against the shoulder 40 by the spring. The tumbler 36 is of magnetic material and plunger 37 is a magnet. The opposite ends 45 and 46 are of North-South polarity or South-North polarity and the plunger 37 and tumbler 36 are held in contact with each other by magnetic forces. The tumbler 36 is just contained in the bore 25 and the plunger 37 is just contained in bore 26. Insertion of key 31 with the appropriate magnetic zone 32 will cause plunger 37 to be pulled down, the tumbler 36 also being pulled down. This locks the inner member 12 to the outer housing 10, the tumbler 36 extending across or spanning the joint surface 20.

The arrangements illustrated in FIGS. 4 and 5 can also be actuated if the key has no actual magnetized zone but is of magnetic material, at least at the appropriate zone. The plunger 37, in both FIGS. 4 and 5, will be pulled downward if a key of magnetic material; or having an insert of magnetic material, is inserted in the slot.

In FIG. 6, the plunger has a main body 47 of non-magnetic material, with end portions 48 and 49 of magnetic material, for example, soft iron. The tumbler 36 is a magnet with its opposite ends 50 and 51 of North-South or South-North polarity. In this example, the tumbler is held by spring 35, which is a tension spring, against the shoulder 40 and is also just contained within the bore 25. The plunger 37 is held in contact with the tumbler by magnetic forces and is just within bore 26. Thus, the inner member 12 is free to rotate relative to the outer housing 10. Insertion of key 31 with either polarity at the appropriate zone will pull down the plunger 37, together with the tumbler 36, and lock the inner member 12 against rotation relative to the outer housing 10. An alternative form of FIG. 6, not shown, is for the plunger 37 to be of magnetic material, in which case if the magnetism of the tumbler 36 is strong enough, no polarized zone is needed in the key but merely a zone of magnetic material.

From the various examples illustrated in FIGS. 2 to 6, it will be seen that a considerable number of variations in the tumbler arrangement can be provided. In the lock mechanism, as in FIG. 1, variations can be made in the tumbler arrangements 27, and different lock mechanisms can be provided with differing arrangements of tumblers. Although shown with the inner member 12 as the movable member, it is possible for the mechanism to be reversed in that the inner member is stationary and the outer housing rotates on the inner member.

Normally both the outer housing 10 and inner member 12 are of non-magnetic material to avoid leakage paths for the magnetic forces and to avoid interference between adjacent tumbler arrangements.

To ensure correct orientation of the key when inserted into the inner member or housing 12, the slot and key can be arranged to have cooperating cross-sections. Thus, the slot can have one or more ridges, or one or more grooves, extending longitudinally, with corresponding grooves or ridges on the key. The provision of such cooperating cross-sections also permits an increase in combinations of locks, in that variations in the cross-sections can be provided.

As the actuating forces are magnetic, the lock can be constructed to be completely weather-proof with no opening into the lock mechanism through which water or dust can enter. The O-rings 18 provide for sealing between the two parts, and lock freezing due to ingress of water can be avoided. Also, locks in accordance with the present invention can be used for vacuum or pressure chambers and also for arrangements in which a liquid is in communication with the lock, as leakage through the lock can readily be prevented.

Although the lock mechanism has been described and illustrated in the form of an inner member rotatable relative to an outer housing, it will be appreciated that a lock mechanism in accordance with the present invention can take other forms. For example, a lock mechanism can comprise two members side by side and having relative sliding movement, and the joint surface can be flat. Instead of the tumbler arrangements being positioned axially along an inner member, they can be positioned across the end of a member, the tumblers extending axially. In this latter arrangement, suitable zones would be provided on the end of the key. Other forms and arrangements can readily be devised.

Claims

I claim:

1. A locking device comprising first and second cylindrical members coaxially mounted with said second member contained substantially within said first member, the outer surface of said second member and the inner surface of said first member forming closely spaced meeting faces, locking means formed by said first member having a first bore extending substantially normal to said meeting face thereof, said second member having a second bore extending substantially normal to said meeting face thereof, the axes of said bores being substantially uniplanar, at least one of said members being movable relatively to the other of said members to place said bores in axial alignment, a tumbler in said first bore and axially slidable therein, a plunger in said second bore and axially slidable therein, said tumbler having an unlocking position wholly within said first bore, said plunger having an unlocking position wholly within said second bore, one of said tumbler and said plunger having a locking position spanning said meeting faces, one of said tumbler and said plunger having a magnetic characteristic, means resiliently urging said tumbler into one of said positions, said tumbler and said plunger being in engagement with each other when in axial alignment, magnetic means for causing axial movement of said tumbler and said plunger and sealing means between said meeting faces at either side of said locking means.

2. A locking device as defined in claim 1, said second member having a key-receiving recess therein, said magnetic means comprising a key insertable in said recess and having magnetic section arranged for axial alignment with said plunger and said tumbler.

3. A locking device as defined in claim 2, said resilient means comprising a compression spring in said first bore urging said tumbler into said locking position, said plunger being a magnet repellable by said magnetic section to move said tumbler to said unlocking position, said first member having a shoulder in said first bore engageable by said tumbler to define said unlocking position.

4. A locking device as defined in claim 2, said resilient means comprising a compression spring in said first bore urging said tumbler towards said plunger, said plunger and said second bore being of substantially equal length, said plunger being repellable by said magnetic section to move into said locking position.

5. A locking device as defined in claim 2, said resilient means comprising a tension spring urging said tumbler into said first bore, said tumbler being of magnetic material, said plunger being a magnet under magnetic attraction of said tumbler and in said locking position, said plunger being attractable by said magnetic section to move into said unlocking position.

6. A locking device as defined in claim 2, said resilient means comprising a tension spring urging said tumbler into said first bore, said tumbler being of magnetic material, said plunger being a magnet under magnetic attraction of said tumbler, said first member having a shoulder in said first bore engaging said tumbler to define said unlocking position thereof, said plunger and said tumbler being attractable by said magnetic section to move said tumbler into said locking position.

7. A locking device as defined in claim 2, said resilient means comprising a tension spring urging said tumbler into said first bore, said tumbler being a magnet, said plunger having at least a portion of magnetic material for attraction by said magnet, said first member having a shoulder in said first bore engaging said tumbler to define said unlocking position thereof, said plunger and said tumbler being attractable by said magnetic section to move said tumbler into said locking position.

8. A locking device comprising first and second cylindrical members coaxially mounted with said second member contained substantially within said first member, the outer surface of said second member and the inner surface of said first member forming closely spaced meeting faces, locking means formed by said first member having a plurality of first bores therein extending substantially normal to said meeting face thereof, said second member having a plurality of second bores extending substantially normal to said meeting face thereof, at least one of said members being movable relatively to the other of said members to a position in which each of said second bores is in axial alignment with one of said first bores, a series of tumblers one in each of said first bores and axially slidable therein, a series of plungers one in each of said second bores and axially slidable therein, each said tumbler having an unlocking position wholly within said first bore, each said plunger having an unlocking position wholly within said second bore, one of each of said series having a locking position spanning said meeting faces, one of each of said series having a magnetic characteristic, means resiliently urging each said tumbler into one of said positions, each said tumbler being in engagement with one of said plungers when said bores are in axial alignment, magnetic means for causing axial movement of said tumblers and said plungers and sealing means between said meeting faces at either side of said locking means.

9. A locking device as defined in claim 8, said magnetic means comprising a key having a plurality of sections each with magnetic characteristics, said second member having a recess for reception of said key, said key having an operative position in said recess wherein each said section is in axial alignment with one of said plungers.

10. A locking device as defined in claim 8, said first member comprising a barrel, said second member comprising a cylinder rotatably mounted in said barrel.