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United States Patent 3,779,052
Deitch December 18, 1973

MAGNETIC LOCK

Abstract

A lock device using magnetic tumblers to release the shackle or bolt of the lock or to open or close switches of a circuit. The magnetic tumblers are mounted in guideways adjacent to a face to shift towards or away from this face responsive to the influence of magnets in a magnetic key placed against the face.


Inventors: Deitch; Ronald S. (Denver, CO)
Appl. No.: 05/175,998
Filed: August 30, 1971


Current U.S. Class: 70/38C ; 200/42.02; 340/506; 340/542; 340/550; 70/129; 70/276; 70/422
Current International Class: E05B 47/00 (20060101); E05b 045/08 (); E05b 047/00 (); E05b 067/22 ()
Field of Search: 70/38R,38A,38B,38C,276,277 200/43,44,46 335/206 340/274

References Cited

U.S. Patent Documents
3680336 August 1972 Schendel
2595769 May 1952 Cooley
3271983 September 1966 Schlage
3474366 October 1969 Barney
3606776 September 1971 Drach, Jr.
Foreign Patent Documents
230,762 Dec., 1963 OE
Primary Examiner: Craig, Jr.; Albert G.

Claims



I claim:

1. A lock having a block means mounted for slidable movement within the body of the lock which is locked-in to secure the lock and locked-out to open the lock, and a tumbler mechanism adapted to effect the locking-in and locking-out of the block means, said lock comprising in combination therewith:

a. a plurality of guideways within the body and traversed by the block means, terminating at the common face of the body;

b. magnetic tumblers shiftably mounted in the guideways to shift to a position adjacent to the face and to a position away from the face, responsive to magnetic influence at the face;

c. an engaging means on each tumbler to engage the block means and lock-in the block means when the tumbler is shifted to a locked-in position, and to release to permit locking-out of the block means when the tumbler is shifted to another position;

d. a means on each tumbler adapted to bias the tumbler to the locked-in position whereby each of the tumblers will engage and lock-in the block means and all must be shifted against their bias means to lock-out and release the block means as by providing selected, magnetic influences at the aforesaid face; and

e. said engaging means includes pins carried by the tumblers and said block means includes sockets adapted to receive said pins.

2. In the organization defined in claim 1, wherein

the magnetic tumblers are adjacent to the face at one side of the block means and at least one of the magnetic tumblers includes:

an arm extending to the opposite side of the block means;

a pin carried upon the arm; and

a socket in the opposite side of the block means adapted to receive the pin.

3. In the organization defined in claim 2, wherein

the arm extends through a slot in the block means.

4. In the organization defined in claim 1, wherein

said magnetic lock is embedded in a structural member with the aforesaid face being at the surface of the structural member, whereby the same may be blended into the surface without changing the appearance of the surface.

5. In the organization defined in claim 1, wherein

said face is planar; and

the end of each guideway is closed by a thin wall portion of the face.

6. In the organization defined in claim 1, including further:

a magnetic key comprising an array of magnets within an embedment, said array corresponding with the arrangement of the aforesaid guideways at the face of the body and selectively oriented, polewise, to attract and move the magnets within the body away from the locked-in state bias.

7. In the organization defined in claim 1, wherein:

said block means includes a shackle arm extending from the body which may be opened when the block is shifted from the locked-in position to the locked-out position.

8. In the organization defined in claim 1, wherein:

the bias means on each tumbler includes a spring adapted to urge the pins into the sockets.

9. A magnetic lock assembly for use with a locking device, the assembly comprising:

a. body means formed from non-magnetic material and having an outer exposed face, said body means also having

1. block means carried within said body means, said block means including means for securing and releasing the locking device,

2. guideway means arranged within the body means transverse to the block means and terminating near said outer face,

3. magnetic tumbler means mounted within said guideway means, said tumbler means being arranged for slidable movement with respect to the block means between a position engaging the block means and a position spaced from the block means,

4. means for biasing said tumbler means to urge the tumbler means to the engaged position and wherein

5. said securing and releasing means includes a cavity formed within said body means wherein said block means is arranged for slidable movement normal to said guideway means between a locked position and an unlocked position, and socket means provided in the surface of said block means arranged to correspond with said guideway means when said block means is in the locked position,

6. said tumbler means includes pin means arranged to be inserted into said socket means when said tumbler means is in the block engaging position,

7. whereby said block means can be moved to the unlocked position when the key means shiftably moves the tumbler means to the spaced position.

10. An electrically operated locking device having a solenoid operated lock, a source of electrical power and a magnetic lock assembly operatively connected by an electrical circuit between said power source and said solenoid lock for controlling said lock; said magnetic lock assembly comprising:

a. body means formed from non-magnetic material and having an outer exposed face, said body means also having

1. block means carried within the body means formed generally as a flat member having a circuit loop adapted to be mounted on either side of said block means,

2. guideway means within the body means normal to the block means and being intersected by the block means to extend to both sides thereof and terminating near the outer face, said loop extending across and being broken at each of the guideway means and a passageway through the block means at the guideway means smaller in diameter than the guideway means,

3. magnetic tumbler means mounted within said guideway means at the side of the block means adjacent to the outer face, said tumbler means being arranged for slidable movement with respect to the block means to a position towards the block means and to a position spaced from the block means adjacent to the outer face,

4. means for selectively biasing the tumbler means towards one of said positions,

5. a means on selected tumbler means extending towards the block means to engage and to close the circuit when the tumbler means is shifted towards the block means,

6. means on other selected tumbler means extending towards and through the passageway in the block means to engage the opposite side of the block means to close the circuit when the tumbler means is shifted towards the outer face, and

b. magnetic key means having magnetic means arranged to correspond to said guideway means and a surface adapted to conform to said body face so that when the key means is held adjacent to the outer face of said body means said tumbler means will be magnetically shifted to the block engaging position closing said circuit so as to energize said solenoid lock.

11. In apparatus operated by an electrical lead of a circuit from a power source, a magnetically actuated switching lock in the electrical lead comprising:

a. a body of non-magnetic material having an exposed face;

b. guideways within the body adjacent to said exposed face;

c. a loop of said electrical lead within the body means intercepting each of the guideways, with the said electrical lead being broken at each guideway to form separated contacts at the guideways;

d. a magnetically responsive tumbler means shiftably mounted in each guideway and being adapted to shift responsive to magnetic influences at the exposed face to a first contacting position where the tumbler means will engage the electrical lead contacts to close the lead at the guideway and to a second open-circuit position where the tumbler means do not engage the electrical leads;

e. a bias means to normally hold the tumbler means at the open circuit position, but permit the tumbler means to shift to the contacting position responsive to selected magnetic influences at the exposed face, to close the circuit lead loop; and

f. a disruptible means at the exposed face adapted to actuate a warning device when the disruptible means is disrupted by tampering with the body means.

12. In the apparatus defined in claim 11, wherein:

said exposed face includes a sheet of non-magnetic, non-conductive material and said disruptible means includes a circuit lead printed upon the sheet.

13. In the apparatus defined in claim 12, including:

a second sheet of non-magnetic, non-conductive material laminated to the first said sheet of non-magnetic, non-conductive material with said printed circuit being sandwiched between the sheets.
Description



This invention relates to locks, and more particularly to locks having magnetic tumblers and as such, will be hereinafter sometimes referred to as a "magnetic lock."

A primary object of the invention is to provide a novel and improved magnetic lock of a foolproof, reliable construction, which eliminates the conventional key slot to present only smooth and continuous surfaces at the exposed portions of the lock.

In the past, there have been many attempts to build foolproof, reliable locks. Some such locks are intricate and expensive, while others are large, heavy and cumbersome. Magnetic locks have also been used. Such locks ordinarily provide magnetic tumblers in a conventional lock cylinder and the tumblers are actuated by a magnetic key. Other magnetic locks rely upon solenoids operated by electrical circuits and these locks are usually comparatively heavy. There remains, in spite of the many types of locks heretofore developed, a need for an improved, simple and reliable lock structure which is capable of being easily opened with a proper key, but is otherwise extremely difficult to open.

The present invention was conceived and developed with the foregoing considerations in view and with the recognition that small, powerful magnets are available on today's market which can be advantageously used in the construction of a lock. The invention comprises, in essence, a lock, of any of several various types, having a plurality of magnetic tumblers in guideways in the body of the lock, which normally restrain the base of a shiftable shackle or bolt to a locking position. These tumblers are biased at various locking positions with respect to the shackle or bolt, but they are all positioned near a common surface of the lock body. A simple magnetic key is placed at this surface in a selected position to exert a proper magnetic influence capable of shifting the tumblers against their bias to release the shackle or bolt and permit the lock to open.

It follows that another object of the invention is to provide a magnetic lock which has a plurality of magnetic tumblers biased to normally hold the shackle or bolt thereof in a closed position, and wherein the magnetic tumblers are positioned and are oriented with respect to their polarities in various alternating ways, thus providing a large possible number of combinations and arrangements of magnetic field patterns in a key which will open the lock and also render the lock impossible to open with a wrong key, with the key improperly positioned, with simple magnets and by other lock picking techniques.

Another object of the invention is to provide a novel and improved magnetic lock which includes a plain contact face where a simple, flat magnetic key may be placed to open the lock and wherein the contact face may be located at the side of a padlock or at the face of a door where it may either be marked or concealed.

Another object of the invention is to provide a novel and improved magnetic lock, devoid of a key slot, which can be more effectively sealed against moisture, fumes, dirt and the like, all of which tend to corrode and/or clog the mechanisms within the lock.

Another object of the invention is to provide a novel and improved magnetic lock having an arrangement capable of being used in many different types of installations including both mechanical and electrical installations.

Other objects of the invention are to provide a novel and improved magnetic lock which is a simple, low cost, reliable, rugged and durable unit.

With the foregoing and other objects in view, my invention comprises certain constructions, combinations and arrangements of parts and elements as hereinafter described, defined in the appended claims, and illustrated in preferred embodiments in the accompanying drawings in which:

FIG. 1 is an isometric view of a padlock incorporating within it the present invention, exemplary of one embodiment thereof.

FIG. 2 is an isometric view similar to FIG. 1, but with portions of the lock broken away to show constructions there-within.

FIG. 3 is a transverse sectional elevation as taken from the indicated line 3--3 at FIG. 1.

FIG. 4 is a sectional plan as taken from the indicated line 4--4 at FIG. 3, but on an enlarged scale.

FIG. 5 is an isometric view of the shackle member of the padlock, per se, and with a portion of the shackle block being broken away to show details otherwise hidden from view.

FIG. 6 is an isometric view of a magnetic key for the lock shown at FIG. 1, and with portions of the key being broken away to show constructions therewithin.

FIG. 7 is a sectional view as taken from the indicated line 7--7 at FIG. 6.

FIG. 8 is a small-scale, somewhat-diagrammatic view of a cabinet door having a concealed lock structure built according to the principles of the present invention, exemplary of a second embodiment thereof.

FIG. 9 is a sectional plan view of a fragment of the cabinet door, the lock structure therein and an adjacent wall portion, as taken from the indicated line 9--9 at FIG. 8, but on an enlarged scale.

FIG. 10 is a fragmentary sectional elevational view of the door and lock structure as taken from the indicated line 10--10 at FIG. 9.

FIG. 11 is an isometric view of the lock structure per se, and with portions of the lock being broken away to show constructions therein.

FIG. 12 is a side elevation view of an automobile wherein a door lock is built according to the principles of the invention, exemplary of a third embodiment thereof. This embodiment involves electrical circuits and the view illustrates, at a broken-away portion and in a diagrammatic manner, a solenoid member and the door bolt.

FIG. 13 is a fragmentary sectional plan view, as taken substantially from the indicated line 13--13 at FIG. 12.

FIG. 14 is a sectional elevational view as taken from the indicated line 14--14 at FIG. 13, but on an enlarged scale.

FIG. 15 is a fragmentary sectional detail as taken from the indicated line 15--15 at FIG. 14 to illustrate the circuitry within the lock structure.

FIG. 16 is a fragmentary sectional detail as taken from the indicated line 16--16 at FIG. 14 to illustrate other protective circuitry which may be used in conjunction with the lock.

FIG. 17 is a circuit diagram which may be used in connection with the locks shown at FIGS. 12 - 16.

FIG. 18 is an isometric view of a key for the lock shown at FIGS. 12 and 13, but with portions of the key being broken away to show one of the magnets within it.

Referring more particularly to the drawing, the padlock illustrated at FIGS. 1 - 5 depicts a simplified structure wherein the padlock body B is formed of a non-magnetic material such as brass or stainless steel. It may be built in any suitable manner to provide a simple, closed, box-like member and suitable cover plates such as p, FIGS. 3 and 4, may be used to enclose the spaces and components within the body. A U-shaped shackle arm 20 extends from spacing openings 21 and 21a at the top surface of this body. The body B is formed with a cavity 22 communicating with, and between, these openings and extending downwardly therewithin and to a base near the bottom surface of the body. A flat, rectangular shackle block 23 is shiftably carried in this cavity. One end of the shackle arm 20 is pivotally mounted upon one side of the block 23 by an arm extension 24, as best shown at FIG. 5. The other end of the arm is spaced a short distance above the block. Thus, when the block 23 is fitted within the cavity 22, the pivoted end of the shackle arm 20 projects from one opening 21 and the free end of the shackle is proportioned to fit into the opposite opening 21a whenever the block 23 is shifted downwardly within the cavity to a locking position, as illustrated at FIG. 2, but to be above the opening 21a so the shackle arm 20 is free to swing and open whenever the block 23 is shifted to an up, or unlocking, position.

A plurality of tumblers hold the block 23 to lock the lock, as will be described. These tumblers are formed as small, short, cylindrical magnets 25 and 25a. These magnets are slidably mounted in cylindrical guideways 26 arranged in a selected array within the lock body B. The array of guideways is transverse to the cavity 22 and thus, they are intercepted by the block 23. The guideways 26 are in mutual spaced parallelism and are normal to the face of the block 23. They bottom out closely adjacent to a front face 27 of the body B which is positioned from the cavity a distance sufficient to accommodate the magnets 25 and 25a and to permit them to shift forwards and away from the block 23 responsive to magnetic influences at the face 27 as may be produced by a key as hereinafter described. When the magnet or an extension arm upon it is moved against the block 23, it will be at a locking position, as will be described, and springs 28 and 28a are mounted in the guideways 26 to bias the magnetic tumblers against the block 23 to the locking position, all as hereinafter further described.

The magnets 25 and 25a are available as small, cylindrical members having surprisingly strong attraction and repulsion characteristics. They may be made of Alnico metal or equivalent materials. Each magnet 25 is attracted, or repulsed, towards or from, the fact 27 depending upon the polarity of that end of the magnet 25, or 25a, which is adjacent to the face 27 and the polarity of the end of a corresponding key magnet which is placed at the face, magnet ends of like polarity repulsing each other and magnet ends of opposite polarity attracting each other as is well known. Accordingly, it is possible to provide a locking mechanism with the array of magnets 25 and 25a which is operated by a key K having a like array of magnets 29, as shown at FIGS. 6 and 7. The possible variations of the polarity arrangements of the tumbler magnets 25 and 25a and of the key magnets 29 will provide a large number of combinations for many different locks with one key operating only the lock for which it was intended.

In the drawing, an array of five magnets is shown in the padlock and key K, but such is only exemplary, for fewer or more magnets may be used. The key is formed as a small block 30 of non-magnetic material and is an embedment carrying the magnets 25a. Visually, the magnets may be concealed in this block. A gripping flange, shown as a ring 31, is provided to this key at the back side of this block. The ring may be a finger ring and is an advantageous mode of carrying the key for a very small padlock.

The magnets 25 will move away from, and the magnets 25a will move towards the face 27 to engage the shackle block, as in the manner shown at FIGS. 2, 3 and 4, since a magnet 25 engages the block 23 when it is moved away from the face 27. A compression spring 28 is conveniently interposed between the magnet and bottom of the socket 26 to bias the magnet against the block adjacent to the face 27. A pin 32 outstands from the end of the magnet 25 to fit into a socket 33 in the face of the block 23, the socket being located in the block so the pin will hold it locked. On the other hand, the magnets 25a engage the block 23 when moved to the bottom of their guideways 26, and this engagement of the block 23 must be at the opposite face of the block. The guideway 26 is provided with a slotway 34 and an arm 35, affixed to the magnet, lies in this slotway to extend through a clearance slot 36 in the block 23. The clearance slot 36 is elongated in the direction of movement of the block 23 to avoid interfering with the arm 35 when the block 23 is shifted from a closed to an open position. The arm carries a head 37 having a pin 32a engaging a socket 33a at the opposite side of the block 23. A compression spring 28a between this head and the backwall of the body, in the guideway 26, biases this head and the magnet 25a towards the face 27.

Because the construction of the padlock will contemplate various arrangements of the magnets 25 and 25a in the several guideways 26, slotways 34 are provided in all of the guideways and the clearance slots 36 in the shackle block 23 are extended to register with all of the slotways. Also, sockets 33 and 33a are provided at each guideway, at both sides of the shackle block 23.

The manner in which the padlock operates is very simple. Whenever it is closed by pushing the shackle arm 20 into the body of the lock with the free end in the opening 21a, as illustrated at FIG. 1, the several pins 32 and 32a will be urged into their respective sockets 33 and 33a. Accordingly, every magnet 25 and 25a in the array will function to secure and hold the shackle block in a locking position. Then the padlock cannot be opened until the key K is properly placed against the face 27 so that magnets 29 of the key will shift magnets 25 and 25a away from the locking position and release the shackle block. A resilient means, not shown, may bias the shackle block to permit the lock to snap open or it may be opened merely by pulling the shackle arm 20.

The door latch, illustrated at FIGS. 8 - 11, uses the same basic locking mechanism L as heretofore described, but the lock is mounted in a cabinet door 40 which, in turn, is hinged in an opening in a wall 41 in a conventional manner. The door latch locking mechanism L includes a latch bolt 42 which moves horizontally, within a guideway 43 at the edge of the door and into a pocket 44 at the edge of the wall opening, such being conventional in door latching arrangements. This bolt is shifted into and out of the pocket 44 to lock and to unlock the door, with such shifting being effected manually by turning a knob 45 outstanding from the face of the door. The knob operates a shifting arm A which, in turn, connects with the locking mechanism L which carries the bolt 42. These mechanisms are conveniently mounted upon a backing plate 46 which is fitted over a pocket 47 cut in the back wall of a cabinet door. The pocket is proportioned to receive the mechanisms carried upon the backing plate 46. Holes 48, at the corners of the backing plate 46, receive mounting screws 49 to secure the unit in place. The guideway 43 connects with the pocket and is reinforced by a sleeve 50. The latch bolt 42 extends through this guideway and inlcudes a head 51 which is telescopically fitted over the bolt to be held at a normally extended position, as illustrated, by a spring 52. The inward face of the head 51 is bevelled to permit the edge of the wall opening to slide the head upon the bolt to permit the door to close when the locking mechanism L is locked. It is to be noted that similar arrangements are provided in conventional locks for the same purpose.

The locking mechanism, similar to that of the padlock heretofore described, includes a body L having a cavity 22' wherein a latch block 23' may shift from a locked to open position. Guideways 26' through this body L traverse the cavity 22', the same as heretofore described, although the drawing shows the direction of block movement as being horizontal instead of vertical. Magnetic tumblers 25' and 25a' are in the guideways 26' at the outer face of the mechanism and these tumblers are biased by springs 28' and 28a' to push pins 32' on the magnets 25' and pins 32a' on the arms 35' of the magnets 25a'. The pins 32' and 32a' engage sockets 33' in the latch block 23' to lock the mechanism.

An outer face of the body, corresponding with the face 27 of the padlock, is omitted but the pocket 47 is formed with a thin shell 53, a portion of the outer wall of the cabinet door 40, which substitutes for face 27. Thus, viewed from the exterior of the door, the location of the locking mechanism L may be completely concealed and the proper location for a key K cannot be found without considerable trouble. This is desirable where an individual, having a proper key and knowing where to place it on the door wall, is to be the only person to open the cabinet. Anyone else, even with the key, will have difficulty in unlocking the door. However, if desired, suitable markings may be used to indicate where the key is to be placed on the cabinet door.

In further detail, the locking mechanism will include slotways 34' in the guideways 26' and clearance slots 36' in the latch block 23' to permit magnets 25a' to use arms 35' which extend through the slotways to the opposite side of the latch block 23' as illustrated and as heretofore described.

Any suitable shifting mechanism may be used to move the latch block 23' and its bolt 42 from the closed to the open position whenever a magnetic key releases the magnetic tumblers. In the arrangement illustrated, this shifting mechanism includes the knob 45 which is mounted upon a square-sectioned shaft 54, which, in turn, extends through the door and through the arm A. The shaft 54 connects with an eccentric 55 mounted on the arm. The shifting arm A includes a pin 56 pivotally connecting it to a slotted ear 57 depending from the block 23'. A spring 58 is affixed to this ear 57 and engages pins 59 on the arm to normally hold the arm in alignment with the ear. The eccentric cam 55 will shift the arm to likewise shift the block 23 to open the lock when the key releases the tumblers. However, if the knob is forced when the tumblers engage the block, the spring 58 flexes, rotating the arm A and preventing the lock mechanism from being damaged.

The embodiment illustrated at FIGS. 12 - 18 depicts an arrangement wherein the lock mechanism E energizes electrical circuits as hereinafter described. Such a lock mechanism may be used for an automobile door as illustrated, and circuit leads 60, energized by the lock mechanism, will connect with a solenoid 61 the armature of which connects with a door-locking bolt 62, as diagrammatically shown at FIG. 12.

In the embodiment illustrated, the body E of this electrical lock is secured against the inner side of the wall of the automobile door as in a mounting base 63. The door may be recessed at the lock to form an inset 64 wherein a magnetic key may be fitted. The face 27" of this inset is of a non-magnetic material of sufficient thinness to permit the magnetic tumblers 25" within guideways 26" in the body E to be actuated by the influence of magnets 29" such as illustrated at FIG. 18. It may also include an alarm initiating means to warn against an attempt to break the lock, as hereinafter described.

The body E is formed of non-magnetic, non-conductive material wherein the array of guideways 26" terminate at the face 27" and are arranged as heretofore described although only four such guideways are shown in this embodiment. A fixed contact block 23" is mounted in a cavity 22" traversing the guideways 26". A hole 67 is positioned in this block 23" at each guideway 26" to permit arms 35" connected to magnetic tumblers 25a" to extend through the block 23". This block carries a bus lead 65 which is at both sides of the block, the bus lead 65 extending to each guideway in a series arrangement and with a circuit break 66 at each guideway 26". This bus lead connects with the electrical leads 60 in series with the solenoid 61.

The magnetic tumblers 25" and 25a" are located between the contact block 23" and face 27", and they are either pulled towards or pushed away from the face by key magnets 29" in the same manner heretofore described. Each tumbler is adapted to move within a section 68 of its guideway adjacent to the face 27 and a stop 69 defines this guideway section and limits the tumbler movement. Springs 28" and 28a" are also in these guideway sections 68 to bias the position of their respective magnetic tumblers to normally "off" or open-circuit position. Each magnetic tumbler carries an axially centered support rod 35", or 35a", whereon an electrically conductive contact head 70, or 70a, is mounted, adjacent to the block 23'. The heads close the circuit of the bus lead 65 when the tumbler is shifted. The rod 35a" of each magnetic tumbler 25a" extends through a hole 67 in the contact block 23" to permit the opposite face of the block 23" to be contacted by the head 70a when the magnet 25a" is pulled from its biased "off" position.

The electrical circuits to operate this lock are shown at FIG. 18 and include a battery 71, and lead 60 is connected thereto. When all of the switches formed by the heads 70 and 70a are shifted to contact the bus lead 65, as by using a proper magnetic key K", the circuit 60 closes to energize solenoid 61 and open the door lock 62.

A safety lead 72", forming a circuit loop parallel with lead 60, may be used in connection with this magnetic switch to give a warning if someone tries to tear the magnetic lock apart. A thin plastic sheet 73 is mounted at the face 27". This sheet has a continuous circuit loop 74 printed upon it, as illustrated at FIG. 17, and the loop 74 is in series with the lead 72. Accordingly, if an intruder were to attempt to open the electrical lock by tearing it apart, the loop 74 would be broken.

The lead 72 is a normally closed circuit and a resistor 75 is provided to minimize current drain and permit only a very small current flow. The flow is sufficient to energize a relay 76 also in the lead 72. The relay 76 includes a normally open switch 76a which, in turn, is in a warning circuit lead 77 paralleling the other circuit leads 60 and 72. This circuit lead 77 includes a warning device such as a horn 78. Thus, whenever the printed circuit loop 74 is broken, the switch 76a closes to actuate the warning device 78. A normally closed shut-off switch 79 is positioned in a common lead of the circuits 72 and 77 to open both circuits 72 and 77 and the switch 79 may be opened whenever it is desired not to use the warning device.

The key K" includes magnets 29" embedded in a block 30" which includes a gripping flange 31" as heretofore described. The array of magnets may be symmetrical about an axis and it is possible to rotate the key when positioning it against a face plate such as 27 or 27". Thus, by simple rotation, one key can provide several combinations of magnet patterns, each capable of opening a specific magnetic lock. This is advantageous when it is desired to provide one key to open several locks, as of a system, the different tumbler combinations being effected by rotating the key.

As set forth, the magnetic tumblers 25 and 25a are necessarily adjacent to the face 27. However, the tumblers 25 are pulled towards the face 27 to release one side of the block 23 while the tumblers 25a are pushed away from the face 27 to release the other side of the block 23. To simplify the lock, the tumblers 25a could be eliminated and only tumblers 25 be used which contact the adjacent face of block 23. Various locking combinations could then be obtained by alternating the polarity direction of the several magnets 25. Such a simplified structure will be suitable for some uses; however, it could not resist tampering as by using a single, strong magnet at the key position which could overwhelm the effects of the opposing polarities of some of the magnets in the lock. The strong magnet would pull all of the tumblers to an open position. Nor could this simplified arrangement resist mechanical tampering, where the inertia effect of the several magnetic tumblers is taken advantage of to move all of them in the same direction, to open the lock.

I have now described my invention in considerable detail. However, it is obvious that others skilled in the art can devise and build other alternate and equivalent constructions which are nevertheless within the spirit and scope of my invention. Hence, I desire that my protection be limited, not by the constructions illustrated and described, but only by the proper scope of the appended claims.

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