AU703446B2 - Lock and key combination - Google Patents

Description

S F Ref: 315610

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

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4 4 54*5

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Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: ASSOCIATED PROVISIONAL [31] Application No(s) PM8761 Peter Barrett Saunders 17 Panorama Avenue Charmhaven New South Wales 2263

AUSTRALIA

Peter Barrett Saunders Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Lock and Key Combination APPLICATION DETAILS [33] Country

AU

[32] Application Date 12 October 1994 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5815 Lock and Key Combination Field of the Invention The present invention relates to key operated locking devices.

Background of the Invention A disadvantage of conventional key operated locks is that they can be picked using either a skeleton key or lock picking tools. This is at least partly due to the fact that the coded tumblers of a conventional key lock are arranged in line with one another, and are easily accessible to lock picking tools through the keyhole of the lock.

Object of the Invention It is an object of the present invention to overcome or substantially ameliorate ee the above disadvantages, Summary of the Invention This invention in one broad form provides a locking device adapted to be operated by a key, said locking device comprising: a front plate including a keyhole adapted to accommodate a said key; at least two movable members positioned inside a casing, each said movable member being movable between a home position and a final position, each said movable member including a keyhole adapted to accommodate a said key, each said movable member being restricted in movement such that said keyholes of said movable 20 members and said front plate cannot be aligned simultaneously; and at least one coded pin tumbler locking mechanism which is capable of being actuated by a said key arranged on each movable member; said locking device being adapted so that when a said key is inserted through said front plate, said key enters the keyhole of a first said movable member which is movable by said key from said home position to said final position, so that the keyhole of said first movable member is then aligned with the keyhole of the next said movable member which can then be entered and moved by said key.

IN:\libtt100736:PVH II I ~I The present invention in another broad form provides a locking device in combination with a key, said key being adapted to operate said lock.

It is preferable that the movable members are rotors. However, members adapted for translational movement are also within the scope of the present invention.

Brief Description of the Drawings By way of example only, certain preferred embodiments of a lock and key combination will now be described with reference to the accompanying drawings, wherein: Figure la is a plan elevation of a guard plate; lo Figure lb is a side elevation of the guard plate of Figure la; Figure Ic is a perspective view of a rotor; Figure 2 is a cross-sectional view of the rotor of Figure Ic, taken through line

A-A;

Figure 3 is a cross-sectional view of the rotor of Figure Ic taken through line

B-B;

Figure 4a is a front elevation of a key; Figure 4b is an end elevation of the key of Figure 4a; Figure 4c is a side elevation of another key; Figure 4d is a cross-section of the key of Figure 4c, taken through line A-A; Figures 5a, 5b and 5c represent the movement of a key through the rotors of a lock; Figure 6 is a cross-section of another rotor; Figure 7 is a cross-section of another rotor; Figure 8 is a cross-section of another rotor; Figure 9 is a plan view of a non-circular rotor; Figure 10 is a partial cross-section of a rotor showing a preferred pin, tumbler and spring-ball detent arrangement; Figures 1 la and lb are cross-sections of pins or tumblers having grooves; 1N:%ibttIO736:BFD -3- Figure 12 is a partial cross-section of another pin and tumbler arrangement; Figure 13 is a partial cross-section of a casing, showing a possible arrangement of tumblers; Figure 14a is a perspective view of an alternative embodiment of a lock adapted for translational movement; and Figure 14b is a top plan view of the lock of Figure 14a.

Description of the Preferred Embodiments In a preferred embodiment of the invention, a two bladed key (Figures 4a 4b) is inserted through a guard plate in which there is a matching keyhole The guard plate is preferably fixed to the casing of the locking device by means of studs or rivets and also preferably includes a key guide The key then enters the keyhole (10) of the first rotor which in its home position (Figure 5a, position in alignment with the guard plate As the key *enters the keyhole (10) of the first rotor it pushes the coded tumblers (11) of the is coded pin tumbler mechanisms (Figure These coded tumblers (11) push the pins (12) out of the rotor and into the outer casing section of the locking device.

The rotor is now able to be turned by the key, in this case clockwise, until the blades (19) of the key (Figure 4) are in alignment with the keyhole (10) of the second rotor This position is called the first rotor's final position (position B).

The key can then be pushed into the second rotor As the key blades (19) vacate the keyhole (10) of the first rotor the springs of the repeat locking mechanism (14) pushes the pins of the repeat locking mechanisms into the keyhole preventing the first rotor from moving out of its final position (Figure 7, position B) until the key is brought back into the keyhole As the key enters the second rotor it actuates the second rotor's coded pin tumbler mechanisms (also see Figure 3) in the same manner as for the first rotor. The key is then able to turn the second rotor in this case in a clockwise direction from position B to C, until the keyhole (10) of the second rotor is aligned with the (N \ib(tj00736:BFD keyhole (10) of the third rotor The rotational motion of the first and second rotors are restricted by the travel restricting mechanism so that the second rotor may only travel between position B and position C (Figure The travel restricting mechanism preferably comprises a groove (7b) in the outer wall of the rotor and a projection (7a) protruding into the groove (7b) from the lock casing Preferably, each rotor comprises a travel restricting mechanism.

To releasably locate the rotors in their home and final position, the lock may also comprise a spring ball detent mechanism The spring-ball detent comprises a spring (30c) and a ball (30d), housed within a recess (30e) in the side of a rotor. The ball (30d) is pressed by the spring (30c) against the inner wall of the casing where it releasably nests in shallow recesses (30a and 30b) corresponding in location to the home and final positions of the rotor. The spring-ball detent (30) assists the operator of the lock to locate the home and final positions of each rotor, and also prevents the rotor from rotating freely within the casing. The additional force required to move the ball (30d) out of the shallow recesses (30a,30b) also hinders the efforts of lock pickers. The spring-ball detent mechanism (30) can be used in conjunction with, or instead of the repeat locking mechanism (14).

The key can then be pushed into the keyhole of the third rotor (Figure 6).

Once the key enters the third rotor (Figure the repeat locking mechanism (14) of the second rotor is actuated, holding the second rotor in position C (Figure 7) until the key is reinserted back into the second rotor when the key is being withdrawn from the lock.

As the key enters the third rotor (Figure the coded pin tumbler locking mechanisms (11,12,13 of Figure 6) are activ.'ted. The rotation of the third rotor (Figure 6) is also restricted by a travel restricting mechanism (7a and 7b) such that the keyholes (10) of the three rotors and the guard plate can never be aligned simultaneously. Once the key is inside the third rotor (Figure the key can turn to position D, so that the final rotor can release a bolt (not shown) of the lock in a conventional manner. The angular range of travel of each rotor is generally designated INs\Ib00736 BFD Ul~i~lPll~i~ Pmrram~narsis~PP1I~Ps~-r~ as It is to be noted, however, that the angle need not be the same for each rotor, and need not even be in the same direction.

To release the key from the locking device, the steps described above are performed in reverse. As the key is withdrawn from each rotor, the springs of the coded pin tumbler locking mechanisms lock the three rotors back in their home positions in the same manner as the repeat lock mechanism (14) locks the rotors in their final positions. The spring-ball detent (30) can also assist in this function.

As an additional measure, the lock may comprise a spring ball stopping mechanism which does not locate the home and final positions of the rotors, but simply acts to prevent free rotation of the rotors.

~Preferably, the lock further comprises at least one return spring mechanism to S" urge each of the rotors back to their home positions if moved or turned to a position in between their final and home positions. This is to prevent the rotors from becoming S"stuck in between their home and final positions, which would make it impossible to insert the key to operate the lock. An example of a return spring mechanism is shown in Figure 8. In this case, the return spring mechanism comprises a spring (31) housed inside the travel restricting groove and bearing against the travel restricting projection The return spring mechanism is also used in conjunction with a detent mechanism, such as the spring-ball detent When the rotor is turned, using the key, from its home towards its final position (in Figure 8, a clockwise rotation), the spring (31) is compressed. If the rotor is turned insufficiently, so that the detent ball does not enter the recess (30b), the spring (31) urges the rotor back to its home position. If the rotor is turned completely into its home position, the detent engages the recess (30b), retaining the rotor in its final position. It is to be noted that the return spring function can be provided by any suitable mechanism, such as a torsional spring connected to the rotor and the casing The third and final rotor of the preferred embodiment of the invention is shown in cross-section in Figure 6. A keyhole ward (21) is preferably included in the INMAib?00736:BFO keyhole of the third rotor to obstruct access to the coded pin tumbler locking mechanisms (11,12,13) for anything other than the correct key, such as lock picking tools.

An example of a preferred key is shown in Figures 4a and 4b. The key preferably comprises two blades which each have a coded key face The blades are supported on a stalk A grip (16) is provided on the end of the stalk.

The key blades (19) correspond precisely in shape to the keyhole (10) of the lock, and preferably comprise grooved or channelled areas The grooved areas (26) are preferably shaped so as to define a crooked path from the stalk (17) to the coded area This hinders the access of lock picking tools to the coded key area (18).

Preferably, the groove (26) is wider at its base than at its opening. More preferably, the blades (19) of the key follow a helical path along their length. The grooved area (26) of the key corresponds in shape to the wards (40) on the keyhole The key also preferably comprises a recessed area (21a) which corresponds to a keyhole ward in the last rotor of the lock. When a double bladed key is used with the lock, two sets of coded pin tumbler mechanisms are provided in each rotor.

This increases the number of coding combinations which can be us;ad. However, a single bladed key is also within the scope of the invention.

A preferred example of a pin (12) and tumbler (11) arrangement is shown in Figure 10. In the arrangement shown in Figure 10, the pin tumbler (11) and spring (13) are secured within the lock by means of plug The spring (13) is preferably a conical shaped compression spring, which becomes flat when compressed.

The tumbler (11) shown in Figure 10 comprises a spherical ball, adjacent to the end of the tumbler closest to the keyhole. The ball (33) is preferably partially housed within a recessed area (42) of the tumbler However, the ball (33) is free to rotate with respect to the tumbler When the correct key is inserted into the keyhole, the ball (33) simply pushes the tumbler (11) towards the pin (12) allowing the lock to open.

However, when lock picking tools are used in an attempt to push the tumbler and pin so tN:\ibttJOO736:BFD -7as to open the lock, the ball (33) will rotate unless pushed in precisely its centre, deflecting the lock picking tool away. Further, the rounded surface of the ball provides 33 functions to reduce the friction between the key and the tumbler reducing wear on both the tumbler, the ball and the key.

Figures 1 la and 1 lb show two preferred cross-sections of the pins (12) or the tumblers (11) to be used with the lock. It can be seen that the pins and tumblers shown in Figures 1 la and 1 lb are of non-circular cross-section, so that the pins and tumblers are unable to rotate within the rotor or the casing of the lock. This irregular shape, which may comprise flat sections and/or recesses or projections in the pins and 1 o tumblers tends to cause the pins and tumblers to jam more readily when an attempt is made to pick the lock. However, when the correct key is used, the pins/tumblers are free to move within the lock. As can be seen in Figure 12, the spring (13) can be housed either partially or wholly within the plug (32) or the pin or neither.

Figure 13 shows an arrangement whereby more pins and tumblers can be placed in a limited area, by staggering the holes in which the pins and tumblers are housed.

It is also to be noted that the rotors do not necessarily have to be circular in shape, as can be seen from the example as shown in Figure 5. The rotors do not necessarily have to rotate through 3600. Accordingly, the superfluous regions of the rotor can be cut away, resulting in a less expensive, lighter lock. In this case, the casing is to be adapted to the particular shape of each rotor so that the axes of rotation are aligned with each other. Similarly, the front plates of the lock need not necessarily be circular.

Figures 14a and 14b depict an alternative embodiment of the present invention, wherein the keyholes of the movable members are laterally offset from each other and the front plate rather than angularly offset as in the previously described embodiment.

The path of movement of the key through the guard plate into the first movable member and then into alignment with the second movable member is shown N:%ib1t00736:BFD by arrows A slot (23) in the guard plate accommodates the lateral motion of the key stalk once the key blades have entered the first movable member. The embodiment of the invention shown in Figures 14a and 14b would also preferably provide travel restricting mechanism(s), return spring mechanisms, detents and coded pin tumbler locking devices similar to those described above.

The embodiments of the present invention illustrated provide a locking device which is an improvement over known locking devices, in that the pin tumbler locking mechanisms which drive the lock are effectively "blocked" by a succession of movable members, preferably rotors.

IN:\hbt100736 BFD 1 8-

Claims (29)

1. A locking device adapted to be operated by a key, said locking device comprising: a front plate including a keyhole adapted to accommodate a said key; at least two movable members positioned inside a casing, each said movable member being movable between a home position and a final position, each said movable member including a keyhole adapted to accommodate a said key, each said movable member being restricted in movement such that said keyholes of said movable members and said front plate cannot be aligned simultaneously; and at least one coded pin tumbler locking mechanism which is capable of being ee.e actuated by a said key arranged on each movable member; said locking device being adapted so that when a said key is inserted through said front plate, said key enters the keyhole of a first said movable member which is movable by said key from said home position to said final position, so that the keyhole of said first movable member is then aligned with the keyhole of the next said movable member which can then be entered and moved by said key. 00.

2. The locking device of claim 1, wherein each said movable member is a rotor rotatably mounted within said casing.

3. The locking device of claim 1 or 2, further comprising one or more 20 travel restricting mechanisms, each said travel restricting mechanism adapted to restrict the movement of a said movable member between its home and final positions.

4. The locking device of any one of claims 1 to 3, wherein each said travel restricting mechanism comprises a groove located on an outer edge of a said movable member and a projection located on an inner surface of said casing, said projection fitting inside said groove, wherein the length of said groove corresponds to the distance between the home and final positions of said movable member.

INAIibtlO0736PVH The locking device of any one of claims 1 to 4, further comprising at least one stopping means, each said stopping means being adapted to prevent a said movable member from rotating or moving unless operated by said key.

6. The locking device of claim 5, wherein said stopping means comprises a spring and a ball housed within a recess in an outside edge of said movable member, said spring adapted to press said ball to the inner surface of said casing.

7. The locking device of any one of claims 1 to 6, further comprising one or more repeat lock mechanisms, each said repeat lock mechanism being adapted to releasably lock a said movable member into its final position.

8. The locking device of claim 7, wherein each said repeat lock mechanism comprises a coded pin tumbler mechanism.

9. The locking device of any one of claims 1 to 8, further comprising one or more detent means, each said detent means being adapted to releasably locate a said movable member into its home position and its final position.

10. The locking device of claim 9, wherein each said detent means comprises a spring and a ball housed within a recess in an outside edge of said movable member, and two recesses in an inner surface of said casing, said spring being adapted to press said ball into one of said recesses when said movable member is in its home position, and into the other said recess when said movable member is in its final position.

11. The locking device of claim 7 or 9, further comprising one or more return mechanisms, each said return mechanism adapted to return a said movable member into its home position, unless said movable member is in its final position.

12. The locking device of claim 11, wherein each said return mechanism comprises a compressible spring housed within said travel restricting groove between said projection and an end of said groove.

13. The locking device of claim 2, wherein said at least two rotors are stacked behind said front plate, said rotors having a common axis of rotation, wherein INhbt00736FD -11 [he i furthcs rotor from said front plate actuates a bolt when turned from its home to its final position.

14. The locking device of any one of claims 1 to 13, wherein each said pin rumbler locking mechanism comprises a plurality of tumblers housed within a said S movable member and a plurality of pins housed within said casing, said pins being pushed into said movable member by springs so that each pin abuts an end of a said tumbler, said tumblers being adapted to push said pins into the casing by means of a said key, allowing said movable member to be moved.

The locking device of claim 14, wherein one or more of said tumblers is non-rotatably mounted within said movable member.

16. The locking device of claim 14 or 15, wherein one or more of said pins are non-rotatably mounted within said movable member and said casing.

17. The locking device of claims 15 and 16, wherein said tumblers and pins are non-circular in cross-sectional shape and/or are grooved. 1

18. The locking device of any one of claims 14 to 17, further comprising at least one ball housed within a said movable member, each said ball adjacent to the other said end of a said tumbler, each said ball being freely rotatable.

19. The locking device of any one of claims 1 to 18, wherein said front plate comprises a flanged portion corresponding in shape to said keyhole and projecting from at least a part of the periphery of siid keyhole.

The locking device of claim 1, wherein each said movable member is adapted for translational movemnt.

21. The locking device of claim 20, wherein said front plate is slotted to accommodate any translational movement of said key.

22. In combination, the locking device of any one of claim 1 to 21, and a key, said key bePng adapted to operate said locking device.

23. The combination of claim 22, wherein said key comprises a stalk and one or two blades extending from an end of said stalk, each said blade having a coded INIhbtt00736:BFD M&I30MMA0 les~rPII I -12- key face adapted to be capable of actuating each said coded pin tumbler locking mechanism.

24. The combination of claim 23, wherein each said key blade comprises at least one groove or channel extending in a longitudinal direction, said keyhole comprising a ward corresponding to each said groove or channel.

The combination of claim 24, wherein said at least one groove or channel is wider at its base than at its opening.

26. The combination of claim 23, wherein the stalk of said key comprises at least one recess and/or groove extending a predetermined distance into the end of 10 said stalk from which said key blade extends, said casing comprising one or more projections extending into the keyhole of the movable member furthest from the front plate, said projections corresponding in shape to said recess and/or groove.

27. A locking device substantially as hereinbefore described with reference to Figures 1-3 and 5a-13.

28. A locking device substantially as hereinbefore described witi; reference to Figures 14a and 14b.

29. In combination, a locking device of claim 27 or 28 and a key, said key being substantially as hereinbefore described with reference to Figures 4a and 4b. DATED this Twenty-seventh Day of September 1995 Peter Barrett Saunders Patent Attorneys for the Applicant SPRUSON FERGUSON IN:\ii)t0073:BFD _M LOCK AND KEY COMBINATION Abstract There is disclosed herein a locking device adapted to be operated by a key. The locking device comprises a front plate and two or more movable members (4,9,20) mounted inside a casing The movable members (4,9,20) each comprise a keyhole (10) adapted to accommodate the key, and are each movable between a home position and a final position. The movable members (4,9,20) are restricted in movement so that the keyholes (10) are never simultaneously aligned. The locking device comprises at least one coded pin-tumbler locking mechanism which is adapted to be actuated by the key. The locking device is operated by inserting the key through the front plate into the keyhole (10) of a first movable member moving the first movable member from its home to its final position, and then inserting the key into S the keyhole of the next movable member a" INAIRb100V44OFD