AU674337B2 - Improvements in locks - Google Patents

Description

P/00/011 Reguation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

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a a 9! a TO BE COMPLETED BY APPLICANT Name of Applicant STADON PTY LTD Actual Inventor: Greg Howe Address for Service: CALINAN LAWRIE, 278 High Street, Kew, 3101, Victoria, Australia Invention Title: "IMPROVEMENTS IN LOCKS" The following statement is a full description of this invention, including the best method of performing it known to us:- -2- This invention relates to locks and refers particularly, though not exclusively, to improvements in pin tumbler locks.

A pin tumbler lock comprises a lock body and a rotatably mounted lock cylinder. In the locked position a number of pin tumblers of different lengths and comprising an upper and lower segment (also called top and bottom pins) are pressed down by springs in the lock body to engage with holes in the lock cylinder, thereby preventing the lock cylinder from rotating. When a key is inserted into the lock, the lower segments of the pin tumblers are raised by exactly the correct amount to bring their tops flush with the outer surface or shear line of the lock cylinder. As the two segments of each tumbler are separate i.e. not interconnected, the lock cylinder is then free to rotate when the key is turned. The cylinder actuates a bolt or any other component to control entry to the locked object. If the wrong key is inserted, it will not raise all or any of the lower tumbler segments to the correct height, and the lock cylinder cannot be rotated.

One problem with pin tumbler locks are that the outer diameter of the lock body is large. This problem is caused by the spring abutting the pin S tumbler and having the length of the spring added to che length of the pin tumbler.

o:oo °2 Also, with normal pin tumbler locks, it is usual that the key can only be withdrawn in one or, at the most, two positions. This can cause difficulties if a lock is required and where the key must be able to be withdrawn from the keyway at different rotational positions.

An object of the present invention is to provide a pin tumbler lock wherein the key may be able to be withdrawn from the lock at different rotational positions.

It is a preferred object of the present invention to provide a pin tumbler lock cylinder where the diameter of the lock body may be able to be reduced.

SAtU 6/9/96S6726.PRV,2 IP~v Iz 1,1/A/Ai~rr 4 The invention provides a lock device including a pin tumbler lock having a lock body and a lock cylinder rotatably located therein and/or axially movable therein, said pin tumbler lock being mounted rotatably within an outer casing, there being at least one interference member located in said lock body and adapted to be located in one of a plurality of recesses in said outer-casing, said interference member being withdrawn radially from said one of said plurality of recesses upon correct operation of a key in said pin tumbler lock to allow said lock body to rotate relative to said outer casing.

In one preferred aspect said lock body has a plurality of top pins, each top pin having a first portion of a first diameter and a second portion of a second diameter, the first diameter being greater than the second diameter; each top pin having a spring over the second portion, the diameter of said spring being of the same order of magnitude as the first diameter.

In order that the invention may be readily understood there shall now be described a preferred construction of a lock mechanism incorporating the preferred features of the present invention, the description being with reference to the accompanying illustrative drawings, in which: *Figure 1 is an exploded perspective view of the pin tumbler lock; a\ 0.

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-4- Figure 2 is a cross-sectional view of the assembled pin tumbler lock of Fig. 1; Figure 3 is a cross-sectional view along and in the direction of arrows 3- 3 of Fig. 2 showing the lock in the locked position; Figure 4 is a similar view to that of Fig. 3 showing the lock in the unlocked position; Figure 5 is an exploded perspective view of a variation of a lock cylinder for the lock of Fig. 1; o Figure 6 is a cross-sectional view similar to that of Fig. 2 showing the 0 10 variation of Fig. 5; Figure 7 is a cross-section view along and in the direction of arrows 7-7 Figure 7 is a cross-section view along and in the direction of arrows 7-7 of Fig. 5; and Figure 8 is a cross-sectional view along and in the direction of arrows 8- *s 06

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e Se s C S S. oCSS 8 of Fig. 7.

a .15 The pin tumbler lock 10 shown in Figs. 1 to 4, includes a lock cylinder 12 rotatably located within a bore 14 of lock body 16. Lock body 16 has a plurality of bores 18 whilst lock cylinder 12 has an equivalent number of bores 20 which are p e aligned in the locked position. Bores 18, 20 contain pin tumblers 22 which each comprise upper segments 24 and lower segments 26 (top and bottom pins) which abut one another.

Upper segments 24 have a first portion 28 of a first diameter at the end of the segments nearest the keyway 29 of the lock cylinder 12. The remainder or second portion 30 of the upper segments 24 is of a reduced or second diameter.

Over the second portion 30 of each upper segment 24 is a spring 32 which biases the C -L-L l~dl pin tumblers 22 towards the keyway 29 by acting on the first portion 28. The external diameter of the spring 32 is approximately the same as the diameter of the first portion 28. In this way, spring 32 then acts as a continuation of the diameter of the first portion 28 allowing the full length of each upper segment 24 to be effective in protecting the shear line 34 of the lock. The compressed spring length plus the total length of the upper segment 24 can be significantly reduced thereby allowing the diameter of the lock body 16 to be corresponding reduced. The length of springs 32 should preferably extend into bores 20. Springs 32 have an additional advantage in that the lock is harder to pick as the spring 32 gives multiple false shear lines in

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view of the coils of the springs.

°Different lengths of segments may be used with the length over that illustrated being increased or decreased in accordance with the requirement of the particular matching lower segment 26. The lower segment 26 is of a different length S* to match the key.

The pin tumbler lock 10 can be located within an outer casing 50 which has a main body portion 52 and an outer end portion 54. The outer end portion 54 is of increased diameter and has holes 56 through which fasteners may be passed, if

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required. The main body portion 52 has a threaded outer surface 58 and a cylindrical central bore 60, into which is placed the pin tumbler lock 10. A counter bore 61 has a plurality of indei,tations 62 in the surface thereof, each indentation 62 being curvilinear.

The lock body 16 has a radial slot 64 opening into its outer surface.

Slot 64 has a roller 66 located therein and which is acted upon by a cam or the like 68 coupled to lock cylinder 12. Cam 68 can be integral with lock cylinder 12 or -6extend from a cylindrical slip-over member 69 as shown. Slip-over member 69 has a ridge 72 (Fig. 2) which matches slot 74 of lock cylinder 12 to provide a positive coupling. Screws 76 ensure that slip-over member 69 and lock cylinder 12 do not separate from one another. A backplate 78 is secured to lock body 16 by screws to complete the pin tumbler lock 10. A drive shaft 82 engages aperture 84 and will be coupled to a mechanism (not shown) which is released or controlled by pin tumbler lock 10. Upon insertion of a key (not shown) into keyway 29 of the pin tumbler lock 10 the lower segments 26 of pin tumblers 22 become aligned with the 9 9 S°°shear line 34 of lock cylinder 12 allowing rotation of lock cylinder 12 within lock body 16. With the turning of the key, the cam 68 moves circumferentially (Fig. 4) to allow *e o the roller 66 to move radially inwardly. This drops roller 66 from the indentation 62 to enable the pin tumbler lock 10 to rotate about its axis within the outer casing o The cam 68 is restricted in radial movement through its engagement with slot 64 to only allow the roller 66 to drop. The cam 68 is centralised by oppositely acting compression springs or the like 70. During the rotation of the pin tumbler lock within the outer casing 50, the roller 66 is biased radially outwardly. Thus, when a o further indentation 62 is encountered, the roller 66 engages therein to prevent further rotation of the pin tumbler lock 10 until the key is again operated. The key can also be withdrawn in any of the predetermined rotational positions of the pin tumbler lock 10 within the outer casing 50 as the key has not been rotated relative to the pin tumbler lock This allows locks incorporating the present invention to be used in situations where key removal in a number of different rotational positions is required. For example, lifts, elevators and escalators.

-7- As will be realised, cam 68 is located within the length of lock cylinder 12 enabling minimum axial length to be maintained. By varying the number and circumferential locations of the indentations 62, the number and positions can bi? varied. Preferably, the outer casing 50 has minimal wall thickness to compliment the reduced radial dimension of the pin tumbler lock 10. Any suitable material may be used such as, for example, acetal plastics. Where the lock is to operate an electrical switch, it is preferred that the outer casing 50 be made of an electrically insulating material. For such use, the lock may use a cam, pin or other drive arrangement to allow mechanical linking to solenoids, switches on other devices, including loiu .ng

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bclts.

Figs. 5 to 8 show a variation of the embodiment shown in Figs. 1 to 4 and the same reference numerals are used to avoid repetition of description. The difference between the two embodiments is that springs 70 have been omitted. A clip spring 86 sits inside a complementary shaped recess 88 of cylindrical slip-over member 69. Legs 90 extend from recess 88 and abut the sidewalls of radial slot 64 in lock body 16, as best shown in Fig. 7. Cam 68 will operate in the same manner as that described with reference to Figs. 1 to 4 with spring 86 providing a self-centering action when the key is released.

Figs. 5 and 8 show a release mechanism for allowing pin tu1mbler lock 10 to be removable from outer casing 50 for repair or replacement. A threaded bore 92 extends for a substantial part of the length of lock body 16 and opens into a radial port 94. One of the screws 80 also opens into radial port 94. Outer end portion 54 of outer casing 50 has a circumferential groove 96 which receives a ball 100 dropped through bore 92. An Allen sa:ew 98 is threaded into bore 92 by an Allen key 102 to -8force ball 100 into radial port 94. Ball 100 will project into groove 96 and prevent removal of a pin tumbler lock 10 from outer casing 50. To remove lock body 16 from outer casing 50 Allen key is inserted into bore 92 and Allen screw 98 removed. Ball 100 can then be withdrawn from groove 96. Turning the key allows roller 66 to be withdrawn into radial slot 64 and lock body 16 can be axially removed from outer casing 50. The use of ball 100 allows a locksmith to repair or replace the device it controls. If removal of pin tumbler lock 10 is not required then the clearance between counter bore 61 of outer casing 50 and lock body 16 will act to prevent such removal. If roller 66 is retracted to clear counter bore 61 but still extend from lock body 16 it will not be possible to axially displace lock body 16 from outer casing from the front of the lock.

In an alterative embodiment (not illustrated) a bolt or lever may be used instead of the roller. With this construction, the bolt would be released from the lock cylinder housing by the use of the key to move the lock body 16 axially into the cylinder. In a further embodiment (not shown) cam 68 can be replaced by a ball.

Lock cylinder 12 may be axially displaceable with respect to lock body 16 and lock cylinder 12 could have a depression for receiving the ball. On axial movement of oo000: said lock cylinder 12 the depression would be aligned with the ball allowing roller 66 to drop,.

Whilst there has been described in the foregoing description preferred constructions of a lock incorporating the principal features of the present invention, it will be understood by those in the technical field concerned that many variations or modifications may be made without departing from the present invention.

Claims (14)

1. A lock device including a pin tumbler lock having a lock body and a lock cylinder rotatably located therein and/or axially movable therein, said pin tumbler lock being mounted rotatably within an outer casing, there being at least one interference member located in said lock body and adapted to be located in one of a plurality of recesses in said outer casinq, said interference member being withdrawn radially upon correct operation of a key in said pin tumbler lock from said one of said plurality of recesses to allow said lock body to rotate relative to said outer casing.

2. The lock of claim 1, wherein said lock cylinder has a restricted rotational movement with respect to said lock body.

3. The lock of claim 11, wherein said interference member is a roller or ball which withdraws into said lock body on correct operation of said key.

4. The lock of claim 3, wherein a cam member is coupled to said sock cylinder and has limited rotation within a slot in said lock body whereby said cam member co-operates with said roller or ball.

5. The lock of claim 4, wherein said cam member is resiliently biased to be self-centered. •2b

6. The lock of claim 1, wherein said interference member, in the withdrawn position, prevents said lock body from being axially withdrawn from said outer casing.

7. The lock of claim 1, wherein said interference member, in a withdrawn p,,sition, allows said lock body and lock cylinder to be axially :23: withdrawn from said outer casing.

8. The lock of claim 1, further including means to prevent axial displacement of said lock body from said outer casing.

9. The lock of claim 8, wherein said means to prevent axial displacement of said lock body from said outer casing includes a circumferential groove in the inner surface of said outer casing, a radial port in said lock body 6/9/96IS6726.PRV,0 said lock body adapted to open into said circumferential groove and a member in said radial port adapted to be movable into and out of engagement with said circumferential groove.

The lock of claim 9, wherein said member is a ba,'l and said ball is forced to engage said circumferential groove by a threaded member entering said radial port.

11. The lock of any one of the preceding claims, wherein, said lock body has a plurality of top pins, each top pin having a first portion of a first diameter and a second portion of a second diameter, the first diameter being greater than the second diameter; each top pin having a spring over the second portion, the diameter of said spring being of the same order of magnitude as the first diameter.

12. The lock of claim 11, wherein in the locked position of said lock, at least one of said springs extends into a corresponding bore of a co- operating bottom pin of said lock cylinder.

13. The lock of claim 11, wherein each spring in the locked position extends into a corresponding bore in said lock cylinder which contains a co-operating bottom pin.

14. The lock cf claim 11, wherein said lock cylinder has a restricted rotational movement with respect to said lock body. A lock device substantially as hereinbefore described with reference to the accompanying drawings. D A T E D this 6th day of September, 1996. STADON PTY LTD By their Patent Attorneys: CALLINAN LAWRIE S' 6/9/96IS6726.PRV,10 l^ ABSTRACT The invention provides a pin tumbler lock (10) having a lock body (16) and lock cylinder (12) rotatably located therein. Lock body (16) has a plurality of top pins (24) with each top pin (24) having a first part (28) and a second part (30) of reduced diameter. A spring (32) fits over each second part (30) to allow the size of the lock to be reduced. I 9 0 s