GB2245637A

GB2245637A - Barrel look and bolt

Info

Publication number: GB2245637A
Application number: GB9014106A
Authority: GB
Inventors: Colin Sidney Middleton
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-06-25
Filing date: 1990-06-25
Publication date: 1992-01-08
Anticipated expiration: 2010-06-25
Also published as: GB9014106D0; GB2245637B

Abstract

A lock comprises a body portion (10) having a hole (20) to rotatably receive a cylindrical lock plug (30). The lock plug (30) has an eccentric projection (36) which is arranged to be located in a slot (58) in a bolt (52). The bolt (52) is biased by a coil spring (66) out of a bore (22) in the body portion (10). The spring (46) is received in a bore (64) in the bolt (52). The lock plug (30) can be turned by a key to cause the projection (36) to engage one end of the slot (58) in the bolt (52) to retract the bolt from a locking position against the action of the coil spring (66). <IMAGE>

Description

Title: LOCK This invention relates to locks and is particularly concerned with a lock intended for use with the antitheft device forming the subject of British Patent Specification No. 2142889.

The locking element of the anti-theft device of this prior British patent specification is illustrated in the locked condition in Fig. 2 of the drawings. With reference to this drawing, when a key is turned in the mechanism 134, a button 151 is partially retracted into said mechanism and, by the action of a spring 153, the mechanism 134 is immediately lifted so a bolt 133 projecting from the end of the mechanism is moved out of apertures 124 and 125.

The button 151 is biased by a relatively short spring (not shown) bearing on the base of the button 151. A problem has been encountered in practice in that the spring becomes coil bound when the button 151 is retracted. This results in the button 151 being only partially retracted and operation of the mechanism 134 is then inconsistent. Owing to space restrictions, it is not possible to use a longer spring to avoid the problem of coil binding.

The present invention aims to provide a lock which overcomes the above-mentioned problem.

In accordance with the present invention, there is provided a lock comprising a cylindrical lock plug received in and rotatable relative to a body portion, a bolt received in the body portion and biased by a spring, the cylindrical lock plug being arranged to displace the bolt against the spring bias upon rotation relative to the body portion, wherein the spring is received in a bore in the bolt.

The present invention will now be described, by way of example, with reference to the drawings, in which: Figure 1 is an exploded cross-sectional view of one embodiment of a lock in accordance with the present invention; and Figure 2 is a fragmentary longitudinal cross-section illustrating the locking element of the anti-theft device of British Patent Specification No. 2142889 in the locked condition.

Referring to Figure 1 of the drawings, the lock comprises a cylindrical body portion 10 having a bolt 16 integrally formed therewith and projecting from one end 12. The bolt 16 has a chamfered end 18. The cylindrical body portion 10 has an eccentric longitudinal hole 20 extending inwards from its other end 14, the hole 20 having a shoulder 21 at the end 14.

The hole 20 intersects a transverse bore 22 near the end 12. The axes of the hole 20 and bore 22 are substantially perpendicular to each other.

A plurality of apertures 24, located between the ends 12 and 14, extend from the exterior of the body portion 10 to the hole 20. Another aperture 26 having an enlarged section 28 also extends from the exterior of the body portion 10 to the hole 20. An external circumferential groove 29 is provided between the apertures 26 and bore 22.

The hole 20 is dimensioned to receive a cylindrical lock plug 30 which has an eccentric projection 36 integrally formed therewith and projecting from one end 32. The other end 34 has a domed face portion 38 integrally formed therewith and the portion 38 has a circumferential shoulder 40 which locates on the shoulder 21 of the hole 20 when the lock plug 30 is inserted in the hole 20.

A longitudinal key slot (not shown) extends from the face portion 38 into the lock plug 30. Apertures, the axes of which are labelled 42, are located between the ends 32 and 34 and extend from the exterior of the lock plug 30 to the key slot. The apertures 42 correspond to and align with the apertures 24 and each aperture 24 contains a respective pin (not shown) biased by an associated spring (not shown). A key inserted into the key slot moves the pins and allows the lock plug 30 to rotate relative to the body portion 10.

The lock plug 30 further has a circumferential groove denoted by the dotted line 44 which is aligned with the aperture 26. A retaining pin 46 having a small end 48 and a large end 50 is located in the aligned apertures 25 and 44 such that the large end 50 is located in the enlarged section 28 of the aperture 26 and the small end 48 is located in the groove 44. This secures the lock plug 30 against axial movement relative to the body portion 10.

A cylindrical sleeve (not shown) fits around the exterior of the body portion 10. The sleeve extends from the groove 29 to the end 14. The sleeve is waged into the groove 29 to secure the sleeve longitudinally of the body portion 10.

The bore 22 is dimensioned to receive a bolt 52 which has an end 56 of varying diameter and a slot 58 intermediate its ends 54 and 56. An eccentric bore 64 extends into the bolt 52 from the end 54 and a spring 66 is contained within the eccentric bore 64. A spring carrier in the form of a pin 70 extends into the spring 66, the pin 70 having a head 68 against which one end of the spring is arranged to bear. The spring 66 thus urges the head 68 of the pin 70 against the bottom of the bore 22 and also biases the bolt 52 out of the bore 22. The eccentric projection 36 of the lock plug 30 is located in the slot 58 and the spring 66 biases the bolt 52 so that one end 60 of the slot 58 bears on the eccentric projection 36.

In use, a key (not shown) is inserted into the key slot and turned. This rotates the lock plug 30 relative to the body portion 10. The eccentric projection 36 moves relative to the body portion 10 and retracts the bolt 52 into the bore 22 by virtue of the engagement of the projection 36 with the end 60 of the slot 58.

Retraction of the bolt 52 causes compression of the spring 66. The pin 70 serves as a guide or carrier for the spring 66 and prevents any tendency of the part of the spring 66 projecting from the bore 64 to buckle.

The spring 66 is located within the eccentric bore 64 and has a longer free length than if it were to bear against the end 54 of the bolt 52. Thus, the spring 66 does not become coil bound and the bolt 52 may be retracted fully in the bore. The need for such retraction will become evident from a reading of the afore-mentioned British Patent Specification No.

2142699.

However, it should be noted that the lock according to the present invention is not restricted to use with the anti-theft device forming the subject of British Patent Specification No. 2142889 and modifications and variations of the above-described embodiment are possible without departing from the scope of the invention.

Claims

1. A lock comprising a cylindrical lock plug received in and rotatable relative to a body portion, a bolt received in the body portion and biased by a spring, the cylindrical lock plug being arranged to displace the bolt against the spring bias upon rotation relative to the body portion, wherein the spring is received in a bore in the bolt.

2. A lock according to claim 1, wherein the spring is provided with a carrier extending into at least part of the spring to prevent the spring from buckling.

3. A lock substantially as hereinbefore described with reference to Figure 1 of the drawings.

3. A lock according to claim 1 or claim 2, wherein the bore is eccentric of the bolt.

4. A lock according to any one of the preceding claims, wherein the cylindrical lock plug has an eccentric projection which engages with an end of a slot in the bolt such that the bolt is displaced upon said rotation of the cylindrical lock plug relative to the body portion.

5. A lock according to any one of the preceding claims, wherein the body portion has a plurality of apertures each containing a respective pin biased by a respective spring into a longitudinal key slot in the cylindrical lock plug, the longitudinal key slot being able to receive a key which moves the pins against their respective spring biases to allow said relative rotation.

5. A lock according to any one of the preceding claims, wherein the cylindrical lock plug has a groove extending at least partially around the circumference, said groove being aligned with an aperture in the body portion and wherein a retaining pin passes through the aperture in the body portion into said groove to secure the cylindrical lock plug against axial movement relative to the body portion.

7. A lock according to claim 5 or claim ó, wherein a sleeve is provided around the body portion to cover the aperture or apertures in the body portion.

8. A lock according to claim 7, wherein the body portion has an external circumferential groove into which a part of the sleeve is swaged to secure the sleeve longitudinally of the body portion.