WO1997001012A1

WO1997001012A1 - A padlock

Info

Publication number: WO1997001012A1
Application number: PCT/AU1996/000375
Authority: WO
Inventors: Raymond Kingsley Sikyr
Original assignee: Total Security (Aust) Pty. Ltd.
Priority date: 1995-06-23
Filing date: 1996-06-21
Publication date: 1997-01-09
Also published as: AUPN378795A0

Abstract

This invention concerns a padlock. Padlocks are in common use to lock shed doors and to secure bicycles, however they have almost limitless applications. This padlock comprises a tubular housing (1) in which there is an inner body (7) from which a shackle (8) extends. The inner body is axially movable relative to the housing between a closed position in which the shackle is lockable, and an open position in which the shackle may be opened. A locking mechanism (10) releasably engages formations on the inner surface of the housing when the inner body is locked to retain the inner body against axial movement relative to the housing, but to allow the inner body rotational movement relative to the housing.

Description

A PADLOCK Technical Field

This invention concerns a padlock. Padlocks are in common use to lock shed doors and to secure bicycles, however they have almost limitless 5 applications.

Background Art

Padlocks generally comprise a housing from which a 'U' shaped shackle extends. In its locked configuration both the free ends of the shackle are captured within the housing. However, when it is unlocked the shackle 10 rises and one of the free ends is released. The shackle is then able to be turned about the other arm to allow it to be hooked, or unhooked, through, say, a staple.

Padlocks of this configuration are vulnerable to a number of security failures. For one, the shackle is accessible to be cut by bolt-cutters. Also, 15 they can be forced open by twisting, or by a wedge inserted between the shackle and the housing to lever them apart. Summary of the Invention

The invention, as currently envisaged, provides a padlock comprising: 20 a tubular housing in which there is an inner body from which a shackle extends; the inner body is axially movable relative to the housing between a closed position in which the shackle is lockable, and an open position in which the shackle may be opened; 25 wherein a locking mechanism releasably engages formations on the inner surface of the housing when the inner body is locked to retain the inner body against axial movement relative to the housing, but to allow the inner body rotational movement relative to the housing. 30 Padlocks having this configuration may be more difficult to lever open since the shackle and housing rotate relative to each other, and this ^f may make it more difficult to find purchase for the lever. The relative axial

' movement of the inner body and housing also allows the shackle to be

^A brought into the housing in the closed configuration, making it more

35 difficult for the shackle to be accessed by bolt-cutters or levers. The housing and inner body are advantageously circular in cross- section, to permit coaxial rotation.

In a preferred embodiment the locking mechanism is carried by the inner body. It may involve a keyed lock that drives a rack radially out of the inner body to engage an annular groove in the inner wall of the housing. The shackle need not be 'U^* shaped, and it may comprise a '7' extending vertically up from the inner body. In the closed configuration the free end of the seven is withdrawn into the housing. As a result, in this configuration almost the entire shackle is withdrawn into the housing. Additional formations on the inner surface of the housing prevent the inner body from slipping out of the bottom of the housing. Further formations engage with a spring-loaded pin that extends from the inner body to prevent the inner body from slipping out of the top of the housing when the padlock is open. Brief Description ofthe Drawings

An example of the invention will now be described with reference to the drawings, in which: figure 1 is a cross-sectional view of a padlock housing embodying the invention; figure 2 is a cross-sectional view of a padlock inner body embodying the invention; figure 3 is a top exploded view of the padlock inner body of figure 3; figure 4 is a cross-sectional view of an assembled padlock embodying the invention in its closed configuration: and figure 5 is a cross-sectional view of the assembled padlock of figure 5 in its open configuration.

The same reference numerals have been used throughout the drawings to refer to corresponding features. Best Modes for Carrying out the Invention Referring first to figure 1, housing 1 comprises a steel sleeve having a smooth cylindrical outer surface 2. The inner surface 3 is generally parallel to the outer surface 2. but is interrupted at three locations. At the bottom there is a narrow lip 4 of slightly smaller diameter. Near the centre there is an annular groove 5 having a large rectangular section. And at the top there is an annular groove 6 having a smaller curved section. Figure 2 shows the inner body 7. This body has a first large cavity penetrating from the top and in which the shackle 8 resides. Shackle 8 is '7^* shaped and the upright of the seven extends vertically from the upper surface of the inner body. The upright of the '7^' is retained within the inner body by a dowel 9 that enters the inner body from the side. The top of the

'7^' extends slightly downwards.

A second large cavity extends up from the bottom of the inner body to house the lock barrel 10. The lock barrel 10 is retained in place by a grub- screw 11 that enters the inner body from the side. The second large cavity intersects with a third large cavity 12 that extends transversely through the inner body. A rack 13 resides in cavity 12, and its teeth engage with teeth of the lock.

A spring loaded pin 14, shown only in figure 3. resides in a horizontally extending passage in the side of the inner body. There is a step formation 15 at the bottom of the inner body.

When the padlock is assembled the inner body is slid down into the housing 1 from the top. The bottom lip 4 of the housing fits snugly into the step formation 15 when the inner body is pushed down to the bottom of the housing to prevent it from being removed from the bottom. In this position the shackle is closed.

The spring loaded pin 9 rides along the inner surface 3 of the housing 1 above the level of the rectangular annular groove 5. When the inner body rises up inside the housing, the pin 9 enters the curved annular groove 6 to positively locate the inner body at the top of the housing, and to prevent it from being pushed out of the top. In this position the shackle 8 is open. To close the shackle the inner body 7 must be pushed down, disengaging spring-loaded pin 9 from the curved groove 6.

When the shackle is closed the key may be operated in the lock barrel 10 to drive the rack 13 out of the inner body and into engagement with the rectangular groove 5. In this locked condition the inner body cannot be moved up inside the housing and the shackle cannot be opened. To open the shackle the key must be operated in the lock to withdraw the rack from the groove. The shackle can then be opened.

Although the invention has been described with reference to a specific embodiment it should be appreciated that it may be embodied in many other forms. For instance, a spring could be incorporated into the arrangement to bias the inner body into the open position. The shackle need not have a '7' shape and could have a conventional 'U' shape, or any other functional shape. If the shackle is not '7' shaped it may not be necessary for it to be withdrawn completely into the housing to be secure. In another alternative the keyed lock could be associated with the housing, provided it still engaged against formations on the inside of the housing to prevent axial movement of the inner body.

Claims

1. A padlock comprising: a tubular housing in which there is an inner body from which a shackle extends: the inner body is axially movable relative to the housing between a closed position in which the shackle is lockable. and an open position in which the shackle may be opened; wherein a locking mechanism releasably engages formations on the inner surface of the housing when the inner body is locked to retain the inner body against axial movement relative to the housing, but to allow the inner body rotational movement relative to the housing.

2. A padlock according to claim 1, wherein the housing and inner body are circular in cross-section.

3. A padlock according to claim 1, wherein the locking mechanism is carried by the inner body.

4. A padlock according to claim 3, wherein the locking mechanism involves a keyed lock that drives a rack radially out of the inner body to engage an annular groove in the inner wall of the housing.

5. A padlock according to claim 1. wherein the shackle comprises a '7^' extending vertically up from the inner body.

6. A padlock according to claim 5. wherein in the closed configuration the free end of the '7^' is withdrawn into the housing.

7. A padlock according to claim 1, wherein there are additional formations on the inner surface of the housing to prevent the inner body from slipping out of the bottom of the housing.

8. A padlock according to claim 1, wherein there are further formations that engage with a spring-loaded pin which extends from the inner body, to prevent the inner body from slipping out of the top of the housing when the padlock is open.