GB2428448A

GB2428448A - Mechanical combination lock resetting aid

Info

Publication number: GB2428448A
Application number: GB0514711A
Authority: GB
Inventors: Kenneth Sidney Ridley
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-07-18
Filing date: 2005-07-18
Publication date: 2007-01-31
Anticipated expiration: 2025-07-18
Also published as: GB2428448B; GB0514711D0

Abstract

A mechanical combination lock resetting aid comprising an aligning and resetting key 1 and a key guide 6 which is rigidly attached to the back of a lock case cover such that it supports, guides and governs the action of the key independent of the lock case and its cover in the aligning and resetting procedure. The aid allows the aligning and resetting of the mechanisms of dial operated mechanical combination locks where the combination numbers have been miss-set or are otherwise unknown and where the back of the lock is accessible. The device allows the user with nominal dexterity to bring a lock where the combination numbers are unknown back into immediate use without requisitioning the attendance of skilled personnel thereby saving time and expense.

Description

MECHANICAL COMBINATION LOCK RESETTING AID

This invention relates to a device for aligning and resetting the mechanism of dial operated mechanical combination locks where the combination numbers have been miss- set or are otherwise unknown and where the back of the lock is accessible.

Mechanical combination locks are commonly actuated by an incorporated dial bearing incised numerical markings usually of one to a hundred. The operation of these locks is occasioned by rotating the dial alternately a given number of times in each direction such that a sequence of numbers, i.e., a combination, is set to a stationary mark on the dial surround. By necessity, security to be afforded by a lock requires the user to reset this operational combination to a personalised selection of numbers which then restricts the opening and subsequent operation of the lock to that user.

Resetting lock numbers first necessitates the setting of the existing combination numbers such that a key may be inserted into the lock mechanism via a keyhole in the back of the lock case cover and turned to unlock the mechanism, which for this descriptive purpose essentially comprises a number wheels each relating to a specific number in the combination. New numbers are then set and the key turned back and removed an action which locks in the new numbers and presents the lock ready for use. Essential location and support for the key (change key) during this process is provided by the inner surfaces of the keyhole in the base of the lock case and in the lock case cover.

A problem arises when the sequence of numbers supposedly set by or given to the user fails to operate the lock. As the key cannot be reinserted, i. e., correct numbers thus unknown, the lock is effectively rendered inoperable and requires the attendance of skilled personnel to reinstate its usability. This same situation arises when combination numbers have been lost or forgotten particularly when equipment has been held in store.

This invention allows the user with nominal dexterity to align and reset the lock mechanism to a known combination of numbers so bringing the lock back into immediate use without requisitioning and waiting for the attendance of skilled personnel thereby saving time and expense.

Component parts of this resetting aid are a special mechanism aligning and resetting key and a key guide which is attached to the back of a lock case cover such that it supports guides and governs the action of the key independent of the lock case and its cover in the aligning and resetting procedure. The design and dimensioning of the key and its guide will vary to accommodate the specific requirements of each particular make and type of lock.

A typical key, its guide and their use will now be described by way of example with reference to the accompanying drawings in which: Drawing 1 / 5, Figure 1 shows an example of a mechanism aligning and resetting key presented in third angle projection.

Drawing 2 / 5, Figure 2 shows an example of a matching key guide presented in third angle projection.

Drawing 3 / 5, Figure 3 shows a typical example of a mechanical combination lock wheel, into the change key hole of which the key fits, presented in third angle projection.

Drawing 4 I 5, Figure 4 shows a cut-away example of a typical combination lock with the key guide attached and the resetting key inserted to the initial stage of the mechanism alignment procedure.

Drawing 5 / 5, Figure 5 shows the same cut-away example of a typical combination lock with the key guide attached and with the key having completed an example wheel alignment and unlocking stage of the procedure.

Referring to drawings I / 5, fig.! and 2 / 5, fig.2 the resetting aid comprises a key 1 and a guide 6.

The key incorporates a locating pin 2 and a manoeuvring bar 5. It embodies a reduced diameter shank 3 with a squared end 4 which engage the square shaped change key hole in each combination lock wheel.

The guide consists of a platform 7 and an integral cylindrical section 8 which accepts the key. Incorporated in the cylindrical section is a staggered slot 9 which governs the action of the key via the key's locating pin. A means of attaching the guide to the lock case cover such that the cylindrical section is directly over the change key hole must be provided, in this instance a screw hole 10 is provided for utilising a lock case cover securing screw.

Drawing 3 / 5, fig. 3 displays a typical combination lock mechanism wheel 11 which incorporates inner and outer sections numbered 12 and 13 respectively. These sections are alternatively held together or released, via a cam and lever arrangement, by the clockwise or anti-clockwise motion of the square change key hole 14 as actuated by the change key during the number changing process. The relevant combination number of a wheel is effected by the angular relationship between the driving shoulders of the inner section 15 and the cut-out 16 in the outer section's periphery.

Drawing 4 I 5, fig. 4 shows the guide 6 mounted on the cut-away lock case cover 17 of a typical combination lock. The guide's cylindrical section 8 is located directly over the change key hole in the cover. The guide is held in place by the utilisation of a lock case cover securing screw 16. The key I is shown inserted in the guide's cylindrical section and through into the lock to the extent that its squared end 4 abuts the outer surface of the third wheel 18 at the point which coincides with the rotary course of the change key square in each wheel.

Thus attached, the resetting aid can be used to sequentially unlock and reset all wheels to a known combination. With light inward pressure being applied to the manoeuvring bar 5 of the key, the lock dial 21 is rotated clockwise so as to drive the third wheel clockwise in unison. As the wheel is rotated the squared end of the key, bearing on the wheel's outer surface in the path of the change key hole, captures and engages the change key hole in the wheel to a depth controlled by the engagement of key's locating pin 2 in its slot 9 in the guide. At this juncture the key is turned anti-clockwise through 900, an action which unlocks the wheel and completes the alignment and unlocking procedure appertaining to that wheel. The key is then pushed forward such that its squared end abuts the outer surface of the second wheel 19. These movements are likewise controlled by the engagement of the key's locating pin in its slot in the guide. This situation is depicted by drawing 5 /5 fig. 5. The procedure for aligning and unlocking the third wheel is repeated for the other wheels, 19 and 20, in the lock.

With all wheels aligned and unlocked the lock's combination of numbers is reset in the normal way and the aligning key removed thereby locking in the selected combination.

The guide acts as a bearing support for the key independent of the lock case and its cover during this process. Removal of the key is a reversal of its staggered insertion procedure following the dictates of the locating pin in its slot in the guide. The guide is then removed, the lock case cover screw replaced and the operation of the lock tested. The usability of the lock has thus been reinstated.

Claims

I A demountable combination lock mechanism alignment and resetting aid comprising a special aligning and resetting key and a key guide, which supports, guides and governs the action of the key independent of the lock case and its cover during the alignment and resetting procedure, incorporating a means for rigid attachment to the outer surface of a lock case cover precisely over the change key hole.
2 A demountable combination lock mechanism alignment and resetting aid substantially as described herein with reference to figures 1-5 of the accompanying drawings.