GB2259546A - Improvements in the locking of sliding drawers - Google Patents

Abstract

A key operated locking mechanism for a sliding drawer comprising sliding bolt having a projection selectively engageable in a keeper recess 8. The recess 8 is formed on a member 7 which slidably mounts into a mounting member 1 fixed to the drawer carcass. On initial locking movement of the bolt the member 7 is pushed into the member 1 and assumes its permanent position thereon. Interengaging elements on the members 1 and 7 (eg ratchet teeth 5, 11) prevent reverse movement. <IMAGE>

Description

" Improvements in the Locking of Sliding Drawers DESCRIPTION This invention is concerned with the locking of a sliding drawer, usually in the pedestal of a desk.

A conventional locking device comprises a key-driven rod which reciprocates vertically in the desk carcass between a position where a lateral projection on the rod engages a fixed recess in the drawer thereby preventing the sliding outward opening of the drawer and a free position.

In accordance with the present invention the locking recess is provided on a member itself upwardly slidably mounted on a part fixed to the drawer. The interconnection between the sliding member and the said part is such that when the lock is first operated the sliding member is slid to its locking position (moved by the projection on the rod) and is thereafter retained in such position for further use.

Thus the sliding member and the part fixed to the desk can have a ratchet-type interconnection permitting movement in one direction only.

The invention will be described by way of example and with reference to the accompanying drawings wherein: Figures 1 and 2 are plan and side views of the fixed member; and Figures 3 and 4 are side and plan views respectively of the sliding member.

Figures 4 and 5 are plan and side views respectively of the fixed member of a second embodiment; and Figures 7 and 8 are side and plan views respectively of the sliding member.

Referring initially to Figures 1 and 2 the fixed member 1 is formed of nylon or other suitable material and comprises a flat laterally elongate generally rectangular plate 2 with holes 3 for screws or other members fixing the plate to the side wall of a drawer (not shown). Two parallel ratcheted rails 4 project forwardly from the plate 2. Each rail 4 has ratchet teeth 5 at the outer edge and a locating projection 6 at the inner. Each tooth has an inclined slope facing downwardly and a steep side facing upwardly thereby allowing ratcheting upward movement only. An upwardly extending lug 12 has a stop projection 13.

The sliding part 7 again formed from nylon or similar essentially incorporates a U-shaped recess 8 facing downwardly and, on either side of the recess parallel tracks 9 dimensioned and shaped to receive the rails 4 of the fixed member 1 with their locating projections 6.

An integrally formed detent 10 is provided in each track, the detent consisting of a short strip resiliently biassed inwardly into the track and three unidirectional ratchet teeth 11 to co-dperate with teeth 5 each with an inclined upwardly facing slope and a steep side facing downwardly.

In use the sliding member is pushed upwardly on first operation of the key, the projection on the upwardly moving rod as previously described entering into the recess 8. Rails 4 slide in tracks 9 the detent 10 riding over the ratchet teeth 5. Return downward movement is prevented by interlocking of teeth 5 and 11 however so the recess is effectively located in the optimum locking position. The stop 13 prevents the sliding member from being slid upwardly right through the fixed member.

The located recess, correctly positioned, is thus effectively fixed allowing the key mechanism to lock and unlock the drawer as in prior arrangements.

The second embodiment will now be described with reference to Figures 5 to 8 of the accompanying drawings.

This second embodiment is presently preferred as it is more readily mouldable from plastics material. In principle it is similar to the first embodiment, the significant difference being that instead of a toothed track being provided within each rail of a fixed member a single central toothed track is provided on the sliding member. Thus similar parts will be designated with similar reference numerals and the fixed member 1 has the plate 2 with holes 3 and parallel rails 4 to control sliding movement of the sliding member. Again in a similar manner a stop 13 is provided to prevent excessive upward sliding movement of the sliding member.

However, the detent on the fixed member is in the form of a resiliently flexible leaf 21 defined by a slot 22, the leaf 21 having a single tooth 23 (Figure 6A) with an inclined face directed downwardly. The leaf 21 is resilient to allow the detent to move on the ratchet.

The sliding member again has the U-shaped recess 8 and parallel tracks 9 to be received in the rails of the fixing member. The ratchet track however, comprises fixed teeth 24 extending in an array (Figure 8A) across the rear of the sliding member, the length of each tooth being approximately twice the width of the resilient detent 23.

In use this second embodiment operates in a similar manner to the first.

Claims (5)

1. A locking arrangeement for a drawer slidable in a carcass wherein a key driven rod reciprocates in the carcass between a position where a projection on the rod engages a fixed recess in the drawer thereby preventing opening of the drawer and a free position characterised in that the locking recess is provided on a member itself slidably mounted on a part fixed to the drawer, the interconnection between the sliding member and the said part being such that when the lock is first operated the sliding member is slid to its locking position and is thereafter retained in such position.

2. A locking arrangement according to Claim 1 wherein the sliding member and the part fixed to the desk have a ratchet-type interconnection permitting movement in one direction only.

3. A locking arrangement according to Claim 2 wherein the interconnection comprises unidirectional ratchet teeth on the one and at least one co-operating and resiliently mounted tooth on the other.

4. A locking arrangement substantially as hereinbefore described with reference to, and as shown in, Figures 1 to 4 of the accompanying drawings.

5. A locking arrangement substantially as hereinbefore described with reference to, and as shown in Figures 5 to 8 of the accompanying drawings.