GB2186626A - Drawer interlock - Google Patents

Abstract

A housing 1 having a plurality of drawers 4 has an elongate, vertically-mounted locking member 9 for preventing a second drawer 4 from being drawn out when a first drawer 4 has already been drawn out. The member 9 is moveable generally perpendicular to its length and the direction of movement of a drawer 4, between an inoperative position, as shown, permitting a drawer to be drawn out and an operative position extending into the path of movement of a drawer out of the housing to prevent other drawers being drawn out. The member 9 is initially engageable, at any point along its length, by an operating member 8 provided on a drawer to pivot it, releasing the grip of magnets 10, and allowing the member 9, when the member 8 has passed, to move bodily under biassing into a position blocking the paths of the members 8 on the other drawers. The interlock is usable, without modification, with any size and number of drawers. <IMAGE>

Description

SPECIFICATION Improvements in and relating to housings and locking means therefor The present invention relates to housings, such for example as cabinets, receiving horizontally slidable support units, such for example as drawers, trays or shelves, which can be at least partially drawn out of the cabinet for access, and specifically to locking means for preventing a second support unit being drawn out of the housing when a first unit has already been drawn out.

Such locking means are known but in the context of housings in which the slidable support units have fixed horizontal positions and individual locking means are provided one for each support unit and having relatively fixed horizontal locations within the housing. Problems arise where the housing is designed to permit the slidable units to take up one of a number of different horizontal positions and to permit variation of the number of slidable units in the housing.

According to the present invention there is provided an assembly comprising a housing adapted to receive a plurality of horizontally slidable support units and locking means for preventing a second support unit from being drawn out of the housing when a first unit has already been drawn out, the locking means comprising an elongate member extending substantially vertically within the housing and which is moveable in a direction generally transverse to the direction of movement of a unit in the housing between an inoperative position permitting a unit to be drawn out and an operative position extending into the path of movement of a unit out of the housing to prevent units in the housing from being drawn out, the locking member being moveable from and to its inoperative position by engagement of the locking member at any point along its length by said first unit being drawn out and pushed back respectively.

Preferably each unit is provided with an element which is adapted for engagement with the locking member as the unit is drawn out or pushed back respectively to move the locking member from or to its inoperative position. The element may also be adapted so that, with the locking member in its operative position, an element on a unit within the housing will come into abutment with the locking member if an attempt is made to draw that unit from the housing, to prevent the unit from being drawn out of the housing.

The locking member is advantageously mounted adjacent a lateral edge of an opening in the housing through which the slidable units are drawn out, so as to be accessible from the outside of the housing for manual manipulation between its operative and inoperative positions.

An embodiment according to the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a front elevation of part of an embodiment of an assembly according to the present invention comprising an embodiment of locking means according to the present invention; Figures 2, 3 and 4 are horizontal sections in the plane Il-Il of Figure 1 through the locking means of Figure 1 showing different relative positions thereof; and Figure 5 is a vertical section through part of the locking means of Figure 2 on the line V-V of Figure 2.

There is shown in the drawings part of a housing in the form of a cabinet 1 having an opening 2 at the front which may be closable by any suitable means (not shown), a rear wall, a top wall (not shown), a. bottom wall (not shown) and side walls 3 of which only one is visible in the drawings. The cabinet is intended to receive a plurality of horizontally slidable units 4, e.g. drawers, trays and/or shelves, of which parts of one such unit are shown in the drawings. Each unit 4 is, as is conventional, provided laterally with runners 5 (of which the runners on one side are shown diagrammatically in Figure 1) which are slidably received in sliding units 6. Each unit 6 is adjustably mounted on the side walls of the cabinet and can be mounted in a number of different horizontal positions for varying the horizontal position of the unit in the cabinet.

This also permits variation in the number of units and the types of units provided in the cabinet.

The cabinet is also provided with locking means for preventing units 4 in the cabinet from being drawn out of the cabinet when one unit 4 has already been drawn out. The locking means comprise an elongate member 7 which extends substantially vertically within the housing, is advantageously as shown positioned adjacent the front edge of a side wall 3 of the housing, and is moveable in a direction generally transverse to the direction of movement of units in the housing between an inoperative position (shown in Figures 1 and 2) permitting a unit 4 to be drawn out of the housing, and an operative position (Figure 4) extending into the path of movement of a unit out of the housing to prevent units in the housing from being drawn out.The locking member 7 is moveable from and to its inoperative position by engagement of the member 7 at any point along its length by a unit 4 as it moves passed the member 7 and, for this purpose, each unit 4 is provided with an operating member 8.

The member 7 comprises an elongate engagement flange 7a which itself extends generally transverse to the direction of move ment of a unit 4 into and out of the housing and moves in a direction generally transverse to the direction of movement of units in the housing between its operative and inoperative positions. In its operative position, flange 7a extends into the path of movement of an operating member 8 on a support unit 4 in the housing and in its inoperative position, flange 7a is positioned to be engaged by a member 8 to be moved therefrom to its operative position.

As shown, flange 7a forms one arm of a generally U-shaped member comprising a base portion 7b and a second arm 7c. Flange 7a forms an acute angle with base portion 7b and base portion 7b is generally perpendicular to arm 7c. member 7 is housed in a generally U-shaped housing 9 which is fixed to the cabinet side wall. Housing 9 comprises arms 9a and 9c which are generally parallel and perpendicular to a base portion 9b, and is dimensioned relative to member 7 to permit member 7 to move to the various relative positions shown in Figures 2 to 4.

In its inoperative position, member 7 is located within housing 9 with its base portion 7b lying parallel to and against housing base portion 9b (Figure 2) and is retained in this position by magnets 10 which, as shown, are mounted at intervals along the length of base portion 7b and are attracted to base portion 9b. Housing 9 is made of a magnetisable material and advantageously wall 9b is of a thickness to form a keeper for each magnet 10.

Alternatively, the magnet may be mounted on base portion 9b of the housing with base portion 7b of member 7 being made of a magnetisable material. It will be appreciated that other retaining means, eg mechanical catches, may be used in place of magnets 10 for retaining member 7 in its inoperative position.

With the member 7 in its inoperative position, as a unit 4 is drawn out of the cabinet, member 8 engages flange 7a and tends to move it outwardly of the cabinet. this causes member 7 to pivot in a clockwise direction (as seen in Figure 2) to bring the flange 7a into abutment with arm 9a of the housing. This movement is positively completed by engagement of the edge of flange 7a in a notch 11 in member 8 and has the effect of peeiing the magnets 10 off the base portion 9b to free the magnets 10 from engagement with base portion 9b.As soon as member 8 has passed and is disengaged from flange 7a, member 7 then moves laterally out of housing 9 (Figure 4) to its operative position in which it extends into the path of movement of the members 8 of units 4 remaining within the cabinet and is abutted by such members in the event that an attempt is made to move such a unit out of the housing.

The lateral movement of the member 7 out of the housing to its operative position may be obtained in a number of different ways. As shown in Figure 5, member 7 is suspended within the housing by a wire 12 extending between a bracket 13 on the housing and the top of member 7. In its operative position, member 7 hangs freely from its suspension which is positioned to obtain the required extent of lateral movement of member 7 out of the housing. In its operative position, member 7 is still partially retained within housing 9 and supported thereby.

To ensure that the member 7 does not move too far out of the housing 9 in its operative position, the housing 9 may be provided with one or more inturned lugs 14 spaced apart along its length, the lugs being arranged to engage the free edge of arm 7c of member 7 in its operative position. Additionally, to ensure that, when member 7 is in its operative position, the flange 7a assumes its operative position along its full length, one or more springs 15 may be provided for biasing the member 7 to its operative position. Advantageously, a spring 15 and a lug 14 are provided at least in the lower end portion of member 7.

Operating member 8 may take a variety of different forms. As shown it comprises a base portion 8a by which it is fixed to a unit 4 and an operating portion 8b which is resiliently flexible about its connection to base portion 8a and which is provided with curved camming surfaces Sc and 8d to either side of notch 11 for engagement with flange 7a of member 7. As a unit 4 is drawn out of the cabinet, initially surface 8c of member 8 engages the end of flange 7a. As flange 7a slides along surface Sc into the groove 11, portion 8b flexes towards base portion 8a and then returns to its relaxed position as member 8 disengages from flange 7a.When unit 4 is pushed back into the cabinet, surface 8d initially engages with the end of flange 7a (in the position shown in Figure 4) and progressively pushes member 7 back into its housing 9 and then tilts flange 7a in an anti-clockwise direction to bring base portion 7b against base portion 9b, engagement of the edge of flange 7a in notch 11 positively pushing member 7 back to its inoperative position and ensuring engagement of the magnets 10 with base portion 9b. The front surface 8e of member 8 is generally planar for abutting flange 7a when flange 7a is in its operative position (Figure 4).

In the above described embodiment, member 8 is preferably moulded of plastics material and members 7 and 9 are bent from sheet metal. It will however be appreciated that other materials may be used save only that base portion 9b of housing 9, or base portion 7b of member 7, must be made of, or include, elements of magnetisable material for cooperation with magnets 10, when provided.

The locking means as described above may be provided at one or both sides of the front opening of the housing.

By virtue of the positioning of the locking means adjacent the front edge of the or one of the side walls of the housing, it or they are accessible from the outside of the housing for manual manipulation in the event that, for example, member 7 inadventently moves to its operative position with all the units in the housing, or it is required to remove a number of units simultaneously from the housing.

The member 7 may be arranged to extend the full height of the opening of the cabinet or, if the cabinet is designed to accommodate sliding units only over part of its height, the member 7 may be arranged to extend over the corresponding part only of the height of the cabinet.

While the locking means described above is designed for use specifically with housings with adjustably positioned sliding units, it will be appreciated that it is equally applicable to housings with sliding units having fixed horizontal positions.

Claims (16)

1. An assembly comprising a housing adapted to receive a plurality of horizontally slidable support units and locking means for preventing a second support unit from being drawn out of the housing when a first unit has already been drawn out, the locking means comprising an elongate member extending substantially vertically within the housing and which is moveable in a direction generally transverse to the direction of movement of a unit in the housing between an inoperative position permitting a unit to be drawn out and an opertive position extending into the path of movement of a unit out of the housing to prevent units in the housing from being drawn, the locking means being moveable from and to its inoperative position by engagement of the locking member at any point along its length by said first unit being drawn out and pushed back respectively.

2. An assembly as claimed in Claim 1, wherein the locking member is held in its inoperative position by magnetic forces.

3. An assembly as claimed in Claim 2, comprising a housing for the locking member and wherein at least one magnet is mounted on one of the housing and locking member and a corresponding portion of the locking member or housing comprises magnetisable material.

4. An assembly as claimed in any one of the preceding claims, wherein the locking member is suspended in the housing and in its operative position hangs freely from the suspension.

5. An assembly as claimed in any one of the preceding claims, comprising a plurality of support units each provided with operating means adapted to move the locking member, when in its inoperative position, from its inoperative position and to abut the locking member when in its operative position.

6. An assembly as claimed in Claim 4 when dependent on Claim 3, comprising a plurality of support units each provided with operating means, each operating means being adapted, when a said first unit is drawn out of the housing and the locking member is in its inoperative position, to engage the locking member and move it to break the said magnetic forces holding it in its inoperative position to allow the locking member to move to its operative position, when the said unit is moved back into the housing, to engage the locking member to return it to its inoperative position, and when the associated unit is a said second support unit and the locking member is in its operative position, to abut the locking member.

7. An assembly as claimed in any one of the preceding claims, wherein the locking member comprises an elongate engagement flange extending substantially vertically within the housing in a plane generally transverse to the direction of movement of units in the housing and which is moveable in a direction generally perpendicular to its length and to the direction of movement of units in the housing between an inoperative position permitting a unit to be drawn out of the housing and an operative position extending into the path of movement of a unit out of the housing.

8. An assembly as claimed in Claim 7, wherein the locking member has a generally U-section, the engagement flange forming one arm of the U and of which the base extends at an acute angle to the flange and the other arm of the U is generally perpendicular to the base, and the locking member is housed in a generally U-section housing whose arms are generally parallel to its base, the locking member in its inoperative position being arranged in the U-section housing with its base against the base of the U-section housing.

9. An assembly as claimed in Claim 8, wherein, when the locking member is in its inoperative position, the base thereof and the base of the U-section housing are held together by magnetic forces.

10. An assembly as claimed in Claim 9, wherein, in moving to its operative position, the engagement flange is moved to a position abutting the corresponding arm of the U-section housing so as to break the magnetic forces between the base of the locking member and the base of the U-section housing.

11. An assembly as claimed in any one of Claims 8 to 10, wherein, in its operative position, the engagement flange extends generally parallel to the corresponding arm of the Usection housing but is partially displaced out of the housing.

12. An assembly as claimed in any one of Claims 1 to 11, comprising means for biasing the locking member to its operative position.

13. An assembly as claimed in any one of the preceding claims, wherein the locking means is provided on a side wall of the housing.

14. An assembly as claimed in any one of the preceding claims, comprising two locking means, one provided on each side wall of the housing.

15. An assembly as claimed in any one of the preceding claims. wherein the housing comprises an opening through which the slidable units are drawn out and the locking means are provided adjacent one or both lateral edges of the opening so as to be accessible from the outside of the housing for manual manipulation of the or each locking member to move it between its operative and inoperative positions.

16. An assembly comprising a housing adapted to receive a plurality of horizontally slidable support units and locking means substantially as herein described with reference to the accompanying drawings.