GB2361024A - Locking arrangement for drawers with slides - Google Patents

Abstract

A locking arrangement for the drawer or drawers of a drawer cabinet, said arrangement comprising a transverse member 1 for mounting across the top of the cabinet, there being at least two lever arms 3 mounted on said transverse member, one at each end thereof, each of which lever arms is movable by operation of a locking device 35 designed to co-operate therewith to cause rocking movement of the transverse member 1 about its longitudinal axis between drawer locking and drawer unlocked positions. Preferably, a third lever arm 4 is mounted on the transverse member 1, or forms part thereof at a central region thereof, said third lever arm also being movable by operation of a locking device designed to co-operate therewith, the locking arrangement being such tat it allows a manufacturer of the cabinet to select a left-hand, or a right-hand, or a central location for the locking device in which case the third lever arm 4 must be provided. The locking device is preferably a key operated barrel lock 35 with an offset activating device 37 on its rear which is designed to co-operate with one of the lever arms, and cause rocking of the transverse member to move it into and out of a drawer locking position.

Description

1 2361024 1 LOCKING ARRANGEMENT FOR DRAWERS WITH SLIDES This invention

relates to a locking arrangement for one or more drawers or storage units (hereinafter called drawers) which are mounted within a frame, carcase or cabinet (hereinafter called cabinet) using telescopic drawer slides. The locking arrangement is particularly designed for locking the drawers of filing cabinets of the type incorporating several drawers supported in the cabinet by drawer slides on either side of the drawers and designed for holding a plurality of files.

Locking systems for locking the drawers of filing cabinets are well known. These locking systems normally have a key operated lock located on the left-hand side of the cabinet of drawers or on the right-hand side of the cabinet of drawers or alternatively located at a central location. Each of these different designs require different components for locking the drawers, i.e. a left-handed set of components, a right-handed set of components or alternatively a set of components for central locking. All these components are slightly different and, invariably, are specially designed to accommodate the desired type of lock of a particular lock manufacturer. Invariably, filing cabinets incorporating drawers supported on drawer slides are manufactured by a furniture manufacturer who buys in the drawer slides from a drawer slide manufacturer and purchases the locking components, either from the slide manufacturer or from the lock manufacturer or, perhaps, even from a third party. This means that the fimiiture manufacturer, if he wishes to offer cabinets having lefthanded or right-handed or central locking, has to carry a large number of component parts which have to be designed for use with a lock of a particular manufacturer. Maintaining a large stock of component parts so as to be able to supply cabinets with left-hand or right- hand or central locking on demand is not cost-effective. There is therefore a demand for a locking arrangement specifically designed for filing cabinets with drawers supported by drawer slides of a universal nature which can be assembled either for left-hand locking or right-hand locking or central locking and which can be used with the lock of any one of a number of lock manufacturers.

It is already known to provide a locking arrangement for filing cabinets of the above type which have a centrally located lock which can be used to lock all the drawers of the filing cabinet in a closed position on both sides thereof, and which can also be used as an anti-tilt 2 device so that, if one particular drawer is opened fully, other drawers in the cabinet cannot be opened at the same time. It will be appreciated that, if the open drawer is full of heavy files, there will be forces acting on the filing cabinet tending to cause the filing cabinet to overturn should another full drawer be pulled out. This known mechanism makes use of a central lock which activates a radially extending lever arm on a rod extending transversely across the top of the cabinet so that rotation of the lock barrel by means of a key will cause the lever arm to swing upwards or downwards, thus causing the rod to rotate clockwise or anticlockwise about an axis at right angles to the barrel of the lock, this rotation of the rod being translated by further lever arms at each end of the rod into vertical movement of a vertically slidable locking bar mounted in the side walls of the cabinet, such vertical movement causing transversely extending pins on the locking bars to move into and out of engagement with stops on the respective drawers. This centrally located locking arrangement is specifically designed for a lock of a particular manufacturer and suffers from the major disadvantage that it can only be operated by a centrally mounted lock.

According to the present invention, we provide a locking arrangement for the drawer or drawers of a drawer cabinet, said arrangement comprising a transverse member for mounting across the top of the cabinet, there being at least two lever arms mounted on said transverse member, one at each end thereof, each of which lever arms is movable by operation of a locking device designed to co-operate therewith to cause rocking movement of the transverse member about its longitudinal axis between drawer locking and drawer unlocked positions. Preferably, a third lever arm is mounted on the transverse member, or forms part thereof at a central region thereof, said third lever arm also being movable by operation of a locking device designed to co-operate therewith.

The locking arrangement is such that it allows a manufacturer of the cabinet to select a lefthand, or a right-hand, or a central location for the locking device; if a central location is chosen, then the third lever arm must be provided. The locking device is preferably a key operated barrel lock with an offset activating device on its rear which is designed to co- operate with one of the lever arms, and cause rocking of the transverse member to move it into and out of a drawer locking position.

3 in the drawer locking position of the transverse member, it is preferred that the lever arms at each end of the transverse member will take up a position which ensures that an interlock mechanism at each side of the cabinet will be prevented from moving from a drawer locking position. The interlock mechanism may include a rod at each side of the cabinet which are prevented from being raised out of a drawer locking position by the presence of the lever arms.

Also, according to the present invention, we provide a locking arrangement for the drawer or drawers of a drawer cabinet in which the or each drawer is supported in the cabinet on drawer slides and the or each drawer is locked in a closed position in the cabinet by a vertically movable interlock system which, when in its locking position, engages with a part of the drawer slide on at least one side of the drawer to prevent the drawer being opened, said interlock system incorporating a rod at the upper end thereof and movable between an unlocked position and a locking position, said locking arrangement including a transverse member adapted to extend between the side walls of the cabinet at an upper end thereof and adapted to be mounted for rotation about its longitudinal axis, there being a lever arm mounted on each end of the transverse member for rocking movement with the transverse member, the lever arm having first and second cam surfaces thereon, one of which is adapted to be contacted by an activating member of a lock when the lock is moved to an unlocked position and the other of which is adapted to be contacted by the activating member of the lock when the lock is moved to a locking position, such activation causing the lever arm and hence the transverse member to be rocked to a unlocking position or a locking position respectively, movement of said lever arm to its locking position moving it, in use, to hold the rod in its locking position.

Preferably, the locking arrangement includes a rotary body at each end thereof adapted for fixedly mounting in an upper front corner of the cabinet, the rotary body having an aperture in a wall thereof, preferably in the form of a laterally projecting spigot which provides a bearing support for one of said lever arms and having two diametrically opposed arcuate slots in said wall, said arcuate slots having a centre of curvature corresponding with the centre of the aperture, there being a projecting peg on the lever arm engaging in one of said slots to control the degree of rocking movement of said lever arm. Preferably, the lever arm has a hollow boss projecting from a side face thereof, which 4 forms a close fit within said aperture, e.g. a central aperture in said spigot to act as a bearing for the lever arm. Preferably also, the hollow in the boss is shaped to form a key with a respective end of the transverse member, which forms a ffiction fit therein, so as to support the latter so that rocking movement of the lever arm and of the transverse member 5 occur as one.

Preferably, the rotary body is shaped to define a shell like housing formed by said wall and a skirt extending therefrom and having an open side facing in the opposite direction to the direction in which the spigot projects, the housing having the lever arm located therein, and the skirt having three apertures therein, two apertures being diametrically opposed to one another and a third being adapted slidably to receive a plunger designed for location on an upper end of the rod of the interlock mechanism.

Preferably, the lever arm comprises a pair of spaced wall portions, arranged in use to 15 extend parallel to the wall of the rotary body, and being spaced apart by two cam bars on which said first and second cam surfaces are provided, the hollow boss extending outwardly from the face of one of the wall portions remote from that to which the cam bars are attached. Preferably, the profile of the wall portions is such as to provide a camming action on an end face of the plunger.

Preferably, the two cam bars are sufficiently spaced apart to receive an activating device in the form of an offset rotary actuator located upon the rear face of a barrel of a key operated lock. This rotary actuator normally has a throw when the key is rotated of the order of 13 to 15 nun and, when the key is rotated in one direction, the actuator will act as a cam which acts against one of said cam surfaces and when the key is rotated in the opposite direction it will act as a cam engaging against the second of said cam surfaces.

The component parts of the locking arrangement are designed so that they can be reversed and used on either end of the transverse member. It is for this reason that two diametrically opposed apertures are provided in the rotary body and why two arcuate slots are also provided in the rotary body.

The transverse member preferably comprises a bar designed to extend across the width of the drawer cabinet, the transverse bar preferably having a flat thereon which forms a key with the hollow in the hollow boss.

From the foregoing, it will be appreciated that a lock may be used in conjunction with the component parts of the locking system, whether they be located at the left-hand end or at the right-hand end of the transverse member since the component parts are the same at each end but are arranged as a mirror image of one another. Hence, the rotary activator of the lock can be engaged between the first and second cam surfaces of the lever arm on the left-hand or the right-hand end of the transverse member and operation of the lock will cause its rotary actuator to activate the lever arm, thus causing that lever arm and the lever arm at the opposite end of the transverse member to rock (due to their being connected by the transverse member) and, as a result, the lever arm at each end of the transverse member will be moved into locking or out of locking engagement with the plunger on the upper end of the rod of the interlock system.

If it is decided to use the locking arrangement with a central lock, as distinct from a lefthand lock or a right-hand lock, it is necessary to modify the transverse member to incorporate a third lever arm therein at a central location thereof of the same general construction as the other two lever arms. In this arrangement, the transverse member therefore comprises two spaced rod portions interconnected by a lever arm, the lever arm incorporating two spaced cam surfaces adapted to be engaged by an operating member such as a rotary actuator of a lock. Preferably, the two cam surfaces are provided by two spaced cam bars extending between a pair of spaced wall portions, the outer surfaces of which have hollow bosses projecting therefrom designed to receive the ends of the rod portions.

A universal lock system in accordance with the present invention is now described by way of example with reference to the accompanying drawings in which:

FIGURE 1 is a schematic representation of a prior art interlock for locking the drawers of a drawer cabinet;

6 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 is a perspective view of the right-hand end portion of a universal locking arrangement according to the present invention; is a perspective view of a rotary body forming part of the arrangement shown in Figure 2; is a perspective view of a lever arm forming another part of the arrangement shown in Figure 2; is a plan view of the lever arm; is a front elevation of the lever arm; FIGURE 7 is a perspective view of a plunger forming part of the arrangement shown in Figure 2; and FIGURE 8 is a perspective view of a rotary support for the arrangement shown in Figure 2.

Referring to Figure 1, the interlock shown therein is a safety system for locking the drawers of a filing cabinet full of drawers, either for security purposes or so as to ensure that not more than one drawer can be moved to an open position at any one time. If more than one drawer which is full of files or the like is opened at any one time, there is a real risk of the whole filing cabinet tipping forward and injuring the user. The interlock system comprises a vertically extending mechanism M supported in the respective sides of the filing cabinet, one of which is indicated at S, designed to co-operate with one of the members E of each slide L located on respective sides of each drawer of the drawer cabinet. At its upper end, each mechanism has an upwardly extending rod R and, when the rod is in its uppermost position represented by the dotted lines D, the interlock is in an unlocked position but when the rod of moved to its illustrated lowered position, the interlock is in a locking position. The system is such that, if a drawer is opened when the interlock is in its unlocked position, then the other drawers cannot be opened. The interlock system relies upon a plurality of interconnected cams co-operating with cam 7 surfaces U on one of the members E of the drawer slide L. Basically, if a drawer is opened (by moving it to the right as shown), then a cam surface U will move against and past a cam C, and this will cause the mechanism M to shift vertically, moving the other cams C into a position in which they block movement of any further drawer to the right. This is because the other cam surfaces U cannot move past the cams C. However, when the mechanism is held in a drawer locking position by the presence of a locking member 0 engaging the top of the rod R, the mechanism cannot move, thus causing each of the cams C to prevent any of the cam surfaces on the slide members E from moving to the right, and thus holding the drawers in their closed, or locked position.

Referring now to Figure 2, a locking arrangement in accordance with the present invention is disclosed which is specifically designed to cooperate with the interlock system shown in Figure 1. It will be appreciated, however, that the locking arrangement could be used with other types of interlock mechanism to lock the drawers of a drawer cabinet in a closed position.

As can be seen from Figure 2, only a right-hand portion, including a central part of the locking arrangement is illustrated and the drawing shows the arrangement fitted with a central lock 37. As can be seen from Figure 2, the locking arrangement comprises a transverse number 1 in the form of two rod portions 2 interconnected by a central lever arm 4. At its right-hand end, the rod portion 1 is connected to a right-hand lever arm 3 which is shown in greater detail in Figures 4 to 6. The lever arm 3 is provided with two spaced cam surfaces 5 and 7 (see Figures 4-6) and is mounted for rotation in a rotary body 9. There would be an identical, mirror image rotary body and lever arm at its left- hand end. The rotary body 9 has a main wall 10 from one face of which a spigot 11 projects, which forms a bearing for the lever arm 3. A pair of diametrically opposed arcuate slots 13 are formed in the wall portion 10 to limit the arc through which the lever arm 3 can rock, there being a projecting peg 15 on the lever arm 3 which engages in one of the slots 13. A hollow boss 17 is provided on the lever arm 3 for supporting the lever arm within the spigot 11.

The wall 10 of the rotary body 9 has a depending skirt 12 extending from its periphery in the opposite direction from the spigot 11, this skirt defining a shell like housing for the lever arm 3. Three apertures 21, 21, 23 are formed in the skirt, the two apertures 21 being 8 diametrically opposed to one anther, and the aperture 23 being formed in a downwardly facing surface 24 of the skirL Each of the apertures 21 provides access to the lever arm 3 to enable the lever arm to be rocked by a rotary actuator of a lock exactly in the same manner as illustrated by the actuator 35 of the lock 37 shown in Figure 2. This lock (not illustrated) would be provided as a right-hand lock for the locking arrangement rather than the central lock 37 illustrated. The rotary body 9 is designed for fixture within a top righthand corner of the drawer cabinet, there being two fixing apertures 14 for this purpose. The aperture 23 is designed slidably to receive a plunger 25 designed to locate upon the upper end of a rod of an interlock mechanism such as the upper end of the rod R shown in Figure 1. One or more channels 18 are provided in the plunger performing a friction fit on the upper end of the rod.

As can more readily be seen from Figures 4-6, the lever arm 3 comprises two spaced wall portions 27 and 29 held in spaced relationship by two spaced cam bars 31 and 33, the surfaces of which define the cam surfaces 5 and 7. The hollow boss 17 extends outwardly from that face of the wall portion 27 opposite the face from which the bars 31 and 33 extend. The spacing between the bars 31 and 33 is sufficient to accept the rotary actuator of a key operated barrel lock as previously indicated.

In the construction shown in Figure 2, a central lever ann 4 is connected to the left-hand end of the rod portion 2, since the Figure 2 construction is shown being operated by a centrally located lock 37 provided with a rotary actuator 35. The central lever arm 4 is similar in construction to the lever arm 3 and comprises two wall portions 41 and 43 spaced apart by cam bars 45 and 47. These cam bars 45 and 47 define cam surfaces which have 1 exactly the same function as the cam surfaces 5 and 7 on the lever arm 3. A hollow boss 49 projects from the outer face of each of the wall portions 41 and 43, the aperture in each of the bosses 49 being shaped to form a friction fit, respectively, with and inner end portion of the rod portion 2 and with an inner end portion of an identical left-hand rod portion (not illustrated).

As can be seen from Figure 7, the plunger 25 has an external surface 26 contoured to form a sliding fit within the aperture 23 and at its end remote from that which is connected to the 9 rod R, it has an enlarged end portion 28 ensuring that it remains captive within the aperture 23.

In Figure 8, a rotary support 20 is illustrated, this support having a circular bearing surface 22 formed therein and having a base 28 with apertures 30 formed therein by means of which the rotary support is connectable to a front face of the drawer cabinet at an upper end thereof, internally. The bearing surface 23 is designed rotatably to support the rod portions 2.

As will be apparent from Figure 2, only the right-hand portion of the locking arrangement of the present invention is illustrated. Extending to the left from the left-hand boss 49 would be a finiher rod portion 2 on the left-hand end of which would be mounted a hollow boss 17 of a lefthand lever arm 3 rotatably supported in a rotary body 9 in exactly the same manner as illustrated in Figure 2 (but as a mirror image thereof). A plunger 25 would extend downwardly out of the aperture 23 in the face 24 of the rotary body. Even though the rotary body would be mounted in mirror image fashion on the left-hand rod portion 2 there would nevertheless be a forwardly extending aperture 21 in the skirt 12 of the rotary body since the rotary body is provided with two diametrically opposed such apertures 21. Furthermore, the projecting peg 15 on the left-hand lever arm 3 would also be supported in an arcuate slot 13 since two such slots are provided in the wall 10.

From the foregoing, it will be appreciated that the locking mechanism described above can be used either with a left-hand barrel lock, a central barrel lock as illustrated or a righthand barrel lock. These barrel locks each have a rotary actuator such as the actuator 35 which would engage between the cam bars 31 and 33 of either the left-hand or the righthand lever arm or as illustrated between the cam bars 45 and 47 of the central lever arm 4. If a construction is chosen with a left-hand lock or a right-hand lock, then the central lever aim 4 is not needed and can be dispensed with altogether, in which case instead of having two bar portions 2 as shown in Figure 2, a single transverse bar may extend between the hollow boss 17 of the left-hand lever arm 3 and the hollow boss 17 of the right-hand lever arm 3.

When a lock such as the lock 37 is operated by turning a key located in a suitable slot in the front of the barrel (identified at 40) rotation of the key through 180' will move the rotary actuator 35 through a 180' arc, resulting in a throw of the rotary actuator 35 of anything between about 13 and 15 nun, depending upon the make of lock. This rotary actuator 35 acts as a cam and engages one of the cam surfaces either on the cam bars 31 or 33, or on one of the cam bars 45 or 47, depending upon whether left-hand, right-hand or central locking is required. If the cam bar 33 or the cam bar 45 is activated by rotation of the lock barrel 40 from the illustrated position shown in Figure 2 to a diametrically opposed position, this will cause rotation of the transverse member 1 anticlockwise as illustrated in Figure 2. On the other hand, if the cam bar 31 or the cam bar 47 is activated, then the transverse member will be moved clockwise but to its illustrated position as shown in Figure 2. This rocking movement occurs throughout the length of the transverse member 1 and actuation of the central lever arm 4 or one of the left-hand or right-hand lever arms 3 will cause the other lever arm or arms to move in the same sense. Such movement in a clockwise sense as shown in Figure 2 will cause the lever arm 3 to move down into engagement with the upper surface of the base 28 of the plunger 25, thus moving the rod to which the plunger is connected downwardly as illustrated in Figure 1 to a locking position such that its cams C will move into blocking engagement with the cam surfaces U on the slide members E of the slides L. This represents the locked position of the locking arrangement and prevents opening of the drawers of the cabinet. However, when the transverse member 1 and its lever arms 3 are moved anticlockwise as shown in Figure 2 so the rod R and its plunger 25 will be able to move upwardly as shown in Figure 1, thus moving the cam C out of to blocking engagement with the cam surfaces U.

From the foregoing, it will be noted that a universal locking arrangement is provided which can be used for left-hand locking, right-hand locking or central locking of the drawer cabinet. Furthermore, by careful design of the respective lever arms and, in particular, the correct selection of the spacing of the cam bars 31 and 33 in the one case, and 45 and 47 in the other case, the rotary actuator 35 of the lock 37 will easily fit therebetween. This allows a lock of many different manufacturers to be used with the locking arrangement.

11 It will of course be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

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Claims (15)

1. A locking arrangement for the drawer or drawers of a drawer cabinet, said arrangement comprising a transverse member for mounting across the top of the cabinet, there being at least two lever arms mounted on said transverse member, one at each end thereof, each of which lever arms is movable by operation of a locking device designed to co-operate therewith to cause rocking movement of the transverse member about its longitudinal axis between drawer locking and drawer unlocked positions.

2. A locking arrangement according to claim 1, wherein a third lever arm is mounted on the transverse member, or forms part thereof at a central region thereof, said third lever arm also being movable by operation of a locking device designed to co-operate therewith

3. A locking arrangement for the drawer or drawers of a drawer cabinet in which the or each drawer is supported in the cabinet on drawer slides and the or each drawer is locked in a closed position in the cabinet by a vertically movable interlock system which, when in its locking position, engages with a part of the drawer slide on at least one side of the drawer to prevent the drawer being opened, said interlock system incorporating a rod at the upper end thereof and movable between an unlocked position and a locking position, said locking arrangement including a transverse member adapted to extend between the side walls of the cabinet at an upper end thereof and adapted to be mounted for rotation about its longitudinal axis, there being a lever arm mounted on each end of the transverse member for rocking movement with the transverse member, the lever arm having first and second cam surfaces thereon, one of which is adapted to be contacted by an activating member of a lock when the lock is moved to an unlocked position and the other of which is adapted to be contacted by the activating member of the lock when the lock is moved to a locking position, such activation causing the lever arm and hence the transverse member to be rocked to a unlocking position or a locking position respectively, movement of said lever arm to its locking position moving it, in use, to hold the rod in its locking position.

4. A locking arrangement according to claim 1, 2 or 3, and which includes a rotary body at each end thereof adapted for fixedly mounting in an upper front corner of the cabinet, the rotary body having an aperture in a wall thereof which provides a bearing 13 support for one of said lever arms and having two diametrically opposed arcuate slots in said wall, said arcuate slots having a centre of curvature corresponding with the centre of the aperture, there being a projecting peg on the lever arm engaging in one of said slots to control the degree of rocking movement of said lever arm.

5. A locking arrangement according to claim 4, wherein the lever arm has a hollow boss projecting from a side face thereof, which forms a close fit within said aperture to act as a bearing for the lever arm.

6. A locking arrangement according to claim 5, wherein the hollow in the boss is shaped to form a key with a respective end of the transverse member, which forms a friction fit therein, so as to support the latter so that rocking movement of the lever arm and of the transverse member occur as one.

7. A locking arrangement according to claim 4, 5 or 6, wherein the rotary body is shaped to define a shell like housing formed by said wall and a skirt extending therefrorn and having an open side facing in the opposite direction to the direction in which the spigot projects, the housing having the lever arm located therein, and the skirt having three apertures therein, two apertures being diametrically opposed to one another and a third being adapted slidably to receive a plunger designed for location on an upper end of the rod of the interlock mechanism.

8. A locking arrangement according to any one of the preceding claims 3-7, wherein the lever artn comprises a pair of spaced wall portions spaced apart by two cam bars on which said first and second cam surfaces are provided.

9. A locking arrangement according to claim 8, wherein the two cam bars are sufficiently spaced apart to receive an activating device in the form of an offset rotary actuator located upon the rear face of a barrel of a key operated lock whereby, when the key is rotated in one direction, the actuator will act as a cam which acts against one of said cam surfaces and when the key is rotated in the opposite direction it will act as a cam engaging against the second of said cam surfaces.

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10. A locking arrangement according to claim 3, or any one of claims 4-9 when dependent on claim 3, wherein a third lever arm is provided at a central location of the transverse member.

11. A locking arrangement according to claim 10, wherein the transverse member comprises two spaced rod portions interconnected by a lever arm, the lever arm incorporating two spaced cam surfaces adapted to be engaged by an operating member such as a rotary actuator of a lock.

12. A locking arrangement according to claim 11, wherein the two cam surfaces are provided by two spaced cam bars extending between a pair of spaced wall portions, the outer surfaces of which have hollow bosses projecting therefrom designed to receive the ends of the rod portions.

13. A locking arrangement according to any one of the preceding claims, wherein the locking device is a key operazed barrel lock with an offset activating device on its rear which is designed to co-operate with one of the lever arms, and cause rocking of the transverse member to move it into and out of a drawer locking position.

14. A locking arrangement substantially as hereinbefore described with reference to the accompanying drawings.

15. A filing cabinet having one or more drawers therein and provided with a locking arrangement as claimed in any one of the preceding claims.