GB2080871A - Storage cabinet - Google Patents

Abstract

In an autolock mechanism in a storage cabinet having a plurality of drawers one above the other, a risk of jamming all the drawers closed is avoided by presenting on each drawer a cam surface 1 on a spring cam 2. Normally when the opening of a drawer begins, the cam surface 1 lifts a tag on a locking bar so that other tag(s) on the bar enter recess(es) 7 on the other drawer(s) to hold them closed. If a tag gets caught beneath a corner 13 to prevent the bar from rising so tending to prevent any of the drawers from opening, any drawer can be opened by pulling the drawer to cause its cam surface 1 to yield beneath the associated tag. <IMAGE>

Description

SPECIFICATION Storage cabinet This invention relates to a storage cabinet having a plurality of drawers arranged one above the other, and more particularly to an autolock mechanism in such a cabinet, for locking the remaining drawer(s) shut when one of them is opened.

In our patent applications Nos 32952/76 and 28190/77 autolock mechanisms are described which comprise an upright locking bar which is displaceable longitudinally of itself between upper and lower positions, one of which is a drawer-locking position and the other a drawer-releasing position, each drawer being furnished with a member arranged by cam action to coact with an associated member on the locking bar to move the locking bar to its drawer-locking position when the opening of the drawer begins, thereby locking the other drawer(s) against being opened. Means are provided for retaining the locking bar in the drawer-locking position when it reaches that position and a cam surface on the drawer returns the locking bar to the drawer-releasing position as the drawer approaches its closed position.

It has been found that on rare occasions, possibly as a result of the cabinet being placed on an uneven floor or vibration or an obstruction finding its way into the mechanism, the locking-bar gets jammed in its drawer-releasing position and so prevents any of the drawers from being opened. It is the object of the present invention to provide means whereby this risk is eliminated.

According to the invention, for each drawer, one of the said two members that coact by cam action is resiliently arranged to yield in the event of the locking bar becoming arrested in the drawer-releasing position, whereby the drawer can still be opened if sufficient force is applied thereto to cause the said one of the members to yield. Preferably one of the members is a resiliently arranged cam on the drawer and the other of the said members is a cam follower, such as a tag, on the locking bar. Very advantageously the cam is a bent leaf spring anchored at one end and arranged to yield against the tag during the beginning of the opening of the drawer and also to yield against the tag during the termination of the closure of the drawer.

In order that the invention may be clearly understood and readily carried into effect mechanism in accordance therewith will now be described, by way of example, with reference to the accompanying drawings, in which Figure 1 is an exploded perspective view showing part of an autolock mechanism incorporated in a filing cabinet; Figures 2, 3 and 4 are respectively a side elevation, plan and front elevation of a bracket presenting cam surfaces; and Figure 5 is a perspective view of an over load spring cam.

Fundamentally the mechanism shown in Fig. 1 is equivalent to mechanism described in our Patent Application No. 28190/77 ex cept that each drawer in the filing cabinet carries a cam surface 1 which, instead of being unyielding, is presented by an overload spring cam 2.

The drawers are arranged one above the other in the filing cabinet. On the outside surface of one side of each drawer 3 is secured, close to the front of the drawer, a lock bracket 4 in which is mounted the associ ated spring cam 2. Spaced above the cam surface 1 is a parallel cam surface 5 extend ing from the lower end of a shouider 6 at the rear of a recess 7 extending above the cam surface 5.

Extending vertically beside the lock brackets 4 (when the drawers are closed) is a channel member 8 secured to the inside surface of the cabinet and containing a vertically reciproca ble locking bar 9 formed with as many in wardly extending tags 10, constituting cam followers, as there are drawers. When the drawers are closed, each tag 10 extends through an aperture in the base of the chan nel member 8 into the associated bracket 4 in an area 7a beneath the recess 7.

When any one of the drawers is opened, the cam surface 1 thereon presses the associated tag 10 upwards lifting the locking bar 9 to an uppermost position while a rack and pinion mechanism 11 drives an arm 1 2 past an over-centre position with respect to a spring 1 3 which then holds the locking bar 9 in its uppermost position in which the respec tive tag 10 associated with the drawer, or each drawer, that has not been opened, serves as a stop positioned in front of the associated shoulder 6, thereby locking that drawer against opening. The movement of the drawer being opened can then continue, car rying its lock bracket 4 considerably beyond the associated tag 10.

When the drawer that has been opened is closed, the cam surface 5, towards the end of the closure movement, engages the tag 10 and forces it downwards causing the rack and pinion mechanism 11 to return the arm 1 2 over the over-centre position. The locking bar 9 is then in the lowermost position with the tags 10 projecting into the areas 7a in the respective brackets 4.

It has been found that, on rare occasions, due to some abnormal circumstance, such as the cabinet being located on an inclined floor, when all the drawers are closed, the tags can become partially located beneath the corners 1 3 between the respective shoulders 6 and cam surface 5. This would prevent the locking bar from rising and so prevent any drawer from being opened were it not for the capacity for the spring cams 2 to yield. Thus, when the locking bar is arrested or jammed in this way, and when a drawer is opened, its respective spring cam 2 is depressed as the cam surface 1 slides under the tag 10 until the surface 1 is clear of the tag.When the drawer is closed the spring cam is again depressed by the tag 10 engaging a cam surface 14 inclined oppositely to the cam surface 1, over part of which surface 14 the tag travels prior to travelling over cam surface 1.

As shown in Fig. 3 the bracket is formed with a horizontal platform 1 5 having close to one end two apertures separated by a bar 16.

The rear end of the spring cam 2 has a bent forward portion 17 with a hook 18 at the end.

The spring cam 2 is retained on the platform 1 5 by engaging the hook 18 over the bar 16 with the portion 1 7 extending beneath the platform 1 5 with intervening packing 21 to the platform edge over which the spring cam curves. The front end of the spring cam is formed with a guide tongue 19 which projects through a slot 20 in the platform 15. The spring cam consists of hardened and tampered spring steel strip. In this example, it is 6 mm wide and in the unstrained condition the cam surface 1 makes an angle of 1 5, to the horizontal and the cam surface 14 is at 21 to the horizontal.

The spring 2 is a low cost component that is very easy to assemble in the lock bracket 4.

Claims (6)

1. In a storage cabinet having a plurality of drawers arranged one above the other, an autolock mechanism for locking the remaining drawer(s) shut when one of them is opened, the autolock mechanism comprising an upright locking bar which is displaceable longitudinally of itself between upper and lower positions, one of which is a drawer-locking position and the other a drawer-releasing position, each drawer being furnished with a member arranged by cam action to coact with an associated member on the locking bar to move the locking bar to its drawer-locking position when the opening of the drawer begins thereby locking the other drawer(s) against being opened, means being provided for retaining the locking bar in its drawerlocking position when the locking bar reaches that position and for returning the locking bar to the drawer-releasing position as the drawer approaches its closed position, one of said members being resiliently arranged to yield in the event of the locking bar becoming arrested at the drawer-releasing position, whereby the drawer can still be opened if sufficient force is applied thereto to cause the said one of the members to yield.

2. A storage cabinet according to Claim 1, in which for each drawer one of the said members is a resiliently arranged cam on the drawer and the other of the said members is a cam follower fixed on the locking bar.

3. A storage cabinet according to Claim 2, in which for each drawer the cam is a bent leaf spring anchored at one end and arranged to yield against the cam follower during the beginning of the opening of the drawer and also to yield against the cam follower during the termination of the closure of the drawer in the event of the locking bar becoming arrested in the drawer-releasing position.

4. A storage cabinet according to any one of the preceding claims, in which for each drawer the associated member on the locking bar serves as a stop to prevent the dmwer from being opened when the locking bar is raised to the drawer-locking position by the opening of one of the other drawers.

5. A storage cabinet according to Claims 3.and 4, in which for each drawer there is also provided a cam surface to act on the cam follower for returning the locking bar to its drawer-releasing position as the closure of the drawer terminates, this cam surface extending from a recess which as a result of opening another drawer the cam follower enters when the locking bar moves to the drawer-locking position, to serve as the stop by engaging an abutment in the recess to prevent the drawer from being opened.

6. A storage cabinet substantially as hereinbefore described with reference to the a companying drawings.