GB1598324A

GB1598324A - Storage cabinet

Info

Publication number: GB1598324A
Application number: GB28190/77A
Authority: GB
Original assignee: Vickers Ltd
Current assignee: Vickers Ltd
Priority date: 1977-07-05
Filing date: 1977-07-05
Publication date: 1981-09-16

Description

(54) STORAGE CABINET (71) We, VICKERS LIMITED, a British Company, of P.O. Box 177, Vickers House, Millbank Tower, Millbank, London, SW1P 4RA., do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: 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.

Storage cabinets are known, including drawers arranged one above the other, in which the drawers can be opened and closed independently of one another. A disadvantage is that more than one drawer can be opened at once and if the drawers are sufficiently laden, this can result in the cabinet toppling over about the front edge of its base. This presents a serious hazard to users of such storage cabinets.

In the present Applicants' earlier British patent application No. 36073/76, (Serial No.

1,564,306), there is disclosed a storage cabinet having a plurality of drawers arranged one above the other and incorporating an autolock mechanism for locking the remaining drawer(s) shut when one of them is opened, the mechanism comprising an upright locking bar which is displaceable longitudinally of itself between upper and lower positions, one of which is a drawerlocking position and the other a drawerreleasing position, means associated with the drawers and operative to bring about locking bar displacement to lock the remaining drawer(s) shut during the initial part of opening one of the drawers, and a spring having a normal position, which the spring occupies when the bar is in the lower position, and an over-centre position, the arrangement being such that as the bar is raised into its upper position, the spring adopts its over-centre position to hold the bar in its upper position. The spring is connected at its two ends to a protecting arm on a pinion engaging the locking bar and to a stationary upright channel member acting as a guide for the displaceable locking bar, respectively. One object of the present invention is to provide an improved spring mechanism for such an autolock mechanism.

According to the invention, there is provided, 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 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, means associated with the drawers and operative to bring about locking bar displacement to lock the remaining drawer(s) shut during the initial part of opening one of the drawers, and retaining mechanism, including a spring, operable by the locking bar and arranged so that when the locking bar is moved from the drawerreleasing position to the drawer-locking position the spring passes through an overcentre position from a first state in which it tends to hold the locking bar in the drawerreleasing position to a second state in which it retains the locking bar in the drawerlocking position the retaining mechanism being arranged so that the spring returns to the first state when the locking bar is returned to the drawer-releasing position.

Preferably the spring is connected to a point in the retaining mechanism that undergoes augmented movement relatively to the movement of the locking bar.

In a preferred construction the retaining mechanism comprises a pinion whose teeth are engaged with complementary teeth on the locking bar and which bears an arm to which the spring is connected.

Conveniently, the upper and lower positions are respectively the drawer-locking and drawer-releasing positions.

In one preferred embodiment of the invention, the storage cabinet additionally includes a key-lock mechanism which is operatively coupled to the locking bar and which is so constructed and arranged as to permit the bar to be raised and lowered when the key-lock mechanism is unlocked but to raise the bar to lock all the drawers shut when the key-lock mechanism is locked.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figures I and IA are exploded, perspective views, showing parts of one form of autolock mechanism, in accordance with the invention, incorporated in a filing cabinet; Figure 2 is a plan view of an upright channel member and associated mechanism; Figure 3 is a front view of the channel member and mechanism of Figure 2 showing two positions of certain parts thereof; Figures 4 and 5 illustrate diagrammatically the operation of the autolock mechanism; and Figure 6 illustrates different working positions of a detail of the mechanism of Figures 1 and 1A.

Referring to Figures 1 to 5 and Figures 1 and 1A in particular, a filing cabinet (illustrated diagrammatically in Figures 4 and 5 only) comprises a number of drawers 1 (for example two drawers) arranged one above the other, the top drawer being shown in Figure 1. It is to be understood that the following description of the top drawer and its associated components of the autolock mechanism applies equally to all the drawers 1.

Arranged just inside the drawer opening in the front of the filing cabinet, on one side (e.g., the right-hand side) of the opening, is an upright channel member 2 which has outwardly directed side wing portions providing feet 3 on opposite sides of the channel by which the channel member is secured to the surface of the side wall of the filing cabinet.

Arranged within the channel of the channel member along one of its sides so as to lie between the base wall of the channel member and the facing wall of the filing cabinet is a locking bar 4 which is U-shaped in cross-section and can slide vertically within the channel member. One of the side walls of the locking bar is cut at locations spaced along its length to provide actuating tags 5 for the drawers, respectively. As can be seen in Figure 1, the tag 5 for the top drawer is bent outwardly at right angles to the locking bar 4 to project through an aperture in the base wall of the channel member 2.

Each actuating tag 5 cooperates with an associated cam track 7, secured to the side wall of the associated drawer 1, in certain positions of the drawer as will be explained hereinbelow, and for this purpose, the upper and lower faces of the tag are inclined downwardly at a small angle, typically 15 degrees, to the horizontal for good bearing contact with the cam track 7. Conveniently, the cam track can be formed from a sheet metal blank which is bent to provide the required shape and then welded, for example to the drawer side.

The locking bar 4 is formed along one edge with teeth 8 (Figure 3) engaged with the teeth of a pinion 22 which is rotatably mounted on the channel member 2 and which bears a radially projecting arm 33.

Conveniently, the pinion and arm can be formed by a single sheet steel pressing. The free end of the arm 33 is bent over to form a tag 24 around which is fitted one end of a tension spring 13 whose other end is fitted around a tag 25 which is stamped from the base wall of the channel member and then bent out of the plane of the base wall.

When all the drawers of the filing cabinet are shut but not locked by a key-lock mechanism to be described hereinbelow, the bar 4 is in its lower position and the spring 13 is in the position illustrated in Figure 4. As the bar 4 is raised by the cam track 7 on opening one of the drawers, the bar rotates the pinion 22 anti-clockwise, and thereby causes the arm 33 to move from the full line position of Figure 3 so that the spring 13 goes beyond its over-centre position. As the drawer is opened further, the locking bar 4 arrives at its uppermost position, in which the spring 13 adopts the position shown in Figures 3 and 5. Then the spring, still under tension, exerts by way of a substantial turning moment on the arm 33 a sufficient upward force on the locking bar to retain it in that position as the drawer is opened further.

Referring to Figure 1, a key-lock mechanism comprises a flag 16 welded to the top end of the locking bar 4, this flag being formed from a length of strip metal but to the required shape. A roller 18 eccentrically mounted relative to a barrel 19 of a keyoperated lock 20, on an arm 21, cooperates with the flag as will be explained in detail hereinbelow with reference to Figure 6.

Operation of the autolock mechanism will now be described in detail with particular reference to Figures 4 and 5. In Figure 4, both drawers 1 of the filing cabinet are closed. It will be seen that the actuating tags 5 are positioned at the entrance to their cam tracks 7. As the top drawer is opened, relative movement between its inclined cam track 7 and actuating tag 5 causes the locking bar 4 to slide vertically in the channel member, thereby bringing the actuating tag 5 associated with the lower drawer into the position shown in Figure 5 where it is opposite a shoulder 9 at the entrance to the cam track. The spring 13 holds the locking bar 4 in its raised position even when the upper drawer 1 is opened fully and the actuating tag 5 is no longer urged upwardly by the cam track 7.It will be noted that any attempt to open the bottom drawer of the filing cabinet will fail because the shoulder 9 abuts with the actuating tag 5 associated with the lower drawer. Thus, while the drawer 1 is open, the lower drawer is locked shut.

When the upper drawer 1 is pushed back towards its closed position, the cam track 7 comes into engagement with the actuating tag 5, a lower boundary 15 of the cam track ensuring that even if the locking bar should drop at all whilst the drawer is fully open, the necessary engagement between the cam track and actuating tag can be guaranteed as the drawer is shut. Owing to the engagement the cam track forcibly displaces the locking bar 4 downwardly and in so doing causes the tension in spring 13 to increase and to pass eventually through its centre state and finally return to the position shown in Figure 4. Then the bottom drawer can be opened, if desired, since the actuating tag 5 associated with it is no longer opposite the shoulder 9 but is in fact aligned with the entrance to its cam track 7.Clearly, the autolock mechanism functions in an analogous way, when the bottom drawer is opened, to lock the top drawer shut.

The key-lock mechanism will now be described with reference to Figures 1 and 6.

The roller 18 is shown in its unlocked position in Figure 1. With all the drawers shut as shown by a broken line in Figure 6, the roller 18 is positioned at the entrance to a channel 23 formed in the end portion of the bent strip metal constituting the flag. If one of the drawers is opened, the resulting vertical displacement of the locking bar causes the flag 16 to move into the position 16' indicated in full lines, while the roller 18 remains stationary. On closing the drawer, the flag 16 returns to its original position with the roller at the entrance to the channel 17.

When (with all the drawers shut) a key is inserted into the lock 20 and turned, the arm 21 rotates through a half revolution anticlockwise so that the roller 18 follows the arcuate path 23 to arrive at the position 18'.

It will be appreciated from Figure 6 that as the roller 18 moves along the path 23 it initially enters the channel 17, then it moves right to the bottom of the channel and then returns to a position 18' at the entrance to the channel 17. During this time, the flag has been raised by the roller 18 from the position indicated in broken lines- to the position 16'. Thus, all the actuating tags on the locking bar are positioned opposite their respective shoulders 9 alongside the entrances to the cam tracks 7 and so none of the drawers can be opened. To unlock the cabinet, it is merely necessary to rotate the arm 21 through a half-revolution in the anti-clockwise sense to lower the locking bar and thereby release the drawers.

Of course, although the description and drawings herein relate to a two-drawer cabinet, the autolock mechanism can be adapted to a filing cabinet with many more drawers merely by providing additional actuating tags on the locking bar and cam tracks on the additional drawers. Then, opening of any one drawer will cause all the others to be locked shut.

In addition to the described autolock mechanism having a positive over-centre locking action, it is simple and cheap to produce in mass production, in particular because the pinion and its arm, and also the locking bar formed with its teeth, can be made in a sheet metal stamping process. In the case of the locking bar, the stamping process is followed by an appropriate bending operation.

WHAT WE CLAIM IS: 1. In a storage cabinet having a plurality of drawers arranged one above the other, an autolock mechanism for locking the remain- ing 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, means associated with the drawers and operative to bring about locking bar displacement to lock the remaining drawer(s) shut during the initial part of opening one of the drawers and retaining mechanism, including a spring, operable by the locking bar and arranged so that when the locking bar is moved from the drawer-releasing position to the drawerlocking position the spring passes through an over-centre position from a first state in which it tends to hold the locking bar in the drawer-releasing position to a second state in which it retains the locking bar in the drawer-locking position, the retaining mechanism being arranged so that the spring returns to the first state when the locking bar is returned to the drawerreleasing position.

2. A storage cabinet according to Claim

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. closed. It will be seen that the actuating tags 5 are positioned at the entrance to their cam tracks 7. As the top drawer is opened, relative movement between its inclined cam track 7 and actuating tag 5 causes the locking bar 4 to slide vertically in the channel member, thereby bringing the actuating tag 5 associated with the lower drawer into the position shown in Figure 5 where it is opposite a shoulder 9 at the entrance to the cam track. The spring 13 holds the locking bar 4 in its raised position even when the upper drawer 1 is opened fully and the actuating tag 5 is no longer urged upwardly by the cam track 7. It will be noted that any attempt to open the bottom drawer of the filing cabinet will fail because the shoulder 9 abuts with the actuating tag 5 associated with the lower drawer.Thus, while the drawer 1 is open, the lower drawer is locked shut. When the upper drawer 1 is pushed back towards its closed position, the cam track 7 comes into engagement with the actuating tag 5, a lower boundary 15 of the cam track ensuring that even if the locking bar should drop at all whilst the drawer is fully open, the necessary engagement between the cam track and actuating tag can be guaranteed as the drawer is shut. Owing to the engagement the cam track forcibly displaces the locking bar 4 downwardly and in so doing causes the tension in spring 13 to increase and to pass eventually through its centre state and finally return to the position shown in Figure 4. Then the bottom drawer can be opened, if desired, since the actuating tag 5 associated with it is no longer opposite the shoulder 9 but is in fact aligned with the entrance to its cam track 7.Clearly, the autolock mechanism functions in an analogous way, when the bottom drawer is opened, to lock the top drawer shut. The key-lock mechanism will now be described with reference to Figures 1 and 6. The roller 18 is shown in its unlocked position in Figure 1. With all the drawers shut as shown by a broken line in Figure 6, the roller 18 is positioned at the entrance to a channel 23 formed in the end portion of the bent strip metal constituting the flag. If one of the drawers is opened, the resulting vertical displacement of the locking bar causes the flag 16 to move into the position 16' indicated in full lines, while the roller 18 remains stationary. On closing the drawer, the flag 16 returns to its original position with the roller at the entrance to the channel 17. When (with all the drawers shut) a key is inserted into the lock 20 and turned, the arm 21 rotates through a half revolution anticlockwise so that the roller 18 follows the arcuate path 23 to arrive at the position 18'. It will be appreciated from Figure 6 that as the roller 18 moves along the path 23 it initially enters the channel 17, then it moves right to the bottom of the channel and then returns to a position 18' at the entrance to the channel 17. During this time, the flag has been raised by the roller 18 from the position indicated in broken lines- to the position 16'. Thus, all the actuating tags on the locking bar are positioned opposite their respective shoulders 9 alongside the entrances to the cam tracks 7 and so none of the drawers can be opened. To unlock the cabinet, it is merely necessary to rotate the arm 21 through a half-revolution in the anti-clockwise sense to lower the locking bar and thereby release the drawers. Of course, although the description and drawings herein relate to a two-drawer cabinet, the autolock mechanism can be adapted to a filing cabinet with many more drawers merely by providing additional actuating tags on the locking bar and cam tracks on the additional drawers. Then, opening of any one drawer will cause all the others to be locked shut. In addition to the described autolock mechanism having a positive over-centre locking action, it is simple and cheap to produce in mass production, in particular because the pinion and its arm, and also the locking bar formed with its teeth, can be made in a sheet metal stamping process. In the case of the locking bar, the stamping process is followed by an appropriate bending operation. WHAT WE CLAIM IS:

1. In a storage cabinet having a plurality of drawers arranged one above the other, an autolock mechanism for locking the remain- ing 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, means associated with the drawers and operative to bring about locking bar displacement to lock the remaining drawer(s) shut during the initial part of opening one of the drawers and retaining mechanism, including a spring, operable by the locking bar and arranged so that when the locking bar is moved from the drawer-releasing position to the drawerlocking position the spring passes through an over-centre position from a first state in which it tends to hold the locking bar in the drawer-releasing position to a second state in which it retains the locking bar in the drawer-locking position, the retaining mechanism being arranged so that the spring returns to the first state when the locking bar is returned to the drawerreleasing position.

2. A storage cabinet according to Claim

1, in which the spring is connected to a point in the retaining mechanism that undergoes augmented movement relatively to the movement of the locking bar.

3. A storage cabinet according to Claim 2, in which the said point is located on a pivoted arm coaxial with and fixed to a pinion whose teeth are engaged with complementary teeth on the locking bar, the radius at which said point is located being greater than the radius of the pinion.

4. A storage cabinet according to Claim 2 or Claim 3, in which the spring is arranged, when the locking-bar is moved from the drawer-releasing position, to undergo a comparatively small movement during which the stress therein is increased until it reaches the over-centre position and then to relax until it reaches the second state, wherein the spring is still under some stress and acts by way of a substantial turning moment on the locking bar to retain it in the drawer-locking position.

5. A storage cabinet according to any one of the preceding claims, in which the means associated with the drawers for bringing about locking bar displacement comprise, for each drawer, a cam track on the drawer and a projection on the locking bar which is engaged by the cam track only during the initial part of the opening of the drawer, but long enough for the locking bar to be moved to its drawer-locking position wherein a projection on the locking bar engages a shoulder on the other drawer, or on each other drawer, to prevent it from being opened.

6. A storage cabinet according to any one of the preceding claims, in which the upper and lower positions of the locking bar are respectively the drawer-locking and drawer-releasing positions.

7. A storage cabinet according to any one of the preceding claims, including a key-lock mechanism which is operatively coupled to the locking bar and which is so constructed and arranged as to permit the bar to be raised and lowered when the key-lock mechanism is unlocked but to move the bar to lock all the drawers when the key-lock mechanism is locked.

8. A storage cabinet substantially as hereinbefore described with reference to the accompanying drawings.