GB1587567A - Locking mechanism - Google Patents

Abstract

The cupboard possesses a locking device which, after one drawer (2) is opened, locks the other drawer (2) against opening. The locking device has, in a space limited by two stops (24, 25), a plurality of sliding members (9, 11, 12), and, for each drawer (2), a locking member (10) which is arranged between two adjacent sliding members. The locking members (10) can be formed by rotatable discs which are in working connection with the associated drawer and which can be introduced between the sliding members. Each disc can be brought into sliding engagement by means of a bolt (13) on the associated drawer. <IMAGE>

Description

(54) LOCKING MECHANISM (71) I, INGE SOLSTAD, a Norwegian Subject, of Edgar B. Schieldrops vei 2D, N-7000 Trondheim, Norway, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to cabinets having a plurality of drawers, such as filing cabinets or chests of drawers.

It is well known that with such cabinets, there can be a risk of the cabinet tipping over if more than a specified number of the drawers is opened at any one time, and means are necessary to prevent this, thereby preventing the cabinet's centre of gravity from being displaced to such a degree that the cabinet might topple over.

At the same time, it is desirable that one should be able to lock all of the drawers with a central locking arrangement. The present mechanism has been invented in response to these needs.

One previously-known mechanism for this purpose utilizes pivotable or sliding locking rods with catch hooks. The known solutions have deficiencies and limitations, however. For instance, several drawers can be opened only if the drawers are pulled simultaneously, but with the exception of this malfunction, only one drawer at a time can be opened, even when limitation to one drawer is not essential to prevent the cabinet from tipping.

An object of the invention is to assure that only a predetermined number of the drawers can be drawn out at the same time. This object is achieved in accordance with the invention, by providing a cabinet having a plurality of drawers and an interlock mechanism effective, upon opening of a predetermined number of the drawers, to prevent any further drawer or drawers from also being opened, said interlock mechanism comprising a plurality of slides disposed in alignment and confined in a space limited between abutments, and, for each drawer, a respective interlock member movable in said space, upon opening of its respective drawer, to cause increase of the combined overall length of the slides and the interlock members, so that opening of said predetermined number of drawers causes the slides and the interlock members to occupy the entirety of the space between the abutments, thereby preventing opening of any further drawer or drawers. By selecting the thickness of material which is introduced into the space limited by the abutments, upon opening of each drawer, relative to the total free space available in the system when the drawers are closed, one can determine the maximum number of drawers that can be opened. In a preferred embodiment, all of the drawers can be locked, by reason of the presence of a central locking mechanism having a blocking member which, for locking the cabinet, can be caused to enter into the said space and, when all of the drawers are closed, to add to the overall length of the slides and interlock members to occupy the entirety of the space between the abutments.In addition, the relationship between the drawers and their associated interlock members can be such that the entire portion of material has to have entered the limited space before the drawer can be opened, or such that it is pressed gradually into the space as the drawer is opened.

In the arrangement of the invention, one can determine in advance and as desired how many drawers are to be permitted to be pulled out or opened at the same time, and the invention assures that no more than this predetermined number of drawers can then be drawn out at any one time. In addition, all of the drawers can be locked by means of a central lock.

The drawers in the cabinet can be arranged one above the other or side by side.

An example of one embodiment of the invention is illustrated in the accompanying drawings, and will be described in more detail with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic side elevation illustrating a two-drawer filing cabinet with the interlock mechanism of the invention embodied therein; Figure 2 is a view similar to Figure 1, but showing the lower drawer of the filing cabinet opened; Figure 3 is a fragmentary sectional plan taken on the line A-A of Figure 1; Figure 4 is a section similar to Figure 3, but taken as indicated by the line B-B of Figure 2; Figure 5 is a view similar to Figure 2 but showing a central locking mechanism of the cabinet having been actuated whilst one of the drawers is open; and Figure 6 is a view similar to Figure 5, but showing the central locking mechanism having become effective upon closing of the said drawer.

The illustrated embodiment of the cabinet of the invention is indicated generally by the reference numeral 1 and has two drawers 2 of which only one drawer 2 can be opened at a time, and comprises an interlock mechanism, indicated generally by the reference numeral 20, mounted in the back of the cabinet. This interlock mechanism 20 comprises a slideway or casing 8 occupied by a plurality of aligned slides each in the form of a bar 9, 11 and 12.

Disposed between the confronting ends of the adjacent bars 9, 11 and 11, 12 are respective interlocking members each in the form of a respective locking disc 10.

Each such disc 10 is disposed so as to project through a respective opening in the slideway or casing 8 and is pivotally carried on a respective fixed pivot pin 14 (see Figures 3 and 4). Each interlocking disc 10 has a relatively thin portion which, in the closed positions of the drawers 2 as shown in Figure 1 is present between the respective confronting ends of the bars 9, 11 and 11, 12. Each such disc 10 also has a relatively thicker portion which is greater than the thinner portion by the amount h as indicated in Figure 1, and is formed with a respective chordallydisposed slot 21 as shown in Figures 3 and 4.

A respective actuating peg 13, carried between mounting brackets 23, is provided at the back of each drawer 2 for co-operation with the respective disc 10 by interengagement with the respective slot 21, it being understood that when the respective drawer 2 is closed the corresponding disc 10 is held by its peg 13 in the Figure 1 position.

As will be evident from Figure 1, the upper and lower ends 24 and 25 respectively of the casing 8 constitute abutments at each end of a space occupied by the slides 9, 11 and 12 and the interlock discs 10 and when the two drawers 2 are closed the combined overall length of these coy ponents is such as to leave empty, above the slide bar 9, a space whose height is equal to the additional thickness h of the' thicker portion of each disc 10.

Accordingly, in this figure, the cabine't not being locked and there being a free space available above the slide 9 for the thickened disc portion associated with one drawer 2, one of the drawers 2 can be pulled out to open it.

Figure 2 shows the cabinet with one drawer opened. As a result, the bar 11 has been separated from the slide bar 12, by movement of the thickened portion of the respective disc 10 therebetween, and the overall length of the bars 9, 11, 12 and discs 10 is such as to occupy the entire space in the casing 8 between the abutments 24 and 25. Accordingly, there is no room for the thickened portion on the other drawer's disc 10 to be brought into position between the ends of its respective bars 9, 11 and such other drawer 2 is thereby prevented from being opened, since it can only be opened upon rotation of its respective disc 10 to permit withdrawal of its peg 13 from the respective slot 21.

Figures 3 and 4 show, in detail, the form of each interlocking disc 10 and its inter-relation with its drawer 10. In the drawer-locking position, the slot 21 in the disc 10 is approximately at right angles to the direction of movement for the respective drawer 2, such that the actuating peg 13 on the drawer is retained in the slot 21.

Figure 4 shows the same disc 10 when the respective drawer 2 has been opened.

When the drawer 2 is pushed back in, the peg 13 on the drawer 2 will be received by the slot 21 in the disc 2 and causes the disc 2 to rotate such that its thickened portion is withdrawn from between the confronting ends between the respective slide bars.

Figure 5 shows how a central locking mechanism of the cabinet can be locked even when one of the drawers 2 is in the open position. The central locking mechanism comprises a push rod 5 projecting into a lateral arm 28 of the casing 8, at the top of the latter and terminating in an enlarged head 29 within a sleeve 30 slidable in the lateral arm 28. The sleeve 30 is closed at its rear end where it carries a locking finger 7 having a tapered end 31. A spring 6 within the sleeve 30 permits lost motion of the push rod 5 relative to the sleeve 30.A spring 4 loads the push rod 5 to the right as viewed in the drawings so that a lock 3 on its front end projects at the front of the cabinet as shown in Figures 1 and 2, and the rod 5 can be pushed inwards to a locking position, shown in Figures 5 and 6, in which it will remain unless released by operation of a key 32 in the lock 3 against the action of the spring 4.

As will be understood from Figure 6, if the push rod 5 is pushed to the locking position when the drawers 2 are closed, the locking finger 7 enters into the free space above the slide bar 9, whereafter the drawers 2 are locked against opening because there is no space available for the bars 9, 11 or 11, 12 to separate to permit rotation of one or the other of the discs 10.

Should the central locking mechanism be actuated when one of the drawers 2 is open, as shown in Figure 5, the finger 7 cannot enter between the slide bar 9 and the abutment 24, but only the tapered tip 31 thereof engages with a correspondingly angled edge 32 of such bar 9, the spring 6 permitting the lock 3 and push rod 5 nevertheless to be pushed into the locked position. When, subsequently, the open drawer 2 is closed, the slide bar 9 is caused to fall by the pressure of the finger 7 which then enters into the Figure 6 position and locks the cabinet against any drawer being opened.

Although the invention has been described in detail with reference to a cabinet having two drawers of which one only can be opened at a time, it will readily be understood that with a multidrawer cabinet the free space available between the abutments 24 and 25 can be such as to enable any predetermined maximum number of drawers only to be opened, whereafter opening of any further drawers is prevented.

WHAT I CLAIM IS: 1. A cabinet having a plurality of drawers and an interlock mechanism effective, upon opening of a predetermined number of the drawers, to prevent any further drawer or drawers from also being opened, said interlock mechanism comprising a plurality of slides disposed in alignment and confined in a space limited between abutments, and, for each drawer, a respective interlock member movable in said space, upon opening of its respective drawer, to cause increase of the combined overall length of the slides and the interlock members, so that opening of said predetermined number of drawers causes the slides and the interlock members to occupy the entirety of the space between the abutments, thereby preventing opening of any further drawer or drawers.

2. A cabinet as claimed in claim 1 wherein each said interlock member is in the form of a disc which is rotated upon opening and closing of the respective drawer.

3. A cabinet as claimed in claim 2 where in each said disc is pivotally located upon a respective pivot pin slidably engaged with the adjacent ends of respective pairs of the slides.

4. A cabinet as claimed in claim 1, 2 or 3 further including a central locking mechanism having a blocking member which, for locking the cabinet, can be caused to enter into the said space and, when all of the drawers are closed, to add to the overall length of the slides and interlock members to occupy the entirety of the space between the abutments.

5. A cabinet as claimed in claim 4 wherein the blocking member is spring loaded so that upon operating the locking mechanism when one or more drawers are open said blocking member is loaded towards entry into said space and enters therein upon closure of the drawer or drawers.

6. A cabinet having a plurality of drawers and an interlock mechanism substantially as hereinbefore described with reference to the accompanying drawings.

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

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. end projects at the front of the cabinet as shown in Figures 1 and 2, and the rod 5 can be pushed inwards to a locking position, shown in Figures 5 and 6, in which it will remain unless released by operation of a key 32 in the lock 3 against the action of the spring 4. As will be understood from Figure 6, if the push rod 5 is pushed to the locking position when the drawers 2 are closed, the locking finger 7 enters into the free space above the slide bar 9, whereafter the drawers 2 are locked against opening because there is no space available for the bars 9, 11 or 11, 12 to separate to permit rotation of one or the other of the discs 10. Should the central locking mechanism be actuated when one of the drawers 2 is open, as shown in Figure 5, the finger 7 cannot enter between the slide bar 9 and the abutment 24, but only the tapered tip 31 thereof engages with a correspondingly angled edge 32 of such bar 9, the spring 6 permitting the lock 3 and push rod 5 nevertheless to be pushed into the locked position. When, subsequently, the open drawer 2 is closed, the slide bar 9 is caused to fall by the pressure of the finger 7 which then enters into the Figure 6 position and locks the cabinet against any drawer being opened. Although the invention has been described in detail with reference to a cabinet having two drawers of which one only can be opened at a time, it will readily be understood that with a multidrawer cabinet the free space available between the abutments 24 and 25 can be such as to enable any predetermined maximum number of drawers only to be opened, whereafter opening of any further drawers is prevented. WHAT I CLAIM IS:

1. A cabinet having a plurality of drawers and an interlock mechanism effective, upon opening of a predetermined number of the drawers, to prevent any further drawer or drawers from also being opened, said interlock mechanism comprising a plurality of slides disposed in alignment and confined in a space limited between abutments, and, for each drawer, a respective interlock member movable in said space, upon opening of its respective drawer, to cause increase of the combined overall length of the slides and the interlock members, so that opening of said predetermined number of drawers causes the slides and the interlock members to occupy the entirety of the space between the abutments, thereby preventing opening of any further drawer or drawers.

2. A cabinet as claimed in claim 1 wherein each said interlock member is in the form of a disc which is rotated upon opening and closing of the respective drawer.

3. A cabinet as claimed in claim 2 where in each said disc is pivotally located upon a respective pivot pin slidably engaged with the adjacent ends of respective pairs of the slides.

4. A cabinet as claimed in claim 1, 2 or 3 further including a central locking mechanism having a blocking member which, for locking the cabinet, can be caused to enter into the said space and, when all of the drawers are closed, to add to the overall length of the slides and interlock members to occupy the entirety of the space between the abutments.

5. A cabinet as claimed in claim 4 wherein the blocking member is spring loaded so that upon operating the locking mechanism when one or more drawers are open said blocking member is loaded towards entry into said space and enters therein upon closure of the drawer or drawers.

6. A cabinet having a plurality of drawers and an interlock mechanism substantially as hereinbefore described with reference to the accompanying drawings.