GB2125869A - Shutter for a cabinet - Google Patents

Abstract

A shutter 50 for a cabinet 10 is arranged to move on opening in a track 24 up the front, across the top and down the back of the structure. The shutter 50 consisting of slats 52 extends around a roller 34, frictionally engaging with tyres or discs 48. A coiled spring 46 is fixed to the roller 34 at one end and at the other to a spigot 40 which engages into a square hole in a bracket 44. The arrangement is so set up that the spring 46 is in a relaxed condition when the shutter 50 is in the half open position. Thus, any movement of the shutter 50 in either direction (i.e. upwards to open the cabinet fully or downwards to close the cabinet fully) stores energy in the spring and prevents the shutter "running away". <IMAGE>

Description

SPECIFICATION Shuttered structures This invention concerns shuttered structures, that is to say open-fronted structures, such as cabinets, cupboards and the like having a sliding shutter or tambour (hereinafter referred to simply as "shutter" for convenience) composed of a plurality of slats pivotally connected to one another, which shutter can be slid up and down for opening and closing the open front of the structure, being guided by its edges in slots at each side of the open front, or by other suitable guide means.

It is already known, for example, to provide for the shutter to wind onto a roller within the structure, at the top thereof, above the upper limit of the open front. This roller can embody a spring which becomes tensioned upon the shutter being unwound from the roller and pulled down to the closed position, so that it assists in subsequent opening of the shutter which involves sliding the shutter upwards. The disadvantage of such an arrangement resides in the fact that the shutter, when wound up onto the roller, occupies a very considerable space in the top of the structure, and accordingly reduces the capacity of the structure.

To avoid this latter disadvantage, it has been proposed, instead of winding up the shutter onto a roller at the top of the structure, to guide the shutter so that it can be caused to slide rearwardly at the top of the structure, and then downwards at the rear of the structure. Then, the extra space is not required at the top of the structure for accommodating the shutter in the open position of the latter, since the shutter occupies only a minimum thickness at the top and rear of the structure when in its open disposition. This arrangement (herein referred to as a "rear-sliding shuttered structure") in its turn, has its own disadvantages. When the shutter is to be opened from its fully closed position, the user has to raise substantially the entire weight of the whole shutter which in the case of large structures can be quite heavy.Moreover as the shutter is progressively raised, more and more of it moves rearwardly and then downwards at the rear of the structure. Thus, there is a rear section of the shutter, disposed at the rear of the structure, of progressively increasing extent as the shutter is opened. This section correspondingly becomes heavier and heavier (with the section of the shutter at the open front of the structure becoming correspondingly lighter and lighter). As a consequence, it is not unusual for the shutter to "run away" from the hand(s) of the user, whilst it is being opened, with consequential risk of damage to the shutter and injury to the user.

An object of the present invention is to provide a rear-sliding shuttered structure wherein the above-described disadvantages are obviated.

With this object in view, the present invention provides a rear-sliding shuttered structure wherein the shutter upon opening and closing serves to rotate a roller, so coupled with energy-storage means that the latter is in a neutral or non-storing condition when the shutter is in the substantially half-open or mid position so that both closing movement and opening movement from the said mid position is accompanied by storage of energy by the said storage means.

The said roller is conveniently a guide roller provided at the top of the opening of the structure and serving to guide the shutter between the front of the structure and below the top of the structure.

Apart from this guide roller, the shutter may be guided by its edges sliding in guide slots at opposite sides of the open front, top and rear of the structure, or on rails engaging with the side of the shutter or by other suitable guide means.

For convenience in ensuring that the guide roller is rotated by movement of the shutter, the said guide roller is preferably formed with a friction surface or surface engaging with the shutter. This is conveniently achieved by the provision of a plurality of resilient tyres or discs around the roller, at appropriate intervals. These tyres or discs may be of expanded plastics or synthetic rubber.

For enabling the arrangement of the invention to be compactly constructed, the energy storage means conveniently comprises spring means in the form of a coil spring or springs housed within the guide roller. This spring means may comprise one or more springs connected by one end with a spigot at one end of the roller and by the other end to the roller, so that the spring or springs are in a substantially relaxed condition in the mid position of the shutter, and are wound up and/or unwound from the relaxed condition upon opening and closing movement of the shutter from the mid position.

Accordingly, the end spigot conveniently is of a form, e.g. square, which will engage in a corresponding recess in the structure and be prevented from rotating relative to the structure, but will rotate relative to the roller.

The invention will be described further, by way of example, with reference to the accompanying drawings which illustrate a preferred embodiment thereof, it being understood that the following descripiton is ilustrative, and not restrictive, of the scope of the invention. In the drawings:~ Fig. 1 is a diagrammatic front view illustrating a practical embodiment of the shuttered structure of the invention, in the form of a cabinet; Fig. 2 is a sectional side elevation taken on the line Il-Il of Fig. 1; Fig. 3 is a fragmentary enlarged sectional detail corresponding to the top right hand corner of Fig. 2; Fig. 4 is a fragmentary section taken as indicated by the line lV-lV of Fig. 3.

The illustrated preferred embodiment of the shuttered structure conforming to the invention is essentially in the form of a substantially rectangular stationery or filing cabinet 10, made of sheet metal, or other suitable material, and openfronted as at 12 so that it comprises a base 14 from which stand up two side walls or panels 16, and a rear panel 1 8, the tops of these two side walls 16 and rear panel are blocked off by a top panel 20.Provided in the side walls 16 adjacent the upright front and rear edges and the top edges thereof at opposite sides of the cabinet, are confronting shutter guide slots 24 each of which extends upwards as at 26 at the respective front edge of the respective side panel 1 6, then curves round and extends rearwardly in the same side panel as at 28, below the top panel of the cabinet, and then again curves downwards as at 30 at the rear of the cabinet to extend downwards in the respective side panel 16.

The front of the top panel 20 of the cabinet has integrally connected therewith a downwardlyprojecting flange 32 and this serves to mask a substantially horizontal guide roller, indicated generally by the numeral 34, disposed in the curve between the top panel 20 and the flange 32. This guide roller 34 fits at one end by a rotatable stub 36 into a socket 38 on the respective side panel 1 6 of the cabinet. At the other end, as shown in Fig. 4, the guide roller 34 has fitted therein a rotatable spigot 40 having a square spring-loaded stub 42 engaged into a square hole in a bracket 44 secured to the respective side panel 1 6 of the cabinet. Accordingly, the spigot 40 is prevented from rotating. A coil spring 46 disposed within the guide roller 34 is connected by its ends to the two spigots 36, 40.

Provided at spaced intervals along the roller 34, and externally thereof, are a number of friction tyres or discs 48, made of expanded elastomer foam. These tyres or discs 48 are of a diameter that a sliding shutter (which has been illustrated only very diagrammatically at 50), comprising a plurality of slats 52, of plastics or like material pivotally connected together, and guided by its edges in the guide slots 26, 28 and 30 above described, extends thereover. The overall height of the shutter 50 is such that it will close the entire front of the cabinet, and in such closed position a small portion of the upper end of the shutter 50 still extends over the tyres or discs 48 and into the horizontal parts 28 of the guide slots below the top panel 20 of the cabinet.

In the assembly of the arrangement as above described, care is taken to ensure that the spring 46 within the guide roller 34 is in a substantially relaxed condition when the shutter is in the halfopen or mid position, that is to say about halfraised in the front of the cabinet, as shown in Figs.

1 and 2 of the drawings. It will accordingly be understood that upon closing the shutter 50 properly at the front of the cabinet, by sliding it downwards from its illustrated mid position, the coil spring 46, which serves as energy storing means, is wound in one direction. In other words, the winding of the spring 46 is effective to counteract the effective increase in weight of the portion of the shutter simultaneously moving into the front slot 26 of the cabinet.

By appropriate choice of the characteristics of the spring 46 the arrangement may be such that only a substantially constant pressure is necessary to move the shutter 50 downwards. The same accordingly applies in opening the shutter 50.

Firstly, from the fully closed position, the energy stored in the spring 46 assists the raising of the shutter 50, and contributes to counteracting the weight thereof present in the front slot 26. As the shutter 50 is raised towards its illustrated mid position, wherein a part of the shutter 50 has passed to the rear of the cabinet and starts to counterbalance the weight of that part which is still at the front, the spring 46 is wound back towards its relaxed condition, so that the shutter 50 is substantially balanced and stationary, under the weight of its portions at the front and rear of the cabinet.

Thereafter, with continued opening of the shutter 50, the spring 46 is again wound, but in the opposite direction to that in the closing of the shutter 50, and stores energy in exactly the same way as above described, to ensure balancing of the shutter 50 and that a substantially constant force needs to be applied for fully opening the shutter 50.

It will thus be appreciated that with the arrangement of the invention, there is no possibility of the shutter 50 "running away during its opening and closing movements, due to shifting of the major mass of the shutter 50 between the front and the rear of the cabinet, and smooth, safe and satisfactory operation of the shutter is achieved.

The invention is not confined to the precise details of the foregoing example and variations may be made thereto. Thus, although in the described case the shutter 50 actually runs over the guide roller 34, this is not essential, and the arrangement may be such that the shutter's movement rotates an independently-mounted roller or like device which serves to supply energy to any suitable energy-storage device to balance the shutter 50 and from which energy is returned to the shutter 50 upon movement of the latter to minimise or prevent running away of the shutter.

The invention is not confined to use as shutters installed on cabinets as described, but can be employed in any environment involving a shutter which, upon raising its front, has a part transferred to vertical movement.

Claims (10)

1. A rear-sliding shuttered structure wherein the shutter upon opening and closing serves to rotate a roller, so coupled with energy-storage means that the latter is in a neutral or non-storing condition when the shutter is in the substantially half-open or mid position so that both closing movement and opening movement from the said mid position is accompanied by storage of energy by the said storage means.

2. A structure as claimed in claim 1 wherein the said roller is a guide roller provided at the top of the opening of the structure and serving to guide the shutter between the front of the structure and below the top of the structure.

3. A structure as claimed in claim 1 or 2 wherein the shutter is guided by its edges sliding in guide slots at opposite sides of the open front, top and rear of the structure, or by rails on the structure engaging with the side of the shutter.

4. A structure as claimed in claim 1,2 or 3 wherein the guide roller is formed with a friction surface or surface engaging with the shutter.

5. A structure as claimed in claim 4 wherein the friction surface is provided by a plurality of resilient tyres or discs around the roller, at appropriate intervals.

6. A structure as claimed in claim 5 wherein tyres or discs may be of expanded plastics or synthetic rubber.

7. A structure as claimed in any preceding claim wherein the energy storage means, spring means in the form of a coil spring or springs housed within the guide roller.

8. A structure as claimed in claim 7 wherein the spring means comprises one or more springs connected by one end with a spigot at one end of the roller and by the other end to the roller, so that the spring or springs are in a substantially relaxed condition in the mid position of the shutter, and are wound up and/or unwound from the relaxed condition upon opening and closing movement of the shutter from the mid position.

9. A structure as claimed in claim 8 wherein the end spigot is of a form which will engage in a corresponding recess provided on the structure and be prevented from rotating relative to the structure, but will rotate relative to the roller.

10. A rear-sliding structured structure substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.