GB2297578A - Drawer closure safety device - Google Patents

Abstract

A safety device for urging drawers fully open or fully closed comprises catch means adapted to be fixed to an item in which the drawer (not shown) is arranged to slide, and co-operating actuator means 2 mounted on the drawer. The catch means is disposed inside a casing 1 and has first and second triggering elements 17, 13 projecting through said casing 1 for engagement by said actuator means 2. The second triggering element 13 is subordinated to the first triggering element 17. First triggering element 17 comprises a plate 4 pivotally mounted on said casing 1 and includes resilient means 9 acting to urge the drawer into its fully opened condition in response to an opening impulse. Second triggering element 13 comprises a connecting rod 12 journalled at one end 11 on plate 4 and guide means 14 at its other end receivable in track 15 provided on casing 1. Track 15 delimits the travel of second triggering element 13. When the drawer is fully closed, second triggering element 13 is restrained at one end of its travel by engagement with actuator means 2.

Description

DRAWER CLOSURE SAFETY DEVICE The object of this invention is a drawer closure safety mechanism specially designed for office furniture, although it is also generally useful for all of those drawers that slide over guiding tracks fitted with bearings and that, because of the smoothness with which they travel, tend to open on their own, constituting a latent danger for any person moving around them.

In a more concrete manner it may be asserted that the mission of the drawer closure safety mechanism proposed in this document is on the one hand to keep the drawer closed and on the other hand to make it easier to open by projecting it outward whenever there is a prior actuation to effect said opening, so that the drawer reacts by closing and staying shut or by opening up and advancing far enough so that it may never remain unobserved hindering the free passage of people or mobile objects and thus cause an accident.

Up to now the inventor, a drawer guiding track manufacturer, has only become aware from patent literature of documents from various sources trying to present specific productions regarding drawer guiding tracks in which, in a more or less ingenious manner, it is accomplished that the drawers may fully project outward at full load and without deformation, without lateral offset and without altering their motion plane.

It is nevertheless precisely the fact that the drawer guiding tracks facilitate surprisingly smooth drawer displacement that makes it necessary to keep them secure to avoid their accidental opening, so that the simpler solution is then usually adopted, which is to lock them, being then necessary to unlock and relock them every time that access to the drawer is sought.

There are no known mechanical means to keep the drawer shut and prevent it from opening accidentally nor are there any means resulting in a firm outward motion of the drawer when a voluntary opening action is effected, so that opening initialization may never be interrupted and later forgotten due to an omission or momentary distraction in such a way that because only a portion of the drawer projects out, we would again found ourselves confronted by a potentially dangerous situation.

It is therefore not possible to offer references related to texts or documents where the problem focused by the object of the invention has been approached before with the intent of solving it, being this the reason why this party shall not offer in this document any reference on which the prior art may be based.

The drawer closure safety mechanism constituting the object of this invention includes the combination of two triggering elements located in a metal casing fixed to the passage of a feeler kingpin fitted to the moving portion of the drawer.

During the drawer opening or closing trajectory by way of the feeler kingpin, said kingpin is acted upon by the triggering elements fitted in combination inside the metal casing, triggering elements that maintain the drawer in the closed position when they lock in, and also project it outward in response to an opening action.

One of the triggering elements is subordinated or slaved to the other, which is the rocking and follow-up one, whereas the subordinated or slave triggering element is a retention unit that moves following a guiding track that determines the limits or end of its trajectory, holding or freeing a compressed helical spring that maintains a constant pushing action in respect of the rocking follow-up triggering element, which acts as the element pushing out the drawer in the deliberate opening stage or as the drawer push in element when it is being closed, but always by the reaction of the spring whenever it is under pressure or freed.

The follow-up rocking triggering element presents a turning point and a pushing crossarm to a pin fitted with a turning holding joint on a crossarm. The pin that supports the action also suffers the action of a helical spring that is telescopic in respect of an end support through which it penetrates and from which it is extracted following the movements of the rocking triggering element.

It must also be mentioned that the pin 7, in its holding joint 8 receives the action of the helical spring 9 which on the other side on its support end is held so that the penetration or extraction of the pin will cause the reaction of the helical spring.

The follow-up rocking triggering element is also connected to a connecting rod that is part of the retention triggering element and which incorporates it; said connecting rod does furthermore end on a crossing spindle that follows the guiding track that determines the helical spring freeing or retention trajectory as regards allowing the pin to telescopically penetrate its guiding track or exit it. A retention span tilted in respect of the motion span of the crossing spindle of the connection rod fitted with the retention triggering element has been provided for this purpose.

On another side the follow-up rocking triggering element is fitted with a notch that determiners on one side an outward pushing crest towards the feeler kingpin and on the other a pushing tooth that causes the triggering element to rock whenever the feeler kingpin enters the notch.

These and other characteristics will be oberved to be duly represented below on the sketches attached to this document, constituting an example of execution purely illustrative, although not limitative, of the practical possibilities of the invention, and which only mission is to act as the means to locate the references that shall allow an identification of the fundamental parts that constitute the object of the invention.

Figure one represents a perspective of the drawer closure safety mechanism, showing below the metal casing the layout of the pushing and follow-up triggering element, as well as the head of the retention triggering element. Within the cut out are also shown the feeler kingpin fitted onto the mobile part of the drawer that shall cause the safety mechanism object of the invention to actuate.

Figure two shows a partly cut away view of the resting mechanism before the feeler kingpin of the mobile section of the drawer acts upon it and also in the position in which it shall be left after said actuation.

Figure three shows a detailed view of how the mobile kingpin inserted inside the follow-up triggering element actuation notch compresses the spring of the pushing pin and moves the retention triggering element, following its guiding track up to the resting position.

Figure four details the mechanism interlock where the kingpin, projected inward, remains under the head of the retention triggering element, keeping the drawer shut.

As shown on the sketches the metal casing is fitted to the guiding portion fixed to the panel supporting the drawer not shown here; under the metal casing moves the kingpin 2 attached to the mobile section of the drawer and being part of the guiding track attached to the drawer, constituting the element capable of movement over the fixed part, Given that the format and constitution of the guiding track is irrelevant and deviates from the end purpose of the invention, it has been decided not to include them for the sake of simplification of the sketches, and they are not therefore shown. It is enough to know that the metal casing 1 is fixed and the feeler kingpin 2 moves in the two directions A-B represented by the arrows 3.

Inside the metal casing 1 is the follow-up rocking triggering element 4 that presents a turning point 5 and a pushing crossarm 6 to a pin 7 fitted with a turning holding joint 8 on the crossarm 6, the pin supports and also suffers the action of a helical spring 9 that is telescopic in respect of an end support 10 and that exerts a constant pressure upon a follow-up rocking triggering element 4, tending to maintain it in the position in which it is shown in Figures one and two.

As shown on the sketches, the follow-up rocking triggering element 4 is connected to a spindle 11 and to a connecting rod 12 presenting a retention triggering element 13 ending on a crossing spindle 14 and following a guiding track 15 turning to form the retention span 16 when the kingpin 2 following the direction A of the arrow 3, hits the lower edge 17 of the follow-up rocking triggering element.

Continuing with the motion which is consequence of a drawer closure pushing action, the kingpin 2 enters the actuation notch 18, so that all of the follow-up triggering device 4 rocks around the spindle 5 moving the pushing crossarm 6 of the pin 7 so that the helical spring 9 is then compressed against its support 10 and is energized, this energy being then retained because the spindle 11 has pushed the connecting rod 12 along its guiding track 15, allowing the kingpin 4 to pass and feel the head of the retention triggering element 13, so that the crossing spindle 14 is then placed in the retention span 16.

The kingpin 2 remains under the action of the triggering element 13 and tends to remain unmoving so that it requires an opening action following the direction B of the arrow 3 to enable freeing the triggering element 13, allowing the kingpin 2 to move towards the notch 18. At that moment the expansion motion of the helical spring 9 starts and the crest 19 pushes the feeler kingpin 4 outward, pushing the drawer out as reflected in figure one, arrow 3, direction B.

The claws 20 shown on the side of the metal casing 1 fix the assembly into grooves fitted to that effect, on the fixed side of the drawer line, so that its assembly is easily accomplished due to the whole mechanism being constituted by a compact set housed in the metal casing 1 and furthermore, due to grooves having been effected by a mechanical process, so that there is no doubt regarding the positional accuracy of the system.

It is not considered necessary to extend this document nor its contents any further to enable any expert in this matter to, on seeing everything shown and referenced herein, effect a practical realization of the invention without necessarily coinciding in shape, size and materials used with the object represented herein, always maintaining its defining essence which must be reflected in the upcoming claims.

Claims (6)

1. A drawer closure safety device comprising catch means adapted to be fixedly secured to an item in which the drawer is arranged to slide and co-operating actuator means mounted on the drawer, said catch means being disposed inside a casing and having first and second triggering elements projecting through said casing for engagement by said actuator means, the second of said triggering elements being subordinated to the first of said triggering elements, said first triggering element comprising plate means pivotally mounted on said casing and resilient means acting to urge the drawer into its fully opened condition in response to an opening impulse and said second triggering element comprising a connecting rod pivotally mounted at one of its ends to said first triggering element and having guide means at its other end receivable in a track provided on the casing, said track delimiting the travel of the second triggering element; the arrangement being such that, when the drawer is in its fully closed condition, the second triggering element is restrained at one end of its travel by engagement with said actuator means.

2. A drawer closure safety device as claimed in claim 1 wherein said plate means of the first triggering element includes a crossarm on which a seating is pivotally mounted, said seating accommodating one end of a shaft which supports a compression spring serving as said resilient means.

3. A drawer closure safety device as claimed in claim 2 wherein said compression spring acts as an over-centre spring exerting a drawer-closing force against said plate means when the drawer is in a closed or nearly-closed condition and a drawer-opening force when the drawer is opened beyond a predetermined equilibrium position.

4. A drawer closure safety device as claimed in any preceding claim wherein said track includes a portion which is inclined with respect to the main section thereof, said inclined portion being provided at the end of the track which accommodates the guide means of the second triggering element when the drawer is in the fully closed condition.

5. A drawer closure safety device as claimed in any preceding claim wherein said plate means includes a notch in which said actuator means is receivable, one side of said notch being constituted by a crest which serves to push the actuator means in the drawer-opening direction in response to the force of said resilient means.

6. A drawer closure safety device substantially as described herein with reference to the drawings.