GB2224310A

GB2224310A - Self-closing door time control

Info

Publication number: GB2224310A
Application number: GB8823302A
Authority: GB
Inventors: Maurice George Dixon
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-10-04
Filing date: 1988-10-04
Publication date: 1990-05-02
Also published as: GB8823302D0

Abstract

When the self-closing door, e.g. a Fire Door, is opened against spring bias, door-mounted spindle C slides in pivoted stay A until spindle tooth B abuts stay peg T to rotate the spindle and cam disc D. This pivots lever H to depress plunger K of pneumatic timer L. Conic plunger end R is thus moved to part levers O to hold disc D. With door release, tooth B re-engages peg T to stop closure. The door closing force tends to turn spindle C making cam wedges E part levers O to urge cone N to return plunger K. After a pre-set time, timer air has escaped to enable plunger return, and levers O can ride over wedges E to allow tooth B to ride past peg T for door return. The timing device is assisted by the closer, and does not need external power. <IMAGE>

Description

SELF CLOSING DOOR TIME CONTROL This invention relates to a device for controlling the time a normally self-closing door may be retained open .

Precautions against damage to persons or property in the event of fire in buildings require that certain doors by self-closing. This feature is inconvenient to the user and consequently in practice many doors are held premanently open by wedges or similar means, to the detriment of the building's defence against fire. The invention herein described holds the door in an open position for a predetermind (short) time to alleviate inconvenience in use; after the predetermind time the Device allows the self-closing mechanism (not part of the Device) to close the door.

Furthermore, the door may be retained in any of several part-way open positions for the pre-set time. This allows the person traversing through the doorway to take a rest part-way when manipulating a waiking frame or wheelchair for example, unhindered by the pressure of the doorspring.

As the effectiveness of the Device is evident each time the door is opened, periodic checks are unnessary and doubt as to reliability is eliminated.

Timing devices in general have no great residual force and tend to be incapable of acting in opposition to a relatively powerful doorspring, either to keep the door open or to operate a trigger mechanism. Accordingly, the Device herein described uses the power of the doorspring to assist, rather than to oppose, the operation of the timer. In certain circumstances, increase of the power of the spring mechanism may be necessary, or even the fitting of a rurther spring, to overcome the increased work the doorspring is required to do.

The Device is in two parts, a stay member and a timer member.

One part is fixed to the door and the other is fixed to the door-frame at the head.

A specific example of the invention is described below with the aid of the following accompanying drawings. For clarity, the casing of the timer member is indicated in outline only, as though transparent, in the followiny drawings, which are in axonmetric projection: Figure 1 shows the Device fitted to a door and frame in the static position, as with the door closed.

Figure 2 shows the timer set, the door having been part-way opened and the spindle and tooth truned by the peg of stay.

Figure 3 shows the timer in mid-position, being aided in return by the action of wedges. This view is from the other side of the timer from Figures 1 and 2 and the timer would in actuality be hidden by the door, which is indicated by broken lines.

Referring to the drawings, the action of the Device is as follows:- As the door is opened, spindle C runs in the slot in stay A until tooth B encounters a peg T mounted thereon. Further opening of door causes the spindle to be turned in the direction of arrow G as shown in Figure 2, so that disc D, by its can shape, presses on lever H, turning it on fulcrum J and depressing the plunger K of timer L.

This causes the other, cone-shaped end N to act upon pincer levers 0 which pivot about fulcrums P, forcing them apart, so that their other ends Q are held together on disc D.

As tooth B slips past a peg T it returns to its static position by virtue of the action of balancing springs M.

The timer L is a commercially produced mechanism adapted to suit this Device. Its design is such that upon the plunger K being depressed it takes a pre-determind, adjustable, span of time to return to its original position, this being accomplished by control of escape of air in the cylinder of which the plunger is a part, against a piston R. Adjustment of the length of time is by a screw S.

The door would normally close on being released, by reason of door-springs fitted, but the closing action is inhibited by tooth B engaging with a peg T on the stay A. The force of the door-spring acting on tooth B via peg T however, tends to turn spindle C and thus disc D in the direction of arrow U.

This makes wedges E engage with ends Q of pincer levers 0, forcing them apart and applying pressure by their other ends on cone N. This assists the return or plunger K.

On the expiry of the pre-set time, plunger K returns to its static position, pincer levers 0 are enabled to ride fully up the wedges E so that tooth B can turn and slip past peg T and all such other pegs between it and the door 5 closed position. Thus the door closes, all parts of the Device returning to the static position shown in Figure 1.

In this manner the door can be opened to any position of several depending on the member of pegs T flitted on part A and will stay in position until the expiry of the pre-set time, when it will return to the closed position.

The particular application described here shows opening towards the viewer, hinged on the right hand side. The Device is capable of application for opposite hand be reversing tooth B on spindle C. Alternative other applications, such as mounting on the other side of the door can be achieved by inverting the timer member and/or reversing relative positions of stay and timer as regards their fixing to door or frame.

In the situation herein described, the door having been opened to one partially open position, it may be further opened to another position and at each stage the timer is re-set. A modiiication may be incorporated by which each peg T further out from the nearest the door frame may be wedge-shaped on the door side and spring-loaded so that tooth B can pass over it without operating the timer. In this way no mater in how many stages the door is opened, although the door will stay in the last position, the expiry ot the time set by the first peg will close the door. The Fire Authority would indicate whether the first or second of these alternatives are acceptable, also the duration of the pre-set time.

Tooth B may be fitted to spindle C by splines for adjustment and to enable it to be turned 1800 to temporarily disconnect the Device.

An alternative to the stay A with pegs T is a quadrant in which the rim is formed with cut-outs as with a cog wheel, but more widely spaced. This would allow the door to open past 900, when the timer part would temporarily pass the quadrant, the retaining action not taking effect until the door returns to the 90"position. Should the door need to be habitually retained open wider than 900on time control, the "quadrant" could be extended over a greater segment of the circle then 900as desired.

Claims

1. A Device for controlling the closing of sel-closiny door so that it may be retained open for a pre-set duration of time, this being achieved without batteries, mains electricity or any form of power requiring renewal, and in which the power inherent in the self-closing mechanism on the door, not being a part of this Device, assists the operation of it.

2. A controlling Device as in Clam 1 by means of which the door may be retained open part-way only in any of several positions for a pre-set time after which the self-closing mechanism closes the door.

3. A controlling Device as in Claim 2 in which each time the door is opended further from one part-way open position to another, the time the door is retained open is further extended so that at each station the time available before closure is the same ie that pre-set.

4. A controlling Device as in Claim 2 in which alternatively to Claim 3, each time the door is opened further from one station to another, no more time is available beyond the first setting of the timer.

5. A controlling Device as in any preceding Claim wherein its action may be temporarily discontinued by simple displacement of one part which is easily accessible,

6. A controlling Device as in Claim 5 in which the displacement and repositioning of the disconnecting part is available for adjustment.

7. A controlling Device as in any preceding Claim wherein its effectiveness is proved eached time the door is opened.

8. A controlling Device as in any preceding Claim whereby the door may be opened beyond 90and either be retained in that position for the pre-set time, or be allowed to return to the 900position on hand release of the door, when the initially pre-set time of remaining would control its closing.

9. A controlling Device for a self-closing door substantially as described herein with reference to drawings Figures 1,2 and 3 herewith.

Amendments to the claims have been filed as follows "A Device for attachment to a self-closing door, separate from the closing mechanism, for controlling the time during which the door may be retained either fully open or in any of several part-way open positions, and which uses the power of the self-closing mechanism to assist the time delay component merely inhibiting the operation of the closer; this being achieved without batteries, mains electrically or any form of poer requiring renewal."