GB2130293A - Door locking mechanism - Google Patents

Abstract

When door 10 is closed, a button 34 on the leading edge 11 is depressed, e.g. by abutment against a door jamb 49 or against another door or other solid object so that sliders 31, 32 are held together and a spring-biassed bolt 13 can move through slots 44 in said sliders 31, 32 to automatically lock the door 10. When door 10 is opened by bolt release means of any known type (not shown), release of the button 34 allows the sliders to be pushed apart, e.g. by leaf spring 40, so that the bolt 13 is firmly engaged by slots 44 and held in its release position. Serrations on the bolt may assist secure engagement. A mechanism having a catch release button on the leading edge of the door is suitable for fitment to doors which open only in one direction, doors which open in both direction and sliding doors. The mechanism is described in the context of emergency exit doors and has two sliding bolts. <IMAGE>

Description

SPECIFICATION Door locking mechanism This invention relates to a door locking mechanism particularly, but not exclusively, of the type incorporating a panic bolt mechanism.

In the specification of our prior Patent No.

20395888 we have described a door lock and panic bolt mechanism comprising a vertical box section channel casing mounted on the door and housing two vertical sliding bolts each formed in two parts, and an actuating mechanism incorporating a pair of slotted plates of U shape to which the ends of the bolts are respectively secured to allow the bolts to rise and fall, pegs on the channel casing extending into slots in the plates, a T member engaging pins projecting from the slotted plates, a square bore of the T member receiving a square spindle associated with a cam and a lever operated by a crush bar to engage and rotate the cam about the spindle to release the bolts.

In this arrangement pressure on the operating or crush bar actuates a lever to rotate the cam and release the bolts. Each bolt is retained in the retracted or release condition by catch means engaging a single notch in a sleeve on the respective bolt. Depression of a button on the face of the door, usually by engagement with a door jamb or lintel when the door is closed, causes the respective catch means to be released so that the respective bolt again projects from the door and thus, when adjacent the door jamb or lintel, locks the door relative to the door frame. In this way the door in question is automatically locked when it is closed.

However, the aforesaid automatic locking mechanism is only applicable to doors which open in one direction, that is to say inwardly or outwardly, as it is essential to have a door jamb or lintel abutting one face of the door when closed.

Moreover, as there is only a single notch into which the respective catch means may engage to hold the bolts in the retracted condition, if the crush bar is not fully depressed (for example if it is pushed by a weak person such as a child) the catch means will probably fail to engage the notch and although the door will be opened the bolts will not be retracted. This is obviously unsatisfactory as the projecting bolt at the bottom may scrape the floor surface and, with projecting bolts, the door cannot easily be closed again.

An object of the present invention is to provide a door locking mechanism generally similar to that described above but applicable to all types of doors, that is to say swingable doors which open inwardly, or outwardly, or both inwardly and outwardly, and also sliding doors.

A further object is to provide a more effec tive catch means and catch release mecha nism than hitherto whereby the bolts will be held in the retracted condition whenever the door is opened, irrespective of whether the release mechanism is weakly actuated.

Pursuant hereto, the present invention pro vides a door locking mechanism comprising a sliding bolt movable between a locking posi tion in which it projects from a door surface and a release position in which it is retracted, bolt release means operative to move the bolt to its release position and catch means which serves to hold the bolt in its release position but may be released to return the bolt to its locking position, characterised in that the catch means is released by depression of a retractable projecting member located on the leading edge of the door.

Advantageously, the catch means comprises co-operative sliders having respective aper tures through which the bolt extends, the sliders being spring-biassed in opposing direc tions so as to engage the bolt between their respective aperture edges when the projecting member is released, that is to say when the door is open, but being pushed together to permit movement of the bolt when the pro jecting member is depressed.

Preferably, a plurality of notches or serra tions are provided around the edge of at least one slider aperture and/or on the region of the bolt extending therethrough to facilitate secure engagement therebetween when the projecting member is released.

The invention will be described further, by way of example, with reference to the accom panying drawings, in which: Figure 1 is a front view of a closed door fitted with a preferred embodiment of the locking mechanism of the invention; Figure 2 is an enlarged sectional detail iliustrating the main central part of the locking mechanism shown in Fig. 1; Figure 3 is an enlarged sectional plan illus trating the same part of the locking mecha nism as in Fig. 2 with the door in the closed position; and Figure 4 is a similar view with the door in the open position.

As illustrated, a preferred practical embodi ment of the door locking mechanism of the invention is mounted adjacent the leading edge 11 of a door 10 within a box section I housing 1 2 which extends vertically of the door 10. Alternatively, of course, the mecha nism may be located in a recess (not shown) formed in the door 1 0. The mechanism com prises a pair of bolts 13, 14, the first bolt 1 3 extending vertically adjacent the upper half of the door 10 and the second bolt 14 extending vertically slightly offset from the first bolt 1 3 adjacent the lower half of the door 10.At their respective ends nearest the middle of the door 10, these bolts 13, 1 4 extend through respective upper and lower transverse walls 15, 1 6 which are joined by a vertical web 17.

The bolts 13, 14 are connected to respective parallel vertical channel section members 18, 19 which in turn are connected to respective rods 20, 21 which project through the opposing transverse walls 16, 1 5. The channel section members 18, 1 9 are biassed away from the walls 16, 1 5 respectively by coils springs 22, 23.

The channel section members 18, 1 9 are each mounted on two pegs which are attached to the web 1 7 and extend through respective elongate slots 25 in the members 18, 19. The members 18, 1 9 are connected by the slotted cross-piece of a T-shaped member 26 mounted pivotally on pegs 27, 28 on the respective members 18, 1 9. Fig. 2 shows the mechanism with the bolts 13, 14 in locking position where the ends thereof project from the top and bottom of the door 10 respectively.It will be appreciated that when the T-shaped member 26 is pivoted clockwise the member 18 and the bolt 1 3 will move downwards against the action of the spring 22 and the member 1 9 and the bolt 1 4 will move upwards against the action of the spring 21 so that the bolts are released and the door 10 can open. In the present example, and as described in our earlier British Patent No.

2039588B, the aforesaid pivoting of the Tshaped member 26 is accomplished by bolt release means in the form of a panic bolt mechanism comprising a transverse crush bar 37 which when pressed down actuates a lever 38 to rotate a cam 39 having a spindle (not shown) of square cross section which engages and moves the T-shaped member.

The present invention lies in the provision of new and effective catch means and catch release means. In the illustrated embodiment, the bolt 13 is provided with a series of serrations in a region 33 a short distance above its passage through the wall 1 5. A pair of co-operative sliders 31, 32, each of Lshaped cross-section, and superimposed by a plate 30, are arranged between retractable projecting member in the form of a button 34 which projects through a rentention plug 35 on the leading edge 11 of the door 10 and a plug 36 in the opposite side of the box section housing 1 2. The aforementioned parts are all supported on an additional cross wall 45. The bolt 1 3 including a part of the serrated region 33 extends through respective slots in the sliders 31, 32 and the plate 30.

As shown in Figs. 3 and 4, the sliders 31, 32 are biassed apart by a doubly curved leaf spring 40 secured by a bolt 41 passing through the sliders 31, 32 and the plate 30 and by respective nuts 42, 43. The slot 44 in the slider 31 which is connected to the button 34 is key-hole shaped and the bolt 1 3 extends through the enlarged region thereof when the sliders 31, 32 are held together by the button 34 being pushed into the leading edge 11 of the door 10.

Operation of the above-described locking mechanism will readily be appreciated.

When the door 10 is closed, as shown in Fig. 3, the button 34 is depressed by abutment against a door jamb 49 so the sliders 31, 32 are held together and the bolt 13 can move freely through the enlarged portion of the slot 44. As long as the crush bar 37 is not depressed, the bolt 1 3 is biassed upwardly by the spring 22 to project from the top of the door and engage an aperture in the door lintel so as to lock the door. Similarly the bolt 14 is biassed downwardly by the spring 23 to lock the bottom of the door.

When the crush bar 37 is depressed, the lever 38 actuates the cam 39 to pivot the Tshaped member 26 to move the channel section members 18, 1 9 vertically downwards and upwards respectively to release the said bolts 1 3 and 14. As soon as the door 10 is actually opened i.e. swung away from the door jamb 49, as shown in Fig. 4 the button 34 is released from the door jamb 49 and projects from the leading edge 11 of the door 10. The sliders 31, 32 are thus pushed apart by the leaf spring 40 which is somewhat released from tension, but only the slider 31 attached to the button 34 can move. The serrated region 33 of the bolt 1 3 is thus trapped in the narrow end of the slot 44 so that the bolts are held firmly in the release position as long as the door 10 is open.

As soon as the door 10 is closed, the button 34 which of course is radiused, is depressed against the door jamb 49 thereby pushing the slider 31 back towards the slider 32 and releasing the bolt 1 3 so that under the action of the springs 22, 23, the bolts 1 3, 14 move immediately to lock the door in the closed position. Accordingly, the door is automatically locked in position whenever it is closed and the button 34 on the leading edge 11 is depressed.

It is advantageous to have a button or other retractable projecting member which forms part of the catch means/catch release means for the bolts at the leading edge 11 of the door because the door can then open inwardly and outwardly or even be formed as a sliding door. Also the button can be depressed by abutment with a door jamb or with another door of a pair of doors. In previously known mechanisms with the button on the face of the door 9 part of the door frame must abut the face of the door when closed so these are only suitable for doors which open in one direction (i.e. through 90 ).

The preferred form of the catch means, namely spring-biassed sliders interacting with a serrated region on one bolt is particularly effective in holding the bolts in the release position when the door is open and automatically locking the door on closure. Provision of a plurality of serrations ensures that the bolts are firmly held in retracted position, even though they may not be fully retracted, as the sliders can effectively engage any part of the serrated region 33. This means that even a weak force applied to the bar 37 will cause the bolts to be held retracted as long as the door is open.

It should, of course, be appreciated that the foregoing is illustrative and not limitative of the scope of the invention and variations are possible. In particular, the serrated region on the bolt may be replaced by a notched region or formed by a threaded region, or serrations or notches may be provided on the edges of the slider slots instead of or in addition to those on the bolt itself. Indeed, the serrations/notches may be dispensed with altogether, but the catch means/catch release means is not then so effective or robust because the sliders do not hold the bolt(s) so securely in the release position. Moreover, the slots need not be key-hole shaped and the bolt may simply be held between edges of cooperating elongate slots of two sliders.

Furthermore, a door to which the proposed locking mechanism is fitted may still open only inwardly or outwardly and its face may abut a part of the frame when closed. In such instance it is possible that the button on the leading edge of the door may be actuated by means on the face of the door abutting the door frame, for example by way of a lever mechanism.

The main advantage of the proposed mechanism is that it can be fitted successfully to any type of door and numerous variations are not required. In particular if the mechanism is to be fitted to the other side or face of the door, the plugs 36 and 35 may be interchanged so that the button 34 is still on the leading edge. The actual bolt actuating and release mechanisms may differ from those described and illustrated. Indeed any such mechanism may be used with any number of bolts.

Claims (6)

1. A door locking mechanism comprising a sliding bolt movable between a locking position in which it projects from a door surface and a release position in which it is retracted, bolt release means operative to move the bolt to its release position and catch means which serves to hold the bolt in its release position but may be released to return the bolt to its locking position, characterised in that the catch means is released by depression of a retractable projecting member located on the leading edge of the door.

2. A door locking mechanism as claimed in claim 1 wherein the catch means comprises co-operative sliders having respective apertures through which the bolt extends, the sliders being spring-biassed in opposing directions so as to engage the bolt between their respective aperture edges when the projecting member is released, that is to say when the door is open, but being pushed together to permit movement of the bolt when the projecting member is depressed.

3. A door locking mechanism as claimed in claim 2 wherein a plurality of notches or serrations are provided around the edge of at least one slider aperture and/or on the region of the bolt extending therethrough to facilitate secure engagement therebetween when the projecting member is released.

4. A door locking mechanism as claimed in claim 1, 2 or 3 wherein the bolt release means comprises a panic bolt mechanism actuated by pressure on a transverse operating or crush bar.

5. A door locking mechanism as claimed in any preceding claim wherein the bolt is spring biassed towards its locking position.

6. A door locking mechanism substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.