Field of the invention

This invention relates to a quick-release mecha¬ nism for doors or similar closure members, primarily for emergency opening, adapted to actuate a lock on the door.

Background of the invention

In the planning of evacuation routes, it is a requirement that the doors along the route open out¬ wardly in the direction of evacuation, and that the doors can be opened without key or other tool. To ensure quick and reliable opening, the doors therefore are provided with special emergency opening devices. One important type of such emergency opening devices is the so-called panic bolt which consists of a hori- sontally mounted bar which, when pressed in, directly actuates the lock and retracts the locking bolt and the latch bolt therein, whereby the door is opened. However, emergency openers of this type suffer from a number of shortcomings. For example, special locks are required in which the panic bolt bar forms a part. Furthermore, there is a direct mechanical coupling between the panic bolt and the latch and locking bolts of the lock. This means that the panic bolt may jam if the lock mechanism is subjected to load, for example by a panicky crowd jostling against the door. Summary of the invention

The present invention aims an obviating the above- mentioned shortcomings and at providing a quick-release mechanism whose release pressure is independent of the load exerted on the door and which is readily connectible to existing locks. According to the main characteristic features of the invention, this is achieved in that the mechanism comprises two indivi¬ dually spring-loaded force-transmitting means, one

of which is connected with the ^" lock and actuated by a first spring striving to move said means into a lock-opening position, while the other means, via a second spring, strives to open the door, and that there is mounted between the said two means a blocking device which, upon manual actuation, releases said first means to open the lock, at the same time as also said second means is released to swing the door open. Brief description of the accompanying drawings In the drawings FIG 1 is a schematic horizontal view illustrating a quick-release mechanism according to the invention mounted on a door leaf provided with a lock and shown in closed position;

FIG 2 is a similar view showing the same mechanism during release of the door lock; FIG 3 is a similar view showing the opening of the door leaf following the release of the lock;

FIG 4 is an exploded view illustrating a further embodiment of the invention; and FIG 5 is an enlarged perspective view illustrating a detail of the embodiment according to Fig. 4.

Detailed description of preferred embodiments of the invention

Figs. 1-3 illustrate a door leaf 1 on which the quick-release mechanism according to the invention is mounted, and the lock 2 associated with the door. The release mechanism proper is here in the form of a one-piece base plate 21 provided with four lugs or brackets 8,8' ;9,9* with throughholes. A rod 3 is displaceably mounted in the holes of the brackets 8,8', and a second rod 4 is displaceably mounted in the holes of the brackets 9,9*. The ends of the rods 3, 4 which extend into the space formed between the

bracket pairs 8 and 9 are hingedly interconnected via a toggle mechanism 7 comprising two links 14 and 15 hingedly interconnected by a pin 13. A release arm or trigger 20 is rigidly connected with one link 15. Mounted between the brackets 9 and 9* is a pressure spring 6 acting between a shoulder 12 which is fixedly mounted on the rod 4, and the bracket 9 ¹ , such that the spring 6 always strives to urge the rod 4 to the left in the drawing. A pressure spring 5 is similarly mounted between the bracket 8' and a shoulder 11 fixedly mounted on the rod 3, such that the latter is spring- loaded in the same direction as the rod 4. At its end remote from the toggle mechanism 7, the rod 4 in this case is provided with a roller 10 engaging the door frame, while the rod 3 at its end remote from the toggle mechanism 7 is hingedly connected with a flat iron 17 or the like connected with the lock 2. Furthermore, Figs. 1-3 show an abutment 16 against which the links of the toggle mechanism abut in an initial position. The abutment 16 is, in this case, slightly wedge-shaped or sloping. The two side members of the door frame are designated 18, 19 in the drawing. Function of the invention Fig. 1 illustrates the release mechanism in a tensioned condition in which the door leaf is closed and the latch bolt 2' of the lock 2 engages the frame side member 19. In this condition, the two links 14 and 15 are arranged such that they are in contact with the abutment 16 in a position near an unstable point of equilibrium in which the three hinge points of the toggle mechanism are aligned relative to one another. The spring 6 urges the rod 4 with the roller 10 against the frame side member 18. Since the toggle mechanism 7 in the position shown in Fig. 1 forms a rigid connection between the rods 3 and 4, the rod 3 cannot be displaced by the spring 5. As shown in

Fig. 2, the two links 14, 15 of the toggle mechanism, upon actuation of the trigger 2, will be swung out and pass the unstable point of equilibrium, whereby the rod 3 is released. Under the action of the spring 5, the rod 3 is now moved to the left in the drawing, whereby the latch bolt 2' is released from the frame side member 19 by pulling or turning of the operating member of the lock 2. In this phase, however, the rod 4 is still locked by the frame side member 18. When the lock 2 then has been completely released from the frame side member 19, the door leaf 1 will swing out under the action of the force exerted by the spring 6 and transmitted by the rod 4 and the roller 10 from the door leaf to the frame side member. The rod 4 is displaced toward the frame side member

18. Since the rod 3 is already in its maximally extended position, the toggle mechanism 7 will again be straigh¬ tened out. The toggle mechanism is slightly spring- loaded toward the abutment 16 and will therefore again pass the unstable point of equilibrium and approach the abutment 16. The entire mechanical linkage formed by the rods 3, 4 and the links 14, 15 has now returned into the position shown in Fig. 1, except that the entire system has been moved toward the frame side member 18. When the door is closed again, the frame side member 18 will urge the rod back in the direction toward the lock 2 against the action of the spring 6. Since the toggle mechanism engages the base plate 21 proper, it constitutes a rigid force-transmitting mechanism, implying that the movement of the rod 4 is directly transmitted to the rod 3. During the common movement of the rods 3 and 4, the links 14, 15 of the toggle mechanism again slide up on the abutment 16 and are straightened out into their initial po- sition near the unstable point of equilibrium. When the rod 3 is back in its initial position, the lock 2 can again engage the frame side member 19, and when

the door has been completely closed, the entire mechanism has returned into the initial position shown in Fig. 1 and is ready to be used again. It should be noted in the context that, in spite of the relatively power- ful spring action of the springs 5 and 6, no appreciable force is required to close the door again against the action of these springs because the leverage of the door leaf is many times greater than the leverage between the roller 10 and the door hinges. Advantages of the invention

With the quick-release mechanism according to the invention, a door or the like can be quickly opened in a reliable manner. The force required to make the toggle mechanism go from the initial position past the unstable point of equilibrium to releasing posi¬ tion is very little since the toggle mechanism is supported by the abutment 16 in a position very close to the unstable point of equilibrium. The release force is, in principle, not greater than the slight spring load actuating the toggle mechanism against the abutment, and the inherent friction of the links comprised by the toggle mechanism. As soon as the toggle mechanism has reached the position remote from the abutment, the door will be quickly opened under the action of the springs 5 and 6. At the same time, the release movement travels but a very short distance, which makes for considerable liberty in selecting and designing the trigger. For example, the trigger may be a relatively large plate which is provided with levers and which, by means of its leverage, can activate the toggle mechanism. Such a design is ad¬ vantageous for emergency opening purposes when it is especially important that the door release mechanism is easy to find and easy to operate. Furthermore, the release of the mechanism is not dependent on the load to which the latch of the door lock at the moment is subjected since the door opening movements are

effected by the springs 5 and 6, not by the toggle mechanism proper. As a result, the door opens easily even if the door, and thus the latch, are under a heavy load. Tests have shown that a horizontally arranged door loaded with weights of up to 200 kg in the vicinity of the door lock can be opened without difficulty by a light touch upon the trigger 20. Furthermore, the door can be readily mounted on existing doors and can be used, without difficulty and without modifica- tions, on both left hung and right hung doors. Adaptation to different door widths is readily made solely be varying the length of the flat iron 17. In addition, the mechanism can be connected to the existing lock of the door. It should be pointed out in the context that the mechanism, because of its low release force and the short release movement, can easily be controlled by remote control means, either mechanically or electro¬ mechanically, although remote control by electromechani¬ cal means is preferred for other uses than precisely emergency opening.

Figs. 4 and 5 illustrate a development in which the two links 14', 15' of the toggle mechanism are mounted in a casing 22 which accommodates also the pressure springs 5", 6' for the two rods 3', 4'. In this embodiment, the toggle mechanism is released by means of a relatively wide pressure plate 23 which extends across substantially the entire width of the door leaf 1' and may be manufactured, in actual practice, in the form of an extruded aluminium or plastic section. On the inner side of the plate 23 there is formed, approximately halfway between the upper and lower edges of the plate, a longitudinal ridge 24 which engages the outer side of the casing 22 and about which the plate can tilt or swing relative to the casing. More particularly, the upper edge portion

25 of the pressure plate will be swung inwards against the door leaf if pressure is applied to the outer

side of the plate in the area above the ridge 24, while the lower edge portion 26 of the plate is swung inwards if pressure is applied to the half of the plate below said ridge. The pressure plate 23 cooperates with a double-acting trigger mechanism comprising an upper contact member 27 in the form of a pivotally mounted angle piece and a lower contact member 28 in the form of a roller rotatably mounted at the lower part of a vertically movable pin 29 located in the aera below the toggle links 14', 15'. A hook 31 serving as a dog is connected with the pin 29 via a cross-pin 30, the upper hook-shaped portion of said hook engaging the essentially horisontal leg of the angle piece 27. In conjunction with the block or abutment 32 (corresponding to the abutment 16 in the embodiment according to Figs. 1-3) with which the toggle links 14', 15' are in engagement, a magnet 33 is provided which continuously strives to maintain the links in distinct engagement with the abutment in an initial position immediately below the unstable point of equi¬ librium. When the upper edge 25 of the pressure plate 23 is tilted inwardly toward the door leaf about the ridge 24 by manual actuation of the plate, for example by a hand, an arm or some other part of the body, the said upper edge will contact the angle piece 27 and cause it to swing counterclockwise as seen in the drawing. As a result, the dog 32 and the pin 29 connected therewith via the cross-pin 30 are caused to move in an upward direction, the pin 29 forcing the links 14', 15* to swing up and past the unstable point of equilibrium while surmounting the retaining force exerted by the magnet 33. In other words, the pressure springs 5', 6' are released in the manner described above, while opening the lock 2 via the rod 3' and swinging the door leaf outwards by means of the rod 4' (which in this case has no contact roller and includes a threaded portion permitting adjustment

of the length of the rod). If, instead, the manual pressure on the plate 23 is applied to the lower half of the plate, the lower edge portion 26 will be swung inwards and directly act upon the pin 29 via the fric- tion-reducing roller 28, such that the pin, in the manner described above, lifts the toggle links from the initial position into the releasing position. Conceivable modifications of the invention

It will be appreciated that the invention can be modified in many different ways within the scope of the appended claims. Thus, the mechanism according to the invention may be used also for closure elements other than doors, for example hatches, gates or windows. The mechanism may also be used for other purposes than emergency opening, for example for the remote control of hatches in silos etc. In its preferred embodiment as illustrated in the drawings, the mechanism is shown to be oriented at right angles to the pivot axis of the door, but it may of course be oriented optionally on the door as long as the basic function is maintained. For example, the rods can be replaced by optional linkages transferring the force from the lock to the toggle mechanism and from the toggle mecha¬ nism to the door frame. Naturally, the roller 10 need not be located at the same level as the lock 2. The toggle mechanism itself can be designed in many different ways. For example, it may consist of a one-piece leaf spring of such a shape that, in the unloaded position, it rests against the abutment, whereby the toggle mechanism will automatically swing past the point of equilibrium towards the abutment when the mechanism is straightened out. Another possible construction is a toggle mechanism in the form of a pin pivotally mounted on each force-transmitting means, said pin carrying a helical spring which also may be slightly pretensioned such that it always strives to move from the unstable point of equilibrium against the abutment.

Naturally, the base plate need not be made in one piece, nor is it necessary to have precisely four lugs or brackets for guiding the rods 3, 4, and the number of lugs may be optionally selected and designed accordingly. Moreover, the blocking device can be in the form of a catch or the like holding the force- transmitting means 5 associated with the lock, in which case the force-transmitting means 4 need not be connected either with the catch or the force-trans- mitting means 5.