EP0318496B1

EP0318496B1 - Arrangement for a spring fracture safety device for an overhead sliding door

Info

Publication number: EP0318496B1
Application number: EP87905307A
Authority: EP
Inventors: Fred Bengtsson
Original assignee: Crawford Door Production AB
Current assignee: Crawford Door Production AB
Priority date: 1986-08-07
Filing date: 1987-08-05
Publication date: 1991-12-27
Anticipated expiration: 2007-08-05
Also published as: DK187088A; NO881485D0; ATE70882T1; NO166666C; NO881485L; EP0318496A1; AU7806287A; FI890355A0; NO166666B; SE8603341D0; FI890355A; SE457814B; SE8603341L; WO1988001002A1; DE3775566D1; DK187088D0

Abstract

An arrangement for a spring fracture safety device intended for a closing element for an overhead sliding door or similar capable of being moved between a raised and a lowered end position, which can be attached to a door actuating spring (1) and is controlled by tracks extending along the intended path of movement of the door, continuous guide rollers or similar control devices. The spring fracture safety device functions efficiently and reliably, irrespective of where along the length of the spring fracture occurs. One free end (1A) of the door actuation spring is capable of being attached via a movement transfer device (9) to a release device (7) for a door braking element (8) interacting with a number of said guide rollers, etc., which braking element can be caused to move between a position (I) in which it is ready for release and a braking position, in which positions the element (8) is respectively kept withdrawn, so that said guide rollers are able to pass freely along the tracks in question, and is caused to project, so as to produce a braking effect by interaction with a door guide roller.

Description

The present invention relates to a spring fracture safety device intended for use in an overhead sliding door or similar closing element which is arranged to move between a raised and a lowered end position and which is attached to a helical door-actuating spring and controlled by guide rollers or similar control means running in tracks extending along the intended path of movement of the door, the helical door-actuating spring being wound about a support to which it is secured by means of a clamp.
One prior-art device of the kind referred to is disclosed in EP-A-0 151 427. In this device, when the spring fractures, its end releases a spring-loaded detent which moves into braking engagement with a sprocket wheel, retarding the movement of the door. A tension detector means is provided to sense the spring tension in order to indicate the occurrence of a spring fracture.
In contrast to this prior-art structure, the present invention provides means to ensure that without any use of fracture sensing means, in the event of fracture of the spring arranged to balance the overhead sliding door, the door is nonetheless positively arrested in its then position, thus obviating all risks for accidents. The principal object of the present invention thus is to provide a device of the kind indicated above which is arranged to function efficiently and reliably in the event of spring fracture, irrespective of where along the length of the spring that said fracture occurs.
This object is achieved by means of an arrangement in accordance with the present invention, which is characterized in
that one free end part of the spring forms a projecting section arranged to cooperate with a stop serving to support the spring end part at a point spaced from the outer extremity of said spring end part during normal door operation conditions,
that a movement transfer device, such as a cable, is secured at its upper end to the outer extremity of the spring end part and at its opposite end to a trigger-off mechanism,
that a door-arresting element which is arranged to cooperate with the guide rollers inside said tracks, is connected to the trigger-off mechanism and arranged in response to actuation by the trigger-off mechanism, to be displaced from a retracted position, wherein it is ready for release and wherein said guide rollers are allowed to travel freely inside their associated track, to a door-arresting position, wherein the element projects into the path of movement of said rollers, thus arresting further door movement,
that the trigger-off mechanism is arranged to hold the door-arresting element in the ready-for-release position thereof when the spring end part is supported by the stop and the spring is held under tension but in the event of a fracture of the spring, resulting in disengagement of the spring end part from its support with consequential stretching of the cable, to trigger-off the door-arresting element, thus causing said element to assume its door-arresting position, wherein it projects into the associated track and thus blocks the path of movement of said rollers therein.
One non-limitative embodiment of the invention will be described in the following with reference to the accompanying drawings, in which;

Fig. 1 illustrates the device in accordance with the invention applied to one of the side tracks for an overhead sliding door in the so-called "door-arresting position";
Fig. 2 illustrates the door-arresting mechanism in the door-arresting position with a door control roller in restrained position;
Fig. 3 illustrates the door-spring part of the device in the door-arresting position, which is triggered off by spring fracture;
Fig. 4 illustrates the same spring in the position in which it is ready for release;
Fig. 5 is a perspective view of a trigger-off device which is a constituent part of the device and which is showed in its ready-for-release position; and
Fig. 6 illustrates the trigger-off mechanism in non-assembled position and in a partially sectioned view.

Fig. 1 illustrates the device in accordance with the invention applied to one of the side tracks of an overhead sliding door 6. A helically wound door-actuation spring 1 is supported by a number of brackets 3 which may be secured at the upper part of a door opening. The spring 1 is connected to the door panel 6 or similar closing element in a manner known in the art and the door panel 6 is provided with a number of guide rollers 5 or equivalent guide means running in guide tracks 4 extending along the lateral edges of the door opening. Via a movement transfer means 9, for instance in the form of a cable 9, one free end 1A of the spring 1 is connected to a mechanism 7 arranged to trigger off a door-arresting element 8 in interacting relationship with the guide rollers 5.
The cable 9 is preferably accommodated in a protected position inside a cable protector tube 10 extending between the free spring end 1A and the door-arresting element 8. End 9A of the cable 9 is attached to a sleeve 11 which is mounted over the spring end 1A whereas the opposite cable end 9B is attached to the trigger-off mechanism 7 in a manner and for a purpose to be described more in detail in the following.
The sleeve 11 is formed with a hole 12 at its outer end and the cable end 9A is passed through said sleeve hole 12 and then bent over and attached to the cable 9 by means of a suitable fastener 13 in order to be securely attached to the cable. The spring end 1A preferably extends straight outwards from the helically wound spring 1, i.e. more or less tangentially with respect to the spring windings, so as to be able to cooperate with a stop 14 on the spring bracket 3. The stop 14 serves to support the spring end 1A when the spring 1 is held under tension during normal operation of the door and its spring 1. A recess 15, having a configuration matching that of the spring end 1A, is formed in the stop 14 for the purpose of receiving and securely retaining the spring end 1A therein, thus preventing the spring 1 from spinning during operation and/or,when placed under tension.
The spring 1 is wound about a sleeve-shaped support 16 which extends around and encloses a shaft 19. The shaft 19 is attached in any convenient manner as known in the art to a cable drum 18 connected to a door operating cable 17, and to said shaft is secured the spring end opposite to that of spring end 1A. In order to prevent the spring end 1A from slipping off the sleeve-shaped spring support 16 it is secured to the latter by means of a clamp 20, which is fastened in a suitable manner, e.g. by means of screws.
The door-arresting element 8 is arranged for movement between Position I, shown in Fig. 5, in which it is ready to be released by means of the trigger-off mechanism 7, and a door-arresting position, Position II, illustrated in Figs. 1 and 2. In Position I, the spring-fracture safety device is in a readiness position in which the guide rollers 5 are able to move freely inside their associated track 4 during normal door-raising and lowering movements. In the event of fracture of the spring 1, on the other hand, the spring-fracture safety device will be released automatically, as will be explained in closer detail in the following, whereby the door-arresting element 8, in response to actuation by the trigger-off mechanism 7, will project into the path of movement 22 of a guide roller 5, for example into the internal space 4A of the track defined by the transversely opposite track surfaces 4B, on either side of the running surface on the guide roller. The track surfaces are arranged to cooperate with the guide roller running surfaces in order to stop the movement of the door.
In accordance with the embodiment shown, the door-arresting element 8 consists of a brake block 23 which is provided with a number of stop projections 24 projecting in the same direction away from the block 23. The brake block 23 is arranged to be moved from Position I in which it is ready to be released in response to actuation from a number of release springs 25, the latter in accordance with the embodiment shown being made from an arcuately bent, resilient material, or in response to spring-actuation in some other way, to ensure that the block 23 is triggered off to its active position, when necessary. The triggering-off of the block 23 is prevented in Position I by means of the trigger-off mechanism 7 which may consists of a pin one end 7A of which is attached to the cable end 9B which, as indicated in the aforegoing is remote from the cable end 9A attached to the spring end 1A. The opposite end 7B of the mechanism 7 is received in an aperture 26 formed in a tongue-shaped attachment 27 which projects in a direction away from the bottom 28A of a trough-shaped casing 28 housing the door-arresting element 8 in its internal cavity 29. As illustrated in Figs. 5 and 6 the attachment tongue 27 projects through a matching reception aperture 30 formed in the brake block 23. When the cable 9 is pulled in the direction of arrow 31 (Fig. 5), the associated springs 25 are free to push the brake block 23 outwards, in the direction of arrow 32, which will occur precisely at the same moment as the fracture occurs in the spring 1, owing to the interconnection in accordance with the invention of components 1A, 9, 9A and 11.
The springs 25 may be arranged for contact with respectively the bottom 28A of the casing and with the rear surface 23A of the brake block. They are provided with guide pins 33 projecting at right angles, for example, from the central part 25A of the spring and thus also from the bottom 28A of the casing so as to project into matching holes 34 in the brake blocks 23.
The casing 28 has fastening means 35 for attachment of the casing 28, e.g. to the exterior or other surface of the door guide track 4, as clearly shown in Figs. 1 and 2. In addition, it is formed with an elongated opening 36 in one of its sides, through which the cable 9 may be inserted to be secured to the attachment 27. The springs 25 are acommodated in a space 28B formed between the bottom 28A of the casing and the brake block, whilst the brake block 23 and its stop projections 24 are fully retracted inside a space 28D defined by an opening edge 28C.
The stop projections 24 are formed with a notch 37 for accommodation therein of a part of the associated guide roller, so as to function as a support for said guide roller 5 and preferably also for a swinging roller holder 38 attached to the door element 6 as will be described in more detail below.
The roller holder 38 consists of two spaced-apart swinging arms 39, 40 which are attached at one end 39A, 40A to a swinging axle 42 accommodated in a bearing 41 attached to the door panel 6, so as to be permitted to be pivoted about the bearing 41. At the opposite ends 39B,40B of the swinging arms a tube 43 is securely attached to the arms 39, 40, and a mounting shaft 44 for a door guide roller 5 is accommodated by said tube 43, as illustrated in Fig. 2. The swinging arms 39, 40 are attached by means of bolted connections 45 to a mounting plate 46, which is secured to the inner face 6A of the door by means of screws 47, and which comprises two flanges 48, 49 projecting at right angles from the door panel 6, one for each arm 39, 40. The bolts 45 are accommodated in curved openings 50 in the flanges and in holes 51 which extend through the swinging arms 39, 40. A suitable mounting component 52, which is received in an adjacent section 6¹ of the door panel and which is attached to the shaft 42 by means of a tongue 53 containing a hole, forms a link between two sections 6¹, 6² of the door panel which are thus hingedly interconnected.
In the event of the fracture of the spring 1 the straight spring end 1A leaves the stop 14 and rotates towards the clamp 20 in the direction of the arrow 54, as illustrated in Figs. 3 and 4. The cable 9 is pulled in the direction of the arrow 31 and causes the trigger-off pin 7 to be withdrawn from the hole 26 in the attachment 27, thus releasing the brake block 23 which can move outwards under spring pressure in the direction of the arrow 32. The stop projections 24 are thus caused to project through appropriate holes 55 in the wall 4D of the track and to adopt a position obstructing the normal path of movement of the guide rollers. When a guide roller 5 reaches a stop projection 24, a part of the roller 5 will be engaged in the support notch 37, and the tube 43 conveniently will abut against a nose-shaped part 56 of the associated stop projection 24. As a result, the previously free falling movement of the door panel 6 towards the ground will be arrested. The lower part 24A of the associated stop projection 24 comes into contact with the lower edge 57 of the through-hole 55. In the presence of a swinging roller holder 38 the roller 5 and the door panel 6 will move relative to one another in the vertical sense, whereby the door panel 6 will be forced to move in the direction of the arrow 58 towards an attachment profile 59 secured to the track 4 and its seal 61 supported by a profile section 60, once the bolted connection 45 has yielded and has permitted the rotational movement of the swinging arms 39, 40 in the direction of the arrow 62 about the hinge connection 40,42. Efficient arresting of the movement of the door panel 6 is achieved in this way owing to the present invention.
The safety device can be re-used after replacement of the broken spring 1, once the constituent parts have been repositioned.
The invention is not restricted to the illustrative embodiment described above and illustrated in the drawings, but may be modified within the scope of the appended claims without departing from the idea of the invention.

Claims

1. A spring fracture safety device for use in an overhead sliding door (6) or similar closing element (6) arranged for movement between a raised and a lowered end position, said door being attached to a helical door-actuating spring (1) and controlled by guide rollers (5) or similar control means running in tracks (4) extending along the intended path of movement of the door, the helical door-actuating spring (1) being wound about a support (16) to which it is secured by means of a clamp (20), characterized in
that one free end part (1A) of the spring forms a projecting section arranged to cooperate with a stop (14) serving to support the spring end part (1A) at a point spaced from the outer extremity of said spring end part during normal door operation conditions,
that a movement transfer device, such as a cable (9), is secured at its upper end to the outer extremity of the spring end part (1A) and at its opposite end to a trigger-off mechanism (7),
that a door-arresting element (8) which is arranged to cooperate with the guide rollers (5) inside said tracks (4), is connected to the trigger-off mechanism and arranged, in response to actuation by the trigger-off mechanism (7), to be displaced from a retracted position (I), wherein it is ready for release and wherein said guide rollers (5) are allowed to travel freely inside their associated track (4), to a door-arresting position (II), wherein the element (8) projects into the path of movement of said rollers (5), thus arresting further door movement,
that the trigger-off mechanism (7) is arranged to hold the door-arresting element (8) in the ready-for-release position (I) thereof when the spring end part (1A) is supported by the stop (14) and the spring (1) is held under tension but in the event of a fracture of the spring (1), resulting in disengagement of the spring end part (1A) from its support (14) with consequential stretching of the cable (9), to trigger-off the door-arresting element (8), thus causing said element (8) to assume its door-arresting position (II), wherein it projects into the associated track (4) and thus blocks the path of movement of said rollers (5) therein.

2. A device according to claim 1, characterized, in that the cable (9) acting as a movement transfer device, is secured to the projection section (1A) of the actuation spring (1), preferably by means of a sleeve (11) having a hole at its other end for securement thereof of the end of the spring.

3. A device according to claims 1-2, characterized in that the cable (9) is housed inside a cable protector tube (10) extending between said spring end (1A) and the door-arresting element (8).

4. A device according to any of claims 1-3, characterized in that the door-arresting element (8) consists of a spring-actuated brake block (23) provided with a number of stop projections (24), said block (23) being accommodated inside a casing (28) which may be mounted to the side of a track (4).

5. A device according to claim 4, characterized in that the brake block (23) is controlled by means of guide means (33) projecting from the bottom (28A) of the casing, which guide means preferably consist of a number of guide pins accommodated in borings (34) in the brake blocke (23).

6. A device according to any of claims 4-5, characterized in that a release spring (25), preferably made of curved spring material, is accommodated in a space (28B) defined between the bottom (28A) of the casing (28) and the brake block (23).

7. A device according to any of claims 4-6, characterized in that one of the stop projections (24) has a notch (37) arranged to receive a part of a guide roller (5) or similar means.

8. A device according to claim 7, characterized in that the stop projections are arranged as to function as restraint means for swinging roller holders (38) attached to the door element (6).

9. A device according to any of claims 4-8, characterized in that the trigger-off mechanism (7) comprises a pin attached to the movement transfer cable (9), which pin is arranged to be connected to an attachment (27) secured to the casing (28) in order to ensure that the brake block (23) is forcibly retained in its ready-for-release position (I).