GB2106589A - Drive mechanism for an up-and-over door - Google Patents

Abstract

A drive mechanism is described which enables an up-and-over door (3) guided on both sides in two places (6,7) in vertical rails (4) and horizontal rails (5) to be opened and closed by means of just one driving motor (18). In order that the exclusively horizontally acting driving power provided by the driving motor (18) may be converted, when the door (3) is fully open, into a force having a vertical component, a four-pivot linkage (20), comprising links 21, 22, 23, 24 is secured to the door (3). The link (23) is prolonged by an arm (25) (Fig. 4) and articulated by way of a thrust rod (28) to a slide (12). The same is moved by way of a telescopic drive rod (29). Since only a single driving motor (18) is needed to move the door (3) horizontally and vertically, costs are reduced. <IMAGE>

Description

SPECiFICATION Drive mechanism for an up-and-over-door.

This invention relates to a drive mechanism for an up-and-over door, such as may be used for garages, the door being guided at least in its lower part in at least substantially vertical guide rails and being secured open by a counter-force, the drive mechanism comprising a guide element for a slide and a drive element for moving the same.

Up-and-over doors guided vertically and horizontally in guide rails are known and commercially available. The advantage of such doors over doors which are guided merely in vertical rails laterally of the door opening is obvious, if for no other reason than that the doors have four-point guidance in both their open and closed positions and so cannot tilt.

However, difficulties have arisen in connection with the drives for automatic opening and ciosing of guided doors of th is kind, since the door must first descend a little in the vertical rail before a horizontally acting or substantially horizontally acting force can produce the closing movement of the door.

Also, the horizontal force suffices to open the door only as far as a specific position, a vertical force then being needed to open the door fully. The vertical force for the opening movement can be provided by a counterweight or spring, in which event the door can be secured open. The vertical drive is then required not only to move the door out of the dead zone of the horizontal drive but also to overcome the force of the counterweight.

Consequently, two drives are required instead of just one and at least the vertical drive must be controllable if the vertical movement is to occur in dependence on or synchronously with the horizontal movement. Unfortunately, the drives then become so expensive that endeavours to provide an up-and -over door meeting all safety requirements are often abandoned.

It is therefore the object of the invention to provide a drive mechanism for an up-and-over door of the kind mentioned having horizontal and vertical guide rails or bars wherein the door can be opened and closed by means of a single driving motor, with a consequent decrease in the cost of the mechanism.

According to the invention, there is provided a drive mechanism for an up-and-over door, the door being guided at least in its lower part in at least substantially vertical guide rails and being secured open by a counterforce, the drive mechanism comprising a guide element for a slide and a drive element for moving the same, wherein the guide element is a horizontal rail, the slide carries a support element extending vertically downwards perpendicularly to the rail, a first member of a four-pivot linkage is rigidly secured to the door, the third member of said linkage, which is disposed opposite the first member of said linkage and is the longest of the four members, forming the coupling and being extended beyond the pivot for connection to the fourth member by an arm, the free end of the elongated third member being pivotally connected to an actuating rod pivoted to the end of the support element, the end of the support element being connected to the drive element by a drive rod.

An embodiment of the invention will be described hereinafter with reference to the drawings wherein: Figure lisa side view of an up-and-over door having horizontal and vertical guide rails and having a horizontal drive, with the various elements of a drive linkage; Figure 2 is a view to an enlarged scale on the line II of Figure 1; Figure 3 is a sectioned view on the line Ill-Ill of Figure 2; Figure 4 shows the movement pattern of the drive linkage when a horizontal force is input to the mechanism, and Figures 5 and 6 are side views of a variant of the drive with the door in its closed position and open position.

Referring to Figure 1, a part 1 of a building, for instance, an outside wall, in which there is an opening 2 for a door can be seen in section. An up-and-over door 3 is guided in a pair of vertical guide rails 4 and in a pair of horizontal guide rails 5, although only one of each of the two pairs is visible in Figure 1. Runners 6,7 are guided in the vertical and horizontal guide rail 4, 5 respectively. A cable 8 is secured in the vertical guide rail 4 near runners 6 and is connected by way of a deflecting roller 9 to a counter-weight 10.

Afour-pivot linkage, 20 is connected to the upper end 3a of door 3. The linkage 20 comprises a first member 21 ridigly connected to the door 3, a member 22 which is the second member as consi dered in the anti-clockwise direction and which is also the shortest member, a third member 23 which is the longest member, and a fourth member 24. The lengths of the members comply with Grashofer's condition that the sum of the shortest member and the longest member must be less than the sum of the other two members. The four-pivot linkage used here therefore meets the condition for a transmis sion adapted to make a complete revolution.

An arm 25 extends the longest member 23 beyond the pivot 26 interconnecting the third and fourth members 23, 24. Arm 25 co-operates with the longest member 23 to form an obtuse angle such that the free end 27 of arm 25 extends at an inclination towards the door 3. Arm 25 is articulated to an actuating rod 28. The longest member 23 therefore forms the coupling of the linkage 20 and the entire force acting on the free end 27 is transmitted to the door 3.

As can be gathered more particularly from Figure 3, the rod 28 is a fork and when in one operative position can be raised by means of the bar 27 as shown in Figures 1 and 2. Correspondingly, the rod 25 should be considered as consisting of parallel rods 25a, 25b; similarly, the four-pivot chain 20 is present in duplicate. The pivots of the chain 20 are continuous pins in both of the individual chains 20.

Only the articulation 29a, 29b between the arms 25a, 25b and the fork of the actuating or thrust rod 28 at- divided into two, in order that the fork may be open at the top and engage over the bar 11.

The bar 11, which is in the form of a tube, guides, with the interposition of four rolls 13, a slide 12. The same carries a vertically downwardly extending support element 14 rigidly connected to slide 12. A drive rod 29 and the actuating rod 28 are individually articulated to the free end of element 14. At its other end the rod 29 is pivoted to a drive element 16 suspended in a driving chain 15. In known manner the same has an entraining member engaged by a finger of the element 16. The element 16 can be released from the chain 15 by pulling on a loop 17.

Rod 29 is telescopic and is maintained in its extended state by a helical spring 30. A second helical spring 33 is disposed between slide 12 and that end 32 of rod 28 which is extended beyond pivot pin 31, the second helical spring 33 serving to damp the rotation of the rod 28. The second spring 33 is guided only at its ends and, therefore, can bend.

A driving motor 18 with gearing is adapted to drive the endless chain 15, the same also being guided by way of a deflecting roller 19 disposed on the inner wall of building part 1.

Referring to the pattern of movements shown in Figure 4, a chain-dotted line A indicates the path of the bottom end of the support element 14 and, therefore, of the pivot pin 31. A chain-dotted line B denotes the path of the articulation 29 between rods 28 and arm 25. A chain-dotted line C indicates the path of the articulation between the link 23 and the shortest member 22 of the four-pivot chain, while a chain-dotted line D denotes the path travelled by the runner 7 in the horizontal guide rail 5.

As will be apparent from consideration of the force applied by the rod 28 in the initial phase PH1 - i.e., as a torque to the runner 7 and as a force, by way of the lever 25, to the link 23-the door 3 is first tilted - i.e., simultaneously with a reduced horizontal movement it makes a small movement vertically downwards.

This overcomes the initial dead centre position and the horizontal movement can begin. When the motor 18 is running at a constant speed, the drive element 16 moves at a constant speed. However, since the slide 12 is retained vertically by the first movement, the drive rod 29 is foreshortened telesco pically,then expands subsequently because of the horizontal movement.

In phase PH2 the fourth member 24 of the linkage 20 is substantially horizontal and the door 3 is moved with increased force horizontally and with a reduced force downwardly. In phase PH3 the door 3 is in its closed position, corresponding to the state of the various members of the mechanism when the actuating rod 28 is pulled at its bottom end to open the door. As will be apparent, the force applied to the pivot pin 31 is disposed substantially at the centre of the stationary member 21 of the linkage 20, so that a considerable force acts horizontally to start with. The two other phases PH2 and PH1 experience the same circumstances in this movement as previously but in the converse order.

The two illustrations of Figures 5 and 6 show a variant of the drive wherein an actuating rod 58 is rotated by a gear drive 60-62. In this embodiment the drive bar 11 and a slide 63 having roli pairs 64,65 and a drive chain 15 are provided. As in the previous embodiment, the linkage 20 with its four members 21,22, 23, 24a is disposed on the garage door 3. In contrast to the embodiment shown in Figures 1 to 4, the fourth member 24a is not straight but bent, so that there are two arms 24aa and 24 ab disposed substantially perpendicularly to one another.

Rod 58 is articulated to the free end 27 of the third member 23 associated, as in the previous embodiment, with an elongating arm 25. Rod 28 is rotatably mounted on support element 44 and is a two-armed lever. At its opposite end the rod 58 has a toothed segment 61 which meshes with a gear 62 rotatably mounted on support element 44. Another gear 60 is rigidly connected to gear 62. The teeth of gear 60 mesh in a rack 59 guided for horizontal movement.

Rack 59 is rigidly secured to drive element 46. A two-armed stop or locking lever 68 is articulated to support element 63, one arm of lever 68 being thrust upwards by a spring 67 and pressing by way of a roller 66 at the end of the other arm on the rack 59, so that after the door 3 has tilited in the open position, the roller 66 drops into a recess 69, as can be seen clearly in Figure 6. This leads to a quasi-rigid connection between the support element 44 and the drive element 46 for as long as the forces operative therebetween cannot overcome the force of the spring 67. A force-limiting element is therefore provided.

Also acting on the door 3 itself is a spring 45 which comes into action between the first member 21 and second member 22 of the linkage 20 to damp impacts of the door in its two end positions.

Consequently, the door 3 is first moved out of the position shown in Figure 5 by means of the linkage 20, so that the horizontally acting thrust can, with the roller 6 engaged in the recess 69, close the door, the same taking up the position shown in Figure 6 as its second end position.

Claims (10)

1. A drive mechanism for an up-and-over door, the door being guided at least in its lower part in at least substantially vertical guide rails and being secured open by a counter-force, the drive mechanism comprising a guide element for a slide and a drive element for moving the same, wherein the guide element is a horizontal rail, the slide carries a support element extending vertically downwards perpendicularly to the rail, a first member of a four-pivot linkage is rigidly secured to the door, the third member of said linkage, which is disposed opposite the first member of said linkage and is the longest of the four members, forming the coupling and being extended beyond the pivot connection to the fourth member by an arm, the free end of the elongated third member being pivotally connected to an actuating rod pivoted to the end of the support element, the end of the support element being connected to the drive element by a drive rod.

2. A mechanism according to claim 1, in which the arm by which said third member is extended includes an angle of from 90 to 180 with said third member.

3. A mechanism according to claim 2, in which said angle is at least substantially 120 , so that the free end of the third member is bent towards the plane determined by the door.

4. A mechanism according to claim 1, in which the drive rod is telescopic and a compression spring serves to retain it in its fully extended position.

5. A mechanism according to claim 4, in which at its pivotal connection to the support element the actuating rod is pressed into an inoperative position by a helical spring disposed parallel to the support element.

6. A mechanism according to any of the previous claims, in which the actuating rod is a two-pronged fork, the four-pivot linkage comprises four parallel members and the pivots between the parallel members are inter-connected by way of spacers.

7. A mechanism according to any of claims 1 to 3, in which the drive rod is a toothed rack and meshes with a first gear mounted rotatably on the support element, and the actuating rod has rigidly connected to it a toothed segment meshing with a second and concentrically mounted gear rigidly connected to the first gear.

8. A drive mechanism for an up-and-over door, substantially as hereinbefore described with reference to, and as shown in, Figures 1 to 4 of the accompanying drawings.

9. A drive mechanism for an up-and-over door, substantially as hereinbefore described with reference to, and as shown in, Figures 5 and 6.

10. Any novel feature or combination of features described herein.