GB2304138A - Up-and-over door assembly - Google Patents

Abstract

A door assembly of the up-and-over type includes a generally planar door (10) and one or more guides (12). A pair of pivot arms (14) each pivotally links one side edge of the door, at a point (15) in the lower half of the door, to a first point (16) on the door frame spaced from the top of the frame and a pair of gas springs (17) each pivotally links a point (19); on the pivot arm to a second point (18) on the door frame below the first point. The pivot arms and gas springs swing outwardly of the doorway as the door moves between its limiting positions.

Description

Door Assembly The present invention is concerned with doors of the so-called "up-and-over" type, which are opened by moving them upwardly and rearwardly from a generally vertical position in which they close the doorway space to a generally horizontal position in which that space is unobstructed. Up-and-over doors are most widely used for domestic garage doorways.

Doors of this general type fall into three main categories, which differ from each other in the nature of the movement from the open position to the closed position of the door. "Canopy" doors are traditionally operated by means of a torsion spring mounted horizontally above the doorway; the spring applies a lifting force to the door via two cables attached to the door sides. In its open position, the lower edge of a canopy door protrudes outwardly from the door space in the form of a canopy. "Nonprotruding" doors are operated in a manner generally similar to that of a canopy door but are fully withdrawn behind the doorway when in the open position. Such doors do not extend outwardly beyond the doorway, for example into a pavement area, during the opening and closing movements and do not form a canopy.

The third general category of up-and-over door is the "retractable" door. Retractable doors are fully withdrawn behind the doorway when in the open position but extend outwardly when in transit between closed and open positions.

An important consideration in designing a door assembly of any of the foregoing types is to counterbalance the weight of the door, either fully or to a significant extent, so that the effort required to move the door between its limiting positions is contained at an acceptable level. This consideration applies whether movement of the door is to be effected either manually or under power.

Numerous designs of operating mechanism have been produced with the object of meeting that aim within the constraints of these three systems.

While developments over the years have certainly assisted the end user in operating up-and-over doors more easily, there remain numerous disadvantages from the point of view of the user, the manufacturer of the doors and/or the installer. For example, all available such doors have many moving parts, all of which are prone to wear. The door assemblies are usually heavy to handle prior to and during installation because of the number of parts. In addition, these assemblies are often difficult and/or time-consuming to install.

A further disadvantge of such prior door assemblies is that, when pre-assembled for storage and distribution, they tend to be too bulky for efficient stacking.

Many prior door assemblies rely upon springs and/or cables for their operation and breakage of either of these components is a hazard, both to the user and to the adjacent equipment. Moreover the lateral dimensions of springs and operating arms mounted on a peripheral framework within a brick garage structure are traditionally such that the width and cost of the framework are greater than is desirable.

The disadvantages of prior up-and-over door assemblies are particularly significant when it is desired to provide a power drive to the door. Taking account of the nature of the door motion between its closed and open positions, it is difficult to provide a controlled door operation which is both smooth and safe. Indeed only fully retractable doors lend themselves adequately to powered operation by available means. Canopy doors and non-protruding doors do not lend themselves readily to satisfactory powered operation, although attempts to drive-such doors are known.

Against this extensive background, it is an object of the present invention to provide an improved door assembly for an up-and-over door, by means of which some at least of the disadvantages of prior such doors are reduced or eliminated.

The door assembly according to the present invention comprises a generally planar door adapted to close a doorway defined by a door frame, one or more guides to define movement of the door between a closed position in which the door is generally vertical within the door frame and an open, generally horizontal position in which the door extends through the upper region of the doorway, a pair of pivot arms, each pivotally linking one side edge of the door, at a point in the lower half of the door, to a first point on the door frame spaced from the top of the frame, and a pair of gas springs, each pivotally linking a point on the adjacent pivot arm intermediate its ends to a second point on the door frame below said first pivot, said pivot arms and gas springs each being adapted to swing outwardly of the doorway during transit of the door between its limiting positions.

The door in the door assembly of the present invention most nearly resembles a canopy door in its operation, in that the foot of the door swings outwardly and upwardly into an open position in which it lies outside the doorway. However the pivot arms and gas springs also swing outwardly and the arc of movement of the door is modified as a result, so that it intrudes on the upper space to the rear of the doorway to a much smaller extent than in the case of a conventional door assembly of the available canopy or other types. This space has become more important in the light of the recent increased popularity of relatively high-sided vehicles, for example four-wheel-drive vehicles, among domestic users having up-and-over garage doors.

Gas springs, sometimes known as gas struts, are readily available in a range of sizes, stroke lengths and force characteristics. They are essentially sealed systems each comprising a pneumatic cylinder and a piston and containing a compressible gas such as nitrogen. As the piston is moved within the cylinder, the gas can pass from one side of the piston to the other through an orifice, the size of which determines the rate of passage of the gas and thus the rate of extension of the gas spring. The force applied by a gas spring is determined by the pressure on the gas in its compressed state. Thus the gas spring may be selected so that the force applied matches the requirements of a given door assembly, in particular the weight of the door.

Each pivot arm provides a pivotal link between the lower half of one side edge of the door and a first point on the door frame spaced from the top of the frame. Preferably that first point lies between about one quarter and one half of the distance down from the top of the frame. The gas spring in turn links a point on the pivot arm, for example towards the frame-mounted end of the arm, to a second point on the door frame below the first point. Preferably that second point lies in the lower half of the frame.

In one form of the present invention, the relative linear dimensions of the pivot arms and gas springs are so selected, and the points of connection of these members to the door frame are so spaced apart, that the members may be secured in adjacent positions during delivery of the door assembly to the site of use, with the gas springs held in their compressed position. In this way, safe and quick installation of the door assembly may be facilitated. A further advantage is that the arrangement also makes it possible more safely to fit a replacement gas spring when required, in that the gas spring may be fitted with the door in its closed position. This nesting together of the pivot arm and gas spring may be aided by forming the arm in a cranked shape.

Movement of the door between its limiting positions is defined by one or more guides. The guides may be disposed vertically, that is at the sides of the door, where they may for example be linear tracks engaged by rollers located in the region of the bottom of the door side, or horizontally. Such horizontal guides may comprise a single centrally disposed guide extending rearwardly from the region of the top of the door in its closed position, or a pair of such guides, engaged for example by rollers in the region of the top of the door sides.

With garage door assemblies of conventional type, in particular retractable doors, incorporating horizontal guide rails extending rearwardly of the door, successful operation depends to a major extent upon the accuracy with which such rails are installed and aligned. To this end, the rails conventionally are mounted upon the wall or roof of the garage. Because the present invention leads to the door extending less far into the garage space, it is possible to mount the resulting shorter guides upon the rear of the door frame, without additional support from the adjacent wall or roof, and thus to deliver the guides pre-assembled to the frame.

The door assembly according to the present invention provides, by means of the force applied by the gas springs to the pivot arm, a counterbalance to the weight of the door, thereby assisting either manual or powered operation of the door. In one preferred form of the invention , operation of the door is power-driven. In a particularly preferred form, the drive may be applied to the door via one or more pinions engaging a rack or racks. For example, a pinion or pinions on the door may engage one or more racks on the door frame, or the pinion or pin ions may be on the door frame and engage a rack or racks on the door. The rack(s) may be rigid or flexible and may be secured to the guides or may be free to move within the guides.In one form of the invention, a single pinion, mounted at the centre of the top of the door frame, engages a pair of flexible racks which, by moving linearly along the guides, drive the door top to its open or closed position.

The invention will now be further described and illustrated, by way of example only, with reference to the accompanying drawings, wherein: Fig.l is a schematic view from the side of one embodiment of door assembly according to the present invention; Fig.2 is an elevation from the side of one combination of pivot arm and gas spring, nested together for storage and delivery of the door assembly; and Fig.3 is a schematic view from the side illustrating the operation of an alternative pivot arm.

The door assembly illustrated schematically in Fig.l includes a door 10 shown in its closed position at 10a and in a partly opened position at lOb. Rollers 11 at the top of each side of the door (only one of which is visible in the drawing) engage horizontal linear guides 12 within the area 13 of a garage which the door 10 is used to close.

A pair of pivot arms 14, one at each side of the door 10, extend between a pivot 15 in the lower half of the door and a further pivot 16 in the upper half of the door frame. Gas springs 17 are pivotally mounted at 18 on the lower half of the door frame and each gas spring is pivoted at its other end, at 19, on the adjacent pivot arm 14.

When the door 10 is in its closed position lOa, the gas spring 17 is unextended and the gas within it is compressed. The force provided by the gas spring assists manual or powered opening of the door by wholly or largely counterbalancing the weight of the door. As the door is opened, both the pivot arm 14 and the gas spring 17 swing outwardly and upwardly relative to the doorway (in a clockwise direction as illustrated). The upper space immediately behind the doorway is intruded upon to a minimal extent by the door mechanism and door as the door opens.

The components illustrated in Fig.2 are designed to adopt close relative positions when the door upon which they are mounted is stored and subsequently delivered before the door assembly is installed for use. The illustrated pivot arm 20 is disposed between a bracket 21 by which it is pivotally mounted upon the door frame and a bracket 22 by which it is pivoted upon the door. The gas spring 23 is pivotally linked to the arm 20 at 24 and is pivoted upon the door frame by means of a bracket 25.

In the position shown in Fig.2, the gas spring 23 is in its state of maximum compression and lies close to the arm 20. These relative positions correspond to a closed condition of the door and the door assembly may be installed in this condition.

A bolt 26, passing through the pivot arm 20 and the bracket 25, secures the arm and gas spring together until the door assembly has been installed. A tab 27 reacts against the thrust stored in the gas spring 12 and prevents the bracket 25 revolving around the bolt 26. After installation of the door assembly, the bolt 26 is removed.

As an alternative, the gas spring may be installed in situ with the door in its open position.

Fig.3 shows a modified form of pivot arm 30, which is cranked at 31. The pivot arm 30 is pivoted upon the door frame at 32 and upon the door 33 at 34. The gas spring 35, illustrated in the closed condition of the door, is pivoted to the arm 30 at 36. As shown, the gas spring is able to be stored in a position very close to the arm 30 when the door is in its closed condition, for example prior to installation of the door assembly.

As will be seen, the door assembly according to the present invention has few moving parts and does not rely upon conventional torsion springs or cables. The assembly as such can be produced to a compact design and in particular can be stored and delivered in a compact collapsed condition ready for easy installation. Although the door has some similarities to canopy doors. it is readily adapted to be power-operated.

Claims (13)

1. An up-and-over door assembly comprising a generally planar door adapted to close a doorway defined by a door frame, one or more guides to define movement of the door between a closed position in which the door is generally vertical within the door frame and an open, generally horizontal position in which the door extends through the upper region of the doorway, a pair of pivot arms, each pivotally linking one side edge of the door, at a point in the lower half of the door, to a first point on the door frame spaced from the top of the frame, and a pair of gas springs, each pivotally linking a point on the adjacent pivot arm intermediate its ends to a second point on the door frame below said first pivot, said pivot arms and gas springs each being adapted to swing outwardly of the doorway during transit of the door between its limiting positions.

2. A door assembly as claimed in Claim 1, wherein said first point on the door frame lies between about one quarter and one half of the distance down from the top of the door frame.

3. A door assembly as claimed in either of the preceding claims, wherein the point of linking of each gas spring to the adjacent pivot arm lies towards the frame-mounted end of the arm.

4. A door assembly as claimed in any of the preceding claims, wherein said second point on the door frame lies in the lower half of the frame.

5. A door assembly as claimed in any of the preceding claims, wherein the relative dimensions of the pivot arms and gas springs are so selected, and the points of connection of these members to the door frame are so spaced apart, that the members may be secured in adjacent positions with the gas springs compressed.

6. A door assembly as claimed in any of the preceding claims, wherein the pivot arms are of a cranked shape.

7. A door assembly as claimed in any of the preceding claims, comprising a pair of guides disposed vertically at the sides of the door.

8. A door assembly as claimed in any of Claims 1 to 6, comprising a single horizontal, centrally disposed guide extending rearwardly from the top of the doorway.

9. A door assembly as claimed in any of Claims 1 to 6, comprising a pair of horizontal guides extending rearwardly into the garage in the region of the top of the door sides.

10. A door assembly as claimed in any of the preceding claims, wherein movement of the door is power-driven.

11. A door assembly as claimed in Claim 10, wherein the drive is applied to the door via one or more pinions engaging a rack or racks.

12. A door assembly as claimed in Claim 11, wherein a single pinion at the centre of the top of the door frame engages a pair of flexible racks which drive the door.

13. An up-and-over door assembly substantially as hereinbefore described with reference to, and as illustrated in, any one or more of Figs.l to 3 of the accompanying drawings.