IMPROVEMENTS IN OR RELATING TO ROLL-UP AND OTHER RETRACTABLE DOORS, SHUTTERS, BLINDS AND THE LIKE

Abstract: Door re-inforcements (14, 15, 16) are automatically positioned and removed by the door's (8) closing and opening movements, respectively. A roll-up, sliding or retractable door (8) is strengthened in its closed position by an arrangement of bars (14, 15, 16) held in position by brackets (17, 18, 19, 20 21, 22) on the door frame. The door (8) by its opening movement, progressively and sequentially catches and removes the bars (14, 15, 16) to a location wherein they will not obstruct the doorway thereby opened. Conversely, the bars (14, 15, 16) are progressively and sequentially replaced by the door's (8) closing movement.

Description: "IMPROVEMENTS EM OR RELATING TO ROLL-UP AND OTHER RETRACTABLE DOORS, SHUTTERS, BLINDS AND THE LIKE" This invention relates to "roll-up", "glide-away" and other retractable or sliding doors including those of the kind comprising a flexible door member which may take the form of a system of parallel slats disposed edge-to-edge in a flexible system guided for movement between a fully closed and a fully open position with respect to a doorway. For the purpose of this specification such a device will be referred to generically as a "door", although the invention may equally be applicable to sliding or roll-up shutters, blinds or other closures. My invention is advantageously applicable to vertical roll-up type doors such as are opened and closed by winding upon a horizontal drum located above the doorway. The drum can be operated by any suitable means e.g. an electric motor with appropriate trip-switches, or manually from ground level such as via a suitable chain and pulley system. The invention is also applicable to doors of the "glide-away" type and others wherein, instead of being rolled up, a flexible door member is simply pulled up and back in guides curved through 90° into a retracted horizontal position beneath the roof of the building to which the door gives access. This latter type can be useful where the interior space, height or clearance between the top of the door and the roof/ceiling is insufficient to accommodate a drum. In the past, such doors have been prone to damage due to pressure of high winds, which pressure tends to "belly" the door inwards like the sail of a square-rigged ship. This effect is seen to be due in large measure to the lack of support for the lower part of the door. For similar reasons such doors are often prone to damage by would-be trespassers, thieves and others attempting unauthorized entry, or to damage by wanton acts of violence and vandalism. In an attempt to strengthen doors against damage through natural or other causes, it has sometimes been the practice to back up a SUBSTITUTE SHEET suitable vehicle, such as a fork-lift truck, against the inside of the door when shut,.especially when the premises are being closed for the night. However this can be troublesome and is easy to forget. An object of the present invention is to improve the ability of a door to withstand inward pressure such as due to very high winds or the depredations of vandals or potential trespassers. The above and other objects and advantages will become apparent hereinafter. In one preferred form of the invention a roll-up or sliding door assembly for a doorway is characterized by door-strengthening means adapted to be progressively and automatically positioned and removed by the door's closing and opening, respectively. But in order that the invention may be better understood reference will now be made to the accompanying drawings which are to be considered as part of this specification and read herewith. In the drawings:- Figure 1 is a rear elevation of a door with strengthening or re-infordng means according to one practical embodiment of the invention, the door being shown fully closed; Fig. 2 is a rear elevation corresponding to Fig. 1 but with the door fully open; Fig. 3 is an enlarged detailed elevation of the region designated 3-3 in Fig. 1; Fig. 4 is a horizontal section- of the Fig. 3 region, as designated by 4-4 in Fig. 1; Fig. 5 is a section across line 5-5 in Fig. 1; Fig. 6 is a section across line 6-6 in Fig. 5, and Hg. 7 is a rear elevation of a door with re-enforcing means according to another practical embodiment of the invention involving articulation of the bracing elements or rods. Referring to the drawings in more detail, the invention is illustrated by reference to a flexible, vertically movable roll-up door 8 of a kind known pgr j s sHdable in a frame including upright vertical side SUBSTITUTE SHEET - 3 - members on either side of a doorway, the left hand member being shown by 9. Fixed to each side member is a channel-section guide 10 wrthin which slides the corresponding edge portion of door 8 between resilient strips 11 of rubber or the like. The bottom or leading edge of door 8 is a bar 12 having a lower, inwardly-projecting flange 12 which forms a ledge or shelf which as the door is raised, is adapted to "catch" bar and to carry the stad. of bars 14, 15 and 16, as best shown in Hg. 2. Bar 14 may be shorter than bar 15 and bar 15 shorter than 16, for reasons which will appear hereinafter. When the door is closed, bars 14, 15 and 16 are supported at the i r ends by pairs of holders (17, 18), (19, 20) and (21,22) respectively fixed to the door guides. Each pair of holders is positioned to "catch"' hold and support the relevant bar as the topmost bar of the stack carried by the descending door, and to allow the rest of the stack to pass Hence in this embodiment each pair of holders must be further apart than the length of the rod supported next below. Thus the brackets comprising each pair are fixed at distances transversely d i splaced somewhat outwards (i.e. away from the doorway) from those next below, and bar 15 is correspondingly longer than 14 and 16 than 15 Bars 14, 15 and 16 may be hollow or solid steel bars of s t atable cross-section and strength, which may depend upon the span of the door. However in the Illustrated embodiment they are of inverted channel-section to provide recessing for bracing *ods 24 as more fully described hereinafter. It will be clear that in the uppermost position of the door there must be enough vertical "hang" of the lower end portion thereof to carry the stack of bars. To assist in locating the bars 14, 15 and 16 in proper stacking position to be "caught" by the relevant holders, the ends thereof may be apertured to receive fixed vertical guide bars such as 23 These guides allow free up-and-down movement of the stack of bars but restrain them against horizontal movement. As a further precaution each bar (except the last or topmost) may have top-bevelled pins (not SUBSTITUTE SHEET shown) projecting upwardly therefrom and receivable in complementary holes in the underside of the bar next above (i.e. next "behind"). The number of bars, and their mutual spacing when the door is shut, can be as desired. It may be found advantageous to space the bars more closely nearer the ground, where the door will be most prone to damage and, consequently, where most strength will be needed. Inter-bar bracing may be provided by rods or struts 24. Each successive pair of bars such as 14, 15 (Figs. 5 and 6) may be inter¬ strutted by two such rods 24 symmetrically arranged about the vertical mid-line of the door. The lower ends of rods 24 are hinged in blocks 25 fixed to bar 14, while their upper ends are adapted to slide in a recess 26 defined by the underside of bar 15. For this purpose the upper end of rod 24 may be provided with a relatively wide head 27 slidable on runners 28 within recess 26. This arrangement tends to assist close stacking of the bars when the door is fully open as shown in Fig. 2, especially if the recesses are wide enough to accommodate rods 24 and blocks 25 in toto. The hinges for the lowest pair of bracing rods i.e. those between bars 12 and 14, may be fixed to flange 13. Considering, for example, the pair of rods 24 between bars 14 and 15, it is clear that their hinges 25 must be sufficiently close in relation to the lengths of the bars and rods, as to enable the full lengths of rods 24 to be accommodated within recess 26 as bar 14 approaches 15 when the door is being opened. Fig. 7 shows an alternative form of strutting whereby inter- bar bracing is provided by articulated links 28 hinged to each other and to the respective bars so as to open and close concertina-wise as the door opens and closes. Preferably the links do not open out to 180° lest this produce a "dead-centre" effect resisting closure. Each successive pair of bars may be interstrutted by two pairs of links symmetrically arranged about the vertical mid-line of the door. The hinges are recessed in the bars so as not to interfere with their dose-stacking when the door is fully closed. The operation of the door will now be described by reference to the embodiment of Figs. 1 to 6. Assuming the door to be closed as in Fig. 1, drum 29 is set in rotation to raise door 8. Bars 14, 15 and 16 remain temporarily in place, but the raising of the door lifts bottom bar 12 towards bar 14 causing the bracing rods between 12 and 14 to turn towards a horizontal position in which they and the relevant hinges are progressively received within the down-facing recess of bar 14. Bar 12 clears holders 17, 18 (as it does all upper holders) but its flange 13 "catches" bar 14 which it lifts from 17, 18 and the two bars, one on top of the other, are lifted so as to clear 19, 20 (as they do all upper holders) but catching bar 15. And so the process of "catching" bars progresses upwardly until the door is fully open and bars 16, 15 and 14 are stacked as closely one upon the other, as the struts permit, and in a location wherein they will not obstruct the doorway : Fig. 2. The re-inforcing system provided by the invention can readily be produced in kit form with bars in standardized lengths capable of being cut shorter, as necessary, and of being fitted with suitable end portions to make up completed bars in the desired effective total lengths. Although the holder-pairs 17, 18 etc. are shown as mutually offset in a transverse direction with bars correspondingly graded in lengths, other shapes and relative dispositions of holders and bar ends may be possible to achieve the same result i.e. bars being progressively deposited on and removed from their respective holders as the door is closed and opened respectively. For example it may be preferable to have an arrangement wherein the holder pairs are mutually offset in a direction at rightangles to the plane of the door. It will be evident from the foregoing that the invention provides a very simple means for strengthening a "roll-up", "glide-away" or other kind of sliding or retractable door, including those moving vertically, horizontally or otherwise. The invention may be incorporated in new installations or may be supplied e.g. in kit form for addition to existing doors. For the purposes of this specification terms such as "up". "horizontal", "vertical", "lowest", "above", "beneath", "height", "lower" are to be understood as applying to a vertically movable door and are not to be regarded as necessarily limiting.

Claims: CLAIMS 1. A roll-up or sliding door assembly for a doorway characterized by door-strengthening means adapted to be progressively and automatically positioned and removed by the door's closing and opening, respectively. 2. A roll-up or otherwise retractable door assembly for opening and closing a doorway between members of a door frame, including means associated with said members for guiding the movement of a flexible door between fully open and fully closed positions, strengthening bars, holders adapted to keep the respective bars in desired positions relative to the door frame when the door is closed or being closed, and to release the bars in response to opening movement of the door, whereby the bars are automatically positioned and removed by the door's closing and opening movements, respectively. 3. A roll-up or retractable door assembly strengthened, when closed, by an arrangement of bars in holders, characterized in that the door, by and in the course of its opening movement, will progressively and sequentially gather and remove the bars to a location wherein they will not obstruct the doorway thereby opened, and the bars will conversely and in reverse order be replaced in the holders by and in the course of the door's closing. 4. A roll-up door assembly as claimed in claim 3 including means associated with the leading edge of the door for catching a lowest bar and for carrying a stack of said bars, the number of stacked bars increasing or decreasing as the door is raised or lowered, respectively. 5. An assembly as claimed in claim 4 wherein the holders are arranged in pairs, one of each pair on each side of the doorway, one pair corresponding to each bar, and each pair being arranged to catch, hold and support the topmost bar of the stack during descent of the door, but to allow the ascending stack to lift, gather and remove it as the door opens, whereby the bar thus lifted becomes the top bar of the stack until the next higher bar, if any, be encountered. 6. An assembly as claimed in claim 4 or claim 5 including guide means adapted to restrain the bars against horizontal movement. 7. _-An assembly as claimed in any one of claims 2 to 6 additionally strengthened by bracing rods pivoted between successive bars so as to turn in response to relative movement between said bars, at least one of the bars being recessed to accommodate the rods in toto as the bars approach one another. 8. An assembly as claimed in claim 7 wherein the upper bar is so recessed on its underside, the lower ends of said rods are pivoted to the lower bar and the upper ends of the rods are slidably received in the recess under the upper bar. 9. An assembly as claimed in claim 7 wherein the rods are articulated each into two hinged links which are themselves hinged at their outer ends to the upper and lower bars respectively so as to open and close concertina-wise as the door closes and opens, respectively. 10. A door assembly substantially as herein described with reference to Figs. 2, 3 and 4, and either Figs. 1, 5 and 6 or Fig. 7 of the accompanying drawings.

Inventors: MIMMO MATTEO, MIMMO, MATTEO
Applicants: MIMMO MATTEO, MIMMO, MATTEO
Application year: 1989
Main classification: E06B9
IPC codes: E06B9