STACKING PANEL SHUTTER DOORS

Abstract

To keep the same size motor when panel numbers are varied, the invention includes a torsion spring counter balancing mechanism for a stacking panel shutter door, wherein one end of the or each torsion spring is fixable to a drive transmission shaft of the stacking panel shutter door, the drive transmission shaft being adapted to raise and lower the or each shutter of the stacking panel shutter door; and the other end of the or each torsion spring is fixable to a separate rotatable member of the stacking panel shutter door; and whereby the mechanism is provided with means adapted to enable both the drive transmission shaft and the rotatable member to rotate, during opening and closing of the stacking panel shutter door, in such a manner as to cause respective ends of the or each torsion spring to travel at different speeds during the opening and closing sequence.

Claims

1. A torsion spring counter balancing mechanism for a stacking panel shutter door, wherein a) one end of the or each torsion spring is fixable to a drive transmission shaft of the stacking panel shutter door, the drive transmission shaft being adapted to raise and lower the or each shutter of the stacking panel shutter door; and b) the other end of the or each torsion spring is fixable to a separate rotatable member of the stacking panel shutter door; and whereby the mechanism is provided with means adapted to enable both the drive transmission shaft and the rotatable member to rotate in tandem in the same direction, during opening and closing of the stacking panel shutter door, in such a manner as to cause respective ends of the or each torsion spring to travel at different speeds during the opening and closing sequence.

2. The mechanism as claimed in claim 1, wherein the drive transmission shaft and the rotatable member rotate at different rates during opening and closing of the stacking panel shutter door.

3. The mechanism as claimed in claim 1, wherein the separate rotatable member is circular in shape.

4. The mechanism as claimed in claim 3, wherein the radius of the drive transmission shaft and the separate rotatable member are different.

5. The mechanism as claimed in claim 1, wherein the separate rotatable member is a drive transmission barrel which surrounds the drive transmission shaft.

6. The mechanism as claimed in claim 1, wherein the mechanism further comprises: a first sprocket operatively connected to the drive transmission shaft; a second sprocket operatively connected to the rotatable member; wherein the first and second sprockets are operatively linked in a sequence (train).

7. The mechanism as claimed in claim 6, wherein the first sprocket is of a different size to the second sprocket.

8. The mechanism as claimed in claim 6, wherein the sprockets are so sized and shaped as to enable the drive transmission shaft to make half or a fraction of the number of turns relative to the drive transmission barrel when the stacking panel shutter door is in operation.

9. The mechanism as claimed in claim 1, wherein the drive trans-mission shaft and the separate rotatable member may be independently operable.

10. A stacking panel shutter door incorporating a torsion spring counter balancing mechanism as claimed in claim 1.

11. A building incorporating a stacking panel shutter door as claimed in claim 10.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying sheets of drawings wherein:

[0026] FIG. 1 is an isometric partial cut-away view of view of one embodiment of a torsion spring counter balancing mechanism fitted to a stacking panel shutter door employing a sprocket and chain mechanism, the cut-away exposing the torsion springs;

[0027] FIG. 2 is an isometric cut-away view of part of the embodiment shown in FIG. 1;

[0028] FIG. 3 is an isometric partial cut-away view of part of the embodiment shown in FIG. 1 detailing the sprocket and chain assembly which cannot clearly be seen in FIG. 1;

[0029] FIG. 4 uses the isometric cut-away view of part of the embodiment shown in FIG. 1 to detail those parts of the torsion spring counter balancing mechanism which, when in operation, travel at full speed and those parts relatively speaking which travel at a fraction of full speed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0030] FIG. 1 shows a chain and sprocket torsion spring counter balancing mechanism forming part of a stacking panel shutter door which is generally referenced 10. Sandwiched between and fitted to opposed proximal 11 and distal 12 cassettes or shutter end plates 11, 12, is a drive transmission shaft 13 and wound around shaft 13 are a pair of torsion springs 14. One end of each torsion spring 14 is fixed to the outer circumference of the drive transmission shaft 13, and the other end of the torsion spring is fixed to a separate rotatable member 15 in the form of an elongate circular drive transmission barrel 15 that is concentric with, is independently rotatable of, and substantially completely overlies the entirety of shaft 13.

[0031] On the outermost face of the proximal plate 11, the mechanism 10 is provided with a sprocket 16, of diameter ‘D’ which is concentric with and fixed to shaft 13 and located elsewhere on the outermost face of the proximal plate 11, is a double sprocket 17 of diameter ‘D/2’ which is fitted to transmission shaft 9 and operatively connected to barrel 15. Sprocket 16 and the first sprocket of the double sprocket 17, are operatively linked in a sequence (train) by transmission chain 18.

[0032] On the innermost face of the proximal plate 11, is located a further double sprocket 19, which is again concentric with shaft 13 but this time fixed to sleeve 20 of barrel 15, both of these sprockets 19 having diameter ‘D/2’: [0033] a) the first sprocket of the double sprocket 19, being linked in a sequence (train) by transmission chain 21 to double sprocket 22 to operate the stacking and un-stacking of the panels of the stacking panel shutter door 10 during opening and closing of the same, the door panel lifting chain 8 being linked to the second sprocket of double sprocket 22; and [0034] b) the second sprocket of the double sprocket 19, being linked in a sequence (train) by transmission chain 23 to the second sprocket of the double sprocket 17.

[0035] The innermost face of the distal plate 12 contains a similar sized sprocket 24 opposite double sprocket 19, but instead of it being a double sprocket, it is a single sprocket 24 and this sprocket 24 is linked in a sequence (train) by a similar transmission chain to that of chain 21 to a similar sprocket to that of sprocket 22 to similarly operate the stacking and un-stacking of the panels of the stacking panel shutter door 10 during opening and closing of the same. Also located on the innermost face of the distal plate 12 is an electric drive motor 26 and sprocket 24 and electric drive motor 26 are linked by drive chain 25.

[0036] The sprocket 16 thus forms part of a drive arrangement to turn it in the same direction as the barrel 15 and in so doing, shaft 13 will be turned in the same direction in tandem with barrel 15. The sprocket 16 is sized (D) such that it will turn at approximately half the speed of the barrel 15 (D/2). This will result in the torsion springs 14 making half the number of turns compared to the barrel 15.

[0037] From a combination of FIG. 1 and FIG. 3, it can be seen that shaft 13 and barrel 15 are only linked by transmission chain 18. If chain 18 is removed, shaft 13 and barrel 15 may be turned independently. The removal of chain 18 will enable shaft 13 and barrel 15 to be independently operable so that it is possible to add or reduce one or two spring turns that may be required to suit a given door height. To do this, chain 18 is first removed with the stacking panel shutter door 10 in the open position (which means the torsion springs 14 are at their rest position and not wound up). Using a turning bar slotted into an aperture (not illustrated) in shaft 13, shaft 13 is manually rotated to add or reduce one turn. Holding shaft 13 in this position, chain 18 is then re-attached. The end effect is that the door will start operating with springs already with one turn added or subtracted. This will enable the chain and sprocket torsion spring counter balancing mechanism forming part of a stacking panel shutter door 10 to be adjusted for each door height as each of the stacking panel shutter doors are usually custom made to fit a particular doorway as doorways come in all shapes and sizes, there being no ‘industry standard’ in terms of door size as each industry has its own different requirements.

[0038] In use, when the drive motor is turned on, sprocket 16 which rotates shaft 13, is driven by double sprocket 17 which is in turn rotates in tandem with barrel 15. As sprocket 16 is sized to turn shaft 13 at about half the speed of barrel 15, the result is that while barrel 15 is turning to wind up both of the torsion springs 14, shaft 13 is turning simultaneously to unwind the torsion springs 14 at about half the speed, thus approximately half neutralizing the turning effects of barrel 15.

[0039] This means that if barrel 15 makes 20 turns, shaft 13 will make only 10 turns. The torsion springs 14 will therefore also be making only 10 turns, but will be winding up to produce torque in the process. As the number of turns the torsion springs 14 need to make are about half those of a conventional torsion spring counter balancing mechanism forming part of a stacking panel shutter door, each torsion spring 14 in the present invention can be shorter in length by about half when compared with a conventional mechanism.

[0040] The benefits of the present invention may be summed up as follows: [0041] a) more springs for a given door width can be fitted which means that the load can be shared amongst more springs enabling lighter-designed (and thus cheaper) springs to be used. In addition, this arrangement will provide a greater flexibility in the selection of spring sizes and quantities to suit a given door weight; [0042] b) as the standard torsion spring is built to make not more than 12 turns, if more turns than that are required, such springs would have to be a custom-made adding to the cost and a manufacturer may not be able to be found that has the capability to make such springs, or even want to make them, thus the present invention frees the Applicant from the 12 turn constraint as well as the maximum workable weight of the door panels, thus limiting the types of materials that we can used on the door.

[0043] For the avoidance of doubt, the barrel 15 in all the Figs show various parts of the barrel 15 cutaway or otherwise removed, such cutaway or removed portions do not exist in reality and are purely present in the Figs to illustrate the torsion springs 14 and the drive transmission shaft 13 more clearly.