WO1997012161A1

WO1997012161A1 - Improvements in door operators

Info

Publication number: WO1997012161A1
Application number: PCT/NZ1996/000102
Authority: WO
Inventors: Mervyn Allen Quartly; Trevor James Bills
Original assignee: Advanced Door Systems Limited
Priority date: 1995-09-26
Filing date: 1996-09-25
Publication date: 1997-04-03
Also published as: AU7100596A; NZ318896A

Abstract

A gearbox for an operator of a closure such as a door. The gearbox includes an input shaft (18) and an output shaft (20) each of which is journalled for rotation by bearings (16 and 17). A drive boss (23) is mounted by pin (24) to each shaft. A toothed sprocket (25) is engaged in a driving manner with shaft (18) via boss (23) while similarly toothed sprocket (26) is engaged with shaft (20) via boss (23). A toothed belt (27) extends about the drive sprockets to transfer drive from the input shaft (18) to the output shaft (20). The toothed sprockets (25 and 26) are of different sizes and interchangeable on the bosses (23) of the respective shafts (18 and 20) to facilitate a change in the gear ratio of the gearbox.

Description

IMPROVEMENTS IN DOOR OPERATORS

BACKGROUND OF THE INVENTION

This invention relates to improvements in operators for closures such as doors.

Electrically powered operators for the opening and closing of doors and other closures such as gates are known. The present invention more particularly relates to an operator which applies a driving force to an edge of the closure such that the closure can be moved between open and closed positions. One known form of such an operator for doors includes a driven threaded shaft located within a track or rail. A drive nut is threaded onto the shaft and moves along the track as the shaft is rotated. The closure is coupled to the drive nut and therefore as the drive nut moves along the threaded shaft the closure is moved between the open and closed positions.

With known operators of this type there is a requirement that the speed at which the drive nut moves can be adjusted. With known operators this is achieved by replacing the drive shaft with one having a thread of a different pitch or by substituting the gearbox located between the motor and the threaded shaft for one having a different gear ratio. This means that a manufacturer must manufacture and hold stocks of leads to increased costs of production and stock holding but also requires careful stock control to ensure that a purchaser receives an operator with the correct threaded shaft and/or gearbox.

SUMMARY OF THE INVENTION

An object of the present invention is thus to provide an operator for the opening and closing of a closure, the operator having a gearbox arrangement which is readily adjustable to change the speed at which an output shaft thereof rotates.

Another problem with operators of this type is one of noise. Noise originates primarily from two sources, namely, the motor drive itself and the mechanical connections between the closure and the output shaft of the motor. Mechanical noise is principally caused by the rotational movement of the threaded shaft within the rail and the drive nut moving along the rail.

It is therefore a further object of the present invention to provide an operator of a type having a threaded shaft rotationally mounted within a rail or track, the construction and arrangement of such being designed to reduce the generation of noise. According to one broad aspect of the invention there is provided a gearbox for an operator of a closure such as a door, the gearbox including input and output shafts joumalled for rotation, there being drive bosses mountable on said output and input shafts, a toothed sprocket engaged with each drive boss and a toothed belt extending about the drive sprockets to transfer drive from the input shaft to said output shaft, the toothed sprockets being of different sizes and interchangeable on the bosses of the respective shafts.

According to a second broad aspect of the invention there is provided an operator for a closure, the operator being characterised by including a gearbox coupled to an output shaft of a motor, the motor output shaft having a toothed sprocket drivingly coupled to a different sized toothed sprocket of a gearbox output shaft, the sprockets being mounted such as to be interchangeable to alter the gear ratio of the gearbox.

In a third broad aspect of the invention there is provided an operator for a closure such as a door, the operator including a threaded shaft located within a rail by a plurality of bearing supports and a drive nut threaded onto the shaft whereby rotation of the shaft results in movement along the rail of the drive nut and the bearing supports the drive nut and/or the bearing supports being characterised by having a plurality of flexible wings which locate in sliding contact with an inner wall surface of the rail but restrict rotational movement of the drive nut and/or bearing supports about the axis of rotation of the threaded shaft.

The operator to which the present invention relates is of a type primarily used for the opening and closing of doors and more particularly garage doors whereby a moving force is applied to one edge (the top edge) of the door so as to move the door between open and closed positions. Such doors can be of the tilt, jamb-tilt or sectional panel types.

Generally the operator comprises a housing in which an electric motor (DC or AC) drives an output shaft generally through a gearbox. Extending from the housing to a fixture adjacent the door is the so-called rail within which a threaded shaft is located by εuitable bearings. This threaded shaft is drivingly engaged with the output shaft of the housing. A drive nut is threadedly located on the threaded shaft and is engaged with the rail such that as the threaded shaft rotates the drive nut moves along the rail. The door is coupled to the drive nut such that movement of the drive nut is reflected in an open or closing movement of the door dependent on the direction of travel of the drive nut along the rail.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an exploded view of a gearbox arrangement which transmits drive from the electric motor of the operator to the threaded shaft, Figure 2 is a plan view of a drive sprocket of the gearbox,

Figure 3 is a cross-sectional view of the drive sprocket of Figure 2,

Figure 4 is a plan view of a drive boss of the gearbox, Figure 5 is a side elevational view of the drive boss of

Figure 4,

Figure 6 is a plan view of a drive nut which is threadedly engaged on the threaded shaft,

Figure 7 is an end elevation view of one half of the drive nut,

Figure 8 is a side elevation view of the half of the drive nut in Figure 7,

Figure 9 is an end elevation of the other half of the drive nut, Figure 10 is a side elevation of the other half of the drive nut in Figure 9,

Figure 11 is an underside plan view of the drive nut,

Figure 12 is an end elevation of a support bearing for the threaded shaft, Figure 13 is a side elevation view of the support bearing of Figure 12, Figure 14 is an end view of the rail illustrating the disposition of the drive nut and support bearings within the rail,

Figure 15 is a side elevation view of a first section of a flexible coupling for location between the output shaft of the gearbox and the threaded shaft,

Figure 16 is an end elevation view of the coupling part shown in Figure 15,

Figure 17 is the other end elevation view of the coupling part of Figure 15,

Figure 18 is a side elevation view of a second part of the coupling,

Figure 19 is an end elevation view of the coupling part shown in Figure 18, Figure 20 is the other end elevation view of the coupling part shown in Figure 18,

Figure 21 is a plan view of a coupling spider to be used with the coupling parts of Figures 15 and 18,

Figure 22 is a side elevation view of the coupling spider,

Figure 23 is a section on line A-A of Figure 21,

Figure 24 is an elevation view of a rail stop to be used with the rail,

Figure 25 is a plan view of the rail stop, Figure 26 is a bottom plan view of the rail stop, and

Figure 27 is a similar view to Figure 12 but showing a modified form of bearing support. DESCRIPTION OF THE PREFERRED EMBODIMENTS

To further describe the elements of construction of an operator of this type incorporating the present invention reference will be made to the following embodiments.

Referring firstly to Figure 1 the gearbox comprises a base 10 which is adapted for mounting to the motor housing or a support for the motor. A gearbox cover 11 is engageable via a skirt 12 over a peripheral wall 13 of the base 10. This gearbox cover 11 includes a shaped recess 14 into which an end of the rail 15 (see Figure 14) can engage.

Located with base 10 are bearings 16 with corresponding bearings 17 aligned therewith being located in the cover 11. The motor output shaft 18 extends through an opening 19 in base 10 to be joumalled between a pair of bearings 16 and 17. A coupling 20 is joumalled within the other pair of bearings 16 and 17 and projects through an opening 21 in wall 22 of recess 14. The projecting end of coupling 20 is drivingly coupled with an end of the threaded shaft which extends longitudinally along rail 15 as will hereinafter be described.

A drive boss 23 is pinned by pin 24 on each of shaft 18 and coupling 20. A pair of drive sprockets 25 and 26 are engageable with shaft 18 and coupling 20 and fit onto the drive bosses 23 such that the sprocket is drivingly coupled to the shaft 18 and coupling 20 respectively. A drive belt 27 engages about the toothed drive sprockets 25 and 26.

The gearbox arrangement is completed by a spacer 28 which engages between the drive sprocket on shaft 18 and the bearing 17 in which the shaft 18 is jou alled.

Accordingly, drive from shaft 18 is transmitted via toothed sprocket 25 to the drive belt 27 which via drive sprocket 26 drives coupling 20 which forms the output shaft of the gearbox and therefore rotates the threaded shaft located within rail 15.

In a preferred form of the invention the drive sprockets and drive bosses are constructed from a plastics material preferably acetal. Each drive boss is therefore moulded as one piece and comprises a pair of diametrically opposed drive elements 30 which are spaced apart by a gap 31. Spanning gap 31 is an arm 32 which has a projection 33 at its free end. A bore 34 extends through the drive boss 23 to receive pin 24. The waisted end portion 35 of each drive boss 23 is located adjacent bearing 16.

Each drive sprocket 25 and 26 includes a flange 37 at one side of the toothed periphery. The drive sprocket which is illustrated in Figures 2 and 3 has a recess 38 at the side having flange 37. Extending from peripheral wall 36 into the recess 38 are a pair of shoulders 39 so shaped and dimensioned as to be engageable into the gaps 31 of a drive boss 23. The drive sprocket illustrated in Figures 2 and 3 is sprocket 25 shown in Figure 1.

The drive sprocket 26 is of the same general construction except that the recess 38 extends inwardly from the non- flanged side thereof. Thus, as shown in Figure 1, the drive sprocket on shaft 18 is reversed relative to the other one located on coupling 20 but due to the different positioning of the recesses 38 in the sprockets both are drivingly engaged with a drive boss 23. Drive sprocket 25 is of greater diameter and thus has more teeth. By way of example, in the illustrated arrangement drive sprocket 25 with 28 teeth while the smaller drive sprocket 26 has only 24 teeth.

When the drive bosses 23 are engaged into recesses 38 the projection 33 of each arm 32 engages against the outwardly located surface of shoulders 39. The inherent flexibility of the arm 33 thus applies a biasing or restoring force to the sprocket arising from any axial movement of the sprocket on the respective shaft 18 or coupling 20.

If an end user, installer, or the like of the operator wishes to change the gearing and thus speed of rotation of the output of the gearbox, ie coupling 20, the cover 11 is simply removed, the drive belt 27 and sprockets 25, 26 lifted off as one and the relative positions of the sprockets interchanged, ie sprocket 26 is placed on shaft 18 and sprocket 25 is placed on coupling 20. The cover 11 is then put back in position. This simple operation changes the gearing between the output shaft 18 and the coupling 20 and can be carried out very quickly.

In accordance with known constructions the threaded shaft 15 iε located between the operator housing (in this case a drive coupling between the end of the threaded shaft and the coupling shaft 20) and a suitable bearing located at the other end of the rail 15. Also in accordance with known techniques a plurality of support bearings are located along the length of the threaded shaft and within the confines of the rail 15. These support bearings can be of the type illustrated in Figures 12 and 13. The bearing essentially comprises a boss 40 having an internal diameter slightly greater than the diameter of the threaded shaft. Projecting diametrically from each side of the boss 40 are substantially U-shaped clips 41 in which rods (not shown) are engageable.

The support bearings of the present invention, however, are characterised by having flexible wings 42 which curve away from the boss 40 and have bulbous or enlarged ends 43. As shown in Figure 14, these bulbous ends 43 slidingly engage in corners of the angular cross-section rail 15. The wings have a degree of flexibility and thus provide a shock absorbing function which not only ensures the support bearings are correctly maintained in position but also reduce transmission of noise from the operation of the threaded shaft to the rail 15.

In accordance with known techniques the support bearings are slidingly movable longitudinally within the rail 15 with the coupling rods between pairs of support bearings resulting in the support bearings moving within the rail 15 commensurate with movement of the drive nut. This ensureε that the support bearings are movable to enable the drive nut to move along the length of the threaded shaft yet by controlling the movement of the bearings by coupling them via the rods they provide maximum support for the threaded shaft over its length.

In a preferred form one of the clips 41' (see Figure 27) includes a bore 81 with a pair of diametrically opposed slots 82 opening into the bore. This enables the end of a coupling rod 83 with projections 84 to be slid through the bore 81 until the projections 84 are clear of the end of the clip, the rod 83 can then be rotated through 90° and pulled back so the projections 84 engage in diametrically opposed recesses 85. The end of the rod 83 is thus captivated inside the retaining clip so as to prevent the rod from being pulled away from the bearing support.

As with the support bearings the drive nut 45 is likewise moulded from a plastics material preferably acetal. As illustrated, the drive nut 45 is moulded in two halves 46 and 47.

Drive nut half 46 is formed by an elongate semi-circular body 48 which is provided with a part thread 49 which extends for at least part of the length and the inner radial surface of the body. This thread 49 combines with thread 49' of the other half 47 of the lock nut so that when the two halves are combined the combined threads 49 and 49 ' engage about the thread of the threaded shaft.

Extending from the main body of nut half 46 is a turret 50 which forms a coupling (in a known manner) with an arm extending from the top part of the closure. Curving away from the external peripheral surface of the main body of each half 46 and 47 are a pair of wings 51 which, as with the support bearings, have enlarged or bulbous ends 52. Also projecting from the main body of nut half 43 are a pair of half clips 53 which combine in the completed nut with clip halves 53' of nut half 47. The clips formed by halves 53 and 53' engage with the aforementioned rods which connect with the support bearings most adjacent each side of the drive nut 45.

Drive nut half 46 is completed by two pairs of legs 55 which have hooked shaped outer ends 56. These legs 55 engage in openings 57 formed in nut half 47. Thus the two nut halves 46 and 47 can be located at diametrically opposite sides of the threaded shaft and pushed together so that legs 55 engage in a snap-lock arrangement in openings 57 to lock the two halves together about the shaft.

Once again, as illustrated in Figure 14 the wings 51 of the drive nut 45 engage via their bulbous ends 52 in the corners of the angular cross-section rail 15. They therefore not only locate the drive nut in a sliding position in the rail 15 but provide a shock absorbing function and lead to a reduction in noise generated by virtue of the shaft rotating and the drive nut moving within the rail.

The present invention thus provides a gearbox arrangement for a door operator whereby the gearing of the output to the threaded shaft can be quickly and conveniently adjusted. The gearbox is quiet in operation in large part due to the use of a drive belt and the non-fixed (axially) mounting of the drive sprockets with the drive bosses. The construction and arrangement of the support bearings and drive nut provide for smooth and quiet operation of the threaded shaft within the rail and movement of the drive nut along the rail. Therefore, the operator is operative at acceptable low noise levels.

To further reduce operating noise, a flexible coupling is preferably provided to couple the output shaft 20 to the threaded shaft. The flexible coupling compriseε first and second coupling parts 60 and 61 which are of moulded plastics construction with a preferred material being acetal. A flexible spider 62 which forms the driving engagement between the coupling parts 60 and 61 (as hereinafter described) is provided. The spider 62 is formed from a resilient material with a suitable material being santoprene.

The first coupling part 60 has a boss 63 which forms a bore 64 into which the end of the threaded shaft can be engaged. A pair of diametrically opposed bores 65 which are transverse to bore 64 enable a pin to be driven through an aligned bore in the shaft so as to pin the coupling part 60 to the shaft.

Extending in an opposite direction to boss 63 are a plurality of sector projections 66, the inner faces of which are provided with a curved transverse recess 67.

The second coupling part 61 is of similar construction, however, the bore 64' and the boss 63' is of a cross- sectional shape which corresponds with that of output shaft 20 so that the boss can simply be slipped over the end of the output shaft 20 in driving engagement therewith. The coupling part 61 similarly has projection 66' with recesses 67' .

The spider 62 has a plurality of radially projecting fingers 68. The external wall surface of the annular body 69 of the spider 62. has a circumferentially extending curved rib 70 which is of a shape commensurate with the shape of recesses 67 and 67'. Thus the spider 62 can be engaged onto say coupling part 60 such that adjacent pairs of fingers 68 engage either side of each of εector projections 66.

The spider 61 fits in a snap lock type engagement due to the location of the rib sections 70 between the pairs of adjacent fingers 68 into the respective recesses 67 of the projection 66. The second coupling part 61 can then be engaged with the first coupling part 60 and spider 62 by locating the sector projection 66' between the other pairs of fingers 68 with once again a snap lock coupling occurring due to the inter- engagement of the rib sector 70 and recesses 67'.

Due to the resilient nature of the spider 62, a flexible coupling prevents any transmission of vibrational noise and thereby further quietens the operation of the door operator/gearbox/threaded shaft. In Figures 24-26 there is shown a rail stop 71. This is of a moulded construction comprising a base 72 from which projects a shaft engagement portion 73 having a curved recess 74 into which the shaft can locate. Projecting from each end of the base 72 is a flange 75 having an opening 76.

The rail stop can be combined with the rail 15 by inserting the projecting portion 73 between the terminal edges 77 of the sides 78 of the rail 15 (see Figure 14). These sides 78 thus engage between the projection 73 and the flanges 75 so that the flanges 75 engage either side of the rail. Once the rail stop has been placed in a position which corresponds with the end point of the travel of the drive nut holes can be drilled in the sides 79 of the rail 15 to align with opening 75 whereupon fastenings can be inserted through the aligned openings to hold the rail stop 71 in position.

The rail stop not only provides an end stop for the drive nut but also the location of the threaded shaft within the recess 74 provides yet further support for the drive shaft to thereby further reduce vibrations in the drive shaft.

Claims

1. A gearbox for an operator of a closure such as a door, the gearbox including input and output shaftε (18 and 20) joumalled for rotation, there being drive bosses (23) mounted on said output and input shafts, a toothed sprocket (25 and 26) engaging with each drive boss and a toothed belt (27) extending about the drive sprockets to transfer drive from the input shaft (18) to said output shaft (20), the toothed sprocketε being of different sizes and interchangeable on the bosses of the respective shafts.

2. The gearbox according to claim 1 wherein each sprocket (25 and 26) includes a flange (37) on one side thereof, said flange extending peripherally beyond the teeth of the sprocket.

3. The gearbox as claimed in claim 1 wherein each drive boss (23) is located by locating means (24) on the respective input and output shafts (18 and 20) so as to be prevented from both longitudinal and axial movement relative to the shaft.

4. The gearbox as claimed in any one of claims 1 to 3 wherein each drive boss (23) includes driving projections which are selectively engageable in drive projection receiving recesses (38) in one of either side of a toothed sprocket (25 or 26).

5. The gearbox as claimed in any one of claims 1 to 4 wherein the toothed sprockets (25 and 26) and drive bosses

(23) are formed from plastics material.

6. The gearbox as claimed in any one of claims 1 to 7 further including a base (10) adapted for mounting to a motor housing or a motor support, a gearbox cover (11) engageable with said base (10), means for receiving within said gearbox and forming said input shaft the output shaft (18) of a motor, the distal end of the output shaft being locatable in bearing means (17) associated with the cover (11).

7. The gearbox as claimed in claim 6 wherein the cover (11) includes an opening (21) through which the gearbox output shaft (20) projects, the cover including an engagement means (14) for engaging with an end of a rail (15).

8. An operator for a closure, the operator being characterised by including a gearbox coupled to an output shaft (18) of a motor, the motor output shaft (18) having a toothed sprocket (25) drivingly coupled to a different sized toothed sprocket (26) of a gearbox output shaft (20), the sprockets being mounted such as to be interchangeable to alter the gear ratio of the gearbox.

9. An operator as claimed in claim 8 wherein the toothed sprockets (25 and 26) are drivingly coupled by a toothed belt (27).

10. An operator as claimed in claim 9 wherein each sprocket (25 and 26) is coupled to a respective motor output shaft (18) and gearbox output shaft (20) by a drive boss (23) fixedly mounted to the shaft.

11. An operator as claimed in claim 10 wherein each drive boss (23) includes a drive projection which is shaped to fit in a drive recess (38) in one of either side of a said toothed sprocket (25 or 26).

12. An operator for a closure such as a door, the operator including a threaded shaft (40) located within a rail (15) by a plurality of bearing supports (40) and a drive nut (46,47) threaded onto the shaft (40) whereby rotation of the shaft results in movement along the rail of the drive nut and the bearing supports, the drive nut and/or the bearing supports being characterised by having a plurality of flexible wings (42 and 52) which locate in sliding contact with an inner wall surface of the rail (15) but restrict rotational movement of the drive nut or bearing supports about the axis of rotation of the threaded shaft.

13. An operator as claimed in claim 12 wherein each of said drive nut (46, 47) and bearing supports (40) includes a pair of means (41) for receiving a part of a coupling rod means (83) such that a coupling rod means is located between pairs of support bearings (40) resulting in such support bearings moving within the rail (15) commensurate with movement of the drive nut (46, 47) .

14. An operator as claimed in claim 12 wherein each bearing support (40) has a pair of such receiving means (41) one of which is provided with anchoring means for anchoring against movement a said part of said coupling rod means (83).

15. An operator as claimed in any one of claims 12 to 14 wherein said flexible wings (42 and 51) curve away from the respective drive nut (46, 47) and/or bearing support (40) to terminate in bulbous or enlarged distal ends (43, 52).

16. An operator as claimed in any one of claims 12 to 15 wherein the drive nut is formed in two halves (46 and 47), each half having a part threaded portion (49) which combines when the two halves are joined together with the other part threaded portion to form a thread which engages about the thread of the threaded shaft (40).

17. An operator as claimed in claim 16 wherein snap lock means (56 and 57) are provided for coupling the halves of the drive nut together.

18. An operator as claimed in any one of claims 12 to 17 further including a flexible coupling between an output shaft of a gearbox (20) driven by a motor and the threaded shaft (40).

19. An operator as claimed in claim 18 wherein the flexible coupling includes a spider (62) having a plurality of projecting fingers (68), said fingers being sandwiched between pairs of driving projections of first and second coupling portions (60 and 61) combined together with the driving projections (66 and 66' ) of said first and second coupling parts alternately locating either side of the fingers (68), said coupling portions including engagement meanε (63 and 63' ) for engaging with said gearbox output shaft (20) and said threaded shaft (40).

20. An operator as claimed in claim 19 wherein said εpider (62) fits in a snap lock type engagement (67 and 67' ) between the pairs of adjacent driving projections (66 and 66' ) of the first and second coupling portions (60 and 61).