WO2006013461A2

WO2006013461A2 - Automatic sliding door assembly

Info

Publication number: WO2006013461A2
Application number: PCT/IB2005/002469
Authority: WO
Inventors: Allan Meyer; Mark Hancock
Original assignee: Hancock, Darren
Priority date: 2004-07-26
Filing date: 2005-07-26
Publication date: 2006-02-09
Also published as: WO2006013461A3

Abstract

An assembly for automatically opening and closing a sliding door of the type including a fixed panel and a moving panel which slides on a track relative to the fixed panel. The assembly comprises a housing defining an internal space; a support frame defining a space which receives and retains a drive assembly including a motor having a drive shaft; a drive wheel operably linked to the motor via said drive shaft. The assembly also includes an idler pulley; at least one drive belt associated with said drive wheel and the idler pulley; wherein, when the drive wheel is energised by the motor, motion is imparted to the drive belt thereby causing the movable panel of the sliding door to move between a first state when the door is closed and a second state when the door is open.

Description

AUTOMATIC SLIDING DOOR ASSEMBLY BACKGROUND

The present invention relates to an automatic sliding door and more particularly relates to an assembly for automatic opening and closing of the door. More particularly the present invention relates to a belt driven automatic door opening and closing assembly which operates responsive to a sensor activated in response to a trigger which may be activated by a person animal or object.

PRIOR ART

Sliding doors exist in many residential and commercial properties. A typical sliding door spans an opening in a building and has a fixed panel normally bounded on three sides and a co operating moving panel which is capable of sliding in a track so that it moves between a closed state in which the moving panel closes an opening and an open state in which the moving panel is slid back and at least partially overlaps the fixed panel to thereby allows access through the opening. The task of opening and closing the door is normally conducted manually. Residential applications of such sliding doors include providing access to verandas, kitchens, dining rooms, ensuites, walk-in wardrobes, built-in wardrobes, balconies, between room and other access applications such as patios. An advantage of a sliding door is that a_sliding door allows access therethrough without the additional space requirement of a swinging door. This provides the user with access to the swept space a swinging door would normally require.

A sliding door keeps an area enclosed whilst allowing access to or from the area. Some advantages include reducing convective heat transfer for reduced heating requirements, reduced dust accumulation (e.g. walk-in wardrobe), reduced air circulation, reduced noise outside an enclosed space, and room division for multi-purpose utilisation. Sliding doors for residential purposes are generally not automated. The purpose of an automated sliding door is to allow the door to be opened and closed without the need for manual intervention. This is particularly advantageous when carrying food through a sliding door, where a person is handicapped or confined to a wheelchair, a pet seeks access through the door and also to provide a self closing facility.

Present commercial applications of automatic sliding doors often use a floor mounted or elevated sensor to determine when a person is approaching. This is not suitable for retrofit in residential applications because of the loss of floor and frame aesthetics in fitting the floor sensors.

Automatic doors are available that use a microwave movement sensor instead of a floor sensor to detect an approaching object. However, this technology is less than perfect because it can operate intermittently and often requires the user to wave a hand (or to walk backwards and forwards again) to activate the movement sensor. The movement sensor sliding door is not suitable for pets because of the need to artificially create sufficient movement to activate the sensor. Elevated motion sensors can also trigger automatically when not required because it can be difficult to accurately position the sensing boundary.

Some residential automatic sliding doors overcome the pet access problem by placing a remote control on the collar of the pet. However, this approach adds to the expense of the unit, and may be damaged by the pet

Domestic automatic sliding doors have in the past employed a pressure sensor to determine if an object is caught in the door. If the door catches a person, the use of the pressure sensor to determine their presence can be quite frightening to the user. Also, the pressure sensor only determines when something obstructs the door closing but could crush an object or limb, if it is behind the door as it opens. There are various sliding door assemblies in the prior art examples of which are described below with reference to various United States Patents. United States Patent 4,231,192 discloses a Linear output force door operator including an electrical drive motor and a linkage arrangement having a drive bar applying driving action through a roller to a slide bar multiplying lever wherein the multiplying lever is pivotally mounted at one end and slidably engaging a roller near the other end which is mounted on a slidable door. That invention is particularly concerned with the operation of doors on railroad passenger cars, and particularly sliding doors arranged between interconnected passenger cars to provide automatic door operation for passenger traffic between the cars. It is therefore important to safeguard passengers using such doors against injury. Such door operators are preferably passenger actuated for opening and automatically actuated for closing although totally automatic operation initiated at a remote location is also contemplated. Further, such operators must have provisions for sensing an obstruction to prevent injury of a passenger that may be in the path of a closing door. This type of door also has a time delay.

United States Patent 4,621,452 disclose a powered sliding door safety system having a safety light beam which travels with and ahead of a closing door. Interruption of the safety light beam by an object in the path of the closing door activates a door control to stop or reverse the closure of the door. A stationary transmitter projects a beam of pulsed infrared light to a convex mirror mounted on the door. The mirror reflects the projected beam ahead of the closing door in a direction transverse to the direction of closure. In one embodiment a plurality of receiver assemblies with overlapping receiving sectors monitor the door closure path and sense the presence of the moving safety beam. Interruption of the safety light beam is detected in a control unit connected to a unit which controls a motor that moves the door.

United States Patent 4,866,881 discloses an automatic door safety system for controlling the opening and closing operation of a sliding door wherein at least two presence sensing detectors are disposed effective to cast beams in overlapping relation to one another and extending across the pathway of the door to be controlled, and manual means or motion detecting detectors effective to provide for the initiation of movement of the door to open position Furthermore programmed computer means are included in the system for the controlled sequencing and pulsing of the presence sensing beams in the opening and closing operation of the door.

In another example United States Patent 4,967,083 discloses a door sensor system for an automatic sliding door and which employs multiple sensor modules. Each of the sensor modules includes both a presence sensor and a motion sensor. In addition, each of the sensor units includes switches for adjusting the size of the presence zone, for selecting either a continuous or a triggered scan mode and for selecting an operating phase to prevent interference. The sensor units are generally mounted above the threshold of the doorway and their operations are synchronized to provide both a traffic sensor and a safety sensor for a sliding door system.

United States Patent 5,594,316 discloses a power supply device for a sensor which can be used for a long time without any wire linking an outside power source and a movable door so as to supply an electric power, an outside power source contact on a transom and a battery contact on a door are connected when the door is in its closed or open position, induced current is generated from a primary circuit on the transom to a secondary circuit on the door by electro¬ magnetic induction when the door is in its closed or open position, or electric current is generated by a generator mounted to the door by utilizing the closing and opening movements of the door.

In another example of an automated sliding door system United States Patent 4,914,859 discloses a mechanism primarily suited to automatic sliding door applications wherein at least a pair of object presence sensing detectors, preferably of the ultra-sonic transducer type are arranged to be placed in linear spaced relation to one another effective to cast sonic beams produced thereby spanning the doorway to which applied. The system of this invention is adaptable to using a conventional door beam sensing mechanism for automatic

Other automatic systems for use with sliding doors are disclosed in United States patents 5,581,944 5,996,281 which are incorporated by reference herein.

Further attempts have been made to improve automated sliding door assemblies an example of which has been disclosed in the Applicant's own PCT international application No. PCT/AU04/001755

None of the prior art assemblies know to the applicants disclose a belt driven assembly for opening and closing a sliding door.

INVENTION

The present invention seeks to provide a further alternative to the known sliding door assemblies using a motor driven belt drive and including means to selectively adjust belt tension and to disengage drive to the belt..

The present invention provides an improved assembly for automatically operating a sliding door and more particularly provides an assembly for automatic opening and closing of the door. The automatic door opening and closing assembly operates responsive to a sensor activated in response to a trigger which may be activated by a person, animal or object. The present invention includes an element attachable to a door and to a drive belt which drives a sliding door open and closed. The assembly also has within its housing and outside the housing an active infrared sensor system to detect the approach of a person, pets or objects. The automatic assembly mechanism can be fitted simply to the sliding door either on the floor or wall or pelmet. It can be mounted inside or outside the room or entry area. The sensor detects the presence of an object; including a pet, such as a cat or dog. The detection of an object, as opposed to detection of movement, overcomes the problem of poor initial detection. A movement sensor must pick up movement as the object approaches the door. The sliding assembly will open whenever an object is within close proximity of the door entrance. If the sensor fails to detect the object initially, the continued presence of the object will ensure the door opens soon afterwards without the need for additional movement.

The sliding door operating assembly maintains the advantages of state of the known sliding doors. The door does not require the large sweep area of a traditional swing door and may be adapted to sliding doors which slide into a wall recess. The sliding door assembly according to the invention keeps an area enclosed whenever the door is not in active use. This is a substantial advantage over manual sliding doors that are frequently left open for convenience of future use.

The automatic door operating assembly ensures that the sliding door is always closed when not in use, keeping out insects, reducing convective mass transfer of ajr to and from an enclosure, reducing heating and air conditioning requirements. Further, dust accumulation within an enclosure, such as a wardrobe, is minimised, as the door will never be left open when not in use as it will automatically close responsive to operation of the sliding assembly. . The automatic door sliding assembly will reduce flying insects entering a residence because the door will be closed whenever it is not in use, and never needs to be propped open to allow convenient no hands usage. When hands are otherwise engaged, the door will automatically open for the user and close when the user has passed through.

According to one embodiment, the assembly operates in conjunction with an active infrared sensor to determine the presence of an object or limb when the door is closing or opening. Thus the door normally will not come into contact with the user by accident, creating a much safer operating environment. In one broad form the present invention comprises:

an assembly for automatically opening and closing a sliding door of the type including a fixed panel and a moving panel which slides on a track relative to the fixed panel; the assembly comprising: a housing defining an internal space ; a support frame defining a space which receives and retains a drive assembly including a motor having a drive shaft; a drive wheel operably linked to the motor via said drive shaft; an idler pulley; at least one drive belt associated with said drive wheel and said idler pulley; wherein, when said drive wheel is energised by said motor, motion is imparted to the drive belt thereby causing the movable panel of the sliding door to move between a first state when the door is closed and a second state when the door is open.

According to a preferred embodiment one drive belt is operably linked to said drive wheel and the idler pulley. Preferably, the drive belt includes means to allow connection of the drive belt to said moving panel to facilitate movement of said panel when said drive belt moves.

Bracket means are provided to connect the belt to the moving panel . The belt locates in a groove in said drive wheel and said pulley which may be a V groove.

The drive motor is preferably disposed in a recess in the support frame. The idler pulley is disposed in longitudinal alignment with said drive pulley and further comprises a belt adjustment assembly for adjusting tension in said belt. The belt adjustment assembly is associated with the idler pulley. The drive wheel is located at a first end of the assembly and the idler pulley is located at a second end of the assembly. The adjustment assembly includes a pivotally mounted cam bracket having a handle at one end and a recess at another end to engage an axle of said idler pulley; wherein the cam is capable of rotation between a first position in which the belt is at maximum tension and a second position in which the belt is a minimum tension. The recess engages the axle of the idler pulley to maintain the belt at maximum tension. The adjustment assembly further comprises a mounting bracket having a slot in which the axle moves rotationally and longitudinally in the slot. The motor has a shaft extending normally to a longitudinal axis of said assembly and is of sufficient length to receive and retain said drive wheel. The shaft transfers drive from said motor to said drive wheel. The shaft via co operates with the motor to transfer drive from the motor via a shaft to the drive wheel.

The drive assembly includes a release mechanism which allows disengagement of the drive wheel from the motor. The release assembly preferably includes a dog clutch which engages a ring and further comprises a cam wheel having an operating handle, the cam wheel including cam surfaces which co operate with said dog clutch to allow release of said drive wheel from operation of said motor. The release mechanism also has an end plate which engages and co operates with said cam wheel . The release mechanism further comprise a micro switch capable of disengaging power to said motor. The operating handle on the cam wheel moves between a first position in which said drive wheel is released from drive by said motor and a second position in which said drive wheel is operated by said motor.

The support frame includes a base and side walls and a cover which engages the support frame to form a housing. The drive wheel is internal of the housing

The support frame has a longitudinal recess in which said motor is disposed and an adjacent parallel longitudinal recess in which said idler pulley is disposed. A controller board operates the motor and drive wheel responsive to a signal.

The sensor is operated by pressure applied to a location remote from said door by a person approaching the door.

The power source for said motor is a battery. The sensor unit is disposed within the housing formed by the cover and said support frame and uses active infrared to detect the presence of an object within a range of influence of the sensor. The sensor has a time delay to ensure that the door will not close on an object or person

In another broad form the present invention comprises: an adjustment assembly for adjusting belt tension in a belt drive assembly for automatically opening and closing a sliding door panel ; the adjustment assembly comprising : the belt drive comprising: a support frame defining a space which receives and retains a drive assembly including a motor having a drive shaft; a drive wheel operably linked to the motor via said drive shaft; an idler pulley; at least one drive belt associated with said drive wheel and said idler pulley; wherein, when said drive wheel is energised by said motor, motion is imparted to the drive belt thereby causing the movable panel of the sliding door to move between a first state when the door is closed and a second state when the door is open; said belt adjustment assembly is associated with the idler pulley and includes a pivotally mounted cam bracket having a handle at one end and a recess at another end to engage an axle of said idler pulley; wherein the cam is capable of rotation between a first position in which the belt is at maximum tension and a second position in which the belt is a minimum tension.

Preferably, the recess engages said axle of said idler pulley to maintain the belt at maximum tension. The adjustment assembly further comprises a mounting bracket having a slot in which said axle moves.

In another broad form the present invention comprises: a drive wheel release assembly for selectively releasing a drive wheel in an assembly for automatically opening and closing a sliding door of the type including a fixed panel and a moving panel which slides on a track relative to the fixed panel; the assembly including : a support frame defining a space which receives and retains a drive assembly including a motor having a drive shaft; a drive wheel operably linked to the motor via said drive shaft; wherein, when said drive wheel is energised by said motor, motion is imparted to the drive belt thereby causing the movable panel of the sliding door to move between a first state when the door is closed and a second state when the door is open; the release assembly comprising; a release mechanism which allows disengagement of said drive wheel from said motor.

The release assembly preferably includes a dog clutch which engages a ring. and a cam wheel having an operating handle, the cam wheel including cam surfaces which co operate with said dog clutch to allow release of said drive wheel from operation of said motor. The release mechanism further comprises an end plate which engages and co operates with said cam wheel, wherein the release mechanism further comprise a micro switch capable of disengaging power to said motor. The operating handle on the cam wheel preferably moves between a first position in which said drive wheel is released from drive by said motor and a second position in which said drive wheel is operated by said motor. A battery may be used to power the motor, which would preferably be rated between 6 to 34 volts. A power pack can intermittently charge or continually charge the battery. Alternatively, the mains power may be used but this can be reduced by a transformer.

It is an object of the present invention to provide an assembly sufficiently economical enough and which incorporates the method of drive as described herein.

Particular examples of the drive mechanism will now be described. Persons skilled in the art will appreciate that many variations and modifications can be made to the examples, without departing from the scope of the invention as outlined above.

BRIEF DESCRIPTION OF THE DRAWINGS:

Figure 1, shows a perspective view of a door sliding assembly according to a preferred embodiment housing cover and end plates removed for clarity of the assembly and other parts.

Figure 2 shows the sliding assembly of Fig.1 from the other side of the slider with housing cover and end plates missing removed for clarity

Figure 3 shows the sliding assembly with the housing cover in place and without the end plates. Figure 4 shows the sliding assembly with the housing cover but without end plates mounted in the pelmet position

Figure 5 shows the drive end of the assembly with the end plate attached and cover missing for clarity

Figure 6 shows the end of the sliding assembly describing the action of the belt Adjustment assembly in the belt tight position and belt relax positioa Figure 7 shows the belt adjustment mechanism isolated from the assembly.

Fig. 8 shows the locking detail of the belt adjustment mechanism.

Figure 9 shows the end of the slider describing the drive release mechanism Figure 10 shows the end of the slider assembly describing the drive release mechanism according to one embodiment.

Figure 11 shows an exploded view of the drive release mechanism of figure 10. Figure 12 shows the operation of the active infrared sensor system. 40 Figure.13 shows a pressure sensor mat to activate the door opening. Figure. 15 shows the automatic door slider may be attached to the pelmet to drive the door or alternately attached to the floor to drive the door as shown in??.

DETAILED DESCRIPTION

Referring to figure 1 there is shown a perspective view of a door actuation assembly 1 for fitting to a sliding door assembly. A typical sliding door assembly comprises a fixed door panel ( or wall) and a moving panel . The moving panel rides on a track usually embedded in concrete base.

Assembly 1 comprises a support frame member 2 having a base 3, side walls 4 and 5 and intermediate dividing wall 6 defining recesses 7 and 8. Recess 7 receives and retains therein drive motor 9 and gear box 10. Recess 8 receives and retains therein a drive wheel 11 connected to drive motor 9 via shaft 12.

Assembly 1 also comprises an idler wheel / pulley 13 disposed at or near end 14 of frame member 2. Disposed about drive wheel 11 and idler pulley 13 is a drive belt 15 which travels about wheel 11 and pulley 13 upon actuation of motor 9. When motor 9 is actuated wheel 11 rotates imparting motion to drive belt 15. Included on drive belt 16 is a connection bracket 17. Bracket 17 is connected to belt 16 via first end 18 and via second end 19 to a moving door panel see figure ???). In the preferred embodiment drive wheel 11 may be disengaged from motor 9 allowing the sliding door moving panel to be selectively manually opened or closed. A micro-switch may be provided, which isolates the electric power from the motor. To power the motor, which can be 6 to 34 volts, a battery 20 can be used which may be rechargeable via a power pack capable of intermittently or continually charging the battery. Alternatively, mains power reduced by a transformer can be used to supply motor 9. Motor 9 is mounted onto the support frame 2 by fixing screws or like fasteners not shown. Wheel 11 is mounted on motor drive shaft 12 and drives belt 16. Belt 16 may be either a tooth belt or a multiple small v-belting. Moving panel attachment bracket 17 attached to the belt 16 is according to one embodiment connected to the door panel by multiple fasteners such as three or four screws ( not shown). Assembly 1 further comprises an electronics panel 21 mounted on support frame 2. Idler pulley 13 is mounted in belt adjustment assembly 22. Figure. 2 shows the same assembly as Figure 1 from an opposite perspective view exposed for clarity with a cover housing and end plates omitted from the assembly 1. In figure 2 battery 20 is shown secured with the battery clamping plate 23 fastened by clamping lugs 24 and 25 which are in turn fixed by screws 26. Figure 3 shows the sliding assembly with the housing cover in place and without the end plates. Figure. 3 shows the cover housing 27 in position on the assembly.

Figure 4 shows the sliding assembly with the housing cover 27 omitted, but without end Fig. 4 shows assembly 1 without endplates, as it would be seen when mounting the assembly at or near the top of a movable panel such as when mounted in pelmet location.

Figure 5 shows the endplate 28 connected to support frame 2. Assembly 1 further comprises a disengagement assembly 29 including belt release lever 30 capable of disengaging belt 6. Release lever 30 engages a release cam assembly 31 { see figure 11) in position with the cover housing 27 missing for clarity.

Figures 6 a & b show end 32 of the sliding door assembly 1 describing the action of the belt adjustment assembly 22. Figure.6 shows the belt adjustment assembly 22. Assembly allows belt 6 to be adjusted between a first state in which the belt is at maximum tightness and a second state in which the belt is at maximum relaxation. The belt adjustment assembly 22 includes cam bracket 33 which is capable of rotational movement between the position shown in figure 6a and the position shown by figure 6b as show by arrow 34. Idler pulley 13 is mounted on shaft 35 which allows pulley 13 to move longitudinally along support frame 2 and along slot 36. Slot 36 may be adjusted in length to increase longitudinal travel of shaft 35 but an appropriate length of travel will be approximately two diameters of shaft 35.

In use, once belt 6 is fitted about pulley 13, belt adjustment assembly 22 is urged towards end 32 of support frame 2 taking up the slack in the belt 6 so it maybe set within the allowable limit of travel to a selected belt tightness. Once in position adjustment assembly 22 may be secured by screws so as to lock adjustment assembly 2 to the base plate 1. To tighten the belt to operating tension, the cam 31 (see figure 11) operated by bracket 33 is locked home as shown in figure 6a as bracket 33 is rotated in the reverse direction of arrow 34. Cam bracket 33 has an overlooking recess 36 ( see figure 8) which engages shaft 35 about which pulley 13 is mounted which holds tension in place by preventing shaft 35 from unwanted longitudinal movement thereby holding belt tension in place.

Figure 7 shows the belt adjustment assembly 22 isolated from the assembly 1.

Assembly 22 comprises saddle bracket 37 defining a space 38 which receives pulley 13 and bracket 33. Figure 8 shows the cam bracket 33 and pulley 13 exploded away from saddle bracket 37. It may be seen that bracket 33 terminates in recess 36 engages shaft 35 when cam bracket 33 is rotated about pivot 39. Figure. 9 shows end 40 of assembly 1 showing drive motor 9 and drive wheel 11 engaging belt 6 Each of those parts are shown mounted in frame 2 as previously described. Cover 27 and end plate 28 removed for clarity. Release lever 30 which connects to cam 31. Figure IO a & b shows two end views of a wheel release mechanism 41 with release lever 30 shown in an unlocked position (figure 10a ) and in the locked position (figure 10b). This arrangement allows a user of assembly 1 to selectively engage and disengage automatic drive to the movable sliding door panel. Figures 10 a & b have corresponding parts previously described with corresponding numbering. In an alternative embodiment, lever 30 may operate engagement and disengagement by rotation rather than elevation and de elevation.

Figure. 11 is an exploded view of the release mechanism of figures 10a and 10b. If and when there is a power failure, the battery will supply power for a few hours operation When this power has run out prior to activating the assembly 1 or during the process of locking a sliding door panel, the release lever 30 is moved from the down position of figure 10b to the up position shown in Figure 10b, this action disengages the dog clutch 42 from the drive pulley 12 allowing the door panel 43 ( see figure 9) to slide freely. Ramps 44 on cam 31 associated with release lever 30 engage ramps 46 on ring 47 which facilitates the required axial displacement movement, which disengages the dog clutch 42 from the drive pulley 12. The door panel 43 can now be moved by hand and will only drive the belt 6 and the pulleys 12 and 13. Ring 47 is locked to end plate 48 by spline 49. End plate 48 is located and secured to wall 5 of frame support 2 by projections 50 in locating holes 51. The action of the rotating movement of release lever 30 contacts micro switch 52 which in turn disengages power to the motor 9. The dog clutch 42 is pinned to motor shaft 12 and the locking and movement of the drive pulley 11 is supplied by spring 53. Bearing 54 supports motor shaft 12 on wall 5 of frame support 2.

Figure 12 shows the assembly 1 as described above fitted to a moving panel 43. Panel 43 is operated according to the embodiment shown by an active infrared sensor system including sensor unit 55 housed within housing 27. Active infrared is used to detect the presence of an object within the balloon regions 56 and 57. During a set up phase, the sensor unit 55 determines the range of the closest permanent object to the sliding door by gradually increasing the intensity of the infrared beam from weak to strong each time an infra red beam is strengthened and an infrared pulse train is sent out of a transmitter LED. Should the signal not be returned the infrared beam strength is further increased until it reaches an object. Upon reaching an object, the sensor units backs back to a distance where the infrared beam just out of range of the object. It is then set for operation. If the infra red beam does not reach an object then it is set for operation at a predetermined limit. Should an object enter the balloon area 56 when door panel 43 is closed, sensor 55 checks balloon region 58 to ensure the area directly behind door panel 43 is clear. If it is, then door panel 43 is activated to open via activation of belt 6. . After a time delay sensor unit 55 assesses that the balloon area 57 and 56 are clear to ensure that the door will not close on an object or person, then it closes door panel 43.

When a person or animal approaches the sliding door to which assembly 1 is fitted, the sensor unit 55 covering the monitoring area determines an object presence. If a rear sensor does not detect a presence in the area which the sliding door is to move to, then the automatic door sliding assembly drives the door to the open position. Provided a sensor covering the door area does not detect anything, the door closes. If a fast moving person or pet moves into a sensor detection area, as the door closes, the door will stop mid closing and open up. In the unlikely event that the door closes on a person pet or object, then the door will detect the presence by a slight door pressure and reopen the door. If there is a person pet or object in the path of the opening door the automatic assembly 1 will stop until such time as the presence is removed. If a person approaches the door from the outside there may be provided an active infrared sensor on an exterior wall, pelmet or fixed door, which will detect a presence approaching and open the door. The door will stay open until the presence moves away from the detection area and then the automatic sliding assembly closes the door. The communication between the electronics of the assembly and the outside sensor may be hard wires or wireless.

Figure 13 shows an alternative approach detection method by using pressure sensitive mats 59 and 60. Figure 14 shows assembly 1 floor mounted and attached to panel 43 via bracket 61. Handle 30 in this embodiment is shown as a rotatable handle which is an alternative to the embodiment shown in figures 1 Oa and 10b.

A. major aim of this invention is to build a unit economical enough to sell in great numbers on the open market and therefore the method of drive has become a major consideration.

It will be appreciated by persons skilled in the art that the inventive concept in any of its aspects and embodiments can be created in a variety of different constructions so that generality of the preceding description is not superseded by the particularity of the attached drawings. Various alterations, modifications and/or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit or scope of the present inventioa

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1 An assembly for automatically opening and closing a sliding door of the type including a fixed panel and a moving panel which slides on a track relative to the fixed panel; the assembly comprising: a housing defining an internal space ; a support frame defining a space which receives and retains a drive assembly including a motor having a drive shaft; a drive wheel operably linked to the motor via said drive shaft; an idler pulley; at least one drive belt associated with said drive wheel and said idler pulley; wherein, when said drive wheel is energised by said motor, motion is imparted to the drive belt thereby causing the movable panel of the sliding door to move between a first state when the door is closed and a second state when the door is open.

2 An assembly according to claim 1 wherein one said drive belts is operably linked to said drive wheel and the idler pulley.

3 An assembly according to claim 2 wherein, the drive belt includes means to allow connection of the drive belt to said moving panel to facilitate movement of said panel when said drive belt moves.

4 An assembly according to claim 3 wherein said means to connect said belt to said moving panel comprises a bracket having a first end which is connected to the drive belt and a second end connected to said moving panel of said door.

5 An assembly according to claim 4 wherein said belt locates in a groove in said drive wheel and said pulley

6 An assembly according to claim 5 wherein, the drive motor is disposed in a recess in said support frame 7 An assembly according to claim 6 wherein idler pulley is disposed in longitudinal alignment with said drive pulley.

8 An assembly according to claim 7 further comprising a belt adjustment assembly for adjusting tension in said belt.

9 An assembly according to claim 8 wherein, the belt adjustment assembly is associated with the idler pulley

10 An assembly according to claim 9 wherein, the drive wheel is located at a first end of the assembly and the idler pulley is located at a second end of the assembly.

11 An assembly according to claim 10 wherein the adjustment assembly includes a pivotally mounted cam bracket having a handle at one end and a recess at another end to engage an axle of said idler pulley.

12 An assembly according to claim 11 wherein the cam is capable of rotation between a first position in which the belt is at maximum tension and a second position in which the belt is a minimum tension.

13 An assembly according to claim 12 wherein said recess engages said axle of said idler pulley to maintain the belt at maximum tension.

14 An assembly according to claim 13 wherein the adjustment assembly further comprises a mounting bracket having a slot in which said axle moves.

15 An assembly according to claim 14 wherein the axle about which said idler pulley rotation is free to move rotationally and longitudinally in said slot.

16 An assembly according to claim 15 wherein the motor has a shaft extending normally to a longitudinal axis of said assembly and is of sufficient length to receive and retain said drive wheel.

17 An assembly according to claim 16 wherein said shaft transfers drive from said motor to said drive wheel.

18 An assembly according to claim 17 wherein the shaft co operates with the motor to transfer drive from the motor via a shaft to the drive wheel 19 An assembly according to claim 18 wherein, the drive assembly includes a release mechanism which allows disengagement of said drive wheel from said motor.

20 An assembly according to claim 19 wherein the release assembly includes a dog clutch which engages a ring.

21 An assembly according to claim 20 wherein the release assembly further comprises a cam wheel having an operating handle, the cam wheel including cam surfaces which co operate with said dog clutch to allow release of said drive wheel from operation of said motor.

22 An assembly according to claim 21 wherein the release mechanism further comprises an end plate which engages and co operates with said cam wheel .

23 An assembly according to claim 22 wherein the release mechanism further comprise a micro switch capable of disengaging power to said motor.

24 An assembly according to claim 23 wherein said operating handle on said cam wheel moves between a first position in which said drive wheel is released from drive by said motor and a second position in which said drive wheel is operated by said motor.

25 An assembly according to claim 24 wherein said support frame includes a base and side walls.

26 An assembly according to claim 25 further comprising a cover which engages the support frame to form a housing.

27 An assembly according to claim 26 wherein, the drive wheel is internal of the housing

28 An assembly according to claim 27 wherein, the assembly includes operating means including at least one sensor responsive to motion of an object approaching the door within a range monitored by said sensor. 29 An assembly according to claim 28 wherein said support frame has a longitudinal recess in which said motor is disposed and an adjacent parallel longitudinal recess in which said idler pulley is disposed.

30 An assembly according to claim 29 further comprising a controller board which operates the motor and drive wheel responsive to a signal.

31 An assembly according to claim 30 wherein the sensor is operated by pressure applied to a location remote from said door by a person approaching the door.

32 An assembly according to any of the forgoing claims wherein the power source for said motor is a battery.

33 An assembly according to claim 32 wherein the sensor unit is disposed within a housing formed by said cover and said support frame and uses active infrared to detect the presence of an object within a range of influence of the sensor.

34 An assembly according to claim 33 wherein the sensor has a time delay to ensure that the door will not close on an object or person.

35 An assembly according to claim 34 wherein the support frame is supported by a floor sur&ce.

36 An assembly according to claim 35 wherein the support surface is a fixed part of the sliding door.

37 An adjustment assembly for adjusting belt tension in a belt drive assembly for automatically opening and closing a sliding door panel ; the adjustment assembly comprising : the belt drive comprising: a support frame defining a space which receives and retains a drive assembly including a motor having a drive shaft; a drive wheel operably linked to the motor via said drive shaft; an idler pulley; at least one drive belt associated with said drive wheel and said idler pulley; wherein, when said drive wheel is energised by said motor, motion is imparted to the drive belt thereby causing the movable panel of the sliding door to move between a first state when the door is closed and a second state when the door is open; said belt adjustment assembly is associated with the idler pulley and includes a pivotally mounted cam bracket having a handle at one end and a recess at another end to engage an axle of said idler pulley; wherein the cam is capable of rotation between a first position in which the belt is at maximum tension and a second position in which the belt is a minimum tension.

38 A belt adjustment assembly according to claim 37 wherein said recess engages said axle of said idler pulley to maintain the belt at maximum tension.

39 A belt adjustment assembly according to claim 38 wherein the adjustment assembly further comprises a mounting bracket having a slot in which said axle moves.

40 An assembly according to claim 39 wherein the axle about which said idler pulley rotates is free to move rotationally and longitudinally in said slot.

41 An assembly according to claim 40 wherein, the drive belt includes means to allow connection of the drive belt to said moving panel to facilitate movement of said panel when said drive belt moves. 42 A drive wheel release assembly for selectively releasing a drive wheel in an assembly for automatically opening and closing a sliding door of the type including a fixed panel and a moving panel which slides on a track relative to the fixed panel; the assembly including : a support frame defining a space which receives and retains a drive assembly including a motor having a drive shaft; a drive wheel operably linked to the motor via said drive shaft; wherein, when said drive wheel is energised by said motor, motion is imparted to the drive belt thereby causing the movable panel of the sliding door to move between a first state when the door is closed and a second state when the door is open; the release assembly comprising; a release mechanism which allows disengagement of said drive wheel from said motor.

43 An assembly according to claim 42 wherein the release assembly includes a dog clutch which engages a ring.

44 An assembly according to claim 43 wherein the release assembly further comprises a cam wheel having an operating handle, the cam wheel including cam surfaces which co operate with said dog clutch to allow release of said drive wheel from operation of said motor.

45 An assembly according to claim 44 wherein the release mechanism further comprises an end plate which engages and co operates with said cam wheel .

46 An assembly according to claim 45 wherein the release mechanism further comprise a micro switch capable of disengaging power to said motor.

47 An assembly according to claim 46 wherein said operating handle on said cam wheel moves between a first position in which said drive wheel is released from drive by said motor and a second position in which said drive wheel is operated by said motor.