TECHNICAL FIELD OF THE INVENTION

This invention relates to an automated roller door or rolls top or roll on covers for the load bin of a truck or light delivery vehicle or the like, or for swimming pools, work pits or the like.

BACKGROUND ART

Roller doors or roll tops have been used for some time to secure the load bin of a truck or LDV or a side or rear cavity of a truck. The Applicant has a proprietary design for an aluminium curtain comprising interlocking slats which slides vertically or horizontally along guide rails. The aluminium retractable curtain slides open and closed along fitted guide channels, and is attached to a spring loaded shaft. The spring ensures the curtain rolls up tightly on to the shaft which accommodates the least possible space used in the load bin area.

Existing automatic roll tops or roller doors are driven via cables and mechanisms mounted within the canister or container housing. This adds a considerable amount of weight and size to the canister or container which houses the roller mechanism. Once fitted, these mechanisms are fixtures.

It is therefore an object of this invention to provide an automated roller system which is compact and lightweight, and may be either retrofitted to existing roll tops, or installed as original equipment, without taking up excessive load bin space.

It is a further object of the invention to provide an arrangement which is remotely operable and which is equally applicable for use with swimming pools or other structures requiring covering. DISCLOSURE OF THE INVENTION

According to the invention, an automated drive mechanism for roller doors and/or roll tops and/ or roll on covers comprises a curtain of inter-locking slats slidable along guide rails located either side of an opening to be covered by the curtain, the mechanism including a pair of electric motors housed within the end slat of the curtain.

In the preferred form of the invention, the motors are located at or near the ends of the end slat, each operatively engaging a sprocket which in turn engages a track located along the length of the opening to be covered, on both sides. The teeth of the sprocket are preferably bevelled.

The track preferably comprises a plastic toothed track located parallel to and below the guide rail on either side of the opening, the sprocket including teeth for engaging the track. Alternatively, the track may comprise an aluminium toothed track which is engaged by the teeth of the sprocket. The teeth of the track are preferably straight rather than bevelled.

If the curtain comprises a roll-top for a swimming pool or the like, the common mounting rail has a more robust design and includes a further horizontal channel located above the two channels described in the load bin version of the rail above. This channel forms the guide rail for the curtain with the top wall of the channel preventing access to the edge of the curtain and also preventing the curtain from being dislodged from the guide rail in the event that excessive weight is placed on the curtain accidentally. A slot and drainage zone are provided as for the common mounting rail for the vehicle load bin.

The motors preferably comprise 12 or 24 volt electric motors which are reversible.

Where the opening to be covered comprises the load bin of a vehicle, the curtain is retractably housed in a canister or the like on a spring-loaded shaft. When the curtain is being closed, the motors draw the curtain against the spring-loaded shaft of the canister. During opening the curtain, the motors assist the curtain to roll back onto the spring-loaded shaft, assisted by the bias of the spring. Where the opening to be covered comprises a swimming pool, skylight or the like, the curtain is driven by the motor along a spiral track which guides the curtain into a rolled configuration when the curtain is in the open position. The rolled curtain may also be contained within a housing in this instance.

In the preferred form of the invention power to the electric motors is provided by means of a pair of contact strips mounted along the length of the guide channels, electric current being supplied to the contact strips by the vehicle electrical system via a control panel. The motors each include a spring-loaded sliding contactor adapted to maintain engagement with the contact strips whilst the curtain is in motion. The sliding contactors each comprise a pair of spring-loaded brass brushes mounted in a rubber stopper which fits into the common mounting rail of the end slat. In the preferred form of the invention positive power is supplied to the contact strip on one side and negative power to the contact strip on the other side of the opening.

Where the curtain is used to cover the load bin of a vehicle, the track is mounted in a common mounting rail comprising top and bottom horizontal channels, the top one housing the contact strip and the bottom one housing the track. The underside of the curtain rests atop the rail which also acts as a guide rail for the curtain. A slot is provided with holes which permit moisture to drain through into a drainage zone within the rail.

The end slat comprises a cover and a base, the cover and base being slidably interengageable. The cover is removable in the event of a breakdown requiring access to the motor for repair purposes. The base includes a horizontal channel for receiving a plate member upon which the sprocket is mounted and a lower compartment for housing the sprocket. The plate member is slidable away from the end of the end slat to permit the sprocket to disengage from the track in the event of a breakdown. The motor is housed above the lower compartment in a space defined by the cover.

The end slat further includes a plastic end cap insertable at each end thereof. The end cap includes a perforated horizontal flange which performs a dual function. Firstly it prevents ingress of dirt and moisture into the space occupied by the motor, and secondly the flange may be broken off to allow the end slat to be pulled beyond the end of the track and permit removal of the end cap and thereafter removal of the cover from the base of the end slat.

Also in the preferred form of the invention, the electric motors are operable by means of a wireless remote control.

The electronic circuit board (control panel) may be mounted within the end slat of the curtain to reduce space consumption in the load bin. The circuit board may further be adapted to include a safety mechanism which ensures that the curtain will remain open in the event that an obstacle is detected in its path of movement. In this form, a suitable detection device may be mounted on the end slat for obstacle detection.

The circuit board may further be adapted to permit temporary opening for a predetermined time period, for example 15 seconds, whilst loading goods and will automatically close thereafter.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention is described below with reference to the accompanying drawings in which:

Figure 1 is an isometric top view of a roll-on cover for a vehicle load bin; incorporating the automatic drive mechanism of the invention;

Figure 2 is an isometric end view of the end slat of the curtain of the cover;

Figure 3 is an isometric bottom view of the motor assembly, with the brass brushes inset in the drawing;

Figure 4(a) is an end view of the end slat base;

Figure 4(b) is an isometric view of Figure 4a;

Figure 5(a) is an end view of the end slat cover;

Figure 5(b) is an isometric view of Figure 5a;

Figures 6 (a) and (b) are isometric and end views respectively of the assembled end slat;

Figures 7 (a) and (b) are isometric back and front views of the end cap for the end slat of figure 6;

Figure 8 is a sectional view through an end portion of the mechanism of the invention; Figures 9 (a) and (b) are an isometric and end views of the common mounting rail for a cover for a vehicle load bin;

Figures 9 (c) and (d) are similar views of a track mounted in the common mounting rail of figures 9 (a) and (b);

Figure 10 is an isometric view of a roll-on cover for a swimming pool;

Figures 11 (a) and (b) are isometric views of a spiral track along which the cover of figure 10 moves;

and

Figures 12 (a) and (b) are isometric and end views of a common rail for use with a cover for a swimming pool.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In Figure 1 , a roll-on cover 10 for a vehicle load bin comprises a curtain 12 having an end slat 14 which is adapted to house the motors 16 for an automated drive mechanism for the cover.

The other end 18 of the curtain is fixed to a spring-loaded shaft (not shown) which is housed within a canister 20 attached to the cab-end of the load bin. The shaft is rotatable within the canister to provide a storage facility for the curtain when in a rolled-up or open position.

In Figure 2, the end slat 14 is shown to comprise a base portion 24 and a cover portion 26. These are more clearly illustrated in Figures 4, 5 and 6 respectively.

The motors 16 are mounted on a slidable mounting plate 22 which fits into channel 23 in the base portion 24 of the end slat. Each motor drives a shaft 32 to which is fixed a sprocket 34. The shaft extends through section 36 of the base 24. The lower section (sprocket housing) is shaped and dimensioned to permit the sprocket to rotate freely.

In order to move along the length of the load bin, a moulded plastic or extruded aluminium track 38 is provided along the length of each side of the load bin including an array of spaced apart slots 40 each dimensioned to receive a sprocket tooth 42. Rotation of the sprockets 34 by the motors 16, drives the end slat 14 and hence the curtain, along the track, assisted by the bias of the spring-loaded shaft. The track is mounted in a common mounting rail (see figure 9).

Electrical current from the vehicle electrical system to the motors 16 is provided by means of electrically conductive contact strips 44 located along the length of the load bin on both sides (see Figure 8). Positive power is fed to one contact strip and negative power to the other. The contact strips 44 engage spring-loaded sliding contactors 46 located at either end of the end slat 14. These contactors comprise spring-loaded electrically conductive brass brushes 48 which ensures unbroken electrical contact with the contact strips 44. The contact strips are insulated within rubber blocks 50, which fit into common mounting rail 58.

The slats of the curtain slide along guide rails 52 located above the tracks.

The base portion 24 and cover portion 26 (Figures 4 and 5) include interengaging formations 54a and b and 56a and b for slidable engagement with the curtain and end caps ( 64 in figure 7) which are provided to secure the cover to the base.

The guide rails 52, tracks 38 and contact strips 44 are all mounted on a common mounting rail 58. The rail 58 is further adapted to receive a cover strip 60 which prevents unauthorised access to the ends of the slats and the guide rails. Slot 48 includes holes (not shown) allowing rainwater and moisture to drain into channel 59 which acts as a drain.

A further canister cover 62 is provided to prevent unauthorised access to the canister 20.

The end caps 64 include perforated flanges 66 which may be broken off to enable the end caps to be removed and the cover 26 to disengage from the base 24 and thereby provide access to the motors in the event of a breakdown.

Turning now to figures 10 through 12, a roll-on cover according to the invention for a swimming pool is described. In figure 10, a roll-on cover 70 includes the same end slat 72 housing the motors as described hereinabove. In this form of the invention however, the curtain of the cover rolls into a spiral track 74 located at either side at the end of the cover. The motors drive the curtain along the track and in so doing roll the curtain up into a spiral configuration.

The spiral tracks 74 are machined into blocks of polypropylene as shown in figures 11 a and b.

In this form of the invention where the curtain is wider, longer and therefore heavier, a modified common mounting rail design 76 is required. Top and bottom channels 78 and 80 are still present for housing the conductive contact strips and track (not shown) respectively. A further channel 82 is also provided which forms the guide rail and includes a pronounced top wall 84 of the channel preventing the curtain from disengaging from the guide rail.