AU2005100075A4 - Powered door system - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT Applicant(s): Razor International Pty Limited Invention Title: POWERED DOOR SYSTEM.

The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 POWERED DOOR SYSTEM F1 SThis invention relates to a powered door system for use 00 with truck and trailer bodies.

c The current method of operating vertical lift doors on articulated trailer bodies and truck bodies involving the lifting and lowered of a door is ergonomically unsound. In particular transport operations where there is a need to load goods from the rear, such as packaged groceries and the like, there is a need to secure the load via a vertical lift door. Due to space constraints at loading docks and supermarkets and the like the mechanism and door itself is internal to the trailer body. Typically a door is made from several close-fitting interconnected panels that need to be not only robust for security reasons but also need to maintain temperature differentials when perishable goods are being transported. Such doors are heavy, in the order of 60kg typically, counterbalance springs are usually deployed to attempt to balance the effort to open or such the door. The counterbalance spring will be located about a rotating shaft located above the door and bracketed to the trailer structure. The spring imparts a torque on the shaft via a coupling, which in turn will provide tension onto two cables located close to the outer edge of the door and be secured to the base of the lowest panel. The cables are fixed to the shaft via cable drums on either side of the shaft. The door panels are contained in tracks at either side of the trailer to ensure smooth and constrained travel. A door will nominally be located horizontally under the ceiling of the trailer when in the open position. An operator will use a grab handle on the lowest panel and lift the door to its fully raised state to allow egress to load and unload the goods within the truck or trailer. When the door is to be closed the reverse occurs where in the operator manually grabs the said handle and pulls down on the door to shut H:\nicoab\keep\Speci\P54982 innovation.doc 28/01/05

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3 the door. In both these scenario's the effort to operate the heavy door is ergonomically unsound. Regardless of the Sinclusion of a counterbalance spring the ergonomic effort 00 to start the door in either direction is too high due to inertia effects and posture. The posture required is unacceptable as the handle is basically at floor level.

It is these issues that have brought about the present invention.

V) According to the present invention there is provided a truck or trailer door comprising a plurality of panels hinged together to form a door, the ends of each panel being adapted to run in spaced rails arranged to be attached to the truck/trailer, a drive shaft carrying at least one cable drum that supports the first cable secured to one end of the door and a second cable secured to the other end, powered drive means coupled to the shaft to induce axial rotation of the shaft whereby, when the shaft rotates in one direction the first cable is pulled moving the door in one direction and when the shaft is rotated in the opposite direction the second cable is pulled moving the door in the opposite direction.

Preferably the shaft supports a cable drum on each end with the first and second cables being respectively located on each drum.

The drive means is either an electric, pneumatic or hydraulic motor.

Preferably control of the drive means relies on load sensing and cut out to ensure that the door is consistently and evenly closed.

In a preferred embodiment means is provided to sense an obstruction and either stop the door motion or H:\nicolab\keep\Speci\P54982 innovation.doc 28/01/05 4 alternatively reverse it.

SPreferably, when the drive means 11 is an electric motor, 00 the power supply is an onboard battery maintained by a charging circuit.

In a preferred embodiment means is provided to balance the weight of the door with a coil spring mounted about the shaft.

V) Preferably, the tension cables are attached to the drive shaft via cable pulleys secured to the shaft.

The cables are mounted via a tension spring on the upper panel to accommodate variations in the projected length of the door to drive shaft cables.

Preferably, the powered drive provides minimal resistance against the drive shaft when power is uninterrupted allowed for the manual operation of the door in the event of a failure of the power system.

An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a perspective view of the rear of a truck or trailer with a powered door partially raised; Figure 2 is an internal view of the door in the partially raised position; Figure 3 is a perspective view of the lower portion of the door showing a powered lifting mechanism with the truck or trailer omitted; and Figure 4 is a perspective view of the upper portion of the H:\nicolab\keep\Speci\P54982 innovation.doc 28/01/05 door showing the lifting mechanism.

SThe drawings illustrate a typical traditional manually 00 operated door system modified to have a powered drive.

The door is made up of several panels 10. As shown in Figure 2, the panels 10 are interconnected by hinges 11 Smounted on the internal side of the door panels 10. A plurality of hinges 11 are used between panels at each V 10 panel joint to ensure a robustness of the door. The outboard hinges include an axle and roller assembly 12.

The low side of the bottom door panel 15 and the upper side of the top door panel 16 include a roller axle assembly 12 on the outer edge consistent with those as mounted in the hinges as abovementioned.

The axle roller assembly 12 is engaged in a roller track 13 on each side of the door. The roller track 13 is fixed by bracketry and fasteners typical to the industry to the trailer 20 internal body. The roller track 13 is so arranged to sweep from the floor at the rear of the trailer 20 vertically and then through a radius 13a (Figure 4) at the top of the trailer to project along and below the ceiling of the trailer 20 body. Thus by way of the roller axle assemblies 12 the door panels 10, are constrained to move in a plane consistent with the roller track 13. A drive axle 21 is located internally at the rear of the trailer and above the door track. A drive motor 4 is mounted with its axis perpendicular to the axis of the axle 21. The motor 4 drives the axle through a gearbox 5. The motor 4 and gearbox 5 are positioned at one end of the axle 21 inside the trailer 20. The axle 21 is connected about the output shaft of the gearbox 5 via a key and keyway or similar means. As shown in Figure 4, the opposite end of the axle 21 is mounted to the trailer structure via a bearing and bracket (not shown).

H:\nico1ab\keep\Speci\P54982 innovationdoc 28/01/05 6 A pair of cable drums 23 are mounted about the axle 21 at each end and secured to the axle 21 via screws (not Ctshown). A pair of steel cables 24 are secured to and wound 00 about each outer cable drum 23 and extend to the outer lower edge of the bottom door panel 15. The cables 24 are pivotally attached to the door panel 15 via a simple bracket 25. A second pair of cables 28 are secured to and wound about the each inner cable drum 23 and extend to the _upper edge of the top door panel 16. They are pivotally attached to the door panel 16 via a tension spring 29 and a simple bracket The axle 21 has a coil spring 26 mounted about it, centrally located and affixed via purpose-designed boss 27. The fixed end of the spring is secured via a bracket 28 to the trailer 20 structure. As the drive motor 4 imparts rotation on the axle 21 the cable drums are rotated and each pair of cables 24, 28 either wind up or unwind as the case may be dependant of the direction of rotation of the axle 21. When the door is to be lowered the top pair of cables 28 pull the upper door panel 16 rearward and the hinge 11 connected panels track rearward and down prescribed by the roller axle assemblies 12 in the roller track 13. The coil spring 26 is provided with an appropriate pretension to progressively balance the weight of the door via the cables 24 as the door panels move from the horizontal portion within the roller track 13 to a vertical portion within the roller track 13. When the door is to be raised the axle 21 is rotated by the drive motor 4 so as to pull on the cables 24 and lift the door panels 10 in the roller track 13 in the opposite motion to that of lowering the door.

An operator activates the door by activating the geared drive motor 4 in the appropriate direction as the case may be. This is achieved through an operated interface such as a keypad, switches or similar (not shown) H:\nicoab\keep\Speci\P54982 innovation.oc 28/01/05 7 0 Although an electric motor is the preferred form of drive means it is understood that the motor could be pneumatic Sor hydraulic.

00 The geared drive motor 4 connection to the axle 21 can be replaced by other forms of interconnected drive mechanisms such as chain, drive belts or mating gears.

The above description illustrates a typical arrangement V) 10 and is not limited as alternative methods may be employed Sto achieve the identical intended result. The mounting of the axle and cables may be varied to achieve the same result. The invention is not limited to only existing truck and trailer mechanisms but can equally be employed on new equipment.

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Claims (3)

1. 2. The truck or trailer door according to claim 1 wherein the shaft supports a cable drum on each end with the first and second cables being respectively located on each drum.
2. 3. The truck or trailer door according to either claim 1 or claim 2 wherein the drive means is either an electric, pneumatic or hydraulic motor.
3. 4. The truck or trailer door according to any one of the preceding claims wherein the control of the drive means relies on load sensing and cut-out to ensure that the door is consistently and evenly closed. A truck or trailer door substantially as hereinbefore described with reference to and illustrated in the accompanying drawings. Dated this 28th day of January 2005 RAZOR INTERNATIONAL PTY LTD By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia H:\nicoab\keep\Speci\P54982 innovation.oc 28/01/05