WO2011035382A2

WO2011035382A2 - Truck mirror adjusting device

Info

Publication number: WO2011035382A2
Application number: PCT/AU2010/001252
Authority: WO
Inventors: Richard John Dalton; Stuart Gerald Hunt
Original assignee: Topdown Solutions Pty Ltd
Priority date: 2009-09-23
Filing date: 2010-09-23
Publication date: 2011-03-31
Also published as: WO2011035382A8; WO2011035382A3

Abstract

A mirror adjusting device (10) comprises an electric motor (12) for moving a truck mirror (14). The electric motor is one of a pair of motors provided in a biaxial motor unit (12). A gearbox (18) is mechanically coupled to the motor (12) and adapted to be mechanically coupled to the truck mirror (14) so as to adjust the plane in which the mirror (14) lies. The device (10) is adapted to adjust the plane in which the mirror (14) lies in first and second substantially orthogonal directions. An electronic controller (26) is operatively connected to the motor unit (12) for controlling the motor speed. A remote control means (28) permits the controller (26) to be operated remotely from within a driver's cabin of the truck on which the mirror (14) is mounted.

Description

TRUCK MIRROR ADJUSTING DEVICE

Field of the Invention

The present invention relates to a mirror adjusting device for adjusting the angle of a mirror mounted externally on a truck and relates particularly, though not exclusively, to such a device for use on vehicles employed in the mining industry.

Background to the Invention

On large semi-trailer and haul-pack trucks of the kind employed in road trains and in the mining industry, external rear vision mirrors are provided on both sides of the vehicle cabin of the prime mover. The mirrors have to be mounted some distance out from the cabin so as to provide a clear view for the driver along the full length of the vehicle. The mirrors are therefore also quite large and typically elongated in a vertical direction to provide a sufficiently extensive rear vision view. When the vehicle is moving the mirrors and mirror mounts are subject to environmental conditions causing shear forces, including high shock loads due to ground conditions and therefore they must be securely mounted to ensure the mirrors do not move or change their orientation. On the other hand it must be possible to adjust the position of the mirror, if required, to accommodate different lengths of vehicles, etc. Currently, such adjustment must be done manually by releasing several nuts and bolts, adjusting the position of the mirror and retightening the nuts and bolts. This operation is cumbersome and time-consuming, and obviously cannot be done while the vehicle is moving.

The present invention was developed with a view to providing a motorised device for automatically adjusting the position of a mirror on a large vehicle, such as a truck, from inside the vehicle cabin. Although automated, motorised rear vision mirrors are well-known on motor cars, these types of mirrors are not suitable for use on trucks. Truck mirrors are much larger and have to be mounted some distance out from the sides of the vehicle cabin and are therefore subject to much higher shear forces due to environmental conditions.

References to prior art in this specification are provided for illustrative purposes only and are not to be taken as an admission that such prior art is part of the common general knowledge in Australia or elsewhere.

Summary of the Invention

According to one aspect of the present invention there is provided a mirror adjusting device for adjusting the position of a truck mirror, the device comprising: an electric motor for moving the mirror; a gearbox mechanically coupled to the motor and adapted to be mechanically coupled to the truck mirror so as to adjust the plane in which the mirror lies; and, a electronic controller operatively connected to the motor for controlling the motor movement at low speed wherein, in use, an operator can adjust the angle of the mirror by activating the electric motor via the controller.

Preferably the device is adapted to adjust the plane in which the mirror lies in first and second substantially orthogonal directions. Preferably the electric motor is one of a pair of motors provided in a biaxial motor unit. Preferably the gearbox is a low speed/high ratio gearbox. Preferably the gearbox is integrated into the same casing with the biaxial motor unit.

Typically the gearbox comprises a first drive shaft adapted to be mechanically coupled to the truck mirror in a substantially horizontal orientation, rotation of the first drive shaft tilting the mirror in the first direction about the axis of rotation of the first drive shaft. Typically the gearbox comprises a second drive shaft substantially orthogonal to the first drive shaft and adapted to be mechanically coupled to a truck mirror mount, rotation of the second drive shaft pivoting the motor unit with the mirror coupled thereto in the second direction about the axis of the second drive shaft. Preferably the motor and gearbox is mechanically coupled to the truck mirror mount via a C-shaped mounting bracket having first and second substantially parallel bracket portions, the second drive shaft being fixed to the first bracket portion. Advantageously the electronic controller comprises a remote control means to permit the controller to be operated from within a driver's cabin of the truck on which the mirror is mounted. The remote control means may be hard wired or wireless. Typically the electronic controller employs a pulse width modulated (PWM) control signal for controlling the speed of the motors in the biaxial motor unit.

Preferably the electronic controller is provided with a motion control circuit adapted to provide slow motion movement of the mirror while maintaining torque.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Likewise the word "preferably" or variations such as "preferred", will be understood to imply that a stated integer or group of integers is desirable but not essential to the working of the invention.

Brief Description of the Drawings

The nature of the invention will be better understood from the following detailed description of a specific embodiment of a mirror adjusting device, given by way of example only, with reference to the accompanying drawings, in which:

Figure 1 illustrates a preferred embodiment of a truck mirror adjusting device according to the present invention;

Figure 2 is an close-up rear perspective view of the truck mirror adjusting device of Figure 1 ;

Figure 3 illustrates the internal circuit board of a preferred electronic controller employed in the truck mirror adjusting device of Figure 1 ; and,

Figure 4 is a functional block circuit diagram of part of the preferred electronic controller of Figure 3.

Detailed Description of Preferred Embodiments A preferred embodiment of mirror adjusting device 0 in accordance with the invention, as illustrated in Figures 1 to 4, comprises an electric motor 12 for moving a truck mirror 14. A typical truck mirror on an off-road truck of the kind employed in the mining industry can be up to 1.5m in length and weigh up to 15kg. Therefore the motor 12 must be capable of withstanding a substantial load, in addition to shear forces caused by environmental conditions such as wind shear and vibration due to road conditions. In this embodiment the electric motor is one of a pair of motors provided in a biaxial motor unit 12. The biaxial motor unit 12 has a load capacity of 25kg balanced load, and is provided in a dual process heat treated gravity die cast aluminium casing. It is highly reliable with minimum backlash, and is constructed from precision-milled internal components with heavy-duty ball races on the major axes. Stainless steel fastenings and weatherproof '0' ring and lip seals provide corrosion resistance and protection in all weather conditions. There is a simple external limit switch adjustment to provide 350° travel. Regenerative braking aids rapid deceleration.

The device 10 as shown in Figures 1 and 2 is mounted on a truck mirror mount 16 for a rear vision mirror on a truck 17 (see Figure 2). The device 10 further comprises a gearbox 18 mechanically coupled to the motor 12 and adapted to be mechanically coupled to the truck mirror 14 so as to adjust the plane in which the mirror 14 lies. In this embodiment the gearbox 18 is a low speed/high ratio gearbox which is integrated into the same casing with the biaxial motor unit 12. Preferably the device 10 is adapted to adjust the plane in which the mirror 14 lies in first and second substantially orthogonal directions. In the illustrated embodiment the gearbox 18 comprises a first drive shaft 20 adapted to be mechanically coupled to the truck mirror 14 in a substantially horizontal orientation, as can be seen most clearly in Figure 1. Rotation of the first drive shaft 20 will cause the mirror 14 to tilt in the first direction about the axis of rotation of the first drive shaft 20. In this embodiment, tilting of the mirror 14 in the first direction provides up and down adjustment of the view in the rear vision mirror 14.

The gearbox 18 further comprises a second drive shaft 22, substantially orthogonal to the first drive shaft 20 and adapted to be mechanically coupled to the truck mirror mount 16. In the illustrated embodiment the second drive shaft 22 is mechanically coupled to the truck mirror mount 16 via a C-shaped mounting bracket 24. The motor unit 22 also has a mounting bolt 25 pivotally mounted to the top of the unit concentric with the axis of the second drive shaft 22. The C-shaped mounting bracket 24 has first and second substantially parallel bracket portions 27a and 27b, which extend in a generally horizontal orientation when the mounting bracket 24 is mounted on the truck mirror mount 16. The second drive shaft 22 is fixed to the first bracket portion 27a, and the mounting bolt 25 is fixed to the second bracket portion 27b, which provides the motor unit 12 with a secure mounting. Rotation of the second drive shaft 22 causes the motor unit 12 to pivot, with the mirror 14 coupled thereto, in the second direction about the axis of the second drive shaft 22. In this embodiment, pivoting of the motor unit 12 results in left to right, or vice versa, (panning) adjustments of the view in the rear vision mirror 14. The mirror motor unit 12 has the flexibility to move a large arc in both the tilt and pan planes (360 degrees in tilt and over 90 degrees in pan). This allows for quick manoeuvring of the mirror 14 into a position for safe and rapid replacement of the mirror lens as required.

The truck mirror adjusting device 10 further comprises an electronic controller 26 operatively connected to the motor unit 12 for controlling the motor speed. In use, an operator can adjust the angle of the mirror 14 by activating the electric motor 12 via the electronic controller 26. In this embodiment, the electronic controller 26 comprises a remote control means 28 to permit the controller 26 to be operated remotely from within a driver's cabin of the truck on which the mirror 14 is mounted. The remote control means 28 may be hard-wired or wireless.

Although a low speed/high ratio gearbox is very effective in reducing a motor speed while maintaining torque, if taken to an extreme the motor will eventually stall. In the present application the bulk and mass of the mirror are great but it is desirable to have the motor unit 12 move the mirror 14 at a relatively low speed, so that fine adjustments of the mirror position can more easily be made. For this reason the electronic controller 26 is provided with a specially designed motion control circuit 30 adapted to provide slow motion movement of the mirror 14 while maintaining torque.

Figure 4 is a functional block circuit diagram of the preferred motion control circuit 30 employed in the controller 26. Typically the motion control circuit 30 employs a pulse width modulated (PWM) control signal for controlling the speed of each motor in the biaxial motor unit 12. PWM motor control facilitates smooth motion and fine adjustment of the mirror position. Four relays 32 control "Up" and "Down" (tilt), "Left" and "Right" (pan) movement of the mirror 14.

A single 24volt DC input 34 is provided for the electronic controller 26, typically supplied from the truck's vehicle battery.

Now that a preferred embodiment of the mirror adjusting device for adjusting the position of a truck mirror has been described in detail, it will be apparent that the described embodiment provides a number of advantages over the prior art, including the following:

(i) It allows automated adjustment of the position of a truck mirror by the truck operator while seated in the vehicle cabin.

(ii) It enables the operator to make fine adjustments to the rear vision mirror to provide a clear view on both sides of the vehicle. (iii) It is simple to install and operate, and can be retrofitted to existing vehicles.

(iv) It obviates the need to release and retighten nuts and bolts whenever the position of the truck mirror needs adjustment. (v) The motor unit has the flexibility to move a large arc which allows safe and rapid replacement of the mirror lens as needed.

It will be readily apparent to persons skilled in the relevant arts that various modifications and improvements may be made to the foregoing embodiments, in addition to those already described, without departing from the basic inventive concepts of the present invention. For example, the electric motor need not be a biaxial motor unit as described. Separate electric motors and/or a different gearbox arrangement could be employed to achieve a similar function. Therefore, it will be appreciated that the scope of the invention is not limited to the specific embodiments described and is to be determined from the appended claims.

Claims

1. A mirror adjusting device for adjusting the position of a truck mirror, the device comprising: an electric motor for moving the mirror; a gearbox mechanically coupled to the motor and adapted to be mechanically coupled to the truck mirror so as to adjust the plane in which the mirror lies; and, a electronic controller operatively connected to the motor for controlling the motor movement at low speed wherein, in use, an operator can adjust the angle of the mirror by activating the electric motor via the controller.

2. A mirror adjusting device as defined in claim 1 , wherein the device is adapted to adjust the plane in which the mirror lies in first and second substantially orthogonal directions.

3. A mirror adjusting device as defined in claim 1 or claim 2, wherein the electric motor is one of a pair of motors.

4. A mirror adjusting device as defined in claim 3, wherein the pair of motors is provided in a biaxial motor unit.

5. A mirror adjusting device as defined in any one of claims 1 to 4, wherein the gearbox is a low speed/high ratio gearbox.

6. A mirror adjusting device as defined in claim 4, wherein the gearbox is integrated into the same casing with the biaxial motor unit.

7. A mirror adjusting device as defined in any one of the preceding claims, wherein the gearbox comprises a first drive shaft adapted to be mechanically coupled to the truck mirror in a substantially horizontal orientation, rotation of the first drive shaft tilting the mirror in the first direction about the axis of rotation of the first drive shaft.

8. A mirror adjusting device as defined in claim 7, wherein the gearbox comprises a second drive shaft substantially orthogonal to the first drive shaft and adapted to be mechanically coupled to a truck mirror mount, rotation of the second drive shaft pivoting the motor and the gearbox with the mirror coupled thereto in the second direction about the axis of the second drive shaft.

9. A mirror adjusting device as defined in claim 8, wherein the motor and gearbox is mechanically coupled to the truck mirror mount via a C-shaped mounting bracket having first and second substantially parallel bracket portions, the second drive shaft being fixed to the first bracket portion.

10. A mirror adjusting device as defined in any one of the preceding claims, wherein the electronic controller comprises a remote control means to permit the controller to be operated from within a driver's cabin of the truck on which the mirror is mounted.

11. A mirror adjusting device as defined in claim 10, wherein the remote control means is hard wired or wireless.

12. A mirror adjusting device as defined in any one of the preceding claims, wherein the electronic controller employs a pulse width modulated (PWM) control signal for controlling the speed of the electric motor.

13. A mirror adjusting device as defined in claim 12, wherein the electronic controller is provided with a motion control circuit adapted to provide slow motion movement of the mirror while maintaining torque.

14. A mirror adjusting device substantially as herein described with reference to and as illustrated in any one or more of the accompanying drawings.