GB1562205A - Apparatus for measuring the angles of motor vehicle axles - Google Patents

Description

(54) APPARATUS FOR MEASURING THE ANGLES OF MOTOR VEHICLE AXLES (71) We, ROBERT BOSCH GMBH, a German Company, of Postfach 50, 7 Stuttgart 1, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to apparatus for measuring the angles of the wheel axles of motor vehicles.

In known measuring apparatus, the image of a scale or measuring diagram is projected by means of a measuring projector onto a wheel mirror mounted on, and at right angles to, the wheel axle to be measured, from which mirror the image is reflected at a specific angle according to the angular position of the wheel axle so as to impinge on a screen on the front of the housing of the measuring projector. According to the deviation of the reflected image from a reticule on the screen, a measurement result is produced which characterises the angular position of the wheel axle to be measured.

In known measuring apparatus, the problem exists that two measuring projectors have to be set up in a specific position for use and each has to be aligned relative to the other oppositely located measuring projector and also has to be aligned relative to the horizontal and the vertical. For this purpose, the measuring projectors can be arranged on rails which are embedded in the floor of the workshop.

Alternatively, however, the measuring projectors can be set up without rails on the floor of the workshop, vertically adjustable feet being mounted on the measuring projectors, so that it is possible to align said projectors. Since measuring locations require a relatively large amount of space in the workshop, it should be possible to remove the measuring projectors after the axles' angles have been measured, so that the space in the workshop is available for other work. However, this means that, with the known measuring apparatus, the aligning operation has to be repeated a large number of times. This is time-consuming, troublesome, and complicates the measuring operation.

Therefore, the invention seeks to develop a measuring apparatus which can be aligned in a simple manner without great expense and which can also be removed rapidly from the measuring location, so that the space in the workshop is available for other work.

In accordance with the invention, there is provided apparatus for measuring the wheel angles of a motor vehicle, comprising a measuring projector for projecting the image of a scale or measuring diagram, in use, on to a wheel mirror mounted on, and at right angles to, the wheel axle to be measured, the reflection of said scale or diagram being projected by the mirror on to a screen, wherein said measuring projector is secured to a pivotal arm which is pivotally movable between a first position wherein the projector is in a predetermined operational position ready for use and a second position wherein said projector is in a non-operational, stored position.

In a particularly advantageous development of the invention the pivot axle of the arm-is mounted on a slidable carriage which is arranged for displacement along a rail.

Advantageously, this rail can be secured to the.ceiling of the workshop space, so that, when the pivotal arms are swung up, the measuring projectors are removed from the floor of the workshop space and do not take up space required for other work.

The invention is described further, by way of example, with reference to the accompanying diagrammatic drawing of a station for measuring the angles of vehicle wheel axles.

The drawing shows a motor vehicle 1 which has been driven on to a measuring station in a workshop, a respective wheel mirror 2 being mounted on and with its plane at right angles to, each of the vehicle wheel axles to be measured. An axle measuring projector 3 is located opposite the wheel mirror 2 and projects onto the wheel mirror an image of a scale or measuring diagram which is reflected from the wheel mirror at a specific angle, the deviation of the reflected image from a reticule on a screen 4 of the axle measuring projector 3 being indicative of the angular position of the wheel axle to be measured.

An axle measuring location normally has two axle measuring projectors 3, although one axle measuring projector 3 may be sufficient in special cases. The arrangement of only one axle measuring projector 3 will be described hereinafter, the oppositely located axle measuring projector 3 being arranged in the same manner.

The axle measuring projector 3 is secured to a pivotal arm 5 which can pivot about a pin 6. The pin 6 is arranged in a sliding carriage 7 which is displaceably mounted on a rail 8. By way of example, the rail 8 is secured to the ceiling of the workshop space.

For measuring the axle, the pivotal arm 5 is released and the axle measuring projector is automatically brought into an operational position by gravity. The axle measuring operation can then be effected. If the axle measuring projector 3 is to be removed from the axle measuring location in the workshop after the axles have been measured, the pivotal arm is swung upwardly, so that it assumes a position substantially parallel to the rail 8 wherein the projector is in a nonsperational stored position. When in this position, the pivotal arm and the axle measuring projector secured thereto are no longer in the way and the space in the workshop is available for other work.

Advantageously, devices are provided by means of which the axle measuring projector can be fixed relative to the vertical after automatic alignment. By way of example, this device may be a stop device which is mounted on the sliding carriage 7 and fixes the pivotal arm 5. Furthermore, it is also necessary to provide a fastening device which retains the pivotal arm 5 in its storage position.

When the axles of the front wheels have been measured, the sliding carriage 7 can be moved along the rail 8, thus displacing the axle measuring projectors such that they are located opposite the axles of the rear wheels of the motor vehicle 1. Thus, it is possible to change the position of the axle measuring projector 3 in a simple manner. In order to mark the various locations at which the sliding carriage 7 should normally stop, it may be advantageous to provide marks or stop devices on the rail for the purpose of determining the position of the sliding carriage.

By means of the described axle measuring apparatus, it is a simple matter to align the axle measuring projectors and to remove the axle measuring projectors from the axle measuring location.

WHAT WE CLAIM IS: 1. Apparatus for measuring the wheel angles of a motor vehicle, comprising a measuring projector for projecting the image of a scale or measuring diagram, in use, on to a wheel mirror mounted on, and at right angles to, the wheel axle to be measured, the reflection of said scale or diagram being projected by the mirror on to a screen, wherein said measuring projector is secured to a pivotal arm which is pivotally movable from a first position wherein the projector is in a predetermined operational position ready for use to a second position wherein said projector is in a nonoperational, stored position.

2. Apparatus as claimed in claim 1, wherein the pivot of the pivotal arm, is mounted on a slidable carriage which is displaceable along a rail.

3. Apparatus as claimed in claim 1 or 2, having means for locking the pivotal arm either in a working position or in a position substantially parallel to the rail.

4. Apparatus as claimed in any of claims 1 to 3, wherein the rail has marks or stops for determining positions of the sliding carriage.

5. Apparatus constructed and arranged substantially as herein particularly described with reference to and as illustrated in the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. measuring projector 3 is located opposite the wheel mirror 2 and projects onto the wheel mirror an image of a scale or measuring diagram which is reflected from the wheel mirror at a specific angle, the deviation of the reflected image from a reticule on a screen 4 of the axle measuring projector 3 being indicative of the angular position of the wheel axle to be measured. An axle measuring location normally has two axle measuring projectors 3, although one axle measuring projector 3 may be sufficient in special cases. The arrangement of only one axle measuring projector 3 will be described hereinafter, the oppositely located axle measuring projector 3 being arranged in the same manner. The axle measuring projector 3 is secured to a pivotal arm 5 which can pivot about a pin 6. The pin 6 is arranged in a sliding carriage 7 which is displaceably mounted on a rail 8. By way of example, the rail 8 is secured to the ceiling of the workshop space. For measuring the axle, the pivotal arm 5 is released and the axle measuring projector is automatically brought into an operational position by gravity. The axle measuring operation can then be effected. If the axle measuring projector 3 is to be removed from the axle measuring location in the workshop after the axles have been measured, the pivotal arm is swung upwardly, so that it assumes a position substantially parallel to the rail 8 wherein the projector is in a nonsperational stored position. When in this position, the pivotal arm and the axle measuring projector secured thereto are no longer in the way and the space in the workshop is available for other work. Advantageously, devices are provided by means of which the axle measuring projector can be fixed relative to the vertical after automatic alignment. By way of example, this device may be a stop device which is mounted on the sliding carriage 7 and fixes the pivotal arm 5. Furthermore, it is also necessary to provide a fastening device which retains the pivotal arm 5 in its storage position. When the axles of the front wheels have been measured, the sliding carriage 7 can be moved along the rail 8, thus displacing the axle measuring projectors such that they are located opposite the axles of the rear wheels of the motor vehicle 1. Thus, it is possible to change the position of the axle measuring projector 3 in a simple manner. In order to mark the various locations at which the sliding carriage 7 should normally stop, it may be advantageous to provide marks or stop devices on the rail for the purpose of determining the position of the sliding carriage. By means of the described axle measuring apparatus, it is a simple matter to align the axle measuring projectors and to remove the axle measuring projectors from the axle measuring location. WHAT WE CLAIM IS:

1. Apparatus for measuring the wheel angles of a motor vehicle, comprising a measuring projector for projecting the image of a scale or measuring diagram, in use, on to a wheel mirror mounted on, and at right angles to, the wheel axle to be measured, the reflection of said scale or diagram being projected by the mirror on to a screen, wherein said measuring projector is secured to a pivotal arm which is pivotally movable from a first position wherein the projector is in a predetermined operational position ready for use to a second position wherein said projector is in a nonoperational, stored position.

2. Apparatus as claimed in claim 1, wherein the pivot of the pivotal arm, is mounted on a slidable carriage which is displaceable along a rail.

3. Apparatus as claimed in claim 1 or 2, having means for locking the pivotal arm either in a working position or in a position substantially parallel to the rail.

4. Apparatus as claimed in any of claims 1 to 3, wherein the rail has marks or stops for determining positions of the sliding carriage.

5. Apparatus constructed and arranged substantially as herein particularly described with reference to and as illustrated in the accompanying drawing.