GB2159276A - Receiving device for a brake disc - Google Patents

Abstract

A receiving device for the measurement (6) of the lateral run-out on the friction surface (39a) of the brake disc (28) has a guiding arrangement rotatably supported in a housing (10) and serving to centre the brake disc (28). The rotatable guiding arrangement consists of the housing (10), thrust ball bearings (15, 16) and discs (17, 18) held together by a threaded rod (31) and lock nuts (32, 33) and (21). For fastening the brake disc (28), a plate (25) is used which has a bore (30) with a slot extending towards an edge, the width of said bore being larger than the diameter of the rod (31). A slight loosening of the screw (26) allows the plate (25) to be removed sideways from the receiving device (1), thereby an easy mounting or removal of the brake disc (28) is enabled. <IMAGE>

Description

SPECIFICATION Receiving device for a brake disc This invention relates to a receiving device for a brake disc for use in the measurement of the lateral run-out existing on a friction surface of the brake disc, which device is provided with a guiding arrangement rotatably supported in a housing and serving to centre the brake disc and with a fastening means for the brake disc.

A known receiving device of the type referred to above consists of a commercially available chuck normally used on lathes. Such chucks allow a good mounting and centering of the brake discs. By means of a profile gauge it is possible to measure the lateral runout on the surface of the brake disc. The lateral run-out defines the measure which results when gauging a brake disc's friction surface from the lowest to the top point. The consequences of a great lateral run-out are a vibrating brake pedal and rubbing of the brake.

Such chucks, however, are disadvantageous in that they are relatively heavy, difficult to handle, and rather expensive. They are particularly bulky and heavy when brake discs of both smaller and larger diameters are to be chucked as with increasing chucking diameters there will also be an increase in the weight of the chuck.

It is thus an object of this invention to provide a receiving device whose design is simple and light-weight and allows good handling, which enables as exact a measurement as possible of the lateral run-out, and where the brake discs to be measured can be mounted and removed easily and fast. Further, it should be possible to mount brake discs of as many different sizes as possible on this arrangement, with the structural efforts being small.

According to the present invention there is provided a receiving device for a brake disc for use in the measurement of the lateral runout existing on a friction surface of the brake disc, which device is provided with a guiding arrangement rotatably supported in a housing and serving to centre the brake disc and with a fastening means for the brake disc, characterised in that the fastening means consists of a rod penetrating the guiding arrangement centrally and connected with the same in a torsionally secured manner, a thread with a nut rotatably supported at the thread being formed at the upper end of said rod; in that between the nut and a support for the brake disc a plate is provided at the guiding arrangement, the cross-section of said plate being essentially rectangular; and in that the plate has a bore with a slot extending towards an edge, the width of said bore being larger than the inside diameter of the rod.

This inventive receiving device enables a particularly simple arrangement, the weight being extremely low. Mounting and removing of the brake disc are performed in a particularly snort time as but a few turns of the nut are sufficient to remove the plate sideways below the nut via the slot without the nut having to be removed during this operation.

An especially small shift is achieved during removing of the plate in that the plate is rectangular and in that the slot is ending at a longer side of the plate. With this design, but a few turns are sufficient to loosen the nut so as to effect that the slight gap resulting between the nut and the support of the brake disc becomes big enough to allow the disc to be lifted slightly and to be removed radially sideways outside. Thereby, an extremely small space is required for mounting the plate which will be of particular advantage if the annular pot of the brake disc approaches the plate very closely. The mounting space for the plate may be especially small if the slot extends vertically in respect of the longer sides of the plate.

In case e.g. brake discs are to be measured whose support for pressing the plate against the brake disc is not annular, but rather consists of separate contact points not even arranged diametrically opposite each other it will be advantageous if between the plate and the support of the brake disc a tightening disc is provided which has a central bore, the diameter of said bore being larger than the inside diameter of the nut and smaller than the length of the disc. This provides for a quick mounting and removal of the tightening disc as soon as the disc has been removed as already described above. All that then is necessary is to remove the tightening disc upwards via the nut.

The guiding arrangement will be particularly simple if two discs are provided which are supported at the housing on bearings and which are pressed against the bearings by means of the rod and the lock nuts. Owing to this simple way of tightening the guiding arrangement it is possible to adjust a particularly small play at the guiding arrangement.

Thus any inaccuracy of the guiding arrangement, thence resulting and making itself felt in the measurement of the lateral run-out of the brake disc, may be kept extremely small, In order to need as few components as possible for the receiving device the upper lock nut also forms the centering disc. In this arrangement the brake disc is received and centered at the outside diameter of the centering disc.

According to this invention it is advantageous to fasten the receiving device on a base plate and to provide a column on the base plate for the reception of the measuring arrangement displaceable along the column.

Thereby a simple and complete measuring arrangement results which even after a change in position does not require any adjustments at the dial gauge or any other parts.

So as to ensure that even without a removal of the nut centering discs of varying sizes may be mounted on the receiving device it is advantageous for the centering disc to have a central bore whence - up to its edge a slot is extending the width of which is larger than the diameter of the rod. In this arrangement it is possible to receive and gauge brake discs of varying sizes in the receiving device because of the easy and quick exchange of the discs.

An embodiment of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a longitudinal section taken through a complete receiving device according to this invention; Figure 2 is a top view on a plate member of Figure 1; and Figure 3 is a top view on a centering disc of Figure 1.

In Figure 1, a receiving device 1 is fastened on a base plate 3 by means of stud bolts 2.

As seen in the drawing, at its lower end the base plate 3 has feet 4 for placing the receiving device 1 on a floor or on a table. Referring to the drawing, to the right of the receiving device 1 a column 5 is fastened on the base plate 3. As seen in the drawing, the column 5 extends upwards and serves to receive and displaceably guide a measuring arrangement 6 illustrated by broken lines. The measuring arrangement 6 consists of a dial gauge 7 with an indicating scale and of an actuating bolt 8 arranged at its lower end for actuating the dial gauge 7. The dial gauge 7 is rotatably and axially displaceably connected with the column by means of a holding device 9. The parts 7, 8, and 9 are only sketched and illustrated by a dash-dot line.

The receiving device 1 essentially consists of an annular housing 10 securely fastened at its lower end to the base plate 3 by means of the stud bolts 2. The housing 10 has a bore 11 interrupted by an annular step 1 2 directed towards the centre of the housing 10. At the upper and lower end of the step 1 2 annular abutment surfaces 13, 14 are designed against which in each case a thrust ball bearing 1 5 or 16, respectively, is resting.Resting at the upper and lower end of the thrust ball bearings 1 5 and 1 6 in each case is a disc 1 7 or 18, respectively, with a central bore 1 9 or 20, respectively, which are centered at the upper or lower ring 23 or 24, respectively, of the thrust ball bearings 1 5 and 1 6. The disc 1 7 is followed upwards by a centering disc 21, a tightening disc 27, a plate 25 with a Ushaped cross-section, with the U pointing upwards, and by a knurled nut 26. The brake disc 28 is centered at the outer circumference of the centering disc 21 by means of its centering diameter 29.

The parts 21, 25, 26, 27 together define a bore 30 which is in alignment with the central bores 19, 20. The bores 19, 20, 30 of the parts 17, 18, 21, 25, 26, 27 are penetrated by a threaded rod 31 which presses the parts 17, 18, 21, 25, 26, 27 against each other or against the housing 10, respectively, by means of nuts 32, 33, and 26 screwed onto the threaded rod 31. The centering disc 21 and the lock nut 33 keep the disc 1 7 in a torsionally secured manner on the threaded rod 31.Thanks to this tightening, the disc 17 firmly connected with the rod 31 is pressed against the upper thrust ball bearing 1 5 and the disc 18 is pressed against the lower thrust ball bearing 1 6. The stronger the tension in the threaded rod 31, the smaller the play of the bearings or rather the inaccuracy of the receiving device 1 which partially depends thereon.

The knurled nut 26 tightens the brake disc 28 relative to the disc 1 7 by means of the Ushaped plate 25 and the tightening disc 27.

In the case of the illustrated brake disc 28 the tightening disc 27 is necessary because, due to the mounted fastening eye 33a, there is no continuous surface at the fastening flange 34 of the brake disc and at the same time the fastening eyes 33 are not diametrically opposite each other.

When using a brake disc with an even fastening flange 34 the tightening disc 27 is not needed and, consequently, may be removed from the receiving device 1. In such an arrangement, the plate 25 is mounted in the reversed direction to that illustrated in the drawing. Thus the arms 35 then pointing downwards are acting on the annular fastening flange 34.

In Figure 2 the bore 30 in the plate 25 can be seen whence the slot 37 proceeds which extends towards the longitudinal side 36. In the top view the U-shaped plate 25 forms a rectangle, together with the arms 35 designed at the narrow sides 38.

In Figure 3 the centering disc 21 is illustrated in which similar to Figure 2 the slot 39 likewise extends radially outwards from the bore 30 towards the edge of the centering disc 21.

Referring to Figures 1 to 3, the operation of mounting the brake disc on the receiving device and the operation of gauging will be explained in more detail: When mounting the brake disc 28, at first, it is slid onto the centering disc 21 until it rests on the disc 17 and is centered on the centering disc 21 by means of its centering diameter 29. Subsequently, one after the other, the tightening disc 27 and the U-shaped plate 25 are slid in sideways until the walls of their bores 30 abut on the rod 31. Then the knurled nut 26 is screwed downwards until the brake disc 28, due to the knurled nut 26 and the parts 21, 25, and 27 is resting firmly and without play on the disc 17.

Now, by means of the holding device 9, the measuring arrangement 6 is turned across the brake disc 28. Thus the actuating bolt 8 which now rests on the friction surface 39a actuates the dial gauge 7. In order to easily measure the maximum lateral run-out the dial gauge 7 is adjusted to zero. By slowly rotating the brake disc 28 it is possible to measure the lateral run-out which in the drawing runs vertically upwards or downwards, respectively, relative to the friction surface 39a. By length ening the lever arm at the holding device 9 it is possible to register the lateral run-out of brake discs of varying diameters. The measurement completed, the brake disc 28 may be removed as already described above, how ever, with the operations being reversed.

When using a brake disc 28 where the contact surface at the fastening flange 34 is even and where said surface remains unprocessed, the relatively small surface will have an advantageous effect on the pressure surface of the arms 35.

Claims (9)

1. A receiving device for a brake disc for use in the measurement of the lateral run-out existing on a friction surface of the brake disc, which device is provided with a guiding arrangement rotatably supported in a housing and serving to centre the brake disc and with a fastening means for the brake disc, characterised in that the fastening means consists of a rod (31) penetrating the guiding arrangement centrally and connected with the same in a torsionally secured manner, a thread with a nut (26) rotatably supported at the thread being formed at the upper end of said rod (31); in that between the nut (26) and a support for the brake disc (28) a plate (25) is provided at the guiding arrangement, the cross-section of said plate (25) being essentially rectangular; and in that the plate (25) has a bore (30) with a slot (37) extending towards an edge, the width of said bore (30) being larger than the inside diameter of the rod (31).

2. A receiving device as claimed in claim 1, characterised in that the plate (25) is rectan gular and in that the slot (37) ends at a longer side (36) of the plate (25).

3. A receiving device as claimed in claim 2, characterised in that the slot (37) extends perpendicularly in respect of a longer side (36) of the disc (25).

4. A receiving device as claimed in claim 2, characterised in that between the plate (25) and the support (17) of the brake disc a tightening disc (27) is provided which has a central bore (30), the diameter of the bore (30) being larger than the inside diameter of the nut (26) and smaller than the length of the plate (25).

5. A receiving device as claimed in any one of the preceding claims, characterised in that two discs (17, 1 8) are provided which are supported at the housing (10) on bearings (15, 1 6) and which are pressed against the bearings (15, 16) by means of the rod (31) and lock nuts (21, 32, 33).

6. A receiving device as claimed in claim 5, characterised in that an upper lock nut (21) also forms the centering disc.

7. A receiving device as claimed in any one of the preceding claims, characterised in that the receiving device is fastened on a base plate (3) and in that a column (5) is provided on the base plate (3) for the reception of the measuring arrangement (6) which is displaceable along the column (5).

8. A receiving device as claimed in any one of the preceding claims, characterised in that the centering disc (21) has a central bore (39) whenceup to its edge a slot (39) is extending the width of which is larger than the diameter of the rod (31).

9. A receiving device for a brake disc, for use in the measurement of the lateral run-out existing on a friction surface of the brake disc, substantially as herein described with reference to and as illustrated in the accompanying drawings.