GB2313480A

GB2313480A - Cam wheel

Info

Publication number: GB2313480A
Application number: GB9710047A
Authority: GB
Inventors: Peter Pohl; Walter Schaetzler; Hans Benda
Original assignee: Daimler Benz AG; Mercedes Benz AG
Current assignee: Daimler Benz AG
Priority date: 1996-05-24
Filing date: 1997-05-16
Publication date: 1997-11-26
Also published as: DE19620984A1; GB9710047D0; DE19620984C2

Description

2313480 INDEXING WHEEL The present invention relates to an indexing wheel.

In an embodiment, the present invention relates to an indexing wheel for actuating a switching means for stopping a motor which drives a part of a vehicle, said part being displaceable between reference positions, and in at least one predetermined position of the displaceable part, the indexing wheel comprising one or a plurality of switching cams.

Such an indexing wheel is known for instance from DE-Cl-4021973. In that case, the indexing wheel is integral with, disposed on the outer periphery, two cam paths which are axially offset in relation to each other. The cams take the form of raised portions projecting in a radial direction and which, respectively via actuating members, actuate two switches which are disposed beside each other in the axial direction. Altogether, these elements constitute the switching means for immobilising the displaceable part. The displaceable part may be for example the cover of a vehicle sliding roof which is driven by an electric motor through a drive pinion and compression-resistant drive cables. The rotary movement of the indexing wheel is stepped down so sharply in comparison with the rotary movement of the drive pinion that, over the entire displacement path of the displaceable part, the indexing wheel is caused to perform a rotary movement of less than 3600, so guaranteeing that each rotated position of the indexing wheel is clearly associated with one specific position of the displaceable part.

As a rule, the displacement paths of the displaceable part vary according to the type of vehicle or electric drive used so that in each case a specially constructed type of indexing wheel with specially disposed cams is 2 required. The type of indexing wheel must not be confused as otherwise the drive has to be dismantled or certain component parts need to be replaced. The use of different types of indexing wheel also increases the costs for the vehicle manufacturer. For example, if two different types of vehicle are being constructed on one belt, then two identification numbers are required to differentiate between the indexing wheels, necessitating a more complicated control or logistics and additional storage space.

Consequently, it is an object of the present invention to provide an indexing wheel which, with the least possible complication, can be used for different displacement paths or drive paths of a displaceable part.

According to a first aspect of the present invention, there is provided an indexing wheel for actuating a switching means, the indexing wheel comprising an adjustable switching cam.

According to a second aspect of the present invention, there is provided an indexing wheel for actuating switching means, the indexing wheel comprising a plurality of switching cams, at least one of the switching cams being adjustable.

According to a third aspect of the present invention, there is provided an indexing wheel for actuating a switching means for stopping a motor which drives a part of a vehicle, said part being displaceable between reference positions, and in at least one predetermined position of the displaceable part, the indexing wheel comprising one or a plurality of switching cams, characterised in that the switching cam or at least one of the,switching cams is adjustable.

3 The present invention also includes a vehicle sliding roof comprising a sliding roof cover, a motor for driving the roof between open and closed positions, a switch for switching the motor on or off at at least one of the open and closed positions of said roof, and an indexing wheel as described above, the switching cam being arranged to actuate the switch at at least one of the open and closed positions of said roof.

The solution according to the invention has the advantage that an identical drive or an identical indexing wheel can be used for different paths or drive paths of a displaceable part. The adjustment of the indexing wheel can be carried out by the manufacturer of the displaceable is part or by the vehicle manufacturer in the completed vehicle, which has logistic advantages. The multiplicity of parts in terms of components, drive motors and spare parts is reduced, resulting in logistic and therefore cost advantages.

In a further advantageous development of the invention, it is envisaged that the switching cam(s) be adjustable between at least two positions in which the switching cam(s) can be locked by catch means. This allows a particularly simple conversion of the indexing wheel to accommodate two or more different drive paths.

Furthermore, it is envisaged that at least one switching cam may be rotatable in a peripheral direction about the centre of the indexing wheel. Consequently, the angular setting of the indexing wheel at which a specific switching function occurs can easily be altered.

Furthermore, the indexing wheel is preferably so constructed that at least one switching cam is axially or radially displaceable. In this way, the indexing wheel can 4 easily be so adjusted that one specific switching function can as desired be activated or deactivated.

Further preferred developments of the invention will emerge from the dependent claims below.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a plan view of an example of an indexing wheel according to the invention; Fig. 2 shows a longitudinal section on the line II-II in Fig. 1; Fig. 3 is a view of a further example of an indexing wheel according to the invention; and, Fig. 4 is a plan view of a third example of an indexing wheel according to the invention.

Figs. 1 and 2 show an indexing wheel which has in its centre a hub 1 with a hub aperture 2. By means of the hub 1, the indexing wheel can be preferably rotatably mounted on a shaft (not shown) which is accommodated in the hub aperture 2. Mounted for displacement in an axial direction on the outer periphery of the hub 1 is a cam part 3 with a cam arm 4 extending in a radial direction and on the radially outer end of which there is a switching cam 5. The cam part 3 has for this purpose a circular aperture through which the hub 1 extends.

The indexing wheel has a substantially plane base part 6 in the marginal portion of which there is constructed a web 7 which projects upwardly (or to the right in Fig. 2) and extends in a peripheral direction. Furthermore, there is in the base part 6 an eccentrically disposed axial bore 10 which marks the position in which the indexing wheel is to be installed in a drive. Constructed on the periphery of the indexing wheel are two fixed switching cams 8, 9 5 which project outwardly in a radial direction.

All hitherto described parts of the indexing wheel with the exception of the cam part 3 are constructed in one piece.

As a function of a rotary movement of the indexing wheel, the switching cams 5, 8, 9 serve to control a switching means in that they come into and out of engagement with actuating members 11, 12 of one or a plurality of switches 13, 14. The fixed switching cans 8, 9 and the displaceable switching cam 5 are provided for the control of different actuating members 11, 12. The actuating members 11, 12 bear on the periphery of the indexing wheel, are offset in an axial direction, and can be constructed as pins. The switches 13, 14 may be microswitches for example.

In the position shown in Fig. 2, the displaceable switching cam 5 is disposed at a distance z from the web 7 in the axial direction. In this position, when the indexing wheel is installed, the displaceable switching cam 5 is offset in the axial direction in respect of the actuating member 11 which it is intended to control, so that no controlling of the corresponding actuating member 11 or the associated switch 13 is carried out by the displaceable switching cam 5. Therefore, the displaceable switching cam 5 is deactivated when it is in the position shown in Fig. 2. This is the case when the indexing wheel is used in a system in which the switching function allocated to the displaceable switching cam 5 is not being used.

6 If, on the other hand, the indexing wheel is to be used in a system in which use is made of the switching function of the displaceable.switching cam 5, the cam part 3 is displaced by means of a suitable tool (or even manually, i.e. without a tool) in an axial direction on the outer periphery of the hub 1 preferably prior to or during installation of the indexing wheel, until such time as the cam arm 4 bears on the web 7. In this position, the displaceable switching cam 5 and the actuating member 11 of the switch 13 are, when the indexing wheel is installed, situated in the same radial plane, i.e. at the corresponding rotated position of the indexing wheel, the switching cam 5 actuates the actuating member 11 in that it pushes it outwards in a radial direction. Therefore. the displaceable switching cam 5 becomes actuated by displacement of the cam part 3 in an axial direction.

The hub 1 and the cam part 3 are preferably so constructed that the cam part 3 can be locked by catch means in both the axial positions described. This can happen for example by virtue of the fact that there are on the outer periphery of the hub 1 two peripheral grooves into which the cam part 3 can be optionally engaged. If only an activation/deactivation of the switching cam 5 is desired, the cam part 3 should be mounted to be rotationally rigid in respect of the hub 1. This can be achieved for example in that on one of the outer periphery of the hub 1 and the inner periphery of the circular opening in the cam part 3 there is an axial groove and on the other of the outer periphery of the hub 1 and the inner periphery of the circular opening in the cam part 3 there is an axial web which engages with the groove.

An alternative embodiment for activating/deactivating a switching cam is shown in Fig. 3. With the exception of the cam part and the hub, the other elements of the indexing wheel are substantially identical to the 7 embodiment shown in Figs. 1 and 2. The cam part 103 of this example comprises two overlapping apertures 120, 121 which are axially offset in respect of each other and which are provided in order to accommodate a hub 101 of the indexing wheel. The cam part 103 is provided with a radially extending cam arm 104 on the radially outer end of which there is a switching cam 105. In the position shown in Fig. 3, the cam part 103 is, by means of the aperture which is more remote from the switching cam 105, preferably mounted on the hub 101 to be rotationally rigid and fixed in an axial direction. In this position, the switching cam 105 projects outwardly so far in the radial direction that, in the corresponding rotated position of the indexing wheel, it actuates the actuating member allocated to it, i.e. is able to push it radially outwardly. Thus, the switching cam 105 is actuated in this position.

In order to deactivate the switching cam 105, the cam part 103 can be displaced radially inwardly against the resistance of projections 123 at the point at which the two apertures 120, 121 meet, so that the cam part 103 is rotationally rigidly and in an axially fixed position mounted on the hub 101 via the second aperture 121 which is closer to the switching cam 105. In this position, the switching cam 105 is displaced so far inward radially that it is no longer able to actuate the actuating member allocated to it and no longer exerts any switching function, i.e. it is deactivated. Without the intervention of any external force, the cam part 103 is, by the elastic force exerted by the projections 123, prevented from any displacement in a radial direction and therefore it is held in the corresponding position.

Any of activating/deactivating the switching cam 105 is for the cam part 103 not to be displaced radially directly against the resistance of the projections 123 but 8 for instance to be moved out of the inactive position in which the cam part 103 is mounted on the hub 101 via the aperture 121 which is closer to the switching cam 105 and moved into the activated position by first pulling the cam part 103 axially off the hub 101 and then remounting it on the hub 101 by means of the aperture 120.

Fig. 4 shows an embodiment of the indexing wheel in which the switching point of a displaceable switching cam, i.e. the angular position of the indexing wheel, in which the switching cam operates the actuating member, is adjustable. The embodiment shown in Fig. 4 is similar to the embodiment shown in Fig. 1. However, the cam part 203 is not axially displaceable on the hub 201 but is rotatable in a peripheral direction about the centre of the indexing wheel. From the position designated A in Fig. 4, a switching cam 205 constructed on the end of a can arm 204 is, by rotation of the cam part 203, pivoted in the peripheral direction into a position designated B. As a result, the switching point of the switching cam 205 changes by an angle a. This means that the indexing wheel with the switching cam 205 inthe position B now triggers a specific switching process sooner or later (according to the rotated position) than in the switching cam position.

This can be used in order to compensate for a longer or shorter displacement path of the displaceable part when the indexing wheel is used in another system. In addition to the positions A and B of the switching cam 205, further variable positions can be provided if the indexing wheel is to be used not only with two but with a plurality of different displacement paths.

Also in the case of the embodiment shown in Fig. 4, it is preferred for the cam part 203 to be adapted to be locked by catch means in both (or in all) positions used, e.g. by the provision of corresponding longitudinal grooves on the outer periphery of the hub 201 and a matching web on 9 the inner periphery of the aperture 202 of the hub part 203 or vice versa.

In addition to the hitherto described embodiments, it is also possible to provide embodiments in which the described displacement possibilities for a single switching cam are so combined that the switching cam can be activated or deactivated both by radial or axial displacement and also displaced by an angle in the peripheral direction in 10 order to alter the switching point.

In principle, it is also possible to have embodiments in which the switching cam is pivotable about a point outside the centre of the indexing wheel in a plane is parallel with the indexing wheel or in which the switching cam is pivotable in a plane at right-angles to the indexing wheel. This likewise permits an optional activation or deactivation of the switching cam.

Furthermore, the indexing wheel can also comprise a plurality of displaceable switching cams which are displaceable either all in the same way or in different ways.

Embodiments of the present invention have been described with particular reference to the examples illustrated. However, it will be appreciated that variations and modifications may be made to the examples described within the scope of the present invention.

Claims

1. An indexing wheel for actuating a switching means, the indexing wheel comprising an adjustable switching cam. 5

2. An indexing wheel according to claim 1, wherein the switching cam is displaceable.

3. An indexing wheel according to claim 2, wherein the switching cam is axially displaceable.

4. An indexing wheel according to claim 2, wherein the switching cam is radially displaceable.

5. An indexing wheel according claim 1, wherein the switching cam is pivotable about a fixed point.

6. An indexing wheel according to claim 5, wherein said pivotable switching cam is pivotable in a peripheral 20 direction about the centre of the indexing wheel.

7. An indexing wheel according to claim 1, wherein the switching cam is displaceable between at least two positions in which said switching cam is lockable by catch 25 means.

8. An indexing wheel according to any of claims 1 to 7, wherein the switching cam is constructed to actuate at least one microswitch. 30

9. An indexing wheel for actuating switching means, the indexing wheel comprising a plurality of switching cams, at least one of the switching cams being adjustable.

10. An indexing wheel according to claim 9, wherein at least one switching cam is displaceable.

11. An indexing wheel according to claim 9 or claim 10, wherein at least one switching cam is axially displaceable.

12. An indexing wheel according to any of claims 9 to 11, wherein at least one switching cam is radially displaceable.

13. An indexing wheel according to any of claims 9 to 12, wherein at least one switching cam is pivotable about a fixed point.

14. An indexing wheel according to claim 13, wherein said pivotable switching cam is pivotable in a peripheral direction about the centre of the indexing wheel.

15. An indexing wheel according to any of claims 9 to 14, wherein at least one switching cam is displaceable between at least two positions in which said switching cam is lockable by catch means.

16. An indexing wheel according to any of claims 9 to 15, wherein the switching cams are constructed to actuate one or more microswitches.

17. An indexing wheel for actuating a switching means for stopping a motor which drives a part of a vehicle, said part being displaceable between reference positions, and in at least one predetermined position of the displaceable part, the indexing wheel comprising one or a plurality of switching cams, characterised in that the switching can or at least one of the switching cams is adjustable.

18. An indexing wheel according to claim 17, characterised in that at least one switching cam is displaceable.

19. An indexing wheel according to claim 18, characterised in that at least one switching cam is axially displaceable.

12

20. An indexing wheel according to claim 18 or 19, characterised in that at least one switching cam is radially displaceable.

21. An indexing wheel according to any of claims 17 to 20, characterised in that at least one switching cam is adapted to pivot about a fixed point.

22. An indexing wheel according to claim 21, characterised in that at least one switching cam is pivotable in a peripheral direction about the centre of the indexing wheel.

23. An indexing wheel according to any of claims 17 to 22, characterised in that the switching cam(s) is (are) displaceable between at least two positions in which the switching cam(s) is (are) lockable by catch means.

24. An indexing wheel according to any of claims 17 to 23, characterised in that the indexing cam(s) is (are) constructed to actuate one or a plurality of microswitches.

25. A vehicle sliding roof comprising a sliding roof cover, a motor for driving the roof between open and closed positions, a switch for switching the motor on or off at at least one of the open and closed positions of said roof, and an indexing wheel according to any of claims 1 to 24, the switching cam being arranged to actuate the switch at at least one of the open and closed positions of said roof.

26. An indexing wheel, substantially as described with reference to Figures 1 and 2 or Figure 3 or Figure 4 of the accompanying drawings.