Abstract
This relates to an actuating unit, in particular for a drum brake, comprising a spacer element which can be fixed on a shoe unit or on a supporting unit, the spacer element having a holding section, via which it can be secured against movement along an activating axis relative to the shoe unit or the supporting unit, the spacer element having a first engagement section which is supported on the respective other one of the units comprising the shoe unit or the supporting unit in a first position of the spacer element, it being possible for the spacer element to be moved into a second position, in which the first engagement section is out of engagement with the shoe unit and the supporting unit, the spacer element spacing the shoe unit and the supporting unit further apart from one another in the first position than in the second position.
Claims
1.-15. (canceled)
16. An actuating unit, comprising: a spacer element configured to be fixed on at least one of a shoe unit and a supporting unit, the spacer element having a holding section via which the spacer element is configured to be secured against movement along an activating axis relative to at least one of the shoe unit and the supporting unit, the spacer element having a first engagement section which is supported in a first position of the spacer element on the respective other one of the shoe unit and the supporting unit not secured by the holding section, wherein the spacer element is configured to be moved into a second position of the spacer element, where the first engagement section is out of engagement with the at least one of the shoe unit and the supporting unit; and a second engagement section of the spacer element being supported on at least one of the shoe unit and the supporting unit in the second position, the spacer element spacing the shoe unit and the supporting unit further apart from one another in the first position than in the second position, wherein the spacer element is configured to be moved from the first position into the second position and from the second position into the first position by way of movement along an actuating axis, the actuating axis lying orthogonally with respect to the activating axis.
17. The actuating unit as claimed in claim 16, wherein the first engagement section has a greater mean extent along the activating axis than a mean extent of the second engagement section of the spacer element along the activating axis.
18. The actuating unit as claimed in claim 16, wherein a movement of the spacer element from the first position into the second position changes a spacing of the shoe unit from the supporting unit along the activating axis.
19. The actuating unit as claimed in claim 16, further comprising: a securing section which secures the spacer element in the first position against at least one of rotation about the actuating axis and movement along the actuating axis relative to the supporting unit or to the shoe unit.
20. The actuating unit as claimed in claim 19, wherein the change in the spacing is within the range from 1 mm to 2 cm.
21. The actuating unit as claimed in claim 20, wherein the change in the spacing is within the range from 2 mm to 1 cm.
22. The actuating unit as claimed in claim 21, wherein the change in the spacing is within the range from 4 mm to 6 mm.
23. The actuating unit as claimed claim 16, wherein the spacer element has a third engagement section which is configured to be brought into a positively locking engagement with the securing section.
24. The actuating unit as claimed in claim 19, wherein the securing section is configured on a clip element which, having been brought into a positively locking engagement with the shoe unit, secures the spacer element against rotation about the actuating axis.
25. The actuating unit as claimed in claim 19, wherein the securing section is at least one of fixed on the spacer element and configured in one piece with the spacer element, the securing section having a geometry which differs from the rotational geometry in relation to the actuating axis, wherein the securing section is configured to be moved by way of movement along the actuating axis into a position in which the securing section engages into a corresponding section on the shoe unit securing the spacer element against rotation about the actuating axis.
26. The actuating unit as claimed in claim 16, wherein a rotation of the spacer element by an angle moving the spacer element between the first and second positions, wherein the angle is smaller than 360.
27. The actuating unit as claimed in claim 26, wherein the angle is smaller than or equal to 180.
28. The actuating unit as claimed in claim 27, wherein the angle is smaller than or equal to 90.
29. The actuating unit as claimed in claim 16, wherein the first engagement section is configured as a rectangular projection, a long edge of the first engagement section having a greater extent than the spacing of two shoe webs of the shoe unit, and a short edge of the first engagement section having a smaller extent than the spacing of the shoe webs from one another.
30. The actuating unit as claimed in claim 29, the spacer element being fixed on an activating piston of the supporting unit, the activating axis running parallel to the actuating axis.
31. The actuating unit as claimed in claim 16, wherein the supporting unit comprises a roller body having cylindrical or barrel-shaped configuration which is supported with a circumferential face of the roller body on an expansion wedge unit of the supporting unit, and wherein the spacer element having a pin-shaped configuration in regions and engaging on the shoe unit with the first engagement section in the first position and with the second engagement section in the second position, the holding section of the spacer element being supported in a cutout of the supporting unit.
32. The actuating unit as claimed in claim 29, wherein the spacer element is configured to be moved between the first and second positions by way of rotation about the actuating axis.
33. A method for dismantling a brake system, comprising: releasing a securing section out of engagement with a spacer element; moving the spacer element along an actuating axis such that the spacer element passes from a first position into a second position; and utilizing of a spacing which is produced on a shoe unit to dismantle the shoe unit, in order to dismantle the shoe unit.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Further advantages and features of the present invention result from the following description of preferred embodiments with reference to the appended figures. It goes without saying that individual features of the preferred embodiments which are described in the individual exemplary embodiments can also be used in embodiments of other examples and other figures, if this has not been ruled out explicitly or is prohibited on the basis of technical circumstances. In the figures:
[0025] FIG. 1 shows the views of a first preferred embodiment of the actuating unit according to the invention;
[0026] FIGS. 2a, b, c show views of three preferred embodiments of the spacer element according to the invention;
[0027] FIG. 3 shows two views of a further preferred embodiment of the actuating unit according to the invention;
[0028] FIGS. 4a, b show two views of one preferred embodiment of the actuating unit according to the invention; and
[0029] FIGS. 5a, b show two views of one preferred embodiment of the actuating unit according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] FIG. 1 shows two views of one embodiment of the actuating unit according to the invention, the left-hand part (identified by I) of FIG. 1 showing the actuating unit in the state, in which the spacer element 2 is situated in its first position I. The view on the right which is identified by II shows the spacer element 2 in its second position II. The spacer element 2 has a first engagement section 24 and a second engagement section 25. As shown in the preferred embodiment, the spacer element 2 preferably has two first engagement sections 24 and four second engagement sections 25. Furthermore, the spacer element 2 preferably has a holding section 22 which preferably has the same diameter in the present embodiment as the second engagement sections 25. The shoe unit 6 preferably comprises two shoe webs 62 which are provided with cutouts which can be brought into engagement in each case with the first engagement section 24 or with a second engagement section 25 of the spacer element 2. In the first position I, the shoe unit 6 or the shoe webs 62 is/are in engagement with the first engagement sections 24. A dashed line shows one preferred clip element 41 which has securing sections 4 which secure the spacer element 2 in the first position I. After the clip element 41 is released, the spacer element 2 can be displaced along the actuating axis A in such a way that the first engagement sections 24 pass out of engagement with the shoe unit 6. Finally, the spacer element 2 can be moved into its second position II, the shoe unit 6 or the shoe webs 62 being in engagement with the second engagement sections 25 of the spacer element in the second position. The second engagement sections 25 have a smaller extent L.sub.25 transversely with respect to the actuating axis or along an activating axis B than the first engagement sections 24. This difference of the extent L.sub.24 of the first engagement sections from the extent L.sub.25 of the second engagement sections 25 therefore defines the change in spacing x, by which the shoe unit 6 moves closer to the supporting unit 8 or moves along or parallel to the activating axis B in the direction of the supporting unit 8. In the embodiment which is shown in FIG. 1, a play (not shown) is preferably produced on the underside of the shoe unit 6 in the second position II of the spacer element 2. It goes without saying that, starting from the first position I, the spacer element might also be moved to the right, in order to be moved into the second position II. This allows, in particular, it to be possible for an actuating unit in accordance with the embodiment which is shown in FIG. 1 to be used both on right-hand side and left-hand side brake systems on the chassis of a commercial vehicle, without structural modifications being necessary. Bevels 21 are preferably provided in the transition region between the first and the second engagement section 24, 25, in order to facilitate the movement of the spacer element 2 from the second position II back into the first position I.
[0031] FIG. 2a shows one preferred embodiment of the spacer element 2 according to the invention, in the case of which it is of pin-shaped configuration and has a first engagement section 24 which has a greater extent along or parallel to the activating axis B than a second engagement section 25. In the case of the substantially cylindrical configuration (shown in the present example) both of the first engagement section 24 and of the second engagement section 25, said extent L.sub.24 and L.sub.25 of the engagement sections 24, 25 is substantially their radius or the radius of the cylindrical circumferential face. In order to be moved from the first position I into the second position II, the spacer element II is preferably moved along the actuating axis A which is shown. In particular, the actuating axis A preferably lies orthogonally or perpendicularly with respect to the activating axis B in said embodiment.
[0032] FIG. 2b shows a second preferred embodiment of the spacer element 2 according to the invention, in the case of which it has a disk-shaped section, on which a first, substantially rectangular first engagement section 24 is configured. In the region of the first engagement section 24, the spacer element 2 has a greater extent L.sub.24 along or parallel to the activating axis B than in the region of the second engagement section 25. As is also shown in FIGS. 4a and b, a shoe unit 6 therefore preferably passes into engagement with the first engagement section 24 of rectangular configuration in the first position of the spacer element 2, and into engagement with the second engagement section 25 in the second position II. It goes without saying that, in the present case, the actuating axis A, about which the spacer element 2 is rotated in order to be moved from the first position I into the second position II, is congruent or parallel to the activating axis B, along which the supporting unit 8 and the shoe unit 6 (both not shown) are spaced apart from one another to a greater or lesser extent.
[0033] Finally, FIG. 2c shows a third preferred embodiment of the spacer element 2 according to the invention, said spacer element 2 being of substantially disk-shaped configuration and having a first engagement section 24 which corresponds to half a cylindrical face, and a second engagement section 25 which has an outer face which differs from the cylindrical shape of the first engagement section 24. Here, the mean extent L.sub.24 of the first engagement section 24 is greater than the mean extent L.sub.25 of the second engagement section 25 along or parallel to the activating axis B. In the present case, the spacer element 2 is arranged with respect to the activating axis B in such a way that the activating axis B intersects the corresponding engagement sections 24, 25 in each case in the face, in which, during use of the spacer element 2 in the first position I and in the second position II, the shoe unit 6 or the supporting unit 8 comes into contact. The distinction or the difference of the extents L.sub.25 and L.sub.24 therefore defines the change in the spacing of the shoe unit 6 from the supporting unit 8 if the spacer element 2 is moved into the second position II.
[0034] FIG. 3 shows a further preferred embodiment of the actuating unit according to the invention which is substantially very greatly similar to the embodiment which is shown in FIG. 1. Furthermore, the embodiment which is shown in FIG. 3 corresponds substantially to the embodiment which is shown in FIG. 2a, it being possible to see further details. The shoe unit 6 preferably has two shoe webs 62 which are in engagement with a first engagement section 24 of the spacer element 2 in the first position I and with the second engagement section 25 of the spacer element 2 in the second position (see the right-hand side in the figure). In the present case, the supporting unit 8 preferably comprises a supporting roller, the internal diameter of which in each case likewise passes into engagement with the first engagement section 24 or with the second engagement section 25. In this way, in the case of a single difference of the extents L.sub.24 and L.sub.25 with respect to one another, twice said difference becomes relevant as a change in the spacing x of the supporting unit 8 from the shoe unit 6. In other words, both the spacer element 2 moves relative to the shoe unit 6 by the respective difference of the extents L.sub.24 and L.sub.25 and, at the same time, the roller element of the supporting unit 8 also moves relative to the spacer element 2 by the magnitude of the difference of the extents L.sub.24 and L.sub.25. In the first position I (shown on the left in FIG. 3), the second engagement section 25 which protrudes out of the actuating unit in the present case can preferably be used as a wear indicator, by a corresponding scale being provided on the housing of the brake unit and the second section 25 which protrudes from the brake shoes being used as a pointer. Furthermore, a clamping ring 43 is preferably provided which has a securing section 4 and engages in the third engagement section 26, in order to secure the spacer element 2 in the first position I and to prevent a movement of the spacer element 2 along the actuating axis A relative to the shoe unit 6, at least relative to one of the shoe webs 62 in the present case.
[0035] FIG. 4a shows a further preferred embodiment of the actuating unit 4 according to the invention, both the first position I and the second position II being shown in the figure in a superimposed way. Furthermore, FIG. 4b shows a view along the activating axis B of the embodiment which is shown in FIG. 4a for illustrative purposes. The spacer element 2 is preferably an integral constituent part of an activating piston of the supporting unit 8 which is configured as an activating unit of the brake system. With preference, furthermore, the spacer element 2 preferably has a first engagement section 24 which is of substantially rectangular configuration. As shown in FIG. 4b, the spacer element 2 can be secured in the first position I by way of a clip element 41 which prevents a rotation of the spacer element 2 about the actuating axis A. Here, the clip element 41 engages on at least a third engagement section 26 of the spacer element 2. Therefore, the securing sections 4 of the clip element 41 secure the spacer element 2 in the first position I against rotation about the actuating axis A by way of engagement on the third engagement sections 26 and on the inner sides of the shoe webs 62. The holding element 45 is shown diagrammatically, which secures the clip element 41 against movement relative to the spacer element 2 and/or to the shoe unit 6. After the holding element 45 and subsequently the clip element 41 have been removed, a user can rotate the spacer element 2 by 90 about the actuating axis A, as a result of which the first engagement section 24 is pushed between the shoe webs 62 of the shoe unit 6 and finally passes out of engagement with the shoe webs 62. In this state, the case which is shown in FIG. 4a and is identified by II is reached, in which the shoe unit 6, in particular preferably the shoe webs 62, is/are supported directly on the second engagement section 25 or lies/lie on the latter. A play between the brake linings and the brake drum which surrounds the actuating unit is produced as a result on the left-hand side of the brake shoe unit 6.
[0036] FIG. 5a and FIG. 5b show a further preferred embodiment of the actuating unit, in the case of which the spacer element 2 is preferably configured as in FIG. 2c. The spacer element 2 is preferably supported in a holding section 22 (not shown) on the supporting roller of the supporting unit 8. In the first position which is shown in FIG. 5a, the spacer element 2 engages here with its first engagement section 24 on the shoe unit 6 and spaces the latter apart with respect to the supporting unit 8, in particular with respect to the activating piston of the supporting unit 8. In the second position II which is shown in FIG. 5b, the spacer element has been rotated by approximately 180, the second engagement section 25 now being in engagement with the shoe unit 6. As identified in FIG. 5a, the second engagement section 25 has a smaller extent L.sub.25 along the activating axis B than the first engagement section 24. Therefore, in the second position II, the shoe unit 6 can move closer to the supporting unit 8, as a result of which a play or gap is produced between the shoe unit 6 and the surrounding brake drum. In the position which is shown in FIG. 5b, the shoe unit 6 can be dismantled easily. The rounded region between the first engagement section 24 and the second engagement section 25 is suitable as a bevel 21 within the context of the present invention, since it facilitates the rotation of the spacer element 2 about the actuating axis A.
LIST OF DESIGNATIONS
[0037] 2 Spacer element [0038] 21 Bevel [0039] 22 Holding section [0040] 24 First engagement section [0041] 25 Second engagement section [0042] 26 Third engagement section [0043] 4 Securing section [0044] 41 Clip element [0045] 43 Clamping ring [0046] 45 Holding element [0047] 6 Shoe unit [0048] 62 Shoe web [0049] 8 Supporting unit [0050] 82 Activating piston [0051] A Actuating axis [0052] B Activating axis [0053] I First position [0054] II Second position [0055] x Change in the spacing [0056] L.sub.24 Mean extent of the first engagement section [0057] L.sub.25 Mean extent of the second engagement section
