EP0575918B1 - Mounting means for supporting an electrical device - Google Patents

Description

The invention relates to a holding device for mounting an electrical component which can be actuated by a rotatable shaft on an object, the electrical component being displaceably guided relative to the object in a first displacement direction and in a second displacement direction which is perpendicular thereto, the two displacement directions being moved around Are offset by 90 ° to the shaft.

Such a holding device is known from EP 0 070 934 A1. There, a potentiometer with a rotatable shaft is slidably attached to a holding plate, the shaft reaching through an opening of the potentiometer, which has a sufficiently large play for the desired displaceability. An annular flange component is rigidly attached to the potentiometer. At the holding plate is fastened to a disk-shaped part which has a projecting pin which runs parallel to the shaft and is guided in an opening in the flange component. A stepped, ring-shaped part engages over the potentiometer in the manner of a union nut and clamps the disk-shaped part with the pin against the holding plate. This stepped annular part is screwed onto the holding plate. With this construction, it is possible to move the potentiometer within two free directions of movement within the free space between a play between the annular flange part and the stepped annular part. This makes it possible to couple the shaft of the potentiometer to a drive part, even if there is a center offset between the drive part and the shaft of the potentiometer.

US 1,459,035 shows a flexible coupling with which two shaft ends to be coupled can be connected to one another. The coupling has a housing with a square recess, the side walls of which form guideways for slide components. Two parallel slide bearing surfaces are provided on each of the shaft ends to be coupled, which can slide along the longitudinally assigned guide tracks of the housing. The corresponding bearing surfaces of the two shaft parts to be coupled are perpendicular to one another. This means that each of the two shaft ends to be coupled can be shifted in one direction, so that, as a result, with coupled shafts a center offset in two directions perpendicular to one another and perpendicular to the longitudinal axis of the shafts is possible.

From DE-PS 35 24 308 and DE-OS 36 24 640 it is also known to mount the rotary driver of a potentiometer relative to the spring support to be rotated so that it can perform a wobble movement. This can cause tilting errors and, to a lesser extent, center offset errors between the axis of rotation of the potentiometer and one of the Potentiometer driving shaft can be compensated.

From DE-OS 37 14 348 (= EP 0 288 930) it is known to mount the moving parts of the potentiometer, such as the potentiometer shaft and the spring support, in a floating manner with respect to the potentiometer housing via spring-elastic damping members, which means that misalignment errors can also be compensated to a certain extent .

Usually, the housing of an electrical component is attached to an object, which then also defines the position of the shaft actuating this component. This leads to problems if the axis of rotation of the electrical component is not correctly aligned with an actuator for this, for example when a potentiometer is used as a rotary position sensor and an actuator actuating the potentiometer shaft is not correctly aligned with the object to which the potentiometer housing is attached is aligned or moves. If, for example, a potentiometer is used as a rotary position sensor for the throttle valve of an internal combustion engine, the rotary shaft of the potentiometer is coupled to the axis of rotation of the throttle valve via a linkage and the potentiometer housing is attached to the engine block, the described negative effects can occur due to vibrations, installation tolerances or thermal expansion. Similar problems occur when adjusting brake linings in vehicles, where the wear of the brake linings is detected by the position of a linkage by a potentiometer. The same applies accordingly to rotary switches that are used to query limit positions or to other electrical components that are actuated by a rotatable shaft.

The object of the invention is therefore to provide a holding device for storage of electrical components of the type mentioned, which is able to compensate even larger dimensional tolerances.

This object is achieved by the features specified in the characterizing part of patent claim 1. Advantageous refinements and developments of the invention can be found in the subclaims.

The basic idea of the invention is therefore to mount the potentiometer housing in a cross slide guide. The two displacement directions are offset by 90 °. The displacement directions are each radial to the axis of rotation of the potentiometer. As a result, apart from frictional forces for displacing the slide components, a force-free compensation of center offset errors between the axis of rotation of the potentiometer and a shaft driving the potentiometer is possible. The strictest linearity of the potentiometer is also guaranteed, in contrast to a coupling of the potentiometer and drive shaft via universal joints.

According to an advantageous embodiment of the invention, the second slide component has a substantially rectangular recess, two opposite side walls of this recess forming a first guide track for receiving the first slide component, which creates a structurally simple, easy to manufacture and easy to assemble holding device.

According to a particularly preferred development of the invention, a metallic leaf spring is embedded in one of the side walls of the first and / or the second slide component, which has two spring-elastic arms projecting over the base body of the respective slide component, at the end of which dome-like projections are fastened. The long-term behavior of the holding device is considerably improved by these metallic leaf springs, since the spring properties of the spring arms are retained even after extremely long operating times. If the respective slide component is injection molded from plastic, the respective leaf spring can be inserted into the mold before injection molding this component and are firmly connected to the slide component by injection molding.

According to a development of the invention, the two slide components each have spring-elastic arms with outwardly projecting projections. These projections slide on the associated guideway, which on the one hand reduces frictional forces and on the other hand prevents the slide components from tilting. The spring-elastic arms additionally compensate for tolerance errors, which is particularly important if the guideway on the object on which the potentiometer is to be mounted is not precisely manufactured or contaminated. Limiting stops are preferably provided in both displacement directions, so that the potentiometer is positioned substantially immediately at the correct position during assembly.

According to an advantageous development of the invention, the first slide component is attached in one piece to the housing of the potentiometer, and thus the potentiometer housing can be manufactured together with the first slide component in one operation, for example as an injection molded part.

According to a further development of the invention, the second slide component has an outwardly projecting bead on the side walls forming the second guideway. This increases the mechanical strength of the holding device. A further embodiment of the invention provides that the first slide component has an annular base body on which the two side walls are formed tangentially, this annular base body simultaneously serving as a bearing for rotatable parts of the potentiometer. This simplifies the design effort for the housing and the first slide component, saves material and at the same time increases the mechanical strength of the first slide component. Finally, both slide components are preferably made of plastic.

Fig. 1

eine teilweise geschnittene Draufsicht der Haltevorrichtung im Einbauzustand;

Fig. 2

eine ähnliche geschnittene Draufsicht nach einem weiteren Ausführungsbeispiel, bei der eines der Schlittenbauteile eine metallische Blattfeder aufweist;

Fig. 3

eine ähnliche Draufsicht eines weiteren Ausführungsbeispieles der Erfindung, bei der beide Schlittenbauteile eine metallische Blattfeder aufweisen;

Fig. 4

eine Draufsicht eines zweiten Schlittenbauteiles mit metallischer Blattfeder;

Fig. 5

einen Schnitt längs der Linie I-I der Fig. 4;

Fig. 6

eine Seitenansicht des Schlittenbauteiles der Fig. 4;

Fig. 7

eine Seitenansicht einer bei verschiedenen Ausführungsbeispielen der Erfindung verwendeten Blattfeder; und

Fig. 8

eine Draufsicht der Blattfeder der Fig. 7.

The invention is explained in more detail below on the basis of exemplary embodiments in conjunction with the drawing. It shows:

Fig. 1

a partially sectioned plan view of the holding device in the installed state;

Fig. 2

a similar sectional plan view according to a further embodiment, in which one of the slide components has a metallic leaf spring;

Fig. 3

a similar top view of a further embodiment of the invention, in which both slide components have a metallic leaf spring;

Fig. 4

a plan view of a second slide component with a metallic leaf spring;

Fig. 5

a section along the line II of Fig. 4;

Fig. 6

a side view of the carriage component of Fig. 4;

Fig. 7

a side view of a leaf spring used in various embodiments of the invention; and

Fig. 8

7 shows a top view of the leaf spring of FIG. 7.

The holding device essentially consists of a first slide component 1, which is displaceable relative to a second slide component 2. The second slide component 2, together with the first slide component 1, can be displaced along a guideway 4 relative to an object 3. In the exemplary embodiment shown, item 3 is an adjusting device for adjusting the brake linings of a motor vehicle. Further details of this object 3 are not important for the invention, which is why its individual parts are also not described in detail. The only important thing is that this object 3 has a guideway (guide spell 4) in which the second slide component 2 is guided.

The first slide component 1 can be moved in a straight line in a first direction of displacement 5; the second slide component 2 can be displaced in a straight line in a second displacement direction 6. The two displacement directions 5 and 6 are perpendicular to one another, that is to say they are rotated 90 ° relative to one another. The electrical component (not shown) is fastened to the first slide component 1, the first slide component 1 preferably being integrated with the housing of the electrical component and projecting therefrom. The axis of rotation of the electrical component is perpendicular to the two displacement directions 5 and 6, so that the two displacement directions 5 and 6 each run radially to the axis of rotation of the component.

The first slide component 1 has two mutually parallel side walls 11 and 12, at the ends of which a spring-elastic arm 13, 14; 15, 16 is attached with projections projecting outwards. The elasticity can be increased in that the arms 13-16 are separated from the housing by incisions or axial recesses. In the exemplary embodiment shown, these two rectilinear side walls 11 and 12 are integrally formed on an annular base body 17 of the first slide component 1, this annular base body 17 being at the same time part of the housing of the electrical component and used for mounting the rotatable parts of the component, for example with a potentiometer for storing the wiper spring support of the potentiometer.

The second slide component 2 consists essentially of a rectangular frame which has a substantially rectangular central recess 20. Two side walls 21 and 22 which run parallel to one another and parallel to the direction of displacement 6 likewise have resilient ends at the ends Arms 23, 24, 25 and 26 with outwardly projecting projections. Two further side walls 27 and 28 running parallel to one another and parallel to the direction of displacement 5 form with their inside the guideway for the first slide component 1. The projections on the arms 13, 14, 15 and 16 lie against the inside wall of the side walls 27 and 28.

The side walls 27 and 28 have outwardly projecting beads 29 and 30, so that only the sections lying between the beads and the side walls 21 and 22 serve as a guideway. The side walls 21 and 22 also serve as a limit stop for the displacement of the first slide component 1.

Similar to the first slide component, the side walls 21 and 22 of the second slide component also have spring-elastic arms 23, 24, 25 and 26 at the end, which likewise have outwardly projecting projections which slide along the guide track 4. The guide track 4 is delimited by steps 31 acting as a limit stop, so that the second slide component can only be moved within these limits. This also makes it clear that the guideway 4 does not have to be continuous but can only consist of four sections, the length of which corresponds to the maximum displacement of the second slide component.

The embodiment of FIG. 2 differs from that of FIG. 1 essentially in that the second slide component 2 has on one of its side walls 21, which is in contact with the guideway 4, a metallic leaf spring 32, which thereby in the side wall 21 is firmly anchored that it is overmolded with the plastic, ie a central portion 35 of the leaf spring 32 is anchored in the side wall 21 of the second slide component 2. Metallic spring arms then extend over the rectangular contour on both sides of this section 35 of the second slide component. These spring arms are provided at their ends with dome-shaped projections 33 and 34, which bear against the associated guideway 4 and serve as sliding bodies. These metallic leaf springs retain their spring properties even after a long period of operation, so that the long-term behavior of the holding device is decisively improved. It is sufficient if such a metallic leaf spring is present only on one of the side walls 21 or 22, which are parallel to the guideway 4, since this compensates for material fatigue, abrasion or other wear on the elastic arms 23 and 24 of the second slide component. Of course, it would be possible without further ado to equip the slide component with two such metallic leaf springs, but this would only increase the manufacturing costs without bringing any technical advantages.

In the exemplary embodiment in FIG. 3, both slide components 1 and 2 are equipped with metallic leaf springs similar to the exemplary embodiment in FIG. 3. The embodiment of FIG. 3 differs from that of FIG. 2 in that the first slide component 1 also has a metallic leaf spring 36 on one of its side walls 11 instead of the resilient arms 13 and 14 of FIG. 1, which has a central section 39 is anchored in the plastic of the first slide component 1 and protrudes from there with two spring arms, at the end of which dome-shaped projections 37 and 38 are attached. These two dome-like projections 37 and 38 slide against the guide track 27. When the first slide component 1 is manufactured, the leaf spring 36 is inserted into the injection mold in a manner similar to that described above, and the plastic is overmolded in the region of the side wall 11 and the central section 39 and thereby firmly anchored. Here, too, it would theoretically be possible to equip the first slide component with two such leaf springs, although this would also not bring any further technical advantages.

4 to 6 show in more detail different views of the second slide component according to the exemplary embodiments of FIGS. 2 and 3. The second slide component is essentially rectangular in the plan view of FIG. 4 and has four side walls 21, 22, 29 and which are at right angles to one another 30. At the corners between the side wall 22 and the side walls 29 and 30 are parallel to the side wall 22 extending resilient arms 23 and 24 which protrude laterally slightly beyond the level of the side wall 22 and thus with their outwardly facing sides precisely defined sliding surfaces form.

On the side opposite the wall 22, the leaf spring is provided, the central portion 35 of which is embedded in the plastic of the side wall 21. As will be explained in more detail in connection with FIGS. 7 and 8, two spring arms protruding from the plastic are connected to this central section by means of offsets, on the ends of which the dome-shaped projections 33 and 34 are attached. The length of the spring arms of the leaf spring 32 is selected so that the ends of the leaf spring and the ends of the opposite plastic spring arms 23 and 24 each project equally far beyond the side walls 29 and 30, respectively.

The slide component 2 furthermore has a base 40 which is stretched between the frame-like side walls 21, 22, 29 and 30 and which has a central opening 41. This base 41 serves to hold the first slide component (see FIGS. 1 to 3) and supports it in a plane perpendicular to the axis of the shaft. 4 and 6 that the side walls 29 and 30 protrude outwards in a central section, so that the two sections of the guideway 27 and 28 are each limited in length.

The central opening 41 of the bottom 40 serves to save material and weight and prevents warping Slide component when the plastic hardens.

7 and 8 finally shows the leaf spring which is used in the exemplary embodiments of FIGS. 2 to 6. The leaf spring 32 is an elongated rectangular strip in plan view (FIG. 8). In the side view of FIG. 7 it can be seen that spring arms 43 and 44 adjoin a middle section 35 via two offsets 41 and 42, the level of which is offset from the plane of the middle section 35. At the ends of the two spring arms 43 and 44, an opening 45 and 46 is provided in each case in order to fasten, for example, rivet, the dome-like projections thereon. Furthermore, the leaf spring has an opening 47 in the middle of the central section 35, which serves to better anchor the leaf spring in the plastic material. When the leaf spring is encapsulated, plastic material penetrates through this opening 47 and forms a bridge between the plastic lying on both sides of the leaf spring, to which the leaf spring is then firmly anchored in its longitudinal direction.

Claims (11)

1. Apparatus for mounting an electrical component on an object, said electrical component being actuatable by a rotaring spindle, wherein said electrical component being displaceably guided relative to the object in a first displacement direction and in a second displacement direction perpendicular to said first displacement direction, the two displacement directions being offset by 90 degrees, with respect to the axis of said spindle, characterized by

   two displaceable slide components (1 and 2), the first (1) of which being mounted on a housing of said electrical component, and being displaceable along a first guideway relative to the second slide component (2) in said first displacement direction, and said second slide component (2) being displaceably guided on a second guideway of the object (3) in the second displacement direction,

   in that said second slide component (2) has a substantially rectangular recess (2) for receiving said first slide component (1), and

   in that opposing side walls (27, 28) of the second slide component (2) are forming said first guideway.
2. Apparatus according to claim 1, characterized in that, said first slide component (1) has two side walls (11, 12) extending parallel with one another said side walls having resilient arms (13, 14, 15, 16) with outwardly jutting projections extending from their ends, wherein said projections being displaceably guided on the side walls (27, 28) of the second slide component (2).
3. Apparatus according to claim 2, characterized in that, in one of the side walls (11) of the first slide component (1) is embedded a metallic leaf spring (36), having two resilient arms extending beyond the base element of the first slide component (1), said arms having cap-like projections (37, 58) secured to the ends thereof.
4. Apparatus according to claim 2, characterized in that, said second slide component (2) has two side walls (21, 22) parallel with each other, each end of which having an arm (23, 24, 25, 26) with protruding projections, said projections being guided displaceably on the guideway (4) of the object (3).
5. Apparatus according to claim 4, characterized in that, a metallic leaf spring (32) is embedded in one of the side walls (21) of said second slide component (2), said spring having two resilient arms extending beyond the base element of the second slide component (2), at the ends thereof cap-like projections are secured.
6. Apparatus according to claim 4, characterized in that, the side walls (21, 22) of the second slide component (2) are adapted to limit the displacement of the first slide component (1).
7. Apparatus according to claim 1, characterized in that, the guide way (4) of the object (3) has steps (31) adapted to limit the displacement of said second slide component.
8. Apparatus according to one of claims 1 to 6,
   characterized in that,
   said first slide component (1) is formed integrally with the housing of said electrical component.
9. Apparatus according to one of claims 1 to 8,
   characterized in that,
   the side walls (27, 28) forming the first guideway of the second slide component have a central section (29, 30) projecting outwardly from a recess (20).
10. Apparatus according to one of claims 1 to 9,
    characterized in that,
    the first slide components (1) has an annular base element (17) on which two side walls are formed tangentially, said annular base element (17) being adapted to simultaneously support the rotating parts of the electrical component.
11. Apparatus according to claims 2 and 8,
    characterized in that,
    the resilient arms (13-16) are separated from the housing of the component by notches or axial cut-outs in the housing.

Images