GB1565101A

GB1565101A - Damping element for an operating linkage and motor car having such damping element

Info

Publication number: GB1565101A
Application number: GB2892277A
Authority: GB
Original assignee: Bayerische Motoren Werke AG
Current assignee: Bayerische Motoren Werke AG
Priority date: 1976-07-16
Filing date: 1977-07-11
Publication date: 1980-04-16
Also published as: DE2632074C3; FR2358290B3; DE2632074B2; FR2358290A1; IT1083895B; DE2632074A1

Description

(54) DAMPING ELEMENT FOR AN OPERATING LINKAGE AND MOTOR CAR HAVING SUCH DAMPING ELEMENT (71) We, BAYERISCHE MOTOREN WERKE AKTIENGESELLSCHAFT, a German Company, of P.O. Box 40 02 40, 8000 Munich 40, Federal Republic of German, 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 a damping element for an operating linkage, more particularly though not exclusively for use in the throttle linkage of a motor car.

In the throttle linkage in a private motor car, vibrations occur which are transmitted from the engine and are transferred to the accelerator pedal. To avoid vibration of the accelerator pedal it has been proposed, for example, in U.S. Patent 3250144 to insert a damping element in the throttle linkage.

Since the damping element of this kind is subjected to tensile stress on the one hand and also to compressive stress on the other hand, it must be resistant to bending forces.

For this purpose an outer member of a prior proposed damping element is cup-shaped in construction and connected with an inner member by way of an encircling elastomeric intermediate layer. By constructing the outer large overall bulk and therefore would take up a correspondingly large amount of space. Furthermore, the damping element would be of considerable mass which would have to be moved by the accelerator pedal.

Finally, a further disadvantage of the prior proposal is that the cup-shaped external part would be costly to produce.

The present invention has as its object, therefore, to provide an improved damping element which, in at least some of its forms, while having the necessary resistance to buckling for an accelerator or throttle linkage, is relatively inexpensive to produce.

Accordingly the invention provides a damping element for longitudinally aligned parts of a linkage, the damping element having an outer member, adapting the outer member for connection to a linkage part, an inner member, means adapting the inner member, for connection to a next following part of such linkage, the outer member partly surrounding at bent a portion of the inner member and being connected to it by way of an elastomeric intermediate layer, the inner member or the outer member or both having longitudinally extending guiding means adapted to co-operate with guide elements of the other member, so that in use of the element in such linkage the said linkage, parts are maintained in alignment and vibration tends to be absorbed by the elastomeric layer.

Since the damping and guiding functions are separated in the case of the damping element proposed by the present invention, the elastomeric intermediate layer used for damping the vibrations introduced into the throttle linkage can be made relatively soft and hence can be chosen with good damping properties, whilst the guiding of the outer and inner members in the loading direction of the linkage parts is achieved in a simple manner by the guide elements acting on the members. As a result the mass of the damping element is also kept to a minimum.

Moreover, it can readily be added to a linkage without involving much work.

According to a subsidiary feature of the invention it is proposed that the guiding distance of at least one guiding means is limited in the longitudinal direction.

The abutment limitation in the longitudinal direction which is provided between the outer member and inner member, assures in an advantageous way, that the damping element can operate temporarily even if the elastomeric intermediate layer becomes detached from the outer and/or inner member.

According to a further subsidiary feature of the invention the outer member of the damping element consists of a substantially U-shaped yoke which comprises in the base region of each of its two arms a slot or the like into which a transerve pin engages which is connected with the inner member, whilst there are provided as guiding means on the inner member two parallel guiding surfaces which are set back from its external periphery and extend parallel with the transverse pin, and these guiding surfaces co-operate with two lateral extensions of the free end region, extending inwardly, of an arm of the U-shaped yoke.

Finally, according to a yet further subsidiary feature the slots which are provided in the U-shaped yoke are lined at least partly with elastomeric material.

A preferred form of the invention will now be described by way of example with reference to the drawings wherein: Figure I shows diagrammatically a throttle linkage of a private motor car having a damping element embodying the invention, Figure 2 is a longitudinal sectional elevation of the damping element drawn to a larger scale, Figure 3 is a plan view of the damping element of Figure 2, and Figure 4 shows the damping element of Figure 2 in side view.

In Figure 1 there is shown a throttle linkage generally designated 1 for the carburetter of an engine of a private motor car (not shown). The linkage 1 includes a damping element 2 which comprises essentially an outer member 4 adapted for connection to a first linkage part 3, and an inner member 6 adapted for connection to a second linkage part 5, the linkage parts 3 and 5 being in longitudinal alignment. The inner member is connected with the outer member 4 by means of an elastomeric intermediate layer 7. The first linkage part 3 is connected with an intermediate linkage generally designated 8 leading to a foot pedal 9.

Figure 2 shows the damping element 2 in longitudinal section. Its outer member 4 consists of a U-shaped yoke having a pair of parallel arms 4'. The free end region 4" of one of these arms extends inwards as shown.

Thus the outer member 4 partly surrounds the inner member 6. The inner member 6 is of circular cross-section. Each of the two arms 4' of the outer member has a slot 10 in its base region extending in the longitudinal direction of the arms. A transverse pin 11 connected with the inner member 6 engages in the two slots 10. The inner member 6 is provided at its end region remote from the transverse pin 11 with a pair of parallel flats constituting guiding surfaces 12 which are parallel to one another, are set back from its external periphery, and are parallel to the axis of the transverse pin 11. These serve as abutments for two lateral extenstions 13 projecting from the end region 4" of the arm 4'. The inner member 6 co-operates with the external part 4 on a broad basis, at locations relatively widely spaced apart, namely on the one hand at end one region by way of the transverse pin 11 and on the other hand at its opposite end region byway of the guiding surfaces 12. As pressure loading, relatively small bending moments occur in the parts of the damping element 2 which are subjected to bending stress, so that the parts subjected to stress in this way can be given relatively small dimensions.

For damping vibrations which come from the engine or drive unit and are introduced into the damping element 2, however, the outer member 4 and inner member 6 can move in their longitudinal direction relatively to one another - in accordance with the elasticity of the elastomeric intermediate layer 7 - the transverse pin 11 being guided in slots 10 and the guide surfaces 12 on the internal walls of the extensions 13. The longitudinal extent of the two slots 10 is made that when the resiliently sprung travel distance of the elastomeric intermediate layer 7 necessary for damping the vibrations is exceeded, the transverse pin 11 abuts on the internal end of the slots 10. The transverse pin 11 at the same time operates as a shear safety element against overloading of the elastomeric intermediate layer 7 which would render the elastomeric layer inoperative. To obtain the smooth cooperation of transverse pin 11 with the outer member 4 the internal wall of the two slots 10 is lined with elastomeric material.

(Others of the guiding means or guide surface or both could also be lined at least in part with elastomeric material).

The outer member 4 is connected with the first linkage part 3 by way of a screw 14 whilst the second linkage part 3 by way of a screw 14 whilst the second linkage part 5 is screwed into the internal part 6. Thus, the inner and outer members have means adapting them for connection to the first and second linkage parts.

WHAT WE CLAIM IS: 1. Damping element for longitudinally aligned parts of a linkage, the damping element having an outer member, means adapting the outer member for connection to a linkage part, an inner member, means adapting the inner member for connection to a next following part of such linkage, the outer member surrounding at least a portion of the inner member and being connected to it by way of an elastomeric intermediate layer, the inner member or the outer member or both having guiding longitudinally extending means adapted to co-operate with guide elements of the other member, so that

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. of the invention the outer member of the damping element consists of a substantially U-shaped yoke which comprises in the base region of each of its two arms a slot or the like into which a transerve pin engages which is connected with the inner member, whilst there are provided as guiding means on the inner member two parallel guiding surfaces which are set back from its external periphery and extend parallel with the transverse pin, and these guiding surfaces co-operate with two lateral extensions of the free end region, extending inwardly, of an arm of the U-shaped yoke. Finally, according to a yet further subsidiary feature the slots which are provided in the U-shaped yoke are lined at least partly with elastomeric material. A preferred form of the invention will now be described by way of example with reference to the drawings wherein: Figure I shows diagrammatically a throttle linkage of a private motor car having a damping element embodying the invention, Figure 2 is a longitudinal sectional elevation of the damping element drawn to a larger scale, Figure 3 is a plan view of the damping element of Figure 2, and Figure 4 shows the damping element of Figure 2 in side view. In Figure 1 there is shown a throttle linkage generally designated 1 for the carburetter of an engine of a private motor car (not shown). The linkage 1 includes a damping element 2 which comprises essentially an outer member 4 adapted for connection to a first linkage part 3, and an inner member 6 adapted for connection to a second linkage part 5, the linkage parts 3 and 5 being in longitudinal alignment. The inner member is connected with the outer member 4 by means of an elastomeric intermediate layer 7. The first linkage part 3 is connected with an intermediate linkage generally designated 8 leading to a foot pedal 9. Figure 2 shows the damping element 2 in longitudinal section. Its outer member 4 consists of a U-shaped yoke having a pair of parallel arms 4'. The free end region 4" of one of these arms extends inwards as shown. Thus the outer member 4 partly surrounds the inner member 6. The inner member 6 is of circular cross-section. Each of the two arms 4' of the outer member has a slot 10 in its base region extending in the longitudinal direction of the arms. A transverse pin 11 connected with the inner member 6 engages in the two slots 10. The inner member 6 is provided at its end region remote from the transverse pin 11 with a pair of parallel flats constituting guiding surfaces 12 which are parallel to one another, are set back from its external periphery, and are parallel to the axis of the transverse pin 11. These serve as abutments for two lateral extenstions 13 projecting from the end region 4" of the arm 4'. The inner member 6 co-operates with the external part 4 on a broad basis, at locations relatively widely spaced apart, namely on the one hand at end one region by way of the transverse pin 11 and on the other hand at its opposite end region byway of the guiding surfaces 12. As pressure loading, relatively small bending moments occur in the parts of the damping element 2 which are subjected to bending stress, so that the parts subjected to stress in this way can be given relatively small dimensions. For damping vibrations which come from the engine or drive unit and are introduced into the damping element 2, however, the outer member 4 and inner member 6 can move in their longitudinal direction relatively to one another - in accordance with the elasticity of the elastomeric intermediate layer 7 - the transverse pin 11 being guided in slots 10 and the guide surfaces 12 on the internal walls of the extensions 13. The longitudinal extent of the two slots 10 is made that when the resiliently sprung travel distance of the elastomeric intermediate layer 7 necessary for damping the vibrations is exceeded, the transverse pin 11 abuts on the internal end of the slots 10. The transverse pin 11 at the same time operates as a shear safety element against overloading of the elastomeric intermediate layer 7 which would render the elastomeric layer inoperative. To obtain the smooth cooperation of transverse pin 11 with the outer member 4 the internal wall of the two slots 10 is lined with elastomeric material. (Others of the guiding means or guide surface or both could also be lined at least in part with elastomeric material). The outer member 4 is connected with the first linkage part 3 by way of a screw 14 whilst the second linkage part 3 by way of a screw 14 whilst the second linkage part 5 is screwed into the internal part 6. Thus, the inner and outer members have means adapting them for connection to the first and second linkage parts. WHAT WE CLAIM IS:

1. Damping element for longitudinally aligned parts of a linkage, the damping element having an outer member, means adapting the outer member for connection to a linkage part, an inner member, means adapting the inner member for connection to a next following part of such linkage, the outer member surrounding at least a portion of the inner member and being connected to it by way of an elastomeric intermediate layer, the inner member or the outer member or both having guiding longitudinally extending means adapted to co-operate with guide elements of the other member, so that

in use of the element in such linkage, the said linkage parts are maintained in alignment and vibration tends to be absorbed by the elastomeric layer.

2. Damping element according to claim 1, wherein the length of travel of at least one guiding means is limited in the longitudinal direction.

3. Damping element according to claim 1 or claim 2, wherein the outer membr comprises a U-shaped yoke having in the base region of each arm of the U a guiding slot extending in the longitudinal direction of the arm, and the inner member carries a transverse pin guided in the slots.

4. Damping element according to claim 3 wherein the inner member at its end remote from the pin has a pair of opposite guiding surfaces co-operating with two lateral extensions of an inwardly extending free end region of one arm of the yoke.

5. Damping element according to Claim 4, wherein said guiding surfaces are a pair of opposite flats recessed from the external periphery of the inner member, the flats being parallel to each other and to a plane that contains the pin axis.

6. Damping element according to any one of the preceding claims wherein the guiding means or the guide elements or both are lined at least in part with elastomeric material.

7. Damping element according to claim 6 in combination with any of claims 3 to 5 wherein the slots in the arms of the yoke are lined at least in part with elastomeric material.

8. Damping element for an operating linkage, the damping element being substantially as shown in and hereinbefore described with reference to Figures 2 to 4 of theaccompanying drawings.

9. A linkage comprising a damping element according to any preceding claim.

10. A motor vehicle having an accelerator connected to a carburetter by way of a linkage according to claim 9.