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Patent Searching and Data


Title:
FLEXIBLE ELEMENT
Document Type and Number:
WIPO Patent Application WO/2003/041975
Kind Code:
A1
Abstract:
The present invention relates to a spring element (1) intended to transmit compression forces and tensile forces between a vehicle frame (14) and a wheel axle (15) arranged movably in relation to the vehicle frame (14), especially between the wheel axle (15) and the end of a bogie beam mounted pivotably in the vehicle frame (14). The spring element (1) comprises a rubber body (4), and a mechanical connection member (6) which extends through the rubber body (4) and is arranged to limit the distancing movement between said vehicle frame (14) and wheel axle (15). The connection member (6) here comprises a coupling device (8) for coupling the connection member (6) in one of said vehicle frame (14) or wheel axle (15).

Inventors:
HJERTH KJELL-OWE (SE)
STIGSSON HAAKAN (SE)
Application Number:
PCT/SE2002/001555
Publication Date:
May 22, 2003
Filing Date:
August 30, 2002
Export Citation:
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Assignee:
VOLVO ARTICULATED HAULERS AB (SE)
HJERTH KJELL-OWE (SE)
STIGSSON HAAKAN (SE)
International Classes:
B60G5/02; B60G7/00; B60G11/24; F16F1/40; (IPC1-7): B60G11/22; F16F1/40
Foreign References:
US1841795A1932-01-19
US4615513A1986-10-07
DE1906805A11970-12-23
FR1324370A1963-04-19
US3677535A1972-07-18
Other References:
See also references of EP 1429929A1
Attorney, Agent or Firm:
Fröhling, Werner (Corporate Patents 0682, M1.7 Göteborg, SE)
Download PDF:
Claims:
Patent Claims
1. A spring element (1) intended to transmit compression forces and tensile forces between a vehicle frame (14) and a wheel axle (15) arranged movably in relation to the vehicle frame (14), especially between the wheel axle (15) and the end of a bogie beam mounted pivotably in the vehicle frame (14), which spring element (1) comprises a rubber body (4), and a mechanical connection member (6) which extends through the rubber body (4) and is arranged to limit the distancing movement between said vehicle frame (14) and wheel axle (15), characterized in that the connection member (6) comprises a coupling device (8) for coupling the connection member (6) to one of said vehicle frame (14) or wheel axle (15).
2. The spring element (1) as claimed in patent claim 1, characterized in that the coupling device (8) comprises a threaded portion (12,23) intended to cooperate with a threaded element (16) when the connection member (6) is coupled to one of said vehicle frame (14) or wheel axle (15).
3. The spring element (1) as claimed in patent claim 2, characterized in that the axis of symmetry of said threaded portion (12,23) substantially coincides with the axis of symmetry of said rubber body (4).
4. The spring element (1) as claimed in patent claim 3, characterized in that said threaded portion (12,23) comprises a stub (11), with internal thread (12), protruding from the spring element (1).
5. The spring element (1) as claimed in patent claim 3, characterized in that said stub (11) is designed with a conical portion (13).
6. The spring element (1) as claimed in patent claim 4 or 5, characterized in that said stub (11) is designed with means (19) for obtaining rotationally fixed, formfit on said vehicle frame (14) or wheel axle (15).
7. The spring element (1) as claimed in patent claim 6, characterized in that said means comprise a bevel (19) which is intended to cooperate with a corresponding bevel (20), for said formfit, arranged on the vehicle frame (14) or the wheel axle (15).
8. The spring element (1) as claimed in patent claim 3, characterized in that said threaded portion (12,23) comprises a stub (22), with external thread (23), protruding from the spring element (1).
Description:
Title Flexible Element Technical field The present invention relates to a spring element intended to transmit compression forces and tensile forces between a vehicle frame and a wheel axle arranged movably in relation to the vehicle frame, especially between the wheel axle and the end of a bogie beam mounted pivotably in the vehicle frame, which spring element comprises a rubber body, and a mechanical connection member which extends through the rubber body and is arranged to limit the distancing movement between said vehicle frame and wheel axle, according to the preamble of patent claim 1 attached.

Prior art SE 436 480 B has already disclosed a spring element intended to transmit compression forces and tensile forces between a vehicle frame and a wheel axle arranged movably in relation to the vehicle frame. The spring element comprises two substantially parallel end-plates with a solid cylindrical rubber body vulcanized between the end-plates, and a connection member permitting limited relative movement between the end-plates. Said connection member comprises a U-shaped link element which projects from each end-plate into the rubber body and whose branch ends are firmly clamped with nuts on the outside of the respective end- plate, and also a ring-shaped link element arranged between the U-shaped link elements. The maximum expansion of the spring element is thus limited, i. e. the maximum distancing movement of the end-plates when the spring element is subjected to tensile force. When fitting the spring element on the vehicle, 8 bolts are used, four for each end-plate, which bolts extend through holes in the respective end-plate.

A disadvantage of the abovementioned design of the

connection member is that the tensile force which the spring element is intended to transmit is transmitted from the bolts via the end-plates, the U-shaped link elements and the ring-shaped link element, which means that the end-plates have to be made relatively strong (thick) so as not to deform on account of the fact that said tensile forces give rise to bending momentum in the end-plates. Another disadvantage is that the securing nuts for the U-shaped link elements take up a relatively large amount of space, which reduces the bearing surface area of the end-plate against the vehicle frame or the wheel axle. Finally, said 8 bolts are relatively awkward to fit, especially in the field in connection with servicing and repairs, because the space available under the vehicle is relatively confined and there are strict requirements that the bolts be tightened with the correct momentum.

Description of the invention It is an object of the present invention to make available a spring element in which the tensile force which the connection member of the spring element is intended to be able to transmit is transmitted directly to at least one of said vehicle frame or wheel axle. It is a further object to make available a spring element which is of compact construction and is not complicated to fit during production and also in the field in connection with servicing and repairs.

This object is achieved with the invention described in patent claim 1. Preferred embodiments of the invention are described in the patent claims which follow.

According to a preferred embodiment of the invention, the coupling device comprises a threaded portion intended to cooperate with a threaded element when the spring element is coupled to one of said vehicle frame or wheel axle. This permits very easy and rapid fitting and dismantling, both during production and also in the

field in connection with servicing and repairs.

According to a further embodiment, the axis of symmetry of said threaded portion coincides with the axis of symmetry of said rubber body. This ensures that the tensile force which the spring element is intended to transfer does not give rise to bending momentum when the spring element is coupled to the vehicle frame or the wheel axle.

According to a further embodiment, the threaded portion comprises a stub, with internal thread, protruding from the spring element, which stub is intended to cooperate with a bolt for coupling the connection member. Because only one stub protrudes from the spring element, the spring element is made relatively compact and thus easier to insert into/remove from the space between the vehicle frame and the wheel axle during fitting/dismantling.

According to a further embodiment, the stub is designed with a conical portion. This makes it easier to fit the spring element to the vehicle frame or the wheel axle.

According to a further embodiment, the stub is designed to be rotationally fixed to said vehicle frame or wheel axle by formfit. This ensures that the spring element does not rotate when said threaded element, preferably a bolt, is screwed in the stub during fitting/dismantling. According to a further embodiment, said formfit is obtained by the fact that the stub is designed with a bevel which is intended to cooperate with a corresponding bevel arranged on the vehicle frame or the wheel axle.

According to an alternative embodiment of the present invention, said threaded portion comprises a stub, with external thread, protruding from the spring element,

which stub is intended to cooperate with said threaded element, preferably a nut, when the connection member is coupled to the vehicle frame or the wheel axle. This permits fitting/dismantling on vehicles where the space on the other side of the vehicle frame or wheel axle in relation to the spring element is so limited that a bolt cannot be inserted and instead there is only room for a nut.

Description of the figures The invention will be described below in connection with the preferred illustrative embodiments and the attached figures, where Figure 1 shows a diagrammatic view of a first embodiment, partly in cross section, of the spring element according to the present invention, Figure 2 shows a diagrammatic side view, partly in cross section, of the spring element coupled to a bogie beam of a vehicle, Figure 3 shows a diagrammatic perspective view of the bevel on said stub, and of the corresponding bevel in the bogie beam for obtaining said rotationally fixed formfit, and Figure 4 shows a diagrammatic view of an alternative embodiment, partly in cross section, of the spring element according to the present invention.

Preferred embodiment Figure 1 shows a diagrammatic view of a first embodiment of the spring element 1 according to the present invention. The spring element 1 comprises a first end-plate 2 and a second end-plate 3 which are substantially parallel when the spring element 1 is

unloaded. Vulcanized between the end-plates 2,3 there is a solid cylindrical rubber body 4 which, in a manner known per se, is strengthened by means of a number of parallel and separate flat metal rings 5 to counteract outward bulging of the rubber body 4 upon compression thereof.

The end-plates 2,3 are also held together by means of a mechanical connection member 6 which comprises a ring-shaped chain link 7 which joins a first coupling device 8, projecting from the central portion of the respective end-plate 2,3 into the rubber body 4, and a second coupling device 9.

Said first coupling device 8 has, on the one hand, a U- shaped link element 10 which extends into the rubber body 4 and is connected to the ring-shaped chain link 7 and, on the other hand, a stub 11, with an internal threaded portion 12, protruding through the first end- plate 2 from the spring element 1. By virtue of the fact that the axis of symmetry of the stub 11 substantially coincides with the axis of symmetry of the rubber body 4, which in turn substantially coincides with and is parallel to the force vector representing the tensile force which the spring element 1 is intended to transmit, ensures that bending momentum and shearing stresses are not generated in the first end-plate 2 of the spring element 1.

The fact that the stub 11 is designed with a conical portion 13 makes it easier to fit the spring element to the vehicle frame 14 or wheel axle 15.

Said second coupling device 9 has a U-shaped link element 16 which is firmly connected in a manner known per se to the second end-plate 3 and which extends into the rubber body 4 and is connected to the ring-shaped chain link 7.

Figure 2 shows a diagrammatic side view, partly in cross section, of the spring element 1 coupled to a bogie beam mounted pivotably in a vehicle frame 14 of a vehicle (not shown). For the sake of simplicity, only the coupling of the connection member 6 to a bogie beam is described. The threaded portion 12 of the stub 11 here cooperates with a threaded element 17, in the form of a bolt, which extends through the bogie beam. The fact that the U-shaped link element 10 of the stub 11 is provided with a flange 18 ensures that the first end-plate 2 bears against the bogie beam even when the spring element 1 transmits a tensile force.

Figure 3 shows a perspective view of the spring element 1 and the bogie beam. By virtue of the fact that the stub 11 is designed with bevels 19a, 19b which are intended to cooperate with corresponding bevels 20a, 20b arranged in the through-passage 21 on the bogie beam for the stub 11, formfit is obtained which ensures that the stub 11 is not caused to rotate when said threaded element 17 is screwed in the stub 11 during fitting/dismantling.

Figure 4 shows an alternative embodiment of the spring element 1 according to the present invention. The structure of the spring element is the same as that of the above-described first embodiment, but with the difference that instead of the described stub 11 with an internally threaded portion 12, the coupling device 8 comprises a stub 22 protruding from the spring element 1 and with an externally threaded portion 23 intended to cooperate with a threaded element (not shown), preferably a nut, when the connection member 6 is coupled to the vehicle frame 14 or the wheel axle 15.

The invention must not be considered as being limited to the illustrative embodiments described above, and instead a number of further variants and modifications

are conceivable within the scope of the attached patent claims. For example, instead of what is described above, the rubber body can accommodate the connection member in a central hole in the rubber body. Moreover, said rotationally fixed formfit can be obtained with another cross section, for example square.