Spring devices – Vehicle – Comprising compressible fluid
Utility Patent
1998-10-23
2001-01-02
Schwartz, Christopher P. (Department: 3613)
Spring devices
Vehicle
Comprising compressible fluid
C267S122000
Utility Patent
active
06168143
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a pneumatic spring in particular for rail vehicles, utility vehicles and busses, comprising a bellows made of elastomer material provided with reinforcing inserts, if required; a pot to whose upper part the bellows is secured, whereby the bellows preferably rolls along the outer wall of the top; a plate-shaped cover arranged spaced from the pot, with the other end of the bellows being secured on said cover; a centrally arranged rod firmly secured on the cover and particularly projecting from the cover, whereby, furthermore, the rod extends parallel with the bellows and immerses in the top; a ball-and-socket joint located between the top and the rod and supported on the inner wall of the pot; as well as a an air pipe (DE-A-38 28 203; EP-A-0 554 573).
2. The Prior Art
Pneumatic springs are frequently employed as secondary spring systems, for example in modern rail-borne vehicles. Such a secondary spring system is expected to be capable of statically conducting horizontal forces of up to 20 KN to the body, namely from the box of the vehicle, permitting in this connection angular deflections of up to 7°. Furthermore, extensive vertical paths of displacement are required combined with low structural heights and a low weight.
SUMMARY OF THE INVENTION
Now, for achieving the object of the invention a pneumatic spring of said type, comprises a combination of the following additional components:
A slide bush, which is arranged between the ball-and-socket joint and the rod and guided sliding on the outer wall of the rod, as well as
an intermediate bush, which is located between the ball-and-socket joint and the slide bush.
The intermediate bush, the slide bush and the ball-and-socket joint operate cylindrically around the rod. The rod (also referred to as a guide shaft) thus forms the core of the overall system. The slide bush and the intermediate bush are each preferably designed as one piece. The slide bush, with has a minimum wall thickness of 0.1 mm, consists of a plastic material capable of sliding, in particular of polytetrafluoroethylene. For the purpose of easier installation, the slide bush has a slot extending through slanted in the axial direction. Concerning the intermediate bush, a thermally conductive material is used, in particular aluminum. A substantial reduction in weight is connected with the use of aluminum as well.
The following variations are usefully employed with respect to the conduction of air:
The tubular rod is provided with at least one opening, which connects the inner space of the rod extending through in the axial direction with the space of the pneumatic spring.
At least one through-extending channel or outer groove is arranged within the intermediate bush in the axial direction, said channel or groove being communicatively connected with the space of the pneumatic spring. Advantageously, several channels or outer grooves are present, which are distributed over the entire circumference of the intermediate bush with substantially equal spacings in between. Air cooling is additionally made available in this way.
A combination of both variations of air conduction is possible as well.
Additional useful designs of the pneumatic spring as defined by the invention are:
The inner wall of the tubular rod is shaped conical within the zone of the slide bush, namely with enlargement of the diameter of the inner space of the rod, which leads to weight saving. An optimization of the conduction of air is connected herewith as well.
The diameter of the ball-and-socket joint amounts to 100 to 200 mm, in particular 130 to 150 mm based on the structural component with the smallest diameter. When a three-layer metal-elastomer composite is used, the elastomer layer arranged in the center has a thickness of 5 to 15 mm, in particular 6 to 10 mm.
The ball-and-socket joint is secured relative to the lower part of the pneumatic spring, in particular in the form of at least one safety ring.
The intermediate bush is secured relative to the lower part of the pneumatic spring as well, in particular in the form of a safety ring, which locks in a notching within the outer surface of the intermediate bush.
REFERENCES:
patent: 3765733 (1973-10-01), Hackman
patent: 3854557 (1974-12-01), Wilcox
patent: 3864922 (1975-02-01), Dial et al.
patent: 3907122 (1975-09-01), Ksienysk et al.
patent: 5338055 (1994-08-01), Mauz
patent: 5544715 (1996-08-01), Phillips
patent: 3828203 (1990-03-01), None
patent: 554573 (1996-03-01), None
patent: 2 284 237 (1993-11-01), None
patent: WO94/13967 (1994-06-01), None
patent: WO95/09092 (1995-04-01), None
JP 07243475A, Sep. 19, 1995, In: “Patent Abstracts of Japan”, vol. 096, No. 001, Jan. 31, 1996.
Lambrecht Dirk
Oertel Holger
Collard & Roe P.C.
Kramer Devon
Phoenix Aktiengesellschaft
Schwartz Christopher P.
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