Land vehicles: bodies and tops – Tops – Cover
Reexamination Certificate
1999-05-21
2001-04-17
Pape, Joseph D. (Department: 3612)
Land vehicles: bodies and tops
Tops
Cover
C296S117000, C296S076000, C296S115000
Reexamination Certificate
active
06217105
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an arrangement for hydraulically operating a rear cover, covering top or the like on a vehicle, with at least one double-acting hydraulic working cylinder, which, on the one hand, is connected to the vehicle and, on the other hand, to the covering top; and its working chambers are in connection with each one side of a switched pressure source via one check valve each, wherein both of the check valves have an mutually releasing device and each of the working chambers parallel with respect to the check valves is kept via a pre-stress valve, which steers into the tank, at a specified pressure level.
2. The Prior Art
Arrangements of the noted type are known and make possible, for example, the automatic operation of vehicle doors, engine hoods, maintenance caps or also of covering tops of trunks or a chamber holding a convertible top. By means of the releasable check valves, it is ensured that, in the case that the operational pressure is turned off or fails, the covering top remains hydraulically blocked in the respective position, in order to switch off uncontrolled movements and thus possibly resulting dangers. The pre-stress valve makes possible the further controlled movement of the covering top in this condition, for example, by hand, to allow for an emergency closure against the force specifed by the pre-stress valve.
A disadvantage of the described known arrangement of the mentioned type is especially the condition that the described emergency operation is only possible in connection with a volume-balanced working cylinder, since otherwise there are problems with the removal or supply of the hydraulic medium to the working chamber on the side of the piston or valve stem. A simple redirection of the excess volume pushed out of the individual working chamber into the tank would still be possible; however, there are problems with the pressure-less re-supply of hydraulic medium to the other working chambers in the case of an emergency, since for the use in vehicle, on the one hand, very thin, flexible lines have to used which, on the other hand, due to the tight accommodations, are relatively long, so that the after-suctioning working chamber is at least partially filled with fumigated air. This then results in that, after the release of the manually-operated covering top in an emergency, these fall back undefined and can cause damage and injury.
It is the object of the present invention to improve a known arrangement of the initially described type such that the described disadvantages can be avoided and especially that, in a simple and safe way, an emergency operation of the covering top is made possible also in the common working cylinders having different working chamber volumes on the side of the piston and valve stem.
SUMMARY OF THE INVENTION
This problem is solved through an arrangement of the initially mentioned type according to the invention in that between at least one working chamber, preferably the working chamber on the piston side, and the corresponding releasable check valve, a separate after-suction line enters which leads to the tank and in which a check valve is inserted which is open in the direction of the working chamber. In the case of a failure of the hydraulic working pressure, a simple and safe emergency operation of the covering top, for example, manually is thus still possible. In the case that the working cylinder is pulled outward manually, the working chamber volume on the side of the valve stem is pushed off into the tank, wherein a failure in the differential volume is suctioned from the tank via the check valve. Since there are no further hydraulic elements in the after-suction line such as valves, jets etc. are connected and the line does not have to fulfill any other functions as well, it can be set up completely for the function of the after-suction and arranged such that even during a very fast manual operation of the rear cover, the covering top or the like, a suctioning of the hydraulic medium is guaranteed without fumigation of air. Thus, furthermore, the secure holding of the manually moved vehicle part in the respective position is ensured, since neither fumigated air is compressed, nor can the hydraulic liquid flow back into the tank.
Of course, the after-suction line with the check valve can also be provided on the valve stem side of the working cylinder and thus ensure the uninhibited after-suction of the hydraulic medium during the manual closing of the covering top or the like as well as the securing afterwards against any unintentional pressing. Thus, especially in the case of gas springs or the like which support the opening process or are automatically activated at a corresponding force, it is ensured that also upon failure of the operational hydraulics the covering top or the like is kept in the manually set position. Also the after-suction and security function for the manual opening and closing by providing an after-suction line with a check valve on the valve stem side as well as the piston side of the working cylinder is thinkable, alternatively also the connection of an after-suction line with a check valve on interchangably one of the lines to the working cylinder via a switching valve.
In a preferred embodiment of the invention, it is provided that the after-suction line enters between the individual working chamber and the neighboring hydraulic part. Thus, the direct and uninhibited after-suction of hydraulic medium from the tank, independently of the equipment of the automatic operation system, and its optimal arrangement with respect to its function during manual operation is made possible.
The invention will be better understood by referring to the attached drawings and the following discussion.
REFERENCES:
patent: 4359119 (1982-11-01), Kammerman
patent: 4644235 (1987-02-01), Ohta
patent: 4688844 (1987-08-01), Hirose et al.
patent: 4749193 (1988-06-01), Hacker
patent: 4779845 (1988-10-01), Bartesch et al.
patent: 4858981 (1989-08-01), Post
patent: 5110175 (1992-05-01), Fischbach
patent: 5279119 (1994-01-01), Shelhart et al.
patent: 5335926 (1994-08-01), Stolle
patent: 5682807 (1997-11-01), Mentink
patent: 5760695 (1998-06-01), Huber
patent: 5788312 (1998-08-01), Lee
Dykema Gossett PLLC
Hoerbiger Hydraulik GmbH
Pape Joseph D.
Patel Kiran
LandOfFree
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