Control mechanism for a door of a motor vehicle with a reciprocating safety valve

A control mechanism for a door of a motor vehicle is suggested that is coupled at a door post on the side of the body so that it can be swung, is actuated via an inside and outside handle and comprises a piston-cylinder unit arranged between the door post and the vehicle door. The unit has a piston provided with passage openings for a pressure medium, the piston interacting with an interior valve that separates two working chamber of the cylinders from one another. The mechanism has an exterior blocking valve controlling the medium flow, this blocking valve being arranged in a control circuit connecting the two working chambers of the cylinder, acting against the flow direction. The blocking valve is controlled by a door handle in such a way that the door can be blocked in at least one intermediate position. The interior valve is held on the piston under the tension of a spring in such a way that when the vehicle door is opened, the passage openings are closed, and when the vehicle door is closed, the passage openings are passable for the medium. The blocking valve is controlled in such a way that, when the door handle is actuated, it takes up a release position, and when the door handle is not actuated, it takes up a closing position in the control circuit.

This invention relates to a control mechanism for the door of a motor 
vehicle that is hingedly connected to a door post on the side of the 
vehicle for swinging movement. Such control mechanism is operable via 
inside and outside door handles and includes a piston-cylinder unit 
arranged between the door post and the vehicle door, which piston-cylinder 
unit has a piston provided with passage openings for a pressure medium, 
the piston interacting with an interior valve separating two working 
chambers of the cylinder with respect to one another. 
From German Published Examined Application (DE-AS) 25 55 062, an arresting 
mechanism having a piston-cylinder unit is known for flaps, doors and 
similar parts in motor vehicles. This unit has passage openings in the 
piston that can be closed by a cover element causing an arresting of the 
mechanism. It is a disadvantage in the case of this type of design, 
especially when it is used for motor vehicle doors, that in the case of 
forces of pressure affecting the flap, i.e., in the case of closing 
pressures, the pressure of the medium on the cover element becomes so 
large that this element lifts off the piston, a flow-through of the medium 
takes place and the flap gives up its arrested position. When outside 
forces affect the flap, the door or similar part, a certain opening angle 
can therefore not be maintained by means of such a device. 
It is an objective of the invention to develop a control mechanism of the 
initially mentioned type in such a way that the door can be arrested in 
any arbitrary intermediate position, but that otherwise it can be opened 
and closed with any easy motion. 
According to the invention, this objective is achieved by providing an 
exterior blocking valve in a control circuit connecting the two working 
chambers of the cylinder and actuable against the flow direction of the 
pressure medium, the blocking valve being controlled by a control 
mechanism responsive to the door handle operation in such a way that the 
door can be blocked in at least one intermediate position. 
In preferred embodiments of the invention, the interior valve is held on 
the piston under spring tension in such a way that during opening of the 
vehicle door the passage openings are closed and during opening of the 
vehicle door the passage openings are permeable to the medium. 
According to an advantageous feature of certain preferred embodiments, the 
blocking valve is controlled in such a way that it takes up a release 
position when the door handle is actuated and a closing position when the 
door handle is not actuated. 
In certain preferred embodiments the blocking valve is developed as a 
safety valve with a control surface acting opposite a pressure column of 
the control circuit. 
Principal advantages achieved by means of the invention consist of the fact 
that the door, when operated via gripping an inside or outside handle, can 
be opened and closed with an easy motion, but that, when the operated grip 
is released, an immediate arresting of the door takes place at any opening 
angle. This is especially advantageous when vehicles are parked in narrow 
spaces so that a banging of the door at the adjacently parked vehicle is 
avoided. Especially also during a stepping-out of the vehicle, a 
significant pressure may be exercised on the door without any change of 
position. According to the known mechanism, this would permit a movement 
of the door which, however, does not take place in the case of the 
construction according to the invention. The reason is that also 
significant applications of force in opening direction on the door leave 
the door unchanged in its position. 
However, when the effect of the force on the door becomes so significant 
that damage may occur, it is provided in certain preferred embodiments of 
the invention that the blocking valve which, at the same time, is designed 
as a safety valve, opens and a further swinging of the door becomes 
possible. A closing of the door from the blocked position, on the other 
hand, is possible at any time in which case the blocking valve will then 
be opened via the handle and a circulating of the medium takes place via 
the control circuit while the interior valve is closed. When, on the other 
hand, the handle is not used for the closing of the door, the door can 
also be closed. In this case, by means of the pressure of the medium on 
the interior valve, this valve is opened, and the medium can flow from one 
chamber to the other so that the closing of the door is not hindered. 
By means of the mechanical and/or electrical connection of the blocking 
valve with the inside and outside handle of the door, a simple actuating 
of the valve is created which operates in such a way that at the same time 
with the operation of the door, a control of the valve takes place so that 
additional switching devices are not required. The mechanical means for 
the adjusting are formed by Bowden cables. 
Further objects, features and advantages of the present invention will 
become more apparent from the following description when taken with the 
accompanying drawings, which show for purposes of illustration only, 
embodiments constructed in accordance with the present invention;

DETAILED DESCRIPTION OF THE DRAWINGS 
The mechanism 1 essentially comprises a piston-cylinder unit 2 that has a 
control circuit 3 in which a blocking valve 4; 4a; 4b is arranged. This 
valve may be arranged inside or outside the unit 2. The unit 2 is held 
between a door 5 and a door post 6 on the side of the vehicle body so that 
it can be pivoted around vertical shafts 7, 7a in which case the piston 
rod, by means of a hinge 22, is connected with the door 5. When the door 5 
is swung in the direction of the arrow 8a (opening), a piston 9 of the 
unit 2 is moved in the direction of the arrow 10, and when the door 5 is 
swung in the direction of the arrow 8 (closing), the piston 9 is moved in 
the direction of the arrow 11. The piston 9 of the unit 2, according to 
FIG. 2, has passage openings 12 for a pressure medium, such as gas, 
hydraulic oil or a similar medium. 
In the case of this embodiment according to FIG. 2, the openings 12 are 
exposed and closed by an interior valve 13 controlled by a spring 14 as a 
function of the movement of the door. The fluid line of the mechanism 1 
forming the control circuit 3, with its inlet and outlet leads into the 
working chambers 15 and 16 of the cylinder which are divided by the piston 
9. The blocking valve 4 is arranged in the control circuit 3 so that it 
acts against the flow direction 17. It can be moved into a closing 
position A and into a release position B as a function of the operating of 
the door handle 20, 21 via mechanical control means 18 or via electrical 
control means 19 (FIG. 6). 
The blocking valve 4; 4a; 4b is connected with the inside handle 20 and the 
outside handle 21 of the door via mechanical control means 18 which may be 
formed by sheathed or Bowden cables. The blocking valve 4 can be adjusted 
via each handle 20 and 21 to the release position B and to the closing 
position A (FIG. 2). 
According to the embodiment of FIG. 6, the mechanical control means 18 of 
FIGS. 1 and 2 are replaced by electrical control means 19. Via the door 
handles 20 and 21, for example, a switch can be actuated by means of 
which, for example, a magnetic valve is controlled which represents the 
blocking valve 4a. 
According to FIG. 7, the blocking valve 4b is at the same time designed as 
a safety valve. It has a control surface 24 which is aimed at the pressure 
column 25 in the control circuit 3 and serves to provide a positive 
counter pressure under certain operating conditions described below. 
In another embodiment according to FIG. 3, a spring-loaded valve 13a and 
13b is provided on both sides of the piston 9a. These valves have the 
effect that during the opening process of the door 5, the piston 9a moves 
in the direction of the arrow 10, in which case the valve 13b lifts itself 
from its seat on the piston 9a and exposes the passage openings 12 (FIG. 
4). When no strong pressure is exercised on the door 5 any longer, the 
door 5 is held in its opened position. An easy-motion adjustment will now 
no longer be possible, when the passage openings 12 are closed via the 
valve 13b. When the door 5 is closed, the valve 13a is lifted off the 
piston 9 so that the passage openings 12a are exposed. By means of an 
adaptation of the springs to the valves 13a and 13b, an easy-motion 
opening and closing is achieved and it is achieved that the door is 
arrested in intermediate positions during the opening, also when subjected 
to pressure. 
The method of operation of the mechanism according to the embodiment of 
FIGS. 1, 2 and 6 is as follows. During the opening of the door 5 from the 
inside via the handle 20 and from the outside via the handle 21, the 
respective handle is pulled into the dash-dotted position. In the process, 
via the control means 18; 19, the blocking valve 4 is pulled from its 
closing position A into the release position B in the control circuit 3. 
As a result, the two working chambers 15 and 16 are connected with one 
another while the medium can pass through, so that the piston 13 
corresponding to the door motion carriers out a motion in the direction of 
the arrow 10. During this process, the passage openings 12 are closed by 
the valve 13. The medium is pressed from the chamber 15 via the opened 
control circuit 3 into the other chamber 16. When the handles 20, 21 are 
let go, these again take up their starting positions (solid lines). As a 
result, the blocking valve 4; 4a; 4b is closed and the flow-through of the 
medium and thus a further motion of the door in opening direction is 
stopped. The door 5 can therefore be immediately arrested in various 
intermediate positions by simply releasing the handles 20, 21. 
So that no damage occurs when the door that is in blocked condition is 
opened further by force, the safety valve is provided (FIG. 6). In the 
case of a certain pressure on the door, this valve 4a opens the control 
circuit 3 so that a further swinging motion of the door is ensured. 
For the easy closing of the door 5, the handle 20 or 21 is actuated so that 
the blocking valve 4, 4a is opened again and a passage of the medium is 
made possible. An easy closing of the door 5 is also possible without 
actuating the handle 20 and 21. By means of the movement of the piston 9 
in the direction of the arrow 11, the medium in the chamber 16 is pressed 
into the passage openings 12 against the valve 13. This valve 13, against 
the tension of the spring 14, lifts off its seat on the piston 9 and 
releases the openings 12, so that the displaced medium can enter the other 
chamber 15. 
Although the present invention has been described and illustrated in 
detail, it is to be clearly understood that the same is by way of 
illustration and example only, and is not to be taken by way of limitation 
.