Operating device for locking mechanisms in doors, hatches and the like
The present invention relates to an operating device for locking mechanisms in doors, hatches or the like, comprising an actuating means for the bolt or corresponding element of the locking mechanism, at least two manually operable releasing means and pipes which connect the actuating means with the releasing means to form a closed system which is filled with a liquid for transferring a volume change in one of the releasing means into a corresponding volume change in the actuating means. 
     The invention is especially intended for use in doors and hatches for vehicles, but it can also be used with advantage for locking mechanisms in other connections. In the following description the application of the invention to vehicles will chiefly be described. 
     For operating locking mechanisms in doors, hatches and the like, it is conventional to use mechanical devices for transmitting a movement from a manually actuated means to the locking mechanism. In many cases, however, these devices are not completely satisfactory. If the manually operable means is placed in the immediate vicinity of the locking mechanism the device will indeed be relatively simple, but in most cases it is not practically feasible to use such a placing. The manually operable means is then placed at a distance from the locking mechanism, and the movements are transmitted by levers, links, cables or the like elements. Such a device will be complicated and expensive, not only since it comprises a great number of details but also since it requires great accuracy both on manufacture of the separate details and on assembly of these in order that the result shall be the one desired. Furthermore, such a device gives rise to relatively large friction, and the forces required for operating the locking mechanism will therefore be relatively large. 
     The object of the present invention is to eliminate the disadvantages described above, and to provide an operating device of the kind mentioned in the introduction, which is simple and cheap in production and assembly and gives greater freedom of choice in placing the details incorporated in the device. This is accomplished by giving the operating device the distinguishing features which are apparent in the following claims. 
     The invention will now be more closely described while referring to the attached drawing, on which FIG. 1 is a schematic perspective view of a device according to the invention built into a vehicle door, and FIG. 2 is a schematic plan view of the device according to FIG. 1. 
     The embodiment of the device according to the invention shown on the drawing is made as an operating device for a locking mechanism in the form of an axially movable locking bolt 1, mounted in the door 2 of a motor vehicle. 
     The device according to the invention includes an operating element in the shape of a flexible metal bellows 3. One end 3a of the bellows 3 is attached to a support plate 4 while the other end 3b of the bellows is free and via a pin 5 attached to it, engages one arm of a bell crank 6, which is pivotally mounted on a pin 7 attached to the support plate 4. The other arm of the bell crank 6 is swivellingly joined by a pin 8 with the rear portion of the locking bolt 1. The latter is displaceably mounted in a guide 10 in the support plate 4, and is together with the details 3-9 suitably built into a housing 11, as may be seen from FIG. 1. In the housing 11 a spring attached to the carrying plate 4, presses the locking bolt 1 into a position projecting away from the housing 11. 
     The bellows 3 is completely sealed, with the exception of its being provided at its end 3a with a union for a pipe 12, from which a number of branch pipes depart. Each of two branch pipes 13 and 14 are connected to a releasing element in the form of a flexible metal bellows 15 and 16 respectively. The bellows 3, 15 and 16 and the pipes 12, 13 and 14 are filled with an operating medium in the form of a gas or liquid which can transmit movement from one bellows to another. Each of the bellows 15 and 16 are intended, on volume change, to initiate a movement in the bellows 3, which thereby actuates the locking bolt 1 via the bell crank 6. Manual compression of one of the bellows 15 or 16 causes an expansion of the bellows 3, causing the locking bolt 1 to be withdrawn into the housing 11 against the bias of the spring 9. So that compression of the bellows 15 will not lead to an expansion of the bellows 16 or vice versa without actuation of the bellows 3, each of the bellows 15 and 16 is mounted in a cover 17. The cover 17 limits the maximum volume of each of the bellows 15 and 16 respectively and is made with an opening through which projects a narrower end portion 15a and 16a of the bellows 15 and 16 respectively. The end portions 15a and 16a can thus be actuated manually to initiate the desired movements. The covers 17 are built into the door 2 so that only the end portions 15a and 16a project from the outside and inside respectively of the door 2. 
     To enable locking the door, i.e. to make the bellows 3 inoperable, an expansion element in the shape of a flexible metal bellows 18 is connected by a pipe 19 to the piping circuit 12,13,14. This connection has great adaptability in relation to the available space, and on the drawing two conceivable connecting possibilities are shown. According to FIG. 1 the pipe 19 is connected to the pipe 13 and according to FIG. 2 the pipe 19 is connected to the pipe 12. The end 18a of the bellows 18 which is fixedly attached to the pipe 19, is attached to the door 2, while the other closed end 18b is free. The volume of the bellows 18 is so selected that when the bellows 18 is allowed to expand freely the bellows 3 is not affected by compression of the bellows 15 or 16. The operating medium pressed out of bellows 15 or 16 causes an expansion of the bellows 18 instead. Adjacent to the free end 18b of bellows 18 there is a shaft 20 rotatably mounted in the door 2. The shaft 20 carries an eccentric 21 attached to it, which has an axial position opposite the bellows 18. In the position shown in FIG. 2 the bellows 18 can expand independent of the eccentric 11, but when the shaft 20 is turned 180° the eccentric 21 will prevent or at least limit the expansion of the bellows 18. This means that movements of the bellows 15 or 16 are transferred to the bellows 3, so that the locking bolt 1 can be operated as has been previously described. 
     The shaft 20 with the eccentric 21 is operated from the inside of the door 2 by a lever 22 and from the outside of the door by a key 23. The latter fits in a lock cylinder 24, which is made in a conventional manner and is non-rotatably attached to the shaft 20. A lock housing (not shown) containing the lock cylinder 24 is mounted in the door 2 in a manner known per se. 
     The invention is not limited to the embodiments described above, but alterations can be made within the scope of the following claims. For example, locking of the door can take place by having a mechanical latching means brought into cooperation with the locking bolt 1 for latching this in a locked position.