Abstract:
A device for removing liquid from a closed cavity, such as from a shock absorber of a motor vehicle, is proposed; the device compresses a drill, which is guided displaceably in a guide housing, a preloading device at one end of the guide housing for displacing the drill in the guide housing, an intermediate piece at the other end of the guide housing, the intermediate piece having a central bore for the drill bit to pass through and at least one fluid connection on the outer circumference for the removal of liquid, and compressing a gripping device, which is fitted to the device and fixes the latter to the wall of the cavity to be emptied.

Description:
BACKGROUND 
     1. Field of the Invention 
     The invention relates to a device for removing liquid from a closed cavity, such as from a shock absorber, a spring strut of a vehicle or the like. 
     2. Description of the Related Art 
     When old vehicles are being disposed of, it is necessary to remove not only petrol and coolant from the vehicle before it is scrapped, but also liquids from closed cavities which are not readily accessible, such as from shock absorbers, spring struts and the like. 
     SUMMARY OF THE INVENTION 
     The invention is based on the object of proposing an appliance by means of which liquids can be removed rapidly and simply from closed cavities, in order then to be disposed of. 
     According to the invention, this object is essentially achieved with a device as claimed in claim  1 . The appliance can be attached to a shock absorber or spring strut, after which the liquid can be removed largely automatically via a suction device which is connected. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be explained in more detail by way of example with reference to the drawing, in which: 
     FIG. 1 is a side view of the appliance attached to a shock absorber, and 
     FIG. 2 is an exploded view of a device according to the invention. 
    
    
     DETAILED DESCRIPTION 
     In FIG. 1, reference numeral  1  designates a spring strut or a shock absorber, which is filled with a hydraulic oil which is to be removed from the shock absorber. Reference number  2  designates, in general terms, a device for removing the liquid from the shock absorber, said device being designed as a hand-held appliance and having various units. 
     Reference numeral  3  designates gripping tongs having gripping jaws  3 . 1  and  3 . 2 , which can be fixed in the gripping position and fix the device  2  to the shock absorber  1 . The shape of the gripping jaws  3 . 1  and  3 . 2  is reproduced in FIG.  2 . The gripping jaw  3 . 2  is of U-shaped design and, at both ends, has holes  4  which are used to accommodate articulation pins. By means of the gripping jaw  3 . 2 , the tongs  3  are articulated at  4  to the circumference of an intermediate piece  5 , the U-shaped gripping jaw  3 . 2  engaging around the approximately cylindrical intermediate piece  5 , to which the articulation pins are fitted. The opposite gripping jaw  3 . 1  is approximately arc-shaped and comes to rest on the circumference of the cylindrical shock absorber  1 , as FIG. 1 shows. Reproduced at  3 . 3  is an adjusting screw, by means of which the tongs  3  can be adjusted to different diameters of a shock absorber  1 . 
     As FIG. 2 shows, the intermediate piece  5  fitted to a guide housing  6  of the device  2  is provided with a continuous central bore  11  and, on the external circumference, with diametrically opposite fluid connections  7  and  8 , which are connected to ducts which run separately in the intermediate piece and open at its end in openings  9  and  10 . Provided on the end of the intermediate piece  5  is a magnetic ring  12 , which facilitates attachment to the shock absorber  1 .  13  is a sealing ring between the magnetic ring  12  and a holding plate  14  for a contact-pressure rubber  15 , which comes to rest on the circumference of the shock absorber  1  and seals off the hole which is to be made on the circumference. 
     The tubular guide housing  6 , which is cut open at the bottom, has a lower part  6 . 1  with a radial opening, through which a drill  16  is inserted, the latter being provided with a drill head  16 . 1  which is located at right angles thereto and which is aligned with the cylindrical intermediate piece  5 . In the exemplary embodiment illustrated the drill  16  is driven by means of compressed air, which is fed at  16 . 2 .  16 . 3  designates a lever for operating the drill. 
     Provided on the side of the guide housing  6  opposite the intermediate piece  5  is a preloading device  18  in the form of a thrust gun having a thrust lever  18 . 1 , a pull-back lever  18 . 2  and a pull-back knob  18 . 3 , by means of which a plunger  18 . 4  can be extended and locked in the extended position.  19  designates a contact pressure plate, which is fastened to the plunger  18 . 4  and acts on a piston  20 , which is designed approximately as a partially longitudinally slotted tube and engages over the drill head  16 . 1  of the drill  16 . The piston  20  is guided in the guide housing  6  and moves the drill  16  in the drilling direction, provision being made for a fastening plate  17 , which is fastened to the end of the piston  20 , so that the drill head  16 . 1  of the drill  16  is held in the piston  20  between the plates  17  and  19 . 
     A threaded spindle  16 . 4 , which is driven by the drill, projects from the end of the drill head  16 . 1 . A tubular driver  21  with an internal thread is screwed onto this threaded spindle  16 . 4 . On the circumference, the driver  21  has a longitudinal slot  21 . 1 , which accommodates a pin  24  which is inserted into a radial bore in a drill spindle  23 , which is guided in the driver  21  so that it is displaceable in the direction of the longitudinal axis. Arranged on the drill spindle  23  is a compression spring  22 , which is supported on a washer  25  held on the drill spindle  23  by means of a circlip  26 . The opposite end of the spring  22  is supported on the end of the driver  21 .  6 . 2  designates a spacer as a part of the housing  6 ; the thrust gun  18  rests on said spacer and is held in the guide housing  6 . 
     The appliance operates as follows. Firstly, by means of the tongs  3 , the appliance is attached to the shock absorber  1  and locked. By pressing the appliance on by means of the tongs  3 , the rubber seal  15  with the holding plate  14  is pressed against the shock absorber to be emptied. At  4 , the tongs  3  are articulated on the intermediate piece  5  by means of the articulation pins or by means of dowel screws in such a way that the pivoting range and the accommodation range of the tongs can easily be changed. After the appliance  2  has been fixed to the shock absorber  1 , the level  18 . 1  on the thrust gun  18  is operated, as a result of which the drill head  16 . 1  of the drill  16  is pushed forward by the piston  20 . While the drill  16  is already operating, the drill spindle  23  is pushed back counter to the force of the spring  22  by a pumping movement by means of the lever  18 . 1 , the spring  22  being compressed. In the process, the drill spindle  23  is displaced in the driver  21 , the driver pin  24  being guided in the longitudinal guide  21 . 1  in the driver. As a result of this prestressing, the drilling operation can be carried out automatically and without any manual contact force. After the hole has been made in the circumference of the shock absorber  1 , the pull-back lever  18 . 2  is operated and therefore the locking in the preloading device  18  is released, at which point the drill spindle  23  is pressed automatically back into the starting position by the still effective force of the spring  22 . 
     A sealing ring is provided at  27  in the central bore  11  in the intermediate piece  5 , and sealed off on the drill head  16 . 1  or a preceding plate, such as the fastening plate  17 , so that the liquid emerging from the hole which has been made can be sucked off via the fluid connection  8 , to which a suction device with a collecting container (not illustrated) is connected. 
     Since a closed space is formed by the sealing ring  27  in the intermediate piece  5  and the seal at  15  on the circumference of the shock absorber  1 , from which space hydraulic oil can be sucked out of the shock absorber  1  by a vacuum pump, a vacuum is produced in this cavity. In order to dissipate this vacuum, which prevents further suction, after the suction device has been shut off, compressed air is introduced briefly at  7 , after which the suction can be continued via the connection  8 . In this case, a changeover is made periodically between the connections  7  and  8  until the cavity in the shock absorber  1  has been completely emptied. 
     The suction line indicated at  28  in FIG. 1 is at least partly of transparent design, so that it is possible to see from outside whether the shock absorber  1  has already been completely emptied or not. 
     A swarf filter is preferably fitted in the fluid connection  8 , in order that the swarf produced in the drilling operation does not get into the vacuum pump. It is also possible to provide a filter in the region of the holding plate  14 , it being possible for this filter to be cleaned easily by means of a locking pin which can be latched in. 
     Various modifications of the device described above are possible. Thus, for example, the magnetic ring  12  can also be omitted, and the gripping device in the form of the tongs  3  can also be designed in another way, for example in the form of a clamp which is placed around the shock absorber  1 . 
     At  28  in FIG. 1, a radial opening is made in the guide housing  6 , through which opening a drill change on the drill spindle  23  can be performed. 
     Instead of the separate ducts with the mouth openings  9  and  10  in the intermediate piece  5  for the connections  7  and  8 , the latter may also be connected directly to the central bore  11 , so that suction is carried out via the front portion of the central bore  11  in the intermediate piece  5 , and compressed air is also periodically introduced via this portion. 
     According to a modified embodiment, the gripping tongs  3  may be fastened by means of the U-shaped gripping jaw  3 . 2  to a ring (not illustrated), which is mounted so that it can rotate on the intermediate piece  5 . In this way, the tongs  3  can be rotated relative to the device  2  into a suitable fastening position. 
     A manually operated valve, by means of which the drill  16  can be set operating and switched off again, can be provided on the compressed-air feed  16 . 2  of the drill  16  (FIG.  1 ). 
     A manually operated valve, by means of which the above-described vacuum equalization can be performed, is expediently provided in the suction line  28  (FIG.  1 ). The suction line  28  having this interposed valve is connected to a suction unit (not illustrated), into which the oil is sucked from the cavity to be emptied in the shock absorber  1 .