Patent Publication Number: US-8118629-B2

Title: Bushing apparatus for electrical and hydraulic lines on a watercraft

Description:
This application is a National Stage completion of PCT/EP2008/062893 filed Sep. 26, 2008, which claims priority from German patent application serial no. 10 2007 048 056.5 filed Oct. 5, 2007. 
     FIELD OF THE INVENTION 
     The present invention relates to an external drive of a watercraft comprising at least two actuators for adjusting a thrust tube, at least one suspension apparatus, which can be fixed to a transom, for pivotably mounting the actuators, and hydraulic and electrical lines to the actuators. 
     BACKGROUND OF THE INVENTION 
     In trimmable and controllable external drives for watercrafts, it is known that the electrical and hydraulic lines required for controlling the actuators, as well as sensing the position of the adjusted drive, are connected from the interior of the watercraft via numerous bushings through the transom of the watercraft. Separate sealing is required at each bushing; in addition, the numerous drill holes weaken the structure of the transom. If the apparatus has to be removed, for example for maintenance, the hydraulic lines have to be pulled out of their bushings and the seals need to be replaced as a result. In addition, the lines either have to be awkwardly disconnected in the interior of the watercraft or in an environmentally critical way outside the watercraft. 
     SUMMARY OF THE INVENTION 
     The objective of the present invention is to provide a bushing apparatus for hydraulic and/or electrical lines with which the above mentioned disadvantages of the known arrangement can be avoided, and a simple and easy to install connection between a hydraulic or electrical line inside and outside the watercraft can be accomplished. 
     A trimmable and controllable external drive of a watercraft comprises at least two actuators for adjusting a thrust tube as well as at least one suspension apparatus, which can be fixed to a transom, for pivotably mounting the actuators. Furthermore, the drive comprises hydraulic and electrical lines to the actuators, the hydraulic or electrical energy for adjusting the actuators and electrical signals from sensors being transmitted by the lines. For this purpose, a bushing apparatus can be arranged on the transom, by means of the bushing apparatus the hydraulic and/or electrical lines are connected inside and outside the transom. Thus, for passing all lines of one or more actuators through the transom only one opening is required, which is sealed against the bushing apparatus once the bushing apparatus has been installed. 
     In an advantageous refinement of the subject matter of the present invention, the bushing apparatus has continuous channels, with connections being arranged on the ends of each channel for electrical and/or hydraulic lines. 
     In addition, according to an embodiment of the present invention, the continuous channels between the connections for hydraulic lines may be empty and an electrical connection can be arranged between the connections for the electrical lines, whose type and function corresponds to that of the electrical line of the actuator. 
     Preferably, in this case, the connections are designed as connecting elements which are sealed and fixed in a housing of the bushing apparatus. If the housing of the bushing apparatus is made of an electrically conductive material, the electrical connecting elements are isolated against the housing of the bushing apparatus. 
     In one variant, the bushing apparatus is fixed to the transom and sealed. 
     In another advantageous variant, the external contour of the housing of the bushing apparatus is cylindrical. The installation in the transom by means of a drilling process is very easy in this way. Moreover, a cylindrical body is easy to seal in a drill hole. 
     In this regard, a further embodiment provides that the bushing apparatus is arranged in a suspension apparatus, which is fixed to the transom. 
     Preferably, the bushing apparatus is guided radially in the suspension apparatus and sealed. The suspension apparatus is radially sealed by means of a sealing element. Likewise, an exact fit can be created in the metallic material by means of a clearance fit. 
     It is also possible to pull out the bushing apparatus toward the inside or outside after releasing an attachment. This is advantageous for installing and removing the bushing apparatus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The present invention will be explained in more detail hereinafter with reference to the exemplary embodiment shown in the drawing: 
       The drawing shows: 
       a longitudinal section of the bushing apparatus as mounted in the suspension apparatus. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The drawing shows a cross-section of the transom  101  of a watercraft in the region of the bushing apparatus  100 . The bushing apparatus  100  has channels  103  in its longitudinal direction, a connecting element  105  for a hydraulic line  112 , or a connecting element  106  for an electrical line  111  being connected to both ends of the channels  103 . The connecting elements  106  for an electrical line  111  are in electrical contact via an electrical connection  104 . The electrical connection  104  is isolated against the housing of the bushing apparatus  120 . The channel  103  has a straight course which was drilled into the housing of the bushing apparatus  120 . The straight shape is particularly advantageous for the hydraulic connections because this minimizes the losses of flow. The housing of the bushing apparatus  120  is cylindrical and is made, for example, of a stainless metallic material in order to withstand the hydraulic pressure on the one hand, and to resist the corrosive environmental conditions on the other hand. The hydraulic  112  and electrical  111  lines are screwed onto the connecting elements  105 ,  106 , by which the lines from the interior of the watercraft are connected to the lines of the actuators. During installation into the shown mounting position, the bushing apparatus  100  is pushed from the left side through a drill hole in the suspension apparatus  102 , in which the housing of the bushing apparatus  120  is guided in a fitting, and further through a drill hole in the transom  101  until the collar  110  abuts against the suspension apparatus  102 . On the opposite side, meaning the inside of the transom  101 , a ring nut  108  is screwed onto a thread  109  for attaching the bushing apparatus  100 , wherein the ring nut  108  is abuts against the counterplate  114  on the inside of the transom  101  to avoid damaging the transom  101 . Subsequently, the lines are fixed from the inside. This results in easy disassemble without having to disconnect the lines  111 ,  112  coming from the actuator. In the assembled position shown, sealing at the outer diameter of the housing of the bushing apparatus  120  is carried out by means of a sealing element. 
     REFERENCE NUMERALS 
     
         
           100  bushing apparatus 
           101  transom 
           102  suspension apparatus 
           103  channel 
           104  electrical connection 
           105  connecting element for a hydraulic line 
           106  connecting element for an electrical line 
           107  sealing element 
           108  ring nut 
           109  thread 
           110  collar 
           111  electrical line 
           112  hydraulic line 
           113  actuator 
           114  counterplate 
           120  housing of the bushing apparatus