Abstract:
A line magazine for a supply line on a semimounted trailer with a king pin and a wedge connector pivoted on the king pin is described. The underlying problem of the invention was to provide a line magazine which prevents the supply line from hanging down in a mechanically simple way, while on the other hand it provides a constant pretensioning of the supply line. The problem is solved according to the invention with a line magazine that comprises a housing and a drum disk mounted in the housing and able to rotate, while the drum disk is preloaded by a spring element and the supply line engages by its front segment of line with the wedge connector and is led out from the housing by its rear segment of line in fixed manner.

Description:
FIELD OF THE INVENTION 
     The invention concerns a line magazine for a supply line on a semi-mounted trailer with a king pin and a wedge connector pivoted on the king pin. 
     BACKGROUND OF THE INVENTION 
     The coupling of a semi-mounted trailer on a tractor generally occurs by backing up the tractor underneath the trailer, whereupon a king pin arranged on the underside of the trailer engages with a fifth wheel located on the tractor and is then locked. For the uncoupling, the trailer is parked in usual manner, the fifth wheel is opened, and the tractor is driven out. To optimize the working conditions of long-haul drivers, there are efforts to automate the coupling and uncoupling of the trailer and the truck or to control this process remotely from the driver&#39;s cabin of the truck. In connection with such remotely controllable fifth wheels, there are already systems in existence that undertake the connecting of supply lines between tractor and trailer in automated manner, along with the coupling and uncoupling of the trailer. By supply lines is meant primarily cables for transmission of electrical energy, but also pneumatic or hydraulic lines. 
     A proven system for connecting the supply lines by a coupling of the trailer comprises a wedge connector that is pivoted on the king pin, per DE 101 55 056 A1, which fits into the wedge-shaped entry opening when the king pin is introduced into the fifth wheel, where it mates with plug contacts. When the tractor drives along curves, the wedge connector is form-fitted in the entry opening and turns relative to the trailer. For this reason, it is necessary to provide a sufficient length of supply line at the trailer side, in order to avoid a breaking of the supply line between the wedge connector and the fifth wheel when negotiating a tight curve. The main drawback, which leads to systematic failures, is that the supply line hangs down when driving on a straight stretch of road and thus there is a risk of damage or breaking. 
     In order to avoid damage to supply lines between a tractor and a trailer, so-called line magazines are already known from the prior art, which maintain the connection line under a tensile stress by means of a spring-loaded cable drum. One such line magazine is disclosed, for example, in DE 817 556 B and comprises a housing with a cable drum mounted therein, able to turn on a hollow axle. The connection line in the noncoupled condition is wound up until the connector touches the housing. The portion wound onto the cable drum is connected to a fixed cable segment led out through the hollow axle via a flat cable connected to both parts. However, this design has proven to be unreliable in daily use, since the use of three cable segments with two connection sites has led to breakages. 
     For this reason, the basic problem of the invention was to provide a robust line magazine, which prevents the supply line from hanging down in a mechanically simple way, while on the other hand it provides a constant pretensioning of the supply line. 
     SUMMARY OF THE INVENTION 
     The problem is solved according to the invention with a line magazine that comprises a housing and a drum disk mounted in the housing and able to rotate, while the drum disk is preloaded by a spring element and the supply line engages by its front segment of line with the wedge connector and is led out from the housing by its rear segment of line in fixed manner. 
     When driving straight, the supply line is for the most part retracted and wound up on the drum disk, so that the supply line is excellently protected against damage, on the one hand, while on the other hand the preloading of the drum disk allows the supply line to unwind when traveling along a curve so that the trailer can swivel relative to the tractor. Furthermore, the supply line is under such tension that, when the trailer swings back after negotiating the curve, there is no danger that parts of the supply line will get caught between the tractor and the trailer. 
     Another benefit of the line magazine is that even when riding without a trailer, the wedge connector is constantly oriented in a ready to enter position, due to the pretensioning of the supply line. This precludes the risk of having a wrongly oriented wedge connector when recoupling a trailer to the fifth wheel or its wedge-shaped entry opening, thereby damaging it. 
     Thanks to the flat configuration of the drum disk, the line magazine overall can be designed rather flat and thus can swivel together with the trailer across the rear end of the tractor when negotiating a curve. 
     The above indicated structural configuration has a continuous, single-piece supply line, which extends from the wedge connector to the exit of the housing or to the consuming devices of the trailer. This substantially improves the operational availability as compared to systems which are based on a rotary transmission, for example, using contact rings or slip brushes. The latter are unsuitable for use in the exposed position underneath a trailer, because of their high vulnerability to failure, dictated in particular by moisture-caused corrosion. 
     Preferably, a drum jacket is formed at the radially outer end of the drum disk, on which the front line segment rests. This drum jacket serves both for guidance and to accommodate the front line segment, which can be led out from the line magazine. 
     The rear line segment, on the contrary, can be laid spirally on the drum disk. It is especially advantageous for the drum jacket to have an opening and for the supply line to be fastened to the drum disk and/or the drum jacket, being fixed at the jacket opening. In this configuration, the supply line is divided by the fastening located in the region of the jacket opening into a front line segment, reaching from the wedge connector to the fastening point, and a rear line segment, extending from the fastening point to the outside of the housing. 
     The front line segment can be laid as a multiple winding on the drum jacket. For the pull-out lengths required in practical use for the front line segment, 2 or 3 turns laid one on top of the other have proven to work well. Thanks to the multiple winding, a minimal height of the drum jacket is required. 
     In order to assure a smooth winding and unwinding of the front line segment of the supply line, the drum jacket should completely surround the drum disk in the circumferential direction. 
     A precise guidance of the front line segment is achieved when the drum jacket is configured as a groove profile, especially a U-profile. The U-profile is formed complementary in shape to the cross section of the supply line and thereby protects the front line segment in the region where it contacts the drum jacket. 
     The groove profile or the U-profile should have an aperture width slightly larger than the diameter of the supply line. This will prevent overshooting during the wind-up. 
     In order to accommodate several turns lying one on top of the other, the groove profile or the U-profile must have a depth corresponding at least to the sum of the diameters of the number of turns lying of the drum jacket. Preferably, the depth of the profile should correspond at least to twice the diameter of the supply line. 
     Advantageously, the spring element is a spiral spring. This can be arranged in a spring space bounded off from the supply line by the drum disk. From this arrangement, one infers that the supply line, for example, its rear line segment, is arranged on the drum disk, and the spiral spring is arranged beneath the drum disk. In an alternative configuration, the spiral spring can also be arranged on the drum disk and the supply line can lie on the inside of the housing, underneath the drum disk. 
     In one favorable embodiment, the spiral spring is fastened stationary to the housing by its first end, and its second end engages with the drum disk and/or the drum jacket. It is especially advantageous for the first end to be fastened in the radial direction on the outside of the housing, and the second end to engage with the drum disk on the inside. 
     One stable configuration of the line magazine can be achieved by mounting the drum disk on a stationary mandrel bearing positioned in the housing. The mandrel bearing can then extend entirely through the housing and thereby stabilize the housing, as well as enable a stable mounting of the drum disk. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For better comprehension, the invention shall now be explained more closely by means of the following eight drawings. These show: 
         FIG. 1 : a bottom view of the line magazine; 
         FIG. 2 : a top view of the line magazine with housing cover removed; 
         FIG. 3 : a cross section along line A-A of  FIG. 2 ; 
         FIG. 4 : an enlarged feature per  FIG. 3 ; 
         FIG. 5 : a cross section along line C-C of  FIG. 2 ; 
         FIG. 6 : an enlarged feature per  FIG. 5 ; 
         FIG. 7 : a top view of the drum disk without supply line, and 
         FIG. 8 : a cross section on the drum disk along line A-A of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a bottom view of the housing  1  of the line magazine with a partly protruding supply line  4 , designed to cushion a tension loading. This can be achieved, for example, in the case of cables, by a jacket which absorbs tensile forces. The housing  1  is composed of the tub  20  and the screwed-on cover  19 . In the bottom view of  FIG. 1 , the housing cover  19  is visible in three corner regions. For the fastening of the line magazine to the underside of a trailer (not shown), the housing  1  has fastening holes  21  at two opposite sides and at the rear side  33 , which extend continuously through the housing cover  19  and the housing tub  20 . 
     In the direction of the front end  32 , a front line segment  5  is shown partly drawn out from the housing  1 . At the end of the front line segment  5  is arranged a trapezoidally tapering wedge connector  6 , which can be introduced into a complementary shaped inlet opening of a fifth wheel and thus enable, for example, an electrical connection. The front line segment  5  is introduced into the wedge connector  6  and secured to it, tension-relieved. 
     When the tractor (not shown) negotiates a curve, the trailer will swing out relative to the tractor. In this case, the wedge connector  6  can swing along with it and the front line segment  5  will be pulled out from the housing  1 . The maximum extension for the line magazine depicted is 850 mm. For example, the broken lines show two swing-out positions  34  of the front line segment  5 . 
     On the rear side  33  of the housing  1 , the rear line segment  7  of the supply line  4  is led out from the housing  1 . This rear line segment  7  is uncoupled from the extension and retraction movements of the front line segment  5 . Therefore, the rear line segment  7  can be connected in simple manner to the stationary lines laid on the trailer. 
       FIG. 2  shows a top view of the line magazine with the housing cover  19  removed. In a middle region of the housing tub  20  there is mounted a drum disk  2  which can turn, and the supply line  4  is partly wound up on it. At the front end  32 , the front line segment  5  of the supply line  4  emerges tangentially from a drum jacket  8 . The drum jacket  8  is formed at the radially outer end of the drum disk  2  and serves exclusively to accommodate the front line segment  5 . The front line segment  5  is for the most part wound up in the line magazine shown in  FIG. 2 . 
     The front line segment  5  is laid clockwise on the drum jacket  8  in the top view and can be recognized in the jacket opening  9   a . Directly inside the jacket opening  9   a  is a line attachment  23 , which fixes the supply line  4  to the drum disk  2 . In a second jacket opening  9   b , the supply line  4  pushes through the drum jacket  8  and is laid in a spiral on the drum disk  2  in the same direction of winding as in the drum jacket  8 . The rear line segment  7  is wound up inwardly in a spiral roughly two times and emerges at the top through an opening  25  in the housing through the cover  19 , not shown in  FIG. 2 . 
     Starting from this line attachment  23 , the supply line  4  is divided into the front line segment  5 , which lies on the drum jacket  8  and can be at least partly extended and retracted from the housing  1  (see  FIG. 1 ), and the rear line segment  7 , which lies on the drum disk  2  and can be led out from the housing  1  is a stationary manner (see.  FIG. 1 ). 
     For sealing purposes and to avoid damage to the rear line segment  7  from rubbing against the housing opening  25 , a rubber sleeve  24  is installed in the housing opening  25 . Furthermore, the rear line segment  7  is secured to the housing cover  19  (also see  FIG. 5 ) with a clamp fitting  26 . 
       FIG. 3  shows a cross section along line A-A in  FIG. 2 . The housing  1  is composed of the housing tub  20 , on which is secured the housing cover  19 , while the housing  1  is open at its front side  3 , allowing the front line segment  5  to swing in accordance with the relative movement of the wedge connector  6  (see  FIG. 1 ). 
     In the outer region of the drum disk  2 , one notices the drum jacket  8 , fashioned with a forklike groove profile  11 , which entirely surrounds the drum disk  2  in the circumferential direction. The drum jacket  8  receives the front line segment  5 , which is wound in two layers, one on top of the other, as a multiple winding  10  in a first level on the drum jacket  8 . 
     Inside the drum jacket  8 , the drum disk  2  is concave on either side and it receives the rear line segment  7 , likewise wound in two layers one inside the other, in a second level at the cover  19  side of the housing. The front line segment  5  of the line magazine as depicted in  FIG. 3  is in a largely wound-up condition. During the pulling out of the front line segment  5  and a resulting rotational movement of the drum disk  2 , the turns of the spirally wound rear line segment  7  migrate inward. When the front line segment  7  is fully extended, there are three or four turns present on the drum disk  2 , the inner one of which can come to lie against a drum sleeve  29 . 
     At the tub  20  side of the housing, a spring space  15  is formed beneath the drum disk  2 , in which a spring element  3  is arranged coaxial to the drum disk  2 . The spring element  3  is a spiral spring, one end of which is fastened stationary to the housing  1  and the opposite end is fastened to the drum disk  2 , ensuring a defined restoring force of the drum disk  2 . 
       FIG. 4  shows an enlarged feature of the region designated as Z in  FIG. 3 . One recognizes here the drum disk  2 , mounted at the center in a mandrel bearing  18 , extending between the housing tub  20  and the housing cover  19 . A major component of the mandrel bearing  18  is the pedestal  27 , through which is inserted a retaining screw  22 . With the help of a nut  28  screwed on from the cover  19  side of the housing, the housing cover  19  and the housing tub  20  are screwed together, giving the housing (see.  FIG. 3 ) great stability. 
     At the same time, the bearing pedestal  27  serves as an upright thrust bearing for the drum disk  2 , rotating about the pedestal  27 . For a low-wear operation and a favorable flow of force, the drum sleeve  29  is inserted at the center of the drum disk  2  and this, in turn, has a slide bearing  30  pressed into it. The slide bearing  30  consequently turns together with the drum disk  2  about the upright bearing pedestal  27 . 
     Moreover,  FIG. 4  shows the configuration of the drum jacket  8 . The groove profile  11  is shaped as a U-profile and opened at the radially outer end to receive the front line segment  5 . The U-profile has two parallel legs, which stand opposite each other with an aperture width  12 . The aperture width  12  is only slightly larger than the diameter  13  of the supply line  4 . At the lowest point  35  of the profile, the two legs of the U-profile merge to form a cone. The overall depth  14  of the groove profile  11  extends from the outermost edge of the drum jacket  8  to the lowest point  35  of the profile, while basically the segment of the parallel legs of the U-profile is suitable for receiving the front line segment  5  and it should have at least a depth able to accommodate two turns of the front line segment  5  wound on each other. 
       FIG. 5  shows another cross section through the line magazine along line C-C of  FIG. 2 . This shows how the rear line segment  7  is led out from the housing  1 . It is led after the exit, not shown in  FIG. 5 , through the housing opening  25  (see  FIG. 3 ) on the top side  36  of the housing cover  19  in the direction of the rear side  33 . For this, the clamp fitting  26  is arranged on the housing cover  19  for a stationary fixation of the rear line segment  7  to the top side  36 . 
       FIG. 6  shows an enlarged feature of the line magazine in the view of  FIG. 5 . Especially noticeable is the fastening of the spring element  3 , fashioned as a spiral spring, to the drum disk  2  by means of a pin  31 . The spiral spring  3  has its second end  17  wrapped around the pin  31 , and its first end  16  is secured to the housing tub  20 . 
       FIG. 7  shows a top view of only the drum disk  2 . At the center of the drum disk  2  is a central borehole  38  to accommodate the mandrel bearing  18  (see  FIG. 4 ). The central borehole  38  is fully surrounded by the slide bearing  30 , which is press-fitted into the drum sleeve  29 , joined to the drum disk  2  as a single piece. In the immediate vicinity of the drum sleeve  29 , the drum disk  2  has another borehole, which is a seat  37  to receive the pin  31  for fixation of the spiral spring  3 . Moreover, the drum jacket  8  is suggested in the marginal region of the drum disk  2 . 
     In  FIG. 8 , the drum disk  2  is shown in a cross section along line A-A of  FIG. 7 .  FIG. 8  shows the symmetrical layout of the drum disk  2 , with two shell-like halves, joined together by individual weld points  39   b  (also see  FIG. 7 ). The drum sleeve  29  is also firmly connected to the drum disk  2  by a circumferential weld  39   a . In  FIG. 8 , the pin  31  stands out against the drum disk  2  and the drum jacket  8 . 
     LIST OF REFERENCE NUMBERS 
     
         
           1  housing 
           2  drum disk 
           3  spring element, spiral spring 
           4  supply line 
           5  front line segment 
           6  wedge connector 
           7  rear line segment 
           8  drum jacket 
           9   a ,  9   b  jacket opening 
           10  multiple winding 
           11  groove profile 
           12  aperture width, groove profile 
           13  diameter, supply line 
           14  depth of groove profile, profile depth 
           15  spring space 
           16  first end of spiral spring 
           17  second end of spiral spring 
           18  mandrel bearing 
           19  housing cover 
           20  housing tub 
           21  fastening holes 
           22  retaining screw 
           23  line attachment 
           24  rubber sleeve 
           25  housing opening 
           26  clamp fitting 
           27  pedestal 
           28  nut 
           29  drum sleeve 
           30  slide bearing 
           31  pin 
           32  front side of housing 
           33  rear side of housing 
           34  swing-out position 
           35  lowest point of profile 
           36  top side of housing cover 
           37  pin seat 
           38  central borehole 
           39   a  weld seam 
           39   b  spot welds