Abstract:
A roll-up leash which comprises a casing ( 1 ) containing a winding drum ( 3 ), pivoting around an axis ( 2 ), biased in the direction of winding. This winding drum ( 3 ) has at least one catch ( 5 ) which, when the leash ( 4 ) unwinds, automatically extends outwards towards a catch stop ( 8 ). This catch stop ( 8 ) can be moved back, by means of a manually operated button ( 14 ), out of the direction of travel of the extended catch ( 5 ). The catch ( 5 ) is positioned swivel-mounted on an end face of the winding drum ( 3 ). To turn the catch ( 5 ) there is a rotating actuator ( 19 ) revolving with the winding drum ( 3 ) but limited relative to the same and having, to synchronise the rotating actuator after passing an idle clearance of the rotating actuator relative to the winding drum ( 3 ), two stops, and with the rotating actuator featuring means to extend and retract the catch ( 5 ) in the case of rotation relative to the winding drum ( 3 ). To prevent the rotary motion of the rotating actuator, at least one magnet is positioned between the casing ( 1 ) and the rotating actuator.

Description:
TECHNICAL FIELD  
       [0001]     The present invention concerns a roll-up leash for pets, mainly for dogs, which comprises a casing containing a winding drum, pivoting around an axis and biased in the direction of winding, which is connected to a locking mechanism, which in turn has at least one outwards moving catch that automatically extends when the leash unwinds and projects in the direction of travel of the extended catch, and a catch stop which, by means of a manually operated button, can be moved back out of the direction of travel of the extended catch.  
       BACKGROUND ART  
       [0002]     Such roll-up leash is the subject of EP-B1-1204312. The roll-up leash described in this document is designed in such a way that the leash locks in the direction of unwinding without the activation of a button, but can always move freely in the direction of winding.  
         [0003]     This means that the dog on the leash can only move away from its owner when the leash is unwinding if the owner wants to give the dog more freedom of movement and thus presses the button to release the leash both in the direction of winding and in the direction of unwinding. To function in this way, the known extending dog leash requires a toothed winding drum and a toothed wheel which engages in this toothing. The axis of this toothed wheel is fixed in a guide which can be moved relative to the casing, so that the toothed wheel can extend under a stop fixed to the casing to lock the winding drum with a catch.  
         [0004]     Simpler mechanisms of this type are already common in cord-type starting devices for internal combustion engines, whereby the starter cord leash engages with a starter bell when the starter cord is pulled, but disengages when the engine starts to run. Reference is made to DE-1476514 for an example of the prior art. This document describes a retaining bolt which supports both a winding drum and a control plate. A clip-like spring, lying against the bolt, makes the control plate more difficult to turn than the winding drum. This means that the control plate can turn the swivelling catches pivoting on the winding drum outwards thus causing them to engage in the starter bell.  
         [0005]     With cord-type starting devices the winding drum only has to be able to make a few rotations to start the engine. Dog leashes, on the other hand, can be up to 8 metres long. Experience shows that a dog on a leash is also constantly moving, which means that the cord drum must rotate constantly at a relatively high speed as the dog runs.  
         [0006]     If a spring were used to brake the control plate, this would cause the bolt and the spring to wear out quickly. Furthermore, given that roll-up leashes are usually made of plastic for cost reasons, the heat generated by the friction of the spring could damage the roll-up leash.  
       DESCRIPTION OF THE INVENTION  
       [0007]     The present invention overcomes these problems with a roll-up leash of the above mentioned type which is designed in such a way that it has the simplest possible structure and will work reliably for as long as required.  
         [0008]     The invention overcomes existing drawbacks by means of a roll-up leash having the features disclosed in the characterising part of claim  1 . The depending claims outline advantageous features of the invention.  
         [0009]     This type of extending dog leash has a considerably simpler structure than that according to the aforementioned patent EP-B1-1204312 as it does not require any sort of toothed wheels. It is therefore cheaper to manufacture and does not make any noise whatsoever when winding and unwinding the dog leash because there are no toothed wheels engaging in each other or unwinding and as no catches have to rattle over a catch toothing. Compared to the cord-type starting device according to the previously assessed DE-1476514, the roll-up leash according to this invention has the advantage that no mechanical friction is required to brake the rotating actuator which means there is no wear and tear and there is no undesired heat build-up.  
         [0010]     In a further embodiment, the roll-up leash has a particularly simple design where a magnet for generating an axial force directed towards the casing is mounted on the rotating actuator. This also makes assembly easier, as the rotating actuator just has to be inserted into casing and is held in place there by the magnetic force alone.  
         [0011]     The catches can also be extended and retracted without contact and thus without friction and wear and tear if, according to another embodiment of the invention, the means of extending and retracting the catch consist of two magnets with opposite poles, positioned one after the other in the direction of rotation of the rotating actuator, and a magnet in the catch, so that, in rest position, the catch is attracted by the first magnet of the rotating actuator and, when the leash winds out, the catch is pushed out by the second magnet of the rotating actuator.  
         [0012]     The same magnets can be used for extending and retracting the catches and for braking the rotating actuator if the magnets in the rotating actuator at the same time serve to generate the polar force directed axially towards the casing by means of a metal ring positioned in the casing opposite the magnets.  
         [0013]     It is also possible to extend and retract the catches using mechanical means. The means of extending and retracting the catch in this case consists of an outward facing arm on the rotating actuator and a slanted surface on the catch which moves towards the arm.  
         [0014]     If the winding drum rotates at high speed when the dog leash is winding up, the catch tends to turn outwards because of the centrifugal force. In that case it would not block the winding drum, but rather slide over the manually operated catch stop and thus cause undesirable noise. This can easily be prevented according to another further embodiment of the invention, whereby the rotating actuator has an arrester hook which latches radially over the catch when the catch is retracted.  
         [0015]     The button to release the dog leash can be locked in the release position so that the user does not need to constantly hold it down to allow the dog the freedom determined by the length of the dog leash if the button for the stop, from its position pressed into the casing is transversely mobile to the button&#39;s direction of retraction with a click projection under a casing stop.  
         [0016]     It is particularly advantageous if the button lies against the end of a single-arm lever, which biases the button away from the casing stop and if the single-arm lever at the same time lies against a lever arm of a two-armed lever, whose other lever arm engages in the mobile catch stop. With this type of design the button tends to move away from the casing stop with its click projection. Therefore, if the user just taps it in its pressed down, locked position, then it will be released from the casing stop and can fully reach its extended position. 
     
    
     ILLUSTRATION OF DRAWINGS  
       [0017]     The invention allows various embodiments. In order to elucidate its basic principle two of these are shown in the drawings and are described below. The drawings show in  
         [0018]      FIG. 1 a  cross-section of a major area of a roll-up leash according to the invention in locked position;  
         [0019]      FIG. 2 a  cross-section of a top area of the roll-up leash in release position;  
         [0020]      FIG. 3 a  section of the top half of the roll-up leash rotated through 90° compared to  FIG. 1 ;  
         [0021]      FIG. 4 a  section of the area of a button on the roll-up leash to lock and release the dog leash;  
         [0022]      FIG. 5 a  diagram of the winding drum with the adjacent components in locked position;  
         [0023]      FIG. 6 a  diagram of the winding drum in release position;  
         [0024]      FIG. 7 a  longitudinal section of the roll-up leash in the winding drum area;  
         [0025]      FIG. 8 a  diagram of a second embodiment of the winding drum with the adjacent components in locked position;  
         [0026]      FIG. 9  the arrangement according to  FIG. 8  in the release position. 
     
    
     DESCRIPTION OF SOME FORMS OF EMBODIMENT OF THE INVENTION  
       [0027]     As shown in  FIG. 1 , the roll-up leash according to the present invention has a substantially cylindrical casing  1  containing a winding drum  3 , pivoting about an axis  2 , on which a leash  4  can wind and unwind. The casing  1  has, in the right area of  FIG. 1 , an integrally moulded grip  17  which is cut off in the drawing. On one side of the winding drum  3  there are, for example, three catches, of which only one catch  5  is depicted, to keep a swivel axis  6  provided on winding drum  3  turnable. Each catch  5  has a cam  7 , which, in the depicted, swivelled out position of the catch  5 , lies against a catch stop  8 . The catch stop  8  is positioned so that it is radially mobile in the casing  1  and is biased by means of a pressure spring  9  in the direction of the winding drum  3 .  
         [0028]     A two-armed lever  10  serves to move the catch stop  8  against the force of the spring  9 . This has a lever arm  11 , which engages in the catch stop  8  and a lever arm  12 , which catches under a single-arm lever  13 .  
         [0029]     To turn the single-arm lever  13 , a button  14  is used, which, for this purpose, can be moved into the grip  17  of the casing  1 . The button  14  has a click projection  15 , which can, when the button  14  is in a pressed down and moved to the left position as seen in  FIG. 1 , latch into a casing stop  16 , which is shown in  FIG. 2 .  
         [0030]     As shown in  FIG. 2 , the button  14  with its click projection  15  rests in the casing stop  16 . This will have caused the lever arm  11  to push the catch stop  8  outwards out of the direction of travel of the catches  5  which means that the winding drum  3  can now rotate freely in both directions of rotation.  
         [0031]      FIG. 3  shows the winding drum  3  with the leash  4  wound around it. There is also a diagram of a spiral spring  18 , which biases the winding drum  3  in the direction of winding.  
         [0032]     On the left side of the winding drum  3 , the catch  5  which lies against the catch stop  8  is clearly visible.  
         [0033]      FIG. 4  illustrates the design of the button  14  which can turn the lever  13 .  
         [0034]     The function of the roll-up leash according to this invention is clearly visible in  FIGS. 5 and 6 .  FIG. 5  shows that on the axis  2  a rotating actuator  19  is pivoted, which lies with a nib  20  against a stop  21  of the winding drum  3 . The winding drum  3  has another stop  22 , which can, when the winding drum  3  rotates relative to the rotating actuator  19  in an anti-clockwise direction, get from the opposite side to the nib  20 . In the catch  5  there is a magnet  23 , which, in the position shown in  FIG. 5 , lies opposite a magnet  24  of the rotating actuator  19 . The magnets  23 ,  24  are magnetised in such a way that opposite poles are facing each other. This means that the magnets  23 ,  24  mutually attract each other. This holds the catch  5  in the depicted, swivelled-in position.  
         [0035]     If the winding drum  3  rotates anti-clockwise relative to the rotating actuator  19 , then the magnet  23  will finish in the rotating actuator  19  via a second magnet  25 . This second magnet  25  is magnetised in such a way that the same poles are opposite each other with magnets  23 ,  25  so that a repulsive force is exerted on the catch  5 .  
         [0036]      FIG. 5  shows the position of the components when the leash  4  winds in.  FIG. 6  on the other hand shows the position when a dog on the leash wants to move away from its owner and the leash unwinds. The catch  5  then ends up with its cam  7  against the catch stop  8  shown in  FIGS. 1, 2  and  3 . A relative rotation between the rotating actuator  19  and the winding drum  3  is therefore required for the functioning of the roll-up leash. How this is accomplished can be seen in  FIG. 7 .  
         [0037]      FIG. 7  shows the casing  1  with the axis  2  which is directly moulded onto the casing  1 . The winding drum  3  is pivoted on this axis  2  and, for its part, holds the catch  5  swivel-mounted with the magnet  23 . The rotating actuator  19 , of which the magnet  24  can be seen in  FIG. 7 , is also pivoted on a collar  26  of the casing  1 . Axially opposite the magnet  24  and other magnets  27  of the rotating actuator  19  there is an iron ring  28  fixed in the casing and positioned coaxially to the rotating actuator  19 . Magnets  24 ,  27  and the iron ring  28  impede a twisting of the rotating actuator  19  on the collar  26 .  
         [0038]     With the embodiment according to  FIGS. 8 and 9 , the rotating actuator  19  has three diagonally outward facing arms  29 ,  30 ,  31 . These arms  29 ,  30 ,  31  catch, as will now be explained for the arm  29 , by means of a recess  32  of the catch. If the winding drum  3  rotates clockwise, the arm  29  lies against a stop  33 , represented by the left edge of the recess  32  seen in  FIG. 8 . On the right side, the recess  32  is restricted by a slanted surface  34 .  
         [0039]     If the winding drum  3  rotates anti-clockwise, as is the case when the cord  4  unwinds, then this slanted surface  34  ends up against the arm  29 . As the rotating actuator  19  is more difficult to turn than the winding drum  3 , the arm  29  pushes the catch  5  outwards, as shown in  FIG. 9 , thereby locking the roll-up leash.  
         [0040]      FIGS. 8 and 9  also show that the arms  29 ,  30 ,  31  each feature at their free end an arrester hook  35 , which, in the position shown in  FIG. 8 —winding in the dog leash  8 —catches over the stop  33  and thus prevents the catches  5 , because of the centrifugal force, from getting outside. This type of arrester hook  35  could also be provided with the embodiment according to  FIGS. 1-7 .  
         [0041]     It should be noted that the roll-up leash according to this invention can also be used for other purposes such as a cord-type starter.  
       REFERENCE LIST  
       [0000]    
       
           1  casing  
           2  axis  
           3  winding drum  
           4  leash  
           5  catch  
           6  swivel axis  
           7  cam  
           8  catch stop  
           9  pressure spring  
           10  two-armed lever  
           11  lever arm  
           12  lever arm  
           10  single-arm lever  
           14  button  
           15  click projection  
           16  casing stop  
           17  grip  
           18  spiral spring  
           19  rotating actuator  
           20  nib  
           21  stop  
           22  stop  
           23  magnet  
           24  magnet  
           25  magnet  
           26  collar  
           27  magnet  
           28  iron ring  
           29  arm  
           30  arm  
           31  arm  
           32  recess  
           33  stop  
           34  slanted surface  
           35  arrester hook