Abstract:
Breakable safety device, comprising a body (1) with alternating securing points (2, 3, 4, 5) and zones of weakness (6, 7, 8) where the zones of weakness are given successively increasing/decreasing breaking strength. A field of using such safety devices are when exercising dogs from a bike.

Description:
REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. application Ser. No. 07/650,433, filed Feb. 4, 1991, now abandoned. 
    
    
     FIELD OF THE INVENTION 
     The present invention concerns an intermediate joint between objects, this intermediate joint being made to be broken at different loads. 
     BACKGROUND OF THE INVENTION 
     To ensure that too large loads between working parts by towing, lifting etc. do not occur, there is normally placed intermediate joints between the loaded parts, these joints breaking or fragmenting above a certain load. Such breaking joints are usually of a throw-away type, and have the drawback that they can not be adjusted to different loads. 
     The purpose of the present invention is to produce such a breaking joint which simultaneously is adjusted to breaking at different loads. 
     The basis for the invention, and which includes a field of use for the freeing safety device according to the invention is the problem of exercising dogs by using a bicycle stand (see U.S. Pat. No. 4,854,269) where the weight and strength of the dogs being exercised, and the corresponding traits of the owner, varies very much. The variation of the maximum load before the dog is freed from the exercising stand represents in itself a problem since a liberating device with a function as described above for the previously known devices, would have to be produced in a variety of different sizes which would have to be sold and used separately. This represents a significant drawback and increased expenses when producing such stands. 
     SUMMARY OF THE INVENTION 
     As a solution for this problem there has according to the present invention been produced a safety releasing device comprising a narrowing body or a body with sections of stepwise lesser material thickness and/or material strength and/or sections of weakness, an where there between such sections are placed securing means for choosing each of the breaking strengths of the releasing device. Such a body may e.g. comprise a band, a pipe a rod or a series of continuously weaker rope sections which are successively secured to each other. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front plant view of the preferred embodiment of the safety release device of the present invention. 
     FIG. 2 is a top plan view of an embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The figure shows a band 1, preferably of a synthetic material such as nylon, light metal or other suitable material, with stamped out or shaped apertures 2, 3, 4 and 5. The band 1 is alternately narrowed 6, 7, 8 to produce zones with successively lesser material strength, thus to produce potential breaking places or zones which are broken at different loads. 
     Such breaking zones may, however, also be produced in other ways, e.g. by alternating partwise cutting, alternating material types with successively lesser strength etc. Breaking zones 15, 14 and 13, shown in FIG. 3, are an alternative or complimentary embodiment of the body of the present invention with stepwise lesser material thickness. 
     In the figure there is also shown a possible securing for two ropes 9, 10 being threaded through the first and last holes 2, 5, and being prevented from slipping out of the holes by being knotted at each end 11, 12 of the ropes. In the location being shown in the figure a breaking will happen at the least possible load, and at successively larger loads as the end rope 9 is moved to the holes 3, 4 closer to the end hole 5. 
     The location of the ropes 9, 10 for the wanted breaking load may of course be performed according to the user&#39;s wish. 
     In a special embodiment for exercising dogs from a bike, as mentioned above, the safety releasing device according to the invention may be made of nylon plate material with a thickness of 1,5 mm and with a length of 85 mm. When using such an embodiment the breaking strength will, when using the hole arrangement 5-2 to secure the ropes 9, 10 as shown on the figure, be 30 kg, whereas it will successively increase to 45 kg and 57.5 kg when using the hole arrangement 5-3 or 5-4, respectively. 
     The present invention has in the above given disclosure been described with reference to a band with four holes and three zones of weakness, but it will be obvious to the person skilled in the art that more or fewer holes/zones of weakness may be used. It will also be obvious to the person skilled in the art that other securing devices than holes may be used, inter alia hooks, screws, pinchers, nails etc. 
     It will also be obvious that such safety devices may be used for other purposes than exercising dogs, and that this area is described only as an example. 
     Additionally, it is also obvious that other securing objects than ropes may be used with the safety device, e.g. wire, hawsers, rods, hooks, bolts, rings etc. 
     The safety device according to the invention may also be produced as an integrated part of objects whose correct function depend on and is limited by maximum loads.