Abstract:
The present invention relates to a skid protections device (3) for wheels preferably snow chains for vehicle wheels. In order to permit quick and simple assembly of snow chains on vehicle wheels the device according to the invention comprises a power aggregate attached to a wheel, coupled to a bracket thereon. The bracket with skid protection means may be mounted at the wheel with the skid protection means extending in working position around the wheel except a part thereof which is prevented from attaching a working position by the wheel engaging a ground. The power aggregate, in coupled condition, moves the blocked part of the skid protection means to the working position when it is released by rotation of the wheel, the skid protection means in working position is movable in peripheral direction relative to the wheel during rotation.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a skid protection device for wheels, preferably snow chains for vehicle wheels. 
     Mounting snow chains on vehicle wheels is often a dirty and time-consuming operation which often must be performed under severe conditions outdoors. 
     OBJECT AND SUMMARY OF THE INVENTION 
     The object of the present invention is to eliminate this problem by simple means the features of which are defined below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 
     The invention will be further described below with reference to the accompanying drawings, in which 
     FIG. 1 is a perspective view illustrating a folded skid protection forming part of the device according to the invention; 
     FIG. 2 is a perspective view showing the unfolded skid protection ready for assembly; 
     FIG. 3 is a perspective view showing the skid protection placed beside a car wheel; 
     FIG. 4 is a front view of the skid protection positioned at the car wheel for assembly; 
     FIG. 5 is a perspective view of the device of FIG. 4; 
     FIG. 6 illustrates the skid protection mounted on the car wheel; and 
     FIG. 7 illustrates the skid protection after disassembly from the car wheel. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Turning first to FIG. 3, there is illustrated a part of a car 1 with a wheel 2 which is to be provided with a skid protection device 3. The skid protection device comprises a bracket 4 with skid protection means in the form of a snow chain 5 which is to be put around the periphery of the wheel 2, more particularly, the tread surface 7 of the tire 6. As best seen in FIGS. 1 and 2, the bracket 4 pivots about an axis 8 on which a coupling member 9 and two retaining elements 10 and 11 are pivotally mounted. The retaining elements 10, 11 are provided with slots for arms 12 and 13 of the bracket 4. The retaining elements 10, 11 are mounted on the axis 8 with the slots provided on the retaining means facing each other. The coupling member 9 may be in the form of a longitudinal rod, the end portions of which are bent towards each other to provide substantially U-shaped hook portions 14 and 15. Likewise, the opposite edge portions of retaining elements 10, 11 may be bent such that these elements, become U-shaped. Each arm 12, 13 comprises two yokes 16 and 17, which extend through the slots in the retaining elements 10 or 11 and extend from the retaining elements 10 or 11 in opposite directions. Each yoke 16, 17 is preferably made of a U-shaped element the shanks 18, 19 of which extend on opposite sides of the axis 8. One end portion 20 at which the shanks 18, 19 are connected to each other, is bent to form a stop to limit the extension of the yokes 16 and 17 respectively by ramming into the edge of the retaining elements 10 and 11 respectively. The free shank end portions of the yokes 16 and 17 respectively, are bent to provide gripping portions 21 and 22 respectively, which engage a U-shaped fastening portion 23, at the web or base portion 24 thereof, in such a way that the fastening portion is pivotable around a pivot axis extending transversely to the yoke 16 and 17 respectively. 
     The snow chain 5 has a first link portion 26, the links of which are arranged on the fastening portion 23 closest to the yoke 16 and 17 respectively, and a link portion 27 the links of which are arranged on the outer end of the fastening portion 23. The links of the first link portion 26 are preferably threaded on the separater shanks 28, 29 of the fastening portion 23 and fastened by means of one or more fastening links 30 of which one is threaded on the web or base portion 24. The links of the second link portion 27 are threaded through eyes 31 formed by bending the separate shanks 28, 29. By varying the number of fastening links 30 between the web portion 24 and the first link portion 26, the distance between the first and second link portions 26, 27 at the fastening portion 23 and thus, the diameter of the entire chain 5, may be altered for quickly adjusting the chain to the diameter of the wheel 2. 
     The distance between the first and second link portions 26, 27 of the chain 5 decreases on opposite sides of the fastening portion 23 and said link portions are mounted in rings 32 positioned approximately half-way between the fastening portions 23. These rings 32 form the narrowest parts of the chain and the first and second link portions 26, 27 are preferably connected to each other via transverse rods 33 positioned approximately half-way between the fastening portions 23 and the rings 32. This construction of the chain 5 facilitates the assembly thereof on the wheel 2 and provides a firm &#34;grip&#34; on the surface. 
     As is evident from FIG. 1, the skid protection device may be folded to a very small &#34;package&#34; by pivoting the arms 12, 13 such that they extend parallel to each other, pushing the yokes 16, 17 together as far as possible the yokes 16, 17 forming the arms 12, 13, folding the fastening portions 23, inwards and putting together the chain 5 in a suitable manner. When the skid protection device 3 is to be mounted, the arms 12, 13 are pivoted set such that they form a cross and the yokes 16, 17 are extended as far as possible (see FIG. 2). Thereby, the skid protection device 3 is ready for assembly on the wheel 2. The wheel 2 is provided with two rubber straps 34 having hooked end portions 35 which hook the straps to the wheel rim 39. 
     As shown in FIG. 4, the rubber straps 34 are hooked preferably such that they are somewhat stretched into tension and the skid protection 3 is then placed close to the wheel 2, with one of the narrowest parts (a ring 32) of the chain 5 beside the portion 37 of the tire 6 engaging the ground 36. The chain is thereby brought around the wheel such that it reaches its working position on the tread surface 7 of the wheel 2 at the upper parts thereof. While the chain 5 lies beside the portion of the wheel 37 engaging the ground 36 with one of its narrowest parts (the ring 32), only a minor portion of the links of the chain 5 will be prevented from reaching their working positions on the tire 6. 
     In this position, the skid protection device 3 slopes downwardly relative to the wheel 2 and may, in this position, be connected to the wheel by means of the rubber straps 34. To enable this connection, the rubber straps 34 are stretched in the direction of arrow A, FIG. 3 and hooked onto the hook portions 14, 15 of the coupling member 9. The rubber straps 34 are dimensioned so that they exert such a large force, shown by arrow B, of FIG. 4, on the skid protection 3 in the direction of the wheel 2, that said straps, through the arms 12, 13, displace the portions of the chain 5 not yet in working position to their working positions when the wheel rotates. In other words, one must only place the skid protection 3 close to the wheel 2, as is shown in FIGS. 3 and 4, connect it to the wheel with the rubber straps 34, as is shown in FIG. 4, and drive away in the car, whereby the rubber straps automatically draw the skid protection device in position on the wheel 2, since the portions of the chain 5 initially lying beside the tire 6 may slide in over the tread surface 7 as soon as these portions are free. As a matter of fact, the wheel 2 need only to rotate partially before said portions of the chain 5 become free by rotating with the wheel and leaving the hindrance constituted by the ground in order to be brought into working position. 
     The rubber straps 34 are designed preferably such that they also exert a force on the skid protection device in the direction indicated by arrow B when the skid protection in its working position on the wheel, whereby said straps efficiently retain the skid protection especially when the chain 5 is provided to move around the wheel. This is essential in many cases, because the chain 5 may have a larger diameter than the wheel and thus, a different velocity than the wheel during rotation thereof. Furthermore, the force on the rubber straps 34 in the direction indicated by arrow B increases the more the skid protection device 3 or portions thereof are forced out of working position in the direction arrow A indicated by during driving. 
     Removal of the skid protection 3 from the wheel 2 is as simple as the mounting. As best seen in FIGS. 6 and 7, this is done by releasing the coupling member 9 from the rubber straps 34 and thereafter pulling the chain 5 away from the upper parts of the wheel 2. While the fastening portions 23 are pivotally connected to the arms 12, 13 the skid protection 3 may be brought down (see FIG. 7) without damaging any fastening portions 23 or the arms 12, 13 under the wheel 2. Thereafter the car is driven forward or backward a small distance until the skid protection 3 is completely free and may be picked up, folded and stored in the luggage compartment in the car. 
     The embodiment described and shown in the drawings is only one of many alternatives of the present invention. Thus the skid protection may be of another type than a snow chain and it is also possible to use skid protections comprising several individual parts. The skid protection may be used for wheels other than vehicle wheels, whereby the parts forming the device may vary in number and shape. Another type of retaining device other than rubber straps 34 may, for example be used for applying forces on the skid protection device and the retaining device may be arranged in a different member than the straps 34, for example, the coupling member 9 maybe connected directly to the wheel, while the retaining device is positioned on the outside of the coupling member. The retaining device may be integral with the skid protection device 3 and may comprise one or more members and it may have power generating means of various types, e.g. elastic straps of another material than rubber, for example, leaf springs. coil springs and gas springs. Also, the bracket 4 and other members of the skid protection may be formed in various ways but still be useful within the scope of the present invention. 
     The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.