Anti-skidding device for tired, particularly pneumatic-tired vehicle wheels on ice and snow

Anti-skidding device for vehicle wheels with tires, particularly pneumatic tires, for ice and snow surfaces. The anti-skidding device 100 consists of a support disk 120 which can be attached at the wheel disk or rim 11. The support disk is provided, adjacent to its periphery, with a plurality of anti-skidding arms 140 which extend radially in a fixed manner, equally spaced apart or are pivotal about axes 141 which extend parallel to the wheel disk bearing axis 117. The anti-skidding arms are prebent sections of plastic which engage over the tire travel surface 14 and carry spikes at their free ends.

BACKGROUND OF THE INVENTION 
The invention relates to an anti-skidding device for tired, particularly 
pneumatic-tired vehicle wheels when used on ice and snow. 
In addition to snow chains, winter tires or so-called adhesive tires are 
used in winter when vehicles are driving on snow-covered inclines or 
gradients. Snow chains are not very popular because it is often difficult 
to apply them to the vehicle tires and because they must be driven in such 
a way that the road surface is not damaged, i.e. the snow chains have to 
be removed on the dry road surface portions following the snow or 
ice-covered portions. In addition, when travelling on dry road surfaces, 
snow chains are subject to considerable wear and do not permit travelling 
at high speeds. Snow chains and adhesive tires are often not available, 
particularly when roads are covered with ice and at short notice, e.g. 
when the icy surfaces are produced by drizzle or spray falling onto the 
frozen road surfaces. In addition, it is not always possible to use spiked 
tires. 
Besides snow chains and adhesive tires, starting aids are known, but they 
are no substitute for snow chains and adhesive tires. These starting aids, 
which are constituted by clamp straps mounted on the tires, merely assist 
in moving the vehicle a short distance out of snow or slush. 
DESCRIPTION OF THE PRIOR ART 
For the purpose of increasing the grip of vehicle wheels, U.S. Pat. No. 
2,443,261 discloses an anti-skidding device, which can be fitted to the 
wheel rims of motor vehicles and which comprises a basic disk and an 
annular disk rotatable about the centre thereof and on which are 
articulated pivoted levers for pivoting in and out triangular 
anti-skidding arms fixed in rotary manner to the basic disk. Thus, on 
rotating the annular disk, the anti-skidding arms are pivoted out from a 
position retracted relative to the tire circumference into a radial 
operating position, so that the pointed end portions project out of the 
plane formed by the tire tread and can engaged in the substrate. In this 
known anti-skidding device, the anti-skidding arms are also located 
alongside the tire sidewall in the pivoted out position and in no way 
engage over the tire thread, so that the increase in the grip of the 
vehicle wheels does not take place through the direct action of the tire 
or its tread on the anti-skidding arms or of the anti-skidding arms on the 
ground surface. During operation, the anti-skidding arms do not form an 
integrated part of the tire in order to achieve an action corresponding to 
that of spikes embedded in the tread profile of a tire. In addition, this 
known anti-skidding device requires a large amount of space. 
A further anti-skidding device for vehicle tires known from French Pat. No. 
1,368,348 comprises a plurality of arm-like fastenings, which can be 
attached by means of a basic disk to the rim of a random vehicle wheel. 
The arm-like fastenings constantly engage over the tread surface in the 
operating position and when not in use cannot be pivoted out of the tread 
surface area. When not in use, the complete anti-skidding device must be 
removed from the rim. 
A further anti-skidding device described in U.S. Pat. No. 2,610,898 
comprises a plurality of spike-like ribs or teeth which, in the operating 
position, can be laterally extended alongside the tire, but do not engage 
over the tire tread. The radially arranged anti-skidding arms are pivoted 
in and out by using a rotatable disk, which can be fitted to a vehicle 
wheel rim. The anti-skidding arms used in this device are rigid and not 
resilient-elastic, because they must engage in the ice or snow-covered 
road surface during the rotation of the wheel. 
DAS No. 2,750,111 discloses an anti-skidding device for tired, particularly 
pneumatic tired vehicle wheels, which comprises a supporting casing formed 
by a basic disk which can be fixed to the wheel disk and an annular disk 
rotatable with respect to the latter about the disk centre, and at least 
two equidistant anti-skidding arms, each of which being rotatably mounted 
on the basic disk and articulated in crank gear-like manner on one end of 
a pivoted lever, whose other end is rotatably connected with the outer 
periphery of the annular disk. On rotating the annular disk relative to 
the basic disk, the anti-skidding arms are pivoted out into a radial 
operating position from a position retracted with respect to the tire 
circumference. Between the basic disk and the annular disk, a gap is 
formed receiving the anti-skidding arms and pivoted levers in the starting 
position. The pivoted levers and anti-skidding arms are made from spring 
steel and dimensioned in such a way that the levers transfer the arms from 
their virtually flat or elongated shape in the starting position into a 
bent shape projecting into the tire tread in the operating positon. 
Although no problems are caused in the fitting of this anti-skidding 
device, it has a complicated construction. 
SUMMARY OF THE INVENTION 
The problem of the present invention is to obviate this problem. The 
invention solves the problem by providing an anti-skidding device for 
tired, particularly pneumatic tired vehicle wheels when travelling on snow 
and ice, which is used for anti-skidding purposes and for increasing the 
grip of vehicle wheels on snow and ice. Despite its effectiveness, it is 
economic to manufacture and permits higher travelling speeds than when 
using snow chains. Its efficiency is better than that of known 
anti-skidding devices, particularly during the braking process. The 
anti-skidding action is obtained by means of spikes, which are held on the 
tire tread and which, compared with snow chains, can be easily fitted and 
removed again at any time, whilst having a simple technical construction. 
According to the invention, this problem is solved by an anti-skidding 
device for tired, particularly pneumatic tired vehicle wheels when used on 
ice and snow, characterized in that the device comprises an annular cover 
disk located in the outer surface area of the tire and having a plurality 
of equidistantly radially fixed anti-skidding arms made from spring steel 
or resilient-elastic plastic materials, whose free ends are slightly rough 
bent and wholly or zonally engage over the tire tread and carry on the 
outside a gripping profile or spikes, as well as a bracing disk for the 
cover disk mounted on the rim, whereby the anti-skidding arms are 
pretensioned in such a way that they engage on the tire tread in the 
operating position. 
The essential advantages provided by the invention are that only a device 
constructed in this way provides an effective anti-skidding means for 
vehicle tires and ensures improved grip of the wheels on ice and snow. Due 
to the fact that the radially directed anti-skidding arms are made from 
spring strip steel or resilient-elastic plastic materials and project from 
the outside of the tire into its tread area, when the tire revolves the 
ends of the arms pass between the tread profile and the substrate, such as 
the road. The anti-skidding device has a relatively small number of 
components and therefore has a simple construction. Thus, its fitting and 
removal can be effortlessly carried out. In addition, the construction is 
completely maintenance-free. 
The requisite tire engagement of the anti-skidding arms is brought about by 
pretensioning the cover disk and the arms. The mounting of the 
anti-skidding device on the rim is preferably in the form of a 
quick-action clamping means, so that the bracing disk is able to brace the 
cover disk and the anti-skidding arms. By rotating the bracing disk, the 
bracing action can be removed and consequently the anti-skidding device 
can be easily detached. The anti-skidding device can be fixed to the rim, 
e.g. on the flange or in the ventilation openings. Fitting and removal of 
the anti-skidding device can take place in a very short time and there is 
no risk of dirtying. 
As a result of the pretensioning of the cover disk and the anti-skidding 
arms, when the anti-skidding device is fitted they engage over the vehicle 
tire on the tread side. The free end of each anti-skidding arm comes to 
rest in the vicinity of the tire tread and as a result of the pretension 
is pressed against the tread, whilst maintaining the approximately 
circular arc shape. 
Due to the pretensioning of the cover disk and anti-skidding arms and the 
fact that the latter are made from spring steel or resilient-elastic 
plastics, the possibility exists to adapt the arms to the tire 
cross-sectional profile in such a way that the free end of each arm comes 
to rest between the tire tread and the substrate when the vehicle is 
travelling or when the wheel is moving. Due to the construction of the 
anti-skidding arms in resilient-elastic manner, in conjunction with the 
pretensioning, an elastic deformation and shaping of the arms is brought 
about when the device is in the operating state. Due to the fact that the 
anti-skidding arms come to rest between the tire tread and the substrate, 
very good adhesion between tire and substrate is ensured. Thus, this 
anti-skidding device is able to achieve the effect of spiked tires. 
No problems are caused in fitting the anti-skidding device, because it is 
merely necessary to fit the cover disk and anti-skidding arms on the rim 
in such a way that the arms come to rest in the tire area, whilst the 
cover disk engages at one end in the rim hump and is held in the 
pretensioned position by means of the bracing disk mounted on the rim and 
connected thereto. The anti-skidding device can be manufacture 
inexpensively because it only consists of a small number of parts. When 
not in use, the anti-skidding device can be housed in a minimum area so 
that the possibility exists of mounting this device on a spare tire 
carried in a vehicle boot or trunk in such a way that the anti-skidding 
arms engage over the spare tire. Since, in addition, the anti-skidding 
device has a relatively flat construction, several such devices can be 
effortlessly held in superimposed manner on the spare tire. Due to their 
arrangement and construction, as well as the pretensioning action, in the 
operating state the anti-skidding arms automatically adapt to the tire 
movements. The anti-skidding device simultaneously protects both the 
vehicle and road due to quiet running. It can be constructed for most 
standard rims, without any modification to the rim being necessary. 
The invention also provides a solution according to which an anti-skidding 
device for tired, particularly pneumatic tired vehicle wheels for use on 
ice and snow is proposed, which is constructed in such a way that the 
device comprises a support disk which can be fixed to the wheel disk or 
rim having a plurality of equidistant, radial anti-skidding arms pivotal 
about axes running parallel to the wheel disk bearing axis and which are 
made from a rough-bent profile of plastic or some other suitable material 
engaging over the tire tread and being provided externally on their free 
ends with a gripping profile or spikes. 
The invention also provides a device for fixing the anti-skidding devices 
to a rim, characterized in that the support disk is fixed to the wheel 
disk or rim by means of rim screws, wheel studs or screw or bolt 
fastenings provided on the rim and has openings for the rim screws, and 
that a locking disk is held on the support disk and is provided with 
devices locking the rim screw to the support disk. 
A device constructed in this way prevents vehicle tires from skidding and 
increases the grip of the wheels on ice and snow. Due to the fact that the 
anti-skidding arms are pivotally held on the support disk fixed to the 
rim, the fitting of the device is effortless in that in the contact area 
between tire and substrate, such as a road or the like, the anti-skidding 
arms can be swung out sideways and then on starting so engage with the 
tire tread that they assume a radial position relative to the other arms. 
The radial forces occurring when travelling are no longer transferred to 
the basic disk in the case of the present anti-skidding device and are 
instead absorbed by the pivotable anti-skidding arms. On braking, the 
anti-skidding arms are placed in front of the tire due to the mass moment 
of inertia which occurs and consequently increase the braking action. The 
anti-skidding arms thereby serve as friction-increasing members. 
As the anti-skidding arms are made from plastic materials, have a certain 
resilient-elastic behaviour and are provided with a material reinforcement 
in the bent end area, when travelling the free ends of the anti-skidding 
arms only lift to a very limited extent from the tire tread. However, on 
passing through that area in which the tire frictionally engages with the 
road, the anti-skidding arms are pressed onto the tire tread, snow and ice 
which has been collected between the anti-skidding arms and the tread is 
forced out due to the interaction between the pressing and lifting effect. 
However, this lifting effect only occurs in the vicinity of the bent free 
ends of the arms and is extremely small. In addition, when travelling, the 
anti-skidding arms assume a radial and equidistant position. The 
pivotability of the arms is a valuable aid in fitting the anti-skidding 
device and also assists the braking action. When travelling, the arms 
always assume a vertical position and have a long life, due to the fact 
that they are made from plastic. 
Fitting the anti-skidding device is effortless and merely involves placing 
on the rim screws fixed to the rim. For this purpose, the support disk 
carrying the anti-skidding arms is placed on the rim screws in such a way 
that their head-like ends project through the openings provided in the 
support disk. The locking disk rotatably arranged on the support disk is 
provided with gripping devices in such a way that on rotating the rotary 
disk, the support disk is locked with the rim screws. By opposite rotation 
of the locking disk, the locking to the rim screws is detachable, so that 
the anti-skidding device can be easily removed. 
After the anti-skidding device has been fixed to the wheel rim, the 
anti-skidding arms engage over the vehicle tire on the tread side. The 
free end of each arm comes to rest in the vicinity of the tire tread. Due 
to the fact that the anti-skidding arms are preferably made from 
resilient-elastic plastics and have a rough-bent profile, the possibility 
exists of adapting the arms to the tire cross-sectional profile in such a 
way that the free end of each arm comes to rest between the tread and the 
substrate when the vehicle is travelling and when the wheel is revolving. 
Due to the fact that the arms come to rest between the tread and the 
substrate, very good adhesion of the tire to the substrate is achieved. In 
this way, it is possible for this anti-skidding device to achieve the same 
effect as that obtained with spiked tires. 
The anti-skidding device can be manufactured in an inexpensive manner, 
because it only comprises a few parts. When not in use, the anti-skidding 
device can be housed in a very small area, which makes it possible for the 
anti-skidding device to be fitted on the spare tire carried in the vehicle 
trunk or boot in such a way that the anti-skidding arms engage over the 
spare wheel tire. Since, in addition, the anti-skidding device has a 
relatively flat construction, a plurality of anti-skidding devices can be 
held without difficulty in superimposed manner on the spare tire. Due to 
their arrangement and construction in the operating state the 
anti-skidding arms automatically adapt to the tire movements. 
The anti-skidding device simultaneously protects the vehicle and road 
through quiet running. It can be constructed for most standard rims, 
without any modification to the latter being necessary, because the 
anti-skidding device is fixed by means of rim screws, which have a special 
construction for this purpose. In those cases when the rims are held by 
nuts on the wheel bolts, the construction of the nuts is adapted to the 
rim screws, so that here again effortless fixing of the anti-skidding 
device is possible. 
Further embodiments of the invention are described in the subclaims, as 
well as hereinafter relative to non-limitative embodiments and the 
attached drawings, wherein show:

DESCRIPTION OF THE PREFERRED EMBODIMENT 
As is shown in FIG. 1, the anti-skidding device 10 comprises an annular 
cover disk 20, a bracing disk 30 and a plurality of anti-skidding arms 40 
radially fixed to the disk 20. The anti-skidding device is fixed to wheel 
11, provided with a tire 13 and simultaneously constituting the rim. Wheel 
11 is provided with a brake member, which is not shown in the drawing. The 
tread area of tire 13 is designated as 14 and the tire sidewall as 15. 
The cover disk 20 comprises a portion 21 running parallel to the tire 
sidewall 15 and to which are fixed the anti-skidding arms 40, as well as a 
lower bent portion 22, whose free end has a bead-like supporting 
projection 23. On the side of portion 22 of cover disk 20 remote from 
projection 23, a holding device 24 is provided in which engages the 
bracing disk 30 with its all-round edge portion 31. This holding device 24 
on cover disk 20 for bracing disk 30 is constructed in annular slot-like 
manner, so that disk 30 with its all-round edge portion 31 is guided and 
held in the annular slot-like engagement and holding profile (FIG. 1). 
Portion 21 of cover disk 20 carrying anti-skidding arms 40, as well as the 
latter, have in the initial, pretensioned position shown in FIG. 2, 
compared with the vertical 16 located on the wheel axis, have a smaller 
angle relative to the portion 22 of cover disk 20 subject to the action of 
bracing disk 30 than in the operating position, so that in the starting 
position, disk 20 and arms 40 are as shown in FIG. 2. If cover disk 20 is 
mounted on rim 11 together with the bracing disk 30, then the disk portion 
21 with anti-skidding arms 40 assumes the engagement position shown in 
FIG. 1 in which arm 40 engages on the outer sidewall 15 of tire 13 in such 
a way that the circular arc-shaped bent free end 41 of the arm wholly or 
partly engages over tire tread 14 of tire 13, this being dependent on the 
length of the bent portion 21. 
Due to the fact that bracing disk 30 is fixed to rim 11 and with its edge 
portion 31 presses the cover disk portion 22 into rim hump 17 and thereby 
holds it in position, portion 21 with anti-skidding arm 40 is under 
certain pretension, which prevents arm 40 from being raised from the tread 
area 14 of tire 13. The pretensioning brings about a further engagement of 
anti-skidding arms 40 on outer sidewall 15 and in tread area 14 of tire 
13. 
In order to also achieve a high contact tension in the operating state, 
i.e. when travelling, portion 21 of cover disk 20 has the cross-sectional 
profile of FIG. 1. Thus, disk 20 has an outwardly tapering, all-round edge 
portion 25, which is bent and shaped in such a way that the free end of 
portion 25 rests on anti-skidding arm 40 and additionally transfers the 
latter into a form projecting into tread area 14 and maintains it in this 
form. 
Each anti-skidding arm 40 fixed to cover disk 20 is made from spring strip 
steel or a resilient-elastic plastic material, which is resistant to very 
low temperatures and high abrasion. Each arm 40 is so constructed that its 
end is bent in circular arc shape in the manner shown in FIG. 1, so that 
the bent portion 41 comes to rest on tread 14 of tire 13. The fixing of 
each anti-skidding arm 40 to cover disk 20 takes place by means of bolt or 
rivet-like connecting means 26, 27, a detachable fixing of arms 40 to disk 
20 also being possible in order to be able to replace worn arms 40. 
In the same way as anti-skidding arms 40, cover disk 20 can be 
correspondingly made from spring strip steel or resilient-elastic plastic, 
so that due to the predetermined pretensioning on one side there is an 
adequate engagement of the anti-skidding arms 40 on the outer sidewall 15 
and in tread area 14 of tire 13. It also has a certain elasticity, so that 
the anti-skidding arms 40 can adapt to the profile shape of the tire 
during movement. 
To increase tension, each anti-skidding arm 40 can have a special 
cross-sectional configuration. According to FIG. 3, the anti-skidding arm 
40 has a circular arc-shaped cross-section, whereas in FIG. 4 it has an 
approximately rectangular cross-section with a reinforcing rib 43 running 
approximately centrally in the longitudinal direction of the arm. 
End 40a of each anti-skidding arm 40 is fixed to cover disk 20 which, by 
means of bracing disk 30, is held in the sidewall area 15 of tire 13, so 
that arm 40 can assume the position shown in FIG. 1. There can be a random 
number of anti-skidding arms 40 on cover disk 20. However, there must be 
at least two such arms and all of them have the same angular spacing. 
Bracing disk 30 is adapted to the rim profile and constructed in 
housing-like manner. The annular cover disk 20 is fixed and pretensioned 
by means of disk 30. To this end, bracing disk 30 with its all-round edge 
portion 31 is supported on cover disk portion 22 by means of the provided 
holding device 24. The means for holding cover disk 20 on rim 11 are 
preferably constituted by quick-action clamping means e.g. by means of 
pointed or shaped supporting projection segments 23, which engage in rim 
hump 17 and are braced with bracing disks 30 by means of spreading 
segments. Bracing disk 30 is rotatably fixed to rim 11 about the wheel 
axis, so that a rotation of disk 30 releases the bracing effect and the 
anti-skidding device can easily be removed. In its edge area, bracing disk 
30 has spaced segment-like portions engaging in the annular slot-like 
profile of holding device 24 on disk 20 in the bracing position, said 
holding device 24 being portion-wise arranged and constructed, so that 
through a rotation of disk 30 the segment-like portions on its edge can be 
moved out of holding device 24, so that the anti-skidding device can be 
removed. However, it is also possible to fix bracing disk 30 to cover disk 
20, so that then the anti-skidding device 20 can be fixed as a structural 
unit to rim 11. The bracing disk 30 can also be fixed to the wheel flange 
18 or into the ventilation openings 18a of the rim. 
Each anti-skidding arm 40 has on the outside of its free end 41 a gripping 
profile or is provided at the end with at least one spike 45. In the 
embodiment of FIG. 1, anti-skidding arm 40 has at its end 41 two spikes 
45. The gripping profile formed in the outside 42 of end 41 of arm 40 can 
be constructed as a groove or land profile, but other profile types can 
also be used. It is important that the adhesion area between tire tread 14 
and the substrate is increased by means of said anti-skidding arm 40. 
Spike 45 arranged on anti-skidding arm 40 can be constructed in per se 
known manner. However, the embodiment of a spike 45 shown in FIG. 5 is 
particularly advantageous, because it simultaneously constitutes an 
adhesion aid on the tire side. Spike 45 comprises a disk-like core member 
47 having an all-round edge portion 47a, which conically tapers upwards 
towards the centre. This core member 47 centrally has a bolt-like hard 
metal core 46, whereof a portion 46a projects from member 47. On the side 
remote from portion 46a of hard metal core 46, core member 47 has a 
holding member 48, whose length approximately corresponds to the thickness 
of the anti-skidding arm 40. This holding web 48 carries at its free end a 
tire-side adhesion member 49, which can for example be constructed in 
spherical cap-like manner. If arm 40 engages with its bent end portion 41 
of tread 14 of tire 13, the adhesion members 49 of spike 45 engage on the 
anti-skidding arm ends in the groove profile of the tire tread, so that 
increased adhesion of the arm ends on the tread is ensured. In this way, 
the position of arms 40 on the tread is ensured by means of the profile. 
The invention is not restricted to the embodiments described hereinbefore 
and shown in the drawing. Variations from the construction of cover disk 
20 fall within the scope of the invention, as does a different 
construction of bracing disk 30, which is to be adapted to the particular 
rim construction. Engagement portion 22 of cover disk 20 can also have a 
different construction, if required by the rim construction. For the 
easier handling of bracing disk 30, it can be provided with a grip-like 
handle, which is not shown in the drawing. 
After fitting cover disk 20 by bracing with bracing disk 30, disk portion 
21 is moved outwards from its initial position and, like the anti-skidding 
arms 40, automatically attempts to reset itself due to the selection of 
materials made, so that arms 40 engage on the tire tread. 
As shown in FIGS. 6 and 7, the anti-skidding device 100 comprises a support 
disk 120 and a plurality of anti-skidding arms 140 fixed to disk 120. The 
anti-skidding device is fixed to wheel 11, which simultaneously 
constitutes the rim, provided with a tire 13. Wheel 11 is provided with a 
brake part not shown in the drawing. The tread area of tire 13 is 
designated as 14 and the outer sidewall of the tire as 115. 
The fixing of support disk 120 to the wheel or rim 11 is brought about by 
means of rim screws 116 (FIGS. 7 and 11) or the wheel bolt. However, screw 
or bolt-like fastenings can be provided on the actual rim for fixing disk 
120 to said rim. 
In the embodiment of FIG. 7, support disk 120 is constructed as an annular 
disk and has in its central area a basic disk 130, which can be held both 
in a rotary manner in disk 120 and fixed to the latter, to which further 
reference will be made hereinafter. A locking disk 150 is rotatably held 
on basic disk 130. 
Basic disk 130 has a plurality of openings 136 for the passage of rim 
screws 116. The number of said openings 136 in basic disk 130 corresponds 
to the number of rim screws 116 used. In the embodiment of the drawing, 
basic disk 130 has four openings 136. If basic disk 130 is integrated into 
support disk 120, i.e. if the latter is constructed as a full-area disk 
then the latter has the number of openings 136 corresponding to the number 
of rim screws 116. 
If the support disk 120 is constructed as a full-area disk and is provided 
with openings 136 for rim screws 116 or in the case of an annular 
disk-like construction of disk 120, basic disk 130 with openings 136 for 
rim screws 116 is fixed thereto, then anti-skidding arms 140 are pivot 
about pivot pins 141 running parallel to the wheel disk bearing axis 117 
on the outer circumference of support disk 120 or adjacent thereto, as 
shown in FIG. 7. 
Each anti-skidding arm 140 comprises a profile member bent at one end. Arm 
portion 142 running parallel to the sidewall 115 of tire 13 is followed by 
the end-side bent portion 143, which engages over tire tread 14 when the 
anti-skidding device is fitted (FIGS. 7 and 18). 
Each anti-skidding arm 140 is made from plastic or other suitable 
materials, plastics being advantageous which have a resilient-elastic 
behavior, but which still have an inherent stability. Each anti-skidding 
arm 140 has at its free end 143 on the side facing tire tread 14 a 
protuberance 147 and on the outside at least one spike 146 made from the 
same plastic material as the anti-skidding arm, note FIG. 15. Protuberance 
147 on the side of arm 140 facing tread 14 increases the friction between 
arm 140 and the profile of tread 14, so that good adhesion of the arm on 
the tread is ensured. Instead of spike 146 made from the anti-skidding arm 
material and shaped at the same time as arm 140 is produced, the free end 
143a of arm 140 can be provided with at least one opening 145a for the 
insertion of a spike made from a metallic material. As each anti-skidding 
arm 140 comprises a wide profile member, it is possible to provide a 
plurality of spikes on the free arm end 143a (FIGS. 14 to 18). 
In addition, each anti-skidding arm 140 is provided with a material 
accumulation 148 in bent area 143b. As a result of material accumulation 
148, the weight of the anti-skidding arm, particularly in bent area 143b 
is increased, so that the weight increase prevents a lateral raising of 
arm portion 142 of arm 140 from the tire sidewall 115. Furthermore, each 
anti-skidding arm 140 can be provided with a reinforcing rib 149, which 
simultaneousely forms the material accumulation 148 (FIGS. 14 to 16). 
Locking disk 150 arranged on basic disk 130 or support disk 120 so as to be 
rotatable about axis 151 has a locking device 250 used for fixing and 
locking the anti-skidding device to the wheel or rim 11, note FIGS. 9 and 
12. This locking disk 150 comprises an approximately square plate member 
150a provided in its four corners with four lateral arms 152, whereof each 
arm 152 is provided with a semicircular engagement recess 153 (FIG. 9). By 
means of the engagement recesses 153 on arms 152 of locking disk 150, 
basic disk 130 placed on wheel 11 is locked in such a way that on rotating 
disk 150 in the direction of arrow X, recesses 153 engage in the portions 
of rim screws 116 passing through openings 136. 
Rim screws 116 are constructed in the manner shown in FIGS. 7 and 11. Each 
rim screw 116 comprises a bolt-like body 260 with an external thread 261 
formed at one end. The other head-like end 264 of rim screw 116 has a 
retracted portion 262 or is provided with an annular slot. The transition 
from the annular slot to the bolt-like body 260 is formed by a 
shoulder-like portion 263, which can be constructed in such a way that it 
simultaneousely forms a contact surface for basic disk 130 without 
impairing the engagement of locking device 250. 
Openings 136 in basic disk 130 have a diameter corresponding at least to 
the diameter of rim screws 116. As shown in FIGS. 8 and 12, openings 136 
are constructed as elongated holes and are arranged in basic disk 130 in 
such a way that the openings 136 with their longitudinal axis come to rest 
in a radial manner. However, it is also possible to give the openings 136 
in basic disk 130 a different configuration. Thus, each opening 136 can 
have a circular portion 136a, whose diameter is larger than that of rim 
screw 116, note FIG. 8. This circular portion 136a is followed by an 
elongated hole-like portion 136b, whose diameter corresponds to that of 
the annular slot 262 of rim screw 116. Openings 136 are arranged in basic 
disk 130 in such a way that portions 136b are located on a circular 
arc-like line. The anti-skidding device 100 is locked to the rim screws 
116 solely through the rotation of basic disk 130, so that portions 136b 
come to rest in the vicinity of annular slots 262 of the rim screws 116, 
so that the locking action is obtained. However, such a construction is 
only possible if basic disk 130 is rotatably mounted in support disk 20. 
In this embodiment, there is no need for a separately constructed locking 
disk 150 provided with locking devices 250. In this case, basic disk 130 
is provided with a handle, not shown in the drawing, in order to be able 
to rotate disk 130 for locking purposes. 
However, if openings 136 in basic disk 130 are in the form shown in FIGS. 8 
and 12, it is necessary to use a locking disk 150 with locking device 250. 
Locking disk 150 is provided with a handle not shown in the drawing, so 
that said disk can be rotated about its rotation axis 151 for locking 
purposes. 
The number of arms 152 carrying the semicircular engagement recesses 153 
and provided on locking disk 150 corresponds to the number of rim screws 
116 used. 
The engagement recesses 153 are arranged on arms 152 of locking disk 150 in 
such a way that on rotating disk 150 in the direction of arrow X, recesses 
153 are at the front and consequently engage with the annular slots 262 of 
rim screws 116. Support disk 120 or basic disk 130 is so arranged relative 
to rim screws 116 when the anti-skidding device 100 is fitted, that it 
comes to rest roughly in the plane formed by the shoulder-like portions 
263 of rim screws 116, so that the arms 152 of the plate-like locking disk 
150 arranged on support disk 120 or basic disk 130 comes to rest in the 
plane formed by the annular slots 262 of screws 116. Thus, on rotating 
locking disk 150, its engagement recesses 153 engage in the annular slots 
262 of rim screws 116. The radial arrangement of openings 136 in basic 
disk 130 also provides the advantage that it is possible to align the 
anti-skidding device 100 with the rim screws 116 during the fixing 
process. In the locked state, the areas of arms 152 adjacent to engagement 
recesses 153 overlap the areas of openings 136 remaining around the rim 
screws 116 placed through the openings, so that a firm seat of 
anti-skidding device 100 on wheel 11 is achieved. 
The previously described locking device shown in the drawing can also be 
replaced by differently constructed locking devices. It is essential to 
bring about locking with the aid of rim screws 116 as a result of the 
construction thereof. 
The locking disk 150 arranged on support disk 120 or basic disk 130 is 
covered by a cover disk 160 held either on disk 120 or disk 130 in such a 
way that the rotation of disk 150 is in no way impaired (FIG. 7). Cover 
disk 160 is provided with an opening 161 through which can pass a handle, 
not shown in the drawing and fixed to rotary disk 150. In addition, cover 
disk 160 has a number of inspection window-like openings corresponding to 
the number of rim fixing screws. Cover disk 160 can be held in rotary 
manner on disk 120 or disk 130 with gripping profiles for manual actuation 
and can be connected to locking disk 150. 
If support disk 120 is fixed to basic disk 130 or if support disk 120 
simultaneously constitutes basic disk 130, then the anti-skidding arms 140 
are pivotably mounted on the circumference of support disk 120 by means of 
pivot means. This pivotability of the anti-skidding arms is achieved by 
riveted or screwed connections 170, which are such that the pivotability 
of arms 140 in the direction of arrow X1 is not impaired (FIGS. 7 and 14). 
Support disk 120 is then provided with an all-round extended portion 120a 
engaging over the articulation area for anti-skidding arms 140. 
However, according to a further embodiment of the invention, it is also 
possible to hold support disk 120 on basic disk 130 in rotary manner. In 
this embodiment, basic disk 130 is locked with rim screws 116 by means of 
locking disk 150. By means of correspondingly constructed guides, disk 120 
can be rotated about disk 130. In this embodiment, anti-skidding arms 140 
are fixed on support disk 120, so that through the possibility of rotating 
support disk 120 a small position change of arms 140 engaged on tire 113 
is possible. 
In those cases when the wheel or rim 11 is held by means of wheel bolts on 
the brake drum, the ends of rim screws 116 remote from screw head 264 are 
provided with an internal thread, so that fixing members constructed in 
this way can be screwed onto the wheel bolt for fitting the anti-skidding 
device 100. 
The number of anti-skidding arms 140 fixed to support disk 120 is a 
function of the size of the tire 13 to be provided with the anti-skidding 
device. To prevent any lateral displacement of anti-skidding arms 140, 
support disk 120 can have arm-like extensions 121, which can be pivotally 
held on arms 140 and which externally engage over the latter (FIG. 6). 
Locking disk 150 is connected to an arresting device 255 in such a way that 
when locking to the rim screws has taken place, locking disk 150 cannot 
become automatically detached from its locking position, this only being 
possible after releasing the arresting device, which can be constructed as 
a push-button catch (FIG. 12). Advantageously, locking disk 150 is then 
constructed as a circular device 250a, in whose circumferential area is 
arranged the arresting device 255, locking disk 250a being provided with a 
stop 255a which cooperates with the arresting device.