Tire chain

A tire chain with separable chain strands the end links of which are connectable at each separation point by use of two connecting elements which can be hooked into each other and which are each safely connected with an end link, wherein each connecting element has a body comprising at least one portion bounding an insertion slot which portion has a cross-section decreased at its free end at the expense of its width and wherein the width of the insertion slot is smaller than the height of each of those portions of the body which bound the insertion slot.

The invention relates to a tire chain, especially anti-skid chain, with at 
least one separable chain strand, the links of which, adjoining each other 
at the separation point, are connectable by use of a connecting element 
having a body with an insertion slot. 
Tire chains of the above mentioned kind are known, in which the end links 
of two chain strand sections to be connected with each other are 
connectable by a single C-shaped connecting element, the insertion slot of 
which is closed by additional locking elements after the end links have 
been mounted. The known tire chains of this type are unsatisfactory, as 
their handling is difficult and practically impossible without tools. 
Another disadvantage is that the locking elements can get lost and that 
not only the assembly of the locking elements but also their disassembly 
is complicated after the chain has been used for a longer period. 
It is the object of the present invention to provide a tire chain of the 
type mentioned in which at the separation points the strands can easily 
and quickly be opened and closed without the aid of tools and without the 
use of locking elements. 
In accordance with the present invention this object is achieved therein 
that each separation point is provided with two connecting elements which 
can be hooked into each other, each being safely connected with an end 
link of the chain strand section to be connected, that at least one of the 
portions of the body bounding the respective insertion slot has a 
cross-section decreased at its free end at the expense of the width of 
said end and that the width of the insertion slot is smaller than the 
height of each of those portions of the body which bound the insertion 
slot. 
The advantage of the tire chain according to the invention consists therein 
that the connecting elements can easily be connected with each other by 
joining them in the region of their insertion slots and then at first 
rotating one of the connecting elements around 90.degree. in a first 
direction and subsequently around a further 90.degree. in a second 
direction. 
As soon as the end links are brought into an essentially aligning position 
in this way the connection between the chain strand sections has been 
established and because of the shape of the insertion slots and of the 
confining parts it is guaranteed that the end links do not come loose 
unintentionally. 
It has been found to be especially advantageous if both connecting elements 
have a C-shaped body, the ends of which, confining the insertion slot, are 
bounded by roof-shaped wedge surfaces, the tops of which lie in the centre 
plane extending through the ends bounding the insertion slots, the 
shoulders adjoining said ends and a bridge portion of the body extending 
parallel to the ends. 
Preferably the wedge planes bounding the insertion slot are X-shaped and 
two wedge surfaces, each arranged at an end bounding the insertion slot of 
the body encircle an angle of about 90.degree.. Such an arrangement offers 
the advantage that the insertion slot can be kept exceptionally small.

11 and 12 in FIG. 1 are the end links of two chain strand sections, which 
are connected with each other by two connecting elements 15 of the same 
form. The connecting elements 15 have a body 16 with two portions 18,19 
bounding an insertion slot 17. The portions 18 and 19 turn each into a 
bridge portion 22 via bows 20 and 21. At the side opposite the insertion 
slot 17 the bridge portion 22 is provided with projection 23. 
The ends of the portions 18 and 19 of the connecting element 15 are 
provided with wedge planes 24, the tops 25 of which lie in the centre 
plane extending through the insertion slot 17, the end portions 18,19, the 
ajoining bows 20,21 and the bridge portion 22 of the body 16. The wedge 
planes are arranged essentially in X-shape and encircle at each end of the 
portions 18 and 19 an angle of about 90.degree.. 
As a comparison of FIGS. 2 and 3 shows, at their ends the portions 18 and 
19 are weakened at the expense of the width b of the respective end, and 
the width w of the insertion slot 17 is smaller than the height h of the 
portions 18 and 19 bounding the insertion slot. 
Portion 18 of the body comprises a projection 26 directed to the bridge 
portion 22 of the body 16. The end link 11 is safely held in the 
connecting element 15 by the projections 23 and 26. 
FIG. 4 shows, that the cross-section of the bow 20 of the body 16, in which 
the end link 11 is suspended, is oval shaped, while the bow 21 has a 
circular cross-section. The cross-section of the bow 21 is larger than the 
cross-section of the end links 11 and 12. The choice of an oval 
cross-section for the bow 20 and the increase of the cross-section 21 
compared to the cross-section of the end links 11 and 12 guarantees a 
great stability of the connecting elements. 
The bridge portion 22 of the body 16 is provided with stop areas 27 to 
avoid clamping of the end links 11 and 12 and of the connecting elements 
15. For reasons of stability the use of a smaller inner pitch of the body 
is advisable. This should be approximately 3 - 31/2 times the material 
thickness of the end links 11 and 12. In case of such a small pitch it 
proves advantageous to arrange the insertion slot 17 diagonally, as can be 
seen from FIG. 1. 
FIG. 5 shows a modified embodiment with a connecting element 28, which is 
combined with a connecting element 15. The connecting element 28 also has 
wedge surfaces 24 in the region of the insertion slot 17. The main 
difference between the two connecting elements 15 and 28 consists therein 
that the connecting element 28 completely surrounds the bow of the end 
link 11. In other words it must be connected to the connecting element 28 
by welding, while in case of the connecting element 15 the fastening of 
the end links can take place by first spreading the portions 18 and 19 a 
little and subsequently pressing them back into the form as shown in FIG. 
1. 
While the connecting elements 15 are provided with four wedge surfaces 24 
each the connecting element 29 according to FIGS. 6 and 8 has only one 
wedge surface, but otherwise it corresponds to the connecting element 15 
in its arrangement and its assembly and disassembly. 
Instead of wedge surfaces 24 a step-like developed end 31 is used in the 
connecting element 30 according to FIG. 8. As FIG. 9 shows such a 
connecting element can also easily be assembled and disassembled.