WO2014027145A2

WO2014027145A2 - Stud for studded tire, and studded tire

Info

Publication number: WO2014027145A2
Application number: PCT/FI2013/050803
Authority: WO
Inventors: Risto MERILÄINEN
Original assignee: Scason Oy
Priority date: 2012-08-17
Filing date: 2013-08-15
Publication date: 2014-02-20
Also published as: WO2014027145A3; RU2015108399A; FI125427B; RU2612278C2; FI20125856A; FI125427B2

Abstract

The invention relates to a stud for a studded tire, comprising a body (1) with a centre axis (K), the body being provided with a stud pin (2) parallel to the centre axis. The body comprises a top flange (3) and a bottom flange (5). The top surface of the top flange (3) is intended to be positioned in the area or vicinity of the tread of the tire, when mounting a stud into a stud hole in the studded tire, the stud pin (2) being arranged in the body (1) in such a manner that one end (4) of the stud pin (2) protrudes from the top surface of the top flange (3). The bottom surface of the bottom flange (5) is intended to be positioned in the vicinity of the stud hole bottom of the tire, and on the edge of the bottom flange (5), on opposite sides of the centre axis (K), retaining surfaces (6) are arranged. On the edge of the top flange (3), retaining surfaces (7) are arranged in alignment with the retaining surfaces (6) on the bottom flange (5) as seen in the direction of the centre axis (K) of the body (1). The retaining surfaces (7, 6) on the top flange (3) and bottom flange (5) are curved surfaces. The invention also relates to a studded tire.

Description

Stud for studded tire, and studded tire

[0001] The invention relates to a stud for a studded tire, the stud comprising a body with a centre axis and a stud pin arranged in the body in the direction of the centre axis, the body comprising a top flange, the top surface of which is intended to be positioned in the area or vicinity of the tread of the tire, when the stud is mounted in the stud hole in the studded tire, and the stud pin is arranged in the body in such a manner that one end of the stud pin protrudes from the top surface of the top flange, and a bottom flange, the bottom surface of which is intended to be positioned in the vicinity of the bottom of the stud hole of the tire, and on the edge of the bottom flange, on opposite sides of the centre axis of the body, retaining surfaces are arranged. The invention also relates to a studded tire.

[0002] Over the decades, at least from the 1960s, studs of various kind have been developed for studded tyres. At different times, different objectives and conditions have been set for studs. From the start, a problem has been keeping the stud in place in the tire and maintaining the position of the stud in the tire so that the traction of the stud remains good. The wear resistance of a stud was also an issue already during the early stages of their development. No restrictions were set on stud projections and stud force during the early stages of development.

[0003] Over time, the problem of road wear caused by the studs emerged and restrictions were imposed on stud projections and stud force of tires generally used in traffic, which had an effect on the structure of the studs.

[0004] However, the essential problems of the early stages of studs, in other words, the studs keeping their correct position and remaining place in the tire, are still acute problems, since the restrictions and regulations related to stud projections and stud force also affect matters that are significant to the studs remaining in the correct position and in place. In addition, the increase in the weight of cars brought about by the advances in car technology and the increase in velocities have introduced their own additional effects on the above- mentioned matters.

[0005] Examples of solutions developed over the decades are described in Finnish patent publications 82815, 89688 and 1 9183 and Finnish patent applications 864821 , 20021966, 20045363 and 20085491. [0006] As stated above, due to the various conditions and restrictions imposed over time, the design of the stud and its parts has become more and more difficult. This is caused by the fact that the stud needs to be a compromise, which endeavours to provide good traction and endurance properties in different driving conditions and on different road surfaces. Today, studs should not wear the road too much, in other words, the stud projections and stud force should be within the allowed limits, and they also may not change essentially during use, in other words, the stud should not wear too quickly and it should remain in place and in the correct position in the tire. The stud should also be inexpensive to manufacture, since the manufacturing costs should remain at a realistic level.

[0007] As a whole, the stud of a studded tire is presently a compromise, in which different regulations and standards set by the authorities must be taken into account. At the same time, the object is to achieve traction properties that are good and stay good over time, a high wear resistance as well as realistic manufacturing costs. Thus, many factors must be considered, which in practice is very difficult.

[0008] The prior-art solutions have so far not provided the best possible final result. This can be seen in that various new solutions are developed continuously by different manufacturers in spite of the fact that development work has been done rather extensively even during the past few years, when the conditions and restrictions set by the authorities have remained mainly unchanged.

[0009] The above-mentioned continuously acute problems, in other words, keeping the stud in place in the tire and maintaining the correct position of the stud during use, are still an acute drawback in the present stud constructions.

[0010] The purpose of the invention is to provide a stud for a studded tire as well as a studded tire, by means of which the prior-art drawbacks can be eliminated. This is achieved by a stud for a studded tire in accordance with the invention. The stud for a studded tire of the invention is characterised in that on the edge of the top flange, there are retaining surfaces that are arranged in alignment with the retaining surfaces on the bottom flange as seen in the direction of the centre axis of the body, and that the retaining surfaces on the top and bottom flanges are curved surfaces. [0011] The invention provides the advantage that the retaining surfaces increase the stability of the stud in the tire in comparison with the prior- art solutions. The advantageousness of the retaining surfaces is further increased by the fact that the stud maintains its initial mounting direction in the tire better than in the prior-art solutions, that is, the stud does not tilt in use, but maintains its original position, which means that the traction of the stud and thus also the tire does not decrease quickly during use. The solution of the invention is also advantageous in terms of production engineering and can be applied to very different stud types.

[0012] The invention will be explained in the following in more detail by means of an embodiment shown in the attached drawing, in which

Figure 1 is a general side view of an embodiment of a stud of the invention,

Figure 2 is a general top view of the embodiment of Figure 1 , and

Figure 3 is a general view of tread parts of a tire, into which studs of Figures 1 and 2 are arranged.

[0013] Figures 1 and 2 show an embodiment of a stud for a studded tire according to the invention. Reference number 1 denotes the body of the stud. Reference marking K denotes the centre axis of the stud in Figure 1.

[0014] Reference number 2 denotes a stud pin arranged in the stud body 1. In the figures, reference number 3 denotes a top flange that is part of the body. The top surface 3 of the top flange is intended to be placed in the area or vicinity of the tire tread, when the stud is mounted in a stud hole in the studded tire. The stud pin 2 is arranged in the body 1 in such a manner that the other end 4 of the stud pin protrudes from the top surface of the top flange 3.

[0015] The stud further comprises a bottom flange 5 as part of the body 1. The bottom surface of the bottom flange 5 is intended to be placed in the vicinity of the stud hole bottom of the tire. On the edge of the bottom flange 5, on opposite sides in relation to the centre axis of the body, retaining surfaces 6 are formed.

[0016] The above-mentioned matters are fully conventional technology to a person skilled in the art and, therefore, they are not explained in greater detail herein.

[0017] According to the essential idea of the invention, retaining surfaces 7 are formed on the edge of the top flange 3. The retaining surfaces 7 formed on the edge of the top flange are arranged in alignment with the retain- ing surfaces 6 on the bottom flange 5 as seen from the direction of the centre axis K of the body 1. Further, it is essential that the retaining surfaces 6 and 7 on the top flange 3 and bottom flange 5 be curved surfaces.

[0018] The retaining surfaces described above increase the stability of the stud in the tire. The retaining surfaces also act to help maintain the mounting direction of the stud during use, in other words, to prevent the stud from tilting into an incorrect position during the use of the tire.

[0019] In the example shown in the figures, the end 2 of the stud pin protruding from the top surface of the top flange 3 is substantially in the shape of a rectangle. In such an embodiment, the curved retaining surfaces on the top flange 3 and bottom flange 5 are preferably arranged essentially parallel to the long sides of the stud pin 2 end 4. However, this is not the only solution and the curved retaining surfaces can naturally also be arranged essentially parallel to the short sides of the stud pin 2 end 4. According to the basic idea of the invention, it is also possible to use four curved retaining surfaces formed on the bottom and top flanges and arranged in pairs in alignment, as stated in claim 1.

[0020] It should also be noted that the invention is in no way limited to a rectangular stud pin, but the essential issue is that the top and bottom flanges have curved retaining surfaces, as stated in the claim. The above- mentioned curved retaining surfaces can also be used with other stud pins than those having a rectangular cross-section, that is, with stud pins having a round, oval, square, triangular cross-section, for instance.

[0021] The curved retaining surfaces 7, 6 on the edge of the top and bottom flanges 3, 5 of the stud are arranged to extend over the edge of the top and bottom flanges as seen in the direction of the centre axis K of the body 1. This detail is clearly shown in Figures 1 and 2.

[0022] Figure 3 is a general cutaway view of a part of the tire 8 tread, to which the studs are fastened in a manner known per se. The tire normally has several dozens of studs. Figure 3 shows by way of example only part of the tread of the tire 8, in which two studs are visible. The tire may have only studs of the invention or alternatively some of the studs may be studs of the invention and some of them other studs. The studs may be positioned in any known manner in the tire, in several rows and staggered in respect of each other, for instance. [0023] The invention is described above by means of an embodiment shown in the figures. However, the invention is in no way limited to the examples of the figures, but may be freely applied within the scope of the accompanying claims.

Claims

1. A stud for a studded tire, comprising a body (1) having a centre axis (K), to which body a stud pin (2) parallel to the centre axis is arranged and which body comprises a top flange (3), the top surface of which is intended to be positioned in the area or vicinity of the tread of the tire, when mounting a stud into a stud hole in the studded tire, the stud pin (2) being arranged in the body (1) in such a manner that one end (4) of the stud pin (2) protrudes from the top surface of the top flange (3), and a bottom flange (5), the bottom surface of which is intended to be positioned in the vicinity of the stud hole bottom of the tire, and on the edge of the bottom flange (5), on opposite sides of the centre axis (K) of the body (1), retaining surfaces (6) are arranged, and on the edge of the top flange (3) retaining surfaces (7) are formed, characterised in that the retaining surfaces (7) are arranged in alignment with the retaining surfaces (6) on the bottom flange (5) as seen in the direction of the centre axis (K) of the body (1), that the retaining surfaces (7, 6) on the top flange (3) and bottom flange (5) are curved surfaces, and that the retaining surfaces (7, 6) on the top flange (3) and bottom flange (5) are arranged to extend over the edge of the top and bottom flanges as seen in the direction of the centre axis (K) of the body (1 ).

2. A stud as claimed in claim 1, in which the end (4) protruding from the top surface of the stud pin (2) top flange (3) is substantially in the shape of a rectangle, characterised in that the retaining surfaces (7, 6) on the top flange (3) and bottom flange (5) are arranged substantially parallel to the long sides of the end (4) of the rectangular stud pin (2).

3. A studded tire with several studs arranged into its tread, characterised in that at least some of the studs are in accordance with claim 1 or 2.