CA3069192C

CA3069192C - Spike for anchoring in a tread of a pneumatic tyre

Info

Publication number: CA3069192C
Application number: CA3069192A
Authority: CA
Inventors: Jan Schlittenhard; Maik Kotter; Torben SPECHTMEYER
Original assignee: Continental Reifen Deutschland GmbH
Current assignee: Continental Reifen Deutschland GmbH
Priority date: 2017-08-24
Filing date: 2018-05-08
Publication date: 2022-05-03
Anticipated expiration: 2038-05-08
Also published as: CA3069192A1; WO2019037900A1; RU2730762C1; DE102017214868A1; EP3672813B1; EP3672813A1

Abstract

A spike for anchoring in a spike hole of a tread of a pneumatic vehicle tyre, having a spike body composed of rubber, a base part situated within the spike body and including a bottom flange and a pin holder in which a spike pin is anchored. The pin holder includes an end portion projecting beyond the spike body and the tread surface. The end portion and the bottom flange are surrounded by a rubber layer, with the bottom flange and the pin holder having an oval form in plan view, with the pin holder being rotationally offset relative to the bottom flange. The spike body has a diameter substantially corresponding to a centre width of the bottom flange, the base part has a height of 40% to 60% of a spike height, and the ratio between a length and a width of the pin holder is 1.10 to 1.18.

Description

Description Spike for anchoring in a tread of a pneumatic tyre The invention relates to a spike for anchoring in a spike hole of a tread of a pneumatic vehicle tyre, having a spike body composed of rubber, a base part, which is situated at least partially within the spike body and which is composed of a bottom flange and a pin holder, in which pin holder there is anchored a spike pin which projects with an end portion beyond the spike body and, when the spike is inserted in the tread, beyond the tread surface, wherein the end portion is surrounded by a rubber layer, and the bottom flange is encased with a rubber layer, wherein the bottom flange and the pin holder are each parts with an oval or approximately oval form in plan view, wherein the oval of the pin holder is rotationally offset through 900 in relation to the oval of the bottom flange, and wherein, in plan view, the bottom flange has a center width and the pin holder has a length and a width.
The invention furthermore relates to a pneumatic vehicle tyre with spikes.
Spikes are generally held in the spike holes of the tread of pneumatic vehicle tyres by a combination of positive engagement and clamping. Conventional spikes generally comprise a spike body composed of aluminum or steel, in which is held the spike pin, which projects beyond the tread surface and is composed of hard metal.
It is customary to use gritting material on winter roads to increase traffic safety. In recent years, the use of sand has been reduced in favor of grit since sand tends to be ground up by tyres into dust or fine dust, which should be reduced or avoided to protect the health of the population. However, the use of grit leads to increased wear on the conventional spikes present in pneumatic vehicle tyres, especially if the spike body thereof is composed of aluminum.
There has therefore already been a proposal to use spikes with spike bodies made of rubber.
Thus, WO 2017/088995 Al, for example, discloses spikes in which the spike pin and/or the bottom flange is or are integrated at least partially into a rubber jacket or into rubber material. WO 2017/088995 discloses variant embodiments of spikes which correspond to a Date Recue/Date Received 2021-06-29

2 spike of the type stated at the outset. The particular advantages of these embodiments consist in the fundamental material properties of the rubber body. Its low density of about 1 g/cm3 makes rubber particularly light in comparison with aluminum and steel.
Replacing aluminum and steel with rubber as a body material leads to a reduction in the spike weight, which has a particularly positive effect on road wear and the formation of fine dust. Road wear is determined principally by the impact energy of the spike. The flexible material properties of rubber have even more advantages. On the one hand, the flexible body material damps impacts, with the result that smaller forces act on stones in the road surface or on particles of gritting material. Thus, road wear and the formation of fine dust are also .. reduced thereby. Moreover, spike bodies composed of rubber are superior to those composed of aluminum or steel in terms of abrasion behavior since they have completely different wear behavior. If the tyre rolls over stones in the road surface and, in particular, grit from gritting material in the vicinity of a conventional spike, the profile in the tread is deformed to a very great extent and "gives way" to the side. The fixed, rigid spike cannot .. follow this "movement of giving way". As a result, a gap is formed between the spike and the rubber, thus exposing the upper and the lateral surface of the spike body to the abrasive action of the stones. Since stones in the road surface and grit are generally harder than aluminum and even steel, the spike body is more severely abraded, resulting in a reduction in the spike body height and the diameter of the spike body. This leads to the spike hole edges being subject to abrasion with a cutting effect. They erode, as a result of which the gap between the spike and the surrounding rubber matrix is enlarged. This favors the penetration of sand and smaller stones, further accelerating spike body abrosion. As a consequence, the lateral retaining forces on the spike are reduced, leading to a reduction in the winter properties due to severe tilting and, in the worst case, to loss of the spike.
The invention addresses the problem of improving a spike of the type mentioned at the beginning, in particular designing it in such a way that it is optimized with regard to flexible deformation and with regard to its suitability for absorbing impact.
.. According to the invention, the problem addressed is solved by virtue of the fact that the spike body is of circular-cylindrical design and has a diameter which corresponds to the center width of the bottom flange or which deviates from said width by up to 1.0 mm, Date Recue/Date Received 2021-06-29

3 wherein the base part has a height of 40% to 60% of the spike height, and wherein the ratio between the length and the width of the pin holder is 1.10 to 1.18.
The pin holder is therefore of almost circular-cylindrical design and is thus encased to an approximately equal thickness by rubber material of the circular-cylindrical spike body. By virtue of the adaptation of its diameter to the center width of the bottom flange of the base part, the spike body has a large rubber volume, wherein this measure, together with the measure that the height of the base part is no more than 60% of the spike height, ensures that the spike body encases both the pin and also the base part with a rubber layer that is ideal for flexible deformation and for damping shocks. Since gap formation is avoided, the body material made of rubber is abraded at substantially the same rate as that of the surrounding rubber matrix, and the spike hole edges are not subject to abrasion with a cutting effect. In the case of rubber spikes according to the invention, there is no reduction in the spike body diameter or increased length reduction, and therefore the lateral retaining forces are maintained at a high level. These effects lead to maintenance of the winter properties, especially "ice performance", of the spike at a high level.
In a preferred embodiment of the spike, the ratio between the length and the width of the pin holder of the base part is up to 1.16. As a result, the external form of the pin holder advantageously approaches that of a circular cylinder to an even greater extent.
Also preferred is an embodiment in which the spike pin is of elongate design in plan view and is anchored in the pin holder in such a way that its longitudinal extent extends along the longitudinal extent of the pin holder. With the preferred orientation of the bottom flange of .. the spike in the installed state in the circumferential direction of the tread, the spike pin is oriented with its longer extent in the axial direction and is therefore particularly effective on an icy underlying surface.
In another preferred embodiment, the bottom flange has, in plan view, a length of 7.0 mm to 9.0 mm and a center width which is 1.0 mm to 2.0 mm less than the length of said flange.
These dimensions of the bottom flange are particularly favorable for good retaining forces of the spike in the tread.
Date Recue/Date Received 2021-06-29

4 Another preferred embodiment is one in which the length of the pin holder is 4.0 mm to 4.5 mm and the width of the pin holder is 0.4 mm to 0.6 mm less than the length of said pin holder.
As mentioned, the bottom flange can be of oval or approximately oval design.
In the case of an approximately oval embodiment of the bottom flange, said flange has straight and mutually parallel side faces along the longer extent of said flange or straight and mutually tapered side faces along the longer extent of said flange, for example. Both embodiments are advantageous for good anchoring of the bottom flange in the rubber material of the tread.
The rubber layer on the upper end portion of the spike pin and on the bottom flange preferably has a thickness of 0.2 mm to 0.5 mm. A rubber layer of this thickness is easy to produce, especially when using an adhesion promoter.
In another preferred embodiment, the bottom flange has, on the underside thereof, a recess with a depth of 0.3 mm to 0.5 mm, which is filled with rubber material, wherein the underside of the bottom flange is at least largely flat. The rubber cushion formed by the recess acts as a damping element in the presence of vertical forces acting on the spike as the tyre rolls.
The total height of the spike is 6.0 mm to 20.0 mm, in particular 8.0 mm to 12.0 mm, and the height of the base part is 40% to 60% of the spike height.
According to an aspect, a spike for anchoring in a spike hole of a tread of a pneumatic vehicle tyre is provided. The spike has a spike body composed of rubber, a base part situated at least partially within the spike body and which is composed of a bottom flange and a pin holder. A spike pin is anchored and projects from the pin holder, with an end portion of the spike pin projecting beyond the spike body and, when the spike is inserted in the tread, beyond a tread surface. The end portion is surrounded by a first rubber layer, and the bottom flange is encased with a second rubber layer, where the bottom flange and the Date Recue/Date Received 2021-06-29

5 pin holder are each parts with an oval, or approximately oval, form in plan view. The oval of the pin holder is rotationally offset through 900 in relation to the oval of the bottom flange, and wherein the bottom flange, in plan view, has a center width and the pin holder, in plan view, has a length and a width, wherein the spike body is of circular-cylindrical design and has a diameter which corresponds to the center width of the bottom flange or which deviates from the center width by up to 1.0 mm, wherein the base part has a height of 40% to 60% of a spike height, and wherein the ratio between the length and the width of the pin holder of the base part is between 1.10 and 1.18.
The invention furthermore relates to a pneumatic vehicle tyre having a tread with spikes that are embodied in accordance with the invention, wherein the spikes are anchored in the tread in such a way that the bottom flanges of said spikes extend in the circumferential direction.
Further features, advantages and details of the invention will now be described in more detail on the basis of the drawing, which illustrates an exemplary embodiment.
In the drawing, Figure 1 shows a plan view of a spike according to the invention, Figure 2 shows a sectional illustration of the spike along the line II-II of figure 1, and Figure 3 shows a sectional illustration of the spike along the line of figure 1.
The spike 1 shown in the figures comprises a base part 2, a spike pin 3 and a spike body 4.
The base part 2, which, in particular, is composed of aluminum, has a bottom flange 5 and a pin holder 6 formed integrally therewith. The base part 2 and the spike body 4 are of symmetrical design in relation to two mutually perpendicular planes of symmetry Si and S2 which intersect along the central vertical axis of the spike 1. In plan view, the bottom flange 5 has an oval or approximately oval shape with two side faces 5a oriented in the longer extent of the oval and parallel to plane of symmetry Si and two arc-shaped end faces 5b connecting these side faces 5a to one another. The bottom flange 5 therefore has its greatest Date Recue/Date Received 2021-06-29

6 length 1F, which is 7.0 mm to 9.0 mm, along plane of symmetry Si, and its greatest width bF
corresponds to the mutual spacing between the straight side faces 5a and is 1.0 mm to 2.0 mm, in particular up to 1.5 mm, less than its length IF. The spike 1 is preferably positioned in the tread of a pneumatic vehicle tyre in such a way that the side faces 5a of the bottom flange 5 run parallel to the circumferential direction of the tread. In the case of an alternative embodiment (not illustrated), the side faces are slightly tapered relative to one another, with the result that, at its one end, the bottom flange has a width which is greater by up to 1.0 mm than at its other end.
On its underside, the bottom flange 5 is provided with a shallow recess Sc, which has its maximum depth tF of 0.3 mm to 0.6 mm at the center of the bottom flange 5.
Situated centrally on the bottom flange 5 is the pin holder 6, which in plan view is an oval body, in which the spike pin 3 is held centrally. In plan view, the pin holder 6 has its greatest extent along plane of symmetry S2, and therefore its maximum length 1p, which is along plane of symmetry S,, is preferably 4M mm to 4.5 mm, and its maximum width bp along plane of symmetry Si is, in particular, 0.4 mm to 0.6 mm less than its length 1p. The ratio between the length and the width of the pin holder 6 is 1.10 to 1.18, in particular up to 1.16.
In particular, the spike pin 3 is composed of a hard metal and is likewise of elongate design in plan view and, according to a preferred embodiment, is of symmetrical design with respect to the two planes of symmetry Si and Sz. Like the pin holder 6, the spike pin 3 has its greatest extent along plane of symmetry S2. In plan view, the spike pin 3 can be of oval or quadrilateral design or can be designed as some other polygon and one end portion 3a thereof projects beyond the spike body 4 in the direction of the vertical axis. In the embodiment shown, the cross-sectional area of the spike pin 3 becomes continuously smaller in the direction of its end portion anchored in the pin holder 6, starting from its outer surface on the end portion 3a. The pin holder 6 thus forms a socket for the spike pin 3 with a wall thickness d which is in the range of 0.9 mm to 1.2 mm.
The spike body 4 is composed of rubber and surrounds the pin holder 6 of the base part 2 as well as that part of the spike pin 3 which projects beyond the pin holder 6 -apart from the end portion 3a - as a circular-cylindrical body in which these parts are embedded. In the Date Recue/Date Received 2021-06-29

7 preferred and illustrated embodiment, the diameter D of the spike body 4 corresponds to the width bF of the bottom flange 5 and, in the case of a bottom flange with tapering side faces, corresponds to the width in the center of the bottom flange, but it can deviate by up to 1.0 mm from this, in particular being less than this. The end portion 3a of the spike pin 3 projects beyond the spike body 4 by 1.3 mm 0.2 mm and is that portion of the spike pin 3 which projects beyond the tread periphery when the spike 1 is positioned in the tread of a pneumatic vehicle tyre and which comes into contact with the underlying surface or the road as the tyre rolls. The end portion 3a of the spike pin 3 is surrounded on the outside by a thin rubber layer 7 of the rubber material of the spike body 4, wherein the outer surface in the tip region of the spike pin 3 preferably does not have a rubber layer.
The bottom flange 5 of the base part 2 is surrounded or encased by a thin rubber layer 8 of the rubber material of the spike body 4. In this case, the recess Sc on the underside of the bottom flange 5 is filled with rubber material, ensuring that the underside of the spike 1 forms a substantially flat surface. The rubber cushion thereby formed in the recess Sc acts as a damping element in the presence of vertical forces acting on the spike 1 as the tyre rolls.
The rubber layers 7, 8 mentioned, which encase the bottom flange 5 and extend around the end portion of the spike pin 3 on the outside, have a thickness of, in particular, 0.2 mm to 0.5 mm. The spike 1 is therefore sheathed by rubber material over all its outer surfaces which come into contact with the rubber material of the tread within the tread. By means of a conventional adhesion promoter for rubber materials, the spike 1 can thus be connected in a particularly durable manner to the rubber material of the tread.
The large rubber volume of the spike body 4, said volume being optimized in the case of spikes according to the invention, prevents the penetration of particles, such as sand or grit, into the region between the spike body 4 and the tread in a particularly effective manner.
These particles are often to be found on roads or on an underlying surface on which tyres provided with spikes are used. Spikes according to the invention therefore retain their effect over the life of the tyre. In the case of an alternative embodiment, which is not shown separately, the spike body which surrounds the pin holder and the spike pin and which, in Date Recue/Date Received 2021-06-29

8 the embodiment shown, is circular-cylindrical can be provided with a waist, a recess which encircles it. The total height H of the spike 1 can vary from embodiment to embodiment and is 6 mm to 20 mm, in particular 8 mm to 12 mm, particularly preferably 9 mm to 10 mm. The total height hi of the base part 2 is 40% to 60% of the spike height H, wherein the bottom flange 5 has a height he of 1.1 mm to 1.4 mm.
Date Recue/Date Received 2021-06-29

9 List of reference signs 1. ............ Spike 2. ............ Base part 3 ....... Spike pin 3a ............ End portion 4 ............. Spike body 5 ............. Bottom flange 5a ............ Side face 5b ...... End face 5c ............ Recess 6 ............. Pin holder 7, 8 .......... Rubber layer bF ............ Width of the bottom flange bp ...... Width of the pinholder D ............. Diameter of the spike body d ............. Wall thickness H ............. Spike height hi ............ Height of the base part hF ...... Height of the bottom flange IF ............ Length of the bottom flange 1p ............ Length of the pin holder Si, S2 ........ Plane of symmetry t ............. Depth Date Recue/Date Received 2021-06-29

Claims

1. A spike for anchoring in a spike hole of a tread of a pneumatic vehicle tyre, having a spike body (4) composed of rubber, a base part (2) situated at least partially within the spike body (4) and which is composed of a bottom flange (5) and a pin holder (6), in which pin holder there is anchored a spike pin (3) which projects with an end portion (3a) beyond the spike body (4) and, when the spike is inserted in the tread, beyond a tread surface, wherein the end portion (3a) is surrounded by a first rubber layer (7), and the bottom flange (5) is encased with a second rubber layer (8), wherein the bottom flange (5) and the pin holder (6) are each parts with an oval or approximately oval form in plan view, wherein the oval of the pin holder (6) is rotationally offset through 900 in relation to the oval of the bottom flange (5), and wherein the bottom flange (5), in plan view, has a center width (bF) and the pin holder (6), in plan view, has a length (10 and a width (bp), characterized in that the spike body (4) is of circular-cylindrical design and has a diameter (D) which corresponds to the center width (bF) of the bottom flange (5) or which deviates from the center width (bF) by up to 1.0 mm, wherein the base part (2) has a height (hi) of 40% to 60% of a spike height (H), and wherein the ratio between the length (1p) and the width (bp) of the pin holder (6) of the base part (2) is between 1.10 and 1.18.

2. The spike as claimed in claim 1, characterized in that the ratio between the length (1p) and the width (bp) of the pin holder (6) of the base part (2) is between 1.10 and 1.16.

3. The spike as claimed in claim 1 or 2, characterized in that the spike pin (3) is of elongate design in plan view and is anchored in the pin holder (6) in such a way that its longer extent extends along the longitudinal extent of the pin holder (6).

4. The spike as claimed in any one of claims 1 to 3, characterized in that the bottom flange (5) has a length (1F) of 7.0 mm to 9.0 mm in plan view.

5. The spike as claimed in any one of claims 1 to 4, characterized in that the center width (bF) of the bottom flange (5) is 1.0 mm to 2.0 mm less than the length (1F) of said flange.

6. The spike as claimed in any one of claims 1 to 5, characterized in that the length (lp) of the pin holder (6) is 4.0 mm to 4.5 mm.

7. The spike as claimed in any one of claims 1 to 6, characterized in that the width (bp) of the pin holder (6) is 0.4 mm to 0.6 mm less than the length (1p) of said pin holder.

8. The spike as claimed in any one of claims 1 to 7, characterized in that the bottom flange (5) has straight and mutually parallel side faces (5a) along the longer extent of said flange.

9. The spike as claimed in any one of claims 1 to 7, characterized in that the bottom flange (5) has straight and mutually tapered side faces (5a) along the longer extent of said flange.

10. The spike as claimed in any one of claims 1 to 9, characterized in that the rubber layer (7, 8) on the end portion (3a) of the spike pin (3) and on the bottom flange (5) has a thickness of 0.2 mm to 0.5 mm.

11. The spike as claimed in any one of claims 1 to 10, characterized in that the bottom flange (5) has, on the underside thereof, a recess with a depth of 0.3 mm to 0.5 mm, which is filled with rubber material, wherein the underside of the bottom flange (5) is at least largely flat.

12. The spike as claimed in any one of claims 1 to 11, characterized in that the height (H) of the spike is between 6.0 mm and 20.0 mm.

13. The spike as claimed in claim 12, wherein the height (H) of the spike is between 8.0 mm and 12.0 mm.

14. A pneumatic vehicle tyre having a tread with spikes that are embodied in accordance with any one of claims 1 to 13, wherein the spikes are anchored in the tread in such a way that the bottom flanges (5) of said spikes extend in the circumferential direction.