DE2231659A1 - AIR HOSE FOR VEHICLE TIRES - Google Patents

Description

Diving. R. ο & ε τ ζ jr. 558-18.965P (18.966H) 6/28/1972

1 | I ■ * b · η 22, Steinedorfetr. 10,

MICHELIN & CIE (Compagnie Generale des Etablissements Michelin), Clermont-Ferrand (France)

Air hose for vehicle tires

The invention relates to an air tube for vehicle tires, the tube wall thickness of which is essentially is uniform and made of rubber with a Shore hardness of less than 50.

The invention defines the object of designing such an air hose so that it can be used without chafer.

Mounting a pneumatic tire on a flat bed rim is generally done using a flap. A chafer is an annular band of rubber or plastic material that covers the rim base and the tire bead tips and serves to prevent the hose from becoming trapped between the rim base and the tire bead tips. To avoid using a flap, you can do

- (Cme 32i) Lr (8)

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Always train the tire so that it can be used without a tube. But even in this case It may be necessary to use a flap if the tire stops working due to damage is tight and can only be used with a hose.

. The use of a chafer, especially with a very large tire, is a source for Difficulties, especially when fitting the tire. The assembly of the rim, fluff tube and tire requires that the openings for the passage of the valve in the flap and the rim are made to coincide and then insert the valve of the hose; and this when the tire itself is already on the rim lies. Taking into account that the flap and hose can weigh 50 and 100 kilograms, and their dimensions are very precisely matched to that of the rim in order to avoid any wrinkling, one understands that the Winding up can be very difficult.

To simplify such tire fitting, it is Of course, it is desirable to avoid the flap and to design the air tube appropriately. Such a Proposal was made in French patent 1,0121. The solution proposed there is to use the Thickness of the wall of the air hose in those areas to reinforce, which are intended to be in contact with the beads of the tire and the rim base or at least to come to the side zones of the rim base. However, this solution, which is basically satisfactory, has proven itself proven to be difficult to implement in practice. she has

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namely, the following disadvantages;

a) The local reinforcement of the wall thickness prevents an overlap "welding" of the two ends of the raw hose section from which the closed air hose is made; butt "welding" is difficult in perform in a satisfactory manner;

b) the envisaged increase in wall thickness must be considerable in order to permit the omission of the flap; this brings with it a considerable increase in weight and, moreover, one is forced to remove the zone or vulcanize zones of normal wall thickness too much to properly vulcanize the areas of increased wall thickness;

c) the reinforcement of the air hose is reduced its flexibility and the ability to conform perfectly to the internal shape of the tire; this favors the wear and tear on the tube from the tire.

The present invention seeks to avoid these disadvantages and to provide an air hose that can be used without a flap create a minimum of irregularity in its structure as well as a minimum of weight increase having.

The air hose according to the invention, its wall thickness is substantially uniform and which consists of rubber having a Shore hardness of less than 50 is essentially characterized in that it is locally reinforced by two narrow circumferential bands on the

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Tubing are welded and made of rubber with a Shore hardness of more than 50.

The following are preferred or preferred properties:

a) The reinforcement bands each have a width between 5 and 15 $ of the hose circumference. You become like that arranged that each covers the tip or edge of a tire bead, taking into account or related on a number of different dimensions of tires and rims;

b) the thickness of the strips is between half and twice the maximum wall thickness of the hose;

c) the bands and the hose are made of elastomer of the same type, preferably of butyl rubber;

d) the tapes are placed on the hose after the ends of the raw hose section have been joined and before vulcanization of the whole placed, which takes place in a form, so that any protrusion to the outside is avoided will;

e) the Shore hardness of the rubber from which the reinforcement tapes are made is between 50 and 65

In order to obtain an even harder rubber than the one used for the manufacture of the raw hose more soot or carbon black and less plasticizer are used. The elastomer used has

a preferably larger percentage of unsaturated Bonds, and a large amount of sulfur and vulcanization accelerators are used.

As one can understand, the surface reinforcement brings of the tube in the zone that comes into contact with the tire bead tips, an effective protection. the Reinforcement acts like a grown thickening, which protects the skin from friction that leads to its destruction can contribute. In the case of the invention, the effectiveness is better as the stiffened zones do not protrude or protrude and they are not particularly exposed themselves.

The invention will be explained using an example which will now be described and illustrated in the drawing is. Fig. 1 shows in radial section an air hose according to the invention and Figo 2 shows in a larger Scale a reinforced zone of the hose according to FIG. 1.

In the drawing one can see an air tube 1, the zone 2 of which comes into contact with the crown of the tire, while the zone 3 rests against the bottom of the rim. This air hose consists in the usual way of a simple rubber hose h of essentially uniform wall thickness, which is a little larger in zone 3 than in zone 3, for example 3 8 min in zone 3 and 3.2 mm in zone 2 This difference in wall thickness is provided in order to facilitate the bending of the raw tube when it exits an extruder, in which one can determine the extrusion speed in the zone

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the larger diameter increases.

According to the invention, the hose h is reinforced by two bands 5 and 6, the maximum thickness of which is 3.5 mm and each of which extends over 7 $ of the circumference of the hose k in width. The external connection of the hose k to the bands 5 and 6 takes place without discontinuity.

- While the hose k consists of a soft mixture, the bands 5 and 6 are made of a hard mixture. What follows are the mixing instructions that are suitable for hose 4 (formula I below) and tapes 5 and 6 (formula II below)?

II

Parts by weight

Butyl type Esso 218 100 Butyl type Esso 325 - Stearic acid 1 zinc oxide 5 Black SRF 50 Black FEF 10 Black HAF - Plasticizing paraffin oil 22nd sulfur 1.5 Tetramethylthiuram disulfide 1 Mercaptobenzothiazole disulfide 0.5

100 1

60 10

0.5

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Vulcanization: I - II

Temperature Duration (minutes) Shore hardness

As a variant, two more. Formulas for suitable mixtures:

I II

170 ° C. 170 ° G 20th 20th 45 55

Parts by weight

Elastomer: ethylene propylene terpolymer (Nordel 132O) 25

Butyl type Esso 218 65

Butyl chlorination type Esso HT IO66 Black SRF zinc oxide
Paraffin oil phenolic resin vulcanisant (SP IO55)

Vulcanization: Temperature Duration (minutes) Shore hardness

The weight gain due to the reinforcement bands according to of the invention is about 13 #.

10 10 70 85 5 20th 15th 5 5 10 170 ° C 170 ° c 30th 30th 45 55

2 Oil-32

Claims (6)

Claims V1. Air hose for vehicle tires with an essentially uniform wall thickness and consisting of rubber with a Shore hardness of less than 50, characterized in that the hose (4) locally reinforced by two narrow circumferential bands (5, 6) which are welded to the hose and made of rubber with a Shore hardness of over 50, 2. Hose according to claim 1, characterized in that the reinforcing strips (5 »6) have a width between 5 and 15 $ of the hose circumference. 3 «hose according to claim 1 or 2, characterized in that the reinforcing strips (5» 6) have a thickness between half and twice the maximum thickness of the hose (4). 4. Hose according to claim 1 _t characterized in that the reinforcing straps (5 '6) of the same kind consist wholly or partly of an elastomer "as the elastomer of the hose (4), for example of butyl rubber. 5. Hose according to claim 1, characterized in that the reinforcing strips (5 # 6) on the curved and welded hose (4) are applied prior to the vulcanization of the whole, which takes place in a form such that that the reinforcements (bands 5t 6) have no 209882/0803 grooves or elevations over the outer surface of the hose, form. 6. Hose according to claim 1 _f, characterized in that the Shore hardness of the rubber of the reinforcing strips (5 »6) is between 50 and 65. Blank page