MULTILAYER INNER TUBE

Abstract

A multi-layer inner tube for a vehicle wheel, the multi-layer inner tube including an inner layer that is in contact with a gaseous filling of the inner tube; and an outer layer that differs from the inner layer, wherein the outer layer is in contact with an exterior environment of the inner tube, and wherein the inner layer and the outer layer are made from a thermoplastic polyurethane; and an intermediary layer made from an ethylene vinyl alcohol copolymer arranged between the inner layer and the outer layer.

Claims

1. A multi-layer inner tube for a vehicle wheel, the multi-layer inner tube comprising: an inner layer that is in contact with a gaseous filling of the inner tube; and an outer layer that differs from the inner layer, wherein the outer layer is in contact with an exterior environment of the inner tube, and wherein the inner layer and the outer layer are made from a thermoplastic polyurethane; and an intermediary layer made from an ethylene vinyl alcohol copolymer arranged between the inner layer and the outer layer.

2. The multilayer inner tube according to claim 1, further comprising: an intermediary layer made from a gel and arranged between the inner layer and the outer layer.

3. The multilayer inner tube according to claim 2, wherein the gel hardens in contact with air.

4. The multilayer inner tube according to claim 4, wherein the gel includes Agarose.

5. The multilayer inner tube according to claim 1, further comprising an intermediary layer that is heat resistant up to 220 C. and arranged between the inner layer and the outer layer.

6. The multilayer inner tube according to claim 1, further comprising: an intermediary layer made from thermoplastic polyeurthane.

7. The multilayer inner tube according to claim 1, wherein the outer layer is foamed.

8. A method for producing the multilayer inner tube according to claim 1, the method comprising: cutting a blank with two hose ends from an endless hose shaped multilayer extruded material; closing the blank into a torus shape; and welding the two hose ends together.

9. The method according to claim 8, comprising: applying a protective layer to an inside of a first hose end; thereafter pushing a second hose end beyond a seam over the first hose end; thereafter pressing the two hose ends together flat at the seam between two clamping jaws that are being moved towards each other; and eventually thereafter welding the hose ends together, wherein the protective layer prevents a welding of an inside of the first hose end.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The invention is subsequently described based on embodiments with reference to drawing figures, wherein:

[0019] FIG. 1 illustrates a sectional view of a first inner tube according to the invention;

[0020] FIG. 2 illustrates a sectional view of a second inner tube according to the invention;

[0021] FIG. 3 illustrates a sectional view of a third inner tube according to the invention; and

[0022] FIG. 4 illustrates a sectional view of a fourth inner tube according to the invention;

DETAILED DESCRIPTION OF THE INVENTION

[0023] The first inner tube 1 according to the invention that is illustrated in a sectional view in FIG. 1 includes an inner layer 2 and an outer layer 3 with a thickness 4 of 170 m respectively, wherein both are made from TPU (trade name BASF Elastollan SP 883) and an intermediary layer (5) with a thickness (6) of 10 m made from EVAL (trade name EVAL F101B). The first inner tube (1) provides a very high level of air tightness.

[0024] The second inner tube 7 according to the invention illustrated in FIG. 2 includes an intermediary layer 11 with a thickness 12 of 50 m made from a gel made from a liquid sealant milk (trade name TUNE One Shot) and Agarosis between an inner layer 8 and an outer layer 9 that have a respective thickness 10 of 150 m respectively. In addition the second inner tube 7 corresponds to the first inner tube 1. The second inner tube 7 is characterized by a high level of fail safety.

[0025] The third inner tube 13 illustrated in FIG. 3 in a sectional view includes a first intermediary layer 18 with a thickness 19 of 100 m between an inner layer 14 with a thickness 15 of 100 m and an outer layer 16 with a thickness 17 of 50 m, wherein all layers are made from the TPU recited supra.

[0026] The third inner tube 13 includes a second intermediary layer 20 with a thickness 21 of 10 m made from the EVAL recited supra between the inner layer 14 and the first intermediary layer 18 and a heat resistant additional intermediary layer 22 with a thickness 23 of 100 m made from a polystyrene-ethylene-butylene-copolymer (trade name KRATON A1535H) between the first intermediary layer 18 and the outer layer 16. The third inner tube 13 is characterized by a high level of air tightness and heat resistance.

[0027] The fourth inner tube 24 according to the invention illustrated in a sectional view in FIG. 4, only includes an outer layer 25 with a thickness 26 of 250 m made from a very soft elastic TPU (trade name BASF Elastollan Soft 45A) and an inner layer 27 with a thickness 28 made from the harder TPU recited supra (Elastolann SP883). The inner tube 24 is characterized by a very low roll resistance and a low level of chum induced energy loss and thus very good driving comfort.

[0028] The illustrated inner tubes 1, 7, 13 and 24 according to the invention are initially produced in an endless manner in a hose shape by blow foil extrusion with TPU on a polyester basis together with the fillings between the TPU layers 2, 3, 8, 9, 14, 16, 18 cut to length and welded together in a torus shape. The outer layers 3, 9, 16 and 25 are foamed. The inner tubes 1, 7, 13 and 24 according to the invention are suitable for a 29 bicycle wheel that is not illustrated and includes an outer diameter of 30 mm in a non-pressurized condition.

REFERENCE NUMERALS AND DESIGNATIONS

[0029] 1 inner tube [0030] 2 inner layer [0031] 3 outer layer [0032] 4 thickness [0033] 5 intermediary layer [0034] 6 thickness [0035] 7 inner tube [0036] 8 inner layer [0037] 9 outer layer [0038] 10 thickness [0039] 11 intermediary layer [0040] 12 thickness [0041] 13 inner tube [0042] 14 inner layer [0043] 15 thickness [0044] 16 outer layer [0045] 17 thickness [0046] 18 intermediary layer [0047] 19 thickness [0048] 20 intermediary layer [0049] 21 thickness [0050] 22 intermediary layer [0051] 23 thickness [0052] 24 inner tube [0053] 25 outer layer [0054] 26 thickness [0055] 27 inner layer [0056] 28 thickness