Device and method for invaginating wheel tubes

Abstract

A device for invaginating wheel tubes is proposed, comprising or consisting of: (i) an invaginating guide (Z), open at the two ends, for receiving a wheel tube to be invaginated, (ii) a first and a second pushing piston (K1, K2), and (iii) a first and a second guide (F1, F2) for said pushing pistons, wherein the pushing pistons (K1, K2) define, in their guides (F1, F2), a plane with the invaginating guide and are arranged such that they can move into the invaginating guide from both sides when moving out of the guides. An associated invaginating method is likewise claimed.

Description

Device and method for inverting wheel tubes FIELD OF THE INVENTION

[0001] The present invention is in the field of means of transport and relates to a device and a method for folding in wheel tubes, in particular wheel tubes for bicycles. TECHNOLOGICAL BACKGROUND

[0002] A bicycle inner tube is a container filled with compressed air that seals the tire (the rim) from the inside to prevent pressure loss if the rim isn't suitable for tubeless tires. It's part of bicycle tires and is made of butyl rubber, formerly also rubber.

[0003] Bicycle inner tubes have a long history: the first patent for an air-filled rubber tire was filed by Dunlop in 1888, followed a year later by Michelin with the replaceable inner tube for bicycles, and the vulcanization of rubber had already been invented by Goodyear in 1839. Since the time of these pioneers of tire development, time has not stood still, as the extensive state of the art technology demonstrates.

[0004] Among the most important developments in recent years are bicycle tubes that are not self-contained, but have two ends, usually sealed with caps. These new types of bicycle tubes are also inserted into the tire, expanding during inflation and eventually butting up against the caps to fill the tire. STATE OF THE ART EP 2704909 B1 (GAADI) relates to a tube for mounting on a wheel, a rim or a guide, which is circular, oval, ellipsoidal or otherwise rounded and is not continuous but has at least two ends. From EP 2693086 B1 (GAADI) a wheel tube for complete covering of a rim is known, which is not closed in itself, but has two ends, which is essentially characterized by the fact that the two end caps and / or the Hoses have a non-constant wall thickness, so that they deviate from the circular shape in relation to their outer cross-section when inflated. OBJECT OF THE INVENTION

[0005] The disadvantage, however, is that these bicycle tubes, which have two closed ends, are naturally very long and, due to their material composition, cannot be easily rolled up or bent. This requires a lot of material for packaging, and the packaged bicycle tubes are also very unwieldy.

[0006] Therefore, the objective of the present invention was to present said bicycle tubes in such a way that they take up less space. Another objective was to provide a device that would enable these new forms of presentation to be realized. DESCRIPTION OF THE INVENTION

[0007] A first subject of the invention relates to a device for inverting wheel tubes comprising or consisting of: (i) a sleeve guide (Z) open at both ends for receiving a wheel tube to be folded in, (ii) a first and a second inverting piston (K1, K2) and (iii) a first and a second guide (F1, F2) for said inverting pistons, wherein the inverting pistons (K1, K2) in their guides (F1, F2) span a plane with the inverting guide and are arranged in such a way that they can move into the inverting guide from both sides when moving out of the guides.

[0008] Surprisingly, it was discovered that a solution that fulfills the described task consists in folding the inner tubes from both sides, thus reducing their length by more than half. This solution can be achieved using the device described above. The tube, sealed on both sides, is inserted into the folding guide and folded in on both sides by retracting the folding pistons. Once the folding pistons are extended again, the folded tube can be removed from the folding guide and replaced with the next blank. The folded inner tubes require significantly less packaging material and are also considerably more manageable. Inversion device

[0009] The central part of the inversion device consists of the inversion guide (Z), into which the wheel tube to be inverted is inserted. In addition, there are two inversion pistons (K1, K2), which invert the wheel tube (R) from both sides, as well as their guides (F1, F2), which are also typically cylinders. The inversion pistons can be extended and retracted mechanically, but preferably by a hydraulic device.

[0010] Typically, the inversion guide (Z) represents an inversion cylinder. However, the guide can also have a square or any other cross-section. Bars arranged around one another can also represent an inversion guide.

[0011] It is advisable if the insertion guide (Z) and the insertion pistons (K1, K2) have at least approximately the same cross-section so that the insertion pistons can be easily retracted into the cylinder. There is preferably a play of a few millimeters here to avoid any friction. The insertion guide (Z) is preferably long, which is at least equal to the length of the wheel tube and is typically between about 50 and about 100 cm, preferably between about 75 and about 90 cm. The cross-section should also essentially correspond to the cross-section of the wheel tube and is typically between about 5 and about 15 cm and preferably between about 8 and about 10 cm. The insertion guide (Z) usually has a hole (B) on its top side. This hole is used to accommodate and push the valve of the wheel tube through.Since the valve is usually located approximately midway along the hose, it makes sense to also drill the hole approximately midway along the guide. The inverting guide (Z) as well as the inverting pistons (K1, K2) and their guides (F1, F2) can be made of stainless steel, aluminum, or plastic. Invagination procedure

[0012] A particular challenge was to develop a method using the device described above with which the invagination can be carried out mechanically without the invaginating pistons pulling out the invaginated part of the tube again in whole or in part when they are extended.

[0013] A further subject of the invention therefore relates to a method for inverting wheel tubes, comprising or consisting of the following steps: (a) providing a device according to at least one of claims 1 to 6; (b) providing a wheel tube (R) closed at both ends and provided with a valve (V); (c) Inserting the hose (R) into the insertion guide (Z), whereby the valve (V) is guided outwards through the bore (B); (d) filling the wheel tube (R) with such a quantity of compressed air that it presses against the inside of the insertion guide (Z); (e) connecting the valve (V) to a pressure relief valve (Ü); (f) Moving the two inverting pistons (K1, K2) out of their guides (F1, F2) into the two open ends of the inverting guide until the wheel tube (R) is inverted on both sides; (g) Bleeding the wheel tube (R); (h) extending the two inverting pistons (K1, K2) from the inverting guide Z into their guides (F1, F2); and (j) Removal of the wheel tube (R) which is folded in on both sides.

[0014] The procedure is explained schematically below using Figure 1 - steps A to D. The reference symbols have the following meaning: Z = Insertion guide K1, K2 = inverting piston F1, F2 = guides of the inverting pistons R = wheel tube V = valve Ü = pressure relief valve B = Hole for the valve Step A

[0015] This step shows the preparation for the inversion process. The wheel tube (R) to be inverted is located along its entire length in the inversion guide (Z). The central valve (V) of the tube protrudes through the hole (B). The tube is filled with enough compressed air via the valve (V) to press it against the inside of the cylinder, which serves as the tube guide. This prevents slipping during the inversion process. The two inversion pistons (K1, K2) are still retracted in their guides (F1, F2). Step B

[0016] This step shows the first phase of the inversion process. Both inversion pistons move into the inversion guide and invert the hose from both sides. The air cushion in the hose prevents the frictional resistance of the cylinder's inner surface from making the inversion process difficult or even becoming so great that it damages the hose. As the inversion pistons move in, a a reduction in volume and an increase in pressure. The excess pressure is released via the valve (V) and the connected pressure relief valve (Ü). Step C

[0017] This step shows the second phase of the inversion process. It's important that the inverted tube is vented first. If there were still air in the tube, the inversion pistons would pull the inverted tube back out, as the inner tube section is pressed against the inversion piston by the air pressure. This way, however, the two inversion pistons can be easily extended from the inversion cylinder. Step D

[0018] This step marks the end of the invagination process. The tube is invaginated from both sides, and the invaginating pistons are back in their original positions. The tube can now be removed and replaced with a new blank.

Claims

PATENT CLAIMS 1. Device for inverting wheel tubes comprising or consisting of: (i) a sleeve guide (Z) open at both ends for receiving a wheel tube to be folded in, (ii) a first and a second everting piston (K1, K2) and (iii) a first and a second guide (F1, F2) for said inverting pistons, wherein the inverting pistons (K1, K2) in their guides (F1, F2) span a plane with the inverting guide and are arranged in such a way that they can move into the inverting guide from both sides when moving out of the guides.

2. Device according to claim 1, characterized in that the cross section of the inversion guide corresponds to the cross section of the two inversion pistons (K1, K2).

3. Device according to claims 1 and / or 2, characterized in that the insertion guide (Z) has a cross-section of approximately 5 to approximately 15 cm.

4. Device according to at least one of claims 1 to 3, characterized in that the insertion guide (Z) has a length of approximately 30 to approximately 60 cm.

5. Device according to at least one of claims 1 to 4, characterized in that the insertion guide (Z) has a bore (B) on its upper side.

6. Device according to at least one of claims 1 to 5, characterized in that the inversion guide (Z) as well as the inversion pistons (K1, K2) and their guides (F1, F2) are made independently of one another from stainless steel, aluminum or plastic.

7. A method for inverting wheel tubes, comprising or consisting of the following steps: (a) providing a device according to at least one of claims 1 to 6; (b) providing a wheel tube (R) closed at both ends and provided with a valve (V); (c) Inserting the hose (R) into the insertion guide (Z), whereby the valve (V) is guided outwards through the bore (B); (d) filling the wheel tube (R) with such a quantity of compressed air that it presses against the inside of the insertion guide (Z); (e) connecting the valve (V) to a pressure relief valve (Ü); (f) Moving the two inverting pistons (K1, K2) out of their guides (F1, F2) into the two open ends of the inverting guide until the wheel tube (R) is inverted on both sides; (g) Bleeding the wheel tube (R); (h) extending the two inverting pistons (K1, K2) from the inverting guide Z into their guides (F1, F2); and (j) Removal of the wheel tube (R) which is folded in on both sides.

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