WO1995029821A1

WO1995029821A1 - Connection unit to connect the valves of the two pneumatic tires in a twin tire set and compensating cap

Info

Publication number: WO1995029821A1
Application number: PCT/EP1995/001595
Authority: WO
Inventors: Katrin Dittrich; Tobias Glauch
Original assignee: Twin-Tec Kraftfahrzeugzubehörentwicklungs- Und Ve Rtriebs Gmbh
Priority date: 1994-04-28
Filing date: 1995-04-27
Publication date: 1995-11-09
Also published as: DE9407057U1; AU2522295A; AT406135B; DE19580410D2; ATA906695A

Abstract

A connection unit (1) to connect the valves of the two pneumatic tires in a twin tire set, which unit (1) has a housing (3) with a chamber (5); an air inlet (7) communicating with this chamber (5); a first airflow line (9) that communicates with the chamber (5) and can be attached, by means of an adapter (17), to the valve housing of one of the twin pneumatic tires, and a second airflow line (11) that communicates with the chamber (5) and can be attached, by means of a second adapter (17), to the valve housing of the other twin pneumatic tire, is characterized by a mechanically, hydraulically or electrically actuated contact (13) mounted in or on the housing (3), a mechanically or hydraulically or electrically or similarly acting remote control element (15) mounted entirely or partially in or on each of the airflow lines (9, 11) and a valve-actuating element (19) situated in each of the two adapters (17), where by actuating the contact (13) the valve-actuating elements (19) can be engaged, via the remote control elements (15), with the valves of the two pneumatic tires for as long as the contact (13) remains active, opening said valves and thus establishing a connection between the pneumatic tires and the air inlet (7) for as long as the contact (13) remains active.

Description

Link for connecting the respective valves of the two pneumatic tires of a twin pneumatic tire and compensation cap

The present invention relates to a connecting member for connecting the respective valves of the two pneumatic tires of a twin pneumatic tire, with - a housing having a chamber, an air inlet connected to this chamber, a first one connected to the chamber and by means of an adapter the valve housing of one of the pneumatic tires of a twin pneumatic tire, an air flow path and a second air flow path which is connected to the chamber and can be connected to the valve housing of the other pneumatic tire of the twin pneumatic tire by means of a second adapter, and a compensating cap for use with a connecting member.

Twin pneumatic tires are used on trucks, buses and trailers in order to increase the number of pneumatic tires that can be mounted on an axle and thus the permissible load capacity. It is known that the use of these twin pneumatic tires presents certain problems, the main problem of which is that if the two pneumatic tires are inflated unevenly, one of the pneumatic tires has to carry more load than the other. The pressure difference is due to the fact that the same tire pressure is rarely present in both, which leads to increased tire wear on a pneumatic tire. This disadvantage is particularly noticeable on severely inflated roads - for example due to ruts - on which one of the pneumatic tires of the twin pneumatic tire is loaded more than the other anyway, which is too excessive and uneven tire wear and excessive heating and fatigue. Among other things, this also reduces safety for the driver of the motor vehicle, passengers and other road users.

The problem of the unequal pressure in the pneumatic tires is exacerbated by the fact that the air connection of the inner pneumatic tire mounted to the center of the axle is difficult to access for filling. This leads to the fact that in practice the correct air pressure of the inner tire is often not given the necessary care and the tire runs with a tire pressure that is too low, even though it has to bear the main load, especially on very high roads.

So-called valve extensions are commercially available to overcome the problems. A first type of these valve extensions consists of a pressure-resistant pressure hose made of coated textile or rubber material, which has an adapter with an internally threaded connection at one end. The adapter is screwed onto the external thread of the valve housing of the valve of the inner pneumatic tire of a twin pneumatic tire. By screwing on the adapter, the valve of the inner pneumatic tire is permanently opened mechanically by means of a valve actuating pin fixedly attached in the adapters and is thus deactivated. At the other end of the pressure hose, this first type of commercially available valve extensions therefore has its own separate valve, which serves as a filling and shut-off valve for the inner pneumatic tire. This first type of commercially available valve extension thus represents in fact an extension of the air volume of the inner pneumatic tire of a twin pneumatic tire. During assembly, the pressure hose is guided through mutually opposite openings in the two rims of a twin wheel. As described, the adapter is screwed onto the valve of the inner pneumatic tire, while the housing of the filling and shut-off valve is mounted at the other end of the pressure hose by means of a commercially available screw clamp fastening on the rim of the outer pneumatic tire, so that both valves for the inner and outer pneumatic tires are now easily accessible from the outside of the vehicle.

When checking the air pressure, however, the driver must check the air pressure of both tires separately and correct them if necessary. This leads to an increased expenditure of time, since two air pressure test and filling processes are necessary. Furthermore, it is by no means ensured that both air tires have the same air pressure after the air pressure check. Even if the driver carries out the air pressure control process extremely conscientiously, which experience has shown is not always the case, measurement and reading errors can result in a different air pressure in the two tires.

Furthermore, the risk of damage to the pressure hose is considerable, since it unhindered damaging external influences, e.g. is exposed to soaring stones or the like while driving. Experience has also shown that the screw clamp attachment mentioned on the rim of the outer tire can become detached, as a result of which the pressure hose then rubs against the rim while driving and is subject to severe mechanical wear and tear, even until it is destroyed. In addition, the pressure hose is also chemical attacks, e.g. exposed to road salt or oil and fuel residues. Over time, this leads to material fatigue and

Changes in the pressure hose and the filling and shut-off valve.

Since the first type of commercially available valve extension is de facto a permanent extension of the air volume of the inner pneumatic tire of the twin pneumatic tire, Damage to the pressure hose or its filling and shut-off valve inevitably leads to a complete loss of pressure in the inner pneumatic tire and thus to a flat tire. In addition to the economic disadvantages, a flat tire while driving is also associated with a high risk for drivers, passengers and other road users. In order to prevent this, the first type of commercially available valve extension must therefore be completely replaced with every tire change, which leads to higher costs.

A second type of commercially available valve extension consists of a hollow plastic or brass rod, which has an inner rod which can be slid but displaceably mounted on the inside and an annular air passage duct surrounding the inner rod. One end of the plastic or brass rod is designed to be screwed onto the valve housing of the valve of the inner pneumatic tire of a twin pneumatic tire. Commercially available air pressure test and filling devices can be connected to the other end. During use, the plastic or brass rod is guided through mutually opposite openings in the rims of the twin wheel. When the rod-shaped valve extension is screwed on, the valve of the inner pneumatic tire is not opened permanently and is rendered inoperative. Rather, the valve of the inner pneumatic tire only opens when an air pressure test and filling device is connected to the other end of the plastic or brass rod. The valve actuating pin of the air pressure test and filling device comes into engagement with the slidingly mounted inner rod and presses it axially at the other end into engagement with the valve pin of the pneumatic tire valve, whereby this is opened. This second type of commercially available valve extension is therefore only subjected to the air pressure of the inner pneumatic tire during the air pressure control and filling process. After detaching the air pressure test and filling device, the same inner rod, which is supported in a tendency, is pressed back into a rest position by the spring force of the valve of the inner pneumatic tire and possibly additionally by a compression spring arranged in the rod-shaped valve extension, as a result of which the pneumatic tire valve of the inner pneumatic tire can close again.

Damage to the rod-shaped valve extension therefore generally no longer results in the complete loss of pressure in the inner pneumatic tire. This increases safety while driving.

However, it is still necessary to fill the outer and inner pneumatic tires of a twin pneumatic tire separately, which leads to the disadvantages described above in terms of time and the risk of different air pressures in the two pneumatic tires.

From DE-OS 2937295 a valve construction for connecting the two pneumatic tires of the twin pneumatic tire is known, which permanently equalizes the pressure in the tires of a twin pneumatic tire, ie also while driving, but isolates the tires from one another as soon as the air pressure in one of the tires drops to a predetermined minimum. The proposed valve construction has a common filling valve which, when the air pressure of the two tires is correct, also serves as a common shut-off valve. In the proposed valve construction, the valves of the two pneumatic tires themselves are opened permanently by means of a screwed-on adapter provided with an opening bolt and are thus deactivated. The two adapters are each connected to a common main chamber by means of a pressure hose, which is automatically shut off separately when a predetermined minimum air pressure is undershot, which is closed by the common filling and, if appropriate, shut-off valve. The proposed design ensures that the air pressure in both Tires of a twin pneumatic tire are generally identical. Furthermore, it is achieved that the filling is easier and faster, since the driver can now supply both tires with the correct air pressure with a single air pressure test and filling process. As a result, experience has shown that the driver will also be more often willing to check the air pressure.

However, the proposed construction also has the problem of the occurrence of a puncture when the pressure hose is damaged - e.g. due to the abrasion of the one pressure hose led through the rim openings - since the valves of both pneumatic tires, as described, are permanently opened by screwing on the adapter and are thus rendered inoperative. Furthermore, the proposed construction is extremely complex and complicated to manufacture. It has therefore not been able to establish itself commercially on the market.

The object of the present invention is to propose a connecting member for connecting the two valves of a twin pneumatic tire which on the one hand permits simultaneous air pressure control and filling of the two pneumatic tires of a twin tire via a common filling valve, but on the other hand if the connecting member is damaged nevertheless does not lead to air loss of one or both pneumatic tires. Also, if one of the two pneumatic tires is damaged, the other pneumatic tire should not suffer any pressure loss. Furthermore, the connecting link should be simple and reliable and economical to manufacture.

The object is achieved in that the

Connecting member - a mechanically, hydraulically or electrically actuated contact arranged in or on the housing, one in whole or in part in or on the air flows. Remotely arranged, mechanically or hydraulically or electrically or similarly acting remote control element and each have a valve actuating element arranged in the two adapters, with the actuation of the contact actuating the valve actuating elements by means of the remote control elements during the period of actuation of the contact to open the valves of the two pneumatic tires can be brought into engagement with them, whereby a connection between the two pneumatic tires and the air inlet can be established during the period of actuation of the contact.

The proposed connecting member thus has a common air inlet for both pneumatic tires of a twin tire, so that the simultaneous air pressure control and filling of both pneumatic tires is ensured with the same air pressure. The valves of the two pneumatic tires are not permanently opened and deactivated by the adapters connected to their valve housings. Rather, the valves of the two pneumatic tires are only opened when a contact is made in or on the housing of the connecting member. This contact is actuated during the control and filling process when the air inlet of the connecting element is connected to a compressed air source. By means of telecontrol elements, the valves of the two air tires are opened during the actuation of the contact, so that a common connection exists between the air volumes of the two pneumatic tires and the air inlet during the time the contact is actuated.

After the actuation of the contact has ended, this connection is canceled again by the valves of the two pneumatic tires closing again. The tire valves are opened by means of the contact and the remote control elements only during the air pressure test and inflation, so that the air pressure of both tires can be checked, increased and decreased together. The valves of the two pneumatic tires, together with the air inlet and the contact in or on the housing of the connecting member, serve as a common filling valve.

By connecting the two adapters of the connecting member, the tire valves are not deactivated, they only remain open for the duration of the air pressure test and inflation process. Each of the two tire valves therefore continues to serve as a shut-off valve for its own tire. If the connecting link or one tire is damaged, this has no influence whatsoever on the air pressure in the other tire. The second tire remains in any case with the correct air pressure. The novel connecting link thus increases active safety, since the risk of a puncture is considerably reduced. For this reason, it is no longer absolutely necessary to completely renew the new connecting link each time the tire is changed.

It is preferred that the telecontrol elements are pressure cables, which are advantageously arranged coaxially or in parallel with the air flow paths. The connection of the contact in the housing with the valve actuation elements in the two adapters is also possible in a variety of other ways, e.g. B. by means of hydraulic or electrical lines and corresponding actuating elements in the adapters. The connection by means of pressure cables is preferred, however, since pressure cables are particularly simple and robust in view of the high mechanical stress and do not require any external energy.

To protect the air flow paths, according to a further development of the invention, these are surrounded by a protective cover, the remote control elements preferably also being arranged in the protective cover. Housing in a protective cover increases given the strong mechanical and chemical stress the life of the connecting member.

According to another development of the invention, the contact is designed as a movable pin, preferably a pin that can be moved along its axis. The pin is advantageously held in a first position by the pressure of an elastic element, in particular by springs, and can be moved into a second position by a mechanical force in order to actuate the contact. The structure and mode of operation of such a contact pin correspond to the valve pins of commercially available pneumatic tire valves.

It is further preferred that the housing has a connector, the shape and size of which is suitable for connecting commercially available air pressure test and filling devices, and that the air inlet is arranged in or on this connector. In a further development of the invention, the pin can be moved by the valve actuating element of a commercially available air pressure test and filling device, as a result of which a compressive force can be exerted on the pressure cables, which force transmits them to the valve actuating elements in the adapters for opening the pneumatic tire valves. Commercially available air pressure testing and filling devices for regulating the air pressure in the twin pneumatic tire can thus be connected to the proposed connecting element.

The valve actuation elements arranged in the adapters are preferably designed as valve actuation pins which can be opened by mechanical engagement with the valve pins of commercially available pneumatic tire valves. For this purpose, the adapters preferably have an internal thread connection, so that they can be attached to the valve housings of commercially available pneumatic tire valves. The proposed link can thus be easily attached and used on commercially available twin pneumatic tires. In order to withstand the high mechanical and chemical stresses in operation, the housing and / or the adapters and / or the protective covers are preferably made of oil, grease and acid resistant materials, in particular of plastic, metal or rubber material.

It is particularly preferred that a display device is arranged in or on at least one of the two air flow paths and / or in or on the chamber, which comprises a display element which is directed to the display by an air flow directed from one of the two air tires into the other the same is either movable or changeable in another way. The use of such a display device makes it easy for the user of the invention to check whether there is complete pressure compensation between the air volumes in the two tires of the twin wheel. If the display element of the display device moves during the period of actuation of the contact or is changed in some other way without compressed air being fed into or out of the air inlet, one of the two pneumatic tires lies in the other directed air flow, which indicates that there is a difference in air pressure between the two pneumatic tires.

In a further development of the invention, the display element is arranged in the chamber of the housing, and the housing, in particular a housing cap, consists at least partially of a transparent material, in particular transparent plastic. Such a design of the connecting member enables a simple and convenient optical reading of the display device by the user, since the display element is accommodated in the housing which is easily accessible to him and he can read the display element simply and conveniently due to the at least partially transparent housing material can. Expensive additional devices, such as signal transmission devices, are then not necessary. The display device preferably comprises an impeller as a display element, which is preferably rotatably arranged coaxially with the movable pin. This is a particularly elegant, space-saving and easy to manufacture design of the display device. In addition, however, a whole series of different designs of the display device are also conceivable, for example a ball which is visible from the outside and is arranged in or on one of the two air flow paths and is supported on both sides by a spiral spring and, in the presence of an air flow, moves its position ¬ changes.

For easier visual recognition of the movement or change of the display element, it is preferred to mark the display element conspicuously and / or to arrange it spatially next to a corresponding marking or scale. For example, the impeller can have blades which are strikingly colored red on one side and green on the other side. By attaching a helical marking to the impeller, the user can even be signaled in which of the two pneumatic tires the flow is directed, i.e. which of the two pneumatic tires has the lower air pressure. This is possible in another way, for example also by using two impellers with a respectively assigned one-way valve acting in the opposite direction, so that depending on the direction of flow only one of the two impellers rotates.

The invention further comprises a compensation cap for advantageous use with the connecting link according to the invention. The compensation cap can be attached to the housing at least substantially in an air-tight manner and comprises an actuatable contact actuating element which is designed to actuate the contact against an elastic bias.

The connecting link according to the invention is self-evident can also be used without the compensation cap according to the invention and completely achieves the stated object; the compensation cap is, however, a useful addition to the connecting link. The compensating cap enables the user of the connecting link to carry out a pressure compensation between the two tires of a twin wheel even without using an air pressure test or filling device.

For this purpose, he actuates the contact actuating element of the compensating cap attached to the housing of the connecting member, which in turn actuates the contact of the connecting member against an elastic pretension and thus connects the air volumes of the two tires of the twin wheel to one another. In this way, air can pass through the two air flow paths from one of the two pneumatic tires, which for some reason - e.g. due to a low leakage - has a higher air pressure than the other pneumatic tire, overflow in the other pneumatic tire with the lower air pressure and bring about a pressure compensation. The at least essentially airtight attachment of the compensation cap to the housing of the connecting member prevents air under pressure from escaping from the two pneumatic tires to the outside. After the actuation of the contact actuation element has ended, the elastic pretension ensures that the contact is no longer actuated and the connection between the two pneumatic tires is closed again.

The described measure for pressure compensation between the two pneumatic tires of a twin pneumatic tire can be carried out anytime and anywhere using the compensation cap according to the invention without the need for a further device such as an air pressure test and filling device.

The compensation cap can be used particularly advantageously if the connecting member has a display device with a display element for displaying one of the two Tires in the other directional air flow. In this case, the user of the invention can not only bring about a pressure equalization between the two pneumatic tires, but he can control it simultaneously by means of the display device and, as soon as he determines from the display device that a complete pressure equalization exists or has taken place Stop the actuation of the contact by means of the contact actuating element.

The compensation cap preferably comprises an attachment section which is designed for attachment to the connector of the housing. This can be done, for example, in that the attachment section has an internal thread for screwing onto the external thread of the connector. In this case, the compensating cap can be permanently screwed onto the external thread of the connector in the manner of a commercially available valve protection cap. Because of the at least essentially airtight attachment to the housing, it not only enables the described pressure equalization between the two tires of a twin wheel, but also offers effective protection against contamination of the connecting member by ingress of dust or the like into the air inlet.

In a further development of the invention, the compensating cap further comprises an actuation section which is at least essentially airtightly connected to the attachment section and at least predominantly consists of an elastic material and / or is elastically connected to the attachment section. The elastic material of the actuating section or the elastic connection to the attachment section then, individually or together with other elastic elements of the connecting member, provides the elastic prestress for the compensating cap. As a result, together with the arrangement and design of an attachment section for attachment to the connection piece of the housing, a compact, simple and easy to manufacture construction of the compensation cap allows.

The contact actuating element is preferably designed as an actuating pin connected to the actuating section, which actuates the contact by exerting a mechanical compressive force on the actuating section, in particular engages with the movable pin. The actuating pin on the compensating cap thus fulfills a similar function to the valve actuating pins of conventional air pressure testing and filling devices and is therefore preferably of the same shape and size as these.

The invention is explained in more detail below with the aid of two exemplary embodiments. The drawings show:

1 shows a first exemplary embodiment of the novel connecting member in partial longitudinal section;

FIG. 2 is a detailed longitudinal sectional view of the housing and the surrounding area of the connecting link from FIG. 1;

3 shows a detailed longitudinal sectional view of one of the adapters and the surrounding area of the connecting link of FIG. 1;

4 shows the housing and the surrounding area of a second exemplary embodiment of the novel connecting member in a purely schematic longitudinal sectional representation;

5 shows a detailed longitudinal sectional view of the housing and (only partially in cross section) of the surrounding area of a third exemplary embodiment of the novel connecting member; 6 shows a detailed longitudinal sectional view of the housing and (only partially in cross section) of the surrounding area of a fourth exemplary embodiment of the novel connecting member;

7 shows a cross-sectional illustration of a further exemplary embodiment of a display device for a connecting member;

8 shows a cross-sectional illustration of an exemplary embodiment of a compensation cap according to the invention.

Fig. 1 shows a first embodiment of the novel connector 1, wherein the housing 3 and the two adapters 17 completely and the two air flow paths 9, 11 are partially shown in longitudinal section. The essentially cylindrical housing 3 is composed of two components, a housing cap 30 and a base part 31 (cf. FIG. 2), the housing cap 30 with hooks 32, which are arranged on parts of its circumference, correspondingly ¬ appropriate openings 33 of the bottom part 31 engages and is sealingly connected to it, whereby a chamber 5 is formed in the interior of the housing 3. By means of locking lugs 41 on the inside of the housing cap 31, which engage in assigned recesses 42 on the outside of the base part 31, and by means of an O-ring 40, the connection of the two components is further strengthened or against the penetration of foreign bodies and -sealed liquids.

The housing 3 has a connector 24, the shape and size of which is designed for the connection of commercially available air pressure test and filling devices. The connecting piece 24 has essentially the shape of an elongated cylinder which has an external thread 24a at its free end - for example for screwing on a commercially available valve protection cap. On the outside, the connecting piece 24 furthermore has a circumferential groove 34 into which mechanical fastenings, such as those used for mounting commercially available valve extensions, can intervene. With their help, the housing 3 can be mounted in a known manner on the rim of the outer tire of a twin pneumatic tire.

In the interior of the connecting piece 24 there is an air inlet duct 7, in which a pin 14 is arranged centrally. The pin 14 is firmly anchored in a plastic body 35 which is displaceably arranged in the chamber 5. While the housing chamber 30, base part 31 and pin 14 have a round cross section, the plastic body 35 has an oval shape in cross section. 1 and 2, the plastic body 35 is shown cut along its long axis. While the outside of the base part 31 lies completely against the inside of the housing cap 30 over its entire circumference, the outside of the plastic body 35 only comes into contact with the inside in a region around the lines of intersection of the long axis of the plastic body 35 which is oval in cross section of the round bottom part 31 in cross section with this in plant. In the longitudinal plane offset by 90 ° in the short axis of the cross-sectionally oval plastic body 35, there are through-openings on both sides of the plastic body 35 between the outside of the plastic body 35 and the inside of the base part 31.

The plastic body 35 has two seats for two metal compression springs 22 along its long cross-sectional axis, the other end of which is supported in each case on the base part 31. Furthermore, two metal pressure cables 16 are anchored along the long axis in cross section of the plastic body 35, which is oval in cross section, in that the plastic body 35 is shaped around the pressure cables 16 by a plastic injection molding process. The two pressure cables 16 are led out of the bottom part 31 and continue to run within a pressure hose 10, 12, respectively are surrounded by a protective cover 23. Both protective sleeves 23 and both pressure hoses 10, 12 are sealingly attached to the bottom part 31 of the housing 3 by pressing. Housing cap 30 and base part 31 consist of a solid plastic, metal or rubber material, while the protective cover 23 is made of a steel-reinforced, rubberized and / or plastic-coated textile fabric.

The metal pressure cables 16 each run displaceably in the respective pressure-resistant pressure hoses 10, 12. Between the outside of the respective pressure cable 16 and the inside of the respective pressure hose 10, 12 there remains an air passage channel 36 with an annular cross section as the air flow path 9, 11.

At the other end of the air flow paths 9, 11 an adapter 17 is arranged, which consists of a solid plastic or metal material (see. Fig. 3). The adapter 17 consists of a housing cap 37 and a base part 38. The housing cap 37 is axially rotatable in the manner of a union nut, but is captively held on the base part 38. The bottom part 38 is connected to the respective protective cover 23 and the respective pressure hose 10, 12 in a sealing manner by pressing. The rotatable housing cap 37 has an opening 39 and an internal thread 25 for screwing the adapter 17 onto the external thread of the valve housing of commercially available pneumatic tire valves. The opening 39 is connected to the air passage channel 36.

There are two alternatives for the assembly of the connecting member 1:

In both alternatives, the pneumatic tires are already filled with an approximately correct air pressure at the start of assembly, so that the narrowing of the free inner cross section of the pressure hoses 10, 12 by the two pressure cables 16 does not play an important role, since in contrast - in regulating the correct air pressure for first filling - no very large amounts of air are necessary. In the first alternative, according to which, for example, the first exemplary embodiment of the invention is assembled, the outer wheel of the twin wheel is first removed from the axle of the motor vehicle. Then the adapter 17 is screwed onto the first pressure hose 10 by means of the housing cap 37 acting in the manner of a union nut on the valve of the inner pneumatic tire, which is located on the vehicle axle. The removed outer wheel is then placed back on the vehicle axle, the openings in the rims being oriented opposite one another so that the housing 3 and the pressure hoses 10, 12 can be moved through the rim openings onto the outside of the outer rim. During this process, the adapter 17 of the first pressure hose 10 naturally remains on the valve of the inner pneumatic tire. Finally, the adapter 17 of the second pressure hose 12 is still to be screwed to the valve housing of the outer pneumatic tire by means of the housing cap 37, which acts like a union nut, and the housing 3 is fastened to the valve body by means of known screw clamp fastenings, as described above Rim of the outer tire of the twin tire mounted.

In another exemplary embodiment of the present invention, not shown here, the region of the first pressure hose 10 which is arranged adjacent to the adapter 17 is rigid, for example by surrounding a plastic tube which is glued to the outside of the first pressure hose 10 or by a such a plastic tube is encased by the protective cover 23. In addition, it is necessary that the housing cap 37 of the adapter 17 of the first pressure hose 10 is in this case not arranged rotatably around the base part 38 in the manner of a union nut, but is fixedly connected to it. In this exemplary embodiment, the second fastening variant is then possible, in which the outer wheel does not have to be removed for mounting the connecting member. Rather, the first pressure hose 10 with the associated adapter 17 are then passed through two mutually opposite openings in the rims of the assembled twin wheel, and the adapter 17 of the first pressure hose 10 is then moved by a rotational movement of the entire, not yet assembled connecting member 1 onto the valve housing of the inner pneumatic tire screwed on. The adapter 17 of the second pressure hose 12 and the housing 3 are then attached in a known manner as in the first alternative.

After assembly of the connecting member 1, a commercially available air pressure test and filling device is connected to the connecting piece 24 of the housing 3. The valve actuating element of the air pressure test and filling device exerts a compressive force on the contact pin 14 in the connecting piece 24. The plastic body 35 is normally pressed against the housing cap 30 by the compressive force of the springs 22. However, if the pressure force of the valve actuating element of the air pressure testing and filling device on the pin 14 exceeds the pressure force of the springs 22, the plastic body 35 is moved in the direction of the base part 31 by compressing the pressure springs 22 (see FIG. 2). The maximum possible displacement of the plastic body 35 in this embodiment of the connecting member 1 is between 2 and 5 mm in order to ensure a certain tolerance range in the event of possible manufacturing-related fluctuations in the length of the two pressure cables 16. The movement of the plastic body 35 exerts a compressive force on the two pressure cables 16 anchored in it, as a result of which the two pressure cables 16 move coaxially in their pressure hoses 10, 12. In the two adapters 17 (cf. FIG. 3), the ends of the pressure cables 16 or the valve actuation pins 20 attached to them are thus moved a little in the direction of the opening 39 and thereby come into engagement with the valve pins of the pneumatic tire valves. the adapters 17 are screwed to their valve housings. The air tire valves open against the pressure of their own valve and there is thus a common air connection path of the air volumes of the two pneumatic tires via the air passage channels 36 of the two pressure hoses 10, 12 and the passage openings in the chamber 5 of the housing 3 to the air inlet 7. Via this common air connection path the air pressure in both tires is set to the same correct value.

After completion of the filling process, the air pressure test and filling device is detached from the connection piece 24, and the plastic body slides back into its original position shown in FIG. 2 by the pressure of the springs 22. As a result, a tension is now exerted on the pressure cables 16, which pulls the ends of the pressure cables 16 located in the adapters 17 or the valve actuating pins 20 connected to them together with the counterpressure of the valve springs in the two pneumatic tire valves into their original position, shown in FIG. 3 drives back. The valve pins of the two pneumatic tire valves are thus released and can return to their closed position. In principle, the springs 22 could also be dispensed with in these processes; the springs 22 serve above all as additional support and protection for the valve springs in the two pneumatic tire valves.

The air passage channels 36 in the two pressure hoses 10, 12 and the chamber 5 in the housing 3 are thus essentially only pressurized with the air pressure during the connection of the air pressure test and filling device, since through the through openings of the chamber 5 in the housing 3 and the air ¬ inlet 7 otherwise there is a permanent connection to the outside air because the metal body 35 does not abut or not completely seal against the housing cap 30 and the bottom part 31.

Since the opening of the pneumatic tire valves of the twin pneumatic tire is triggered by a displacement of the two pressure cables 16 , should preferably be used as pressure ropes 16 Bowden ropes which do not change their length when the pressure hoses 10, 12 of the finished connecting member 1 are bent, in order to rule out unintentional opening of the pneumatic tire valves. Furthermore, the materials of the connecting member 1 should be oil, grease and acid resistant in order to withstand the attack of road salt, grease and fuel residues.

Instead of the pressure cables 16, e.g. micro-hydraulic lines can also be used in the pressure hoses 10, 12 for transmitting the pressure force, which then act on corresponding hydraulic control elements in the adapters 17 for actuating the valve pins.

4 shows a second exemplary embodiment of the connecting element 1. This embodiment also has a chamber 5 in a housing 3. In the chamber 5, a lever 50 is rotatably mounted on an axis of rotation 51. FIG. 4 shows a longitudinal section through the connecting member 1, the axis of rotation 51 running perpendicular to the image plane. The housing 3 is fastened to the rim of the outer wheel or to the valve housing of the valve of the outer pneumatic tire in such a way that the adapter 17 associated with the first air flow path 9 can be screwed directly to the valve housing of the valve of the outer pneumatic tire by means of its internal thread 25. The pressure hose 57 is guided in operation through mutually opposite openings in the two rims of the twin wheel in the direction of the center of the carriage, so that the adapter 17 belonging to the second air flow path 11 can be screwed to the valve housing of the inner pneumatic tire in the manner already described .

A commercially available air pressure test and filling device can be connected to the connecting piece 24, which has an external thread 24a. Inside the connector 24 is located in an air inlet channel 7, a pin 14 which is displaceable by the valve actuating element of the air pressure test and filling device. If a pressure force is exerted on this pin by this valve actuating element, the two-sided lever 50 rotates clockwise in FIG. 4 by a certain angle about its axis of rotation 51. In this second exemplary embodiment, the telecontrol elements 15 consist of a pressure rod 52 in first air flow path 9 and from a pressure cable 16 in the second air flow path 11. Due to the rotary movement of the two-sided lever 50 about the axis of rotation 51, a pressure force is exerted on the pressure rod 52 and the pressure cable 16, through which the valve actuating pins 20 in the two adapters 17 in the way already presented in the first embodiment can be moved. In this second exemplary embodiment, an elastic element for returning the lever 50 to its rest position shown in FIG. 4 was dispensed with, this task is left entirely to the valve springs in the two valves of the twin pneumatic tire. The chamber 5 in the housing 3 is accessible for assembly or repair through a side opening 58, which in operation is closed by a cover (not shown) sealed with a 0-ring 40.

In this exemplary embodiment of the connecting member 1, a transmission of the compressive force through micro-hydraulic lines and corresponding hydraulic control elements is again possible.

5 shows a cross section through the housing 3 of a third exemplary embodiment of the connecting element according to the invention, which has a display device 100 with a display element 101 for displaying an air flow directed from one of the two pneumatic tires into the other. The structure of this third embodiment is very similar to the structure of the first embodiment of FIGS. 1 and 2, it will therefore only be referred to in the following Differences between the two exemplary embodiments are discussed, which are essentially due to the arrangement and design of the display device 100. Corresponding parts are provided with the same reference numerals in both exemplary embodiments.

In the third exemplary embodiment of the connecting member 1, the plastic body 35 arranged in the housing 3 is provided with an extension 43 which is arranged coaxially with the pin 14. The pin 14 is received and fastened centrally in the extension 43, for example glued or molded.

Correspondingly, the housing cap 30 of the housing 3 is also longer than the first embodiment. In this third exemplary embodiment of the connecting member 1, the housing cap 30 consists of a transparent plastic, indicated by the hatching.

An impeller 102 can be rotated on the extension 43 as a display element 101 of the display device 100, but is otherwise fixed. For this purpose, the cylindrical extension 43 has two bead rings 44, the axial distance of which essentially corresponds to the length of the hollow cylindrical axis part 104 of the impeller 102. To assemble the impeller 102 on the cylindrical extension 43, the impeller 102 with its axis part 104 is pushed over the bead ring 44 facing the air inlet 7, which is designed to be slightly elastic, in the manner of a snap fastening. The housing cap 30 is then snapped onto the bottom part 31 of the housing 3 in the manner already described. The extension 43 thus serves as an axle bearing for the axle part 104 of the rotatable impeller 102. The axis 103 of the impeller 102 is thus arranged coaxially with the pin 14.

You practice, for example using the valve actuating pin of a commercially available air pressure test and filling device or by means of the actuating pin 155 of a compensating cap 149, a pressure force on the pin 14, the plastic body 35 receiving the pin 14 with the injected pressure cables 16 is axially displaced by the pressure force, and a connection is established between the two pneumatic tires. The filling connection of the commercially available air pressure testing and filling device or the fitted compensation cap 49 placed on the connection piece 24 of the housing 3 thereby close the air inlet 7 of the chamber 5 from the surrounding outside air, so that no compressed air leaves the chamber 5 can escape outside. If there is now a lower air pressure in one of the two pneumatic tires than in the other, an air flow will start in the direction of the pneumatic tire with the lower air pressure. This air flow causes the impeller 102 to rotate about its axis 103. The user can easily perceive this rotation due to the transparent housing cap 30 and thus receives the information that there is no complete pressure compensation between the two pneumatic tires. If the pressure equalization has occurred, the rotation of the impeller 102 comes to a standstill.

In order to make it easier for the user of the invention to recognize the rotation, the blades 105 of the impeller 102 are preferably noticeably colored, e.g. alternately or colored red and green on one side. With a suitable configuration of the display device 100, the direction of rotation of the impeller 102 depends on the direction of the air flow. The user of the invention can then use the direction of rotation of the impeller 102, which he e.g. can recognize on the basis of a marking in the manner of a helix on the axle part 104 of the impeller, in which pneumatic tire of the twin pneumatic tire the lower air pressure prevails.

FIG. 6 shows a fourth exemplary embodiment of a connecting element 1, which is very similar to the connecting element of the third exemplary embodiment from FIG. 5. While at that 5 but the axial movement of the axis part 104 of the impeller 102 is limited by two bead rings 44 on the extension 43 of the plastic body 35, in the fourth embodiment of FIG. 6 the axis part 104 of the impeller 102 is in each case one Direction at an area 45 of the plastic body 35 and in the other direction at an area 46 of the housing cap 30. In this way, the bead rings 44 can be dispensed with. After the housing cap 30 has been snapped onto the bottom part 31 of the housing 3, the axis part 104 of the impeller 102 of the display device 100 is securely axially fixed between the plastic body 35 and the housing cap 30. With a suitable dimensioning of the housing cap 30, the rotatability of the impeller 102 is completely ensured.

FIG. 7 shows a further embodiment variant of a display device 100 for displaying an air flow directed from one of the two air tires into the other. This exemplary embodiment of a display device 100 comprises a tube 110 with a sight glass 111 in the center made of glass or of transparent plastic. A mark 114 or a scale graduation is attached to the sight glass 111. The tube 110 is inserted directly into the first pressure hose 10 in the vicinity of the housing 3.

In principle, it is also possible not to install the display device 100 in one of the two air flow paths 9, 11 and to connect the two air flow paths 9, 11 via a chamber 5, but to form them as a connection between the two air flow paths 9, 11. The display device 100 is then preferably arranged in relation to the air flow parallel to the chamber 5; however, it is also possible for the display device 100 to be the only connection that can be made between the two pneumatic tires.

In the sight glass 111 of the display device 100 there is a ball 112, which is on both sides in the longitudinal axis of the Tube 110 is supported by two coil springs 113. These two spiral springs 113 with a small spring constant are supported with their respective other ends on the suitably designed ends of the sight glass 111 or the tube 110. Under the action of an air flow passing through the tube 110 with the sight glass 111, the ball moves in the direction of the tube end with the lower air pressure. The marking 114 or the scale on the transparent sight glass 111 of the display device 100 makes it easy to see from the outside whether the position of the ball 113 changes or not when the contact 13 is actuated. The direction of the displacement also makes it easy to determine in which of the two air tires the lower air pressure prevails. This variant of the display device 100 can also be easily integrated in or on the housing 3 of a connecting member 1 with a suitable design.

8 shows an exemplary embodiment 149 of a compensation cap in a cross-sectional illustration. The compensation cap 149 shown has the outer shape and size of a commercially available valve protection cap. With its internal thread 154 on the hollow cylindrical attachment section 153, it can be screwed onto the external thread 24a of the connecting piece 24 of a connecting member 1. The compensation cap 149 has an additional sealing ring 152, due to which the compensation cap 149 can be attached airtight to the connector 24 of the housing 3 of a connecting member 1. A substantially hemispherical actuating section 150 is connected in an airtight manner to the hollow cylindrical mounting section 153. The actuation section 150 is made of an elastic rubber material and is permanently connected to the attachment section 153, for example by injection molding the hollow-cylindrical attachment section 153 made of plastic onto the hemispherical actuation section 150. The actuating section 150 carries an actuating pin 155 as the contact actuating element 151. Presses the elastic actuation section 150 made of rubber is moved from the outside, so the actuation pin 155 moves generally axially in the direction of the attachment section 153. If the compensating cap 149 is screwed onto the connecting piece 24 of one of the above-described exemplary embodiments of the connecting element 1 according to the invention, the actuating pin 155 comes into engagement with the movable pin 14, and a connection is established between the two pneumatic tires and the - through the compensation cap 149 on the connection piece 24 is produced in an airtight manner with respect to the chamber 5. This results in a pressure equalization between the air volumes of the two Luftrei¬ fen, without pressurized air can escape to the outside.

The pressure compensation can be carried out using the compensation cap 149 alone, for example without the need for a commercially available air pressure test and filling device. If the pressure on the actuating section 150 made of rubber is ended, the actuating pin 155 moves back into its starting position due to the elasticity of the rubber material, likewise the pin 14 does, and the valves of the two pneumatic tires close again. The fact that a pressure equalization takes place between the two pneumatic tires and when it is finished can advantageously be easily observed if the connecting member 1 to which the equalizing cap 149 is attached has an indicator device 100.

Claims

Expectations

1. Connection element for connecting the respective valves of the two pneumatic tires of a twin pneumatic tire, with a housing having a chamber, an air inlet communicating with this chamber, a first one that is connected to the chamber and by means of an adapter to the

Valve housing of an air flow path connectable to the pneumatic tires of a twin pneumatic tire, a second air flow path connected to the chamber and connectable to the valve housing of the other pneumatic tire of the twin pneumatic tire by means of a second adapter, characterized by - an in or on the housing ( 3) arranged, mechanically, hydraulically or electrically actuated contact (13), each a wholly or partly in or on the air flow paths (9, 11) arranged, mechanically or hydraulically or electrically or similarly acting telecontrol element (15) and a valve actuation element (19) arranged in each of the two adapters (17), the actuation of the contact (13) causing the valve actuation elements (19) by means of the remote control elements (15) during the period of actuation of the contact (13) to open the valves of the two pneumatic tires can be brought into engagement with them, - whereby during the Duration of actuation of the contact (13) a connection between the two pneumatic tires and the air inlet (7) can be established.

2. Link according to claim 1, characterized gekennzeich¬ net that the remote control elements (15) are pressure cables (16), which are preferably arranged coaxially or in parallel with the air flow paths (9, 11).

3. Connecting link according to claim 1 or claim 2, da¬ characterized in that the air flow paths (9, 11) are surrounded by a protective cover (23), preferably the remote control elements (15) are also arranged in the protective cover (23).

4. Link according to one or more of the preceding claims, characterized in that the contact is a movable pin (14) which is preferably movable along its axis.

5. Link according to claim 4, characterized gekennzeich¬ net that the pin (14) by the pressure of an elastic element (21), in particular by springs (22), is held in a first position, and for actuating the contact ( 13) can be moved into a second position by a mechanical force.

6. Connecting element according to one or more of the preceding claims, characterized in that the valve actuating elements (19) are valve actuating pins (20) which can open these commercially available pneumatic tire valves by mechanical engagement with the valve pins.

7. Link according to one or more of the preceding claims, characterized in that the adapters (17) have an internal thread connection (25) so that they can be fastened to the valve housings of commercially available pneumatic tire valves.

8. Link according to one or more of the previously Impending claims, characterized in that the housing (3) has a connecting piece (24), the shape and size of which is suitable for connecting commercially available air pressure test and filling devices, and the air inlet (7) in or on this connecting piece ( 24) is arranged.

9. Link according to claim 8 in conjunction with claim 3 and claim 4, characterized in that the pin (14) is movable by the valve actuating element of a commercially available air pressure testing and filling device, thereby causing a pressure on the pressure cables (16) Force can be exerted, which they transmit to the valve actuation elements (19) in the adapters (17) for opening the pneumatic tire valves.

10. Connecting element according to one or more of the preceding claims, characterized in that a display device (100) is arranged in or on at least one of the two air flow paths (9, 11) and / or in or on the chamber (5) which comprises a display element (101) which is either movable or otherwise changeable by an air flow directed from one of the two pneumatic tires into the other to display the same.

11. Connecting element according to claim 10, characterized in that the display element (101) is arranged in the chamber (5) and the housing (3), in particular a housing cap (30), is at least partially made of a transparent one Material, in particular see-through plastic.

12. Connecting element according to claim 10 or 11, characterized in that the display device (100) comprises a wing wheel (102) as a display element (101) which is preferably rotatable coaxially with the movable pin (14) is arranged.

13. compensation cap for use with a connecting member according to one or more of the preceding claims, characterized in that the compensation cap (149) can be attached at least substantially airtight to the housing (3) and an actuatable contact actuating element ( 151), the contact (13) is designed to be operable against an elastic bias.

14. Compensation cap according to claim 13 in conjunction with claim 8, characterized in that an attachment section (153) of the compensation cap (149) is designed for attachment to the connection piece (24) of the housing (3) and preferably an internal thread (154) for screwing onto the external thread (24a) of the connection piece (24).

15. compensation cap according to claim 14, characterized gekennzeich¬ net that the compensation cap (149) comprises an actuating portion (150) which is at least substantially airtight with the mounting portion (153) and at least predominantly consists of an elastic material and / or is elastically connected to the attachment section (153).

16. Compensating cap according to claim 15, characterized gekennzeich¬ net that with the actuating section (150) an actuating pin (155) is connected as a contact actuating element (151), the contact by exerting a mechanical compressive force on the actuating section (150) (13) can be actuated, in particular can be brought into engagement with the movable pin (14).