The present invention.relates- to a movable tire stud system, optionally operated ^" by solar cells and wireless remote control, allowing a quick traction adjustment from the driver's seat when required for ^" better road grip on slippery and icy roads.

A wide variety of systems for improving traction on icy and slippery roads have been constructed. Ebwever, most systems do not function satisfactorily in the long run. They are often worn out too quickly due to the considerable wear and tear such systems must endure during the course of driving. Many systems, like Icelandic laid-open publication #121970 require air pressure t© move studs in and ou . like in βkβck absorbers, the air will compress and consequently such, studs are easily forced back into the tires without improving traction satisfactorily.

Other systems, like U.S.Patent # 294-1566, requires studs to penetrate the tire casing. According to professionals, penetration of the tire casing will in the long min lead to air leakages and humidity in the tire causing steel belt corrosion and tire separation.

Norwegian patent application #922913 and WO Al 9416913 do not have the disadvantages mentioned aboveiregariiiβig use of air pressure and tire casing penetration because that system is based on incompressible hydraulic fluid and mounted into the tires on the outside of the tire casing. However, such a movable stud system should preferably he used on larger tires or on tires especially molded and thereby having sufficient rubber thickness for suchα a system.

Experiments has led to the stud system hereby presented as it has several advantages. First, it may be mounted on small vehicle tires presently on the market without considerable changes in the production of suchi tires. Secondly, the stud system mentioned! herein ajnβo?e-3Ccess3aieand easy ^ βugpiαrand. maintaia than most systems molded into the tires.

Many attempts have been,made to adjust components on a spinning wheel from the driver's seat. Publications show various connections between the wheels and an hydraulic pump positioned in the vehicle body. Suc arrangements necessitate the use of rotating unions that sooner or later will leak due to the considerable wear and tear on such components .

The present invention solves this problem by a new combination of solar cells (50,55) and wireless remote control(6A,6B ,6D) and an hydraulic pump L)!©r air-free, incompressible fluid positioned in the wheel rim center. Considering that the movable studs are only used occasionally afld that the hydraulic pump is frequently exposed to sunrays or dayli ht, solar cells seems very suitable for such a system. Besides, such facilities makes it easier for the drivers to consentrate on the traffic and thereby increase trai± ^' ic safety. To avoid traffic jam due to icy and slippery roads, traction adjustment from the driver's seat may he a good solution.

At last , but not at least , the present invention offers a considerably shorter braking distance on icy, slippery roads than by tne use of ordinary studs. his is possible by designing the studs with a narrowed portion close to the stud tip. That makes the stud tip edge sharper so that the stud grips the ice like a claw. A tilting cylinder-shaped ordinary tire stud will slide much, more easily due to it's shape. In other words, not only will the present invention help drivers to get more easily from one place to another on icy, slippery roads, it may also offer better traffic safety, less accidents and saved lives.

Consequently, there is an obvious need for the movable stud system as presented herein. The need is met by makin available a stud system of the type precisely defined in the appended patent claims.

The stud system in accordance with, the present invention is hereby described more closely by referring to exemplary embodiments"^hereof and withreference to. the en løsed dra ngB wherein:

Figure 15 shows the main part of the adjustable stud system including one transmitter (6B) located at the exterior of the vehicle body. The transmitter is connected to a control panel in the driver's compartment. For example, by pressing switches connected to the transmitter, the driver thereby sends signals by wireless remote control to the receiving remote control(6A) located in the wheel rim, making the hydraulic pump _ - .' ^■ .

^ oτe the studs (90) in or out, to a rectracted or protruded position in the stud hole or sleeve/housing (18) . The hydraulic pump (1) , including electromotor (4) , recharge- ahlfi'battery (5), remote control for sigal reception (6A) , piston (12) , piston guides (11) , hydraulic pressure chamber(3) and solar power cell(s) (50,55) is for, example located centrally in the wheel rim in a cylindrically shaped box, preferably made of metal, o ether constituting an hydraulic pump (1) . To avoid rotation of the piston (12) when the electromoter ( ) is running, the piston guide pins (11) are protruding into the piston (12) to keep it in a stable position and counteract -rotatio . Consequently, the shaft(75) connected coaxialiy to the electromotor (4) , will screw the piston back or forth-, depending on which, way the electomotor is rotating. Wires connect the solar cells to battery and motor. Figure 100 shows a cross section of the wheel, including the hydraulic pump (1) and components as mentioned above. The piston (12) has a sealing (12A) to avoid leakage and maintaining hydraulic pressure ,< necessary to move studs(90)

! out or to achieve vacuum and stud retraction when the piston is screwed back towards the electromotor(4) . Hydraulic conduits between the kydrittliei ump (1) and the studs (90) may for instance be shaped like tubes(9), preferably reinforced by a flexible steel sleeve (9) and a wire (TO). The wire (70) shown on figure 14 0 will counteract the centrifugal force when the wheel is rotating, thereby keeping the studs and stud housing means(90,l8) in a stable position.. Elastic means (40,45) which, may for example be springs or thick rubber tubes , will function as shock absorbers or protection for the hydraulic conduits (9).

Figure 14 shows the wheel seen from the outside. The tube (24) positioned like a circle in. the wheel rim, functions like a distributor of hydraulic fluid from the pump (1) to the hydraulic tubes (9) and stud housing meaas(30) A wire (17) attached, to ^" -jfiha..stud- housing means (30) by the tire shoulder;, may be tightened by a nut (35), thereby pulling the stud housing meaas closer tb the tire. A lid ( 0 may be ' _j tightened by screws(9 ) , thereby both fastening the wire (17) to the stud housing means (30) and also fastening-_the hydraulic tube (9) better to the stud housing means.

Figure llH.< Ξ}Afigure 10^ JJP shows stud housing means (18) having protruding edges (23) adapted to fit the adjacent tire shoulder pattern to better secure the studs in their position when friction, braking or acceleration tend to tilt the studs. A nut (80) mounted on the stud housing means (18) is designed to be gripped by a tool, so that studs are easily replaced when needed.

Figure 100 also shows an air storage compartment (96} for air pressure reserves transferable to the tire, optionally available.

Instead of the electromotor (4) there may be mounted a handle by which it is possible to screw the piston (12) hack and orth. hereby also moving studs (90). If so, there is no need for the solar cell (50,55), remote control (6a,6B, battery(5) when the pump is only operated manually..

Figure 6R and figure 7D shows a cross section of the tire where also a wire(16) positioning the movable stud system to the tire is shown. At each end of the wire (16) the wire has an enlargement (19)ϋke a nut or wire-head, by which, the stud housing means (18) may be pressed towards the tire by tightening the nut at the end of the wire.

Fig.200 shows a cross section of a tire having a protecting shield (26B) on the outside of the hydraulic conduits(9). , Inside the shield (26B) there may he a passage through, which I may be treaded a thin hydraulic tube ( $ ^■■ }■ to be fastened to a tube (24) mounted in a circle paralell or close to the rim i edge. Said thin tutoe may be iCfcteeked to other tube (24)

which serves as a distributor ot hydraulic fluid to the studs or channels the fluid back to the pressure chamlser in the rim when the studs move back to retracted position.

Fi .100 shows a cross section also of a protecting shield (26A) which is shaped almost like loose white side walls to be mounted on tires for ornamental reasons. However, in figure 100^ ; _Q the shield serves both as means for positioning the hydraulic tubes correctly on the tire side walls, being attached to the tubes (y) by clips, screws^etc. &»d—βisβ- protecting the hydraulic tubes 19) from shocks when driving.

The wire (16) mounted m or at the tire tread may be stiff

®r-*asy to bend or twist by consisting or several small wires attached together. The wire may also * -have a shape that is more flat and wide, like a ban y _t e/f a strong, durable material, for example metal-, to be mounted on the tire tread.

Figure 10 show a stud (90) having a narrow section close to the stud tip. been from the side, tne stud tip's flat end has in relation to tlie stud tip's side an angle of less than Oυdegreeε , enabling th.e stud to grip the ice like a claw, especially when being tilted slighy±y. The outer diameter at" the end of the

, and