Abstract: A rubber composition for a tire tread, or a pneumatic tire using the same in a tire tread portion, wherein the tread portion contains a diene rubber; and carbon black and/or silica; and a gas-encapsulated thermoplastic resin and, further, a short fiber, a hard particle and/or a liquid polymer, and wherein the gas-encapsulated thermoplastic resin particle is obtained by expanding, upon heating. at a temperature of an expansion starting temperature thereof or more, prior to vulcanization of a rubber, a thermally expansible thermoplastic resin particle, which comprises a thermoplastic resin having an expansion starting temperature of from 70° C. to less than 120° C. and having a heat resistance to withstand vulcanization of rubber, followed by vulcanization to uniformly disperse the gas-encapsulated thermoplastic resin in the rubber, or a short fiber, a hard particle and/or a liquid polymer is further compounded to give a high frictional force on ice.

Abstract: 1. A rubber composition for a tire tread containing: (i) 100 parts by weight of a diene rubber, and (ii) 1 to 20 parts by weight of an elastic gas-encapsulated thermoplastic resin hollow particle having a particle size of 5-300 .mu.m, which is obtained by expanding, upon heating during vulcanization, a thermally expansible thermoplastic resin containing an encapsulated liquid or solid substance capable of generating a gas by vaporization, decomposition or chemical reaction upon heating to form the hollow-type expanded particle and, optionally containing (iii) 1 to 20 parts by weight of a short fiber or (iv) 1 to 20 parts by weight of a hard particle.

Abstract: The stud unit of the present invention is used for skid-proof tires of vehicles. On a snow- or ice-covered road, a force acts on a front end of a stud contacting the road when the vehicle is braked or accelerates and the tire treads consequently slip, so that the stud is kept projecting from a cylinder due to mutual engagement of the stud and the cylinder. On a dry road, the treads of the tire hold the road without slipping, so that no force acts on the stud to cause it to incline, and the stud can smoothly retract into the cylinder.

Abstract: Cylinders each having open end and an internal engagement section in the mid-portion thereof are fixed in holes bored on an outer circumferential face of a tire tread. In each cylinder, a stud passing through a through-hole of the engagement section and having an expanded section at the front end thereof is inserted with play. The stud is biased toward the front end of the cylinder by a spring provided between a lid closing the rear opening of the cylinder and the expanded section. When the tire slips on a snow- or ice-covered road, the stud inclines and a large-neck section of the front end of the stud engages the rim of the cylinder to maintain the stud in a projected state. The projected large-neck section bites the surface of the road to prevent slippage. On a dry road, the stud 32 is pushed into the cylinder by the weight of the vehicle against the elasticity of the spring.

Abstract: The invention provides a pneumatic tire for mounting on a wheel hub, the tire having a plurality of ground engaging pads disposed around the periphery of the tire. Each pad is capable of at least a limited degree of rotational displacement about a radial axis relative to the tire, so that the tire may turn through the limited rotation relative to any pad which is in ground contact. A means is provided for returning each pad to its undisplaced position when the pad has moved out of contact with the ground.

Abstract: A lightweight device for obtaining improved traction efficiency of rubber tired vehicles without adding ballast weight. The device has high-strength, thin-gauged traction intensifying means secured to a driving tire, providing higher drawbar pull at higher rate of travel speed by utilizing stronger sub-surface soil and extended tire life; and includes actuating means, for engaging and disengaging the traction enhancing means for convenient conversion to allow travel on pavement.

Abstract: An improved track belt assembly wherein the anchor plates have fastening means which are disposed axially inward of the reinforcing belt structure.

Abstract: The track belt assembly of the present invention comprises a plurality of shoes spaced about the periphery of a load-supporting structure. A reinforcing belt structure is disposed on the side of the shoe opposite the ground-engaging side thereof. Each shoe is secured at its lateral ends to the belt reinforcing structure by two separate anchor plates disposed on the side of the belt opposite that which is adjacent the shoes.

Abstract: A tire having a layer of uncured rubber in its tread portion is fitted to a hub and an annular protective chain is placed over the uncured rubber. The tire is inflated and the protective chain is tensioned by chains connected to the lateral edges of the chain and extending radially inwardly to the axis of and axially away from the central plane of the tire by means of a telescopic jack aligned with the axis of the tire. The tire is vulcanised by sealably enclosing it in a cover, venting the space between the cover and tire, and curing the rubber in an autoclave in which the tire is a loose fit.

Abstract: A skid-preventing device includes a stud which is embeddable into the rubber tread of a vehicle tire and comprises a cylindrical stem portion and a bottom flange portion affixed to the base of the stem portion. A hard metal rod engaging pin is affixed to the end of the stem portion opposite the base. A locking ring is engaged over the stem portion between the flange and the pin. The locking ring is of slightly larger diameter than the hole provided in the tire tread for the stud, thus the stud is retained in the tread hole by the frictional force of the locking ring against the inner wall of the hole.