Abstract: A traction device for vehicle wheels comprises an expandable and contractible member (10) mounted next to a wheel (70) or in between dual wheels (12, 14). In another embodiment the device comprises an air chamber (106, 134) formed in the tread of the tire (120).

Abstract: A spike for the running surface of a motor vehicle tire, especially a snow tire, with, as seen from above, an out-of-round, elongated, plate-like spike root (2, 2a), the greatest extension of which defines a longitudinal axis (7a), and an out-of-round, elongated upper part (4, 5) of the spike, the greatest extension of which defines a longitudinal axis (6a). In order to be enabled to accept even greater forces from below, the spike root (2, 2a) and the upper part (4, 5) of the spike are twisted in relation to each other, so that the longitudinal axis (6a) of the upper part (4, 5) of the spike encloses an angle (15, 15a) varying from zero with the longitudinal axis (7a) of the spike root (2,2a).

Abstract: The present invention relates to compounds of the formula where R1, R2 and R3 are independently selected from alkoxy radicals having from 1 to 8 carbon atoms; R4 and R5 are independently selected from the group consisting of alkylene having 1 to 12 carbons, arylenes having 6 carbon atoms and alkarylenes having 7 to 10 carbon atoms and n is an integer of from 1 to 10. These compounds may be used in rubber compositions.

Abstract: An apparatus which is used to cover a tire in order to prevent the tire from leaving marks on an area the tire travels across. The apparatus uses an elongated flexible piece of material of sufficient length to cover the outside circumference of the tire. The piece of material is used to cover the outside circumference of the tire to prevent the tire from leaving marks on an area the tire travels across. A connector is used for connecting a first end of the piece of material to a second end of the piece of material thereby securely coupling the piece of material to the outer circumference of the tire.

Abstract: A vulcanizable rubber composition for treads of vehicle tires, comprises:

Abstract: An automobile tire having an anti-skidding function and useful throughout all seasons is provided which permits the automobile to run while maintaining the anti-skidding function even if it encounters a snowless road during a travel on a snow-covered road, which does not require frequent operations of extending and retracting the spike pins and which poses no problem of pollution. Air chambers 3 are formed in the tread 2 of the tire. Branch tubes 4A of an air supply and evacuation tube 4 are connected with the air chambers 3. The tread surface has bosses 2B extending outwardly therefrom at locations corresponding to those portions 2A of the peripheral walls of the air chambers facing the tread surface, the bosses allowing portions of the tread to be bulged from and depressed into the tread surface depending on the air pressure in the air chambers. On-off valve means 6 may be provided in connecting portions between the air chambers 3 and the air supply and evacuation tube 4.

Abstract: An elasticized sock (22) is formed from a cowling of elastomer material which is so limp in the normally relaxed state thereof as to be essentially formless; and the sock is stretched about the outer periphery (18) of a movable boss, i.e., the welt of a shoe sole (2), the flange of a brake pedal, or the tire of a car wheel, and tightly engaged with the boss so as to interpose a portion of the sock between the boss and an interactive surface there opposite. Part of the elasticity with which the sock is stretchable about the boss, arises from the fact that the portion of the sock interposed between the boss and the interactive surface, comprises a network of elongated strands of elastomer material which lends elasticity to the portion.

Abstract: An improved traction enhancing article is provided which is applicable to many different items such as shoes, skateboards, snowboards and the like. The traction enhancing article has a plurality of regularly spaced cleats embedded in a flexible base which, in at least one embodiment, has an adhesive backing allowing it to be removably secured to a variety of different items. The cleats are preferably formed of aluminum and have a hexagonal base which tapers to a rounded top. Both sides of the surface are roughened to enhance traction and to ensure the cleat remains embedded in the base even under extreme stress conditions.

Abstract: A traction device for a wheeled vehicle comprises a rotor mounted to a supported component of the vehicle and displaceable between a deployed position, in which the rotor is close to the ground and in contact with the tire of a driven wheel of the vehicle so that when the tire rotates, the rotor rotates through frictional engagement therewith, and a stowed position, in which the rotor is farther from the ground and is spaced from the wheel. At least one elongate traction element is attached to the rotor at a location spaced from the axis of rotation of the rotor, so that when the rotor rotates due to frictional engagement with the rotating tire, the traction element is subject to centrifugal force and is extended from the rotor and passes between the tire and the ground.

Abstract: A rubber composition includes a rubber component and particulates of a crystalline syndiotactic-1,2-polybutadiene resin dispersed therein. The particulates have an average particle diameter of 1 to 500 .mu.m, and the melting point of the crystalline syndiotactic-1,2-polybutadiene resin is not less than 110.degree. C. The compounding ratio of the resin is 5 to 60 parts by weight relative to 100 parts by weight of the rubber component. The rubber composition is useful for tires, other rubber articles, etc. With respect to tires in particular, a pneumatic tire includes a rubber composition used for a tread, wherein the rubber composition includes a rubber component and particulates of crystalline syndiotactic-1,2-polybutadiene resin. The matrix portion of the tread rubber other than the above particulates is preferably a foamed rubber.

Abstract: Adjustable studded tire system for operation while driving or parking. The system includes a hydraulic pump unit which by elastic tubes molded into the outer layer of the vehicle tire can move studs into and out of the vehicle tire without having any part of the stud system penetrate the tire casing.

Abstract: A traction enhancement device for vehicle wheels for use in the event of an emergency. The traction enhancement device includes a traction member for being placed across the periphery of the tire of a drive wheel. A first strap is connected with one end of the traction member and is provided with a series of closely spaced ramped serrations. A second strap is connected with the other end of the traction member and is provided with a sleeve for receiving therethrough the ramped serrations portion of the first strap, wherein a detent engages the ramped serrations in a ratchet-type manner so as to permit the first strap to slide in the sleeve in only one direction. The traction member may be provided with an engagement surface having an irregular contour to thereby enhance traction of the tire with respect to the surface in question.

Abstract: A traction mat for vehicles has panels of flexible resilient material interconnected by sets of overlapping links which enable the panels to be folded in a stacked arrangement.Recesses or slots in the upper faces of the panels provide grip for a vehicle's tires and holes in the panel enable the panel to be pushed down through mud to a solid surface.

Abstract: A tire chain ramp member in cooperation with a tire chain assembly is arranged to receive the cross link portion of the tire chain within a groove directed into the top wall of the ramp structure. The ramp top wall accommodates a tire member thereon to permit case of mounting of the tire chain assembly relative to the vehicle tire, wherein subsequently the vehicle is driven from the ramp.

Abstract: A tire structure includes bag-like members capable of expansion and contraction and which are buried in anti-slip grooves in the tire surface, and an air supply coupled to the bag-like members for supplying air to inflate the bag-like members to cause them to expand and project outwardly of the tire surface. The air supply may include stems coupled to an air source in the wheel part of the tire structure. Normally, the tire structure can be run as a usual tire. When running on a frozen road or the like, the tire structure permits functions and effects like a tire with a chain coupled thereto to be obtained by a simple operation to inflate and expand the bag-like members to cause them to project outwardly of the tire surface, and without need of any cumbersome operation of mounting a chain to the tire.

Abstract: In an anti-skid device for motor vehicles, having a plurality of chain strands (10) distributed over the periphery of a holder (4), which holder can be set into a rotational motion, the holder exhibits a hub (6) having a ring collar (11). The ring collar (11) is surrounded by the ring bar (ring web) (18) of a friction wheel (7). Two plates (14, 15) of a pair of clamping plates are pressed by screw connections (16) against the side faces of the ring collar (11) and of the ring bar. The lower plate (15) is provided with slots (18) through which the ends of end links (20) of the chain strands (10) protrude into chambers (19) disposed in the ring bar (8) of the friction wheel. The anchorage of the end 1 inks (20) in the chambers (19) is here served by bolts (21).

Abstract: An anti-skid device for vehicles comprising a plurality of chain strands fastened to a holder which can be set in a rotational movement by means of the wheel of a vehicle against which the holder can be moved an pressed by a carrier. To move the carrier, a drive unit is used which can be operated by compressed gas. The compressed gas is delivered by a gas reservoir formed by at least one exchangeable compressed-gas cartridge which can be opened and connected to a gas pipe leading to the drive unit by means of a device in the driver's cab of the vehicle comprising a lever and a plunger for actuating a hollow needle piercing through he seal of the compressed-gas cartridge.

Abstract: A traction mat is provided for use under a wheel of a motor vehicle on a soft sand terrain which consists of a generally rectangular housing having a plurality of spaced apart treads. A pair of wires extend from one end of the housing and are connected to two lug nuts on the wheel. When the wheel is driven slowly the housing will go under the wheel with the threads providing traction.

Abstract: A pneumatic tire is provided with a central tread area circumferential groove extended thereabout and a skid chain consisting of a link chain section having opposite ends and a generally cylindrical expansion spring semi-permanently interposed between and connected to the skid chain section opposite ends, the link chain section and expansion spring being seatingly received within the groove with the convolutions of the normally closed convolution expansion spring being slightly spaced apart and the link chain section having a generally square cross sectional shape including rounded corners to enable the final segment of the link chain section to be placed within or removed from the groove to be "rolled" over the associated side area of the outer peripheral tread area of the tire.

Abstract: A new and improved apparatus for tightening a chain installed on a tire that is mounted on a wheel of a motor vehicle includes a hub assembly and a plurality of tension assemblies. Each tension assembly includes a first end for connecting to the hub assembly, a tensioning element connected to the first end, and a second end connected to the tensioning element. The second end is connected to a portion of the chain, such that the hub assembly and the tension assemblies exert tension on the chain in a radial direction toward the hub assembly. More specifically, the tension assemblies are attached to the hub assembly and the chain in pairs, and the tension assemblies of each pair are arranged in opposed relation. That is, the first ends of each pair are in opposed relation with respect to the hub assembly, and the second ends of each pair are in opposed relation with respect to the chain. At least one of the tension assemblies further includes a threaded shaft movable within a sleeve.

Abstract: The present invention provides a rubber composition which is useful for the treads of studless tires which provides improved grip properties on frozen roads and preserves good performance after being used for a long period of time. The rubber composition of the present invention comprises a base rubber and an inorganic halide which has a melting point of 180.degree. C. or more, an average particle size of 20 to 600 micrometer and a solubility of 5 g or more in 100 g of water at 0.degree. C.; said inorganic halide being present in an amount of 3 to 35 parts by weight based on 100 parts by weight of said base rubber.

Abstract: A vehicle traction assist device about two feet long that is adapted to be placed at a drive wheel of the vehicle and is stamped from a flat plate of 11 gage cold rolled steel. Apertures are punched out to provide cross bars (30, 32, 34) that are given a 90.degree. twist at each end to provide a central blade portion that engages both the tire tread and the underlying surface.

Abstract: A device for improving the winter road holding properties of automobiles is disclosed, which includes anti-skid members arranged in grooves in tire treads so as to surround lugs of the tread. A long working life of the anti-skid members may be attained if means are provided for moving the anti-skid members between non-retracted settings and retracted positions in which the anti-skid members are in the grooves.

Abstract: An anti-skid device of the type including an arm, carrying in its outer end a chain-provided pulley that is brought in contact with a vehicle wheel so that the chains are thrown in under the vehicle wheel. The arm is, in its inner end, journaled in a U-shaped or fork-shaped bracket via a short axle that, in its ends, rests in bowl-shaped hemispherical bearings that are threaded into the legs of the bracket. The bearing bowls are pretensioned against the axle. At the apex of the shaft's spherical ends, recesses are made that take-up lubrication grease and, in this way, a point-like contact between the bearing shells and the axle is eliminated.

Abstract: A cover is used to replace worn tread of a lawnmower tire without requiring replacement of the entire wheel and tire unit. The cover includes a sidewall section formed of nylon stretch material, and a tread section formed of rubber or the like. Pressure sensitive adhesive covers essentially the entire inner surface of the tread section and affixes the cover to the tire being retread when forced against the tread section of that tire. Backing material is in sections and covers the adhesive for storage. One of the sections is approximately ninety degrees in arc length.

Abstract: The invention concerns a sleeve-mounted spike (10) fitted on a vehicle tire, comprising a rivet (11), a head (12), a tip (13) and a sleeve (14). The clearance (15) between the sleeve (14) and the rivet (11) increases in the direction towards the tip (13). The sleeve (14) has been shaped so that the hole in the sleeve (14) for the rivet (11) has been disposed to increase in diameter towards the tip (13).

Abstract: An emergency motor vehicle tire traction improving device for attachment or mounting to a conventional motor vehicle tire is made substantially totally of multi-strand polymeric plastic rope and includes three or more separate lengths of the rope connected together in a pattern that defines a ladder having inside and outside parallel, coextensive runners and a plurality of transverse rungs connecting corresponding points of the runners, whereby the device is mounted to the tire by drapping it over the tire with the runners parallel with the direction of rotation of the tire and the rungs across the tire treads, with one end of each runner connected to the other end thereof and an elastic device attached to one of the runners pulling that runner uniformly toward the axis of the tire. When so mounted to the tire, the tire traction, particularly on ice and snow, is improved.

Abstract: In an anti-skid device for motor vehicles with a plurality of chain strands (2,3,4,5) retained in a support (1) which can be set into a revolving motion and connected to the latter by intermediate pieces (7) forming resilient spreading arms, the chain strands are combined to form chain strand groups (6) which consists of at least two chain strands. The chain strands (2,3,4,5) of the chain strand groups (6) are of fine-linked construction and connected to the intermediate pieces (7) by rings (23).

Abstract: In order to attach a tire mat to the circumference of a tired wheel, a front flexible elongate member is slidingly passed through attachment fittings on the mat spaced around the periphery of the front side of the wheel, and a rear flexible elongate member is slidingly passed through attachment fittings on the mat spaced around the periphery of the rear side of the wheel. Respective sliding attachment members are then used to attach parts of each elongate member together so as to enable relative sliding movement between the parts and so as to cause the elongate member to form an intermediate loop portion which extends through the attachment fittings on the associated side of the wheel and a further portion outside the loop portion.

Abstract: An anti-skid device for preventing slippage of a wheel is disclosed. The anti-skid device comprises a cylindrical expandable member disposed on a tread portion of a tire, and compressed fluid supplying means. The expandable member has anti-skid members implanted at a radially outer portion of the expandable member, and the expandable member is formed with a hole at a radially inner portion thereof. The compressed fluid supply means is connectable to the hole of the expandable member. The expandable member is expanded upon supply of compressed fluid into the hole, and is shrunk upon discharge of the compressed fluid therefrom.

Abstract: Anti-skid device of a kind that includes a chain-provided pulley that on use if brought to contact with the side of the vehicle wheel so that when the vehicle wheel is rotated the chain pieces (2) are successively thrown in between wheel and ground in order to improve the traction. The anti-skid device is rotatably journaled in an arm (7) that in turn is fastened to a housing (8) that is turnably journaled on a stub axle (9). The turning movement of the arm and the housing is achieved in one direction by a bowden wire (20) and in the other dirction by a return spring (23). The stub axle (9) of the housing (8) is fastened to a plate (10) that in turn is fastened to a tube (11) by means of welding. The tube (11) is in turn arranged in clamps (12 and 13), that in turn are fastened to the bolts holding together the vehicle axle and its spring.

Abstract: A grip plate to aid in freeing a vehicle from being stuck on a slippery surface, comprising a flat rectangular iron plate with a lip at one end and an upstanding lug at the other end, with an upward angular portion of the plate between the lug and the main body portion of the plate.

Abstract: A wheel capable of changing traction surface and track by varying the usual axis of rotation. The amount of this contacting surface can be varied and the path can be varied from usual linear to curvilinear contact. Full X, Y, and Z operation is characterized by largely symmetrically curved sinoisoidal-like motion.

Abstract: A centrifugal chain assembly having a holder for a skid prevention device for a motor vehicle which can be put into operation when needed and which can be made inoperative again is formed by a plurality of elements which are axially movable and also pivotable relative to one another, which, by their construction and movability provided for adjustment can be employed equally at both sides of a motor vehicle and can be used for different types and models of motor vehicles. An adjustable ball joint is provided between a centrifugal wheel and the free end of a pivot arm, which pivots the centrifugal wheel, together with chain lengths secured to the centrifugal wheel, from a rest position into an operative position, in which the centrifugal wheel abuts against the side face, directed inwardly of the motor vehicle, of a driven motor vehicle wheel and is set in rotation by the wheel during travel.

Abstract: Anti-skid device especially for motor vehicle comprising elastic arms (2) assembled to a disc unit. In use the disc unit is brought close to the vehicle wheel, the friction of which is to be increased, and the outer ends (3) of the arms are successively drawn in between wheel and ground to increase the friction. Apart from their friction increasing portion (3) the arms (2) are extremely elastic and extend practically to the centre of rotation and bearing of the disc. Above the arms there is arranged a disc (5) extending out to the vicinity of the transition of the arms (2) into the friction increasing members (3). Moreover, beneath the arms a ring (6) is arranged which is attached between the arms (2) to the points (7) of attachment of the disc. In this way the disc is given a plane appearance ensuring that the friction increasing members (3) of the arms can obtain defined feed-in positions relative to the vehicle wheel.

Abstract: Anti-skid device for vehicles including a chain provided pulley (1) arranged rotatable on an arm (4) journalled on a shaft (5). The shaft is connected with an eccentric pulley. Cables (7,7') extend around the eccentric pulley and are also fastened to the eccentric pulley. The two cables are in flexible pipes led to an air cylinder (8) and an air spring (9) respectively and movement of arm and chain provided pulley (1) from parking position to working position is achieved by the air cylinder pulling in the cable that in turn turns the pulley and the connected arm (4). A shelf (15) is arranged below the parking location of the chain provided pulley (1). When the chain provided pulleys are parked the chains are drawn over the edge of the shelf (15) and they are thus pulled up from possible contact with the ground. In this way it is possible to use necessary chain length together with a very low mounting of the device.

Abstract: A cast, low density metal disk for anti-skid devices which has a periphery of sufficiently small width that when it contacts the wet side wall of a tire on a vehicle it spreads the film of water to each side and leaves an essentially dry area of contact between the disk and the tire instead of hydroplaning on it. The periphery preferably is covered with an anti-skid material, e.g., rubber. Chains are pre-turned or twisted in the same direction a tire tends to turn them when rolling over them to avoid further twisting with consequent shortening in use and they are given a non-circular, e.g., square cross section to increase their anti-skid properties. The chains are welded at one end to a steel ring which is removably fastened to the under surface of a disk by bolts.

Abstract: An off road vehicle of the kind having fluid-distensible bag rollers for supporting the vehicle load uses bag rollers which are constructed to afford maximum flexibility in both the walls and tread and which are also constructed to be dynamically balanced.A top drive roller is associated with a bag roller in certain embodiments of the off road vehicle in ways which minimize bag wear.Specific bag constructions are provided for improved operation of the off road vehicle for on-highway use.The bag roller in a fixed position serves as a transport device for supporting and moving material having uneven and/or fragile surfaces and, in a specific embodiment, is mounted in a support for use as a transportation element in a conveyer system, or as a forceful puller for lineal objects, such as pipelines, accommodating uneven dimensions.

Abstract: A tire is provided with an element which cleans it during driving and is formed as a rigid substantially closed member fitted in a groove of the tire and movable radially outwardly during rotation of the tire to dislodge soil, snow etc. It may be provided with transverse portions and ground-engaging projections.

Abstract: A tire traction device includes at least two continuous circumferentially extending tread groove bead members adapted to nest within respective circumferentially extending tread grooves of selected vehicle tires. A plurality of circumferentially spaced transverse traction elements are integral with and connect the tread groove bead members. The traction elements are configured and dimensioned to overlie the tread of the tire and to thereby improve the traction thereof. Preferably a circumferentially extending traction element is provided intermediate the tread groove bead members and the transverse traction elements are arranged in circumferentially spaced pairs connecting the tread groove members and the circumferential traction element.

Abstract: This invention relates to an anti-skid device for motor vehicles, which device is of the known kind at which a friction pulley abuts a drive wheel and the pulley is provided with chain links, the free ends of which are thrown in between the tire and the ground. The invention is characterized in that the friction pulley (8,19) is supported on one end of an arm (6), which at its other end is supported pivotally about a journal (5) rigidly connected to the vehicle or the spring system thereof, and pneumatic means (10) are provided by action of a control means in the driver's cab to swing the arm (6) with the pulley (8,19) from a protected non-operative position to a pneumatically resilient contact against the tire (23).

Abstract: The traction device of the invention is for use with a vehicle wheel supported by lugs and having a tire. The traction device has a base with openings for the reception of at least two but less than all, the lugs for supporting the base. A plurality of spaced radial arms are supported by the base with each having an end adapted to extend beyond the outer periphery of the tire and protrude into an icy surface. Each of said ends is adapted to lie in a vertical plane adjacent to the outer side wall of the tire. The end of each arm may advantageously be free to move in and out while being spring biased outwardly, be threadably attached to the arm for movement inwardly and outwardly, or be pivotally connected to the arm for movement into and out of an operative position. The said ends may extend different distances beyond the outer periphery of the tire. Preferably, the base is secured on less than all of the lugs and has a bearing recess accommodating a nut on a lug to which the base is not secured.

Abstract: A vehicle traction device for passenger cars and alike including a flexible belt-like traction mat with transverse corrugations on one side and substantially smooth on the other side. One end of the mat is pivotally secured to anchoring means including a flexible anchoring pad and ground gripping element.In use, the traction mat is first arranged to form a loop relative to the anchoring means. With its corrugations facing a tire and its smooth side facing the ground the traction mat will easily be drawn under a spinning wheel until that end of it, which is secured to the anchoring means becomes choked by the anchoring means. The tractive effort then developed causes the anchoring means to become wedged and thus assuring its fixed position, whereby the traction mat is prevented from being propelled away by the driven wheel.

Abstract: A traction device for a motor vehicle comprising a hose connecting the vehicle's exhaust pipe to an air pressure pump inlet. The outlet of the pump is detachably connected to the inlet valve of the vehicle's tire. An outlet valve for exiting cold air is connected to another hose communicating with a temperature gage and a pressure gage.

Abstract: The present invention is primarily for providing traction for the tires of automotive vehicles in particular on snow and ice surfaces. The tire generally comprises pairs of deep and shallow channels in close proximity with each other around said tire to extend transversely from the side walls thereof toward a tread portion, said pairs being uniformly spaced at intervals around the periphery of said tire. The tire of the invention includes traction units which are always recessed in the deep channels to provide no traction, and when the traction units are disposed in the shallow channels, they provide effective traction. In addition, the invention comprises a device for converting from one type of tire to another and also a mechanism having a pneumatic bumper for protecting a supporting unit and a shifting unit from breakage when a tire is punctured.

Abstract: A pneumatic tire includes a breaker belt interposed between the tread and the tire carcass, the belt including opposing elastic layers with a sheet interposed between the layers, the sheet having a plurality of perforations therein and comprising a material having a relatively high modulus of elasticity with respect to the layers.

Abstract: A skid prevention device for tires, which tires are provided with longitudinally- and radially-extending rows of treads separated by discrete, laterally-extending rows of recesses, includes a plurality of elongated, generally U-shaped metal claws disposed within the rows of the recesses of the tire, the outer ends of which have spikes secured thereto, and the inner ends of which are pivotably supportable in the recesses of the tire. The device also includes means for pivotably mounting the inner ends of the claws in the recesses of the tire for movement between an extended position, in which the claws are pivoted upwardly with their spikes extending radially outwardly beyond the upper surface of the treads of the tire, and a retracted position, in which the claws are pivoted downwardly with their spikes lying below the upper surface of the treads of the tire. In addition, the device includes means for pivotably moving the claws between the extended and retracted positions thereof.

Abstract: An anti-skid device for a vehicle tire includes a plurality of individual anti-skid units mounted on the outer surface of each tire. Each of the anti-skid units includes a resilient member having an anti-skid surface mounted in a recessed portion of the tire. Each anti-skid unit further includes an adjusting mechanism mounted in the tire and coupled to the resilient member for adjusting the position of the resilient member to vary the anti-skid surface from a retracted position within the recessed portion of the tire to an extended position with the anti-skid surface beyond the outer surface of the tire.

Abstract: An endless tire-mounted anti-skid belt is produced by spreading an endless fibrous mesh to the diameter of the vehicle tire on which the belt is to be mounted, impregnating the spread endless mesh with a hot-vulcanizable elastomer dissolved in a solvent, drying the impregnated spread endless mesh until at least 80% of the solvent has been removed, repeating the impregnation and drying steps several times until a desired thickness of elastomer has been deposited on the spread endless mesh, and curing the elastomer by vulcanization in an autoclave under hot steam.

Abstract: An improved automobile tire that incorporates studs for engaging a roadway surface during times when covered by snow and especially by ice; the studs protruding from a narrow area around the tire which during normal use in non-icy weather is concave so to form an annular recess in order that the studs do not engage the roadway; the tire having a separate air cell just behind the annular recess which is inflatable during icy weather by a separate valve so to push outwardly the recess thus exposing the studs beyond the remainder of the tire outer periphery.