Abstract: A universal chassis frame is disclosed having a ladder-frame construction configurable to position a rear axle(s) at variable distances from a back of a vehicle's cab to provide customized rail/bed lengths for different electric truck classes. The chassis frame includes a central frame having a pair of main frame rails to support at least two battery modules substantially within an intra-frame space. A front subframe supports the cab, a front portion including a pair of upper frame members mounted above the corresponding main frame rails, and a front axle unit mounted under the front subframe. A rear subframe supports at least one rear axle unit mounted under the rear subframe and any of multiple configurable rear payload units via a common connection interface affixable to the main frame rails so the rear subframe's location with respect to the main frame is longitudinally variable from the back of the cab.

Abstract: Embodiments are disclosed for face syncing in a distributed computing environment. In an embodiment, a method comprises: obtaining, by a processor, media assets that include faces of individuals; detecting, by the processor of a mobile device, the faces on the media assets; generating, by the processor, faceprints for the detected faces; clustering, by the processor, the faceprints into clusters; generating, by the processor, a face crop image for each cluster; and sending, by the processor, the face crop images to a network-based, distributed syncing service.

Abstract: A removable drum shell kit for a compactor drum includes a plurality of links coupled together. The plurality of links includes a longitudinal member having an inner surface contacting the compactor drum and an outer surface contacting a ground surface. The plurality of links includes at least one cleat assembly coupled to the outer surface of the longitudinal member. The plurality of links includes at least one first coupling member coupled to the longitudinal member extending towards a first side of the longitudinal member and at least one second coupling member coupled to the longitudinal member extending towards a second side of the longitudinal member. The first coupling member is coupled to a corresponding second coupling member of another link towards the first side of the link, and the second coupling member is coupled to a corresponding first coupling member of another link towards the second side of the link.

Abstract: A steering system for an industrial truck includes a first wheel set configured to be hydraulically steerable, a second wheel set configured to be hydraulically steerable, a first hydraulic linear motor connected to the first wheel set, and a second hydraulic linear motor connected to the second wheel set. The first hydraulic linear motor is provided as a first synchronizing cylinder. The second hydraulic linear motor is provided as a second synchronizing cylinder. The first synchronizing cylinder and the second synchronizing cylinder are operatively connected to each other.

Abstract: An electrically assisted bicycle is provided with a so-called single-shaft motor drive unit that can satisfactorily keep torque detection capability. The outer periphery of a crankshaft 7a has a cylindrical human-power transmission member 28 having a torque sensor 31 for detecting a human driving force and a combined force member 29 that combines a human driving force and an auxiliary driving force from a motor 21. A one-way clutch is not provided on a driving force transmission path including the crankshaft 7a, the human-power transmission member 28, and the combined force member 28. The human-power transmission member 28 and the combined force member 29 are always rotated in response to a rotation of the crankshaft 7a.

Abstract: A vehicle track assembly includes a track framework including a frame structure, a drive drum, and a plurality of idler wheels supported by the frame structure. A drive track is arranged about and cooperatively engages the plurality of idler wheels and the drive drum. An adjustable ski is connected to the framework. The ski may extend forward of the track. An adjustable rearward extending ski may extend rearward of a track assembly. An indicator pole is coupled to the assembly to provide an indication of the angle of rotation of the assembly.

Abstract: A self-propelled single axis motor driven work machine for propelling and/or for driving communal or agricultural work devices mounted on a mounting device. A drive motor is fastened to an undercarriage or machine chassis, and a drive axle protrudes transversely of the direction of movement from both sides of the undercarriage or machine chassis and is hydraulically driven by the drive motor. The drive axle has at both ends a wheel connected to a drive shaft which is connected on the operator's side thereof to the undercarriage and machine chassis with mounted guide rods for manually steering the work machine and for arranging an actuating member for operating and controlling drive units having hydraulic pumps and hydraulic motors, for driving and steering the wheels of the drive axle.

Abstract: A maneuvering drive for a trailer includes a fastening means for fastening to the trailer, a carrier movable relative to the fastening means, a drive motor held by the carrier, a drive roller rotatable drivable by the drive motor and a braking means for braking a rotary movement of the drive roller. The drive motor and the braking means are arranged coaxially to each other. In the flux of force between the drive motor and the drive roller a transmission device is provided, which has no self-locking feature.

Abstract: A device for adapting a manual wheelchair to drive with a powered wheel is disclosed. The device attached to the wheelchair provides means for raising the wheelchair front caster wheels and simultaneously having the powered wheel contact the driving surface. The disclosed device may be rotated so that the powered wheel lifts from the surface as the front caster wheels are lowered to contact the driving surface enabling manual operation of the wheelchair. The disclosed device includes a mechanism for steering the powered wheel, controls for varying the forward or backward speeds and braking. The device may be detached from the chair and is adaptable to fit a large variety of wheelchairs with capability for ergonomically adjusting the steering column for the comfort of the user. Optional human interface devices may be incorporated so the chair occupant may control speed and steering by operating a joystick, head array or other such devices.

Abstract: A hospital bed with a chassis and with four rollers arranged on the chassis has at least one further auxiliary roller that can be brought into contact with the floor or that can alternatively be driven. The auxiliary roller is mounted on a rigid frame and, together with the frame, can be raised or lowered relative to the chassis by pivoting. A drive motor is secured on the frame and drives the auxiliary roller. A separate pivot drive is provided for raising and lowering the auxiliary roller. The separate pivot drive is secured entirely on the frame and pivots with the frame.

Abstract: A conveyor mover which may be used to move an auger conveyor or a belt conveyor from one location to another such as between grain bins. The mover is secured to the framework axle of the conveyor and is movable between a lower ground engaging position to an upper transport position. The mover includes at least one drive wheel which may be driven in either a forward direction or a rearward position. In one embodiment, a steer wheel assembly is secured to the conveyor tube adjacent the lower end thereof.

Abstract: A patient support including a traction device for powered movement of the patient support.

Abstract: This invention is a control device to vary the contact conditions of the tread of a vehicle to improve driving functions, such as skid prevention, noise reduction, road surface protection or road marking, by the choice of the appropriate trodden tips in given road conditions. The trodden tips and connected parts are unified to make a unit which is attached or detached with a simple connection such as the insertion at a convenient position, which enables the device to function properly with a lowered safety factor, reducing the size only to avoid damages of the device and around.

Abstract: A grain auger mover assembly is disclosed which may be used to move either a conventional grain auger or a grain auger having a swing hopper auger associated therewith. The grain auger mover of this invention is remotely controlled.

Abstract: A patient support including a traction device for powered movement of the patient support.

Abstract: A universal attachment device for attaching lawn care equipment including but not limited to leaf catchers, plug-core aerators, utility carts, and fertilizer spreaders to the sulky of a commercial walk-behind mower, the attachment device features a mounting shaft; a vertical pivot mount disposed on the first end of the mounting shaft for engaging a mounting plate disposed on the sulky; and a vertically oriented mounting channel disposed on the second end of the mounting shaft, the mounting channel functions to a base attachment shaft disposed on the piece of lawn care equipment or the lawn care equipment directly.

Abstract: A reverse drive mechanism is configured to rotate at least one wheel of a multi-wheeled device in a reverse direction so that the device moves in that reverse direction. One particular application involves a motorcycle conversion assembly in which at least one of the rear wheels of the conversion assembly is driven in the reverse direction so as to back-up the motorcycle.

Abstract: The invention discloses an anti-skid mechanism operating device (1) for vehicles comprising an operating unit (2) and an operating arm (3) pivotally supported thereby and intended to carry a rotary anti-skid device (4) and to operate the latter between an active and a passive position. The operating device (2) comprises a worm gear (6) and a driven worm (5) adapted to engage said worm gear (6) for operation of the operating arm (3). The driven worm (5) is resiliently displaceable along an axis (A) of said worm (5).

Abstract: A patient support including a traction device for powered movement of the patient support. The traction device includes a storage position and a use position.

Abstract: A trailer which can be used to tow a vehicle and which can be towed by the same vehicle while that vehicle is inside the trailer and lowered down to ground level.

Abstract: An anti-skid device for a vehicle for positioning a traction member beneath a vehicle wheel includes a support member that is attached to the vehicle, a pivoting swing arm with a traction wheel with traction members thereon, and a drive assembly attached to the support member and to the swing arm so as to extend and retract the swing arm. The drive assembly includes a gear-reduced electric motor that is coupled to a worm that meshes with a worm gear that is attached to the swing arm shaft. As the motor moves in a first direction, the gear mesh causes the arm to deploy and, in a reverse direction, the swing arm retracts. Spring-biasing is provided so as to maintain pressure of the traction wheel against the vehicle wheel and limit switches are provided so as to turn the drive motor on and off.

Abstract: A hand truck driving apparatus includes a dolly that has a frame having a bottom end, a top end and pair of lateral sides. A plate is attached to the frame adjacent to the bottom end and extends forward of the frame. A stabilizer is attached to and extends rearward of the frame. A pair of support wheels is rotatably attached to the stabilizer adjacent to the bottom end of the frame. A drive platform is removably attached to the dolly. A drive apparatus is mounted on the drive platform. The drive apparatus moves the drive platform and the dolly when the drive apparatus is actuated.

Abstract: The present invention provides a kit for attaching a manually operated wheelchair to a motorized scooter having a seating apparatus and supporting structure and a floor, comprising: (a) a motorized scooter attachment angle iron, wherein the angle iron comprises: (i) a vertical wall; and (ii) a horizontal wall, the horizontal wall forming approximately a right angle to the vertical wall, wherein the horizontal wall has at least two embedded elongated slots; (b) an angle iron attachment adjustable bar, wherein the adjustable bar comprises (i) a left elbow shaped tubular segment having a horizontally oriented bottom end and a vertically oriented top end; (ii) a right elbow shaped tubular segment having a horizontally oriented bottom end and a vertically oriented top end; and (iii) a straight middle tubular segment having a diameter larger than the left segment and the right segment, so as to permit the left segment to insert into a left end of the middle tubular segment and so as to permit the right segment to i

Abstract: The present invention is a powered hospital bed mover or bed transfer system. The bed mover includes a bed attachment mechanism that is vertically displaceable relative to a base that includes an electrically powered drive wheel and a pair of support castors. The attachment mechanism includes a pair of horizontally oriented jaws with jaw openings that face away from each other. Each jaw includes a contact switch in its bottom surface and a contact switch in its jaw opening. The contact switches indicate to the mover and its user that the mover is properly engaged with the frame of a hospital bed. The jaws are horizontally displaceable and diverge from each other to engage vertical frame members of a hospital bed. A control panel has a joystick adapted to control the speed and direction of travel for the mover. The control panel also has controls for actuating the jaws, changing the elevation of the attachment mechanism, and locking at least one of the support castors.

Abstract: A hospital bed includes a carrier frame, a driven wheel unit disposed below the frame, a motor unit, a drive wheel unit disposed below the frame and coupled operably to the motor unit in such a manner that actuation of the motor unit results in rotation of the drive wheel unit. A lifting-and-lowering device interconnects the frame and the drive wheel unit for lowering and lifting the drive wheel unit with respect to the driven wheel unit between an upper position, in which, the drive wheel unit is disposed at an elevation above the driven wheel unit, and a lower position, in which lower surfaces of the driven and drive wheel units are flush with each other.

Abstract: An anti-skid device for use in cooperation with a vehicle wheel for positioning a traction member beneath the vehicle wheel includes a frame assembly constructed and arranged to be attached to the vehicle, a swing arm pivotally connected to the frame, and an electric, linear actuator having an extendable shaft. The anti-skid device includes a double pivot link where one end is attached to the frame assembly and the opposite end is attached to the swing arm. The linear actuator is attached to a movable pressure plate and a biasing spring is positioned between the movable pressure plate and a back plate for applying and maintaining contact pressure of the traction wheel against the vehicle wheel. In the preferred embodiment, the traction member is a length of chain that is connected to the traction wheel for positioning between the vehicle wheel and the road surface.

Abstract: A vehicle that uses a steel lug wheel assembly while in the field and has retractable rubber tires for transport on paved roads. The vehicle is capable of simultaneously performing multiple farm operations in a field. The multiple farm operations include shredding, chiseling, tilling, as well as pulling any farm implement device such as a planter or a fertilizer.

Abstract: A motor drive for a bicycle is provided. The motor drive includes a drive wheel and a motor device driving the drive wheel. The drive wheel contacts the ground and moves the bicycle by rotating friction between the drive wheel and the ground. The motor device includes a fixing portion that attaches the motor device to the frame of the bicycle, and a driving portion that holds the drive wheel and drives the drive wheel. The driving portion is pivotable with respect to the fixing portion between a parking state and a driving state. The drive wheel is spaced from the ground in the parking state, and contacts the ground in the driving state.

Abstract: A self-propelled sulky for attachment to existing non-self-propelled equipment, thereby enabling the equipment to be converted into a self-propelled equipment with a modular propulsion system. The sulky includes a frame, a motor mounted to the frame, wheels rotatably mounted to the frame, a device for transferring power from the motor to at least one of the wheels, a device for controlling the power transferring device and thereby the ground speed and direction of the sulky, a device for connecting the sulky to a rearward end of the non-self-propelled equipment to enable pushing of the non-self-propelled equipment with the sulky, and a support structure on the frame for supporting an operator in a standing position.

Abstract: A stretch mounting unit includes a unit body detachably mounted on a stretcher, a drive device attached to the unit body for providing an output, a center shaft for receiving the output of the drive device, a coupling that couples the drive device and the center shaft for transmitting the output of the drive device to the center shaft, a roller pressed on the center shaft to produce torque, a carrier swingably disposed on the center shaft, a pair of wheels rotatably mounted on the carrier and rotated by the torque of the roller, and a friction clutch provided rotatably on the center shaft and associated with the carrier for swinging the carrier until one of the pair of wheels touches the ground.

Abstract: An improved snow chain system for wheeled vehicles that can be rapidly deployed and rapidly retracted, includes a rotatably-mounted friction drive disc having a circumferential edge that is pressure biased against the sidewall of a tire. Multiple arcuate chain attachment plates, which interlock much like a laminar puzzle, are placed end-to-end to form a ring-shaped unit. The ring-shaped unit is held together and to a planar surface on the friction drive disc by a plurality of bolts, each of which passes through a single attachment plate and through the friction drive disc. Each arcuate attachment plate has either one or two chain segments attached thereto. In the case where only a single chain segment is attached, a U-shaped anchoring chain link is welded to the attachment plate. In the case of attachment of a pair of chain segments, a M-shaped anchoring link is employed.

Abstract: Disclosed is a power assist anti-tip wheel system for invalid carriage including at least one connecting support, at least one assist anti-tip wheel, and at least one power driving means. The connecting support is fixedly or detachably connected at one end to a front or a rear side of the invalid carriage. The anti-tip wheel is associated with the connecting support so that it is located in front of or behind the invalid carriage. The power driving means is also associated with the connecting support to drive the anti-tip wheel to rotate when the invalid carriage travels onto a slope or passes a recess or a bulge on a road surface and two drive wheels thereof become suspended and idling. The power driving means can be automatically actuated via a sensing circuit or be manually actuated via a push button.

Abstract: An auxiliary wheel conversion assembly for a motorcycle comprises a quick connect and disconnect structure, including a generally U-shaped frame having side frame members on opposite sides of a receiving pocket to receive the rear drive wheel of the motorcycle when connected thereto, a cross-bar across the rear between the two side frame members, an auxiliary wheel mounted along and to the outside of each side frame member, such wheels being of the same size as the rear drive wheel and substantially in axial alignment therewith when the conversion assembly is connected to the motorcycle.

Abstract: A detachable motorized wheel assembly for a golf cart has a support framework removably attachable to the rear section of a golf cart of the type having oppositely disposed and spaced apart wheels. The assembly includes a motor driven wheel positioned between and rearward of the spaced apart wheels of the golf cart. The assembly further includes a golf bag support device having a number of support loops. Each loop having a first section outwardly disposed from the top of the support framework. Each loop further having a second section disposed upwardly from the first section to form an obtuse angle between the first and second sections.

Abstract: A detachable propulsive device for a wheelchair includes a longitudinal skeleton frame, a driving unit attached to the front of the skeleton frame, a handle for steering the propulsive device, dimensions adjusting unit, and auxiliary wheels. The dimensions adjusting unit carries four retaining clips and allows to adjust distances between these clips lengthwise and widthwise, so that the clips are capable of engaging and holding side members of the bottom frame of the wheelchair of any desired length and width. The length adjusting mechanism of the dimensions adjusting unit includes a system of telescopically movable hollow tubes with U-shaped cross sliding rails secured to them, while the width adjusting mechanism includes sliding arms carrying the retaining clips on their outer ends and sliding longitudinally along the U-shaped cross sliding rails in the lateral direction. The auxiliary wheels at the rear of the propulsive device are lifted from the ground once the device has been attached to the wheelchair.

Abstract: An assembly for converting a two-wheeled motorcycle into a three-wheeled motorcycle which provides independent suspension for each of the rear wheels and which has a relatively low unsprung weight, thus not substantially impairing the performance of the motorcycle after it is converted to a three-wheeled vehicle. The assembly may be bolted to the frame of a motorcycle, without the need for welds or other permanent connections, so that the three-wheeled motorcycle can be converted back into a two-wheeled motorcycle when desired.

Abstract: An adjustable apparatus for mounting a rear axle to a motorcycle frame in a process of converting a two wheel motorcycle to a three wheel motorcycle includes a pair of mounting plates to be connected to the rear axle, a pair of mounting arms to be connected between the mounting plates and the original motorcycle frame, and adjustable connecting joints to be disposed between the mounting arms and the mounting plates and between the mounting arms and the original motorcycle frame. The alignment of the rear axle relative to the longitudinal axis and line of travel of the motorcycle may be adjusted by adjusting the connecting joints to effectively shorten or lengthen the effective length of the mounting arms.

Abstract: The present invention relates to an individual vehicle usable in a manual or a motorized version, in particular a wheelchair or a tricycle, including a chassis (1) provided at the rear with two bearings designed to receive removable wheels (2). According to the invention, this vehicle is able to be equipped with a self-contained propulsion unit (12) comprising driving wheels (13), a structure (14) for rotationally driving the driving wheels, a support suitable for supporting the bearings when the removable wheels (2) are removed, a locking device suitable for cooperating with a retaining device (11) provided on the chassis (1) when the bearings rest on the support, and a control (17) for moving the locking device between an active and an inactive position.

Abstract: An anti-skid mechanism for vehicles interposes a series of blades or fins between the wheels and the road surface. The fins are mounted upon a sprocket chain or endless belt which rotates about a pair of sprocket wheels with straight section of the sprocket chain aligned near the contact point of the tire with the road. The fins are consecutively laid upon and removed from the road surface in a straight line between the wheel and the road surface. The flat sprocket chain and its mounting upon the sprocket wheels provides a high degree of stability of movement of the blades which in conjunction with the straight orientation of the chain or belt and attached blades under the wheel maximizes the static coefficient of friction between the wheel and the road.

Abstract: A device for translating linear to rotary motion comprising a housing member, a rack member disposed in the housing member for longitudinal movement therein and having a starting position, a shaft in the housing having a pinion thereon engaged by the rack, the shaft being journalled in the housing and being disposed generally perpendicular to movement of the rack member, the shaft extends outwardly of the housing and has a rotative driving member thereon, the rack member has a longitudinal opening therein at one end thereof receiving the cylinder of gas cylinder-piston assembly, the piston of the gas cylinder piston assembly engages an end wall of the housing whereby upon movement of the rack member the gas in the cylinder is compressed and energy is stored therein, a slave cylinder in the housing member is adapted to receive fluid under pressure from an external source, a floating piston in the slave cylinder is arranged to act upon and linearly drive the rack and thereby rotate the pinion, the shaft and the

Abstract: The positioning and attachment of the auxiliary snow-chain device, intended to be arranged under a motor vehicle, is carried out with the aid of suspension locations, preferably three in number (101, 102, 103), which are integrally cast with a cage (1) housing means for driving a swivel arm (3) bearing a small wheel. Each suspension location is made up of a lug provided with a center bore (14) which is traversed by a threaded element having a diameter appreciably less than that of the bore. The top and bottom faces of each lug are rounded. The triangular arrangement of the lugs, which co-operate with components for integration with the vehicle, permits fine positioning at the same time as reliable attachment of the snow-chain device.

Abstract: A vehicle for use in ski-area snow grooming operations and also for use in summer maintenance operations which is provided with a four-wheel hydrostatic-drive transmission and four-wheel steering. The vehicle has a frame/body/engine assembly which provides a centrally located low center of gravity and high operator visibility. The vehicle has a relatively broad wheel base which is further broadened by mounting of at least four snap-on wheels. A wrap-around cleat assembly is mountable on each of four multiple-wheel sets for increasing traction in snow. An engine-driven snow processing apparatus operable in both a snow blading state and a snow compacting state is provided.

Abstract: The device is made up of a double-action jack (4, 5, 6, 7, 12, 13), a case (9), a tip (10) and a fixing means (11). A rack (15), integral with the piston (12) of the jack, rotatingly drives a pinion (17) guided by two bearings (23, 24). On the fluted end (36) of the shaft (22) of the pinion there is fixed a swivel arm (2) having an axis perpendicular to the axis of articulation (18). This axis forms with the axis (16) of the rack an angle .alpha. other than 90 degrees. Owing to this angle .alpha., the swivel arm and a small wheel (3) attached thereto, when swivelling from a retracted position to an engaged position, move in a plane which is oblique relative to the horizontal, even though the cage (1) of the device may be placed in such a way that its axis is horizontal.

Abstract: A chain-carrying pulley (1) is journalled on a shaft (3) fastened to an arm (4) pivotally connected to another arm (5) which in turn is rigidly fastened to the rear axle casing (6) of a vehicle. An inflatable bellows (7) extends between the arms. When inflated, for instance by pressurized air, the bellows displaces the movable arm (4) from a folded position relative to arm (5) bringing the pulley (1) into contact with the wheel. The pulley is returned to a storage position by springs (10) joined to the arms when the bellows is deflated.

Abstract: A safety control for a baby's walker comprising a typical baby's walker having a horizontally extending peripheral frame supported on four peripherally spaced apart legs having rollers or wheels and a seat secured to and extending downwardly from the peripheral frame for the baby to sit in, the seat having two apertures for the baby's legs to extend through and to reach the floor when the baby stands and begins to walk, moving the walker as he goes and using the walker as a support and restraint to keep from falling, the walker in accordance with this invention having a motor connected to drive one or more wheels on command to move the walker and the baby in it away from a location of danger such as a electrical outlet, the head of a stairs, an open window, a hot stove, a whirling fan and the like.

Abstract: In an anti-skid device for motor vehicles with a plurality of resilient spreading arms (5) distributed over the circumference of a support (1) which can be set into a revolving motion for chain strands (3) forming anti-skid means, the spreading arms (5) are formed by compression springs (8) which are precompressed by connecting elements (13) which connect the chain strands (3) to the support (1).

Abstract: The trailer disclosed is hitched to an all-terrain vehicle, particularly an all-terrain tricycle, not just by the conventional universal-swiveling trailer hitch but also by spring struts. The springs extend and converge forwards and upwards from the ends of the trailer axle to attachment points behind the seat of the vehicle. The springs aid in making the combined vehicle and trailer more manageable over rough ground. The springs especially curb a tendency of a tricycle when under power to rear up at the front. The invention is particularly for use when tracks are added between the trailer wheels and the vehicle wheels.

Abstract: A steerable, powered, front wheel driven, three-wheeled vehicle for a handicapped person which is movable selectively in a forward or rearward direction and has a vehicle frame supported in part by a pair of transversely spaced rear wheels suitable for indoor travel, is adapted to outdoor use by backing its rear wheels onto a transversely extending, auxiliary frame supported on a pair of transversely spaced driven outdoor wheels. The auxiliary frame has a transversely extending cradle mounted such that, in a first forwardly and downwardly tilted position of the auxiliary wheel frame, the forward portion of the cradle rests substantially on the ground and, in a second position, in which the frame is generally level, the front and rear portions of the cradle are both disposed above the ground, and the rear wheels of the powered vehicle are supported by the cradle above the ground.

Abstract: Relatively heavy duty and large auger assemblies often used in present day farming are difficult to move and maneuver around a farmyard or the like and it is not always convenient to hitch a tractor to such auger assemblies for relatively short distance moving. This invention includes a small electric or gasoline motor or engine which can be operatively connected to a small wheel which is mounted within a frame secured to the auger assembly framework and which engages the ground. Means are provided so that this small wheel can be rotated in either direction. A small castoring wheel assembly supports the rear end of the auger assembly and when the small wheel is operatively connected to the motor, the wheel may be rotated slowly thus enabling the auger assembly to be moved as desired. Directional control is by steering the rear end of the auger assembly manually.A further embodiment connects the motor and the main supporting ground engaging wheels directly.

Abstract: A wheel attachment to provide extra needed traction by a motor drawn vehicle when traveling on roadways covered with snow, ice or mud. It comprises a plurality of circularly spaced, flexible traction members overhanging the tread of a pair of wheels and control means operable from the driving position of the vehicle to selectively couple or uncouple the attachment relative to the wheels. The control means may comprise a driver's switch for operating an electromagnetically operated pin on the traction device cooperable with a hole in a disc rotatably mounted on a spindle at each wheel to selectively couple the device operatively to the hub at the respective wheel. Other alternative means are provided to control such coupling.