Abstract: A curved backing insert is held in a backrest frame and adjustable to conform to the spine of a person leaning against the backrest. The backing insert comprises at least one elastic bow having a first end supported by said frame, a second end vertically spaced from said first end, and an intermediate vertex portion including a vertex. First stressing means are adjustable to move said second end so as to change the height and curvature of said bow. Second stressing means are adjustable to adjust said vertex relative to said first and second ends.

Abstract: A centrally disposed, torsion-proof carrying tube contains a propeller shaft operatively connected to the driven axle assemblies and equipped with supports for the body of the vehicle. Each axle assembly has a spur gear differential associated therewith and comprises two bevel gear trains succeeding the differential and accommodated in a gear housing flanged to the central carrying tube. The body supports comprise at least two cross members joined to the carrying tube and two longitudinal members secured to the cross members. Each wheel is mounted on a stub axle carried by a longitudinal control arm pivoted to a cross member on an axis which is transverse to the longitudinal direction of the vehicle. Two universal-joint shafts drive the two wheels of each axle assembly. Each universal-joint shaft is associated with one of the bevel gear trains and is enclosed in a splash-proofing shell tube connected by ball-type joints to the adjacent stub axle and to the adjacent gear housing, respectively.

Abstract: In a reciprocating internal-combustion engine, a power unit comprises cylinders 1, cylinder heads 2, pistons, connecting rods, a crankshaft and crankshaft bearings. Soundproofing supporting members mount the ends of the power unit in an outer pan 7 which is connected to a flywheel housing 8. Soundproofing supporting members 12, 12a, 13 are coaxial with the crankshaft and center the power unit and hold it against substantial axial movement in the outer pan. An oil seal 14 is fitted between the power block and the top rim of the outer pan.

Abstract: A steering head for a bicycle comprises a mounting shaft having a lower end secured to the forward end of the main bicycle frame, the mounting shaft projecting upwardly from the forward frame end. A bearing sleeve is rigid with the fork head of the front wheel fork of the bicycle and is rotatably mounted on the mounting shaft.

Abstract: The device is provided in a two-wheeled vehicle comprising a tubular steering head, a tubular fork shaft rotatably mounted in said tubular steering head and having a shell aperture, two fork blades, upper and lower fork bridges firmly connecting said fork blades to said fork shaft, and a steering lock having a bolt and operable to move said bolt into said tubular fork shaft through said shell opening to said locking position, and out of said tubular fork shaft. A rod is longitudinally slidably mounted in said tubular fork shaft and has a lower end portion which is enlarged in width and extends under said bolt when the latter is in said locking position. A hook is secured to said lock and movable therewith between a lower position, in which said hook cooperates with said upper fork bridge to form a closed latch therewith, and an upper position, in which said hook is spaced above said upper fork bridge.

Abstract: A gear comprises a hub and a gear ring mounted thereon, each formed with peripherally spaced apertures and interlocking elements extending peripherally between adjacent apertures to hold the hub and gear ring against axial movement relative to each other. The apertures of the hub and gear ring register. Torque is transmitted between the hub and gear ring by a plurality of first abutments on the hub which have radially outwardly facing surfaces adjoining respective apertures therein, a plurality of second abutments on the gear ring which have radially inwardly facing surfaces adjoining respective apertures therein and radially aligned with respective outwardly facing surfaces, and a plurality of prestressed elastomeric spring elements disposed in the registering apertures. Each spring element engages the radially aligned surfaces and is retained in the apertures by a retaining disc secured to the hub and engaging the spring element on one side of the gear.

Abstract: A drive for a road wheel mounted in the frame of a motor-assisted bicycle comprises a drive housing pivotal transversely to the plane of the wheel and connected to the frame by an interposed elastomeric sleeve deformable by the pivotal movement of the drive housing. An engine in the housing has a crankshaft and a drive shaft is non-rotatably connected to the crankshaft. A bevel wheel is non-rotatably mounted on the drive shaft and a pressure roller is aligned with the bevel wheel in the axial direction of the road wheel, the bevel wheel and pressure roller being engageable with the road wheel on opposite sides thereof. A spring arm secured to the housing and carrying the pressure roller normally urges the bevel wheel and pressure roller into engagement with the respective sides of the road wheel.

Abstract: A breech-closing mechanism for an automatic rifle having a breech chamber and a first locking and stop device comprises a longitudinally movable slide formed with a cam slot, a second locking device rigid with a longitudinally slidably bolt mounted in the slide and rotatable relative thereto. A longitudinally movable locking member is non-rotatably mounted in the slide and a radial cam follower pin is rigid with the bolt and extends through an angled slot in the locking member into the cam slot. The locking member is spring-urged forwardly relative to the slide and is carried along by the slide into engagement with the first locking and stop device. The slide moves forwardly relative to the locking member against the spring force when the locking member is in said engagement until the pin is at the forward end of a longitudinal arm of the angled slot.

Abstract: The wheel comprises a hub having a periphery provided with peripherally spaced, radially projecting lugs. An integral wheel body comprises a central ring which surrounds the hub and is secured to the lugs, and spokes radiating from the ring. The hub and ring define air flow passages disposed radially between the hub and ring.

Abstract: A shifting mechanism for a motor vehicle transmission comprises first and second stationary pivots transversely spaced apart. A range shifting fork is pivotally movable about said first pivot to a plurality of range control positions, which include a slow range position, a fast range position, and a no-load position. An axle shifting fork is pivotally movable about said second pivot to a plurality of clutch control positions, which include a clutch-engaging position and a clutch-disengaging position. A bridge extends transversely to the shifting paths and has one end portion connected to the range shifting fork and a second end portion connected to the axle shifting fork. A first pivotal joint is spaced from said first pivot and pivotally connects said first end portion of said bridge to said range shifting fork. A second pivotal joint is spaced from said second pivot and pivotally connects said second end portion of said bridge to said clutch control fork.

Abstract: A rifle trigger mechanism comprises a sear spring-urged into an intercepting position and pivotal into a non-intercepting position. An intermediate lever is pivotal into a locking position in which it backs the sear in the intercepting position. A trigger is pivotal from an intermediate position forwardly to a preset position and rearwardly to a triggered position. The trigger has an extension for direct engagement with the lever in the locking position when in the intermediate position, to be clear thereof when in the preset position, and to cause the lever to move out of the locking position to release the sear for a movement out of the intercepting position in response to a movement of the trigger from the intermediate to the triggered position. A compression spring opposes a trigger movement to the preset position and is arranged to cause the trigger to move beyond the intermediate position to the triggered position when the trigger has been slightly moved from the preset toward the intermediate position.

Abstract: A barrel is fixedly inserted in and protrudes from a grip and comprises a barrel chamber. A piston is provided on the outside of said barrel and rigid therewith. A breechblock comprises a cylinder surrounding said barrel and piston before said grip and defining with said barrel an annular chamber, which is sealed against said barrel. Said breechblock is movable along said barrel to and from a forward position. A counterrecoil spring urges said breechblock to said forward position. A piston is disposed in said annular chamber and rigid with said barrel and arranged to be disposed at the rear end of said annular chamber when said breechblock is in said forward position. Transverse bore means are formed in said barrel and communicate with the interior of said barrel adjacent to said barrel chamber. Longitudinal passage means are provided, which are laterally enclosed and connect said transverse bore means to said annular chamber.