Abstract: An overriding clutch adapted for use within both metallic and synthetic resin structures has a housing of generally annular cross section with at least three equidistantly spaced recesses about its inner periphery each having a radial throat portion and a secantally extending portion elongated in the direction opposite the normal direction of rotation of the shaft. The radially outer surface of the secantal portion has a secantally extending rectilinear ramp portion which is inclined to a smaller radial dimension. A roller bearing in the recess has a diameter slightly larger than the throat, and the radial depth of the recess to the ramp surface is less than the diameter of the roller bearing so that the outer circumference of the roller bearing extends radially inwardly of the housing to provide a bearing surface for the shaft. A spring in the elongated portion of the recess biases the roller along the ramp surface.

Abstract: The drive assembly for a form feeding tractor has a flexible endless belt comprising an endless band member of synthetic resin with a generrally planar outer surface and metallic drive pins spaced about its circumference. The band member has a series of spaced apart drive sections each with a plurality of drive teeth extending transversely thereof on its inner surface, and the metallic drive pins are disposed in the spaces between the drive sections. The pins have a base section which extends through the band member with a circumferential groove intermediate its length and into which the band member extends, and the band member has platform portions on its inner surface which extend about the base portions on the pins.

Abstract: A resuscitation mask has a base member with an inflatable bladder about its periphery which will rapidly and effectively seal against the face of the patient upon initial flow of air into the mask from the rescuer. A delivery member causes air to flow to the bladder to effect the inflation and then a valve member precludes further inflation. A one-way valve and filter in the conduit from the delivery member to the base member precludes flow of air and body fluids from the patient to the mouthpiece, and diverts exhaled air to the atmosphere about the mask.

Abstract: A tractor for driving web material has an endless belt which travels about spaced apart drive and idler sprockets, one of which is an entrance sprocket and the other an exit sprocket. The idler sprocket is journalled in a support member which is movable on the tractor chassis by an adjusting member to vary the spacing between the sprockets and thereby adjust the tension in the belt. The belt carries the paper over a rectilinear path between the sprockets and the chassis has upper surfaces along that path which rise prior to the exit sprocket to lift the paper on the drive pins on the belt and provide a ramp surface clearance to effect clearance of the drive pins in the perforations of the paper so that they rotate downwardly without excessive wear and friction between the web around the perforations and the surface of the pins.

Abstract: A tractor for a web feeding assembly having spaced support and drive shafts has a chassis providing a pair of apertures extending therethrough and a belt extending thereabout. A drive pulley mounted in one of the chassis apertures is engaged with the driven surface of the belt and has an aperture therethrough receiving the drive shaft. A convexly arcuate belt support surface cooperates with the drive pulley to define the web drive path for the belt therebetween. A resilient spring clamp is mounted adjacent the other aperture in the chassis and releasably clamps the tractor on the support shaft. The mounting desirably permits the clamp to rotate about the axis of the aperture receiving the support shaft.