Abstract: A shock-absorbing sprocket or gear assembly or like torsionally elastic device is described having resilient cushioning means interposed between mating lugs of the hub and rim to smooth and dampen torsional shocks and vibrations produced by a power drive train. An improved radial bearing surface is provided which maintains symmetry of the bearing load with respect to the drive, and which ensures concentricity between the hub and rim and keeps the rim from wobbling axially or orbiting radially with respect to the hub during operation. The cushioning means are configured relative to the hub and rim to accommodate angular displacements of at least 9.degree.. A power transmission drive system employing the shock-absorbing sprocket of the invention is also described.

Abstract: A sprocket for use with positive drive belts of the type with oppositely facing curvilinear driving surfaces, the sprocket having improved symmetrical teeth with a cross-section profile defined by axially oriented, oppositely facing driving surface portions that extend from the top land of the tooth at an angle of about 15 degrees or less to the sprocket tooth, each driving surface of the sprocket tooth blending into an oppositely facing oblique surface at an angle of about 150 to about 170 degrees that provides a positive clearance between the sprocket tooth and side portions of a meshing belt tooth to direct egress of material away from the sprocket, the oblique surfaces define a sprocket tooth base that is wider than the sprocket tooth top land and bottom land portions between sprocket teeth providing positive clearance between the bottom land portions and belt tooth tips.