Abstract: A powered propulsion apparatus that is attachable to and detachable from, a wide range of conventional wheelchairs without modification of the propulsion apparatus or the wheelchairs. The propulsion apparatus converts a conventional manually powered wheelchair into a power driven wheelchair. The apparatus clamps to the front wheels of a conventional wheelchair with a clamping mechanism that is adjustable to accommodate a wide range of wheel-spacings and wheel sizes and accommodates an inexactitude of alignment between the clamps and the wheelchair. The clamping mechanism secures the wheel chair to the propulsion apparatus without damage or stress to the wheelchair components.

Abstract: A powered propulsion apparatus that is attachable to and detachable from, a wide range of conventional wheelchairs without modification of the propulsion apparatus or the wheelchairs. The propulsion apparatus converts a conventional manually powered wheelchair into a power driven wheelchair. The apparatus clamps to the front wheels of a conventional wheelchair with a clamping mechanism that is adjustable to accommodate a wide range of wheel-spacings and wheel sizes and accommodates an inexactitude of alignment between the clamps and the wheelchair. The clamping mechanism secures the wheel chair to the propulsion apparatus without damage or stress to the wheelchair components.

Abstract: An earth boring bit having a body provided with a shank having a tubular bore and a head along the opposite end of said body having flow passages communicating with the bore, the head having face portions including a center end face portion, a nose portion, a shoulder portion, and a gage portion along the maximum diameter of the bit, and cutting elements mounted over said face portions having cutting faces oriented in the direction of rotation of the drill bit, the areas of the cutting faces of the cutting elements ranging from a maximum at the center face portion to a minimum at the gage portion of the bit. The cutters may be individually mounted, mounted in groups, arranged in random patterns, and arranged in a variety of other patterns, including radial longitudinal rows circumferentially spaced around the bit face.