Sheave Sheave A sheave () is a pulley with a grooved wheel for holding a belt, wire rope, or rope. The grooved wheel spins on an axle or bearing inside the frame of the block. This allows the wire or rope to move freely minimizing friction and wear on the cable. Sheaves can be used to redirect a cable or rope, lift loads, and transmit power. The words "sheave" and "pulley" are sometimes used interchangeably. A sheave can also refer to a pulley which has an adjustable operating diameter for use with a mechanical belt. This is accomplished by constructing the
Tackle (gridiron football position) Tackle (gridiron football position) Tackle is a playing position in American and Canadian football. Historically, in the one-platoon system prevalent in the late nineteenth and early twentieth centuries, a tackle played on both offense and defense. In the modern system of specialized units, offensive tackle and defensive tackle are separate positions, and the stand-alone term "tackle" refers to the offensive tackle position only. The offensive tackle (OT, T) is a position on the offensive line, left and right. Like other offensive linemen, their job is to block: to physically keep defenders away from the offensive player who has the football