US Patent 7377886 Adjustable pull exerciser

A pull exerciser includes two attachment members, two positioning devices respectively attached to the attachment members at a location opposite to a grip portion of an associated attachment member, and at least one resilient cord. Each positioning device includes a positioning block and a positioning plate removably received in the positioning block. Each of the positioning blocks and the positioning plates includes at least one positioning hole. The resilient cord has two ends extendible through the positioning hole of each positioning block and each positioning plate. An end piece is fixed to each end of the resilient cord. The end pieces of the resilient cord are mounted to at least one of the positioning plates.