Patent ID: 7475841

Claim:
A spring retractable reel which pneumatically governs the retraction of a line of material, the spring retractable reel comprising: a frame; a spool rotatably supported on said frame; a spring for biasing said spool to take up the line of material; an air motor mounted on said frame, said air motor comprising: a housing having a chamber therein; a rotor having an axial shaft and a plurality of vanes, said rotor being eccentrically disposed relative to said chamber of said housing; a first port in communication with ambient air and opening into said chamber on a first side of said rotor; and a second port in communication with ambient air and opening into said chamber on a second side of said rotor; an adjustable valve for adjustably restricting a flow of ambient air through said second port, said valve defining a second sized opening sized smaller than a first sized opening of said first port; a first sprocket mounted on spool for rotation therewith; a second sprocket mounted on said shaft of said rotor; a chain for fixedly coupling the rotation of said spool and said first sprocket to the rotation of said second sprocket in both an unwinding direction and a retraction direction, and said first sprocket being larger than said second sprocket; and wherein when the line of material is pulled off said spool in said unwinding direction, said spring is tensioned and said rotor rotates generally freely as a flow of ambient air is draw through said valve into said chamber and generally unrestricted out said first port into ambient air, and when said spool rewinds the line of material under the action of the spring in said retraction direction, said rotor rotates in an opposite direction, which in turn draws a flow of ambient air through said first port, a portion of the flow of the ambient air drawn through said first port being restricted from exiting said second port due to said valve thereby compressing air within said chamber to regulate the speed at which said spool rewinds the line of material.