Cover for truck beds

Claim 1

A cover for an open-topped truck bed having side walls, said cover comprising: a. a pair of track members affixed to said truck bed side walls adajcent their upper edges and extending substantially the full length thereof, b. a carriage carried by said tracks for movement therealong and including a bridge member extending transversely across the top of said truck bed, c. a pulley mounted rotatably at the rearward end of said truck bed, d. a cover sheet reel mounted rotatably at the forward end of said truck bed on a horizontal transverse axis, e. a pliably flexible cover sheet wound on said reel extending rearwardly therefrom, and secured at its rearward edge to said bridge member, f. a cable drum affixed coaxially to and rotatable with said cover sheet reel, g. a flexible cable wound on said drum oppositely to the winding of said cover sheet on said reel and extending rearwardly from said drum around said pulley, then forwardly and affixed to said carriage, h. reversible power means for rotating said reel and drum selectively in either direction, whereby said cover sheet is reeled in and said cable is simultaneously paid out or vice versa, said power means being self-locking in the sense that said reel and drum cannot be turned by any amount of torque applied thereto by tension in said cover sheet or said cable, said cable drum being of larger diameter than the maximum diameter of the cover sheet roll on said reel, whereby said cable is alwayS paid out from or wound onto said drum at a greater linear rate than said cover sheet is respectively wound onto or pair out from said reel, and i. tensioning means operable to take up any slack developing in said cable, whereby to maintain tension in said cover sheet.