Magnetic tape threading and compliance element guiding apparatus

Claim 1

A helical scan magnetic tape recorder including a rotary magnetic head scanner and means spaced from said rotary scanner for receiving a cassette including spaced, coplanar, supply and take-up reels having magnetic tape spooled on said reels with a span of magnetic tape extending between said reels, tape threading and guiding apparatus comprising, supply and take-up capstans spaced from said cassette and said rotary scanner; supply and take-up compliance elements; means for counting said supply and take-up compliance elements for movement (1) between cassette loading positions in which said elements are located behind said tape span of a received magnetic tape cassette, (2) tape vacuum loading positions in which said elements draw said tape out of said cassette and partially contact said tape with said rotary head scanner, and (3) operating positions in which said elements draw said tape around said respective capstans and tension said tape during tape transport past said rotary head scanner; wherein said mounting means includes supply and take-up carriages respectively supporting said supply and take-up guide elements and further includes supply and take-up drive means respectively coupled to said supply and take-up carriages for driving said carriages between said positions; and wherein said drive means include divergent screw drives engaging said respective carriages, a reversible motor, and a gear assembly for connecting said motor to said screw drives, wherein rotation of said motor in one of said reversible directions causes said screw drives to drive said carriages in a threading direction and wherein rotation of said motor in the other of said reversible directions causes said screw drives to drive said carriages in an opposite unthreading direction.