Scanning device for helical type video tape recorder

In a scanning device, for use in a magnetic tape instrument of the type using magnetic heads and diagonal track scanning with the magnetic tape following a path over the scanning device, and comprising an outer two-part stationary guide drum having a central axis and supporting an inner head assembly revolving about an axis of rotation, and including a head-wheel supporting the magnetic heads and a motor having a driving shaft, the improvement comprising:

• transmission means operable to couple said driving shaft with said head-wheel, comprising a sleeve disposed on said driving shaft, and a driving flange connected to said sleeve and defining a surface disposed in a plane substantially perpendicular to said axis of rotation, said head-wheel defining a face normally disposed in a plane substantially perpendicular to the axis of rotation and operable to be aligned in abutment with and frictionally engaged by said surface, both said surface and said head-wheel being substantially circular in shape, said surface having an external diameter of at least one-half the outer diameter of said head-wheel, the magnetic heads being disposed on said face, said transmission means including a ball bearing supporting at least partially said inner head assembly, a rotatably mounted inner ring, said sleeve being supported by said inner ring, an outer threaded ring, and a jacket encompassing said bearing and abutting said threaded ring, said threaded ring and said jacket being located within one of said two-part stationary guide drums whereby said driving flange will drive said head-wheel when the motor is activated.