A helical wrap tape transport system having a plurality of components cooperating to provide a low friction and highly accurate transport of magnetic tape for video broadcasting. The transport system has a helical scanner assembly with a rotating scanning drum having helical surface V-grooves which create an air bearing for magnetic tape wrapped across the drum and oppositely mounted recording transducers which permit continuous recording on a 180.degree. tape wrap around the drum, and a stationary drum on a common axis with the rotating drum having a fixed control track transducer for synchronizing tape transport at the scanning assembly. The transport system has further, air bearing guide posts and a pair of vacuum columns which continuously monitor a tape supply loop which in combination with the guide posts provide a section of low inertia recording tape, the transport of which can be controlled by a single high friction drive capstan.
BACKGROUND OF THE INVENTION
This application is a division of Ser. No. 354,227, filed Apr. 25, 1973, now U.S. Pat. No. 3,890,641, issued June 17, 1975, which in turn is a continuation-in-part of Ser. No. 285,923, filed Sept. 1, 1972, now abandoned.
A rotary magnetic head assembly for use in recording and playing back video signals including a rotary head drum, a stationary head drum, and magnetic heads. The rotary head drum is supported by a driving shaft and has an outer surface which is generally cylindrical. The rotary drum is rotatable when driven by the shaft. The stationary head drum is disposed coaxially with the rotary drum, and has an outer surface which is generally cylindrical and substantially equal in diameter to the outer surface of the rotary drum. The rotary drum has a first surface opposing the stationary drum with shape formed by a generatrix not perpendicular to the shaft such as a conical or cylindrical. The stationary drum has a second surface opposing the first surface of the rotary drum. The second surface is generally of a shape about the shaft, which is complementary to the first surface to form an air gap between the rotary and stationary head drums through which air flows to form an air film on the outer surfaces of the drums. The magnetic heads are supported on the rotary drum closely to the outer surface of the rotary drum in the gap. The generatrices may preferably be straight, stepwise or gently curved. Coil windings of a rotary transformer of the first and second surfaces may be mounted in grooves provided on the first and second surfaces, and affixed therein by a fixing agent to preferably form smooth and flat surfaces continuous to the first and second surfaces, respectively.
The present invention relates to a rotary head assembly for a magnetic recording and reproducing device such as VTR. A stationary center shaft is mounted on the side of a stationary cylinder while a rotary sleeve which is fitted over said stationary center shaft for rotation about the axis thereof is disposed on the side of a rotary cylinder. A lubricating oil is injected between the rotary sleeve and the stationary center shaft so that a space between the cylinders may be utilized so as to provide a hydraulic bearing portion. Thus, the rotary head assembly may be made compact in size and to a higher degree of accuracy. In addition, the thrust load carrying point of the hydraulic bearing portion is located on the side of the rotary cylinder, and the portion adjacent to the thrust load carrying point has a sealing arrangement or construction so as to prevent the leakage of lubricating oil and to stabilize the rotation of the rotary cylinder.
The present invention relates to a rotary head assembly for a magnetic recording and reproducing device such as VTR. A stationary center shaft is mounted on the side of a stationary cylinder while a rotary sleeve which is fitted over said stationary center shaft for rotation about the axis thereof is disposed on the side of a rotary cylinder. A lubricating oil is injected between the rotary sleeve and the stationary center shaft so that a space between the cylinders may be utilized so as to provide a hydraulic bearing portion. Thus, the rotary head assembly may be made compact in size and to a higher degree of accuracy. In addition, the thrust load carrying point of the hydraulic bearing portion is located on the side of the rotary cylinder, and the portion adjacent to the thrust load carrying point has a sealing arrangement or construction so as to prevent the leakage of lubricating oil and to stabilize the rotation of the rotary cylinder.
In a rotary head assembly for magnetic recording and reproducing apparatus such as VTR, fluid or hydraulic radial and thrust bearings are provided between a stationary sleeve whose one end is closed fluid-tightly and a rotary shaft rotatably extended into said stationary sleeve, whereby the rotary head assembly may be made compact in size and easy to assemble, may rotate with a higher degree of reliability and may completely seal lubricant.
In a rotary head assembly for magnetic recording and reproducing apparatus such as VTR sets, of the type comprising a stationary shaft having its one end securely joined to a stationary member, a rotor fitted over the stationary shaft for rotation, a drive means for driving or spinning the rotor and heads mounted on the rotor, the position N of a thrust support for supporting the rotor is so selected as to coincide with the center of gravity G of the rotor or as to be located between the center of gravity G and the center of gravity G.sub.1 of the rotor except an aggregate of component parts of said drive means mounted on the rotor, the center of gravity G being depending upon the center of gravity G.sub.1 and the center of gravity G.sub.2 of the aggregate of component parts mounted on the rotor, whereby the adverse effects of the precession of the rotor on the precision rotation or spinning thereof can be avoided.
