Abstract: A dynamoelectric machine that is both inexpensive and efficient has a rotor including one or more permanent magnets, the working faces of which lie in a spheroid and are centered on the equator of the spheroid. Surrounding the rotor is a brushless stator having spirally wound stator coils. Each coil has a cup-shaped working face centered on said equator and closely spaced from the working faces of the magnet. This dynamoelectric machine can be small, lightweight, and almost twice as efficient as any prior dynamoelectric machine that is equally inexpensive.

Abstract: A cleaning device for removing debris from the tape of a reel to reel magnetic data tape cartridge includes a cleaning material mounted adjacent the tape path to constantly contact and remove debris from the tape. Preferably, the cleaning material both wipes debris from the tape and retains the debris. The cleaning material may be mounted to rotate in response to the movement of the tape past the cleaning material. An alternate emebodiment which permits both sides of the magnetic tape to be cleaned includes mounting the cleaning material on a arm which is pivotably mounted to the cartridge. The arm pivots to maintain contact with the tape and is shaped to provide a plurality of contact portions between the cleaning material and the tape.

Abstract: An economical power-reducing circuit for either a fluorescent lighting fixture or for a high-intensity, low-voltage incandescent lamp has an electrolytic capacitor and a diode connected in parallel with the capacitor. When used in a fluorescent lamp fixture, the circuit reduces power consumed by the fixture, both when used as a lamp substitute or as an attachment that does not eliminate a lamp. When used with a high-intensity, low-voltage incandescent lamp, the power-reducing circuit eliminates a transformer, thus saving both cost and weight. It also should provide a power saving at no reduction in brightness, and should prolong the life of in the incandescent lamp.

Abstract: Appliances such as fluorescent lamps and low-voltage DC motors can be operated from household AC without a transformer by employing a current-limiting circuit which is compact, lightweight, reliable, draws less energy, and has fewer power consuming components than do prior devices for driving those applicances. The current-limiting circuit has 4 rectifiers in a bridge circuit and a current-limiting capacitor which should be selected to match the load, a larger capacitor being necessary to supply a larger current. When used to drive a discharge lamp, the current-limiting circuit should also contain an inductive coil in series with the current-limiting capacitor. Otherwise there may be undue flicker. The inductive coil and capacitor together improve the power factor and therefore reduce the current drawn from the line without reducing the lamp output.

Abstract: A dynamoelectric machine has a brushless, substantially ironless stator coil of a long electrical wire conductor which comprises a large number of straight legs which are grouped into spaced bundles to form a thin-walled structure that may be cylindrical as in FIG. 1 or flat as in FIG. 6. The thin-walled structure may be supported by a plastic framework or may be adhered to a thin, correspondingly cylindrical or flat, ferromagnetic sheet. A ferromagnetic sheet not only supports the coil, but also enhances efficiency by providing a return path for electromagnetic flux. A plastic framework is lighter in weight.

Abstract: The novel rotor or stator comprises a symmetrical assembly of permanent-magnet segments, the working faces of which are separated. Each segment is magnetized to have one pole extending across one-half of its working face and the opposite pole extending across the other half. Because adjacent halves of adjacent working faces have like polarity, it appears that flux emanating from the segments between adjacent magnet segments is redirected more orthogonally with respect to the working faces, thus enhancing efficiency. The segments may either be parts of a single permanent magnet or individual pieces, and their working faces may together define either a cylinder or a plane.

Abstract: A head positioning add mechanism for a multitrack data cartridge recorder including a stepper motor, a lead screw driven by the stepper motor and a head mounting slide engaged with the lead screw by a partial female thread for incrementally moving a recording/playback head transverse to the path of a magnetic recording tape to enable accurate positioning of the head at any given track across the tape.

Abstract: Stretched surface recording disk (SD) 10 comprises an annular support 12 having raised annular ridges 42 and 28 at its inside and outside diameters 22 and 30 with a base portion 24 in between the two ridges, and an annular recording medium film 14 held in radial tension and stretched across the base portion by adhering the film to attachment surfaces 48 and 36 near the inside and outside diameters respectively. The SD is annealed twice during manufacture to relieve stress in the stretched film 14. This annealing results in SD essentially free from track anisotropy and stress distribution anisotropy in the plane of the disk. As a result, data tracks are more stable than in previous SD, track density can be greater, and the SD is generally more reliable.

Abstract: The novel axial fan may have a cylindrical shroud, an impeller mounted coaxially within the shroud, and a bell-shaped deflector extending across the exhaust to redirect the airflow toward radially outward directions. A malleable blank may be cut and shaped to form the impeller having at least three blades, the peripheries of which define a cylinder coaxial with the shroud. The impeller should have a depth-to-radius ratio exceeding 0.5.

Abstract: A recording disc is provided by a disc-shaped, formed-sheet-metal support across which a flexible recording sheet is stretched. The formed-sheet-metal support has a central spindle opening which can be precisely centered by simultaneously punching the spindle opening and the circular periphery, thus permitting high-speed rotation of the recording disc in use.

Abstract: Stretched surface recording disk (SD) 10 comprises an annular support 12 having raised annular ridges 42 and 28 at its inside and outside diameters 22 and 30 with a base portion 24 in between the two ridges, and an annular recording medium film 14 held in radial tension and stretched across the base portion by adhering the film to attachment surfaces 48 and 36 near the inside and outside diameters respectively. The SD is annealed twice duringmanufacture to relieve stress in the stretched film 14. This annealing results in SD essentially free from track anisotropy and stress distribution anisotropy in the plane of the disk. As a result, data tracks are more stable than in previous SD, track density can be greater, and the SD is generally more reliable.

Abstract: The axial fan produced by the novel method may have a cylindrical shroud, an impeller mounted coaxially within the shroud, and a bell-shaped deflector extending across the exhaust to redirect the airflow toward radially outward directions. A malleable blank may be cut and shaped to form the impeller having at least three blades, the peripheries of which define a cylinder coaxial with the shroud. The impeller should have a depth-to-radius ratio exceeding 0.5.

Abstract: Three or more ferromagnetic elements are symmetrically arranged about the face of a permanent-magnet rotor of a turntable motor. Those elements extend to a plane perpendicular to the axis of a rotor. When a magnetic recording disc which has a rigid, planar ferromagnetic surface is moved toward that plane, magnetic attraction secures the disc to the turntable. Preferably the turntable includes a spindle which fits into a central opening in the disc to center the disc on the turntable.

Abstract: A receptacle and a cover open like a clam shell to a small angle for access by transducing heads to a magnetic recording disc which is rigid at least at its hub. When closed, the rigid hub is forced into a seat at a drive-access opening in the receptacle, and this seating plus peripheral contact between the cover and the receptacle provide an essentially dust-proof chamber for the recording disc.

Abstract: A circular, shape-retaining cover is fastened to the hub of a rigid recording disc to provide a cartridge. The cover rotates with the disc and undergoes snap-action between a normal conical shape enclosing the periphery of the disc and an inverted conical shape providing free access to the recording surface from the entire periphery of the disc.

Abstract: Optical recording disc having a rigid, dimensionally-stable support which keeps a plastic film taut and flat so that an optically-recordable coating on the plastic film resists the dimensional changes and warping which it otherwise might experience if unsupported. The optically-recordable coating may include an energy-absorbing layer which develops discontinuities immediately upon impingement by a focused laser beam and thus provides DRAW capability.

Abstract: Stretched surface recording disk (SD) 10 comprises an annular support 12 having raised annular ridges 42 and 28 at its inside and outside diameters 22 and 30 with a base portion 24 in between the two ridges, and an annular recording medium film 14 held in radial tension and stretched across the base portion by adhering the film to attachment surfaces 48 and 36 near the inside and outside diameters respectively. The SD is annealed twice .[.duringmanufacture.]. .Iadd.during manufacture .Iaddend.to relieve stress in the stretched film 14. This annealing results in SD essentially free from track anisotropy and stress distribution anisotropy in the plane of the disk. As a result, data tracks are more stable than in previous SD, track density can be greater, and the SD is generally more reliable.