Abstract: A fuel vaporizer and method of fuel vaporization are described for use with a fuel such as propane, that is know to tend to liquefy at low temperatures and to vaporize at high temperatures. The vaporizer and method described pertain to a series of internal walls and cavities which promote heat-exchange and transfers heat from a fluid engine coolant to the fuel. The transfer of heat and vaporization of fluid occurs by virtue of movement of the fuel through a series of countercurrent passages created by the walls and cavities, with increasing cross-sectional dimensions in the passages to accomodate the expansion of fuel from the liquid to the gaseous state. The heat is transferred by conduction across a metallic interface which forms part of the vaporizer and which separates the fuel from the coolant.

Abstract: A printing apparatus for printing on a substrate, including a base mounting a storage spool for printing ribbon, a ribbon take-up spool, and there being a ribbon path from the storage to the take-up spool through a printing station, a print head relative to which the substrate and the ribbon move during a printing operation. The apparatus further including a shuttle moveable relative to the base, the shuttle having a ribbon guide about which the ribbon is entrained, the arrangement being such that relative movement between the print head and the ribbon is achieved by movement of the shuttle relative to the base.

Abstract: A conical filter device inserts into a duct having flow passing from upstream to downstream. The filter device includes fluted filter media having flutes formed therein and a housing. The filter forms a seal between the outer edge of the filter at the downstream side and the housing. The upstream face of the filter is conical shaped in a first embodiment and frusto-conical in a second embodiment with the housing roughly corresponding to the shape of the filter. The filter elements are formed by winding layers of filter media to form a circular cross-section. The elements are moved axially as they are wound or placed on a shaping form while the sealant is still pliable to shape the element.

Abstract: Servo elements contained within a tape head detect a lateral displacement the magnetic tape relative to the tape head and generate position error signals corresponding to such lateral displacement. To aid in servo monitoring, the position error signals are sampled at predetermined times and the samples output or stored in machine-readable form. Each sample is classified as bad if it exceeds a predetermined threshold. Samples are analyzed to determine, for each time a bad position error signal occurs, how many successive position error signals are also bad. Samples are also analyzed to determine the relationship between bad position error signals samples and total samples. This data may be used for a number of different purposes. For example, this information may be used to identify differences between performance on top and bottom servo edges, or problems with the servo writing mechanism. Performance variations among different servo elements may also be identified.

Abstract: A high resolution, independent position sensor is provided, having application in a magnetic tape drive and other environments in which a linear or angular position is to be monitored. Analog outputs from an inexpensive, low resolution optical encoder are processed to correct gain and offset distortions and are used as the basis for an interpolation process. If a code strip having a 127-micron grating is used, a resolution of about 0.125 microns can be achieved.

Abstract: An improved and apparatus is provided in a tape drive for servo-controlling a tape head position relative to a magnetic tape as the magnetic tape travels past the tape head thereby reducing track mis-registration on the magnetic tape. Servo elements contained within the tape head detect a lateral displacement of the magnetic tape position relative to the tape head and generate position error signals corresponding to such lateral displacement. The position error signals are then filtered to generate a low frequency position error signal, a midrange frequency error signal, and position reliability signals. The tape head is then positioned by a head actuator according to the low frequency position error signal to adjust to the lateral movement of the magnetic tape. The midrange frequency error signal is compared to a distortion threshold to determine if errors exist due to tape edge vibrations or distortion of the magnetic tape.