A modular drain field section and a method for making a drain field section are disclosed having upper and lower casings which are connected together to form each drain field section. Both upper and lower casings have a center pipe portion which, when connected together, forms a central pipe and each casing has troughs on both sides of the center pipe portion. The lower casing troughs have a plurality of openings therein and a spillway connects the central pipe with the lower casing troughs. The...

For imaging distant radiation sources, a collimator is rotated about its own axis while that axis moves about a fixed axis pointing toward the overall field of view of the collimator. Radiation from the source will be transmitted through the collimator during each of its revolutions about its axis. The angular position of the collimator about its axis, and the angular position of the collimator axis about the fixed axis, at the time of each such transmission, define a response plane. Computerize...

A power metal-oxide-semiconductor field-effect transistor (MOSFET) having high switching speed capabilities is shown. The high switching speed is facilitated by narrow channel length which is defined by the difference in lateral diffusion junctions of the P substrate and N source diffusions. The high current capability is produced by the large channel width. The high voltage capability is caused by the use of FET substrate P diffusions designed to be located apart from one another by very small ...

The field shell of an electromagnet is formed with angularly spaced flanges which define a magnetic pole and which also serve as a mounting hub for a coil assembly consisting of a bobbin and a multiple turn winding. Resilient fingers on the bobbin snap into openings in the flanges to hold the bobbin and the shell in assembled relationship. Tabs are located between and project inwardly from the flanges and are used to mount the shell in a fixed position.

A carton stacking guide assembly for guiding the stacking of cartons in tiers, such as on pallets, includes elongated hinge bars extending parallel along opposite sides of a support platform, such as the load supporting platform of a cargo vehicle, with detachable first and second guide panels connected together at right angles to each other and hingedly connected to the guide bar for extending vertically from the support platform for guiding the stacking of cartons at the corners of a stack. Th...

Metal detectors having parallel magnetic fields produce signals which vary depending upon the shape and orientation of a metal object passing through the field. An improved metal detector sensor includes a magnet of special configuration having a multi-directional magnetic field resulting in a detector which is insensitive to orientation of the detected metal. One embodiment of the magnet is a pattern of cylindrical poles with the opposing pole central to the cylinder, thus creating a multiplici...

An electromagnetic field compensated cable having an electrically insulating casing (20, 40, 50) includes a structure (21-22, 41, 51) that effects cancellation of electric and/or magnetic field components due to current flow through the cable. One configuration includes a central twisted pair of insulated leads (21, 22) wherein only one end of each of the leads (23, 24) is terminated in a connector (25, 26). Another configuration has a central structure of conductive wire of alternating rectangu...

Oil-resistant resilient mats to protect oil field workers from dangerous, high voltage electrical discharge comprise a first oil-resistant flexible resilient elastomer of extremely high dielectric strength which is usable by itself as a mat and also in combination with other oil-resistant elastomers of higher mechanical strength but less dielectric strength at high voltages and with metallic electrically conductive meshes to equalize mechanical and electrical stress across the first elastomer. T...

The invention provides a highly focussed ultrasonic wave throughout a large depth of field without any mechanical motion. One embodiment of the invention providing two focussed fields includes a front to back arrangement of a converging lens, a transducer without any backing material to dissipate ultrasound, a converging lens, and a transducer. To focus in the far field, the front transducer transmits and receives via the front lens. To focus in the near field, the rear transducer transmits and ...

In a rotating machine converter controlled drive, the EMF vector components formed from the stator current and stator voltage are integrated by means of a-c voltage integrators, the output quantities of which establish the components of the machine flux vector. In the converter control the parallel and normal components of the stator current relative to this flux vector are introduced. The a-c voltage integrators include zero controllers in a feedback circuit, into which the difference between t...