Abstract: A magnetic seal for rotating shafts having a first and second annular members. Each of the annular members having a source of magnetic force with the lines of magnetic force being axially aligned with the shaft. A stationary insert positioned in said housing and having a sealing face adjacent the annular members. The first and second annular rings being rotatively connected with the second ring being sealed to the shaft and a face related to the second member for sealing contact with the face of the insert. The first of the rings secured to the shaft for annular rotation.

Abstract: This invention is a novel pressure relief valve wherein the operative pressure generated must overcome the gravitational force of the ball seated in the resilient member.

Abstract: The fueling station of the invention consists of a vacuum insulated storage vessel for delivering LNG to a pressure building tank. The pressure building tank holds a quantity of LNG and a natural gas head. The pressure in the pressure building tank is lowered using liquid nitrogen (LN.sub.2) to condense the natural gas head and is raised by vaporizing the LNG. A valve system connects the supply of LNG in the pressure building tank to the vehicle being supplied to allow either LNG or natural gas to be delivered to the vehicle tank and allows natural gas in the vehicle tank to be vented back to the fueling station. The fueling station of the invention includes suitable controls for controlling the pressure of the LNG delivered to the vehicle, the pressure in the fueling station itself and the pressure in the vehicle.

Abstract: A play feature for a pinball game having a plurality of wheels rotatable about a horizontal axis and having a plurality of ball receiving sockets formed therein. Each wheel can pick up a pinball from a first position on the playfield and after rotating through approximately 180 degrees discharge the pinball at a second position on the playfield. The wheels are arranged in a series whereby the discharge position of the upstream wheel corresponds to the pick up position of the downstream wheel. In this manner the pinball can be conveyed across the playfield in a stepped fashion as it is transferred from the upstream wheel to the downstream wheel. The rotation of the wheels is coordinated by using a single drive motor operatively connected to each of the wheels by a transmission member.

Abstract: Apparatus for sensing distances between two objects by using multiple pulses from the detector and from the object to be detected by using a transmitter and not using any reflected waves the reliability and the ability to reject clutter is improved. The periods between transmission are accurately controlled so that there is no signal returned until the object to be detected generates such a signal. As a result it is possible to accurately measure the distance between two objects and indeed the system may be used between two objects when both are in motion.

Abstract: A seed dispenser is provided for an agricultural planter and is designed to dispense seeds of substantially uniform size and shape, to which end the dispenser has a drum-like casing provided with horizontally spaced apart upright walls spanned and joined by a cylindrical wall that together define a seed-receiving chamber within which runs a circular plate or disk whose rim is formed with seed cells of uniform size and shape according to the size and shape of the seeds, the cells being uniformly angularly spaced about the rim of the plate and adapted to pick up seeds, one per cell, at the lower part of the chamber and to convey to seeds upwardly and around and past the upper portion of the chamber, ultimately releasing the seeds through an outlet opening for discharge to the ground.

Abstract: A magnetic field heating device for heating metal including a means to create an alternating magnetic field passing this magnetic field through a dissimilar metal part to uniformly heat the part. This differs from induction heating of metal parts because the part is heated uniformly rather than being restricted to the skin or outside portions of the part. This unique heating is accomplished by utilizing a novel magnetic loop for creating a high density alternating magnetic field in the metal part to be heated.

Abstract: A boat has a top retractable from a normal, relative high position, to a retracted relatively low position via a plurality of supports arranged as parallel linkages. The boat carries an upright structure that normally projects above the level of the retracted roof and that would form an obstacle to passage of the boat under low bridges, for example. The upright structure may be a head or galley having a hinged upper part that retracts along with the retracting roof, thus diminishing the height of the structure to about the level of the retracted roof.