Abstract: A water pressure system includes a pressure tank installed underground within the well casing of a well. The water pressure system includes a submersible pump connected to the inlet of the pressure tank by a drop pipe. The outlet of the pressure tank is connected to a second drop pipe and in turn to a discharge pipe for distribution of pressurized water to a house or other building. A pressure switch is connected to the pressure tank for controlling the submersible pump. The pressure tank includes an outer sidewall with an inlet end and an outlet end. An expandable diaphragm bladder located within the outer sidewall is connected between the inlet and outlet of the tank. A tube extends through the center of the bladder between an inlet opening and an outlet opening. The tube has a plurality of holes therein to allow water to flow through the tube and into and out of the expandable bladder. Pressurized air fills the empty space between the bladder and the outer sidewall to pressurize the water in the bladder.

Abstract: The present invention relates generally to an apparatus that increases the conversion efficiency of optical parametric oscillators and also reduces overall system size and susceptibility to vibration. The first embodiment of the present invention incorporates a PPLN OPO architecture which includes mirrored coatings on the entry surface area and exit surface area of a monolithic nonlinear optical medium. The coatings act as mirrors, however, the mirrors are actually affixed to the PPLN element. In the first embodiment of the present invention, the PPLN element is a dual grated element. The second embodiment of the present invention uses a single grated PPLN element.

Abstract: A vessel which is self-righting and stable without the need for a weighted base is comprised of a planar base and sides whose cross section is an arc of an involute defined by a circle inside the cup. The most extended point on the involute is at or adjacent to the rim of the cup while the least extended point is the point where the side joins the planar base. In preferred embodiments, the vessel includes both a cup portion and a lid which retains liquids in the cup portion such that the overall center of gravity remains on the side of the reaction force vector at the point of contact between the cup and the surface on which it is placed, toward the center of the vessel.

Abstract: A cover for closing an opening of a container which is easily removable from the container. The cover is elongated and has two opposite narrow ends and two opposite elongated ends. The cover is attached to the container by latching means positioned at the narrow ends. The container includes an outwardly extending lip positioned on the upper edge of the container. The cover includes a flange resting on the outwardly extending lip. The latching means includes an inwardly extending protrusion extending from a connecting portion of the latching means beneath the outwardly extending lip to lock the latching means to the container. The cover includes pressure points for deforming the cover in an elongated direction. Latching means are provided on the narrow ends and may be released by deforming the cover in an elongated direction.

Abstract: A filter apparatus in which a generally horizontal bed of filter material is supported on a porous support and is divided by spaced partitions into individual filter cells above the support and individual filter compartments below the support, and a carriage is mounted for movement along the filter bed and has a collector hood that moves along the top of the bed to collect backwash effluent therefrom and a backwash head arranged to direct backwash fluid into the compartments below the porous support. A pair of spaced scarifier blades are provided in the collector hood to scarify the upper surfaces of the filter bed. The backwash head is advantageously in the form of a jet pump arranged to entrain water from filtrate launder that communicates with the filtrate compartments.