Abstract: Disclosed herein is a portable back support comprising a base plate, cushion means attached to the base plate: the cushion means having an upper portion and a lower portion, the lower portion having a pair of laterally spaced extremities, the base plate having an arcuate shape in transverse section thereby enabling the extremities to provide lateral support: the lower portion further comprising expansion means, the expansion means enabling the contour of the cushion to be varied.

Abstract: A ring blade for cutting or for defensive purposes comprises a ring with a top section and a movable crown member mounted in this top section. The ring is adapted for placement on a person's finger. The crown member has an elongate slot formed therein and a blade member is arranged in this slot. First and second pin members are provided to pivot the blade member from a retracted position where the blade is located in the slot to an extended position where the blade is exposed. The blade member is connected to the top section by one of the pin members and it is connected to the crown member by the other pin member. Movement of the crown member towards the top section causes the pin members to pivot the blade member to the extended position. Preferably the top section has a V-shaped cavity and the crown member is also V-shaped so as to fit inside this cavity.

Abstract: A security lock for a door used to open and close an opening defined by a door frame, the door having a reciprocable bolt movable into and out of a hole in the door frame. The lock comprises an elongate lock member having a flat end section with a central opening at one end of the lock member and a shank portion at the opposite end thereof. The flat end section is insertable between an edge of the door and the door frame. A hook element is connected to this end section and is located adjacent the central opening so as to project into the hole in the door frame during use of the lock. An integral tongue element has one end thereof connected to the shank portion and has a door engaging portion biased by spring action to move from a first position where the door can be opened or closed to a second position where the door is blocked and prevented from opening. Preferably the lock is made from spring steel.

Abstract: A mattress pad or cover is disclosed for a conventional inner-spring or foam type mattress. The mattress cover has a quilted cover portion and a downwardly depending peripheral skirt that wraps around the mattress to hold the cover portion in place. The skirt has elastic sewn around its lower peripheral edge to keep the skirt tucked under the mattress. The cover portion has a first thick layer of fiberfill and a second conterminous thin layer of fiberfill. A metalized film is needle-punched to the thin fiberfill layer and a fabric cover envelops a fiberfill and film layers.

Abstract: An intrusion detection system for a space secured in part by a deflectable physical barrier includes a cable sensor mounted on the barrier in such manner that it stretches and flexes in response to deflection of the barrier, thereby to produce an output signal representing such movement. A signal processor receives the signal from the coaxial cable and provides an output affirmative signal if the amplitude of the cable signal, within a predetermined frequency range lying below about 30 Hz, exceeds a predetermined level for a predetermined time interval.

Abstract: An FM/CW radar system is disclosed for determining a safe stopping distance between a moving vehicle and a potential obstacle. The radar signal is modulated linearly over several slopes. A microstrip phased array transmit/receive antenna is also disclosed having a hybrid tap, corporate feed structure. Signals from the antenna are amplified and filtered, and passed through an analog to digital converter to a signal processor, which performs a Fast Fourier Transform on the signals to convert them from time domain data to frequency domain data. The frequency domain data is then used to solve target range and doppler equations, determine safe stopping distances, and sound or display alarms if the safe stopping distance has been violated. A sensitivity control adjusts for road conditions or operator reaction time variations.

Abstract: A telephone privacy protector for connection to a common exchange line and each one of at least two telephone operated devices sharing a line includes a voice connecting circuit for connection between a respective telephone line operated device and the line. There is a control deice connected to the circuit having an on and off state wherein the control device in the on state permits the voice connecting circuit to operate. There are means for turing the control device on when the respective telephone line operated device goes off hook provided that no other telephone line operated device sharing the line is off hook. There are means for providing a residual charge to the control device in order to reactivate same after the respective telephone line operated device is placed momentarily on hook and then returned to an off hook state while any other telephone line operated device connected to the line is off hook.

Abstract: The invention relates to an improved energy exchange structure, comprising generally parallel plates, joined to define a hollow passageway for the generally circular flow of fluid between an inlet and an outlet, said plates undulating in cross-structure to define obliquely disposed crossing opposing valleys, and comprising multiple sets of generally parallel valleys and an involute disposition of said valleys.

Abstract: A multi-gasket sealing assembly or mount is disclosed for improved mounting of a swimming pool water skimmer in an opening in a pool wall of the type having a metal wall portion and a flexible inner sheet liner. The water skimmer has a housing defining a water inlet chamber for intake of water and an annular chamber end portion which protrudes through the pool wall opening. The housing also has an outwardly projecting peripheral flange spaced from the chamber end portion, the flange being bolted to the metal wall portion. A continuous gasket is located around the chamber end portion. An annular face plate is connected to the chamber end portion to compress the gasket and also to press the pool liner against the metal wall portion to prevent water from getting behind the liner. Another gasket is compressed between the peripheral flange and the metal wall portion to seal against the ingress of sand and other particulate matter into the skimmer from behind the pool wall.

Abstract: An improvement in circumferential flow heat exchangers of the type having a stack of heat exchange units each formed from first and second thin plates having grooves and ribs, wherein the grooves and ribs on facing surfaces of the first and second plates of a unit cross one another and cooperate to define a first flow path extending once about the interior of such unit through less than about one circumscription and grooves and ribs on facing surfaces of first and second plates of adjacent units cross one another and cooperate to define a second flow path, characterized in that the first and second plates of each unit are configured to provide the second flow path with a cross-sectional area exceeding the cross-sectional area of the first flow path.

Abstract: An exploding box is disclosed having upright sides which are provided with horizontal ribs or grooves which lock a false box bottom in position while the sides are maintained in an upright position by a top cover or lid. The false bottom is biased upwards by a compressed spring. When the top cover is removed, the upright sides of the box fold outwards, releasing the false bottom. The false bottom then springs upwards, springing forth any contents in the box.

Abstract: A method of mixing fluids and mixing equipment is disclosed wherein an orifice plate is caused to be reciprocated at right angles to the plane of the orifice plate in a fluid to generate a ring vortex through the orifice, the orifice in the plate and the stroke of the plate are defined by the relationship 0.8.ltoreq.L/d.ltoreq.3.8, where L is the stroke of the plate and d is the diameter of the orifice.

Abstract: A method and apparatus is disclosed for mixing or agitating fluids using vortex rings in which a tube of inside diameter d is inserted into the fluid with an open end in the fluid. Fluid is drawn into the tube, and a slug of fluid is propelled a distance L down and out of the tube to create a vortex ring at the exit of the tube for propagation through the fluid. The ratio of L/d is between 0.8 and 3.8. The propelling means preferably involves a pulser cylinder communicating with the tube and a piston positioned in the pulser cylinder for reciprocating motion towards and away from the fluid to be mixed or agitated, or a bellows serving a similar function. The propelling means provides a generally square wave pressure impulse to the fluid to eject it from the tube in the form of a vortex ring.

Abstract: A chute is disclosed for passing articles such as laundry between floors or walls in a building. The chute has a tubular frame to be securely inserted in an opening in a planar partition, and a flexible tube attached to and hanging from the frame. The tubular frame has a peripheral wall defining an inlet in communication with one side of the planar partition and an outlet extending beyond the other side of the planar partition. A peripheral flange is outwardly directed from the peripheral wall adjacent to the inlet and is adapted to rest against one side of the planar partition. A gripping projection extends transversely from the peripheral wall and is spaced from the other side of the planar partition. The flexible tube is releasably attached to the gripping projection. A lid is movably connected to the frame to open and close the inlet.