Abstract: A system for converting the mechanical energy of ocean waves to electrical energy comprises a weighted member supported from a piezoelectric element for applying a preselected strain to the element. In one embodiment, the element is supported by a float floating on the surface of the water. In another embodiment, the element is supported above the surface of the water and the weighted member, of negative buoyancy, is immersed in the water. The system functions, in use, as an oscillating, weighted spring and, for tuning the system to cause it to enter into mechanical resonance in response to passing waves, means are provided for tuning the natural frequency of the oscillating system.

Abstract: An anti-fouling device comprises a layer of piezoelectric material, preferably a poled plastic material such as a PVDF polymer, for mounting on the hull of a watercraft. The layer has electrodes on opposite major surfaces thereof, and the layers are connected to a power supply comprising a battery and a d.c. to a.c. converter. The converter generates an a.c. voltage at a frequency, e.g., 20 KHz, for causing vibrations of the layer, such vibrations serving to retard the growth of water dwelling organisms in the craft. The layer electrodes are also connected to an a.c. to d.c. converter for converting a.c. energy to d.c. energy suitable for trickle charging the power supply battery. Accordingly, during transit of the craft through the water, water induced hull vibrations cause vibrations of the layer for generating a.c. energy for storage in the battery, which stored energy is used for causing anti-fouling vibrations of the energy generating layer.

Abstract: Disposed within a float on the surface of a body of water is a vertically suspended, resilient piezoelectric element provided with a preselected strain by a hanging weight. The piezoelectric system functions as a weighted coiled spring which is driven into oscillation in response to movements of the float in response to passing surface waves. Preferably, the natural frequency of the system is selected in correspondence with the frequency of the passing waves for causing the system to oscillate in resonance with the passing waves. Additionally, a mechanism is provided for automatically adjusting the natural frequency of the system in response to changing wave conditions for maintaining the system in resonance with the waves.

Abstract: A known type of piezoelectric power generating system for converting the mechanical energy of waves on a body of water comprises a float and a piezoelectric power generating element suspended, under tension, between the float and a bottom anchor. For preventing excessive vertical stretching of the piezoelectric element in response to the presence of excessively high waves, a protective element is coupled between the float and the bottom anchor for effectively limiting the rise of the float above a preselected height corresponding to the maximum straining desired for the piezoelectric element. The coupling is automatic and occurs only at those instances when the piezoelectric element elongation is approaching its maximum amount, and automatic decoupling occurs immediately upon the float falling to a height where non-excessive straining occurs.

Abstract: An electrical energy generator comprises a cylindrical stator, a cylindrical liner of a piezoelectric material in concentric contact with the stator, and an armature rotatable about the liner. In one embodiment, as the armature rotates, the armature squeezes successive portions of the liner against the stator for alternately compressing and decompressing the liner portions for causing them to generate electrical energy. In another embodiment, the armature causes alternating stretching and destretching of successive portions of the liner between spaced apart portions of the stator for causing the liner portions to generate electricity.

Abstract: There is disclosed a calliper, useful for measuring how much fat can be pinched beneath the skin, having jaws (4,6) pivotally mounted for relative pivotal movement. The movement is amplified by a gear train (24, 26, 28, and 30). The final gear wheel (30) drives a toothed wheel the movement of which is sensed by an opto sensor (34). A digital readout indicates the spacing between the jaws for indicating the spacing between measuring surfaces of the jaws. In contrast to conventional callipers, which are used only to transfer a dimension from an object to be measured to a measuring device, the callipers disclosed give a direct reading of the spacing between the measuring surfaces.

Abstract: A four-region semiconductor device (that is a p-n-p-n or n-p-n-p device) including at least one further region utilizes integral FET structure for diverting carriers away from an interior region of the device and shunting them to a main current-carrying electrode of the device, whereby the device is provided with a turn-off capability. The device requires only a small amount of energy for its turn-off control gate, and utilizes a high percentage of its semiconductor body for carrying current through the device. High speed turn-off is achieved in a particular embodiment of the device.

Abstract: A display apparatus for underwater use comprises a hermetically sealed enclosed including a liquid crystal display device. The device comprises a liquid crystal cell disposed between layers of light polarizers and a light reflector. The combination of cell, polarizers and reflector displays either bright images on a dark background or the reverse. To make the edges of the cell substantially invisible, for improving readability of the display, the liquid crystal cell is surround by a matting comprising the identical layers of light polarizers and reflector used in combination with the liquid crystal cell. A common matting can be used with a mosaic of cells to create the appearance of a single, large area cell, or with several cells to display independent images.

Abstract: A plasma generating apparatus includes a plasma containing region and an R.F. coil for generating R.F. electric fields within the plasma region for creating a plasma from a gas flowed through the region. A capacitive shield is disposed between the coil and the plasma region for limiting the amount of capacitive coupling while not completely eliminating it, between the R.F. coil and the plasma region. The shield can include a means for varying the shielding effect thereof during processes employing the plasma.

Abstract: A bedside grab bar or post for better enabling infirm persons to get into and out of a bed without assistance. The grab bar is in the shape of an inverted U including two vertical legs removably attachable to a bed side rail. The grab bar may be disposed along the length of the bed at an adjustable distance from the head of the bed to accommodate the user of the bed and has a relatively small width, thereby leaving ample space for movement onto and off the bed in the open space between the grab bar and the bottom end of the bed and without movement of the grab bar.

Abstract: A wrench of a conventional worm gear-rack mechanism type includes a fixed jaw and a movable jaw adjustable by means of a worm gear in driving engagement with a rack mechanism of the movable jaw. The rack mechanism is movable within a slot extending through the fixed jaw; the slot being disposed to one side of an object gripping surface of the fixed jaw and along an axis perpendicular to the gripping surface. For locking the movable jaw in position when an object is being gripped between the two jaws, the movable jaw is provided with a threaded stud which extends axially of the slot and outwardly beyond an exterior surface of the fixed jaw. A nut is mounted on the stud portion extending beyond the exterior surface, the nut serving to prevent unclamping movement of the fixed jaw when the nut is screwed along the stud and into contact with the exterior surface.

Abstract: In exercise apparatus for underwater use including an apparatus frame, and movable members mounted on the frame to be moved by a user of the apparatus, flap members, e.g., flat plates, are mounted on the movable members for movement therewith within the surrounding water. The water resists movement of the flap means, hence provides resistance to movement of the members moved by the user. Disclosed are apparatus which, in use, simulate the movements of a cross-country skier, an ice-skating speed racer, and a rower of a row boat. Arrangements are also disclosed for selectively varying the resistance to movement provided by the flap members in response to the direction of movement of the movable members.

Abstract: Counting and division circuits include an input differential stage connected to a cross-coupled differential stage. The input stage includes first and second IGFETS whose gate electrodes are respectively connected to first and second inputs, whose drains are respectively connected to first and second outputs, and whose sources are connected to the drain of a third IGFET whose source is grounded. The cross-coupled stage includes fourth and fifth IGFETs which are cross-coupled in that the gate of the fourth IGFET and the drain of the fifth IGFET are directly connected to the first output and the gate of the fifth IGFET and the drain of the fourth IGFET are directly connected to the second output. The sources of the fourth and fifth IGFETs are connected in common to the drain of a sixth IGFET whose source is grounded.

Abstract: A diagnostic method for determining in vivo mechanical strength and structural integrity of hard tissues such as bones, in a non-invasive and non-dramatic manner. The method separates ultrasound energy affected by surrounding soft tissues, and thus permits unbiased determination of ultrasound parameters that represent the hard tissues. The mechanical strength of hard tissues is then determined on the basis of the ultrasound parameters, including the amount of energy propagated, the velocity of the ultrasound and the degree of dispersion together with the characteristic response of the hard tissues.

Abstract: Underwater exercise apparatus includes at least one paddle, which is coupled to an axle causing the paddle to rotate in response to rotation of the axle. When under water, the paddle produces resistance to the rotation of the axle. In a preferred embodiment, the paddle may be made part of a treadmill for underwater use for varying the resistance to movement of the treadmill belt. In a treadmill embodying the invention, the axle of one of the rollers supporting the belt, which roller is tightly coupled to the belt, extends beyond the side edge of the belt. Directly connected to the extending end of the axle, for rotation therewith, is a paddle. In use, movement of the belt causes rotation of the paddle through the water. The water resists the movement of the paddle which, in turn, resists movement of the belt. The amount of resistance to belt movement is a function of the speed of movement of the belt and the size of the paddle which is designed to be readily changed as desired.

Abstract: In exercise apparatus for underwater use including an apparatus frame, and movable members mounted on the frame to be moved by a user of the apparatus, flap members, e.g., flat plates, are mounted on the movable members for movement therewith within the surrounding water. The water resists movement of the flap members, hence provides resistance to movement of the members moved by the user. Disclosed are apparatus which, in use, simulate the movements of a cross-country skier, an ice-skating speed racer, and a rower of a row boat. Stop are also disclosed for selectively varying the resistance to movement provided by the flap members in response to the direction of movement of the movable members.

Abstract: A screwdriver for alternative use with Phillip head screws and slotted head screws is disclosed comprising a handle and a shank extending therefrom, the leading end of the shank terminating in a Phillips head screw engaging bit. The leading end portion of the shank is bifurcated by a rearwardly extending slot, and an elongated blade tipped with a slotted head screw bit is slidingly disposed along the slot. The blade is provided with a series of gear teeth along each edge and a nut is mounted around the shank for engagement with the blade teeth. The nut maintains the blade within the slot, and rotation of the nut controls the axial positioning of the blade to positions either forwardly or rearwardly of the Phillips bit.

Abstract: An optical effect is produced in cooperation with the normal use of an article of manufacture, e.g., a toy such as a frisbee or a ball, or an article of clothing, such as a shoe, by mounting on the article a piezoelectric element for generating electrical energy in response to movement of the article and an optical effect device, such as a neon bulb, gas plasma, liquid crystal, or electroluminescent device, electrically connected to and energized by the element in response to such movement. In one embodiment, the element and device each comprises a thin, layer-like structure, the element and device structures being laminated or attached together.

Abstract: A float on a body of water is mechanically coupled to a piezoelectric material member for causing alternate straining and destraining of the member in response to the up and down movement of the float in response to passing waves, thereby causing the member to generate electricity. The output impedance of the float is matched to the input impedance of the member for increasing the energy transfer from the float to the member.