Abstract: A variable ratio transmission includes an input and an output, having an expansible chainwheel. A first drive path is provided to rotate the chainwheel and a second drive path is provided to increase the diameter of the chainwheel upon application of a first input torque and to decrease the diameter of the chainwheel upon application of a second input torque of opposite sense to the first input torque. The first and second drive paths are connected to the input so that the second drive path has a mechanical advantage over the first to provide an increase in diameter of the chainwheel prior to its rotation.

Abstract: A tool is retained in a socket of a mineral cutter by an elastomeric element acting between the shank of the tool and the wall of the socket. The element is formed with corrugations that abut the wall of the socket and oppose the forces applied to the cutter of the tool.

Abstract: A refrigeration system includes a heat rejection loop and a heat absorbtion loop interconnected by a phase separation device. Refrigerant is circulated in the heat rejection loop by a positive displacement pump thereby permitting the pressure of refrigerant in the condensor to fluctuate as the ambient temperature fluctuates. This increases the capacity of the system and reduces the work performed by the compressors. A bypass line is provided between the phase separation device and the condensor to allow the compressors to be switched off completely when the ambient temperature is below the evaporator temperature. The output of the compressors is also used as a heat source to defrost the evaporators as required.

Abstract: A method and apparatus for reconstructing the three-dimensional coordinates of an identifiable contour on an object without relying on markers or pre-existing knowledge of the geometry of the object is described. The technique is defined as Contour Radiography. In the preferred embodiment two X-ray sources irradiate an object possessing a radiographically identifiable contour and then the two images of the contour are projected onto an X-ray film at spaced locations on the film plane. These images are digitized by the tracing of the image curves with a cursor or some other means thereby establishing the coordinates of an arbitrary number of image points. The digital data thus obtained is processed in accordance with a Contour Radiography (CONRAD) algorithm to identify corresponding points on the two curves which originate from the same point on the physical contour. The spatial coordinates of the X-ray sources are determined using a special calibration system.

Abstract: The invention is a method for making ice in a container the side walls of which are cooled to cool a solution of less than eutectic concentration to form ice crystals wherein the sides of the container are continuously mechanically scoured at a rate that prevents the formation of ice crystals on the wall of the container when the heat exchange relation of the solution with the side of the chamber is at least 4000 BTU's per square foot of container side.

Abstract: A system for determining the first dental occlusion prematurity is presented. A sensor adapted to be inserted in the mouth of a patient comprises two flexible strips with spaced electrical conductors connected to a liquid crystal display. Each of the strips has a layer of dilatant material on one side. When the patient bites, the upper and lower conductors complete an electrical circuit and from the resistance of this circuit the location of the first prematurity relative to the strip is determined. One edge of the strip is used as a reference point on the sensor and the distance from this edge to the location is displayed on the liquid crystal display. The dilatant layer also retains the impression of the teeth and the location identified by the visual display and the impression are compared to give the exact location of the first prematurity. The sensor is reusable on the same patient to determine subsequent prematurities by squeezing it to remove the impression of teeth on the original bite.

Abstract: A wood burning stove comprises a fire chamber of which the upper part is constituted as a heat exchanger. A primary air supply is provided as is a secondary air supply, the secondary air supply permitting air to be mixed with the gaseous products of combustion to support complete combustion of those gaseous products. Both air supplies have dampers, the damper of the secondary air supply being automatic and opening as the damper of the primary air supply is closed. The secondary air supply comprises an inlet manifold interconnecting a plurality of tubular elements which form a fire supporting grate, the tubular elements leading the secondary air beyond the fire to a region in which mixing of that air with the gaseous products of combustion is effected, secondary air passing through the tubular elements being preheated by the burning fuel supported on the grate.

Abstract: The invention involves new high voltage current limiting fuses employing composite metal fuse elements. One metal of the composite is aluminum which is of high conductivity and high melting point while the other is cadmium which is of low melting point, so that melting of the low melting point metal occurs at any and all locations along the element when its temperature reaches the said low melting point. The resulting composite exhibits properties that are not the mean of the metals employed and has a reversible resistance characteristic thus facilitating the design of the fuse for low current fault interruption.

Abstract: A fluid sampling apparatus for taking samples of fluid from predetermined depths in a body of water comprises a receptacle for releasably holding therein a sample collection bottle. A single suspension means such as a rope is provided, by means of which the assembly can be raised and lowered. Attached to the bottom of the suspension means is an interference fit stopper such as a cork and a resilient engaging means, for releasably engaging ribs on the neck of a bottle disposed within the receptacle. As the assembly is lowered by means of the suspension means, it is suspended by means of the resilient releasable means engaging against ribs on the bottle neck. When it has been lowered to the required depth, the suspension means is jerked suddenly upwardly, causing the resilient releasable means to release the bottle, with consequent removal of the stopper to permit filling of the bottle.

Abstract: A portable transparent display device consists of two elements, viz. (1) a flexible transparent generally flat receiving element (e.g. disk-shaped), one face of which is recessed to form a receiving space, the side walls of the receiving element defining the receiving space slanting inwardly and upwardly from the bottom thereof; and (2) an insertable element, mating with and insertable into the aforesaid receiving space and removably locked into position by the inclined side walls defining the periphery of the receiving space of the receiving element. A thin paper insert or the like bearing a message or photograph, etc. may be clamped between the receiving element and the insertable element and the device used for display of the message or photograph, etc. through the transparent receiving element. The insertable element may be provided with a clasp at the rear surface for attaching the device to the clothing of the wearer.