Abstract: A structure for mounting a planar array of photovoltaic panels to a roof is formed from a set of parallel spaced juxtaposed rails which are intersected by a set of parallel spaced juxtaposed runners that extend perpendicular to the rails. Both the runners and the rails are formed of sheet metal and are shaped in cross section so as to partially surround a space. Both the rails and the runners have upwardly opening apertures bordered by flanges. The flanges of the rails are coplanar with the flanges of the runners. The photovoltaic modules rest on the flanges, thereby covering the apertures and enclosing the space within the rails and the runners. This space serves as a protective raceway for the electrical interconnections and wiring. Because the entire structure is a single electrical conductor, grounding of the modules is simplified. Compared to other mounting systems, the structure is lighter in weight, simpler to install, extremely strong, and protective of the electrical interconnections.

Abstract: A hopper that greatly reduces the tendency of the particulate material to form bridges within the hopper is shaped so that its walls slope downward more steeply at the bottom of the hopper and slope less steeply with increasing height above the outlet. In one embodiment the slope decreases continuously with increasing height above the outlet. In another embodiment the hopper is formed of successive sections, each joined around its circumference to the next-lower section, the wall of each section being less steeply inclined than the wall of the adjoining next-lower section. Exact relationships are given, relating the slopes of successive sections, and if the hopper is built in conformity with these relationships, arching of the particulate material is eliminated.

Abstract: Instead of applying the maximum cooling effect that can be produced, the method and apparatus disclosed applies only a carefully controlled cooling that is adequate to maintain the fluid in the pipe in a frozen condition but which maintains the temperature high enough to prevent damage to the metallurgical structure of the pipe. At the same time, the apparatus creates permanent documentation of the temperatures at selected stations along the pipe throughout the process, thereby providing proof that the pipe sustained no thermal damage.

Abstract: Many types of processors of particulate materials operate more efficiently when they receive the particulate material in a steady stream. Most feeders tend to discharge in pulses. A hopper is interposed between the feeder and the processor. Surges in the feed rate are accumulated in the hopper, and lapses in the feed rate are compensated by the propensity of the hopper to discharge at a constant rate. Initiation of hopper flow is accomplished by use of a trap door. Mismatch between average feeder output rate and hopper discharge rate is corrected by use of an adaptive hopper having an outlet the size of which is slowly altered to maintain a constant amount of material in the hopper. A bypass hopper is used to control extremely variable input flow rates.

Abstract: In a kaleidoscope having an object chamber containing a fluid and containing a number of objects, the objects are caused to move by setting in motion the fluid within the object chamber, using energy derived from a source mounted on the kaleidoscope. In a preferred embodiment, the fluid in the object chamber is set in motion by a small electrically powered pump that is powered by a battery mounted on the kaleidoscope under control of a microprocessor that relates the operation of the pump to the production of lighting effects and sound effects produced within the kaleidoscope. The apparatus results in a display of persistently moving patterns, even when the object chamber remains stationary, and requires no intervention by the user.

Abstract: One type of kaleidoscope has an object cell that contains a multitude of small objects immersed in a viscous liquid. By inverting the object cell, a user can enjoy a continuous ever-changing display of pleasing and colorful symmetrical images as the objects cascade through the viscous liquid under the influence of gravity. Eventually the objects settle to the top or bottom of the object cell as determined by their densities, and the viewer needs to invert the object cell again. It is desirable to prolong each cascade so as to reduce the frequency with which the object cell must be inverted. Several ways of accomplishing this are disclosed. The walls of the cell may converge and may be provided with bumps or other surface irregularities. The movement of the objects may be impeded by the provision of fixed obstacles within the object cell. In another approach, an upwelling and circulation of the viscous liquid is produced by a simple pump that is mobilized by inverting the object cell.

Abstract: A patio umbrella that includes a dining table and a fuel-burning radiant heater avoids overheating of the upper canopy by mounting the support on which the upper canopy rests in the shadow cast by a reflector that converges upwardly to a chimney portion. The reflector is affixed to the housing of the combustion chamber. In addition to reflecting radiant heat downwardly onto the table and the diners, the reflector shields the upper canopy support from radiant heat and provides a duct for venting the products of combustion. As the latter pass up through the chimney portion, cooler air is drawn up through the space between the reflector and the upper canopy support thereby preventing hot air from stagnating there. The upper canopy support is mounted to the reflector and spaced above it by a number of insulative ceramic spacers.

Abstract: A method and apparatus for planarizing silicon wafers initially having wavy surfaces, such as might result from having been cut from a boule by means of a wire saw. A vacuum is applied to one side of a porous ceramic plate, and a perforated resilient pad is applied to the opposite side of the porous ceramic plate. The resilient pad is affixed to the ceramic plate by a peelable adhesive, and the vacuum extends through the perforations of the resilient pad to permit a wafer to be mounted on the exposed side of the resilient pad. The perforations in the resilient pad are distributed uniformally across the wafer, so that the atmospheric pressure pushing the wafer against the resilient pad is also uniform across the wafer. However, the wafer is not deformed while it is held in place for grinding. Because the wafer is not held in an elastically deformed condition while it is ground, the wafer has no tendency to spring back to its original wavy shape.

Abstract: An apparatus and a method for producing accurate straight cuts in a slab of stone, concrete, or the like. A carriage conveys the cutter along two parallel rails that lie directly upon the upper surface of the slab to be cut. In a preferred embodiment of the invention, neither rail is connected to anything else, and a sheet of resilient material is bonded to the underside of each rail. A calibration instrument is disclosed, which is used to facilitate spacing the rails specific distances on either side of the desired cut line. Because the rails can be moved one at a time in the preferred embodiment, the apparatus is highly portable. In an alternative embodiment in which portability is not an important consideration, the rails may be permanently connected by rigid lateral members.

Abstract: Apparatus for use in a semiconductor wafer polishing machine of a type in which the wafer is picked up and held by a suction cup effect between the wafer and a resilient diaphragm on the wafer carrier. The apparatus permits the presence or absence of a wafer on the carrier to be sensed so that this information can be used in controlling the operation of the machine. In normal operation, a vacuum is applied to a downwardly-opening plenum that is covered by a resilient diaphragm. The present invention is the addition to the wafer carrier of an air conduit opening into the plenum through an air port and connected to an orifice so that air can flow through the orifice, through the air conduit and the air port into the plenum at a rate that is slow relative to the capacity of the vacuum pump. The present invention further requires the addition of a pressure sensor for sensing the pressure in the air conduit or alternatively in the vacuum conduit.

Abstract: A food shelf attached to the lower end of a vertical threaded rod engages a nut that is attached to the summit of an arch that rises from a horizontal frame. The frame may be removably set onto a receptacle containing a source of heat, or the same frame can be supported above a source of heat on a set of removable legs. In each case, the height of the food shelf above the source of heat may be adjusted by turning the vertical threaded rod.

Abstract: A spa is maintained at a ready-to-use temperature by a daily heating cycle that is initiated by a filter cycle clock, which traditionally has been used only for programming the circulation of the spa water through a filter. Once a daily heating cycle has been initiated, it normally concludes only when the temperature of the spa water reaches a desired temperature that the user has preset into a thermostat. However, for safety the heating cycle is terminated immediately in the event the heater temperature becomes excessive, since this event could result from lack of water or inadequate circulation.

Abstract: A set of two templates for use in cutting patches, each patch having first and second straight sides that in general are not parallel, whereby the patches can be arranged in a sequence with the first straight side of each patch except the first patch collinear with the second straight side of the previous patch, and with the second straight side of each patch except the last patch collinear with the first straight side of the next patch. The shape of the first template is the shape of the sequence of patches. The second template includes a sheet of a transparent material having a straight edge and bearing markings showing the successive patches in the sequence arranged along the straight edge and oriented so that the second straight side of each patch, except the last patch, is collinear with the straight edge.

Abstract: A type of stapler has a handle that permits it to be used like a hammer. The end of the handle is modified to permit it to receive the body of a utility knife. The latter is retained within the handle by a screw that replaces the screw which previously held the halves of the utility knife together. The blade-retracting lever of the utility knife is made accessible on the upper portion of the handle. The blade of the utility knife can be extended and retracted at the end of the tool opposite the staple-dispensing end of the stapler. The handle of the stapler serves as the handle of the utility knife. The tool thus formed is useful to persons who work with sheets of material that must be stapled to an underlying structure then trimmed to the shape of the structure and/or cut free from a roll of sheet material.

Abstract: A method for use in mass-producing, from a plane sheet of metal, a three-dimensional structure consisting of plane mirrors and plane structural members, said three-dimensional structure of a type in which each mirror or structural member has at least one edge that is collinear with an edge of another mirror or structural member, whereby said three-dimensional structure can be formed by bending the sheet of metal along various edges, the method including the steps of: producing masks bearing images defining the location of bending grooves, shallow grooves, separation grooves and holes for indexing pins, selecting a mask, applying a coating of photoresist to both sides of the sheet of metal, transferring the images on the selected mask to the coating of photoresist, removing those portions of the coating of photoresist to which the images were transferred, etching the sheet of metal where the portions of the coating of photoresist were removed, removing the remaining photoresist from the sheet of metal, and rep

Abstract: A portable instrument for locating leaks through the wall of a chamber uses a non-dispersive infrared (NDIR) type detector. The instrument includes a gas sampling probe into which a continuous sample of gas is drawn by a small suction pump. The sample is conducted from the probe through a flexible conduit and through a gas sample chamber. The gas sample chamber contains a source of light or infrared radiation and a detector. A narrow pass band filter is interposed between the source and the detector, and the pass band of the filter is centered on an absorption band of the test gas that is to be detected. When the test gas is present, it absorbs some of the radiation. The detector produces an electrical signal representative of the concentration of the test gas. The detector is connected to a signal processing circuit that responds to rapid changes of test gas concentration but ignores slow changes in concentration, thereby reducing the false alarm rate.

Abstract: The stroller includes a frame inclined downward and forward, the frame having left and right side frame members joined by a handle at their upper rear ends. A single front wheel is mounted on an axle at the lower front end of the frame. Left and right swing arms extend downward and rearward from pivotal attachments on the left and right side frame members, respectively. Left and right rear wheels are mounted on axles at the lower ends of the swing arms. There is no rigid connection or horizontal member between the front and rear axles, thereby permitting the stroller to clear higher curbs or carry cargo that extends into the space between the front and rear axles, while also reducing the weight of the stroller. On each side of the stroller a resilient member is detachably connected between the swing arm and a point on the side frame member above and to the rear of the point at which the swing arm is attached.

Abstract: A one-piece article having a uniform cross section includes a number of portions that interact to releasably grip a cylindrical object (18). Two jaws (14, 16) extend from a base (12) and are shaped to embrace the cylindrical object. The base (12) and one of the jaws (14) are rigid. A second jaw (16) melds into the base and has a gripping surface that closely follows the contour of the cylindrical object. The distal end (22) of the second jaw diverges from the cylindrical object and reverts back to the base, terminating in a free end (24). This free end serves as an actuator for releasing the cylindrical object. When the free end is pressed by the user in the direction of the first jaw (14), the reverted portion (26) pivots about a fulcrum (30) formed by an extension of the base to draw open the second jaw, thereby releasing the cylindrical object.