Abstract: A structure on which stringers for a free-standing circular staircase are formed in accordance with a time-saving method is disclosed. The structure comprises upper and lower metal patterns connected by vertical beams. The patterns have a plurality of rays attached to a central hub. The beams are attached to equidistant rays at a given distance from the center of the respective pattern. Clamps are affixed at successively higher positions along the perimeter of the circle formed by the beams that hold the stringer while it is being laminated with epoxy resin, until it has become rigid.Separate sets of beams may be used to form inner and outer stringers for a staircase, or the outer stringer may be formed on the same set of beams after the inner stringer has become rigid.

Abstract: A fluted piston for a volume-compensated pressurized adjustable length positioner. The cylinder is charged through the charging/discharging valve so that the opposed fluid chambers defined inside the cylinder bore by the slidably movable piston are filled with compressible fluid at elevated pressure. An actuating rod in the piston operates a valve in the piston to open communication between the opposed chambers and allow selective extension and retraction of the piston rod. The large-diameter piston rod has an elongated head configuration formed by flute ribs. These ribs provide bearing support for the extended piston rod and create a volume compensating space in the piston head to account for the large ratio of extended-rod cylinder volume to retracted rod cylinder volume.

Abstract: A gas cylinder for applications requiring height adjustments such as found in chairs, stools, or like structures supported by columns. The cylinder has an elongated rechargeable unit of double-wall construction provided with a springless check valve inside a fluid port thereof preferably all of molded plastic. A single-piece sealed plunger assembly includes a single actuating rod with velocity controls incorporated therein which permit vertical extension from collapsed to fully-extended positions. Depression of the actuating rod allows circulation of the pressurized fluid between the chambers, with pressure force acting to extend the plunger when the unit is unloaded. When the unit is loaded, the plunger can be retracted.

Abstract: A wrench is formed of two jaws which are shaped to conform to standard fasteners, such as hex nuts, and are supported within a housing for translation relative to each other for gripping the fastener. Closing force on the jaws is exerted by a pivoting handle acting through an overcenter linkage. A crank-shaped lever is positioned contiguous to the overcenter linkage permits operation of the wrench with the jaws being either tightly clenched or slightly withdrawn from the fastener. One end of the overcenter linkage is connected to the housing by a screw which is rotated to set a spacing between the jaws.

Abstract: A stable, mechanically formed brazing shape comprising a polymer matrix which may be composed of thermosetting and thermoplastic resins in various combinations and braze alloys or compounds which when formed by extrusion, dried, and cured is able to replace brazing pastes, loose powders and tapes in many brazing applications especially those requiring the deposition of a uniform amount of alloy in the brazed or bonded joint. The fabrication of shapes of various cross sections by extrusion is also described.

Abstract: A dual purpose electronic instrumentation device for teaching the principles of electricity and electronics and for testing electrical systems is disclosed which includes a housing, having electronic circuitry arranged within it with control, display and terminal elements extending externally of the housing. The housing is divided into at least two portions with a first portion being movable relative to the second portion to expose or conceal a display surface having a receptacle for receiving one or more plug-in circuit cards, wherein the control, display and terminal elements of the housing and the receptacle of the display surface are interconnected with the electronic circuitry for testing electrical systems which are electrically coupled to the terminal elements and the receptacle. When the display surface is concealed, the instrumentation device is for testing electrical devices electrically coupled to the terminal elements of the housing.