Abstract: An audio mixer for combining stereo phonograph, stereo high impedance and low impedance input signals having a means for audio previewing one or more of said inputs simultaneously including a means for visually indicating which signals are being previewed, further including a means for audio previewing said signals in a monophonic signal, further including a means for combining said inputs in the final amplifier stage such that the output signal is in a monophonic state, further including a means for disabling said low impedance input from the final output means.

Abstract: Sheets of heat-deformable material, such as glass, are shaped to non-uniform curvatures that include a localized sharply bent portion near one side portion of the sheet by lifting the sheet while the latter is at a deformation temperature range on a lower lifting mold of special construction that includes spaced, transversely extending slats having upper edge surfaces defining the non-uniform bend and a longitudinally extending end slat whose upper edge surface defines a transverse curve that merges with the upper edge surfaces of said transversely extending slats.

Abstract: The present invention provides a multi-leveled storage system located immediately above a glass sheet bending lehr. The multi-leveled storage system includes an elevator which enables an operator to transfer empty bending molds in groups from a return conveyor located above the roof of a bending lehr onto any one of several storage levels and to replace the tranferred molds with molds needed to produce a different pattern by transferring the different pattern molds from a selected storage level and to transfer said molds needed for said different pattern onto the return conveyor of the conveyor system used for handling glass sheet bending molds. The present invention also enables an operator to shuffle molds between different storage levels to facilitate future mold exchange operations.

Abstract: A vacuum holder for holding sheets of heat-softenable material such as glass thereagainst by vacuum during their fabrication into shaped sheets comprising a lower sheet wall that has flanking portions slit longitudinally to provide strips extending longitudinally from a central portion, the width of the strips being limited to limit transverse bulging as the holder becomes hot during a sheet shaping campaign. Longitudinal slots of increasing length from a selected transverse line, preferably one traversing the geometric center of the sheet, control longitudinal bulging of the holder.

Abstract: A deformable vacuum holder having a glass facing wall of flexible sheet material subject to local distortion for shaping heat-softened material, such as glass sheets, has a deformable sheet of insulator material attached mechanically to said glass facing wall for engaging the flexible glass facing sheet wall of the vacuum holder. The deformable sheet has a smooth surface less subject to distortion than said glass facing wall facing the engaged glass sheet surface to avoid having scratches and other surface irregularities of the glass facing wall mar the vision area of the shaped glass sheet and is mechanically supported against the flexible sheet wall beyond the margin of the engaged glass sheet instead of being adhered to said flexible sheet wall.

Abstract: The invention involves a method and apparatus for bending glass sheets to an S-shaped transverse bend with a longitudinal bend. The heat softened glass sheets are serially conveyed onto a gas hearth bed having a downwardly curved end portion at the downstream end thereof such that the glass sheet curves into conformation with the gas hearth, then by means of a curved outline mold lifting the glass sheet vertically into conformation with an overlying vacuum mold, holding the shaped sheet into contact with the vacuum mold by vacuum while lowering the outline mold, then moving a shuttle ring beneath the glass sheet, discontinuing the vacuum such that the glass sheet is deposited onto the shuttle ring and then moving the shuttle ring and glass sheet laterally for further processing.

Abstract: The present invention relates to the simultaneous shaping and lamination of lightweight laminated transparencies, particularly those that are suitable for use in aircraft. The plies of an assembly to be shaped and laminated are assembled with additional elements to form a flexible cell of air impervious material. The cell includes an air impervious flexible wall defining a peripheral space around the assembly and porous material in the space. The cell containing the assembly is mounted over a vacuum mold and heated to sag the cell and its assembly to the contour of the mold while evacuating the cell while the cell and said assembly are exposed to atmospheric pressure.The cell is cooled while still under evacuation until the shape of the assembly is set, then is separated from the vacuum mold. The resulting assembly thus shaped and laminated is separated from the cell.

Abstract: A vacuum mold for supporting a flexible sheet of interlayer material for assembly against a bent glass sheet or between a pair of bent glass sheets of matching configuration has a first apertured wall shaped to conform to the shape of the bent glass, and a second apertured wall of conforming shape adapted for coupling to a vacuum source to form and hold the flexible sheet of interlayer material against the mold in unwrinkled condition. The mold is pivoted to a carriage from a mold loading orientation of convex elevational configuration to a mold unloading orientation of concave elevational configuration.

Abstract: Bending a glass sheet to a complicated shape that comprises one portion bent sharply relative to a main portion of the sheet involving the use of a vacuum holder, an auxiliary shaping rail and means to correlate the movement of the shaping rail with that of the glass sheet during a bending cycle to insure that the glass sheet is clear of the auxiliary shaping rail except for such time in the glass sheet bending cycle that requires the auxiliary shaping rail to engage the glass sheet portion to be sharply bent against the corresponding portion of the vacuum holder. Another feature incorporated in a preferred embodiment of the present invention facilitates ready removal of glass fragments whenever a flawed glass sheet fractures at or beyond a shaping station outside a furnace where the glass sheet is heated to its deformation temperature.

Abstract: A ring-like member for use in lifting a glass sheet from a given path to the vicinity of a vacuum holder at a shaping station has its movement coordinated mechanically with stop means that engages the leading edge of a glass sheet at an edge locating position when said ring-like member is below said given path and mechanically retracts from said edge locating position in unison with said ring-like member when said ring-like member moves in the direction of the thickness of said glass sheet to engage and lift said glass sheet. This mechanical coordination of movements avoids rubbing the glass sheet edge in the direction of the glass sheet thickness during its lifting without requiring complicated and expensive coordinating equipment.

Abstract: A glass sheet is press bent between a pair of bending molds of complementary shape provided with covers using burning gas source means that supplies heat by directing burning gas flames toward the bottom edge of a glass sheet. The burning gas source means is constructed and arranged to be directed toward the path taken by the glass sheet when the latter moves into a shaping position with the press bending molds retracted and to pivot away from the mold covers when the press bending molds engage the glass sheet including its bottom edge during the shaping of the sheet. Preferably, the burning gas source means has a shape that conforms with the shape of the bottom edge of the glass sheet undergoing press bending and has an upwardly directed downstream portion to provide clearance as the glass sheet moves into said shaping position in a direction such that a recessed lower edge portion thereof is the leading edge of the glass sheet during its path of movement into the shaping station.

Abstract: Vacuum is applied to help separate a press bent glass sheet from between a pair of complementary press bending molds during the separation of said molds after completing said press bending.

Abstract: A deformable vacuum holder used in the shaping of sheets of glass or other deformable materials is provided with a plurality of longitudinally extending helical coil springs that enhance the durability of the deformable vacuum holder. When the outer diameter of the springs approximates the thickness of a chamber comprising said holder, the springs improve the resistance of the holder to collapse in response to the application of vacuum to said holder.

Abstract: Multiple chamber vacuum holders for use in shaping sheets of glass or other heat-softenable material to complex shapes require a different level of vacuum in adjacent vacuum chambers. A porous fiber glass cover used with such vacuum holders provide passages for residual air in adjacent passages to tend to equalize when a sheet is held against the porous cover. The present invention helps maintain a difference in level of vacuum between adjacent vacuum chambers by interposing a narrow space vented to atmosphere between adjacent vacuum chambers of the multiple chamber vacuum holder.

Abstract: In the art of shaping sheets of glass and other deformable materials comprising engagement of said sheets while hot by a vacuum holder in a relatively hot atmosphere and removing the holder into a cooler atmosphere to cool the holder between successive shaping cycles, production of shaped sheets was limited by the time necessary for the holder to cool during its exposure to said cooler atmosphere to a temperature suitable for beginning a subsequent sheet shaping cycle. The present invention lessens this necessary time by drawing cold air by suction from said cooler atmosphere between successive shaping cycles, thereby increasing the maximum production rate possible.

Abstract: Treating a plastic sheet blank, preferably an acrylic resin sheet, along its edge surface by applying a groove of non-uniform depth to its edge surface along a side of the blank having a length to blank thickness ratio that exceeds a critical ratio for the given blank thickness to improve the conformance of the outline of the compression stretched sheet to one similar to the outline of the thick blank prior to its compression stretching and so stretch the blank more uniformly along its orthogonal axes during the compression stretching of said blank to form said sheet.

Abstract: The present invention relates to a ring-like member for use in a glass sheet bending and tempering process most adapted to a process wherein a glass sheet is released from engagement against a vacuum mold of a shape having sharply bent regions about longitudinally spaced, transversely extending lines of relatively sharp bending onto said ring-like member. The vacuum mold has a distance between the sharply bent regions at operating conditions that either equals or is slightly less than the distance desired in the bent glass. In a preferred embodiment, the ring-like member is split into two shaping rails, which are separable to adjusted positions wherein the sharply bent regions are spaced to conform to the distance desired therebetween in the bent glass sheet.

Abstract: A deformable vacuum mold for shaping glass sheets to complicated shapes includes mold stiffening structure engaging the central portion of the mold, mold lifting means engaging the longitudinal end portions of the vacuum mold to lift the latter relative to the mold stiffening structure and optional bar means adjustable in position and orientation to provide local control imparted to the shape of the vacuum mold when the longitudinal end portions of the mold are lifted. The deformable vacuum mold may also include a pair of lifting means providing different amounts of lift to the longitudinal end portions on opposite sides of the longitudinal center line of the mold and approximately equal amounts of lift to the longitudinal end portions on opposite sides of the transverse center line of the mold.

Abstract: Lightweight aircraft transparencies are shaped to a desired configuration by laying up a plurality of flat oversized plastic sheets in a desired sequence to form a flat assembly. Portions of the marginal edges of the flat assembly are supported on a female support ring having a non-planar supporting surface. The assembly is first shaped at a temperature below its deformation temperature to a preliminary shape where its marginal edge portions conform to the non-planar supporting surface of the female support ring. While the marginal edges of the preliminarily shaped assembly are maintained in conformity with the female support ring, the assembly is uniformly exposed in an enclosed autoclave to elevated pressures to minimize outgassing and to elevated temperatures above its deformation temperature. A male form having an outline smaller than the female support ring engages the central portion of the preliminarily shaped assembly to impress the desired final shape thereto, e.g., a compound configuration.

Abstract: In tempering a glass sheet to a high temper by heating the sheet to approximately its softening point followed by rapid chilling using a quenching composition that comprises a tempering medium having high heat transfer characterisitcs, the heat-softened glass sheets are protected from breakage during fabrication and resulting optical distortion by applying the tempering medium through exit orifices of a delivery system toward the heated glass in a novel cycle. The initially applied tempering medium has a low heat transfer rate and is mixed with a second tempering medium having a higher heat transfer rate to gradually increase the heat transfer rate of the mixed tempering medium. In a specific embodiment, dry air is the first tempering medium and a sublimable material, such as carbon dioxide, is the second tempering medium. The delivery system has an uninsulated portion that assures that initially the sublimable material is applied as a gas.