Abstract: The present disclosure describes a multi-mode headset incorporating both bone conduction and aural transducers. Bone conduction plates of the headset rest on a users' temples, just in front of each ear in one implementation, and create sound through vibrations in a first mode, allowing the user to listen to the headset while still leaving environmental or external sounds audible. In a second mode, the user detaches aural transducers or earbuds from an attachment point and inserts them into the user's ears, blocking external noise and providing passive and/or active noise isolation. In a third mode, both the bone conduction plates and aural transducers may be used simultaneously, providing additional amplitude and potentially wider frequency response. The headset may include a switch, such as a magnetic proximity sensor detecting the position of the aural transducers, to control a mixer or amplifier to re-route audio through the aural transducers.

Abstract: A method and apparatus for fusing a bell connector to the end of a corrugated thermoplastic pipe are disclosed in which an expandable mandrel grips a preformed bell and a pipe support grips a pipe co-axial with the longitudinal axis of the bell. A pipe trimmer for facing the pipe end may be moved into and out of the axis of the pipe if necessary for trimming the pipe end to provide a uniform planar flange face and a heater, combined with a supporting flange, moved sequentially into and out of the axis of the pipe and bell for heating the opposed faces of the trimmed end of the pipe and the end of the bell to a desired fusing temperature. Upon heating of the opposed faces of the bell and the pipe to a predetermined fusing temperature, the said faces of the bell and the pipe are abutted against each other, with the back side of the corrugated pipe flange face fully supported by the supporting flange, i.e. backing ring, at a predetermined pressure for a time sufficient to fuse the bell and pipe together.

Abstract: A floating dock comprising a pair of flotation tanks arranged in parallel side-by-side relation, a plurality of transverse, equispaced double-saddle brackets having a pair of spaced-apart saddles each adapted to receive a flotation tank straddling said tanks along the length of the tanks, and connector means adapted to partially encircle each tank and to seat in a recess between corrugations extending from each saddle for connecting the tanks to the saddle brackets. The flotation tank comprises a cylindrical smooth inner wall and a corrugated outer wall coextensive and concentric with said inner wall defining a plurality of equispaced peripheral annular flotation cells extending along the inner cylindrical wall, and a closure plate at each end of the cylindrical walls connected to the inner and outer walls in a water-tight relationship defining a central flotation cell.

Abstract: A method and apparatus for fusing a bell connector to the end of a corrugated thermoplastic pipe are disclosed in which an expandable mandrel grips a preformed bell and a pipe support grips a pipe co-axial with the longitudinal axis of the bell. A pipe trimmer for facing the pipe end may be moved into and out of the axis of the pipe if necessary for trimming the pipe end to provide a uniform planar face and a heater moved sequentially into and out of the axis of the pipe and bell for heating the opposed faces of the trimmed end of the pipe and the end of the bell to a desired fusing temperature. Upon heating of the opposed faces of the bell and the pipe to a predetermined fusing temperature, the said faces of the bell and the pipe are abutted against each other at a predetermined pressure for a time sufficient to fuse the bell and pipe together.

Abstract: A method and apparatus for production of smooth or corrugated small and large diameter thermoplastic tubing and composite tubular structures. The apparatus includes a supporting framework, a plurality of mold carriages mounted on said framework for reciprocal linear travel therealong, at least one mold block mounted on each of said mold carriages, each said mold block comprising a pair of opposed semi-cylindrical segments mounted on a carriage for transverse linear reciprocal travel therealong for closing and opening of said mold block, an actuating mechanism for moving said opposed mold segments towards and away from each other, and a single actuating mechanism for selectively moving said carriages.

Abstract: A method and apparatus for fusing a bell connector to the end of a corrugated thermoplastic pipe are disclosed in which an expandable mandrel grips a preformed bell and a pipe support grips a pipe co-axial with the longitudinal axis of the bell. A pipe trimmer for facing the pipe end may be moved into and out of the axis of the pipe if necessary for trimming the pipe end to provide a uniform planar face and a heater moved sequentially into and out of the axis of the pipe and bell for heating the opposed faces of the trimmed end of the pipe and the end of the bell to a desired fusing temperature. Upon heating of the opposed faces of the bell and the pipe to a predetermined fusing temperature, the said faces of the bell and the pipe are abutted against each other at a predetermined pressure for a time sufficient to fuse the bell and pipe together.