Abstract: A headset includes at least one ear cup having front and rear cavities separated by a driver. The cup includes a pressure equalization port coupling the front cavity to space outside the cup, the pressure equalization port having a cross-sectional area greater than 2 mm2 and being significantly longer than it is wide, providing a principally reactive acoustic impedance, such that the pressure response of the front cavity including the port to signals input via the driver may be effectively linear over a wide range of pressure levels within the front cavity.

Abstract: A headset includes at least one ear cup having front and rear cavities separated by a driver. The cup includes a pressure equalization port coupling the front cavity to space outside the cup, the pressure equalization port having a cross-sectional area greater than 2 mm2 and being significantly longer than it is wide, providing a principally reactive acoustic impedance, such that the pressure response of the front cavity including the port to signals input via the driver may be effectively linear over a wide range of pressure levels within the front cavity.

Abstract: Apparatus and method to mix audio provided by a radio with audio provided by an ICS in which the audio of the radio being mixed with audio provided by the ICS and presented to one ear of a user, and in which audio provided by the ICS is presented to the other ear of the user without being mixed with audio provided by the radio.

Abstract: A noise reduction headset including a negative feedback active noise reduction signal processing path for providing active noise reduction, an electronic communication signal processing path, a talk-through signal processing path for providing talk-through capability, comprising at least one talk-through microphone separate from the electronic communication signal processing path, and a switching element for disabling one or both of the noise reduction signal path and the talk-through signal path.

Abstract: Apparatus and method to monitor the coupling of one or two audio devices and to augment the function of a PTT switch to causes the PTT function of one audio device to be engaged regardless of which of the two operated positions into which the switch is moved in response to there being only the one audio device coupled to the apparatus and in response to the one audio device being a radio, to cause the PTT function of either one of two audio devices to be selected to be engaged depending on which operated position to which the PTT switch is moved in response to there being only one audio device in the form of an intercom system (ICS) coupled to the apparatus with the other audio device in the form of a radio being coupled through the ICS, and to allow the PTT to be used to select the PTT function of either one of two audio devices to be engaged in response to there being two audio devices in the form of radios coupled to the apparatus.

Abstract: A push-to-talk (PTT) switch with biasing to a first center position in which in which the PTT function of neither one of up to two audio devices is engaged, also having a first operated position to which the switch may be moved by hand operation to cause the PTT function of the first one of the two audio devices to be engaged, and further having a second operated position to which the switch may be moved by hand operation to cause the PTT function of the second one of the two audio devices to be engaged.

Abstract: A push-to-talk (PTT) switch with biasing to a first center position in which in which the PTT function of neither one of up to two audio devices is engaged, also having a first operated position to which the switch may be moved by hand operation to cause the PTT function of the first one of the two audio devices to be engaged, and further having a second operated position to which the switch may be moved by hand operation to cause the PTT function of the second one of the two audio devices to be engaged.

Abstract: Apparatus and method to monitor the coupling of one or two audio devices and to augment the function of a PTT switch to causes the PTT function of one audio device to be engaged regardless of which of the two operated positions into which the switch is moved in response to there being only the one audio device coupled to the apparatus and in response to the one audio device being a radio, to cause the PTT function of either one of two audio devices to be selected to be engaged depending on which operated position to which the PTT switch is moved in response to there being only one audio device in the form of an intercom system (ICS) coupled to the apparatus with the other audio device in the form of a radio being coupled through the ICS, and to allow the PTT to be used to select the PTT function of either one of two audio devices to be engaged in response to there being two audio devices in the form of radios coupled to the apparatus.

Abstract: Apparatus and method to mix audio provided by a radio with audio provided by an ICS in which the audio of the radio being mixed with audio provided by the ICS and presented to one ear of a user, and in which audio provided by the ICS is presented to the other ear of the user without being mixed with audio provided by the radio.

Abstract: A conical reactor head for use in chemical processes or other systems is provided. The reactor head includes a robust internal insulator to boost efficiency while maintaining safety by allowing the reactor head to self-radiate at high temperatures. The reactor head also includes a plurality of support lugs to protect its bottom flange from scratches or other damage when the reactor head is set on the ground. The reactor head is adapted to connect to a catalyst-containing barrel which is specially designed to facilitate easy installation and removal of catalysts or other equipment from outside the barrel. The reactor may be coupled with a rotation vane to induce laminar flow at the inlet of the reactor to increase reactor efficiency and prolong catalyst life.

Abstract: An active noise reduction headset with active noise reduction and talk-through, and switching circuitry related thereto.

Abstract: A two-compartment container has a lid portion and a base portion hingedly connected to one another and openable and closable in the manner of a clamshell. Both the lid portion and the base portion have partitions, which extend from the hinge and which are aligned with one another. When the container is closed, the partitions abut against one another, effectively isolating the two compartments formed in the base portion by its partition from one another. The base portion includes a locking flap which fits into a gap between the partition in the lid portion and its face and seals it to further isolate the two compartments from one another.

Abstract: A conical reactor head for use in chemical processes or other systems is provided. The reactor head includes a robust internal insulator to boost efficiency while maintaining safety by allowing the reactor head to self-radiate at high temperatures. The reactor head also includes a plurality of support lugs to protect its bottom flange from scratches or other damage when the reactor head is set on the ground. The reactor head is adapted to connect to a catalyst-containing barrel which is specially designed to facilitate easy installation and removal of catalysts or other equipment from outside the barrel. The reactor may be coupled with a rotation vane to induce laminar flow at the inlet of the reactor to increase reactor efficiency and prolong catalyst life.

Abstract: A conical reactor head for use in chemical processes or other systems is provided. The reactor head includes a robust internal insulator to boost efficiency while maintaining safety by allowing the reactor head to self-radiate at high temperatures. The reactor head also includes a plurality of support lugs to protect its bottom flange from scratches or other damage when the reactor head is set on the ground. The reactor head is adapted to connect to a catalyst-containing barrel which is specially designed to facilitate easy installation and removal of catalysts or other equipment from outside the barrel.

Abstract: A conical reactor head for use in chemical processes or other systems is provided. The reactor head includes a robust internal insulator to boost efficiency while maintaining safety by allowing the reactor head to self-radiate at high temperatures. The reactor head also includes a plurality of support lugs to protect its bottom flange from scratches or other damage when the reactor head is set on the ground. The reactor head is adapted to connect to a catalyst-containing barrel which is specially designed to facilitate easy installation and removal of catalysts or other equipment from outside the barrel.

Abstract: A vertical movement clip for attaching a channeled beam or stud member to a horizontal building member. The clip has the advantage of easily sliding into the interior of the stud and wedging between two parallel legs of the stud member to fit securely therein. The clip also has the advantage of providing an attachment flange that securely attaches to and holds the floor to the stud and prevents most all horizontal movements and yet allows for vertical floor movement relative to the stud. A second embodiment includes a first and second arm having bent portions for increased loading capacity.

Abstract: A vertical movement clip for attaching a channeled beam or stud member to a horizontal building member. The clip has the advantage of easily sliding into the interior of the stud and wedging between two parallel legs of the stud member to fit securely therein. The clip also has the advantage of providing an attachment flange that securely attaches to and holds the floor to the stud and prevents most all horizontal movements and yet allows for vertical floor movement relative to the stud.