Abstract: A novel aerial boom system for use atop a vehicle and having linear movement sensors associated with hydraulic cylinders for moving lower and upper booms such that a microprocessor associated with the system can determine the instantaneous position of each boom and coordinate movement of the booms with respect to each other and with the vehicle to prevent undesired contact and to gradually decelerate boom movement as the boom approaches its limits to avoid shock from sudden stop of boom movement. When the novel system is used with a fire fighting vehicle, two variably spaced, independently controllable, fluid discharge nozzles can be used to fight one or two separate and distinct fires simultaneously. A piercing nozzle can be associated with the outer end of the upper boom that is independently controllable in both the vertical plane and in the horizontal direction to enable piercing of a wall independent of boom movement to assist penetration.

Abstract: A forward-mounted fluid-dispensing boom on a fire-fighting vehicle that can move between a retracted position and a fully extended position directly in front of the vehicle.

Abstract: A fluid discharge nozzle assembly that has both a piercing nozzle for fighting fires behind a wall member and a foam/spray nozzle for applying fire-retardant fluid to an open fire. The piercing nozzle is movable only in a vertical plane. The foam spray nozzle is movable in both the vertical plane with the piercing nozzle and in a direction perpendicular to the vertical plane so that, when the piercing nozzle is to be used, the foam/spray nozzle is movable to a position perpendicular to the longitudinal axis of the piercing nozzle to provide maximum clearance of the piercing nozzle during use of the piercing nozzle.

Abstract: An automatic levelling device for a fluid nozzle pivotally mounted on the outer end of an aerial boom such that, irrespective of the vertical position of the boom, the nozzle will remain in a horizontal plane. Either manually operated control of the fluid nozzle vertical position or automatic control that maintains the fluid nozzle in a horizontal plane can be selected by a switch.

Abstract: An aerial boom system for a fire-fighting vehicle which has a hollow piercing nozzle on the outer end thereof for passing through the wall of a structure such as an aircraft fuselage to the interior of the structure where a fire-retardant material may be injected. The nozzle may pierce the fuselage from a remote distance because of the extensible boom. It has thereon a torque limiter to protect the nozzle assembly when forces are applied to the nozzle assembly in a direction transverse to the piercing direction.

Abstract: An aerial lift for use with a vehicle for positioning the nozzle on the outer end of an upper boom coupled at its inner end to the outer end of a lower boom with selectively raising and lowering the lower boom in a plane from and above the horizontal and rotating the lower boom about a vertical axis, and independently articulating the upper boom about its inner end with respect to the lower boom such that the upper boom is selectively movable above and below the horizontal plane.

Abstract: A plastic filterware having a filter membrane made at least in part of cellulose nitrate welded to the filterware and a method of making same.

Abstract: A plastic filterware having a filter membrane consisting essentially of cellulose nitrate welded to a surface of a membrane support member.The weld can be substantially in the shape of a ring having a width of about 2.29 millimeters. The filterware can include an upper receiving chamber for receiving liquid to be filtered, a support member at the lower end of the receiving chamber and a lower receptacle below the support member of receiving filtrate.

Abstract: A headset for communication with both FM and AM circuit signals comprising a first earphone for receiving only FM signals and a second earphone for receiving only AM signals and first and second switches associated with the headset and coupled to the FM and AM circuits for selectively transmitting a response to either of the received signals on a corresponding one of the FM and AM circuits.

Abstract: A disposable filtration unit having a breakaway reservoir to facilitate recovery of the filter membrane.