Abstract: A power operated retractable floor extension, extending outward from the floor of a mass transit vehicle. When extended, the floor portion bridges any gap between the vehicle floor and adjacent platform, thereby providing improved passenger access to the vehicle. Generally speaking, the extended member complies with existing United States Federal Regulations.

Abstract: A compact mechanical lock for bi-parting handles of passenger doors used on mass transit vehicles. Rotating lock cams cooperating with an interlocking lock plate to ensure proper closure of each panel prior to lock actuation.

Abstract: A method and apparatus for low NOX combustion of natural gas in a compact steam boiler having output steam delivery controlled by predetermined outlet steam pressure. The compact boiler employs a small high heat release combustor discharging into a forced draft convective heat exchange section. In operation, the compact boiler is completely and automatically self-operating, employing flue gas recirculation (FGR) wherein the FGR is admitted into the burner combustion air through a valve controlled by boiler flue gas NOX content. A novel bell mouthed flue gas scoop is utilized in the boiler stack upstream of the NOX sensor. In an alternate combustion chamber design, a cylindrical water wall coil surrounds the combustion process, increasing boiler efficiency through the inherent large temperature difference between the coil and the combustion in process, along with reducing the combustion temperature and further reducing the NOX content of combustion products.

Abstract: An improved transponder for use in identifying an controlling vehicles wherein transponders mounted on vehicles respond to signals from a fixed location interrogator providing information relative to the vehicle or other data as required. The transponder disclosed in particular utilizes an improved method of providing frequency shift keyed (FSK) signals in response to a trigger or command signal received from a ground mounted loop or antenna. As disclosed, the transponder of the invention generates FSK signals through programming multiple microprocessor loops of predetermined duration, each loop providing microprocessor highs and lows for transmission to the interrogating station. Utilization of the inherently accurate microprocessor cycle time to generate distinct FSK signals avoids problems with ordinarily used analog frequency generating devices.

Abstract: A power door operator for vehicles requiring uninterrupted car surfaces in a door area and minimal use of car interior space, particularly in the closed position. The equipment provided utilizes a rotary motor drive and distributed gear system for moving opposing door panels away from an opening in the car wall. Movement of the doors into and out of the car door opening is accomplished through use of controlled reaction travel of the rotary drive motor.

Abstract: Method and apparatus for reducing the NOX levels in stack emissions of compact boilers and fluid heaters through selective injection of exhaust flue gases into the combustion process. Flue gas injection into the primary and secondary air of the burner along with flue gas injection directly into the combustion process is utilized. Injection of generated steam from a compact boiler, selectively injected into the combustion process is also provided.

Abstract: A stabilizing arm for use in power operated doors in mass transit vehicles. Doors are of the type where a door panel is moved out of an opening in the car side wall to an opened position outside the car side wall. Stabilization is achieved by moving a rotating arm out of the side wall and capturing the panel in its opened position, thereby minimizing possible hazards in passenger passing through the car opening and damage to the doors either by passengers or others. Operation of the arm is sequenced in the door opening cycle.

Abstract: A method and apparatus for low NOX combustion of natural gas in a compact steam boiler having output steam delivery controlled by predetermined outlet steam pressure. The compact boiler employs a small high heat release combustor discharging into a forced draft convective heat exchange section. In operation, the compact boiler is completely and automatically self-operating, employing flue gas recirculation (FGR) wherein the FGR is admitted into the burner combustion air through a valve controlled by boiler flue gas NOX content. A novel bell mouthed flue gas scoop is utilized in the boiler stack upstream of the NOX sensor. In an alternate combustion chamber design, a cylindrical water wall coil surrounds the combustion process, increasing boiler efficiency through the inherent large temperature difference between the coil and the combustion in process, along with reducing the combustion temperature and further reducing the NOX content of combustion products.

Abstract: A pair of flexible interlocking edges for power operated doors primarily used on mass transit vehicles such as subway cars. If door closing is prevented, edge design allows withdrawal of obstructions, including deformable objects caught in the interstices of mating edges.

Abstract: Rotary locks used on transit vehicle doors when opened and closed by a rotating helical door drive member. In a preferred embodiment, a first lock utilizes a negative thread portion of the helical drive. A second lock utilizes a rotating lock pawl and stop. The drive and lock can be used to operate door systems with and without separate door hangers. Compensation for camber variations in car structure is provided through the use of spherical mounts or drive member journals.

Abstract: Method and apparatus for reducing the NOX levels in stack emissions of compact boilers and fluid heaters through selective injection of exhaust flue gases into the combustion process. Flue gas injection into the primary and secondary air of the burner along with flue gas injection directly into the combustion process is utilized. Injection of generated steam from a compact boiler, selectively injected into the combustion process is also provided.

Abstract: A power door operator for multi-passenger mass transit vehicles, typically buses, features electric actuation of dual swinging doors. A manual activator having an ergonometrically correct actuating plunger, for emergency door opening, operates a sleeved clutch. Fixed to the sleeve clutch is a drive bar with arms having individually adjustable lengths. The drive arms actuate outboard door shaft levers on individual door leaf through door drive rods intermediate the door arms and drive arms. Each rod incorporates spherical rod ends. The drive arms also actuate limit switches establishing door opened and door closed circuitry for energizing the electric drive system. The adjustable length clutch door drive arms provide a convenient device for controlling door leaf closing sequence and residual or door holding force when the doors are in a closed position.

Abstract: A system for detecting objects in the path of a power operated, movable door operating in a mass transit vehicle, which would obstruct door closing. The system also includes an integral method for detection of a "free wheeling" door occasioned by failure of the door mechanical drive. Method and apparatus disclosed utilize door handle locating devices such as electrical switches located at predetermined points along the door closure track. A combination of door locations along the closure track centrally define positions signaling either door linkage failure with attendant "free wheeling" door, and/or door obstruction, in each case, the system disclosed prevents train motion until the improper door condition is remedied. The combination provides a reduction in passenger hazards occasioned by train movement with defective operator linkage and/or door obstruction due to trapped passengers or other impediments to door closure.

Abstract: A method and apparatus for low NOX combustion of natural gas in a compact steam boiler having output steam delivery controlled by predetermined outlet steam pressure. The compact boiler employs a small high heat release combustor discharging into a forced draft convective heat exchange section. In operation, the compact boiler is completely and automatically self-operating, employing flue gas recirculation (FGR) wherein the FGR is admitted into the burner combustion air through a valve controlled by boiler flue gas NOX content. A novel bell mouthed flue gas scoop is utilized in the boiler stack upstream of the NOX sensor. In an alternate combustion chamber design, a cylindrical water wall coil surrounds the combustion process, increasing boiler efficiency through the inherent large temperature difference between the coil and the combustion in process, along with reducing the combustion temperature and further reducing the NOX content of combustion products.

Abstract: Antennas designed for use in producing effective electromagnetic capture zones for transponders mounted on moving vehicles. The antenna systems disclosed are principally designed to be mounted at or near the surface of a roadway carrying the vehicle whose transponder is to be interrogated. A principal advantage of the antennas of the invention is minimal interference with normal operation of the road and greatly reduced cost of installation when used in providing vehicle identification, toll collection, or communication with the transponder carrying vehicle.

Abstract: A power door operator for transit vehicles utilizing a rodless pneumatic cylinder as a prime mover in opening and closing doors in the sidewall of a transit vehicles. Door movement having a controlled, predetermined door edge force is achieved through mechanical coupling an external piston of the rodless cylinder and vehicle doors through and endless toothed belt. Magnetic coupling between internal and external pistons of the cylinder provide controlled force having a maximum or breakaway value applied to the operated door. A novel reaction lock operated by admission of pressurized air to the cylinder latches or unlatches the operated door in its closed position subsequent or prior to door closing or opening. Control of door motion at the ends of its travel is achieved through the use of a novel differential area internal piston in the pneumatic cylinder.

Abstract: An improved pressure switch of the pulse or pressure wave sensitive type includes a switch housing with an internal diaphragm chamber. A relief vent with a fixed orifice disk is provided in the diaphragm chamber. A diaphragm is mounted in the diaphragm chamber which includes an electrical contact mounted on and movable with the diaphragm. An adjustable contact is threaded through a tapped terminal link in the switch housing to position a contact surface on the adjustable contact adjacent to the electrical contact mounted on the diaphragm. The adjustable contact includes a slotted end. A slotted, round lock nut is threaded on the adjustable contact. To provide an electrically reliable contact, a biasing member is positioned between the round lock nut and the tapped terminal link providing a positive thread bias on the contacting threads of the adjustable contact and the terminal link.

Abstract: A flow meter for use with a fluid source includes a chamber of known volume, and level sensors for detecting fluid boundaries at either end of the known volume. A valve between the fluid source and chamber is opened at a defined time until fluid level within the chamber rises above the upper sensor, whereupon the valve is closed. As the fluid level falls past the upper sensor a second time level is measured, with both time intervals being terminated as the level falls to the lower level sensor. The average flow rate as the fluid falls between the two sensors is calculated by a computer, and the total volume is then calculated using the longer measured time interval. Flow rates over long time periods can be accurately measured.

Abstract: A power door operator for transit vehicles utilizing a rodless pneumatic cylinder as a prime mover in opening and closing doors in the sidewall of a transit vehicles. Door movement having a controlled, predetermined door edge force is achieved through mechanical coupling an external piston of the rodless cylinder and vehicle doors through an endless toothed belt. Magnetic coupling between internal and external pistons of the cylinder provide controlled force having a maximum or breakaway value applied to the operated door. A novel reaction lock operated by admission of pressurized air to the cylinder latches or unlatches the operated door in its closed position subsequent or prior to door closing or opening. Control of door motion at the ends of its travel is achieved through the use of a novel differential area internal piston in the pneumatic cylinder.

Abstract: Disclosed is an operator for a door mounted by frame means so as to be slidable along a track between open and closed positions. The door has a peripheral edge which is engaged to provide a positive locking of the door. The operator includes a shaft rotatably mounted alongside the door. A locking pawl is mounted to the shaft for rotation therewith so as to be movable between an unlocked position remote from a door edge and a locked position overlying the door edge so as to block the opening thereof. A lockout lever is also attached to the shaft for rotation therewith, and is movable between an idle position whereat the shaft is rotated to bring the locking pawl to its unlocked position and a lockout position whereat the shaft is rotated to bring the locking pawl to its locked position.