Abstract: A lock mechanism enabling locking of a bi-parting set of right hand and left hand door panels respectively suspended from a right hand and left hand door operators, to be driven by the door operators for covering and uncovering an aperture disposed within a passenger transit vehicle. Such lock mechanism disposed intermediate the door operators. The lock mechanism is capable of operating in a pushback and non pushback arrangement providing a fully-locked state, for each of the two bi-parting doors of a passenger transit vehicle. The integrated design allows the central lock mechanism to be installed and/or maintained over a doorway with only minimal adjustments needed to assure that the door lock assemblies operate in unison. As compared to separate door lock assemblies for each door panel as is typical of prior art designs, the central lock mechanism enables the door panels to be closed and locked more reliably and with better sealing against weather and noise.

Abstract: A system verifies the authenticity of input signals used in the operation of an apparatus. The system includes two input registers, a microprocessor, and one circuit network for each input signal. Each circuit network generates twin binary signals in response to its input signal. Specifically, twin logic one signals are generated by a circuit network when its input signal goes active state. Conversely, twin logic zero signals are generated when the input signal goes inactive. Each circuit network conveys the first binary signal to a dedicated location in one input register and the second binary signal, after inversion, to a dedicated, mirror-imaged location in the other input register. Whenever any bit in either or both input registers changes, the microprocessor reads both input registers to ascertain the state of the bits they contain.

Abstract: A lock mechanism enabling locking of a bi-parting set of right hand and left hand door panels respectively suspended from a right hand and left hand door operators, to be driven by the door operators for covering and uncovering an aperture disposed within a passenger transit vehicle. Such lock mechanism disposed intermediate the door operators. The lock mechanism is capable of operating in a pushback and non pushback arrangement providing a fully-locked state, for each of the two bi-parting doors of a passenger transit vehicle. The integrated design allows the central lock mechanism to be installed and/or maintained over a doorway with only minimal adjustments needed to assure that the door lock assemblies operate in unison. As compared to separate door lock assemblies for each door panel as is typical of prior art designs, the central lock mechanism enables the door panels to be closed and locked more reliably and with better sealing against weather and noise.

Abstract: A self-locking memory circuit for a tri state data bus having multiple bit lines. The circuit includes a non-inverting buffer chip for connection to each bit line and a resistor having a predetermined electrical resistance connected across the buffer chip. The chip and resistor provide a predetermined impedance to the flow of electrical current in the self-locking circuit. The circuit changes its state when the current of the latest information on a bit line builds or lowers above or below threshold levels of the self-locking circuit.

Abstract: Method of detecting obstructions encountered by a motorized door. The method includes providing a signal processor with one or more signals indicative of a predetermined door trajectory profile for at least a segment of a stroke of the door, the door trajectory profile providing an ideal speed and/or position versus an elapsed time since a beginning of the segment of the stroke. A door position signal from a position encoder for the door is received into the signal processor. The method includes generating one or more signals indicative of the velocity and/or position of the door from the door position signal and generating a trajectory discrepancy signal based on the velocity and/or position in relation to the ideal speed and/or position. A motor control signal is generated based on the trajectory discrepancy signal and the motor control signal is connected to motor control circuits connected to drive the motor for the door.

Abstract: Method of controlling a motorized door by offloading the burden to a separate motion control processor. The method includes generating, in a central processor for the door, one or more signals indicative of a predetermined door speed profile for a stroke of the door. The predetermined door speed profile provides an ideal velocity versus an elapsed time since a beginning of the stroke. The signals are communicated to a motion control processor and the motion control processor also receives door position signals from a position encoder. The motion control processor generates signals indicative of the velocity of the door based on the door position signals and it generates error signals based on discrepancies between the velocity of the door and the ideal velocity. It generates motor control signals based on the error signals and the motor control signals are communicated to the motor of the door.

Abstract: Method of facilitating release of an object caught by one or more closing transit vehicle door(s) in a motorized door system having a two stage lock, the two stage lock having a fully locked position and a pushback lock position. The method includes detecting the presence of the object by the effect of the object on either the position or the velocity of the door(s). The method also includes determining whether the door(s) are in a pushback range between the fully locked position and the pushback lock position. If an object is detected and the door(s) are in the pushback range, then one or more signals are supplied to a motor of the door(s) to move the door(s) in the door opening direction to or toward the pushback lock position.

Abstract: Apparatus and method for testing an optical encoder used to determine position of a moveable member. The optical encoder supplies a first binary signal indicative of a position of the moveable member and a second binary signal indicative of the position. The first binary signal and the second binary signal are in quadrature relationship. The apparatus has a first delay device connected to receive the first binary signal. The first delay device produces a first delayed binary signal. The apparatus also includes a first logic gate connected to receive the first binary signal and the first delayed binary signal. The first logic gate produces a first edge detection pulse signal. The apparatus further includes a second delay device connected to receive the second binary signal. The second delay device produces a second delayed binary signal. The apparatus further includes a second logic gate connected to receive the second binary signal and the second delayed binary signal.

Abstract: A motor protection circuit for an electric motor driven by a pulse width modulated amplifier. It has a capacitor and a first conduction path connected to a first terminal of the capacitor and connectable to a first conductor. It also has a second conduction path connected to the second capacitor terminal and connectable to a second conductor. There is a DC voltage difference between the first conductor and the second conductor. There is a third conduction path between the first terminal and the second terminal. The third conduction path having a resistance which is lower than the resistance of the first conduction path plus the resistance of the second conduction path. The third conduction path passes through a switch which has an input connection to be opened and closed thereby.

Abstract: The invention is a dynamic brake for a power door which is moved by an electric motor having at least two terminals. The motor is energized by a pulse width modulated door drive amplifier connected to a first power line and a second power line. The door drive amplifier has a first group of switches connecting the motor terminals to the first power line and it has a second group of switches connecting the motor terminals to the second power line. The dynamic brake has a brake control signal generator connected to receive an input signal indicative of a need to apply the dynamic brake and it has at least one output signal line connected to a control input of at least two of the switches in the first group of switches.