초록 ▼

For an automatic flue damper assembly of the type in which the motor of a clockwork mechanism is energized to hold the damper closed and the mechanism is mechanically biased to move the damper to an open position in the absence of motor energization, a stopping or braking arrangement is provided whi

For an automatic flue damper assembly of the type in which the motor of a clockwork mechanism is energized to hold the damper closed and the mechanism is mechanically biased to move the damper to an open position in the absence of motor energization, a stopping or braking arrangement is provided which applies DC to the motor for dynamic braking as the damper closely approaches its open position. Additionally, the remote possibility of a damper hang-up at an intermediate position resulting from a residual magnetic locking torque is substantially eliminated through the provision of an AC trickle circuit connected to the motor.

대표청구항 ▼

A control system for a furnace flue damper assembly of the type in which an AC damper motor energized from an AC line holds the damper in a closed position while the furnace is off, and biasing means drives the motor in a deenergized condition in a direction to move the damper to an open position wh

A control system for a furnace flue damper assembly of the type in which an AC damper motor energized from an AC line holds the damper in a closed position while the furnace is off, and biasing means drives the motor in a deenergized condition in a direction to move the damper to an open position when the furnace is to come on in response to a thermostatic demand for heat, comprising: a thermostatic switch for controlling furnace operation; electrically energized flow means; relay means including actuating means and controlled switch means, said controlled switch means having first and second positions corresponding to said relay actuating means being energized and deenergized, respectively; a damper position responsive switch operable from open to closed when said damper has moved in an opening direction to closely approach a full open position; a thermostatic switch controlled circuit connected across said line including said thermostatic switch in series with one branch circuit including said electrically energized fuel flow means and said damper position responsive switch in series, and in series with another branch circuit including said relay actuating means in parallel with said one branch circuit; a first, full AC, motor energization control circuit connected in parallel with said thermostatic switch controlled circuit and across the line, said first circuit including said relay controlled switch means in said second position and said motor in series for energizing said motor at full AC; and a second, braking circuit including in series a rectifier, said relay controlled switch means in said first position and said motor, said second, braking circuit being connected across AC concurrently with closure of said damper position responsive switch to effect a DC supply to said motor to dynamically brake said motor at said close approach of said damper to a full open position.