MOTOR CONTROL SYSTEM

• US 3,737,749 A
• Filed: 06/16/1972
• Issued: 06/05/1973
• Est. Priority Date: 06/16/1972
• Status: Expired due to Term

• Current Assignee: Theodore F. Schmit
• Original Assignee: Theodore F. Schmit
• Inventors: Schmit, Theodore F.
• Primary Examiner(s): Dobeck, B.
• Application Number:
  US05/263,458
• Time in Patent Office: 354 Days
• Field of Search: 318/286,DIG.2,471,472,476 317/12R 116/173
• US Class Current: 318/472
• CPC Class Codes: G09F 17/00 Flags; Banners; Mountings therefor
• CPC Class Codes: G09F 2017/0025 Raising or lowering devices
• CPC Class Codes: H02P 23/24 Controlling the direction, e.g. clockwise or counterclockwise

Abstract

A system for controlling the operation of a reversible electric motor employed in raising and lowering a flag in an automatic flagpole, including thermally responsive current-sensing switching devices and an electromagnetic relay means in a circuit with the motor and arranged to reverse the motor'"'"''"'"'s direction in response to a predetermined overloading due to obstruction to the free movement of the flag-carrying halyard driven by the motor and to restart the motor in its original direction of rotation after a predetermined time delay.

Claims

1. A control system for periodically reversing the direction of rotation of an electric motor and restoring the original direction of rotation thereof after predetermined time delay in response to mechanical overload of means driven thereby comprising:

electromagnetic relay means, two microswitch means, and two thermally responsive current-sensing switching devices, all in circuit with said motor and a source of electrical energy;

said relay means comprising plural contacts connected in said circuit to cause said motor to rotate in either of two directions corresponding, respectively, to the energized and de-energized condition of said relay means;

each said microswitch means being operable to isolate said motor from said source of energy in response to predetermined movement of the driven mEans, each said thermally responsive device comprising a current-sensitive heater means and a movable contact operably responsive thereto, said heater means thereof being in series circuit with an associated one of said microswitch means;

whereby each said switching device is operated by its respective heater means in response to overload-induced excessive current in said circuit thereby to temporarily actuate said relay means from one to the other of its said energized and deenergized conditions and reverse said motor, until said associated one microswitch means operates to isolate said motor or said switching devive returns to its original circuit position, after a predetermined time delay in response to cooling of its heater means, whichever occurs first, restoration of said switching device to its original circuit position causing actuation of said relay means to the other of its said conditions to automatically restore the motor'"'"''"'"'s original direction of rotation.

2. The invention of claim 1, and a motor protector device in circuit with said motor to isolate the same from said source of energy, whereby the reversing cycle is repeated until the overload of the driven mean is overcome, or until said protector device operates to isolate said motor.

3. A system for controlling a reversible electric motor drivingly coupled with a flag-carrying halyard in an automatic flagpole assembly, the systemy being operable to automatically reverse the direction of rotation of the motor in response to an obstruction to the free operational movement of the halyard and to restore the original direction of rotation of the motor after predetermined time delay comprising:

electromagnetic relay means, two microswitch means, and two thermally responsive current-sensing switching devices, all in circuit with said motor and a source of electrical energy;

said relay means comprising plural contacts connected in said circuit to cause said motor to rotate in either of two directions corresponding, respectively, to the energized and deenergized condition of said relay means;

each said microswitch means being operable to isolate said motor from said source of energy in response to predetermined movement of the driven means, each said thermally responsive device comprising a current-sensitive heater means and a movable contact operably responsive thereto, said heater means thereof being in series circuit with an associated one of said microswitch means;

whereby each said switching device is operated by its respective heater means in response to overload-induced excessive current in said circuit thereby to temporarily actuate said relay means from one to the other of its said energized and deenergized conditions, and reverse said motor, until said associated one microswitch means operates to isolate said motor or said switching device returns to its original circuit position, after a predetermined time delay in response to cooling of its heater means, whichever occurs first, restoration of said switching device to its original circuit position causing actuation of said relay means to the other of its said conditions to automatically restore the motor'"'"''"'"'s original direction of rotation.

4. The invention according to claim 3, and a motor protector device in circuit with said motor to isolate the same from said source of energy, whereby the reversing cycle is repeated until the overload of the driven means is overcome, or until said protector device operates to isolate said motor.

5. The invention according to claim 3, and a pair of actuating lugs carried on the halyard, each of which operatively engages an associated one of said microswitch means.