ELECTRIC DOOR OPENER

• US 3,874,117 A
• Filed: 09/28/1973
• Issued: 04/01/1975
• Est. Priority Date: 09/28/1973
• Status: Expired due to Term

• Current Assignee: Raymond H. Boehm
• Original Assignee: Raymond H. Boehm
• Inventors: Boehm, Raymond H.
• Primary Examiner(s): Downey, Kenneth
• Application Number:
  US05/401,841
• Time in Patent Office: 550 Days
• Field of Search: 49/25,30,263,264,267,273,274,340 318/442
• US Class Current: 49/264
• CPC Class Codes: E05F 15/63 operated by swinging arms
• CPC Class Codes: E05F 15/79 using time control
• CPC Class Codes: E05Y 2201/216 Clutches
• CPC Class Codes: E05Y 2201/246 by motors, magnets, springs or weights
• CPC Class Codes: E05Y 2201/462 Electromagnets
• CPC Class Codes: E05Y 2900/132 Doors

Abstract

An electric door opener to be utilized in conjunction with a standard door closer or door check to provide the elements of automatic door control. The door opener is typically mounted on the transom of the door and includes an electric motor having a drive shaft that operates through a worm grear mechanism and an electromagnetic clutch to drive a gear train. The output of the gear train is operably connected to a linkage attached to the door. An approach switch, associated with an approach mat or a photoelectric eye, is located ahead of the door, while a safety switch is similarly associated with a safety mat or photoelectric eye located behind the door. With the closing of the approach switch by a pedestrian approaching the door, high voltage power is supplied to the motor and clutch to enable the motor to drive the gear train and pivot the linkage to move the door to the open position. In addition, closing of the approach switch will also supply low voltage power to the motor. When the door is in the full open position a limit switch is actuated which acts to remove high voltage power from the motor, leaving only low voltage power on the motor. The low voltage power supplied to the motor is sufficient to overcome the force of the door closer and maintain the door in the open position. A time delay is incorporated in the system which provides time for pedestrian movement from the approach mat to the safety mat, and to clear the safety mat before the door closes.

Claims

1. An electric door opener to be operably connected to a door to open the same, comprising a uni-directional electric motor having an output shaft, a worm gear unit connected to said output shaft, gear means having an input and an output, electromagnetic clutch means interconnecting the worm gear unit and the input of the gear means, said clutch means having an engaged and a disengaged position, a pivotable linkage connecting the output of the gear means to the door, operation of said gear means acting to pivot the door through said linkage to an open position, approach switch means located ahead of the door and disposed to be actuated by a person approaching the door, means responsive to actuation of said approach switch means for engaging said clutch means and for supplying the combination of high voltage power and low voltage power to said motor, deactivation of said approach switch means curtailing the supply of power to said motor and disengaging said clutch means, and limit switch means responsive to opening of the door to a predetermined position for withdrawing the high voltage power and maintaining the supply of low voltage power to said motor whereby the low voltage power will retain the door in the open position.

2. The door opener of claim 1, and including time delay means for delaying the curtailing of power to said motor and the disengagement of said clutch means for a predetermined time after deactuation of said approach switch means.

3. The door opener of claim 2, and including safety switch means located behind the door and disposed to be actuated by a person located behind the door, and means responsive to actuation of said safety switch means for engaging said clutch means and for supplying the coMbination of high voltage and low voltage power to said motor, so that the door will be maintained in the open position while said safety switch means is actuated.

4. The door opener of claim 2, and including means operably connected to said time delay means for selectively varying said predetermined time.

5. The door opener of claim 4, and including means responsive to actuation of said approach switch means and said safety switch means for preventing opening of said door.

6. In combination, a door to enclose a doorway and movable between an open and a closed position;

a door closer having a force operating to move the door from the open to the closed position; and

a door opener separate from said door closer to move the door from the closed to the open position;

said door opener comprising a uni-directional electric motor having an output shaft, a worm gear unit connected to said output shaft, gear means having an input and an output, electromagnetic clutch means interconnecting the worm gear unit and the input of the gear means, said clutch means having an engaged and a disengaged position, a pivotable linkage connecting the output of the gear means to the door, operation of said gear means acting to pivot the door through said linkage to an open position, approach switch means located ahead of the door and disposed to be actuated by a person approaching the door, means responsive to actuation of said approach switch means for engaging said clutch means and for supplying the combination of high voltage power and low voltage power to said motor, deactivation of said approach switch means curtailing the supply of power to said motor and disengaging said clutch means, and limit switch means responsive to opening of the door to a predetermined position for withdrawing the high voltage power, said low voltage power being sufficient to overcome the closing force of the door closer to thereby maintain the door in the open position until deactivation of said approach switch means.

7. The combination of claim 6, wherein said approach switch means is associated with a walk-on floor mat.

8. The combination of claim 6, and including safety switch means located behind the door and disposed to be actuated by a person located behind the door, and means responsive to actuation of said safety switch means for engaging said clutch means and for supplying the combination of high voltage power and low voltage power to said motor, so that the door will be maintained in the open position while said safety swtich means is actuated.

9. The combination of claim 8, wherein said safety switch means is associated with a walk-on floor mat.

10. The combination of claim 6, and including time delay means for delaying the curtailing of power to said motor and the disengagement of said clutch means for a predetermined time after deactuation of said approach switch means.

11. In combination, a door to enclose a doorway and movable between an open and a closed position;

a door closer to move the door from the open to the closed position, and a door opener to move the door from the closed to the open position, said door opener comprising an electric motor having an output shaft, a worm gear unit connected to said output shaft, gear means having an input and output, electromagnetic clutch means interconnecting the worm gear unit and the input of the gear means, said clutch means having an engaged and a disengaged position, a pivotal linkage connecting the output of the gear means to the door, operation of said gear means acting to pivot the door through said linkage to an open position, a first electrical circuit connected to a source of high voltage power, a transformer having a high voltage winding connected in said circuit and having a pair of low voltage windings, an approach switch located ahead of the door and disposed to be closed by a person approaching the door, a safety switch located behind the door and disposed to be closed by a person being in a position behind the door, a second electrical circuit connected to a first of said low voltage windings, said approach switch and said safety switch being connected in parallel in said second circuit, a relay connected in said second circuit and having a plurality of contacts, whereby closing of said approach switch or said safety switch will energize the relay to actuate said relay contacts, a third electrical circuit connected to the source of high voltage power, said motor and said clutch means and a first of said contacts being connected in series in said third electrical circuit whereby closing of said first contact through energization of said relay will operate said motor and engage said clutch means, a fourth electrical circuit connecting the second low voltage winding to said motor, a second of said contacts being connected in series with said motor in said fourth circuit, whereby energizing of the relay will close said second contact to thereby supply low voltage power to said motor, and a limit switch disposed to be actuated when the door is opened to a predetermined position and connected in the third circuit, actuating of the limit switch will open the third circuit to cut off the supply of high voltage power to the motor, whereby the low voltage power supplied to the motor through said fourth circuit will retain the door in the open position.

12. The combination of claim 11, and including a capacitor connected in parallel with said relay in said second circuit, the discharge of said capacitor acting after opening of said approach switch means and said safety switch means to continue energization of said relay for a predetermined period of time.

13. The combination of claim 12, and including a variable resistance disposed in parallel with said relay and said capacitor in said second circuit, adjustment of said variable resistance acting to adjust the predetermined period of time.

14. The combination of claim 11, wherein a solid state switch unit is connected in said third circuit, said switch unit includes a triac and a diac, said limit switch being connected in said third circuit in a manner such that closing of said limit switch will bypass firing voltage to said switch unit and prevent firing of said triac to thereby cut off the supply of high voltage power to the motor.

15. The combination of claim 14, and including voltage dividing means connected across said third circuit and including variable resistance means and a capacitor, said voltage dividing means arranged to set the voltage at which the triac fires to thereby vary the magnitude of the high voltage power supplied to the motor.