U.S. patent number 3,874,117 [Application Number 05/401,841] was granted by the patent office on 1975-04-01 for electric door opener.
This patent grant is currently assigned to R. H. Boehm Company, Inc.. Invention is credited to Raymond H. Boehm.
United States Patent |
3,874,117 |
Boehm |
April 1, 1975 |
ELECTRIC DOOR OPENER
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.
Inventors: |
Boehm; Raymond H. (Racine,
WI) |
Assignee: |
R. H. Boehm Company, Inc.
(Racine, WI)
|
Family
ID: |
23589444 |
Appl.
No.: |
05/401,841 |
Filed: |
September 28, 1973 |
Current U.S.
Class: |
49/264; 49/30;
49/340; 318/442 |
Current CPC
Class: |
E05F
15/63 (20150115); E05Y 2201/246 (20130101); E05F
15/79 (20150115); E05Y 2201/462 (20130101); E05Y
2201/216 (20130101); E05Y 2900/132 (20130101) |
Current International
Class: |
E05F
15/12 (20060101); E05f 013/00 () |
Field of
Search: |
;49/25,30,263,264,267,273,274,340 ;318/442 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Downey; Kenneth
Attorney, Agent or Firm: Andrus, Sceales, Starke &
Sawall
Claims
I claim:
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.
Description
BACKGROUND OF THE INVENTION
Automatic door operators are commonly used in supermarkets,
airports, department stores, and other high volume traffic areas
where pedestrians are burdened with packages or luggage. Automatic
door operators are normally installed in the transom of the door,
or alternately, under the floor, and are usually actuated by
walk-on approach mats or a photoelectric eye. The automatic door
operator performs the functions of opening the door, cushioning the
opening action, stopping the opening action, closing the door and
cushioning the door in the closed position. Automatic door
operators are relatively complex in structure, expensive to install
and maintain, and require frequent maintenance by specially trained
service personnel.
Door closers or door checks are commonly used in association with
residential, commercial or industrial doors. The conventional door
closer provides opening speed control, opening cushioning, a stop
for the opening action, as well as providing closing power and
closing cushion for the door. The conventional door closer is
mounted externally on the transom or on the door itself, and as the
door is manually opened, the door closer stores energy to provide
the closing power when the door is released. Conventional door
closers are relatively inexpensive, reliable and easy to install
and maintain.
SUMMARY OF THE INVENTION
The invention relates to an electric door opener to be utilized in
conjunction with a standard door closer or door check, together
accomplishing automatic door operation with reliable, easy to
install and maintain, relatively low cost elements. The electric
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 gear drive 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, which can take
the form of a walk-on approach mat or a photoelectric eye, is
located in front of the door and a safety switch, which can
similarly take the form of a safety mat or photoelectric eye, is
located to the rear of the door. As a pedestrian steps on the
approach mat, the approach switch is closed which acts to energize
the motor and the electromagnetic clutch to thereby drive the gear
train and pivot the linkage to move the door to the open position.
When the door is fully opened a limit switch is actuated which acts
to remove the full power from the motor, leaving only low voltage
power on the motor. The low voltage power is sufficient to overcome
the force of the door closer and maintain the door in the open
position.
The door opener also includes a time delay which provides time for
a pedestrian to leave the approach mat and reach the safety mat
before the door will begin to close. Through use of a variable
resistor the time delay can be selectively changed to suit the
particular system.
The door opener of the invention is adapted to be used in
conjunction with a standard door closer, and can be used with
either new or existing doors. As the door opener does not include a
mechanism for controlling closing of the door, the overall
structure is simplified and the cost is substantially reduced over
that of conventional automatic door operators which provide both an
opening and closing function.
The unit includes a symmetrical housing which can be directly
installed on either right hand or left hand doors and can be
utilized with either center hung or butt hinged doors without
modification to the opener or to the door.
The door opener of the invention also includes simple adjustments
for opening speed of the door, time delay before closing, and
direction of operation. The door opener also provides a power
operated low voltage holding action to hold the door in the open
position when a pedestrian is either on the approach or the safety
mat, so that there is no danger of overheating the motor under this
"hold-open" condition.
DESCRIPTION OF THE DRAWINGS
The drawings illustrate the best mode presently contemplated of
carrying out the invention.
In the drawings:
FIG. 1 is a perspective view of the door opener of the invention as
associated with a door;
FIG. 2 is a vertical section of the door opener;
FIG. 3 is a horizontal section taken along line 3--3 of FIG. 2;
FIG. 4 is a section taken along line 4--4 of FIG. 2;
FIG. 5 is a section taken along line 5--5 of FIG. 2; and
FIG. 6 is a wiring diagram.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a hinged door 1 which is mounted within a
doorway defined by a frame 2. The frame includes a pair of vertical
jambs 3 which are connected at their upper ends by a transom or
lintel 4. A standard door closer or door check 5 is associated with
the door and can be a conventional hydraulic or mechanical type.
The door closer 5 includes a housing 6 which is mounted on the
transom and a pair of pivoting arms 7 are connected to the door.
When the door is opened, energy will be stored by the door closer 5
which will then act to return the door to the closed position in a
conventional manner.
Door 1 is adapted to be opened by a door opener which is indicated
generally by 8 and is mounted on the transom 4. As best shown in
FIG. 2, the door opener 8 includes an electrical control box 9
which contains the electrical components of the system and lead
wires 10 are connected to the electrical components and are
provided with a plug 11 which can be engaged with a standard 110
volt output. A three-conductor socket, not shown, is also furnished
on the control box 9, to provide connections to the approach mat
and safety mat, the function of which will be hereinafter
described.
The door opener 8 also includes a permanent magnet motor 12, a worm
gear reducing unit 13, a clutch assembly 14, and a gear box 15. To
mount the opener on the transom 4, gear box 15 is provided with a
pair of flanges 16 which are connected by bolts 17 to the transom
(FIG. 3).
As best shown in FIG. 5, the drive shaft 18 of motor 12 is
connected to the worm gear reduction unit 13 which includes a worm
19 which drives gear 20 mounted on the upper end of vertical shaft
21. The worm gear unit 13 not only provides a stage of reduction,
but also will act to prevent the door from being slammed to the
open position by a gust of wind during the opening cycle.
The lower end of the shaft 21 is keyed to a hub 22 of the clutch
assembly 14. The hub 22 is journalled for rotation within a
non-rotatable annular electromagnetic core 23. The clutch assembly
14 also includes an armature unit 24 including a central hub 25 and
an outer ring 26. Ring 26 is normally spaced from the lower surface
of the hub 22 to provide an air gap therebetween. The hub 25 of
armature unit 24 is connected to the upper end of a shaft 27 and a
flat spring 28 connects the hub 25 to the ring 26. When the core 23
is energized a magnetic field will be developed which will move the
ring 26 upwardly into engagement with the hub 22, thereby bending
the spring 28 upwardly, to provide a driving connection between the
shaft 21 and the shaft 27. When core 23 is deenergized, the force
of the deformed spring 28 will move the ring 26 downwardly out of
engagement with the hub 22 to thereby disconnect the shafts 21 and
27.
As illustrated in FIG. 2, the shaft 27 is journalled for rotation
within the gear box 15 and carries a gear 29 which drives a gear 30
mounted on shaft 31, which is similarly journalled within the gear
box 15. Shaft 31 carries a small gear 32, which is engaged with a
large gear 33 on shaft 34, and shaft 34 also carries a small gear
35 which drives a gear segment 36 mounted on the shaft 37. The
lower end of shaft 37 projects outwardly of the gear box and is
connected to one end of an arm 38. The opposite end of arm 38 is
pivotally attached to one end of an arm 39 and the opposite end of
arm 39 is pivotally connected to a clevis 40 that is attached by
screws to the door 1. With this construction, rotation of the shaft
37 will cause the arms 38 and 39 to pivot to move the door to the
open position.
As shown in FIG. 2, a pin 42 is mounted within a central bore in
the shaft 37 and pin 42 is provided with an enlarged head 43 that
is located in a recess 44 in the end of the shaft 37. The upper end
of the pin 42 projects beyond the end of the shaft 37 and carries a
cam 45. A pair of Belleville springs 46 surround the pin 42 and
provide frictional contact between the cam 45 and the shaft 37 to
restrict free rotation of the pin within the bore of the shaft. Cam
45 pivots with the shaft 37 and the arm 47 of a switch unit 48
rides against the peripheral surface of the cam 45. When the door
is pivoted to the full open position the cam 45 is adapted to
actuate the switch unit 48, as will be hereinafter described.
The door opener is adapted to be actuated by closing of an approach
switch as a pedestrian approaches the door. As shown in FIG. 1, the
approach switch is associated with an approach mat 49 which is
located on the floor in front of the door 1. As the pedestrian
steps on the approach mat 49, the approach switch is actuated to
thereby operate the door opener. In addition to the approach
switch, a safety switch is associated with a safety mat 50 that is
located on the floor behind the door. While the drawings illustrate
the approach and safety switches to be associated with mats, it is
contemplated that various types of switches can be utilized, such
as those actuated by photoelectric eyes, push bars, sonic
actuation, or the like.
As shown in the wiring diagram, FIG. 6, 120 volt power from lines
51 and 52 is supplied to the high voltage winding 53 of a
transformer 54. The power lines 51 and 52 are also connected
through lines 55 and 56 to full wave bridge 57, the output of which
is connected to coil 23 of the clutch assembly 14, and to full wave
bridge 58, the output of which is connected to the permanent magnet
motor 12. Line 59 is connected across lines 55 and 56 and a
variable resistor 60 and capacitor 61 are connected in line 59.
Line 62 connects line 59 with line 55 and solid state switch unit
63 is connected in line 62 and serves to control the current flow
through line 55. Switch unit includes a diac 64, and a triac 65.
The variable resistor 60 and capacitor 61 function as a voltage
dividing network, and adjustment of resistor 60 will determine the
point in the half cycle in which the triac will fire and thus
provides a speed control for the motor.
Transformer 54 also includes a pair of low voltage windings 67 and
68, and in practice the winding 67 can be 28 volts while winding 68
is 14 volts.
Lines 69 and 70 of a control circuit connect winding 67 to full
wave bridge 71 and the command or approach switch 72 and the safety
switch 73, associated with approach mat 49 and safety mat 50,
respectively, are connected in parallel in line 69. The output of
bridge 71 is connected to relay 74 by lines 75 and 76, and
capacitor 77 and a variable resistor 78 are connected across line
75 and 76.
Lines 79 and 80 of a low voltage circuit connect the low voltage
winding 68 to full wave bridge 81, and the output of bridge 81 is
connected to the motor 12 by lines 82 and 83.
As the pedestrian walks on the approach mat 49, switch 72 closes
and the relay 74 is energized. Energizing relay 74 will close the
normally open contacts 74-1, will open the normally closed contacts
74-2, will close the normally open contact 74-3 in line 79 and will
close the normally open contacts 74-4 in line 56. With the closing
of contacts 74-4 power will then be supplied from the power lines
51 and 52 to the motor 12 and clutch coil 23 to operate the motor
and engage the clutch. Closing of contacts 74-3 will serve to
supply low voltage power to the motor though the lines 79 and 80.
Engagement of the clutch provides a driving connection between the
motor 12 and the gear train to thereby pivot arms 38 and 39 and
move the door to the open position.
When the door moves to its fully opened position, the cam 45 will
close the normally open limit switch 84 of the switch assembly 48.
Limit switch 84 is connected in line 85, which is connected between
line 55 and line 59. With the closing of limit switch 84 power will
follow the path of least resistance through line 85, thereby
by-passing the switch unit 63 so that the supply of high voltage
power to the motor 12 will be terminated, since the triac is off.
The low voltage power being supplied through lines 79 and 80 to the
motor will be sufficient to maintain the door in the open position
against the force exerted by the door closer 5. This situation, in
which low voltage power is supplied to the motor 12, will continue
to exist while the approach switch 72 is closed.
If the pedestrian moves through the open door from approach mat 49
to the safety mat 50, approach switch 72 will open, and the
capacitor 77 is employed to maintain energization of the relay 74
in the event the approach switch 72 and safety switch 73 may both
momentarily be open as the pedestrian passes through the doorway.
Capacitor 77 also provides a time delay when the pedestrian leaves
the safety mat 50, or leaves the approach mat 49 and does not step
onto the safety mat 50, before the door will begin to close and
permits the pedestrian to be safely out of the way of the door when
it begins its closing action through operation of the door closer
5. Adjustment of the variable resistor 78, which is typically
mounted on the control box 9, permits the duration of the time
delay to be selected for each installation.
When the pedestrian has stepped off of the safety mat 50, and there
is no pedestrian on the approach mat 49, both the switches 72 and
73 will be open, and after discharge of the capacitor 77 relay 74
will be deenergized. Contacts 74-1, 74-3 and 74-4 will then open
while contacts 74-2 will close to shut off power to the motor 12
and to clutch coil 23 and permit the closer 5 to return the door to
the closed position without torque being transmitted back through
the motor.
The door opening logic can be illustrated by the equation:
Qn + 1 = S.Q.sub.n + S.A
where Q is the state of memory element (relay 74) and when Q = 1
the relay is energized and when Q = 0 the relay is deenergized; n
is a state of time and n + 1 is the next state of time;
A is the approach mat switch and A = 1 when the switch is closed
and A = 0 when the switch is open;
S is the safety mat switch and S = 1 when the switch is closed and
S = 0 when the switch is open.
Using the above equation, the following table of conditions can be
determined:
INPUTS OUTPUT ______________________________________ A S
Q.sub.n.sub.+ 1 0 0 0 0 1 Q.sub. n 1 0 1 1 1 Q.sub. n
______________________________________
Thus, the next state of the relay 74 (Q.sub.n.sub.+1) is
deenergized if A and S are 0, is equal to the existing state if S
is 1 and A is 0 or 1, and is energized if A is 1 and S is 0.
The door opener of the invention is adapted to be used in
conjunction with a standard door closer and may be associated with
any new or existing door. It can be mounted on the door and is
symmetrical for installation in either left hand or right hand
doors. The door opener can be utilized with any type of contact
closure, such as walk-on floor mats, photoelectric eyes, pushbars,
or the like.
The door opener includes simple adjustment for the opening speed
through operation of the variable resistor 60 and for the time
delay through operation of variable resistor 78.
Various modes of carrying out the invention are contemplated as
being within the scope of the following claims particularly
pointing out and distinctly claiming the subject matter which is
regarded as the invention.
* * * * *