US3319696A - Automatic overhead door opener - Google Patents

Description

y 15, 7 J. R. WIEGAND 3,319,696

AUTOMATIC OVERHEAD DOOR OPENER Filed June 4, 1965 3 Sheets-Sheet 1 106 l LIN/l wrrcn John 7?. H11 egand BY W47 ATTURNEYS'.

INVENTOR y 16, 1967 J. R. WIEGAND 3,319,696

AUTOMATIC OVERHEAD DOOR OPENER Filed June 4, 1965 3 Sheets-Sheet 2 ATTU .5.

AUTOMATIC OVERHEAD DOOR OPENER Filed June 4, 1965 3 Sheets-Sheet I t I 52 INVENTOR J0/7/7 R Mega/7d BY 5 ifiawzas.

United States Patent Ofitice 3,319,696 AUTOMATIC OVERHEAD DOOR OPENER John R. Wiegand, Valley Stream, N.Y., assiguor to Wiegand Electronics Co., Inc, County of Union, N.J., a corporation of New .lersey Filed June 4, 1965, Ser. No. 461,366 9 Claims. (Cl. 160188) It is one object of the invention to provide a door opener adapted for installation on a conventional door mounted in a doorway having rails at sides of the doorway for guiding the door to open to an open overhead position.

Another object is to provide a door opener as described with a winch actuated by a control circuit operated by a pushbutton switch for opening and closing the door.

Still another object is to provide a door opener for an overhead door with a spring loaded drawbar arranged to prevent opening the door manually.

Another object is to provide a control circuit for a door opener with a limit switch actuated by a winch gear at upper and lower limits of travel of the door, and with a pushbutton operated latch switch for actuating and reversing a motor which drives a Winch.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

FIG. 1 is a perspective front view of a garage door in closed position with a door opener embodying the invention installed thereon.

FIG. 2 is an enlarged vertical sectional view taken on line 22 of FIG. 1, parts being broken away.

FIG. 3 is a further enlarged fragmentary vertical sectional view taken on line 33 of FIG. 2, showing parts of the mechanism of the door opener.

FIG. 4 is a still further enlarged view partially in section of portions of the mechanism of FIG. 3, shown in one operating position.

FIG. 5 is a view similar to a portion of FIG. 4 showing parts of the mechanism in dilferent operating position.

FIG. 6 is an exploded sectional view of parts of the mechanism of FIGS. 4 and 5.

FIG. 7 is a diagram of the electrical control system of the door opener.

Referring first to FIGS. 1 and 2 there is shown the door opener 10 including a flexible cable 12 having a loop 14 at its lower end secured to a bracket 16 mounted on the outer side of lowermost section 17 of a garage door 20. The bracket is located near the bottom of section 17. The door 20 has sections 17, 18, 19 secured together by hinges 22 at the rear side of the door. Above the door is lintel 24 of the front wall 25 of a garage or other building 26 provided with rectangular door opening 28. Just above the door on the outside of the lintel is a lamp 30 which lights during operation of the door opener as described below. At one side of the door opening on wall 25 is a key operated lockswitch 32, used to actuate the mechanism of the door opener. At opposite sides of the door opening and at lateral edges of the door are curved channel shaped rails 33 of conventional type on which the door 20 can be drawn up. In rails 33 are engaged rollers 34. The rollers are supported by shafts 35 mounted in brackets 35a on the rear side of door section 19.

The door opener 10 further includes a housing 36 in which is a reversible motor 37 best shown in FIG. 3. Housing 36 is shown in FIG. 2 mounted on a bracket plate 38 at the rear side of the lintel 24. Bracket plate 3,319,696 Patented May 16, 1967 38 is mounted by bolts 39. An outwardly or rearwardly extending angle bar 40 is mounted on plate 38 adjacent to housing 36.

Just below angle bar 40 is a bracket 42 on lintel 24 carrying an idler pulley 44. Below pulley 44 and bracket 42 on the rear side of door section 19 is an angle bracket 46 held by bolts 47. On rearwardly extending arm 49 of the bracket 46 is a rivet or pin 50 pivotally supporting a draw bar 52 in a vertical position. The bar 52 carries idler pulley 54 at its upper end. At the lower end of bar 52 is a rearwardly extending arm 56. At the outer end of arm 56 is attached the lower end of a spring 60. The upper end of the spring is engaged with loop 62 at the upper end of cable 12. Another spring 64 is attached at its upper end to the outer end of bracket arm 56. The lower end of spring 64 is attached to an arm of a small angle bracket 65 mounted near the lower end of door section 19.

Referring now to FIGS. 2 and 3, there is shown a winch pulley 66 having a hub 67 provided with a spur gear 68. The pulley, hub and gear are all forming an integral unit secured to drive shaft 70' of a gear reduction unit 71 in the housing of motor 37 to which the unit 71 is coupled in conventional manner.

The gear 68 is meshed with a splined gear 72 loosely mounted on one end of a nonrotatable shaft 74 so as to be rotatable independently of the shaft. The shaft 74 is pivotally engaged by a pin 76 at its other end. The shaft extends through a stationary bracket 78 having a U- shaped insert 77. In this insert is a spring 79 which bears on the bight of insert 77 and on the side of the shaft to bias it into a horizontal position. The two turns of cable 12 around winch 66 constitutes a slip clutch arrangement. The splined gear 72 has an externally threaded hub 73 meshed with internal thread 81 of cup gear 83 which has a ball bearing at the other end to have this gear roll freely, with the bearing fastened onto the shaft 74; see FIGS. 4, 5 and 6. The cup gear has a smooth outer cylindrical wall 83. Between wall 83" and the grooved periphery of winch 66 passes the cable 12. The cable is wound twice fully around the winch to define a double turn 84.

It will be noted in FIG. 2 that the cable 12 extends upwardly from bracket 16 at the front of the door, then enters the space S between the top of the door and bottom of the lintel 24. The cable is entrained at the rear of pulley 44 and then passes upwardly to form the double turn 84 around winch 66. Then the cable extends rearwardly over pulley 54, and down to join the upper end of spring 60 at loop 62.

In housing 36 on plate 38 is mounted bracket 78 in which is a limit switch 86. This switch has an operating arm 87 pivotally mounted on bracket '87 at its upper end to actuate the finger 88 of the switch. At its lower end the arm 87 carries a rotatable roller 89 which bears against one end 72' of splined gear 72. The roller 89 contacts the gear 72 even in its extreme right position shown in FIG. 3. A coil spring 90 has one end engaged in a hole 91 in shaft 74, and its other end bears on the end 72' of gear 72.

In the housing 36 are also mounted transformer 94 and relay 96 forming parts of the electrical control circuit 100 of the door opener. The circuit is shown schematically in FIG. 7 to which reference is now made.

The circuit includes :a power supply cable 102 from which power can be drawn from a conventional power supply source. One wire 103 is grounded. The other wire 104 is connected to contacts 105, 106 of limit switch 86. The limit switch is a double-pole double-throw switch. In the position shown in FIG. 7, one pole 108 contacts fixed contacts 105, 107 and is open with respect to fixed contacts 106, 109. The other pole 110 is shown closed with fixed contacts 111, 112 and is open with respect to contacts 113, 114.

Relay 96 is a latch relay having a coil 116 connected in series with normally open pushbutton switch contacts 118 of the manually operable key switch 32 and secondary winding 119 of stepdown transformer 94. The primary winding 120 of the transformer is connected to power supply wires 102, 103. Relay 96 has two movable contacts 122, 124. Contact 122 moves between fixed contacts 123, 125. Contact 124 moves between contacts 1'26, 127. Lamp 30 is connected between ground and switch contact 109.

Contact 107 is connected to contact 127. Contacts 124 are connected to armature winding 130 of motor 37. The armature Winding in turn is connected to both contacts 123 and 112. The field winding 132 of the motor is connected to contacts 111, 114 and contact 122. Contact 113 is grounded as is contact 125.

In operation of the door opener including control circuit 100, suppose the door 20 is closed as shown in FIGS. 1 and 2. The cable 12 will be taut which will hold the draw bar 52 vertical since the cable is entrained over pulley 54 as shown in FIG. 2. The springs 60 and 64 will both be tensioned. In this position of the draw bar, it will not be possible to open the door manually by lifting it, because the draw bar will not be able to pass the rearwardly extending horizontal arm of angle bar 40.

If it is now desired to open the door automatically a suitable key will be inserted into the key switch 32 and turned to close the contacts momentarily. This will energize relay 96 and contacts 122, 124 will shift to the right as viewed in FIG. 7 to close with contacts 125 and 127 respectively. This will apply power to the armature and field of the motor which will start. The shaft 70 will turn so as to pull up the cable 12. As the part of the cable extending from turn 84 to spring 60 lengthens the spring contracts permitting spring 64 to contract and draw bar 52 swings outwardly or rearwardly as indicated by dotted lines in FIG. 2. The motor continues to operate and the door is drawn up along rails 33 to an overhead position.

When the cable 12 reaches the limit of its upward travel with the door 20 in an overhead horizontal position winch 66 slips in the cable turn 84 while the shaft 70 with gear 68 continues to rotate. While the cable 12 was being drawn up the cup gear 83 rotates along with gear 72. Both gears 72 and 83 rotate freely on shaft 74. When the cable stops moving, the stationary cable frictionally engages the wall 83 of cup gear 83 so that this gear remains stationary. The continuing rotation of gear 68 now rotates gear 72 along which slides axially to the left as shown in FIGS. 35 while its splines still retain engagement with gear 68. As gear 72 moves to the left it moves roller 89 and switch arm 87 so that the limit switch is thrown from the right position shown in FIG. 7 to its alternate left position. Pole 108 then closes with contacts 106, 109 and pole 110 closes with contacts 113, 114. In this situation, the power supply to the field and armature windings at contacts 105, 107, 108 is broken and the motor stops. If the motor should tend to overrun, the teeth of gear 68 will slip with respect to the splines of gear 72 as shaft 74 will move laterally in the slip clutch arrangement previously mentioned. When the motor stops, gear 72 remains in its left position. The motor will stop, leaving the door in fully open position. When the motor stops, with the door open, the lamp will be lighted through closed contacts 106, 108, 109.

When it is desired to close the door the key switch 32 can again be operated momentarily. The relay 96 will again be actuated to move contacts 122, 124 back to the left position shown in FIG. 7. The motor will now be energized through relay contacts 106, 108, 109 and will be reversed in its direction of rotation. This will permit the cable 12 to move upwardly past pulley 54 around winch 66 and down past pulley 44. The motor will continue this drive while the door itself descends due to its own weight. The slowly moving cable 12 will limit the speed of descent of the door. The lamp 30 will remain lighted.

While the door is descending gear 72 remains in its left position and arm 87 of switch 86 is held in its position since cup gear 83 turns with gear 72. When the door reaches the bottom of the doorway opening 28 and is stopped at the ground G the cable 12 will again become taut and the drawbar will again assume a fully vertical position to tension springs 60 and 64. When the cable 12 stops moving around winch 66, the winch 66 which is now turning in reverse direction will slip in the cable turn 84. Then gear 83 will be held frictionally by the stopped cable and gear 72 will be turned by gear 68 to reengage fully in gear 83. This will permit switch arm 87 to swing to the right. The switch poles 108, will then be restored to the position shown in FIG. 7. The light of lamp 30 will then go out, and the motor circuit will open.

There has thus been provided a door opener which operates automatically for opening and closing an overhead door. In operation, the motor 37 drives the winch 66, around which are two turns of a flexible cable 12, the ends of said cable being fastened to the outside bottom of door 20 then up and twice around the winch 66 then over a small pulley on top of the drawbar and then onto the spring 60. When the door hits an obstruction going up or down or reaches its upper or lower limit, the cable 12 will slide on the winch 66, since the spring 60 is not holding the cable 12 too tight. When this cable 12 slips on the winch, the idler pulley will stop also because it is riding on top of the two turns of cable which stopped moving. When this happens, the motor is still driving the winch and the gear 68 is driving the gear 72 with its thread 73, since the idler pulley is standing still and the gear is rotating out of its threaded housing, the lever 87 will move over to activate the limit switch 86 and stop the motor.

When the latching relay 96 is activated, the motor 37 is started in opposite rotation. The diameter relation is such that the gear 72 stays out of its thread housing until another obstruction stops the cable again whereupon the idler stops with the cable again and the gear 72 rotates its thread into the idler stopping the motor again. Instead of a key operated switch 32 a simple pushbutton switch can be mounted on the wall 25. Alternatively the pushbutton or key operated switch can be mounted on a post (not shown) spaced forwardly from door 20. The control circuit can have switch 32 arranged for operation by remote radio control.

While I have illustrated and described the preferred embodiments of my invention, it is to be understood that I do not limit myself to the precise constructions herein disclosed and that various changes and modifications may be made within the scope of the invention as defined in the appended claims.

What is claimed is:

1. A door opener for a door mounted between curved guide rails at a doorway and movable between a lowered closed position and an overhead open position, comprising a cable attachable at one end to said door near its bottom end, a winch assembly mountable on a lintel over said doorway, said winch assembly including a winch pulley, said cable being entrained on said pulley for pulling the door upwardly on said rails and for paying out the cable as the door descends, -a reversible motor in said assembly operatively connected to and driving said pulley, a coil spring connected at one end to the other end of the cable, a bracket mountable on said door, a vertical drawbar pivotally mounted on said bracket, an idler pulley carried at the upper end of said drawbar and guiding an end part of said cable beyond said winch pulley, an arm extending outwardly of the lower end of said drawbar, the other end of said coil spring being connected to said arm for holding said end part of the cable in a taut position when the door is lowered, whereby said drawbar is held in a vertical position, and an angle bar mountable over said drawbar to prevent passage of said drawbar and manual opening of said door.

2. A door opener for a door mounted between curved guide rails at a doorway and movable between a lowered closed position and an overhead open position, comprising a cable attachable at one end to said door near its bottorn end, a winch assembly mountable on a lintel over said doorway, said winch assembly including a winch pulley, said cable being entrained on said pulley for pulling the door upwardly on said rails and for paying out the cable as the door descends, a reversible motor in said assembly operatively connected to and driving said pulley, a coil spring connected at one end to the other end of the cable, a bracket mountable on said door, a vertical drawbar pivotally mounted on said bracket, an idler pulley carried at the upper end of said drawbar and guiding an end part of said cable beyond said winch pulley, an arm extending outwardly of the lower end of said drawbar, the other end of said coil spring being connected to said arm for holding said end part of the cable in a taut position when the door is lowered, whereby said drawbar is held in a vertical position, and an angle bar mountable over said drawbar to prevent passage of said drawbar and manual opening of said door, another bracket mountable on said door below the first named bracket, and another spring connected between the drawbar arm and said other bracket for pivoting said drawbar to clear said angle bar when the cable starts to elevate the door and the first named spring contracts as said end part of the cable lengthens.

3. A door opener for a door mounted between curved guide rails at a doorway and movable between a lowered closed position and an overhead open position, comprising a cable attachable at one end to said door near its bottom end, a winch assembly mountable on a lintel over said doorway, said winch assembly including a winch pulley, said cable being entrained on said pulley for pulling the door upwardly on said rails and for paying out the cable as the door descends, a reversible motor in said assembly operatively connected to and driving said pulley, a horizontal nonrotatable shaft, an internally threaded cup gear freely rotatable on one end of said shaft, a splined gear having an external threaded hub freely rotatable on said shaft and engaged in said cup gear, said cup gear being located adjacent said winch pulley for engaging a turn of said cable on said winch pulley to turn therewith, and a spur gear integral with said winch pulley for turning therewith, said spur gear being meshed with said splined gear to turn the same alone when the cup gear is held stationary by a stationary turn of the cable on the winch pulley so that the splined gear moves axially with respect to the cup gear.

4. A door opener for a door mounted between curved guide rails at a doorway and movable between a lowered closed position and an overhead open position, comprising a cable attachable at one end to said door near its bottom end, a winch assembly mountable on a lintel over said doorway, said winch assembly including a winch pulley, said cable being entrained on said pulley for pulling the door upwardly on said rails and for paying out the cable as the door descends, a reversible motor in said assembly operatively connected to and driving said pulley, an electric power supply for energizing the motor, horizontal nonrotatable shaft, an internally threaded cupgear freely rotatable on one end of said shaft, a splined gear having an external threaded hub freely rotatable on said shaft and engaged in said cup gear, said cup gear being located adjacent said winch pulley for engaging a turn of said cable on said winch pulley to turn therewith, a spur gear integral with said winch pulley for turning therewith, said spur gear being meshed with said splined gear to turn the same alone when the cup gear is held stationary by a stationary turn of the cable on the winch pulley so that the splined gear moves axially with respect to the cup gear, a manually operable normally open switch, and a two-position latching relay connected in circuit with said switch, power supply and motor for starting the motor in either of two directions of rotation when the switch is closed while the door is in closed and open positions respectively.

5. A door opener for a door mounted between curved guide rails at a doorway and movable between a lowered closed position and an overhead open position, comprising a cable attachable at one end to said door near its bottom end, a winch assembly mountable on a lintel over said doorway, said winch assembly including a winch pulley, said cable being entrained on said pulley for pulling the door upwardly on said rails and for paying out the cable as the door descends, a reversible motor in said assembly operatively connected to and driving said pulley, an electric power supply for energizing the motor, a horizontal nonrotatable shaft, an internally threaded cup gear freely rotatable on one end of said shaft, a splined gear having an external threaded hub freely rotatable on said shaft and engaged in said cup gear, said cup gear being located adjacent said winch pulley for engaging a turn of said cable on said winch pulley to turn therewith, a spur gear integral with said winch pulley for turning therewith, said spur gear being meshed with said splined gear to turn the same alone when the cup gear is held stationary by a stationary turn of the cable on the winch pulley so that the splined gear moves axially with respect to the cup gear, a manually operable normally open switch, a two-position latching relay connected in circuit with said switch, power supply and motor for starting the motor in either of two directions of rotation when the switch is closed while the door is in closed and open positions respectively, and a twoposition limit switch having a pivotable arm located for lateral movement by said splined gear when the splined gear moves axially, said limit switch being connected in circuit with said reversible motor and power supply for interrupting the supply of power to the motor for stopping the motor at each end of travel of said door at fully closed and fully open positions thereof.

6. A door opener for a door mounted between curved guide rails at a doorway and movable between a lowered closed position and an overhead open position, comprising a cable attachable at one end to said door near its bottom end, a winch assembly mountable on a lintel over said doorway, said winch assembly including a winch pulley, said cable being entrained on said pulley for pulling the door upwardly on said rails and for paying out the cable as the door descends, a reversible motor in said assembly operatively connected to and driving said pulley, a coil spring connected at one end to the other end of the cable, a bracket mountable on said door, a vertical drawbar pivotally mounted on said bracket, an idler pulley carried at the upper end of said drawbar and guiding an end part of said cable beyond said winch pulley, an arm extending outwardly of the lower end of said drawbar, the other end of said coil spring being connected to said arm for holding said end part of the cable in a taut position when the door is lowered, whereby said drawbar is held in a vertical position, and an angle bar mountable over said drawbar to prevent passage of said drawbar and manual opening of said door, another bracket mountable on said door below the first named bracket and another spring connected between the drawbar arm and said other bracket for pivoting said drawbar to clear said angle bar when the cable starts to elevate the door and the first named spring contracts as said end part of the cable lengthens, a horizontal nonrotatable shaft, an internally threaded cup gear freely rotatable on one end of said shaft, a splined gear having an external threaded hub freely rotatable on said shaft and engaged in said cup gear, said cup gear being located adjacent said winch pulley for engaging a turn of said cable on said winch pulley to turn therewith, and a spur gear integral with said winch pulley for turning there- 7 with, said spur gear being meshed with said splined gear to turn the same alone when the cup gear is held stationary by a stationary turn of the cable on the winch pulley so that the splined gear moves axially with respect to the cup gear.

7. A door opener for a door mounted between curved guide rails at a doorway and movable between a lowered closed position and an overhead open position, comprising a cable attachable at one end to said door near its bottom end, a winch assembly mountable on a lintel over said doorway, said winch assembly including a winch pulley, said cable being entrained on said pulley for pulling the door upwardly on said rails and for paying out the cable as the door descends, a reversible motor in said assembly operatively connected to and driving said pulley, a coil spring connected at one end to the other end of the cable, a bracket mountable on said door, a vertical drawbar pivotally mounted on said bracket, an idler pulley carried at the upper end of said drawbar and guiding an end part of said cable beyond said winch pulley, an arm extending outwardly of the lower end of said drawbar, the other end of said coil spring being connected to said arm for holding said end part of the cable in a taut position when the door is lowered, whereby said drawbar is held in a vertical position, and an angle bar mountable over said drawbar to prevent passage of said drawbar and manual opening of said door, another bracket mountable on said door below the first named bracket, and another spring connected between the drawbar arm and said other bracket for pivoting said drawbar to clear said angle bar when the cable starts to elevate the door and the first named spring contracts as said end part of the cable lengthens, a horizontal nonrotatable shaft, an internally threaded cup gear freely rotatable on one end of said shaft a splined gear having an external threaded hub freely rotatable on said shaft and en gaged in said cup gear, said cup gear being located adjacent said winch pulley for engaging a turn of said cable on said winch pulley to turn therewith, and a spur gear integral with said winch pulley for turning therewith, said spur gear being meshed with said splined gear to turn the same alone when the cup gear is held stationary by a stationary turn of the cable on the winch pulley so that the splined gear moves axially with respect to the cup gear, a two-position limit switch having a pivotable arm located for lateral movement by said splined gear when the splined gear moves axially, and an electric power supply for energizing the motor, said limit switch being connected in circuit with said reversible motor and power supply for interrupting the supply of power to the motor for stopping the motor at each end of travel of said door. at fully closed and fully open positions thereof.

8. A door opener for a door mounted between curved guide rails at a doorway and movable between a lowered closed position and an overhead open position, comprising a cable attachable at one end to said door near its bottom end, a winch assembly mountable on a lintel over said doorway, said winch assembly including a winch pulley, said cable being entrained on said pulley for pulling the door upwardly on said rails and for paying out the cable as the door descends, a reversible motor in said assembly operatively connected to and driving said pulley, a coil spring connected at one end to the other end of the cable, a bracket mountable on said door, a vertical drawbar pivotally mounted on said bracket, an idler pulley carried at the upper end of said drawbar and guiding an end part of said cable beyond said winch pulley, an arm extending outwardly of the lower end of said drawbar, the other end of said coil spring being connected to said arm for holding said end part of the cable in a taut position when the door is lowered, whereby said drawbar is held in a vertical position, and an angle bar mountable over said drawbar to prevent passage of said drawbar and manual opening of said door, a horizontal nonrotatable shaft, an internally threaded cup gear freely rotatable on one end of said shaft, a splined gear having an external threaded hub freely rotatable on said shaft and engaged in said cup gear, said cup gear being located adjacent said winch pulley for engaging a turn of said cable on said winch pulley to turn therewith, and a spur gear integral with said winch pulley for turning therewith, said spur gear being meshed with said splined gear to turn the same alone when the cup gear is held stationary by a stationary turn of the cable on the winch pulley so that the splined gear moves axially with respect to the cup gear.

9. A door opener for a door mounted between curved guide rails at a doorway and movable between a lowered closed position and an overhead open position, comprising a cable attachable at one end to said door near its bottom end, a winch assembly mountable on a lintel over said doorway, said winch assembly including a winch pulley, said cable being entrained on said pulley for pulling the door upwardly on said rails and for paying out the cable as the door descends, a reversible motor in said assembly operatively connected to and driving said pulley, a horizontal nonrotatable shaft, an internally threaded cup gear freely rotatable on one end of said shaft, a splined gear having an external threaded hub freely rotatable on said shaft and engaged in said cup gear, said cup gear being located adjacent said winch pulley for engaging a turn of said cable on said winch pulley to turn therewith, and a spur gear integral with said winch pulley for turning therewith, said spur gear being meshed with said splined gear to turn the same alone when the cup gear is held stationary by a stationary turn of the cable on the winch pulley so that the splined gear moves axially with respect to the cup gear, means pivotally mounting said nonrotatable shaft adjacent to said motor, and spring means bearing laterally on said shaft, whereby said shaft moves laterally in a slip clutch arrangement when the motor overdrives said spur gear after splined gear moves to each of two extreme axial positions with respect to said cup gear.

References Cited by the Examiner UNITED STATES PATENTS 2,923,541 2/1960 Gessell 189 2,936,830 5/1960 Mosher 160188 2,954,224 9/ 1960 Schneider et al 42-28 X 3,207,502 9/1965 Houk 160-188 X DAVID J. WILLIAMOWSKY, Primary Examiner.

HARRISON R. MOSELEY, Examiner.

I. K. BELL, Assistant Examiner.

Claims (1)

1. A DOOR OPENER FOR A DOOR MOUNTED BETWEEN CURVED GUIDE RAILS AT A DOORWAY AND MOVABLE BETWEEN A LOWERED CLOSED POSITION AND AN OVERHEAD OPEN POSITION, COMPRISING A CABLE ATTACHABLE AT ONE END TO SAID DOOR NEAR ITS BOTTOM END, A WINCH ASSEMBLY MOUNTABLE ON A LINTEL OVER SAID DOORWAY, SAID WINCH ASSEMBLY INCLUDING A WINCH PULLEY, SAID CABLE BEING ENTRAINED ON SAID PULLEY FOR PULLING THE DOOR UPWARDLY ON SAID RAILS AND FOR PAYING OUT THE CABLE AS THE DOOR DECENDS, A REVERSIBLE MOTOR IN SAID ASSEMBLY OPERATIVELY CONNECTED TO AND DRIVING SAID PULLEY, A COIL SPRING CONNECTED AT ONE END TO THE OTHER END OF THE CABLE, A BRACKET MOUNTABLE ON SAID DOOR, A VERTICAL DRAWBAR PIVOTALLY MOUNTED ON SAID BRACKET, AN IDLER PULLEY CARRIED AT THE UPPER END OF SAID DRAWBAR AND GUIDING AN END PART OF SAID CABLE BEYOND SAID WINCH PULLEY, AN ARM EXTENDING OUTWARDLY OF THE LOWER END OF SAID DRAWBAR, THE OTHER END OF SAID COIL SPRING BEING CONNECTED TO SAID ARM FOR HOLDING SAID END PART OF THE CABLE IN A TAUT POSITION WHEN THE DOOR IS LOWERED, WHEREBY SAID DRAWBAR IS HELD IN A VERTICAL POSITION, AND AN ANGLE BAR MOUNTABLE OVER SAID DRAWBAR TO PREVENT PASSAGE OF SAID DRAWBAR AND MANUAL OPENING OF SAID DOOR.

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