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Publication numberUS3481387 A
Publication typeGrant
Publication dateDec 2, 1969
Filing dateJan 18, 1968
Priority dateJan 18, 1968
Publication numberUS 3481387 A, US 3481387A, US-A-3481387, US3481387 A, US3481387A
InventorsFrederick A Purdy
Original AssigneeFrederick A Purdy
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Door operator
US 3481387 A
Abstract  available in
Images(2)
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Claims  available in
Description  (OCR text may contain errors)

Dec. 2, 1969 F. A. PURDY 3,431,337

DOOR OPERATOR Filed Jan, 18, 1968 2 Sheets-Sheet 1 Dec. 2, 1969 Filed Jan. 18 1968 F. A. PURDY DOOR OPERATOR 2 Sheets-Sheet 2 United States Patent 3,481,387 DOOR OPERATOR Frederick A. Purdy, 870 United Nations Plaza, New York, N.Y. 10017 Filed Jan. 18, 1968, Ser. No. 698,901 Int. Cl. Ef 15/20; E05d 15/38 U.S. Cl. 160-188 11 Claims ABSTRACT OF THE DISCLOSURE A motor operated door having a light sensitive cell for actuating the door motor for opening and closing the door and a safety switch in the motor control circuit, the safety switch being connected by a spring and chain to a collar on the motor shaft so that, if the door is stopped by an obstruction during opening or closing, the spring and chain will open the switch to stop the motor after the motor has operated through its normal cycle.

BACKGROUND OF THE INVENTION This invention relates to motor operated doors and, more particularly, to a safety switch in the motor control circuit for such a door.

In my U.S. Patent No. 3,248,630 there is shown and described a motor operated door wherein a motor, connected through a double-disc, spring compressed, grip sheave and cable to the door, is actuated by the headlight beam of a vehicle to open and close the door. When the motor, in opening the door, brings the door to its fully opened position, the motor is reversed and, when next operated, closes the door. Conversely, when the door reaches its fully closed position, the motor is again reversed for subsequent door opening.

As has been noted, the motor is connected to the door through a double-disc, spring compressed, grip sleeve and a cable. The cable is gripped between the spring compressed discs and, in normal operation, the motor, in turning the grip sheave, operates the cable connected to the door. The spring on the grip sheave is adjusted so that, during such normal operation, the discs of the grip sheave grip and turn the cable but, if the door encounters an obstruction, such as, a bicycle, tool, or the like, the cable slips between the grip sheave discs. This, of course, prevents damage to the door, the control mechanism and the obstructing object but, unless the motor is turned off, the motor continues to run.

SUMMARY OF THE INVENTION In the instant invention, a double-disc, spring compressed, grip sheave is afiixed to the end of a door operating motor shaft and the motor shaft is connected to a switch in the electric leads supplying electrical power to the motor. The switch is connected to the motor shaft in such a way that, during normal operation of the motor in the first direction to open the door and in the reverse direction to close the door, the switch remains closed and power to the motor is not interrupted by the switch. However, if the door encounters obstruction, or is otherwise held in position while the motor is running, thereby causing a cable to slip on the grip sheave, after the motor has turned to grip sheave a prescribed distance beyond the grip sheaves normal cycle of operation to open, or close, the door, the switch is then opened, thereby cutting olf the power to the motor and stopping the motor.

The switch, and the connection of the switch to the shaft in the instant invention are relatively simple. Once the obstruction holding the door has been removed, the connection of the switch to the motor shaft can be easily reset and the door operator will, thereafter, open 3,481,387 Patented Dec. 2, 1969 and close the door in the normal cycle, without interference from the switch, until such time as an obstructron to opening or closing of the door again occurs.

DESCRIPTION OF THE DRAWINGS The instant invention will be understood from the following description and the appended drawings illustrating the preferred embodiment of the invention and in which:

FIGURE 1 is an elevation-view, partially broken away, and partially in diagram, and viewed toward one jamb of a garage-doorway, showing a bracket on the doorways inner facing and cable-pulleys on the bracket, portions of the vertical and horizontal tracks and the curve track, the door operator motor mounting, with switch, and the motor control circuitry, diagrammatically;

FIGURE 2 is a view, partly in section, taken along line 2--2 of FIGURE 1;

FIGURE 3 is a view taken along line 3-3, FIG- URE 2;

FIGURE 4 is a view taken along line 4-4, FIG- URE 3;

FIGURE 5 is an elevation-view of the switch; and

FIGURE 6 is a top plan view of a portion of the mechanism of FIGURE 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Door 2 is of the conventional overhead type and is made up, in the usual manner, of horizontally extending sections hinged together, only the top section being shown in FIGURE 1. Door 2 is guided in vertical track 4, curve track 6 and horizontal track 8 by track engaged roller 10 connected by pin 12 and bracket 14 to door 2'. A counterbalancing spring 14 is connected by pulleys 16, 18 and cable 20 to door 2, in conventional manner, for counterbalancing the weight of the door as the door is opened and closed, in the customary manner employed with both manual and motor operated doors.

As shown in FIGURE 1, door 2 is connected by pin 12, carried by bracket 14, to links 22, 24, 26, 28, 30 and rollers 32, 34, 36, 38, 40, and by plate 44, held by cotter pin 43 on shaft 42 of roller 40, to endless cable 46 which, at the forward end of horizontal track 8, passes around pulley 48 mounted on the door frame and, at the opposite end of the track, passes around grip-sheave, generally designated 50. For purpose of adjusting the tension of endless cable 46, turn-buckle 52 is attached, .at its opposite ends, to the ends of cable 46 to form the cable in an endless loop around pulley 48 and grip-sheave 50. The upper and lower runs of cable 46 have, adjustably affixed to the cable, shipper buttons 54, 56, respectively, for purposes later described.

As has been noted, when grip-sheave 50 is rotated in a first direction, door 2 is moved from the closed position to the open position and, When grip-sheave 50 is rotated in the opposite direction, door 2 is moved from the open position to the open position. This is accomplished by reversing the direction of the drive of grip-sheave 50 when door 2 reaches its fully opened and fully closed position by a mechanical linkage, such as shown and described in my U.S. Patent 3,248,630 which mechanical linkage is tripped by shipper buttons 54, 56, in the manner described in my aforementioned patent, to control the operation of the electrical control circuitry of the motor driving grip-sheave 50. For purposes of illustration and a better understanding 'of the instant invention, the mechanical linkage for controlling the circuitry of the grip-sheave drive motor and for reversing the drive direction of grip-sheave 50 is not shown or described, reference being had to the illustration and description thereof in my aforementioned patent.

Referring to FIGURES 1 and 2, grip-sheave 50 is made up of two tapered faced pulley heads 62, 64 keyed to shaft 66 of grip-sheave drive motor 68. Pulley half 64 is urged, by compression spring 70, on shaft 66, toward pulley half 62 to grip cable 46 between the tapered faces of pulley halves 62, 64. The compression of spring 70, urging pulley half 64 toward pulley half 62, is adjusted by nuts 72, 74 threaded onto the end of shaft 66. Motor 68 and grip-sheave 50 are supported in frame 76 afiixed to horizontal track 8, or to the garage structure.

Switch, generally designated 80, having housing 82, is glued, welded or otherwise suitably attached to frame 76. Stationary contact 84 is carried in housing 82 by a fixed, non-conductive, mounting 86, mounted in fixed position in housing 82. Contact 84 is connected, by lead 88, to one side of power source 90. Moveable contact 92, mounted in non-conductive mounting 94 slideable in housing 80, is connected by lead 96 to motor 68, for purposes to be described. At the upper end of switch 80 a nonconductive guide 98 is fixed to housing 80 by cotter key able mount '94, urging contact 92 toward and into contact with fixed contact 84.

Referring to FIGURES 2 and 5, rod 100, with moveable mount 94 and moveable contact 92, is moveable in housing 80 and guide 98 in the direction of the arrow in FIGURE but, for reasons more obvious hereinafter, is not rotatable in guide 98. The upper end of rod 100 is connected by tightly coiled spring 110, press fitted through an opening 112 through the end of rod 100, and chain 114 to collar 120 clamped on shaft 66 between collars 122, 124. For reasons later described, collar 120 is not keyed to shaft 66 but, during normal operation of motor 68, turns with shaft 66. Chain 114 is of a length slightly more than one half the length of the circumferential travel of the outer surface of collar 120 and, for the first half of each cycle of rotation of collar 120 during the opening or closing of the door, chain 114 is unwound from collar 120 and during the remaining half of each cycle is wound onto collar 120, for purposes to be described.

In operation, as described in my aforementioned US. Patent 3,248,630 the light beam from the headlights 130 of a vehicle 132, when directed to light sensitive cell 134, energizes motor 68 to open, or close, the door, depending upon whether the door is to be opened or closed and the preset condition of reversing switch 136, all as described in my aforementioned patent. For the first half of the operating of the opening or closing cycle, chain 114 is unwound from collar 120 and, for the remainder of the cycle, is wound onto collar 120. During normal operation, collar 120 rotates with shaft 66 and there is no slippage between collar 120 and shaft 66. Because chain 114 is slightly longer than half of the circumferential travel of collar 120, chain 114 is unwound from and rewound on collar 120 as the collar rotates with the shaft during normal operation. Thus, during such normal operation, there is no movement of contact 92 and, insofar as switch 80 is concerned, electrical power to motor 68 is maintained.

If, during the operation of motor 68 to open, or close, door 2, door 2 should encounter an obstruction or be held, the increased load on cable 46 overcomes the frictional door-driving urge applied by spring 70 upon cable 46, allowing slippage by cable 46, thereby preventing overload and damage to motor 68. Thus, while door 2 is in engagement and held by the obstruction motor 68 and shaft 66 continue to rotate. Such continued rotation also continues the rotation of collar 120 to wrap chain 114 around rotating collar 120. After the full length of chain 114 is wound onto collar 120, the continued rotation of collar 120 with motor 68 and shaft 66 causes chain 114 and spring 110 to move rod 100, moveable mount 94 and moveable contact 92 upward in housing 82 of switch 80, separating contacts 84, 92 and opening the circuit to motor 68. When contacts 84, 92 are opened, electrical power to motor 68 is cut off and the motor is stopped. Thus, when door encounters an obstruction or is held, operation of motor 68 continues only until contacts 84, 92 are opened. The obstruction, or whatever else might be holding door 2, can then be removed. Once the obstruction is removed and the door is free to operate, collar 120 can be rotated, manually, on shaft 60, to free chain 114, close contacts 84, 92 and, by continued manual rotation of collar 120, the interrupted cycle of motor 68, shaft 66, whether opening or closing door 2, can be completed and, after completion, collar 120 can be manually rotated on shaft 66 a few degrees further to reset safety switch for subsequent normal operation of the door. To facilitate manual rotation of collar 120, or to loosen chain 114, chain 114 may be detached from collar 120, by hand, and re-attached after collar 120 is reset. For this purpose, a ball-chain is preferred and the ball-chain 114 may be attached to collar 120 by a suitable ballchain attachment, such as a Type A coupling as manufactured by Ball Chain Manufacturing Company, Inc., Mount Vernon, NY.

If, while door 2 is being held by an obstruction, and motor 68 and shaft 66 are rotating and turning collar 120, switch 80 should become jammed or frozen so that contacts 84, 92 cannot be opened by chain 114 and spring 110, collar 120 slips on shaft 66 thereby avoiding damage to the motor, shaft, switch and housing. It is preferred, however, that contacts 84, 92 open and stop motor 68.

In carrying out the instant invention, rod of switch 80 could, of course, be connected to collar 120 by various mechanical connections. Because of the mechanical linkages of the motor reversing mechanism, not shown on the instant drawings, it is preferred, however, to use the illustrated arrangement of spring and chain 114. In such arrangement, spring 110, as chain 114 is wound on to and unwound from collar 120, directs the chain into the area under the motor and out of the way of the mechanical reversing linkage.

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention described.

What is claimed is:

1. A door-operator comprising, a motor, a door, a shaft on said motor, a grip-sheave on said shaft, an endless cable connected to said door and around said grip-sheave so that, when said motor is driven in a first direction, said motor drives said grip-sheave and opens said door and, when said motor is driven in the opposite direction, said motor drives said grip-sheave and closes said door, power means connected to said motor for driving said motor in said first and said opposite directions, a switch in the connection of said power means to said motor and means on said motor shaft connected to said switch for opening said switch and stopping said motor after said motor has driven said grip-sheave through a full cycle in a first direction to open said door and through a full cycle in the opposite direction to close said door, said grip-sheave including means for slipping said endless cable on said gripsheave when said door is obstructed while being driven by said motor in said first and said opposite directions so that after said motor has driven said grip-sheave through a full cycle in said first or opposite direction and said door is obstructed said means on said motor shaft connected to said switch will open said switch and stop said motor.

2. A door-operator as recited in claim 1 in which said means on said shaft is a collar and said collar is connected to said switch by a chain.

3. A door-operator as recited in claim 2 in which said collar is connected to said switch by a chain and spring.

4. A door-operator as recited in claim 3 in which said chain in unwound from and wound onto said collar as said motor drives said grip-sheave.

5. A door-operator as recited in claim 4 in which said chain is about one-half the length through which the cir cumference of said collar is driven when said motor is driving said grip-sheave through a full cycle to open said door and through a full cycle to close said door.

6. A door-operator as recited in claim 5 in which said grip-sheave includes a first disc, a second disc and a compression spring, said compression spring urging said discs into gripping engagement with said cable.

7. A door-operator comprising, a motor, a door, a shaft on saidrnotor, door-drive connections from said shaft to said door for opening said door when said motor is driven in a first direction and for closing said door when said motor is driven in the opposite direction, power means connected to said motor for driving said motor in said first and said opposite directions, a switch in the connection of said power means to said motor and means connected to said switch for opening said switch and stopping said motor after said motor has driven said door through a full cycle in said first direction to open said door and through a full cycle in said opposite direction to close said door, said door-drive connections from said shaft to said door including means which, when said door engages an obstruction while said motor is opening or closing said door, permits said motor to drive said shaft While said door is so obstructed so that after said motor has driven said shaft through one of said cycles and said door is obstructed said means connected to said switch opens said switch and stops said motor.

8. A door-operator as recited in claim 7 in which said means connected to said switch is a collar on said shaft and said collar is connected to said switch by a chain.

9. A door-operator as recited in claim 8 in which said collar is connected to said switch by a chain and spring.

10. A door-operator as recited in claim 9 in which said chain is unwound from and wound on said collar as said motor drives said shaft.

11. A door-operator as recited in claim 10 in which said chain is about one-half the length through which the circumference of said collar is driven when said motor is driving said shaft through a full cycle to open said door and through a full cycle to close said door.

References Cited UNITED STATES PATENTS 3/1951 Hall 49-499 4/1966 Purdy 318--266 US. Cl. X.R.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2545775 *May 2, 1946Mar 20, 1951Harvey H HallGarage door operating device
US3248630 *Jun 15, 1962Apr 26, 1966Frederick A PurdyDoor-operators
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4231190 *Oct 4, 1978Nov 4, 1980My-D-Han-D Manufacturing Co.Remotely controlled gate opener
US4452292 *May 10, 1983Jun 5, 1984Firmagroup Australia Pty. Ltd.Automatic door opener
US4501963 *Nov 3, 1982Feb 26, 1985Automatic Roller Doors, Australia, Pty., Ltd.Reversing device for roller doors
US5566508 *Sep 19, 1994Oct 22, 1996American Sterilizer CompanyDrive system for a sliding chamber door
US7886735 *Nov 6, 2006Feb 15, 2011Bsh Bosch Und Siemens Hausgeraete GmbhDrive mechanism for a down draft vent system
US8485177Oct 8, 2010Jul 16, 2013Bsh Bosch Und Siemens Hausgeraete GmbhDrive mechanism for a down draft vent system
US20070137635 *Nov 6, 2006Jun 21, 2007Bsh Bosch Und Siemens Hausgerate GmbhDrive mechanism for a down draft vent system
US20110028082 *Oct 8, 2010Feb 3, 2011Bsh Bosch Und Siemens Hausgerate GmbhDrive mechanism for a down draft vent system
DE2328836A1 *Jun 1, 1973Dec 19, 1974Krueger H Maschf KgSchlaffseilsicherung fuer trag- oder hubseile, insbesondere fuer heb- und senkbare garagentore
Classifications
U.S. Classification160/188, 49/25, 49/28, 49/360
International ClassificationE05F15/16
Cooperative ClassificationE05F15/1661, E05Y2900/106
European ClassificationE05F15/16B9D