US 3436862 A
Description (OCR text may contain errors)
April 1969 R. F. STANSBERRY 3,436,862
AUTOMATIC DOOR LOCK ACTUATOR Sheet Filed Oct. 6. 1966 A!)ril 1969 R. F. STANSBERRY 3,436,862
AUTOMATIC DOOR LOCK ACTUATOR Filea Oct. 6. 1966 Sheet of2 INVENTOR.
@i BMW/4M 14 TTO/Q/VEV United rates atent O 3,436,862 AUTOMATIC DOOR LOCK ACTUATOR Robert F. Stansberry, Beverly Hills, Mich., assignor to Taylor Garage Doors, a division of Garland Manufacturing Company, Detroit, Mich.
Filed Oct. 6, 1966, Ser. No. 584,806 Int. Cl. Ef 11/00, 15/00; F16h 9/00, 11/00 US. Cl. 49-358 Claims ABSTRACT OF THE DISCLOSURE A latching mechanism for reversible drive systems, such as are used to open and close overhead garage doors, and which prevents forced drive through the driven member. A chain or like drive means which is alternately taut and slack in one run, depending upon the direction of drive, is used to position a follower relative to a latching pawl which allows forward drive in either direction but prevents forced drive in a reverse direction.
This invention relates to reversible drive mechanisms of the type used with power operated garage door closures and, more pertinent, to locking mechanisms for use therewith.
Most power operated garage door closures are belt or chain driven and include a friction clutch or like means to allow drive slippage when the door encounters some unforeseen obstacle in its travel. Unfortunately, such slippage also allows a garage door to be forced open by unauthorized persons and requires the use of some type of separate locking means.
Completely separate locking means, as on manually operated garage doors, are too easily forgotten. Accordingly, some type of locking device associated with the door operating mechanism, and readily disconnected therefrom in the event of a power failure, is much preferred.
This invention is directed to a relatively simple and economical locking device which may be incorporated in a reversible chain or like drive means, as a part thereof, and requires no connecting cables to remote latching means or over-center links and the like as are presently known.
The locking device of this invention takes advantage of the reversed slack and taut sides in a chain or like drive means, in changing drive directions under power, and of the changing functional aspects of driven and driving members when efforts are made to move the door other than under power.
More specifically, as used with power operators for garage doors which include a sprocket chain drive, the locking device of this invention includes a follower engaged to the drive chain to sense its different directions of rotational drive as determined by the slack and taut sides in driving in different directions. A latching pawl is disposed for holding engagement with the drive chain, through the follower or otherwise, when the garage door is closed, and to prevent reverse drive other than under power. When the door is opened under power the pawl is automatically disengaged due to the changing direction of the drive means. However, in all other situations it must be manually disengaged since forced drive changes the operating functions of the drive and driven sprockets and the chain remains engaged with the latching pawl.
The invention will best be known and more fully appreciated in the description which follows of a preferred embodiment for use with a power operated garage door closure.
In the accompanying drawings:
FIGURE 1 is an inside view of a garage door closure showing a power operating mechanism provided on the upper panel thereof.
FIGURE 2 is a greatly enlarged cross-sectional view of the drive mechanism for the power operated-door of the first drawing figure as seen in the plane of line 22 thereon.
FIGURE 3 is a cross-sectional view of the latching pawl and its mounting as shown in the plane of line 3-3 of the preceding drawing figure.
FIGURE 4 is similar to the second drawing figure with the direction of rotation drive reversed and the latching pawl shown in an inoperative position.
FIGURE 5 is similar to the second and fourth drawing figures, as rotated and shows the position of the drive mechanism, and particularly the latching pawl, during the course of overhead travel for the garage door on which provided.
In the first drawing figure the inside of a garage 10 is shown with a door opening 12 that is closed by an overhead sectional door 14. The garage door 14 opens upwardly and is guided on guide tracks 16 along the edges of the door opening and extending back thereover into the garage.
A drive mechanism and operator 18 is mounted on the top panel of the garage door 14. This is of the type shown by co-pending patent application SN 416,579, now Patent No. 3,311,159 entitled Garage Door Hardware and, as shown best in the second drawing figure, includes a drive motor 20 provided in a housing 22 and connected by drive means to a drive shaft 24 extending across the top of the garage door and journaled in a half bearing support 26 provided on a support or brace 28 connected to the top door panel. One or more torsion springs 30 are provided on the drive shaft 24 for counter-balancing the weight of the door. A cable and drum arrangement 32 on one or both ends of the drive shaft 24 assist in the raising and lowering of the door.
Looking at FIGURE 2, and like FIGURES 4 and 5, more closely:
The upper door panel 34 supports the drive shaft 24 on which is provided a driven sprocket wheel 36. It is connected, in turn, to a drive sprocket 38 by means of a sprocket chain 40. The drive sprocket 38 is on a common shaft with a friction clutch (not shown) and a driven pulley 42 which is connected to a drive pulley 44 by means of a drive belt 46 for drive by the motor 20'.
The drive chain 40 is provided with some slack and in comparing FIGURES 2 and 4 it will be appreciated that when the rotational direction of the sprocket 40 is counterclockwise in closing the garage door, the chain is taut on the left side and slack on the right side. Conversely, in opening the garage door the rotational direction of the sprocket chain 40 is clockwise and the right side of the chain is taut while the left side is slack.
The latching mechanism 50 of this invention includes a triangular shaped plate 52 that is pivotal about the same axis 54 as the drive sprocket 38. Mounted on the pivotal plate 52 are a pair of followers 56 and 58; of which only the follower 56 need include sprocket teeth. These are disposed to receive and guide the sprocket chain 40 between them in passing to and from the drive gear 38 and are spaced close enough to take out most of the slack in the chain. Accordingly, the pivotal plate 52 will change pivotal positions and rock back and forth as one side or the other of the chain becomes taut in reversing the rotational and drive direction of the sprocket chain.
A guide shoulder 59 is provided on the pivoal plate 52 to assure sprocket tooth engagement between the chain and the idler sprocket or follower 56. On one end of the pivotal plate is also provided a pawl actuating pin 60. Its
purpose will be more fully appreciated in the description which follows immediately hereafter.
A support arm or plate 62 is secured to the housing brace 28 and has an end 64 extended up and relatively over but behind the pivotal plate 52. A ratchet tooth latching pawl 66 is pivotally mounted on the end of the support arm 62. It includes a handle 68 which is fixed to one end and it has the other end 70 formed for holding engagement with the idler sprocket 56. It is provided with a cam surface 72 on its underside for engagement by the activating pin 60.
In the position of the latching pawl 66 shown by FIG- URE 2, it is weighted by the handle 68 for latching engagement with the sprocket tooth follower 56. In such position, it will be appreciated that the pawl actuating pin 60 on the corner of the triangular shaped pivotal plate 52 is behind the cam surface 72 formed on the underside of the latching pawl member. Disposed over the latching pawl 66 and fixed to the end 64 of the support arm 62 is a stop pin 74 for limiting the travel of the latching pawl 66 when it is disengaged from the idler 56.
When the garage door 14 is traveling across the top of the guide tracks 16, towards a closed position, the pivotal plate 52 is disposed as shown in FIGURE 5 with the follower 56 held out by the taut side of the drive chain 40. The latching pawl 66 is held out of engagement with the idler sprocket 56 by the free hanging handle 68 secured on the other side of its pivotal axis from the ratchet toothed end 70 thereof. It is similarly disposed even when the drive direction of the chain is reversed in the overhead travel position to open the door; as best seen in turning FIGURE 4 ninety degrees.
When the top panel 34 of the garage door 14 turns on the curved guide track 16 to the vertical position in closing, as shown in FIGURE 2, the hanging handle 68 pivots and holds the latching pawl 66 into ratchet engagement with the idler sprocket 56.
In the closed and rest position of the garage door 14, the latching pawl 66 is engaged with the idler 56 and through it to the drive chain 40.
When the garage door 14 is raised under power, the drive sprocket 38 is driven in the opposite direction and the sprocket chain 40 is pulled taut on the opposite side, which is the right side in the drawing figures. This moves the idler sprocket 58 outwardly and causes the pawl actuating pin 60 on the corner of the pivotal plate 52 to cam and lift the latching pawl out of engagement with the idler 56.
The position of the latching pawl 66 and the handle 68 fixed thereto, at this precise moment, is essentially as shown in FIGURE end of the latching pawl and the pawl to the limit of stop 74. However, the pin stays under the pawl and never goes beyond its terminal end.
When the direction of travel for the garage door 14 is reversed from its fully opened position or otherwise, to close the door, the drive chain 40 draws straight on the left or upper side causing the pivotal plate 52 and its followers 56 and 58 to assume the position shown in FIGURE 5. This causes the actuating pin 60 to travel back and out of the way behind and under the latching pawl and allows the free-hanging handle 68 to pivot the pawl back into latching position as the door closes once again.
In any instance in which there is a power failure when the door is closed, the handle 68 may be raised to move the latching pawl 66 out of engagement with the follower 56 and the door may be forcibly raised. However, otherwise, as will now be discussed, the door is locked in its closed position.
Following through the sequence once more:
When the garage door is being closed under power, the drive chain 40 is taut on the upper side or run as shown in the last drawing figure. The ratchet tooth pawl 66 is disposed as shown, towards the stop pin 74, weighted as it is by the free hanging handle 68.
4. The actuating pin 60 travels to the As the top panel of the garage door, on which the drive mechanism is mounted, turns the corner of the guide track 16, in closing the door, the weight of the handle 68 pivots the pawl 66 into the position shown in the second drawing figure. The idler sprocket 56 is being driven clockwise, with reference to the drawing, and rotates freely under the latching pawl end 70 momentarily on their first contact.
When the garage door is closed, the power is off and the mechanism and latch remain in this position.
In trying to forcibly open the garage door, the large driven sprocket wheel 36 becomes the driving member and accordingly the drive chain is held taut on the latching side. In trying to force the chain drive to travel clockwise, in the drawing, the chain is held by the guide 59 against the idler 56 and it is urged counter-clockwise and into the latching pawl. The relative overcenter engagement of the pawl with the idler provides a locking linkage that cant be upset by any normal effort to raise the garage door manually or otherwise.
However, from inside the garage the handle 68 may be lifted to release the pawl 66 from its engagement with the idler 56, and therethrough to the drive chain. Then and only then can the garage door be raised manually.
Although opening the door with the power off, after the pawl is disengaged, requires reverse drive of the chain and the locking side stays taut, once the top door panel turns the corner the pawl is weighted by the handle out of the way. The slip in the friction clutch (not shown) for the drive belt 46 enables the door to be fully opened so that the garage can be used until the power failure or whatever is corrected.
With the garage door down, and power available, when the drive sprocket 38 is reversed, as necessary to open the door, the latching pawl 66 is automatically disengaged.
In opening the garage door under power, the drive chain 40 becomes taut on the right or lower side causing the pivotal plate 52 to rock to the position shown in the fourth drawing figure. As this is occurring, the pin 60 on the corner of the pivotal plate rides up the cam surface 72 on the underside of the latching pawl 66 and kicks it out of engagement with the idler 56, which is simultaneously moving out of its range.
The actuating pin 60 on the pivotal plate 52 travels to the tip of the latching pawl 66 and holds it out of latching engagement until the top panel of the garage door turns the guide track corner. Thereafter, the weight of the pawl handle 68 holds the pawl against the stop pin 74 as the door travels along the overhead track section.
When the direction of drive is reversed, to close the garage door, the pivot plate 52 moves the actuating pin 60 from its position under the tip of the latching pawl 66 back under and behind the pawl. This allows the pawl 66 to pivot back into latching position relative to the idler 56, under the influence of the handle 68, as the door turns the guide track in closing.
From the foregoing, it will be appreciated that a reversible drive means may be provided with a latching mechanism that is self-actuating under full power conditions and may be made operative only when the power is off. Although the drive means in the embodiment shown is rotated in being provided on a traveling door, it will be appreciated that the relative movement this causes the latching pawl might be accomplished by other means. Similarly, the engagement of the pawl with a sprocket toothed follower might be changed and direct engagement with the drive chain or some other part of the drive means might be provided.
The broad scope of the present invention is in the sensing of the rotational direction of travel of reversible drive means for actuating latching means and in taking into consideration the fact that the function of the driving and driven members is reversed in changing from power operation to forced drive conditions.
1. A locking device for reversible drive mechanisms,
a drive member and a driven member having a common circumscribing drive means provided therebetween and including sufiicient slack to provide a taut and a slack side in being driven in opposite rotational directions,
means engaging said drive means for actuation of itself in relatively opposite directions in response to the rotational direction of said drive means as determined by the taut and slack sides thereof,
and means operatively responsive to the disposition of said engaging means for locking engagement with said drive means precluding forced drive in a reverse rotational direction therethrough.
2. The locking device for reversible drive mechanisms of claim 1,
said engaging means being pivotally mounted for rocking movement in said different directions.
3. The locking device for reversible drive mechanisms of claim 2,
said drive means including a sprocket chain,
and said locking means including a locking pawl.
4. The locking device for reversible drive mechanisms of claim 3,
said pivotally mounted means including an idler sprocket in driven engagement with said sprocket chain,
and said locking pawl being engaged to said sprocket chain through said idler sprocket.
5. The locking device of claim 4,
said locking pawl having overcenter engagement with said idler sprocket precluding unintentional reverse chain drive and a cam surface for disengagement thereof by said pivotally mounted means in the course of permissive reverse chain drive.
'6. Latching means for power operated reversible chain drive mechanisms, and comprising,
a drive chain provided between driving and driven members and having sufiicient slack for providing alternating taut and slack runs on opposite sides thereof in being driven in opposite rotational directions,
means pivotal about the rotational axis of one of the driving and driven members for said chain and guiding on said chain for rocking movement in accord with the taut and slack changes in at least one of the runs thereof,
an idler sprocket provided on said pivotal means and in free rotating engagement with said chain,
a ratchet tooth pawl pivotally mounted on a fixed axis and disposed for engagement with said idler sprocket in one of the pivotal positions of the pivotal means on which it is provided for precluding the forcible reverse rotation thereof and of said drive chain therewith,
and cooperating cam surface and pin means provided on said pawl and pivotal means for the disengagement of said pawl from said idler sprocket in the reverse drive of said chain under power.
7. The latching means for reversible chain drive mechanisms of claim 6, comprising,
means providing for relative pivotal movement of said pawl from engagement with said idler sprocket and for engagement therewith only near the termination of one direction of reversing rotational drive imparted to said drive chain.
8. The latching means for reversible chain drive mechanisms of claim 7,
said last mentioned means including a carriage mount having the latching means and reversible drive mechanism provided thereon and being tiltable near the termination of rotational drive imparted to said drive chain in one direction,
and said pawl being weighted for disengagement from said idler sprocket except as tilted with said carriage mount.
9. The latching means for reversible chain drive mechanisms of claim 8,
said carriage mount including a panel of an overhead opening garage door closure and having said power operated reversible drive mechanisms provided thereon for power actuation of said door closure.
10. Latching means for use with power operated overhead opening garage door closures provided on the door closure and traveling therewith, and comprising,
a power driven mechanism including a drive chain having sufiicient slack to provide alternating taut and slack runs in being driven in opposite rotational directions,
means pivotal about the axis of the drive sprocket for said drive chain and having spaced followers provided thereon for receiving said drive chain therebetween and being sufficiently closely spaced for rocking movement of said pivotal means in accord with the taut and slack changes in said drive chain,
one of said followers including an idler sprocket in free rotating engagement with said drive chain,
and a ratchet tooth pawl pivotally mounted on a fixed axis for engagement with said idler sprocket,
said pawl being weighted for locking engagement with said drive chain by engagement with said idler sprocket when the garage door is closed and for disengagement therefrom when the garage door is open,
and cooperating cam means provided on said pivotal means and said pawl for disengagement of said pawl from said idler sprocket in the reversal of drive direction imparted to said drive chain under power.
References Cited UNITED STATES PATENTS 2,924,982 2/1960 Harrer 74-220 DAVID J. WILLIAMOWSKY, Primary Examiner. I. KARL BELL, Assistant Examiner.
US. Cl. X.R. 49-280; 74-220; l60188