US3038536A - Door operating mechanism - Google Patents

Description

June 12, 1962 H. G. RIGBY DOOR OPERATING MECHANISM 2 Sheets-Sheet 1 Filed Dec. l5, 1959 June 12, 1962 H. G. RIGBY DOOR OPERATING MECHANISM 2 Sheets-Sheet 2 Filed Deo. l5, 1959 Nw @Y Harvey G. .ZErLyZy INVENTOR.

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Arm/@Ney United States Patent O 3,038,536 DOOR OPERATING MECHANISM Harvey G. Rigby, 2223 Duncan Ave., Cornwells Heights, Pa. Filed Dec. 15, 1959, Ser. No. 859,725 1 Claim. (Cl. 160-193) This invention relates to mechanisms for opening and closing hingedly sectional doors of the type having an endless chain connected to the door and driven by an electric motor for alternately moving the door from a vertical closed position to a horizontal overhead open position, and reversing its movement to its closed position. Such doors for garages or other buildings are usually provided with rollers at their edges mounted in right angular channel tracks or guides supported in the building on opposite sides of the door opening for guiding the door in its opening and closing movements. The vertical and horizontal portions of the tracks are joined by a curved portion to facilitate the travel of the door from one position to the other.

`One of the principal objects of my invention is to provide a mechanism for opening and closing a door of the character mentioned of more simplified and economical construction than previous mechanisms of the type referred to and which will be more eicient and reliable in operation, and also in which the individual parts of the mechanism can easily be replaced.

`In my improved door operating mechanism I employ only a single chain for operating the door lift, thus dis.- pensing with belts and pulleys, ropes and chains used in previous mechanisms; and the opening and closing movements of the door are controlled by a single electrical push button. Any desired number of such buttons connected in the electrical circuit with the motor may be installed in various convenient locations. The motor may also be operated from a vehicle or other remote location by means of a radio control.

Another important object of this invention is to provide a mechanism of the character mentioned with convenient and effective means for disconnecting the motor from the chain drive in the event of a power failure.

A further object of the invention is to provide automatic means for disconnectingy the chain drive from the motor in the event of the door becoming stuck, wedged or frozen to the iloor or frame of the building, thereby eliminating any danger of breaking the mechanism or damaging the door.

A still further important feature of my improved door operating mechanism resides in the construction whereby the worm gear which connects the motor with the chain drive is supported solely by two ball bearings in the gear housing, so that a two-section chain sprocket operating shaft which extends through an axial bore in the worm gear is entirely free from any strain which might otherwise be imparted by rotation of the gear. In the construction referred to, both sections of the shaft can be entirely withdrawn from the worm gear, leaving it undisturbed in its bearings.

Other objects and advantages of my invention will appear or be pointed out in the following specification in Which reference is directed to the accompanying drawings forming a part thereof, and in which:

FIG. l is a sectional view through the central portion of a door of the character mentioned with my improved door operating mechanism connected thereto;

FIG. 2 is a detail side elevation of my improved roller carrier connection from the operating chain to the door;

FIG. 3 is a section taken on the line 3 3 of FIG. 2;

FIG. 4 is a diagram showing the electrical connections from the door operating chain to the motor;

FIG. 5 is a frontal view of a two-point switch actu ated by the door operating chain;

FIG. 6 is a -section through the worm gear housing taken on the line 6-6 of FIG. l;

FIG. 7 is a detail top plan, partly in section showing the front sprocket adjacent the door `and roller carrier track;

FIG. 8 is a side elevation of the parts shown in FIG. 7;

FIG. 9 is an end view of the coupling end of one section of the two-section chain operaitng shaft; and

FIG. l0 is a detail View showing a cushioning device between the door lift connection, or draw bar, and the door.

Referring to the drawings in which like numerals designate like pants in the several views 10' designates a garage or other building having a front wall 12 (FIG. l) provided with a door opening 14. Right angular channel tracks 16, having curved portions 18 joining their vertical and horizontal portions, `are mounted on the Wall 12 on opposite sides of the opening 14. A door 20 consisting of horizontal hinged sections is freely mounted against the rear of the opening 14 and has rollers 22 at its edges in the channel tracks for guiding the door in its opening and closing movements. The door 20 may be held under lifting tension by means of elongated springs 24 connected to the bottom of the door at each edge through cables 26 -mounted on stationary pulleys 28, journaled in brackets 17 through which the tracks 16 are attached to the wall 12, and a floating pulley 30, for reducing the force required by the operating mechanism, hereinafter to be described, in opening the door.

My improved door operating mechanism includes a worm gear housing 32 (FIGS. 1-5) having an upwardly facing base portion 34 for attachment through hangers 36 to `a joist 38 (FIG. l) or other support in the building 1t). Operating shaft housings 40 and 42 extend horizontally from each side of the housing 32, and a twosection shaft comprising sections 44 and 46 is journaled in these housings. Shaft section 44 is journaled in ball bearings 48 in housing 40 and has a reduced portion 50 projecting therefrom, forming a shoulder 52 immediately outside the surface of the housing for a purpose hereinafter explained. 'Ihe section 44 has a coupling slot or recess 56 in its inner end (FIG. 9) and a thrust flange or collar 58 a short distance back from this end `and abutting the adjacent ball bearing 48. Shaft s'ection 46 is journaled in plain bearings 60 and 62 in housing 42, this shaft having on its inner end a at or rectilin-ear key portion 64 coengageable with the recess 56 in section 44 lfor coupling the two sections together. Section 46 is axially shiftable toward and from section 44 by means of a lever 66 connected through ball bearing 68 to the outer end of the section and in engagement at its upper end with the wor-m gear housing 32. A detent 70 in the bearing 60 is designed to hold the section 46 into or out of coupling engagement with section 44. A worm gear 72 has oppositely projecting hubs 74 which are journaled in ball bearings 76 in the opposed inner ends of the housings 40 and 42. This worm gear has an axial bore 78 through which the two-section shaft loosely extends. The hub 74 in housing 40 abuts the thrust llange 58 on the opposite side from that abutting the ball bearing 48 to hold shaft section 44 against axial movement. The bore 78 being of slightly greater diameter than shaft sections 44 and 46 permits free movement of the sections therein, the worm gear being supported solely by the ball bearings 76 independently of the shaft sections, so that no strain is exerted on the shaft sections by the Worm gear. A key 80 (shown in broken lines in yFIG. 6) in opposed slots in shaft `section 42 and the bore 78 of the worm gear renders that shaft section axially shiftable toward and from lshaft lsection 44, but non-rotatable in said worm gear.

A worm shaft 82 is journaled in the housing 32 at right angles to shaft sections 44 and 46 and a worm 84 is mounted on the shaft in engagement with the worm gear 72. An electric motor 86 is coupled (by means not shown) to the worm shaft 82 for driving said shaft, and the motor 86 `may be mounted on the housing 32 (as indicated in FIG. 1).

A sprocket 88 is rotatably mounted on the reduced portion 50 of shaft 44. Also loosely mounted on said reduced portion on opposite sides of sprocket 88 are friction drive disks 90. The supporting inner face plate 92 is pinned or otherwise fixedly mounted on the reduced portion 50 adjacent the shoulder 52 on shaft 44, the. supporting outer face plate 92 being loosely mounted on the reduced portion l50 of the shaft 44. The outer end of reduced portion 50 is threaded and provided outwardly of the pressure plate Y916 with an adjustable nut 98. A helical spring 100 is interposed between pressure plate 98 and opposed face plate 92, thisspring urging the `loosely mounted members `of the assembly toward Vthe iixedly mounted inner face plate 92. It should here be pointed out that the shaft 44 may be of uniform ldiameter with a fixed collar 94 serving in place of the shoulder 52. Another sprocket 102 is mounted between supports '104 on the Wall 12 in alignment with sprocket 88. An endless chain 106 is mounted on the two sprockets. The sprocket 102 may be journaled in longitudinally adjustable bearings 105 on the supports 104, and provided with screws 108 or other suitable means for adjusting the tightness of the chain. Forming a link in the chain 106 is a carrier 110 having rollers 112 mounted on an'inverted T-shaped track 114 attached at its front end to the supports 104 and at its other end to a relay housing 115, mounted on the Worm gear housing 32, or other suitable support, so that the track is aligned between the two sprockets. A strip 116 of wood or other non-metallic material is mounted on top of the track for supporting the chain, which is attached to depending'lugs 118 and 120 on the carrier 110. A draw -bar V122 is pivotally connected to one end of lug 118 land at its other end to a spring cushion assembly 124 comprising top and bottom cross bars 126 rigidly mounted on rods 128 and an intermediate bar 130 slidably mounted on said bars and having helical springs 132 interposed between it and the top bar. The bottom bar is rigidly attached at 133 to the top of the door 20. The door lift or draw -bar 122 projects slidably through an opening in the top bar and is rigidly attached to the intermediate bar 130, so that a pull on the draw bar will be cushioned by the springs 132.

Oppositely facing, one-way switch actuating dogs 134 are attached to the endless chain 106 for the actuation of a two-point electrical limit switch 136 pivotally mounted on the relay housing 115. This switch is for the purpose of stopping the motor 86 at the end of the travel of the chain in each direction when the door 20 arrives at open or closed position. Accordingly the dogs 134 are spaced apart longitudinally of the chain the correct distance to bring the door from its closed to its overhead open position. The dogs 134 are pivotally mounted on and between depending portions of special links 138 of the same length as the links of the chain 106 (FIG. in which they are connected, so that their 1ocation in the chain can be varied to accommodate doors of different lengths, or heights. Each dog is provided in its front end with a recess in which a depending switch actuating lug 140l is pivotally mounted in a manner to permit only forward pivotal movement. The limit switch 136 has two upwardly diverging arms 142 and, as shown in FIG. 5, one of the arms has been moved to its limit position by the lug 140. As alsor shown in broken lines in FIG. 5, the lug 1-40 will fold and ride idly over the other arm when moved in a reverse direction, leaving that arm to be actuated by the other dog on the chain. The positions of the arms 142 as shown in FIGS. l and 5, and also in the electrical diagram FIG. 4, are those immediately following the movement ofthe door to its down or closed position. The limit switch has two contacts 144 and 146 and is connected at 148 with a transformer 150i. As shown in FIGS. 4 and 5, the limit switch includes a single depending arm 143 disposed between and designed for alternate engagement with contacts 144 and 146. Contacts 144 and 146 are connected through a sequence relay 152, mounted in the relay box 115, with the reversing coils 154 and 156 (FIG. 4) of the motor 86. The switch 136 is on contact 144 but the relay switch is fopen and will not be closed until actuated by a push-button switch 158 connected in the circuit with the relay. The motor relay and push button switch may be of conventional types but the combination ofthe limit switch 136 and the actuating dogs 134 is of special construction for control of the motor and chain operation. 'Push button switches 158 (shown only schematically in FIG. 4) of the single 'plunger type are preferably used in connection with the relay 152.

As already mentioned, the door with its operating instrumentalities is shown in FIG. l as immediately after having been moved to its closed position. To open the door it is necessary to actuate one of the push button switches 158 which will close the open switch of the relay 152 thus activating reversing coil 156 of the motor 86, which will then rotate until the other dog actuates the upright arm 142 of the limit switch 136, thereby activating the relay and breaking the connection with reversing coil 156, which immediately stops the motor and the opening movement of the door, also setting the yrelay switch in position for the closing movement of the door'upon actuation of either one of push button switches 158, Wherever located. Also instead of push button switches, a radio relay 160 may be operated from a motor vehicle or other location.

If, in the opening or closing movement of the door, it should become stuck for any reason the friction clutch disks will permit free rotation of the reduced shaft portion 50 of the shaft section 44 while the sprocket remains stationary, thereby preventing breakage of parts of the mechanism or damage to the door. The. clamping force of the disks 90 against the sides of the sprocket may be adjusted by means of the nut 98 on `the end of the reduced section. The shaft sections 44 and 46 may also be instantly uncoupled Vb-y means of the lever 66.

From the foregoing description it will be seen that my friction drive assembly is of a fixed nature. To adjust the torque of the assembly the nut 98 is tightened to exert barely enough torque to lift the door 20. If the door should -be jammed, frozen by ice or by snow in the sprocket 88, the shaft will rotate through the sprocket 88 and not damage the door. To start the door in motion it is necessary only to press any one of the push buttons 158, which can be installed in various locations. If the door is stuck, frozen or jammed, or the power fails the two operating shafts 44 and 46 can be disengaged by pulling the lever 66, after which the whole assembly will float freely, and can be manually operated in a normal manner. To start the assembly in motion again the lever 66 is pushed in to engage the shafts 44 and 46. When the door is in motion, say on an opening cycle, it can be stopped in travel `anywhere in that cycle, but cannot be reversed until it has reached its full travel. The same applies on the closing cycle. When the door is fully closed it is locked and cannot be pried open from outside or inside.

Obviously, various modifications or changes may be made in my improved door operating mechanism. without `departing from the spirit and scope of my invention. Therefore, it should be understood that the embodiment of my invention shown and described is intended to be illustrative, only, and restricted only by the appended claim.

I claim:

In a mechanism for operating a hingedly sectional overhead opening door including a horizontal endless chain having its front end connected to said door and mounted on a sprocket supported above said door, said chain being mounted `at its rear end on another sprocket carried by a shaft journaled in a housing and geared to a reversible electric motor having its respective reversing coils connected in an electrical circuit with a relay; a twopoint electrical switch mounted on a support below the 1rear end of said chain and connected in said electrical circuit, said switch having a pair of horizontally spaced contacts connected through said relay with the reversing coils of said motor, said switch also having a rotatable member comprising a pair of horizontally spaced, upwardly projecting arms and a single depending contact arm, the latter being disposed between said pair of contacts for alternate engagement therewith; and a pair of 20 horizontally spaced depending and oppositely facing one- Way switch actuating dogs on said chain for alternately abutting and overriding engagement with the inner edges of said upwardly projecting arms for alternately shifting said Contact arm from one of said contacts to the other; said chain shaft being in two disengageable sections extending through an axial bore in a worm gear rotatably connected to the motor through a worrn on the motor shaft, the forward section of the shaft on which the sprocket is mounted being vrotatable but axially stationary and the rearward section being keyed to but axially shiftable within the bore of the worm gear and provided with means for axially shifting it into and out of engagement with the forward section of the shaft, said worm wheel having axially projecting hub portions journaled in bearings in the shaft housing independently of the bearings of the two shaft sections.

References Cited in the le of this patent UNITED STATES PATENTS 1,649,797 Winn Nov. 15, 1927 2,099,191 Blodgett NOV. 16, 1937 2,163,514 Farren June 20, 1939 2,262,719 Collins Nov. 11, 1941 2,589,480 Curtis Mar. 18, 1952 2,850,088 Purdy Sept. 2, 1958

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