US 3336968 A
Description (OCR text may contain errors)
Aug. 22, 1967 A. CURTIS GARAGE DOOR WITH ANTI-JAMMING ROLLERS Filed March 29, 1965 5 Sheets-Sheet l ATTOP/Yfif g- 22, 19567 G. A CURTIS 3,336,968
GARAGE DOOR WITH ANTIJAMMING ROLLERS Filed March 29, 1965 5 Sheets-Sheet 5,:
Aug. 22, 1967 cu s 3,336,968
' GARAGE noon WITH ANTI-JAMMING ROLLERS Filed March 1965 5 Sheets-Sheet 5 I i Ar'raiA/x Aug. 22, 1967 ca. A. CURTIS I 3, ,968
GARAGE DOOR WITH ANTI-JAMMING ROLLERS Filed March 29, 1965 5 Sheets-Sheet 4 INVENTOR Gar 4. (027/5 ATTOE/VE'Y.
Aug. 22, 1967 I Filed March 29, 1965 G. A. CURTIS I 3,336,968
GARAGE DOOR WITH ANTI'JAMMING ROLLERS 5 Sheets-Sheet 5 94 i will Z 7. INVENTOR Gu A (yer/5 United States Patent 6,336,968 GARAGE DOOR WITH ANTLJAMMING ROLLERS Guy A. Curtis, 1042 Greyton Road, Cleveland Heights, Ohio 44112 Filed Mar. 29, 1965, Ser. No. 443,248 9 Claims. (Cl. 160-488) This invention relates to overhead articulated lift doors and openers therefor, and particularly to a reversible driving mechanism and the combination thereof with a new articulated lift door suspension by which positive and efiicient, but safe, opening and closing of the door are consistently obtained even under adverse weather conditions.
The reversible driving mechanism or opener of the present invention is an improvement on the reversible driving mechanism disclosed in my United States Letters 1 Patent No. 3,012,520, issued Dec. 12 1961. It employs an 'overload switch operating clutch which is an improvement on the general type of overhead clutch switch cutout disclosed in my United States Letters Patent No. 2,825,776, of Mar. 4, 1958.
Several difficulties encountered in connection with overhead articulated lift doors for garages, with which the present invention is concerned, are pointed out in my above Patent No. 3,012,520.
The present invention, while retaining the door operations and safety features therein disclosed, operates in a more positive and improved manner than prior structures. More specifically, the door opener has a positive mechanical drive, instead of a friction drive, yet one which can be released readily for manual operation in event of electric power failures. While maintaining a positive and rapid drive, it relieves and absorbs shocks heretofore imposed on such doors in overcoming their static inertia during starting and in opposing their dynamic inertia as they reach a fully open or fully closed position, or as they strike obstructions during their travel.
Another improvement resides in the manner of suspending the door on its tracks so that the raising and lowering forces can be applied at one end only without causing binding of the door, and so that jamming of the door due to ice and snow and the like on the tracks is greatly reduced or eliminated.
Another advantage resides in the overload clutch and cutout switch combination by which positive operation of the switch, with consequent safety, is obtained.
Other objects and advantages will become apparent from the following description, wherein reference is made to the drawings, in which:
FIGURE 1 is a right side elevation of an overhead articulated lift door in closed position, with its left side track and suspension, and its reversible driving mechanism or opener, the track and connections of the door therewith at the right edge of the door being omitted for clearness in illustration, and the opener and a fragment of the door when the door is in the raised position being indicated in dotted lines;
FIG. 2 is an enlarged side elevational view of the door operator shown in FIG. 1;
FIG. 3 is an inboard side elevation of the door operator shown in FIG. 2 and viewed as indicated by line 3-3 therein;
FIG. 4 is a diagrammatic reduced front elevation of the door and a portion of the tracks, showing the reactionary forces by which forces imposed on the door by the opener are resisted;
FIG. 5 is an enlarged fragmentary right side elevation of a portion of the door and its left side mounting rollers, the track being omitted for clearness in illustration;
FIG. 6 is a fragmentary rear view, partly in section, of the door and roller structure of FIG. 5, as viewed from line 66 in FIG. 1 and 5, a portion of the track being broken away for clearness in illustration;
FIGS. 7A and 7B are, respectively, enlarged fragmentary horizontal sectional views of a portion of the door and its left hand track, and is taken on line 7A-7A and 7B7B, respectively, in FIG. 6;
FIG. 8 is a wiring diagram showing the electrical control system for the door opener;
FIG. 9 is a fragmentary outboard side elevation of the door opener and overload clutch switch cutout, and is taken on line 9-9 in FIGURE 3, and shows the relative position of the parts of the overload clutch switch cutout ile the operator is driving the door into fully closed position and the clutch is slipping, immediately preparatory to tripping of the switch;
FIG. 10 is a view similar to FIG. 9 showing the position of the overload clutch switch cutout parts during normal rotation of the clutch While the door is between open and closed positions;
FIG. 11 is a view similar to FIGS. 9 and 10*, but showing the position of the overload clutch switch cutout parts when the operator is driving in the door opening direction, the reverse from FIG. 9, into fully open position, the clutch is slipping, and the switch is about to be tripped in the opposite direction from FIG. 9; and
FIG. 12 is a vertical fragmentary sectional view of the overload clutch switch cutout, and is taken on the lines 12-12 in FIG. 10, parts thereof being shown in elevation for clearness in illustration.
Referring to the drawings, the invention is shown as applied to an articulated door 1, having three upright horizontally elongated, articulated panels 1a, 1b, and 1c. The panels are hingedly connected together by the hinges 2. The door 1 is suspended and guided for lifting and lowering by tracks 3, arranged at opposite edges of the door, respectively. Since the two tracks are mirror images of each other, only one track and the door connections therewith is described herein in detail.
Referring to FIG. 1, the track 3 for the left side of the door is illustrated. This track 3 in FIG. 1, has an upright portion 3a, a curved portion 3b which extends from the top of the portion 3a rearwardly into a garageand which is concave downwardly and rearwardly, and which is connected at its rear end to a horizontal rear portion 30. The track 3 is adapted to lie along one vertical edge of the door opening and is supported in the upright position illustrated in FIG. 1, preferably by being secured to the garage or building structure.
Such a door must be suspended so as to be easily lifted and lowered without binding on the tracks due to any cantilever effect or to the forces imposed for lifting and lowering the door.
For example, as illustrated in FIG. 4, the door 1 may be from 8 to 15 feet Wide. Assuming the door is in lowered position, and the upward force indicated by the letter F is applied at the upper left corner for raising the door, a turning moment, indicated by the arrow M is imposed, tending to rock the door edgewise clockwise in FIG. 4. The moment M must be withstood by reactionary forces, indicated by arrows UR at the top and arrow LR at the bottom.
On the other hand, if a downward force indicated by the dotted arrow F is applied to the upper left corner, it produces a turning moment, indicated by the dotted arrow M which is relatively minor because the right end of the door is continuously urged downwardly by the door Weight.
To assure the application of these forces while eliminating binding of the door 1 in the tracks 3, the left hand edge of the door is provided with rollers 5, 6, 7, and 8. The rollers 5, 6, and 7 are arranged adjacent the tops of the panels 1a, 1b and 10, respectively. The bottom roller 8 is adjacent the bottom of the lowermost panel 1c.
All rollers are mounted on suitable brackets 9 which are secured to the door by suitable bolts 10. In the form illustrated, the rollers 5 and 8 are conventional rollers such as usually provided on such doors, and are alike in form and function. These conventional rollers generally are mounted on pivots, or have their pivots mounted, so that the rollers can migrate slightly axially to accommodate themselves to departures of portions of the track form in the normal track width or straightness.
The rollers 6 and 7 are duplicate dual rollers and are best illustrated in FIGS. 5 through 8 wherein the roller 7 is referred to in detail. The roller 7 comprises a rocker 12 on which separate rollers 13, respectively, are mounted with their axes in spaced relation endwise of the rocker 12. The rocker 12 is connected by a rock shaft 14 to its associated bracket 9, the shaft being held in fixed position axially by a collar 15 so that it can resist thrusts edgewise of the door. The axis of the shaft 14 is horizontal and lies in a plane parallel to its associated door panel. The rollers 13 are mounted on pintles 16, respectively, for rotation relative thereto and preferably in fixed position axially thereof. The pentiles 16 are secured to the rocker 12 in fixed axial position relative thereto. The pintles 16, and therefore, the axes of rotation of the rollers 13, lie in horizontal planes, respectively, but each is oblique to the axis of the shaft 14 for effecting the proper cooperation of its roller 13 with the track. With dual rollers 13, the rock shaft may or may not rock slightly about its axis as the dual rollers 13 and rocker 12 assure that the axes of the pintles 16 will retain their initial obliquity with respect to the axis of the shaft 14.
Referring to FIGS. 5 through 78, each track 3 has a front margin 17 and a rear margin 18, and is arranged so that it has at least two parallel track faces 20 and 21 spaced apart from each other edgewise of the door. For example, in the form illustrated in FIGS. 7A and 7B, the face 20 is outboard, edgewise of the door, and the face 21 is inboard, and both are on the rear margin 18. For purposes later to be described, the faces 20 and 21 ar shown as parts of a continuous surface curvilinear and concave toward the front margin 17. When these faces are at one margin of the track, as illustrated, the obliquity of the pintles 16 of the rollers 13 is such that one of the rollers 13 engages the outboard track face 20 and the other engages the inboard track face 21.
The upper roller 5 and the bottom roller 8 may be mounted on pintles 22, respectively, which are horizontal. The pintles 22 may be secured with their axes in a fixed oblique position also, and if so the obliquity of the bottom roller 8 is opposite from that of the upper roller 5, so that the roller 8 normally engages the outboard track face 20 and the roller 5 and the inboard track face 21. Thus it will be seen that since the inboard track face 21 faces generally away from the adjacent edge of the door, it provides the reactionary forces such as UR and conversely, the outboard track face 20 provides the reactionary forces such as LR The forces UR and LR thereby resist the moment M as the door is being raised by the force P of the opener. Corresponding rollers may be provided on the right edge of the door to resist the moment M in like manner, if desired. The rollers 6 and '7 cooperate for guided rolling movement of the door along the tracks. Due to the curvilinear continuous surface of the concave face of the margin 18, snow, ice, and contaminating foreign matter are easily dislodged. The rollers can selfadjust to irregularities in the faces 20 and 21 by slight movements edgewise of the door, and can relieve binding stresses.
The door 1 may be counterbalanced by the conventional spring 23 and cable 23a. One end of the cable is 4 connected to the bottom panel 1a of the door and the other end is anchored to the wall of the garage. One end of the spring 23 is anchored to the rear wall of the garage. A pulley 24 on the other end of the spring cooperated with the cable for applying the counterbalancing force of the spring to the door, as illustrated in FIG. 1.
In order to lift and lower the door thus suspended, a door opener 25 is provided. The door opener 25 comprises a body having a upright wall 25a, top wall 25b, and a bottom wall 250. The top wall is provided with an upwardly extending flange 26 which supports single rollers 27, which can ride slightly on the track portion 3b and along the entire length of the track portion 30 during operation of the door.
The rollers 27 are mounted on fixed pintle 28, respectively. The axes of the pintles 28 preferably lie in parallel vertical planes, and are oblique to the horizontal so that the rollers engage the inboard track face 21.
Mounted on the bottom wall 25c is an electric motor 31 which drives a reduction gear transmission 32, the output shaft 33 of which carries a sprocket 34. The sprocket 34, through a chain 35, drives a complementary larger sprocket 36 which is mounted on, and for co-rotation with, a shaft 37. Mounted on the shaft 37 is a carriage driving sprocket 38, sprocket 36, shaft 37 and driving sprocket 38 being connected for co-rotation in fixed relation to each other.
The sprocket 33 is in driving engagement with a chain 41 The chain 40 is secured alongside the track portions 3b and 3c by suitable anchor means. The anchor means comprise a bracket 41 secured to the rear end of the track portion. The bracket 41 has an aperture through which extends a rod 42. The forward end of the rod 42 is connected to the chain 40. A shock absorbing compression spring 43 is mounted on the rod 42 and at one end bears against the bracket 41 and at the other end against an adjustable nut 44.
The anchor means also includes at the forward end of the chain a bracket 45 having a flange portion 45a with an aperture therethrough, through which extends a rod 46. The rear end of the rod 46 is connected to the chain 41). The opposite end carries a nut 47 between which and the flange 45a is a shock absorbing spring 48. Thus the chain can be drawn to the tension required, assuring proper operation of the door and at the same time relieving the chain, door, and operator from undue shocks when the door opener 25 starts suddenly, or when the door strikes an obstruction or reaches the end of its travel either in rising or lowering.
The bracket 45 may be mounted on the usual backing strip of the track or on a suitable plate on the garage wall structure. It is preferably supported on a pivot 49 so that it can swing downwardly and permit the opener to move partway along the curved portion 37 of the trackway. The brackets 41 and 45 are preferably at an elevation so that the force applied by their springs to the chain urge it upwardly out of driving engagement with the sprocket 38.
To hold the chain 40 in positive driving engagement with the sprocket 38 against the force of the springs of the anchor means, a hold-down shoe 51 is provided. A rock lever 52 is connected by a pivot 53 to the carriage 25. The shoe 51 is connected to the lever 52 by a pivot 54 for rocking to self-adjusted position with respect to the chain 40. The opposite end of the lever 52 is pivotally connected to a depending latch arm 55 having notches 5o for engaging a suitable pin 57 on the carriage at different selected positions of the arm 55. A spring 58 normally urges the arm 55 is a direction for latching engagement with the pin 57. A chain or cord 59 is connected to the lower end of the arm 55 and hangs sufficiently below the carriage 25 so that it can readily be grasped by an operator standing on the floor of the garage and manipulated for releasing the shoe 51 from the chain in the event it is desired to move the door manually, as in case of a power failure. It is again noted .creased tension on the spring and .spring 43 or 48, as the case may .operator in either direction, the inertial forces imposed that the chain 40 is supported at its ends normally slightly above the level for proper engagement with the sprocket 38 so that if the shoe 51 is removed from the chain 40, then, due to force of the springs 44 and 48, the chain 40 is lifted slightly clear of the sprocket, so that it engages so lightly and near the outer ends of the sprocket teeth that the sprocket can readily slide past the chain by camming the chain 40 upwardly.
The carriage 25 is connected by a link 60 to a suitable bracket 61 on the door so that as the carriage moves from front to rear along the track portions 3b and 30, it can raise the door, and as the carriage moves from rear to front it can lower the door. By this arrangement a very positive and effective drive is provided. As hereinbefore described, the rollers 27 on the carriage 25 are capable of transferring a reactionary force, such as UR from the track in the outboard direction. The link 60 and its connection'with the door and carriage are made sufliciently strong to transmit the force UR to the upper left-hand corner of the door. Thus the rollers 27 are operatively connected to the top of the door, and can be considered as upper door rollers for the purpose of preventing cocking of the door on its tracks.
It is desirable that when the door approaches closely or reaches the end of its path of travel, or is stopped by some obstruction while it is being lowered or raised, that the electric power to the operator be shut off. Furthermore, it is desirable that adjustment be provided for stopping the door in the proper either raised or lowered positions. For this purpose, adjustable abutment elements 62 may be provided. These elements preferably are C- shaped and adapted to receive the chain 40 transversely through their open side and to be secured in fixed position thereon. For this purpose each element 62 is provided with sets of aligned apertures 63 and 64, through .which pins can be dropped to pass between the adjacent .pivot pins of the links of the chain, as illustrated in FIG- URE 2. The stop is fastened on the chain 40 in this manner in a position to be engaged by the adjacent edge of the carriage 25, as the carriage moves toward the end of the chain with which the particular element 62 is associated. When so engaged, the element stops the movement of the carriage abruptly relative to the chain, but the springs 44 and 48 absorb the shock.
It is noted that the set of apertures 63 and 64 are spaced apart a distance so that their pins 66 can pass through adjacent links of the chain. However, the apertures 63 are nearer one end of the element than the other set, and certain adjustment is provided in the stop position, depending upon which end of the element 62 is disposed toward the carriage 25. The spacing of thesets of apertures from the ends is preferably such that the apertures 63 are spaced from one end one-half the distance between the two sets of apertures, and the apertures 64 are spaced from the other end a distance equal to that between the sets of apertures. The adjustment can be effected readily, by moving the stop position one link in each direction, or by reversing its ends for moving the stop position a half link in either direction. It is apparent that when the carriage strikes the forward abutment element 62, and is stopped thereby, it imposes an ina shock thereon, which is relieved by the spring 43. When it strikes the rear abutment it imposes additional tension on the spring 48, which relieves the shock and then brings the door easily to the desired final position upon the restoration of the be. Upon starting the are also relieved by one or the other of the springs 43 and 48.
It is desirable, however, that power to the motor be -cut off promptly upon the carriage 25 striking either abutment, or upon the door being stopped by an obstruc- .tion. For this purpose, thecircuit illustrated in FIG. 8
is used for controlling the motor, and the switch of the circuit, in turn, is controlled by an overload clutch switch cutout, later to be described.
As illustrated in FIG. 8, the motor 31 is a reversible motor having a field 70 and an armature 71. The power source includes an extensible and contractible coiled electric cable comprising the lines L and L which are connected to external power lines. One terminal of the field is connected to the line L, and the other terminal to a lead line 73 which is connected to two terminals 74 and 75 of the reversing switch. The other line L is connected by a manual or relay operated double throw switch S to lines 76 and 77 having terminal contacts 78 and 79, respectively. The terminals of the armature are connected to the terminals 80 and 81, respectively, of the blades 82 and 83, respectively, of a double blade, double throw switch, indicated generally at 84.
It will be seen from FIGURE 8 that, assuming the switches S and 84 are in the positions indicated in solid lines, one terminal 71a of the armature 71 will be connected to the power source through the switch S, line 76, contact 78, and blade 82. The other terminal 71b of the armature 71 will be connected through blade 83 and line 73, into the source in series with the field 70. On the other hand, when the switch 84 is tripped by the cutout to the position shown in the dotted lines, the armature will be disconnected from the source until the switch S is tripped in the opposite direction to the dotted position. When the switch S is so tripped, the terminal 71b of the armature is connected in a reverse relation, through the switch S, line 77, and blade 83 and the terminal 71a is connected to contact 74 and line 73 to the field 70, thus reversing the armature and field and so reversing the motor.
In order to operate the switch 84, an overload clutch switch cutout such as described in my US. Letters Patent No. 2,825,776, is provided, the structure of that patent being modified to provide more positive action.
As mentioned, a sprocket 34 is mounted on, and for rotation with, the output shaft 33 of the speed reducer 32. This sprocket, in turn, drives the sprocket 38, which moves the carriage along the track. However, when the carriage reaches the end of its run, it necessarily prevents further rotation of the sprocket 38 and hence of the sprocket 36, which normally would stop the sprocket 34 and motor. An overload clutch connection is provided between the sprocket 34 and the shaft 33 normally for causing co-rotation of the sprocket and shaft, but relieving the sprocket 34 and shaft 33 from driving relation by stopping the carriage when the sprocket 34 is stopped.
The overload clutch switch cutout comprises a plate 85 having a hub 86 secured by a key 87' to the shaft 33 for co-rotation therewith. Mounted on the shaft for rotation relative thereto is a cup 88 which is connected by a suitable spline 89 to the hub of the sprocket 34 for co-rotation therewith. The cup 88 has a bottom wall 88a and a peripheral side wall 881). The outer end of the shaft 33 carries a wing nut 94) between which and the hub 86 of the plate 85 a compression spring 91 is disposed. The compression of the spring may be adjusted and the spring urges the plate 85 endwise of the shaft 33 toward the bottom of the cup 88. On the bottom wall 88a of the cup 88 is a friction brake lining 92 which engages the adjacent face of the plate 85 and provides a friction drive through the shaft 33 and plate 85 to the cup 88. This friction drive is adequate to drive the carriage 25 along the track through the sprocket 36 and chain 40. However, when the carriage 25 strikes one of the abutment elements 62, it is stopped and thereby stops the sprockets 38, 36, and 34 and the cup 88. This overloads the clutch so that the plate 85 is rotated relative to the cup 88 by the motor 31.
In order to trip the switch 84 at such time, a switch tripping device is mounted on the plate 85. In the form illustrated, this device comprises a shaft 93 rigid with the plate 85 and parallel to, and eccentric to, the axis of the shaft 33. A friction roller 94 is mounted on the shaft 93 for rotation relative thereto. A switch tripping device, including a disc 95, having a hub 95a, is also mounted on the shaft 93 for rotation relative thereto. A friction spring washer 96 is interposed between the end of the roller 94 and the disc 95 for providing a light frictional drive so that the two co-rotate together when free to rotate. It is apparent that upon stoppage of the cup 88 and continued rotation of the plate 85, the roller 94 rolls along the inside of the side Wall 8812 of the cup 88. The disc 95 has an inturned finger 97 which engages the side Wall 8812 of the cup and limits the rotation of the disc 85 in either direction of rotation about the axis of the shaft 93 after rotation of the disc through about 270 from either of its extreme positions.
Thus, referring to FIGURE 9, let it be assumed that the motor is driving the carriage in a forward direction, the clutch is slipping, and the switch 84 is about to be tripped. Due to rotation of the plate 85' relative to the cup 88 in the direction indicated by the arrow a, roller 94 rolls along inside of the side wall 88b of the cup in the direction indicated by the arrow 12. This rotation continues until the finger 97 strikes the inner wall 88b and'arrests further rotation of the disc 95. The roller may continue rotating, but the disc 95 will remain fixedly in position and restrained against further rotation in the direction indicated by the arrow b,,the spring washer 96 slipping so long as the disc 95 is thus restrained. The spring washer 96 is adequate to provide only a very light pressure for rotating the disc 95 when the disc is free and unrestrained otherwise.
Mounted on the disc 95 is a generally W-shaped semifloating trip finger 98 which is urged by a spring 99 against pins 100 on the disc 95. In FIGURE 9, one end 98a of the finger 98 is positioned to engage a lever 102 of the reversing switch 84 and throw it in a direction indicated by the arrow c. When the finger 98 engages the lever, the disc is constrained .by the finger 97 from continuing rotation in the direction indicated by the arrow b. Hence the finger 98 throws the switch lever 102 in the direction indicated by the arrow c. The final position in the direction indicated by the arrow must be such that the lever can be re-engaged upon reversal of the rotation of the plate 85, yet the finger 98 must pass the lever in the direction of the arrow c. For this purpose the spring 99 is provided, and permits the finger to snap past the end of the lever 102 and return into the path of the lever for operating the lever upon reversal of the rotation of the plate 85.
Upon reversal of the carriage 25', the plate 85 and cup 88 rotate together in a direction indicated in FIGURE by the arrow d. However, when moving in this direction, the same end of the finger 98 again strikes the end of the lever 102. Since the washer 96 affords little resistance to free rotation of the disc 95, as the finger 98 strikes the end of the lever 102, the disc 95 is rotated by the lever 102 to the position illustrated in FIGURE 10. The finger 97 thereby is moved away from the wall 88b, thus rendering the finger 98 inoperative to operate the lever 102.
Assuming, therefore, that the carriage continues rearwardly until it strikes the rear element 62, then, as illustrated in FIGURE 11, the plate 85 is caused to rotate, indicated by the arrow e, thus causing the roller 94 to rotate as indicated by the arrow 1. This rotation continues until the finger 97 strikes the interior of the wall 88b of the cup 88 and arrests further movement in the same direction. This disposes the other end of the finger 98 in position to strike the lever 102 and move it in the direction indicated by the arrow g, in FIG. 11. In this position it throws the switch to the reverse position from that in which it was operating.
Upon the next reversal, the finger 98 would again engage the lever 102 and thereby be caused to rotate the disc to an ineffective position, as described heretofore, so that the operation can be repeated in successive opposite directions.
It is apparent from the foregoing description that the door is well suspended so that it cannot jam on the track under the influence of lifting and lowering, but can move freely to raised and lowered position. Apositive drive is provided for lifting and lowering of the door by the operator and this positive drive is not reduced by wear and the like, as in the case of frictional drives.
Furthermore, complete safety against damage to the operator, track, or door is provided by means of the cutout switch. Severe jarring or jamming due to impacts and inertial forces are relieved by the shock absorbing springs which hold the chain in tensioned condition. By adjustment of the abutment elements along the chain, positions for throwing the reversing switch can be selected so that the door coasts to exactly the position without a sudden stop. Furthermore, even though the drive is positive, it can be released readily in the event of power failure so that the door can be raised and lowered by hand. This can be accomplished by an operator standing on the floor level and merely throwing the latch lever out.
Having thus described my invention, I claim:
1. An articulated lift door and support comprising a pair of spaced, parallel tracks, each track having a forward upright portion and a coplanar curved portion at the upper end thereof, the coplanar curved portion being concave rearwardly, an articulated door having articulated segments and having its margins adjacent the tracks, respectively, lower guide rollers mounted on the door near the bottom at its margins, respectively, upper guide rollers operatively connected to the door at the upper margins, respectively, said upper and lower guide rollers at each margin of the door being in rolling engagement with the track at the associated margin, each track having rail inboard and outboard faces extending lengthwise thereof, the out-board face facing generally inboard toward said one margin of the door and the inboard face facing generally outboard away from said one margin of the door, sets of dual upper and lower rocking rollers at the margins of the door arranged one set adjacent each juncture of adjacent articulated door segments at each margin of the door, each set comprising a rocker and an upper roller and a lower roller mounted on the rocker, pivot means connecting each rocker to its associated door segment for rocking about an axis extending horizontal and parallel to the plane of the door segment on which the rocker is mounted, and means connecting the upper and lower dual rollers of each set to their associated rocker with the axes of the rollers substantially horizontal and oblique to the normal plane of the associated segment of the door, the obliquity being related to the faces so that the lower dual rollers engage and roll along the track faces facing inboard and the upper rollers roll along the track faces facing outboard.
2. A structure according to claim 1 wherein each track has an extension extending rearwardly from the rear end of said curved portion, a single power driven carriage is provided and is mounted on one of said tracks for movement therealong, force transmitting means connects the carriage to the upper portion of the door adjacent said one track for lifting and lowering the door by the carriage as the carriage moves along the track.
3. A structure according to claim 2 wherein the upper guide rollers are on the carriage and the force transmitting means provides the operative connection of the upper guide rollers on the carriage with the door.
4. A structure according to claim 1 wherein said faces of each track are divergent from each other in a direction forwardly and rearwardly of the associated track.
5. A structure according to claim 1 wherein said faces of each track are areas of a continuous curvilinear surface at one margin of the track and which surface is concave toward the opposite margin.
6. A structure according to claim 1 wherein the rockers are constrained from movement relative to the door axially of their pivot means.
7. A structure according to claim 6 wherein the dual rollers of each rocker are constrained from axial movement relative to their associated rocker.
8. A structure according to claim 1 wherein the upper guide rollers and lower guide rollers are movable axially relative to the door.
9. A structure according to claim 1 wherein each track has front and rear margins, said track faces of each track are at the same margin of the track, the axes of the lower guide rollers are oblique relative to a plane parallel to the normal plane of the door, the axes of the upper guide rollers are oblique to said plane in the 10 opposite direction from the axes of the lower guide rollers.
References Cited UNITED STATES PATENTS 1,817,909 8/1931 Blodgett 160189 1,848,311 3/1932 Brower 49-199 2,825,776 3/1958 Curtis 20061.46 2,846,534 8/1958 Morrill 200-61.46 X 2,925,267 2/1960 Volf 160-188 3,012,520 12/1961 Curtis 49-199 X 3,066,729 12/1962 Gessell 160-193 DAVID J. WILLIAMOWSKY, Primary Examiner. HARRISON R. MOSELEY, Examiner. P. M. CAUN, Assistant Examiner.