WO1993016262A1

WO1993016262A1 - High speed overhead sectional door assembly

Info

Publication number: WO1993016262A1
Application number: PCT/CA1993/000060
Authority: WO
Inventors: Eddy Desrochers
Original assignee: Indoco 2000 Inc.
Priority date: 1992-02-17
Filing date: 1993-02-17
Publication date: 1993-08-19
Also published as: AU3488793A; GB9203328D0; CA2130358A1

Abstract

An overhead door assembly for opening and closing a door opening comprises a plurality of door sections (10) having hinges (12) for hingedly joining the door sections (10) together. A pivot (26) on an upper end region of each door section (10) pivotally connects a tandem arm (28). Each tandem arm (28) has at opposite ends thereof a rotatably mounted roller (20). A lowermost door section has a roller (21) rotatably mounted at the lowermost region of the door section. Two lead arms (29) each have a first end pivotally connected to the pivot (26) of the uppermost door section and an opposite end having a rotatably mounted roller (25). An axle (14) is rotatably mounted above the door opening (22) and having springs (16) for urging the axle (14) to rotate in opposite senses. Drums (15) are fixedly mounted on the axle (14) and aligned with each side of the door opening (22). Two cables (19), each extend from the lowermost door section about the drum (15) and extending to the opposite end of the lead arm (29). Two guides (24) extend upwardly along each side of the door opening (22) for guiding the door sections (10) as the door travels to open and close the door opening (22). A motor (32) drives the axle (14) in one sense tensioning the cable (19) extending from the lowermost door section for opening the door and for driving the axle (14) in an opposite sense tensioning the cable (19) extending at the opposite end of the lead arm (29) for closing the door.

Description

HIGH SPEED OVERHEAD SECTIONAL DOOR ASSEMBLY Field of Invention

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This invention relates to overhead sectional doors and in particular to a overhead sectional door assembly capable of opening and closing at a relatively high

5 rate. Background of Invention

In the prior art, overhead sectional doors, one electric motor is generally used to drive a drum cable system or gear system to open and close the door. The prior art devices have many precision components which are not only bulky but have a high

10 inertia which limits the speed at which the doors may be opened and closed.

The overhead sectional doors of the type contemplated by the present invention usually have relatively large enough door openings to allow trucks, vans, automobiles, forklifts and the like to pass therethrough. When the doors are open, a significant amount of air, either heated air or cooled air, may pass through the opening

15 with the amount of air lost being proportional to the time which the door is kept open. The cost of heating or cooling the air which is lost out the door can be significant. Therefore if the door opening and closing time were kept to a minimum, cost savings would be experienced in terms of energy costs, improved traffic flow of vehicles and reduced incidents of accidental collisions with the door.

20 At present, door opening speeds are usually limited to about 15 cm per second (6 inches per second). If prior art doors are operated at higher speeds, the doors experience increased stresses due to increased momentum which tend to overly compress the sections during acceleration due to inertia and tear the sections apart during deceleration due to momentum. Summary of Invention

The disadvantages of the prior art may be overcome by providing a high speed door assembly capable of operating at high rates of opening and closing speeds to reduce the time which the door opening is left exposed. In particular, the invention provides a door mounting assembly which permits the sectional door panels to pivot and thereby travel at a high rate of speed.

According to one aspect of the invention, there is provided an overhead door assembly for opening and closing a door opening. The assembly comprises a plurality of door sections adapted to close the door opening, the door sections having hinges for hingedly joining the door sections together, each of the door sections having a pivot for pivotally connecting a tandem arm at an upper end region thereof, the tandem arms pivotally mounted at a mid-point thereof, a lowermost door section having a roller rotatably mounted at the lowermost region of the door section, each tandem arm having at opposite ends thereof a rotatably mounted roller; a lead arm having a first end pivotally connected to the pivot of the uppermost door section and an opposite end having a rotatably mounted roller; an axle rotatably mounted above the door opening and having two biasing means for urging the axle to rotate in opposite senses; two drums having a grooved drum surface and fixedly mounted on the axle, each mounted to align with each side of the door opening; two cable extending from the lowermost door section wrapped at least four times about the drum and extending to the opposite end of the lead arm, each of the two cables having biasing means for tensioning the cables; a guide means extending upwardly along each side of the door opening for guiding the door sections as the door travels to open and close the door opening, the guide means comprising two rails, each adapted to receive the rollers, one mounted on each side of the door opening, the rails have a first section for positioning the door for closing the door opening and a second section for storing the door when the door opening is open; the rail, drum and cable on each side of the door opening are substantially in alignment; an electric motor operable connected to a selective drive clutch for selectively transmitting driving forces to the axle; a limit switch mounted on the axle and adapted to de-energize the electric motor when the door is fully open or fully closed; whereby as the axle is driven in one sense, the cable portion extending from the lowermost door section is tensioned opening the door and as the axle is driven in an opposite sense, the cable portion extending from the opposite end of the lead arm is tensioned closing the door. Description of the Drawings

An embodiment of the invention is illustrated in the drawings, in which: Figure 1 is a front elevational view of a sectional overhead door according to the preferred embodiment; Figure 2 is a top sectional view along the line I-I of the embodiment of

Figure 1 illustrating the door within the side channels; Figure 3 is a partial front elevational view of the embodiment of Figure 1 illustrating the tandem arms; Figure 4 is a side elevational view of the frame of the embodiment of

Figure 1; Figure 5 is a view of the selective clutch drive of the operator of the embodiment of Figure 1;

Figure 6 is sectional view of a sprocket of the operator of the embodiment of Figure 5; Figure 7 is a sectional view of the screw hub of the operator of the embodiment of Figure 5; Figure 8 is a plan view of the clutch shaft of the operator of the embodiment of Figure 5; Figure 9 is sectional view of a friction disc of the operator of the embodiment of Figure 5; Figure 10 is sectional view of a thrust bearing of the operator of the embodiment of Figure 5;

Figure 11 is sectional view of a collar of the operator of the embodiment of

Figure 5; Figure 12 is a plan view of the disc of the limit switch of the embodiment of

Figure 1;

Figure 13 is a sectional view along the line VI- VI of the disc of the limit switch of the embodiment of Figure 12;

5 Figure 14 is a plan view of the limit switch of the embodiment of Figure 12.

Figures

15 and 16 is a plan view showing the horizontal seres on the limit switch.

Figure 17 is a plan view showing the disc or screw attached to the main shaft.

Detailed Description of the Preferred Embodiment

10 As illustrated in Figure 1, the sectional door consists of a sections 10 which are hinged together by hinges 12. Above the door opening is mounted an axle 14 connected having torsional springs 16 mounted thereon and adapted for assisting axle 14 to rotate. Axle 14 is rotatably mounted above the door.

On each side of the door opening 22 is a frame 18 for receiving the rollers

15 20 of door sections 10. Frame 18 is fixed to the wall surface immediately adjacent to the door opening 22 presenting a channel 24 for receiving rollers 20. Cable drums 15 are fixed to axle 14 to rotate therewith and are positioned above each side of frame 18. Cable drums 15 preferably have a ribbed drum surface for spacing the cable as it is wound or unwound therefrom.

20 Each of the outer hinges 12 has a transversely extending bore to receive pin 26 which extends beyond each end of hinge 12. The inner end is prevented from slipping out by a cotter pin or the like. Pivotally connected at the outer end of pin 26 is tandem arm 28 at the mid-point thereof. At each end of tandem arm 28, rollers 20 are rotatable mounted.

Referring to Figure 4, frame 18 is a conventional frame for sectional doors which extends from the floor and hung from the ceiling of the structure. The angle between the vertical section and the horizontal section is can vary between 10 to 90 degrees depending on where the door is stored in the open position, either vertically against the wall or horizontally as illustrated. The distance of the hinge pivot to the door section increases proportionately such that when the door is in a closed position, the door is substantially vertical. At the leading edge of the door, roller 21 is rotatably mounted by bracket

23. On each side of the door cable 19 is attached. Cable 19 extends from the leading edge upwardly about drum 15 approximately four times and then horizontally to roller 25. Preferably, cable 19 is connected to roller 25 by a torsion spring 27 to maintain tension on the cable at all times. Pivotally extending between the uppermost hinge 12 at the pivot with tandem arm 28 and roller 25 on the horizontal section of the frame 18 is lead arm 29.

The operator used to drive the door of the preferred embodiment generally comprises a selective clutch drive 30 and a drive motor 32. Drive motor 32 is mounted at a convenient location and operable to rotate clutch shaft 34. Clutch 30 is mounted on clutch shaft 34 and has take-up drive sprocket 36 and idler drive sprocket 38. Axle 14 upon being drivenly rotated by sprockets 28 and 26 will be rotated either to close or open the door, respectively.

Take-up chain 40 extends about take-up drive sprocket 36 and take-up sprocket 28 presenting an endless chain. Similarly, idler chain 42 extends about idler drive sprocket 38 and idler sprocket 26 presenting an endless chain. Clutch 30 generally comprises retaining ring 52, collar 54, thrust bearing 56, sprockets 36 and 38, friction disc 58 and screw hub 60, all mounted on clutch shaft 34. As illustrated in Figure 4, clutch 30 has screw hub 60 mounted at the axial mid- length of clutch shaft 34 and axially therefrom has equivalent components on each side thereof.

As illustrated in Figure 8, clutch shaft 34 has two circumferential bearing surfaces 62 and 64 on opposite sides of external thread 66. At each end of clutch shaft 34, ring groove 68 extends circumferentially about the shaft and below the surface of bearing surfaces 62 and 64. A central bore 70 extends axially of clutch shaft 34. One end of the central bore 70 is counter-bored presenting a larger diameter bore 72. Along the length of central bore 70, keyway 74 extends axially from one end of the clutch shaft 34 to the counter-bore 72. At the end of clutch shaft 34 opposite counter-bore 72, a pair of tapped bores 76 spaced at right angles to each other extend radially through bearing surface 74 to central bore 70. Screw hub 60 has a central hub 78 having an internally tapped bore 80 extending axially thereof. The screw thread of bore 80 is complementary with external thread 66 of clutch shaft 34. Preferably, the threads can be one of any known threading suitable for power transmission.

Extending from opposite ends of hub 78 are flanges 82 presenting a substantially planar frictional surface 84. The inside corner between flange 82 and hub 78 is illustrated as having a weld 86. However, hub 78 and flanges 82 can be manufactured as an integral unit.

Sprocket 36 has an axially extending central bore 88 having at each end of the bore a counter-bore 90. Bearing 92 is placed within counter-bore 90 to present a circumferentially extending inside bearing surface. Sprocket teeth 94 extend radially at one end of take-up drive sprocket 36. Flange 96 extends from the end opposite teeth 94. However, sprocket 36 and flange 96 can be manufactured as an integral unit. Idler drive sprocket 38 is identical to the construction of take-up drive sprocket 36 although the number of teeth may vary depending on the ratios and speed desired.

Collar 54 comprises a ring having a central bore 98 extending axially therethrough. Extending into one of the axial surfaces of collar 54 is a plurality of bores 100 having a diameter to receive compression springs 99 therein. Compression springs 99 may be replaced by spring discs where loads warrant such change.

Thrust bearing 56 comprises a pair of thrust washers 102. Sandwiched between the thrust washers 102 is a thrust assembly 104 having bearing material 106 extending circumferentially on each face of thrust assembly 104. Each thrust washer and thrust assembly has an axially extending circular opening. Friction disc 58 comprises a ring of clutch or brake material having a central circular opening 108. Depending on the desired loads, friction disc 58 could comprise two rings of clutch or brake material sandwiched between a metallic ring.

Drive motor 32 has a motor shaft (not illustrated). The motor shaft will

5 have a diameter complementary to the internal bore 70 and counter-bore 72 of clutch shaft 34. Along the narrower diameter portion of the shaft, the motor shaft has a keyway complementary to keyway 74. Drive motor 32 is of the type operable to drive shaft in either rotation or counter-rotation direction.

To assemble, screw hub 60 is screwingly engaged with the external thread 10 66 of clutch shaft 34 until its rests at substantially the midway point of the length of the shaft. Friction disc 58 is mounted onto clutch shaft 34. One friction disc is mounted on each side of screw hub 60. Idler drive sprocket 38 is mounted onto shaft 34 until flange 96 abuts with friction disc 58. Similarly, take-up drive sprocket 36 is mounted onto shaft 34 from an end opposite that of idler drive sprocket 38. As is apparent, screw hub 60 15 will be sandwiched between take-up drive sprocket 36 and idler drive sprocket 38. A thrust bearing 56 is mounted on each end of clutch shaft 34 until it abuts with sprocket 36 and 38 respectively.

Compression springs 99 are inserted into bores 100 of collar 54. Collar

54 is then mounted onto the shaft 34 until the face having bores 100 abuts with the

20 thrust bearing 56 nearest the idler drive sprocket 38. Retaining ring 52 is an applied about the shaft 34 until it rests within ring groove 68 presenting an abutment surface preventing collar 34 from sliding off shaft 34. Compression springs 99 bias the thrust bearing 56 towards the idler drive sprocket 38.

The partially assembled clutch 30 is then mounted onto the motor shaft.

Key 112 is applied to the keyway 74 until fully registered therein. Hex bolts 114 are screwingly engaged into tapped bores 76 of clutch shaft 34 until the heads of hex bolts

114 rest below the surface of bearing surface 64 and retain the clutch shaft 34 onto the motor shaft.

A second collar 54 having compression springs 99 inserted within bores

100 is applied to over the end of shaft 34 until it abuts with thrust bearing 56. A second retaining ring 52 is applied to retaining ring groove 68 fully securing collar 54 onto shaft

34. Compression springs 99 bias the thrust bearing 56 towards the take-up drive sprocket 36.

The distance between ring grooves 68 at each end of the shaft 34 must be such that when clutch 30 is fully assembled, screw hub 60 is able to move axially relative to sprockets 36 and 38. When screw hub 60 is closer to sprocket 36 than sprocket 38, sprocket 38 is able to freely rotate. Equally, when screw hub 60 is closer to sprocket

38 than sprocket 36, sprocket 36 is able to freely rotate.

Upon rotation of shaft 34, screw hub 60 will advance along the external thread 66, causing screw hub 60 to move relatively closer to sprocket 36. Upon further advancement of screw hub 60 along shaft 34 towards sprocket 36, the frictional forces between friction disc 58 and screw hub 60 and sprocket 36 will increase up to a point where screw hub 60 and sprocket 36 will rotate together with rotation of screw shaft 34. Upon counter rotation of the shaft 34, screw hub 60 will retract along the external thread 66 and become disengaged from sprocket 36. Screw hub 60 will continue to detract and move relatively closer to sprocket 38 than sprocket 36 until the frictional forces between screw hub 60 and frictional disc 58 and frictional disc 58 and

5 sprocket 38 increase until screw hub 60 and sprocket 38 rotate together with shaft 34.

When screw hub 60 is rotating together with either sprocket 36 or 38, the opposite sprocket is permitted to freely rotate about the shaft 34.

The limit switch 17 which controls the travel of the door is mounted directly onto axle 14. Limit switch 17 generally comprises a disc 260 has a central hub

10 262 having an axially extending bore 264. Hub 262 has radially extending threaded bores for receiving bolts 266 for securing the disc onto the end of axle 14. One face of disc 260 has a single spirally groove 268.

Arm 270 is pivotally mounted onto frame 18 or some other suitably fixed surface by pivot pin 272 which is at one end of arm 270. At an opposite end region, pin 15 274 extends substantially perpendicular to arm 270 and is adapted to be inserted into groove 268 of disc 260 and travel therealong.

The remote end of arm 270 has two threaded bores extending substantially perpendicular to the swing of the arm. Threaded therein are bolts 276 and 278 having locking nuts threaded thereon. Bolt 276 and bolt 278 are threaded from opposite sides 20 of arm 270.

Mounted on frame 18 or some other suitably fixed surface are contact relays 280 and 282. Relays 280 and 282 are mounted near the extreme swings of arm 270, i.e., when the arm is either at the beginning of groove 268 or at the end thereof, which corresponds with either the closed position of the door or the open position of the door depending on the rotation of disc 260.

The action of the limit switch is not unlike that of a phonograph needle running in the groove of a phonographic record. As the pin 274 travels along groove 268 the remote end of arm 274 swings proportionally, moving between the relays 280 and 282.

The bolts 276 and 278 are adjusted to trip the relay 280 and 282, respectively, when the door has reached the limits of its travel. Once the system has been set, the locking nuts 284 and 286 are tightened locking the bolts in their position.

As the disc 260 synchronously rotates as axle 14 rotates, arm 270 will swing causing the bolts 276 and 278 to move towards either relay 280 or relay 282. When relay 280 is tripped, the electrical energy to motor 32 is terminated stopping the travel of the door. Upon re-energizing the motor, the motor will turn in the opposite direction causing axle 14 to rotate in the counter direction. Arm 270 will travel to the other relay until it is tripped de-energizing the motor 32 stopping the travel of the door.

In operation, the motor 32 is energized drivingly rotating idler chain 42 rotating idler sprocket 26 and in turn causes axle 14 to rotate. Drum 15 will wind cable 19 from the vertical section pulling upwardly on the leading edge of door opening the door and unwind at the opposite side. Rollers 20 will travel upwardly in channels 24 until the door is fully in the horizontal section and the limit switch 17 de-energizes motor 32. Re-energizing motor 32 is the opposite rotation will drivingly rotate take- up chain 40 to drivingly rotate axle 14 in the counter direction. Drum 15 will wind cable

19 from the horizontal section pulling the trailing edge of the door closing the door and unwind cable at the opposite side. Drum 15 will rotate until de-energized by the limit switch when the door is fully closed.

The unique arrangement of the lead arm 29 and tandem arms decreases the apparent radius of the track 24 thereby decreasing the inertial effects of the door during high speed opening and closing. Further, the invention increases the number of rollers carrying the load of the door reducing the per unit load on the rollers improving the speed capabilities of the door.

The unique cable arrangement also increases the speed of operation of the door. First, when the limit switch 17 stops the motor 32 as the door approaches a fully open position, drum 15 ceases to turn and the cable pulls on the spring loaded trailing edge slowing and smoothly stopping the door in the fully open position thereby reducing the stresses on the door. Second, the spring maintains tension on the cable at all times preventing the cable from jumping from the grooved drum surface which is common during high speed cable winding. Third, since the cable is in tension, a compressive force is maintained on the panels 12 of the sectional door thereby reducing the stress off the hinges allowing the door to operate as a unit rather than individual sections.

The limit switch 17 is directly mounted onto axle 14 which prevents the switch from becoming asynchronous with the opening and closing of the door. If the travel of the door is interrupted for any reason, the travel of the limit switch is interrupted at the same rate. For instance, if a vehicle is caught in the closing of the door, the door will stop advancing stopping axle 14. When the vehicle is removed and the door closed, the hmit switch 14 is still synchronous with the travel of the door. If a timing belt were used, the belt may slip as the door travel is interrupted causing the timing of the systems to be disrupted.

In the preferred embodiment, the door can be safely operated at speeds up to 90 cm per second (36 inches per second). However, the ratio of either sprockets 26 and 28 can been reduced to close the door at 76 cm per second (30 inches per second).

Clutch 30 also acts as a brake when the operator is not in operation. As motor 32 is de-energized, clutch 30 stops acting as a clutch and acts as a brake stopping the door curtain 10 and maintaining the door curtain 10 where it was stopped. Further, the closing of the door can be safely stopped by an ordinary person as only 40 lbs force is required to disengage the drive.

It will be obvious to those skilled in the art that various modifications and changes can be made to the operating system without departing from the spirit and scope of this invention.

Claims

I claim:

1. An overhead door assembly for opening and closing a door opening, said assembly comprising, a plurality of door sections adapted to close said door opening, said door sections having hinges for hingedly joining the door sections together, each end of each of said door sections having, at an upper end region thereof, a pivot for pivotally connecting a tandem arm, each tandem arm having at opposite ends thereof a rotatably mounted roller, a lowermost door section having a roller rotatably mounted at the lowermost region of said door section; two lead arms, each having a first end pivotally connected to the pivot of said uppermost door section and an opposite end having a rotatably mounted roller; an axle rotatably mounted above the door opening and having biasing means for urging said axle to rotate, two drum means, each fixedly mounted on said axle and aligned with each side of said door opening, two cable means, each extending from the lowermost door section about said drum means and extending to said opposite end of said lead arm, said cable means having biasing means for tensioning said cable means, two guide means extending upwardly along each side of said door opening for guiding said door sections as said door travels to open and close said door opening, said guide means adapted to receive said rollers for rolling therein; a drive means for driving said axle in one sense tensioning said cable means extending from the lowermost door section for opening said door and for driving said axle in an opposite sense tensioning said cable means extending at said opposite end of said lead arm for closing said door.

2. An overhead door assembly as claimed in claim 1 wherein each of said guide means, drum means and cable means are substantially in alignment along each side of said door opening.

3. An overhead door assembly as claimed in claim 2 wherein said cable means is wrapped at least four times about said drum means.

4. An overhead door assembly as claimed in claim 3 wherein said rails have a first section for positioning said door for closing said door opening and a second section for storing said door when said door opening is open.

5. An overhead door assembly as claimed in claim 4 wherein said first section of said rails is between 10° and 90° relative to said second section.

6. An overhead door assembly as claimed in claim 5 wherein said door sections are provided with mounts for pivotally receiving said tandem arms.

7. An overhead door assembly as claimed in claim 1 wherein said tandem arms are pivotally mounted at a mid-point thereof.

8. An overhead door assembly as claimed in claim 1 wherein said two drums have a grooved drum surface.

9. An overhead door assembly as claimed in claim 1 wherein said drive means is an electric motor operable connected to a selective drive clutch for selectively transmitting driving forces to said axle.

10. An overhead door assembly as claimed in claim 9 wherein said axle is provided with a limit switch adapted to de-energize said electric motor when the door is fully open or fully closed.

11. An overhead door assembly for opening and closing a door opening, said assembly comprising, a plurality of door sections adapted to close said door opening, said door sections having hinges for hingedly joining the door sections together, each of said door sections having a pivot for pivotally connecting a tandem arm at an upper end region thereof, said tandem arms pivotally mounted at a mid-point thereof, a lowermost door section having a roller rotatably mounted at the lowermost region of said door section, each tandem arm having at opposite ends thereof a rotatably mounted roller; a lead arm having a first end pivotally connected to the pivot of said uppermost door section and an opposite end having a rotatably mounted roller; an axle rotatably mounted above the door opening and having two biasing means for urging said axle to rotate in opposite senses, two drums having a grooved drum surface and fixedly mounted on said axle, each mounted to align with each side of said door opening, two cable extending from the lowermost door section wrapped at least four times about said drum and extending to said opposite end of said lead arm, each of said two cables having biasing means for tensioning said cables, a guide means extending upwardly along each side of said door opening for guiding said door sections as said door travels to open and close said door opening, said guide means comprising two rails, each adapted to receive said rollers, one mounted on each side of said door opening, said rails have a first section for positioning said door for closing said door opening and a second section for storing said door when said door opening is open; said rail, drum and cable on each side of said door opening are substantially in alignment; an electric motor operable connected to a selective drive clutch for selectively transmitting driving forces to said axle, a hmit switch mounted on said axle and adapted to de-energize said electric motor when the door is fully open or fully closed, whereby as said axle is driven in one sense said cable extending from the lowermost door section is tensioned opening said door and as said axle is driven in an opposite sense said cable extending from said opposite end of said lead arm is tensioned closing said door.

12. An overhead door assembly as claimed in claim 11 wherein said first section of said rails is between 10° and 90° relative to said second section.