WO1993000498A1

WO1993000498A1 - Limit switch for a rolling door

Info

Publication number: WO1993000498A1
Application number: PCT/CA1992/000261
Authority: WO
Inventors: Eddy Desrochers
Original assignee: Indoco 2000 Inc.
Priority date: 1991-06-20
Filing date: 1992-06-19
Publication date: 1993-01-07
Also published as: GB9113428D0; AU2147692A; CA2111839A1

Abstract

A limit switch for a rolling door assembly includes a disc (60) rotatably mounted for synchronized rotation with a take-up axle (16). The disc (60) has a face having a spiral groove (68) with a length proportional to the length of travel of a rolling door (10) between the open and closed positions. An arm (70) has one end pivotally mounted and has an opposite end frictionally engaging the groove (68) of the disc for pivotal movement between a first position corresponding to the open position of the door and a second position corresponding to the closed position of the door. A first relay (80) is operably connected to the drive and adapted to close when the arm is in the first position stopping the drive. A second relay (82) is operably connected to the drive and adapted to close when the arm is in the second position stopping the drive.

Description

LIMIT SWITCH FOR A ROLLING DOOR Field of Invention

This invention relates to a limit switch for controlling the limit of travel of a rolling door. Background of Invention

The use of rolling doors is well known. Rolling doors have been used extensively in industrial and mining applications.

In the prior art rolling doors, an electric motor is generally used to selectively drive a take-up barrel and a take-down barrel. An actuator selectively drives each barrel for opening and closing a rolling door. The door is rolled up on the take-up barrel to open the door opening. The door is unrolled from the take-up barrel and guided by the take-down barrel into guides extending about the sides of the door opening to close same.

Limit switches are used to control the travel of a rolling door. Prior art limit switches use a horizontal bolt with at least two nuts which are displaced therealong by the rotation of the bolt. As the two nuts engage contact switches, the progress of the door is stopped at either an open or closed condition.

However, such limit switches must be operably connected to the actuator by a further belt and pulley. As a result such systems are in constant need of adjustment due to belt slippage. Service personnel must climb ladders to access the belts and pulleys since such systems are required to be near the actuator which is usually overhead of the door opening. Further, head room is required for the installation of such systems. Rmrrmary of Invention

The disadvantages of the prior art may be overcome by providing a limit switch which is mounted on the take-up barrel axle for limiting the travel of the rolling door.

According to one aspect of the invention, a limit switch for a rolling door assembly is provided. The limit switch comprises a disc rotatably mounted for synchronized rotation with a take-up roller. The disc has a face having a spiral groove with a length proportional to the length of travel of a rolling door between the open and closed positions. An arm has one end pivotally mounted and has an opposite end frictionally engaging the groove of the disc for pivotal movement between a first position corresponding to the open position of the door and a second position corresponding to the closed position of the door. A first relay is operably connected to the drive and adapted to close when the arm is in the first position stopping the drive. A second relay is operably connected to the drive and adapted to close when the arm is in the second position stopping the drive. According to another aspect of the invention, a limit switch for a rolling door assembly is provided. The limit switch comprises a cylinder rotatably mounted for synchronized rotation with a drive. The cylinder has a circumferential surface having a thread with a length proportional to the length of travel of a rolling door between the open and closed positions. A first nut is threadingly mounted at a first position corresponding to the open position of the door and a second nut is threadingly mounted at a second position corresponding to the closed position of the door. A first relay is operably connected to the drive and adapted to close when the first nut is in the first position stopping the drive. A second relay is operably connected to the drive and adapted to close when the second nut is in the second position stopping the drive. A retaining plate is connected between the first and second nut fixing the distance therebetween. Brief Description of the Drawings

An embodiment of the invention is illustrated in the drawings, in which:

Figure 1 is a front elevational view of the roller door and limit switch according to the present invention; Figure 2 is a 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 side elevational view of the embodiment of Figure 1; Figure 4 is a partial front view of the selective clutch drive of the operator of the embodiment of Figure 1; Figure 5 is a plan view of the disc of the limit switch of the embodiment of Figure 1;

Figure 6 is a sectional view along the line VI-VI of the disc of the limit switch of the embodiment of Figure 1; Figure 7 is plan view of the limit switch of the embodiment of Figure 1; and

Figure 8 is a plan view of the limit switch of the second embodiment. Detailed Description of the Preferred Embodiment

As illustrated in Figure 1, the roller door consists of a door curtain 10 which can be rolled up, which is made preferably from a flexible material, and which can be unwound for closing a door opening 12. Above the door opening is mounted a take-up roller 14 connected to door curtain 10. Take-up roller 14 is rotatably mounted about take-up axle 16 for integral rotation therewith. On each side of the door opening 12 is a frame 18 for receiving the edge of door curtain 10. Frame 18 is fixed to the wall surface immediately adjacent to the door opening 12 presenting a channel 20 for receiving door curtain 10. Guide roller or idler roller 22 is mounted on idler axle 24 which is in turn mounted on frame 18 for rotation substantially perpendicular t the direction of the opening of the door curtain 10. Idler roller 22 guides door curtain 10 into the guide channels 20. At one end of idler axle 24, idler sprocket 26 is fixedly mounted thereon. Similarly at the end of take-up axle 16, take-up sprocket 28 is mounted thereon. Axles 16 and 24 are suitably mounted for rotation in bearings 17 and 25, respectively, mounted on each side frame 18.

Axles 16 and 24 upon being drivingly rotated by sprockets 28 and 26 respectively, will rotate idler roller 22 and take-up roller 14, respectively.

Operator or drive 29 generally comprises a selective clutch 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.

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. Mounted on each end of idler axle 24, between frame 18 and idler roller 22 is take-down sprocket 44 for engaging with take-down chain 46. Take-down chain 46 is mounted between base sprocket 48 and take-down sprocket 44. Dog 50 is connected to chain 46. The lower outer edge component 49 is connected between dog 50 and door curtain 10. Dog 50 is releasably connected to edge component 49 to permit emergency opening of the door curtain.

Disc 60 is illustrated in figure 1 as being mounted on take-up axle 16. However, it is noted that the disc could be mounted at either end of axle 16 or either end of axle 24 to achieve the desired results.

Disc 60 has a central hub 62 having an axially extending bore 64. Hub 62 has radially extending threaded bores for receiving bolts 66 for securing the disc onto an axle. One face of disc 60 has a single spiral groove 68.

Arm 70 is pivotally mounted onto frame 18 or some other suitably fixed surface by pivot pin 72 which is at one end of arm 70. At an opposite end region, pin 74 extends substantially perpendicular to arm 70 and is adapted to be inserted into groove 68 of disc 60 and travel therealong.

The remote end of arm 70 has two threaded bores extending substantially perpendicular to the swing of the arm. Threaded therein are bolts 76 and 78 having locking nuts threaded thereon. Bolt 76 and bolt 78 are threaded from opposite sides of arm 70.

Mounted on frame 18 or some other suitably fixed surface are contact relays 80 and 82. Relays 80 and 82 are mounted near the extreme swings of arm 70, i.e., when the arm is either at the beginning of groove 68 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 60.

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 74 travels along groove 68 the remote end of arm 74 swings proportionally, moving between the relays 80 and 82.

The bolts 76 and 78 are adjusted to trip the relay 80 and 82, respectively, when the door has reached the limits of its travel. Once the system has been set, the locking nuts 84 and 86 are tightened locking the bolts in their position.

Upon drivingly rotating take-up drive sprocket 36 will cause take-up chain 40 to drivingly rotate take-up sprocket 28. Take-up sprocket 28 will cause take-up axle 16 to rotate causing take-up roller 14 to rotate. Upon rotation of the take-up roller 14, door curtain 10 will be rolled up opening door opening 12.

Drive sprocket 38 will cause door curtain 10 to close while take-up drive sprocket 36 is disengaged from the drive allowing it to freely rotate. Since take-up drive sprocket 36 freely rotates, take-up roller 14 is free to rotate as the door curtain 10 advances downwardly to close door opening 12. conversely, when take-up drive sprocket 36 drivingly rotates take-up barrel 14, idler drive sprocket freely rotates permitting idler barrel 22 to freely rotate as door curtain 10 advances upwardly to open door opening 12.

As the disc 60 synchronously rotates as axle 16 rotates, arm 70 will swing causing the bolts 76 and 78 to move towards either relay 80 or relay 82. When relay 80 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 16 to rotate in the counter direction. Arm 70 will travel to the other relay until it is tripped de- energizing the motor 32 stopping the travel of the door.

Referring to Figure 8, a second embodiment of the limit of the present invention is illustrated. The limit switch of the second embodiment comprises a cylinder 90 having an external thread 92 thereon. Cylinder 90 is fixed to the end of shaft 16 by a key and keyway arrangement 104. However, any manner of attachment means would be suitable.

At one end of the thread, adjusting nut 99 is threadingly engaging the thread 92. At the opposite end of thread 92 is adjusting nut 98. The position of nut 99 corresponds to either the open or closed position of the rolling door 10. The nut 99 is adapted to engage contact switch 96, which is mounted on a suitably fixed surface which can mounted on frame 18. The position of nut 98 corresponds to opposite position of the rolling door 10 relative to nut 99. The nut 98 is adapted to engage contact switch 100, which is mounted on a suitably fixed surface such as frame 18.

A retaining plate 102 is a rectangular piece having a pair of slots for receiving nuts 99 and 98 at opposite end of the plate 102. Retaining plate 102 is slidably mounted on a suitably fixed surface such as frame 18. The distance between slots 106 and 108 and contact switches 96 and 100, respectively, is directly proportional to the travel distance of the door and the number of rotations required for the door to be fully opened or closed. To install, the axle 16 will be rotated such that door 10 will be in an open position. Adjusting nut 99 is advanced along thread 92 until it engages and just trips contact switch 96. Nut 99 is inserted and fixed in slot 106. Nut 98 is advanced along thread 92 to be inserted and fixed in slot 108.

In operation, the drive 32 is engaged and the door 10 begins to close. Axle 16 will rotate, causing cylinder 90 to rotate. Nut 99 is ganged to nut 98 and since retaining plate 102 is prevented from rotating, nut 99 and nut 98 will advance along thread 92 in unison. Nut 99 and nut 98 advance until nut 98 engages and trips contact switch 100 which disengages drive 32, stopping the advance of door 10 in a closed position.

In reverse operation, the drive 32 is re-engaged and the door 10 begins to open. Axle 16 will rotate, causing cylinder 90 to rotate. Nut 98 and nut 99 will advance along thread 92 in unison. Nut 98 and nut 99 advance until nut 99 engages and trips contact switch 96 which disengages drive 32, stopping the advance of door 10 in an open position.

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

Claims

I claim:

1. A limit switch for a rolling door assembly comprising a take-up roller (14) , a flexible door (10) adapted for winding onto and unwinding from the take-up roller for opening and closing said door, guide means (20) for guiding said flexible door from an open position to a closed position, drive means (29) for effecting travel of said door between said open and closed positions, said limit switch comprising, a disc (60) rotatably mounted for synchronized rotation with said take-up roller, said disc having a face having a spiral groove (68) thereon, said spiral groove having a length proportional to the length of travel of said door between the open and closed positions, and an arm (70) having one end pivotally mounted and an opposite end frictionally engaging the groove of said disc for pivotal movement between a first position corresponding to said open position of the door and a second position corresponding to said closed position of the door as said opposite end travels along said groove, a first relay (80) operably connected to said drive means and adapted to close when said arm is in said first position stopping said drive means, a second relay (82) operably connected to said drive means and adapted to close when said arm is in said second position stopping said drive means. whereby upon activation of said drive means said door travels until the door reaches either the open or closed position.

2. A limit switch as claimed in claim 1 wherein said rolling door assembly further comprises a frame (18) for mounting about a door opening (12) and said take-up roller (14) is rotatably mounted on said frame and above said door opening.

3. A limit switch as claimed in claim 2 wherein said disc is mounted on a common shaft (16) with said take-up roller (14) , said arm (70) is pivotally mounted to .said frame and extending substantially tangentially to said groove and said opposite end region of said arm is provided with a pin (74) extending substantially perpendicular to said arm for travelling along in said groove.

4. A limit switch as claimed in claim 3 wherein said arm has contact means (76, 78, 80) for contacting said first and second relay, said contact means lockably extensible for adjusting the location of said first and second positions.

5. A limit switch as claimed in claim 4 wherein said contact means comprises a first and second bolt (76, 78) having a locking nut (86) thereon and threadingly engaging said arm.

6. A limit switch as claimed in claim 2 wherein said guide means comprises a take-down roller (22) rotatably mounted on said frame (18) and operably connected to said drive means and means for driving the leading edge of said door to a closed position.

7. A limit switch as claimed in claim 6 wherein said disc is mounted on a common shaft (16) with said take-down roller, said arm is pivotally mounted to said frame and extending substantially tangentially to said groove and said opposite end region of said arm is provided with a pin (74) extending substantially perpendicular to said arm for presenting to said groove.

8. A limit switch as claimed in claim 7 wherein said arm has contact means (76, 78, 80) for contacting said first and second relay, said contact means lockably extensible for adjusting the location of said first and second positions.

9. A limit switch as claimed in claim 8 wherein said contact means comprises a first and second bolt (76, 78) having a locking nut (80) thereon and threadingly engaging said arm.

10. A limit switch for a rolling door assembly comprising a frame (18) for mounting about a door opening (12) , a take-up roller (14) rotatably mounted on said frame and above said door opening, a flexible door (10) adapted for winding onto and unwinding from the take-up roller for opening and closing said door, guide means (20) for guiding said flexible door between an open position and a closed position comprising a take-down roller (22) rotatably mounted on said frame and take-down means (42, 46, 48) operably connected to said take-down roller (22) for driving the leading edge of said door to a closed position, drive means (29) operably connected to said take-up roller and to said take-down roller for effecting travel of said door between said open and closed positions, said limit switch comprising, a disc (60) rotatably mounted for synchronized rotation with said take-up roller, said disc having a face having a spiral groove (68) thereon, said spiral groove having a length proportional to the length of travel of said door between the open and closed positions, and an arm (70) having one end pivotally mounted to said frame and an opposite end region frictionally engaging the groove of said disc for pivotal movement between a first position corresponding to said open position of the door and a second position corresponding to said closed position of the door as said opposite end region travels along said groove, said opposite end region of said arm having a pin (74) for travelling in said groove, a first relay (80) operably connected to said drive means and adapted to close when said arm is in said first position stopping said drive means, a second relay (82) operably connected to said drive means and adapted to close when said arm is in said second position stopping said drive means, contact means (76, 78, 80) mounted on said arm for contacting said first and second relay, said contact means lockably extensible for adjusting the location of said first and second positions, said contact means comprising a first and second bolt (76, 78) having a locking nut (80) thereon and threadingly engaging said arm, whereby upon activation of said drive means said door travels until the door reaches either the open or closed position.

11. A limit switch as claimed in claim 10 wherein said disc is mounted on a common shaft (16) with said take-up roller.

12. A limit switch as claimed in claim 10 wherein said disc is mounted on a common shaft with said take-down roller (24) .

13. A limit switch for a rolling door assembly comprising a take-up roller (14), a flexible door (10) adapted for winding onto and unwinding from the take-up roller for opening and closing said door, guide means (20) for guiding said flexible door from an open position to a closed position, drive means (29) for effecting travel of said door between said open and closed positions, said limit switch comprising, a cylinder (90) rotatably mounted for synchronized rotation with said take-up roller, said cylinder having an external thread (92) thereon, said thread having a length proportional to the length of travel of said door between the open and closed positions, and a first nut (99) threadingly engaging said cylinder at a first position corresponding to said open position of the door and a second nut (98) threadingly engaging said cylinder at a second position corresponding to said closed position of the door at an opposite end of said thread, a retaining plate (102) adapted to slide longitudinally of said cylinder and ganged to said first and second nut for rotation thereof in unison, a first relay (96) operably connected to said drive means and adapted to close when said nut is in said first position stopping said drive means, a second relay (100) operably connected to said drive means and adapted to close when said nut is in said second position stopping said drive means, whereby upon activation of said drive means said door travels until the door reaches either the open or closed position.