LIMIT POSITION SAFETY DEVICE FOR A ROLLING DOOR

Abstract

A limit position safety device for establishing upper and lower limit positions of a rolling door that can be raised when rolled onto a generally horizontal shaft when the shaft rotates in a first direction and lowered when the shaft rotates in an opposing direction. The device includes two electrical limit switches each actuatable to reflect when an associated limit position of the rolling door has been reached. Actuators are movable to selectively actuate one of the limit switches at associated upper or lower limit positions of the rolling door. Drive gear are directly coupled to the shaft for moving the actuators in response to movements of the rolling door horizontal shaft. Accordingly, the direct drive gears always provide a direct physical connection or link between the rolling door shaft and the actuators to provide reliable indications of the position of the rolling door.

Claims

1. A limit position safety device for establishing upper and lower limit positions of a rolling door that can be raised when rolled onto a generally horizontal shaft when the shaft rotates in a first direction and lowered when the shaft rotates in an opposing direction, said device comprising two electrical limit switches each actuatable to reflect when an associated limit position of the rolling door has been reached; actuators movable to selectively actuate one of the limit switches at associated upper or lower limit positions of the rolling door; and direct drive gear means coupled to the horizontal shaft for moving said actuators in response to movements of the rolling door horizontal shaft, whereby said direct drive gear means always provides a direct physical connection or link between the rolling door shaft and said actuators to provide reliable indications of the position of the rolling door.

2. A safety device as defined in claim 1, further comprising a fire door operator; a limit position safety device for establishing upper and lower limit positions of a rolling door that can be raised when rolled onto a generally horizontal shaft when the shaft rotates in a first direction and lowered when the shaft rotates in an opposing direction, said device comprising two electrical limit switches each actuatable to reflect when an associated limit position of the rolling door has been reached; actuators movable to selectively actuate one of the limit switches at associated upper or lower limit positions of the rolling door; and direct drive gear means coupled to the horizontal shaft for moving said actuators in response to movements of the rolling door horizontal shaft, whereby said direct drive gear means always provides a direct physical connection or link between the rolling door shaft and said actuators to provide reliable indications of the position of the rolling door.

3. A safety device as defined in claim 2, wherein said fire door operator includes a substantially enclosed housing and said device is mounted on the exterior of said housing.

4. A safety device as defined in claim 3, wherein said limit switches are coupled to said horizontal shaft by a gear set composed of a plurality of meshed gears.

5. A safety device as defined in claim 4, wherein said gear set includes at least one gear extending through an opening in said housing.

6. A safety device as defined in claim 1, wherein said actuators are threadedly mounted on an externally threaded travel bar or work shaft, whereby rotations of said direct drive gear means are translated to linear movements of said actuators.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following descriptions are in reference to the accompanying drawings in which the same or similar parts are referenced by the same numerals throughout the several drawings, and wherein:

[0021] FIG. 1 is a side elevational view of one embodiment of the present invention illustrating a hand operated chain assembly to manually operate the operator to raise and lower a rolling door;

[0022] FIG. 2 is an exploded view of the operator shown in FIG. 1;

[0023] FIG. 3 is an exploded perspective view of the internal components of the operator shown in FIGS. 1 and 2 as viewed from the housing side;

[0024] FIG. 4 is similar to FIG. 3 shown with the drive gears and the sun gear coupled to each other;

[0025] FIG. 5 is an exploded perspective view of the device as shown in FIG. 4, as viewed from the direction of the carrier and hub that receive and are connected to the shaft of the rolling door;

[0026] FIG. 6 is a side elevational view of an alternate embodiment of the operator utilizing twin DC motors to drive the operator;

[0027] FIG. 7 is an exploded view of the operator shown in FIG. 6;

[0028] FIG. 8 is an exploded view of a bridge gear box used in conjunction with the operator shown in FIG. 1;

[0029] FIG. 9 is a side elevational view of a still further embodiment of the invention driven by an external motor;

[0030] FIG. 10 is an exploded view of the operator shown in FIG. 9;

[0031] FIG. 11 is an exploded view, in elevation of the operator shown in FIG. 4;

[0032] FIG. 12 is a top plan view of the limit position safety device shown in FIGS. 1-3, 5-7, and 9-11;

[0033] FIG. 13 is a side elevational view of the limit position safety device shown in FIG. 12; and

[0034] FIG. 14 is an end or side elevational view of the device shown in FIGS. 12 and 13.

DETAILED DESCRIPTION

[0035] Referring now to the figures, in which identical or similar parts are designated by the same reference numerals throughout, and first referring to FIG. 1, an operator in accordance with the present invention is generally designated by the reference numeral 10.

[0036] The operator 10 is mounted on a side drive bracket plate 12 secured to a vertical channel or wall angles 14. A rolling door 16 shown in FIG. 2 is typically mounted on a barrel assembly 18 shown in FIG. 3 that defines an axis A and is operated by the controller 10. The fire door operator 10 is used to control a rolling door that can be raised when rolled onto the barrel assembly 18 when the shaft 18a rotates in a first direction and lowered when the shaft rotates in an opposing direction, as is known in the art. The shaft 18a can be any one of a number of different diameters depending on the size and the weight of the rolling door.

[0037] The operator 10 includes a generally cup-shaped housing 20 has interior space 20a as shown in FIG. 5, mounting flanges 20b and a central opening 20c as shown in FIG. 4. The housing forms a peripheral annular wall 20d, a flange 20e with an opening is formed along the periphery as shown, for example, in FIG. 4. While one axial end of the housing 20 is open the other end is substantially closed by a wall 20f formed with at least one lateral opening 20g from the axis A offset, two openings being shown in FIG. 4. The axis A is coextensive with the shaft 18a when assembled and mounted on the shaft.

[0038] Referring to FIGS. 4 and 5, the operator is provided with a main outer gear in the form of an annular ring mounted within the housing 20 for rotation about the axis A and is formed with exterior teeth 22a and radially inwardly spaced interior teeth 22b. Planet gears 24 are meshed with the interior teeth 22b and a sun gear 26 is meshed with the planet gears 24 for rotation about the axis A.

[0039] A carrier 32 in the form of a circular plate or disk is fixedly attached to a hub 34 in any conventional manner and shares rotations with the carrier 32. The carrier 32 is also secured to the planetary gears 24, as indicated. The hub 34 can be secured to the shaft 18a in any suitable or conventional manner. The hub 34 includes a mounting plate 34a attachable to the carrier 32 and an annular extension 34b formed at the radial end opposite to the mounting plate with external teeth 34c. A keyway 34d is shown for securing the shaft 18a to the hub 34 for sharing rotations therewith.

[0040] A locking mechanism 36 is provided for normally locking the main outer or ring gear 22 in relation to the housing 20. The locking device, in the example shown, is a rocking arm 36 positioned in proximity to the exterior teeth 22a of the annular ring 22 and provided with locking teeth 36a configured to mesh with the outer or exterior teeth 22a of the main or ring gear 22. In a locking position, the teeth 36a engage the teeth 22a and prevent the ring gear 22 from rotating about the axis A. The rocker arm 36a can be manually or electromechanically urged from its normal biased locking position to move the locking teeth 36a out of engagement with the exterior teeth 22a thereby releasing the outer or gear ring 22. The rocker aim 36 can be controlled manually by a string or pull chain attached to a loop 36b shown in FIG. 4. However, the rocker arm 35 can also be moved from its normally biased position by any known actuating devices, such as salenoids, step motors or the like. When the main outer or ring gear 22 is released it can freely rotate within the housing 20 and is not exposed to contaminants or exterior objects that can potentially interfere with that movement.

[0041] One of the features of the invention is the use of a direct drive limit switch 38 shown, for example, in FIG. 5. As shown, the direct drive limit switch assembly 38 is connected by means of a reduction gear set 40 that includes gears 40a-40c, the gear 40c being directly coupled to the outer or exterior teeth 34c of the hub 34. Rotation of the hub 34 is directly indicative of the rotational speed of the barrel assembly or shaft 18a that, therefore, the speed at which the rolling door or curtain 16 is dropping. The direct drive limit switch 38 is also indicative of the position of the rolling door 16. When the door reaches its upper position or its lower position the drive limit switch 38 generates electrical signals that can be used to stop any motor drive from further attempting to raise a door any higher or dropping it any lower. The limit switch assembly is also discussed in U.S. Pat. No. 8,069,896. An important feature of the invention is provision of a slot or opening 20e (FIG. 4) in the housing 20 through which the gear 40a of the direct drive limit switch can extend so that at least a portion of this gear 40a projects below or outside of the housing 20. This allows the direct drive limit switch 38 to be mounted outside of the housing 20 while still maintaining precise information of the movements of the sun gear 26c and the position of the rolling door.

[0042] An opening 26h is provided in the wall 26d for providing access to the outer teeth 22a of the ring gear 22 when the rocker arm 36 is mounted on the housing 20. Similarly, an opening 26i is provided on the annular wall 20d to enable the gear train 40 to engage the direct drive limit switch assembly 38 which is likewise mounted exteriorly of the housing 20.

[0043] When the rocker arm 36 is moved from a locking position in which the teeth 36a engage the teeth 22a on the ring gear to an unlocking position these teeth disengage from each other. The ring gear is freed to rotate as is the sun gear 26 as well as the hub 34 and the carrier 32. This allows the shaft 18a to freely rotate and the door rolled up on the barrel assembly to drop under its own weight. However, when the door starts to accelerate and pick up speed the dropping speed must be regulated or controlled to avoid excessive speeds and potential hazards. Other known release devices can be used such as fusible links, electromechanical release devices such as solenoids and motor controlled release devices.

[0044] In FIGS. 1 and 2 such control over the rotational speed of the hub 34 and the carrier 32 is provided by features shown in FIGS. 1 and 2 and FIGS. 3-5. Such speed control is provided by a governor 42 that includes a centrifugal mechanism 42a, a shaft 42b and a gear 42c that is always engaged with the outer teeth 22a of the ring gear 22. The shaft 42b extends through an opening in the flange 20e formed on the housing 20. Other braking mechanisms can be used, such as an electromagnetic clutch 60 coupled by means of a chain 62 to a sprocket 64 mounted on a bracket 66. The sprocket 64 is coupled by means of a bearing 70 to a gear 72 that is always engaged with the outer teeth 22a of the ring gear. When the ring gear starts to accelerate excessively upon release by the rocker arm 36 the electromagnetic clutch 60 detects the speed and creates counter force that resists further increases in the speed of the ring gear. Braking devices, including viscous governors and other braking devices well known to those in the art can be used with different degrees of advantage.

[0045] Drives for raising and lowering the door are applied via the sun gear 26, as indicated, through the outer teeth 26c that mesh with the drive gears 30. Other known ways for applying rotational forces to the sun gear cam be used and contemplated.

[0046] In FIGS. 1 and 2 drive is provided by a hand chain assembly 28, the details of which are more fully described in U.S. Pending patent application Ser. No. 16/584,330 which is incorporated as if fully set forth herein. For this purpose, two openings 26g are provided in the housing 20 as shown in FIG. 4. The chain 46, driven by the hand chain assembly 48, is coupled to sprocket gear 52 to a bridge gear box 50, more fully described in connection with FIG. 8. Bridge gear box 50 includes a housing 50a having a cover 50b. A drive shaft 50c is coupled to an idle spur gear 50d meshed with two spur gears 50e and 50f as shown. The spur gears 50e and 50f are coupled to spur gear shafts 50g and 50h, respectively, mounted on bearings 50i and 50j. The drive shaft 50c and gear sprocket 52 are also mounted on a drive shaft bearing 54. As will be clear, rotation of the gear sprocket 52 and the drive shaft 50c transmits rotational torque by means of the spur gear 50d to the spur gears 50e and 50f thereby rotating spur gear shafts 50g and 50h. These are coupled, in turn, to drive gears 30 that are coupled to and transmit rotational forces to the sun gear by way of the outer teeth 26c.

[0047] Instead of hand chain assembly 48 any other suitable drive can be used. For example, referring to FIGS. 6 and 7, twin DC motors 44a, 44b each coupled to a right angle degree gear box 44c, 44d, respectively, each of the gear boxes has a shaft that extends through the openings 26g of the housing and coupled to the drive gears 30 as with the gear shafts 50g, 50h. Other devices can be used such as direct drive chain hoists, reduced drive chain hoists and compound reduction chain hoists.

[0048] In a similar manner, referring to FIGS. 9 and 10, an external motor 56 can be used to drive the chain 46. The motor 56 is electrically coupled to the limit switch assembly 38 to prevent continued rotation of the motor 56 when the limit switches indicate that the door has reached a lower most or an upper most position and, the bridge gear box 50 can be used to transmit the drive power of the motor 56 to the drive gears 30 and, therefore, to the sun gear 26. The motor 56 can be of a third party operator 74, so that the operator of the present invention can be used with third party operators in the aforementioned drive mechanism.

[0049] It will be appreciated that the use of a ring gear 22 provided with exterior or outer teeth 22a and inner teeth 22b in the planetary gear system 10 render the operator extremely versatile and, in effect, universal in that it can be adapted to work with almost any drives and braking systems. Additionally, by utilizing a direct drive gear set 40 coupled to the hub 34, therefore, also to the shaft attached to the hub the direct drive limit switch assembly can be mounted outside of the housing. This facilitates servicing it and adjustments of the direct drive limit assembly without requiring disassembly of the entire unit.

[0050] Referring to FIGS. 12-14, details of the safety position limit switch 38 are shown. The switch 38 includes a metal housing 60. The shape or nature of the housing 60 is not critical although, as shown, it is preferably open to expose the interior of the housing to make it readily accessible for making easy and rapid adjustments. The metal housing 60 includes a bottom wall 60a and spaced parallel side walls 60b and 60c as shown. The side walls 60b and 60c rotatably support the gear 40a mounted on a gear or work shaft 62 rotatably mounted on the side walls. The gear or work shaft 62, or at least that portion thereof between the side walls 60b, 60c is provided with an exterior thread and is in the nature of a travel bar or worm drive gear. The gear shaft 62 can be rotatably mounted on the metal housing 60 in any conventional or suitable manner. A bearing 66 may be used to minimize friction. Limit nuts or followers 68, 70 are treadedly meshed with the travel bar 64 to convert the rotational movements of the gear 40a and shaft 62 into linear movements of the limit nuts 68, 70 along the axis AA of the travel bar or worm gear 64. Rotation of the travel bar in one direction results in the limit nuts or followers 68, 70 to linearly move in one direction while a reversal of rotational movement of the gear shaft 62 causes the limit nuts or followers to linearly move in the opposite direction.

[0051] A micro-switch 72 is mounted proximate to the travel bar 64 as shown and has a lever 74 configured and arranged to engage the nut or follower 68 when the nut 68 is moved to a position to deflect the lever 74 sufficiently to activate the micro-switch 72 and change its state from normally open to normally closed or vice versa. Similarly, a micro-switch 76 is provided with a lever 78 configured and arranged to selectively contact the limit nut or follower 70. The nuts or followers can be manually moved on the travel bar or worm gear 64 to adjust their positions to correspond to the upper and lower limits of the rolling door. An adjuster guide plate 80 can be moved relative to the travel bar 64 to enable the nuts or followers 68, 70 to be manually adjusted. Once placed in their desired positions the guide plate 80 can be secured to the bottom wall 60a while engaging the limit nuts or followers to ensure that they do not move relative to the travel bar or worm gear 64 other than upon rotation of the gear or work shaft 62.

[0052] While the invention has been shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.