Patent Application
20140332172
1. Field of the Invention
The present invention relates to a door curtain anti-dropping device for an electric rolling door, and particularly, to a door curtain anti-dropping device driven by a winding shaft of a rolling door, wherein when a door operator chain is broken such that door curtain drops down with an abnormal speed, the anti-dropping device can lock the winding shaft immediately.
2. Description of the Related Art
For a rolling door, generally, it is quite heavy. Especially, for a large-sized warehouse door, it can reach even up to several tons. Hence, once it drops down vertically out of control, its destruction and lethality is very horrible. Therefore, building code basically has requirements for a rolling door design. That is to say, when a door curtain is moved up or down, the possibility of dangers caused by human factors or non-human factors, shall not happen. According to the inventor's practical experience, the main factors of potential dangers comprise: power outage and broken chain which can make the door curtain drop down by its own weight. As such, a conventional rolling door is installed with a preloading mechanism for balancing partial weight of the door curtain. However, it can be understood that the preloading mechanism only keeps the door curtain balance at the upper end point or the bottom end point. Once the door curtain departs from the upper end point, if it loses control, the door curtain still drops downward under the influence of the gravity.
Many known related documents for preventing the door curtain from dropping down abnormally are proposed. For example, as shown in
The above-mentioned patent can lock the winding shaft, when the door curtain drops down abnormally. However, once the winding shaft is locked, it is quite troublesome to unlock the lock state of the winding shaft. It is necessary to dismantle the door operator, and therefore, there is still a room for the mechanism to improve.
A main objective of the present invention is to provide a door curtain anti-dropping device for an electric rolling door, wherein when a door operator is running, the door curtain anti-dropping device detects the rotational speed of a winding shaft. Once an abnormal rotational speed of the winding shaft is detected, a brake mechanism locks the winding shaft immediately.
Another objective of the present invention is to provide a door curtain anti-dropping device for an electric rolling door, wherein the rotational speed of the winding shaft is reduced secondarily by a reducer mechanism to make the brake mechanism of the door curtain anti-dropping device lock the winding shaft by using a small braking force.
To attain the above objectives and other objectives, according to a door curtain anti-dropping device for an electric rolling door of the present invention, the electric rolling door comprises a door operator and a rolling door curtain. The door operator comprises a drive shaft, coupled to the winding shaft of the rolling door, the drive shaft driving the winding shaft to wind or unwind the door curtain of the rolling door. The door curtain anti-dropping device comprises: a first rotating shaft, one end of which is coupled to the winding shaft of the rolling door curtain and driven together with the winding shaft; a reducer mechanism, including an input end and an output end, the input end coupled to the other end of the first rotating shaft, the reducer mechanism used for reducing the rotational speed of the first rotating shaft; a brake mechanism, comprising a central shaft, a linkage disc, a first movable brake disc, an elastic element and an electromagnetic generator, the central shaft firmly connected to a housing, the linkage disc pivoted on the central shaft and coupled to the output end of the reducer mechanism, the linkage disc being rotatable with respect to the central shaft, the first movable brake disc pivoted on the central shaft and constantly receiving an elastic force from the elastic element to push and brake the linkage disc, the electromagnetic generator firmly disposed on one side of the first movable brake disc, the electromagnetic generator electrically excited to attract the first movable brake disc; a rotational speed detecting module, comprising at least one detector, disposed on one side of the linkage disc, for detecting the rotational speed of the linkage disc; and a control circuit, electrically connected to the electromagnetic generator and the rotational speed detecting module.
Accordingly, when the door operator is running, the control circuit controls the electromagnetic generator to be electrically excited so as to attract the first movable brake disc, and then to release the linkage disc and to drive the first rotating shaft and the winding shaft. Once the door curtain drops down abnormally, and an abnormal rotational speed of the linkage disc is detected by the rotational speed detecting module, the control circuit electrically switches off the electromagnetic generator to make the first movable brake disc of the brake mechanism brake the linkage disc so as to prevent the winding shaft from rotating continuously.
Preferably, the door curtain anti-dropping device for an electrical rolling door of present invention further comprises a centrifugal brake mechanism, disposed between the reducer mechanism and the brake mechanism. The centrifugal brake mechanism reduces the rotational speed of the first rotating shaft by a centrifugal force.
Furthermore, the input end of the reducer mechanism comprises a first wheel disc, disposed at the other end of the first rotating shaft. The reducer mechanism comprises a housing, a second rotating shaft, a plurality of primary planetary gears and a plurality of secondary planetary gears. On an inner wall of the housing, a first annular gear and a second annular gear are disposed. The plurality of primary planetary gears are equiangularly pivoted on one side end face of the first wheel disc via a plurality of shaft pins, and the plurality of primary planetary gears are engaged with the first annular gear. One end of the second rotating shaft comprises a first central gear, located at the central portion among the plurality of primary planetary gears and engaged with them. The other end of the second rotating shaft comprises a second wheel disc. The plurality of secondary planetary gears are equiangularly pivoted on one side end face of the second wheel disc via a plurality of shaft pins, and the plurality of secondary planetary gears are engaged with the second annular gear. The output end of the reducer mechanism comprises a second central gear, located at the central portion among the plurality of secondary planetary gears and engaged with them. Accordingly, the rotational speed of the winding shaft is secondarily reduced by the primary planetary gears and the secondary planetary gears. Therefore, the brake mechanism can lock the winding shaft by only using a small braking force.
Also, the brake mechanism further comprises a second movable brake disc and a brake pad. The second movable brake disc is sleeved on the central shaft and located on one side of the linkage disc. The second movable brake disc is movable axially. The brake pad can be rotatably pivoted on the central shaft and located between the first movable brake disc and the second movable brake disc. The end face of the linkage disc facing the second movable brake disc is provided with a plurality of guide rods. The brake pad is put on the plurality of guide rods. The brake pad can slide axially along the plurality of guide rods, and the brake pad is rotated together with the linkage disc. The electromagnetic generator surrounds the central shaft. The electromagnetic generator includes a through hole at its central portion. At a bottom portion of the through hole, a thrust bearing is provided. The elastic element is received within the through hole. One end of the elastic element abuts on the thrust bearing, and the other end storing an elastic force abuts on the first movable brake disc. Two side end faces of the second movable brake disc are each provided with a brake lining for braking the linkage disc and the brake pad, respectively, and the end face of the first movable brake disc facing the brake pad is also provided with a brake lining for braking the brake pad. Accordingly, when the control circuit electrically switches off the electromagnetic generator, the first movable brake disc is pushed by the elastic force of the elastic element, so as to push against the brake pad and the second movable brake disc toward the linkage disc, and then to clamp the first movable brake disc, the brake pad, the second movable brake disc and the linkage disc together, thereby creating a progressive three-stage brake effect.
Preferably, the detector of the rotational speed detecting module is provided outside the linkage disc for detecting its rotational speed. The detector can be selected from one of an optoelectronic switch, a Hall magnetic force sensor, a miniature toggle switch and a reflective optoelectronic sensor.
Preferably, the brake mechanism further comprises a brake releasing mechanism, which can be manually operated to separate the first movable brake disc from the brake pad, so as to loose the first movable brake disc and the linkage disc. Accordingly, it is convenient to unlock the winding shaft at the first installation of the rolling door. Even though the winding shaft is locked under an abnormal condition in the future, the winding shaft can be easily unlocked in a manual operation, thereby solving the trouble of being necessary to dismantle the door operator in the prior art.
a is an exploded perspective view showing part of elements of a manual brake release mechanism;
a-4c are perspective views of the circled parts in a regular speed detecting module which is applied to the door curtain anti-dropping device of the present invention, wherein the circled part of
a shows that the brake state of the brake mechanism as shown in
a are the prior art transferred from U.S. Pat. No. 7,686,150, wherein
First, referring to
As shown in
The reducer mechanism 30 is received in a housing 20′. On a right inner wall of the housing 20′, a first annular gear 32 is provided, and on a left inner wall of the housing 20′, a second annular gear 33 is provided, the first and second annular gears being spaced apart a distance. The reducer mechanism 30 comprises a second rotating shaft 31, a plurality of primary planetary gears 34, 34′ and a plurality of secondary planetary gears 35, 35′. The second rotating shaft 31 passes through the central portion of the reducer mechanism 30. The plurality of primary planetary gears 34, 34′ are equiangularly pivoted on one left side end face of the first wheel disc 212 via a plurality of shaft pins 34a, the plurality of primary planetary gears 34, 34′ being engaged with the first annular gear 32. The first end of the second rotating shaft 31 includes a first central gear 311, located at the center among the plurality of primary planetary gears 34, 34′ and engaged with them. The other end of the second rotating shaft 31 comprises a second wheel disc 312. The plurality of secondary planetary gears 35, 35′ are equiangularly pivoted on one left side end of the second wheel disc 312 via a plurality of shaft pins 35a, the plurality of secondary planetary gears 35, 35′ being engaged with the second annular gear 33. Also, the output end 301 of the reducer mechanism is coupled with a third rotating shaft 41. A first end of the third rotating shaft 41 includes a second central gear 411, located at the central portion of the plurality of secondary planetary gears 35, 35′ and engaged with them. The rotational speeds of the second rotating shaft 31 and the third rotating shaft 41 are reduced by the plurality of primary planetary gears 34, 34′ and the plurality of secondary planetary gears 35, 35′.
A centrifugal braking mechanism 40 is disposed around the third rotating shaft 41, a second end of the third rotating shaft 41 being provided with a shaft coupling 412, and on a left side end face of the shaft coupling 412, a connecting portion 412a being provided. The centrifugal brake mechanism 40 governs rotational speed of the third rotating shaft 41 by centrifugal force. When the rotational speed of the third rotating shaft 41 exceeds a predetermined value (for example, 1800 rpm), it is limited by a friction force occurred on the inner wall of the housing by the centrifugal force.
A brake mechanism 50 is comprised of a central shaft 51, a linkage disc 53, a first brake disc 55, a second brake disc 57, an elastic element 59 and an electromagnetic generator 60. A first end of the central shaft 51 is free, and a second end thereof is secured to an end plate 20b which is firmly connected with the housing 20. The linkage disc 53 pivots on the first end of the central shaft 51. A right side end face of the linkage disc 53 is provided with a shaft coupling portion 531 for coupling to the connecting portion 412a of the shaft coupling 412, and hence the linkage disc 53 rotates together with the third rotating shaft 41. The first brake disc 55 and the second brake disc 57 are sleeved on the central shaft 51 to move axially, and the first brake disc 55 is located between the linkage disc 53 and the second brake disc 57. Furthermore, the brake mechanism 50 comprises a brake pad 56, which is slidably sleeved on the central shaft 51, and located between the first brake disc 55 and the second braking disc 57. On a left side end face of the linkage disc 53, a plurality of guide rods 533 are provided. The brake pad 56 can slid axially along the plurality of guide rods 533, and the brake pad 56 is rotated together with the linkage disc 53. Two side end faces of the first brake disc 55 are each provided with brake linings 58a, 58b for abutting against the linkage disc 53 and the brake pad 56, respectively, and a right side end face of the second braking disc 57 is also provided with a brake lining 58c for abutting against the brake pad 56.
The electromagnetic generator 60 faces the second brake disc 57, surrounds the central shaft 51 and is firmly disposed on a partition plate 20a which is secured together with the housing 20. The electromagnetic generator 60 has a through hole at its central portion. At the bottom portion of the through hole, a thrust bearing 64 is provided, and the elastic element 59 is received within this through hole. By way of one end of the elastic element 59 pressing against the thrust bearing 64, and the other end pressing against the second brake disc 57, the brake pad 56, the first brake disc 55 and the linkage disc 53 are stacked together. By way of using the brake linings 58a, 58b on the left and right side end faces of the first brake disc 55 to press against the linkage disc 53 and the brake pad 56, respectively, and the brake lining 58c on the right side end face of the second brake disc 57 to press against the brake pad 56, there occurs a progressive three-staged brake effect. When the electromagnetic generator 60 is electrically excited, the second brake disc 57 is attracted and retracted. At the same time, the brake pad 56, the first brake disc 55 and the linkage disc 53 are loosen to release the brake effect.
A rotational speed detecting module 62, as shown in
As such, in the case that the electric rolling door is in a normal condition, and the door operator 1 is operated, the electromagnetic generator 60 is first excited by the control circuit so as to attract the brake disc 57, and release the linkage disc 53, and then the first rotating shaft 21 and the winding shaft A are driven by the door operator.
However, once the chain 12 of the door operator 1 is broken, which makes the door curtain D drop down, and the detector 621 detects that the rotational speed of the linkage disc 53 exceeds 1800 rpm (according to the gear ratio of the reducer mechanism 30, the rotational speed of the third rotating shaft 41 should be less than 1800 rpm), the control circuit can judge that the electric rolling door is in an abnormal condition, and switches off the electromagnetic generator 60 immediately, that is, the brake mechanism 50 is restored to brake state. Hence the winding shaft A is locked.
Moreover, the brake mechanism 50 preferably further comprises a brake-releasing mechanism 70 for manually separating the brake disc 57 from the brake pad 56, so as to loose the first brake disc 55 and the linkage disc 53.
The brake-releasing mechanism 70 of the present invention is illustrated in
In addition, as shown in
When a rolling door is installed at the first time or a winding shaft A is locked in an abnormal condition in the future, the winding shaft A must be unlocked. First, the pull rope 77 is pulled, for example toward the right side, and fastened; the second end of the draw bar 75 is actuated by the swing of the linkage plate 76, which renders the U-shaped member 74 of the first end of the draw bar 75 to push the U-shaped plate 72 to slide left together with the second brake disc 57. Thereby, the brake is released. Moreover, the brake-releasing mechanism 70 further comprises a sensor switch 78. When a manual release brake is performed, the draw bar 75 can trigger the sensor switch 78, and then, the sensor switch 78 can switch off the door operator 1.
The preferred embodiments of the present invention are illustrative only, and are not limited to the details disclosed in the drawings and the specification. Many changes can be made by those having ordinary skill in the art without departing from the equivalent changes and modifications made by the claims of the present invention, and should belong to the scope of the prevent invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102116875 | May 2013 | TW | national |
