ADJ USTING STRUCTURE FOR LIMIT SWITCH

FIELD OF THE I NVENTION

The present invention relates to a transmission mechanism of a rolling door, and more particularly to an adjusting structure for a limit switch. BACKGROUND OF THE I NVENTION

The existing motor-type transmission device of the rolling door comprises a driving plate, a stationary plate, a driving motor, a limit switch controller, and a clutch for driving a hub of the door plate that couples with its surface so as to roll up the rolling door automatically.

The door position controlling and driving structure of the conventional transmission device of the rolling door is mounted on the stationary plate of the hub so as to roll up or down the door plate by driving the clutch via the transmission gear set and the limit switch . If the rolling door has a deviated door position, the limit cam must be first unscrewed to be adjusted by an angle. Next, the limit cam is screwed. I n addition, it is not easy to maintain and not easy to adjust in this limited space. Accordingly, if there is a need to perform the maintenance, the spindle and d riving plate of the rolling door must be detached in sequence. Therefore, it needs further improvement in practicability. SUM MARY OF THE I NVENTION A major object of the present invention is to provide an adjusting structure for a limit switch so as to rough and fine adjust the limit switch for controlling the contactness between a limit cam and the limit switch. It is easy to operate the adjusting structure

without any need to detach the component one by one. In addition, the limit switch can be adjusted to an optimum condition by the use of the adjusting structure that allows the rough and fine adjustments. In order to achieve the above-mentioned object, an adjusting structure for a limit switch of the present invention is for coupling with a transmission mechanism of a rolling door. The transmission mechanism has a stationary plate and a driving plate. The stationary plate has two gear shafts mounted thereon, and the driving plate has a gear mounted thereon. Each gear shaft is axially coupled with a gear set and an adjusting structure. The gear sets are both engaged with the gear of the driving plate. Each gear set has an internal gear. The present invention is characterized in that the adjusting structure comprises a base, a worm gear shaft, an elastic positioning plate, a limit cam and an upper cover, wherein the adjusting structure has a shaft holder on the center, an action trench on one side, and a shaft bracket on the other side for holding the worm gear shaft. In addition, the worm gear shaft comprises a spindle and a worm gear. The worm gear has a plurality of brake trenches on the outer surface. The elastic positioning plate mounted in the base is designed for touching the brake trenches of the worm gear so as to fix the worm gear shaft after the rotation of the worm gear shaft. The worm gear is partially projected to the outside of the base. The limit cam is fixedly coupled with the shaft holder. The limit cam has a limit control plate extending from the other side. The limit control plate is projected into the action trench. The base has an internal gear formed on the outer surface to engage with the internal gear of the

gear set.

Accordingly, in comparison with conventional structure, the present invention can adjust the limit switch without detaching the components one by one. BRI EF DESCRI PTION OF THE DRAWINGS

These and other features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings, wherein: FI G. 1 is a first elevational diagram of the present utility model;

FIG. 2 is a second elevational diagram of the present utility model;

FIG. 3 is an elevational diagram showing the assembled structure of the present utility model;

FI G. 4 is an elevational diagram showing the decomposed structu re of the present utility model;

FIG. 5 is a schematic view showing that the adjusting structure of the present utility model is coupled with the transmission device of the rolling door;

FIG. 6 is an elevational diagram showing the decomposed structure of the present utility model; and

FIG. 7 is a schematic view showing the action relationship between the adjusting structure and the limit switch of the present utility model.

Description of marks in the drawings:

I - stationary plate;

I I - gear shaft

12- gear set;

121 - ring gear;

122- internal gear; 2- driving motor; 3- clutch switch;

4- limit switch;

5- driving plate; 51 - gear;

6- adjusting structure; 61 - base;

611 - shaft holder;

612- internal gear;

61 3- action trench;

614- shaft bracket; 62- worm gear shaft;

621 - spindle;

622- worm gear;

623- brake trench;

63- elastic positioning plate; 64- limit cam;

641 - gear part;

642- limit control plate;

65- upper cover;

66- elastic device; 67- outer cover; and

68- fastener. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1 and FIG. 5 , an adjusting structu re for a

limit switch of the present invention is for coupling with a transmission mechanism of a rolling door.

The transmission mechanism of the rolling door comprises a stationary plate 1 , a driving motor 2, a clutch switch 3, two limit switches 4 and a driving plate 5, wherein the driving plate 5 is mounted on the inside of the stationary plate 1 , and the driving motor 2 and the clutch switch 3 are mounted on the stationary plate 1 . The above-mentioned driving motor 2 is designed for coupling with a door-open limit control mechanism and a clutch switching controller. The gear sets of the driving plate 5 can drive the limit switches 4 by rotation.

As shown in FIG. 6, the present invention uses two adjusting structures 6 so as to adjust the limit switches 4 for providing the rolling door with an optimum position. Two gear shafts 11 are mounted on the stationary plate 1 , wherein two gear sets 12 are axially coupled with the gear shafts 11 respectively for engaging with a gear 51 of the driving plate 5. The above-mentioned gear 51 is mounted on the driving plate 5.

The structure of the adjusting structure 6 is shown in FIG. 1 through FIG. 4 and FIG. 6. The adjusting structure for the limit switch of the present invention generally uses at least one adjusting structure 6 to touch at least one limit switch 4 so as to adjust it. The adjusting structure 6 comprises a base 61 , a worm gear shaft 62, an elastic positioning plate 63, a limit cam 64 and an upper cover 65, wherein the gear 51 of the driving plate 5 is mounted on the stationary plate 1 near two limit switches 4. The base 61 of the adjusting structure 6 has a shaft holder 611 on the center, and an action trench 613 is formed on one side of the base

61 . In addition, a shaft bracket 614 is formed on the other side of the base 61 for holding the worm gear shaft 62.

The both ends of the worm gear shaft 62 are pivotally mounted on the shaft bracket 614. The above-mentioned worm gear shaft 62 comprises a spindle 621 and a worm gear 622. Several brake trenches 623 are formed on the outer surface of the worm gear 622. The elastic positioning plate 63, which is mounted on the inside of base 61 , is designed to touch the brake trench 623 formed on the worm gear 622 so as to fix and stop the rotated worm gear shaft 62. Partial portion of the worm gear 622 is projected to the outside of the base 61 for the purpose of adjusting the rotation of the worm gear shaft 62 easily.

The shaft holder 611 of the base 61 can be fixedly coupled with the limit cam 64, which is fixedly coupled with the shaft holder 611 . In addition, a limit control plate 642 is extended from the other side of the limit cam 64. After fixedly coupling the limit cam 64 with the shaft holder 611 . The limit control plate 642 is projected into the action trench 613.

After being positioned one by one, these above-mentioned components are fixedly covered with the upper cover 65.

Referring again to FIG. 3, FIG. 5 and FIG. 6, the gear set 12 has a ring gear 121 on the border for engaging with the gear 51 . The gear set 12 has an internal gear 122 on the surface for engaging with an internal gear 612 (shown in FIG. 2) formed on the outer surface of the base 61 of the adjusting structure 6. The adjusting structure 6 is axially mounted on the gear shaft 11 . In addition, the adjusting structure 6 is axially fixed on the gear shaft 11 by an elastic device 66 and an outer cover 67 via a fastener 68.

When the limit switch 4 of the rolling door is unable to provide the exact door position, the door position must be adjusted manually. However, the conventional adjusting method needs to detach much more components, and it is performed in the small space. Accordingly, the conventional adjusting method is labor-consuming, time-consuming and not easy to maintain. However, the present invention engages the internal gear 612 of the base 61 of the adjusting structure 6 with the internal gear 122 of the gear set 12. When the base 61 is rotated, the internal gear 612 can rotate the limit cam 64 for further shifting the limit control plate 642 by an angle. Once the limit control plate 642 is shifted, the limit switch 4 can be rough adjusted and controlled by a large angle.

Another mode to fine adjust the limit switch 4 is performed by using the worm gear 622 of the worm gear shaft 62, which is partially projected to the outside of the base 61 . When fine adjusting the worm gear 622 manually, the spindle 621 can be simultaneously rotated so as to rotate a gear part 641 that engages with the spindle 621 for thereby rotating the limit cam 64. In addition, the limit control plate 642 can be simultaneously rotated by an angle. Because the small angle adjustment can be achieved by the use of the worm gear shaft 62, the limit switch 4 can be fine adjusted .

Furthermore, after rotation of the worm gear shaft 62, the elastic positioning plate 63 can be elastically inserted into the brake trench 623 for fixing the worm gear shaft 62 so that the worm gear shaft 62 can be fixed after adjustment.

By using the adjusting structure 6 for rough and fine

controlling the rotation of the limit switch 4, the limit cam 64 can be controlled to touch the limit switch 4. In addition, it is easy to adjust and control the adjusting structure 6 without the need to detach any component. In addition, the limit switch 4 can be adjusted to an optimum condition by the rough and fine adjustments.

The present invention is not limited to the embodiments described above, but all changes and modifications thereof not constituting departures from the spirit and scope of the present invention are intended to be covered by the following claims.