JP2596736Y2 - Transmission gear system for venetian blinds - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a gear device for transmitting the rotation of a hollow operating rod suspended from a head box of a venetian blind to a rotating shaft passing longitudinally in the head box.

[0002]

2. Description of the Related Art A venetian blind in which a slat is opened and closed by rotating a hollow operation rod suspended from a head box and operating a lifting / lowering cord pulled out from a lower end of the hollow operation rod is a hollow operation rod. And a gear device for transmitting the rotation of the shaft to the rotation shaft in the head box. Such a transmission gear is known from Japanese Utility Model Publication No. 62-37915. In this known device, a pinion is fixed to a rotating shaft passing through a head box in a longitudinal direction, an inscribed gear meshing with the pinion is fitted in a case, and a driven bevel gear is integrally formed with the inscribed gear, and a hollow is also formed in the case. A hollow drive bevel gear fixed to the upper end of the hollow operation rod is fixed to the upper end of the operation rod, and the driven bevel gear meshing with the driven bevel gear is extended. And was pulled out from its lower end.

[0003]

Since the elevating cord and the guide roller for guiding the elevating cord passing in the head box in the longitudinal direction are located below the rotating shaft, the position of the rotating shaft in the head box is increased. It is desirable to widen the space below the head box. However, in this case, the diameter of the inscribed gear becomes large, so that the front and rear widths of the head box are enlarged, the head box becomes large, and the cost is increased.

[0004] Further, since the two meshing points of the intermediate inscribed gear could not be arranged in the diameter direction, there was a problem that one of the rotation directions of the hollow operating rod was heavy and the other was light. The present invention has been made to solve these problems, and the purpose is to increase the position of the rotation axis in the head box without increasing the front-back width of the head box. An object of the present invention is to provide a gear device that does not cause a difference in operation between light and heavy depending on the direction of the hollow operating rod.

[0005]

In order to achieve the above-mentioned object, the present invention employs a means in which a driven bevel gear is fixed to a rotating shaft and a driving bevel gear is fixed to the upper end of a hollow operating rod, respectively. The circumscribed intermediate bevel gears are interposed, and the axes of all these bevel gears are arranged on the same plane.

[0006]

The drive gear, driven gear and intermediate gear are bevel gears having relatively small diameters and circumscribing each other, and their axes are all on the same plane. To increase the space,
Even if the position of the rotary shaft on which the driven gear is externally fixed is raised, the rotary shaft can be installed inside the head box having a relatively small width in the front-rear direction. This downsizing of the headbox reduces the overall cost of the blind. The two points at which the driving of the intermediate gear and the driven gear mesh with each other are diametrically opposed, so that the intermediate gear does not become heavy or light depending on the rotation direction.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described based on an embodiment shown in the drawings. The venetian blind shown in FIG. 1 has a hollow operating rod near a one end of a head box 10 through a hollow universal joint 11.
Hanging 12, the hollow operation rod 12 is rotated, the ladder code 17 is shifted forward and backward to open and close the slat 13, and the bottom rail 15 is operated by operating the lifting cord 14 pulled out from the lower end of the hollow operation rod 12. This is a method of raising and lowering the slat 13. The hollow universal joint 11 is fixed to a shaft end of a hollow drive bevel gear 23 of a transmission gear device 20 projecting obliquely downward from the head box 10. The rotation shaft 16 extends in the head box 10 in the longitudinal direction, and penetrates the transmission gear device 20.

As shown in FIG. 2, the transmission gear device 20 includes a case 21 fixed to the head box 10, a lid 22 of the case, and three relatively small-diameter bevel gears 23 rotatably supported by the case. 24, 25 are provided. The drive gear 23 is hollow, and the elevating cord 14 passes through the inside. The driven gear 25 is externally fitted so as to rotate integrally with the rotating shaft 16 penetrating the transmission gear device 20. The axes of the driving and driven gears 23 and 25 are on the same plane and are orthogonal to each other, and the axis of the intermediate gear 24 interposed between the driving and driven gears is also located on the same plane as the axis of the driving and driven gears. I do. Therefore, the driving points of the intermediate gear 24 and the engagement points with the driven gears 23 and 25 are diametrically opposed.

As shown in FIG. 2 and FIG.
Is guided by a guide roll 26 attached to the lid 22 of the transmission gear device 20, and enters the drive gear 23 from the upper end thereof. As shown in FIGS. 2 and 4, the projection 27 of the case 21 is fitted into the opening 19 of the head box 10 to regulate the position of the transmission gear device 20. The shaft end of the drive gear 23 connected to the hollow universal joint projects from the protrusion 27.

As shown in FIGS. 1 and 4, since the rotating shaft 16 is located at a relatively high position near the upper surface opening in the head box 10, the rotating shaft 16 is located below the rotating shaft 16 in the head box 10 of the transmission gear unit 20. Therefore, a wider space than before can be secured. As shown in FIG. 5, a metal plate 28 is attached to the lid 22 in contact with both end surfaces of the guide roll 26 to smooth the rotation of the guide roll and prevent mutual abrasion.

Each of the gears 23, 24, 25 has a small diameter,
Since the front and rear width of the case 21 that accommodates the gear is also small, the front and rear width of the head box 10 is smaller than that of the conventional case.

[0012]

As described above, in the device of the present invention, a relatively large-diameter inscribed intermediate gear is interposed between the hollow drive gear connected to the hollow operating rod and the driven gear integrated with the rotary shaft. Unlike the conventional one, a similarly small circumscribed intermediate gear is interposed between the relatively small-diameter drive and driven gears, and the axes of these gears are arranged on the same plane. By reducing the size of the headbox that houses the case, it is possible not only to reduce costs, but also to arrange the meshing of the intermediate gear in the diametric direction, so that it is possible to prevent differences in operation weight due to rotation direction. It has an excellent effect that it can be done.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of a venetian blind provided with an apparatus according to an embodiment of the present invention;

FIG. 2 is a sectional view taken along the line II-II of FIG. 1,

FIG. 3 is a side view of the device of FIG. 1 viewed from the opposite side;

FIG. 4 is a front view of the apparatus of FIG. 1,

FIG. 5 is a plan view of the device of FIG. 1,

[Description of Signs] 10: Head box, 11: Hollow universal joint, 12: Hollow operating rod, 13: Slat, 14: Elevating cord, 15: Bottom rail, 16: Rotary shaft, 17: Ladder cord, 20: Transmission gear Device, 21: Case, 22: Lid, 23: Drive gear, 24: Intermediate gear, 25: Driven gear, 26: Guide roll, 27: Projection, 2
8: Plate

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E06B 9/307 E06B 9/322

Claims (1)

(57) [Scope of request for utility model registration] 1. A case (21) having a projection (27) that fits into an opening (19) of a head box (10), and a hollow universal joint (11) that is supported by the case and protrudes from the projection. And a driven gear (25) supported by the case and fixed to the rotating shaft (16) of the venetian blind so as to rotate integrally therewith. ), An intermediate gear (24) supported by the case and interposed between the driving and driven gears, and a lifting / lowering cord of a venetian blind attached to the case (21) and being inserted into the driving gear (23). In the transmission gear device (20) provided with a guide roll (26) for guiding the drive gear and the driven gear (23, 25) and the intermediate gear (24) to each other, and their shaft centers are the same. Bevel gear located on a plane And venetian blind transmission gearing.