FIELD OF THE INVENTION

The present invention relates to curtain components and more specifically to a double-drum type curtain drum module to be implemented in a blind or a hinged screen with sunshade blades.

BACKGROUND OF THE INVENTION

Curtains are installed inside a building to achieve sunshade or internal-shielding. Curtains primarily classifies into two major groups, hinged screens and retractable curtains. The hinged screens further subdivide into Venetian blinds, Roman shades, Cellular Shades, roller blinds, zebra shades, etc. The hinged screen with sunshade blades furls and curls the curtain control cord to change the sunshade area by adjusting the raising/lowering of the screens. And the pull of the curtain auxiliary cord is utilized to adjust the tilting angle of the sunshade blades so that the shading ratio is changed. Conventional curtain control components installed inside the transverse grooved rail includes a force-return component and a drum assembly. The curtain control cord is furled on the drum of the drum assembly. The curtain auxiliary cord is fixed at the curtain auxiliary cord rotator in the drum assembly.

In the conventional drum assembly, a control cord access hole and two curtain auxiliary cord access holes are disposed at the bottom of the shell base. The drum and the curtain auxiliary cord rotator are installed in intervals and the control cord access hole is relatively away from the area between the curtain auxiliary cord access holes to avoid cord curling. However, the force exerted by the control cord near the control cord access hole is oblique to the curtain auxiliary cord leading to rubbing against the uppermost sunshade blades in the said conventional drum assemblies. Moreover, the control cord is outwardly exposed to affect overall appearance. Furthermore, when the position of the curtain auxiliary cord rotator is installed too high, the installation of the curtain may be impacted. The fixing element of a curtain must partially cover the curtain transverse grooved rail. When the auxiliary cord rotator is over-protruded, the fixing element may not cover the drum assemblies leading to inconvenient installing locations for curtains.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide a double-drum type curtain drum module to modularize curtain control components, to resolve the issue of rubbing against the uppermost sunshade blades due to the force exerted by the control cord near the control cord access hole being oblique to the curtain auxiliary cord and to provide more freedom in the location selection of curtain installation.

The second purpose of the present invention is to provide a double-drum type curtain drum module to pass two control cords through one control cord reset opening to increase weight-lifting capability of the control cord and to avoid cord curling of the control cord during raising/lowering of the curtain.

According to the present invention, a double-drum type curtain drum module is disclosed comprising a shell base, a first guide wheel, a second guide wheel, an auxiliary cord rotator, a first cord drum and a second cord drum. The shell base is configured for installing inside a curtain fixing grooved rail. The shell base has a first compartment and a second compartment. The first compartment has at least two first reinforcing bars arranged in parallel. A plurality of first wheel-connecting grooves are formed on the first reinforcing bars. The second compartment has a plurality of second wheel-connecting grooves formed on a bottom surface of the shell base. A connecting channel is formed between the first reinforcing bars and exposed from the bottom surface of the shell base. The connecting channel extends into the second compartment so that the first wheel-connecting grooves and the second wheel-connecting grooves are formed in the connecting channel. The first compartment further has at least two auxiliary cord access holes at the bottom surface of the shell base. A plurality of first shaft ends of the first guide wheel are installed inside the first wheel-connecting grooves. A control cord reset opening is formed from the first guide wheel to a first end of the connecting channel and located in the first compartment. The control cord reset opening is aligned between the auxiliary cord access holes. A plurality of second shaft ends of the second guide wheel are installed inside the second wheel-connecting grooves. A control cord transferred opening is formed from the second guide wheel to a second end of the connecting channel and located in the second compartment. A first vertical distance between the first guide wheel and the bottom surface of the shell base is greater than a second vertical distance between the second guide wheel and the bottom surface of the shell base. The auxiliary cord rotator is installed inside the first compartment for driving an auxiliary cord. The first cord drum and the second cord drum are installed inside the second compartment and are interlocked to each other to furl and curl a first control cord and a second control cord respectively. A first driving shaft joint hole is formed through a first axial line of the first cord drum.

Therefore, the double-drum type curtain drum module discloses by the present invention is one of the module kits of curtain control components. When the double-drum type curtain drum module is installed with a force-return braking module, a power module, etc. inside the transverse curtain fixing grooved rail, two high and low wheel-connecting grooves installed inside the corresponding compartments are coupled by the connecting channel to form the vertically corresponding control cord reset opening under the auxiliary cord rotator. The control cord reset opening is aligned between the auxiliary cord access holes to resolve the issue of rubbing against the uppermost sunshade blades due to the force exerted by the control cord near the control cord access hole being oblique to the curtain auxiliary cord and to provide more freedom in the location selection of curtain installation.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a three-dimensional assembly view of a double-drum type curtain drum module according to the preferred embodiment of the present invention.

FIG. 2 is a three-dimensional component exploded view of the double-drum type curtain drum module according to the preferred embodiment of the present invention.

FIG. 3 is a bottom view of the bottom surface of the double-drum type curtain drum module according to the preferred embodiment of the present invention.

FIG. 4 is a three-dimensional assembly view of the double-drum type curtain drum module during the installations of two control cords and an auxiliary cord according to the preferred embodiment of the present invention.

FIG. 5 is a three-dimensional assembly view of the double-drum type curtain drum module after the installations of the control cords and the auxiliary cord according to the preferred embodiment of the present invention.

FIG. 6 is a cross-sectional view of the double-drum type curtain drum module along the section line 6-6 in FIG. 5 according to the preferred embodiment of the present invention.

FIG. 7 is a cross-sectional view of the double-drum type curtain drum module along the section line 7-7 in FIG. 5 according to the preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the attached drawings, the present invention is described by means of the embodiment(s) below where the attached drawings are simplified for illustration purposes only to illustrate the structures or methods of the present invention by describing the relationships between the components and assembly in the present invention. Therefore, the components shown in the figures are not expressed with the actual numbers, actual shapes, actual dimensions, nor with the actual ratio. Some of the dimensions or dimension ratios have been enlarged or simplified to provide a better illustration. The actual numbers, actual shapes, or actual dimension ratios may be selectively designed and disposed and the detail component layouts may be more complicated.

According to the preferred embodiment of the present invention, a double-drum type curtain drum module 100 is illustrated in FIG. 1 for a three-dimensional assembly view, in FIG. 2 for a three-dimensional component exploded view, and in FIG. 3 for a bottom view. FIG. 4 illustrates for a three-dimensional assembly view during the installation of two control cords 220, 230 and an auxiliary cord 210. FIG. 5 illustrates a three-dimensional assembly view of the double-drum type curtain drum module 100 after the installation of the control cords 220, 230 and the auxiliary cord 210. FIG. 6 illustrates a cross-sectional view of the double-drum type curtain drum module 100 along the section line 6-6 in FIG. 5. FIG. 7 illustrates a cross-sectional view of the double-drum type curtain drum module 100 along the section line 7-7 in FIG. 5. The double-drum type curtain drum module 100 comprises a shell base 110, a first guide wheel 120, a second guide wheel 130, an auxiliary cord rotator 140, a first cord drum 150 and a second cord drum 160.

Referring to FIGS. 1 to 3, the shell base 110 is configured for installing inside a curtain fixed grooved rail which is a top connecting beam of a blind. The shell base 110 has a first compartment 111 and a second compartment 112. The first compartment 111 is configured to install the auxiliary cord rotator 140 and to prevent the interference between two extending portions of the auxiliary cord 210. The second compartment 112 is configured to install the first cord drum 150 and the second cord drum 160. Normally the internal space of the first compartment 111 is taller but smaller than the internal space of the second compartment 112. Preferably, a plurality of alignment notches 171 may be formed at a plurality of corners of two sidewalls of the shell base 110 to reinforce the fixing effect of the shell base 110 inside the curtain fixed grooved rail.

The first compartment 111 has at least two first reinforcing bars 113 disposed inside. The first reinforcing bars 113 may be disposed in parallel and symmetrically arranged at the two opposing sides along the axle of the first compartment 111. The first compartment 111 further has a plurality of first wheel-connecting grooves 115 formed on the first reinforcing bars 113.

The second compartment 112 has a plurality of second wheel-connecting grooves 116 formed on a bottom surface of the shell base 110 as shown in FIGS. 2, 3, and 6. Moreover, a connecting channel 117 is formed on the bottom surface of the shell base 110 and between the first reinforcing bars 113 as shown in FIGS. 2 to 4. The connecting channel 117 extends to the second compartment 112 to couple the first wheel-connecting grooves 115 and the second wheel-connecting grooves 116. That is to say, the first wheel-connecting grooves 115 and the second wheel-connecting grooves 116 are formed in the connecting channel 117. Additionally, the first compartment 111 has a plurality of auxiliary cord access holes 118 at the bottom surface of the shell base 110 as shown in FIGS. 3, 4, 5 and 7. Preferably, a plurality of second reinforcing bars 114 are obliquely disposed on a bottom inner face of the second compartment 112. A second height of the second reinforcing bars 114 from the bottom surface of the shell base 110 is smaller than a first height of the first reinforcing bars 113 from the bottom surface of the shell base 110 as shown in FIGS. 2, 4 and 6. Referring to FIGS. 2 to 4 again, the second reinforcing bars 114 may be U-shaped. An area of the second compartment 112 surrounded by the second reinforcing bars 114 may be hollowed out, i.e., a plurality of hollow-out area 119 are formed at the bottom of the second compartment 112. Thus, the status of collecting the control cords of the first cord drum 150 and the second cord drum 160 may be observed from the bottom surface of the shell base 110 through the hollow-out area 119.

A plurality of first shaft ends of the first guide wheel 120 are installed inside the first wheel-connecting grooves 115. A control cord reset opening 121 is formed from the first guide wheel 120 to a first end of the connecting channel 117 and is located in the first compartment 111 as shown in FIG. 3. The control cord reset opening 121 is aligned between the auxiliary cord access holes 118. In other words, the control cord reset opening 121 and the auxiliary cord access holes 118 are arranged along a straight line. And the control cord reset opening 12 is located at a middle point of the auxiliary cord access holes 118.

A plurality of second shaft ends of the second guide wheel 130 are installed inside the second wheel-connecting grooves 116. A control cord transferred opening 131 is formed from the second guide wheel 130 to a second end of the connecting channel 117 and is located in the second compartment 112 as shown in FIG. 3. Moreover, a first vertical distance between the first guide wheel 120 and the bottom surface of the shell base 110 is greater than a second vertical distance between the second guide wheel 130 and the bottom surface of the shell base 110 as shown in FIGS. 2 and 6. Referring to FIGS. 2 and 6, each of the first wheel-connecting grooves 115 has a first opening upwardly and each of the second wheel-connecting grooves 116 has a second opening downwardly so that the first opening and the second opening face in opposite directions. Preferably, the first guide wheel 120 comprises a first pulley 122 and a first fixed shaft 123 penetrating through the first pulley 122 where the first shaft ends are formed at the ends of the first fixed shaft 123. A plurality of first slopes 124 are formed at a plurality of edges of the wheel surface of the first pulley 122. Furthermore, the second guide wheel 130 comprises a second pulley 132 and a second fixed shaft 133 penetrating through the second pulley 132 where the second shaft ends are formed at the ends of the second fixed shaft 133. A plurality of second slopes 134 are formed at a plurality of edges of the wheel surface of the second pulley 132. Thus, the first pulley 122 of the first guide wheel 120 and the second pulley 132 of the second guide wheel 130 may easily slide without producing any friction inside the first wheel-connecting grooves 115 and the second wheel-connecting grooves 116. What is more, a plurality of control cords 220, 230 are slid on the first pulley 122 of the first guide wheel 120 and the second pulley 132 of the second guide wheel 130 without sliding out of their wheel surfaces.

The auxiliary cord rotator 140 is installed inside the first compartment 111 for driving the auxiliary cord 210 as shown in FIGS. 4, 5 and 7. An adjusting shaft joint hole 141 is formed through the axial line of the auxiliary cord rotator 140 for an adjusting shaft to penetrate through. Two extending portions of the auxiliary cord 210 pass through the auxiliary cord access holes 118 as shown in FIG. 7. Through fine-tuning of the adjusting shaft, the auxiliary cord rotator 140 may be slightly swung to drive the auxiliary cord 210, one side for up and another side for down to control the tilting angles of the curtain sunshade blades. To be more specific, the radial body of the auxiliary cord rotator 140 has a sandwich portion 142 to fix the auxiliary cord 210.

The first cord drum 150 and the second cord drum 160 are installed inside the second compartment 112. And, the first cord drum 150 and the second cord drum 160 are interlocked to each other to furl and curl the first control cord 220 and the second control cord 230 respectively as shown from FIGS. 4 to 6. A first driving shaft joint hole 151 is formed through a first axial line of the first drum 150 for a control shaft 240 to penetrate through as shown in FIG. 1. The rotation of the control shaft 240 simultaneously drives the rotation of the first cord drum 150 and the second cord drum 160. When in use, the control shaft 240 may further penetrate through a force-return braking module or a power module not shown in the figures. Preferably, a second driving shaft joint hole 161 is formed through a second axial line of the second cord drum 160 for the control shaft 240 to selectively penetrate through. Therein, the first axial line and the second axial line are arranged in parallel, and a third axial line of the auxiliary cord rotator 140 is higher than a plane formed by the first axial line and the second axial line. To be more specific, a first wheel side of the first cord drum 150 and a second wheel side of the second cord drum 160 are meshed each other by a plurality of gear teeth. In other words, the first cord drum 150 has a first wheel side 152 with a plurality of first gear teeth. The second cord drum 160 has a second wheel side 162 with a plurality of second gear teeth. The first gear teeth of the first wheel side 152 is intermeshed with the second gear teeth of the second wheel side 162 to enable the first cord drum 150 and the second cord drum 160 to simultaneously rotate but in opposite directions.

Referring to FIGS. 5 and 6 again, the first guide wheel 120 is configured for guiding the first control cord 220 and the second control cord 230 to pass through the control cord reset opening 121, the second guide wheel 130 is configured for guiding the first control cord 220 and the second control cord 230 to pass through the control cord transferred opening 131. The furling conditions of the first control cord 220 and the second control cord 230 control the raising status of a blind.

Referring to FIGS. 4 to 7, the first control cord 220 may be furled inside the first cord drum 150. The second control cord 230 may be furled inside the second cord drum 160. The first control cord 220 and the second control cord 230 may be curled from the second compartment 112 through the control cord transferred opening 131 and are circled around the second guide wheel 130. And, the first control cord 220 and the second control cord 230 may extend into the connecting channel 117 to furl into the first compartment 111, then are circled around the first guide wheel 120 to curl from the control cord reset opening 121 as shown in FIG. 6. The auxiliary cord 210 may be fixed on the auxiliary cord rotator 140 by suspension. Both extending portions of the auxiliary cord 210 may pass through the auxiliary cord access holes 118 as shown in FIG. 7. The swing condition of the auxiliary cord rotator 140 controls the tilting statuses of a plurality of sunshade blades in the blind placed at a plurality of interval nodes of the auxiliary cord 210.

Therefore, the double-drum type curtain drum module 100 disclosed in the present invention modularizes curtain control components to concentrate a plurality of control cords 220, 230 and changes the access positions of the cord outlet to the control cord reset opening 121 which is aligned between the auxiliary cord access holes 118. The conventional issue of rubbing against the uppermost sunshade blades is resolved due to the force exerted by the control cord near the control cord access hole being oblique to the curtain auxiliary cord and more freedom in the location selection of curtain installation is provided. Moreover, two control cords 220, 230 pass through the control cord reset opening 121 to increase weight-lifting capability of the control cords 220, 230 and to avoid cord curling of the control cords 220, 230 during raising/lowering of the curtain.

The above description of embodiments of this invention is intended to be illustrative but not limited. Other embodiments of this invention may be obvious to those skilled in the art in view of the above disclosure which still may be covered by and within the scope of the present invention even with any modifications, equivalent variations and adaptations.