TRANSMISSION DEVICE WITH TOOTHED CABLE

The invention is related to a toothed steel cable transmission mechanism, especially with an electric motor which, trough a reduction gear unit, drives a worm pertaining to a worm gear assembly engaging the toothed steel cable for linear movement in a curved section.

Traditional transmission mechanisms have the drawback that additional articulated lever or steering mechanism is required to change transmission direction due to the rigid characteristic of the mechanism components. Thus, the whole mechanism has increased dimensions and poor transmission efficiency. Its application is also limited.

The main objective of the invention is to improve the traditional transmission mechanism that has the drawback in failure to transmit forces in a curved path without additional steering mechanism.

After improvement, the transmission of forces through a curved mechanism can be achieved. This is the most important feature of the invention.

To achieve the above objective and function, the technical approach and scheme includes:

• A toothed steel cable transmission mechanism, which consists of a toothed flexible steel cable, which is a long and thin steel line with surface teeth and bendability; a steel cable elbow tube, which is a hollow tube to provide proper protection and guidance for the passing steel cable on its curved path; an electric motor, e. g. a DC motor driving a reduction gear unit to reduce output RPM; a worm provided on the output end of the reduction gear unit and engaging the worm wheel of a a worm gear assembly consisting of the worm wheel as the driving gear and a coaxial gear as the driven gear engaging the teeth of the toothed steel cable and driving the same; a steel cable guide in form of a hollow sleeve with a pair of ears for securing the engagement between the passing toothed steel cable and the driven gear of the gear assembly.
• When the above mechanism is working, the motor with linear transmission characteristic transmits forces through the reduction gear unit to the worm and the worm gear assembly to drive the toothed steel cable to make linear movement in bendable structure.
• The above toothed steel cable transmission mechanism can have a top cover to accommodate the driven gear of the gear assembly and a middle cover and a bottom cover to accommodate the worm and the driving gear of the worm gear assembly. The top cover also has a connector to fit the ears of the steel cable guide.
• For the above transmission mechanism, the control of transmission direction for the toothed steel cable is through the motor steering and the worm and worm gear assembly.
• For the above transmission mechanism, the end of the toothed steel cable is the power output end, which depending on applications can connect to peripherals that need switches or movement such as hopper windows, awning windows, casement windows, tilt-turn windows, sliding windows, window blinds, air vent system and skylights, or angle or height adjustment for hospital beds or sleep beds.
• When the above toothed steel cable transmission mechanism is applied to window opening and closing, it is associated with a window actuator on the window frame, so the pull-push forces from the power output end of the toothed steel cable are transmitted to the window through the toothed steel cable.
• Regarding the technical approach and mechanism to achieve the objective of the invention, embodiments with illustrations in figures are described in details as follows:

• Figure 1: a three-dimensional exploded view of the structure of the transmission mechanism according to the invention.
• Figure 2: a three-dimensional view of the assembled mechanism.
• Figure 3: the two-dimensional illustration of the operation principle of the invention.
• Figure 4: a partial cross-sectional view of the transmission mechanism of the invention.
• Figure 5: an embodiment of the invention in application for a smoke vent window.
• Figure 6: a plurality of smoke vent windows as an example for the invention.

To further explain the details of the invention, examples are given as follows:

• Please refer to Figure 1 for the three-dimensional exploded view of the structure of the invention. The toothed steel cable 1 is a thin and long steel line that is bendable and has surface teeth 10. The elbow tube 2 is a hollow tube to properly protect and guide the passing toothed steel cable 1 on a curved path. The motor 3 is an electric motor, preferrably powered by direct current. The motor is connected with a reduction gear unit 30 that is made of a gear assembly. The worm 4 is a rod with threads 40 and mounted on the output end 31 of the reduction gear unit 30. The worm gear assembly 5 is consists of two coaxial gears. The driving gear 50 of the worm gear assembly 5 is the worm wheel engaging and driven by the worm 4 to drive the coaxial driven gear 51 that engages and drives the toothed steel cable 1 in linear movement.
• The toothed steel cable guide 6 is a hollow tube 60 to secure the close contact between the passing toothed steel cable 1 and the driven gear 51 of the worm gear assembly 5. The toothed steel cable guide 6 has a pair of ears 61 which connect to slots 70 for securing the toothed steel cable guide 6 with top cover 7 to prevent disengagement between the toothed steel cable 1 and the driven gear 51 of the gear assembly when in operation.
• Please refer to Figure 2 for the three-dimensional exterior assembly diagram. The DC motor 3 has linear transmission characteristic and transmits torque to the worm 4 and worm gear assembly 5 and drives the toothed steel cable 1 to make curved movement. Then the toothed steel cable 1 is driven through the elbow tube 2 which forces it to follow the curved path and provides protection and a change of orientation. The close match between the toothed steel cable 1 and the worm gear assembly 5 is achieved through the toothed steel cable guide 6. The exterior of the worm 4 and the worm gear assembly 5 is protected by a top cover 7, a middle cover 8 and a bottom cover 9.
• Please refer to Figure 3 for the two-dimensional illustration of the operation principle of the invention. The power output of DC motor 3 has linear characteristic. After conversion by the reduction gear unit 30, the torque is transmitted by the worm 4, which further transmits the power to the worm gear assembly 5 and drives the toothed steel cable 1 to perform a linear movement in the curved elbow tube 2.
• Please refer to Figure 4 for a partial cross-sectional view of the transmission mechanism of the invention. The space inside the top cover 7 is to accommodate the driven gear 51 of the worm gear assembly 5. The space enclosed by the middle cover 8 and the bottom cover 9 is to accommodate the driving gear 50 of the worm 4 and worm gear assembly 5. The toothed steel cable 1 passes the hollow sleeve 60 of the toothed steel cable guide 6 and drives the driven gear 51 of the worm gear assembly 5.
• From this figure, it is clear that the power transmission path is from the worm 4 to the driving gear 50, then through the coaxial driven gear 51 to the toothed steel cable 1.
• Please refer to Figure 5 for an embodiment of the invention for a smoke vent window. The figure shows an example of a hopper window with fire fighting significance. Depending on applications, the mechanism of the invention is used to actuate peripherals switchable or moveable, such as hopper windows, awning windows, casement windows, tilt-turn windows, sliding windows, window blinds, air vent system and skylights, or height adjustment for hospital beds or sleep beds. The opening and closing of the window panel 10d is brought about by the actuator 10a on the window frame 10c, which converts the power and transmits the power through the toothed steel cable 1 to the window panel 10d, so the window panel 10d is pushed open or pulled closed.
• The linear movement of the toothed steel cable 1 inside the actuator 10a is activated by an authorizing main operator 10e or a manual switch 10g, which sends a fire alarm signal to the central control box 10f. Upon receiving the signal, the central control box 1 0f activates the DC motor assembly 3 and further transmits power through the actuator 10a to the toothed steel cable 1.
• Please refer to Figure 6 for a smoke vent window. The figure shows an example of a multi-panel hopper window. On the window frame 10c for the individual window panel 10d there is an actuator 10a. Its independent power source (DC motor assembly 3) is used to control the opening and closing of the window panel 10d. Each switch assembly has a pipe (containing electric line and signal line) connecting to the central control box (containing microcomputer control chip) that operates on logic judgment.
• In summary, the invention provides application technology for the toothed steel cable transmission mechanism. It is mainly through a DC motor to drive a worm and a worm gear assembly, and further drives a toothed steel cable for linear movement in a curved structure. This is the major improvement over the traditional transmission mechanism. The invention provides advanced breakthrough on applications of toothed steel cable transmission mechanism and is subject to patent application approval. The above description for the invention is only the preferred embodiment. It is specially noted that any modification based on the same technical approach and design concept in the invention shall fall into the scope of the invention.