A method for altering the spring constant (k) of a torsion spring for a roller blind, the method including (i) locating a dampener at a predetermined length along a longitudinal axis of the torsion spring, and (ii) tightening an end of the torsion spring against the dampener to increase the spring constant. Further disclosed is a roller blind system having a cylinder, a fabric attached to the cylinder for winding and unwinding from said cylinder, a torsion spring and a damper moveable along the longitudinal axis of the spring.

A method for altering the spring constant (k) of a torsion spring for a roller blind, the method including (i) locating a dampener at a predetermined length along a longitudinal axis of the torsion spring, and (ii) tightening an end of the torsion spring against the dampener to increase the spring constant. Further disclosed is a roller blind system having a cylinder, a fabric attached to the cylinder for winding and unwinding from said cylinder, a torsion spring and a damper moveable along the longitudinal axis of the spring.

The invention relates to a spring operated roller blind system, wherein the roller blind (1) comprises an adjusting mechanism (30) for adjusting an end position of the flexible sheet member. The adjusting mechanism comprises a spindle (36) and a connecting member (31) that is connected to the roller shaft for rotation around the spindle. The adjusting mechanism further comprises a first bearing (7) for the roller shaft that defines a first end position for the connecting member (31). At least one of the bracket connectors (21) comprises a pin (33) for detachable mounting in a cooperating recess (35) on the adjusting mechanism, wherein the pin and the recess have an unround cross section.

The invention relates to a spring operated roller blind system, wherein the roller blind (1) comprises an adjusting mechanism (30) for adjusting an end position of the flexible sheet member. The adjusting mechanism comprises a spindle (36) and a connecting member (31) that is connected to the roller shaft for rotation around the spindle. The adjusting mechanism further comprises a first bearing (7) for the roller shaft that defines a first end position for the connecting member (31). At least one of the bracket connectors (21) comprises a pin (33) for detachable mounting in a cooperating recess (35) on the adjusting mechanism, wherein the pin and the recess have an unround cross section.

A desired range of lift force to raise a window shade is used to select the window shade hardware such as, for example, the optimal LAM. A desired lift force may be 5 pounds for ADA compliance. However, if the user wants to exert less effort to lift the window shade, the user may request an increased lift force of 6 or 7 pounds. Therefore, if a lift force range between 3-8.5 pounds is desired, the system selects the optimal LAM to maintain and guarantee that the lift force required to operate the shades will not exceed the desired range of between 3-8.5 pounds.

A desired range of lift force to raise a window shade is used to select the window shade hardware such as, for example, the optimal LAM. A desired lift force may be 5 pounds for ADA compliance. However, if the user wants to exert less effort to lift the window shade, the user may request an increased lift force of 6 or 7 pounds. Therefore, if a lift force range between 3-8.5 pounds is desired, the system selects the optimal LAM to maintain and guarantee that the lift force required to operate the shades will not exceed the desired range of between 3-8.5 pounds.

A roller shade actuation device includes a driver arranged in a winding drum, a shaft fixed to a support frame outside one end of the winding drum and inserted into the winding drum, and a transmission mechanism for realizing power transmission between the driver and the shaft. The driver includes a housing relatively fixed to the winding drum, a rotation power member arranged in the housing, and a driving gear coaxial with and fixed to an output shaft of the rotation power member. The transmission mechanism includes a first transmission gear meshed with the driving gear, a synchronous gear coaxial with the first transmission gear, and a fixed gear fixed to the shaft and meshed with the synchronous gear. Axial directions of the output shaft and the shaft are vertical, and the synchronous gear and the fixed gear are bevel gears whose axial directions are perpendicular to each other.

A method of making a roller blind is provided. The roller blind has a roller with a sheet mounted thereto for being rolled thereon and unrolled therefrom between first and second positions. At the first position, the sheet is fully rolled about the roller. At the second position, a hanging portion of the sheet hangs from roller in order to fully cover a window height. The portion rolled on the roller defines a roll therewith having a varying radius between the first and second positions. The hanging portion has a varying weight between the first and second positions. The spring is fitted into the roller. The blind provides a blind force on the spring equal to the varying weight multiplied by the varying radius. The spring is provided to have a spring constant with a numerical value that is equal to the numerical value of the weight of a sheet strip unrolled from the roll at a one radian rotation. Thus, the blind force is be equal to the spring force thereby balancing the roller blind. A rolled blind obtained by this method is provided.

A method of making a roller blind is provided. The roller blind has a roller with a sheet mounted thereto for being rolled thereon and unrolled therefrom between first and second positions. At the first position, the sheet is fully rolled about the roller. At the second position, a hanging portion of the sheet hangs from roller in order to fully cover a window height. The portion rolled on the roller defines a roll therewith having a varying radius between the first and second positions. The hanging portion has a varying weight between the first and second positions. The spring is fitted into the roller. The blind provides a blind force on the spring equal to the varying weight multiplied by the varying radius. The spring is provided to have a spring constant with a numerical value that is equal to the numerical value of the weight of a sheet strip unrolled from the roll at a one radian rotation. Thus, the blind force is be equal to the spring force thereby balancing the roller blind. A rolled blind obtained by this method is provided.

A roller shade actuation device includes two actuators arranged in a winding drum, a shaft inserted into the winding drum, and a transmission mechanism. Each actuator includes a housing fixed to the winding drum, a rotary power member arranged in the housing, a driving gear fixed to an output shaft of the rotary power member and coaxial with the output shaft, and a first transmission gear rotatably mounted to the housing and meshed with the driving gear. The actuators are connected linearly in sequence. The driving gear of one actuator adjacent to the transmission mechanism is transmission-matched with and connected to the transmission mechanism, and the driving gears of the remaining actuators are meshed with the first transmission gears of neighboring actuators adjacent to the transmission mechanism. The actuators are connected in series to form an actuator combination through the driving gears and the first transmission gears.