Speed reducer for retractable screen systems

1. A retractable screen system, adapted to, when installed, cover an opening of a structure, the retractable screen mechanism comprising:

two tracks constructed to be mounted to said structure on opposing sides of the opening;

a screen comprising a screen material mounted on a frame having two flexible opposing sides corresponding to and adapted to engage the two tracks;

a spool mechanism extending between the flexible opposing sides and engaging a third side of the frame, the screen being adapted to wind up on the spool mechanism, the spool mechanism being biased to the wind up position; and

the spool mechanism having a speed reducer comprising a resistance structure moving through a viscous fluid to reduce the speed of the biased screen when moving to the wind up position.

2. The retractable screen system of claim 1 further comprising:

a latch mechanism mounted to a fourth side of the frame opposite the third side, the fourth side extending between the two flexible opposing sides, the latch mechanism engaging a corresponding latching mechanism mounted on the corresponding side of the structure opening to latch the screen in an extended position.

3. The retractable screen system of claim 1 wherein:

the spool mechanism comprises an elongated housing having a U-shaped profile and a rotating axle contained therein and a plate partially covering the open side end of the elongated housing, the elongated housing and the plate defining a slot, the third side of the screen extending through the slot to engage the axle, the axle engaging a spring mechanism at one end thereof, the spring mechanism being biased to hold the screen in the wind up position, the speed reducer being mounted at the other end of the axle.

4. The retractable screen system of claim 3 wherein:

the speed reducer comprises a hollow housing having a shaft extending coaxially and rotatably mounted therewithin, the resistance structure being a plurality of vane blades extending laterally from the shaft to the sidewall of the housing, the viscous fluid being contained within the housing, the housing being mounted to and rotating with the axle, the shaft extending outwardly from the housing, the shaft being fixedly mounted to prevent rotation thereof, whereby the housing rotates about the shaft.

5. The retractable screen system of claim 4 wherein:

the viscous material is a hydraulic oil.

6. The retractable screen system of claim 4 wherein:

a plurality of ribs extend inwardly from the housing to add turbulence to the flow of the viscous fluid to increase the resistance thereof.

7. The retractable screen system of claim 6 wherein:

each of the plurality of ribs are bent slightly in one direction to further increase turbulence.

8. The retractable screen system of claim 4 wherein:

the vane blades curve away from a radial orientation in one direction to further increase turbulence.

9. The retractable screen system of claim 3 wherein:

the speed reducer comprises a housing having a cap at one end thereof and a jackscrew rotatably received within the housing, the jackscrew having one end extending through the cap, the housing being filled with the viscous fluid; and

a disk having one or more tabs which ride in one or more tracks within the interior of the housing, the disk being rotatably received on the jackscrew and traveling upwardly and downwardly along said jackscrew as the jackscrew rotates.

10. The retractable screen system of claim 9 wherein:

the housing is mounted and rotates with the axle, the one end of the jackscrew being fixedly mounted, the housing rotating about the fixedly mounted jackscrew.

11. The retractable screen system of claim 1 wherein:

the screen material is a fabric.

12. A retractable screen system, adapted to, when installed, cover an opening in a structure, the retractable screen mechanism comprising:

two tracks constructed to be mounted on opposing sides of the opening;

a screen comprising a screen material mounted on a frame having two flexible opposing sides corresponding to and adapted to engage the two tracks;

a spool mechanism extending between the flexible opposing sides and engaging a third side of the frame, the screen being adapted to wind up on the spool mechanism, the spool mechanism being biased to the wind up position;

a latch mechanism mounted to a fourth side of frame opposite the third side, the fourth side extending between the two flexible opposing sides, the latch mechanism engaging a corresponding latching mechanism mounted on the corresponding side of the structure opening to latch the screen in an extended position; and

the spool mechanism having a speed reducer comprising a resistance structure moving through a viscous fluid to reduce the speed of the biased screen when moving to the wind up position, the spool mechanism comprising an elongated housing having a U-shaped profile and a rotating axle contained therein and a plate partially covering the open side end of the elongated housing, the elongate housing and the plate defining a slot, the third side of the screen extending through the slot to engage the axle, the axle engaging a spring mechanism at one end thereof, the spring mechanism being biased to hold the screen in the wind up position, the speed reducer being mounted at the other end of the axle.

13. The retractable screen system of claim 12 wherein:

the speed reducer comprises a hollow housing having a shaft extending coaxially and rotatable mounted therewithin, a plurality of ribs extend inwardly from the housing to add turbulence to the flow of the viscous fluid to increase the resistance thereof, each of the plurality of ribs being bent slightly, in one direction to further increase turbulence, the resistance structure being a plurality of vane blades extending laterally from the shaft to the sidewall of the housing, the vane blades curving away from a radial orientation in one direction to further increase turbulence, the viscous fluid being contained within the housing, the housing being mounted to and rotating with the axle, the shaft extending outwardly from the housing, the shaft being fixedly mounted to prevent rotation thereof, whereby the housing rotates about the shaft.

14. The retractable screen system of claim 12 wherein:

the speed reducer comprises a housing having a cap at one end thereof and a jackscrew rotatably received within the housing, the jackscrew having one end extending through the cap, the housing being filled with the viscous fluid; and

a disk having one or more tabs which ride in one or more tracks within the interior of the housing, the disk being rotatably received on the jackscrew and traveling upwardly and downwardly along said jackscrew as the jackscrew rotates, the housing being mounted and rotating with the axle, the one end of the jackscrew being fixedly mounted, the housing rotating about the fixedly mounted jackscrew.

15. A speed reducer for use in retractable screen systems having an axle biased to wind up a screen to a wind up position, the speed reducer comprising:

a housing having a cap at one end thereof and a jackscrew rotatably received within the housing, the jackscrew having one end extending through the cap, the housing being filled with a viscous fluid; and

a resistance structure in the form of a disk having one or more tabs which ride in one or more tracks within the interior of the housing, the disk being rotatably received on the jackscrew and traveling upwardly and downwardly along said jackscrew as the jackscrew rotates, the resistance structure moving through the viscous fluid to reduce the speed of the screen when moving to the wind up position.

16. The speed reducer of claim 15 wherein:

the housing is mounted to and rotates with the axle, the one end of the jackscrew being fixedly mounted, the housing rotating about the jackscrew.