Compact motorized tensioning device for footwear
A tensioning system for articles of footwear and articles of apparel is disclosed. The tensioning system includes a spool system that can be engaged or disengaged from a driveshaft through the use of a cam device. The motorized tensioning device includes a torque transmitting system that allows for incremental tightening, incremental loosening and full loosening of the tensile element.
1. An article of footwear, comprising:
an upper;
a sole structure; and
a motorized tensioning device seated in the sole structure and comprising:
an electric motor;
a cam device comprising one ramped edge extending circumferentially about a substantial majority of a circumference of the cam device from a first edge of the cam device to a second edge of the cam device;
a spool;
a tensile element wound, at least in part, around the spool;
a driveshaft, coupled to the electric motor, extending through the spool and coupled to the cam device to deliver torque to the cam device to cause the spool to turn to increase or decrease tension on the tensile element; and
an engagement plate configured to:
engage with and receive torque from the cam device;
couple to the spool in an engaged state to cause the spool to rotate with the drive shaft; and
space apart from the spool in a disengaged state to cause the spool to rotate independently of the drive shaft.
2. The article of footwear of claim 1 , wherein:
the cam device includes a step portion; and
the engagement plate comprises a first spoke portion, the first spoke portion configured to be flush against a first end of the step portion of the cam device when the spool system is in the disengaged state.
3. The article of footwear of claim 2 , wherein the engagement plate further comprises a second spoke portion, the second spoke portion configured to be flush against a second end of the step portion of the cam device when the spool system is in the engaged state, the second end of the step portion being disposed on an opposite side of step portion relative to the first end.
4. The article of footwear of claim 3 , wherein the second end of the step portion has a greater height than the first end of the step portion.
5. The article of footwear of claim 1 , wherein the ramped edge comprises a first linear portion joined to the first edge, a second linear portion joined to the second edge, and a slope portion between the first linear portion and the second linear portion.
6. The article of footwear of claim 5 , wherein the first linear portion is disposed beneath the first spoke portion of the engagement plate in the disengaged state and describes a first height and the second linear portion is disposed beneath the second spoke portion in the engaged state and describes a second height greater than the first height.
7. The article of footwear of claim 1 , wherein the tensile element is substantially wound around the spool when the article of footwear is under tension and substantially unwound from the spool when the article of footwear is loosened.
8. The article of footwear of claim 1 , wherein the first tensile element can be freely unwound from the spool system in the disengaged state.
9. The article of footwear of claim 1 , wherein the spool is substantially elongated and includes a substantially cylindrical shape, wherein the spool comprises an opening extending between a first spool end and a second spool end, and wherein the driveshaft extends through the opening.
10. The article of footwear of claim 9 , wherein a first portion of the driveshaft extends axially outward from the second end of the spool, wherein the cam device surrounds the first portion.
11. The article of footwear of claim 1 , wherein a second portion of the driveshaft extends axially outward from the first portion of the driveshaft, wherein the engagement plate surrounds the second portion.
12. The article of footwear of claim 1 , wherein the motorized tensioning system and a motor assembly that is configured to transmit torque to the driveshaft are disposed in a housing, the housing seated in the sole structure.
13. A method of controlling, in an article of footwear, a motorized tensioning device having a spool, the method comprising:
turning a driveshaft in a first direction using an electric motor, causing the driveshaft to turn a cam device in the first direction, causing a ramped edge of the cam device to push against a lower surface of an engagement plate such that a rotation of the cam device increases an axial distance between the cam device and the engagement plate;
increasing the axial distance between the spool is coupled to the cam device and the engagement plate, thereby transitioning the spool system from an engaged state to a disengaged state; and
in the disengaged state, imparting a force on one of an upper of the article of footwear and a tensile element of the article of footwear to freely unwind the tensile element around the spool.
14. The method of claim 13 , further comprising:
turning a driveshaft in a second direction, the second direction being a direction opposite to that of the first direction, the driveshaft turning a cam device in the second direction; and
decreasing an axial distance between the cam device and the engagement plate, thereby transitioning the spool system from the disengaged state to the engaged state.
15. The method of claim 14 , further comprising, in the engaged state, turning the spool in the second direction to wind the tensile element about the spool.
16. The method of claim 14 , wherein:
the cam device includes a step portion; and
increasing the axial distance includes placing a first spoke portion of the engagement plate flush against a first end of the step portion of the cam device.
17. The method of claim 16 , wherein the engagement plate further comprises a second spoke portion, wherein decreasing the axial distance includes placing the second spoke portion configured flush against a second end of the step portion of the cam device, the second end of the step portion being disposed on an opposite side of step portion relative to the first end.
18. The article of footwear of claim 17 , wherein the second end of the step portion has a greater height than the first end of the step portion increasing the axial distance includes traversing, with the first spoke portion.
19. The method of claim 18 , wherein the ramped edge comprises a first linear portion joined to the first edge, a second linear portion joined to the second edge, and a slope portion between the first linear portion and the second linear portion.
20. The method of claim 19 , wherein the first linear portion is disposed beneath the first spoke portion of the engagement plate in the disengaged state and describes a first height and the second linear portion is disposed beneath the second spoke portion in the engaged state and describes a second height greater than the first height.