Footwear heel spring device
A device configured to surround a portion of a foot-receiving cavity at a heel region of an article of footwear comprises a control bar having a center segment, a first side arm extending from the center segment, and a second side arm spaced from the first side arm and extending from the center segment. The control bar may include a series of slats. A base supports the control bar and is connected to the first side arm and the second side arm. The control bar is biased to an unstressed position with the center segment a first distance from the base, and elastically bends under an applied force to a loaded position with the center segment a second distance from the base less than the first distance. The device stores potential energy that returns the control bar to the unloaded position upon removal of the applied load.
1. A device for easing foot entry into an article of footwear, the device comprising:
a control bar that includes a series of slats, each slat having:
a center segment;
a medial side arm extending from the center segment to a medial end; and
a lateral side arm extending from the center segment to a lateral end;
wherein a lowermost one of the slats is thinner in a direction perpendicular to a longitudinal axis of the lowermost one of the slats than an uppermost one of the slats; and
wherein the medial side arm and the lateral side arm of each slat bends and the center segment of each slat pivots downward and rearward relative to the medial end of the medial side arm and the lateral end of the lateral side arm under an applied force to a loaded position, storing potential energy that returns the center segment of each slat to an unloaded position upon removal of the applied force.
2. The device of claim 1 , wherein:
the control bar defines slots extending between the slats;
the slats are spaced apart from one another by the slots when the control bar is in the unloaded position; and
one or more of the slots close between the slats so that adjacent center segments contact one another in the loaded position.
3. The device of claim 2 , wherein the adjacent center segments are configured to slide against one another when the adjacent center segments contact one another.
4. The device of claim 2 , wherein the slats are wider than the slots.
5. The device of claim 1 , wherein a lowermost one of the slats is shorter from the medial end to the lateral end than an uppermost one of the slats.
6. The device of claim 1 , wherein the device is a single, unitary, one-piece component.
7. The device of claim 1 , wherein the device has an extension extending downward from the center segment of one of the slats.
8. An article of footwear comprising:
a footwear upper including a flexible covering defining at least a portion of an ankle opening;
a sole structure secured to and underlying the footwear upper;
a heel spring device comprising a control bar operatively connected to the footwear upper;
wherein the control bar includes a series of slats, each slat having:
a center segment disposed rearward of the ankle opening;
a medial side arm extending from the center segment to a medial end disposed at a medial side of the article of footwear; and
a lateral side arm extending from the center segment to a lateral end disposed at a lateral side of the article of footwear;
wherein the control bar defines slots extending between the slats and terminating above the sole structure;
wherein the control bar pivots rearward under an applied force to a loaded position, storing potential energy in the heel spring device that returns the control bar to an unloaded position upon removal of the applied force, the flexible covering moving with the control bar.
9. The article of footwear of claim 8 , wherein:
the slats are spaced apart from one another by the slots when the control bar is in the unloaded position; and
one or more of the slots close between the slats so that adjacent center segments contact one another in the loaded position.
10. The article of footwear of claim 9 , wherein the adjacent center segments are configured to slide against one another when the adjacent center segments contact one another.
11. The article of footwear of claim 9 , wherein the slats are wider than the slots.
12. The article of footwear of claim 8 , wherein a lowermost one of the slats is shorter from the medial end to the lateral end than an uppermost one of the slats.
13. The article of footwear of claim 8 , wherein a lowermost one of the slats is thinner than an uppermost one of the slats.
14. The article of footwear of claim 8 , wherein:
the control bar has an extension extending from the center segment of one of the slats;
the footwear upper includes a pocket; and
the extension is disposed in the pocket to operatively connect the footwear upper to the control bar.
15. The article of footwear of claim 8 , wherein:
the footwear upper further comprises a collar secured to the flexible covering; and
the collar is disposed above the center segment of an uppermost one of the slats so that the center segment of the uppermost one of the slats is between the collar and the sole structure.
16. The article of footwear of claim 8 , wherein at least a portion of the control bar is disposed outward of an outer surface of the flexible covering in a heel region of the article of footwear.
17. The article of footwear of claim 8 , characterized by the absence of a rigid heel counter between the center segment of the control bar and the sole structure.
18. A device for easing foot entry into an article of footwear, the device comprising:
a control bar that includes a series of slats, each slat having:
a center segment;
a medial side arm extending from the center segment to a medial end; and
a lateral side arm extending from the center segment to a lateral end;
wherein:
the medial side arm and the lateral side arm of each slat bends and the center segment of each slat pivots downward and rearward relative to the medial end of the medial side arm and the lateral end of the lateral side arm under an applied force to a loaded position, storing potential energy that returns the center segment of each slat to an unloaded position upon removal of the applied force;
the control bar defines slots extending between the slats;
the slats are spaced apart from one another by the slots when the control bar is in the unloaded position;
the slats are wider than the slots; and
one or more of the slots close between the slats so that adjacent center segments contact one another in the loaded position.
19. A device for easing foot entry into an article of footwear, the device comprising:
a control bar that includes a series of slats, each slat having:
a center segment;
a medial side arm extending from the center segment to a medial end; and
a lateral side arm extending from the center segment to a lateral end;
wherein:
the medial side arm and the lateral side arm of each slat bends and the center segment of each slat pivots downward and rearward relative to the medial end of the medial side arm and the lateral end of the lateral side arm under an applied force to a loaded position, storing potential energy that returns the center segment of each slat to an unloaded position upon removal of the applied force;
the control bar defines slots extending between the slats;
the slats are spaced apart from one another by the slots when the control bar is in the unloaded position;
the device has an extension extending downward from the center segment of one of the slats; and
one or more of the slots close between the slats so that adjacent center segments contact one another in the loaded position.
20. An article of footwear comprising:
a footwear upper including a flexible covering defining at least a portion of an ankle opening;
a sole structure secured to and underlying the footwear upper;
a heel spring device comprising a control bar operatively connected to the footwear upper;
wherein:
the control bar includes a series of slats, each slat having:
a center segment disposed rearward of the ankle opening;
a medial side arm extending from the center segment to a medial end disposed at a medial side of the article of footwear; and
a lateral side arm extending from the center segment to a lateral end disposed at a lateral side of the article of footwear;
the control bar pivots rearward under an applied force to a loaded position, storing potential energy in the heel spring device that returns the control bar to an unloaded position upon removal of the applied force, the flexible covering moving with the control bar;
the control bar defines slots extending between the slats;
the slats are spaced apart from one another by the slots when the control bar is in the unloaded position;
the slats are wider than the slots; and
one or more of the slots close between the slats so that adjacent center segments contact one another in the loaded position.
21. An article of footwear comprising:
a footwear upper including a flexible covering defining at least a portion of an ankle opening;
a sole structure secured to and underlying the footwear upper;
a heel spring device comprising a control bar operatively connected to the footwear upper;
wherein:
the control bar includes a series of slats, each slat having:
a center segment disposed rearward of the ankle opening;
a medial side arm extending from the center segment to a medial end disposed at a medial side of the article of footwear; and
a lateral side arm extending from the center segment to a lateral end disposed at a lateral side of the article of footwear;
the control bar pivots rearward under an applied force to a loaded position, storing potential energy in the heel spring device that returns the control bar to an unloaded position upon removal of the applied force, the flexible covering moving with the control bar;
the control bar has an extension extending from the center segment of one of the slats;
the footwear upper includes a pocket; and
the extension is disposed in the pocket to operatively connect the footwear upper to the control bar.