Cushioning element, footwear, insole, deformable filling, and envelope
Cushioning element ( 4 ) for footwear, having a deformable filling ( 12 ) and an envelope ( 10 ) that encloses the deformable filling. The envelope is arranged for forming at least one flow channel ( 837 ). In use, at least part of the deformable filling flows into the at least one flow channel as a result of increased pressure of the deformable filling caused by a mechanical load The deformable filling contains solid bodies and further contains a lubricating fluid for mutually lubricating the solid bodies. A dimension of the at least one flow channel is arranged for hindering entrance of the solid bodies into the at least one flow channel during cushioning.
1. Cushioning element for footwear, having a deformable filling and an envelope that encloses the deformable filling, wherein the envelope is arranged for forming at least one flow channel, wherein, in use, at least part of the deformable filling flows into the at least one flow channel as a result of increased pressure of the deformable filling caused by a mechanical load, wherein the deformable filling contains solid bodies and further contains a lubricating fluid for mutually lubricating the solid bodies, wherein the at least one flow channel is dimensioned for hindering entrance of the solid bodies into the at least one flow channel during cushioning,
wherein the envelope has an elastically variable volume, and
wherein the envelope is arranged for forming the at least one flow channel by developing, substantially reversibly, a bulge in at least one deformable portion as a result of increased pressure of the deformable filling exerted on the at least one deformable portion, caused by the mechanical load, and
wherein the at least one flow channel is dimensioned for inhibiting entrance of the solid bodies into the at least one flow channel during cushioning.
2. Cushioning element according to claim 1 , wherein the solid bodies are substantially spherically shaped.
3. Cushioning element according to claim 1 , wherein a diameter of the solid bodies is in a range between 0.1 millimeter and 2 millimeter.
4. Cushioning element according to claim 1 , wherein the solid bodies are, at least partly, made of teflon.
5. Cushioning element according to claim 1 , wherein a volume ratio of the solid bodies and the lubricating fluid is in a range between 1 and 10.
6. Cushioning element according to claim 1 , wherein the viscosity of the lubricating fluid is arranged for, and the at least one flow channel is further dimensioned for, obtaining that the at least part of the deformable filling that flows, in use, into the at least one flow channel as a result of the pressure of the deformable filling caused by the mechanical load, is formed by between 10% and 20% of a volume of the lubricating fluid of the deformable filling.
7. Cushioning element according to claim 1 , wherein the square A c 2 of a value of a cross-sectional area A c of the at least one flow channel, which cross-sectional area is transverse to a flow direction of the at least part of the deformable filling into the at least one flow channel, divided by the product of the viscosity η of the lubricating fluid and a length L of the at least one of flow channel, is at least 0.001 cm 3 /(Pa s) and/or at most cm 3 /(Pa s), so that 0.001≧A c 2 /ηL and/or A c 2 /ηL≧10, and preferably is around 0.02 cm 3 /(Pa-s).
8. Cushioning element according to claim 1 , wherein a total number of the flow channels is in a range from 3 to 12.
9. Cushioning element according to claim 1 , wherein the bulge can be developed repeatedly without fracturing.
10. Cushioning element according to claim 9 , wherein the at least one flow channel is in fluid connection with a resilient member.
11. Cushioning element according to claim 9 , wherein the at least one deformable portion has a reduced rigidity compared to a remaining portion of the envelope.
12. Cushioning element according to claim 11 , wherein a size of the deformable portion is adapted for having a dimension of the bulge in a direction of the flow of the deformable filling into the bulge that is larger than a dimension of the bulge transverse to the direction of the flow of the deformable filling into the bulge.
13. Cushioning element according to claim 11 , wherein the remaining portion of the envelope includes a support member that comprises at least one aperture to define the at least one deformable portion.
14. Cushioning element according to claim 13 , wherein the support member has at least one funnel that extends from the aperture and is arranged to receive the at least one bulge.
15. Cushioning element according to claim 14 , wherein the funnel has a restriction arranged for limiting a size of the bulge.
16. Cushioning element according to claim 15 , wherein the restriction is formed by a closed end wall of the funnel.
17. Cushioning element according to claim 1 , wherein the at least one deformable portion comprises a resilient material.
18. Cushioning element according to claim 1 , wherein the at least one deformable portion is one of a plurality of mutually similar deformable portions, and wherein the bulge is one of plurality of mutually similar bulges, wherein the cushioning element is arranged for developing, substantially reversibly, the plurality of bulges from the respective deformable portions as a result of increased pressure of the deformable filling exerted on the plurality of deformable portions, caused by the mechanical load.
19. Cushioning element according to claim 1 , wherein the deformable filling and/or the lubricating fluid is, at least partly, formed by at least one of a viscoelastic fluid and a viscoelastic solid.
20. Cushioning element according to claim 1 , wherein the deformable filling and/or the lubricating fluid is, at least partly, formed by a shear-thickening fluid.
21. Cushioning element according to claim 1 , arranged for absorbing a mechanical shock.
22. Insole provided with a cushioning element according to claim 1 .
23. Footwear, provided with a cushioning element according to claim 1 .
24. Cushioning element for footwear, having a deformable filling and an envelope that encloses the deformable filling, wherein the envelope is arranged for forming at least one flow channel, wherein the envelope is provided with at least one deformable portion that has a reduced rigidity compared to a remaining portion of the envelope, wherein the cushioning element is arranged for developing, substantially reversibly, a bulge in the at least one deformable portion as a result of increased pressure of the deformable filling exerted on the at least one deformable portion, caused by a mechanical load, and the bulge is formed in a cavity of a support member, and
wherein the deformable filling contains solid bodies, and
wherein the at least one flow channel is dimensioned for inhibiting entrance of the solid bodies into the at least one flow channel during cushioning.