Fluid Systems and Foot Support Systems Including Inflatable Foot Support Chambers with Varying Foot Support Pressure and Footwear Products Including Such Systems

Abstract

Fluid systems switch between a high pressure configuration and a low pressure configuration. Such fluid systems may be incorporated into sole structures and/or footwear in which the fluid systems may be used to vary foot support pressure between a high pressure foot support configuration (e.g., a firmer and more responsive configuration for more active uses) and a low pressure foot support configuration (e.g., a softer and more comfortable configuration for standing or less active uses). Some examples of this technology may use a manually activated interface to switch between the high pressure foot support configuration and the low pressure foot support configuration. In other examples, the fluid system may be configured to automatically change between the high pressure foot support configuration (e.g., when the wearer moves) and the low pressure foot support configuration (e.g., when the wearer remains stationary).

What is claimed is: 
     
         1 . A foot support system for an article of footwear, comprising:
 a foot support bladder;   a first pump including a first pump inlet and a first pump outlet;   a first fluid line placing the first pump outlet in fluid communication with the foot support bladder for supplying fluid to the foot support bladder; and   a slow pressure release component in fluid communication with the foot support bladder, wherein the slow pressure release component releases fluid from the foot support bladder to change the foot support bladder from a high pressure foot support configuration to a low pressure foot support configuration.   
     
     
         2 . The foot support system according to  claim 1 , wherein the slow pressure release component remains open at all times. 
     
     
         3 . The foot support system according to  claim 1 , wherein the slow pressure release component remains open while the first pump supplies fluid to the foot support bladder. 
     
     
         4 . The foot support system according to  claim 1 , wherein the slow pressure release component remains open at all times that fluid pressure in the foot support bladder is above a minimum threshold pressure. 
     
     
         5 . The foot support system according to  claim 1 , wherein the slow pressure release component releases fluid from the foot support bladder at a slower rate than a pumping rate at which the first pump supplies fluid to the foot support bladder. 
     
     
         6 . The foot support system according to  claim 1 , wherein the slow pressure release component includes: (i) a second fluid line that opens into the foot support bladder, (ii) a flow rate reducing component for restricting flow rate through the second fluid line, and (iii) a low pressure relief valve located in the second fluid line downstream from the flow rate reducing component; or
 wherein the slow pressure release component includes: (i) a second fluid line that extends from the first fluid line, (ii) a flow rate reducing component for restricting flow rate through the second fluid line, and (iii) a low pressure relief valve located in the second fluid line downstream from the flow rate reducing component.   
     
     
         7 . The foot support system according to  claim 1 , wherein the slow pressure release component includes: (i) a second fluid line that opens into the foot support bladder, and (ii) a flow rate reducing component for restricting flow rate through the second fluid line; or
 wherein the slow pressure release component includes: (i) a second fluid line that extends from the first fluid line, and (ii) a flow rate reducing component for restricting flow rate through the second fluid line.   
     
     
         8 . The foot support system according to  claim 7 , wherein the flow rate reducing component includes a fluid line insert having an always open orifice extending through the fluid line insert. 
     
     
         9 . The foot support system according to  claim 1 , further comprising:
 a high pressure relief valve configured to release fluid from the foot support system when necessary to prevent over-inflation of the foot support bladder.   
     
     
         10 . The foot support system according to  claim 9 , wherein the high pressure relief valve is located in a fluid line that extends from and is in direct fluid communication with one of the first pump, the foot support bladder, or the first fluid line. 
     
     
         11 . The foot support system according to  claim 1 , wherein when in the low pressure foot support configuration, the foot support bladder has a first height dimension, when in the high pressure foot support configuration, the foot support bladder has a second height dimension, and wherein the second height dimension is greater than the first height dimension. 
     
     
         12 . A sole structure for an article of footwear, comprising:
 a midsole component including an upper-facing surface and a ground-facing surface;   a foot support bladder having a foot supporting portion mounted on the upper-facing surface of the midsole component;   a first foot-activated pump including a first pump inlet and a first pump outlet, wherein the first foot-activated pump moves fluid in response to force applied by a wearer's foot;   a first fluid line placing the first pump outlet in fluid communication with the foot support bladder for supplying fluid to the foot support bladder; and   a pressure control system for maintaining fluid pressure in the foot support bladder between a maximum threshold value and a minimum threshold value, wherein the pressure control system includes a slow pressure release component in fluid communication with the foot support bladder, wherein the slow pressure release component continuously releases fluid from the foot support bladder when the fluid pressure in the foot support bladder is above the minimum threshold value.   
     
     
         13 . The sole structure according to  claim 12 , wherein the minimum threshold value corresponds to atmospheric pressure. 
     
     
         14 . The sole structure according to  claim 12 , wherein the slow pressure release component includes: (i) a second fluid line that opens into the foot support bladder, (ii) a flow rate reducing component for restricting flow rate through the second fluid line, and (iii) a low pressure relief valve located in the second fluid line downstream from the flow rate reducing component; or
 wherein the slow pressure release component includes: (i) a second fluid line that extends from the first fluid line, (ii) a flow rate reducing component for restricting flow rate through the second fluid line, and (iii) a low pressure relief valve located in the second fluid line downstream from the flow rate reducing component.   
     
     
         15 . The sole structure according to  claim 12 , wherein the slow pressure release component includes: (i) a second fluid line that opens into the foot support bladder, and (ii) a flow rate reducing component for restricting flow rate through the second fluid line; or
 wherein the slow pressure release component includes: (i) a second fluid line that extends from the first fluid line, and (ii) a flow rate reducing component for restricting flow rate through the second fluid line.   
     
     
         16 . The sole structure according to  claim 15 , wherein the flow rate reducing component includes a fluid line insert having an always open orifice extending through the fluid line insert. 
     
     
         17 . The sole structure according to  claim 12 , wherein the pressure control system further includes a high pressure relief valve configured to divert fluid moved by the first foot-activated pump away from the foot support bladder when the fluid pressure in the foot support bladder is at the maximum threshold value. 
     
     
         18 . The sole structure according to  claim 17 , wherein the high pressure relief valve is located in a fluid line that extends from and is in direct fluid communication with one of the first fluid line, the first foot-activated pump, or the foot support bladder. 
     
     
         19 . The sole structure according to  claim 12 , wherein when the foot support bladder is at the minimum threshold value, a foot supporting surface of the foot support bladder retracts to a location such that the upper-facing surface of the midsole component is positioned to directly support a portion of the wearer's foot adjacent the location where the foot support bladder has retracted. 
     
     
         20 . The sole structure according to  claim 12 , wherein when the fluid pressure in the foot support bladder is at the minimum threshold valve, the foot support bladder has a first height dimension, when the fluid pressure in the foot support bladder is at the maximum threshold valve, the foot support bladder has a second height dimension, and wherein the second height dimension is greater than the first height dimension.