Patent Publication Number: US-2011047817-A1

Title: Sole construction for shoe having self-pumping extendable spikes

Description:
FIELD OF THE INVENTION 
     This invention relates generally to sports shoes and more specifically involves a shoe with retractable spikes. 
     BACKGROUND OF THE INVENTION 
     Shoes with spikes or cleats are often worn for sports that require good foot traction. For example, golf players use spiked shoes for safer and more stable walking and standing on wet grass and slopes. 
     Historically, golf shoes had small metal spikes attached to the soles, such as by a threaded connection in the sole. Such spikes were durable and provided good traction, but damaged the grass of golf courses and scratched or gouged interior floors. Golf players were typically required to remove their spiked shoes before entering offices or clubhouses associated with golf courses. Most golf courses have now even banned or restricted use of metal spikes altogether. 
     Another type of golf spike that is less damaging to grass and floors is a blunt spike of hard plastic, which may be single- or multi-pronged. Most golf courses allow these plastic spikes to be used both on grassy fairways and on most interior surfaces. 
     Plastic spikes have four main disadvantages. First, they can still damage the finely groomed grass of the greens, and even leave a slight indentation. 
     Second, on some surfaces, plastic spikes are more slippery than most conventional shoes. For example, on a smooth or wet floor or exterior walking surface, plastic spikes can cause the wearer to slip and fall. 
     Third, plastic spikes are not as durable as metal ones. Although the grass of the actual golf course does not wear out plastic spikes too quickly, walking on concrete sidewalks and parking lots, for example, does shorten the life of plastic spikes greatly. 
     Fourth, plastic spikes collect grass and mud that reduces the ability to provide good traction with the ground. 
     Attempts have been made to provide non-damaging shoes for golf by including mechanisms to extend the spikes only when needed. Such mechanisms include cleats that are cranked by hand or moved by one or more levers. These retracting spikes have been found to have certain disadvantages of their own. For example, the mechanism may be prone to becoming jammed by mud or rust. The mechanism may be so difficult to operate that it is necessary to sit down to safely extend or retract the spikes. The inevitable mud and grass that creep into the moving parts cause wear and corrosion, shortening the useful life of the mechanism. Mechanical mechanisms add to the weight of the shoe and make the sole less flexible. Thus, despite attempts to create better shoes, golf players still have considerable inconvenience associated with their footwear. 
     There is a great need for shoes that provide traction when needed but that do not have the disadvantages of conventional golf spikes. There is further a need for spikes that do not damage golf greens or other fine-textured grass. There is a need for a golf shoe that can be worn on the course, in the clubhouse or other buildings, and for walking on sidewalks and across parking lots without excessive wear. There is a need for a durable spiked shoe that is safe to walk in on all surfaces. 
     In the case of retracting spikes, there is a need for a shoe that is easy enough to operate that it does not interrupt the game unduly or require the user to sit. Such a shoe would preferably be self-contained and not require the wearer to carry auxiliary equipment or replace expendable parts. 
     SUMMARY OF THE INVENTION 
     The present invention is a sole assembly for a shoe for golf or other sports, with plastic spikes that may be easily extended when needed and retracted when not needed. The spikes are activated by pneumatic pressure that is generated by the wearer&#39;s own movement. The selection mechanism for extending or retracting the spikes is a switch that can be operated with a single click. 
     The sole assembly includes an integral pump that selectively compresses air into a reservoir, powered by the wearer&#39;s walking motion. Air from the reservoir expands plenum chambers that exert downward force on spike assemblies. Air pressure is maintained by check valves. The spikes protrude from apertures in the outsole then retract when air pressure is released. Mud and grass are scraped from the spikes as they retract. 
     The plenum chambers are formed in a thin plenum membrane of durable, resilient synthetic rubber that is attached between midsole and outsole. The moving portion of the plenum membrane is attached to a rigid ferrule, which moves like a piston inside the complementarily-shaped aperture. The aperture walls support the plenum membrane such that over-distortion of the material does not occur, preventing cracking of the rubber from stress. 
     The plenum members are biased in an upward position. When air pressure is released by striking the switch, plenum members and attached spikes retract into the sole. 
     All components of the sole assembly, including valves, may be constructed from synthetic polymeric materials to avoid corrosion and any need for lubrication. The pump device consists of a compressible bladder and a pressure reservoir, both made of resilient rubber. They are designed to flex with the sole assembly and not create discomfort to the wearer. All materials are selected for durability and reliability of the sole assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded side perspective view of the sole assembly of the present invention. 
         FIG. 2  is a top perspective view of the outsole portion of the sole assembly of  FIG. 1 , with most pneumatic components in place. 
         FIGS. 3A and 3B  are cross sectional views taken along lines  3 - 3  of  FIGS. 5A and 5B , respectively, shown in retracted and extended positions, respectively. 
         FIG. 4  is an enlarged perspective of the spike assembly of  FIG. 1 . 
         FIGS. 5A and 5B  are top, side perspective views, partly cut away, of the sole assembly of  FIG. 1  in the retracted and extended positions, respectively. 
         FIG. 6  is a bottom perspective view of the midsole portion of the sole assembly of  FIG. 1   
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is a sole assembly  10  that may be attached to many styles of shoe upper (not shown) to create a shoe with cleats or spikes that may be extended or retracted depending on need. 
       FIG. 1  is an exploded side perspective view of sole assembly  10  of the present invention. Sole assembly  10  generally includes a midsole  20  for attaching to a shoe upper, an outsole  90  for providing a durable walking surface, spike assemblies  70  that selectively protrude from the bottom of outsole  90 , and a pneumatic system  40  that activates the movement of spike assemblies  70  by compressed gas, such as air. 
     Outsole  90  includes a front portion  91  for supporting the front part of a foot, a rear portion  92  for supporting the heel of a foot, and an arch portion  93  for supporting the arch of a foot. Typically, a shoe heel  95  of especially durable material is attached to the bottom of rear portion  92 . With shoe heel  95  attached, heel  95  and front portion  91  contact the ground when the wearer walks; arch portion  93  either does not contact the ground or does not bear much weight. 
     Outsole  90  preferably includes shallow cut-outs in its upper face, to accommodate components of pneumatic system  40 . A plurality of apertures  94  pierce outsole  90  from upper face to bottom face. Apertures  94  also pierce shoe heel  95  in like manner. Pneumatic system  40  further includes heel pneumatic subsystem  43 , which activates the movement of spike assemblies  70  through shoe heel  95 . 
     Midsole  20  and outsole  90  are attached together, such as by adhesive as is well known in the art, with a plenum membrane  30  sandwiched between. Midsole  20 , outsole  90 , and plenum membrane  30  when attached together collectively form a sole body  15 . Plenum membrane  30  is a sheet of strong resilient material such as nitrile, Viton, silicone rubber, or other suitable material, which includes a plurality of plenum members  33  formed into it, such as by a molding process. Plenum membrane  30  may be front plenum membrane  31 , adapted to be sandwiched between midsole  20  and front portion  91  of outsole  90 ; or may be heel membrane  32 , adapted to be sandwiched between rear portion  92  of outsole  90  and shoe heel  95 . 
     Sole assembly  10  further includes a plurality of spike assemblies  70 , consisting of a spike body  71  for providing traction and a ferrule  80 , which might also be comprehended as a thrust bearing for moving spike body  71  between a retracted and an extended position. 
       FIG. 2  is a top perspective view of outsole  90 , with many of the components of pneumatic system  40  installed in their respective cut-outs. Pneumatic system  40  includes pump means  42  for supplying compressed air to activate spike assemblies  70 , switch valve  55 , and sections of tubing  60  connecting the components such that compressed gas can be conducted to spike assemblies  70  or released to the atmosphere, as needed. 
     Pump means  42  is for supplying compressed air to activate movement of spike assemblies  70  from retracted to extended position. In the preferred embodiment shown and described herein, pump means consists of a hollow, compressible bladder  41 , a compressed air reservoir  45  in pneumatic communication with bladder  41 , such as being connected by tubing  60 , and two check valves  51   a,b  for maintaining air pressure within pneumatic system  40  at a selected value. Compression of bladder  41 , such as by the wearer&#39;s weight during walking, forces air into reservoir  45 , where pressure builds with each step. 
     Other means for providing compressed air through a wearer&#39;s walking movement are envisioned but not illustrated, such as a flexible hollow pipe arranged in serpentine fashion within sole body  15  so as to be compressed progressively from rear to front as the wearer steps first on heel  95  then transfers weight toward front portion  95 . 
     Bladder  41  has a resilient bias toward being in an expanded position. Bladder  41  is compressed by the weight of the wearer&#39;s downward step and the air inside bladder  41  is forced into reservoir  45 . As the wearer steps forward and lifts weight from above bladder  41 , bladder  41  returns to the expanded position, drawing in additional air through inlet tube  63 . 
     Bladder  41  is most efficiently shaped to conform to the outline of the bottom of wearer&#39;s heel, although design details may vary. Reservoir  45  may be of the same shape as bladder  41  or of other shapes chosen for efficient operation and fit within sole assembly  10 . In the preferred embodiment illustrated herein, reservoir  45  is shown as a pair of elongate tubes that are connected together. The reason for separating reservoir  45  into two elongate halves is to provide a shape that flexes with the wearer&#39;s foot so as not to impede walking. 
     A plurality of apertures  94  disposed in front portion  91  of outsole  90  are shaped to receive plenum members  33  and ferrules  80  from above and spike bodies  71  from below. In the preferred embodiment show and described herein, plenum members  33  are portions of plenum membrane  30  that are formed during the molding process to be in the shape of dome springs that are upwardly biased. The complex shape of plenum members  33  can best be understood from  FIG. 3 , as will be explained below. 
       FIG. 4  is a bottom perspective view of spike assembly  70 . Spike assembly  70  includes spike body  71  and ferrule  80 . Spike body  17  includes a threaded connector  74 , and ferrule  80  includes a threaded hole  81  for accepting threaded connector  74 . Ferrule  80  has a top surface  82 . 
     Spike body  71  further includes a flange  72  and a spike shaft  75  including a tip  76  for contacting the ground and increasing traction. Flange  72  includes a plurality of engagement holes  73  for accepting a pronged tool (not shown) to aid connecting and disconnecting spike body  71  to and from ferrule  80 , such as to replace spike body  71  if tip  76  is damaged. 
     Each plenum member  33  is attached to top surface  82  of one ferrule  80 . This may be accomplished by gluing. In the most preferred embodiment, plenum members  33  are created by molding suitable material in the shape of front membrane  31  and heel membrane  32 . Furthermore, it is most preferred to attach ferrules  80  to plenum members  33  by the process of co-molding, as is well known. That is, an appropriate number of ferrules  80  are placed into a prepared mold then the molten rubber material is forced into the mold to create front and heel membranes  31 , 32  in which each ferrule  80  is embedded strongly beneath one plenum member  33 . 
     Plenum members  33  may alternatively be individual units that are not connected together. Plenum members  33  may take various forms other than the one illustrated and described herein, as may be readily appreciated by those skilled in the art. 
       FIGS. 5A and 5B  are top, side perspective views, partly cut away, of the sole assembly of  FIG. 1  in the retracted and extended positions, respectively.  FIG. 6  is a bottom perspective view of the midsole portion of the sole assembly of  FIG. 1 . 
     As seen in  FIG. 6 , the bottom face of midsole  20  includes plenum cutouts  24  that mirror the position of apertures  94  in outsole  90 . However, plenum cutouts  24  are relief cutouts only and do not pass through midsole  20 . Plenum cutouts  24  are connected in series by air channel  22 . Air channel  22  is disposed so as to align with the outlet of supply tube  62 , best seen in  FIG. 2 . 
     When outsole  90 , plenum membrane  30 , and midsole  20  are attached together to create sole body  15 , air channel  22  cooperates with supply tube  62  to supply compressed air to all plenum members  33  of front plenum membrane  31 . After passing through air channel  22 , compressed air enters heel tubing  64  and is conducted downwardly through borehole  96  to activate plenum members  33  of heel membrane  32 . 
     Looking especially now at  FIGS. 3A and 3B , it can be seen that spike assembly  70  is moved from a retracted position ( FIG. 3A ) to an extended position ( FIG. 3B ) by expansion of plenum (or “expansion”) chamber  34 . In  FIG. 3A , plenum chamber  34  is in contracted position, plenum member  33  and ferrule  80  are almost entirely retracted within plenum cutout  24 , and spike tip  76  barely protrudes below the bottom surface of outsole  90 . 
     In  FIG. 3B , plenum chamber  34  is in expanded position due to introduction of compressed air through air channel  24 , the end of which is seen at the back of plenum chamber  34 . Plenum chamber  34  is defined by plenum cutout  24  forming its upper wall and the upper portion of the side walls and by plenum member  33  forming its bottom wall and bottom portion of side walls. Plenum cutout  24  is relatively rigid and is unaffected by introduction of compressed air. Plenum member  33  is resilient and movable, and everts downward when the pressure within plenum chamber exceeds its design value, typically about  5 - 45  psi. When plenum member  33  is forced downward as in  FIG. 3B , it pushes spike assembly  70  to its extended position in which the entire spike shaft  75  protrudes below the bottom of outsole  90 . 
     In  FIG. 3A , plenum member  33 , in contracted position, can be seen to be a generally dome-shaped portion of plenum membrane  30 , with spike assembly  70  attached beneath the upwardly-biased dome. In  FIG. 3B , plenum member  33  has been moved to an everted position by the pressure of compressed gas or air introduced between midsole  20  and plenum membrane  30  through tubing  60 , connected to pump means  42 . In the everted position of  FIGS. 5B and 3B , a plenum cavity  34  is created, which is maintained in the expanded position by being filled with compressed air from pump means  42 . 
     The deviations from a simple convex dome shape adapt plenum member  33  to fit tightly around ferrule  80  and also adapt plenum member  33  to move spike assembly  70  a longer downward distance when plenum member  33  moves from its contracted to its everted position. Plenum member  33  “pops” from contracted to everted position without significant stretching of any portion of plenum member  33 . In the everted position, the walls of plenum member  33  are supported by the shaped walls of aperture  94  and by rigid ferrule  80  so as to protect plenum member  33  against over-expansion. The shape of plenum member  33  and support from aperture  94  and ferrule  80  cooperate to provide a movement mechanism for spike assemblies  70  that is very durable and robust. 
       FIGS. 3A and 3B  show midsole  20  as including cut-out portion  24  to accept each plenum member  33  in its contracted position and to form part of the volume of plenum cavity  34  when plenum member  33  is everted. This is a preferred embodiment of the present invention, but alternative designs are possible and will be obvious to those with skill in the art. 
     To assemble sole assembly  10 , midsole  20  is attached to an appropriate shoe upper (not shown) as is well known. The shoe upper may be of a sort suitable for wearing while playing sports, including golf or soccer, or may be of a sort suitable to wear hiking on loose soil or mud, or for walking on snow or ice. 
     Front plenum membrane, with attached ferrules  80 , is placed over front portion  91  of outsole  90  such that ferrules  80  each nest into an aperture  94 . The components of pneumatic system  40  are placed in their respective cut-outs in outsole  90 . Sections of tubing  60 , such as flexible tubing of durable synthetic rubber, are used to connect the components as shown in  FIG. 2 . Tubing  60  includes an intake tube  61 , supply tube  61 , outlet tube  63 , and heel tube  64 . 
     Supply tube  62  connects the plenum members  33  in series to pump means  42  via switch valve  55 . Plenum members may be connected to each other by small sections of tubing  60 , or more preferably, by channels  24  cut into the bottom surface of midsole  20  as shown in  FIG. 6 . Heel tube  64  passes through a borehole  96  through outsole  90  to supply compressed gas to heel subsystem  43 . Spike assemblies  70  are typically disposed in the front and heel portions of the sole assembly only, because arch portion  93  does not bear much weight of the wearer. 
     After the upper portion of pneumatic system  40  is assembled on the top surface of outsole  90  and heel tube  64  is inserted into borehole  96 , midsole  20  and outsole  90  are attached together with plenum membrane  30  between them. Typically, suitable adhesive is spread over the flat (non-cut-out) upper surfaces of outsole  90  and the complimentary surfaces of the bottom of midsole  20 . Then midsole  20  and outsole  90  are pressed together, optionally in a mold, so as to create a gas-tight bond among outsole  90 , midsole  20 , and plenum membrane  30 . 
     In similar manner, heel pneumatic subsystem  43  is assembled on the bottom of outsole  90  and outsole  90  and shoe heel  95  are glued together with heel membrane  32  sandwiched between them. Heel tube  64  connects the plenum members  33  in series to pump means  42  so as to activate spike assemblies  70  located in heel  95 . 
     Because air channel  24  will not function efficiently if partially obstructed by adhesive, the adhesive applied between midsole  20  and outsole  90 , and between outsole  90  and heel  95 , is preferably metered and located precisely. This may be done by use of a sheet of preformed solid adhesive, by screen printing the adhesive, by offset printing, by machine-controlled syringe dispensing, or similar technique as is well known. 
     Finally, spike bodies  71  are connected to ferrules  80  by screwing them into threaded holes  81 . Optionally, a tool (not shown) with prongs adapted to fit into engagement holes  73  may be used to rotate spike body  71 . 
     As the wearer walks, bladder  41  is alternately compressed and released. When bladder  41  is released, bladder  41  fills to its natural expanded state by drawing air through inlet tubing  61  and check valve  51 . When bladder  41  is compressed, the air is prevented by check valve  51   a  from returning through inlet tube  61 , so the air is forced on ward from bladder  41  into pressure reservoir  45  via check valve  51   b.    
     The air then flows to switch valve  55 , which includes a switch, such as pushbutton  58 , or a toggle switch, rocker switch, or other suitable switch means. Switch valve  55  is a two-way valve, which can direct air received from reservoir  45  either to supply tube  62  or to outlet tube  61 , as selected by the wearer using pushbutton  58 . 
     If “relief” mode is selected, a small amount of air is drawn into inlet tube  61  and released from outlet tube  63  with each step. The pressure of this circulating air is not enough to evert plenum members  33  and extend spike tips  76  against the weight of the wearer. 
     To activate spike assemblies  70  to increase the traction of the shoe during wearing, switch valve  55  is set to retain pressure within pneumatic system  40 . Pushbutton  58  may be manipulated by hand, by tapping it with a golf club or hiking stick, or by tapping the heel of one shoe against the switch  28  of the other shoe. Only a single click is required to change switch valve  55  from “pressure” mode to relief mode, or vice versa. 
     With switch valve  55  in pressure mode, compressed air from reservoir  45  is directed through supply tube  62  to pressurize plenum members  33 . The pressure is usually sufficient to evert plenum members  33  immediately and extend spike tips  76  substantially below outsole  90 . Should there be insufficient pressure stored in reservoir  45 , pump means  42  will add the additional pressure needed as the wearer takes the next few steps. Switch valve  55  maintains pneumatic system  40  closed so that spike tips  76  remain extended and support wearer&#39;s weight. 
     Check valves  51   a, b  are adapted to maintain pneumatic system  40  at a predetermined pressure when pressure mode is selected. Check valves  51   a, b  prevent backflow of compressed air until the target pressure is reached. After that, check valves  51   a,b  will allow excess air to escape, in order to prevent undue stress on pneumatic system  40  and to maintain a comfortable flexibility and softness of sole assembly  10  for walking. 
     Depending upon the intended use for a shoe with the sole assembly  10  of the present invention, the bottom surface of outsole  90  may be generally smooth. In this case, it may be preferable that spike body  71  be dimensioned such that tip  76  is flush with the bottom surface of outsole  90  or retracts to be slightly above the bottom of outsole  90 . 
     Alternatively, outsole  90  may have permanent tread features such as ripples, ridges, or other texture pattern. In this case, it may be desirable that spike body  71  retract only sufficiently that tip  96  protrudes slightly from outsole  90  in the retracted position. Many design choices may be made while enjoying the advantages of the present invention. 
     Although particular embodiments of the invention have been illustrated and described, various changes may be made in the form, composition, construction, and arrangement of the parts herein without sacrificing any of its advantages. Therefore, it is to be understood that all matter herein is to be interpreted as illustrative and not in any limiting sense, and it is intended to cover in the appended claims such modifications as come within the true spirit and scope of the invention