Abstract:
An adjusting mechanism alters the heel height on a prosthetic foot, and works independently of any articulating ankle joint or foot style, without changing the original dynamic alignment of a prosthetic leg. In a two chamber hydraulic closed system—a fluid material is allowed to flow through the two chambers by means of pistons that push the fluid material equally from one chamber to another until the desired heel height is obtained. Once the correct position is obtained, the ports are closed by means of a push button stop, which closes the ports and stops all transfer of fluid between the ports holding the heel in position during use.

Description:
[0001]     This application is a continuation-in-part of U.S. patent application Ser. No. 10/998,091, titled “Adjusting Mechanism For A Prosthetic”, filed Nov. 24, 2004, incorporated herein by reference. This application claims further priority to U.S. Provisional Patent Application Ser. No. 60/525,289, titled: “Heel Height Adjusting Mechanism For A Prosthetic Foot,” filed Nov. 25, 2003, incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to prosthetics, and more specifically, it relates to an adjusting mechanism for a prosthetic.  
         [0004]     2. Description of Related Art  
         [0005]     A variety of adjustable prosthesis joints are known; however, they are generally expensive to manufacture, complex and larger than desirable.  
         [0006]     For example, U.S. Pat. No. 5,957,981 claims an adjustable prosthesis joint to set the angular relation between an attachment socket for connecting the joint to a cooperating body member and a prosthesis detail, the prosthesis joint comprising a housing; a chamber disposed in the housing; an intermediate wall fixed within the chamber to subdivide the chamber into at least two communicating chamber portions, wherein the cross-section of the chamber is curved so that the wall subdivides the chamber into two cylindrical curved chamber portions; an adjustable valve provided in a valve housing in connection to the wall, wherein the adjustable valve is movable between a closed position and an open position; a flow medium to communicate between the chamber portions through the valve; at least two pistons wherein each piston is movably disposed in one of the two chamber portions and the pistons are interconnected to and are adapted to be uniformly displaced in relation to the wall under flow of the flow medium through the valve in the open position between the chambers.  
         [0007]     Another example of a prostheses joint that is complex, expensive to manufacture and large is found in U.S. Pat. No. 5,704,945, which claims a brake-action knee joint for a leg prosthesis, comprising: an upper prosthetic part; a lower prosthetic part; a joint pin which includes a rotary piston and which is connected in a torsionally rigid fashion to the upper part of the joint; a rocker which forms a central part of the joint, the rocker having an extension-side end fixed to a rocker pin lying parallel, ventrally and distally with respect to the joint pin and having a flexion-side end, wherein the rocker surrounds the joint pin; and a braking device activated by foot loading, which includes a closed, fluid-filled displacer chamber; a valve plunger having an open position and a closed position; a valve-plunger spring; and a first adjusting device mounted on the lower prosthetic part of the joint and connected to the valve plunger; wherein the displacer chamber concentrically surrounds the joint pin over its circumference, at least partially and is arranged in an associated end of the central part of the joint, wherein the rotary piston divides the displacer chamber into an extension chamber and a flexion chamber, which are connected to one another by way of an oil line which can be completely or partially closed by the valve plunger; and wherein the valve plunger is mounted in the central part of the joint in such a way as to be displaceable counter to the action of the valve-plunger spring pushing it into its open position and, when the central part of the joint is pivoted in the direction of flexion about the rocker pin, is pushed into its closed position by the adjusting device.  
         [0008]     It is desirable to provide a simplified, relatively inexpensive and small mechanism for adjusting the angular position of a prosthetic. The present invention provides such a mechanism.  
       SUMMARY OF THE INVENTION  
       [0009]     It is an object of the present invention to provide an adjusting mechanism for adjusting the relative position of a prosthetic device with respect to another device, attachment or human or animal body part.  
         [0010]     It is another object to provide a method for fabricating an adjusting mechanism.  
         [0011]     These and other objects will be apparent to those skilled in the art based on the disclosure herein.  
         [0012]     The invention is an adjusting mechanism for adjusting the position of a prosthetic. In the exemplary embodiment, the adjusting mechanism alters the heel height on a prosthetic foot, and will work independently of any articulating ankle joint or foot style, without changing the original dynamic alignment of a prosthetic leg. Each individual patient as necessary can accomplish this, after delivery of a prosthesis.  
         [0013]     The exemplary embodiment is designed as an infinitely adjustable heel height positioning unit and fixture alignment tool used in artificial legs. This is accomplished in the adjusting mechanism of the present invention by means of a two chamber hydraulic closed system wherein a fluid material is allowed to flow through the two chambers by means of pistons which push the fluid material equally from one chamber to another until the desired heel height is obtained. Once the correct position is obtained, the ports are closed by means of a push button stop, which closes the ports and stops all transfer of fluid between the ports holding the heel in position during use. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The accompanying drawings, which are incorporated into and form a part of the disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.  
         [0015]      FIG. 1 , shows a perspective view of an exemplary embodiment of the present invention.  
         [0016]      FIGS. 2A-4F  show a series of views of an exemplary embodiment of the present invention.  
         [0017]      FIG. 5  shows a top cut-away view of the valve in the open position.  
         [0018]      FIG. 6  shows a top cut-away view of the valve in the closed position.  
         [0019]      FIG. 7  shows a perspective view of an exemplary embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]      FIG. 1  shows a perspective view of an embodiment of the present invention. Upper support unit  10  includes a standardized male connector  12 , which is well known in the art. A grease insertion port  14  is shown on one side of upper support unit  10 . Another grease insertion port  15  (not shown) is on the opposite side of the grease insertion port  14 . A set screw can be sealed in place in each grease insertion port after the desired amount of grease has been inserted into the internal valve and cylinder system discussed below. A piston  16  is shown protruding from the bottom of the upper support unit  10 . Another piston  17  (not shown) is located parallel to and on the opposite side of the upper support unit  10  from piston  16 . A valve control button  18  is shown on one side of upper support unit  10 . This button  18  is connected to a valve control shaft  20  that is internal to the upper unit  10  and thus not shown in this figure.  
         [0021]     Referring again to  FIG. 1 , a lower support unit  22  includes a standardized female connector  24  (not visible in this view). Set screws are usable to secure the unit to another connector similar to connector  12  of a unit to which the present invention may be attached. Lower unit  22  includes a first bridge portion  28  through which a rotation axis pin  30  may be passed. A second bridge portion  29  is located on the opposite side of the lower unit  22  parallel to the first bridge portion  28 . Upper unit  10  includes a rotation through hole  32 , which provides a clear path for the pin  30  to pass. When assembled, pin  30  is passed through bridge  28 , hole  32  and bridge  29  and secured in place with securing mechanisms  34  and  35  (not shown).  
         [0022]      FIGS. 2A-4F  show a series of views of an exemplary embodiment of the present invention.  FIG. 4B  shows a side cut-away view of the assembly. Note the valve control buttons  18  and  19  connected to valve control shaft  20 . Shaft  20  includes a port  40  and seals  42 . Upper unit  10  includes a bored out diameter  44  on one end that is large enough that valve control button  19  may be pushed in toward the center of the assembly. This will cause the valve control shaft  20  to slide within a through hole  46  within which shaft  20  is located, such that port  40  is aligned with valve ports  48  and  49  shown in  FIG. 4E .  FIG. 4E  is a side cut-away view of the assembly perpendicular to the view of  FIG. 4B . Thus, shaft  20  is located in hole  46  of  FIG. 4E . As discussed above with reference to  FIG. 1 , a volume of grease is forced into grease entry ports  14  and  15 , which ports are subsequently sealed. The volume of grease fills the internal area, which is under vacuum, in this embodiment. Pistons  16  and  17  are located within cylinders  50  and  51  respectively and include seals  52 . When button  19  is pressed up against the stop of bored out hole  44 , shaft  20  slide such that port  40  aligns with ports  48  and  49 . In this position, which is referred to herein as the “unlocked” position, the pistons can move up and down in the cylinders. For example, when piston  16  moves up in cylinder  50 , the constant volume of grease forces piston  17  down in cylinder  51 . When button  18  is pushed, it forces shaft  20  to move such that port  40  is no longer aligned with ports  48  and  49 . In this position, which is referred to herein as the “locked” position, force applied to either piston will not move that piston because the grease cannot flow within the system.  
         [0023]     The assembly can be attached to a prosthetic, placed in the unlocked position, the angle is adjusted between the upper unit and the lower unit, and then the assembly is locked. In practice, e.g., a practitioner or user could attach the assembly to a prosthetic (prosthesis) and the end user could place it in the unlocked position. The user could then adjust the angle between the upper unit  10  and the lower unit  22  so that the assembly was comfortable. The user could then place the assembly in the locked position to hold it in the desired alignment.  
         [0024]     The present invention can be made in a variety of ways. Examples of suitable materials are metals (e.g., aluminum, titanium) and plastics. The invention can be machined or cast. The following is a description of a machining method. In the first step, the raw material is placed into a CNC Lathe. Material is removed to form a straight diameter and a spherical radius on one end of a shaft. A parting tool separates the part from the bar stock. In the second step, the part is placed into a fixture in a CNC Milling machine and is held by the straight section that was produced in the first step. Material is removed by use of an end mill cutting tool to create two straight sections, leaving a solid body of material extending from one side of the round stock to the other side. Two holes are then drilled from the top of the part to form the piston chambers. The bottoms of the holes are then flattened by means of a drill-type cutting device. A hole is then drilled on the flat surface at the bottom of the piston chambers to connect to a hole to be drilled perpendicular to the piston chamber at a later time. A boring tool is then used to size each piston hole to a +0.0015/−0.000 nominal diameter of the mating piston.  
         [0025]     In the third step, the part is then moved in the fixture so that it is held horizontally to be trimmed and gripped by the flat sections machined in the second step. A hole is then drilled into the body of the part to form the chamber used to insert the grease into the finished product. A second hole is then drilled to flatten the bottom of the first hole drilled in this step. This first hole crosses the hole drilled in the bottom of the piston chamber hole described in the second step to allow a connection between these two chambers. A small hole is drilled at the bottom of the grease filled hole to a depth to enter a hole to be drilled perpendicular to this hole in a later step. A high-pressure port tool is then used to create a seal surface for a high-pressure plug to be installed during final assembly of the finished product. The port hole is then tapped to connect with the high pressure plug described above. The part is then turned 180 degrees and this process is repeated.  
         [0026]     In the fourth step  4 , the part is then moved in a fixture and held perpendicular to the grease fill holes, and timed by the flat sections machined in the second step. A hole is drilled through the material at the end furthest from the spherical radius end of the part machined in step  1 , to be referred to as hole  1 . A second hole is then drilled through the material closer to the spherical end of the part, to be called hole  2 . An end mill cutting tool is then used to remove the remaining rough stock below the spherical radius of the part, creating a raised radial section of material around hole number  2 . A counter bore is then milled into the raised boss of material surrounding hole number  2 . A larger counter bore is then machined into the flat section of material in which hole number  1  was drilled. A corner radius cutting tool is then used to radius the top edge of the counter bore surrounding hole number  2 , the edge of the bottom of the counter bore and hole number  2 , and the bottom of the counter bore and hole number  1 . A reamer is then used to size hole number  1  to a diameter of +0.000/−001 of the diameter of a mating pin to be installed during final assembly. A high precision reamer is then used to size hole number  2  to a diameter of + or −0.0003 of a specific size to be used by an additional tool to be used later. A roller burnishing tool is then used to provide a specific diameter of + or −0.0005 to a mating part to be used in final assembly in hole number  2 . This tool also provides a finish to be used as a sealing surface for a series of o rings to be used in the final assembly of the part; additionally the tool provides for a smooth edge of the hole drilled in the bottom of the grease fill holes, drilled in the third step, connecting the grease fill holes to hole number  2 . The part is then turned over 180 degrees and the above procedures with the exception of drilling, reaming and burnishing of holes number  1  and  2 , are repeated.  
         [0027]     In the fifth step, the part is then moved in the fixture so that the diameter turned in step number  1  is facing upward. The part is held and timed by the flat sections milled in step number  2 . An end mill cutting tool is then used to cut angular flat sides in a square pattern parallel and perpendicular to the flat sides milled in step  2  and wherein the sides of the square pattern are angled so that the top of the square has larger sides than the bottom. In the last step, the part is then placed in the fixture horizontally so that holes number  1 , and  2  described in step number  4 , are perpendicular to the surface being held, and is timed by the flats milled in step  2 . An end mill cutting tool is then used to cut the bottom end of the part farthest from the spherical radius end in an angular pattern to allow clearance for a mating part to be used in the final assembly. A radius cutting end mill tool is then used to radius the top edge of the profile cut described above. The part is turned over 180 degrees and the radius tool is then run on the opposite side of the profile cut described above. The part is then cleaned and deburred.  
         [0028]      FIG. 5  shows a top cut-away view of the embodiment of  FIGS. 1-4F . This is a view of a horizontal plane near the centerline of the valve. The valve  20  is in the open position. In  FIG. 4E , port  48  (which is a passageway from grease entry port  14  to hole  46 ) and port  49  (which is a passageway from grease entry port  15  to hole  46 ) may appear horizontally aligned from a cursory look at this side view. A closer look at the side view of  FIG. 4E , as shown in the parent application, shows that port  48  has an apparently slightly larger diameter that port  49 . This was intended to indicate the offset of these two ports. The views of  FIGS. 5 and 6  clarify that port  48  is offset from port  49 . Port  40  in valve shaft  20  aligns with both valve port  48  and valve port  49 . In this embodiment, port  40  simply comprises a smaller diameter of valve shaft  20  than at adjacent diameters of the valve shaft with respect to the port  40 . Notice the positions of the seals  42 , which are not positioned to prevent flow or pressure communication between valve port  48  and valve port  49 . Note that even if the diameter of the shaft was not reduced at the positions of alignment with valve port  48  and valve port  49 , nonetheless, pressure would likely leak between valve port  48  and valve port  49 ; however, reducing the diameter reduces the resistance to flow between valve port  48  and valve port  49 . This configuration is not intended to be limiting as other configurations would be understood based on this disclosure.  
         [0029]      FIG. 6  shows a view of the configuration of  FIG. 5  except that the valve  20  is in the closed position. Notice that when the valve shaft  20  is placed in this position, port  49  is no longer aligned with port  40  and a seal  42  is between port  48  and port  49 , thus preventing liquid or pressure, etc, communication therebetween. Again, this configuration is not intended to be limiting. Other configurations would be understood based on this disclosure.  
         [0030]      FIG. 7  is a side cut-away view of an embodiment of the invention. A shaft would be located in hole  106  in upper unit  110 . Similar to  FIG. 1 , a volume of grease is forced into grease entry ports  114  and  115 , which ports are subsequently sealed. The volume of grease fills the internal area, which is under vacuum, in this embodiment. Pistons  116  and  117  are located within cylinders  150  and  151  respectively and include round cross-section seals  152  and square cross-section back-up seals  153 . When the button on the shaft in hole  106  is pressed up against a stop, the shaft slides such that a port in the shaft aligns with ports  148  and  149 , which are offset similarly to ports  48  and  49  of  FIGS. 5 and 6  in one embodiment. In this position, which is referred to herein as the “unlocked” position, the pistons can move up and down in the cylinders. For example, when piston  116  moves up in cylinder  150 , the constant volume of grease forces piston  117  down in cylinder  151 . When the button is pushed, the shaft to moves such that the port in the shaft is no longer aligned with ports  148  and  149 . In this position, which is referred to herein as the “locked” position, force applied to either piston will not move that piston because the grease cannot flow within the system. The upper unit includes a through hole  134  through which a shaft would be placed. The shaft would also travel though holes in the lower unit  122 . The upper unit would have limited rotation around the shaft with respect to lower unit  122 . Upper unit  110  includes a standardized male coupling configuration  112 . In this embodiment, lower unit  122  includes threaded holes  170  and  174 . A screw  172  is inserted into hole  170  and a screw  176  is inserted into hole  174 . Lower unit  122  includes a standard female receptacle  124  for coupling to a standardized male coupler.  
         [0031]     The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. The assembly is characterized as having an upper unit and a lower unit, which characterization is intended to show the relative positions of the two units, but is not intended to limit the usable orientation of the assembly, e.g., the assembly can be inverted, or used in another orientation without departing from the scope of the invention. The embodiments disclosed were meant only to explain the principles of the invention and its practical application to thereby enable others skilled in the art to best use the invention in various embodiments and with various modifications suited to the particular use contemplated.