SYSTEM FOR CONNECTING A PROSTHESIS COMPONENT TO A PROSTHESIS SHAFT

Abstract

A shaft system for a leg prosthesis with the shaft system featuring a prosthesis shaft which has a wall made of fiber-reinforced plastic material and which features at its proximal end an entrance opening and at its distal end a fastening assembly for the connection of prosthesis components and the attachment of tensioning elements and functional parts of the prosthesis such as locks, draw-in and connecting elements. In order to enable on such a shaft system the feasibility and faster adaptability to the requirements of a user of this shaft system, it is proposed to provide the aforementioned passage opening with at least one reinforcement element. This allows easier fitting of a prosthesis because of the possibility of a faster and simpler repositioning if needed or the faster exchange of prosthesis components.

Claims

1. Shaft system for a prosthesis with the shaft system featuring a prosthesis shaft which has a shaft wall comprising plastic material reinforced with fibers and which features at its one end a proximal entrance opening and it its distal end a fastening system for the connection of prosthesis components and/or functional parts of the prosthesis such as locks, draw-in and connecting elements, with a passage opening at the distal end in the shaft wall of the prosthesis shaft, wherein the passage opening is provided with at least one reinforcement element surrounding it and wherein the fibers in the shaft wall are run through an opening in the middle of the reinforcing element.

2. Shaft system according to claim 1, wherein several reinforcement elements are present which are interconnected by means of tensioning elements.

3. Shaft system according to claim 1, wherein the at least one reinforcement element is in the form of a circular lamella and features at least one extension in radial direction which can be positioned between layers of fiber reinforcements for the plastic material of the shaft wall.

4. Shaft system according to claim 1, wherein the passage opening is provided with an end bead featuring at least one bearing surface.

5. Shaft system according to claim 1, wherein a portion of a prosthesis component and/or of a functional part of the prosthesis passing through the passage opening can be anchored on the wall of the prosthesis shaft in a rotable and arrestable manner in respect to the stump axis.

6. Method for the manufacture of a shaft system according to claim 1 with these steps: a) Installation of a place-holder on a shape model of an amputation stump, b) Enveloping the place-holder and the shape model with fibers for a fiber-reinforced plastic material in approximately twice its length with creation of an excess, c) Passing the excess length through a centrally located opening of a reinforcement element and arranging the reinforcement element on the place-holder, as well as d) Folding back the excess length on the reinforcement element and placement on the shape model and e) Enclosing the shape model, the fibers and of the returned excess length with a vacuum hose and filling with a plastic material matrix.

7. Method for the manufacture of a shaft system according to claim 6, wherein the steps b) to d) are repeated several times prior to performing step e).

8. Method for the manufacture of a shaft system according to claim 6, wherein after step d) and before step e) there is a step during which a molded part is attached on the place-holder which determines the contour of the passage opening.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0053] Additional advantages and characteristics of the invention become evident in the following descriptions of examples of implementation.

[0054] FIG. 1 shows a shaft system according to the invention in a perspective view with a partial section through the passage opening.

[0055] FIG. 2 shows the distal shaft end with a passage opening in perspective view.

[0056] FIG. 3 shows a reinforcing element with a schematically shown course of fibers for the fiber-reinforced plastic of a prosthesis shaft.

[0057] FIG. 4 shows the section view of a reinforcing element with fibers surrounding it.

[0058] FIG. 5 shows a perspective view of reinforcing elements with borings corresponding to a four-hole plate.

[0059] FIG. 6 shows the distal end of a prosthesis shaft with a passage opening and a prosthesis connecting element inserted into it. FIG. 6A is an isolated view showing the fibers, end bead and reinforcement elements.

[0060] FIG. 7 shows a prosthesis shaft during its manufacture.

[0061] FIG. 8 shows a prosthesis shaft during a further step in its manufacture.

[0062] FIG. 9 shows an example of implementation of a reinforcing element with an extension.

[0063] FIG. 10 shows an example of implementation of a reinforcing element in a perspective view.

[0064] FIG. 11 shows a top view of a reinforcing element in a different implementation.

DETAILED DESCRIPTION OF THE INVENTION

[0065] FIG. 1 shows a shaft system 1 for a prosthesis according to an example of implementation of the present invention. Visible is a prosthesis shaft for a stump of an upper or lower leg with a shaft wall 2 made of plastic material reinforced with fibers 3.

[0066] This prosthesis shaft has a proximal opening 4 for accepting an amputation stump and a distal end 5 with a passage opening 7. In the example shown here, this passage opening is essentially in the shape of a circle. Its shape may however also be oval, polygonal or angular.

[0067] At the distal end 5 one recognizes in a partial cutaway the schematically represented synthetic fibers 3 of the shaft wall 2 as they are wound around in several reinforcements 10 arranged around the passage opening 7 and thereby building up the latter to an end bead 6.

[0068] In this example of implementation four reinforcements 10 are integrated into the end bead 6. Ideally, to every layer of fibers 3 reinforcing the plastic material, a reinforcement 10 is attributed by wrapping the fiber fabric 3 around these reinforcements 10 and so envelops these reinforcements as completely as possible. This creates an inseparable connection between the fibers 3 reinforcing the plastic material of the prosthesis shaft 2 and the essentially superimposed reinforcements 10 that build up the end bead 6.

[0069] Depending on the requirements, the number of superimposed reinforcements 10 can be increased, the stability of the end bead 6 increasing in reproducible manner with each layer added in this way.

[0070] On the end bead 6, one can identify a bearing surface 16 which is situated on the inside of the prosthesis shaft and the contour of which is created in the manufacturing process described below, in order to reach a counterfort especially defined in its shape for a clamping plate 8 attached here for a connecting element 9, as shown in FIG. 6 and explained further below.

[0071] In the example of implementation shown here in FIG. 1 in particular, the passage opening 7 and the end bead 6 have a circular shape so that all connecting elements can be rotated into any desired position and can be arrested in relation to the prosthesis shaft 1.

[0072] All prostheses components to be coupled onto the prosthesis shaft can easily be attached and removed.

[0073] The layers of reinforcement elements 10 may consist of various materials. In a preferred implementation, they are made of metal to achieve a high degree of stability and a low overall height. Thereby it is also pos-sible to keep the overall height of the end bead 6 with an optimal connection to the shaft wall 2 made of fiber-reinforced synthetic material as low as possible.

[0074] FIG. 2 shows in a perspective view the distal end 5 of a prosthesis shaft 2, where on the outside of an end bead 6 a bearing surface 15 is visible, on which a prosthesis connecting element as shown in FIG. 6 is to be attached in the passage opening 7 at the end bead 6.

[0075] FIG. 3 shows in a perspective view a schematically presented reinforcement element 10 in the form of a circular lamella with a fiber 3 running uninterruptedly through the interior of the ring. A centrally located opening 11 provides sufficient room for this leadthrough of the entire fabric made of fibers 3 and a plastic matrix of the prosthesis shaft as well as for the leadthrough of functional parts 17, tensioning elements 14 and for the connection of prosthesis components 9, as shown in FIG. 6.

[0076] If the reinforcement element 10 is executed in metal, during the tie-off and the simultaneous heating of the fabric consisting of fibers 3, the reinforcement element 10 will also expand. During the subsequent cooling, the reinforcement element 10 will contract again and will wrap itself around the plastic material in circular and form-fitting fashion. The expansion and subsequent contraction of the metal are more pronounced than on the plastic material thereby strengthening the bond between the reinforcement element and the plastic material.

[0077] FIG. 4 shows a section through a reinforcement element 10 with the course of fibers 3 wrapped around a reinforcement element 10. One can see how the fibers 3 are tightly running over all sides of the reinforcement element 10 without any interruption. The close contact of the fibers 3 with the reinforcement element 10 is so pronounced that no additional conglutination of the fibers with the reinforcement element 10 is necessary.

[0078] In this example of implementation it is also possible to discern the installation of a tensioning element 14. With this tensioning element 14 it is possible, when necessary, to tension and keep together several layers of wrapped and stacked reinforcement elements 10.

[0079] For this purpose, FIG. 5 shows a preferred execution of reinforcement elements 10 which are, virtually like a known four-hole plate, equipped with a large central opening 11 through which, during the manufacture of the prosthesis shaft, the fibers 3 are passed for the purpose of strengthening of the plastic material constituting the latter.

[0080] The reinforcing elements are provided with holes 13. These are intended for the passage of tensioning elements 14 and may also be used for the connection of prosthesis components that are not shown here. These holes 13 are being kept open during the manufacturing process of the connection element using place-holders for such tensioning elements 14.

[0081] FIGS. 6 and 6A show a section through the distal end 5 of the shaft system.

[0082] One can see the end bead 6 with several superimposed reinforcement elements 10 and the schematically shown reinforcement with fibers 3 of the shaft wall which is installed in the end bead 6.

[0083] In this example of implementation, the end bead 6 represented here is provided on its exterior and on its interior side with steps and so offers an appropriate seat for a clamping plate 8 installed from the proximal direction, and from the distal direction a corresponding connection element 9 between which the end bead 6 and the reinforcement elements 10 inside the latter are braced by means of these connecting tension elements 14.

[0084] In this variant, not only the fibers 3 which reinforce the plastic material of the prosthesis shaft are installed through the opening 11 of the reinforcement elements 10, but also the tensioning elements 14 are passed through the opening passage 7 which is formed by the opening 11.

[0085] In the design version shown here the connecting element 9 which is adjustably connected with the clamping plate 8 via the tensioning elements 14 in the form of screws, also features a functional part 17, for example in the form of a liner lock shown here but only in schematic form.

[0086] The connecting element 9 is provided for the connection of prosthesis components which are not shown here. It becomes clear in this representation that only the reinforcing elements 10 enter into an inseparable connection with the shaft wall 2, whereas the connecting element 9 and consequently all prosthesis elements to be mounted on the prosthesis shaft via this connecting element 9 and thus utilized in this shaft system 1 have to be done in a detachable manner.

[0087] FIG. 7 shows in a perspective view the shaft system 1 while in production.

[0088] In a first manufacturing step a place-holder 19 is installed on a shape model 20 of an amputation stump, at the distal end of the future shaft.

[0089] The shape model 20 and the place-holder 19 are being covered with a hose fabric of fibers 3 while keeping an excess length 21. Over this excess length, a reinforcing element 10 in the form of a circular lamella is placed on the place-holder which is also called a dummy. This rein-forcing element 10 fixates the fabric hose of fibers 3 with its excess length 21 and possible also additional reinforcing strips 18 on the place-holder.

[0090] Also shown in FIG. 7 is an extension 12 which protrudes from the reinforcement element 10 in its form of a circular lamella. This extension 12 is placed on the shape model 20 and thus effects an additional stabilization of the end bead 6.

[0091] Later on, during the manufacturing process, the excess length 21 of the fiber fabric is draped over the reinforcing element 10 and back over the shape model 20, with the reinforcing element being completely enveloped by the fibers 3 of the fiber fabric, so that it will later be firmly connected without interruption of the plastic structure with the fiber-reinforced plastic material of the shaft wall.

[0092] This process is repeated as often as needed, so that any number of layers of fibers 3 can be bundled in the area of the end bead 6.

[0093] It is also possible to provide individual fabric strips 22 instead of a fabric hose, in order to achieve targeted reinforcement of the shaft wall.

[0094] FIG. 8 shows in a perspective view the last manufacturing step in a schematic representation.

[0095] Here already several layers of fibers 3which are no longer separately recognizable particularly if processed in fabric hoseshave been placed over several reinforcing elements 10 on the shape model 20. The superimposed fabric hoses form a homogeneous structure at the distal end 5 of the shaft, with the place-holder 19 being exposed and protruding from the shaft wall.

[0096] A structural part 23 is put over the place-holder 19 and is in contact with the fabric of fibers 3.

[0097] For the subsequent pouring of plastic material, a vacuum hose 24 is attached to the prepared, fabric-covered molded blank of the shaft.

[0098] During the subsequent casting process, due to the interior shape of the molded part 23 and the shape of the dummy and the place-holder at the end bead 6, several fully shaped bearing surfaces 15, 16 are created at the distal end 5 of the prosthesis shaft.

[0099] Excess casting resin is isolated from the prosthesis shaft by the molded part 23, thereby making unnecessary any finishing work such as for example grinding off the end bead in order to create plane bearing surfaces.

[0100] After the casting the molded part 23 and the place-holder 19 are removed.

[0101] The simple manufacturing method produces, without any finishing work, a fully formed end bead 6 around a passage opening 7 with precisely formed bearing surfaces 15, 16 for a form-fitting and highly stressable connection of the prosthesis shaft with attachable prosthesis components.

[0102] FIG. 9 shows a top view of a reinforcing element 10 with an extension 12 and the principle of the fibers 18 introduced through the central opening 11 of the reinforcement element 10 in the form of a circular lamella, thereby ensuring their intimate adhesion to the reinforcement element 10.

[0103] The reinforcement element 10 may also be equipped with several extensions 12. Essentially, the reinforcement elements 10 were inexpensively producible molded parts not intended for re-use and remaining in the prosthesis shaft. In especially preferred variants these parts are stamped or produced in an injection molding process.

[0104] FIG. 10 shows in a perspective view the schematic structure inside the end bead 6 with two, relative to the passage opening 7 which is sur-rounded by the end bead, essentially axially layered reinforcement elements 10, and the course of the fibers 3 passing between these. In a particularly effective implementation every individual layer of the fibers 3 which later strengthen the plastic material of the prosthesis shaft, is placed, together with additional strengthening strip or ribbons 18 around each reinforcement element 10.

[0105] FIG. 11 shows in a top view the schematic structure with a different arrangement inside the end bead 6 with radially superimposed reinforcement elements 10. These have increasingly larger free interior diameters so that the inner openings 11 can accept somewhat smaller reinforcement elements with fibers or strengthening strips wrapped around them. This method of construction is particularly appropriate when a lower height is required for an end bead.

[0106] In a particularly preferred implementation every individual layer of plastic-strengthening fibers 3 is placed with strengthening ribbons 18 around each reinforcement element 10.

LIST OF COMPONENTS IN DRAWINGS

[0107] 1. Shaft system [0108] 2. Shaft wall [0109] 3. Fibers [0110] 4. Proximal opening [0111] 5. Distal end [0112] 6. End bead [0113] 7. Passage opening [0114] 8. Clamping plate [0115] 9. Connecting piece [0116] 10. Reinforcements [0117] 11. Centrally located opening [0118] 12. Extension [0119] 13. Holes [0120] 14. Tensioning elements [0121] 15. Bearing surface [0122] 16. Bearing surface [0123] 17. Functional parts [0124] 18. Additional strengthening strips [0125] 19. Place-holder [0126] 20. Shape model [0127] 21. Overlap or excess [0128] 22. Fabric strip [0129] 23. Molded part