# US 4,397,048 A · Reinforced plastics artificial limb component and method for making same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,397,048 A - Document ID: US4397048A - Status: Granted - Kind: A - Application number: 06/303,860 - Filed: 1981-09-21 - Granted: 1983-08-09 - Earliest claimed: 1980-09-26 - Assignees: Chas. A. Blatchford & Sons Limited - Inventors: Eric Brown; Neil L. Hancox - Web page: https://patentgrep.com/patent/US4397048A ## CPC - A61F 2/5046: {for designing or making customized prostheses, e.g. using templates, finite-element analysis or CAD-CAM techniques} - A61F 2/60: Artificial legs or feet or parts thereof - B29C 70/228: {the structure being stacked in parallel layers with fibres of adjacent layers crossing at substantial angles} - B29C 70/342: {using isostatic pressure} - B29C 70/446: {Moulding structures having an axis of symmetry or at least one channel, e.g. tubular structures, frames} - A61F 2/5044: {Designing or manufacturing processes} - A61F 2002/5053: {using a positive or a negative model, e.g. casting model or mould} - A61F 2002/5055: {Reinforcing prostheses by embedding particles or fibres during moulding or dipping, e.g. carbon fibre composites} - A61F 2250/0028: differing in fibre orientations - B29C 43/12: using bags surrounding the moulding material {or using membranes contacting the moulding material} - B29K 2105/0809: {Fabrics} - B29K 2307/00: Use of elements other than metals as reinforcement - B29L 2023/00: Tubular articles (B29L2024/00 takes precedence {; catheters B29L2031/7542}) - B29L 2031/7532: {Artificial members, protheses} - Y10S 273/23: High modulus filaments - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract An artificial limb component having one portion with an open channel cross-section and method for making the component in which woven sheets of carbon fibre reinforced plastics material in prepreg form are laid up on an inflatable expandable moulded mandrel, which is then placed in a lower mould half, a corresponding upper mould half being placed on the lower half to complete the mould. Air pressure is applied via pipe to the interior of the mandrel which is expanded within the mould halves to compress the prepreg sheets to the required shape. ## Claims ### Claim 1 A lightweight, load-bearing shin component for an artificial leg, the component comprising an elongate upper portion of open channel shape in cross section, an elongate lower portion of closed tubular cross section, and an intermediate hollow portion joining the upper portion to the lower portion, the component being molded from a plurality of sheets of plastics material, at least two of the sheets having reinforcement fibers, the reinforcement fibers of at least one of the said at least two sheets running at a predetermined non-zero angle to reinforcement fibers of at least one other of the said at least two sheets said intermediate hollow portion being a transition portion between two portions of said component both having different configurations, in cross-section, from each other. ### Claim 2 (depends on 1) A component according to claim 1 wherein the upper portion is of rectangular three-sided open channel shape in cross section and the lower portion is of circular cross section. ### Claim 3 (depends on 1) A component according to claim 1 wherein the elongate upper and lower portions each has a longitudinal axis, the two longitudinal axes being disposed at an angle relative to each other. ### Claim 4 (depends on 1) A component according to claim 1 wherein the reinforcement fibers are carbon fibers. ### Claim 5 (depends on 1) A component according to claim 1 wherein the component has a length direction and wherein the said at least two sheets each has reinforcement fibers disposed at right angles in the sheet. ### Claim 6 (depends on 1) A component according to claim 1 wherein the component has a length direction and wherein fibers of one of the said two sheets are disposed parallel to the length direction and fibers of the other of the said two sheets are disposed diagonally to the length direction. ### Claim 7 A method of molding a lightweight, load-bearing shin component for an artificial limb, the method comprising the steps of providing a plurality of sheets of plastics material, at least two of the sheets having reinforcement fibers, the reinforcement fibers of at least one of the said at least two sheets running at a predetermined angle to reinforcement fibers of at least one other of the said at least two sheets, placing the sheets between an expandable internal mandrel and a rigid external mold, and expanding the mandrel to compress the sheets between the mandrel and the mold, the mold including three differently shaped portions which cause the component to be formed with an elongated upper portion of open channel shape in cross section, an elongate lower portion of closed tubular cross section, and an intermediate hollow portion joining the upper portion to the lower portion where said component is to have an open channel shape, the open side being achieved by disposing said sheets on three sides of said mandrel only. ### Claim 8 (depends on 7) A method according to claim 7 wherein the sheets are placed on the expandable mandrel so that when the mandrel is expanded the sheets are expanded and compressed between the mandrel and the mold. ### Claim 9 (depends on 7) A method according to claim 7 wherein the mandrel is an inflatable hollow molded element. ### Claim 10 (depends on 9) A method accoding to claim 9 wherein the molded element is of silicone rubber. ### Claim 11 (depends on 7) A method according to claim 7 wherein the reinforcement fibers are carbon fibers.