# US 5,708,955 A · Method of manufacturing a component for an electromagnetic friction clutch assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,708,955 A - Document ID: US5708955A - Status: Granted - Kind: A - Application number: 08/558,906 - Filed: 1995-11-16 - Granted: 1998-01-13 - Earliest claimed: 1995-11-16 - Assignees: Dana Corporation - Inventors: James R. Ungrue - Web page: https://patentgrep.com/patent/US5708955A ## CPC - B22F 7/06: of composite workpieces or articles from parts, e.g. to form tipped tools {(B22F7/002 takes precedence)} - F16D 27/112: with flat friction surfaces, e.g. discs - F16D 69/027: {Compositions based on metals or inorganic oxides} - F16D 2027/008: {Details relating to the magnetic circuit, or to the shape of the clutch parts to achieve a certain magnetic path} - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES ## Abstract A method for manufacturing a component for use in an electromagnetically actuated clutch, such as an armature or a pole piece, having one or more flux breaks provided therein includes the initial step of providing a mold having an upstanding central post which defines an annular mold cavity. A quantity of powdered metal material is disposed within the mold cavity. The powdered metal material is formed from a magnetically permeable material, such as a ferromagnetic material. Next, one or more preforms of a non-magnetically permeable material are disposed within the mold cavity. The preform is placed on top of the quantity of powdered metal material axially above the desired location for the magnetically non-conductive region of the component to be formed. Then, a ram of a press machine is moved axially downwardly into engagement with the preform and the powdered metal material contained within the mold. As the ram moves downwardly, it initially engages the preform, moving it axially downwardly through the powdered metal material until the preform engages the lower surface of the mold. Further downward movement of the ram compresses both the preform and the powdered metal material into a single integrated component preform. Lastly, the ram is retracted to permit removal of the component preform, and the component preform is placed in a conventional sintering oven to form the final component. ## Claims ### Claim 1 A method for manufacturing a component for use in an electromagnetically actuated clutch comprising the steps of: (a) providing a mold which defines a mold cavity; (b) providing a quantity of a magnetically permeable material within the mold cavity; (c) providing a quantity of a non-magnetically permeable material within the mold cavity; and (d) compressing the quantity of the magnetically permeable material and the quantity of the non-magnetically permeable material within the mold to form a single integrated component having regions of the magnetically permeable material and the non-magnetically permeable material therein so as to define separate pole regions within the component. ### Claim 2 (depends on 2) The method defined in claim 2 wherein said step (a) is performed by providing an upstanding central post within the mold to define an annular mold cavity. ### Claim 3 (depends on 1) The method defined in claim 1 wherein said step (b) is performed by providing a quantity of a powdered metal magnetically permeable material within the mold cavity. ### Claim 4 (depends on 3) The method defined in claim 3 wherein said step (b) is performed by providing a quantity of a ferromagnetic powdered metal magnetically permeable material within the mold cavity. ### Claim 5 (depends on 4) The method defined in claim 4 wherein the ferromagnetic powdered metal magnetically permeable material is formed from an iron alloy. ### Claim 6 (depends on 1) The method defined in claim 1 wherein said step (c) is performed by providing a preform of the non-magnetically permeable material. ### Claim 7 (depends on 6) The method defined in claim 6 wherein said step (c) is performed by forming the preform of the non-magnetically permeable material prior to disposing it within the mold. ### Claim 8 (depends on 7) The method defined in claim 7 wherein said step (c) is performed by forming the preform from an alloy of stainless steel powder. ### Claim 9 (depends on 8) The method defined in claim 8 wherein said step (c) is performed by forming the preform to have a density which is generally in the range of from 6.3 to 6.6 grams per cubic centimeter. ### Claim 10 (depends on 1) The method defined in claim 1 wherein said step (d) is performed by moving a ram of a press machine axially downwardly into engagement with quantity of the magnetically permeable material and the quantity of the non-magnetically permeable material. ### Claim 11 (depends on 1) The method defined in claim 1 further including the step of sintering the component. ### Claim 12 (depends on 1) The method defined in claim 1 wherein said step (b) is performed by providing a quantity of a powdered metal magnetically permeable material within the mold cavity, and wherein said step (c) is performed by providing a preform of the non-magnetically permeable material on top of the powdered metal magnetically permeable material. ### Claim 13 (depends on 12) The method defined in claim 12 wherein said step (d) is performed by moving a ram of a press machine axially downwardly into engagement with the quantity of the magnetically permeable material and the preform. ### Claim 14 (depends on 13) The method defined in claim 13 wherein the ram initially engages the preform so as to move it axially downwardly through the powdered metal material until the preform engages the lower surface of the mold. ### Claim 15 (depends on 14) The method defined in claim 14 wherein further downward movement of the ram compresses both the preform and the powdered metal material into the component. ### Claim 16 (depends on 15) The method defined in claim 15 further including the step of sintering the component. ### Claim 17 (depends on 1) The method defined in claim 1 wherein the component is an armature for use in an electromagnetically actuated friction clutch. ### Claim 18 (depends on 1) The method defined in claim 1 wherein the component is a pole piece for use in an electromagnetically actuated friction clutch. ### Claim 19 (depends on 1) The method defined in claim 1 wherein said step (b) is performed prior to said step (c). ### Claim 20 (depends on 1) The method defined in claim 1 wherein said step (c) is performed prior to said step (b).