# US 11,077,875 B2 · Rack and a method for producing a rack for a steering gear of a motor vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,077,875 B2 - Document ID: US11077875B2 - Status: Granted - Kind: B2 - Application number: 16/315,981 - Filed: 2017-07-04 - Published: 2019-08-01 - Granted: 2021-08-03 - Earliest claimed: 2016-07-06 - Assignees: Thyssenkrupp Presta AG; thyssenkrupp AG - Applicants: Thyssenkrupp Presta AG; thyssenkrupp AG - Inventors: Reinhard Bader; Markus Mages; Ralf Eckstein; Juergen Dohmann; René Feuerstein - Web page: https://patentgrep.com/patent/US11077875B2 ## CPC - B62D 3/126: {characterised by the rack} - B21K 1/76: elements not mentioned in one of the preceding groups - B21K 1/767: {Toothed racks} - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) - B21K: MAKING FORGED OR PRESSED METAL PRODUCTS, e.g. HORSE-SHOES, RIVETS, BOLTS OR WHEELS (making particular articles by working sheet metal without essentially removing material B21D; processing wire B21F; making pins, needles or nails B21G; making particular articles by rolling B21H; forging machines, pressing machines, hammering machines, in general B21J; making chains B21L; plating B23K) ## Abstract A rack for a steering gear includes a toothed portion with a toothing extending along a longitudinal axis, and a generally cylinder-segment-shaped back opposite the toothing and having a back radius. A method for producing such a rack includes forming a cylindrical blank with an unmachined radius between a toothed die part having a toothed mold clearance and a back die part having a back mold clearance in a die cavity. The die may have a generally cylinder-segment-shape. In an open position of the die, the blank may be inserted between the toothed mold clearance and the back mold clearance. The toothed die part and the back die part in a forging stroke for closing the cavity may then be moved in a closing direction to a closed position. The back radius of the back mold clearance may be larger than the unmachined radius of the blank. ## Claims ### Claim 1 A method for forming a rack for a steering gear of a motor vehicle, wherein the rack includes a toothed portion that has a toothing that extends along a longitudinal axis, and a back that is generally cylinder-segment-shaped, the back lying opposite the toothing, the method comprising: positioning a cylindrical blank with an initial radius in a cavity of a die that is split in a separation plane parallel with the longitudinal axis, the die comprising a toothed die part having a toothed mold clearance configured to form the toothing and a back die part having a back mold clearance configured to form the back, with the back die part having a generally cylinder-segment-shape defining a back radius; wherein the toothed mold clearance and the back mold clearance are mutually spaced apart relative to the separation plane; moving the toothed die part and the back die part in a forging stroke for closing the cavity in a closing direction to a closed position; and forming the rack such that the toothing has a width that is greater than twice the initial radius of the blank and such that a back width of the rack produced by the forging stroke is greater than twice the initial radius of the cylindrical blank, with the back width being measured at the back of the rack, opposite the toothing, and being measured exclusive of any burrs. ### Claim 2 (depends on 1) The method of claim 1 wherein the back is D-shaped in cross section. ### Claim 3 (depends on 1) The method of claim 1 wherein the back is V-shaped in cross section in which V-shaped leg faces form secants of an envelope circle. ### Claim 4 (depends on 1) The method of claim 1 wherein a toothing width of the toothed die part, as measured transversely to the longitudinal axis, is larger than the unmachined radius of the cylindrical blank. ### Claim 5 (depends on 1) The method of claim 1 comprising holding in a holding installation a transition portion of the cylindrical blank in a manner neighboring the toothed die part and the back die part. ### Claim 6 (depends on 1) The method of claim 1 wherein a back axis in a toothed region when forming is radially offset relative to the longitudinal axis, in a direction toward the back, by a spacing. ### Claim 7 (depends on 1) The method of claim 1 wherein the cylindrical blank is a rod portion. ### Claim 8 (depends on 1) The method of claim 1 wherein the cylindrical blank is a tubular portion. ### Claim 9 (depends on 1) The method of claim 1 comprising machining the cylindrical blank so as to configure a shaft portion that in a direction of the longitudinal axis adjoins the toothed portion in an integral manner. ### Claim 10 (depends on 1) The method of claim 1 comprising forming the toothed portion on a toothed segment that is connected to a functional segment.