# US 11,298,765 B2 · Toothed rack and method for producing a toothed 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 11,298,765 B2 - Document ID: US11298765B2 - Status: Granted - Kind: B2 - Application number: 16/315,956 - Filed: 2017-07-04 - Published: 2020-07-16 - Granted: 2022-04-12 - Earliest claimed: 2016-07-06 - Assignees: Thyssenkrupp Presta AG; thyssenkrupp AG - Applicants: Thyssenkrupp Presta AG; thyssenkrupp AG - Inventors: Ralf Eckstein; Reinhard Bader; Markus Mages - Web page: https://patentgrep.com/patent/US11298765B2 ## CPC - B23F 9/00: Making gears having teeth curved in their longitudinal direction - B21K 1/767: {Toothed racks} - B62D 3/126: {characterised by the rack} - F16H 55/06: Use of materials; Use of treatments of toothed members or worms to affect their intrinsic material properties - F16H 55/26: Racks - B23F: MAKING GEARS OR TOOTHED RACKS (by stamping B21D; by rolling B21H; by forging or pressing B21K; by casting B22; arrangements for copying or controlling B23Q; machines or devices for grinding or polishing, in general B24B) - 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) - 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) - F16H: GEARING ## Abstract A rack for a steering gear of a motor vehicle may include a toothed portion having a toothing, and a shaft portion. Separate segments comprising at least one in each case bar-shaped toothed segment and one shaft segment are provided, are aligned on a common longitudinal axis, and are connected to one another at a joint. The method may involve providing a raw material piece having a piece length that is a multiple of a segment length, thermally continuously hardening the raw material piece across a multiple of a segment length to produce a hardened semi-finished segment product, cutting to length a hardened segment from the hardened semi-finished segment product, providing a further segment, and joining the hardened segment to a further segment. ## Claims ### Claim 1 A method for producing a rack for a steering gear of a motor vehicle, the method comprising: providing a raw material piece having a piece length that is a multiple of a segment length; thermally continuously hardening the raw material piece across a multiple of the segment length to produce a hardened semi-finished segment product; cutting to length a hardened segment from the hardened semi-finished segment product, wherein the hardened segment is bar-shaped; aligning the hardened segment and a second segment that is bar-shaped on a longitudinal axis; and joining the hardened segment to the second segment. ### Claim 2 (depends on 1) The method of claim 1 wherein the thermal continuous hardening comprises continuously heating and continuously cooling the raw material piece, wherein the continuous cooling of the raw material piece occurs downstream of the continuous heating of the raw material piece with respect to a throughput direction. ### Claim 3 (depends on 1) The method of claim 1 comprising performing continuous annealing downstream of the thermal continuous hardening with respect to a throughput direction. ### Claim 4 (depends on 3) The method of claim 3 comprising performing the annealing in a locally dissimilar manner to generate locally dissimilar material properties along a length of the hardened semi-finished segment product. ### Claim 5 (depends on 1) The method of claim 1 wherein the raw material piece that is provided is at least one of hot-formed, cold-formed, or subtractively machined. ### Claim 6 (depends on 1) The method of claim 1 wherein the raw material piece that is provided is a rod or a tube. ### Claim 7 (depends on 1) The method of claim 1 wherein the raw material piece that is provided is a round material. ### Claim 8 (depends on 1) The method of claim 1 comprising continuously grinding the raw material piece after the raw material piece is thermally continuously hardened. ### Claim 9 (depends on 1) The method of claim 1 wherein for configuring a joining face, the cutting to length provides an end face of the hardened segment. ### Claim 10 (depends on 1) The method of claim 1 comprising welding the segments to one another. ### Claim 11 (depends on 1) The method of claim 1 wherein a first functional portion of the hardened segment comprises at least one of a rack portion, a threaded portion, or a connection portion. ### Claim 12 (depends on 11) The method of claim 11 comprising joining a second functional portion to at least one of the second segment or the hardened segment. ### Claim 13 (depends on 1) The method of claim 1 wherein the thermally continuously hardening occurs in a continuous furnace. ### Claim 14 (depends on 1) The method of claim 1 comprising moving the raw material piece continuously relative to a means for heating the raw material piece during the thermally continuously hardening. ### Claim 15 (depends on 1) The method of claim 1 comprising moving the raw material piece continuously relative to a means for quenching the raw material piece during the thermally continuously hardening. ### Claim 16 (depends on 1) The method of claim 1 wherein lengths of the raw material piece are hardened sequentially during the thermally continuously hardening.