# US 5,704,561 A · Wear-resistant hard-surfacing for the rolls of high-pressure roll presses for size reduction of granular material > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,704,561 A - Document ID: US5704561A - Status: Granted - Kind: A - Application number: 08/523,748 - Filed: 1995-08-28 - Granted: 1998-01-06 - Earliest claimed: 1994-09-05 - Assignees: Deutz Aktiengesellschaft - Inventors: Jakob Ansen; Frank Fischer-Helwig; Ludger Alsmann; Michael Wollner - Web page: https://patentgrep.com/patent/US5704561A ## CPC - B02C 4/305: {Wear resistant rollers} - B02C: CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN ({household tools and machines for pulverising foodstuffs, e.g. coffee and spice mills A47J42/00; pharmaceutical mortars A61J3/02; mechanical processing of refuse and garbage B03B9/06; dressing mould materials by grinding B22C5/04}; obtaining metallic powder by crushing, grinding or milling B22F9/04; {recovery of plastics by disintegrating B29B17/00; crushing raw materials in starch making C08B30/02; beaters for papermaking D21D1/02; crushing devices specially for transport in mines E21F13/002; slag crushing devices F23J1/00; fuel milling devices in combustion apparatus F23K1/00; household devices for crushing coal F24B15/02; ice disintegrating devices F25C5/02}) ## Abstract The rolls of high-pressure roll presses for the compressive size reduction of granular material are hard surfaced with nub pins which are wear-resistant and suitable for autogenous wear protection. The nub pins, which have a long potential service life even under the action of high compressive loads, have a radially inner pin part (13) which is easily welded to the roll surface (12) and a radially outer harder pin part (14) protectively covering the radially inner pin part. ## Claims ### Claim 1 A high-pressure roll press for the size reduction of granular material comprising: a pair of counter-rotatable rolls each having a roll surface (12) and a plurality of outwardly projecting cylindrical nub pins welded onto said roll surface (12) at predetermined intervals from one another to form pockets (17) for the accommodation of compacted fine granular material, each of said nub pins including a radially inner cylindrical pin part (13) of easily weldable material, said radially inner part (13) being welded to said roll surface (12) and a radially outer cylindrical pin part (14) protectively covering said inner pin part (13), said radially outer pin part (14) being materially bonded to said radially inner pin part (13) and consisting of a material substantially harder than said easily weldable material of said radially inner pin part (14), said nub pins extending radially from said roll surface (12) to a height greater than approximately 5 mm and said predetermined intervals being smaller than approximately 40 mm. ### Claim 2 (depends on 1) The roll press of claim 1 wherein said radially outer pin part (14) consists of a sintered hard alloy. ### Claim 3 (depends on 1) The roll press of claim 1 wherein said radially outer pin part (14) consists of ceramic material. ### Claim 4 (depends on 1) The roll press of claim 1 wherein said radially outer pin part (14) consists of hard surface weld material. ### Claim 5 (depends on 1) The roll press of claim 1 wherein said hard material of the radially outer pin part (14) has a hardness of more than 58 HRC (Rockwell C hardness test). ### Claim 6 (depends on 1) The roll press of claim 1 wherein said radially outer pin part (14) is friction welded to said radially inner pin part (13). ### Claim 7 (depends on 1) The roll press of claim 1, wherein said radially outer pin part (14) is materially bonded to said radially inner pin part (13) by arc welding. ### Claim 8 (depends on 1) The roll press of claim 1 wherein said radially outer pin part (14) is materially bonded to said radially inner pin part (13) by explosive weld cladding. ### Claim 9 (depends on 1) The roll press of claim 1 wherein said radially outer pin part (14) is fabricated by powder-metallurgical methods and sintered onto said radially inner pin part (13). ### Claim 10 (depends on 1) The roll press of claim 1 wherein said radially outer pin part (14) and said radially inner pin part (13) are fabricated separately powder-metallurgical methods and then sintered together. ### Claim 11 (depends on 1) The roll press of claim 1 wherein said radially outer pin part (14) and said radially inner pin part (13) are fabricated jointly by powder-metallurgical methods whereby said parts are sintered together. ### Claim 12 (depends on 1) The roll press of claim 1 wherein said radially outer pin part (14) and said radially inner pin part (13) are a prefabricated unit. ### Claim 13 (depends on 1) The roll press of claim 1 and further comprising a roll body (10) and a roll shell (11) removably secured to said roll body (10), said roll shell (11) being a riding ring presenting said roll surface (12) to which said nub pins are welded.