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US 4,940,288 AGranted
Earth engaging cutter bit
AssigneeKennametal Inc.
InventorsStephen P. Stiffler, Wayne H. Beach
Life of this patent
Estimating the term…
Abstract
A cutter bit for use in construction and/or excavation applications is provided having a hard wear resistant tip joined to a steel shank. The wear resistant tip is rotational symmetric about its longitudinal axis and has a rear end having a socket therein in which is bonded a steel protrusion on the forward end of the steel shank. The tip socket and an outer rearmost facing surface on the tip rear end have respective pluralities of first and second bumps formed thereon and protruding therefrom for spacing, centering and aligning the tip on the bit body to facilitate formation of a braze joint of a desired given cross-sectional thickness profile between the tip and bit body.
Claims28
An earth engaging cutter bit for excavating comprising:
- a ferrous body having a longitudinal axis and a forward end;
- a cemented carbide tip;
- said cemented carbide tip having:
- a rounded foremost earth engaging surface;
- a second earth engaging surface which extends radially outwardly while extending rearwardly of said rounded foremost earth engaging surface;
- an annular rearmost surface facing said forward end of said ferrous body and oriented in a first plane perpendicular to said longitudinal axis;
- an inwardly facing surface extending forwardly and inwardly from said annular rearmost surface;
- and a rearwardly facing surface located radially within said inwardly facing surface and forwardly of said annular rearmost surface;
- a braze joint joining said rearwardly facing surface, said inwardly facing surface and said annular rearmost surface to said forward end of said ferrous body;
- and wherein said braze joint has an average thickness adjacent said rearwardly facing surface which is smaller than the average thickness of said braze joint adjacent said rearmost annular surface and which is smaller than the average thickness of said braze joint adjacent said inwardly facing surface.
7 more elements
An earth engaging cutter bit for excavating comprising:
- a ferrous metal body having a longitudinal axis and a forward end;
- a cemented carbide tip for engaging and excavating earth formations;
- said cemented carbide tip having:
- an annular rearmost surface facing said forward end of said ferrous body;
- an inwardly facing surface extending forwardly and inwardly from said annular rearmost surface;
- and a rearwardly facing surface located radially inwardly of said inwardly facing surface and forwardly of said annular rearmost surface;
- a braze joint joining said rearwardly facing surface, said inwardly facing surface and said annular rearmost surface to said forward end of said ferrous body;
- and wherein said braze joint has an average thickness adjacent said rearwardly facing surface which is smaller than the average thickness of said braze joint adjacent said rearmost annular surface and which is smaller than the average thickness of said braze joint adjacent said inwardly facing surface.
5 more elements
A cutter bit comprising:
- a ferrous body having a longitudinal axis and a forward end;
- a cemented carbide tip having:
- a first rearwardly facing surface with a socket therein extending forwardly therefrom and having a second rearwardly facing surface located a distance, D, from said first rearwardly facing surface;
- said forward end of said ferrous body having a first forwardly facing surface and a second forwardly facing surface;
- wherein said second forwardly facing surface is radially inside of said first forwardly facing surface and located forward of said first forwardly facing surface by a distance, H;
- wherein said first rearwardly facing surface of said cemented carbide tip is bonded to said first forwardly facing surface of said ferrous body and said second rearwardly facing surface of said cemented carbide tip is bonded to said second forwardly facing surface of said ferrous body;
- and wherein H is greater than D.
4 more elements
A cutter bit comprising:
- a ferrous metal body having a longitudinal axis and a forward end;
- a cemented carbide tip;
- said cemented carbide tip having:
- an annular rearmost surface facing said forward end of said ferrous body;
- an inwardly facing surface extending forwardly and inwardly from said annular rearmost surface;
- and a rearwardly facing surface located radially inwardly of said inwardly facing surface and forwardly of said annular rearmost surface;
- a braze joint joining said rearwardly facing surface, said inwardly facing surface and said annular rearmost surface to said forward end of said ferrous body;
- wherein said braze joint has an average thickness adjacent said rearwardly facing surface which is smaller than the average thickness of said braze joint adjacent said rearmost annular surface;
- means disposed between said tip and said body and being formed on one thereof and protruding toward the other thereof for engaging the other and placing said tip in a spaced relationship relative to said body for facilitating formation therebetween of said braze joint having the predetermined desired thicknesses;
- and
- wherein said protruding means includes a plurality of first bumps formed on and protruding from said inwardly facing surface of said tip and being spaced from one another and a plurality of second bumps formed on and protruding from said rearmost facing surface of said tip and being spaced from one another.
8 more elements
A cutter bit comprising:
- a ferrous metal body having a longitudinal axis and a forward end;
- a cemented carbide tip;
- said cemented carbide tip having:
- an annular rearmost surface facing said forward end of said ferrous body;
- an inwardly facing surface extending forwardly and inwardly from said annular rearmost surface;
- and a rearwardly facing surface located radially inwardly of said inwardly facing surface and forwardly of said annular rearmost surface;
- a braze joint joining said rearwardly facing surface, said inwardly facing surface and said annular rearmost surface to said forward end of said ferrous body;
- wherein said braze joint has an average thickness adjacent said rearwardly facing surface which is smaller than the average thickness of said braze joint adjacent said rearmost annular surface;
- means disposed between said tip and said body and being formed on one thereof and protruding toward the other thereof for engaging the other and placing said tip in a spaced relationship relative to said body for facilitating formation therebetween of said braze joint having the predetermined desired thicknesses;
- and
- wherein said protruding means includes a plurality of bumps formed on and protruding from said rearmost facing surface of said tip and being spaced from one another.
8 more elements
Dependencies are inferred from the claim text.