Drill bit

Claim 2

A drill bit comprising, a head, a plurality of cutter assemblies supported on said head, a plurality of said assemblies including, a saddle having spaced apart legs, a journal having a central bore and a shoulder at each end, each of said saddle legs having an outer shoulder adapted to receive the journal shoulders, a roller cutter, bearing means rotatively supporting said roller cutter on said journal between said legs, said legs having aligned bores, a bushing mounted in each of said bores and adapted to engage within the central bore of said journal to retain said journal shoulders against said saddle leg shoulders, and means for releasably securing said bushings in their mounted position whereby the journal is held against movement relative to said saddle, by engagement of said journal shoulders on said saddle leg shoulders.

Claim 3

A drill bit according to claim 1, wherein said journal are tapered in an inward direction toward the base of said saddle legs so that tightening of said securing means tends to draw said saddle legs together and to wedge said journal in a direction away from said saddle base.

Claim 4

A drill bit according to claim 1, including lubrication means communicating from the exterior of said assembly through said bore to said bearing means.

Claim 5

A cutter assembly, comprising a saddle having spaced apart legs, a journal having a central bore therethrough, a roller cutter, bearing means for supporting said roller cutter for rotation on said journal, means for mounting said journal with said roller cutter thereon between said saddle legs, and means for preventing rotation of said journal with respect to said saddle legs, said bore through said journal being eccentric with respect to said bearing means with the smallest thickness of said journal being the unloaded side of said journal.

Claim 6

A cutter assembly, comprising a saddle having spaced apart legs, a journal having a central bore therethrough, a roller cutter, bearing means for supporting said roller cutter for rotation on said journal, means for mounting said journal with said roller cutter thereon between said saddle legs, and means for preventing rotation of said journal with respect to said saddle legs, said bore through said journal being eccentric with respect to said bearing means with the smallest thickness of said journal being the unloaded side of said journal.

Claim 7

A cutter assembly according to claim 4, including, lubrication means communicating from the exterior of said assembly through said bore to said bearing means.

Claim 8

A cutter assembly according to claim 4, wherein said mounting means includes said saddle legs having aligned bores, an annular bushing mounted in each of said leg bores, each of said bushings being adapted to engage within said central bore of said journal, and a bolt extending through said journal bore and said bushings to retain said journal between said saddle legs.

Claim 9

A cutter assembly according to claim 4, wherein said rotating prevention means includes a shoulder on the outer end of each of said saddle legs, and a shoulder at each end of said journal and adapted to engage said leg shoulders to prevent said journal from rotating with resPect to said saddle.

Claim 10

A cutter assembly according to claim 7, wherein said shoulders are tapered in an inward direction toward the base of said saddle legs whereby tightening said mounting means wedges said journal in its position between said saddle legs.

Claim 11

A cutter assembly according to claim 5, including a ball loading hole communicating from said central bore to said bearing means, and a plug positioned in said ball loading hole to retain ball bearings in said bearing means, said plug having a passage therethrough to provide communication for lubricant from said central bore to said bearing means.

Claim 12

A cutter assembly according to claim 6, including a lubrication fitting installed in said bolt accessible from the exterior of said saddle, a passage through said bolt to communicate from said fitting to the interior of said central bore, and a passage through said journal to communicate from said central bore to said bearing means whereby said bearing means may be lubricated from the exterior of said saddle.

Claim 13

A drill bit comprising, a head, a plurality of cutter assemblies supported on said head, a plurality of said assemblies including, a saddle having spaced apart legs and a base, a journal having a bore and a shoulder on at least one end, at least one of said saddle legs having an outer shoulder adapted to receive said journal shoulder, a roller cutter, bearing means rotatively supporting said roller cutter on said journal between said legs, said legs having aligned bores, and means coacting with said aligned bores for retaining said journal shoulder in engagement with said saddle leg shoulder, at least one of the engaging shoulders of said saddle legs and said journal being tapered in an inward direction toward the base of said saddle so that tightening of said retaining means tends to draw said saddle legs together and to wedge said journal in a direction away from said saddle base.

Claim 14

A drill bit comprising, a head, a plurality of cutter assemblies supported on said head, a plurality of said assemblies including, a saddle having spaced apart legs and a base, a journal having a bore and a shoulder on at least one end, at least one of said saddle legs having an outer shoulder adapted to receive said journal shoulder, a roller cutter, bearing means rotatively supporting said roller cutter on said journal between said legs, said legs having aligned bores, and means coacting with said aligned bores for retaining said journal shoulder in engagement with said saddle leg shoulder, at least one of the engaging shoulders of said saddle legs and said journal being tapered in an inward direction toward the base of said saddle so that tightening of said retaining means tends to draw said saddle legs together and to wedge said journal in a direction away from said saddle base.

Claim 15

A drill bit according to claim 11 wherein said securing means includes, a bushing mounted in each of said bores in said saddle legs to engage within the bore of said journal to retain said journal shoulders in engagement with said saddle shoulders, and means for releasably securing said bushings in their mounted position whereby the journal is held against movement relative to said saddle.

Claim 16

A cutter assembly comprising, a saddle having spaced apart legs and a base, a journal having a bore and a shoulder on at least one end, at least one of said saddle legs having an outer shoulder adapted to receive said journal shoulder, a roller cutter, bearing means rotatively supporting said roller cutter on said journal between said legs, said legs having aligned bores, and means coacting with said aligned bores for retaining said journal shoulder in engagement with said saddle leg shoulder, at least one of the engaging shoulders of said saddle legs and said journal being tapered in an inward direction toward the base of said saddle so that tightening of said retaining means tends to draw said saddle legs together and to wedge said journal in a direction away from said saddle base.

Claim 17

A cutter assembly comprising, a saddle having spaced apart legs and a base, a journal having a bore and a shoulder on at least one end, at least one of said saddle legs having an outer shoulder adapted to receive said journal shoulder, a roller cutter, bearing means rotatively supporting said roller cutter on said journal between said legs, said legs having aligned bores, and means coacting with said aligned bores for retaining said journal shoulder in engagement with said saddle leg shoulder, at least one of the engaging shoulders of said saddle legs and said journal being tapered in an inward direction toward the base of said saddle so that tightening of said retaining means tends to draw said saddle legs together and to wedge said journal in a direction away from said saddle base.

Claim 18

A cutter assembly according to claim 13 wherein said securing means includes, a bushing mounted in each of said bores in said saddle legs to engage within the bore of said journal to retain said journal shoulders in engagement with said saddle shoulders, and means for releasably securing said bushings in their mounted position whereby the journal is held against movement relative to said saddle.