US4306727A — Dynamic seal for rolling cutter drill bit

Claim 1

Independent Claim 146 words

In a rolling cutter drill bit of the type having a plurality of downwardly extending legs, each leg having a cylindrical journal extending therefrom, with a cutter body rotatably mounted on each said journal by bearing means, and a seal between said cutter and said journal outwardly of said bearing means, the improvement comprising: said seal comprising a compound seal assembly having a rigid circular ring with a generally L-shaped cross-sectional configuration and having a relatively smooth, flat sealing surface formed externally thereon; and a generally frusto-conical resilient ring adapted for snugfitting relationship on said journal and against said rigid ring; shoulder means on said rigid ring and said journal arranged to prevent rotation of said rigid ring on said resilient ring; and, said cutter having a smooth flat counterbore surface therein arranged to rotatingly and sealingly engage said smooth flat surface on said rigid ring.

Claim 2

Dependent Claim 146 words

In a rolling cutter drill bit of the type having a plurality of downwardly extending legs, each leg having a cylindrical journal extending therefrom, with a cutter body rotatably mounted on each said journal by bearing means, and a seal between said cutter and said journal outwardly of said bearing means, the improvement comprising: said seal comprising a compound seal assembly having a rigid circular ring with a generally L-shaped cross-sectional configuration and having a relatively smooth, flat sealing surface formed externally thereon; and a generally frusto-conical resilient ring adapted for snugfitting relationship on said journal and against said rigid ring; shoulder means on said rigid ring and said journal arranged to prevent rotation of said rigid ring on said resilient ring; and, said cutter having a smooth flat counterbore surface therein arranged to rotatingly and sealingly engage said smooth flat surface on said rigid ring.

Claim 3

Dependent Claim 23 words

The drill bit of claim 1 wherein said rigid ring is formed of metal and said resilient ring is formed of an elastomer.

Claim 4

Dependent Claim 31 words

The drill bit of claim 1 or claim 2 wherein said resilient ring is selected from a material which exhibits good static sealing qualities and good resistance to high temperature deterioration.

Claim 5

Dependent Claim 30 words

The drill bit of claim 1 or claim 2 wherein said resilient ring is selected from a material which exhibits good static sealing qualities and good resistance to corrosive fluids.

Claim 6

Dependent Claim 38 words

The rolling cutter drill bit of claim 1 or claim 2 wherein said metal ring is formed from a hard metal selected from the group of cast metal, cast iron, steel, steel alloy, aluminum alloy, and copper-beryllium alloy.

Claim 7

Dependent Claim 45 words

The rolling cutter drill bit of claim 1 or claim 2 wherein said metal ring is formed from a hard metal selected from the group of cast metal, cast iron, steel, steel alloy, aluminum alloy, and copper-beryllium alloy, and said elastomer ring comprises silicon rubber.

Claim 8

Dependent Claim 116 words

A compound static-dynamic circular seal assembly for sealing the bearing structure of a rolling cutter drill bit against intrusion of foreign detritus from outside the drill bit, said seal assembly adapted for placement between the cutter and bearing journal of a rolling cutter drill bit, and said assembly comprising: a hard, rigid dynamic seal ring having a generally L-shaped cross-sectional configuration, a smooth flat external sealing surface, and means thereon for locking engagement on a bearing journal; and, a resilient static seal ring adapted for static peripheral sealing abutment between a bearing shaft and said rigid ring, and further adapted to provide resilient biasing of said rigid ring axially on a bearing shaft against a cutter.

Claim 9

Dependent Claim 116 words

A compound static-dynamic circular seal assembly for sealing the bearing structure of a rolling cutter drill bit against intrusion of foreign detritus from outside the drill bit, said seal assembly adapted for placement between the cutter and bearing journal of a rolling cutter drill bit, and said assembly comprising: a hard, rigid dynamic seal ring having a generally L-shaped cross-sectional configuration, a smooth flat external sealing surface, and means thereon for locking engagement on a bearing journal; and, a resilient static seal ring adapted for static peripheral sealing abutment between a bearing shaft and said rigid ring, and further adapted to provide resilient biasing of said rigid ring axially on a bearing shaft against a cutter.

Claim 10

Dependent Claim 33 words

The seal assembly of claim 7 wherein said resilient seal ring has a short frusto-conical configuration and is formed of an elastomer exhibiting good static sealing ability and good high temperature deterioration resistance.

Claim 11

Dependent Claim 30 words

The seal assembly of claim 7 or claim 8 wherein said rigid ring is formed of a hard metal selected from the group of steel, steel alloy, and copper-beryllium alloy.

Claim 12

Dependent Claim 37 words

The seal assembly of claim 7 or claim 8 wherein said rigid ring is formed of a hard metal selected from the group of steel, steel alloy, and copper-beryllium alloy, and said elastomer is a silicon rubber.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1984-12-21	1985-06-22	1985-12-22	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1988-12-21	1989-06-22	1989-12-22	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1992-12-21	1993-06-22	1993-12-22	$7700.00	Window Closed / Lapsed

Dynamic seal for rolling cutter drill bit

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