US4593775A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-piece pressure relief valve
Assignee: Smith International Inc
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Filing: 1985-04-18
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Granted: 1986-06-10
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Expires: 2005-04-18
Abstract
Abstract A pressure compensating lubricant reservoir system is disclosed for a rotary cone rock bit. The system comprises a two-piece canister and flexible boot, one side of the boot being vented to the dome area of the bit. An O-ring is utilized adjacent the reservoir cover cap to seal the lubricant within the reservoir cavity. In order to prevent damage to the O-ring, the cover cap part of the canister forms a circumferential groove therearound to accept the O-ring. An intermediate disc is trapped between the cover cap and the resilient boot and serves to close out the O-ring groove in the cover cap. With a prior art one-piece canister, the O-ring is put into position in a groove formed by the canister, followed by insertion of the canister into a lubricant cavity formed by the bit body. Damage to the O-ring often occurs when the outer peripheral edge of the O-ring passes by a cover cap snap ring retention slot at the reservoir cavity entrance. The O-ring can now be placed in the reservoir cavity without damage to the ring.
Inventors
- 👤 John P. Chaney
- 👤 William Van De Nobelen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:26
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/08; E21B10/22; E21B10/24
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
272 words
A pressure compensation lubricant reservoir mechanism for a sealed bearing rotary cone rock bit comprising: a rock bit body, said body forming an open-ended lubrication cavity therein, said body further forming lubrication conduits from said cavity to one or more rock bit bearings and at least one channel formed by said body communicating from said cavity to a dome portion formed by said rock bit body, an expandable boot forming a boot retention flange at an opened end thereof, said boot flange seats against a shoulder portion formed by said body within said cavity, a first hollow canister having first and second opened ends shaped to fit within said cavity, said second end of said canister seats against said boot flange, a second cover cap canister having first and second ends, shaped to complement said first canister, said second end of said cover cap forming an annular recessed L-shaped receptacle therearound, said receptacle accepts a resilient packing gland therein, said second end of said cover cap seats against said first end of said first canister to close out said L-shaped receptacle for said packing gland, and spring biasing means adjacent said first end of said cover cap canister, said spring means is positioned between a cover cap retainer, said cover cap retainer is retained within a means formed in said bit body within said cavity, said spring means biases said second cover cap canister and said first canister against said boot flange, the resilient packing gland being positionable within said reservoir cavity without damage during an assembly of said lubricant reservoir mechanism thereby assuring a cover cap seal for said lubricant reservoir.
Claim 2
Dependent Claim
272 words
A pressure compensation lubricant reservoir mechanism for a sealed bearing rotary cone rock bit comprising: a rock bit body, said body forming an open-ended lubrication cavity therein, said body further forming lubrication conduits from said cavity to one or more rock bit bearings and at least one channel formed by said body communicating from said cavity to a dome portion formed by said rock bit body, an expandable boot forming a boot retention flange at an opened end thereof, said boot flange seats against a shoulder portion formed by said body within said cavity, a first hollow canister having first and second opened ends shaped to fit within said cavity, said second end of said canister seats against said boot flange, a second cover cap canister having first and second ends, shaped to complement said first canister, said second end of said cover cap forming an annular recessed L-shaped receptacle therearound, said receptacle accepts a resilient packing gland therein, said second end of said cover cap seats against said first end of said first canister to close out said L-shaped receptacle for said packing gland, and spring biasing means adjacent said first end of said cover cap canister, said spring means is positioned between a cover cap retainer, said cover cap retainer is retained within a means formed in said bit body within said cavity, said spring means biases said second cover cap canister and said first canister against said boot flange, the resilient packing gland being positionable within said reservoir cavity without damage during an assembly of said lubricant reservoir mechanism thereby assuring a cover cap seal for said lubricant reservoir.
Claim 3
Dependent Claim
19 words
The invention as set forth in claim 1 wherein said expandable boot is formed from an elastic rubber material.
Claim 4
Dependent Claim
19 words
The invention as set forth in claim 2 wherein said expandable boot is formed from a synthetic nitrile compound.
Claim 5
Dependent Claim
15 words
The invention as set forth in claim 1 wherein said packing gland is an O-ring.
Claim 6
Dependent Claim
15 words
The invention as set forth in claim 4 wherein the O-ring is formed from rubber.
Claim 7
Dependent Claim
18 words
The invention as set forth in claim 5 wherein the O-ring is formed from a synthetic nitrile compound.
Claim 8
Dependent Claim
17 words
The invention as set forth in claim 1 wherein the spring biasing means is a belleville spring.
Claim 9
Dependent Claim
17 words
The invention as set forth in claim 7 wherein the spring biasing means is a coiled spring.
Claim 10
Dependent Claim
39 words
The invention as set forth in claim 1 wherein the cover cap retainer is a snap ring, said cover cap retainer means formed by said bit body within said cavity is an annular groove that retains said snap ring.
Claim 11
Dependent Claim
41 words
The invention as set forth in claim 1 wherein said expandable boot is convoluted forming outer and inner portions, said outer and inner portions being substantially concentric, the inner portion of said boot is closed off to retain a lubricant therein.
Claim 12
Dependent Claim
58 words
The invention as set forth in claim 10 wherein said expandable boot has a rigid cylindrical ring adjacent said outer portion forming a flange at one end, the flange complements said boot retention flange, said cylindrical ring extends partway down the length of the boot and serves to support and reinforce said outer portion of said expandable boot.
Claim 13
Dependent Claim
23 words
The invention as set forth in claim 11 wherein said rigid cylindrical ring is encapsulated within said outer portion of said expandable boot.
Claim 14
Dependent Claim
17 words
The invention as set forth in claim 12 wherein said rigid cylindrical ring is formed of metal.
Claim 15
Dependent Claim
37 words
The invention as set forth in claim 1 wherein said boot retention flange at an opened end thereof is formed in a torroidal shape, said flange acting as a deformable O-ring upon assembly of the reservoir mechanism.
Claim 16
Dependent Claim
271 words
A pressure compensation lubricant reservoir mechanism for a sealed bearing rotary cone rock bit comprising: a rock bit body, said body forming an open ended lubrication cavity therein, said body further forming lubrication conduits from said cavity to one or more rock bit bearings and at least one channel formed by said body communicating from said cavity to a dome portion formed by said rock bit body, an expandable boot forming a boot retention flange at an opened end thereof, said boot flange seats against a shoulder portion formed by said body within said cavity, a first hollow canister having first and second opened ends shaped to fit within said cavity, said second end of said canister seats against said boot flange, a second cover cap canister having first and second ends, shaped to complement said first canister, said second end of said cover cap forming an annular recessed L-shaped gland therearound, said gland accepts an elastic O-ring therein, said second end of said cover cap seats against said first end of said first canister to close out said L-shaped gland for said O-ring, and spring biasing means adjacent said first end of said cover cap canister, said spring means is positioned between a snap ring cover cap retainer, said snap ring being retained within an annular groove formed in said bit body within said cavity, said spring means biases said second cover cap canister and said first canister against said boot flange, the O-ring being positionable within said reservoir cavity without damage during an assembly of said lubricant reservoir mechanism thereby assuring a cover cap seal for said lubricant reservoir.
Claim 17
Dependent Claim
271 words
A pressure compensation lubricant reservoir mechanism for a sealed bearing rotary cone rock bit comprising: a rock bit body, said body forming an open ended lubrication cavity therein, said body further forming lubrication conduits from said cavity to one or more rock bit bearings and at least one channel formed by said body communicating from said cavity to a dome portion formed by said rock bit body, an expandable boot forming a boot retention flange at an opened end thereof, said boot flange seats against a shoulder portion formed by said body within said cavity, a first hollow canister having first and second opened ends shaped to fit within said cavity, said second end of said canister seats against said boot flange, a second cover cap canister having first and second ends, shaped to complement said first canister, said second end of said cover cap forming an annular recessed L-shaped gland therearound, said gland accepts an elastic O-ring therein, said second end of said cover cap seats against said first end of said first canister to close out said L-shaped gland for said O-ring, and spring biasing means adjacent said first end of said cover cap canister, said spring means is positioned between a snap ring cover cap retainer, said snap ring being retained within an annular groove formed in said bit body within said cavity, said spring means biases said second cover cap canister and said first canister against said boot flange, the O-ring being positionable within said reservoir cavity without damage during an assembly of said lubricant reservoir mechanism thereby assuring a cover cap seal for said lubricant reservoir.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-09 | 1989-12-09 | 1990-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-09 | 1993-12-09 | 1994-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-09 | 1997-12-09 | 1998-06-10 | $7700.00 | Window Closed / Lapsed |