US4439167A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shock absorber assembly
Assignee: NOV Inc
•
Filing: 1982-03-01
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Granted: 1984-03-27
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Expires: 2002-03-01
Abstract
Abstract A shock absorber assembly adapted to be used with a drill string dampening intermittent shocks and vibrational forces encountered with a drill string, the shock absorber assembly including a mandrel, a tubular body reciprocally mounted with respect to the mandrel, and a dampening device including an annular chamber adapted to be filled with a compressible fluid and a flexible wall with the mandrel adjacent the annular chamber for permitting flexure of the mandrel as needed for dampening.
Inventors
- 👤 Thomas R. Bishop
- 👤 Archie W. Peil
- 👤 Wayne A. Kovar
- 👤 Roger D. Chancey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:31
CPC Classifications
E; E21; E21B; E21B17/00; E21B17/02; E21B17/04; E21B17/07
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
209 words
A shock absorber assembly adapted to be used with a drill string for dampening intermittant shocks and vibrational forces encountered with the drill string during drilling operations, comprising: a mandrel having a mandrel bore adapted to be mounted with the lower end of the drill string; an elongated tubular body having an open upper end for receiving said mandrel therein, said elongated tubular body mounted for longitudinal reciprocal movement with respect to said mandrel; dampening means including an annular chamber and flex means for dampening the intermittant shocks and vibrational forces; said annular chamber formed between said mandrel and said elongated tubular body; said flex means being an impervious wall forming a part of said mandrel adjacent said annular chamber for inward flexing of said impervious wall toward said mandrel bore of said mandrel; and, said annular chamber adapted to be filled with a compressible fluid whereby the intermittant shock and vibrational forces on said mandrel cause compression of said compressible fluid within said annular chamber whereby said compressed fluid exerts a uniform force within said annular chamber along the substantial length of said flex means thereby causing flexure of said flex means to effectuate the dampening of the intermittant shock and vibrational forces encountered with the drill string.
Claim 2
Dependent Claim
209 words
A shock absorber assembly adapted to be used with a drill string for dampening intermittant shocks and vibrational forces encountered with the drill string during drilling operations, comprising: a mandrel having a mandrel bore adapted to be mounted with the lower end of the drill string; an elongated tubular body having an open upper end for receiving said mandrel therein, said elongated tubular body mounted for longitudinal reciprocal movement with respect to said mandrel; dampening means including an annular chamber and flex means for dampening the intermittant shocks and vibrational forces; said annular chamber formed between said mandrel and said elongated tubular body; said flex means being an impervious wall forming a part of said mandrel adjacent said annular chamber for inward flexing of said impervious wall toward said mandrel bore of said mandrel; and, said annular chamber adapted to be filled with a compressible fluid whereby the intermittant shock and vibrational forces on said mandrel cause compression of said compressible fluid within said annular chamber whereby said compressed fluid exerts a uniform force within said annular chamber along the substantial length of said flex means thereby causing flexure of said flex means to effectuate the dampening of the intermittant shock and vibrational forces encountered with the drill string.
Claim 3
Dependent Claim
44 words
The shock absorber assembly of claim 1, wherein said dampening means includes: said mandrel having an outer annular surface forming an inner portion of said annular chamber; and, said flex means includes an annular detent formed in said outer annular surface of said mandrel.
Claim 4
Dependent Claim
17 words
The shock absorber assembly of claim 1, wherein: said annular chamber is formed having a differential volume.
Claim 5
Dependent Claim
102 words
The shock absorber assembly of claim 3, wherein: said elongated tubular body has an inner bore; said mandrel has an upper outer annular surface and lower outer annular surface, with the diameter of said upper outer annular surface being greater than the diameter of said lower outer annular surface; said inner bore and portion of said upper and lower outer annular surfaces forming said annular chamber having said differential volume, whereupon longitudinal reciprocal movements between said body and said mandrel result in a variable compression of said compressible fluid in said annular chamber substantially caused by said differential volume in said chamber.
Claim 6
Dependent Claim
35 words
The shock absorber assembly of claim 1, further comprising: bearing means mounted between and adjacent the said open upper end of said tubular body and said mandrel for preventing unwanted lateral displacement during drilling operations.
Claim 7
Dependent Claim
43 words
The shock absorber assembly of claim 1, further including: limiting means mounted with said mandrel within said annular chamber for limiting movement of said mandrel between a fully extended and fully contracted position of said mandrel with respect to said elongated tubular body.
Claim 8
Dependent Claim
26 words
The shock absorber assembly of claim 1, wherein: the smallest diameter portion of said mandrel is positioned adjacent the lower portion of said elongated tubular body.
References Cited (Backward Citations)
US2025100A
Cited
US2240519A
Cited
US2520306A
Cited
US2712435A
Cited
US2987129A
Cited
US3033011A
Cited
US3225566A
Cited
US3281166A
Cited
US3350900A
Cited
US3370657A
Cited
US3606297A
Cited
US3735828A
Cited
US3750423A
Cited
US3815692A
Cited
US3949150A
Cited
US3947008A
Cited
US3998443A
Cited
US4031716A
Cited
US4055338A
Cited
US4130000A
Cited
US4067405A
Cited
US4171025A
Cited
US4133516A
Cited
US4145034A
Cited
US4331006A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-27 | 1987-09-26 | 1988-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-27 | 1991-09-26 | 1992-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-27 | 1995-09-26 | 1996-03-27 | $7700.00 | Window Closed / Lapsed |