Patent US4077470A successfully refreshed from Google Patents.
US4077470A
Expired / Lapsed
US
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Well centralizer and method of making
Assignee: Weatherford Lamb Inc
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Filing: 1977-01-27
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Granted: 1978-03-07
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Expires: 1997-01-27
Abstract
Abstract A well centralizer and method of making having axially spaced collars for attachment about a casing and a plurality of outwardly bowed elements connected to each collar. Each end of the bows has a generally U-shaped offset which is connected in a circumferential opening in a collar and a locking tab extends from the collar inside of the offset and extends through the collar opening between the bow offset and the collar and locks the offset in the collar opening. The axial portions of the collar on each side of the opening are radially recessed outwardly for receiving one end of the bowed element and the length of the locking tab is sufficiently long to extend through the opening and engage the outside of the collar to firmly and securely lock the bow in place and maintain a consistent internal diameter of the centralizer collar. The collars and bows are easily assembled in the field by insertion of the bow ends into the collar and pressing the free end of each locking tab about a bow end.
Inventors
- 👤 Burlie Newton Dane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:24
CPC Classifications
E; E21; E21B; E21B17/00; E21B17/10; E21B17/1014; E21B17/1021; E21B17/1028; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49636; Y10T29/49707; Y10T29/49826; Y10T29/49947; Y10T29/49954
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
112 words
In a centralizer having axially spaced collars for attachment about a casing and a plurality of outwardly bowed elements connected to each collar, the improvement in connecting means between one of said bowed elements and one of said collars comprising, a circumferential opening in said collar forming opposing shoulders on opposite sides of the opening, a generally U-shaped offset in the end portion of said bowed element positioned in said opening, and a locking tab extending from the collar across the inside of said offset and extending through the opening between the offset and the collar thereby locking the offset in the opening and locking the locking tab in a holding position.
Claim 2
Dependent Claim
112 words
In a centralizer having axially spaced collars for attachment about a casing and a plurality of outwardly bowed elements connected to each collar, the improvement in connecting means between one of said bowed elements and one of said collars comprising, a circumferential opening in said collar forming opposing shoulders on opposite sides of the opening, a generally U-shaped offset in the end portion of said bowed element positioned in said opening, and a locking tab extending from the collar across the inside of said offset and extending through the opening between the offset and the collar thereby locking the offset in the opening and locking the locking tab in a holding position.
Claim 3
Dependent Claim
20 words
The apparatus of claim 1 wherein length of the locking tab is longer than the circumferential extent of said opening.
Claim 4
Dependent Claim
145 words
In a centralizer having axially spaced collars for attachment about a casing and a plurality of outwardly bowed elements connected to said collars, the improvement in connecting means between each end of each of said bowed elements and one of said collars comprising, portions of the collar being radially recessed outwardly for receiving one end of each bowed element, a circumferential opening in each recessed portion forming opposing shoulders on opposite sides of the opening, said opening being longer than the width of the bowed element, a generally U-shaped offset in the end portion of each bowed element positioned in one of said openings and held against longitudinal movement by said opposing shoulders, and a locking tab extending from the collar across the inside of the offset and extending through the opening between the offset and the collar thereby locking the offset in the opening.
Claim 5
Dependent Claim
145 words
In a centralizer having axially spaced collars for attachment about a casing and a plurality of outwardly bowed elements connected to said collars, the improvement in connecting means between each end of each of said bowed elements and one of said collars comprising, portions of the collar being radially recessed outwardly for receiving one end of each bowed element, a circumferential opening in each recessed portion forming opposing shoulders on opposite sides of the opening, said opening being longer than the width of the bowed element, a generally U-shaped offset in the end portion of each bowed element positioned in one of said openings and held against longitudinal movement by said opposing shoulders, and a locking tab extending from the collar across the inside of the offset and extending through the opening between the offset and the collar thereby locking the offset in the opening.
Claim 6
Dependent Claim
45 words
The apparatus of claim 3 wherein the length of the locking tab is longer than the circumferential extent of said opening wherein the tab extends through the opening and engages the outside of the collar to securely lock the tab and bowed element in place.
Claim 7
Dependent Claim
187 words
One half of a collar for use in a centralizer which has axially spaced collars and connected bowed elements comprising, a semi-circular collar half having connecting means at each end for connection to another semi-circular collar half, said collar half having a plurality of circumferential openings, each opening forming opposing shoulders axially spaced on opposite sides of the opening, the parts of the collar half on each axial side of each opening being recessed outwardly for receiving one end of a bowed element, a locking tab extending from the collar half from one side of each opening, said locking tabs being bent inwardly of the collar half for allowing the insertion of one end of a bowed element between a locking tab and a collar recess, the free end of each locking tab being bent toward the collar half whereby when an end of a bowed element is inserted in a recess, and the locking tab is pressed against the bowed element the free end will pass through the opening between the bowed element and the collar half and lock the element and the tab in place.
Claim 8
Dependent Claim
187 words
One half of a collar for use in a centralizer which has axially spaced collars and connected bowed elements comprising, a semi-circular collar half having connecting means at each end for connection to another semi-circular collar half, said collar half having a plurality of circumferential openings, each opening forming opposing shoulders axially spaced on opposite sides of the opening, the parts of the collar half on each axial side of each opening being recessed outwardly for receiving one end of a bowed element, a locking tab extending from the collar half from one side of each opening, said locking tabs being bent inwardly of the collar half for allowing the insertion of one end of a bowed element between a locking tab and a collar recess, the free end of each locking tab being bent toward the collar half whereby when an end of a bowed element is inserted in a recess, and the locking tab is pressed against the bowed element the free end will pass through the opening between the bowed element and the collar half and lock the element and the tab in place.
Claim 9
Dependent Claim
207 words
In the method of making a centralizer having a collar and a connected bowed element, the improvement comprising, stamping two substantially parallel slots in a portion of the collar, said slots being longer than the width of the bowed element and generally transverse to the longitudinal axis of the collar, cutting a line in the collar between said parallel slots at one end of said slots thereby forming a locking tab positioned in an opening between said slots, bending the free end of said tab toward the outside of said collar portion, recessing the part of the collar on either side of the opening outwardly for receiving one end of a bowed element, moving the locking tab inwardly of the collar portion for allowing insertion of one end of the bowed element between the locking tab and the collar recessed part, installing one end of a bowed element having a U-shaped offset in the collar recess with the U-shaped offset positioned in the opening and outside of said locking tab, and pressing the locking tab toward the bowed element and passing the free end of the locking tab through the opening and between the bowed element and the collar thereby locking the bowed element in the opening.
Claim 10
Dependent Claim
207 words
In the method of making a centralizer having a collar and a connected bowed element, the improvement comprising, stamping two substantially parallel slots in a portion of the collar, said slots being longer than the width of the bowed element and generally transverse to the longitudinal axis of the collar, cutting a line in the collar between said parallel slots at one end of said slots thereby forming a locking tab positioned in an opening between said slots, bending the free end of said tab toward the outside of said collar portion, recessing the part of the collar on either side of the opening outwardly for receiving one end of a bowed element, moving the locking tab inwardly of the collar portion for allowing insertion of one end of the bowed element between the locking tab and the collar recessed part, installing one end of a bowed element having a U-shaped offset in the collar recess with the U-shaped offset positioned in the opening and outside of said locking tab, and pressing the locking tab toward the bowed element and passing the free end of the locking tab through the opening and between the bowed element and the collar thereby locking the bowed element in the opening.
Claim 11
Dependent Claim
202 words
In the method of making a centralizer having axially spaced collars and connected bowed elements, the improvement comprising, stamping in a plurality of locations in each collar two substantially parallel slots, said slots being longer than the width of the bowed elements, cutting a line in each collar between each pair of parallel slots at one end of said slots thereby forming a locking tab positioned in an opening between each pair of slots, bending the free end of each tab toward the outside of said collar portion, recessing the axial parts of each collar on each side of each opening outwardly for receiving one end of a bowed element, moving the locking tab inwardly of the collar for allowing insertion of one end of a bowed element between each locking tab and a collar recess, installing one end of a bowed element having a U-shaped offset in each collar recess with the U-shaped offset positioned in an opening and outside of a locking tab, and pressing the locking tabs toward the bowed elements and passing the free ends of the locking tabs through an opening and between a bowed element and a collar thereby locking the bowed elements in the openings.
Claim 12
Dependent Claim
202 words
In the method of making a centralizer having axially spaced collars and connected bowed elements, the improvement comprising, stamping in a plurality of locations in each collar two substantially parallel slots, said slots being longer than the width of the bowed elements, cutting a line in each collar between each pair of parallel slots at one end of said slots thereby forming a locking tab positioned in an opening between each pair of slots, bending the free end of each tab toward the outside of said collar portion, recessing the axial parts of each collar on each side of each opening outwardly for receiving one end of a bowed element, moving the locking tab inwardly of the collar for allowing insertion of one end of a bowed element between each locking tab and a collar recess, installing one end of a bowed element having a U-shaped offset in each collar recess with the U-shaped offset positioned in an opening and outside of a locking tab, and pressing the locking tabs toward the bowed elements and passing the free ends of the locking tabs through an opening and between a bowed element and a collar thereby locking the bowed elements in the openings.
References Cited (Backward Citations)
US3356147A
Cited
DE2545181A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-03-06 | 1981-09-05 | 1982-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-06 | 1985-09-05 | 1986-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-06 | 1989-09-05 | 1990-03-07 | $7700.00 | Window Closed / Lapsed |