# US 8,464,752 B2 · External position indicator of ram blowout preventer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,464,752 B2 - Document ID: US8464752B2 - Status: Granted - Kind: B2 - Application number: 12/827,459 - Filed: 2010-06-30 - Published: 2012-01-05 - Granted: 2013-06-18 - Earliest claimed: 2010-06-30 - Assignees: Hydril USA Manufacturing LLC - Applicants: David Albert Dietz; Aaron P. Smith - Inventors: David Albert Dietz; Aaron P. Smith - Web page: https://patentgrep.com/patent/US8464752B2 ## CPC - E21B 33/062: {with sliding rams} - G01B 7/02: for measuring length, width or thickness (G01B7/004, G01B7/12 take precedence) - Y10T 29/49826: Assembling or joining - Y10T 137/8158: With indicator, register, recorder, alarm or inspection means - Y10T 137/8275: Indicator element rigidly carried by the movable element whose position is indicated - Y10T 137/8292: Movable indicator element is a pointer - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Method and blowout preventer for sealing a well. The blowout preventer includes a body having first and second chambers, the first chamber extending substantially perpendicular to and intersecting the second chamber; a ram block configured to move within the first chamber to seal a first region of the second chamber from a second region of the second chamber; a rod connected to the ram block and configured to extend along the first chamber; a piston connected to the rod and configured to move along and within the first chamber; a bonnet configured to receive the piston, the bonnet being detachably attached to the body; and an indicator device partially mounted outside the bonnet and configured to indicate a physical position of the ram block within the body. ## Claims ### Claim 1 A blowout preventer for sealing a well, the blowout preventer comprising: a body having first and second chambers, the first chamber extending substantially perpendicular to and intersecting the second chamber; a ram block selectively moveable from within the first chamber to the second chamber to define a seal in the second chamber; a connecting rod connected to the ram block and configured to extend along the first chamber; a piston connected to the connecting rod and configured to move along and within the first chamber and move the ram block in and out of the second chamber; a bonnet configured to receive the piston, the bonnet being detachably attached to the body; an indicator device having at least a portion disposed outside the bonnet when the ram block is in the first chamber and in the second chamber, and configured to indicate where the ram block is within the body; and a third magnet are disposed at an end of the piston opposite the first magnet and along an axis of the first chamber, with the second magnet between the first and third magnets, so that when the piston moves within the bonnet, the first magnet and third magnet move the second magnet to indicate a position of the ram. ### Claim 2 (depends on 1) The blowout preventer of claim 1, wherein the indicator device comprises: a first magnet attached to the piston within the bonnet; an alignment rod attached to an outside of the bonnet; and a second magnet provided outside the bonnet and configured to move along the alignment rod together with the first magnet. ### Claim 3 (depends on 2) The blowout preventer of claim 2, further comprising: a scale provided on the outside of the body such that a position of the second magnet relative to the scale is indicative of the position of the ram block inside the body. ### Claim 4 (depends on 2) The blowout preventer of claim 2, further comprising: two sensors provided outside the bonnet, each sensor configured to detect a presence of the first or second magnet next to the sensor such that a movement direction of the ram block is determined. ### Claim 5 (depends on 2) The blowout preventer of claim 2, wherein the first magnet is a circular magnet disposed at a periphery of the piston. ### Claim 6 (depends on 1) The blowout preventer of claim 1, wherein the indicator device comprises: a tail-rod extension connected to the piston and configured to exit the bonnet; and a seal disposed between the tail-rod extension and the bonnet for maintaining a pressure differential between an inside and outside of the bonnet. ### Claim 7 (depends on 6) The blowout preventer of claim 6, wherein the tail-rod extension includes marks that indicate the position of the ram block inside the body. ### Claim 8 (depends on 6) The blowout preventer of claim 6, further comprising: a marker attached to the tail-rod extension and configured to indicate a position of the ram block inside the body. ### Claim 9 (depends on 6) The blowout preventer of claim 6, further comprising: a tube having partially transparent sidewalls and that is attached to the bonnet and configured to receive the tail-rod extension, wherein the tail-rod extension is configured to bend when inside the tube and outside the bonnet. ### Claim 10 (depends on 6) The blowout preventer of claim 6, wherein the tail-rod extension is located off-center relative to a central axis of the bonnet. ### Claim 11 A blowout preventer for sealing a well comprising: a body having first and second chambers, the first chamber extending substantially perpendicular to and intersecting the second chamber; a ram block selectively moveable from within the first chamber to the second chamber to define a seal in the second chamber; a connecting rod connected to the rain block and configured to extend along the first chamber; a piston connected to the connecting rod and configured to move along and within the first chamber and move the ram block in and out of the second chamber, a bonnet configured to receive the piston, the bonnet being detachably attached to the body; an indicator device having at least a portion disposed outside the bonnet when the ram block is in the first chamber and in the second chamber, and configured to indicate where the ram block is within the body that is indicative of the position of the ram block inside the body, a scale on an external surface of the body, and an indicator that moves with movement of the ram adjacent the scale for representing a location of the ram such that the at least one component is visible from the outside of the body. ### Claim 12 An indicator device to be attached to a movable part of a blowout preventer for sealing a well, the indicator device comprising: a first magnet configured to be attached to a piston within a bonnet of the blowout preventer; an alignment rod configured to be attached to an outside of the bonnet; a second magnet attached to the alignment rod, outside the bonnet, and configured to move along the alignment rod when pushed or pulled by the first magnet; a scale provided on the outside of the bonnet such that a position of the second magnet relative to the scale is indicative of the position of a ram block inside the blowout preventer; and a third magnet disposed on the piston axially spaced apart from the first magnet, so that when the second magnet is axially between the first magnet and the third magnet, the first magnet and the third magnet each move the second magnet in response to movement of the ram. ### Claim 13 (depends on 12) The indicator device of claim 12, further comprising: two sensors provided outside the bonnet, each sensor configured to detect a presence of the first or second magnet next to the sensor such that a movement direction of the ram block is determined.