# US 11,442,193 B2 · Passive arm for bi-directional well logging instrument > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,193 B2 - Document ID: US11442193B2 - Status: Granted - Kind: B2 - Application number: 16/757,991 - Filed: 2019-05-17 - Published: 2022-03-10 - Granted: 2022-09-13 - Earliest claimed: 2019-05-17 - Assignees: Halliburton Energy Services, Inc. - Applicants: Halliburton Energy Services, Inc. - Inventors: David R. Beard - Web page: https://patentgrep.com/patent/US11442193B2 ## CPC - E21B 47/00: Survey of boreholes or wells (monitoring pressure or flow of drilling fluid E21B21/08) - G01V 3/02: operating with propagation of electric current - E21B 17/1021: {with articulated arms or arcuate springs} - E21B 23/01: for anchoring the tools or the like (E21B23/02 - E21B23/06 take precedence; anchoring of drives in the borehole E21B4/18) - E21B 47/0025: {generating an image of the borehole wall using down-hole measurements, e.g. acoustic or electric} - G01V 3/38: Processing data, e.g. for analysis, for interpretation, for correction - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) ## Abstract A downhole tool may comprise a tool body that is a structural support for the downhole tool, an upper arm attached at one end to the tool body, a pad attached at an opposite end of the upper arm, a lower arm attached at one end to a sliding block and attached to the pad at an opposite end of the lower arm, and a passive arm connected to the lower arm and the tool body. A method may comprise disposing a downhole tool into a borehole, applying a force to a passive arm, applying a second force from the passive arm to the lower arm in response to the force applied to the passive arm, and moving the lower arm and the passive arm in a longitudinal direction along an axis of the downhole tool. ## Claims ### Claim 1 A downhole tool comprising: a tool body that is a structural support for the downhole tool; an upper arm attached at one end to the tool body; a pad attached at an opposite end of the upper arm; a lower arm attached at one end to a sliding block and attached to the pad at an opposite end of the lower arm; a passive arm connected to the lower arm and the tool body, wherein the passive arm is directly connected to the lower arm via a pin and slot arrangement; and a spring in which the sliding block is connected to at one end and an actuator is connected at the opposite end of the spring. ### Claim 2 (depends on 1) The downhole tool of claim 1, further comprising one or more pins that connect the upper arm to the tool body and the pad. ### Claim 3 (depends on 2) The downhole tool of claim 2, the one or more pins connect the lower arm to the tool body and the sliding block. ### Claim 4 (depends on 1) The downhole tool of claim 1, wherein an actuator moves the spring and in turn the sliding block through the spring. ### Claim 5 (depends on 1) The downhole tool of claim 1, wherein the passive arm is connected at one end to the tool body by a pin and connected to the lower arm by a second pin. ### Claim 6 (depends on 5) The downhole tool of claim 5, wherein the second pin is placed within a slot that is formed in the lower arm. ### Claim 7 (depends on 6) The downhole tool of claim 6, wherein the second pin is moveable along a longitudinal length of the slot. ### Claim 8 (depends on 1) The downhole tool of claim 1, wherein the passive arm is attached inside the lower arm. ### Claim 9 (depends on 1) The downhole tool of claim 1, wherein the pad further comprises one or more electrodes. ### Claim 10 A method comprising: disposing a downhole tool into a borehole, the downhole tool comprises: an upper arm attached to the downhole tool at one end and a pad attached to an opposite end of the upper arm; a lower arm attached to the downhole tool at one end and the pad at an opposite end of the lower arm; and a passive arm attached to the downhole tool at one end and the lower arm at an opposite end of the passive arm, wherein the passive arm is directly connected to the lower arm via a pin and slot arrangement, and wherein the passive arm is attached outside the lower arm; applying a force to a passive arm; applying a second force from the passive arm to the lower arm in response to the force applied to the passive arm; and moving the lower arm and the passive arm in a longitudinal direction along an axis of the downhole tool. ### Claim 11 (depends on 10) The method of claim 10, further comprising applying a second force to the upper arm. ### Claim 12 (depends on 11) The method of claim 11, further comprising moving the upper arm and the lower arm in the longitudinal direction along the axis of the downhole tool. ### Claim 13 (depends on 10) The method of claim 10, further comprising moving the pad radially inward. ### Claim 14 A downhole tool comprising: a tool body that is a structural support for the downhole tool; a pad; a lower arm attached at one end to a sliding block and attached to the pad at an opposite end of the lower arm, wherein the lower arm includes a slot; and a passive arm connected to the lower arm and the tool body, wherein the passive arm is directly connected to the lower arm via a pin and slot arrangement, wherein the passive arm includes a pin that is placed within the slot of the lower arm, and wherein the pin moves longitudinally within the slot. ### Claim 15 (depends on 8) The downhole tool of claim 8, wherein the passive arm is positioned inside the lower arm.