# US 2015/0027007 A1 · Excavating Attachment with Laterally Pivotable Working Arm for Excavating Beneath a Buried Utility > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0027007 A1 - Document ID: US20150027007A1 - Status: Published application - Kind: A1 - Application number: 14/334,982 - Filed: 2014-07-18 - Published: 2015-01-29 - Earliest claimed: 2013-07-25 - Inventors: Kelvin R. Doherty - Web page: https://patentgrep.com/patent/US20150027007A1 ## CPC - E02F 5/18: for horizontal holes {or inclined holes} - E02F 3/963: {Arrangements on backhoes for alternate use of different tools (backhoes per se E02F3/30; quick-acting devices to connect tools to arms E02F3/3609, for arms to tractors or the like E02F3/627)} - E02F 5/003: {for uncovering conduits} - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) ## Abstract An attachment is provided for us on an articulated boom of an excavator in order to excavate earth from beneath a buried pipeline or other utility. The attachment features at least one working arm pivotally mounted to a base plate for movement relative to the base plate about an axis passing therethrough. A working end of the arm is thereby movable between a retracted position overlying the base plate and a deployed position reaching laterally outward from an edge of the base plate. With the excavator facing in a longitudinal direction of the utility, and the attachment carried beside the utility at a short depth therebelow by the boom of the excavator, the arm can be deployed and retracted in order to sweep material out from under the pipeline and onto the base plate. The material is then lifted to the surface by raising of the excavator boom. ## Claims ### Claim 1 An excavating attachment comprising: a base; a coupling unit attached to the base and arranged for removable coupling to a working machine for carrying of the excavating attachment thereby; a working arm pivotally coupled to the base and pivotal relative thereto about a pivot axis passing through the base, the working arm having a working end for engaging the earth and a non-working end lying opposite said working end; and an actuator coupled to the working arm and operable to control movement of the working end of the working arm on a respective side of the coupling unit between a deployed position situated laterally outward from the base on the respective side of the coupling unit and a retracted position located nearer to the coupling unit than in the deployed working position. ### Claim 2 (depends on 1) The excavating attachment of claim 1 comprising a second working arm pivotally coupled to the base and pivotal relative thereto about a second axis passing through the base, the second working arm having a second working end that is movable on a second side respective side of the coupling unit between a second deployed position situated laterally outward from the base on the respective side of the coupling unit and a second retracted position located nearer to the coupling unit than in the second deployed working position. ### Claim 3 (depends on 2) The excavating attachment of claim 2 wherein the actuator is coupled to both working arms. ### Claim 4 (depends on 3) The excavating attachment of claim 3 comprising a locking mechanism operable to lock either one of the working arms against movement by the actuator while leaving the other working arm free for movement by the actuator. ### Claim 5 (depends on 4) The excavating attachment of claim 4 wherein the locking mechanism comprises a removable locking pin selectively engagable with either of the working arms in a manner also engaging the base. ### Claim 6 (depends on 1) The excavating attachment of claim 1 wherein the actuator is a hydraulic actuator arranged for coupling to hydraulic lines of the working machine for control of the actuator from an operator cabin of the working machine via a hydraulic system of the working machine. ### Claim 7 (depends on 1) The excavating attachment of claim 1 wherein the base comprises a flat plate. ### Claim 8 A method of excavating earth from beneath a buried utility running on a longitudinal axis, the method comprising: (a) with an excavating attachment carried on the free end of an articulated boom of a working machine that is facing along the longitudinal axis, situating the attachment within an access hole dug out beside the buried utility at a position placing a base and one or more working arms of the excavating attachment at a depth below the utility; (b) pivoting one of the working arms of the excavating attachment relative to the base from a retracted position of the working arm to a deployed position of the working arm, in which a working end of the working arm reaches laterally outward beyond a respective side of the base to engage the earth beneath the buried utility; and (c) working loose at least some of the earth beneath the utility with the working end of the working arm from step (b). ### Claim 9 (depends on 8) The method of claim 8 wherein step (c) comprises displacing the attachment along the longitudinal axis to scrape away at least some of the earth beneath the utility with the working end of the working arm. ### Claim 10 (depends on 8) The method of claim 8 further comprising step (d) of retracting the working end of the working arm back toward the respective side of the base and using the working arm to sweep loosened earth onto the base during retraction of the working end of the working arm back toward the respective side of the base. ### Claim 11 (depends on 8) The method of claim 8 wherein step (c) comprises working loose only part of the earth beneath the utility, and further comprising repetition of steps (a) to (c) on a second side of the buried utility via a second access hole dug out on said second side of the utility. ### Claim 12 (depends on 11) The method of claim 11 wherein the working machine faces the same direction in the repetition of steps (a) to (c) as in the preceding performance of steps (a) to (c), and the working arm used in the repetition of steps (b) and (c) is a second working arm deployed from a second side of the base. ### Claim 13 (depends on 8) The method of claim 8 wherein step (b) and the repetition of step (b) comprise using a same actuator to deploy the two working arms. ### Claim 14 (depends on 13) The method of claim 13 comprising, between step (c) and the repetition of step (a), unlocking the second working worm used in the repetition of steps (b) and (c) and locking the working arm used in steps (b) and (c). ### Claim 15 (depends on 8) The method of claim 8 wherein step (b) comprising using a hydraulic power system of the working machine to pivot the working arm into the working position.