# US 8,788,157 B2 · Control method for driving a ripper > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,788,157 B2 - Document ID: US8788157B2 - Status: Granted - Kind: B2 - Application number: 14/063,082 - Filed: 2013-10-25 - Published: 2014-02-20 - Granted: 2014-07-22 - Earliest claimed: 2010-09-14 - Assignees: Komatsu Ltd. - Applicants: Komatsu Ltd. - Inventors: Satoru Shintani; Tomohiro Nakagawa; Ryouichi Nagasaka - Web page: https://patentgrep.com/patent/US8788157B2 ## CPC - E02F 9/20: Drives; Control devices (gearings in general F16H; controlling in general G05; electric multi-motor drives H02K, H02P) - E02F 3/7609: {Scraper blade mounted forwardly of the tractor on a pair of pivoting arms which are linked to the sides of the tractor, e.g. bulldozers} - E02F 3/961: {with several digging elements or tools mounted on one machine (for backhoes E02F3/964 takes precedence)} - E02F 5/32: Rippers {(E02F5/106 takes precedence, ripper or scarifying teeth mounted on blades E02F3/8152; ripper tips E02F9/2875)} - E02F 9/2004: {Control mechanisms, e.g. control levers (control levers per se G05G)} - E02F 9/22: Hydraulic or pneumatic drives {(for dipper or bucket arm position control E02F3/43, for blade position control for graders E02F3/844; for turntables E02F9/121; for fork-lift trucks B66F9/22)} - E02F 9/26: Indicating devices {(E02F5/145 takes precedence)} - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) ## Abstract A method for driving a ripper is provided in which the movement of a ripper attached to the rear of the body of a bulldozer is controlled. The method includes a first step in which the ripper is operated while the bulldozer is moving forward or is stopped, a second step in which the bulldozer is reversed and the ripper is raised, and a third step in which the ripper is automatically raised. ## Claims ### Claim 1 A control method for automatically controlling a ripper attached to a rear portion of a body of a bulldozer, the bulldozer having a ripper lifting device configured to raise and lower the ripper, a ripper tilting device configured to tilt the ripper in and out, an operating lever that is moveably provided and configured to actuate the ripper lifting device and the ripper tilting device, and a steering lever that is moveably provided and configured to control a drive unit of the bulldozer, said method comprising: a first step in which it is determined whether ripping work by the ripper has ended; a second step in which at least a first control of pulling the ripper out of a ground is automatically executed when it is determined that the ripping work has ended. ### Claim 2 (depends on 1) The control method for automatically controlling a ripper according to claim 1, further comprising a third step in which a user selects among a plurality of automatic control modes, the automatic control modes including at least a first mode in which only the first control is executed automatically in the second step. ### Claim 3 (depends on 2) The control method for automatically controlling a ripper according to claim 2, wherein it is determined that the ripping work has been ended when the steering lever has been moved to a reverse side during the ripping work and the operating lever has been moved to a lift position. ### Claim 4 (depends on 3) The control method for automatically controlling a ripper according to claim 3, wherein the automatic control modes include a second mode in which a second control of tilting back the ripper is executed automatically in the second step when it is determined both that the ripping work has ended and that the operating lever has been moved to a tilt-back position. ### Claim 5 (depends on 3) The control method for automatically controlling a ripper according to claim 3, further comprising a fourth step in which the first control is released when it is determined that the hydraulic pressure in a hydraulic circuit of the bulldozer has risen over a specific relief pressure, or that the bulldozer is moving forward or is stopped, or that the operating lever has been moved to a lowering position, or that at least a specific amount of time has elapsed since the operating lever was moved to the lift position. ### Claim 6 (depends on 4) The control method for automatically controlling a ripper according to claim 4, further comprising a fourth step in which the second control is released when it is determined that the hydraulic pressure in a hydraulic circuit of the bulldozer has risen over a specific relief pressure, or that the bulldozer is moving forward or is stopped, or that the operating lever has been moved to a tilt-in position, or that at least a specific amount of time has elapsed since the operating lever was moved to the tilt-back position. ### Claim 7 (depends on 4) The control method for automatically controlling a ripper according to claim 4, wherein the automatic control modes include a third mode in which the first and second controls are executed automatically when it is detected that the ripping work has ended. ### Claim 8 (depends on 1) The control method for automatically controlling a ripper according to claim 1, wherein it is determined that the ripping work has been ended when the steering lever has been moved to a reverse side during the ripping work and the operating lever has been moved to a lift position. ### Claim 9 (depends on 4) The control method for automatically controlling a ripper according to claim 4, further comprising; a fourth step in which the first control is released when it is determined that the hydraulic pressure in a hydraulic circuit of the bulldozer has risen over a specific relief pressure, or that the bulldozer is moving forward or is stopped, or that the operating lever has been moved to a lowering position, or that at least a specific amount of time has elapsed since operating lever was moved to the lift position; and a fifth step in which the second control is released when it is determined that the hydraulic pressure in a hydraulic circuit of the bulldozer has risen over a specific relief pressure, or that the bulldozer is moving forward or is stopped, or that the operating lever has been moved to a tilt-in position, or that at least a specific amount of time has elapsed since the operating lever was moved to the tilt-back position.