# US 2013/0153310 A1 · Suspension System and Control Method for Track-Propelled Machines > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153310 A1 - Document ID: US20130153310A1 - Status: Published application - Kind: A1 - Application number: 13/330,887 - Filed: 2011-12-20 - Published: 2013-06-20 - Earliest claimed: 2011-12-20 - Assignees: Caterpillar Paving Products Inc. - Inventors: Craig M. Steffen - Web page: https://patentgrep.com/patent/US20130153310A1 ## CPC - B62D 55/116: Attitude or position control of chassis by action on suspension, e.g. to compensate for a slope - B60G 17/0155: {pneumatic unit} - B60G 17/056: Regulating distributors or valves {for hydropneumatic systems}(B60G17/044 - B60G17/048, {B60G17/0416} take precedence; {Fluid interconnection systems to control vehicle inclination B60G21/06, B60G21/10}; valves per se F16K) - B62D 55/065: Multi-track vehicles, i.e. more than two tracks {(soil-shifting machines E02F; mining machines E21C)} - B62D 55/084: Endless-track units or carriages mounted separably, adjustably or extensibly on vehicles, e.g. portable track units (B62D55/07 takes precedence) - B62D 55/112: with fluid springs, e.g. hydraulic pneumatic - B60G 2300/09: Construction vehicles, e.g. graders, excavators - B60G 2300/32: Track vehicles - B60G 2500/30: Height or ground clearance - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) - B60G: VEHICLE SUSPENSION ARRANGEMENTS (air-cushion vehicles B60V; {cycle suspensions B62K25/00}) ## Abstract A suspension system for cold planer with four tracks is disclosed. The suspension system includes a hydraulic cylinder for each track, an additional bypass valve for each hydraulic cylinder and an additional bypass valve that bypasses the operation of the front control valves that control the elevation of the front tracks during a cutting operation. During transport or roading of the cold planer, the bypass valves are energized by a controller and the energized bypass valves provide communication between the head ends of the left side cylinders and the head ends of the right side cylinders. During roading, the energized bypass valves also provide communication between the rod ends of the front cylinders and between the rod ends of the rear cylinders. ## Claims ### Claim 1 A suspension system for a tracked vehicle, the system comprising: a left front cylinder, a left rear cylinder, a right front cylinder and a right rear cylinder, each of said cylinders including a head end and a rod end, a left front bypass valve, a left rear bypass valve, a right front bypass valve, a right rear bypass valve and a front central bypass valve, the left front bypass valve in communication with the head end of the left front cylinder and the left rear bypass valve, the left rear bypass valve in communication with the head end of the left rear cylinder and the left front bypass valve, the right front bypass valve in communication with the head end of the right front cylinder and the right rear bypass valve, the right rear bypass valve in communication with the head end of the right rear cylinder and the right front bypass valve, the front central bypass valve in communication with the rod end of the left front cylinder and the rod end of the right front cylinder, the rod end of the left rear cylinder in communication with the rod end of the right rear cylinder. ### Claim 2 (depends on 1) The system of claim 1 wherein the left front bypass valve, the right front bypass valve, the left rear bypass valve, the right rear bypass valve and the front central bypass valve are linked to a controller, wherein, when the controller sends signals to open the left and right front bypass valves, the left and right rear bypass valves and the front central bypass valve, communication is established between the head ends of the left front cylinder and the left rear cylinder through the left front bypass valve and the left rear bypass valve, the head ends of the right front cylinder and the right rear cylinder through the right front bypass valve and the right rear bypass valve, and the rod ends of the left front cylinder and the right front cylinder through the front central bypass valve. ### Claim 3 (depends on 1) The system of claim 1 further including a left front control valve in communication with the head end and the rod end of the left front cylinder, a right front control valve in communication with the head end and the rod end of the right front cylinder, and a rear control valve in communication with the head end and the rod end of the left rear cylinder and the head end and rod end of the right rear cylinder. ### Claim 4 (depends on 3) The system of claim 3 wherein the right front control valve is in communication with the rod end of the right front cylinder and the left front control valve is in communication with the rod end of the left front cylinder. ### Claim 5 (depends on 1) The system of claim 1 wherein the rear central control valve is in communication with rod ends of the left and right rear cylinders and the left and right rear bypass valves. ### Claim 6 (depends on 1) The system of claim 1 further including a left front counterbalance valve in communication with the head and rod ends of the left front cylinder, a right front counterbalance valve in communication with the head and rod ends of the right front cylinder, and a rear central counterbalance valve in communication with the head and rod ends of the left and right rear cylinders. ### Claim 7 (depends on 2) The system of claim 2 wherein the left front control valve, the right front control valve and the rear central control valve are in communication with a pump and a drain. ### Claim 8 (depends on 1) The system of claim 1 wherein the left and right front bypass valves, the left and right rear bypass valves and the front central bypass valve are directional control valves with at least two connections and at least two positions including a closed position and an open bidirectional flow position. ### Claim 9 (depends on 6) The system of claim 6 wherein the left front counterbalance valve is also in communication with the left front bypass valve and the left front control valve, and the right front counterbalance valve is also in communication with the right front bypass valve and the right front control valve. ### Claim 10 (depends on 6) The system of claim 6 wherein the rear central counterbalance valve is in communication with the head and rod ends of both the left and right rear cylinders. ### Claim 11 A suspension system for a tracked vehicle having four tracks, the system comprising: a left front cylinder, a left rear cylinder, a right front cylinder and a right rear cylinder, each of said cylinders including a head end and a rod end, a left front bypass valve, a left rear bypass valve, a right front bypass valve, a right rear bypass valve and a front central bypass valve, the left front bypass valve in communication with the head end of the left front cylinder and the left rear bypass valve, the left rear bypass valve in communication with the head end of the left rear cylinder and the left front bypass valve, the right front bypass valve in communication with the head end of the right front cylinder and the right rear bypass valve, the right rear bypass valve in communication with the head end of the right rear cylinder and the right front bypass valve, the front central bypass valve in communication with the rod end of the left front cylinder and the rod end of the right front cylinder, the rod end of the left rear cylinder in communication with the rod end of the right rear cylinder, the rear central control valve is in communication with rod ends of the left and right rear cylinders and the left and right rear bypass valves, wherein at least the left front bypass valve, the right front bypass valve, the left rear bypass valve, the right rear bypass valve and the front central bypass valve being linked to a controller, wherein, when the controller sends signals to open the left and right front bypass valves, the left and right rear bypass valves and the front central bypass valve, communication is established between the head ends of the left front cylinder and the left rear cylinder through the left front bypass valve and the left rear bypass valve, the head ends of the right front cylinder and the right rear cylinder through the right front bypass valve and the right rear bypass valve, and the rod ends of the left front cylinder and the right front cylinder through the front central bypass valve. ### Claim 12 (depends on 11) The system of claim 11 further including a left front control valve in communication with the head end and the rod end of the left front cylinder, a right front control valve in communication with the head end and the rod end of the right front cylinder, and a rear control valve in communication with the head end and the rod end of the left rear cylinder and the head end and rod end of the right rear cylinder. ### Claim 13 (depends on 12) The system of claim 12 wherein the right front control valve is in communication with the rod end of the right cylinder and the left front control valve is in communication with the rod end of the left front cylinder. ### Claim 14 (depends on 11) The system of claim 11 further including a left front counterbalance valve in communication with the head and rod ends of the left front cylinder, a right front counterbalance valve in communication with the head and rod ends of the right front cylinder, and a rear central counterbalance valve in communication with the head and rod ends of the left and right rear cylinders. ### Claim 15 (depends on 12) The system of claim 12 wherein the left front control valve, the right front control valve and the rear central control valve are in communication with a pump and a drain. ### Claim 16 (depends on 11) The system of claim 11 wherein the left and right front bypass valves, the left and right rear bypass valves and the front central bypass valves are directional control valves with at least two connections and at least two positions including a closed position and an open bidirectional flow position. ### Claim 17 (depends on 16) The system of claim 16 wherein the left front counterbalance valve is also in communication with the left front bypass valve and the left front control valve, and the right front counterbalance valve is also in communication with the right front bypass valve and the right front control valve. ### Claim 18 (depends on 16) The system of claim 16 wherein the rear central counterbalance valve is in communication with the head and rod ends of both the left and right rear cylinders. ### Claim 19 A method for suspending a cold planer having at least four tracks while roading the cold planer, the cold planer including a left front cylinder, a left rear cylinder, a right front cylinder and a right rear cylinder, each of said cylinders including a head end and a rod end, the cold planer further including a left front bypass valve, a left rear bypass valve, a right front bypass valve, a right rear bypass valve and a front central bypass valve, the left front bypass valve in communication with the head end of the left front cylinder and the left rear bypass valve, the left rear bypass valve in communication with the head end of the left rear cylinder and the left front bypass valve, the right front bypass valve in communication with the head end of the right front cylinder and the right rear bypass valve, the right rear bypass valve in communication with the head end of the right rear cylinder and the right front bypass valve, the front central bypass valve in communication with the rod end of the left front cylinder and the rod end of the right front cylinder, the rod end of the left rear cylinder in communication with the rod end of the right rear cylinder, the method comprising: opening the left and right front bypass valves, the left and right rear bypass valves and the front central bypass valve to establish communication between the head ends of the left front cylinder and the left rear cylinder through the left front bypass valve and the left rear bypass valve, the head ends of the right front cylinder and the right rear cylinder through the right front bypass valve and the right rear bypass valve, and the rod ends of the left front cylinder and the right front cylinder through the front central bypass valve. ### Claim 20 (depends on 19) The method of claim 19 wherein at least the left front bypass valve, the right front bypass valve, the left rear bypass valve, the right rear bypass valve and the front central bypass valve are linked to a controller, the method further including sending signals from the controller to open the left and right front bypass valves, the left and right rear bypass valves and the front central bypass valve prior to roading.