# US 2012/0235100 A1 · Dynamic Vibration Control Systems and Methods for Industrial Lift Trucks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2012/0235100 A1 - Document ID: US20120235100A1 - Status: Published application - Kind: A1 - Application number: 13/312,722 - Filed: 2011-12-06 - Published: 2012-09-20 - Earliest claimed: 2011-03-18 - Assignees: The Raymond Corporation - Inventors: Paul P. McCabe; John B. Kirk; Bryce Gregory; Michael G. Field - Web page: https://patentgrep.com/patent/US20120235100A1 ## CPC - B66F 9/07586: {Suspension or mounting of wheels on chassis} - B60G 17/08: Characteristics of fluid dampers (adjusting fluid dampers in general F16F9/44 - F16F9/53) - B62B 3/0612: {power operated} - B62B 5/0006: {Bumpers; Safety devices} - B62B 5/0069: {Control} - B66F 9/07559: {Stabilizing means} - B66F 17/003: {for fork-lift trucks} - F16F 7/01: using friction between loose particles, e.g. sand - F16F 15/02: Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems ({F16F15/005 takes precedence } ; layered products B32B; suppression of vibration in ships B63; {relieving load on bearings, using magnetic means F16C39/06}) - B60G 2300/022: Fork lift trucks, Clark - B60G 2600/02: Retarders, delaying means, dead zones, threshold values, cut-off frequency, timer interruption - B60G 2800/91: Suspension Control - B62B 2301/00: Wheel arrangements; Steering; Stability; Wheel suspension - F16F 2224/0283: piezoelectric; electro- or magnetostrictive - F16F 2224/045: magnetorheological - B66F: HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD ({invalid lifting devices A61G7/10; } mounting artificial islands on piles or like supports E02B17/00; scaffolding combined with lifting devices E04G1/22; lifting devices for sliding forms E04G11/24; lifting of buildings E04G23/06; shores or struts E04G25/00; lifts or other hoisting devices on ladders E06C7/12; props for mining E21D15/00) - B60G: VEHICLE SUSPENSION ARRANGEMENTS (air-cushion vehicles B60V; {cycle suspensions B62K25/00}) - B62B: HAND-PROPELLED VEHICLES, e.g. HAND CARTS OR PERAMBULATORS; SLEDGES (characterised by animal propulsion B62C; propulsion of sledges by driver or engine B62M) - F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION ## Abstract A lift truck includes systems and methods for improved vibration control. Vibration control features reduce or eliminate motion of the truck in one or more of the X-axis, Y-axis, and Z-axis. Some embodiments may include, alone or in combination with the vibration control, stability control to further stabilize the motion of the truck. ## Claims ### Claim 1 A lift truck having vibration control, the lift truck comprising: a tractor unit; vertically movable forks mounted relative to the tractor unit, the forks being vertically movable between an upper position and a lower position; a vertical support mounted relative to the tractor unit, and a platform mounted relative to the vertical support, the platform for mounting electrical components; and the vertical support comprising a hollow tube at least partially filled with a vibration damping material to damper vibrations from reaching the platform. ### Claim 2 (depends on 1) The lift truck as set forth in claim 1 further including a first sensor to provide a first value of motion of the lift truck in at least one of an X-axis and a Y-axis and a Z-axis. ### Claim 3 (depends on 2) The lift truck as set forth in claim 2 wherein the first sensor comprises a first accelerometer. ### Claim 4 (depends on 3) The lift truck as set forth in claim 3 wherein the first accelerometer is mounted relative to the platform. ### Claim 5 (depends on 2) The lift truck as set forth in claim 2 further including a second sensor to provide a second value of motion of the lift truck in at least one of the X-axis and the Y-axis and the Z-axis. ### Claim 6 (depends on 5) The lift truck as set forth in claim 5 wherein the second sensor comprises a second accelerometer. ### Claim 7 (depends on 6) The lift truck as set forth in claim 6 wherein the second accelerometer is mounted relative to the tractor unit. ### Claim 8 (depends on 1) The lift truck as set forth in claim 1 wherein the hollow tube includes at least one hollow portion separated by a damper section, the damper section containing the vibration damping material. ### Claim 9 (depends on 8) The lift truck as set forth in claim 8 wherein the vibration damping material comprises at least one of a magneto-rheological fluid, a piezoelectric material, an electroactive polymer, and a granular material. ### Claim 10 (depends on 8) The lift truck as set forth in claim 8 wherein the at least one hollow section contains a granular material. ### Claim 11 (depends on 1) The lift truck as set forth in claim 1 further including a mounting frame base, the vertical support mounted relative to the mounting frame base. ### Claim 12 (depends on 5) The lift truck as set forth in claim 5 further including control circuitry coupled to at least one of the first and second sensors and the vibration damping material to control a degree of vibration damping. ### Claim 13 (depends on 12) The lift truck as set forth in claim 12 wherein the vibration damping material is a phase changing material. ### Claim 14 (depends on 12) The lift truck as set forth in claim 12 further including at least one caster mounted relative to the tractor unit; and an actuator to lock movement of the caster on a side of the lift truck based on a direction that the control circuitry determined the lift truck to be moving. ### Claim 15 A lift truck having vibration control, the lift truck comprising: a tractor unit; vertically movable forks mounted relative to the tractor unit, the forks being vertically movable between an upper position and a lower position; a vertical support mounted relative to the tractor unit, and a platform mounted relative to the vertical support, the platform for mounting electrical components; the vertical support comprising two or more cylinders that function as a mass-damper system to damper vibrations from reaching the platform, the mass-damper system include a spring, a fluid, and a variable valve; and control circuitry coupled to the variable valve, the control circuitry to control a flow of the fluid through the variable valve to control a degree of vibration damping. ### Claim 16 (depends on 15) The lift truck as set forth in claim 15 further including a sensor coupled to the control circuitry, the sensor to provide a value of motion of the lift truck in at least one of an X-axis and a Y-axis and a Z-axis. ### Claim 17 (depends on 16) The lift truck as set forth in claim 16 wherein the sensor comprises an accelerometer. ### Claim 18 (depends on 17) The lift truck as set forth in claim 17 wherein the accelerometer is mounted relative to the platform. ### Claim 19 (depends on 16) The lift truck as set forth in claim 16 wherein the value of motion provided by the sensor is used to control the flow of fluid through the variable valve. ### Claim 20 (depends on 15) The lift truck as set forth in claim 15 further including at least one caster mounted relative to the tractor unit; and an actuator to lock movement of the caster on a side of the lift truck based on a direction that the sensor determined the lift truck to be moving. ### Claim 21 (depends on 15) The lift truck as set forth in claim 15 wherein the platform includes positioning equipment. ### Claim 22 A method of reducing vibrations on a lift truck, the method comprising: providing a lift truck, the lift truck comprising: a tractor unit; and vertically movable forks mounted relative to the tractor unit, the forks being vertically movable between an upper position and a lower position; providing a vertical support mounted relative to the tractor unit; providing a platform mounted relative to the vertical support, the platform for mounting electrical components; damping vibrations from reaching the platform with at least one of a vibration damping material in the vertical support and a mass-damper system; and providing control circuitry coupled to the at least one of the vibration damping material and the mass-damper system to control a degree of vibration damping. ### Claim 23 (depends on 22) The method as set forth in claim 22 further including providing a sensor coupled to the control circuitry, the sensor to provide a value of motion of the lift truck in at least one of an X-axis and a Y-axis and a Z-axis. ### Claim 24 (depends on 23) The method as set forth in claim 23 further including providing at least one caster mounted relative to the tractor unit; and activating an actuator to lock movement of the caster on a side of the lift truck based on a direction that the sensor determined the lift truck to be moving.