Leveling system for lift device

Patent metadata

Field	Value
Publication number	US-9890024-B2
Application number	US-201715482601-A
Country	US
Kind code	B2
Filing date	Apr 7, 2017
Priority date	Apr 8, 2016
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

A leveling assembly for a lift device includes a carrier arm, an axle, a first actuator, and a second actuator. The carrier arm includes a base that defines a first interface configured to pivotally couple the carrier arm to a chassis of the lift device to facilitate a pitch adjustment of the leveling assembly, a projection that defines a second interface, and a transition that extends angularly between the base and the projection such that the projection is elevated relative to the base. The axle defines a third interface positioned to engage with the second interface to pivotally couple the axle to the carrier arm to facilitate a roll adjustment of the leveling assembly. The first actuator is pivotally coupled to a first lateral end of the axle. The second actuator is pivotally coupled to an opposing second lateral end of the axle.

First claim

The invention claimed is:

1. A lift device, comprising:
a chassis having a front end and a rear end;
a boom pivotally coupled to the chassis;
a rear leveling assembly including:
a rear carrier arm pivotally coupled to the rear end of the chassis to facilitate a rear pitch adjustment of the rear leveling assembly;
a rear axle pivotally coupled to the rear carrier arm to facilitate a rear roll adjustment of the rear leveling assembly, the rear axle having a first lateral end and an opposing second lateral end;
a first rear actuator pivotally coupled to the rear end of the chassis and the first lateral end of the rear axle; and
a second rear actuator pivotally coupled to the rear end of the chassis and the opposing second lateral end of the rear axle, wherein the first rear actuator and the second rear actuator facilitate providing active control of the rear pitch adjustment and the rear roll adjustment; and

a front leveling assembly including:
a front carrier arm pivotally coupled to the front end of the chassis to facilitate a front pitch adjustment of the front leveling assembly;
a front axle pivotally coupled to the front carrier arm to facilitate a front roll adjustment of the front leveling assembly, the front axle having a first lateral end and an opposing second lateral end;
a first front actuator pivotally coupled to the front end of the chassis and the first lateral end of the front axle; and
a second front actuator pivotally coupled to the front end of the chassis and the opposing second lateral end of the front axle, wherein the first front actuator and the second front actuator are configured to be selectively fluidly coupled to facilitate providing passive control and selectively fluidly decoupled to facilitate providing active control of the front pitch adjustment and the front roll adjustment based on a mode of operation of the lift device.

2. The lift device of claim 1 , wherein the front carrier arm defines a front carrier arm pivot interface and the front axle defines a front axle pivot interface positioned to engage with the front carrier arm pivot interface, the front carrier arm pivot interface and the front axle pivot interface configured to cooperatively receive a fastener to pivotally couple the front axle to the front carrier arm.

3. The lift device of claim 2 , wherein the rear carrier arm defines a rear carrier arm pivot interface and the rear axle defines a rear axle pivot interface positioned to engage with the rear carrier arm pivot interface, the rear carrier arm pivot interface and the rear axle pivot interface configured to cooperatively receive a second fastener to pivotally couple the rear axle to the rear carrier arm.

4. The lift device of claim 2 , wherein the front carrier arm has:
a base defining a chassis pivot interface that pivotally couples the front carrier arm to a lower end of the front end of the chassis;
a projection defining the front carrier arm pivot interface that pivotally receives the front axle pivot interface; and
a transition extending between the base and the projection at an angle such that the projection is elevated relative to the base.

5. The lift device of claim 1 , wherein the front leveling assembly further includes one or more valves positioned to facilitate at least one of (i) selectively isolating the first front actuator and the second front actuator from a high pressure fluid source and (ii) selectively fluidly coupling the first front actuator to the second front actuator.

6. The lift device of claim 1 , further comprising:
a plurality of tractive elements, one of the plurality of tractive elements coupled to each end of the front axle and the rear axle; and
a drive system configured to facilitate at least one of driving and steering each of the plurality of tractive elements independently.

7. The lift device of claim 1 , wherein the first front actuator and the second front actuator are configured to be selectively fluidly decoupled during a transport mode such that the front leveling assembly is configured to be actively controlled to provide the front pitch adjustment and the front roll adjustment.

8. The lift device of claim 7 , wherein the first front actuator, the second front actuator, the first rear actuator, and the second rear actuator are configured to facilitate reducing an overall height of the lift device to a target height in the transport mode.

9. The lift device of claim 1 , wherein the first front actuator and the second front actuator are configured to be selectively fluidly decoupled during a calibration mode such that the front leveling assembly is configured to be actively controlled to provide the front pitch adjustment and the front roll adjustment.

10. The lift device of claim 9 , wherein the first front actuator, the second front actuator, the first rear actuator, the second rear actuator, and the boom are configured to be returned to a nominal position to facilitate zeroing out a sensor of the lift device in the calibration mode.

11. The lift device of claim 10 , wherein the sensor includes at least one of a displacement sensor, a roll sensor, a pitch sensor, and a load sensor.

12. The lift device of claim 1 , wherein the first front actuator and the second front actuator are configured to be selectively fluidly decoupled during a boom operation mode such that the front leveling assembly is configured to be actively controlled to provide the front pitch adjustment and the front roll adjustment.

13. The lift device of claim 12 , wherein a speed of the lift device is limited during the boom operation mode.

14. The lift device of claim 12 , wherein the first front actuator, the second front actuator, the first rear actuator, and the second rear actuator are configured to be actively controlled while the boom is in use in the boom operation mode.

15. The lift device of claim 1 , wherein the first front actuator and the second front actuator are configured to be selectively fluidly coupled during a driving mode such that the front leveling assembly provides passive control of the front pitch adjustment and the front roll adjustment.

16. The lift device of claim 15 , wherein operation of the boom is limited during the driving mode.

17. A leveling assembly for a lift device, comprising:
a first carrier arm including:
a base defining a first interface configured to pivotally couple the first carrier arm to a chassis of the lift device to facilitate a pitch adjustment of the leveling assembly;
a projection defining a second interface; and
a transition extending between the base and the projection at an angle such that the projection is elevated relative to the base;

a second carrier arm pivotally coupled to an opposing side of the chassis;
a first axle defining a third interface positioned to engage with the second interface of the first carrier arm to pivotally couple the first axle to the first carrier arm to facilitate a roll adjustment of the leveling assembly, the first axle having a first lateral end and an opposing second lateral end;
a first actuator pivotally coupled to the chassis and the first lateral end of the first axle; and
a second actuator pivotally coupled to the chassis and the opposing second lateral end of the first axle;
a second axle pivotally coupled to the second carrier arm, the second axle having a first lateral end and an opposing second lateral end;
a third actuator pivotally coupled to the opposing side of the chassis and the first lateral end of the second axle; and
a fourth actuator pivotally coupled to the opposing side of the c

Assignees

• Oshkosh Corp

Inventors

• Hao Jihong
• Puszkiewicz Ignacy

Classifications

• B66F11/04

  for movable platforms or cabins, e.g. on vehicles, permitting workmen to place themselves in any desired position for carrying out required operations ({Working platforms on fork-lift trucks B66F9/127; } vehicle aspects of service vehicles B60P3/14; platforms for cleaning windows A47L3/02; devices for rescuing persons from buildings A62B1/02; liftable or lowerable platforms for use on ladders E06C7/16; maintenance travellers for bridges E01D19/10; scaffolds on an extensible sub-structure E04G1/22) · CPC title

• B60G2400/60

  Load · CPC title

• B66F9/065

  non-masted (mobile jacks of the garage type mounted on wheels or rollers B66F5/00) · CPC title

• B60G21/007

  means for adjusting the wheel inclination · CPC title

• B60P3/125

  by supporting only part of the vehicle, e.g. front- or rear-axle · CPC title