Loader lift arm

Patent metadata

Field	Value
Publication number	US-2018305889-A1
Application number	US-201815957170-A
Country	US
Kind code	A1
Filing date	Apr 19, 2018
Priority date	Apr 19, 2017
Publication date	Oct 25, 2018
Grant date	—

Abstract

Disclosed embodiments include power machines and related structures of lift arms, implement carriers, follower links, and driver links which improve manufacturability, reduce component failures, and improve power machine design and functionality. In some embodiments, lift arm structures include cast lower lift arm portions. The cast lower lift arm portions include contoured upper ends which are sleeved onto contoured lower ends of upper lift arm portions to control stress points and to reduce stresses on welds. The follower link structures can include follower links which are configured to be positioned at least partially outside of the lift arm structure to improve rear visibility. The driver link structures can be configured to be laterally overlapping with innermost surfaces on the lift cylinder, but configured such that as the lift arm is raised the laterally overlapping portions are moved above the innermost surfaces of the lift cylinder.

First claim

What is claimed is:

1 . A lift arm structure for a power machine, the lift arm structure comprising:
an upper lift arm portion comprising first and second upper lift arm sections each having a proximal end and a distal end and configured to be rotatably coupled to the power machine at the proximal end; a lower lift arm portion comprising a first lower lift arm casting and a second lower lift arm casting, the first and second lower lift arm castings respectively secured to the first and second upper lift arm sections, each of the first and second lower lift arm castings having a cross-member attachment aperture and an implement carrier attachment aperture formed therein; and a cross-member extending between the cross-member attachment apertures of the first and second lower lift arm castings.

2 . The lift arm structure of claim 1 , wherein the first and second lower lift arm castings further including tilt cylinder attachment apertures formed therein and configured to pivotally attach a tilt cylinder to each of the respective first and second lower lift arm castings.

3 . The lift arm structure of claim 2 , wherein each of the first and second lower lift arm castings is formed of a single cast piece of material, and wherein the cross-member attachment aperture, the implement carrier attachment aperture, and the tilt cylinder attachment aperture of each of the first and second lower lift arm castings are machined apertures formed in the single cast piece of material.

4 . The lift arm structure of claim 1 , wherein each of the first and second upper lift arm sections has a contoured bottom interface at the distal end, wherein each of the first and second lower lift arm castings has a contoured top interface, and wherein when the first and second lower lift arm castings are secured to the respective ones of the first and second upper lift arm sections, the contoured bottom interfaces of the upper lift arm sections are sleeved over portions of the corresponding contoured top interfaces of the lower lift arm castings.

5 . The lift arm structure of claim 4 , wherein the contoured bottom interface of each of the first and second upper lift arm sections includes a top extending member, a bottom extending member, and an inlet section positioned between and separating the top extending member and the bottom extending member, and wherein the contoured top interface of each of the first and second lower lift arm castings comprises a protruding section configured to be positioned in the inlet section of the corresponding one of the first and second upper lift arm section between the top extending member and the bottom extending member.

6 . The lift arm structure of claim 5 , wherein the top extending member of each of the first and second upper lift arm sections extends further relative to the proximal end than the corresponding bottom extending member.

7 . The lift arm structure of claim 5 , wherein the contoured bottom interface of each of the first and second upper lift arm sections and the contoured top interface of each of the lower lift arm castings are configured to control locations of highest tension under load and highest compression under load between the upper lift arm portion and the lower lift arm portion.

8 . The lift arm structure of claim 1 , wherein each of the first and second upper lift arm sections includes a first portion and a second portion that are pivotally coupled to each other.

9 . The lift arm structure of claim 1 , wherein the lift arm structure includes a four-bar linkage arrangement.

10 . An implement carrier configured to be pivotally coupled to a lift arm structure of a power machine, the implement carrier comprising:
first and second implement carrier plate castings providing implement interface surfaces configured to engage with an implement to be mounted on the lift arm structure of the power machine, wherein each of the first and second implement carrier plate castings has formed therein a lift arm attachment aperture configured to pivotally attach the implement carrier plate casting to the lift arm structure, a tilt cylinder attachment aperture configured to pivotally attach a tilt cylinder to the implement carrier plate casting, and a cross-member receiving collar; and a cross-member secured to and extending between the cross-member receiving collars of the first and second implement carrier plate castings.

11 . The implement carrier of claim 10 , wherein the cross-member receiving collar of each of the first and second implement carrier castings comprises at least one side aperture extending through a side of the cross-member receiving collar to provide weld locations between the cross-member and the cross-member receiving collar.

12 . The implement carrier of claim 11 , wherein the at least one side aperture extending through the side of the cross-member receiving collar is configured to provide collar deformability to allow deformation of the collar to absorb stresses on the implement carrier plate casting.

13 . The implement carrier of claim 10 , wherein each of the first and second implement carrier plate castings further comprises a tilt stop machined surface configured for contacting the lift arm structure to prevent further movement, in one direction, of the implement carrier plate casting relative to the lift arm structure.

14 . The implement carrier of claim 10 , wherein each of the first and second implement carrier plate castings are formed of a single cast piece of material, and wherein the lift arm attachment aperture and the tilt cylinder attachment aperture of each of the first and second implement carrier plate castings are machined into the implement carrier plate casting.

15 . A follower link structure for a four-bar lift arm structure of a power machine, the follower link structure comprising:
first and second follower link castings configured to be disposed on opposite sides of the power machine, each of the first and second follower link castings comprising a pivot aperture configured to pivotally attach the follower link casting to a frame of the power machine, a cross-member receiving collar, and an extension member extending between the pivot aperture and the cross-member receiving collar, the extension member having a first portion at least partially in-line with a main portion of a lift arm of the power machine when viewed from directly behind the power machine and a second portion outward from the first portion such that a follower link casting lift arm attachment point is outside of the lift arm structure; and a cross-member extending between the cross-member receiving collars of the first and second follower link castings.

16 . The follower link structure of claim 15 , wherein each of the first and second follower link castings are formed of a single cast piece of material.

17 . The follower link structure of claim 15 , wherein for each of the first and second follower link castings, the first portion of the extension member angles outward to transition between positions which are in-line with the main portion of the lift arm and the second portion of the extension member.

18 . A power machine comprising:
a frame having an axle tube with a rear axle extending therefrom; a lift arm structure including a main lift arm portion and a driver link, the driver link having a frame pivot attachment and a main lift arm portion pivot attachment such that the driver link is pivotally coupled to the frame and to the main lift arm portion, wherein the frame pivot attachment of the driver link

Assignees

• Clark Equipment Co

Inventors

• Schiwal Branden

Classifications

• E02F3/3414

  the arms being pivoted at the rear of the vehicle chassis, e.g. skid steer loader · CPC title

• E02F3/38 Primary

  Cantilever beams {, i.e. booms;, e.g. manufacturing processes, forms, geometry or materials used for booms (for booms with cable suspension arrangements E02F9/14 takes precedence)}; Dipper-arms {, e.g. manufacturing processes, forms, geometry or materials used for dipper-arms}; Bucket-arms {(E02F3/34 takes precedence)} · CPC title

• E02F3/627 Primary

  Devices to connect beams or arms to tractors or similar self-propelled machines, {e.g. drives therefor (connection of beams or booms or arms to the frame per se E02F3/382; connection of scraper bowls to the vehicle main body E02F3/653; connecting devices for agriculture tractors A01B59/06)} · CPC title

• B22D25/00

  Special casting characterised by the nature of the product (B22D15/02, B22D17/16, B22D19/00 take precedence; casting stereotype plates B41D3/00) · CPC title

• A01B63/24

  Tools or tool-holders adjustable relatively to the frame · CPC title