IP Library Granted Patent US 12,404,652
Granted Patent B2
US 12,404,652 · App. 18/636,849 · Granted Sep 2, 2025

Loader lift arm

Inventor: Branden Schiwal (Bismarck, ND)
Assignee: Doosan Bobcat North America, Inc.
E02F3/38B22D25/00B22D25/02E02F3/3414E02F3/3686E02F3/382E02F3/422E02F3/627A01B63/24
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Quick Facts
Patent No.
US 12,404,652
App. No.
18/636,849
Granted
Sep 2, 2025
Kind
B2
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.

Claims (13)

1. A power machine comprising:

a frame;

a lift arm having a forward end;

a driver link, the driver link pivotally coupled to the frame using a frame pivot attachment such that the driver link pivots about a first pivot axis relative to the frame and the driver link pivotally coupled to the lift arm using a lift arm pivot attachment such that the driver link pivots about a second pivot axis relative to the lift arm;

a lift cylinder pivotally coupled to the frame and to the lift arm and configured to raise and lower the forward end of the lift arm, the lift cylinder comprising a lift cylinder body and a rod, wherein the rod extends from a top end of the lift cylinder body;

tractive elements configured for rotation;

wherein the frame pivot attachment is positioned such that the first pivot axis is rearward of an axis of rotation of a rearmost tractive element; and

wherein the lift arm pivot attachment is positioned lower than and rearward of the top end of the lift cylinder body when the lift arm's forward end is in a fully lowered position, such that, when the lift arm pivot attachment crosses from a position rearward of the lift cylinder body top to a position forward of the lift cylinder body top as the lift arm's forward end is raised by the lift cylinder, the lift arm pivot attachment is higher than the top end of the lift cylinder body.

2. The power machine of claim 1 , and further comprising an operating position which serves as an operator station.

3. The power machine of claim 2 , wherein a main portion of the driver link is positioned inboard, toward the frame of the power machine, of the lift cylinder body, and a portion of the lift cylinder body is positioned inboard, toward the frame of the power machine, of a portion of the lift arm pivot attachment which encircles the second pivot axis.

4. The power machine of claim 1 , wherein a main portion of the driver link is positioned inboard, toward the frame of the power machine, of the lift cylinder body, and a portion of the lift cylinder body is positioned inboard, toward the frame of the power machine, of a portion of the lift arm pivot attachment which encircles the second pivot axis.

5. The power machine of claim 1 , further comprising an axle establishing the axis of rotation.

6. The power machine of claim 1 , wherein the driver link comprises the lift arm pivot attachment.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 16, 2024
From: SCHIWAL, BRANDEN
To: DOOSAN BOBCAT NORTH AMERICA INC.
Reel/Frame 067121/0345 →
Continuity (4)
Continuation 17185150 · Feb 25, 2021
Division 15957170 · Apr 19, 2018
Provisional Application 62487153 · Apr 19, 2017
Related Publication 20240344293A1 · Oct 17, 2024
References Cited (60)
US 1679879A · Russell · 1928 [cited by applicant]
US 4141160A · Olson · 1979 [cited by applicant]
US 4159796A · Braithwaite · 1979 [cited by applicant]
US 4260322A · Cameron · 1981 [cited by applicant]
US 4428173A · Knell · 1984 [cited by applicant]
US 4904151A · Biemans et al. · 1990 [cited by applicant]
US 5599158A · Ajilore · 1997 [cited by applicant]
US 6106217A · Knell · 2000 [cited by applicant]
US 6325589B1 · Jang et al. · 2001 [cited by applicant]
US 6386822B1 · Burr · 2002 [cited by applicant]
US D468754S · Dershem et al. · 2003 [cited by applicant]
US 6508019B1 · Sasaki et al. · 2003 [cited by applicant]
US 6616398B2 · Dershem et al. · 2003 [cited by applicant]
US 6637111B2 · Sasaki et al. · 2003 [cited by applicant]
US 6851886B2 · Anderson · 2005 [cited by applicant]
US 7264435B2 · Layko et al. · 2007 [cited by applicant]
US D600721S · Shimomura et al. · 2009 [cited by applicant]
US 7824145B2 · Kisse · 2010 [cited by applicant]
US 7881845B2 · Nichols · 2011 [cited by applicant]
US D646302S · Lanting et al. · 2011 [cited by applicant]
US D646303S · Lanting et al. · 2011 [cited by applicant]
US D654514S · Jamieson et al. · 2012 [cited by applicant]
US 8342789B2 · Yasuda et al. · 2013 [cited by applicant]
US 8419339B2 · Okumura et al. · 2013 [cited by applicant]
US 8545163B2 · Yasuda et al. · 2013 [cited by applicant]
US 8556014B2 · Smith et al. · 2013 [cited by applicant]
US 8616318B2 · Kotani et al. · 2013 [cited by applicant]
US 8631580B2 · Randall et al. · 2014 [cited by applicant]
US 8821104B2 · Yasuda et al. · 2014 [cited by applicant]
US 8992158B2 · Springer et al. · 2015 [cited by applicant]
US 9945093B1 · Belliveau · 2018 [cited by applicant]
US 20030082040A1 · Bares · 2003 [cited by examiner]
US 20030126772A1 · Masumoto et al. · 2003 [cited by applicant]
US 20040170472A1 · Anderson · 2004 [cited by applicant]
US 20070104566A1 · Layko et al. · 2007 [cited by applicant]
US 20080035357A1 · Heitlinger · 2008 [cited by applicant]
US 20080175701A1 · Kisse · 2008 [cited by applicant]
US 20100143086A1 · Yasuda et al. · 2010 [cited by applicant]
US 20100158653A1 · Webb et al. · 2010 [cited by applicant]
US 20110091307A1 · Yasuda · 2011 [cited by examiner]
US 20110299965A1 · Randall et al. · 2011 [cited by applicant]
US 20130158836A1 · Smith et al. · 2013 [cited by applicant]
US 20130216347A1 · Breuer et al. · 2013 [cited by applicant]
US 20150003949A1 · Kusama · 2015 [cited by applicant]
US 20150071752A1 · Carthy et al. · 2015 [cited by applicant]
US 20150336778A1 · Ditzler et al. · 2015 [cited by applicant]
US 20170086366A1 · Noll · 2017 [cited by applicant]
EP 2947209A1 · 2015 [cited by applicant]
JP 2010059683A · 2010 [cited by applicant]
JP 2010059684A · 2010 [cited by applicant]
WO 2008118308A1 · 2008 [cited by applicant]
WO 2010023715A1 · 2010 [cited by applicant]
WO 2008134820A1 · 2018 [cited by applicant]
Invitation to Pay Additional Fees And, Where Applicable, Protest Fee mailed Jul. 13, 2018 for International Application No. PCT/US2018/028290 filed Apr. 19, 2018, 12 pages. [cited by applicant]
International Search Report and Written Opinion mailed Sep. 25, 2018 for International Application No. PCT/US2018/028290 filed Apr. 19, 2018, 23 pages. [cited by applicant]
U.S. Patent Office issued prosecution for U.S. Application No. 15/957,170, filed Apr. 19, 2018, including: Notice of Allowance and Fees Due (PTOL-85) issued Dec. 15, 2020, 8 pages; Non-Final Rejection issued Jun. 29, 20… [cited by applicant]
Communication pursuant to Article 94(3) EPC for European patent application No. 18 723 164.2, dated Nov. 11, 2020, 4 pages. [cited by applicant]
Non-Final Rejection for U.S. Appl. No. 17/185,150, mailed Feb. 2, 2022, 8 pages. [cited by applicant]
Final Rejection for U.S. Appl. No. 17/185,150, mailed Sep. 29, 2022, 15 pages. [cited by applicant]
Communication pursuant to Article 94(3) EPC for European patent application No. 17 823 164.2, dated Sep. 30, 2021, 7 pages. [cited by applicant]