Boom assembly

Patent metadata

Field	Value
Publication number	US-8974172-B2
Application number	US-201213419844-A
Country	US
Kind code	B2
Filing date	Mar 14, 2012
Priority date	Jul 12, 2011
Publication date	Mar 10, 2015
Grant date	Mar 10, 2015

Abstract

A boom has a central connection plate attached between a pair of side plates, and a rear portion side of a cover plate on a front boom portion and a front portion side of a cover plate on a rear boom portion are connected thereby. A pivoting support for a working tool cylinder used to move a working tool connected to a foremost portion of the front boom portion is provided on a front side of a top portion on each of the left and right side plates. The central connection plate is formed with a connection plate projection projecting from a front portion attached to the rear portion of the cover plate toward a midway portion so as to approach the pivoting support.

First claim

What is claimed is:

1. A boom assembly having a rounded shape curved at a center in the length direction so as to protrude on an upper side from a lateral view, the boom assembly comprising:
a boom having a rear boom portion and a front boom portion, the rear boom portion extending horizontally from a vehicle body and the front boom portion extending downward from a central portion of the boom when a working tool attached to a foremost end of the boom is positioned in contact with the ground, wherein
the front boom portion and the rear boom portion are configured from integral cover plates and from left and right lateral plates, the upper surfaces of the front boom portion and the rear boom portion are formed with a curved surface in the length direction, and lower portions of the left and right lateral plates are connected by bottom plates; and
rear portions of the left and right lateral plates of the front boom portion and front portions of the left and right lateral plates of the rear boom portion are connected by a pair of side plates having a boom cylinder pivoting support and a working tool cylinder pivoting support, and the cover plate of the front boom portion, the cover plate of the rear boom portion, and the side plates are integrally connected by a central connection plate positioned between the pair of side plates, wherein
the central connection plate is formed with a connection plate projection projecting from a front portion attached to a rear portion of the cover plate of the front boom portion toward a midway portion so as to approach the working tool pivoting support.

2. The boom assembly according to claim 1 , wherein the connection plate projection is formed to project in a peaked shape so as to vertically overlap behind the working tool cylinder pivoting support in a state where the boom is lowered and the working tool is in contact with the ground.

3. The boom assembly according to claim 2 , wherein the central connection plate comprises:
a front attachment portion overlapping with and attached to the rear portion of the cover plate of the front boom portion;
a front inclined portion curving upward from the front attachment portion and inclining by projecting so as to approach the working tool cylinder pivoting support at a distance from the rear portion side of the cover plate;
a rear inclined portion inclining downward from the projecting end portion of the front inclined portion;
an extended projection portion projecting by extending to the rear from the lower end portion of the rear inclined portion; and
a rear attachment portion projecting to the rear from the extended projection portion and overlapping with and attached to the front portion of the cover plate of the rear boom portion; and wherein
the connection plate projection is configured from the front inclined portion and the rear inclined portion.

4. The boom assembly according to claim 1 , wherein the central connection plate overlaps portions of the front and rear boom portions.

5. The boom assembly according to claim 1 , wherein the central connection plate further comprises:
a rear attachment portion attached to a front portion of the rear boom portion.

6. The boom assembly according to claim 5 , wherein the connection plate projection of the central connection plate is closer to the front portion attached to a rear portion of the cover plate of the front boom portion than to the rear attachment portion of the central connection plate.

7. The boom assembly according to claim 1 , wherein the boom assembly is arranged on a front loader tractor.

8. A boom assembly curved at a center in the length direction so as to protrude on an upper side from a lateral view, the boom assembly comprising:
a boom having a rear boom portion and a front boom portion, the rear boom portion extending horizontally from a vehicle body and the front boom portion extending downward at a central portion of the boom when a working tool attached to a foremost end of the boom is positioned in contact with the ground, wherein
the front boom portion and the rear boom portion have a squared U shape in cross-section configured from cover plates and left and right lateral plates, and lower portions of the left and right lateral plates are connected by bottom plates; and
rear portions of the left and right lateral plates of the front boom portion and front portions of the left and right lateral plates of the rear boom portion are connected by a pair of side plates having a boom cylinder pivoting support and a working tool cylinder pivoting support, and the cover plate of the front boom portion, the cover plate of the rear boom portion, and the side plates are integrally connected by a central connection plate positioned between the pair of side plates, wherein
the central connection plate is formed with a connection plate projection projecting from a front portion attached to a rear portion of the cover plate of the front boom portion toward a midway portion so as to approach the working tool pivoting support.

9. The boom assembly according to claim 8 , wherein the connection plate projection is formed to project in a peaked shape so as to vertically overlap behind the working tool cylinder pivoting support in a state where the booms are lowered and the working tool is in contact with the ground.

10. The boom assembly according to claim 9 , wherein the central connection plate comprises:
a front attachment portion overlapping with and attached to the rear portion of the cover plate of the front boom portion;
a front inclined portion curving upward from the front attachment portion and inclining by projecting so as to approach the working tool cylinder pivoting support at a distance from the rear portion side of the cover plate;
a rear inclined portion inclining downward from the projecting end portion of the front inclined portion;
an extended projection portion projecting by extending to the rear from the lower end portion of the rear inclined portion; and
a rear attachment portion projecting to the rear from the extended projection portion and overlapping with and attached to the front portion of the cover plate of the rear boom portion; and wherein
the connection plate projection is configured from the front inclined portion and the rear inclined portion.

11. The boom assembly according to claim 8 , wherein the central connection plate overlaps portions of the front and rear boom portions.

12. The boom assembly according to claim 8 , wherein the central connection plate further comprises:
four bends with three of said four bends forming the connection plate projection; and
a rear attachment portion attached to a front portion of the rear boom portion.

13. The boom assembly according to claim 12 , wherein the connection plate projection of the central connection plate is closer to the front portion attached to the rear portion of the cover plate of the front boom portion than to the rear attachment portion of the central connection plate.

14. The boom assembly according to claim 8 , wherein the boom assembly is arranged on a front loader tractor.

15. A left and right pair of boom assemblies curved at a center in the length direction so as to protrude on an upper side from a lateral view, the boom assemblies comprising:
a pair of booms, each having a rear boom portion and a front boom portion, the rear boom portion extending horizontally from a vehicle body and the front boom portion extending downward at a central portion of each boom when a working tool attached to a foremost end of the booms are positioned in contact with the ground, wherein

Assignees

• Nishi Ryoichi
• Kubota Kk

Inventors

• Nishi Ryoichi

Classifications

• E02F3/38

  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

• E02F3/34 Primary

  with bucket-arms {, i.e. a pair of arms, e.g. manufacturing processes, form, geometry, material of bucket-arms (with a single arm E02F3/283)} directly pivoted on the frames of tractors or self-propelled machines · CPC title

• E02F3/627

  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