Backstop position changing device for crane

Patent metadata

Field	Value
Publication number	US-11999599-B2
Application number	US-202017636247-A
Country	US
Kind code	B2
Filing date	Aug 28, 2020
Priority date	Sep 9, 2019
Publication date	Jun 4, 2024
Grant date	Jun 4, 2024

Abstract

A changing device easily and safely changes the posture of the backstop of a crane between a support posture and a storage posture. The backstop posture changing device is provided with a first support member, a second support member, a push-up mechanism, and a connection member. The first support member and the second support member are rotationally connected to a backstop and a lower boom respectively. When a cylinder rod of the push-up mechanism is extended with respect to a cylinder body, a push-up member pushes up the first support member and the posture of the backstop is changed from a storage posture on the lower boom to a support posture in which it is possible to support a boom while the crane is in a working posture.

First claim

The invention claimed is:

1. A backstop posture changing device for crane, the crane including a crane body, a derricking body having a derricking body base end portion rotatably supported by the crane body in a derricking direction and a derricking body distal end portion on a side opposite to the derricking body base end portion, a backstop having a backstop base end portion supported so as to be rotatable around a horizontal reference rotation center axis at a portion of the derricking body between the derricking body distal end portion and the derricking body base end portion and a backstop distal end portion disposed on a side opposite to the backstop base end portion,
the backstop posture changing device being configured to be attached to the derricking body and to change the posture of the backstop between a support posture and a storage posture by turning the backstop with the backstop base end portion as a fulcrum in a falling state of the derricking body that is a state where the derricking body is fallen with respect to the crane body, and, in the support posture, the backstop extending obliquely upward from the derricking body in such a manner that the backstop distal end portion of the backstop contacts with the crane body in accordance with the rising of the derricking body from the falling state, thereby the backstop restricts the falling of the derricking body backward, and, in the storage posture, the backstop distal end portion of the backstop being disposed closer to the derricking body than the backstop distal end portion in the support posture,
the backstop posture changing device comprising:
a first support member having a first base end portion connected to a portion of the backstop between the backstop distal end portion and the backstop base end portion so as to be rotatable around a first rotation center axis parallel to the reference rotation center axis, a first rotation end portion opposite to the first base end portion, and a pushed-up portion disposed between the first base end portion and the first rotation end portion;
a second support member having a second base end portion connected to a portion of the derricking body between the derricking body base end portion and the backstop base end portion so as to be rotatable around a second rotation center axis parallel to the reference rotation center axis, and a second rotation end portion disposed on the opposite side of the second base end portion and connected to the first rotation end portion of the first support member so as to be relatively rotatable around an intermediate rotation center axis parallel to the reference rotation center axis, the second support member being arranged such that a first straight line connecting the first rotation center axis and the intermediate rotation center axis and a second straight line connecting the second rotation center axis and the intermediate rotation center axis form a first angle, thereby the second support member maintain the backstop in the support posture together with the first support member, and the second support member being arranged such that the first straight line and the second straight line form a second angle of an acute angle smaller than the first angle, thereby the second support member maintain the backstop in the storage posture together with the first support member;
a push-up mechanism disposed so as to be interposed between the first support member and the second support member and including a cylindrical cylinder body having a base end portion supported by the second support member so as to be rotatable around a first cylinder rotation center axis parallel to the reference rotation center axis, and a cylinder rod inserted into the cylinder body so as to extendable and contractable with respect to the cylinder body on a side opposite to the base end portion, and a push-up member disposed at a distal end portion of the cylinder rod and capable of pushing up the pushed-up portion of the first support member to rotate the first support member relative to the second support member around the intermediate rotation center axis in accordance with the extending of the cylinder rod with respect to the cylinder body from a state where the first straight line and the second straight line form the second angle, thereby the first straight line and the second straight line forming the first angle; and
a connection member detachably attached to at least one of the first support member and the second support member and capable of connecting the first support member and the second support member to each other so as to hold a state in which the first straight line and the second straight line form the first angle and the backstop is in the support posture.

2. The backstop posture changing device for crane according to claim 1 , wherein the push-up member includes:
a first supported portion supported by the distal end portion of the cylinder rod so as to be rotatable around a second cylinder rotation center axis parallel to the reference rotation center axis;
a second supported portion supported by the second support member so as to be rotatable around the intermediate rotation center axis; and
a push-up portion disposed between the first supported portion and the second supported portion and capable of pushing up the pushed-up portion of the first support member as the cylinder rod extends relative to the cylinder body.

3. The backstop posture changing device for crane according to claim 1 , wherein the push-up portion can be separated from the pushed-up portion in association with contraction of the cylinder rod with respect to the cylinder body in a state where the connection member holds the relative posture of the first support member and the second support member.

4. The backstop posture changing device for crane according to claim 1 , further comprising a storage connection member capable of detachably connecting the first base end portion of the first support member and the derricking body so as to hold the backstop in the storage posture in a state where the cylinder rod is contracted with respect to the cylinder body.

5. The backstop posture changing device for crane according to claim 1 , wherein the connection member includes:
a connection base end portion rotatably supported around a connection rotation center axis parallel to the reference rotation center axis at a portion of the first support member between the first base end portion and the first rotation end portion; and
a connection distal end portion disposed on a side opposite to the connection base end portion,
the second support member includes:
a connected portion disposed between the second base end portion and the second rotation end portion and allowing the connection distal end portion to be detachably connected to the connected portion so as to hold the support posture of the backstop; and
a guide portion that holds the connection distal end portion at a standby position that is a position between the second base end portion and the connected portion in the storage posture of the backstop, and guides the connection distal end portion of the connection member that rotates around the connection rotation center axis from the standby position to the connected portion as the cylinder rod extends relative to the cylinder body.

6. The backstop posture changing device for crane according to claim 5 , wherein the second support member further includes a connection member restraint portion that restrains the connection distal end portion of the connection member at the standby position so as to prevent the connection member from rotating around the connection rotation center axis in a state in which the backstop is in the storage posture, and allows the connection distal end portion to move from the sta

Assignees

• Kobelco Constr Mach Co Ltd

Inventors

• Miya Eiji
• Tsunoo Taisuke
• Sakurai Hitoshi
• Inoue Hideo
• Nagai Kouichiro

Classifications

• B66C23/76 Primary

  and movable to take account of variations of load or of variations of length of jib · CPC title

• B66C23/82

  Luffing gear · CPC title

• B66C23/92 Primary

  Snubbers or dashpots for preventing backwards swinging of jibs, e.g. in the event of cable or tackle breakage · CPC title