Traversing hoists – Adjustable to transport or nonuse position – Collapsible or foldable boom
Patent
1998-10-05
2000-03-14
Brahan, Thomas J.
Traversing hoists
Adjustable to transport or nonuse position
Collapsible or foldable boom
212168, 212270, B66C 2368
Patent
active
060360356
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to an apparatus and a method for extending and storing a jib of a mobile crane.
BACKGROUND ART
Some mobile cranes include a jib in addition to a boom which can be freely extended and shortened. Such a crane provided with a jib is illustrated in FIG. 32, for example. A conventional mobile crane provided with a jib will be described hereinafter with reference to FIG. 32. The mobile crane includes an upper revolving superstructure 8, which is free to revolve; a lower traveling body 1; and a boom 3, which is freely extended and shortened and is freely raised and lowered, nearly in the center of the upper revolving superstructure 8. Outriggers 2 are provided in front of and behind and on both sides of the lower traveling body 1 in order to maintain the safety of the body of the vehicle during an operation of the crane. When the boom 3 is, for example, a three-stage telescopic boom, the boom 3 comprises a base boom 4, an intermediate boom 5, and a top boom 6.
The mobile crane includes a main hook 10 at the front end of a wire rope 11 for the main hook 10, which is hung from the front end portion of the top boom 6, and lifts loads with the main hook 10. The operation of a winch makes it possible to windup or let out the wire rope 11 or to extend, shorten, raise, lower, and rotate the boom 3 so as to move loads to a predetermined height and position. However, there are cases where a working range of the boom 3 only is so small that the working range needs to be further enlarged depending on the circumstances of the working site where the mobile crane is placed.
In order to achieve the enlargement of the working range, a jib 7 is connected to the front end portion of the top boom 6, whereby an operation by the jib 7 can be conducted. When not being used, the jib 7 is disconnected from the top boom 6 and is stored, for example, on the left side of the base boom 4 as shown in FIG. 32. When being used, the jib 7 is rotated and extended outwardly in front of the top boom 6. Therefore, the jib 7 is rotatably connected to the top boom 6 via connecting pins 35a and 35b, which are provided respectively on the top and the bottom of the left side of the front end portion of the top boom 6. The jib 7 can be rotated around the connecting pins 35a and 35b within the angle range from the left side of the top boom 6 to the front thereof so as to be extended ahead of the top boom 6.
The jib 7 comprises a jib body 40, a jib bracket 30 for connecting the jib body 40 to the front end portion of the top boom 6, and a jib derricking cylinder 50 for raising or lowering the jib body 40 in relation to the jib bracket 30. The jib bracket 30 is rotatably connected to the jib body 40 via a pivot pin 31, which is vertical to the longitudinal axis of the jib body 40 in a horizontal surface. The jib derricking cylinder 50 is rotatably connected to the jib bracket 30 via a pivot pin 51, which is parallel to the pivot pin 31; and the jib derricking cylinder 50 is rotatably connected to the jib body 40 via a pivot pin 52, which is parallel to the pivot pin 31. The jib body 40 is raised or lowered around the pivot pin 31 in relation to the jib bracket 30 by extending or contracting the jib derricking cylinder 50.
A guide sheave 22, for guiding a wire rope 21 for the auxiliary hook 20, is provided on the upper face of the front end portion of the top boom 6. An end sheave 23, for guiding the wire rope 21 from the guide sheave 22 to the auxiliary hook 20, is provided on the front face of the front end portion of the top boom 6. A guide sheave 32, for guiding the wire rope 21 for the auxiliary hook 20 to the front end of the jib body 40, is provided on the upper face of the jib bracket 30. When the jib 7 is not used, the wire rope 21 for the auxiliary hook 20 is wound up and let out by way of the end sheave 23. When loads are lifted by the jib 7, the auxiliary hook 20 is used. Therefore, the wire rope 21 needs to be changed. The wire rope 21 is removed from the end sheave 23. After the jib 7 is extende
REFERENCES:
patent: 4828124 (1989-05-01), Iga
patent: 5115925 (1992-05-01), Koizumi
patent: 5143233 (1992-09-01), Loizumi
Asano Kazuyoshi
Hasegawa Takeshi
Mukaino Masayuki
Brahan Thomas J.
Komatsu Ltd.
Komatsu Mec Kabushiki Kaisha
LandOfFree
Apparatus and method for extending and storing jib of crane does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for extending and storing jib of crane, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for extending and storing jib of crane will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-160992