Luffing Jib Crane Articulation for Compact Punch Leverage
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Solution Overview
Problem
Conventional luffing jib cranes face challenges in improving performance without increasing the length of the punch, which results in space constraints during transport and the need for structural reinforcements, while also affecting productivity and weight distribution.
Innovation Solution
The luffing jib crane design relocates the articulation of the luffing boom to the base of the counter-jib's central section, below the top where the punch is fixed, effectively increasing the fictitious length of the punch without physical lengthening, optimizing weight distribution and reducing effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the length of the punch is increased to improve productivity and reduce the impact of luffing jib weight on tie rod lines, then luffing speed and load curve performance are improved, but the crane occupies more space for transport and requires greater structural reinforcements on the counter-jib
Solution Approach 1:
The invention relocates the articulation point of the luffing boom from the top of the counter-jib (vertical dimension) to the base of the central section (horizontal dimension), effectively extending the punch in the horizontal direction rather than vertically. This dimensional shift allows the punch to appear longer in terms of structural leverage without physically increasing its length, thus maintaining compact transport dimensions while improving luffing performance
Solution Approach 2:
The counter-jib central section is divided into distinct functional zones: the base portion where the luffing boom articulates, the upper portion where the punch is fixed, and the intermediate section. This segmentation allows the punch to be positioned optimally for structural reinforcement while the articulation point is relocated to the base, achieving improved luffing speed without increasing overall punch length
2Productivity
If the length of the punch is increased to improve productivity and reduce the impact of luffing jib weight on tie rod lines, then luffing speed and load curve performance are improved, but greater structural reinforcements on the counter-jib are required
Solution Approach 1:
Instead of extending the punch length horizontally which would require proportional structural reinforcement, the invention uses vertical positioning to create effective leverage. By articulating the luffing boom at the base of the central section and fixing the punch at the top, the design creates a vertical moment arm that provides structural efficiency without requiring additional reinforcement material
3Device complexity
If the articulation of the luffing boom is positioned at the top of the counter-jib, then the structure is simpler, but the punch length is effectively reduced impacting productivity and luffing speed
Solution Approach 1:
The invention transitions the articulation from a vertical positioning (top of counter-jib) to a horizontal positioning (base of central section). This spatial reconfiguration creates an effective punch length equivalent to the distance between the base and top of the central section, thereby improving luffing speed while maintaining structural simplicity through the use of existing counter-jib components
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances accessibility, maintenance, and productivity by reducing effort and weight, while maintaining structural integrity and reducing the impact on tie rod lines, thus optimizing crane performance.
Implementation Method 1
a luffing winch which includes a luffing motor which rotates, in both directions and via a reduction gear, a luffing drum, around which is wound a luffing cable
Implementation Method 2
a luffing cable which passes over one or more pulleys arranged at the top of the punch, and which also passes over the pulleys of a luffing block
Implementation Method 3
The luffing block is connected, by a line of tie rods, to the luffing jib
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
Luffing jib crane (1) comprising a mast (2) surmounted by a rotating part (4) orientable about a vertical axis (20) and comprising: - a rotating pivot (5) pivotally mounted on the mast; - a counter-jib (6) comprising a central section (60) and a horizontal radial section (61) directed towards the rear and fixed on the central section which comprises a base (64) fixed on the rotating pivot and a top (65) surmounting the base; - a luffing jib (7) directed towards the front and having a rear end (71) articulated on the base of the central section of the counter-jib, below the top, in a manner diametrically opposed to the radial section of the counter-jib; - a punch (8) fixed on the top of the central section of the counter-jib, and extending obliquely upwards and backwards from the top.