# US 8,783,994 B2 · Traction rod for bracing a crane jib

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- Number: US 8,783,994 B2
- Document ID: US8783994B2
- Status: Granted
- Kind: B2
- Application number: 13/148,787
- Filed: 2010-02-05
- Published: 2012-03-22
- Granted: 2014-07-22
- Earliest claimed: 2009-02-11
- Assignees: Vallourec Deutschland GmbH
- Applicants: Thomas Müller
- Inventors: Thomas Müller
- Web page: https://patentgrep.com/patent/US8783994B2

## CPC

- B66C 23/82: Luffing gear
- Y10T 403/553: Laterally inserted section
- Y10T 403/7079: Transverse pin
- Y10T 403/7084: Bolt, rivet, or screw
- B66C: CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES ({specially adapted for lifting invalids A61G7/10;} rope, cable, or chain winding mechanisms, braking or detent devices therefor B66D; specially adapted for nuclear reactors G21)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The invention relates to a traction rod for bracing a crane jib, comprising a metallic tubular body and coupling elements which are connected to both ends thereof in an articulated connection of the traction rods among each other by means of bolts. According to the invention, the tubular body and the coupling elements can be detachably connected to each other, dispensing the need for a bonded connection, wherein the region of the connection is dimensioned in such a manner and is low on notch effects that, by calculation, the entire load capacity of the tube cross-section can be exploited with respect to a highest possible fatigue strength.

## Claims

### Claim 1

An articulated connection of a first traction rod to a second traction rod for bracing a crane jib, each of the first and second traction rods comprising:
a metallic tubular body having a longitudinal extent and a tube cross-section and at least one end with a wall thickening, wherein an outside diameter of the wall thickening is greater than an outside diameter of the tube cross section and a transition region from the tubular body to the wall thickening is unitary and constructed to be free of projections and low on notch effects, and
a coupling element detachably connected to the at least one end of each metallic tubular body of the first and second traction rods in absence of a material connection therebetween, with the coupling element of the first traction rod constructed for articulated connection to the coupling element of the second traction rod with a bolt extending transversely through openings in both the coupling element of the first traction rod and the coupling element of the second traction rod,
wherein the at least one end with the wall thickening is dimensioned such that a fatigue strength corresponds to a calculated full load capacity of the tube cross-section.

### Claim 2 (depends on 1)

The articulated connection of claim 1, wherein the full load capacity of the tubular body is calculated based on a nominal wall thickness of the tube cross-section, wherein a region of the wall thickening comprises an exterior thread, wherein the wall thickening is dimensioned so as to prevent the exterior thread from weakening the nominal wall thickness in the connection region.

### Claim 3 (depends on 2)

The articulated connection of claim 2, wherein the detachable connection is a screw connection, with the coupling element comprises in the connection region an interior thread that mates with the exterior thread.

### Claim 4 (depends on 1)

The articulated connection of claim 1, wherein the unitary transition region forms a shoulder, wherein the coupling element formfittingly abuts the unitary transition region for transmitting a pulling force, wherein the coupling element at an end of the first traction rod is constructed as a father element and the coupling element at an end of the second traction rod is constructed as a mother element, wherein the father element of the first traction rod is configured for insertion into the mother element of the second traction rod in an overlap region and for articulated connection with a bolt in the overlap region.

### Claim 5 (depends on 4)

The articulated connection of claim 4, wherein the coupling element is symmetrically split into two shells in relation to a longitudinal axis of the tubular body, with the two shells being connected with one another for attachment on the tubular body.

### Claim 6 (depends on 2)

The articulated connection of claim 2, wherein the wall thickening is produced by hot upsetting.

### Claim 7 (depends on 2)

The articulated connection of claim 2, wherein the wall thickening is produced from an overlay weld.