US3893571A

US3893571A - Cable flex limiting device

Info

Publication number: US3893571A
Application number: US473862A
Authority: US
Inventors: Roger Metailler
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1974-05-28
Filing date: 1974-05-28
Publication date: 1975-07-08
Anticipated expiration: 1992-07-08

Abstract

A device is disclosed for limiting the flexing of cables of a crane crab mounted for movement on a boom. A C-shaped frame has a back portion mounted transversely of the boom so that the two branch portion of the C-shaped frame extend below the boom to define a space of sufficient size for the crane crab to move therethrough. An opening is defined between the ends of the branches below the travel path of the crab. A pulley is mounted on mounting structure which is secured at least on the end of one of the branches of the C-shaped frame. A bent arm is retractably mounted on the mounting structure. The bent arm has a lower vertical leg adjacent the pulley and an upper leg extending transversely across the opening between the ends of the branches of the C-shaped frame.

Description

United States Patent 1191 Metailler 1 CABLE FLEX LIMITING DEVICE [75] Inventor: Roger Metailler, Grenoble, France [73] Assignee: Ford Motor Company, Dearborn,

FOREIGN PATENTS OR APPLICATIONS 27,563 3/1964 Germany 1451 July 3,1975

Primary Examiner-Robert J. Spar Assistant ExaminerR. B. Johnson Attorney, Agent, or Firm-William E. Johnson; Keith L. Zerschling [57] ABSTRACT A device is disclosed for limiting the flexing of cables of a crane crab mounted for movement on a boom. A C-shaped frame has a back portion mounted trans versely of the boom so that the two branch portion of the C-shaped frame extend below the boom to define a space of sufficient size for the crane crab to move therethrough. An opening is defined between the ends of the branches below the travel path of the crab. A pulley is mounted on mounting structure which is secured at least on the end of one of the branches of the C-shaped frame A bent arm is retractably mounted on the mounting structure. The bent arm has a lower vertical leg adjacent the pulley and an upper leg extending transversely across the opening between the ends of the branches of the C-shaped frame.

3 Claims, 3 Drawing Figures CABLE FLEX LIMITING DEVICE BACKGROUND OF THE INVENTION This invention relates to a device for limiting the flex ing of the cables of a crane crab which is movable on a travel path mounted at the lower part of a boom of a crane, or of a traveling bridge, of any other type of lifting equipment. The device of this invention is of the type of devices which are mounted on the boom of a crane to support, at least temporarily. cables running to the crane crab, i.e., the cables for traction or lifting. The device temporarily supports these cables so as to prevent these cables from being caught on various construction during the travel of the crab or the rotation of the boom to bring them into operative position for lifting or other type of crane work.

SUMMARY OF THE INVENTION This invention relates to a device for limiting the flexing of cables and, more particularly, to a device for limiting the flexing of cables of a crane crab mounted for movement on a boom.

In accordance with the teachings of this invention, the device of this invention includes the following structure. A C-shaped frame has a back portion mounted transversely of the boom so I that its two branch portions extend below the boom to define a space of sufficient size for the crane crab to move therethrough. An opening is defined between the ends of the branches of the C-shaped frame below the travel path of the crane crab. A mounting structure is provided on at least an end of one of the branches of the C-shaped frame. A pulley is mounted on the mounting structure by a horizontal shaft. The pulley is rotatable about the shaft. A bent arm is retractably mounted on the mounting structure. The bent arm has a lower vertical leg adjacent the pulley and an upper leg extending transversely across the opening between the ends of the branches of the C-shaped frame. The upper leg of the bent arm is joined to the lower leg at a position above the top of the pulley.

When the retractable bent arm is in its operating position, its upper leg forms a guide which prevents a cable from passing through the opening separating the two branches of the C-shaped frame. The upper leg also acts to direct the cable to a groove of the pulley if the cable deflects above a certain amount from a fully tensioned position.

In its preferred form, the device of this invention is constructed such that each end of the branches of the C-shaped frame have the mounting structure, pulley, and bent arm attached thereto. The lower portion of the bent arm is rotatable about the mounting structure so that when the lift crab penetrates into the C-shaped frame and the lift cables come in contact with either one of the bent arms, the arm contacted will rotate to let the lift cable go therepast.

BRIEF DESCRIPTION OF THE DRAWINGS The device of this invention will be understood best by reading the description that follows with reference to the attached drawings. These drawings show a nonlimitive example of a device constructed in accordance with the teachings of this invention.

In the drawings,

FIG. 1 is an elevation view, partly in cross-section, of the device of this invention.

FIG. 2 is a side elevation view taken along line 2-2 of FIG. I.

FIG. 3 is a view taken along line 33 of FIG. I.

DESCRIPTION OF THE PREFERRED EMBODIMENT Construction In FIG. I the flex limiting device of this invention is generally identified by the numeral 10. In FIG. I, a load crab I2 is shown which has a pair of vertical support members I4 on opposite ends thereof. These support members have a pair of shafts 16 to which rollers 18 are affixed. The rollers are movable over travel paths 20 formed on rails 22.

The rails 22 form part of a boom structure for the crane. A cross member 24, forming a portion of the boom structure in a well known manner, has a pair of upstanding support rails 26 bolted thereto which, in turn, have a cross brace 28 secured thereto. the cross member 24 supporting the rails 22 at opposite ends thereof. As is well known in the art, the load crab I2 is movable on the travel paths 20 into and out of the drawing as viewed in FIG. I. The cables, not shown, which pull the crab back and forth, when they are under tension will fill the space generally designated by A in the figure. When the same cables are not under tension they sag and fall into the general area designated by the letter B. The cables will sag even lower than the designated area B if it were not for the device of this invention. As is also well known in the art, the load crab 12 will have cables, not shown, in its central portion which will extend downwardly as viewed in FIG. 1 to a suitable pulley block.

In accordance with the preferred embodiment of this invention, a C-shaped frame is defined which includes as a back portion thereof the cross brace 28. The C- shaped frame also has branch portions, generally identified by the numerals 30 at opposite ends of the cross brace. The branch portions have downwardly extending legs 32 and inwardly extending legs 34, the upper end portion of the downwardly extending legs being secured to the cross brace.

At the lower end of the downwardly extending leg 32 of the branch portion 30, support structure generally identified by numeral 36 is provided. The support structure includes an L-shaped vertical plate 38 and a horizontal plate 40. One leg of the L-shaped plate 38 is secured to the downwardly extending leg and the other leg of the L-shaped member has secured thereto a shaft 42. The shaft supports a pulley 44 for rotation. The shaft also has a front portion 46 having an opening therein which rotatably supports a lower portion 48 of a bent arm 50. The bent arm has an upper portion 52 which is connected to the lower portion at a point above the topmost portion of the associated pulley 44. Any horizontally extending cable coming in contact with the upper portion of the bent arm 50 will be directed into the associated pulley for rotational support.

The lower portion 48 of the bent arm 50 supports a member 54 located below the horizontal plate 40. The member 54 is connected by spring 56 to a stationary member 58. Thus the bent arm 50, which is rotatably mounted in the front 46 of the shaft 42, is spring biased to a normal position in which the upper portion 52 thereof overlies the opening between the ends of the branches 30 of the flex limiting device of this invention.

Operation ln operation. if the cables to the load crab l2 flex greatly because there is insufficient tension therein. the cables will come into contact with the upper portions 52 of the bent arms 50 and be directed theredown into the groove of an associated pulley 44. The cables thereby will be supported and will not hang down and become engaged in other construction.

When the vertical cables leading from the load crab 12 to the tackle block, not shown, come into contact with the bent arms 50 as the crab 12 is moved back and forth, or in and out of the drawing as viewed in FIG. 1, the bent arms will be able to pivot about their rotational mounting in the front 46 of the shaft 42. This action permits the cables from the crab to the tackle block to pass through the opening between the inwardly extending legs 34 of the branch portions 30. Once the cables have passed through the opening, the springs 56 act on the members 54 in order to rotate the bent arms 50 back to their normal position in which they fill the opening between the two inwardly extending legs and are thus in a position for receiving any cable which is in a flexing mode.

There has been disclosed herein a device for limiting the flexing of a cable of a crane crab. Many modifications of this invention will be apparent to those skilled in the art in view of the teachings of this specification. It is intended that all such modifications which fall within the true spirit and scope of this invention be included within the scope of the appended claims.

I claim:

1. In a boom having a movable crane crab mounted for movement thereon with cables, the improvement comprising a device for limiting the flexing of said cables comprising:

a generally C-shaped frame with a horizontal back portion and two generally vertically depending branches, means mounting said back portion transversely on said boom so that a portion of said branches extend below said boom to define a space of sufficient size for said crane crab to move therethrough;

a pulley mounting structure attached to at least one end of one of said branches. a horizontal shaft rotatably mounted on said pulley mounting structure, a pulley rotatably mounted on said shaft;

an arm mounted on said shaft, said arm having a lower vertical portion and an upper bent portion, means operatively connecting said arm to said shaft so that said arm is rotatable therewith. said upper bent portion of said arm being located above said pulley and extending in a direction transversely of said boom so as to guide a flexing cable over said pulley and means for retractably connecting said arm to said pulley mounting structure to maintain said arm in a normal vertical position.

2. The device of claim 1 further comprising: a pulley mounting structure, a shaft, an arm and a pulley mounted on the other branch of said C-shaped frame and wherein the upper bent portions of said arms converge at their end at a generally central location relative to said boom and crane crab.

3. The device of claim 1 wherein said means for retractably mounting said arm includes: spring means coupled between said pulley mounting structure and said lower vertical portion of said arm.

* l a: a:

Claims

1. In a boom having a movable crane crab mounted for movement thereon with cables, the improvement comprising a device for limiting the flexing of said cables comprising: a generally C-shaped frame with a horizontal back portion and two generally vertically depending branches, means mounting said back portion transversely on said boom so that a portion of said branches extend below said boom to define a space of sufficient size for said crane crab to move therethrough; a pulley mounting structure attached to atleast one end of one of said branches, a horizontal shaft rotatably mounted on said pulley mounting structure, a pulley rotatably mounted on said shaft; an arm mounted on said shaft, said arm having a lower vertical portion and an upper bent portion, means operatively connecting said arm to said shaft so that said arm is rotatable therewith, said upper bent portion of said arm being located above said pulley and extending in a direction transversely of said boom so as to guide a flexing cable over said pulley and means for retractably connecting said arm to said pulley mounting structure to maintain said arm in a normal vertical position.