US3430776A

US3430776A - Derrick cranes and swinging derricks

Info

Publication number: US3430776A
Application number: US634806A
Authority: US
Inventors: Robert Morrison
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-04-24
Filing date: 1967-04-24
Publication date: 1969-03-04
Anticipated expiration: 1986-03-04

Description

March 4, 1969 R. MORRISON 3,430,776

DERRICK CRANBS AND SWINGING DERRICKS Filed April 24, 1967 Sheet of s INVENTOR POBEET MO'QP/SON B A Wad /M, hwmgf4m AT TORNEY March 4, 1969 MoRR|soN 3,430,776

DERRICK CRANES AND SWINGING DERRICKS Filed April 24, 1967 Sheet 2 of 5 INVENTOR IZOBEET MOBWSOM ATTORN March 4, 1969 R. MORRISON 3,430,776

DERRICK GRANES AND SWINGING DERRICKS Filed April 24, 1967 Sheet 3 of 5 I N V E N TOR ROSE/57' MOEF/SO/V Ward/was, bud 1M 5" :ZZ M

AT To R NEY March 4, .1969 R. MORRISON 3,430,776

DERRICK CRANES AND swnmwa nmmrcxs Filed April 24. 1967 Sheet 4 o! s INVENTOR $35557 MORE/S ON ATTORN March 4, 1969 R. MORRISON 3,

DERRICK CRANES AND SWINGING DBRRICKS Filed April 24, 1967

Sheet

5 or 5 INVENTOR EOBEET MOEEISON B Y W United States Patent Office 3,430,776 Patented Mar. 4, 1969 3,430,776 DERRICK CRANES AND SWINGING DERRICKS Robert Morrison, 9 Gateside Ave., Greenock, Renfrewshire, Scotland Filed Apr. 24, 1967, Ser. No. 634,806 US. Cl. 2123 Int. Cl. 1366c 23/52, 23/62 5 Claims ABSTRACT OF THE DISCLOSURE The invention relates to derrick cranes and swinging derricks and particularly to means for promoting speed and accuracy of operation, wide range of working, and stability when under load.

The invention has particular application to derrick cranes and swinging derricks used for loading and unloading ships in which work it is essential that maximum stability is available so as to ensure that any fore and aft, sideways (port or starboard) or other movement of the ship which may occur while work is in progress does not interfere with safe and rapid handling of the cargo.

Unless the structure is firmly mounted and the members of the rigging used for effecting movement of the crane are properly designed, rigged and adjusted in strength, length and disposition so that the interaction and combination of stresses applied in each of the members are correlated with the incidental stresses which arise in other members during operation there is a danger that a member of the rigging may be damaged or broken and/or the load go out of control.

It is possible, for example, in the operation of a derrick crane or a swinging derrick for the stresses to become unbalanced so that effort exerted to slew or swing the derrick may result in a build up in the topping or luffing rigging of tension in excess of the slewing effort with the result that an operation intended to slew the derrick becomes secondary to a topping operation and positive control of the load is lost.

It is among the objects of the invention to avoid such disadvantages and to provide a derrick in which the stresses and strains in the several members are balanced at all times during operation and when at rest.

According to the invention there is provided means included in the rigging of a derrick crane or swinging derrick effective to divide the topping effort and/ or the slewing effort in balanced proportions so as to maintain a balanced relation and interaction between the topping effort and slewing effort during a topping or a slewing operation.

Thus the means for dividing the topping effort may comprise one or more delta plates, rings or shackles, or equivalent means and/or pulley sheaves and the means for dividing the slewing effort may comprise one or more delta plates, rings or shackles, and/or pulley sheaves or rigid members pivotally secured to the jib of the derrick and to the slewing rigging.

One construction according to the invention is illustrated by way of example in the accompanying diagrammatic drawings, in which:

FIGURE 1 shows the rigging of the jib head of a swing ing derrick;

FIGURE 2 shows the mast, jib, the jib trunnion or gooseneck, and the rigging for topping, slewing, and cargo lifting;

FIGURE 3 shows an alternative rigging for topping and slewing, and

FIGURE 4 shows in 4a, 4b, and 40 to 4 the distribution and the relative values of forces in the topping and slewing rigging for the constructions illustrated in FIG- URES l and 2, FIGURE 3, and four additional alternative systems of rigging respectively, and, in 4g, a construction including rigid members pivotally secured to the jib and to the slewing rigging.

In the construction illustrated in FIGURES 1 and 2 the mast is denoted by 1, the jib or boom, which is adapted to turn on pintle or trunnion means disposed at or near the base of the mast, by 2, and the topping wire by D.

The topping wire D is led from topping winch A to

pulley sheaves

3, 4 and 5, and is then secured to a delta plate 6 from which two wires or ropes F pass to two pulley sheaves 7, each of which is secured to the jib 2, around further pulley sheaves 8, and are then secured to the jib 2 at 9. These compensate for (a) any twisting action on derrick head when the derrick is being slewed (b) afford assistance in level lufling and level slewing and (0) reduce slewing stress on the jib and topping riggmg.

Slewing wires E from slewing winch B pass around slewing blocks 10 and are secured to the pulley sheaves 8. The slewing blocks are positioned so as to give slewing spread, align the slewing wires, and reduce end bending moment.

C denotes the cargo loading winch from which the lifting wire, shown in dotted lines, passes over pulley sheave 11 near the top of the mast and over pulley sheave 12 at the top of the jib to hang vertically in a position ready for use.

After rigging, a preventor wire or cable H is included, one end being attached to the delta plate 6 and the other to the jib, with sufficient slack to allow free movement of the delta plate.

In operation the topping movement, that is to say, the movement of the jib in a vertical plane, is effected by operation of the winch A which acts through the topping Wire D, the

pulley sheaves

3, 4 and 5, the delta plate 6, and the pulley sheaves 7.

The slewing movement, that is to say, any positive sideway movement of the jib, is effected by operation of the winch B which acts through the slewing lines E and the pulley sheaves 8.

As shown in the diagram of forces in FIGURE 40, a force of 1 ton, for example, on a slewing wire, results in a tension of /2 ton, in each of the topping wires secured to the delta plate 6, and therefore a tension in the topping line D of 1 ton. There is therefore no danger of the balance of forces between slewing and topping being upset by having the resultant force in a topping wire during a slewing operation greater than the slewing force.

In the construction and alternative system of rigging illustrated in FIGURE 3 the jib 2 is pivotally secured to the mast near the base of the mast and a delta plate 6 is used to balance the slewing effort in the slewing system. The two slewing wires E, port and starboard, from the slewing winch B are each connected to the base of the delta plate 6, after passage of each through a pulley sheaves lay out comprising, two sheaves 10 secured to the mast 1, two lower slewing block systems denoted by X and Y and an upper slewing block system, denoted by Z, and, if required, through grouping blocks or sheaves G. The lower slewing block systems X and Y are located at the limits of the required slewing spread, and connection of the upper slewing block Z to the jib 2 is made by means of slewing pendants denoted by E.

The path of each of the two slewing wires is; from winch B to sheave 10, to lower slewing block X, to upper slewing block Z, to lower slewing block Y and then, either direct to delta plate 6 or, by the alternative route indicated in dotted lines, through sheaves or blocks G to delta plate 6.

In the topping (or lufiing) system the line from the topping winch is passed through a pulley sheave block 3 near the top of the mast to a pulley sheave 4 at the end of jib and back to a second pulley sheave block 5 near the mast head and then to the apex of the delta plate 6.

The four additional alternative force diagrams shown in FIGURE 4 result from the inclusion of additional pulley sheaves and/or from different dispositions of pulley sheaves and delata plates in the rigging.

The topping span or spans can be rigged from separate wires, but preferably from one and the same wire, that is to say, the topping span is virtually a single acting twoway purchase which equally distributes the loading so that in the outboard position there is no extreme loading on the long or trailing slew tackle and the loading throughout the wire is constant so that there is no slackening of the wire on either of the outboard spans.

As the topping and lufiing systems are corelated when the ship is on a level keel the locus of the derrick head is maintained at a constant distance from a horizontal plane until the distance is altered by heaving on the topping or lufiing winch.

It will be obvious to those skilled in the art that the derrick crane of the present invention can utilize any type of cable means, such as wire or rope, for controlling the topping and slewing movements of the boom.

I claim:

1. A derrick crane comprising:

a support surface having a mast extending outwardly therefrom;

a boom movably mounted adjacent one end thereof for permitting same to swingably move relative to said mast, said boom having load-lifting means associated therewith;

a topping winch and topping cable means for controlling the movement of said boom in a plane substantially parallel to the longitudinal axis of said mast, one end of said topping cable means being wound on said topping winch;

a slewing winch and slewing cable means having a portion thereof wound on said slewing winch for controlling the sideward movement of said boom relative to said mast, the opposite ends of said slewing cable means being operatively associated with said boom; and

balance means interconnecting the opposite ends of said slewing cable means to the other end of said topping cable means for causing the force on each of the opposite ends of said slewing cable means to be substantially equal to the force on the other end of said topping cable means, said balance means including balancing cable means secured at a first point thereon to the other end of said topping cable means and secured at a second point thereon to said boom with said second point being spaced from said first point, said balancing cable means further being operatively interconnected to the opposite ends of said slewing cable means at a location thereon between said first and second points.

2. A derrick crane as defined in claim 1, wherein said balancing cable means includes a pair of intermediate cable means with one end of each of said intermediate cable means being operatively interconnected to the other end of said topping cable means, each of said intermediate cable means having an intermediate portion thereof operatively associated with one of the ends of said slewing cable means, and the other end of each of said intermediate cable means being operatively connected with said boom.

3. A derrick crane as defined in claim 2, wherein said balance means further includes a pair of guide members with each one of the opposite ends of said slewing cable means being secured to one of said guide members, each of said intermediate cable means passing around one of said guide members with said other end of said intermediate cable means being secured to said boom.

4. A derrick crane as defined in claim 3, wherein said balance means further includes a rigid member connected between the topping cable means and the intermediate cable means with the other end of said topping cable means and the one end of each of said intermediate cable means being secured thereto.

5. A derrick crane comprising:

a mast having first pulley means thereon;

a boom movably mounted adjacent one end thereof and having second pulley means thereon, said boom having load-lifting means associated with said second pulley means;

a topping winch and topping cable means wound on said winch and passing around said first pulley means;

a pair of slewing blocks positioned on opposite sides of the base of said boom;

a slewing winch and slewing cable means having an intermediate portion thereof wound on said slewing winch with the ends of said slewing cable means extending outwardly from the slewing winch and passing around said slewing blocks;

a first pulley member secured to one end of said slewing cable means;

a second pulley member secured to the other end of said slewing cable means;

first and second intermediate cable means passing around said first and second pulley members, respectively, with one end of each of said intermediate cable means being secured to said boom; and

means connecting the other end of said first and second intermediate cable means to the free end of said topping cable means.

References Cited UNITED STATES PATENTS EVON C. BLUNK, Primary Examiner.

HARVEY C. HORNSBY, Assistant Examiner.

US. Cl. X.R.