US3777901A

US3777901A - Derrick cranes

Info

Publication number: US3777901A
Application number: US00216625A
Authority: US
Inventors: R Morrison
Original assignee: SPEEDCRANES Ltd
Current assignee: SPEEDCRANES Ltd
Priority date: 1971-01-08
Filing date: 1972-01-10
Publication date: 1973-12-11
Anticipated expiration: 1990-12-11
Also published as: BR7200131D0

Abstract

A derrick crane in which the rigging is secured by at least two pendant members to the deck or base member at determined positions transversely of the central position of the jib and is connected to pulley members interposed in the rigging of the crane and thereby to the head of the jib and to the head of the mast, operation of the winches in the same direction effecting a topping or lowering of the jib and operation of the winches in opposite directions effecting a slewing of the jib.

Description

United States Patent [191 Morrison 1 DERRICK CRANES [75] Inventor: Robert Morrison, Greenock,

Scotland [73] Assignee: Speedcran'es LlmitetLGourock,

Scotland 22 Filed: Jan. 10,1972

211 Appl. No.: 216,625

[30] Foreign Application Priority Data Jan. 8, 1971 Great Britain 1,040/71 [52] US. Cl. 212/58, 212/3 [51] Int. Cl. B66C 23/06 [58] Field of Search 212/58, 3, 8

[56] References Cited UNITED STATES PATENTS 2,613,001 10/1952 Green 212/3 2,754,975 7/1956 Farrell 212/3 3,057,484 10/1962 Tevisan 212/58 R X Dec. 11, 1973 3,286,851 3,375,937 3,528,561 9/1970 3,620,504 11/1971 Morrison 212/58 R X FOREIGN PATENTS OR APPLICATIONS 572,626 11/1958 Belgium ..2|2/3 Primary Examiner-Richard E. Aegerter Auorney-woodhams, Blanchard & Flynn [57] ABSTRACT A derrick crane in which the rigging is secured by at least two pendant members to the deck or base member at determined positions transversely of the central position of the jib and is connected to pulley members interposed in the rigging of the crane and thereby to the head of the jib and to the head of the mast, operation of the winches in the same direction effecting a topping or lowering of the jib and operation of the winches in opposite directions effecting a slewing of the jib.

5 Claims, 12 Drawing Figures DERRICK CRANES The invention relates to derrick cranes and particularly to means for effecting and controlling slewing, that is to say a side to side movement, of the jib.

In convention derrick crane constructions when used on vessels it is usual, in addition to the cargo runner, to have a single jib and to have two topping wires from the head of the jib, one taken by means of a pendant to the port side extremity and one taken by means of a pendant to the starboard side extremity of a cross-member located at the top of the mast of the crane, or to the heads of two masts mounted one on each side of the vessel.

Hauling in or paying out of both of the topping wires results in topping or lowering of the jib. Hauling on one wire and paying out on the other provides a slewing movement and, by varying the relative speeds of the two wires, a combination of topping and slewing can be obtained.

It is a disadvantage of the conventional constructions that it is difficult to maintain control of the jib throughout a slewing movement and particularly when the load is swung outboard to the extremity of the slewing arc.

It is among the objects of the invention to minimise this disadvantage and to provide a construction in which control of the slewing movement is effective at all positions of the slewing arc so that the load can be lowered and accurately deposited at a determined position, on the deck or in a hold of the vessel, or on shore when the vessel is lying adjacent a quay.

According to the invention, in a derrick crane having a mast supported on a deck or base member, a jib pivotable about a position at or adjacent the base of the mast, and at least two winches disposed symmetrically and transversely of the central position of the jib, the rigging is secured by at least two pendant members to the deck or base member at determined positions transversely of the central position of the jib and is connected to pulley members interposed in the rigging of the crane and thereby to the head of the jib and to the head of the mast, operation of the winches in the same direction effecting a topping or lowering of the jib and operation of the winches in opposite directions effecting a slewing of the jib.

Connection of the rigging to the mast may be either to the upright member of the mast or to a cross member thereon.

Advantageously in a construction in which there is a cross-member on the mast strut members may be provided, each pivotally secured at one end to the cross member and disposed so that their other ends engage the rigging to form effective lever arms for the jib.

According to the invention furthermore strut members are provided, each pivotally secured at one end to the deck or base member of the crane, and disposed so that their other ends engage the pendant members to form effective lever arms for the jib.

In an alternative construction the lines from the winches pass to slewing blocks secured to the deck or base member, then to pulleys at the head of the jib then to pulleys at the head of the mast, or a cross member thereon, and then back to the head of the jib where they are secured. V A 7,

To increase the lifting power of the crane, additional pulleys and/or lines may be included in the rigging to provide a double or multiple purchase.

The invention is illustrated by way of example in the accompanying diagrammatic drawings in which:

FIG. 1a is a skeleton diagram of the rigging of a crane according to the invention from which, for clarity and simplification the jib has been omitted;

FIG. lb is a corresponding plan view;

FIG. 2 is a plan view of rigging in which an additional line has been included to provide a double purchase on the jib (not shown);

FIG. 3 is a plan view of rigging in which additional pulley members have been included to provide a multiple purchase on the jib (not shown);

FIG. 4 is a view of a construction similar to that of FIG. la but in which the pulleys at the head of the mast are secured to a cross member thereon;

FIG. 5 is a plan view of rigging similar to that of FIG. 3 providing a multiple purchase but in which the pulleys at the head of the mast are secured to a cross member;

FIG. 6 is a diagrammatic plan view of a construction in which deck strut members are used;

FIG. 7 is a corresponding view showing the disposition at one extreme of the slewing arc;

FIGS. 8 and 9 illustrate an alternative construction to that shown in FIGS. 6 and 7; and

FIGS. 10 and 11 illustrate an alternative construction of a crane in which the lines from the winches pass to slewing blocks secured to the deck or base member, then to pulleys at the head of the jib, then to pulleys secured by mast strut members to a cross member at the head of the mast then back to the head of the jib where they are secured.

In the construction shown in FIGS. la and 1b the winches 2 are provided adjacent the foot of the mast l and each winch line passes from winch 2 to pulley 3 secured to the head of the mast and then to pulley 4 located near the head of the jib (not shown) and secured to the jib at 5, the line then passing to and around pulley 6 and back to pulley 4. Pulley 6 is secured to the deck by pendant 7.

When both winches 2 are operated in the same direction a raising or lowering of the jib is effected through pulleys 3 and 4, the movement of the pulleys 6 being controlled by the pendants 7.

When one winch 2 is operated in one direction and the other in the opposite direction then relative changes effected'in the rigging will result in changes in the effective lengths of the pendant members, one being increased and the other being decreased to permit a combined topping and slewing operation of the jib.

Operation of only one winch, the other being held stationary, will also effect a combined slewing and topping operation.

In the construction illustrated in FIG. 2 additional pulleys 8 secured to pulleys 4 have been introduced into the rigging to increase the purchase on the jib to a double purchase.

In the construction shown in FIG. 3 pulleys 8 secured to pulleys 4, pulleys 9 secured to pulleys 3, and pulleys 10 secured to the jib provide a multiple purchase on the jib.

The constructions shown in FIGS. 4 and 5 are similar to those shown in FIGS. la and 3 respectively, but the pulleys 3 at the head of the mast are secured to a cross member A thereon.

In the construction illustrated in FIGS. 6 and 7, deck strut members 11 are provided with one end 110 of each strut pivotally secured to the deck or base member at 12, the other end 1 1b of each strut member being attached to a short supporting pendant 12a which is se- 5 cured at 12b to an anchor position on the base member, 12b being located out of line with the line 1la-11a and in a direction towards 11b. It will be seen that the ends 11b of the strut members may be connected to the rigging either by a long pendant 13 or by ashort pendant 14.

In operation of the crane according to FIGS. 6 and 7 as the jib 21 is slewed the strut members 11 pivot about the positions 12 on the deck and are effective to take the strain and to provide a lever arm at any position of the slewing are on either side of the mast, thereby facilitating the control of the jib during the slewing.

In the alternative construction illustrated in FIGS. 8 and 9 there are substituted for anchor positions 12b of the construction of FIGS. 6 and 7 two anchor positions (15A, 16A) and (15B, 16B) on each side of the line of the jib 21 and disposed so that (15 A, 15B) and (16A, 16B) are on opposite sides of a line of reference (as illustrated by the dash-dot line) through the base of the jib and perpendicular to the longitudinal axis of the jib when the jib is stored in its central horizontal position as shown in FIG. 9, 15A and 15B being on one side of the reference line, 16A and 16B on the opposite side of the reference line, 15A and 15B being closer to the base of the jib than 16A and 16B. These anchor positions are connected to the pulleys 6 by pendants 14.

The effect of this construction is to make either (15B 16A) or (15A-l6B) the effective base line of the anchor positions when the jib 21 is in the extreme slew positions and thereby maintain stability of the jib over a much greater angle on each side of the central position.

In the construction shown in FIGS. and 11, the lines from the winches 2 pass to slewing blocks secured to the deck or base member, and disposed in positions in line, or substantially in line with the base of the jib 21, then to pulleys 16 at the head of the jib then to pulleys 17 secured by mast strut members 19 to a cross-member thereon, and then back to the head of the jib 21 to which they are secured at 18.

The strut members 19 pivotally secured to the cross member may be utilised as hereinbefore described to take the strain and provide a lever arm for the jib.

I claim:

1. In a derrick crane having a mast supported on a deck or base, a jib pivoted about a position at or adjacent the base of the mast, and first and second winches disposed symmetrically and transversely of the central position of the jib, the improvement comprising:

a rigging system coacting between the jib and the winches for controlling the movement of the jib, said rigging system including first and second rigging means respectively coacting with said first and second winches for effecting a topping or lowering of the jib when the winches are operated in the same direction and for effecting a slewing of the jib when the winches are operated in opposite directions;

said first rigging means including a first plurality of pulleys associated with the jib and the mast and first cable means coacting with and extending between the first plurality of pulleys and said first winch;

said second rigging means including a second plurality of pulleys associated with the jib and the mast and second cable means coacting with and extending between the second plurality of pulleys and the second winch;

control means associated with said rigging system for controlling the slewing movement of said jib at all positions of the slewing arc, said control means including first and second pairs of anchor positions provided on the base or deck on opposite sides of the line of the jib when it is in its central position, said first pair of anchor positions including first and second positions disposed on opposite sides of a line of reference passing through the base of the jib and perpendicular to the line of the jib when it is in its central position, said second pair of anchor positions including third and fourth positions disposed on opposite sides of said reference line, said first and third positions both being disposed on one side of said reference line and said second and fourth positions both being disposed on the other side of said reference line, said second and fourth positions being closer to the base of the jib than the first and third positions, respectively; and

said control means including first pendant means connecting said first and second anchor positions to said first rigging means and second pendant means connecting said third and fourth anchor positions to said second rigging means.

2. A derrick crane according to claim 1, wherein said first pendant means includes first and second pendant members each having an end thereof connected to said first and second anchor positions, respectively, the other ends of said first and second pendant members being connected to a first pulley associated with said first rigging means; and

said second pendant means including first and second pendant members each having an end thereof connected to said third and second anchor points, respectively, the other ends of said pendant members being connected to a first pulley associated with said second rigging means.

3. A derrick crane according to claim 1, wherein said first and second rigging means each includes a first pulley connected to said jib adjacent the free end thereof and a second pulley spaced from said jib, and the cable means associated with each rigging means having one end thereof connected to said jib with said cable means then passing over said second pulley and then passing over said first pulley and having the other end thereof connected to its respective winch.

4. A derrick crane according to claim 3, wherein said first and second pendant means are respectively connected to said second pulley as associated with said first and second rigging means, respectively.

5. A derrick crane according to claim 4, wherein said first pendant means includes first and second pendant members each having an end thereof connected to said second pulley, the other ends of said first and second pendant members being connected to said first and second anchor positions, respectively;

said second pendant means including third and fourth pendant members each having an end thereof connected to the second pulley associated with said second rigging means, the other ends of said third and fourth pendant members being connected to said third and fourth anchor positions,

respectively.

Claims

1. In a derrick crane having a mast supported on a deck or base, a jib pivoted about a position at or adjacent the base of the mast, and first and second winches disposed symmetrically and transversely of the central position of the jib, the improvement comprising: a rigging system coacting between the jib and the winches for controlling the movement of the jib, said rigging system including first and second rigging means respectively coacting with said first and second winches for effecting a topping or lowering of the jib when the winches are operated in the same direction and for effecting a slewing of the jib when the winches are operated in opposite directions; said first rigging means including a first plurality of pulleys associated with the jib and the mast and first cable means coacting with and extending between the first plurality of pulleys and said first winch; said second rigging means including a second plurality of pulleys associated with the jib and the mast and second cable means coacting with and extending between the second plurality of pulleys and the second winch; control means associated with said rigging system for controlling the slewing movement of said jib at all positions of the slewing arc, said control means including first and second pairs of anchor positions provided on the base or deck on opposite sides of the line of the jib when it is in its central position, said first pair of anchor positions including first and second positions disposed on opposite sides of a line of reference passing through the base of the jib and perpendicular to the line of the jib when it is in its central position, said second pair of anchor positions including third and fourth positions disposed on opposite sides of Said reference line, said first and third positions both being disposed on one side of said reference line and said second and fourth positions both being disposed on the other side of said reference line, said second and fourth positions being closer to the base of the jib than the first and third positions, respectively; and said control means including first pendant means connecting said first and second anchor positions to said first rigging means and second pendant means connecting said third and fourth anchor positions to said second rigging means.

2. A derrick crane according to claim 1, wherein said first pendant means includes first and second pendant members each having an end thereof connected to said first and second anchor positions, respectively, the other ends of said first and second pendant members being connected to a first pulley associated with said first rigging means; and said second pendant means including first and second pendant members each having an end thereof connected to said third and second anchor points, respectively, the other ends of said pendant members being connected to a first pulley associated with said second rigging means.

5. A derrick crane according to claim 4, wherein said first pendant means includes first and second pendant members each having an end thereof connected to said second pulley, the other ends of said first and second pendant members being connected to said first and second anchor positions, respectively; said second pendant means including third and fourth pendant members each having an end thereof connected to the second pulley associated with said second rigging means, the other ends of said third and fourth pendant members being connected to said third and fourth anchor positions, respectively.