US3829992A

US3829992A - Alignment system for the operating conduits of a grab

Info

Publication number: US3829992A
Application number: US00314932A
Authority: US
Inventors: N Reid; R Stanley
Original assignee: GEOCHEM SERVICES HOLDINGS Ltd; JARVIS GEOCHEM Ltd
Current assignee: GEOCHEM SERVICES HOLDINGS Ltd; JARVIS GEOCHEM Ltd
Priority date: 1971-12-22
Filing date: 1972-12-14
Publication date: 1974-08-20
Anticipated expiration: 1991-08-20
Also published as: EG11627A; IE37228B1; DE2263067A1; GB1376327A

Abstract

A crane assembly, especially for excavating, comprises a support structure from which a working device, especially a hydraulic grab, is suspended by a mail cable. Operating conduits for the working device pass over sheaves mounted on the support structure adjacent the main cable. By horizontal adjustment of the sheaves the main cable and conduits are kept coplanar over a range of orientations of the grab, thereby controlling the orientation of the grab and facilitating lowering of the grab into a narrow trench without fouling of the conduits. In a preferred embodiment two sheaves are each mounted on an arm pivotally mounted on the jib of a crane adjacent the main cable and adjustment of the sheaves is achieved by swinging the arms into the appropriate position.

Description

[ Aug. 20, 1974 ALIGNMENT SYSTEM FOR THE OPERATING CONDUITS OF A GRAB Inventors: Neil George Reid, London;

Raymond Eric Stanley, Kent, both of England Assignees: Jarvis Geochemical Limited;

Geochemical Services (Holdings) Limited, both of London, England Filed: Dec. 14, 1972 Appl. No.1 314,932

Foreign Application Priority Data Dec. 22, 1971 Great Britain 59631/71 US. Cl 37/103, 37/184, 173/85, 175/238, 212/44, 214/658, 254/190 R Int. Cl. E021 5/02, E02f 9/14 Field of Search 173/85; 175/238; 214/656-658; 212/44, 42, 59, 81, 84;

References Cited UNITED STATES PATENTS Brosius Schneider Maki 254/190 R X 3,139,729 7/1964 Miotti 37/183 R UX 3,479,077 11/1969 Martin et a1. 212/42 X 3,516,433 6/1970 Guinot 212/44 X FOREIGN PATENTS OR APPLICATIONS 1,086,413 8/1960 Germany 214/658 1,246,200 8/1967 Germany 212/59 A Primary Examiner-Clifford D. Crowder [5 7] ABSTRACT A crane assembly, especially for excavating, comprises. a support structure from which a working device, especially a hydraulic grab, is suspended by a mail cable. Operating conduits for the working device pass over sheaves mounted on the support structure adjacent the main cable. By horizontal adjustment of the sheaves the main cable and conduits are kept coplanar over a range of orientations of the grab, thereby controlling the orientation of the grab and facilitating lowering of the grab into a narrow trench without fouling of the conduits. In a preferred embodiment two sheaves are each mounted on an arm pivotally mounted on the jib of a crane adjacent the main cable and adjustment of the sheaves is achieved by swinging the arms into the appropriate position.

8 Claims, 5 Drawing Figures PATENTEn-mszo m4 3.829.992

saw 1 or s ALIGNMENT SYSTEM FOR THE OPERATING CONDUITS OF A GRAB The present invention relates to a crane assembly comprising a cable-supported working device such as a grab,'having provision for accommodation and control of the orientation of the working device.

When a device, such as a hydraulically operated grab, is operated underground it can be difficult to control the orientation of the grab or other device about a vertical axis, especially for insertion of the device into a narrow trench. Moreover, any power supply cables or the like (such as electric cables or hydraulic holes) necessary for the operation of the device can foul the edges of the excavation and be damaged.

It is known for example from British Pat. Specification Nos. 192,546, 207,703, 266,446 and 266,449 to slew a load suspended from a support structure by a plurality of cables by passing each of the cables over s sheave adjustable with a horizontal component of movement. It is further known from British Pat. Specification No. 998,306 to pass an operating cable for a grab suspended from the jib of a crane round rollers mounted on an upstanding arm and to open and close the grab by movement of the arm. Finally, it is also known from British Pat. Specification Nos. 389,858 and 409,632 to control the attitude of a grab or bucket by at least two cables passing from the crane or winch to the grab.

However, despite the long time for which these disclosures have been in existence, it has not to our knowledge yet been proposed to adjust horizontally the operating conduits of a working device such as a grab in order to keep them coplanar with each other and the main cable, thus influencing the orientation of the working device and facilitating lowering of the working device into a restricted zone such as a narrow trench.

The present invention now provides a working device suspended by at least one main support cable from a support structure, and provided with a plurality of takeoff sheaves each mounted adjacent the support cable on the support structure for generally horizontal movement, over each of which sheaves an operating conduit passes to the working device so that by horizontal adjustment of the sheaves relative to the main cable the conduits may be kept substantially coplanar with each other and with the main cable at any of a range of orientations of the working device.

Generally horizontal movement" means that the sheaves are mounted for movement having a horizontal component. The invention is not restricted to the sheaves having no vertical component of movement.

The underground working device can be for example a hydraulically or pneumatically operated grab, an electric grab, an electric pump or any other electrically or hydraulically operated excavating or the like device.

The operating conduits canbe the hydraulic or pneumatic hoses, electrical cables or simply auxiliary support wires.

The mounting of the take-off sheaves for horizontal movement enables the conduits to be aligned with respect to the main support cables as desired. In this way, not only can the conduits be prevented from fouling the sides of the excavation, but the orientation of the underground working device relative to the support structure can be controlled.

Preferably, there are two take-off sheaves, which are mounted for rotational movement and displacement in two generally parallel planes on either side of the main support cable. Conveniently, each sheave may be mounted on the lower end of an arm provided at its upper end to the support structure. Means such as quadrants can then be provided to secure the arm in the desired position and obtain the desired alignment of the conduits.

In a preferred form of the invention particularly used for excavation, the crane assembly comprises a crane from the jib of which the at least one main cable depends, the working device being a grab hydraulically operated through the conduits.

This preferred apparatus is advantageously used when, for reasons of space or ground contour, it is desirable to excavate a narrow trench using an excavator travelling parallel to the trench. The take-off sheaves are adjusted so that with the grab over or in the trench the line joining the hoses coincides with the centre line of the trench. The grab can then be lowered into the trench without the hoses fouling the sides of the trench even though the jib be at an angle to the trench. Moreover, the alignment of the hoses will influence the orientation of the grab about its vertical axis and can be used to ensure that the grab is at a suitable angle to the centre line of the jib so that it is always lowered into the trench in the correct alignment.

A preferred subsidiary feature of the invention is the provision of a device for adjusting and fixing the alignment of the working device or (in the preferred form of the invention, the hydraulic grab) about the main support rope. In most instances the main support rope will have at least two runs passing at the bottom through a sheave or sheaves in a block. According to this preferred feature of the invention an aligning lock is provided between the block and the working device to adjust and secure the orientation of the working device about a vertical axis with respect to the block.

This feature can be used in conjunction with the adjustable take-off sheaves in the preferred form of the invention to ensure that the grab is correctly aligned with respect to the jib about a vertical axis. When setting up the apparatus the aligning lock is adjusted and secured so that when the grab is over the trench it is in the correct alignment with respect to the centre line of the trench, and the take-off sheaves are then adjusted so that the hoses are also in correct alignment by the aligner and lock as well as by the hoses.

A second preferred feature of the invention is the provision of spring-loaded take-up reels for the operating conduits. These can be mounted on the support structure to take up slack in the operating conduits. In the preferred form of the invention they are mounted on the jib.

It is preferred to provide indicia on the take-off reels by which the amount of each hose paid out may be observed. It is then possible for the operator to find whether the grab is tilted in the plane of the vertical portions of the hoses, as may happen when one jaw encounters a rock or other hard material. This feature is particularly valuable when the operating device is operating at a substantial depth or under a liquid.

It is envisaged that the invention will be particularly useful when a narrow trench (say, 1-4 feet wide) is being dug with a hydraulically operated grab to a substantial depth (say about 50 ft. deep), for a concrete structure such as diaphragm wall which is to be cast in situ; the walls of the trench can be supported by keeping the trench filled, as it is dug, with a slurry, such as a bentonite-water mud, the hydraulic grab operating under this liquid.

The preferred form of the invention will now be described with reference to the drawings. It will however be understood that the principles of the invention are not limited to the particularly described application to a hydraulic grab operated from a mobile excavator to dig a narrow trench, and that they may advantageously be applied, for example, to an electric excavating device or any other device operating underground and supported by cable or cables.

The invention is illustrated in the accompanying drawings, in which:

FIG. 1 is a side elevation of an excavator equipped with the control system of the present invention;

FIG. 2 is an isometric view of the same excavator in operating position adjacent a trench;

FIG. 3 is a schematic plan view of FIG. 2;

FIG. 4 is an enlarged view of the tip of the jib of the excavator shown in FIG. 1;

FIG. 5 is a side view of the adjustable grab aligner and lock shown at 11 in FIG. 1.

FIGS. I and 2 show an excavator 1 having a jib or boom 2 on the outer end of which a main sheave means S is journalled. A main support cable or hoist rope 3 is trained over the sheave S and suspends a hydraulically operated working grab device 4. Pivoted to the top end of the jib is a pair of arms 5, 5' carrying a take-off sheaves 6, 6' respectively (only one arm and one takeoff sheave appears in FIG. 1). The angular position of the arms about their pivots is controlled by the quadrants 7, 7. The hoses 8, 8' having conduits for the hydraulic grab pass over the take-off sheaves 6, 6 to the grab 4, and at the other end are taken up on springloaded hose reels 9, 9'. The grab 4 is supported from the hoist rope 3 by a conventional block 10 and an adjustable grab aligner and lock 11 which is shown in detail and on a larger scale in FIG. 5 and is more particularly described below with reference to that figure.

It will be noted that in FIG. 2 the excavator l is arranged for movement parallel to the trench.

In FIG. 3 the hose reels 9 and 9, the quadrants 7 and 7' and that part of the hoses 8, 8 between the hose reels and the take-off sheaves 6 6 have been omitted for clarity. This figure shows how by relative generally horizontal movement of the take-off sheaves 6, 6' the vertical portions of the hoses 8, 8 can be aligned with the direction of the trench. In FIG. 3 the arms 5, 5' are shown adjusted to a position where the vertical portions of the hoses 8, 8 are aligned with the centre-line of the trench and descend vertically from the take-off sheaves 6, 6 into the cavity.

The capability of aligning the vertical portions of the hoses with the hoist rope and the centre-line of the trench has certain advantages. Firstly, fouling of the hoses against the trench walls is largely eliminated. Secondly, the grab can be lowered directly into the trench each time without re-alignment. The hoses resist rotation of the grab about a vertical axis so that once the arms 5,5 are correctly adjusted the grab, when lowered towards the trench, will always be correctly aligned. This is particularly important when a hydraulically operated grab of the type illustrated is being used to excavate a narrow, deep trench, as for a diaphragm wall. This pre-alignment of the grab is facilitated by the use of the adjustable grab aligner and lock described below. Thirdly because the grab can thus be aligned at a predetermined angle to the jib (in conventional outfits it will naturally orient itself at right angles to the jib) the excavator can operate close to the trench by virtue of the acute angle between the jib and trench centrelines (shown in FIGS. 3 as 45). The excavator can thus operate in a smaller space. Further, because the excavator has to turn through a smaller angle between the trench and the point where excavated material is being dumped, as compared with a conventional outfit where the jib is normal to the trench, time is saved.

FIG. 4 shows in detail the take-off sheave 6 and the way in which it is mounted on the jib 2. The quadrant 7, secured to the jib 2, comprises two identical parallel spaced plates between which the arm 5 passes. A row of holes 40 is provided in the quadrant through one of which a pin is passed to secure the arm in any desired position. Generally horizontal movement of the takeoff sheave 6 between the extreme positions shown in full and broken outline, and securing of the sheave in any one position, is thus obtained.

FIG. 5 shows the adjustable grab aligner and lock 11, by means of which the grab is suspended from the conventional sheave block 10. Sheave block 10 comprises a sheave 50, a hook 51 and a flat-sided shank 52. The hook 51 is conventionally pivotally mounted in shank 52 for free rotation about a vertical axis. The grab aligned and lock 11 comprises an upper plate 53 integral with cheek plates 54 (only one of which appears in FIG. 5) a pin 55 connecting the cheek plates, and a lower member comprising a square end 56 to fit the Kelly bar socket on top of the grab integral with a central plate 57. The cheek plate 54 lie against the flat side faces of the shank 52 so that relative rotation between the former and the latter is prevented. The centre plate 57 is sandwiched between the upper plate 53 and a ring 58. Bolts 59 pass through the upper plate 53 and ring 58 and may be tightened to clamp the central plate 57 between them, thus preventing relative rotation between the upper and lower members of the grab aligner and lock.

When the apparatus is being set up for operation in a particular location the desired angle between the centre line of the grab and the centre line of the jib is determined. The grab aligner and lock is adjusted by rotating the square end 56 to make the desired angle with the cheek plates 54, and bolts 59 are tightened. The cheek plates 54 engage the non-rotating part of the sheave block 10 and prevent relative angular rotation of the grab and sheave block about a vertical axis. Tilt of the grab in the plane normal to that of FIG. 5 is also resisted.

As explained above, the hose take-up drums 9 and 9 are spring loaded so as to take-up automatically any slack in hoses 8 and 8. It is a preferred feature of this invention that indicia are provided on these drums which can be observed by the operator from his position in the crane 1. By observing these indicia the operator can tell whether a similar length of hose has been paid out from each drum. Clearly if the grab in the bottom of the trench tilts in the plane of the trench (and cannot be seen to do so by the operator) its tilting will be revealed by relative rotation of the drums 9 and 9.

This feature is of particular utility when the grab is operating at the bottom of a deep trench and/or under an opaque liquid such as a bentonite slurry.

We envisage that the control system of our invention could be supplied in kit form and used to adapt conventional excavators. The arms, quadrants, take-off sheaves, hose reels and grab aligner and lock can all be fixed to a conventional excavator in a short time and without specialized labour.

What is claimed is:

11. A crane assembly comprising a working device suspended by at least one main support cable from a support structure, and provided with a plurality of takeoff sheaves each mounted adjacent the support cable on the support structure for independent generally horizontal movement relative to each other and to the main support cable, over each of which sheaves an operating conduit passes to the working device so that by horizontal adjustment of the sheaves relative to the main cable the conduits may be kept substantiallly coplanar with each other and with the main cable at any of a range of orientations about a vertical axis of the working device.

2. The assembly of claim 1, in which the said take-off sheaves are mounted for rotational movement and displacement in two generally parallel planes on either side of the main support cable.

3. The assembly of claim 2 in which each sheave is mounted on the lower end of an arm pivotally mounted at its upper end to the support structure.

4. The assembly of claim 1 in which the support structure comprises a jib from which at least one main cable depends, and the working device is a grab hydraulically operated through the conduits.

5. The crane assembly of claim 4 for excavating a narrow trench with the grab operating under a slurry introduced into the trench.

6. The assembly of claim 1 in which the said conduits are taken up on reels mounted on the support structure.

7. The assembly of claim 1 in which the main cable comprises at least two runs and passes through a sheave block from which the working device is suspended by an aligning lock such that the working device and sheave block can be relatively rotated about a vertical axis and then clamped in a desired relative orientation.

8. In a crane assembly comprising a support structure including a boom, a main sheave means on the outer end of the boom, a main support cable passing over said main sheave means, a working device suspended by said main support cable, and a plurality of operating conduits passing between the support structure and the working device, the improvement which comprises a plurality of take-off sheaves each mounted adjacent the main support cable on the support structure for rotation on axes parallel to each other and to the axis of rotation of the main sheave means and for independent generally horizontal movement relative to each other and to said main sheave means, over each of which take-off sheaves one of said operating conduits passes to the working device so that by horizontal adjustment of said take-off sheave relative to each other and to the main sheave means the conduits may be kept substantially coplanar with each other and with the main support cable at any of a range of orientations about a vertical axis of the working device.

Claims

1. A crane assembly comprising a working device suspended by at least one main support cable from a support structure, and provided with a plurality of take-off sheaves each mounted adjacent the support cable on the support structure for independent generally horizontal movement relative to each other and to the main support cable, over each of which sheaves an operating conduit passes to the working device so that by horizontal adjustment of the sheaves relative to the main cable the conduits may be kept substantiallly coplanar with each other and with the main cable at any of a range of orientations about a vertical axis of the working device.