US3146898A - Boom leveling and compensating means - Google Patents

Description

Sept- 1964 B. H. KERSTING BOOM LEVELING AND COMPENSATING MEANS 4 Sheets-Sheet 1 Filed Feb. 20 1963 INVENTOR' BERNARD 14/. Kmsm/a P 1, 1964 B. H. KERSTING 3,146,898

BOOM LEVELING AND COMPENSATING MEANS FiledFeb. 20, 1963 4 Sheets-Sheet 2 INVENTOR. BERNARD A. VKEAS 7/6' p 1964 B. H. KERSTING BOOM LEVELING AND COMPENSATING MEANS 4 Sheets-Sheet 3 Filed Feb. 20 1963 INVENTOR.

BERNARD H KE/PS 7//V6 ATTOQMEY p 1964 B. H. KERSTING 3,146,893

BUOM LEVELING AND COMPENSATING MEANS Filed Feb. 20, 1963 4 Sheets-Sheet 4 INVENTOR. BERNARD H kmsrm a aw/W ATTOQNEY.

United States Patent 3,146,898 BOOM LEVELING AND COMPENSA'I'ING MEANS Bernard H. Kersting, Port Charlotte, Fla, assignor, by mesne assignments, to McDowell-Wellman Engineering Company Filed Feb. 20, 1963, Ser. No. 259,919 5 Claims. (Cl. 214-14) This invention relates to a traveling shiploading apparatus for use on a pier at which a boat or collier may be docked, and more particularly to a rope or cable and pulley system which coacts with a laterally movable boom and supporting structure to achieve two important effects in such loading apparatus. Briefly, these effects are maintaining the boom substantially .level during'inshore and offshore movement of the boom, i.e., movement ,of the boom toward and away from the pier, and offsetting the tendency of the loaded boom to upset the boom carrying shuttle.

In the loading of a vessel, it is common practice to carefully distribute the load introduced through a given hatch for the purpose of maintaining the ship in proper trim. One means of accomplishing this is to cause the loading mechanism and trimmer to traverse the ships hold from side-to-side during loading through a given hatch. A laterally movable boom including a bulk material conveying belt, a telescoping chute and trimming apparatus is usually employed to provide such side-to-side movement. It is in providing such lateral movement of the boom with respect to the ship that difiiculty is encountered in controlling the elevation of the outer extremity of the boom and its depending telescoping chute and trimmer. The present invention provides a simple and efficient means for effecting what may be called level luffing, or maintaining the boom at substantially the same horizontal level during traverse between inshore and offshore positions without reeling in or paying out cable or rope from the main boom hoist drum.

Additionally, the rope-pulley system which accomplishes the above-desired result is adapted to the accomplishment of still another and independent desired result, that of compensating for the forces exerted by the boom on the boom shuttle carriage to which it is pivotally connected. During docking, it is necessary to raise the boom out of the path of the superstructure of the ship. Hence, to permit raising of the boom, it is customarily pivoted to a shuttle or carriage at its inshore or proximal extremity. The offshore or discharge extremity of the boom is provided with a telescoping chute and trimmer assembly, and to support this weight, supporting cables are reeved through pulleys secured adjacent the offshore extremity of the boom. These cables are in turn reeved through pulleys or sheaves at the upper extremity of a tall mast which extends above the boom and is supported on the front struts or front portal of the shiploader.

In such a structure, the load at the offshore extremity of the boom exerts forces which would normally tend to rotate the boom about the point where the boom support ing pulleys are secured, and thus tend to raise the shuttle to which the proximal extremity of the boom is attached.

The cable system of the present invention is adapted to be so connected that it also serves to apply load compensating forces to the shuttle, the effect of which is to offset those forces acting through the pivot on the shuttle and tending to derail it.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the appended claims, the following description and annexed drawings setting forth in detail certain illustrative embodiments of the invention, such disclosed means constituting,

however, but a few of the various forms in which the principle of this invention may be employed.

The invention will be better understood by having reference to the annexed drawings which illustrate a preferred embodiment of the invention, and wherein:

FIG. 1 is a side elevation of a shiploader and showing the laterally extending boom and the boom shuttle to which it is pivotally connected, the cable pulley supporting mast and the supporting structure.

FIG. 2 is a front elevation showing the front elevation of the mast, the front portal and trucks which permit movement of the shiploader along tracks on the pier, and end views of the shuttle and the boom.

FIG. 3 is a diagram showing the cables or ropes and sheaves in side elevation for operating the boom and effecting level luffing and load compensation simultaneously, and ropes and sheaves for moving the shuttle-boom assembly laterally along the trackway carried by the traveling shiploader.

FIG. 4 is a perspective reeving diagram not to scale and showing the rope-pulley drum system for the boom hoist and for effecting level luiiing-load compensation, one side only being shown.

FIG. 5 is a perspective reeving diagram not to scale and showing the rope-pulley-drum system for moving the boom shuttle car.

Briefly stated, the present invention is an improvement in a shiploading apparatus which is characterized by a supporting frame, an upwardly extending mast carried by said frame, and an elevated trackway horizontally disposed in the frame. A boom shuttle car is provided and is movable back and forth along the trackway in response to suitable means for effecting such movement. There is also provided a laterally extending elongated boom which is pivotally secured at one extremity to the shuttle car. The boom is provided with suitable bulk material conveying means, such as a conventional endless belt and roller system. To effect movement of the boom in a vertical plane, there is provided a cable and pulley system, with respect to which the present invention is particularly directed. A separate cable-pulley-drum system is also provided to effect movement of the shuttle car back and forth along the trackway.

The novel reeving system of the present invention includes pulley means located on the boom intermediate its extremities, on the mast crown, and on the shiploader frame adjacent the outer extremity of the trackway. Movable pulley block means are also provided and are adapted to move between the mast crown pulley means and the shiploader frame pulley means. Rotatable drum means are provided to which one end of the cable is secured, such cable being reeved successively from the drum means through the mast crown pulley means, the boom pulley means and the movable pulley block means, with the remaining free end of the cable being secured at any convenient point on the shiploader frame or mast or anchored to a cable supply drum to facilitate cable replacement.

A separate cable or pair of cables, is provided having one end secured to the movable pulley block, and the remaining end secured to the shuttle car, the intermediate portion of the cable being reeved around the pulley secured to the shiploader frame adjacent the end of the trackway. Assuming the rotatable hoist drum to be stationary, the movement of the shuttle car back and forth along the trackway causes a corresponding movement of the compensating movable pulley block means. Such motion serves to take up or pay out cable from or to the cable length extending between the mast crown and the outer extremity of the boom. The result of this is that the outer extermity of the boom is maintained substantially in the same horizontal plane while the shuttle car moves along the trackway.

The location of the pulley means involved in this apparatus may be selected in such manner as to maintain the boom in precisely the same plane during traverse of the boom shuttle car along the trackway. However, other factors must be considered, including, for example, the number of cable lengths and pulleys required to sustain the load of the boom and the optimum location of the boom pulley means from the standpoint of load considerations. Provision for these engineering considerations will result in minor deviations of the outer extremity of the boom from a truly horizontal plane, these deviations being of a magnitude of approximately 4 feet or less in the course of the traverse of a trackway 45 feet long. Such deviations from the truly horizontal plane in an apparatus of the size hereinafter more particularly described are contemplated in the term substantially level.

With more particular reference now to FIG. 1, there is here shown a side elevation of a preferred form of apparatus embodying the principles of the present invention. The movable or traveling shiploader device of FIG. 1 includes, therefore, a pair of front legs mounted on suitable trucks 11 through suitable load equalizing means, such as equalizer beams 12. Rear legs, such as leg 14 (FIG. 1), are similarly disposed and maintained on wheeled trucks, such as truck 15. Trucks 11 and 15 are adapted to follow rails secured to a pier, and enabling movement of shiploading apparatus to preselected positions along the pier. Front legs 10 and rear legs 14 support horizontal beams, such as beam 16, and cross beam 1'7 in a box-like structure to provide an elevated horizontal platform or track girders to which are secured suitable rails 18. Extending upwardly from and forming an integral structure with front legs 10 are struts or column members 19 for supporting crown beam 20 which in turn provides a mounting for the mast crown pulley means 21.

At this point, it would be well to point out that cable and pulley means of the present invention are provided in duplicate for each side of the traveling boom. However, for convenience, reference will be had in the following description to the pulley and cable system on one side only, it being understood that such system is duplicated for the opposite side of the apparatus, as best shown in FIG. 2.

The upwardly extending tower columns 19 and the cross crown beam 20 defining a mast generally indicated at 22, and which in a practical installation of the apparatus of the present invention generally includes an operators cab, not shown. Extending upwardly and forwardly from rear legs 14 and intersecting mast 22 at its upper extremity there is provided a tension beam 23, one of such beams being provided for each side of the apparatus. Beam 23 provides a reaction member for the load sup ported by the cable passing over pulley means 21 at the mast crown. In a specific embodiment, the mast crown beam is approximately 85 feet above the pier level.

Disposed on the trackway 18 for movement therealong is a wheeled shuttle car generally indicated at 25 and comprising a box-like framework mounted on forward and rear flanged wheels 26 and including additional means, hereinafter described, to prevent uplift of the forward end of the shuttle. The forward extremity of shuttle car 25 is provided with a supporting bracket 27 to which boom 28 is secured by means of a pivot pin 29. Suitable driving means are provided for effecting movement of the shuttle car 25 along track 18. In the present embodiment, as best shown in FIG. 5, these means include a motor 30 operating a winch 31, and through a suitable cable system such as shown in FIG. 5 causing movement of the shuttle car in a desired direction. The rear portion of the shuttle car 25 is provided with a horizontally extending arm 32, shown in FIG. 5, and to which cable means generally indicated at 33 are secured for purposes hereinafter more particularly described.

As best shown in FIG. 2 there is provided a shiploader pulley block generally indicated at 34 supported on upwardly extending bracket 35 which in turn, is welded to cross beam 17.

Boom 28 is of conventional structure and may, for example, be provided with a telescoping chute having secured to its lower extremity trimmer means 41 also of conventional design. Endless conveyor belt 42 discharges its bulk material burden against a deflector 43 which guides the discharged material into hopper 44 for delivery through telescoping trimmer 41 and ultimately to the hold of a vessel. The precise structures of the boom 28, the material conveying means carried thereby, the telescoping chute and the trimmer form no part of the present invention.

A bulk material, such as coal may be supplied to the conveyor belt 42 carried by boom 28 also by any suitable conventional delivery means such as supply conveyor means generally indicated at 45 and only partly illustrated in FIGS. 1 and 2.

At a suitable location on the shiploader frame, such as platform extending outwardly from legs 14, there may be conveniently provided a boom hoist means 51 including a rotatable drum 52 for reeling and unreeling cable to effect elevation or lowering of the boom 28. For example, when a ship is docking or undocking, the boomchute, and trimmer assembly must be moved out of the way of the ships superstructure. Elevation of the boom 28 to the parked position partially shown in dotted lines in FIG. 1 is effected by the boom hoist mechanism 51. Mechanism 51 is of conventional design.

Referring now more particularly to FIG. 3 there is here shown a rope and sheave diagram for the apparatus shown in greater detail in FIGS. 1 and 2. Portions of the structure are shown in dotted lines to illustrate various positions and the effect upon the rope and sheave locations.

In the preferred embodiment, the cable for one side of the apparatus is a continuous cable of conventional design and construction anchored at one end to the winch on rotatable drum 52 and reeved through the sheaves of the mast crown pulley means 21, the boom pulley means 59 and the movable pulley block means 60, the remaining end of the cable being secured at any convenient point on the mast, or on a reeving supply winch for convenient replacement of the cables, for example, such reeving being pursuant to the diagram shown in FIG. 4. It will be understood that a corresponding cable-pulley-drum system will be provided for the opposite side of the apparatus.

The compensating pulley block means 60 moves in response to the shuttle car 25 on the trackway 18. This coaction is effected by means of one or more separate cables 61 secured at one extremity to the compensating pulley block means 60, and at its opposite end is anchored to laterally extending arm 32 on shuttle car 25, the intermediate portion of the cable 61 being reeved around shiploader frame pulley 34a. Shiploader pulley 34a is located adjacent the outer extremity of trackway 18 and is so related to the laterally extending arm 32 in its horizontal disposition as to be slightly lower with respect to arm 32. The effect of this is to cause cable 61 to proceed downwardly and forwardly from laterally extending arm 32 to engage sheave 34a. While other means of compensating for the forces exerted on shuttle car 25 by boom 28 through pivot 29 may be provided, the means shown in the annexed drawings and particularly FIG. 3 provide a unique, economic and very effective method for compensating for such forces. It will be observed from FIG. 3 that the force components at the point of anchor of cable 61 to arm 32 on shuttle car 25 tends to negate or nullify the forces components exerted by the boom 28 at pivot point 29. The effect of such an arrangement is to stabilize shuttle car 25 on trackway 18 and to offset the shuttle lifting tendencies of boom 28 which operates as a lever with its fulcrum at boom pulley means 59.

Compensating moving pulley block 60 traverses a path extending between crown pulley means 21 and shiploader pulley means 34a. car traverse is 45 feet horizontally. When the boom is fully extended in an offshore direction, the compensating movable pulley block 60 is disposed adjacent the shiploader pulley 34a as shown in the dotted lines in FIG. 1. The length of this path from maximum to minimum position is equivalent to the horizontal length of travel of the shuttle, which in the specific case mentioned, is 45 feet.

The movement of compensating movable pulley block 60 serves the additional function in the system herein described of providing means for storing or paying out cable in response to the position of the boom in a given horizontal plane as the shuttle car travels along trackway 18. In loading material into a vessel, difficulty is encountered because the holds of colliers vary in width and it is necessary in many cases to traverse a hatchway from one side of the vessel to the other to deliver bulk material uniformly so as to maintain the vessel in proper trim. Maintenance of a substantially level position of the boom during the traverse of the hatch from one side of the vessel to the other is a desirable objective in that loading and trimming is facilitated. During such traverse, the boom hoist 51 is stationary. Thus, movement of the outer extremity of the boom inwardly, for example, in an inshore direction, causes a shortening of the distance between crown pulley means 21 and boom pulley means 59. The excess cable must, therefore, be taken up by adjustment of the position of the compensating movable pulley block means 60 through which the cable is reeved along the pathway between the crown pulley means 21 and the shiploader pulley means 34.

The path of movement of pulley block 60 is fixed. The path of movement of the cable 62 extending from the crown pulley means 21 to the boom pulley means 59 is variable. A convenient mathematical relation for the amount of rope which must be stored in the compensating portion of the system involving compensating pulley block 60 is determined according to the following formula:

Z=Y (csc ot-csc a where Z is the length of rope, Y is the vertical distance between the horizontal plane in which boom pulley block means 59 desirably moves and the top of the mast at pulley means 21, c is the angle described by the lines 62 and the horizontal plane in which pulley block 59 moves, and a is the final angle described by the lines 62 with respect to the same horizontal plane in the new position. The number of lines 62 required to adequately support boom 28 is determined by the load factors according to conventional engineering principles. If the movement of the boom in a given horizontal plane must be at least 45 feet, the compensating amount of rope, Z, will be a function of the number of cable lines 62 extending between the crown pulley means 21 and the boom pulley means 59. In a specific embodiment, it has been found that the number of such lines is 6 (for each side of the boom). From a knowledge of the angle 0c and (1 (these being the angles at the maximum offshore and minimum offshore extensions of boom 28) it is possible to calculate how much rope Z is required to be taken up by the compensating pulley and cable extending coacting between crown pulley means 21 and shiploader frame pulley means 34. As indicated above, the maximum travel is in one instance 45 feet. In such embodiment, the length of rope Z between maximum offshore and minimum offshore extension of boom 28 calculates to be approximately 180 feet. When 6 part boom lines are used, this means that the maximum distance between crown pulley means 21 and boom pulley means 59 diminished by the minimum distance between crown pulley means 21 and boom pulley means 59 is approximately 30 feet. Ac-

In a specific embodiment, the shuttle cordingly, if feet of rope needs to be taken up in the compensating means, and only 45 feet are available to do this, 4 part compensating lines are required for this purpose and thus a Z-sheave pulley block is used in conjunction with 2-compensating crown pulley means 21 providing a total of 4 lines.

FIG. 5 shows a reeving diagram in perspective and drawn to no particular scale, for effecting movement by means of cable and pulleys of the shuttle car 25. This is a conventional reeving system and, as indicated above, any suitable means for positioning the shuttle car along trackway 18 may be used such as, for example rack and gear means. The shuttle car driving means forms no part of the present invention.

There has thus been provided an improved traveling shiploading apparatus which is characterized in that laterally extending boom will be maintained in a substantially horizontal predetermined plane without adjustment of the boom hoisting means to compensate for the change in the length of the boom lines extending from the crown of the mast to the outer end of the boom. The compensating means is also adapted to provide load compensating forces upon the shuttle car thereby stabilizing the shuttle car against normally upsetting forces exerted by the boom on such shuttle car. The cable-pulley reeving system of the present invention enables accomplishment of both these desired ends in a simple integral arrangement far more economically than heretofore possible.

Other modes of applying the principle of this invention may be employed instead of those specifically set forth above, changes being made as regards the details herein disclosed, provided the elements set forth in any of the following claims, or the equivalent of such be employed.

It is, therefore, particularly pointed out and distinctly claimed as the invention:

1. In a shiploading apparatus having a supporting frame, an upwardly extending mast carried by said frame, an elevated trackway horizontally disposed in said frame, a boom shuttle car movable back and forth along said trackway, means for moving said shuttle car along said trackway, and a laterally extending elongated boom, including bulk material conveying means, pivotally secured at one extremity of said boom to said shuttle car, the improvement which comprises in combination:

(a) boom pulley means secured to the boom intermediate its extremities;

(b) mast crown pulley means secured to the upper extremity of said mast;

(c) pulley means secured to the shiploader frame adjacent the outer extremity of said trackway;

(d) compensating movable pulley block means adapted to move along a path between said mast crown pulley means and said shiploader frame pulley means;

(2) a cable reeved through all said pulley means;

(1) rotatable drum means having one end of said cable secured therein;

(g) said cable being reeved successively from said drum means through said mast crown pulley means, the boom pulley means and the movable pulley means, and means for securing the free end of said cable; and

(h) a separate cable coacting between said movable pulley block and said shiploader. frame pulley in response to the position of said shuttle car to regulate the amount of cable extending between said mas-t crown pulley means and the boom pulley means while said drum means are stationary, to maintain the free end of the boom substantially level as the shuttle moves along said trackway.

2. A shiploading apparatus in accordance with claim 1 wherein the linear travel of said compensating movable block is equal to the linear travel of said shuttle car.

3. A shiploading apparatus in accordance with claim 1 wherein the separate cable (h) is secured at one end to said movable pulley block and is secured at the other end to said shuttle car and coacts in its intermediate portions with said shiploader frame pulley means.

4. A shiploading apparatus in accordance with claim 3 wherein the shuttle car has forward and rear extremities and said boom is secured to the forward extremity and said separate cable is secured to said rear extremity.

5. A shiploading apparatus in accordance with claim 4 & wherein the point of attachment of the separate cable to said shuttle car is elevated with respect to said shiploader frame pulley whereby said cable means proceeds downwardly and forwardly from said point of attachment such that the forces exerted on said rear extremity tend to offset those exerted by the boom on the forward extremity.

No references cited.

Claims (1)

1. IN A SHIPLOADING APPARATUS HAVING A SUPPORTING FRAME, AN UPWARDLY EXTENDING MAST CARRIED BY SAID FRAME, AN ELEVATED TRACKWAY HORIZONTALLY DISPOSED IN SAID FRAME, A BOOM SHUTTLE CAR MOVABLE BACK AND FORTH ALONG SAID TRACKWAY, MEANS FOR MOVING SAID SHUTTLE CAR ALONG SAID TRACKWAY, AND A LATERALLY EXTENDING ELONGATED BOOM, INCLUDING BULK MATERIAL CONVEYING MEANS, PIVOTALLY SECURED AT ONE EXTREMITY OF SAID BOOM TO SAID SHUTTLE CAR, THE IMPROVEMENT WHICH COMPRISES IN COMBINATION: (A) BOOM PULLEY MEANS SECURED TO THE BOOM INTERMEDIATE ITS EXTREMITIES; (B) MAST CROWN DULLEY MEANS SECURED TO THE UPPER EXTREMITY OF SAID MAST; (C) PULLEY MEANS SECURED TO THE SHIPLOADER FRAME ADJACENT THE OUTER EXTREMITY OF SAID TRACKWAY; (D) COMPENSATING MOVABLE PULLEY BLOCK MEANS ADAPTED TO MOVE ALONG A PATH BETWEEN SAID MAST CROWN PULLEY MEANS AND SAID SHIPLOADER FRAME PULLEY MEANS; (E) A CABLE REEVED THROUGH ALL SAID PULLEY MEANS; (F) ROTATABLE DRUM MEANS HAVING ONE END OF SAID CABLE SECURED THEREIN; (G) SAID CABLE BEING REEVED SUCCESSIVELY FROM SAID DRUM MEANS THROUGH SAID MAST CROWN PULLEY MEANS, THE BOOM PULLEY MEANS AND THE MOVABLE PULLEY MEANS, AND MEANS FOR SECURING THE FREE END OF SAID CABLE; AND (H) A SEPARATE CABLE COACTING BETWEEN SAID MOVABLE PULLEY BLOCK AND SAID SHIPLOADER FRAME PULLEY IN RESPONSE TO THE POSITION OF SAID SHUTTLE CAR TO REGULATE THE AMOUNT OF CABLE EXTENDING BETWEEN SAID MAST CROWN PULLEY MEANS AND THE BOOM PULLEY MEANS WHILE SAID DRUM MEANS ARE STATIONARY, TO MAINTAIN THE FREE END OF THE BOOM SUBSTANTIALLY LEVEL AS THE SHUTTLE MOVES ALONG SAID TRACKWAY.

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