US1914613A - Rod grab for heapable material - Google Patents

Description

June 20, 1933. .P, NEFFENDORF GEN. GAERTNER 1,914,613

ROD GRAB FOR HEAPABLE MATERIAL '.Filed April 26, 1930 .5 Sheets-Sheet l June 20, 1933- P. NEFFENDO'RF GEN. GAERTNER 1,914,613

ROD GRAB FOR HEAPABLE MATERIAL Filed-April 26, 1930 5 Sheets-Sheet 2 Jjzzlezzl ars June 20, 1933. P. NEFFENDORF GEN. GAERTNER 1,914,513

ROD GRAB FOR HEAPABLE MATERIAL Filed. April 26, 1939 5 Sheets-Sheet 3 Jzwe ziarx June 20, 1933. P. NEFFENDORF GEN. GAERTNER 1,914,613

ROD GRAB FOR HEAPABLE MATERIAL Filed April 26, 1930 5 Sheets-Sheet Patented June 20, 1933 UNITED STATES PATENT GFFEE PAUL NEFFENDORF GEN. GAERTNER, OF VLAARDINGEII, NETHERLANDS, ASSIGNOR TO NAAMLOOZE VENNOOTSGHAP HAVENBEDRIJF VLAAR-DINGEN-OOST, OF VLAAR- DING-EN, NETHERLANDS ROD GRAB FOR HEAPABLE MATERIAL Application filed April 26, 1930, Serial No.

The following conditions have to be fuli'ilied partly or completely by a grab for heapable goods especially when heavy and lumpy material, such as heavy lump ore has to be dealt with.

Light dead weight;

(2.) Large span;

(3.) Great closing force; l

Full grabbing 1n spite of the hght rad weight t *iill grabbing also under the most unfavorable conditions; for example when t heap of heapable material has a flat surthe same time many of these conditions as ble in the most various manners. In to obtain a greater opening width of a") it has been proposed to extend the hrms of the grab beyond the points at a ch the closing ropes act. The pull of the closing ropes has, however, been la a horiaent l direction, which is unfavorable for the closing movement, so that the maximum pening width of the grab could not be turned to account. Similar grabs have further been equipped with closing rope guides, so that the puli of the closing ropes 1s upwardiy directed in the open position of the I The result of this attempt was however a grab with less closing force in the eel position, which could not be used for tance for reloading ore.

This invention relates to grabs for heapabie material of the type in which rods 447,725, and in Germany October '7, 1929.

hingedly connected to the grab head are hingediy connected to the outer edge of the grab bucket jaws, said bucket jaws being hingedly connected by side arms rigidly fixed on them, and has for its object a new construction of such grabs, designed to fulfil the conditions above mentioned in a practically perfect manner and with the simplest mean-2.

The invention consists in arranging the closing ropes to act on the side arms at points between the hinge point of the side arms and the hinge point of the grab bucket jaws and the rods at the same time guiding the closing ropes in such a manner that the pull of the closing ropes on the side arms has a large component directed upwardly when the grab is in the open position, but a large component directed horizontally when the grab is closed. By this arrangement is obtained in the Sirst instance in a manner known per se a specially great opening width of the grab, this being demanded for instance in ships re-loading service, in order that remnants of cargo can be gripped and conveyed under a deck and between decks. At the same time the advantage is attained that this new grab in any position possesses the most favorable direction of the pulling force created by the closing ropes. it has, owing to the horizontal direction of a large component of the force excited by the closing ropes when the grab is closed, a very high closing force, and the upward direction of a large component of the force excited by the closing ropes when the grab is open permits opening the same up to the complete utilization of its gripping width, i. e. up to the horizontal position of its arms. Even an opening beyond this position does not prejudice in this new grab the subsequent closing movement tobe initiated and effected by the closing ropes, as the pull exerted by the closing ropes is upwardly directed. Even the stops may be omitted, which are commonly used for limiting the opening movement of the grab and which are frequently the cause for strong prejudicial shocks and vibration of the grab and of the elements carrying the same.

This fundamental idea of the invention can be realized for instance in a very simple manner by guiding some of the sections of the closing ropes between the two points at which the closing ropes act on the side arms of the grab, over rope pulleys which hold the closing ropes raised in the middle of the grab when the grab is open. Specially favorable forms of construction of the grab are obtained, if the rope pulleys, over which the closing ropes are guided, are so arranged, that they are lowered when the grab is closing and raised when the grab is opening.

The invention further consists in employing an arrangement of a pair of toggle joint levers for initiating the opening movement of the grab, the emptying rope of the grab being fastened to the toggle point of the levers. This pair of toggle joint levers which has already been proposed for other kinds of grab constructions is specially adapted for the new grab construction; it exerts an opening action on the grab until the weight of the grab bucket jaws and of the extended side arms of the grab begins to take effect in opening the grab.

It is specially advantageousto conduct the portions of the closing ropes between the two engaging points on the side arms of the grab over the hinge point of the pair of toggle joint levers and thereby utilize the raising and lowering of this hing point. The com. mon hinge point of the toggle levers is used for carrying the rope pulley or rope pulleys which hold the closing ropes raised in the middle of the grab when the grab is open.

In all embodiments ofthe invention the closing ropes, which are slack when the grab is open, are prevented from sagging in arcshape and being soiled by the heapable material; i. e. a state of affairs which generally leads to extraordinarily great wear of ropes is avoided.

The grab head, which according to the invention may carry also the closing rope equalizer, is preferably constructed in such a manner, that when the grab is fully opened, it bears on the hinge points of the toggle joint levers supported by the emptying rope, so that it is carried directly by the emptying rope, when the grab is in opened position. This construction of the grab head can be carried out in several forms; thus for example the grab head may be provided with separate arms or stops which in the desired position bear against the axle joining the hinge points of the toggle joint levers.

In order to enable a further opening of the grab even after the grab head has been couled with the emptying rope, a sliding hinged joint is provided between the lower ends of the rod and the grab bucket jaws or between the upper ends of the rod and the grab head. The invention roughly explained above enables an almost rectilinear horizontal course of the grab edges, when opening and closing the grab, it the length of levers and the relative positions of the pivot points are correctly chosen. According to the invention the lever lengths and the relative positions of the .i'ulcrums and stationary points of the entire lever system of the grab are selected in such a manner, that this rectilinear course of the grab edges is obtained on a horizontal path, also when the grab is freely suspended.

It is wort-h mentioning, that the new grab possessses in opened condition a lesser total height than in closed condition, whereby it favorably differs from the known rod grabs, where the contrary is the case.

The invention relates to various special forms of construction of the new grab hereinafter described.

A further feature consists in the proposal to utilize the new suggestions separately, in groups or in common with ro d grabs which have more than two gripping buckets or jaws which are generally arranged in star-shape in the grab head.

Several embodiments of the invention are illustrated by way of example in the accompanying drawings in which Fig. 1 shows the grab in side elevation in closed condition.

Fig. 2 is an end view of the closed grab.

Fig. 3 shows the grab in side elevation in open condition.

Fig. 4 shows a constructional detail.

Fig. 5 is a diagram illustrating the guiding of the closing ropes of the form of construction illustrated in Figs. 1 to l.

Fig. 6 shows a modified form of construction in partly open and entirely open condition (the latter in dotted lines).

Figs. 7 and 8 show details of the construction of the protecting shield "for the closing ropes.

Fig. 9 is a diagrammatic view of the guiding of the closing ropes of the form of construction illustrated in Fig. (3.

Fig. 10 shows the manner of operation of a grab as illustrated in Fig. 3.

Figs. 11 and 12 show the manner of operation with rod grabs according to the form of construction illustrated in Fig. 6.

Figs. 13 and 14 show the fitting of the catch plates on the grab arms.

Sheet 1 shows in the Figs. 1 to 5 a form of construction based upon the conversion of a generally known rod grab of old type into an automatic grab according to the invention.

In the drawings a are the grab buckets, which carry side arms 5. The latter are hingedly connected the one with the other at c and of such length that, when the grab is closed, the hinge point 0 comes approximately to the same height as the upper hinge points (I of the grab rods 6. The latter engage at f with the grab buckets, i. e. through interposition of slot guides g. The slots of these slot guides can either be situated in the ends of the rods 6 or also in the wall or in an extension of the buckets a.

A pair of toggle joint levers h engage at 2' on the grab rods 6. The oint 7c of these toggle levers carries an axle with a number of pulleys, of which one (Z) serves for the reception of the emptyingor opening rope m, which in this manner supports the joint point of the toggle levers, when it is stretched.

The grab head a has a (Z pivot points for the rods 6. It carried further an axle with a number of pulleys for guiding the closing rope or the closing ropes. The grab head a has further two reversing pulleys p for the closing ropes, which are designated by g. The guiding of the closing ropes g is separately shown in Fig. 5, the axle 7c in the joint of the toggle levers It being shown bent in the diagrammatic'view, to simplify the illustration.

Above the grab head a a cross head 1" with joint 8 is interposed in the emptying ropes m, whereby is obtained, that the grab can be easily turned by hand when the closing ropes g are loose. 7

The equalization of the emptying rope m is effected by a lever 25 (Fig. 3) and that of the closing rope by a lever a (Fig. 5).

As can be seen from the drawings (Fig. 1), the closing ropes act when the grab is closed so that the grab is positively held shut. -VVith opened grab, in which the closing ropes are at first loose, the stretching of same effects the upward bending of the arms '6 until the engaging points of the ropes q are lying on these arms approximately at the height of the axle 7c, whereupon the further movement of the closing ropes acts towards closing of the grab buckets. The points, on which the closing ropes Q engage on the arms Z), are situated at a point between the fulcrums c and the fulcrums f and carry axles 'v with a number of pulleys, over which the closing rope is wound according to the diagram shown in Fig. 5.

TVith the rope guide shown, it is possible, to uniformly load closing rope and opening rope in the usual manner when the closed and loaded grab is being hoisted up. By loosening and releasing the closing rope or the clos- 7 ing ropes the emptying rope acts to opening of the buckets, in that the pair of toggle joint levers presses the rods 6 in outward direction. The levers 6, formed by the side arms of the grab buckets are then bent in downward direction and act from a certain position so that they complete the opening movementof the grab. In the meantime the grab head bears by means of stops to 011 the axle k in the hinge point of the toggle joint levers, so that the rods 6 are relieved of bending stresses as soon as the slot guides 9 become eitective at the fulcrums between rods and grab buckets. In completely open position the grab then hangs in the manner shown in Fig. .3, the closing rope being loose on the emptying rope m,

which at the same time supports also the grab head a through the intermediary of the stops w. (Fig.

Sheets 2 and 3 show a special form of construction of the closing rope guiding and of the closing rope protection.

Difiering from the example of the closing rope guiding shown in Fig. 5, the two closing ropes are guided in this modified form of the closing rope guiding in the manner shown in Figs. 6 and 9. The ropes q pass in the head a each along one guide pulley p, each onto a roller of the axles o of the bucket arms 6, then over the pulleys for changing direction of rope, already mentioned, of the axle I} to the other grab side, where they are wound around a second roller of the axles o and end in the closing rope equalizer is, which in the form of construction shown consists of a rope drum, suspended by means of pendulum like elements on the axle is.

This pendulum-like suspension prevents damaging of the equalizer, if the same should by any accident come into touch with the heapable material gripped by the grab. It then shifts to the side with impediment.

Fig. 7 is a side elevation of the protecting shield of the rope, partly in sections.

Fig. 8 is a top plan View of the protecting shield.

These Figs. 7 and 8 show how this shield is mounted 011 the rod grab. The protecting shield proper A, which covers a portion of the circumference of the rope rollers B, is mounted between two discs C, which are mounted on the axle V concentric to the same.

A connecting bolt D of these discs C establishes a positive connection with the closing rope 9 whereas two bolts G ensure the positive connection with the other side of the closing rope g.

The bolts D and G ensure the actually most favorable position of the protecting shield A for every single position, which the grab buckets or grab bucket arms may assume.

The bolts D and G may be fitted with rotatable sleeves or small sized rope pulleys to avoid a sliding friction against the closing rope.

As shown in Fig. 7 the whole protecting device can be easily interchanged with the aid of a cut out portion H closed by a filler I.

Sheet 6 shows in Fig. the utilization and operation possible with the new grab of the forms of construction above described and similarly also with trim grabs of known type in a ships hold.

The invention consists further in arranging and constructing grabs for heapable material of the above stated rod grab construction so that the grab buckets, preferably hingedly connected the one with the other by means of arms, can be opened so wide that the planes through the grab edges form the one to the other an over obtuse angle, that is a greater angle than 180.

By this construction of the grab an advantage is obtained in first instance, which will be best explained by means of a practical example with the aid of the accompanying drawings.

Fig. 10 shows a ships hold with two grabs, the grab edges of which are open forming an angle of 180. It will be seen that for removing the material at the side of the hold the grab must be swung laterally from below its point of suspension, so that an angular pull must be exerted on the ropes. Fig. 11 is a similar view to Fig. 10 showing two grabs, the grab edges of which open to form an angle exceeding 180. As is clearly shown by the grab on the right of this figure, it is possible to remove the material from the side of the hold with the grab suspended substantially vertically below its point of suspension. Thus a straight pull is exerted on the ropes.

In the hitherto applied working manner the grab for trimming work is lowered in closed state by a jib crane, a trolley crane or the like, through the deck hatchway into the hold, and then opened. The open grab is then lowered approximately to the height of the upper edge of the lateral heap of heapable material approximately into the position shown at the right in Fig. 10. The grab is then moved horizontally by means of the trolley or jib which carries the same, until its ropes strike against the hatchway edge, where they are bent and let the grab oscillate towards the ships wall under the deck. At the moment, when the grab arrives in the position shown on the left side of Fig. 1, the jgrab ropes are slackened, whereupon the grab comes to rest on the heaped material, which is then gripped by the same and can be conveyed.

At this operation the danger exists first, that the grab, when oscillating in the posi tion Fig. 1 at the left, damages the ships wall, and further the danger, that the other grab edge, which has a comparatively long dropping way, demolishes the floor covering owing to its being loaded by a great portion of the grab weight. These dangers are double great, as the crane conductor cannot see himself the position and the situation of the grab, but is dependent on signs and shouts of an assistant, when he attends the crane for lowering, opening, swinging and relowering the grab.

If, according to the invention, the grab arms or the planes imagined through the grab edges form the one to the other, as shown in Fig. 11, a greater angle than 180, the grab can first be opened or during the opening be lowered until it is close above the floor of the hold (Fig. 11 on the right hand). Striking of the grab against the hold floor is not prejudicial either for the floor nor for'the crane nor for the grab, as the latter strikes with the downwardly bent hinge point of the bucket arms against the floor, whereby the shock is elastically intercepted.

When the grab is being moved from this position (Fig. 2 at the right) to the left, neither the bucket edge, which is in front in the direction of movement can oscillate against the ships wall, nor can the other bucket edge drop onto the floor covering from a greater height, as the hcapable material intercepts the grab. The shape of the lower surface of the grab even adapts itself to the surface shape which finally exists in the heapable material, so that the contact surface is very large.

By the greater length of the ropes the oscillating movement of the grab becomes also more favorable than formerly. Only a quite short lowering movement is further necessary, to lower the grab onto the heap of material.

The measures of the invention take effect in general in multiple respect, i.e.:

(1.) as maximum saving of the hold floor,

(2.) as maximum saving of the side wall of the hold or of the ship,

(3.) as saving of the grab, of the rope fittings and of the crane installation,

(4.) as more favorable and more reliable working of the grab and (5.) as simpler attending of the grab at the trimming.

This form of construction of the new grab also presents the possibility, to carry out in an ore-ship with the new grab trimming and unloading work also at the side of the propeller tunnel, which cannot be done with a tongsor rod-grab of the hitherto known construction. This effect is due to the peculiar movement of the grab edges, which prior to the closing movement proper move first away from each other a certain distance and therefore can clear these specially unfavorable spots of the hold, provided the crane is cleverly conducted.

The above stated advantages of the new grab construction are obtained also in the other applications of the grab and at other working methods either all at the same time or some of them.

According to the invention the grab buckets may be fitted on the grab edge planes with wheels or rollers N (Fig. 11), so that each bucket forms so to say a vehicle which, can be moved on the hold floor. According to the invention buffers, preferably in the form of resilient rollers M are preferably arranged at the hinge points of the grab arms, said buffers adapted to take up the first shock, when the open grab comes to rest on the floor.

lVhen closing the grab, these rollers N may serve for the guiding of the two grab buckets a, as their edges are brought into register and press tightly the one against the other.

Fig. 13 illustrates diagrammatically the arrangement of supportingand catchingfaces on the grab arms, and opened grab viewed from below and viewed from the side shown in Fig. 14.

The plates P strengthen the frame formed by the side arms Z2 and the grab buckets a and limit at the same time the width of the opening at disposal for filling the grab buckets, which is indicated in Fig. 14 by small arrow lines. The plates P may be interchangeable or adjustable, so that with the aid of the same the width of the filling openings or scooping openings of the grab buckets may be altered, for instance in order to prevent excessive loading of the grab and of the crane carrying the same, when changing from a heapable material with a light specific to a material with a heavy specific gravity.

I claim:

1. A grab for heapable material, comprising in combination a grab head, closing rods hingedly connected at one end to said head, grab buckets hingedly connected to the other end of said rods, pivotally connected arms carrying and rigidly connected to said buckets, pulleys on each of said arms at an equal distance from their pivot point, closing ropes extending around and connecting said bucket arm pulleys, and lifting pulleys for said ropes suspended below said head adapted to hold up said ropes between said bucket arm pulleys and to exert an upward pull on both of said bucket arm pulleys to lift said arms at the commencement of the closing movement of the grab.

2. A grab as specified in claim 1, comprising in combination with the closing rods and the lifting pulleys, of toggle levers, each connected at one end to said rods, and of a common pivot axle connecting said levers and carrying said lifting pulleys.

3. A grab as specified in claim 1, comprising in combination with the head, the dos ing rods and the guide pulleys, or" toggle levers each connected at one end to said rods of a common pivot axle connecting said levers and carrying said guide pulleys, and of an abutment on the under side of said head adapted to limit the upward movement of said toggle levers and the opening movement of the grab.

4. A grab as specified in claim 1, comprising in combination with the closing rods, and the buckets, pin and slot connections between said rods and said buckets adapted to allow a displacement of said buckets relative to said rods during the opening and closing of the grab.

5. A rod grab as specified in claim 1, in which the hingedly connected bucket arms are each rotatable in upward direction around their pivot point through an angle exceeding so that, when the grab is in open position, the downwardly directed edges of the grab buckets form an angle greater than 180.

A rod grab for heapable material, comprlsmg in combination with a grab head, grab buckets, hinged arms connecting said buckets the one with the other, rods connecting said buckets with said grab head, a toggle joint lever system for spreading said rods, an axle in said system, closing ropes for the grab, pulleys in said grab head for changing direction of said closing ropes, and an equalizer for said closing ropes arranged pendulum-like underneath said axle of said toggle joint lever system.

In testimony whereof I aflix my signature.

PAUL NEFFENDORF GEN. GAERTNER.

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