US2795061A - Grab buckets - Google Patents

Description

June 11', 1957 J, BRETON 2,795,061

' GRAB BUGKETS Filed Nov. 20. 1950 5 She'ets-Sheet 1 une BRETON Y 2,795,061

GRAB BUcKErs Filed Nov. 2o. 195o 5 sheets-sheet 2 Hfs/1 TMR/vins J. BRETON GRAB BUCKETS Jne 11, 1957 5 SheebVs--Sheet 3 Filed Nov. 2o. 195o J. BRETON GRAB BUCKETS June 11, 1957 Filed Nov. 2o. 195o s shets-sneet 4 June'11, 1957 Filed Nov. 20. 1950 J. BRETON GRAB BUCKETS 5 Sheets-Sheet 5 2,793,661 enna BUCK-nrs .lean Breton, Pavillons-sous'-Bb's, Francev Application November 20, 195), Serial No. 196,690 claims pnonty,.appncatisn rraa'tssvember 21, 1949l 1 Claim. (Cl. 37--lt4y In grab buckets of known types, also called hoisting buckets, such yas used in lifting, excavating, and like apparatus, the opening operation of ysaid buckets is commonly controlled by the weight of a heavy part; drum, tackle beam, and the like, on which is wound the control cable operated from the cabin by the operator. The result' is that in order to ensure a complete opening of both scoops or jaws of the bucket, the weight of said part must be substantial.y `During the closing movement of the bucket, when picking-up thel load of material,` an importantv portion of the power is thus used for lifting the drum orv other heavy member which constitutes a dead Weight; Y

The main object of the present invention is the provision of a bucket which does away With this disadvantage.

One object of the invention is t`o provide meansV for picking-up a more substantial load than by means of usual buckets. In fact, withy equ'al total Weights, the bucket according tothe invention has a'greater capacity and' therefore a greater loading volume.

Another object of the invention is to provide very heavy, and'thus very resisting scoops, most ofthe Weight being reserved for said scoops without the overall weight of the bucket being greater than that of usual buckets.

Still another object of the presentrinvention is to make unloading possible from a reduced height. In fact', in normal buckets, the opening operation causes a Vdownward movement of the assembly and it is difficult for'the operator to appreciate the suitable height at which he must stop the bucket above the unloading spot, priorto opening. The device embodying the invention `enables "the bucket to be opened while causing only a small vertical' downward shift of said bucket and even, in some cases, an upward movement thereof.

VA further object of the invention is 'to provide a bucket which is of a reduced height when opened, which enables the bucket to assume a tilted position in places which would not be accessible for other types of buckets, such as in ship holds and coal bunkers. The unit mayconse'- qnently be opened at a reduced height, thus avoiding the material being dropped from a great height and losing part of the value of crumbly products such as, for instance, coal, in which case the formation of dust is thus avoided. This advantage also provides a better distribution of the load When being discharged.

Still a further object of the invention is to provide an easy `opening of the bucket, even when transporting tacky materials, such, for instance, as wet bauxite which, when stored in buckets of the known type, has a tendency to cause a mutual adherence of the jaw lips, o'r to remain partly in the bucket when the latter is opened to `an insutlicient extent.

Likewise, another object of the inventionis to provide a larger opening breadth of the bucket, which facilitates the gathering up of dispersed materials and avoids the finishing up of the unloading of trucks or ships, or cleaning up of wharves with the help of men handling shovels.

A further object of the invention is to provide a bucket 2,795,061 Patented June l1, 1957 of a reduced height when closed, whichrmakes it possible, for av given crane device, to' stock on a larger height, or to use a device of lesser height when the filled bucket has to be swung over' an obstacle.

Another object of the invention is to provide a bucket the scoop of which can be completely filled and closed, whatever the position of the bucket as it is brought down y open on the loading'place.

Still another objectpof the invention is tofprovide a bucket in which the length of cable which is necessary for the opening fand closing operation is relatively small,

Ywhich for a givenlifting apparatus, increases theV operating output rate.

A further object is to provide a bucket having a rugged main hinge, which is never in contact with thev handled product.

The grab bucket according to the invention fundamentally comprises a` pair oflscoops hinged to a light head with, on the one hand, a devicefast with said heady which transforms the vertical pull of a closing and supporting cable of lthe bucketv into two lateral converging forces pulling together the two scoops, and, on the yother hand, a device transmitting to said scoops, outside their hinging Hpoints on the said light head and in the opening direction, the pull of a bucket opening and supporting cable,.

the irst above mentioned device' exerting no opposition to the opening of thescoops under the pull of the closing and supporting cable, while the second above mentioned device exerts no opposition to the closing of theI scoops under the pull of the opening and supporting cable, the

application points of'both devices acting Von the scoops, the lengths of their various lever arms, `and `thevaluesof the forces applied to the scoops being computed and/or determined by experience, due account being taken of the frictions yand reactions` of thev material to be seized, so that the above precisedl effects be obtained and that the head be preferably as light as conditions will permit.

In the presentspecication, the word cable must be understood as .also meaning `any llexible element having resistance and flexibility properties of the kind of those of a oable,such as a chain.

The bucket according to the invention thus comprises a light gear or head, carrying the hingingmcans of both scoops, and `a mechanism'transforming'the Vertical pulling force of a so-called supporting and closing cable intotwo conv-erging pulling forces, acting on both scoops to draw them together, the said scoops being, on the other hand, connected to a lsot-called supporting and opening cable directly or indirectly acting uponfthe said scoops to move themA apart and to raise them.

'Ihe pulling force may be advantageously transmitted through force multiplying devices, adapted to reduce the veffective weight of the movable gear orl head, particularly lwhen handling uneasily prehensible or very heavy materials, `and also to make easier the opening of the scoops when loading tacky materials. However, in loading light and easily prehensible materials, such as corn, such multiplication of the forces acting on the scoops is less useful, or evenv unnecessary.

The invention will now beV described in detail with referenceto the drawings illustrating various constructional embodiments of the invention. In said drawings:

Fig. l is a diagrammatic front elevational view of a 'lirst embodiment of the invention, the bucketibeing shown in the open position;

Fig. V2 is a front elevational view at an enlarged scale of the mechanism actuating the bucket, in the open position; i

Fig. 2a is a diagrammatic view representing the arrangement of the cable for'opening the bucket;

Fig. 3 is an end elevational View of the same embodi- 3, ment in the open position with parts broken away and other parts in section;

Fig. 4 is a diagrammatic front elevational view of the same bucket in the closed position;

Fig. 5 is a view similar to that of Fig. 2, the bucket being in the closed position;

Fig.` 5a is a diagrammatic showing, in perspective, of the arrangement of the cables for closing the bucket;

Fig. 6 is a view similar to that of Fig. 1 of another embodiment of the invention;

Fig. 7 is a view similar to that of Fig. 4, of said embodiment with the bucket in the closed position;

Figs. 8, 9 and l0 are diagrammatic elevational front views of three further embodiments of lthe invention, the bucketbeing shown in the open position.

In the embodiment shown in Figs. 1 to 4, the two scoops 1 and 1a of the bucket are hinged, by means of arms 2 and 2a on a shaft 3, fast with a movable head 4, the said head carrying the members serving for opening as for closing scoops 1 and 1a, as described below.

A scoop-opening bucket-supporting cable 8, is wound onthe control winch (not shown) and is fixed, at its other end, at 9, to head 4, after passing around a reversing pulley 8a and under a tackle pulley 10, carried on a bar 5 (Figyia).

Said bar 5 is supported on a shaft 11 about which it may oscillate and which also carries the tackle pulley 10. A reversingpulleylla ensures a correct position of said cable 8. Tie- bars 7 and 7a are hinged,respectively at one end 6 and 6a to the bar 5 and at the other end 6b and 6c to scoops 1 and 1a.

In order to open the bucket, said bucket being assumed to be closed, the driver couples the winch of cable 8, while slackening a cable 13. This cable 13,being the scoop-closing and bucket-supporting cable, is tixed at one end in the groove of a pulley 14 on which it is` wound. Pulley 14 is freely rotatable on a sleeve 15 and is fast with a drum 16 of appreciably smaller diameter on which is iixed one end of a cable 17 passing over a pulley 18 rotatable on a shaft 19 carried by a frame 20. After passing over reversing pulley 18, cable 17 is wound round a pulley 21 oflarger diameter in the groove of which the end of said cable 17 is fixed (Fig. 5a).

On sleeve are also keyed two pulleys 22 and 22a. The pulleys 14, 16, 21, 22 and 22a rotate about a shaft 15a carried by frame 20. In the groove of pulley 22 a cable 13C is fixed and wound; in the groove of pulley 22a a cable 13d is tixed and wound. Both cables 13C and 13d respectively pass under reversing pulleys 2S and 25a Y pivoted on a housing 26, fast with frame 20. Cables 13a and 13d are respectively connected to jaws 1 and 1a at points 24 and 24a. The whole assembly forms a diiierental, force multiplying winch, commonly called chinese winch.

The bucket operates as follows:

The bucket being assumed to be suspended by means of cable 8, while cable 13 is slackened, said bucket is brought downwards, preferably at great speed, by the bucket operator, onto the heap of material to be loaded.

The lower part of scoops 1, 1a penetrate to a certain depth into said material. The operator then `slackens cable 8 and couples the winch, of cable 13; the pull of said cable 13 rotates pulley 14 which drives pulley 16 and the latter winds up cable 17, thus rotating pulley 21; pulley 21 rotates pulley 22 and winds up cable 13e, which after passing under reversing pulley 25 exerts a pull on scoop 1. Similarly pulley 22a driven by pulley 21, rotales together with sleeve 15; cable 13d, after passing under reversing pulley 25a exerts a pull on scoop 1a. Thus, cables `13C and 13a' produce convergent forces which draw scoops 1, 1a together. The bottom parts 28, 28a of the scoops thus penetrate into the material to be handled, and movement of the scoops toward each other will cause material to enter thereinto, thus increasing the loading of the scoops and causing them to penetrate more deeply into the material as the scoops progressively close.

During this displacement head 14 is moved downwards and then remains fixed during the loading phase, its weight being designed for such purpose, account being taken of the reduction of the pulling force of cable 13 undel the action of the gearing-down device. Frame 20 and the members which it carries may be made lighter by forming them at least partly from a light alloy.

During the closing operation of the bucket, bar 5 is driven downwards due to the downward displacement of the jaws relatively to head .4, this movement occuriing without resistance, due to cable 8 being maintained in slackened condition.

When the scoops are drawn together to a maximum extent the driver maintains the winch of cable 13 coupled andsaid cable 13 becomes the supporting and lifting cable of the bucket, While cable 8 remains slackened. The bucket is thus lifted up to the desired height and f Vthen transported, in closed condition, above the unloading spot.

The unloading is accomplished by coupling the winch of the opening cable 8 and by slackening cable 13. The upwardly exerted pull on bar 5 drives said bar 5 upwards with respect to head 4, said movement being aided by the tackling of cable 8. While nearing the hinge axis of the scoops the bar 5 lifts said scoops by means of the tie rods 7, 7a and restores the whole bucket assembly to the condition shown in Fig. 1. The opening of the scoops, thus obtained, causes the material they Ycontained to be dropped down and the bucket is ready for a further loading operation.

In the embodiment shown in Figs. 6 and 7, scoops 1 and 1a are also hinged at 3 on a head 4. The bucket closing and supporting cable `8 is bifurcated into two cables 8a and 8b which are fixed at 33, 33a to arms 31, 31a, pivoted at 32 on head 4.

The bucket opening and supporting cable 13 is bifurcated into two cables 13a, 13b passing under pulleys 29, 29a rotatably mounted on head 4 and fixed at 30 and 30a respectively, to scoops 1 and la. Cables 13e and 13d connect said scoops to points 34, 34a of levers This bucket operates as follows:

The bucket being assumed to be open (Fig. 6) it is suspended by means of the opening and supporting cable 8, arms 31, 31a and their hinges 32, to head 4. Due to the weight of the bucket, the said arms assume the position shown in Fig. 6. Their pull on cables` 8c, 8d causes scoops 1, 1a to swing upwards, due to lever arms 33--32 and 33a--32 being longer than lever arms 31--32 and 31a- 32, suitably dimensioned. The lifting of the scoops by means of these pulls is made possible due to the fact that cable 13 was previously slackened. The bucket then `is rapidly lowered onto the heap of material to be handled,

by the operator who maintains cable 13 slackened until the scoops 1, 1a are brought into seizing position.

The operator, while maintaining cable 8 slackened, then couples the winch of closing cable 13. Due to the pull of cables 13,13a and 13b, scoops 1, 1a are swung about their hinge` 3, coming nearing to each other while at the Sametime penetrating into the mass to be handled.

During this movement, cables 8c, 8d being slackened, arms 31,` 31a flap down, and are finally brought to the position shown at Fig. 7, the operator having, for such purpose, suticiently slackened cable 8.

The bucket is then raised due to the pull being maintained on cable 13, up to the unloading position, whereafter the operator couples the winch of cable Sand slackens cable 13. Arms 31, 31a swing upwards and bring the parts of the bucket to the position shown at Fig. 6. The material is dropped and the bucket is ready Yfor a further loading operation. u In the modication shown in Fig. 8, the bucket, still more diagramniatically shown in a half-open position, is

generally conformed as in Figs. 1 and 3, except that bar 5 is arranged above head 4. The operation of this bucket is the same as in the embodiment shown in said Figs. 1 to 3. The bucket again comprises scoops 1, 1a, bar 5, tie- rods 7 and 7a, head 4 and closing cables 13, 13a and 13b together with their reversing pulleys 25, 25a. The operation is fundamentally the same as in Figs. 1 and 3, except that there is no pulling force multiplier in the path of cables 8 and 13. Such multipliers might be applied to this embodiment, by a suitable adaptation of the arrangements shown in Figs. l and 3.

In the modification shown in Fig. 9 there is to be found again the same fundamental structure as in Figs. l and 3. However, instead of a so-called chinese winc the pull multiplying mechanism comprises a drum 14a rotatable in head 4 and fast with a second drum 36 of smaller diameter, on which are fixed and wound both pulling cables 13, 13b acting on scoops 1, 1a, to draw them together, the cable 3 passing around pulley 3S.

According to a further modification shown in Fig. 10, cable 13 is fixed to and wound on a drum 14a rotatable at 35a in head 4. A pulley 36 is fast with said drum, land on said pulley is fixed and wound a cable 13b passing first on a tackle pulley 37 carried by tie-rod 7, then on a reversing pulley 38, carried on head 4, and finally being fixed at 37a on tie-rod 7a. The pulling effect applied to cable 13 is thus transmitted to scoops 1 and 1a which draws them together, the force being multiplied due to the tackling of the said cable.

The operation of such a bucket is similar to that of the embodiment shown in Fig. 1.

In embodiments comprising a bar 5, be it inside or outside of the bucket proper, the said bar may have a guiding device on head 4. This guiding comprises, for instance, a slide 38 (Fig. 3) fast with the bar and sliding along a guide bar 39 fixed on said head 4 or on frame 20 (Figs. 1 and 3). The bar may, besides, be duplicated, each half bar bordering frame 20 which could then comprise Ia second slide cooperating with a further guide carried on the other side of the frame.

What I claim is:

A clam shell bucket comprising a head, a pair of scoops having similar open ends capable of coinciding when said scoops are together and the opposite ends of said scoops being closed, a pair of arms pivotally connected at one end to said head and each arm having the opposite closed end of one of said scoops connected to the other end of said arm with said arms divergng from one another from their pivotal connection to said head, said scoops being positioned on said arms extending towards one another, an elongated supporting and guiding member fixedly connected at one end portion to and extending from said head between said arms, a cross bar extending laterally of said guiding member between said arms and slidably connected at a medial portion to said guiding member for longitudinal movement along said member, a pair of ties with each tie pivotally connected at one end to an end portion of said bar opposite to the other tie and pivotally joined at its opposite end directly to the interior of one of said scoops adjacent the open end of the scoop, a pulley rotatably mounted on said cross bar medial portion, a cable having one end connected to said head and passing around said pulley for at times moving said pulley and said cross bar towards said head with said ties pivoting said arms moving said Scoops from one another, a plurality of pulleys rotatably mounted on the opposite end portion of said guiding member and a cable connected to said scoops and passing around said pulleys for at times pulling said scoops to one another moving said cross bars from said head.

References Cited in the file of this patent UNITED STATES PATENTS 734,433 Saunders July 21, 1903 859,240 McMyler July 9, 1907 861,669 McMyler July 30, 1907 897,246 Andresen Aug. 25, 1908 936,727 Kiesler Oct. 12, 1909 1,171,393 Morris Feb. 8, 1916 1,439,549 Haun Dec. 19, 1922 1,708,597 Stub Apr. 9, 1929 2,090,817 Sollis Aug. 24, 1937

Images