US1796351A - Grab bucket - Google Patents

Description

March H7, 193i. w vooRwlNDE 1,796,351

GRAB BUCKET Filed June 2l, 1928 2 Sheets-Sheet l Patented Mar. 17, 1931 UNITED STATES PATENT OFFICE GRAB BUCKET Application led .Tune 21, 1928, Serial No. 287,225, and in Great Britain December 8, 1927.

My present invention relates to grabbuckets for handling granular material such as coal, ore, etc. and more especially to grabbuckets as used for discharging sea-vessels.

6 When discharging Ships by means of grabbuckets, the inconvenience is experienced that the width of the hatchways vis considerably less than that of the shi so that such buckets can have access to on y a relatively small portion of the cargo. Consequently, it is necessary for the ore, coal or the like, which is banked up against the sides of the ship, to be trimmed to the central portion in alignment with the hatchway in order that it can be gathered up by the grab-bucket.

The principal object of my invention is a grab-bucket adapted by a special arrangement and constructionv of its parts to be opened so wide that its scraping scoops assume'a substantially horizontal position and that, when the ropes from which the bucket is suspended run close to the coamings of the hatchway, the outer scoop extends almost to one ships side and the material banked up against this side can be gathered up without being trimmed to vertically below the hatchway.

According to the invention therefore, a grab-bucket is provided composed of two scoops or spade arm members hinged together and interconnected by bucket opening links, and provided with two separate rope systems, one for opening the bucket by spreading the links apart under the inliuence of the gravity pull of the bucket, and one for closing the bucket by drawing the scoops towards one another, the said rope systems being arranged entirely within the arms of the scoops and the distribution of the weight being such that the scoops are substantially horizontal when the bucket is freely suspended from its bucket opening rope or ropes.

In order that m invention-may be clearly understood, I sha l now proceed to describe the same with reference to the annexed drawing, which diagrammatically illustrates, by way of example only and not of limitation,

five different embodiments thereof.

scoop 7 being provided with corresponding- On the drawing:

Fig. 1 shows the first embodiment in halfway open position.

Fig. 2 shows the same embodiment in its wide open position. l

Fig. 3 shows the second embodiment in half-way open position.

Fig. 4 shows the third embodiment in halfway open position.

Fig. 5 shows the fourth embodiment in half-way open position.

. Fig. 6 shows the fth embodiment in halfway open position.

.Referring more particularly to Figs. 1 and 2, the scraping scoops 6 and 7 are connected to each other at vtheir tops by a hinge-pin 8. Pivotally connected to scoop 6 as at 9 is one end of a link 10, the other end of which forms thev case for a sheave 11 revoluble about a pin 12 having its bearings in said case and also in the forked end of a second link 13 pivoted to the scoop 7 as at 14. The bucketopening rope 15, the live end of which is secured, for instance, to a winding drum (not shown) of a trolley trav- 75 eling over an overhead trackway, passes through a hole in pin 8 downwardly to and half-way around sheave 11 and thence upwardly to a pin 45 xed to scoop 6 near the bucket head, where it is dead-ended.

Rotatably mounted within scoopv 6 and approximately midway thereof are two sheaves 16 suitably spaced apart with their axes in a line or at a small angle with each other,

sheaves 17. The bucket-closing rope system comprises two ropes 18 and 19, the live ends of which are secured to a second windingdrum on the trolley or the like. Rope 18 runs downwardly over a guidenpulley 20 rotatably mounted in scoop 6 in the bucket head, thence to and three-quarterway around one sheave 16, thence to and three-quarterway around one sheave 17 and thence to a pin 21 fixed to scoop 6, where it is deadended. Similarly, rope 19 runs downwardly over a guide pulley 22 rotatably mounted in scoop 7 in the bucket head, thence to and three-quarterway over the second sheave 17,

thence to and three-quarterway around the second sheave 16 and thence to a gin 23 fixed to scoop 7, where it is dead-ende L The modus operandi of the described grabbucket will now be understood by anyone skilled in the art. When the bucket assumes its closed position, its weight is supported by and distributed over the three ropes 15, 18 and 19. If now the bucket-closing ropes '18 and 19 are equally paid out, the drum of the bucket-closing rope 15 remaining stationary, the gravity pull in rope l5 will cause pin 45 to descend at a rate twice that of pin 12, so that the distance between said pins decreases and the angle between the bucket-opening links 10 and 13 increases until the scraping scoops 6 and 7 assume a substantially horizontal position as shown in Fig. 2, when the system is in equilibrium. It will be understood that during the paying out of ropes 18 and 19, by far the greater part of the weight of the scraper is taken up by rope 15.

It is pertinent here to remark that the downward movement of pins 45 and 12 tends to lower the centre of gravity of the whole system, whereas the simultaneous spreading out of the scoops under the iniuence of the links 10, 13 tends to raise it. The resulting movement of the centre of gravity can, as a matter of course, only be in downward direction because the gravity pull is the only force actinr upon the system, so that the distribution of3 the weight must be so that there is still a tendency for the centre of gravity to descend as long as the scoops do not assume a substantially horizontal position.

Thereafter, ropes 15, 18 and 19 are paid out simultaneously, until the scoops are in contact with or quite close to the heap of material to be raised, whereupon ropes 18 and 19 are simultaneously hauled in, with the result that the scoops are forced towards one another until the bucket is closed. The three ropes 15, 18 and 19 are then Wound up simultaneously until the bucket has reached the spot where the material is to be discharged when the ropes 18 and 19 are again paid out and the bucket is opened.

It will be understood that the bucket in its closed position can be lowered into the hatchway with its ropes running close to the coamings, so that when the bucket is opened, the outer scoop extends to quite near the ships side.

From the drawing it follows that the length of link 13 exceeds that of link 10. This construction is advisable with a view to the eccentric position of pin 45.

In the described embodiment, as well as in the embodiments to be described hereinafter, all parts of the bucket openin T and closing system are accommodated insidie the scraper-scoops. Moreover, partitions 24: and 25 fitted within said scoops prevent the material gathered up by the bucketfrom contacting with the said system and, thereby, from interfering with the proper operation thereof.

The construction shown in Fig. 3 differs from that according to Figs. 1 and 2 in that the guide pulleys 20 and 22 are not mounted on pins secured to the scoops, but on a tension equalizing lever 26 rotatably mounted on pin 8. Moreover, rope 15 passes from sheave 11 upwardly to and halfway around a rcvoluble sheave 27 mounted in the bucket head, whereupon it passes downwardly to pin l2, where is is dead-ended. W'ith a rope thus roven the force whereby the bucket is opened is increased, which permits of the bucket-opening links 10, 18 engaging the scoops in points nearer to the hinge- "pn 8. Obviously, the number of sheaves in the tackle serving for opening the bucket under the influence of the gravity pull of the bucket itself can still further be increased and the same applies to the bucketclosing system.

In the grab-bucket shown in Fig. 4, the bucket-closing system is substantially the same as the one illustrated in Fig. 1. Instead of one single bucket-opening rope, however, there are two ropes l5 and 15a and these pass over an individual sheave 11 or 11a, then upwards and around a sheave mounted on the same spindle as sheave 2O or 22, then again down and around a sheave mounted on the same spindle as sheave 11 or 11a and finally upwards to be secured to a fixed pin 45 or 45a mounted in the bucket head.

In accordance with Fig. 5, the link hingepin 12 carries two sheaves 11, 11a axially spaced apart, a transverse sheave 20a being mounted in the bucket head. The bucketopening -rope 15 runs downwardly through a hole in pin 8, thence to and halfway over sheave 11, thence upwardly to and halfway over sheave 20a, thereupon, downwardly to and halfway over sheave 11a and thence upwardly through another hole in pin 8 to the trolley or the like. As to the bucket-closing system, this is substantially in accordance yvith that described wth reference to previous gures.

Referring now to Fig. 6, the bucket-closing system is again substantially the same as the one shown in Fig. 1, but the opening link mechanism here comprises two cam sheaves 29, 30, hinged as at 31, 32 to the scoops and interconnected by a horizontal link 33` pivotally connected to both. Also in this construction there are two bucketopening ropes 15, 15a passing through holes in pin 8 and secured to the ends of cam sheaves 29, 30 away from their pivots 31, 32.

In all embodiments described hereinbefore the scoops are hinged on one common pin 8, but evidently they could as well be hinged to two pins fitted in parallel relation to a spective scoops and the outer ends inclined` downwardly and toward each other, a shaft journalled in the outer ends of the links for connecting the same together, a pulley wheel on the shaft, one of the said links being extended to form a guard for the pulley wheel, an opening cable trained through the aperture pivot pin about the pulley wheel and extended in a reverse direction and rigidly ixed at a point within the grab-bucket so that when a pull is exerted on said cable the scoops. will be moved uotwardly into a horizontal position, means for closing the scoops including pairs of pulley wheels located inside the partly closed portions of the scoops and positioned in opposite relation and below the link connections, idler pulley wheels arranged on opposite sides of the main pivot pin, and closing cables anchored within the closed portions of the scoops and each extended across and trained about one of the closing pulley wheels on the opposite scoop and again extended and trained about one of the pulley wheels on the scoop in which the cable is anchored prior to being passed upwardly and trained about one of the idler pulleys, said cables running clear of the toggle-links during the opening and closing movement so as to avoid :Erictional contact between the said parts.

In testimony whereof I affix my signature.

WILLEM VOORWINDE.

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