USRE11476E - Dredqing-machine - Google Patents

Description

.R Sm m A M G Bm B WR D Reissued Mar. 5, 1895.

' {er-red. The turn table is connected to the, winding machinery by a chain'2. All these:

UNITED STATES PAT NT OFFICE.

WILLIAM B. mass, or

SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO THE DREDGING-MAC'HINE.

SPECIFICATION forming part o Reissued Letters Patent No. 11,476, dated March 5, 1895'. "th'iginll lio- 502.934, amt August a, was. L-ppliustionfor reissue filed September, 1894. Burial No.528,048;

- To all whom it may conccrru.

Be it known that I, WILLIAM B'. Pnnss, a citizen of the United States, residing at San Francisco, in the county of San Francisco and State of California, have invented certain new and useful Improvements in Dredging-Mas.

chines; and I do hereby declarethat the following is a full, clear, and exact description thereof. 4 v

This invention relates to dredging machines, and more especially to that class of dredgers in which a bucket composed of two sections hinged together, is suspended from a. swinging boomor derrick, and connected to suitable hoisting mechanism carried by a floating ing hull o. scow.

In Letten Patent No. 426,681, granted to me. 'April 29, 890, I described and showed a dredging appa. atus of the type above referred to; and my present invention consists in certain improvements upon the construction of the bucket shown in that patent and upon the -means. for'hoisting, lowering, opening, and closing the hinged sections or jaws of thebucket. The mechanism for supporting the boom and for swinging it to "discharge the bucket is preferably like that shown in the said patent, but forms no essential part of the present invention which will be-fully understood by reference to the following detailed description, and to the accompanying drawings, in which- Figure 1, is a side elevation of the whole dredging apparatus. Fig. 2, is an elevation of the bucket ,with the jaws opened. Fig. 3, is a-detail view of the end of the boom showing the cap and sheaves for the passage of the hoisting chains. 4

A represents the hull of the dredger hav ing a deck house to contain the boilers, en-

gine and winding machinery. B is a hollow rotary'mast, stepped in the hull,,and' having secured near its lower end the foot of the-projecting boom C. D isa turn-table secured to the mast, and connected to the boom by jaws 1, as in my former patent, or bychai'ns if pre-.

parts aresubstantially as shown in' my former patent,-and are of the construction I prefer to use, but form no part of my present invention. They are shown in the drawings however, in order to give'a general idea of the rela-' I tivepositions and operations of the boom mast and winding mechanism.

The dredge bucket is llustrated detail .in Fig. 2. It consists oi .two sections E and F, preferably of heavy boiler iron, each, in

side elevation being approximatelyin the shape of a quadrant of a circle. To each end of each section is firmly bolted a heavy arm G, each pair of's n'ch arms being ivoted together by a transverse pin 3.

In my patent-before referred t'o,I described and showed means for suspending and operatm the hinged sectional bucket upon which tween the boom and bucket. In like manner,

the bucket sections were suspended f rem a second sheave block by a chain, one end of which was connected to each section. Each sheave block was then suspended by anindependent chain fixed to the extreme end of the boom,

then passing, first, around its appropriate block, then back to a pulley on the boom, and

thence to themast and winding-ge'ar. These devices haveprovedto be'unnecessarily com; plicated; and though I obtained such a p'ur-" Q chase as to giveapower much in excess of that required, the hoisting movements were extremely slow and the working capacity of the machine was not more than fifty per cent. of that of a dredge construct ed according to present'invention. There are'other dissheave-block system of suspension vhich I withthe detailed description of my present improvements.

Referring to chains H are secured to the corners of the bucket sections and extend toa simple ring I upon which they can move freely. From this ringa single chain J passes overs. sheave at the extremity of the boom and thence to the mast and winding mechanism The chat. us K by which the closing and hoisting of the tucket sections are controlled, are secured to links Leach composed of two bars 4, 4, or

Fig 2 it will beseen that tour transverse pins of the links and hence thereis no side-strain'as there would be ii-they were.

attachcdto the arms, G, atthe side,.as would be necessary. In the second place, as shown by Fig. 2,'if the-chains were attachcddirectly .to the endsof the levers they would interfere with the action ofthe arms-and bucket by chafing'and friction.- chains' work entirely free, without obstruction. When so foldedon the arm the apparatus is compact and theshort cross chains K are held ree from entanglement, by reason of their connectionwith the. ring. .As the buckets close, the links unfold and extend the connections between the arms andring and this improves the leverage in v the closing of the bucket. It will be seen that by theseimproveinents ail sheavcjblocks and tackieoi that character are entirely done away with, and that the'pull from the hoisting machincry to the bucket is direct. Furthcrmoreihe hoisting chains are self-'adiusting in ihssupg, so that if by chance one side of.

porting ring, the bucket should not enter the s' iL'thcchain on one side'will slackcn aud thusrelieve the strain which would probably ensue if adevice which creates such friction as a sheave block were used torsupportingthe chains. Asin this case both chains pass over the boom at its extremity, and at that point only, I amable to use the construction shown in Fig. 3, which would be impractical with the device shown'in my former patent. In thatpatent Ishowed both hoisting chains passing through a hole and over sheave in the wooden boom. My present improvement consists in a hollow cap and sleeve mounted upon the extreme end'of the boonnwhich is formed into a bearing for it. This cap, which is a single steel casting, contains the sheaves over which the hoisting ropes pass; and being loose on the,end ol the boom, although held in place bythe weight of the bucket, will remain in placeand keep the sheaves in line in case the-boom itself should become twisted from any cause. The cast cap moreover prevents all the wear to whichthc wooden boom is subjected by the old construction.

In operating the bucket and supposing the parts to be in the position shown in Figs. 1 and 2, I assume that it has been dropped upon the bottom ready to take its load, and that the sections are open. The first pull is upon the chain M, which causes the sections to close 'lines in Fig. 2.

It might be possibleto connect the By using the links, the

having sheaves .for hoisting and take the load. The strain is continued upon tbischain M, which now becomesa hoisting chain, the bucket being closed and the parts being in the position shown by dotted When the bucket has been hoisted above the surface of the water, or in any case, to the boom is swung around, carrying the bucket to a position just above the point where it is proper point of elevation, the

desired to discharge the contents. At thattime the operator in control of the w nding machinery relaxes the chain M, and winds up the chain I through the chains II, opens'the bucket and dumps the load. The boom is then swung back to the point where the dredging is being done, and theopenlbucket is once more in position to be lowered upon the bottom to receive another load. I

What I claim is- J; and this latter strain operating 1. In combination with the ballot a d redger and with winding m'achincry,a swinging boom having guide sheaves at or near its extrcmit-y, a bucket com posed of two sections pivoted together, outwardly extendingaugular' levelr arms secured to said bucket sections, a hoisting'chain' connected to a ring and thence by connections to the extensions of the lever arms, and a dumping chain connected to a 1 ring and thence by chains to the bucket sections, said hoisting and dumping chains passing over the sheavesat the boom end and thence to-the winding machinery, substantially as described.

I 2. In combinatio'n-wi th the boom of a dredge I I and dumping chains, a'dredgc' bucket composed of two-sections each having an arm 6' with outwardly bent extensions G, lin ksL pivoted tothe outer too ends of these extensions, andconnected at their upper ends by a ring to a chain M, a chain J connected by chainsI-I to the corners of the bucket sections, the chains J and M'bcing arranged on the boom sheaves, ailsubstantially as described. I

3. In combination with the bucket sections, an arm G, fixed to each side of each section, and having an outwardly bent extension, a link composed of two bars pivoted on-theouter end of each extension and connected at'its upper end by a chain to a ring, and'a chain M, connected to said ring,all substantially as described.

4. In adredging machine, a cwingingboom,

in combination with a loose slccveand cap at its extremity, a suspended bucket,- and hoist- 'ing chains from said bucket passing over sheaves jonrnaled in said cap, substantially as set forth.

In testimony whereof I afiix my signature, in presence of two witnesses, this 22d day of Jun 'e,'1894. r I

' I WILLIAM i3. PLESS.

-Witnesses:

M. 11.3mm, L. W. Saar.

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