US2067000A - Dragline dredge - Google Patents

Description

5, 1937. QSBOIRNE" 2,067,000

DRAGLI NE DREDGE Filed Aug. 22, 1955 3 Sheets-Sheet l EDMUND U saw/v5 Jan.- 5, ,1937.

E. OS BORNE DRAGLINE DREDGE Filed Aug. 22, 1935 s Sheets-Sheet 2 fffff'fff" EDMUND 055 Jan. 5, 1937.

E. OSBORNE 'DRAGLINE DREDGE Filed Aug. 22, 1935 3 Sheets-Sheet 3 Patented Jan. 5, 1937 a to PATENT OFFICE DRAGLINE DEED GE Edmund Osborne, Mission, British Columbia, Canada Application August 22, 1935, Serial No. 37,388 In Canada November 5, 1934 4 Claims.

This invention relates to improvements in dragline dredges and dredging equipment, particularly adapted for gold dredging operations upon bars and gold bearing gravels of rivers, creeks 5 and stream beds.

' For a proper understanding of the nature and scope of my invention, it is deemed advisable to set out in as brief a manner as possible some of the inherent difficulties met with in subaquatic gold recovery operations, especially those conducted in swift running waters and handling or working fine gold bearing gravels.

The principal reason for the large number of failures in dredging operations is not because the 15 ground is not rich enough to make a profit, but

because the operations permit the largest percentage of values to escape through disturbance of the gravel bodies before they are entrapped or bucketed.

This fact is not generally recognized except by practical gold dredging operators and accounts for the failure of many promising dredging prop- 'ositions, as the problem calls for entirely different methods and equipment from those used in ordinary dredging operations.

It is an indisputable fact that when initial operations are started to scoop up gravels carrying fine gold Values off a bar or river-bed in swift running waters the recovered gravels will not assay up to the average values per yard of the previous assays shown by tests before the commencement of dredging operations, and this fact is accounted for by the reason that when an ordinary dredging or scoop bucket is let down upon the gravels and dragged over them (generally against the current) for'the purpose of filling the bucket, it sets up a disturbance in the gravels ahead of the bucket and the fine gold and black sand being of greater specific gravity 40 and finer molecular structure than the conglomerate, in which it is found, settles to the bottom of the disturbed gravels and escapes under the lip of the bucket and is carried further down stream by the current before the bucket can entrap and hold these values.

It is one of, the objects of my invention to minimize this condition, both by the manner of operation and by the structure of bucket used.

50 It is a further object of my invention to provide a dredge having an improved form of tipple that automatically aids in dumping the bucket.

It is a still further object of my invention to provide a dredge having an improved type of line carriage for hoisting the bucket and carrying the bucket inwards in the dredge superstructure during dumping operations.

It is still another object of my invention to provide a dredge having an improved haul-back to minimize the disturbance of the gravels ahead 5 of actual digging operations.

These and other objects, coupled with an improved method of dredging operations that permits of actual digging operations being carried on in practically still waters, while operating in 10 swift running creeks, rivers and streams, comprise the essential characteristics of my invention which is more fully described in the following specification and illustrated in the accompanying drawings forming part of this application, and in which:

Figure 1 is a perspective side elevation of the dredge showing the principal features of construction and assembly. This View shows the dredging bucket in the dumping position on the balanced tipple and wheeled carriage at the head of the inclined runway.

Figure 2 is a front end perspective view of the dredge and shows the dredging bucket being hoisted for dumping. The wheeled carriage is '5 shown at the lower end of the runway.

Figure 3 is a plan view of the deck of a pontoon hull showing the tapering well built into the front half of the hull and the main bed stringers projecting over the front or bow of thehull carrying the bottom roller.

Figure 4 is a diagrammatic illustration of the dredge and its manner of operation. This view shows the dredging bucket being hauled back under the front portion of the hull into position for lowering and digging.

Figure 5 is another diagrammatic illustration of the dredge showing the dredging bucket being lowered for digging by the haul-back line. This view and Figure 4 illustrate the manner of oper- 40 ation of digging a hole into the gravel beds and preserving a straight back wall which prevents the escape of fine gold values being wasted away by swift currents as they are caused to settle in the bottom of the hole being dug or dredged.

Figure 6 is a detail of the haul-back sheave positioned at the inner end of the well of the pontoon. V

Figure '7 is a cross sectional view of the wheeled carriage showing the mounting of the large sheave thereon and also showing the inner side of one of the tracks of the inclined runway, and the mounting of the pivoted stop arm for holding the carriage at the bottom of the runway.

In these. drawings like numerals indicate like parts, the numeral 1 indicates a pontoon structure comprising the hull of a floating dragline dredge.

In the forward half of the pontoon I is constructed a tapering well portion 2 (see Figure 3) to permit of the operation of the dredging bucket over a large ground area through being enabled to draw the bucket inwards to the inner end of the well before finally lowering it for digging purposes (see Figures 4 and 5).

Built on top of the deck of the pontoon I is a superstructure 3 having an inclined runway 4 at the top thereof, on which is mounted a wheeled carriage 5 carrying a large centrally disposed sheave 6.

The centre portion of the framework of the superstructure 3 immediately encloses or bounds the tapering well portion 2 and projects over the bow or front portion of the pontoon I, as at 'I for approximately one-third of the length of the pontoon I.

The inclined runway 4 also projects over the extended front framework I and is supported by the braces 8, and such projection permits the centrally disposed sheave 6 mounted on the wheeled carriage 5 to become aligned over the front framework 7 to permit the hoisting of the dredging bucket 9, as shown in Figure 2.

The lower portion of the front extended framework I is walled in by metal plates II] to comprise a background for the dredging bucket 9 and prevent it from turning and twisting during hoisting operations.

The lower end of the framework I has mounted therebetween a wide roller I I over which the main line I2, bucket 9 and haul-back line I3 operate when the dredge is working.

One end of the main line I2 is connected to the bail I4 of the bucket 9 and the intermediate portion passed over the large sheave 6 of the wheeled carriage 5 and the opposite end connected to the drum of the winding engine I5, shown mounted upon the upper platform I6 of the superstructure 3 in Figures 1 and 2.

Attached to each corner of the bottom of the bucket 9 is chain linkage terminating in an eye ring I! to which is attached the end of the haulback line I3.

The haul-back line I3 is passed over and between a pair of sheaves I8 positioned on the deck of the inner end of the well 2 formed in the pontoon I, and then passes over another sheave I9 mounted at the back end of the upper platform I6 and connected to one of the drums of the winding engine I5.

In the upper portion of the front extended framework 1 and above the portion covered by the metal plates I0 is mounted a balanced tipple 20 (see Figure 2) having a flanged contact lip 2| secured transversely across its face adjacent the top and flanged sides 26.

Mounted upon the inner sides of the inclined runway is a pair of pivoted stop arms 22 balanced by counterweights so that they always assume a position adapted to engage with the wheeled carriage 6 when the latter is at the bottom or lower end of the runway 4, and hold the carriage from movement during hoisting operations (see Figure 7).

Attached to the upper corner of the pivoted stop arms 22 is a cable 23 engaging with a small sheave 24 mounted upon the inner face of the inclined runway which is led to an operating lever 25 positioned adjacent the winding engine I5 by which the stop arms may be manipulated to make them engage or disengage with the wheeled carriage 5 by movement of the lever 25 and cable 23.

In operation the dredge works as follows: Assuming the bucket 9 is being lowered in Figure 2, the weight of the bucket is sufficient to cause it to descend until it passes over the roller II at the bottom of the framework when it is desirable to check its downward descent and to haul it backwards towards the inner end of the well 2 by use of the haul-back line I3 (see Figure 4 illustrating this phase). To prevent the bucket 9 touching bottom and disturbing the gravel bed before being lowered, the main line I2 is being braked oh its drum so as to maintain the bucket in the approximate position shown in Figure 4.

This procedure is carried on until the bucket is hauled back as far as possible when the main line I2 is completely slackened off and the bucket assumes the position illustrated in the diagrammatic view shown in Figure 5, after which the bucket is lowered by the haul-back line I3 and its own weight, varying from fifteen hundred to two thousand pounds is sufficient to cause it to dig and penetrate the gravel beds to form a hole therein much after the manner illustrated in Figures 4 and 5.

After the haul-back line becomes slack, indicating that the bucket is at or near the bottom, the main line is tightened and the bucket hauled along the bottom until the main line assumes a nearly vertical position, indicating that the bucket has completed its digging cycle and is ready for hoisting.

In hoisting, the bucket passes over the wide bottom roller and travels up the front of the framework 1, as shown in Figure 2, until the top edge of the bucket contacts the flanged lip 2I secured upon the upper face of the balanced tipple 20, after which the operator will disengage the balanced stop arms 22 with the wheeled carriage 5 by manipulation of the lever 25 adjacent the winding engine and allow the wheeled carriage 5 to ascend the inclined runway 4 under the pull of the main cable I2 until the bucket 9 causes the balanced tipple 20 to tip over and dump the bucket 9, as illustrated in Figure 1, after which a slight pull on the haul-back cable I3 will cause the tipple 20 to right itself and by slackening the main cable I2 the carriage 5 is allowed to descend the inclined runway and is locked in a stationary position by manipulation of the lever 25 which causes the stop arms 22 to engage with the end of the carriage 5, as illustrated in Figure 7, and the whole cycle of dredging is recommenced.

Having now fully described my invention, what I claim and desire to be protected in by Letters Patent, is:

1. In a dragline dredge of the kind described, comprising a pontoon hull having a longitudinal tapering well formed in the front half of said hull, an overhead superstructure mounted upon said hull and bounding said well, a haul-back sheave mounted at the inner end of said well, a haul-back line mounted in said sheave, a winding engine, a dredging bucket, an inclined runway on said superstructure, a carriage on said runway, a sheave on said carriage, said line having one end connected to said winding engine and the opposite end to the bottom of said dredging bucket, said bucket having a bail connected to said main line, said main line being passed over and between said sheave on said carriage, a balanced tipple in the front over said superstructure and in the path of the ascending dredge bucket, a contact lip upon the front of said tipple adjacent the top thereof, whereby when said winding engine is operated in a hauling and hoisting direction said dredge bucket is caused to ascend said superstructure and the top edge of said dredging bucket is caused to contact the lip upon said balanced tipple, through the main line being carried forwardly by the carriage mounted upon the inclined runway at the top of said superstructure, thereby causing said tipple to overbalance and dump the said dredge bucket, after which said main line is slackened allowing the wheeled carriage and dredging bucket to be carried to the lower end of said inclined runway by gravity where said dredging bucket is lowered and hauled into digging position by said haul-back line to re-commence the cycle of digging and dredging operations.

2. In a dragline dredge of the kind described, comprising in combination with a superstructure, an inclined runway mounted on top of said superstructure, a wheeled carriage adapted for traversing said runway, a centrally disposed sheave mounted upon said carriage, a main line mounted on saidsheave, a dredge bucket to which one end of said line is attached, a winding engine to which the other end of said line is attached, a haul-back line attached to said bucket and winding engine, an adjustable stop mounted on said inclined runway adapted for engaging and holding said carriage at the bottom and lower end of said runway, clumping mechanism on said superstructure, releasing means for said stop whereby when said releasing means is operated the said stop is caused to disengage with said carriage and said carriage and main line having said dredge bucket attached to one end thereof are caused to ascend said inclined runway under the action of said winding engine until said bucket engages with said dumping mechanisms after which the said carriage carrying said bucket is caused to descend by gravity said inclined runway to the lower end thereof through the slackening of said main line when said stops engage with said carriage to arrest further movement and by the continued slackening of the main line the dredging bucket is lowered and hauled into position for further dredging operations by said haul-back line.

3. In a dragline dredge of the kind described, comprising in combination with a superstructure, an inclined runway mounted on top of said super structure, a wheeled carriage adapted for traversing said runway, a centrally disposed sheave, mounted upon said carriage, a main line mounted on said sheave, a dredge bucket having a bail, a winding engine, said line having one end attached to said bail and the opposite end to said winding engine, a balanced tipple mounted upon the front of said superstructure and in the path of the dredge bucket when ascending, a contact lip on the face of said tipple adjacent the top thereof adapted to engage with the top edge of said bucket and cause said bucket to assume a dumping position through said bucket conveyed along said inclined runway and deposited upon said tipple which causes said tipple to overbalance and dump said dredge bucket.

4. In a dragline dredge of the kind described, comprising in combination with a superstructure, an inclined runway mounted on the top of said superstructure, a wheeled carriage adapted for traversing said runway, a sheave mounted upon said carriage, a main line mounted on said sheave, a dredge bucket having a bail, a winding engine, said line having one end attached to said bail and the opposite end to said winding engine, a balanced tipple mounted upon the front of said superstructure and in the path of said dredge bucket when ascending, said tipple being of tapering with and having its upper edges flanged to form guides for said dredge bucket, a contact lip on the face of said tipple adjacent the top thereof, said lip adapted to engage with the top edge and side of said bucket and cause said bucket to assume a dumping position through said bucket being conveyed along said inclined runway and being deposited upon said tipple which causes said tipple to overbalance and dump said dredge bucket.

EDMUND OSBORNE.

Images