Abstract of
GB606934
606,934. Drag-line excavators. WILKINS, E. G. Jan. 22, 1946, Nos. 2104 and 5843. [Class 68 (i)] In a drag-line excavator the tipping of the bucket is controlled by the dragline cable having a portion or an attachment secured at the outer end to a hoist rope and passing under a pulley or guide near the front of the bucket so that when the hoist rope is taut and tension is applied to the drag-line cable there is a component of force on the pulley or guide acting to raise the front of the bucket. In one form, as illustrated in Fig. 2, the tipping is controlled by one or more cables 27. One end of each cable 27 is fixed to the hoist line 15 and passes under a pulley 26, journalled near the mouth of the bucket 17, to be secured at the other end to the bucket in close proximity to the bottom of the pulley. A stop 30 on the cable 2 7, co-operates with an abutment 31 on the bucket to control the angular position of the bucket when the hoist and drag-line cables are taut. In a modification, as shown in Fig. 5, the dragline cable is provided with two chains 40 that pass through fairleads 41 and are secured to the hoist cable, the angular position of the bucket when both the hoist and drag-line cables are taut again being controlled by a stop 42 co-operating with the fairleads. The fairleads may be formed in the upper outer edges of a somewhat rectangular U-shaped mouth of the bucket, whilst the back may be higher than the front of the bucket and be formed in a cylindrical arc merging with the bottom of the bucket.
is:1. An excavator of the type described in which the drag-rope or chain has a portion or an attachment secured at the outer end to the hoist-rope and passing' under a 80 pulley or guide near the front of the bulcket so that when the hoist-rope is taut and tension is applied to the drag-rope there is a coomponent of force on said pulley or guide acting to raise the front 85 of the bucket.
2. An excavator as claimed in claim I in which the drag-rope or chain is attached to the front of the bucket and a tipping, rope is fixed at one end to a point 90 on the hoist-rope, passes under a pulley journalled near the mouth of the bucket and is fixed at the otiler end to a point on the drag-rope or chain.
3. An excavator as claimed in claim 2 95 w-herein a stop secured to the tipping rope between the pulley and the point of attachment to the hoist-rope determines the angular position of the bucket when the hoist-rope and drag-rope are taut by 100 engagement with an abutment on the bucket.
4. An excavator as claimed in claim 2 or claim 3 wherein the point of attachment of the drag-rope or chain is in close 105 proximity to the bottom of the pulley of the tipping rope.
5. An excavator as claimed in claim 2, 3 or 4 wherein more than one such tipping rope is used. 110 6. An excavator as claimed in claim 1 wherein the drag-rope or chain passes through a fairlead or under a pulley near the front of the bucket and is secured to a point on the hoist-rope. 115 7. An excavator as claimed in claim Pi waherein a stop is provided on the dragrope att the bucket side of the fairlead or pulley, said stop cooperating with an abutment on the bucket so that during 120 dragging the drag is applied to the bucket through the abutment and during hoisting when both hoist-rope and drag-rope or; chain are taut the angular position of the bucket is determined. 125 S. An excavator as claimed in claim (.
or claim 7 wherein in the neighbourholod of the bucket boh the hoist-rope and the drag-rope or chain are attached to tfwo chains leading respectively to the two 130 6OG.!M4):
fj 606,984 outer sides of the bucket.
9. An excavator as claimed in claim 5 or claim 8 wherein the bucket has a somewhat rectangular U-shaped mouth, and embodied in the upper outer edges of said mouth are fairleads or pulleys to accormmod ate the drag chains or tipping ropes.
10. An excavator as claimed in claim 9 wherein the bucket is of wedge shape in 1.0 side view being higher at the back than at the mouth.
11. An excavator as claimed in claim 9 or claim. 10 wherein the back of the bucket is in the form of a cylindrical arc merging with the bottom of the bucket to avoid a 15 sharp corner in which soil might lodge.
12. An excavator as claimed in any of the preceding claims substantially as described with reference to the drawings accompanying provisonal specifications 20 Nos. 2104146 and 5843146.
Dated the 22nd day of January, 1947.
BOTJLT, WADE & TENNANT, 111 & 112, Hatton Garden, London, E.C.1, Chartered Patent Agents, Leamington Spa: Printed for His Majesty's Stationery Office, by the Courier Press.-1948.
Publshed at The Patent Office, 25, Southampton Buildings, London, W.C.2, from which copies, price is. Od. each (inland) Is. Id. (abroad) may be obtained.
One Complete Specification left (under Section 16 of the Patents and
Designs Acts, 1907 to 1946): Jan. 22, 1947.
Specification Accepted: Aug. 23, 1948.
Index at acceptance:-Class 68(i), F12.
PROVISIONAL SPECIFICATION
No. 2104 A.D. 1946.
Improvements in Drag-line Excavators I, EDw.ARID GEorrir.Y WixxiNs, a British Subject, of Lion House, Red Lion Street, Richmond Surrey, do hereby declare the nature of this invention to be as follows: This invention relates to improvements iii drag-line excavators, i.e. to that type of excavator in which a bucket (or shovel) having a cutting edge or teeth is dropped into the soil with its forward edge leading, after which the bucket (or shovel) is dragged by a rope or chain so as to scoop -up the soil, after which the bucket (or shovel) is held in a horizontal position and is hoisted by a hoist-rope, both the dragrope and hoist-rope being operated by power winches on the excavator body.
One object of the invention is to enable a drag bucket to be brought into a horizontal position (suitable for hoisting or for holding the load) at any time when the hoist-rope is taut no matter what angle the drop-rope or chain makes with the vertical.
26 Normally the hoist-rope in a drag-line excavator is pivotally attached to the bucket to allow the bucket to turn about said pivot. Normally also the drag-rope or chain is attached to the front of the bucket or to an arch at the front of the bucket and one known method of enabling the bucket to be tilted (either mouth-downwards for digging or for emptying or into a horizontal position to hold the load or for hoisting or for digging) is to use a tipping rope which passes from the top of the arch of the bucket round a sheave on the hoist-rope and thence to a point on the drag-rope so that in certain positions of the hoist- and drag-ropes the tipping rope is under tension and at other positions the tipping rope is slacked away.
According to this invention an exca4b vator bucket has a hoist-rope pivotally connected thereto and a drag-rope or chain has a portion (or an attachment) secured -.Prioe 11-]1 at the outer end to the hoist-rope and passing under a pulley or guide near the front of the bucket so that when the hoist-rope 50 is taut and tension is applied to the dragrope there is a component of force on said pulley or guide acting to raise the front of the bucket to any desired position. Said portion or attachment at the outer end of 55 the drag-rope may have a stop to determine the angular position of the bucket when the hoist-rope and drag-rope are taut.
According to one form of this invention 60; an excavator bucket has a hoist-rope pivotally connected thereto and a dragrope gr chain attached near the front or mouth of the bucket and a tipping rope is fixed at one end to a point on the hoistrope and passes under a pulley journallefd near the mouth of the bucket and is then fixed to a point on the drag-rope so that when the hoist-rope is taut it is possible by pulling on the drag-rope to apply tension to the tipping rope and- raise the front of the bucket.
The point of attachment of the drag-:
rope or chain is in close proximity to the bottom of the pulley of the tipping rope 7& and the result is that so long as the hoistrope is taut the tension can he applied to the tipping rope no matter what angle the drag-rope makes with the vertical. By this means it is possible to stop a dragging 80 operation at any desired stage and hold the bucket in a horizontal position to retain its load for hoisting and an operator can therefore perform a dragging operation at any chosen path and length 0ot 85.
stroke with corresponding economy in power and in time.
In an alternative arrangement there is no tipping rope. The excavator bucket has a hoist-rope pivotally connected 90, thereto and- a drag-rope or chain passes through a fairlead near the front of the bucket and is provided with a stop on the bucket side of the fairlead and the end of I:
t i 1- - --- 1 ---------- W_ 606-,,;9:34 the drag-rope is secured to a point on the hoist-rope so that when both hoist-rope stand drag-rope are taut, the angular position of the bucket is determined. Preferably in the neighbourhood of the bucket both the hoist-rope and the drag-rope are.
attached to two chains leading respectively to the two outer sides of the bucket.
The nature of this invention and of subsidiary features will be appreciated from the following description of an example, reference being made to the accompanying drawings in which:Figure 1 is a diagram showing an excavator body and jib or boom and a drag-line bucket in several positions; Figures 2 and 3 are a side elevation and a plan of a drag-line bucket with hoistrope, drag-rope and tipping rope arranged in accordance with this invention, and Figure 4 is a side elevation of the bucket on a larger scale to illustrate certain details.
Figures., 6 an(l 7 illustrate modifications.
Referring first to Figatre 1, the excav-ator body 1.2 is shown mounted on a caterpillar tractor 13 and is provided with the usual jib or boom 14. The excavator body 12 contains at least two winehes. one of which controls the hoist-rope 1]5 and the other of which controls the drag-line 16, both of which operate on the bucket 17.
The bucket itself may take various forms but a typical example is illustrated in Figure.s 2, 3 and 4.
This invention is primarily concerned with the method of controlling the position of the bucket. The hoist rope 15 terminates in chains iS rotatably coupled on each side of the bucket to a pivot or stub axle 19 and the position of this pivot is so chosen that when the drag-rope 16 is slack the bucket, if empty or full, will tip with the mouth downwards, but if the bucket has a normal charge of soil, the centre of gravity of the bucket and charge will not be far in front of the. pivot 19 (so that no excessive force is required to keep the bucket in a horizontal position).
The drag rope 16 terminates in two chains 20 coupled to links 21 pivoted on vertical hinge pins 22 held by hinge plates 23 on either side of the bucket near t5 the front.
The front of the bucket is reinforced by aln arch 24 and the lower forward edge of the bucket is provided with teeth 25. Sear the bottom of the arch 24 on each side is a pulley 26 and it is preferable that the bottom of this pulley shall be in close proximity to the point where the chain 20 engages the link 21. The tipping rope 27 is coupled at its oiter end 28 to the hoistrope 1-5, it passes under the pulley 26, and the inner end of the tipping rope is coupled at 29 to the dirag-rl)e 16. In the arrangemlent illustrated, there are two tipping ropes 27. The two ends 28 are coupled to the tvo chains 18 andI these two 70 tipping ropes 27 pass under the two pulleys 26 on either side of the arch 24, [xi order that any tension oin the tipping rope 27 nmay be equalised, the two parts may be continuous and 1iria pass around 75 a fairlead or pulley at 29. When tension is applied to the (drag-rope 16 and thence to the tippinog ropes 2'7, it may be desirable to arrest the tipping action whenl the bucket has reapched a horizontal or selected 80 position, and for this purpose a stop 30 may be fixed on the outer part of the tippilln' rope to engage a corresponding a)utellent 31 secured to each side of the bucket and a buffer springo 32 may be 85 interposed between the stop 30 and abutmleent 31. The openings 33 in the arch aadjacent to the pulleys 26 allow for the escape of any dirt picked up by the tipping rope 27 and led to the pulleys 26. r 90 The operation of the device of Figures 1, 2. 3 and 4is as follows:-.Assuminthat the bucket is empty, that +lo drag-rope 16 is slack and the hoist-rope lo supporting the bucket, then the bucket hangs 9,5 mouth-downwards. In this position by easing oft on the hoist-rope 15 (and keeping the drag rope 16 slack) the bucket 1.7 is dropped (or swung out and dropped) to engage the soil in the excavation. The 100 drag rope 16 is then brought into plav in the well-known manner and dragging continues to any extent desired by the operator and it is important to note that the dragging operation may be arrested 105 when the hoist rope 1-5 is vertical. If now it is desired to raise the bucket, the hoist rope is made taut and it will be seen that the tension on the tipping' rope 27 can hold the bucket in the horizontal position 110 or any selected position for retaining its charge. During hoisting. the drag rope 16 is kept taut an(l therefore the tipping' rope 27 is kept taut and the desired position of the bucket is retained. It will be 1]5 noticed that as the point of attachment of the c hains 20 to the links 21 is in close proximity to the bottom of the pulley 26, the tension in the tipping rope 27 does not vary With the angular position of the 120 chains 20 in relation to the arch 24 and this gives the operator a wide range of choice in applying tension to the tipping rope 27.
When the boom 14 and excavator body 12.5 have been slewed to bring the bucket into position for discharge, the slackenin- of the drag-rope 16 allows the bucket 17 to tilt mouth-downwards and discharge its contents. 130 the fairlead 41 enables dragging to be carried out normally but the relative 25 lengths of the-t aut chains 18 and the taut chains 40 bet-ween faiir'leads 41 and chains 18 determine the. angular position, of the bucket 17 abonut;its,,pi'v.ot 19. Two winches on the excavalttofbody 'operate the excavator in I. very simple ' mnanner. and for discharging the bucketilt. is, only necessary to slacken the drag-line 16.
Figure 7 illustrates. a detail modification in which -the fairlead 43 has the axis 35 of the orifice arranged in line with that part of chain 40 which leads to chains 18 and the long link 44 in each chain 40 engages a shoulder on fairlead 43 to provide in a definite manner for the lifting '40 of the forward end of the bucket 17.
Referring now to Figures 5 and 6, a modification is shewn where therelis-:no tipping rope. The hoist-rope 15, _bucket 17', chains 18, pivot 19, arch 24 and teeth 2.5 are arranged at. in Figures r1-4 butt in this case the drag-line 16 is coupled to two chains 40 which pass- through, fairleacds 41 -s secured to the bottom outer. ends., of the arch 24 and the chains 40,at their outer ends are secured.to the two chains 18.
Each of the chains 40 is provided with a stop 42.which--cansengage with the fairlead 41 as indicated in Figures 5 and 6.
The operation of the device illustrated in Figures 5 and 6 is as follows: -When the drag-line 16 is slack and the bucket 17 is hanging on the hoist rope 15, the bucket hangs mouth downward, but when the drag-line is taut (and the hoist-rope 15 is taut-(a) the bucket is brought to and kept in the horizontal position (or any desired position). The engagement of stop 42 with PROVISIONAL SPECIFICATION
No..5843 A.D. 1946.
Improvements in Drag-line Excavators I, En WARD GEOFFREY WILRINS, a British Subject, of Lion House. Red Lion - Street, Richmond, Surrey, do hereby de4a clare the nature of this invention to be as follows: - This invention relates to improvements in drag-line excavators and is cognate with or a modification of that described in Application No. 2104/46.
Acoording to the present modification the excavator bucket has a somewhat rectangular U-shaped mouth, and emnbodied in the upper outer edges of said mouth are fairleads td accommodate the drag ropes or chains which also act as tipping ropes or chains.
The bucket is preferably made without an arch over the mouth and is preferably of wedge shape in side view being higher at the back than at the mouth. The back may be in the form of a cylindrical arc merging with the 'bottom of the bucket to avoid a sharp corner in which soil might lodge.
The Provisional Specification No.
2104/46 was accompanied by drawings numbered Figures 1 to 7.
The present modification is illustrated in the accompanying drawings markied Figures 8 and 9 'of which, Figure 8 is a side view of the bucket and the chains which act on it; and Figure 9 is a. section on the line 9-9 of Figure 8. 75 As illustrated, the bucket is coupled and operated as described with reference to Figure 5, 6 and 7 of Specification No.
2104/ 46. Thus the bucket 17 is oonnected to the hoist chains 18 by pivots or stubaxles 19. The front of the bucket is reinforced by a rectangular U-shaped mouth 45, the bottom 46 being.fiat while the sides terminate at their lupper edges in fairleads 47'. which accommodate the 85 chains 40 which are attached to the drag line and also- acts as tipping chains being provided with stops 42'to determine the attitude of the bucket when the chains 40 are taut. The bucket is wedge shaped in 90 side view, the bottom being flat while the back 48 is curved. The pivots'19 are so disposed that whether the bucket be empty or full 'it will tip mouth downwards when the hoist chains 18 are taut and the drag 95 chains 40 are slacked away. The teeth 2'5 are provided at the bottom edge of the mouth.
Dated this 25th day of February, 1946.
BOULT, WADIE & TENNANT, 11 & 112, Hatton Garden, London, E.C.1, Chartered Patent Agents.' 606,934 za v G0,9.34 COMPLETE SPECIFICATION
Improvements in Drag-line Excavators I, EDWARD GEOFFRELY WILKINS, at British Subject, of Lynwick, Rudgwick, Sussex, (formerly of Lion House, Red Lion Street, Richmond, Surrey), do herebv declare the nature of this invention anid in what manner the same is to be performed, to be particularly described and ascertained in and by the following statement:
This invention relates to improvements in drag-line excavators, i.e. to that type of exeavator in which a bucket (or shovel) having a cutting edge or teeth is dropped into the soil with its forward edge leading, after which the bucket (or shovel) is dragged by a rope or chain so as to scoop up the soil, after which the bucket (or shovel) is held in a horizontal position and is hoisted bv a hoist rope pivotally attached to the bucket, both the dragrope and hoist-rope being operated by power winches on the excavator body. Ain excavator of this type will be referred to in this specification and in the accom-
Panying claims as -- an excavator of the type described."
One object of this invention is to enable a drag bucket to be brought into a horizontal position (suitable for hoisting or for holding the load) at any time when the hoist-rope is taut no matter what angle the drag-rope or chain makes with the vertical.
Normallv the hoist-rope in a drag-line excavator is pivotally attached to the bucket to allow the bucket to turn about said pivot. Normally also the drag-rope or chain is attached to the front of the b)ucket or to an arch at the front of the qO bucket and one known method of enabling the bucket to be tilted (either mouthdownwards for digging or for emptying.
or into a horizontal position to hold the load or for hoisting or for digging) is to use a tipping rope which passes from the top of the arch of the bucket round a sheave on the hoist-rope and thence to a point on the d1rag-rope so that in certain positions of the hoist- and drag-ropes the tipping rope is under tension and at other positions the tipping rope is slacked away.
According to this invention an excavator bucket of the type described has a portion or an attachment secured at the outer end to the hoist-rope and passing under a pulley or guide near the front of the buck-et so that when the hoist-rope is taut and tension is applied to the drag-rope there is a component of force on said (0 pulley or guide acting to raise the front of the bucket. Said portion or attacllient at the bucket end of the drag-rope may have. a stop to determine the angular positi(n of the bucket when the hoist-rop)e and drag-rope are taut. 65 According to one formi of the invelitioli the drag-rope is attached to the front of the bucket and a tipping rope is fixed at one end to a point on the hoist-rope passes under a pulley journalled near the mouth 70 of the bucket and is fixed at the other end to a point on the drag_-rope or chain.
More than one such tipping rope may be used.
The point of attachment of the dragrope or chain is in close proximity to the bottom of the pulley of the tipping rope an(l the result is that so long as the hoistrope is taut the tension can be applied to the tipping rope no matter what angle 8o the drag-rope makes with the vertical. BY this means it is possible to stop a dragainin operation at any desired stage and hoMl the bucket in a horizontal position to retain its load for hoisting and an operator 8.5 ecfin therefore perform a dragging operation at any chosen path and length of stroke with corresponding economy in pow'er and in time.
In an alternative arrangemient there is 90 no tipping rope. The excavator bucket has a hoist-rope pivotally connected thereto and a dra-rope or ehain passes through a fairlead near the front of the bucket and is provided with a stop on the 95 bucket side of the fairlead and the end of the drao-rope is secured to a point on the hoist-rope so that when both hoist-ropte and drag-rope are taut. the angular position of the bucket is determined and so 100 that during dragging the drag is applied to the bucket through the stop. Preferably in the neighbourhood of the bucket 1)0oth the hoist-rope and the drag-rope are attached to two chains leading respec-105 tivelv to the two outer sides of the bucket.
The excavator bucket has preferably a somewhat rectangular U-shaped mouth and embodied in the upper outer edges of said mouth are fairleads or pulleys to 110 accommodate the drag-chains or tippingropes.
The bucket is preferably made without an arch over the mouth and is preferably of wedge shape in side view being higher 115 at the back than at the mouth. The back may be in the form of a cylindrical are merging with the bottom of the bucket to avoid a sharp corner in which soil might lo(lde. 120 The nature of this invention and the manner in which it is to be performed pulleys 26 on either side of the arch 24.
In order that any tension on the tipping rope 27 may be equalised, the two parts may be continuous and may pass around a fairlead or pulley- at 29. When tension 70 is applied to the drag-rope 16 and thence to the tipping ropes 27, it may be desirable to arrest the tipping action when the bucket has reached a horizontal or selected position, and for this purpose a stop 3() 75 may be fixed on the outer part of the tipping rope to engage a corresponding abutment 31 secured to each side of the bucket and a buffer spring 32 may be interposed between the stop 30 and abut- 8P ment 31. The openings 33 in the arch adjacent to the pulleys 26 allow for the escape of any dirt picked up by the tipping rope 27 and led to the pulleys 26.
The operation of the device of Figures 85 1, 2, 3 and 4 is as follows:-Assuming that the bucket is empty, that the drag'rope 16 is slack and the hoist-rope 15 supporting the bucket, then the bucket hangs mouth-downwards. In this position by 90 easing off on the hoist-rope 15 (and keeping the drag-rope 16 slack) the bucket 17 is dropped (or swung out and dropped) to engage the soil in the excavation. The drag-rope 16 is then brought into play in 95 the well-known manner and dragging continues to any extent desired by the operator and it is important to note that the dragging operation may be arrested when the hoist-rope 15 is vertical. If now 1Q0 it is desired to raise the bucket, the hoist rope is made taut and it will be seen that the tension on the tipping rope 27 can hold the bucket in the horizontal position_ or any selected position for retaining its 105 charge. During hoisting, the drag'-rope 1.6 is kept taut and therefore the tipping rope 27 is kept taut and the desired position of the bucket is retained. It will be noticed that as the point of attachment of 110 the chains 20 to the links 21 is in close proximity to the bottom of the pulley 26, the tension in the tipping rope 27 does not vary with the angular position of the chains 20 in relation to the arch 24 and 115 this gives the operator a wide range of choice in applying tension to the tipping rope 27.
When the boom 14 and excavator body have been slewed to bring the bucket into 129 position for discharge, the slackening of the drag-rope 16 allows the bucket 17 to tilt mouth-downwards and discharge its contents.
Referring now to Figures 5 and 6, a 125 modification is shewn where there is no tipping rope. The hoist-rope 15, bucket 17, chains 18, pivot 19, arch 24 and teeth are arranged as in Figures 1-4 but in this case the drag-line 16 is coupled to two lwill now be described with reference to the drawings accompanying the provisional specification No. 2104146 and cognate specification No. 5843146, in which:-.
Figure 1 is a diagram showing an excavator body and jib or boom and a drag-line bucket in several positions; Figures 2 and 3 are a side elevation and plan of a drag-line bucket with hoistrope, drag-rope and tipping rope arranged in accordance with this invention, and Figure 4 is a side elevation of the bucket on a larger scale to illustrate certain details.
Figures 5, 6, 7 and 8 illustrate modifications in the form of bucket, and Figure 9 is a section on the line 9-9 of Figure 8.
Referring first to Figure 1, the excavator body 12 is shown mounted on a caterpillar tractor 13 and is provided with the usual jib or boom 14. The excavator body 12 contains at least two winches, one of which controls the hoistrope 15 and the other of which controls the drag-line 16, both of which operate on the bucket 17. The bucket itself may take various forms but a typical example is illustrated in Figures 2, 3 and 4.
This invention is primarily concerned with the method of controlling the position of the bucket. The hoist-rope 15 terminates in chains 18 rotatably coupled on each side of the bucket to a pivot or stub axle 19 and the position of this pivot is so chosen that when the drag-rope 16 is slack the bucket, if empty or full, will tip with the mouth downwards, but if 'the bucket has a normal charge of soil, the centre of gravity of the bucket and charge will not be far in front of the pivot 19 (so that no excessive force is required to keep the bucket in a horizontal position).
45. The drag-rope 16 terminates in two chains 20 coupled to links 21 pivoted on vertical hinge pins 22 held by hinge plates 23 on either side of the bucket near the front.
The front of the bucket is reinforced by an arch 24 and the lower forward edge of the bucket is provided with teeth 25. Near the bottom of the arch 24 on each side is a pulley 26 and it is preferable that the bottom of this pulley shall be in close proximity to the point where the chain engages the link 21. The tipping rope 27 is coupled at its outer end 28 to the hoist-rope 15, it passes under the pulley 26, and the inner end of the tipping rope is coupled at 29 to the drag-rope 16. In the arrangement illustrated, there are two tipjing ropes 27. The two ends 28 are coupled to the two chains 18 and these two tipping ropes 27 pass under the twa 606,934 a chains 40 which pass through fairleads 41 secured to the bottom outer ends of the arch 24 and the chains 40 at their outer ends are secured to the two chains 18.
Each of the chains 40 is provided with a stop 42 which can engage with the fair-i lead 41 as indicated in Figures.; and 6.
The operation of the device illustrated in Figures.5 and 6 is as follows:-WXhen the drag-line 16 is slack and the bucket 17 is hangitno on the hoist-rope 1-, the bucket ]iangs mouth downward, but when th drag-line is taut (and the hoist-rope 1.5 is taut) the bucket is brought to and kept in the horizontal position (or any desired position). The engagement of stop 42 with the fairlead 41 enables dragging to be carried out normally but the relative lengths of the taut chains 1S and the taut chains 40 between fairleads 41 and chains 18 determine the angular position of the bucket 17 about its pivot 19. Two winches on the excavator body operate the excavator in a very simple manner, and for discharging the bucket it is only necessary to slacken the drag-line 16.
Figure 7 illustrates a detail modification in which the fairlead 43 has the axis of the orifice arranged in line with that part of 3{} cain 40 which leads to chains iS and the long link 44 in each chain 40 engages a shoulder on fairlead 43 to provide in -i definite manner for the liftino' of the forward end of the bucket 17.
AA modification in the form of the bucket shown in Figures 5, 6 and 7 is indicated at Figures S and 9. Referring to these latter Figures, the front of the bucket 17 is reinforced by a rectangular U-shaped mouth 4.5, the bottom 46 being flat while the sides terminate at their upper edges in fairleads 47 which accommodate the clainis 40 which are attached to the dragline and also act as tipping chains being' 4,5 provided with stops 42 to determine the attitude of the bucket when the chains 40 are taut. The bucket, is wedge shaped in side view, the bottom being flat while the back 48 is curved. The pivots 19 are so 0 disposed that whether the bucket be empty or full it will tip mouth downwards w-hen the hoist chains 18 are taut and the drag chains 40 are slacked away. The teeth 25 are provided at the bottom edge of the mouth.
The shape of the bucket is designed so that more soil can be held at the rear than at the front. This is an advantage since during the dragging operation, the soil is swept to the rear by the movement of the bucket. The back- 48 is curved to merge with the bottom to avoid a sharp corner in which soil may lodge.
It will be appreciated that the advantag(eous form of the bucket illustrated in Figures 8 and 9 may be used in place of that shown in Figures 2, 3 a-nd 4 by replacing the fairleads by pulleys for thie tippigl. ropes and by atttaehing links to the front of the bucket so that the (Iral(hails may be secured thereto.
Having now prticularly described and as:ertained the nature of my said invention andl in what manner the same is to be
