April 26, 1966 J, w, PAGE 3,247,606
DRAGLINE EXCAVATING BUCKET AND HITCH Filed MaICh 16, 1964 4 Sheets-Sheet 1` E59. i Z E Ljd/Z jy@ April 26, 1966 J. w. PAGE 3,247,606
DRAGLINE EXCAVATING BUCKET AND HITCH Filed March 16, 1964 4 Sheets-Sheet 2 April 26, 1966 .1.w. PAGE DRAGLINE EXCAVATING BUCKET AND HITCH 4 Sheets-Sheet 5 Filed March 16, 1964 N -mZrL April 26, 1966 .1. w. PAGE DRAGLINE EXCAVATING BUCKET AND HITCH 4 Sheets-Sheet 4 Filed March 16, 1964 United States Patent Office Patented Apr. 26, 1966 DRAGL TE EXCAVATING BUCKET AND HETCH John W. Page, Chicago, Ill., assignor to Page Engineering Company, a corporation of Hlinois Fiied Mar. 16, 1964, Ser. No. 352,726 9 Claims. (Cl. 37-135) This application is a continuation-in-part of my application entitled Bucket, Serial No. 200,101, filed .lune 5, 196-2 and now abandoned.
This invention relates to improvement in buckets and, more especially, dragline buckets designed for excavating, digging, scraping, dragging, and the like.
Upon loading buckets of conventional design, such as buckets used in dragging operations, when the bucket becomes filled, it is often lifted in a somewhat vertical direction to be carried to an unloading site. Such buckets are usually equipped with one or more holding lines to assist in raising the cutting end of the bucket after the bucket has been lifted from the ground. Such lifting of the cutting or front end of the bucket is for the purpose of decreasing spillage of the load therefrom. Such buckets are suf-ciently large, e.g., having a capacity of about 17 tons, that spillage of even a fractional part of the load may result in a tremendous loss of load from the bucket when expressed in terms of weight alone. Although the front end of the bucket is raised to prevent or decrease spillage during carrying of the bucket, such raising is not accomplished until the bucket leaves the ground and during the process of lifting the bucket from the ground substantial spillage can occur.
It is the current practice to load dragline buckets at a point on the ground spaced substantially inwardly toward the digging machine from a point vertically beneath the end of the boom. This is necessaly so that upon the initial lifting of the bucket, the control lines will maintain the bucket substantially upright and spillage will be minimized. The bucket must be dumped at a point directly under the free end of the boom. It becomes necessary, once the control lines have lifted the bucket from the ground, to return the bucket to a point directly under t'ne boom end which is commonly called fishing out the bucket. Once the load is dumped, the digging machine pivots to return to the original digging area. The bucket is returned inwardly and a new digging cycle is started. 'I'he time spent fishing in the bucket or returning it to the initial digging point is substantially a wasted motion representing a loss in operating time of the machine.
In a digging machine, the bucket can be swung out to a position under the free end of the boom point quite rapidly. In contrast, there is a limit on the speed at which the bucket can be pulled inward toward the machine or fished in. The bucket can be pulled in at about 200 feet la minute with most machines being limited to 175 feet a minute. Thus, by cutting down the amount of movement of the bucket toward or away from the machine, and especially toward the machine, an increase in the number of trips per hour results. The importance of reducing every second of cycle time becomes most significant when the cost of the operation of the digging machine is considered. For; example, a digging machine capable of handling 30 cubic yard buckets operates at a project cost of about $1,750 an hour. Most such large machines operate 24 hours a day, 7 days a week. Thus, even a 10% reduction in cycle time can result in a savings of $4,200 a day on a 30 cubic yard digging machine.
Additionally, in dragline buckets of conventional design, eg., having rounded backs on substantially square backs, portions of the load often become lodged in the back of the bucket and are not removed during normal operations of the bucket. Such portions of the load which become stuck in the back of the bucket result in a decrease in the bucket capacity for the next load and also result in expenditure of additional power to move the bucket from the unloading site back to the digging or loading site, unless removed prior to return of the bucket for reloading. In some cases, it has been a practice to drop the bucket from an elevation, preferably loading end first, to dislodge the stuck portion of the load upon striking the ground. Such practice not only wastes time, but also requires the use of additional materials for reinforcing the bucket structure.
t is therefore a primary object of this invention to provide a new and improved digging machine which is provided with a bucket of such a design and an associated mounting arrangement for the control lines which,V in combination with the bucket design, renders the digging machine capable of digging greater quantities of solid material per unit of time.
Another object of my invention is to provide a new and improved digging machine provided with a bucket of a specific design and a mounting arrangement associating the control lines with the bucket in such a manner that the combination of the bucket design and control line mounting arrangement permits the bucket to be lifted from a point substantially vertically below the boom end without spillage of solid material from the bucket.
A further object is to provide a bucket having a fulcrum member adapted to support the bucket while raising the front of the bucket with the bucket Vstill on the ground. An additional object is to provide such a bucket with a fulcrum member wherein the fulcrum is approximately under the combined center of gravity of the bucket and its load.
Still another object is to provide a new and improved hitch means for a dragline bucket which cooperates with the control lines of the bucket so that when a lifting force is applied only to the lift line, a loaded bucket may be lifted from any point under the boom without dumping the load.
A yet further object of my present invention is to provide a bucket with a back which permits scouring of the inside of the bucket back by action of solid materials traveling up the back during filling of the bucket, and to further provide a bucket which may be lifted vertically without substantial loss of load.
A still further object of this invention is to provide a dragline bucket with a back which forms a rearward and upward sloping wedge for raising material lforced into the Xbucket and against the back so that the materials being forced up the back of the bucket effect a general scouring operation with respect to the back.
An additional object is to provide such a bucket wherein there is a forward bend in the back wall well up the back wall, which bend is sufficiently open so that the portion above the bend still slopes rearward and upward. The bend is adapted to divert solid mate-rial traveling up the back wall forward into the top part of the bucket.
A specific object is to provide a dragline bucket having two sides, which are battered as viewed from the interior, a dump-ing trunnion on each side, a bottom, a forward cutting edge on the bottom and a back which slopes upward on a rearward angle with respect to the bottom and behind the dumping trunnion.
Another specific object is to provide a dragline bucket having two sides, a dumping trunnion on each side, a bottom, a forward cutting edge on the bottom and a fulcrum portion which is adjacent to the juncture of the bottom and back of the bucket and on which the bucket may be rocked to raise the front end of the bucket prior to lifting the bucket from the ground.
A more specific object is to provide an archless dragline aga-7,606
bucket for a digging machine including a fulcrum portion on the bottom of the bucket on which the bucket may be rocked to raise the front end of the bucket prior to lifting the bucket from the ground, and a mounting arrangement on the bucket securing the digging machine control lines to the bucket in such a manner that the bucket may be raised from a position substantially directly underneath the free end of the boom without spillage of the contents of the bucket.
Other objects of this invention are to provide a bucket according to the foregoing which has an arch between the front end portions of the sides and interconnecting the sides and to provide an archless bucket in accordance with any of the foregoing objects. Other objects will be apparent to those in the art from the following descriptions and from the drawings in which:
FIGURE 1 is a side view of an embodiment of the bucket of this invention containing a load;
FIGURE 2 is a side view of the embodiment of FIG- URE 1 which has been pivoted on a fulcrum to raise the front end preparatory to lifting;
FIGURE 3 is a side view of another embodiment of the bucket of this invention;
FIGURE 4 is a side elevational view of a digging machine utilizing the bucket and hitch means of this invention showing in phantom outline the starting position for lling the bucket at a point directly under the end of the boom and further showing the bucket in full outline in a position which is closely adjacent to the starting position directly under the boom from which the lled bucket may be lifted without spillage of the contents of the bucket;
FIGURE 5 is a diagrammatical illustration of a digging cycle of the digging machine;
FIGURE 6 is a fragmentary side elevational view of a dragline bucket illustrating the hitch means of this invention;
FIGURE 7 is a section view taken along the line 12- 12 of FIGURE 6;
FIGURE 8 is a fragmentary side elevational view of the bucket and hitch means shown in FIGURE 6 but illustrating the bucket in a dumping position;
FIGURE 9 is an enlarged view of the beam member of the modified hitch means of this invention;
FIGURE 10 is a top view in partial section of the beam member shown in FIGURE 9; and
FIGURE 11 is a fragmentary perspective view of a smaller capacity dragline bucket using a further modified hitch means of this invention.
I shall first describe in detail the bucket shown in FIGURES l and 2. The bucket, indicated in general by reference numeral 10, is provided with the usual cutting lip or forward cutting edge 14 provided with the usual teeth 15. Numeral 13 indicates the bottom of the bucket and 12 indicates the back thereof. The bucket has tWo battered sides which slope outwardly from bottom to top. One side of the bucket is indicated by 11 and, although the other side of the bucket is not shown, it is to be understood that it is of configuration similar to but reversed from the configuration of side 11. Wherever an element is described herein as in association with one side of the bucket, it is to be understood that a similar element is in similar association with the other side. In some instances, which will be evident herein, the very same elements will be associated with both sides, e.g., bottom 13 and back 12 described above.
The bucket illustrated in FIGURES 1 and 2 is provided with arch 16 which spans the extended portions of the sides of the bucket anterior to cutting edge 14. The juncture of the arch with each side is reinforced with a corner plate indicated at 18 with respect to side 11.
Bucket 10 has pivot support or dumping trunnion 17 for attachment to lifting chain 20. Fulcrum surface or portion 19 joins bottom 13 with back 12 and is located at the general intersection of the bottom, back and sides of the bucket.
Bridle chain 2'7 which is connected to the leading edge of each side of the bucket at 28 attaches the bucket to hauling or pull line 26 as shown at 29. Holding or dump line 23 is attached to hauling line 26 as shown generally at 29 and is also attached to arch 15 as shown at 24. Holding line 23 passes through sheave block 25, commonly known as a dump block. Sheave block 25 and the pair of lifting chains are connected through clevis means 21 to lifting line 22 at a common point. The load in the bucket is shown generally at 30.
In operation, the lifting action is applied from a digging machine boom or other means through lifting line 22. As tension on lifting line Z2 increases, block 25 is pulled upward. In essence, the lifting line is pulling through block 25 on a two-part line, ie. holding line 23, one end of which is fixed and held by the load cable or hauling line 26, so that as the lifting line pulls upward the slack in holding line 23 is taken up at the bucket end. The front end of the bucket moves upward at twice the speed of the upward movement of block 25. The bucket rocks on fulcrum portion 19 to the position shown in FIGURE 2. The raising of the front end of the bucket prior to lifting the bucket from the ground decreases the tendency of the load to spill from the bucket during the subsequent lifting operation. The quick upward lifting of the front end of the bucket serves to assist in saving a good deal of the material loaded in the bucket.
In general, with respect to the fulcrum portion and tilting of the bucket about the fulcrum portion, the easier the' bucket rocks on the fulcrum portion the more readily the front of the bucket is lifted prior lto picking the bucket up from the ground. As the fulcrum portion is moved closer to the cutting edge of the bucket or to the teeth on the cutting edge, it becomes easier to rock the bucket on the fulcrum portion. However, it is believed that the practical forward limit for location of the fulcrum portion is vertically under the combined Center of gravity of the bucket and its load with the bucket and load in lifting position. Usually, the fulcrum portion is very close to being vertically under the dumping trunnion of the bucket. In accordance with usual practice, the center of gravity of the bucket C-1 is forward of the trunnions as is the center of gravity of the bucket and load combined C-2 to automatically dump the load when the pull line is released.
Referring again to FIGURE 1', the angle of perpendiculars dropped from a point on the side of the back laterally spaced from the center of gravity of the bucket and its load to the back of the bucket and to the ground or bottom of the bucket when the bucket is in digging position, is indicated at angle d (delta). This angle will be approximately twice the size of the angle of the bottom of the bucket as carried above the horizontal during carrying of the bucket, as indicated by d (delta) prime in FIGURE 2.
The fulcrum in accordance herewith can be applied to any conventional bucket without regard to the upward sloping back which gives scouring action in accordance' herewith. For example, a fulcrum can be applied to a conventional bucket simply by cutting oi the lower back corner of the bucket at an angle sufficient to provide the fulcrum action. After cutting olf the corner, of course, it is necessary to reenclose the bucket with a plate or the like across the cut so that the bucket is capable of retaining a load. Although fulcrum surface 19 in FIG- URES 1 and 2 is shown as a curved surface, it is evident that other surfaces, e.g. a straight line or series of straight lines, can be used.
Referring now more particularly to FIGURE 3, the structure illustrated therein is evident in View of the discussions of FIGURES 1 and 2, the same elements having the same reference numbers raised by 100. However, FIGURE 3 illustrates an archless bucket which has no arch spanning the forward projections of the sides. Additionally, there are provided connections, e.g., as indicated at 124, of a bridge type holding line .123 to each side of the bucket well in front of dumping trunnion 5. 117. Two dumping blocks, one of which is indicated at 125, are mounted on opposing ends of a spreader bar 116 which spreads the two-piece or bridle lifting chain 120 for rotation of the bucket between the two parts of the bridle lifting chain. The bridle lifting chain is connected to the dumping trunnion on the sides by the lower ends of the chain. The chain is also connected to lifting line 122 through clevis means 121. One strand of the two-piece or bridle holding line 123 passes through each dumping block and the two strands are attached to two opposite sides of the bucket. In other particulars, the bucket and its operation are the same as described with reference to the embodiment of FIGURES 1 and 2.
The upward tilting afforded by the association of the control lines and bucket fulcrum portion results in more dirt carried in each load, promoting eiiiciency of operation. One feature of the archless bucket in that buckets of greater load capacity may be used with machines rated for use with arch type buckets of smaller load capacity. The removal of the arch reduces the weight of the bucket by to 15 percent, thus permitting a bucket replacement with an archless bucket of larger capacity.
Another means of further promoting operational eiliciency is to increase the number of digging cycles which can be completed in a given amount of time. Trips per hour is a common yardstick for dig-ging machine pei'- formance, and the more trips that can be made in one hour, the more dirt that will be hauled by the machine, resulting in a greater return in a monetary investment in the machine. To this end, another feature of the novel bucket configuration of this invention is that the bucket is capable of being fully loaded in a much shorter dragging distance. It has been found that with the bucket of this invention, the bucket may be fully loaded when it has been pulled through a distance of 11/2 to 21/2 bucket lengths. This distance is appreciably shorter than previous experiences with former buckets wherein a pull through a length of five buckets was not unusual. This feature tends to reduce the digging cycle time by reducing the time of the bucket loading portion of the cycle.
One previous problem in reducing the cycle time of the digging cycle was that it was necessary to finish the dragging or lling of the bucket at a point spaced substantially inwardly from a point vertically beneath the free end of the boom for if the lift line was generally vertical, the front end of the bucket would drop upon initial lifting, causing spillage of the contents of the bucket. This meant that the starting point of the digging cycle had to be spaced substantially inwardly from the point directly below the free end of the boom point resulting in wasted time required to pull in or iish in .the bucket to a point where the digging cycle could be initiated.
FIGURE 4 shows a bucket 14) with an improved novel hitch arrangement 154 which perm-its the digging cycle to be initiated at a point almost directly under the boom point, increasing the trips per hour capability of the digging machine byreducing the amount of time for each cycle.
Referring now to FIGURE 4, there is shown a digging machine 30 having a boom structure 32 for supporting and controlling a dragline bucket. This digging machine, shown in this figure, has a cab which is approximately 57 feet long by 23 feet high with a 200 foot boom. The bucket 140 is approximately 15 feet in length. Such a digging machine can support and operate a bucket having a capacity of up to 40 cubic yards of soil. The digding machine is stationed on a bench or shelf. of earth 34 for removing soil from a lower level 36.
FIGURE 5 diagrammatically illustrates one digging cycle. The numeral 30a represents the center of rotation of the digging machine and the boom is represent ed by the longitudinal line 32a. The initial digging point which marks the beginning of the digging cycle is represented by point A. Point B represents that point at which the bucket is filled and is lifted to be swung over to the dump point represented by C. In order to dump the bucket, thebucket must be brought out to a point directly under the end of the boom, so that as the boom traverses thebucket through the arc BC the bucket is also released or fished out to a point where it is directly under the boom point. The arc CA represents that portion of the travelof the boom which brings the empty bucket back to the original digging point A.
One form of the hitch means of this invention is shown in FIGURES 4 and 6-10. Bucket 140 is provided with upstanding sides 141. Pull or haul line 144 is secured to dump lines 146 through mounting means 148. Dump lines 146 are reeved over sheave blocks 150 and extend downwardly, and outwardly to their securement with the front end of the sides of the bucket by link means 152. The sheave blocks 150 are mounted in the free end of a modiiiedhitch means 154 which is pivoted to the bottom or free end of the lift line 142. Pull lines or pull chains 156 are also secured at one end to the pull line at 14S and at the other end to the front ends 0f the sides of the bucket through link means 15S.
The bucket 141i is also provided with a lifting bail which includes a spreader bar 160 positioned above the bucket, extending thereacross and connected to the lift line 142 by diverging lift chains 162. The lift chains are connected to the hitch means by link means 164 and diverge downwardly and outwardly to extend through the opposed free ends of the spreader bar 160. The lift chains are pivoted to trunnions 165 which preferably a-re positioned on the sides of the bucket which, preferably, are generally rearwardly spaced from the center of gravity of the bucket and its load.
The bucket 140 is provided with a at bottom portion 166, a forward kdigging portion 167 having teeth 167a, an obtuse uptu-rned back portion 16S and an intermediate interconnecting fulcrum portion 169. In the bucket 140, the upturned back portion 168 is also similarly provided with a substantially upright terminus portion 1680.
The hitch means 154 includes two similar hitch beams 170 which are generally hat elongate metal bars ared outwardly at each front end 174. An opening 174:1 is formed in each front end through which one sheave block is connected to each beam. The two beam members are secured to a common intermediate bar 178 to form a beam unit. Bar 178 is provided with an opening 178a in the upstanding linger portion 178b to which the free end of the lift line is pivoted. Rear end 180 of each bar is provided with an opening la to which the chains 162 are connected by link means 164.
In FIGURE 1l there is shown a modified form of the hitch of this invention for use with a smaller bucket 240 utilizing but a single dump -line 246. Again, the bucket is quite similar to the bucket previously shown having a flat bottom portion 266, forward digging portion 267 with digging teeth 267a, an obtuse upturned back portion 26S and an intermediate interconnecting fulcrum portion 269 as well as the upright terminus portion at the end of the back portion 268a. The sides 241 are battered, similar to the other buckets, and two pull chains 256 are secured by link means 258 to the front end lof the bucket. A single dump line 246 is reeved over a sheave block 250 which is secured to hitch means 254. Hitch means 254 is pivoted to the free end of lift line 242. Diverging lift chains 262, connected to the rear of the hitch means by link means 264, diverge downwardly and outwardly through the free ends of spreader bar 260 and are pivoted to the dumping trunnions 265 at either side of the bucket. dumping trunnions are preferably laterally spaced from the center of gravity of the bucket and its load.
The free end of the dump lines 246 is reeved over the sheave block 250 and connected by a ring 290 to two diverging dump chains 291 which are outwardly as well as forwardly and downwardly to their respective connections 292 with the front ends of the sides of the bucket.
Fhe hitch means 254 includes a single solid bar hitch beam 254' having an opening in the forward end for receiving 1 clevis ring 25411 to which the sheave Vblock Z50 may be rttached. Openings are provided in the top and rear of seam 254 to which the lift line and lift chains are connected.
The hitch means of this invention supports the respec- :ive dump and lift lines in such a manner as to promote vhe uplifting of the front end of the bucket and the tiltng about the fulcrum portion in response to lifting force applied only by the lift line to the hitch means so that :he front end of the bucket is tilted upward before the fulcrum portion is raised from the ground, thus retaining substantially all the load in the bucket and reducing the ;ime required for each digging cycle.
FIGURE 8 illustrates the bucket in a dumping position avherein tension on the pull line 144 has been released :o permit the open end of the bucket to tilt downwardly ;o a substantially vertically upright position from which the contents of the bucket may be easily dumped. The illustration of the position of the related control lines and litch structure of the bucket 140, as shown in FIGURE 8, is also illustrative of the bucket 240 in a similar position. When the bucket 149 is released to its full dumpng position, it can be seen that here also the dump line is spaced from the back and sides of the bucket due to the hitch beam of the hitch means, which holds the dump line theave blocks spaced a substantial distance forwardly of :he lift line.
The inclination of the back of the bucket in accordance with this invention provides for the scouring action which inhibits the retenton of part of the load lodged in the Jack part of the bucket. The back of the bucket acts like a wedge when drawn into material being loaded. l`he wedge action elevates the material in the bucket, cnabling the bucket to be more fully loaded, especially with a much higher or deeper load at the rear of the bucket. The entering material is deected upward by the sloping Jack or wedge action and the motion of the material upward provides a scouring action up the back of the bucket, eliminating annoyances of sticking material. The rearvardly and upwardly sloped or inclined back can be located on the bucket at practically any position behind the dumping trunnion to obtain the beneficial scouring action. However, where the inclined back is combined in a bucket with the fulcrum, it is advantageous to position the back so that the lower end of the back is coincident with or adjacent to the fulcrum and preferably approximately under the combined center of gravity of the bucket and its load with the bucket in lifting position.
It wiil be noted with reference to FIGURE l that an inward deviation, indicated at reference numeral 31, is provided in back 12. This inward, or forward deviation forms a blunt or obtuse angle in the back and the devia- :ion is suiciently angular to direct solid load materials traveling up the back into the bucket while being sufticiently open or blunt to prevent retention of load within the deviation during unloading operations. The portion of the back above the deviation still slopes at an obtuse angle with respect to the bottom of the bucket. The deviation can be considered as an inward angle or bend in the back which does not materially interfere with the scouring action and does not provide a crevice for packing and holding a portion of the load within the bucket.
In a preferred bucket structure for use in combination with the sloping back in accordance with this invention, 1s included in the illustrated embodiments, the sides of he bucket are battered, i.e., slope outwardly in their upyard extension from bottom to top of the bucket. The )utward slope of the sides in the bucket of FIGURE 1 is )ne horizontal linear unit per l vertical linear units and :he batter of the sides of the bucket of FIGURE 3 is one iorizontal unit per 8 vertical units. Thus, the battered sides provide a bucket wherein the tops of the sides are considerably more widely spaced than the bottoms. This constnuction gives considerable advantage in that the first portion of the load enters the bucket from the cutting edge and succeeding portions follow the first portion resulting in the rst portion being pushed to the top of the bucket by wedge action of the back. With the battered sides, as the load lifts up in the bucket, it is continuously going to a Wider area, thus decreasing or eliminating the friction of the load on the sides of the bucket. The sloping of the back also may function as a batter making it easier for the load to rise upward along the back of the bucket because the load is going to a larger cross-sectional areal as it is lifted upward.
Buckets and 24), shown in FIGURES 4, and 6-11, as previously noted, are provided with the similar coniigurational characteristics discussed relative to bucket -10 permitting the scouring action and improved loading action similar to that discussed here in detail relative to the bucket 10.
The excavator structure of this invention provides a bucket having a fulcrum portion on the bottom of the bucket operably associated with the bucket control lines in such'a manner so as to cause the front portion of the bucket to tilt upward before the fulcrum portion is elevated from the ground. The bucket contiguration illustrated enables the bucket to be iilled by pulling through a much shorter distance than that required for former buckets. Also, the bucket configuration alords a scouring action which results in substantially all of the material carried in the bucket being dumped when the bucket is moved to a dumping position. Furthermore, the hitch means disclosed provides sutiicient lifting force to the front end of the bucket by way of the beam member and dump lines, so that the bucket may be lifted Without spilling its load, even when the bucket is almost directly vertically beneath the free end of the boom. The hitch means keeps the dump lines spaced a sufficient distance from the back and sides of the bucket when the bucket is in the dumping position so as to prevent dump line chang.
Thus, the excavator structure of this invention provides a means for transferring greater quantities of solid material per unit of time lby providing a bucket wherein spillage at initial lifting is eliminated due to the fulcrum portion and its relation to the control lines, substantially all of the bucket load is dumped when the bucket is moved to the dumping position because of the scouring action afforded by the bucket configuration, and bucket loading is accomplished in pulling the bucket through a shortened distance also due to the bucket configuration. Down time due to dump line cable chafing is eliminated and cycle time is reduced by permitting digging to be accomplished at a point substantially directly vertically beneath the free end of the boom as a result of the novel hitchl means which affords initialL tilting of the front end of the bucket even when the lift line is substantially vertical.
The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, for some modications will be obvious to those skilled in the art.
1. An excavator stnucture, comprising: a bucket having side walls, a bottom wall and a rear wall joined, said bucket being provided with a bottom including a forward digging portion and a fulcrum portion rearward of and inclined upwardly from said forward portion, said rear wall extending generally upwardly from the fulcrum portion, said `bucket being further provided with dumping trunnions on either side of the bucket above said fulcrum portion; a dump line secured to the front of said bucket for holding the front of the bucket in different positions of elevation; a lift line connected to said trunnions for raising the bucket from a digging position wherein said forward portion is generally horizontal by rocking said bucket on said fulcrum portion as a result of a lifting force applied by said lift line to raise said bucket forward portion and lower said rear portion prior to elevation of said fulcr'um portion fromthe earth by said lift line.
2. The excavator structure of claim 1 wherein the fulcrum portion is approximately under the combined center of gravity of the bucket and its load.
3. The excavator structure of claim 1 wherein said fulcrum portion is curved with the center of curvatu-re of said fulcrum generally coincident with the center of gravity of the bucket and its load.
4. The excavator str ucture of claim 1 wherein the dumping trunnions are positioned on eithe-r side of the bucket at a point generally rearwardly spaced from the center of gravity of the bucket and its load.
5. An excavator structure, comprising: a bucket provided with battered sides and a bottom including a generally ilat forward digging portion; a curved fulcrum portion rearward of said forward portion and a substantially upright rear portion extending generally upright from the fulcrum portions, said forward, fulcrum and rear portions being joined in series forming bottom and back walls ofthe bucket, the center of curvature of said fulcrum portion being substantially coincident with the center of gravity of the bucket and its load, said bucket being further provided with dumping trunnions on either side ofthe bucket above said fulcrum portion; a dump line secured to the front of the bucket for holding the front end of the bucket in different positions of elevation from generally horizontally during digging to generally vertically downward during dumping of the bucket load; a lift line connected to said trunnions for raising Ithe bucket from a digging position wherein said forward portion extends generally horizontally by rocking said bucket about and upon said fulcrum portion as a result of a lifting force applied by only said lift line raising said :bucket forward portion and lowering said rear portion prior to elevation of said fulcrum portion from the ground by said lift line.
`6. The excavator structure of claim 5 wherein the dumping trunnions are positioned on either side of the bucket at a point generally rearwardly spaced from the combined center of gravity of the bucket and its load.
7. In combination with a dragline earth excavating machine having a lift cable and a pulling cable controlled by winding drums for respectively lifting and dragging a dragline excavating bucket `suspended as a free body from said lines,
an improved excavating bucket having a bottom including a forward digging portion,
upwardly extending side walls and an upwardly extending rear wall joined to the side Walls,
all said walls being joined to the bottom,
trunnions on the side walls for pivotally connecting the bucket to the lift cable,
said bucket having a fulcrum portion including plate members departing upwardly from the bottom of the bucket at an area of the bottom forward of the bucket to an extent at least directly below fthe trunnions when the bucket is in generally horizontal digging position,
said fulcrum portion providing means for supporting the bucket and contents upon the earth while allowing relatively easy turning of the bucket upon the fulcrum to raise the digging front portion and lower .the back portion when it is desired to raise the bucket with said lift line.
8. A dragline earth excavating machine bucket for connection to a lift cable and a pulling cable controlled by winding drums for respectively lifting and dragging the dragline excavating bucket suspended as a free body from said lines, comprising:
an improved excavating bucket having a bottom including a forward digging portion,
upwardly extending side walls and an upwardly extending rear wall joined to the side walls, j
all said walls being joined to the bottom,
trunnions on the side Walls for pivotally connecting the bucket to the lift cable,
said bucket having a fulcrum portion in its bottom including plate members angled upwardly in relation to the bottom of the bucket beginning at a line across the bottom from side to side forwardly of the bucket at least directly below the trunnions when the bucket is in generally horizontal digging position,
said fulcrum por-tion providing means for supporting the bucket and contents upon the earth While allowing relatively easy turning ofthe bucketupon the fulcrum to raise the digging front portion and lower the back portion when it is desired to raise the bucket with .said lift line.
9. A dragline excavator structure, comprising:
an archless dragline bucket provided with upstanding side walls,
a bottom wall with a digging lip at its front,
and a rear wall,
said bottom and rear walls being edge-joined to the respective side walls forming an open-front digging bucket,
a lift line and lift chains connected together and the chains in turn connected to :the bucket to raise and lower the bucket,
an elongated beam member having a rearward portion with spaced attaching means generally aligned across the beam for respectively pivotally receiving the lift line and lift chains, said pivotally received lines when tensioned raising the beam to a substantially horizontally forward extending cantilever position over the bucket,
said beam member having means providing a bifurcated forward encl,v each of said ends having a ring opening for securing a sheave loosely to each ring opening,
a sheave housing swingably secured to each n'ng opening and a sheave inthe housing,
a dump line reeved over each sheave and having a portion extending about its sheave downwardly and outwardly from the beam member toward the respective side Wall of the bucket, such dump line portions being in alignment with the bucket rear wall when the latter is swinging forwardly between said lift chains and being held forwardly of the path of the swinging bucket by said beam member.
References Cited bythe lExaminer UNITED STATES PATENTS 1,313,911 8/1919 Potter 37-116 1,570,845 1/ 1926 Kurtz.
1,579,945 8/1926 Kelley 37--135 1,766,053 6/ 1930 Brendlin 37-135 1,826,920 10/1931 Brendlin 37-135 2,168,643' 8/1939 Berser 37--135 2,200,315 5/ 1940 Weimer 37-116 2,629,190 2/1953 Berser 37-135 2,904,906 9/ 1959 Smith 37-135 3,112,572 12/1963 Lorsen 37-135 FOREIGN PATENTS 648,399 1/ 1951 Great Britain.
OTHER REFERENCES H. L. Nichols, Moving the Earth. Holliday Corp. 1959. FIGURES 13-83 :and pp. 13-67 to 13-69.
ANTONIO F. GUIDA, Acting Primary Examinez'. BENJAMIN HERSH, Examiner. G. T. MOLLE/R, W. A. SMITH III, Assistant Examiners.