US 3541710 A
Description (OCR text may contain errors)
O 24,1970 5'. w. SANKEY E DRAGLINE BUCKET AND REEVING THEREFOR F'iied Aug. 22, 1967 2 Sheets-Sheet 1 INVENTOR EDWIN H.8ANKEY W- Bevan MANN ma wwufiu ATTORNEYS BY 5 Sol-u i tumume,
Nov. 24, 1970 E.W.$ANKEY EI'AL 3,541,710
I DRAGLINE BUCKET 'AND REEVING THEREFOR I Filed Aug. 22, 1967 2 Sheets-Sheet I INVENTORS Eowm H. SANKEY RoBEz-r W.BEQ.GMANN masofz'wwim ATTORNEYS United States Patent 3,541,710 DRAGLINE BUCKET AND REEVING THEREFOR Edwin W. Sankey and Robert W. Bergmann, Marion, Ohio, assignors to Marion Power Shovel Company, Inc., Marion, Ohio, a corporation of Delaware Filed Aug. 22, 1967, Ser. No. 662,500 Int. Cl. E02f 3/46; H02p 5/22 U.S. Cl. 37-115 11 Claims ABSTRACT OF THE DISCLOSURE This invention relates to the application of force to a body to be moved, and particularly where the application is made by attachment of the force applying means to more than two points on the body to be moved, and to a particular construction of a body to be moved.
Throughout the years, larger and larger excavating machines have been developed and built. The increase in size has brought problems relative to the weight and strength of the buckets themselves, and the bucket weights have created additional problems of suspension and handling.
Dragline buckets of from 160 to 180 cubic yard capacities are now in use. Buckets of even larger capacities are being demanded. It is obvious that the only way in which the capacity of the bucket can be increased is to enlarge its overall dimensions. In the process of widening the bucket, the lip section carrying the teeth, as well as the arch, or bail, connecting the forward edges of the sides, become much wider. Both of these spans would be so great for increased capacity buckets that they would have to be of extremely heavy design in order to be strong enough to withstand the terrific strains which would be imposed. This, in turn, would so greatly increase the weight of the bucket in proportion to its increased capacity that the resulting structure would hardly be practical. Some way had to be found to increase the capacity of the bucket without an inordinate increase in bucket weight.
In handling dragline buckets up to approximately 70 cubic yards in size, two hoist ropes and two dragline ropes of approximately three and one-half inches in diameter can be used. When larger buckets were developed, it was necessary to use four drag ropes, two attached to each side of the bucket, and the four were trained about a single drum. By using four ropes of four-inch diameter, it has been possible to handle buckets up to the present limit of capacity.
It is now desired to construct buckets of over 200 cubic yard capacity. Using present methods, it would require at least five inch diameter wire rope to handle a bucket of this size without overloading. This size rope is impractical, both from a manufacturing standpoint and from the standpoint of manipulating and handling in the field.
More than four ropes might be used, but with attachment being made to the bucket at only two points and only one drum being used, complex and unwieldy equalizers would be required. It can be seen that, when using one drum, the total tension might be applied to the bucket at only one point if the digging loads were concentrated 3,541,710 Patented Nov. 24, 1970 at that point, and this must be taken into account when selecting rope size. Thus, when using two points of attachment, the tension at one point could be twice what otherwise might be considered to be the average tension per point; likewise, with three points of attachment, the tension at one point might be three times that considered as average. It follows, then, that the use of multiple points of attachment does not, in itself, permit the use of smaller ropes. It should also be recognized that it is neither necessary nor desirable that the total tension be applied at one point.
SUMMARY OF THE INVENTION The general object of the present invention is to provide a means for imparting force, or motion, to a body, with the attachments to the body being made at more than two points movable at the same speed, with the application of forces to the attachment points being in definite ratio, and to the construction of a particular body to be moved.
A more specific object of the present invention is to provide a practical, relatively lightweight excavating bucket which will make it feasible to manufacture larger capacity buckets, and to provide an improved rope reeving arrangement so that larger loads can be handled with wire rope of diameters that can be manipulated in the field.
Another object of the invention is to provide a bucket which will have a partition, or partitions, intermediate its sides extending throughout the length of the bucket, so that the widthwise spans of the toothed lip and the arch will be reduced, in effect, to a fraction of the total span of the bucket.
A further object of the invention is to utilize the bucket partition as an additional point of attachment of forceapplying lines, so that the total number of lines may be in excess of those previously used and thus permit the use of smaller diameter cables, or lines.
It is also an object to provide an increased number of hoist ropes for raising and lowering the bucket.
A still further object is the provision of a plurality of winding drums for the respective draglines, hoist lines, or other force-applying lines, with the drums of each plurality providing a maximum tension in proportion to the number and size of the ropes wrapped upon it.
Other objects of the invention will become apparent from the following description of one practical embodiment thereof when taken in conjunction with the drawings which accompany, and form part of, this specification.
BRIEF DESCRIPTION OF THE DRAWING FIG. 2 is an enlarged perspective view of the bucket I and the attachment of the cables to the bucket; and
FIG. 3 is a view of a portion of a modified cable reeving arrangement.
DESCRIPTION OF THE PREFERRED EMBODIMENT The method of force application of the present invention can be employed in the movement control of bodies of many types, such as dragline buckets, power shovel dippers, shovel crowd motions, lift bridges, car or barge pullers, etc. It can be applied by the use ofropes, racks and pinions, etc. In fact, a basic requirement is that the force be attached to the body to be moved at more than two points which will have equal movement, and the force be applied to the several points of attachment in definite ratio. In order to simplify the disclosure, the invention will berdescribed in connection with a dragline bucket as the body and a six line reeving of ropes as the force-applying means.
Referring to the drawings in detail, and first to FIGS. 1 and 2, the bucket 1 of the improved design, has the usual back 2, bottom 3 and sides 4. The bottom terminates at its forward edge in a lip 5, having the usual teeth 6. The upper, forward corners of the sides 4 are joined by the arch 7. Each side carries an adjustable trunnion hitch 8 and each side has a forward projection with a plurality of openings 9 for the selective connection of the draglines.
In order to brace the bucket, and to make it possible to use a somewhat lighter construction than would otherwise be required, the bucket is provided with a vertical central partition 10. The partition is the full height and extent of the sides 4, and is Welded along its back to the bucket back wall 2 as at 11, and along the bucket bottom wall 3, as at 12. The partition has an upwardly extending provjection 13 at its forward end which has its top welded to the undersurface of the arch 7 at the center of the arch. Thus the partition divides the bucket into two compartments 14 and 15, with the partition forming the divider between the two. This, in effect, creates two buckets in side-by-side relation. Thus, the free span of the bucket lip and the arch 7 are cut in half and these elements can be made of much lighter construction than would ohterwise be necessary. It is to be noted that the partition also has a forward extension 16, which has a plurality of openings 17 for connection of draglines.
The bucket will be suspended from the boom point by hoist lines 18, and its digging and attitude will be controlled by draglines 19.
The dragline includes chains 20 which have clevices 21 at their ends, with pins 22 through selected ones of the openings 9 in the bucket side walls. A third chain 23 has its clevice 24 coupled to the opening 17 of the central partition 10. At the opposite ends of the chains 20 and 23, there are singletrees 25 and 26, respectively, freely pivoted at their centers on the chain ends. Pairs of cables 27 are connected to the ends of each of the singletrees 25, while another pair of cables 28 is connected to the ends of the singletree 26. Thus, there is a pair of cable connected for equalized pull to each of the dragline chains 20 and 23. The cables, or ropes, 27 and 28, are trained over as many sheaves as may be required to lead them to the drag drums 29 and 30. As shown, the lines run over three, double groove, lower fairlead sheaves 31 and three, double groove upper fairlead sheaves 32.
The outside cables 27, which lead from the side walls of the bucket, are wound upon the drag drum 29, while the central cables 28, which are connected through chain 23 to the partition 10, are wound upon the drag drum 30. This arrangement puts four cables upon drag drum 29 and two upon drum 30. Each drum has a set of spiral grooves for each cable Wrapped upon it. The cables are under tension, due either to the digging loads or the force of gravity on the bucket, so that the cables will lay in the grooves and be wrapped uniformly. The drums are sufiiciently large that the cables will be wrapped in only one layer. The two drag drums are independently driven by direct current motors with Ward Leonard Electric Control providing the motors with a drooping speed-torque characteristic in order to automatically proportionately divide the load between the motors for the respective drums. The well known Ward Leonard system consists of a direct current motor having its armature circuit voltage supplied by a set of generators wherein the voltage is adjustable and the motor speed and torque characteristics are governed by excitation of the generator set. Excitation to provide a drooping speed-torque characteristic decreases motor speed as motor torque increases in the motoring or positive sense, and increases motor speed as torque increases in a braking or negative sense. Such a motor and control system is disclosed in an article entitled Modern Electric Power Shovels by J. F. Weis, appearing in Electrical Engineering of September 1955, pp. 782 through 787, and a booklet published by Marion Steam Shovel Company, now by change of name Marion Power Shovel Company, Inc. of Marion, Ohio, entitled A.C. Facts D.C., booklet 281. By having twice as many motors on the drum 29, which has four cables attached, as on the drum 30, which has two ropes attached, twice the total line pull will be obtained from the drum 29 as from the drum 30, and this ratio will be maintained under varying load conditions. Thus, there will be a proportional pull on each of the six cables at all times, so that each cable will carry its proportionate share of the load and the pull will be applied evenly to the sides and center partition of the bucket.
Hoist line 18 is connected to the bucket by means of hoist chains 33. The lower ends of the chains are connected to the trunnion hitches 8, and the upper ends are connected to a bar 34. Intermediate the ends of the chain, there is the usual spreader bar 35. Bar 34 has links 36 pivotally connected to its ends, and a link 37 pivotally connected to its center. Each of the links has a singletree equalizer pivotally connected to its upper end. Equalizers 38, pivotally connected to the outer links 36, each carry a pair of hoist ropes 40. Equalizer 39, connected to link 37, carries a pair of hoist ropes 41. The ropes are connected to the ends of the equalizers in substantially the same manner that the drag ropes are connected to the equalizers 25 and 26. Hoist ropes 40 and 41 will run around three, double groove sheaves 42 at the boom point of the machine, and over three, double groove, hoist deflection sheaves 43 located on the gantry or some other convenient position. The outside ropes 40 are wound upon a hoist drum 44, and the inner hoist ropes 41 are wound about the hoist drum 45. Here, again, there are twice as many ropes on the drum 44 as on the drum 45. Therefore, the number of motors 46 for drum 44 will be twice the number of motors 47 for drum 45. This is in the same ratio as the motors 48 for drag drum 29 and motors 49 for the drag drum 30. The electrical system for the hoist is similar to that previously described for the drag.
In order to control the bucket attitude, the usual dump rope 50 will be connected to the drag chains 20, pass around the sheaves of dump block 51 attached to the bar 34, and about an equalizer sheave 52 mounted on the arch 7 of the bucket.
FIG. 3 of the drawing shows the slightly modified arrangement of the hoist ropes. In order to simplify the disclosure, the same reference characters previously used have been applied to the same parts in FIG. 3 with a prime added. It will be noted that the drag line arrangement is identical to the previously described reeving.
In the modified embodiment, the hoist ropes 40' and 41 are carried over the sheaves 43 as before. In this case, however, one rope of each of the pairs 38 is carried to the drum 44' and the other rope of each of the pairs 38 is carried to the drum 45'. One rope of the center pair 39' is wound upon the drum 44' and the other rope of this pair is wound upon the drum 45. This arrangement puts one cable of each of the three pairs on drum 44 and one cable of each of the pairs on drum 45'. As the number of ropes is the same on each drum, the number of motors 46' and 47' will be equal. This arrangement follows the same basic principle as the form first described, merely the attachment of the several cables to the respective drums is different.
In the above discussion, wherever the numbers of motors driving the respective drums have been given, it is to be understood that it is assumed the cables are all identical and the motors are identical. If various sizes of motors and ropes are used in combination, the same linear speed of rope movement and desired ratio of force application must be maintained under all conditions.
While in the above several embodiments of the invention have been disclosed, it will be understood that the particular details of construction illustrated and described are merely by way of example and the invention may take other forms within the scope of the appended claims.
What is claimed is:
1. Apparatus for applying force to a plurality of attachment points of a movable body in a predetermined ratio comprising, a plurality of power driven force applying means, at least three attachment points on the body equal in number to the number of force applying means for connection to the force applying means, a plurality of separate connecting means each individually extending between and connecting one of said force applying means to one of said attachment points, and means to control the force applying means to return to said predetermined ratio of force application at each point of attachment in response to variations in load from said predetermined ratio at the points of attachment.
2. Apparatus as claimed in claim 1 wherein, the body is an excavating bucket, the force applying means are cable drums, and the means to control the force applying means are motors in driving connection with the drums, the motors having a drooping speed-torque characteristic.
3. In a dragline excavating machine including a bucket moved by hoist and draglines, the improvement which comprises, the bucket having vertical sides and at least one vertical partition intermediate the sides and extending lengthwise of the bucket, the bucket sides and partition at their forward edges each being attached to a separate dragline.
4. In a dragline excavating machine as claimed in claim 3 wherein, the separate draglines are wound upon a plurality of drums driven by motors having a drooping speedtorque characteristic to provide a predetermined ratio of tension on each drag line.
5. Ina dragline excavating machine as claimed in claim 4 wherein, the hoist line includes a plurality of separate lines wound upon a plurality of drums driven by motors having a drooping speed-torque characteristic to provide a predetermined ratio of tension on each hoist line.
6. In a dragline excavating machine as claimed in claim 3 wherein, there are two separate drag lines to each side of the bucket and two lines to the bucket partition, the lines to the bucket sides being wound upon one drag drum and the lines to the bucket partition being wound upon another drag drum, the respective drag drums being driven by motors having a drooping speed-torque characteristic and the numbers of motors driving the respective drums being in the same ratio as the numbers of lines wound upon the respective drums.
7. In a dragline excavating machine as claimed in claim 6 wherein, each two lines to thebucket sides and the two lines to the partition are respectively interconnected by means of equalizers.
8. In a dragline excavating machine as claimed in claim 7 wherein, the hoist line includes a plurality of separate lines wound upon a plurality of hoist drums, with the respective hoist drums being driven by numbers of motors in the same ratio as the numbers of lines wound upon the respective hoist drums, the motors driving the hoist drums having a drooping speed-torque characteristic to provide predetermined ratio of tension on all hoist lines.
9. In a dragline excavating machine as claimed in claim 3 wherein, the bucket has a toothed front lip bridging the bottom front ends of the sides, and an arch interconnecting the top front ends of the sides, and the partition is secured to the front lip and arch.
10. A dragline bucket having a bottom, back and sides and at least one partition extending vertically from the bottom parallel to the sides, the bottom having a toothed front lip extending between the sides, and an arch interconnecting the top front edges of the sides, the partition being connected to the bucket back, bottom, front lip and arch.
11. A dragline bucket as claimed in claim 10 wherein the bucket sides and partition have means at their forward edges for connection of draglines.
References Cited UNITED STATES PATENTS 1,714,120 5/1929 Bailey 37-135 2,341,838 2/1944 Bager 37-135 2,359,303 10/1944 Davidson 37-135 2,380,431 7/1945 Harding et a1. 37-116 2,525,528 10/1950 Deal 37-135 2,669,042 2/1954 Swank 37-135 2,414,473 1/ 1947 Mahnke 254-172 3,033,526 5/ 1962 Priest 254-183 3,057,162 10/1962 Lee 254-172 3,261,591 7/ 1966 Campbell et al 254-172 3,273,860 9/1966 Weisenbach 254-184 3,285,575 11/1966 Grifiiths 254-183 3,402,824 9/1968 Zweifel 254-185 2,393,622 1/ 1946 Adams et al 318-156 X 2,534,917 12/1950 King 318-140 X 2,567,427 9/1951 Fox 318-140 X 2,834,927 5/1958 Halter 318-156 X 2,856,572 10/1958 Pinto 318-156 X 3,047,786 7/ 1962 Denouden 318-156 X 3,078,406 2/ 1963 Zweifel et al. 318-140 X OTHER REFERENCES Modern Electric Power Shovels by I. F. Weis, Electrical Engineering, September 1955.
AC. Facts D.C., Booklet 281 by Marion Steam Shovel, prior to 1928, pp. 3, 6, 7, 11, 12, 13.
ROBERT E. PULFREY, Primary Examiner E. H. EICKHOLT, Assistant Examiner US. Cl. X.R. 37-118, 254-184: 318-156