US1973136A

US1973136A - Excavating machine

Info

Publication number: US1973136A
Application number: US646695A
Authority: US
Inventors: C O Davis
Original assignee: Individual
Current assignee: Individual
Priority date: 1932-12-10
Filing date: 1932-12-10
Publication date: 1934-09-11
Anticipated expiration: 1951-09-11

Description

Se t. 11, 1934. L. M. ATKINSON 1,973,136

' EXCAVATING MACHINE I Filed. Dec. 10, 1932 2 Sheets-Sheet 1 INVENTOR L. ewi s IYLAl'kins an BY Z M ATTORNEYS.

Sept. 11,1934. L M. so 1,973,136

EXCAVATING MACHINE Filed Dec. 10, 1932 2 Sheets-Sh 2 FIG. 6,

2'4 .0 a 2 49 A d Q 45 a o a U. n L 5 22 46, I

K (7 Z7 44 J 34 gm 'LLL'F :46 21s /2 ,1 Q Q I I. /4' 28 PM I FIG T 0 fl [Q] xv INVENTOR.

L. Ewis M.A1Ikins an Y mechanism Patented Sept. 11, 1934 paired s r EXGAVATING MACHINE IzeWisllLiAtkinson, Pittsburg, K'ans.; C. 0; Davis administrator oi said' Lewis M. Atkinson, de-

Application: Deceinben-lO, 1932, Serial No. 646,695, 'YClaims: (01. 214-1 5) The present invention relates to: excavating use as a part of large revolving shovels, such as coal-stripping shovels; and shovel'sior the strip-'- ping and loading of ores, it is not limited to such use; it may be applied to the smaller excavatingmachines where the load or work is gathered by the use of a dipper, scoop, or similar unit adapted to penetrate the mass laterally in c'ontr'adistinc- 1 tion to clam shell buckets which penetrate the mass by a direct fall or substantially vertical downward movement.

The principal" object of the invention is-to-pro vide mechanism associated with theloadhoisting to counteract the weight of, or the force of gravity acting upon thee'xcavating mem her and accessories, and in some instances theload of material carried by the excavating member, so as to increase the efliciency and stability, 1 and reduce the expense of operation of the equipment.

Another objectof the invention is to .providecounteracting mechanism associated with the. load hoisting mechanism so as toreduce the horse 25. power required by the prime movers, such as.

or internal combustion engines, or electric. motors to operate the excavator; thereby increasing the dirt moving capacity of the excavator equipped with the present invention by utilizingpower now lost in hoisting'and. l'oweri'ngthe excavating member and accessories. of the excavating machine are heavier than the load to be lifted and by theme of the counteracting mechanism, the eniciency and capacity of the excavating machine are materially increased.

Another object of the invention is to. utilize a. vertically guided weight, preferably of a variable nature, much heavier than'the parts ofv theload" hoisting mechanism which it is to counteract, and by the use of motion transmitting and speed reducing mechanism operatively connected with" the weight and load hoisting mechanism, provide optimum counteraction with but short lineal travel of the weight as compared with the lineal travel of the excavating member. This makes. possible relatively short guides for the weight, reducing the cost of manufacture and increasing stability of the structure on its base.

A further object of the invention is to provide means for adjusting the position of the weight in guide, independently of movement'of the; excavating member. This is particularly advan-- tageous where the excavating machine is equipped. with a boom capable of being raised and lowered and where such change. in position of the boom These parts! effects the motion transmitting and speed reduc-' ing' mechanism between the load hoisting mechanism andthe weight. Such adjusting means also makes possible the use of relatively short guides forthe weight since, by adjustment, its path of travel or amplitude'oi movement may be maintained substantially the same during a load engaging and lifting operation even tho the position or the boom be changed by raising or lower ing same as required, according to the conditions met during-different excavating operations. The adjusting means alsoenables the operator totake up stretch in the cables, which may form a part of the hoisting mechanism and the motion transmitting and speed reducing mechanism, which cables are lengthened as a result of normal wear. In a practical example, the motion transmitting and-speed reducing mechanism may be pluralpart tackle and by suspending the weight through. J

two of such and utilizing the adjusting means for each, the: weight may be suspended plumb in its guide instead of sagging on either side asa result of one weight supporting cable wearing faster,

and hencelengtheningto-a. greater degree, than thecableon the opposite side of the weight.

Another object of the invention is to provide counteracting mechanism which will serve its: purposeas hereinbefore set forth and also aid in maintaining the stability of themachine, thereby avoiding the use of heavy ballast weight, now commonly used at the rear of the excavator cab opposite to the end supporting the boom, and which ballast, as now commonly used, serves but one purpose,to offset the weight of the mass at the opposite side of the center of gravity of the machine. v

A, further object of the invention is to provide counteracting mechanism which may be appliedto the conventional or now commonly used excavating machine without considerable change or replacement of parts.

Otherobjects and advantages of the invention willappear in the following detailed description' taken in, connection with the accompanying drawings, forming a part of this specification, and in which drawings:---

- Figure 1 is a view partly in elevation and partly in vertical section showing an excavating machine equipped with one form of the present invention.

Figure 2 is a fragmentary view in plan, with parts broken away to show details.

Figure 3 is an end elevation of the machine, same having, been swung on its base thru an arc of ninety degrees from the position shown in Figure 1.

Figure 4 is a View on an enlarged scale, partly in elevation and partly in vertical section, show ing the weight, a portion of the motion transmitting and speed reducing mechanism, and means for adjusting the latter so as to maintain the same path of travel for the weight, regardless of the position of the boom.

Figure 5 is a detail view in elevation showing a modification or such adjusting means.

Figure 6 is a view similar to Figure 1 showing a modification or" the invention, and particularly well adapted for use as an addition to conventional or now commonly used excavating machine.

Figure 7 is a view similar to Figure 2 but show-,

ing the'modification as disclosed in Figure 6.

In the drawings, wherein similar characters designate similar or like parts throughout the several views, A designates a carriage of the excavating machine; B the revolving frame mounted thereon; C load collecting and hoisting mechanism on frame B and comprising a boom D, boom hoist E, load engaging unit or excavating member F, boom machinery G and excavator hoistI-I; and J counteracting mechanism associated with the load collecting and hoisting mechanism C, and comprising a weight K, a support and guide L for the weight, motion transmitting and speed reducing mechanism M, and means N for adjusting the motion transmitting and speed reducing mechanism to change the relative position of, the weight K in itsguide, independently of movement of the load engaging unit.

In the example shown, the carriage A comprises a base 8, supported by trucks 9. s

The frame B may be revolubly mounted upon ;that the inventionmay be applied to other types of excavating machines and perhaps its only limitation that it is not applicable to excavating machines using clam shell buckets intended to penetrate the mass to be lifted, by direct fall, or a substantially vertical downward movement. The boom D is pivotally connected at its foot 12 to the end 10 of frame B, by brackets 13, a pivot pin 14 or other suitable assembly permitting the boom to be swung upwardly and downwardly by use of the boom hoist E. The boom is provided with a sheave 15 at its point for cooperation with the excavator hoist H. The load engaging unit' or excavating member F comprises a dipper 16 and a dipper handle 17, the latter being'provided with a rack 18 for cooperation with the boom machinery G. Such machinery, in the example shown, comprises a shipper shaft 19 having a pinion 2O thereon for meshing relation with the rack 18, the shipper shaft 19 beingrotated J through gear 21 thereon, meshing with a pinion 22 on the shaft of motor 23. By this boominachinery, the excavating member F may be proiected and retracted with respect to the boom in the usual manner. p

In the example shown, the'boom hoist E comprises four-part tackle 24 associated with a drum 25, operated in any suitable manner, such as by mechanism including worm 26 and worm wheel 2'7.

The excavator hoist H, in the example shown, comprises a drum 28, rotated by a gear 29, meshing with a pinion 30 on the shaft 31 of prime movers 32, and suitable tackle 33 connecting the excavating member Fwith the drum. In the example shown, the prime movers 32 are electric motors, suitable current being supplied thereto through motor-generator set 34. As a typical example, the drum 28 may be of the type provided with oppositely running grooves, start ing at the center, so that two lines or cables are operatively connected to the drum, and to the dipper bail 36, the cables 35 running over boom point sheaves 15 in the usual way.

Concerning the counteracting mechanism J as shown in Figures 1-5, the weight K is preferably in the form of a large receptacle 37 containing a quantity of material 38 of considerable weight, such as fragments of metal. The effective weight of the unit may therefore be varied by adding material to, or removing material from the receptacle 37. Thus optimum counteraction, utilizing the weight, may be had by experiment and observation of the equipment in operation. The weight 3'? is preferably provided with oppositely disposed grooves 39 for cooperation with rails 40 of the support L, these rails 40 providing a guideway 41 in which the weight moves. The support L comprises uprights 42, a cross beam 43, braces 44, extending upwardly and diagonally from the frame B to the beam 43, and tie members 45 connecting beam 43 with an A-frame 46, forming a part of the boom hoist E. I

In the example shown, ,the motion transmitting and speed reducing mechanism M is in the form of threepart tackle altho it is to be distinctly understood that this is merely by way of example, since other plural-part tackle may be used, or other mechanism associated with the hoisting mechanism and the weight, to move in unison, and so that the weight has less linear movement than the excavating member during a hoisting operation. As shown in Figures 1 and 2, thethree-part tackle is duplicated adjacent opposite ends of the weight, and it suflices to describe one thereof. In the form shown in Figures 1, 2, 3 and ,4, the three-part tackle coniprises a multiple sheave block 50 carried by supportL; a sheave 51 secured to weight K;' and, a cable 52 having its one end portion secured to and adapted to be wound on the same drum 28, that forms a part of the load hoisting mechanism, and its other end portion secured, as at 53, to a projection 54 of block 55 which supports sheave 51. Thus there is a run 56 of cable, from drum 28 to sheave block 50 which may be taken upon the drum 28, on thesame surface thereof. formerly occupied by the cable 35, as the dipper descends; a run 156 of cable between sheave block 50 and sheave 51; a run 5'? of cable from sheave 51 back to sheave block 50; and, a run 58 of cable from sheave block so to the point of attachment 53 to the Weight. Looking at Figure 1, if the drum 28 is rotated counterclockwise the dipper 16 will descend, and the weight K will. ascend in its guideway 41. However, the linear movement of the weight Kwill be considerably less than the dipper 16, because of this motion transmitting and speed reducing mechanismoperatively connected to the load hoisting mechanism and the weight. The. weight K may be made many times greater than the excavating member and its load and in fact may be made sufiiciently heavy to overbalance the dipper, dipper handle and load, if desired, so as to reduce the horse power required at prime mover 32, during a hoisting operation, and to facilitate disengagement of the load from the mass during the initial operation of the load collecting and hoisting mechanism for accumulating the load in the dipper. By locating the weight K and support L at the end 11 of frame B, the weight,

assists in maintaining the stability of the excavating machine at the side of the axis of rotation of the frame on its base 8, opposite to the boom D, excavating member F, boom machinery G and those portions of the excavator hoist H as are to the side of said vertical axis opposite end 11.

By overbalancing the dipper, dipper handle and load, as above set out, important advantages are gained. The weight K in the example shown being more than three times heavier than the dipper, dipper handle and load, effectively assists in maintaining the stability of the revolving frame B on the carriage A, and the carriage A on the ground. This is especially advantageous when the boom machinery G and the hoist 1-1 have been operated to extend the dipper 16 remote from the.

boom D with the dipper handle 17 substantially horizontal, (as when dumping the load from the dipper) at which time there is a tendency to tip the machine in the direction of the dipper if there is not suflicient counteracting weight adjacent the end 11 of the frame B. If the machine is electrically operated, as by use of the motors 32 and the motor-generator set 34, regeneration during the lowering of the dipper is eliminated, reducing the heating of the hoist motors and generators. In isolated places where the excavating machine must be operated by an electrical power plant located in the immediate vicinity of the excavating operations, the power. plant capacity need not be as great as where there is equipment which regenerates electricity during the lowering of the dipper and is subjected to extreme peak loads for lifting and causing the. dipper to pene-' trate the mass of material to be hoisted or moved. According to this embodiment of the present invention, the load peak during digging or penetrae tion or" the dipper into the material to be dislodged and collected is reduced to a minimum.

Assuming that it is desirable to change the position of the boom D, by moving it upwardly, the dipper and dipper handle remaining in the same relative position to the boom as shown in Figure 1, he weight K will descend, since, in order to ..-.ntain this relative position of the dipper handle to the boom, it will be necessary to rotate drum 28, to take up the slack in cable 35. On the other hand, if the boom D is to be lowered from the position shown in Figure l, the dipper handle still retaining its same relative position to the boom, the weight K must be lifted, since drum. 28 must be rotated to play out more cable 35 and this rotation. of the drum lifts the weight through mechanism M. For this, and other reasons, the means N is provided for adjusting the motion transmitting and speed reducing mechato change the relative position of the weight in its guideway 41, independently of movement of the excavating member. This may be accomplished, as shown in Figure 1, by supporting the multiple sheave block so by a screw threaded it 66, extending through an opening 61 in beam 43, the shaft receiving a nut 62, or a wheel having an internally screw threaded hub, the shaft 60 having a swivel connection with block 50, as shown at 63. The nut 62 may engage a bearing 64 resting upon beam 43. Thus by rotating nut 62, the plural-part tackle may be bodily moved upwardly or downwardly, according to the direction of rotation of the nut, and the relative position of the weight K in its guideway changed, While the load hoisting mechanism remains inert. This device may also be used to take up line wear and to make sure that the weight K is suspended plumb, as hereinbefore described.

If desired the multiple sheave block 50 may be dispensed with, and single sheave blocks provided as shown in Figure 5, each independently supported by a device N. This permits the blocks 70 to independently swivel on the shafts co, for the sheave receiving the run 56 of cable is most likely to be subjected to wear, as the cable moves on and off the drum 28, this independent swiveling of the blocks, reducing wear to a minimum.

In the form of invention shown in Figures 6 and 7, the arrangement is similar to that shown in Figures 1-4, with the exception that the motion transmitting and speed reducing mechanism M has connection with the load hoisting mechanism C, at bail 36 of dipper 16, instead of to the drum 28 of the excavator hoist E. This makes necessary the use of another boom point sheave for each run of cable 81 from the bail 36, over the sheave, to the multiple sheave block 50. 'In this example, while the weight K may be many times heavier than the dipper 16 and its handle 1'7, so as to assist in maintaining the stability of the excavating machine, it should not be made so heavy as to overbalance the empty dipper and associated parts. In this form, if the boom D is raised or lowered, the dipper and its handle still retaining the same relative position to the boom D, the weight K is proportionately lowered or raised, respectively, which emphasizes the importance of means N, otherwise it would be necessary to provide a much longer guideway 41 for the weight.

In the example shown, the invention has been applied to large revolving shovels, such as are used for coal or ore stripping, that is, for removing the overburden, or for digging canals, but it is to be understood that the invention may be applied to smaller excavating machines, and when so doing it may be desirable to support the weight K by motion transmitting and speed reducing .mechamsm operatively connected to the central portion of the weight, instead of duplicating this mechanism with connections adjacent opposite ends of the weight. Other means than that comprising the shaft 16 and nut 62 may be utilized to adjust the weight in its guide-- way, independently of movement of the load engaging unit, or this means shown in Figure 4 may be connected between the block 55 and weight K, or the means may be provided at the beam 43, as well as at the weight, where the boom D is intended for considerable movement ina vertical plane. In actual reduction to practice I have found that the application of my invention to excavating machines materially increases the capacity of the machine for doing work, both as to load hoisted, and time required for hoisting operations. As an example, an excavating machine equipped with two 250 H. P. motors to operate the excavator hoistv with a dipper having a capacity of 12 yards, successfully operated a dipper of 18'yard capacity, after being equipped with my invention. As another example, an excavating machineyhaving motors of a total of 560 H. P. capacitmformerly using a dipper of 16 yard capacity was equipped with one for 18 yard capacity after application of ing that the conditions concurrent with the adoption of the mechanism will necessarily vary, it is desired to emphasize'the fact that various minor changes in details of construction, pro-. portion and arrangement of parts may be resorted to, required, without sacrificing any of the advantages of the invention as defined in the appended claims.

I claim:

1. In an excavating machine, the combination with a frame, and load hoisting mechanism carried thereby, including, a boom pivotally carried by the frame, a boom hoist for aising and lowering said boomya load engaging unit, and a hoist for said load engaging unit including a hoist line having a running connection with the boom remote from the pivotalconnection ofthe.

boom with the frame, of mechanism to counteract the weight of the load engaging unit, comprising, a weight, a guide for the weight carried.

by the frame, motion transmittingand speed reducing mechanism operatively connecting a moving part of the load hoisting mechanism and said weight to move in unison-so that the Weight has less linear movement than the load engaging unit during a hoisting operation, and means for adjusting said motion transmitting and reducing mechanism to change the relative position of said weight in its guide, independently of movement of the load engaging unit, to compensate for a change in position of the boom relative to the frame.

2. In an excavating machine, the combination with a frame, and load hoisting mechanism carried thereby, including, a boom pivotally carried by the frame, a boom hoist for raising and lowering said boom, a load engaging unit, and a hoist for load engagin unit including a hoist lne having a running connection with the boom.

remote from the pivotal connection of the boom with the of mechanism to counteract the weight of the load engaging unit, comprising, a weight, a support carriedby the frame and proa guideway for the Weight, plural-part tackle between the support and weight and sus-- pending the weight in said guideway, said tackle operatively connected to a moving part of the load hoisting mechanism to move in unison I therewith and so that the weight has less linear movement than the load engaging unit during a hoisting oper tion, and means for adjusting the tackle to change the relative position of the weight its guideway, independently of movement the load engaging unit, to compensate for a change in position of the boom relative to the frame.

3. In an excavating machine, the combination with a frame, and load hoisting mechanism carried thereby, including, a boom pivotally carried by the frame, a boom hoist for raising and lowering said boom, a load engaging unit, and a hoist for said load engaging unit including a hoist line having a running connection with the boom remote from the pivotal connection of the boom with theframe, of mechanism to counteract the weight of the load engaging unit, comprising, a weight, a support carried by the frame and providing a guideway for the weight, plural-part tackle between the support and weight and suspending the weight in said guideway, said tackle operatively connected to a moving part of the load hoisting mechanism to move in unison therewith and so that the weight has less linear movement than the load engaging unit during a hoisting operation, and means for bodily moving the tackle and weight relative to the support.

4. In an'excavating machine, the combination with a frame, a boom pivotally carried thereby, a boom hoist for raising and lowering said boom, a load engaging unit and a hoist for said load engaging unit carried by the frame and including a hoist line having a running connection with the boom remote from the pivotal connection of the boom with the frame, of mechanism to counteract the weight of the load engaging unit and its load, comprising, a weight, a guide carried by the frame, motion transmitting and speed reducing mechanism operatively connecting a moving part of the load engaging unit hoist and said weight to move in unison so that the weight has less linear movement than the load engaging unit during a hoisting operation, and means for adjusting said motion transmitting and speed reducing mechanism to change the relative position of said weight in its guide, independently of movement of the load engaging unit, to compensate for a change in position of the boom relative to the frame.

5. In an excavating machine, the combination with a frame, a boom pivotally carried thereby, a boom hoist for raising and lowering said boom, a load engaging unit, and a hoist for said load engaging unit carried by the frame and including a hoist line having a running connection with the boom remote from the pivotal connection of the boom with the frame, of mechanism to counteract the weight of the load engaging unit and its load, comprising, a weight, a support carried by the frame and providing a guideway for the weight, plural-part tackle between the support and weight and suspending the weight in said guideway, said tackle operatively connected to a moving part of the load engaging unit hoist to move in unison therewith and so that the Weight has less linear movement than the load engaging unit during a hoisting operation, and means for adjusting the tackle to change the loo relative position of the weight in its guideway, in-

dependently of movement of the load engagingunit, to compensate for achange in position of the boom relative to the frame.

6. In an excavating machine, the combination with a frame, a boom pivotally carried thereby, a boom hoist for raising and lowering said boom, a

load engaging unit, and a hoist for said load enand weight and suspending the weight in said guideway, said tackle operatively connected to a moving part of the load'engaging unit hoist to move in unison therewith and so that the weight has less linear movement than the load engaging unit during a hoisting operation, and means for bodily moving the tackle and weight relative to the support.

'7. In an excavating machine, the combination with a frame, and load hoisting mechanism carried thereby including a load engaging excavating member, of mechanism to counteract the weight of the said member comprising a support providing a vertical guideway, a weight movable in said guideway, motion transmitting and speed reducing mechanism operatively connecting a moving part of said load hoisting mechanism and said weight to move in unison so that the weight has less linear movement than the load engaging and