US1785492A - Back digger - Google Patents

Description

D.16,193o. 1 l AORLOFP '1,785,492

BACK DIGGER- Filed April 22, 1929 WOW duim/wu,

lo into the trench durin Patented Dec. 16, 1930 U1\11TED .STATES PATENTOFFICE 7 ARTHUR ORLOFE, or GREEN RAY, WISCONSIN, AssIeNoR TO NORTHWEST ENGINEER- I." ING CORPORATION, OE GREEN RAY, WISCONSIN, A CORPORATION OE WISCONSIN p l RACK D I'GGER y Application filed April 22,

The invention relates" to excavators and more particularly those of the type usually called pull shovels, trench hoes or back digers. M Y g The usual'typefof'pullshoveh' wherein the hoist cable extendsfout tothe outer endrof the boom and' over sheaves at the end of the boom, or associated with .the dipper handle so that 'said hoisting lineand its sheaves get "digging, present a fruitful source of trou le inasmuch as it is impossible-to keep dirt and grit from falling into the sheaves, with resultant troubles due to rapid wearing of the moving parts, particularly the cable, as when small stones get between the cable and sheaves, cutting and consequent breakage are apt to result. According to the present invention these disadvantages are overcome by providing a hoisting cable separate from the clipper stick to raise and lower the boom and to utilize the compression forces transmitted through the boom due to the weight of the boom, clipper and dipper handle-to effect the operation of 2,5 other means which move the dipper and its stick angularly relative'to the boom.

' A further object of the invention is to provide a novel arrangement for swinging the dipper and its handle relative to the boom l 30 wherein the desired effect is obtained of having less outwardswinging force upon the flipper handle occur when the boom is lowered into the trench than' when it is elevated in the dumping position. This is obtained in the present arrangement becausein the upper position the weight of the clipper and its` handle tendsto move the dipper inward while in the extreme lower position this weight tends tovswing the dipperv outward.

Consequently, in the lower positions less additional force is required to swing the dipper voutwardly to a certain angle with respect to .the boom.

A further Object of the invention is to provide a swinging support for the the piv- 1929. serial No. 357,067.

otal mounting of the boom which support is .i

connected-by cablefwith the dipper handle :to effect an angularfoutward :movement-Of the dipperand flipper handle' relativegto the vboom in different positions thereof and under P' the control of another Acable .which also feffects .an'inwardswinging movement of the dipper and its handle relative to the'boom.

The invention further consists inthe several features hereinafter set forth and more particularly defined by claims at the conclusion hereof.- v i The drawing shows an elevation view of an excavatorV embodying the invention.

Referringi'to the drawings the numeral 4? designates the traveling base of the machine equipped 'with endless propelling treads 5 driven in known manner from a suitable prime mover 7 on the rotating base 6 of the machine, 8 a swinging boom pivot support or lever pivotally connected at one end bya pin 9 to the base 6 and having the boom 10 pivotally connected to said lever at an intermediate point by a pin 1l whereby said boom is mounted for up and down movements relative to the machine'base'and also for angular movements relative to said support 8.

A dipper handle or stick, 12 isfpivotally 'connected intermediate its ends by a pin 13 to the outer end of the boom vandcarries a dip- -per 14 facing toward ythe machine and in operative position relative to the' trench and to effect the retention of the load in the'dipper when the boom is in an elevatedposition, or to retain the dipper in any .desired angular 'position against forces tending to move it outwardly relative t0 the boom.

For raising and lowering the boom, dipper and dipper handle, a hoisting cable 20 passes from the hoist drum 21 over a guide sheave 22 on the shear leg 23, thence around a sheave 24 mounted on the medial portion of the boom or back from its forward end and is dead ended on the machine, as by a connection with said shear leg. Thus winding in on the hoisting cable raises the boom l0 and the parts carried thereby and paying out of this cable lowers these parts. f .ff

The drums 17 and 21 are equipped as usual with brakes and clutches to control theirv operation.

The free end 25 of the boomsupport enlever 8 has a'link' or pull connection "with 'the up' per end of the dipper handle. This centreel tion preferably comprises a cable 26 whose" ends are suitably pivotally connected-respeotively lvith said end 25 and with said handle, -as at 2A vW'ith this construction when the boom is in a raised position 'a portion of its'weight and that of the 4dipper and dipper handle' will react against the rocking or pivotal lever or supprtlS through which it` is connected-to the base of the machine and willtend to swingI the -treefendv of 'said lever "8 inwardly and through this reaction exerta pull on Vthe cable 26'toward the'machine, which is of a length to thereby produce a pull onthe dipper handle which acts to swing the dipper handle and -dipper outward relative to theboom, as shown in full lines in the drawing.' When, however, the dipper is lowered into the trench, the weight of the boom tends to pull the lever 8 outward, with the result that there is less tendency to swing the dipper, outward, as shown by the dotted line position of the parts, and under these conditions a hauling in of the drag line I6 causes the inward swinging 0r digging movement of the dipper and a retention of the dipper in its inward position relative to the boom after digging permits the hoisting cable to be operated to raise the boom and dipper to an elevated position and the swinging of the boom to a position of discharge,'.at which time a paying out of the drag line permits the lever 8 and cable 26 to effect :the outward movement of the dipper handle and dipper Vto discharge its load or, if desired, the dipper may be provided with a bottomdumping door, long well known in excavators, for discharging its load, or other forms of discharge means for the dipper may be fused, 4 i

From the foregoing description it will be noted that I have provided a pull shovel constructionin which the' component of weight of the parte exerted along the boom is used to e-lect' movement of means operatively connected tothe dipper handle to effect shifting y movements ofthe dipper and dipper stick and that such component has a greater effect when the boom is in a raised position than when it is in a lowered, digging position.

I desire it to be understood that this invention is not to be limited to any particular form or arrangement of parts except insofar as such limitations are included in the claims or necessitated by the prior art.

What I claim as my invention is:

1. In an excavating machine, the combination of a base, a movable boom support mounted ,on vsaid base, aboom Apivotally mounted on said support for .up and down movements and so that its pivot moves relative to the base of the machine during the diggingV cycle, a dipper handle pivotally mounted on the outer end -portionof said boom and carrying a dipper working toward themachine during digging, a hoisting cable associated with the boom, and means associated with said support and moved thereby funder the forces exerted thereon bythe boom for effecting shiftin movements of the dipper and dipper han le relative to' `|the boom.

2. In an excavating machine, the combination ofa support .pivotallyA mounted .on :the

machine, aboom Ipivotally mounted/0n said Lsupport for up and down movements-.and

for moving saidsupport during the dig ing cycle,` adipper handle pivotally mounte' on the outer end portion of said boom and car'- rying a dipper working toward the machine duringdigging, a hoisting cable associated with the boom, and pulling means associated with said support and dipper handle for shifting the dipper outwardly relative to the boom under the shifting action of said boom on said support.

3. In an excavating machine, the combination of a movable boom support, a boom mounted on said support for up and down movement and for moving said support during the digging cycle, a dipper handle pivotally mounted on the outer end portion of said boom and carrying a dipper working toward the machine during digging, a hoisting cable associated with the boom, means associated with said support and moved thereby under forces exerted thereon by the outward shift'of said dipper and for swinging it inwardly toward'the boom.

4. In an excavating machine, the combination of a support pivotally'mounted on the machine, a boom pivotally .mounted on said support for up and down movements and for moving said support, a: dipper handle pivot-- ally mounted on the outer end portion of said boom and carrying" a 'clipper working toward the machine duringdiggng, a hoisting cable associated with the boom, pulling means associated with said support and dipper handle for shifting the dipper outwardly relative'to the boom -under the lshifting' action of said booml n 'said support, and separately cotrolled means opposing the outward shift of said dipper and 'for swinging it inwardly toward the boom.

5. In an excavating machine, the combination of a support pivotally mounted at one end on the machine, a boom pivotally mounted on said support, intermediate its ends, for np and down movements and for moving said support, a dipper handle pivotally mounted on the outer end portion of said'boom and carrying a dipper working toward the machine during digging, a hoisting cable associated with the boom, and a cable connection between the free end ot said support and the dipper handle for shifting the dipper and dipper handle outwardly relative to the boom under the shifting action of said boom on said support.

6. In an excavating machine, the combination of a boom mounted for up and down movements, a dipper handle pivotally mounted on the outer end portion of said boom and carrying a dipper Working toward the ma.- chine during digging, a hoisting cable for raising and lowering the boom, a movable supporting means for the boom for converting the weight component of the boom acting along the same into a pulling force exerted on the clipper handle for swinging the dipper outwardly relative to the boom, and means -tor transmitting this pulling force t0 said dipper handle.

7 In an excavating machine, the combination of a boom mounted for up and down movements, a dipper handle pivotally mounted on the outer end portion of said boom and carrying a dipper working toward the machine during digging, and means including a movable support for the boom operatively connected te saiddipper handle and actuated by a weight component of the boom Jfor swinging the dipper handle and dipper outwardly relative to the boom, said means under the action of the boom exerting a lesser swinging force upon the dipper'handle when the boom is lowerei into digging position than when said boom is in an elevated pesition.

8. In an excavating machine, the combination ot' a base, a swinging boom, a dipper handle pivetally mounted on the onter end portion of said boom and carrying a dipper working toward the machine during digging, movable means for supporting the inner end of the boom tor movement relative to said base, means for moving the dipper handle relative to the boom by said supporting means dni-ing the digging cycle, and means for raising and lowering said boom.

9. In an excavating machine, the combination of a base, al lever pivotally mounted on said base, a boom pivotally mounted on said lever for up and down movements and for moving said lever during the digging cycle,

' a dipper handle pivotally mounted on tne outer end portion of said boom and carrying a dipper Working toward the machine during digging, a hoisting cable associated with the boom, and means operatively connecting said lever, at a point spaced from the connection of said lever to said base, to said dipper handle for eiecting shifting movements of the dipper and dipper handle relative to the boom on the movement of said lever.

In testimony whereof, I alix my signature.

ARTHUR ORLOFF.

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