US2084449A - Power shovel - Google Patents

Description

June 22, 1937.

w. RQ NEEsE i 2,084,449

POWER SHOVEL Filed July 25, 1936 2 Sheets-Sheet 1 31W CMM /4472 727? f /l/Efsf Junezz, 1937. W, R, NEE-SE v 2,084,449

k POWER sHovEL Filed July 23, 195e 2 sheets-rime*L 2 MNHN..

glu/ventola Patented .lune 22, 1937 UNITED STTES OFFICE 3 Claims.

This invention relates to power shovels of the type wherein a dipper for moving material is attached to the end of a dipper arm carried on a pivoted traversing arm.

The principal object of the invention is to provide a means for hoisting the dipper to insure that it will have suicient power to remove material in cutting away a bank regardless of the formation thereof. Considerable di'iculty has l-O been experienced with conventional power shovels when operating to strip a bank for the reason that many times portions thereof are of such close texture or of such hardness that sufficient power cannot be applied through the usual hoist line to raise the dipper and cut away the bank.

Another object of the invention is to provide such a power shovel wherein the dipper is hoisted or lifted by a double hoist line and in which the free ends of the hoistline are wound up on separate winding drums having different diameters.

A still further object of the invention is to provide a selective power transmission for the winding drums to enable them to be operated either individually or jointly.

The invention also contemplates arranging for the interlocking of the controls in such a manner that the operator may, at will, apply to the dipper, power from one or the other of the winding drums or he may apply power to them together and also provide means for braking either or both of the drums through an interlocking foot brake which may be manipulated to temporarily brake the drums or to permanently hold them in position.

In the drawings:

Fig. 1 is a side view of a power shovel rigged in accordance with this invention.

Fig. 2 is a diagrammatic view illustrating the hoist line and winding drums.

Fig. 3 is top plan view of the hoisting drum mechanism.

Fig. 4 is a side view partly in cross section taken on line 4 4 of Fig. 3.

Figs. 5 and 6 are fragmental views showing the interlocking of the hand and foot control levers.

Speciiically in the drawings numeral l denotes a power shovel having the usual power plant and control cabin 2, mounted on turn table 3, carried by endless track chains 4. A boom 5 is pivoted to the front portion of the cabin framing and extends outwardly and upwardly terminating in two lifting pulley sheaves o and l. The position of the boom 5 is regulated by conventional elevating rigging. Also carried by the boom intermediate its ends is a roller or pulley mechanism 8 for applying thrust or crowd to dipper arm 9 on whose outer end is aixed a dipper bucket I0. The thrust or traversing mechanism of the boom will not be described in detail as it forms no part of this invention as any conventional means may be used for these purposes.

A pivoted bail l i is affixed to the dipper bucket 5 lil and secured thereto is lifting pulley l2 through which the hoisting cable passes.

Mounted interiorly of cabin 2 is a suitable prime mover i3 which may be electric, steam, gasoline 10 or Diesel operated. Also within the cabin are two hoisting drums I4 and l5 loosely mounted on horizontal shaft it journalled between vertical side plates il securely affixed to the flooring I8. Power drive gear i3 is keyed to one end of shaft 15 E6 and secures rotation through pinion 20 driven by any suitable drive means from prime mover I3. As shown in Figs. 2 and 3, winding drums i4 and l5 are each alxed to similar brake and power transmission drums 2l and 22 respectively. It will be necessary to describe only one of said 0 brake and power drums as they are identicaL Referring to Fig. 4 brake drum 2l of winding drum l5 has mounted interiorly thereof an internally expanding brake band 23 that functions as a power transmitting clutch and is carried on flexible brake shoe 24, the end 25 of the shoe being affixed to cross bar 2'6 loosely carried on shaft `I6 while the opposite or free end 2l of the brake shoe is carried on the arm of bell-crank 28. Power to expand the brake shoes and contact the winding drums is secured through the medium of booster clutch brakes comprising small diameter drums 29 keyed on the ends of shaft I6. Each booster includes an operating arm 3B having an off-set lug 3l passing through arcuate slot 32 formed in the side wall of the booster brake drum and connected through link to the free end of the bell-cranks 28. Flexible contracting brake bands 33 pass around the booster brake drums and are anchored at one end to lugs 34 fastened to the side plates Il, while the free ends are secured to operating rods v33 whose outer ends terminate in arms 31. The oif-set portions of the arms are attached to rods 38 pivoted to the lower ends of hand levers 33. A horizontal rotary rod 4E! transmits power from the operating handle 39 connected up to drum i4 while power is transmitted to the brake drum afxed to drum l5 through rotary sleeve 4l surrounding one end of rod 40. Each of the brake drums 2| and 22 is provided with a positive braking and holding means comprising contracting brake bands 42 encircling the drums and terminating in bell-cranks 43 pivoted to horizontal'rod 44. The oi-set portion of shovel is provided with mechanism for hoisting the bell-cranks 43 are moved through reciprocation of rods 45, receiving movement from cams 46 which are rotated by means of levers 4T affixed to foot levers 48. Positive latching dogs 49 are freely mounted on shaft 44 and may be manually pivoted to engage with teeth 50 carried on rack wheels 5I affixed to each of the brake drums 2| and 22.

In operation a continuous hoisting line or cable 60 is secured at its ends to hoisting drums I4 and I5 and passes up and around sheaves 6 and 1 mounted on the end of boom 5 while pulley I2 secured to the arbor II of the dipper bucket I is hung in the loop of the line 60.

To raise the dipper bucket the operator pushes either of the operating handles 39 whereupon pressure is applied to the booster brake 2S and as the booster Vbrake drum is aixed *to shaft I6 it tends to retard the rotation thereof and permit off-set lug 3| to move or slide to the end of the arcuate slot 32 and thus give movement to arm .'30 which is .transmitted through the crank 28 and expand the internal brake band .2I and rotate therewith. Power is transmitted from the shaft I6 to the hoisting drum as long as the operating lever is in forward position. When the operating lever is brought back to vertical or neutral position the springs 52 draw the free end lof the brakedrums away from their inner peripheries to disconnect the transmission of power. Inasmuchas both of the hoisting .drums `I4 and I5 are loosely mounted on the power shaft, power maybe applied to either of the drums or they maybe operated simultaneously.

In working the shovel andk particularly while stripping down banks of material it has been found that v.the geological formation of the bank changes in character and thus the same upward stroke .of the dipper may encounter soft, `medium and hard sections. When Va power the dipper las ldescribed in this .application the .operatorhas at his command adequate facilities yfor c'opingwith any material formation which .may be encountered. As the dipper strikes a particularly hard formation the hoist line 60 maybe slowly drawn .in by applying Atorque .to the :small diameter winding drum I5 which will raise the dipper bucket with tremendous lifting power. If .a comparatively soft formation is being operated on the shovel operator need only Aapply .power 'to the 4larger 4diameter hoistdrum I4 .or on the other .hand when the formation .is quite Ysoft or light in weight power may be applied simultaneously to both ofV the winding .drums which will cause the bucket to .ascend quite rapidly. Ineffect, therefore, the operator has `at hisinstant command a .differential yhoist :mechanism Vsimilar in many characteristics ,to the low, second and high speed gearing of an automobile. y

The foot pedals 48 connected through operating levers 41 and reciprocating rods 45 rotate bell-crank 43 to tighten outer brake bands 42 when it is desired tov slow up or arrest the rotation of the winding drums. The foot pedals 48 are also provided with rack Ateeth 62 to .engage a suitable latch fastened to the floor plat I8 so that the operator may temporarily lock the brakes to hold the drums and dipper in any desired position. The foot pedals 48 Aare of the rconventional pivoted type so that the teeth 62 may be readily disengaged from the latch. If it is desirable to permanently lock the brakes the operator manually engages the dogs 49 with ratchet teeth 50 formed on wheel 5I. The dogs 49 are loosely hung on rod 44 and may be pivotedV therearound to engage a .tooth on the ratchet wheel 5I when the operator desires that the drums be positively locked. It is a very small matter to disengage these latches when manual operation is desired.

Provision is also made for operating `the foot pedals 48 or the hand levers 39 simultaneously. This is accomplished by having a, pivoted plate 63 attached to one of the foot pedals so that yin operative position it overlies both pedals and consequently pressure applied on the plate 63 will depress both pedals. When it is desired to operate -the pedals individually it is only necessary for the operator to kick the plate 63 over upon its pivot to lie out of engagement therewith. A somewhat similar device is, utilized for interconnecting the hand levers 39 and in the form shown in Fig. 5 consists of a pivoted fork 64 which `may be readily swung to horizontal position'to tie the two handles `together where they are offsetat65. It will be understood that the keeper f64 is readily moved to the inoperative position shown in Fig. 5 to disengage fthe handles, one from the other- What I claim is:

l. A power shovel plant of the character `described including fan `elevating arm A'carrying fa dipper, .an Aelevating sheave secured to the said dipper., `a prime .mover carried -on the said shovel, a plural-ity of winding drums also :carried -On said shovel, said drums .being loosely mounted on a single horizontal shaft secured between vertically extending spaced .brackets secured to the side frames of theshovel plant, means for transmitting `power to said :drums from said prime mover, the said drums being of substantially `diiferent vdiameters, .a .hoisting cable attached at either -end -to said drums, `saidcable ypassing throughsaid-elevating sheave Aand power take-olf 'devices including booster .brakes enabling each of said vwinding drums .to :operate independentlyfofeach other, the said Ibooster .brakes each comprising an offset brake drum attached to .each of the Winding drums .and each having a y'transverse arm loosely aiiixed tothe said winding drumshaft, an-offset lug .on each of saidlevers and an arcuate slot in `eachfof .saidlbrake drums adapted -to be engaged bythe .said lugs, tension means foreach of -said .drums :for .moving the end `of said arcuate slot againstsaid lug yand expanding brake shoes lcarried -interiorlyiof each of said winding drums connected to and :expanded .by said `transverse 4levers.

2. In a power shovel, a platform, a boom pivot- .ed to one `end of mid-platform, a clipper farm supported by and moveable with said boom, a dipper .secured to :the outer-'end -of said arm, a sheave connected thereto, .two .parallel `sheaves Amounted .on the 'upperfend of mid-boom, ahorizontalpower driven shaft mounted in brackets secured to said platform, two :winding drums loosely mounted-on said shaft, one of said drums being 'of substan- .tially larger .diameter than Ithe other of said drums, .a'sin'gle cable threaded .through said dippershea'ves :and having one of its @ends secured s to `'each of said drums, foot-operated brakes` for .arresting rotation of eachof said Adrums,hand` levers operating booster brakes 'for applying vpower'from fsaid .shaft rto .either Aof saiddrums in- .dividually or jointly, ratchet wheels securedlto Yeach of said Winding drums .and manually operated .locking :.dogsfor engagement with said ratchet Wheels.

3. A .power .shovel of the type described, invcluding a material `lifting dippeiga .pulley attached of each of said drums, means for expanding each of said shoesby the rotation of the individual drums and a manually operated tension band for applying torque to said winding drum shaft to which each of said brake shoes are pivoted to en- 5 gage said brake shoes with said drums.

WALTER R. NEESE.

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