US1529399A - Excavating shovel - Google Patents

Description

Mmh 10. 1925.

P. BURKE l IXCAVATING SHOVEL m 2 t 9, 2 .m 5, h. l u e a 1v Lu E9 V1 mmv, mmm Bum Aa .Vu PA mm In.. F%\

March l0, 1925- March l0, l925- P. BURKE EXCAVATING SHOVEL Filed March 17, 1924 3 Sheetsheet :3

Patented Mar. v10, 1925.

UNITED STATES A 1,529,399y PATENT OFFICE.

PAUL BERRE, 'or GREEN BAY, WISCONSIN, AssIGNoR To NORTHWEST ENGINEERING COMPANY, or GREEN BAY, WISCONSIN, A CORPORATION or WISCONSIN.

.ExoAvATlNG sHovEL Application mea March 17, i924, serial No. 699,827.

' T0 aZZ 'whom it may, Concern:

. Be it known thatI, PAULBURKE, a citizen of the United States of-f-A'mericn, and resident of Green Bay, in the county of Brown and State of Wisconsin, have invented new and useful Improvements in Excavating Shovels, of which the following is a description, reference `being had to the accompanying drawings, which are a part of this specification. Y v

The invention relates to excavating machines.

In excavating machines in" which the dipper and its handlel or stick are mounted to swing and shift relative to its supporting boom, it is sometimes necessary and highly desirable to hoist the dipper when the stick is in an extended position so that the contents of the dipper may be deposited at the desired point. In machines of this general type a dipper stick of reasonable length, or one Substantially' longer than the distance between the shipper shaft and the point of the boom, can be thrust out when about in horizontal position, but hoisting from then on -will gradually retract thedipper and stick until finally the` sheave associated with the dipper meets the sheave at the outer end of the boom so that some means are neces1 3o sary to hold the stick in extended position.

It has heretofore'been quite common practice in some designs of shovels of this eneral type to use a brake controlled by the operator, either by hand or bv foot, to prevent the retraction of the extended stick, but such constructions put an additional duty upon the operator and complicate the control mechanism. The object of this invention is to rovide a bra-ke which operates lv'automatical to prevent inward movement of the stick during hoisting and under a predetermined tension so that slippage may occur under excessive loads imposed under some conditions of operation, and which brake is automatically released when the stick is retracted without the use of additional controls.

A further and more particular object of the invention is toprovide a shovel of theV rope-thrusting type in which the tension of the inward thrusting line is utilized to effect the release of a brake so arranged as to provide a predetermined braking force to restrain inward translation of the stick except when such tension is applied, and to so asso Ciate this brake with the operating cable that the free outward translation of the stick is not interfered with.

Theinvention further consists in the sevinvention;--Fig. 2 is a detail sectional view taken on the line 2--2 of Fig. 4; Fig. 3 is a detail sectional view taken on the line 3--3 of Fig. 1; Fig. 4 is a detail plan view of the shovel mechanism embodying the invention; Fig. 5 is a detail sectional view taken on the line 5-5 of Fig. 3 with parts shown in full; Fig. 6 is a side elevation view of a shovel embodying' the invention showing a modilied cable arm arrangement; Fig. 7 is a detail plan view of shovel mechanism shown in Fig. 6.

In the drawings the numeral 6 designates the boom, which may be of any suitable construction, vertically pivotally attached at its lower end to the rotating base 7 of the machine, which base is of well known construction. Y A hoisting drum 8 and an auxiliary drum- 9 are mounted on the base 7 in any suitable manner and driven from a primemover, not shown, on the base. The drums 8 and 9 may .be of any well known construction equipped with clutches and brakes to control their operation. The boom is adapted to be raised or lowered and held in various positions of vertical adjustment by well known means, such as the cables 10 connecting pulleys 11 on the outer end of the boom to parts on the rotating base.

A shipper shaft 12 is secured in the arms of a casting 13 on the boom and the saddle blocks or stick guides 14 are loose on this shaft. The dipper stick 15 is preferably of the divided type, that is, composed of two sections, each being slid'ably mounted in one of the blocks 14 and both adapted to swing with said blocks about the shaft 12. The dipper or shovel 16 may be ofany suitable construction and is mounted, as usual, at the lower end of the stick.

A hoisting cable 17 passes from the drum` 8 over a sheave 18 on a shaft 19 at the outer end of the boom, thence. downwardly through a padlock sheave 20, ivotally connecte to t e dipper and pre erably transversely disposed with respect to the sheave 18, thence upwardlyto the larger art of av compound drum 21 on which it isv cad-ended, said drum being loosel mounted on the shaft 19. A cable 22 is cad-ended on the smalle-r side 23 of the compound drum 2 1 and passes once or more around a sheave or drum'24 on the shaft 12 and is dead-ended at the upper end of the A stick in any suitable manner, as by anchorage to stop member 25, bolted at its ends to the sections of the stick. While a sheave may-be used in place of the compound drum 2l with acontinuous hoist and thrust cable passing over thissheave, the 'compound drum increases the leverage and thereby uts'a greater pull on the crowding line 22 tian on the line 17.

A cable 26,secured to and wound upon the drum 9, passes over a sheave 27 loose on the shaft l2, thence downwardly and around a sheave 28 at the lower end of the in one direction of rotation, that is counterclockwise, by means offa series of pawls p1vota1ly mounted on one facev of the drum -24 andV engageable-with an internal ratchet wheel 34 formed. .in the drum 32. The brake drum 32 is ada ted to be engaged by a brake-band 35. v ne `end 36 of this band is secured to an arm"37' on a rock-'shaft 38 Vmounted in the casting 13 and the other end of this 4 band is secured to said casting as by anl adjusting screw .39 which passes through an opening in a. projection 40- of said casting and yhas an adjusting nut 41 thereon by which the tension of the brakeband may be adjusted. A release lever 42 is also connected to the shaft 38 and a j spring 43 cpnnecting said lever 42 with the `vboom exerts a `.tension upon said lever, tending at all timesto rotate said lever 42 and arm,;37 in a clockwise directionand hence set the brake. ,The end 31 of the cable 26 is secured to the lower end of the lever 42.

The Voperation of the construction'just described is as follows: When the drum 9 is prevented fromturning, by its brake, therebyjholding the line 26, and the line-17 is pulled in, the dipper moves approximately in the arc of acircle of which the shi per shaft is the center. The dipper having een v" dura.wn in toward the machine `and lowered lupon the' material to -be "excavated, and with .the braking 'effectl o n'the drum v9 released' to allow cable 26 to pay out, cable 17 is wound in, causing the dipper pivoted about the shaft 12 to swing relative to said shaft and shift outwardly with respect to the boom since the pull of said cable 17 turns the drum l 2l putting a pull, here greater than the hoisting effect because of the compound.

drum, on line 22, which thereupon forces the dipper stick outward. Conversely, if it is desired to move the dipper stick farther in, hoisting with line 26 produces this effect. lVhile the compound, or differential drum is preferred, -it is to be understood that the invention is not to be limited thereto. Thus, by a proper manipulation of the lines 17 and 26any desired swinging and thrusting movement of the dipper and its handle may be' effected. Furthermore, since the line 22 which effects the thrust is actuated by the hoist, a crowding effect equal to the full driving force of the engine 1s secured.

With this and other constructions, however, when the stick is in an extended position and hoisting is continued until the stick is approaching. at` or above the horizontal,

the hoisting cable 17 and other forces, such as the weight of the dipper 'and its contents, tend to shift the stick inwardly, which is not desired when the dumping of the dipper is to be effected with the stick extended.. With the brake, however, the drum 32 is, prevented fromrotating in -a counterclockwise direction and, consequently, rotation of the drum 24 is prevented in the same direction, which is thedirection of rotation induced by the tendency of the stick toimove inward, and hence the brake will hold the stick against inward movement through the holding of the cable 22 associated with the stick,.and the braking tension determined by the adjustment of the spring 43 is suiiicienty to hold the stick against inward movement under ordinary conditions. However, under some conditions of operation, as in the case where the stick is in a fully extended position and the stop member engages the saddle blocks 14, in order to relieve any tendency of the cable 22 being stretched or tensioned too greatly, the brake is allowed to slip, because under'such conditions` the brake tension is insulicient to prevent rotation of the drum. Thus, the brake may slip when a predetermined maximum tension has been set up in the cable 22 by its resisting the inward shifting movement of the stick and thus prevent injury to said cable. Under normal operation, however, 'the braking means prevents inward translation of the stick. If, then, .with the stick lfrexteded, theoperator desires to move it inwardly,

that is to retract it` the cable 26 is wound' in,

increased tension being applied until the end 31 of saidl cable swings the'arm 42 toward and against the stop 30, thereby releasing the brake. Upon such release the dipper drum 24 and is dead-ended at t stick 15 is free to move inwardly under the 'action of cable 26, said cable on being drawn in shortening up its run between the sheaves 27 and 29 andthe sheave 28. It will be understood that sufficient wraps fof cable22 are provided around the drum 24 so thatthat portion of said cable between said .drum and the upper end of the stick cannot slip and, therefore, the sections of the dipper stick will be` held against inward movement, by the brake, as long as the cable 26 is allowed to remain slack. During the outward translation of the stick the drum 24 is free to turn in a clockwise direction as the pawls 33 then ride freely over the ratchet wheel 34. y

As illustrative of a construction in which the compound drum is not used, I show in Figs. 6 and 7 a shovel mechanism which diiers from that previously 4described only in the use of a single cable 17 for hoisting the dipper and moving it outwardly instead of the two cables 17 and 22, and as the other parts, including the brake mechanism and its control, are the same the same numerals have been used. It will be noted in this case that the cable 17 is anchored to the drum 8, passes around the same, thence over the s heave 18 and around the padlock sheave 20 and up over a sheave 18 of the same diameter as the sheave 18 and loose on the shaft 19, and thence backwardl around the e upper end of the stick by 'anchorage to the stop member 25. Theo eration of this construction is similar to t at previously described except that the pull on the hoisting portion of the cable 17 1s the same as the pull .on the crowding portion of said' cable, it being noted that as the cable 17 is wound in by f its drum 8 the dipper handle is hoisted and at the same time the drum 24 is revolved in a clockwise direction thereby shortening up on the crowding run of said cable, that is, the run between said drum and the upper. end of the stick, and shifting the dipper stick outwardly.

From the foregoing descri tion it willA be noted that I have provide means which provide a predetermined braking tension against inward translation of thestick when it is desired to hold the dipper stick ex tended, but which permits the dipper stick to be moved outwardly for the digging operations, and which tension is released without any special operation on the part of the operator when 1t is desired to retract the stick, as such release occurs on the operation of the retraction mechanism for the stick.

I desire it to be understood that this invention is not to be limited to any specic form or arrangement of parts exce t in .so far as such limitations areinclude in the claims or necessitated by the prior art.

`nation with a boom, of a dipper and dipper handle mounted thereon to swing and shift with respect thereto means for hoisting the dipper, means forshifting the dipper handle inwardly, means including a brake for applying a: predetermined and substantially constantforce to counteract the shifting of the dipper handle in an inward direction, and means actuated by said shifting means for releasing said brake.

3. In an excavating machine, the combination ywith a boom, ofa dipper and dipper handle mounted thereon to swing and shift with respect thereto, means for hoisting the dipper, means for shifting the dip er handle inwardly, means including a bra e for restraining the shifting of the dipper handle .in an inward direction under normal condi- 4. In an excavating machine, the combinaf tion. with a. boom, of a dipper and dipper handle mounted thereon to swing and shift with respect thereto, means for hoistin the dipper, means including a cable for shi ting the di )per handle inwardly, means including a rake for applying a predetermined and substantially constant force to counter` act the shifting of the dipper handle in an inward direction, and means, utilizing the tension in said cable, for releasing said brake.

5. In an excavating machine, the combination with the sup orting boom, of a dipper and dipper han le mounted thereon to swing and shift with respect thereto, of means for hoistin and thrusting the dipper outwardly inclu ing a thrust-cable connected to said dipper handle, a brake to hold said dipper and dipper handle against inward shiftin movement Within mined limits o tension set up in sald thrust cable, a cable for retracting said dipper handle, and means under control of said retracting cable and actuated' thereby to repredeterF y thrust-cable associated with said drum'and Adipper handle for shifting said handle outwardly, a brake-drum connected to turn with said cable-drum during inward movement of the stick and to be free of said drum during outward movementof the stick, a brake member associated with said .brake-drum and to apply a constant braking force thereto whereby to hold said drums against turning and thereby hold said thrust-cable to prevent inward shifting movement of said dipper handle, means for shifting the dipper handle inwardly, and means actuated by said inward-shifting means to release said brake member.

7. In a power shovel, the combination of a boom, a dipper and clipper handle mounted theron to shift and swing with respect thereto, a cable-drum, means including a thrust-cable associated with said drum and the dipper handle for shifting said handle outwardly, a brake for said drum permitting free outward movement of said sticks but operating within predetermined tension limits for said thrust-cable to hold said 'drum and cable to prevent inward move- -ment of said handle, a retracting cable for shifting the dipper handle inwardly, and means, actuated by said retracting cable, to release said brake.

8. In a power shovel, the combination of a boom, a dipper and dipper handle mounted thereon to shift and swing with respect thereto, a cable-drum, means including a thrust-cable associated with said drum and n dipper handle for shifting said handle outwardly, a brake-drum having a pawl and ratchet connection with said cable-drum to turn with said drum during inward move'- Inent of the stick and be free of said drum during outward movement of saidstick, a

brake member, associated with ksaid brakedrum to apply a constant braking force thereto whereby to hold said drums against turning and thereby hold said thrust-cable to prevent inward shifting movement of said ldipper handle, means for shifting the dipper handle inwardly, andmeans actuated by said inward-shifting means to release said brake-member.

9. In a power shovel, the combination of a boom, ofvv a dipper and dipper handle mounted thereon to shift and swing with respect thereto, a shipper shaft having a cable-drum mounted thereon, a thrust-cable f passing over said drifm and connected to the PAUL BURKE.

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