US3533524A

US3533524A - Counterweight removal arrangement for hydraulic excavators or the like

Info

Publication number: US3533524A
Application number: US771050A
Authority: US
Inventors: John H Wilcox
Original assignee: Bucyrus Erie Co
Current assignee: NORTHWEST ENGINEERING Co A CORP OF
Priority date: 1968-10-28
Filing date: 1968-10-28
Publication date: 1970-10-13
Anticipated expiration: 1987-10-13
Also published as: GB1278513A; DE1949783A1

Description

Oct. 13, 1970 J. H. WILCOX 3,533,524

COUNTERWEIGHT REMOVAL ARRANGEMENT FOR HYDRAULIC EXCAVATORS OR THE LIKE Filed Oct. 28, 1968 if 1 g ,7

s gheets-Sheet 1 It .2 3 /5 ML 3 /5 /4 3 /7 m it u /'7 i 5 20 :1: 20 i- ZZ/ $1 22 I III, I 1: m. 2

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INVENTOR JOHN H.WILCOX BY fW AT T'ORNEY 3,533,524 LIC Oct. 13, 1970 J. H. WILCOX COUNTERWEIGHT REMOVAL ARRANGEMENT FOR HYDRAU EXCAVATORS OR THE LIKE 3 Sheets-Sheet 2 Filed ON. 28, 1968 INVENTOR JOHN H.WILCOX Oct. 13, 1970 J H. WILCOX 3,533,524

COUNTERWEIGHT REMVAL ARRANGEMENT FOR HYDRAULIC EXCAVATORS OR THE LIKE Filed 001;. 28, 1968 5 Sheets-Sheet 5 INVENTOR JOHN H. W LCOX .ATTORNEY United States Patent 3,533,524 COUNTERWEIGHT REMOVAL ARRANGEMENT FOR HYDRAULIC EXCAVATORS OR THE LIKE John H. Wilcox, Evansville, Ind., assignor to Bucyrus-Erie Company, South Milwaukee, Wis., a corporation of Delaware Filed Oct. 28, 1968, Ser. No. 771,050 Int. Cl. E02f 3/00 US. Cl. 214142 4 Claims ABSTRACT OF THE DISCLOSURE A hydraulic back-hoe excavator includes a counterweight mounted at the lower rear edge of the working frame by means of vertical suspension members having upper ends pivotally connected to the frame and lower ends pivotally connected to the counterweight. When the front end of the frame is elevated by moving the excavator bucket downwardly against the ground, the counterweight can swing down and away from the frame and can thus be placed on a supporting crib and disconnected. In a preferred embodiment, the suspension members are extensible and retractable to enable the counterweight to be lowered slightly before the front end is elevated to insure that the counterweight will clear the working frame. Also, provision is made for locking the counterweight to the working frame when it is mounted, and a centering plug arrangement is provided to insure proper orientation of the counterweight.

BACKGROUND OF THE INVENTION This invention relates to counterweighted hydraulic excavators and like machines; and, more particularly, it resides in an improved counterweight removal arrangement for such machines.

It is frequently desirable to have the counterweights of excavators readily removable so that they can be transported separately. Various devices and arrangements for removing counterweights have been developed and can be found in prior art patents. Many of the prior arrangements, however, have not proven entirely satisfactory from the standpoints, for example, of cost, complexity, strength, safety and/ or ease and efficiency of operation.

SUMMARY OF THE INVENTION The present invention contemplates a counterweight removal arrangement for a hydraulic excavator or similar machine in which a counterweight is swingably mounted at the rear of the frame so that it can be lowered and dismounted simply by lifting the front end of the machine. The object of the invention is to provide an improved counterweight removal arrangement of this general type which is highly effective, strong, and readily adaptable to various machines while still being relatively simple and inexpensive to manufacture, assemble and use. Other objects and advantages will become apparent from the following description in which there are shown, by way of illustration and not of limitation, presently preferred embodiments of the invention.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat schematic rear view of a hydraulic back-hoe excavator incorporating a counterweight removal arrangement embodying the invention,

FIG. 2 is a fragmentary schematic side view of the excavator and counterweight removal arrangement shown in FIG. 1,

FIG. 3 is a fragmentary view in cross section through the plane 33 shown in FIG. 1.

FIG. 4 is a reduced schematic side view of the excava- "ice tor and counterweight removal arrangement of FIG. 1 showing the front end of the excavator in an elevated position,

FIG. 5 is a view similar to FIG. 3 but showing a hydraulic excavator incorporating another form of counterweight removal arrangement embodying the invention,

FIG. 6 is a fragmentary schematic side view of a hydraulic excavator incorporating still another form of counterweight removal arrangement embodying the invention,

FIG. 7 is a schematic rear view of the excavator and counterweight removal arrangement shown in FIG. 6, and

FIG. 8 is a fragmentary side view of the excavator and counterweight removal arrangement of FIG. 6 showing the excavator in a tilted position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, and particularly to FIGS. l4, there is shown a hydraulic back-hoe type of excavator 1 which is more or less conventional in overall construction and includes a crawler type carrier vehicle designated by the reference numeral 2. The excavator 1 also includes a working frame 3 which is rotatably mounted on the carrier vehicle 2 and which includes a machinery platform 4 and a machinery housing 5 that encloses the operating machinery. The excavator 1 also has a boom 6 pivotally footed on the machinery platform 4, parallel hydraulic hoist cylinders 7 (only one of which can be seen), a handle 8, a hydraulic dig cylinder 9, a bucket 10 and a hydraulic wrist cylinder 11. It will be apparent as this description progresses that other specific forms of machines might be provided with a counterweight removal arrangement according to this invention, so long as they include some boom or equivalent means to raise one end. For this reason, and since the construction and operation of the excavator 1 are well understood by those skilled in the art, the various elements thereof are not shown and will not be described in greater detail.

The excavator 1 is provided with a counterweight 13 received in a suitable recess at the lower rear end of the working frame 3 so as to counterbalance loads handled by the bucket 10 and thereby increase the load handling capacity of the excavator.

As best seen in FIGS. 1 and 2, the top surface of the machinery housing 5 is provided with a pair of aligned, horizontally spaced, U-shaped support brackets 14. The support bracket 14 are themselves supported by suitable struts or other frame elements (not shown) within the machinery housing 5. The brackets 14 serve as a mounting for the ends of a counterweight support shaft 15 which extends transversely between and through suitable openings in the brackets 14 to overhang both sides of the machinery housing 5 at the rear thereof. Near each end, the shaft 15 is provided with a circumferential groove 16.

Vertically suspended from each end of the shaft 15 is a turnbuckle suspension member 17. Each turnbuckle 17 includes a threaded sleeve 18 and an upper rod'19 and a lower rod 20, each such rod having an inner threaded end received in the sleeve 18 and an outer loop end. The loops of the upper rods 19 are pivotally supported in the circumferential grooves 16 on the shaft 15. With this turnbuckle construction, the overall length of each member 17 can be varied by rotating the sleeve 18. This construction is quite desirable, but other forms of extensible and retractable suspension members, such as hydraulic cylinders, may be used if desired.

The counterweight 13 has apertured U-shaped brackets 22 suitably attached to or formed on each side of its top surface under respective ends of the shaft 15. The loop ends of the lower suspension member rods 20 are removably and pivotally attached to respective brackets 22 by traverse pins 23, the counterweight 13 thus being sup ported by the members 17. The pins 23 can be held in place by any suitable means such as, for example, spring clips (not shown) at each end thereof.

As best seen in FIG. 3, the middle portion of the counterweight 13 is substantially L-shaped in cross section, comprising a horizontal bottom leg 24 Which fits closely against the underside of the rear end of the machinery platform 4 and a vertical rear leg 25 which fits snugly beneath a rear overhanging portion of the machinery housing 5. To secure the counterweight 13 against movement and to help support it when it is in mounted or working position, the counterweight 13 is connected and locked to the machinery platform 4 by bolts 26 which extend through bolt holes 27 in the counterweight 13 and aligned holes 28 in the platform 4. There is preferably a set of two forwardly and rearwardly spaced bolts 26 and

holes

27, 28 at each lateral end of the counterweight 13, and one such set is seen in FIG. 3. To insure proper orientation of the counterweight 13 and resulting alignment of the

bolt holes

27, 28 when the counterweight 13 is moved into mounted position a pair of tapered centering plugs 29 (only one of which can be seen) are provided on the platform 4, with one plug 29 being between the members of each pair of bolts 26. The plugs 29 project downwardly from the underside of the platform 4, and are received in tapered, mating cavities 30 provided on the top surface of the leg 24. Although the structure shown is quite satisfactory, other means of locking and orienting the counterweight 13 can be employed.

In FIGS. 1-2, the counterweight 13 is shown in mounted or working position wherein it is raised and close to the working frame 3. The counterweight suspension members 17 are fully vertical and the pins 23 are in place. The counterweight 13 is bolted securely to the machinery platform 4 and is supported primarily by the bolts 26 and to a lesser extent by the suspension members 17, shaft 15 and brackets 14.

When the counterweight 13 is to be dismounted, the excavator 1 is first maneuvered into a position such that the rear end of its working frame 3 is directly in front of a supporting block or crib 31 seen in FIG. 4. The bolts 26 are then removed to free the coutnerweight 13 from the platform 4. The turnbuckle suspension members 17 are then extended slightly by turning the sleeve 18, this extension serving to lower the counterweight 13 a short distance sufficient to swing clear of the lower rear edge of the housing 5 and associated elements such as the plugs 29 when the excavator 1 is tilted as will be described.

The next step in dismounting the counterweight 13 is for the operator to elevate the front end of the machine. This is accomplished in conventional fashion by lowering the boom 6 and pressing the bucket 10 against the ground until the machine reaches the tilted position of FIG. 4. As the front end raises, the rear end pivots about the rear end of the carrier vehicle 2, and the counterweight 13 swings downwardly and rearwardly about a pivot point defined by the shaft 15. When the machine reaches the position of FIG. 4, the counterweight 13 has been brought to rest on the supporting crib 31. When this has occurred the lower ends of the suspension members 17 are disconnected by removing the pins 23, and the operator can then raise the boom 6 to bring the excavator 1 back to its normal, untilted position.

To effect remounting, the counterweight 13 is first moved to its dismounted position on the crib 31 in whatever manner is appropriate. Thereafter, essentially the reverse of the foregoing dismounting procedure is followed, with the excavator 1 being tilted, the pins 23 inserted, the excavator lowered, the members 17 retracted and the bolts 26 reinserted. It is during retraction of the members 17 that the plugs 29 and recesses 30 come into play, insuring that the counterweight 13 is brought into place with its holes 27 in alignment with the holes 28 of the platform 4.

FIG. 5 illustrates a second embodiment of the counterweight removal arrangement of the invention, and like reference numerals have been used for like elements. Un like the arrangement hereinbefore described, in this embodiment there are suspension members 33 which are of a unitary, non-extensible construction. In order to insure that the counterweight will nevertheless clear the lower rear edge of the platform 4 and housing 5 when the front end of the excavator 1 is lifted, there is a somewhat modified counterweight 13a in which the upper surface of the bottom counterweight leg 24a slopes or curves down warclly and to the left as seen in FIG. 5, and the upper surface of the rear counterweight leg 25a slopes or curves downwardly and to the right as seen in FIG. 5. Alternatively, the suspension members 33 can be made long enough so that the counterweight 13 is, when in mounted position, spaced a sufficient distance below the rear of the machinery housing 5 and machinery platform 4 so that there will be adequate clearance when the excavator 1 is tilted. No centering plug is shown, and with a non-extensible suspension member the use of an orienting plug and cavity is not feasible. If desired, however, a plug could be used with a groove in the top surface of the counterweight that opens through its forward surface.

FIGS. 6-8 illustrate a third embodiment of the counterweight removal arrangement of the invention, and again like numerals have been used for like parts. In this embodiment, a pair of upwardly extending, elongated, U- shaped counterweight support brackets 34 are mounted at the rear of the machinery platform '4, suitable recesses 41 being provided therefor in the housing 5. At the top of the arms of the brackets 34, there are cutout portions or notches 35. The lower rear edges of the brackets 34 in this instance are curved to insure that the counterweight will clear such edges when the front end of the excavator is elevated. A counterweight 36 has brackets 37 on the top surface thereof, and a unitary, non-extensible, strut like suspension member 38 is pivotally attached at the lower end thereof to each bracket 37 by means of a removable pin 39. The upper ends of the suspension members 38 are provided with trunnions 40 that project outwardly on opposite sides of said members and which are cradled in the notches 35 to pivotally support the counterweight 36. As can be seen in FIG. 7, the counterweight 36 is provided with a pair of oppositely disposed side flanges 42 that extend forward, closely alongside the rear side portions of the platform 4. The flanges 42 and an adjacent side of the platform 4 are provided with aligned bolt holes 43 and 44, respectively, through which bolts 45 are passed so that counterweight 36 can be locked in mounted, working position.

When the counterweight 36 is to be dismounted, the locking bolts 45 are first removed from the bolt holes 43, 44. As the front end of the excavator 1 is elevated, the counterweight 36 swings down and away from the rear end of the machinery platform 4 and is brought to rest on a crib 31. Continued elevation of the front end of the excavator 1 will cause the rear end thereof to be lowered further and result in the trunnions 40 at the upper end of each suspension member 38 automatically moving out of the bracket notches 35, whereupon the suspension members 38 can be folded downwardly as shown in dotted lines in FIG. 8 to effectively disconnect the counterweight 36. The reverse of the foregoing dismounting procedure is followed for rernounting the counterweight 36.

While I have illustrated and described my invention herein in preferred forms for use with a back-hoe type of hydraulic excavator, it will be readily appreciated that the invention is equally useful with other machines, such as certain front end loader types of hydraulic excavators, which require a removable counterweight, and which have the capability of lifting one end. Furthermore, although preferred forms of the invention have been shown and described, variations are possible without departure from the spirit of the invention. Instead of using a pair of counterweight suspension members, for example, a single suspension member centered at the rear of the working frame could be employed. In view of these and other possible modifications in structure and application, the invention is not intended to be limited by the showing herein, or in any other manner, except insofar as may specifically be required.

I claim:

1. In a hydraulic excavator or the like having a working frame, a boom at the front end of the frame, and boom operating means adapted to apply a positive downward pressure on the boom whereby such boom can be worked against the ground to elevate the front end of the excavator to produce a tilt at the rear, the combination therewith of:

counterweight mounting means positioned at the rear of the excavator at a substantial height above said working frame;

a counterweight having second mounting means thereon; and

an elongate suspension member having an upper end pivotally connected to said counterweight mounting means and a lower end connected to the second mounting means on the counterweight to thereby mount the counterweight in pendulum fashion with its center of gravity beneath the elongate suspension member, the counterweight thereby being adapted to swing, in response to gravity, down and away from the rear of the working frame upon elevation of the front end of the excavator, and at least one end of said suspension member being releasably connected to its respective mounting means to detach the counterweight from the excavator.

2. In a hydraulic excavator or the like having a working frame, boom means at the end of the frame adapted to elevate said front end, and a counterweight mounted closely beneath the rear end of the working frame, the combination therewith of:

first mounting means on the working frame above the counterweight;

second mounting'means on the counterweight; and

a suspension member having an upper end pivotally connected to the first mounting means and a lower end pivotally connected to the second mounting means, the counterweight being adapted to swing down and away from the rear end of the frame upon elevation of the front end of the frame, at least one end of said suspension member being releasably connected to the respective mounting means, and said suspension member is extensible and retractable to enable the counterweight to be lowered a sufficient distance below the frame so that the counterweight can swing clear of said frame without interference.

3. The combination of claim 2 wherein there is an orienting plug projecting outwardly from the lower rear portion of the working frame, and a mating cavity on the counterweight which receives the plug to orient the counterweight.

4. In a hydraulic excavator or the like having a working frame, boom means at the front end of the frame adapted to elevate said front end, and a counterweight at a lower rear portion of the frame, the combination therewith of:

first mounting means on the Working frame above the counterweight having a support bracket with an upwardly opening notch at its top;

second mounting means on the counterweight; and

a suspension member having a transverse trunnion near its upper end adapted to be removably cradled in said notch and a lower end pivotally connected to the second mounting means, the counterweight being adapted to swing down and away from the rear end of the frame upon elevation of the front end of the frame.

References Cited UNITED STATES PATENTS 701,887 6/1902 Jackson. 2,722,320 11/1955 Dobeus et al 21249 X 3,375,021 3/1968 Grider 212-49 X HUGO O. SCHULZ, Primary Examiner