US3120310A - Tilting-boom log-handling crane - Google Patents

Description

Feb. 4, 1964 K. E. ROBERTS ETAL 3,120,310

TILTING-BOOM LOG-PANDLING CRANE Filed May 20. 1960 2 Sheets-Sheet 1 JNVENTORSkrS ew 6, P055 3% M. P085975 Y WMZM Feb. 4, 1964 K. E. ROBERTS ETAL 3,120,310

' TILTING-BOOM LOG-HANDLING CRANE Filed May 20, 1960 2 Sheets-Sheet 2 l8 i b, /9 25 Z INVENTORS. Z x z/vlv'r/l Baa-P75 BY At my M. P0362725 W m4 2 my.

United States Patent 3,126,310 TILTING-BOQM LGG-HANDLING (IRANE Kenneth E. Roberts, Box 2%, Montesano, Wash, and Alvin M. Roberts, Brooldyn, Wash. Filed May 20, 19%, Ser. No. 30,522 3 Claims. (Cl. 2l2-- i2.5)

This invention relates to a crane intended primarily for piling and unpiling and for loading logs onto a truck in the woods.

For this purpose, it is a principal object to provide such a log-handling crane which can be operated more quickly than a conventional type of crane and which will have better control over logs being hoisted, particuledly for swinging them sidewise and for shifting them lengthwise. An incidental object is to be able to grab a log effectively nearer one end than the other instead of it being necessary to support the log at its center or at locations spaced a substantial distance apart lengthwise of the log.

Another object is to provide such a crane which can grab a log automatically without requiring a workman to set a line or sling around the log.

Such a crane also is compact and readily mobile to facilitate its use.

These objects and advantages can be accomplished by a crane having a boom tiltably supported on the upper end of a mast, which boom has a pair of log-gripping tongs pivotally mounted on its hoisting end and a logengaging abutment located between such tongs and the crane mast. The crane is rigged to control both the inclina ion of the mast and the tilt of the boom relative to the mast for the purpose of hoisting logs, shifting them lengthwise and lowering them, and the mast and boom assembly are further mounted on a turntable for conjoint swinging about a vertical axis.

FIGURE 1 is a top perspective view of the crane.

FIGURE 2 is a plan view or" the crane.

FIGURE 3 is a side elevation view of the crane with parts broken away.

FIGURE 4 is a front elevation view of the crane.

FIGURE 5 is a fragmentary side elevation view of a portion of the mast and boom in a relationship difierent from that shown in HGU'RE 3.

FIGURE 6 is a fragmentary side elevation view of the hoisting end portion of the boom shown converted for use as a shovel, and PlGUR-E 7 is a similar view shown converted for use as a hoe.

In the drawings, the chassis of the hoist is shown diagrammatically, it being understood that suitable cab and control mechanism of conventional character would be provided for the crane. Such crane is mounted on a turntable 1 which preferably is supported on a mobile chassis which is supported on and self-propelled by endless tracks 2. The hoisting operation is effected and contro led by suitably driving two cable drums 3 and 4 by suitable power mechanism of conventional type, which is not shown. The control mechanism would eiiect rotation of either drum in either direction independently of the other so that the drums could be operated either separately or simultaneously at any desired speed and could be held in any desired position by suitable bra-1e mechanism. Ordinarily it will be necessary to provide power mechanism for such drums only to drive them in a winding direction and to control paying out of the lines in the unwinding direction.

On the turntable 1 is swingably supported the mast 5 mounted on a horizontal pivot 6. The upper portion of this mast carries a pivot 7 on wmch the boom 8 composed of two spaced apart parallel spars 9 is mounted. These spars preferably are spaced apart sufficiently to receive between them the upper end portion of the mast 5, as sh wn best in FIGURES l, 2 and 4. The pivot 7 should be located closer to the heel end of the boom than to its hoisting end and the spars are connected adjacent to their heel ends by a shaft it and preferably also by a cleat 11. The hoisting end portions of these spars are interconnected by a shaft 12 which serves as a pivotal support for log-engaging tongs 13 movable between open and closed positions in a plane parallel to the axis of the pivot defined by shaft 12. In addition, these spa-rs are interconnected by an abutment 14 located between the tongs 13 and the mast 5.

Both the degree of inclination of the mast 5 and the angle of tilt of the boom 8 relative to the mast can be controlled by two lines wound on drums 3 and 4 which are connected to the boom 8 at opposite sides of the pivot 7 connecting the mast and boom, as shown in FIGURES 1 and 3. Thus the inclination of the mast is controlled by varying appropriately the effective length of the control lines either separately or conjointly and such swinging of the mast usually is accompanied by swinging of the boom relative to the mast. The load tending to tip the mast downwardly is resisted primarily by the line connected to the boom between the mast and the hoisting end of the boom and such resisting force can be applied m re effectively by rigging this line to react from an anchor frame 15 upstanding from the turntable 1. This frame is composed of posts 16 connected by a cross bar 17 and supported by inclined brace struts 18. i

The line 19, acting principally to resist the tendency of a load on the boom to tilt the mast 5 downward, is wound on the drum 3 on turntable 1 and extends from such drum upward over sheave 2% on the cross bar 17 of the anchor frame, then around a sheave 21 journaled on one spar 9, back around two sheaves 22 journaled in a yoke 23 swingable on the cross bar 17 to maintain the stretches of the line engaging such sheaves in spaced relationship, out again around the other sheave 21 on the other spar 9 and back to a line end securing anchor 24 on the portion of the anchor frame 15 remote from the sheave 2G.

The tilt of the boom 8 relative to the mast 5 is controlled also by the other line 25 which is wound on the drum 4 and extends from such drum to a sheave 26 carried by the heel portion of the boom overhanging beyond the mast pivot 7, then down around a sheave 27 mounted on the lower portion of the mast 5, upward again around a second sheave 26 carried by the heel overhang of the boom and down again to an anchor 28 shown as being on the anchor frame 15 but which could, if desired, be on the turntable such as adjacent to the drum 3. It will be noted in FIGURES 1 and 2 that, with the exception of the standing end portion of the line 25, all the stretches of such line are located between the stretches of the line 19 engaging the sheaves 22 which are held apart by the spaced locations of such sheaves, as described above. The standing end portion of line 25 may also extend between such stretches of the line 19, if desired.

In use, to hoist a log line 2'5 will be paid out to dispose the boom g in a generally upright position and then both lines w and 25 may be paid out simultaneously to enable the mast 5 and boom 8 to swing down-ward conjointly until the log-engaging tongs 13 engage the side of a log. Further conjoint lowering of the mast and boom will cause the log to wedge the tongs open so that they will be engaged around a log and will be closed on it by the weight or" the tongs arms. if the lines 1 and 25 are then reeled in, the log will be hoisted because the weight of the log will tend to maintain the tongs arms closed. If the tongs are engaged with the log at its center of gravity, the log will be lifted in a horizontal position as illustrated in FIGURE 3. Also, if it is desired to shift the log lengthwise away from the crane, the line 25 will be reeled in to tilt the boom 8 upward toward horizontal position, as shown in FIGURE 3.

With the log thus hoisted, the turntable 1 may be rotated in one direction or the other to a location where it is desired to deposit the log, and if it is desired to shift the log still further outward lengthwise from the crane, line 25 can be reeled in and line 19 paid out to effect such shifting of the log at the same time that it is lowered. While the turntable 1 is being swung, the log L gripped by the tongs can be maintained parallel to a vertical plane substantially parallel to the mast 5 and boom 8 by engaging the log with abutment 14 although the tongs 13 are mounted to swivel about the horizontal axis of pivot 12 and also are mounted for swivelling about an axis perpendicular to the axis of pivot 12. Much better control over the log L is maintained than if it were on the end of a hoisting line. The log has little tendency to depart from a vertical plane parallel to mast 5 and boom 8, even when mast 5 is swung by rotation of the turntable. The log can be swung end-for-end in controlled fashion by dragging one end of the log as the mast is swung by the turntable. To deposit the log after it is lowered, it is merely necessary for the tongs to be lowered so that the arms will swing open and the bottom is moved lengthwise of the log to drag the tongs onto the log in closed condition. The boom can then be swung to slide the tongs oil the log.

The crane may have a reach which is too short to enable the tongs 13 to be engaged at the center of gravity of the log. In that case, the tongs can be engaged with a portion of the log closer to the end adjacent to the crane, as shown in FIGURE 5. As the line is reeled into hoist the log either conjointly with or independently of line 19, the end of the log adjacent to the crane will be raised above the opposite end of the log until the end portion of the log adjacent to the crane engages the abutment 14, as shown in FIGURE 5. Thereafter, the log will be lifted in a position substantially parallel to the boom 8. Thus supported, the log can be moved sidewise by rotation of the turntable 1 and moved lengthwise in one direction by reeling in line '19 to swing the mast 5 toward the vertical position or paying out line 19 while reeling in line 25 to swing the mast farther toward horizontal position.

When the log has been shifted approximately to the desired position where it is to be deposited, line 19 can be paid out somewhat while line 25 is paid out to a greater extent so that the lengthwise position of the log will not be shifted appreciably while the boom 8 is being tilted downward to deposit the log. When the ton-gs 13 have been relieved of the weight of the log, they may be released from'the log as described previously.

While the operation of the crane has been described above in connection with the operation of handling logs, it is possible to convert the crane so that it will hoist dirt by converting the crane into a scoop shovel as shown in FIGURE 6, or into a backhoe as shown in FIGURE 7. To efiect such conversion, it is merely necessary to re place the tongs 13 suspended from the end of the boom 8 by a scoop shovel head29 having a dumping door 30 released by a trip line 31, or by substituting the backhoe head 32, shown in FIGURE 7, on the end of the boom 8. The same rigging described for operation of the crane can be used to manipulate the boom '8 for digging with and dumping either the shovel or the hoe.

In manipulating the shovel head 29, the line 19 would be reeled in and the line 25 paid out until the hoisting endof the boom 8 has been swung toward the mast 5 beyond vertical and such mast has been lowered sufficiently to enable the digging edge 33 of the scoop shovel to contact the ground. Thereupon, the line 2-5 will be reeled in to swing the boom 8 upward toward the position of FIGURE 6. Next the turntable 1 can be rotated and the position of the scoop shovel head adjusted by appro priate swinging of the boom and toast 5 to a desired location for dumping the dirt and .thedirt can then be dumped by pulling on the trip line 31 to release the door 30. As the shovel head is swung into a position to take another scoop of dirt in the manner described, the force of gravity acting on the door 39 will automatically engage the latch again so that the scoop shovel can be refilled.

To use the hoe head 32, both lines 19 and 25 will be paid out to swing the mast 5 downward while the boom 8 is maintained inclined downward slightly until the digging edge 34 is engaged with the ground. Thereupon, line 19 will be reeled in while line 25 is paid out to swing the boom 8 toward vertical position to enable the backhoe head 32 to execute a scooping action. When the hoe head has thus been filled with dirt, line 19' will con tinue to be reeled in while line 25 will be paid out to raise the hoe above the ground. The mast can then be swung by rotation of the turntable 1 to a location for dumping the dirt and the line 25 can then be reeled in to swing the hoisting end of the boom upward for dumping the dirt from the hoe head. The digging operation can then be repeated in this manner.

We claim as our invention:

1. A tilting boom crane comprising a base, a mast, mast pivot means supporting said mast on said base for swinging about a substantially horizontal axis, a boom, boom pivot means located between the ends of said boom and tiltably supporting said boom on the upper portion of said mast, load-supporting means carried by said boom at one side of said boom pivot means, and rigging operable to apply force for swinging said mast relative to said base and for tilting said boom relative to said mast, said rigging including a sheave mounted on the lower portion of said mast, a first line connected to said boom at a location between said boom pivot means and said loadsupporting means, a second line connected to a portion of said boom at the side of said boom pivot means remote from said load-supporting means and located a distance from said boom pivot means greater than the distance between the connection of said first line to said boom and said boom pivot means, and said second line being looped from its connection to said boom downward around said sheave, and means operable to vary the effective lengths of said lines, for tilting said boom rela tive to said mast principally by varying the effective length of said second line and for swinging said mast relative to said base principally by varying the eifective length of said first line.

2. A tilting boom crane comprising a base, a mast, mast pivot means supporting said mast on said base for swinging about a substantially horizontal axis, a broom, boom pivot means located between the ends of said boom and tiltably supporting said boom and the upper portion of said mast, load-supporting means carried by said boom at one side of said boom pivot means, a sheave mounted on the lower portion of said mast, boom-tiltingline-engaging means on said boom at the side of said boom pivot means opposite said load-supporting means, line length-varying means carried by said base and located a distance from.

said mast pivot means approximately equal to the distance of said boom-tilting line-engaging means from said boom pivot means, boom-tilting line means interconnectmeans to effect principally tilting of said boom relative to said mast, and mast-swinging line means connected to a portion of said boom between said load-supporting means and said boom pivot means, disposed adjacent to said boom pivot means and variable in effective length to 5 effect principally swinging of said mast relative to said base.

3. A tilting boom crane comprising a base, a mast, mast pivot means supporting said mast on said base for swinging about a substantiaily horizontal axis, a boom, boom pivot means located between the ends of said boom and tiltably supporting said boom on the upper portion of said mast, load-supporting means carried by said boom at one side of said boom pivot means, and rigging operable to apply force for swinging said mast relative to said base and for tilting said boom relative to said mast, said rigging including first lineholding means, a first line extending, independently of said mast, directly between said first line-holding means and a location on said boom between said boom pivot means and said loadsupporting means, second line-holding means lower than said first line-holding means, a second line crossing said first line and extending between said second line-holding means and a portion of said boom at the side of said boom pivot means remote from said load-supporting means and spaced from said boom pivot means a distance considerably greater than the distance between said boom pivot means and the location on said boom to which said first line extends, and means operable to vary the eflective lengths of said lines, for tilting said boom relative to said mast principally by varying the efiective length of said second line and for swinging said mast relative to said base principally by varying the effective length of said first line.

References Cited in the file of this patent UNITED STATES PATENTS 1,884,861 Remde Oct. 25, 1932 2,930,045 Billings Feb. 11, 1936 2,303,852 Linn Dec. 1, 1942 2,595,864 Lawry May 6, 1952 2,656,059 Troyer Oct. 20, 1953

Claims (1)

1. A TILTING BOOM CRANE COMPRISING A BASE, A MAST, MAST PIVOT MEANS SUPPORTING SAID MAST ON SAID BASE FOR SWINGING ABOUT A SUBSTANTIALLY HORIZONTAL AXIS, A BOOM BOOM PIVOT MEANS LOCATED BETWEEN THE ENDS OF SAID BOOM AND TILTABLY SUPPORTING SAID BOOM ON THE UPPER PORTION OF SAID MAST, LOAD-SUPPORTING MEANS CARRIED BY SAID BOOM AT ONE SIDE OF SAID BOOM PIVOT MEANS, AND RIGGING OPERABLE TO APPLY FORCE FOR SWINGING SAID MAST RELATIVE TO SAID BASE AND FOR TILTING SAID BOOM RELATIVE TO SAID MAST, SAID RIGGING INCLUDING A SHEAVE MOUNTED ON THE LOWER PORTION OF SAID MAST, A FIRST LINE CONNECTED TO SAID BOOM AT A LOCATION BETWEEN SAID BOOM PIVOT MEANS AND SAID LOADSUPPORTING MEANS, A SECOND LINE CONNECTED TO A PORTION OF SAID BOOM AT THE SIDE OF SAID BOOM PIVOT MEANS REMOTE FROM SAID LOAD-SUPPORTING MEANS AND LOCATED A DISTANCE FROM SAID BOOM PIVOT MEANS GREATER THAN THE DISTANCE BETWEEN THE CONNECTION OF SAID FIRST LINE TO SAID BOOM AND SAID BOOM PIVOT MEANS, AND SAID SECOND LINE BEING LOOPED FROM ITS CONNECTION TO SAID BOOM DOWNWARD AROUND SAID SHEAVE, AND MEANS OPERABLE TO VARY THE EFFECTIVE LENGTHS OF SAID LINES, FOR TILTING SAID BOOM RELATIVE TO SAID MAST PRINCIPALLY BY VARYING THE EFFECTIVE LENGTH OF SAID SECOND LINE AND FOR SWINGING SAID MAST RELATIVE TO SAID BASE PRINCIPALLY BY VARYING THE EFFECTIVE LENGTH OF SAID FIRST LINE.

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