US2684767A - Horizontal boom unloader - Google Patents

Description

July 27, 1954 k. P. FOX

HORIZONTAL 500M UNLOADER 3 Sheets-Sheet 1 Filed Jan. 6, 1951 INVENTOR y 27, 1954 R. P. FOX

HORIZONTAL BOOM UNLOADER 3 Sheets-Sheet 2 Filed Jan. 6, 1951 Aw & AN M 6 0 O INVENTOR Robert P Fox BY 914! I AT TORNEY July 27, 1954 i, FQX 2,684,767

HORIZONTAL; BOOM UNLOADER Filed Jan. 6, 1951 .s Sheets-Sheet 3 IN VENTOR'- Robert 1? Fox BY QbWmQm A ORNEY Patented July 27, 1954 UNITED STATS PATENT OFFICE Iron Works, of Minnesota Inc., Duluth, Minn, a. corporation Application January 6, 1951, Serial No. 204,803

5 Claims.

My invention relates to an improvement in horizontal boom unloader wherein it is desired to provide a novel and effective means of handling clamshell buckets and the like.

In horizontal boom unloading devices, Where the hoisting equipment is located at one end of the boom, complicated and expensive equipment is necessary for controlling the elevation of the bucket as it moves longitudinally of the boom. The bucket is usually supported from a trolley movable longitudinally of the boom. As the tro ley moves along the boom, the bucket tends to change elevation unless particular means are provided for holding the load at a constant elevation. The present invention is designed to provide a simple and effective means for maintaining the load at a fixed elevation as the trolley travels along the boom. As a result the expensive and complicated mechanisms usually required for this purpose may be eliminated.

An object of the present invention lies in the provision of a boom supporting a longitudinally movable trolley and a longitudinally movable fleeting block. The load line from the hoisting drum to the clamshell bucket and thebucket closing line extend from the hOiStlng drums over the movable fleeting block and then over the trolley sheaves to the clamshell bucket which is suspended below the trolley. The position of the trolley is regulated by cables simultaneously 3 winding .and unwinding from a trolley drum. One set of cables extends from the trolley drum to the trolley while the other set of cables extends about an idle sheave at the boom extremity. These cables then pass over sheaves on the fleeting block and are dead ended in the boom extremity. Thus as the trolley drum rotates in a direction to pull the trolley toward the trolley drum, the line is payed out to the fleeting block permitting the fleeting block to also move toward the trolley drum. As a result the bucket may be maintained at a constant elevation during movement thereof along the boom if the hoist drums remain stationary.

A feature of the present invention lies in the provision of a fleeting block which is so arranged that it is mounted half way between the trolley and the boom extremity. As a result as the trolley moves away from the boom extremity the length of line from the hoist drums to the trolley sheaves remains constant. As a result by holding the hoist drums stationary the bucket may be maintained at a constant elevation.

A feature of the present invention lies in the fact that the hoisting mechanism is particularly adaptable for use in conjunction with horizontal booms which are either supported for lateral movement along tracks or rotative movement about a fixed or movable axis. Furthermore, the boom is supported by an A frame of relatively low height and the boom is horizontally hinged on the machinery deck of the unloader. This construction adds to the simplicity and rigidity of the structure and improves the appearance of the apparatus.

A feature of the present invention lies in the provision of a fleeting sheave block which traverses between the boom extremity or boom point and the midpoint of the boom and which is supported by the boom. This structure permits the load to be controlled without the aid of intermediate deflecting or fleeting sheaves.

These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of my specification:

Figure 1 is a top plan view of the boom unloader showing the general arrangement of parts thereof.

Figure 2 is a side elevational view of the boom unloader as it would appear mounted upon parallel tracks.

Figure 3 is a sectional view through the boom and through both the trolley and the fleeting sheave block showing the construction thereof.

Figure 4 is a diagrammatic view showing the line reeving system employed.

Figure 5 is a top plan view of the trolley.

Figure 6 is a top plan view of the fleeting block.

The unloader is indicated in general by the letter A. In the particular form of construction illustrated the unloader is mounted upon parallel tracks I0 and H. However, in other forms of construction the unloader may be supported for pivotal movement about a vertical pivot.

The unloader includes a frame l2 provided at its forward end with leg supports i3 and at its rear end with leg supports M. Ballast is usually provided to the rear end of the frame [2 so as to counter-balance the boom and the load supported thereby. A machinery deck I6 is supported upon the frame I2. A suitable cab ii is provided upon the machinery deck It for enclosing the hoisting mechanism. and operator. This cab is omitted in Figure l of the drawings for simplicity of illustration.

An upwardly and rearwardly inclined frame It is connected at its lower end to the machinery deck [5 and is connected by suitable gusset plates to frame braces 2|. The frame braces 21 are connected at 22 to the frame [2 adjacent to the machinery deck.

An A frame 23 is pivotally supported at 24 to the machinery deck 16 and the boom 25 is pivoted at the same pivot point 24. A fixed cable 26 is dead ended to the gusset plate 20 at 21 and is dead ended to the peak of the A frame at 29. This line 26 normally supports the A frame in fixed position and limits the downward pivotal movement of this A frame. A boom elevating line 3!! is connected to a drum 3! and extends over a sheave structure 32 at the top of the frame I9 and about a sheave structure 33 at the peak of the A frame and is dead ended to one or the other of these elements. The A frame 23 may be swung in a counter-clockwise direction as viewed in Figure 2 by this boom elevating line 30.

Fixed cables 34, 35 and 36 connect the extremity of the A frame 23 with various points throughout the length of the boom 25. Thus the boom 25 is maintained in fixed angular relation to the A frame and the boom may be elevated by raising the A frame 23. By actuating the boom elevating line 3d, the boom may be swung upwardly with the A frame As best illustrated in Figure 3 of the drawings, the boom includes a pair of spaced angle members 3i and 39 which serve as tracks for the trolley M. A second pair of angle members at and '52 are supported above the angles 3'! and ill and form a second pair of tracks for supporting a fleeting block 43. The two sets of angles are connected by suitable boom braces such as it and which form a part of the boom structure. The trolley 45! includes a pair of longitudinally extending members 45 and il connected at opposite ends by frame members 419 and 58. Transversely extending shafts 5i extend through the frame members 46 and ll and act to support trolley wheels 52 and 53. The wheels 52 and 53 are flanged to remain on the track. The trolley wheels 5'2 and 53 support the trolley for movement longitudinally of the tracks 37 and 39. These tracks may be further reinforced by reinforcing plates 54 and 55.

Thus the trolley comprises a generally rectangular frame supported by trolley wheels at each end thereof. A transverse shaft 5% extends through the frame members it and i? intermediate ends of the trolley. This shaft 55 supports spaced sheaves 5i and 59 which are mounted. upon ball bearings 6D and G i.

The fleeting block 43 is somewhat similarly arranged and includes side frame members 52 and 63 connected by end frame members 66. A pair of parallel shafts '65 extend through the side frame members 52 and 63 near opposite ends thereof to support rollers lit and $7 on opposite sides of the fleeting block frame. These rollers ride upon the angle members 4! and 52 and are held substantially in engagement thereby by laterally extending flanges 69 and it} supported by the fleeting block frame members 62 and 63. The flanges 69 and T0 extend beneath the angle members Al and i2 and hold the fleeting block from disengagement therewith.

The fleetin block frame sides 62 and E3 support a transversely extending shaft l'i. This shaft H supports a pair of relatively small diameter sheaves l2 and 13 and a pair of larger diameter sheaves M and 15. As will be later described in detail the sheaves l2 and 73 are designed to accommodate the trolley cables which regulate the location of the trolley 50. The sheaves l4 and 75 are designed to accommodate the load line and the bucket closing line.

The boom point '16 is equipped with a pair of sheaves ll and '19 which are designed to accommodate the trolley cables. These sheaves Ti and F9 are aligned with the sheaves "i2 and E3 on the fleeting block and act to guide the cable from the trolley drum to the fleeting block. In Figure l of the drawings I disclose a line reeving diagram which shows the manner of operation of the fleeting block. In this view I disclose a holding drum 8!! designed to accommodate the holding line of the clamshell bucket and a closing drum 8| designed to accommodate the closing line of the bucket. The hoisting line or load holding line is indicated at 82 while the bucket closing line is indicated by the numeral 83.

The cables 82 and 83 extend over the sheaves i4 and i5 and extend in a return direction along the boom to pass over the trolley sheaves 5i and 59. The lines extend downwardly from the sheaves 51 and 59 to the clamshell bucket 84. The drums and 8! are so controlled that the holdin drum may remain stationary while the bucket is closed. As soon as the bucket is in closed position both drums BB and El rotate in unison to lift the bucket.

The trolley drum 85 is provided with two parallel cables 8% which extend the full length of the boom and extend over the sheaves TI and '59 located at the point of the boom. These cables 8-3 then extend in a reverse direction along the boom to pass about the sheaves l2 and '23 of the fleeting block. These cables are then dead ended at the boom point as indicated at 8?.

Two cables 39 are payed out from the trolley drum 85 as the cables 8% wind upon the same. These cables are attached to the trolley it at the point 90. The cables 86 and 89 may be the same cables which merely extend about the trolley drum, or may be separate cables wound upon the troll y drum.

The fleeting block 43 is always located at half the distance toward the boom point from the trolley 45]. When the trolley .51 is at the anchored end of the boom, the fleeting block 13 will be located at substantially the mid-point of the boom. As the trolley moves toward the boom point, the line 86 is wound upon the trolley drum. Due to the fact the trolley cables 36 pass over the sheaves l2 and 73 of the fleeting block and are not anchored thereto, the fleeting block 63 will be drawn toward the boom point at half the rate the trolley M will move toward the boom point. The trolley is moved toward the boom point by the weight of the bucket suspended therefrom, this weight tending to draw the trolley it directly beneath the fleeting block 63. If the line 32 is unwound from the trolley drum the trolley is permitted to move toward the point of the boom.

When it is desired to move the load toward the anchored end of the boom, the trolley drum 85 is rotated in the opposite direction acting to wind the cable 89 upon the drum and to pay out the cables 86. Due to the fact that the line 86 is looped about the sheaves 72 and 73 of the fleeting block, each foot of movement of the line 36 causes the fleetin block to move six inches away from the boom point. Thus the trolley is always twice as far from the boom point as is the fleeting block 53.

If during movement of the load, the drums 8B and 81 remain stationary, movement of the trolley 46 in either direction will hold the bucket 86 at the same elevation. This is caused by the fact that as the trolley moves toward the anchored end of the boom, the fleeting block also moves toward the boom and at a proportional rate which makes the length of line between the drums 80 and iii and the trolley 40 constant. As the trolley 40 moves toward the boom point, the fleeting block 53 also moves toward the boom point at a proper rate to hold the length of line from the hoisting drum to the trolley constant. Obviously the load may be lifted or lowered during movement of the trolley when such action is desired.

As previously stated the position of the trolley and fleeting block is regulated by two parallel cables 86. It will be noted that one of these cables is connected to each side of the trolley on opposite sides of the sheaves 51 and as which support the load. It will also be noted that these two parallel cables extend over sheaves l2 and 73 on opposite sides of the sheaves T4 and F5 on the fleeting block which carry the load cables. This double cable arrangement is of particular advantage. By placing a trolley line on each side of the load sheaves in the fleeting block and in the trolley it is possible to carry the effect of the load line pull between the reactive trolley line pulls without objectionable flange loads in the trolley or fleeting block wheels which would necessarily result if a single trolley line were used and located between the sets of double hoisting line sheaves.

In accordance with the patent statutes, I have described the principles of construction and operation of my horizontal boom unloader, and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1. An unloader including an elongated boom, a fleeting block supported for longitudinal movement on said boom, fleeting block sheaves individually rotatably supported by said fleeting block, a trolley supported for longitudinal movement on said boom, trolley sheave means rotatably supported by said trolley, a hoisting drum supported adjacent to one end of said boom, a trolley drum supported adjacent to said hoisting drum, a hoisting line extending from said hoisting drum around one of said fleeting block sheaves to reverse the direction thereof, over said trolley sheave means, and downwardly toward the load, a trolley line extending about the trolley drum for actuation thereby, one end of said trolley line being connected to said trolley and the other end extending longitudinally of the boom, a sheave on said boom adjacent to the other end thereof about which said trolley line extends to reverse its direction, said trolley line extending about another of said fleeting block sheaves to reverse its direction, said trolley line being dead ended to said other end of said boom, said fleeting block being, at all times, substantially midway between said trolley and said other end of said boom.

2. The structure described in claim 1 in which the load line includes a second cable, and including a second hoisting drum to which the second cable is attached.

3. The structure defined in claim 1 and in which the trolley line comprises two spaced cables in parallel relation.

4. The structure defined in claim 1 and in which the trolley line comprises two spaced cables in parallel relation, the second of which extends over a third fleeting block sheave and in which the said one fleeting block sheave over which the hoisting line extends is located between said other fleeting block sheave and the third fleeting block sheave.

5. An unloader including an elongated boom, a fleeting block supported for longitudinal movement along said boom, four fleeting block sheaves rotatably supported on said fleeting block, a trolley supported for longitudinal movement on said boom, a trolley drum and a pair of hoisting drums supported adjacent to one end of said boom, a pair of sheaves supported adjacent the other end of said boom, a pair of trolley lines extending about said trolley drum for actuation thereby, one end of each of said trolley lines being secured to said trolley, the other ends of'said trolley lines extending over said sheaves at said other end of said boom, said trolley lines then extending over two of said fleeting block sheaves, and being dead ended at said other end of said boom, a pair of hoisting lines, one being secured to each hoisting drum for actuation thereby, said hoisting lines extending over the remaining two sheaves on said fleeting block, a pair of trolley sheaves on said trolley, said hoisting lines extending over said trolley sheaves and extending downwardly therefrom, said fleeting block being supported substantially midway between said trolley and said other boom end.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 505,637 Rasch Sept. 26, 1893 827,247 Lovell July 31, 1906 1,181,171 Sawyer May 2, 1916 1,710,798 Kidder Apr; 30, 1929

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