US2763218A - Portable general utility crane - Google Patents

Description

' Sept. 18, 1956 P. GRAHAM PORTABLE GENERAL UTILITY CRANE Filed April 22, 1952 3 Sheets-Sheet l INVENTORE Phi/[1p Graham Afforney Sept. 18, 1956 H M 7 2,763,218

PORTABLE GENERAL UTILITY CRANE Filed April 22, 1.952-

3 Sheets-Sheet 2 J II I 34 264 613: #:w:

Afforney Sept. 18, 1956 P. GRAHAM 2,763,218

I ORTABLE GENERAL UTILITY CRANE Filed April 22, 1952 3 Sheets-Sheet 3 .I I l i OG 26a la lb I 26 4 "1' 'l I I I I g IN VEN TOR.

4 Phil/1b Graham United States Patent 2,763,218 PORTABLE GENERAL UTILITY CRANE Phillip Graham, Dormant, Pa. Application April 22, 1952, Serial N 0. 283,576 8 Claims. (Cl. 104-426 This invention relates to a portable and convertible crane which is useful for a wide variety of material handling operations either in shops or out in the field.

Small cranes of various conventional types have the outstanding disadvantage of being very limited in use and not being convertible to fill the need for an all around, utility crane to meet variable conditions in shops and the construction field.

An object of this invention is to provide a crane which is of such construction that it can be quickly converted and adjusted to suit many conditions for lifting and moving loads.

Another object is to erated by one man in to another operation.

A further object of the invention is to provide a crane which is particularly useful as a one ton capacity crane which would make the crane readily portable and easily disassembled and carried on a small truck or utility trailer. Most of the parts serving in conversions on the crane are designed so as to be readily available when required and are not obstructions when not in use. I

A still further object is to provide a novel crane which has a basic skeleton or frame which makes it specially adapted to suit varying needs.

Other objects and advantages of the present invention provide a crane which can be up conjunction with and as an aid will become apparent from a study of the following de- 7 scription taken with the accompanying drawing wherein:

Figure 1 is a schematic elevational diagram of a crane embodying the principles of my invention;

Figure 2 is a sectional elevation taken along line 2 2 of Figures 1 and 4;

Figure 3 is a fragmentary plan view taken along line 3--3 of Figure 1;

Figure 4 is a fragmentary elevational view taken along line 4-4 of Figure 3;

Figure 5 is a fragmentary sectional elevation taken along line 5-5 of Figure 4';

Figure 6 is an enlarged fragmentary sectional plan view showing masts and mast tracks or guides, taken along line 66 of Figure 4;

Figure 7 is a schematic elevational diagram showing a second arrangement or conversion for use of the crane for a different operation than that shown in Figure l; and

Figure 8 is a schematic elevational diagram showing a third arrangement or conversion of the crane.

Referring to Figure 1 which shows a schematic elevation of the crane, together with Figures 2, 3, 4, 5 and 6 which show details of the crane illustrated in Figure l, numeral 1 denotes a monorail beam which may be a structural I beam supported by adjustable towers T1 and T2.

The towers T1 and T2 are, in general, identical. A conventional monorail. crane trolley 2 moves along the top surfaces of the bottom flange of beam 1. Stop angles 1d are bolted to the ends of beam 1.

The brake Zn on the underside of the trolley 2 (see .porary fixed route with Figure 4) is a lever arrangement to prevent unwanted movement of the trolley 2 and the load, particularly when beam 1 is tilted for gravity movement of a load. The brake 2a is engaged by pulling cable 20 and it is diseng'a'g'ed by releasing the pull on the cable.

The one end of brake lever 2a is made to bear against the bottom flange of beam 1 for the braking action. The wearing end of brake lever 2a is heavier than the other end so the brake will disengage when the pull on the cable 20 is released. The hoist 3 is hooked onto trolley 2. The hoist 3 may be either a conventional manual operated type, such as a chain block, or a conventional power operated type, such as an electric or pneumatic powered hoist. The hoist 3 usually has a chain "with a hook on the lower end which is attached to load 4 with sling chains. The chain is raised or lowered to suit the operation by means of power or manual effort, through the use of the mechanism in the hoist. I

There are many occasions when a load 4 can economically bejr'noved from one position to another over a temgravity as the power means. With such set-ups, the beam 1 which is normally used in a horizontal position, would be tilted down very slightly in the direction of the load movement, which is to the right as shown in Figure 1. The towers T1 and T2 have features, which will be explained in detail later, to allow beam 1 to be tilted considerably, or to be maintained in. a horizontal position.

Figure 7 is a schematic elevation of the crane showing a setup with the beam 1 tilted considerably wherein conditions are such that beam 1 has to be tilted to enter the covered truck 45 and still maintain a sufficient height to allow movement of the load 4.

A counterforce carriage 5 is attached to one end of cable 6 and the trolley 2 is attached to the other end of the cable. Cable 6 is rigged with pulleys 6a and 6b as shown in Figure 4.

When a load 4 is lifted, its weight along with the weight of the trolley 2 and hoist 3, is greater than the weight of carriage 5 which, in this arrangement, acts as a counterweight. When the brake 2a on trolley 2, as shown in Figure 4, is released, the force of gravity causes the load to move towards the lower end of beam 1 to the desired unloading position. The counterweight force of carriage 5, being heavier than that of the weight of trolley 2 and hoist 3, would cause the units to return to their original loading position. Carriage 5 can pass through the towers T1 and T2 as can trolley 2, hoist 3 and load 4.

When it is necessary to move loads up a steep grade, when conditions are such as is shown in Figure 7, or to move loads slowly up or down a grade under full control with a means for safely stopping the movement by remote control, a reversible motor 5a on carriage 5 is used to move the load. A removable worm gear attached to motor 5a engages rack 1c which is fastened to the top of beam 1. The Worm gear is removed when car ria'ge 5 is to act as a counterweight.

Another arrangement, with carriage 5 out of operation, is a suitable manual or powered winch 50 mounted on beam 1. It is attached to cable 6 in place of carriage 5, which it would activate. Cable 6 would be unhooked from trolley 2 when it is not being used.

The bulb angles 11; and 1b which are fastened to the top flange of beam 1 by such means as welding, stiffen the beam 1 to prevent it from failing laterally from heavy loads. The angles also offer limited protection from snow and rain for the crane parts below it: Continuous beading along the heels of the angles 1a and lb will cause rain Water to drip and thus divert it from going under angles to beam 1, etc. Angles 1a and 1b act as rails for the wheels on carriage 5. The bulbs on the angles preindicates raised or vent the wheels from rising and thus prevent carriage from jumping the track and disengaging the gear from the rack 10. Angles 1a and 1b act also as braking surfaces to hold towers T1 and T2 in desired positions with respect to beam 1 as will be explained in detail later. Bent plates or built-up members are used instead of bulb angles.

A means of moving the load 4 laterally, which would be desirable under some conditions, is to have pin connected links 7 from the tower T1 connected to trolley 2. When the tower is moved, either by manual or powered means, the load will thus move. This arrangement is practical for moving heavy loads, especially those cantilevered to load or unload covered trucks and boxcars, the tower T1 offering close support for the load. The tower (or towers) are pushed manually, or by a motorized vehicle. It has motors on its wheels at the ground for powered movement. Since the tower is fastened by links 7 to trolley 2, when carriage 5 (or a winch 50 described previously) is used to move trolley 2, it will also move the tower linked to it. When the load is linked to a tower, the operator stands on the tower platform 43 to operate this linked arrangement, thus traveling with the load, but not under or too near it where there would be danger from a load spilling or slipping from its chains. This is a safe setup to move hot metals and volatile chemicals. These pin connected links 7 are unfastened from trolley 2 and allowed to hang from the tower masts when this setup is not being used. Most small trolley and hoist controls are ropes hanging down to within reach of the operator. When the operator is to stand off to a side, these controls are rigged with pulleys, etc., to the desired position, or there may be dual controls.

The tower T1 is shown as being of tubular construction although other types of structural members may be substituted. These identical towers T1 and T2 are adjustable in height so that at their lower limit they can be used where head room is small and at their higher limit where a high lift is needed. Lower masts 8 have pulleys 8a and 8b near their tops. Dot-dash outlines 80 above the tower extended positions of masts 8 and the pulleys when extension mast sections are inserted below (not shown). Upper masts 9 are adjacent to masts 8. Extension masts 10, shown below masts 9, may also be used below both masts 8 and 9 to increase the height of the tower. The extension masts 10 are fastened with pins. Pin holes are indicated in all masts for various uses, including anchoring masts to the tower base. They also prevent the masts from turning in their sockets. Pins may be inserted in masts 8 below bent plates 26 as a secondary safety means to preevnt the tower top from falling because of failure of cables 22.

Masts 8 are supported by a truss framework, which has wheel assemblies at each end. The top chord truss member is 11, and the bottom chord truss member is 12, which has its ends bent up diagonally. Vertical truss members 13 and diagonal truss members 14 join the top and bottom chords together. Mast sockets 15 are bent plates. Sockets 15 can take either or both masts 8 and 9 at the same time. The tower framework would, in general, be welded except where bolted and pin connections would be used to allow quick dissassembling and end erecting of towers when the crane is to be knocked down into suitable shipping sections to make it highly portable. Diagonal tubular pieces 16 are at the top of the ends of the truss. The vertical tubular truss ends 17 engage the wheel supports 18a for swiveled wheels 18. A tower T1 moves on the two swiveled wheels 18 over the ground or floor surface. The supports 18a revolve in tubes 17 when the tower is steered. The lower part of the shank of support 18a is threaded to engage threaded sleeve 18c and lock nut 18d. Sleeves 18c have circular grooves (not shown) to receive set screws -in stops 19 so that the tower by direct lift, but

- winches.

through vertical tubes 17 to prevent relative longitudinal movement of supports 18a. Thus the crane may be lifted with the wheels secured. The upper part of support 18a that engages tube 17 is not threaded. The shaft of support 18a is hollow to allow electric Wires to lead down to a reversible motor 1812. By turning of threaded sleeves 180, the tower elevation is adjusted to obtain a true position. This threaded jacking arrangement is used to compensate for uneven ground or floor surfaces on which the crane sets. The turning of sleeve 18c, but not the support 18a, raises or lowers the wheel assembly by means of the threaded engagement. Lock nut 18d locks the setting of the support 18a and the sleeve 18c. The removable jacking handle 18.2 is used to turn sleeve 18c and lock nut 18d. The wheel 18 is attached to the forked part of support 18a. Wheel 18 is not centered with the shaft of support 18a, thus wheel 18 is swivel mounted.

When tower T1 is moved, the wheels may, in general, swivel to the proper direction. These towers T1 and T2 may be moved by various means. With many possible conditions, towers would be pushed manually. Where power is available and frequent moving of towers T1 and T2 is desirable, electric motors 18b, attached to wheel supports 18a, are used to move tower wheels 18 and thus the tower, or towers. Motors 18b are geared to wheels 18 with a gear arrangement such as that used on automobile starting motors in free wheeling systems so that when power is turned off, the gears disengage. This would allow wheels 18 to revolve freely when the tower is pushed or pulled by other means than motors 18b. Some possible uses of this crane would require a steering mechanism. Sprockets 18] on supports 18a engage a steering chain 20b which will be described later. To prevent unwanted movement of a tower when it is set on a grade, two stops or brakes 19 are used to hold the tower in a set position. The bottom of brake 19 has a flat shape to contact the ground surface to prevent movement of the tower when desired. There are holes in the bottom of brake 19 to allow it to be further secured by bolting or nailing to prevent sliding or toppling such as when it is attached for use on a truck body. When the crane is used at times in a fixed position, a tower farthest from a cantilevered beam end may be bolted down to a fioor or other support by means of the holes will not rise when an cantilevered load creates a greater moment. The shaft of brake 19 is threaded to engage a threaded nut welded to the inside of vertical member 13. By turning the crank end of brake 19, a threaded jacking movement is obtained. The bottom of brake 19 is raised before moving the towers. A sprocket 20a is keyed to steering wheel 20. Sprocket 20a engages chain 20b, and chain 20b engages sprockets 18f. A reversible electric motor 200 has a beveled gear attached which engages beveled gear 20d which is keyed to sprocket 20a.

On a very light crane, the masts are extended manually it would be more practical if frequent variation in the vertical height of towers is to be made, to use a winch arrangement or raising and lowering the tower tops and thus beam 1. In Figs. 2 and 4, winches 21 are shown attached to the truss member 11. The winches are turned by hank crank 21a for manual operation. Crank shaft 21a has a worm gear engagement with the winch shaft. A reversible electric motor 21b engages the crank shaft 21a for power operation of the These Winches 21 take-up or play-out mast cables 22 to raise and lower masts 9 and thus trolley beam 1. A common shaft is used for the two winches 21. Pulleys 23 are attached to truss member 11. They guide cables 22 from winches 21 to the mast tops. The upper ends of cables 22 are fastened to U shaped plates 26 which are pin connected to masts 9.

When inserting mast extensions 10 below masts 9, masts 9 are first raised with winches 21. Mast extensions 10 are then attached and the tower top of the structure is lowered with winches 21 until the extensions are lowened into sockets 15. Plates 26 would then be disengaged from masts 9 and be fastened to extensions 10. Another set of extensions 10 may be fitted below masts 8, first raising masts 8 manually. After extensions 10 are added, the masts are lowered into sockets 15. When the crane is set up for use at only the minimum height, masts 8 and its supplementary parts are omitted.

Figure 6 shows interlocking mast track sections 49a and 49b with retainers 49c and 49d. This interlocking of mast sections makes a stronger crane as the adjoining masts work in unison.

When the crane is rigged and used to lift loads high, such as to the second story of a building under construction, the masts must resist considerable bending. Masts are therefore braced as follows: U-shaped bent plates 26a are pin connected or welded to masts 9. These plates tie the masts to some of the bracing members. Horizontal tubular members 27 and 28 are in compression. Di-

agonal bracing members are 29, 30, 31, 32 and 33. Ad-

justable bracing chains 34 and 35 have a hook at the end for adjustment take-up.

Towers T1 and T2 should, in general, have masts in a nearly vertical position to prevent excessive bending. In Figures 1, 4 and 8, the masts are shown tilted slightly to the left to thus slope beam 1. Since it would be desirable to tilt beam 1 to suit conditions where gravity, power, etc., is used, the towers are adjustable so the masts may be maintained in nearly a vertical plane for strength. Effective lengths of chains 41 are adjusted to allow beam 1 to be tilted. Effective lengths of chains 34 and 35 are adjusted to suit the desired tower height. Channels 24 may be spliced for ease in assembling and dismantling the crane. Bent plates and channels 24. Pins 36a and plates 25. Bent plates 36a are welded to plates 25. Bent pin plates 37, which are supported by pins 36, bear against plates 25. Wheel supporting channels 38 are fastened to plates 37. nel sections which connect channels 38. The flanged wheels 40 on wheel supporting channels 38 engage the underside of the top flange of beam 1, thus allowing lateral movement of tower T1 and T2 or beam 1 to suit conditions. The wheel supporting framework pivots about pins 36. To prevent unwanted movement of beam 1 from its relation to the towers for such conditions as shown in Figure 7, as an example, the beam 1 would roll down-hill except for the action of brakes 42 and 42d shown in Figures 3 and 4. These brakes have surfaces which are made to bear against the angles 1a and 1b on beam 1. Brakes 42 and 42d are threaded with left and right hand threads to engage threads on brake shaft 42a. Shaft 42a is supported from diaphragm channels 39. A pulley or sprocket 42b engages an endless cable or chain which is operated from the ground level by the operator. A pull on the cable or chain revolves the shaft and spreads or brings closer together the brakes 42 and 42d to bear against angles 1a and 1b and thus cause a braking action.

Since towers T1 and T2 are movable in relation to their position with the beam 1, the towers may be spread apart or pushed closer together to suit loads, floor aisles, and other working conditions. Thus the crane may be set up with the towers spread far apart to thus move a light load over a long span, or the towers may be pushed close together to form a short effective span to safely lift and carry a heavy or maximum load. The beam 1 is the critical member for heavy loading conditions. It would be uneconomical to make the beam 1 strong enough to carry the maximum load over the maximum span, when conditions are such that the maximum possible loads are rarely lifted and then only for a short lateral movement. Most small cranes are occasionally used for lifting and moving loads that are rated as excessive. A trolley 2 and a hoist 3 of greater capacity may be quickly Diaphragms 39 are made of chanare bolted or welded to masts 9-. 36 are supported by bent plates suit conditions.

substituted when required. While excessive overloading a light crane is a dangerous practice, it is done so frequently that a means for shortening the effective beam span between tower supports for carrying an overload is safer than cutting the factor of safety. A beam 1 failure may cause a serious accident. The failure of trolley 2 or hoist 3 is usually far less serious.

More than one trolley and hoist (not shown) may be mounted on monorail beam 1 to handle heavy or long loads. As shown in Figure 2, there is an opening in the tower through which the trolley 2, hoist 3, and load 4 may move. Thus when, as shown in Figure 7, a covered truck 45 is being loaded, the beam 1 has a cantilevered arrangement from the towers T1 and T2, and this passage of load through tower T2 can be made. The counterweight is necessary only when the moment made by the cantilevered beam end and the load is greater than the moment of the remainder of the beam 1 farthest from the cantilever, unless other means are used to compensate for the cantilevered loading condition.

When positioning for cantilever arrangements similar to that shown in Figure 7, the beam 1 may be moved laterally and the towers T1 and T2 kept stationary when the beam is projected for short periods into box cars and trucks while loading and unloading. Beam 1 is rolled in and out of the right-of-way, with or without a load, to A truck may be backed up to allow a cantilevered end of beam 1 to enter the truck.

The snaking of equipment to a new location with its own power is a practice frequently used in construction work. This may be done with the crane by taking a cable 44a with hooks on its ends, shown by dot-dash outline in Figure 2, and fastening it to the hook on hoist 3 which is the power means, the other end of the cable being attached to a fixed object, such as a tree, as a deadman or anchorage, which is located in the general direction of the contemplated movement. The removable pulley 44, which can be swiveled, is used to turn the direction of the pull from hoist 3 from vertical to horizontal. Th'e crane, or only a tower on the crane, may be thus moved by snaking. A cable (not shown) may be attached to the crane to tow it or it may be pulled with the winch 50. The crane may also be pushed by another vehicle.

When the crane is used as a utility crane in a large structural steel fabricating shop, it may be lifted and moved from one part of the shop to another by the large overhead cranes that are usually available. The crane arrangements shown in Figures 1 and 7 may have a pivotable connection 48, shown with a modified arrangement in Figure 8, fastened to it to prevent crane toppling, to allow pivotal moving of the crane and to prevent deflection in beam 1, as will be described farther in connection with Figure 8.

Platform 43 on the tower base, besides being able to carry an operator or a counterweight, may be used to support and carry loads which have been lifted and moved onto it by trolley 2 and hoist 3. Such loads as liquids would be dangerous to carry far while being suspended from beam 1 from which they may sway and cause spilling.

Figure 8 shows a modified arrangement which has one end of the beam 1 supported by a building structure 47, rather than a tower T2. A tower T2 (not shown) may be used also, if beam 1 is long and an additional support is required to safely carry the load. A pivotal and rockable support 46 is fastened to the building and to the beam 1. This set-up allows the crane to act similarly to a jib crane. The load may be moved by some of the methods previously described.

Connection 48 may be of a conventional type with Wheels and it may then move along a building member. Connection 48 may be fastened high on a building with a cable or rod (not shown) connecting it to a. suitable connection on beam 1. The advantage of a support from quick stopping when hitting adapted to be rolled on said beam above is to prevent toppling of the crane as caused by an obstruction.

Thus it will be seen that I have provided an economical, highly efl'icient crane capable of performing a wide variety of operations, and which is portable and convertible to suit various material handling operations.

While I have illustrated and described several embodiments of my invention, it will be understood that these are by way of illustration only, and that various changes and modifications may be made within the contemplation of my invention and within the scope of the following claims.

I claim:

1. A portable, general utility crane comprising a pair of spaced towers of adjustable height and a monorail beam supported substantially horizontally between the top portions of the towers, and a trolley adapted to be rolled on said beam for supporting a load, each tower including, on the top portion thereof, a pivotally mounted carriage normally at right angles thereto for providing a Wheeled support for said beam to allow rolling movement of said carriage on the monorail beam, said towers being supported by wheeled elements, whereby said towers may be selectively moved together or spread apart to suit varying loading conditions and whereby said monorail beam may be disposed at an angle of less than 90 with respect to said towers for moving loads to different levels.

2. A portable, general utility crane comprising a pair of spaced towers, a monorail beam supported substantially horizontally between said towers, and a trolley for supporting a load, each tower including, on the top portion thereof, a wheeled carriage at right angles thereto and in rolling engagement with the top portion of the monorail, and wheeled supporting elements for said towers, whereby said towers may be selectively moved closer together or farther apart to suit varying load conditions.

3. A crane as recited in claim 2 together with means for selectively adjusting the height of said towers.

4. A crane as recited in claim 1 wherein said towers comprise a plurality of mast eleme slidable and adjustably connected adjust the height of the tower,

rollers for supporting said crane.

5. A crane as recited in claim 2 together wi for selectively adjusting the h nts which are relatively together to selectively and swivelly mounted th means eight of said towers,

and

means for providing a counterforce to move the trolley along said monorail from a 6. A portable, general utility lower level to a higher level. crane comprising a pair of spaced towers, a monorail beam supported substanbe moved.

7. A crane as recited in cl a trolley adapted to be rolled load, each tower including les thereto and wheeled on ail, and wheeled supwhereby said towers together or farther apart said towers each having h which the load may aim 2 wherein one of said wheeled supporting elements for one of said towers includes steering means and tower under the control of said steering means.

8. A crane as recited in claim wheel supporting enabling controlled rolling movement of said crane.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Germany Sept. 17,

power means for rolling said 2 wherein both of said elements include steering means for

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