US2772004A

US2772004A - Portable gantry crane

Info

Publication number: US2772004A
Application number: US290647A
Authority: US
Inventors: Jack D Noble
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-05-29
Filing date: 1952-05-29
Publication date: 1956-11-27
Anticipated expiration: 1973-11-27

Description

Nov. 27, 1956 J. D. NOBLE PORTABLE GANTRY CRANE 9 Sheets-Sheet 1 Filed May 29, 1952 m 9% M $1 med Mm m E w. W m G .QN NW N. wm. nm w NM NM h mm c/aaifl Noble W M @M Nov. 27, 1956 J. D. NOBLE 2,772,004

PORTABLE GANTRY CRANE Filed May 2S3, 1952 9 Sheets-Sheet 2 JNVENTOR. cfac/f 2. Waie BY 42% @M Nov. 27, 1956 .1. D. NOBLE PORTABLE GANTRY CRANE 9 Sheets-Sheet 3 Filed May 29, 1952 mum INVENTOR. c/ockfl /V0 6. BY 9 Nov. 27, 1956 J. D. NOBLE 2,772,004

PORTABLE GANTRY CRANE Filed May 29,- 1952 1N VEN TOR. (700% A A afiie J. D. NOBLE 2,772,004

PORTABLE GANTRY CRANE Nov. 27, 1956 9 Sheets-Sheet 5 INVENTOR. R cfaakfi moi/e Nov. 27, 1956. J. D. NOBLE 2,

PORTABLE GANTRY CRANE Filed May 29, 1952 llufil INVENTOR. cf0o fi Nofiie Nov. 27, 1956 J. D. NOBLE PORTABLE GANTRY CRANE 9 Sheets-Sheet 7 Filed May 29, 1952 mm mm Q Nov. 27, 1956 Filed May 29; 1952 J. D. NOBLE PORTABLE GANTRY CRANE 9 Sheets-Shes h 8 INVENTOR. c/Ockfl A ois Nov. 27, 1956 J. D. NOBLE 2,772,004

PORTABLE GANTRY CRANE Filed May 29; 1952 9 Sheets-Sheet 9 m/M/w: fac% J. A ofile Wtiowwea United States Patent C PORTABLE GANTRY CRANE Jack D. Noble, Lafayette, Calif.

Application May 29, 1952, Serial No. 290,647

6 Claims. (Cl. 212-71) This invention relates to a portable gantry crane, and is more particularly concerned with a transportable crane of the gantry type of substantially heavy duty capacity and which is well adapted for use on or as a structural part of motor vehicles, trailers, ships, barges or floating dry docks, and particularly for the transferring of loads of any character from rail cars to trucks, trucks to trucks, and from trucks to planes or vice versa, or from or to pallets, as well as the raising and discharging of relatively small water craft and ships.

One problem solved by the present invention has long existed for contractors, the military and other like operations where a temporary freight transfer point must be set up, usually on short notice, used for a period and then moved quickly to another point.

Another problem solved by the present invention particularly as it applies to contractors and the like is in the few men it takes to operate the device, especially as the device may be used only several times a week. Specially trained engineers were required to operate cranes heretofore in use, whereas the present device is so simple that the truck driver who is receiving the load can manipulate the push button controls for the crane.

Another problem solved by the present invention is in providing a gantry crane in which there is always a positive connection between the bridge and the columns so there are never the many dangers inherent in having the bridge ends loose while lifting or lowering it.

Another problem solved by the present invention is in providing a gantry crane which can be moved from place to place in a repair or maintenance yard where large units of machinery are being assembled or disassembled.

A primary object of the invention is thus to provide a fool-proof portable, light weight unitary gantry crane which is readily collapsible to minimum dimensions and which in such condition is transportable from preceding to succeeding places of service, which is there capable of being readily and speedily erected to a full operative position in a minimum of time, and which is then capable of lifting and transferring relatively heavy loads, as required.

A further object of the invention is to provide a portable gantry crane wherein the esential frame and structure thereof, embodying a bridge member for a transversing hoist and one or a pair of bridge member supporting towers or columns are pivotally and slidably interconnected by pivoted positioning guide members whereby they nest one upon the other on the bridge which forms the necessary supporting structure or chassis of the vehicle. In such a use, the bridge member is provided with required running gear including a pair of road engaging wheels adjacent one or both ends thereof, and one end thereof is provided for ready attachment to a wheeled unit for transportation of the folded portable unit, as is required.

'A still further object of the invention is to provide a portable gantry crane of the above noted character 2,772,004 Patented Nov. 27, 1956 ice wherein the pivoted positioning guide member forming the interconnection between each end of the bridge member and the bridge supporting towers or columns therefor includes means having a sliding engagement with the supporting towers, and wherein power means are provided for swinging the guide members to a vertical position and thereafter slidably raising the bridge members thereon to an operative position adjacent the upper ends of the supporting members.

Another object of the invention is to provide a portable, foldable, compact gantry type crane wherein an independent support can be used to support one end of the bridge and the other support is secured to the bridge by a pivoted positioning guide member in which the support slides and is folded into nested transporting position on the bridge.

Other objects and advantages of the invention will become apparent in the course of the following detailed description taken in connection with the accompanying drawings, wherein:

Fig. 1 isa side elevational view showing the gantry crane structure in collapsed nested transporting position as a trailer vehicle chassis with the tractor engageable end thereof temporarily supported apart from the tractor by a pair of extensible props, pivotally connected at their upper ends to the bridge beam of the crane.

Fig. 2 is a side elevational view corresponding to Fig. 1, showing the erection of the crane in an initial stage thereof.

Fig. 3 is also a side elevational view showing the supporting columns pivoted into raised ground supported and operative position preparatory to the elevation of the bridge beam up the columns.

Fig. 4 is a further side elevational view showing the bridge beam elevated partway up the columns as it is being raised into its operative position adjacent the upper ends of the towers.

Fig. 5 is a side elevational view showing the bridge beam in fully elevated operative position and with the bridge-steadying and bracing members, which are pivotally carried thereby, swung into operative engagement with cooperating engaging means on the columns.

Fig. 6 is an end elevational view of the erected crane as observed from the right hand end of Fig. 5.

Fig. 7 is an opposite end elevational view as observed from the tractor end of Fig. 5.

Fig. 8 is a horizontal sectional view as observed in the plane of :line 88 of Fig. 4.

Fig. 9 is a horizontal sectional view as observed in the plane of line 9-9 on Fig. 4.

Fig. 10 is a horizontal sectional view as observed in the plane of line 1010 on Fig. 3.

Fig. 11 is a vertical sectional view as observed in the plane of line 1111 on Fig. 1.

Fig. 12 is a top plan view of the gantry crane when in operative setup position, as shown in Fig. 5, and illustrating the top of the bridge structure and associated traversing hoist.

Fig. 13 is a fragmental horizontal sectional view as observed in the plane of line 13-13 on Fig. 5.

Fig. 14 is a fragmental perspective View on an enlarged scale particularly illustrating one form of the pivoted positioning guide member connecting the bridge beam to the column.

Fig. 15 is a fragmental perspective view of an alternative locking means when the beam is in its Working position.

Fig. 16 is a diagrammatic view showing the layout of the locking means between the column and each pivoted guide means.

ing-pin; and

Fig. 1 8 is an elevational view of the same.

a trailer, it is obvious that it can as well form part of a railway car, a truck, a tractor, a boat or barge or any other means for transporting, where for convenience and ease of movement it is desirable to collapse the unit during transport and to. erect it quickly at the point of use.

Also it is distinctly understood that in describing one form of the invention, it is not to be limited to such form except as is required by the art and the appended claims, because manufacturers may vary the details of the component parts while still retaining the combination comprising the invention.

Viewed in its broadest aspect, the invention comprises the crane bridge, the supporting column orcolumns at one or both ends, and a pivoted positioning guide member pivoted to each end of the bridge that has a column and in which each supporting column slides. With these are combined the turn-buckles to rotate the guide members to lift or lower the columns, the braces to align the structure at the base of each column, the power units to lift the crane bridge to the tops of the columns, and to operate the hoist mechanism and the crane car, and the braces to hold the bridge and columns at right angles to each other, as well as other components.

Referring now in detail to the accompanying drawings illustrating one form of my improved gantry crane, there is shown the basic pivotally connected. primary structural elements; the relatively long crane bridge beam 10.which also serves as'the chassis of the vehicle, the

pairof supporting columns

11 and 12 and the pivoted positioning guide members'9. These pivotally connected elements provide in unfolded and fully erected condition the rigid gantry crane frame structure of the traversinghoistof Fig. 5. When fully folded in the transporting condition of Fig. l, the bridge beam comprises the vehicle trailer chassis with the columns nested on top. The bridge beam 10 shown is of elongated open rectangular form for movement of the traversing hoist including the load lifting cables, etc., within the space between the laterally spaced side girders 13 thereof. These girders, as shown in Fig. 14, are of hollow formation for the sake of light weight, yet rigid construction.

The bridge beam 10 is provided inwardly of one end with a two wheel truck or dolly of usual heavy duty construction and which will include appropriate suspension springs and tire equipped wheels, brakes, etc., designated in its entirety as 14. It is shown fixedly connected as a unit to the beam 10 whereby when the crane structure is in its completely collapsed condition of Fig. 1, it is in the form of an easily transported trailer. Preferably the dolly 14 is left attached to the bridge beam 10 when it is lifted into operative position (Fig. but it can be made detachable. It speeds up dismantling and movement of the crane to leave it attached.

On the other end of the bridge beam 10, a fifth wheel construction is provided on the under side of the beam adapted for readily detachable pivotal connection with the swivel platform mounting of a tractor 15, for towing the structure as a trailer vehicle and thus transporting the crane and traversing hoist mechanisms as a unit from one position of use to another. In lieu of the fifth wheel any other wheeled support may be connected to this end of the bridge beam.

When used as a semi-trailer, the bridge beam is provided with a pair of laterally spaced jacks or prop members 16 which have corresponding ends thereof pivotally connected to brackets 17 depending from the lower faces of the spaced side girders 13 forming the body of the bridge beam and the chassis of the trailer; As shown in Fig. l, the lower ends of these jacks or props when in the lowered position are adapted to engage the -ground or preferably to rest upon supporting pads or rafts 18. The jacks support the collapsed crane struc- 4 ture in required horizontal position upon detachment from the tractor 15 and during the initial steps of erecting the supporting

columns

11 and 12. The brackets 17 are provided with two sets of

apertures

19 and 20 for removable reception of a lock pin engageable in aligning apertures in the props 16 for maintaining the same in inoperative and operative positions respectively.

As will be seen later, it is important in erecting the i crane to have the columns supported level and plumb with each other. 7

The pivoted positioning guide members 9 are shown made of a pair of side plates 21, tied together by a cross piece 22 so as to be U-shaped in cross section. This gives them a desired rigidity and avoids any twisting as the column swings up or down about the pivot shaft 23. This shaft extends laterally through aligned holes in the end of the bridge beam girders 13 and have their ends fixed to the plates 21. There is sufiicient clearance between each column and its associated guide member 9 to allow the column to slide easily in the guide member when lifting or lowering the bridge beam. The means of preserving alignment and preventing binding between the column and the guide members during raising orlowering of the beam 10 will be explained later.

The supporting column or tower 11 includes a pair of laterally spaced and braced oppositely inclined

hollow members

25 and 26, providing a hollow or skeleton structure for lightness of construction and which have'their upper ends rigidly connected by a cross frame member lar pair of laterally spaced and braced hollowmembers 31 and 32 whose upper ends are likewise rigidly interconnected by a frame 'member 33. The lower ends of the

members

31 and 32 are rigidly interconnected by, a hollow supporting base member 34 similar in construction to the base member 28.

The opposed innerrails or edges of each pair of columns 25 and. 26 and 31 and 32 are uniformly spaced and are parallel from end to end thereof. It is in this space that the pivoted guide members 9 slide.

To preserve alignment and prevent binding between the guide members 9 and each of the columns 11 and '12as the bridge beam Ill is lowered or raised, the following has been found satisfactory, although not vital as other means of preserving alignment may be devised. On each side plate 21 of each guide member Q, I provide vertically spaced rollers 35 and roller pinions 36. The pairs of rollers 35 are rotatably mounted On each side plate 21 adjacent the inner side edges so they will frictionally V,

engage the longitudinal inner vertical face of each

hollow member

25, 26 and 31, 32, as is clearly indicated in Figs. 3 to 5, and shown in detail in Fig; 14. Y i

The longitudinal outer vertical faces of each

hollow member

25, 26,. 31 and 32 have a toothed rack 37 extending throughout the length thereof. The vertically spaced pinions 36 on each side plate 21 are mounted so as to mesh with these racks 37. At least one of said pinions is keyed to a single shaft 36a which is rotatably journaled in the plates 21 so that said'pinions will rotate together. 'The laterally aligned and connected pinions cooperating with the vertical racks 37 are thus constrained to uniform rotation so that the bridge beam 10, to which the guide plates are pivotally connected, cannot cant laterally and cause binding during elevation or lowering of the bridge beam on the columns.

While each guide member 9 has'a pivotal connection with the bridge beam through theshaft 23, as above deextreme;

scribed, means may be provided for releasably locking such members against such pivotal movement when the beam is in its raised operative position. Said means may comprise an L-bracket 39 having the vertical leg thereof rigidly secured to each guide plate 21 (see Fig. 14), with a locking finger 40 pivotally connected to the upper face of each girder 13, so its free end is movable into and out of locking position with the upper face of the horizontal leg of the bracket 39 which rests upon the upper face of the girder 13. When the crane beam has been lowered and it is desired to nest the columns on top of the beam as in Fig. 1, the fingers 40 are swung out of engagement with the brackets 39.

A preferred form of mechanism for locking the plates 21 of the guide members 9 to theadjacent column is shown in Fig. 15 where a bar 38 with a perforation 38a is secured to the end of the beam 10. This hole 38a is aligned with the top surface of the L shaped bracket 39. A housing 39a is formed over the bracket 39 to provide an opening 3%, the same size as the hole 380. When the column 11 is at right angles to the beam these holes 38:; and 39b align and in them is driven a snug fitting pin 3317 having a tapered nose 380. Before lowering the column the pin 38b is removed.

When erecting each

column

11 or 12, or when laying them down, the movement is effected by rotating its guide means 9 about the axis of shaft 23 through an angle of 90 degrees. One means for doing this comprises a turnbuckle structure 42 and an arm 41. The arm has one end keyed to the shaft 23 and its other end pivotally connected to the turnbuckle structure. The other end of the turnbuckle is pivotally connected to a block 43 projecting laterally outwardly from an adjacent side face of the bridge beam 16. Preferably th weight of each

column

11 and 12, above the pivot point 23, is about equal to the weight of its base (and the parts carried in the base) so the force required to be exerted by the turnbuckle 42 is kept at a minimum.

Whenever either

column

11 or 12 is to be moved from a collapsed position to an erect position, or vice versa, it is essential that the column be locked to the pivoted guide member 9. One means for accomplishing this is shown in Figs. 16 to 18, and comprises a pair of spring pressed pins 44, 45 mounted in each side plate 21 so they can extend through the plate and into

holes

46, 47 in the side of each

column

11, 12. The pin 44 and its corresponding

holes

46, 48 are offset in relation to the pin 45 and its

holes

47, 49 so that as the column slides in the guide 9, the pin 45 will not get into either of the

holes

46 or 48, and the same for the pin 44 as to the

holes

47 or 49. In addition to supporting the column in the guide 9 while it is moved through an arc of 90 degrees, the pins also support the beam 10 at the top of the columns when the cran is set up. This means that the shear strength of the pins and the number of pins used must be calculated to support the beam 10 and any load that is to be hoisted by the crane. In Fig. the beam 10 is shown raised slightly above its lowest position on the column 11 so as to show the

holes

46, 47 into which the

pins

44, 45 will fit. At the top of the column the

holes

48, 49 are engaged by the

pins

44, 45 respectively.

One form of pin mechanism is shown in Figs. 17 and 18 where the pin 44 has a cross head 50 with a depth stop 51 on each sid adjacent a guide rod 52. The springs 53 engage the cross piece and cause the pin to enter the

hole

46 or 48 when in alignment at the top or the bottom of the column. A ring 54 in the outer end of the pin may be connected to a suitable line for withdrawing the pin when it is desired to move the column in the guide 9.

The remaining parts and accessories comprising the device will b explained in connection with describing the operation of erecting the crane. Assuming that the crane is being used by the military where heavy objects are to be lifted from one carrier into another carrier, and'that position.

the; carriers can be brought alongside each other and directly under the beam of the crane, the driver will bring the tractor and the trailer to rest with the beam lying approximately directly over the place where he two carriers will be placed once the crane is erected. This may be over two adjacent railroad tracks, two roadways, or a roadway and a railroad track, or the like. The operator should select ground where the base of each column can be on a good firm footing and wher the base of each column can be adjusted into the same horizontal plane as the other. Several flat members 18, called pads or rafts, are carried in each base 28, 34 so they can be used as a footing under the adjusting screws when aligning the columns with each other so they are plumb.

The first step, once the beam is in correct position, is for the legs 16 to be lowered onto a raft and adjusted up or down until the beam 10 is horizontal in a fore and aft direction. If it slopes a little in a crosswise direction, this can be corrected when setting up the columns. When the weight of the beam 10 rests on the legs 16 and the wheels 14, the driver disconnects and pulls the tractor 15 out of the way.

The next step is to erect the

columns

11 and 12 and, as shown in Fig. 2, this can go on simultaneously if the beam 14 is in substantially a horizontal plane crosswise, as well as fore and aft. If the beam is not level, as would be the case where one wheel 14 is lower than the other, then unless it is easy to raise the low wheel up level with the other, it is preferable to raise column 11 and, get it plumb before raising the other column 12. To raise column 11, the operator turns the turnbuckle 42. The locking pins 44, 45 are engaged in

holes

46, 47 in each column so that the column is locked to the pivoted positioning guide member 9, thus as column 11 moves up into the position shown in Fig. 2, the column will not slide in its guide member 9, but the two parts will move as one about the shaft 23 into the position shown in Fig. 3. This rotation brings the column 11 into a vertical position with its base 23 into or nearly into contact with the ground. Still assuming that one wheel 14 is lower than the other, this will mean that the column 11 tilts toward the low side. The leveling and bracing operation called for here is substantially the same as is necessary if the column did not tilt.

The operator extends the outriggers (see Fig. 9) 55 and 56 which are nested in transverse pockets 55a, 56a in the base. Each outrigger has a jack screw 57 at its outer end and there are like screws 58 in the ends of the pockets in the base which gives four screw jacks by which the column can be adjusted until it is in a true vertical An additional outrigger 59 in the form of a tubular arm 60 is pivoted to the base 28 at 61 and has an extensible arm 62 with a screw jack 57. This serves primarily as a brace during the period when the beam 11? is being lifted or lowered on the

columns

11 and 12 when its locking pins 38b and braces 76 are not in place. It may or may not be needed under all circumstances. When the base 23 comes down level with the ground, the operator has no. difliculty in getting out of the pocket 23a the rafts 18 to be placed under each of the screw jacks 57.

The operator can now lift the column 12, and he does this by turning its turnbuckle 42. The base comes down into the position shown in Fig. 3 and he proceeds to extend the outriggers (Fig. 8) 64 and 65 from their pockets 64a, 65a in the base 34. Then he adjusts the four screw jacks 66, 66a to bring the column 12 into alignment with the column 11. The outrigger 67, carried by the tube 63 pivoted to. the base 34, is extended to brace the column during lifting and lowering of the beam 11 The pads or rafts 18 were carried in the pocket 34a of the base 34. The operations so far described have resulted in the

columns

11 and 12 being on a firm foundation and being parallel to each other.

Before the beamis lifted, the operator must secure the locking finger 41) in case that device is used. In cases where the pins 38b of Fig. are used, the operator will engage these in the aligned holes 38a and 3912 as soon as the beam and the column are at right angles to each other. e V

The next operation is to lift the beam 10 on the columns from the position it occupies in Fig. 3 to the elevated position of Fig. 5. Fig. 4 shows it part way up the columns. I have already explained how the connected pinion gears 36 and the racks 37 preserve alignment of each guide member 9 as it moves up or down on its associated column. In most cranes, the sizes are such that power means are required to lift the beam 10 into position or to lower it. Such power means may be of many different forms. The one shown here is designed to assurethe smooth concurrent movement of the guide members 9 up their columns so there will be no binding, as might occur if one were to be advanced ahead of the other.

A winch 69 is supported within each of the

columns

11 and 12 and each is driven by its own gear drive unit 70 driven by a reversible motor 71 with suitable speed reduction means. These motors are linked together electrically so they'operate in synchronism, thereby assuring an equal movement of each end of the beam 10 as it moves up or down on the

columns

11 and 12.

j Each beam end has secured to its midpoint 72 a cable 73 which passes over the

pulleys

74 and 75 in the top of the columns and then runs down inside the column to the drum on the winch 69.

Before starting to lift the beam 10, the operator will hold the

pins

44, 45 extracted from their

holes

46, 47 until'the beam is hoisted enough to where the pins will press against the smooth side of the column and will not fall back into the holes. Note that the

pins

44, 45 will fall into the

holes

48, 49 at the top of the column as soon.

as the beam reaches its top elevated position. Now assume that the beam 10 has reached its top position it is held there by the locking pins 44, 45 which have a shear strength in excess of the weight of the beam 10, plus the load being hoisted.

The next operation is to secure the brace rods 76 to the

adjacent columns

11 and 12. Preferably a line is secured to the loose end of each brace so the operator can climb the ladder 77 on each column and pull the brace over to fit the end with the hole 78 on the pin 79 in the column. At all other times, these braces are secured in brackets 80 on the beam 18. It is preferable that each brace be placed on its bracket 80 before lowering the beam. When lifting the'beam, it is an advantage while thebeam is near the ground, to have lifted each brace out of its bracket 80 and let the loose end drag over the ground as the beam 10 moves up. Then all that needs to be done is to pull the end over and place it on the pin 79 when the beam reaches the top. When these braces 76 are in place, each hinged

outrigger

59, 68 may be loosened and swung back in against its base to clear the way for the vehicles that are to pass between the

columns

11 and 12.

The next step is to place the hoist mechanism in operation. This comprises a trolley 81 supported on flanged wheels 82 which run on tracks 83 secured along the top of the beam girders 13. The trolley frame 84 has a pair of longitudinally spaced and aligned pulleys 85 which are rotatably journaled within the frame at one side of the longitudinal center thereof, and a second pair of longitudinally aligned and spaced pulleys 86 which are rotatably journalled within the frame at the opposite side of the longitudinal center thereof.

As seen in Fig. 12, both pairs of

pulleys

85, 86 are disposed between the pairs of track engaging wheels 82 and the pair of pulleys 85 are in a plane in laterally spaced relation to a plane in which the pair of pulleys pulleys are respectively in the longitudinal vertical planes of thepairs of pulleys and 86. V

A horizontally disposed pulley 89 is rotatably supported on a stub axle 90 projecting-vertically upwardly from a platform 91 rigidly supported on the column, 12 end of the bridge beam, and the axle 99 is in a vertical plane intermediate the

pulleys

85, 87 and the

pulleys

86, 88. a

A hoist drum 30 located near the base of column 11 is preferably driven by a reversible motor 92. and reduction gearing 93. A'cable 94 has one end thereof fixed to the hoist drum adjacent one end thereof. The cable thence extends up and over one of the pulleys 85, down and around one of the two pulleys 95 rotatably journalled in a bl cck 96. The cable then extends upwardly and over the other pulley 85, around the horizontal pulley 89, thence over one of the pulleys 86 and down aroundthe other block pulley 95 and up and over the other pulley 86 and back to the drum 3i] to which the other end of the cable is connected. The block 96 is provided with a work engageable hook 97. The hoist drum 30 is provided with spiral grooves 98 converging inwardly from its opposite ends and the end portions of the cables are wound upon the drum and are initially guided by the grooves. It will be seen from the above that upon rotation of the drum 30, the block 96 will be elevated or lowered by the reversible motor 92.

The construction further includes means for moving the trolley 81 back and forth along the tracks 83 on the girders 13 of the bridge beam 10. Such means preferably comprises a sprocket chain'99' (Fig. 12) disposed between the girders 13 and having the opposite ends thereof secured to opposite ends of the trolley frame 84 providing an elongated loop-form chain having upper and lower runs, the former of which extends through the frame 34. The opposite looped ends of the chain extend 7 around sprocket wheels 1G0 rotatably journalled on the beam 14 adjacent the opposite ends thereof. Only one of the sprocket wheels'100 is shown, the other one being disposed beneath the platform 91. As indicated in Fig. 12, a reversible motor 101 is preferably connected through reduction gearing to the shaft of the sprocket wheel'100 at the column 11 end. of the bridge beam. In order to provide ready access to the top of the crane, the

columns

25, 26, 31, 32 are provided with'suitable steps or ladders 77. V 7

All of the controls for operating the hoist are centered at the panel 102 or can be by a pendent type of push button box hanging down from the bridge beam 10. No further description of the crane operation is necessary as this is standard and well known. 7

When the time comes to move the crane to another location the dismantling proceeds with great speed and by slack in the lifting cables 73 is taken up to release the strain on the pins before they are disengaged. It is important that the ends of the beam 10 move downwardly at the same speed. When the beam is at the bottom of the columns, the latches 49 should be disengaged (or the pins 38b, if they are used, should be driven out) and the

pins

44, 45 should be engaged in the

holes

46, 47. This latter assures that when the pivoted guide member 9 lifts the column off the ground to swing it down onto the a beam, the column will not slide down through the guide member.

. The trolley 81 is narrowerthan the space between the

hollow members

25, 26 and 31, 32 of each column so it will not interfere with the columns nesting on top of the beam-10. The operator, before swinging the columns down onto the beam, should load all the pads or rafts 18 into the pockets 28a, 34min the bases so they will add their effect as a counterweight and because it would be difiicult to lift them into the pockets after the latter are 9 rotated 90 degreessand are high upon the trailer. A motor generator set 103 to provide current for the lifting motors may be mounted on th 2 column 12.

Now that the operation of the crane is clear it should be easier to appreciate the importance in the combination of the pivoted positioning guide members 9 which are an integral part of each end of the bridge beam 10 and coordinate the action between the beam 10 and the

columns

11, 12 so the beam is never disconnected from the columns or free to swing or be damaged or produce an off-balance weight.

Summarized, the pivoted positioning guide member 9 functions (a) To maintain a positive connection between the beam 10 and the columns;

(b) To guide the beam 10 up or down on the columns;

To support the columns when they are moved from on top the beam to their erect position or when they are moved from their erect position down onto the beam;

(d) To support the beam on the columns when the beam is elevated in working position;

(2) To keep the columns aligned in every position;

(f) To position the-columns when first erected while the base Outriggers are being adjustedso thereafter it is only necessary to retain the columns parallel to permit correct erection of the. beam 1t and (g) To provide a portable gantry crane which is ready for immediate erection with no bearings or parts to disconnect from the beam at the bottom and to reconnect when it is elevated to the top of the columns.

While the invention has been described for use with two

columns

11, 12 pivoted one to each end of the bridge, the invention may also be applied in a form where the column 12 is omitted and the support of the end of the bridge from which the column is omitted is provided by any handy structure, such as a side of a building, a high-lift fork truck, or other device. In this case, the end of the bridge without the column is lifted simultaneously with the lifting of the other end, preferably by having the lifting cable passed from a block on the other structure and led back to the drum 36 on the column 11.

While I have shown

rectangular members

25, 26, 31, 32 comprising the

columns

11 and 12, these may be round or any other shape. Also a single round tube may be used as the

columns

11, 12 in which case the pivoted guide members 9 will be shaped to fit.

Having set forth the invention in accordance with a preferred structural embodiment thereof, what is claimed and desired to be secured by U. S. Letters Patent is:

1. A portable and collapsible gantry crane, comprising an elongated, horizontally-disposed bridge beam having a pair of spaced-apart parallel girders joined together at their ends; a pair of positioning guide members pivoted to said bridge beam, one adjacent each end, each said guide member having a pair a parallel side plates lying adjacent the exterior side faces of said beam, a pair of coaxial horizontally-disposed pinions, one journaled on the outside of each side plate, and a pair of horizontally-disposed coaxial rollers, one journaled on the outside of each said side plate, said rollers being spaced apart from said pinions and generally collinear therewith; a pair of supporting columns, each comprising a pair of parallel side girders with their interior facing surfaces spaced apart wider than the exterior surfaces of the side girders of said beam, so as to be nestable therearound and braced by end girders at each end, each said column side girder having racks on one surface engaged by said pinions, its other side being engaged by said rollers; releasable means for securing said guide members rigidly to its associated column; and other releasable means for rigidly securing said guide members to the ends of said beam; means for rotating said guide members about said beam when said guide member is rigidly secured to its associated column for erecting said columns so that they are parallel to each other 10 at each end of said beam and for loweringsaid column, one over the other to nest around said beam and parallel to it; and means for moving said guide members along said columns when said columns are erected and said guide member is rigidly secured to said beam instead of to said column, so as to raise and lower said beam between said erected columns.

2. A portable and collapsible gantry crane, comprising an elongated, horizontally-disposed bridge beam having a pair of spaced-apart parallel girders joined together at their ends; a trolley narrower than said beam and movably supported therein; hoist means on said trolley; a pair of positioning; guide members, one adjacent each end of said bridge beam, each said guide member comprising a pair of parallel side plates lying adjacent and parallel to the exterior side faces of said beam, a pivot shaft journaled in said beam and rigidly secured to said side plates and holding them together, a pair of coaxial pinions, one journaled on the outside of each side plate, and a pair of coaxial rollers, one journaled on the outside of each said side plate along an axis parallel to the axis of said pinions, said rollers being spaced apart from said pinions and generally collinear therewith; a pair of supporting columns, each comprising a pair of parallel side girders with their interior surfaces spaced apart wider than the exterior surfaces of the side girders of said beam so as to be nestable therearound, and completed by end girders at eachend, each said column side girder having racks on one outer surface engaged by said pinions, with its other side surface being engaged by said rollers; releasable means for securing each said guide member rigidly to its associated column; extensible means having one end secured to said beam and the other end to said guide member for rotating said guide members about said beam; means for rigidly securing said guide members to said columns, while they are moved into an erect position parallel to each other at each end of said beam, or while they are moved into a lowered position to lie one over the other on said beam and generally parallel to it; and power means for raising said guide members simultaneously when said columns are erect and said guide member is rigidly attached to said frame, so as to raise and lower said beam between said erected columns while maintaining it in a substantially level position, the movement of said pinions in said racks being synchronized to prevent canting of said beam.

3. A portable and collapsible gantry crane, comprising an elongated, horizontally-disposed bridge beam; a pair of positioning guide members pivoted to said bridge beam, one adjacent each end on a horizontal axis, each said guide member having a pair of parallel side plates lying adjacent the exterior side faces of said beam, a pair of coaxial pinions, one journaled adjacent each side plate, and a pair of coaxial rollers likewise journaled adjacent each side plate along an axis parallel to the axis of said pinions, said rollers being spaced apart from said pinions and generally collinear therewith; a pair of supporting columns, each having a pair of racks on one side engaged by said pinions while its opposite side is engaged by said rollers; releasable means for securing each said guide member rigidly to one said column; releasable means for securing each said guide member rigidly to said beam; means for rotating said guide members about said beam when said guide members are rigidly secured to said columns, for erecting said columns so that they are parallel to each other at each end of said beam and for folding said columns inwardly around said beam; and means for moving said guide members along said columns when said columns are erected and each said guide member is rigidly attached to said beam, so as to raise and lower said beam.

4. A portable and collapsible gantry crane, comprising an elongated horizontally disposed bridge beam having a pair of spaced-apart parallel girders joined together means for rotating said guide members about said beam when said guide members are rigidly secured to said columns, for erecting said columns so that they are parallel to each other at each end of said beam and for folding in said columns, one over the other, to nest around said beam and parallel to it; means for securing said guide members against relative movement in respect to said beam about said horizontal pivot; and means for moving said guide members in parallel along said columns when said columns are erect and said guide member is rigidly secured to said beam.

5. The crane of claim 4 in which said rotating means comprise permanently connected extensible means having one end anchored to said frame and the other end anchored to said guide members,

6. A portable and collapsible gantry crane, comprising a horizontal bridge beam; a pair of positioning guide members horizontally pivoted to said bridge beam; a pair of supporting columns, each com-prising a pair of parallel side girders with their facing inside surfaces spaced apart wider than the exterior surfaces of; the beams side girders and braced by end girders at each end, each said guide member being movable along one said column but not separable therefrom; releasable means for securing each said guide member rigidly to its associated column; means for rotating said guide members about said beam when said guide members are rigidly secured to said columns, for erecting said columns so that they are parallel to each other at each end of said beam, and for folding in said columns, one over the other, to nest around said beam and generally parallel to it; releasable means for rigidly securing said guide members to said beam; and means for moving said guide members in parallel along said columns when said columns are erect and said guide memberis rigidly secured to said beam. so as to raise and lower said beam.

References Cited in the file of this patent UNITED STATES PATENTS 1,064,385 Sawyer June 10, 1913 2,357,583 Franco Sept. 5, 1944 2,593,630 Thompson Apr. 22,1952

FOREIGN PATENTS I 325,812 Germany Sept. 21, 1920 705,784 Germany May 9, 1941 France June 2, f 1947