Selective beam gantry crane

A self-mobile gantry frame has disposed thereon a trolley suspending a load lifting frame. The load lifting frame is stabilized against sway in a direction perpendicular to the gantry beam by a stabilizing beam selectively engageable with the load lifting frame.

BACKGROUND OF THE INVENTION 
Self-mobile gantry cranes are used for handling cargo containers, truck 
trailers and other bulky cargo in dock yards, rails yards, and other 
areas. Typically these cranes include an elevated horizontal gantry beam 
supported above the ground on legs, forming an inverted "U" shaped frame. 
The gantry crane is moveable longitudinally on fixed rails, tracks or 
guidable wheels. The hoisting operation is accomplished by a winch or 
similar device which raises and lowers cables attached to a lifting frame, 
hook or other load engaging means from which the load is suspended. 
Typically, the load carrying cables are attached to one or more trolleys 
which run transversely along the horizontal gantry beam. This arrangement 
permits the load to be moved vertically by the hoisting apparatus, 
transversely by the trolley and longitudinally by moving the entire gantry 
structure along the ground on its rails or wheels. 
Because the load is suspended on flexible cables, longitudinal or 
transverse movement of the hoisting apparatus tends to cause sway of the 
load being carried. While excessive sway is not desirable, a certain 
amount of sway can be accommodated when handling cargo containers and most 
other bulky cargo. However, when the gantry cranes are being used to 
handle truck trailers, especially in the operation of placing truck tailer 
bodies on flatbed rail cars for "piggyback" shipping, sway of the load is 
particularly undesirable. This is because the truck trailer bodies must be 
accurately positioned with respect to a "fifth wheel" on the flatbed rail 
car to which the truck trailers are attached for rail shipment. Therefore, 
when handling truck trailer bodies, it is customary to provide means on 
the gantry crane for stabilizing the load against sway. 
In the past, efforts to reduce the sway of loads suspended from such gantry 
crane apparatus have included reeving arrangement in which the hoisting 
cables diverge outwardly and upwardly and thus tend to resist sway. See, 
for example, U.S. Pat. No. 3,825,128 and 3,086,661. Other patents have 
suggested the use of a separate stabilizing system (U.S. Pat. Nos. 
3,746,182, 4,273,242) and the use of tag lines (U.S. Pat. No. 3,352,324). 
Probably the most successful solution has been to provide a horizontal 
stabilizing beam which is guided on the gantry legs and raised and lowered 
along with the load lifting frame to provide a stabilizing support. Such 
structures are shown in U.S. Pat. Nos. 3,161,309, 3,176,853 and 3,251,496. 
The use of a horizontal stabilizing beam which rises and falls with the 
lifting apparatus handling the cargo is not desirable, however, on 
so-called "combination" gantry cranes which are adapted to handle both 
truck trailer bodies and cargo containers. This is because, when handling 
cargo containers, the gantry frame customarily is moved across several 
rows of containers at one time. The presence of the horizontal stabilizing 
beam at the top of the load lifting frame prevents the frame from being 
lowered below the top of the highest row of containers and thus makes it 
impossible to handle containers lower thwn the highest container in any 
row over which the gantry frame is operating. For this reason, so-called 
combination gantry frames typically have included stabilizing devices 
which are disposed only above the lifting frame itself and which do not 
extend transversely between the legs of the gantry frame. See, for 
example, the stabilizing device of U.S. Pat. No. 4,273,242. 
SUMMARY OF THE INVENTION 
The present invention provides an improved hoisting apparatus in which a 
stabilizing means may be selectively engaged with the lifting frame of the 
hoisting apparatus. The stabilizing means may be engaged operatively with 
the lifting frame when particular stability of the load being handled is 
desired as, for example, when handling truck trailer bodies. When the 
crane is being used to handle loads where stability against sway is less 
critical, or when the stabilizing device might interfere with operation of 
the gantry crane (as, for example, when handling cargo containers) the 
stabilizing device may be moved to an inoperative position. 
It is, therefore, the primary object of the present invention to provide an 
improved hoisting apparatus in which the lifting frame and the load 
carried thereby may be selectively stabilized against sway. 
A further object is to provide such an apparatus in which the means for 
stabilizing the lifting frame and load against sway comprises a 
stabilizing beam guided for vertical movement in a gantry frame, but which 
may be selectively retained in a raised, inoperative, position. 
A still further object is the provision of such an apparatus in which the 
stabilizing beam is an idler beam which does not require the provision of 
independent hoisting apparatus for raising the lowering the stabilizing 
beam. 
A further object is to provide such an apparatus including means for 
retaining the idler stabilizing beam always in a substantially horizontal 
position. 
A still further object is to provide a self-mobile gantry crane adapted for 
handling both cargo containers and truck trailers which includes means for 
selectively stabilizing the loads being handled against sway in a 
direction generally perpendicular to the longitudinal axis of the gantry 
beam.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, there is illustrated a moveable hoisting apparatus or 
gantry crane 10 which comprises a supporting structure including a 
substantially horizontal transverse support member or gantry beam 12 
supported at its outer ends by a pair of generally vertical legs 14. Each 
of the legs 14 has its lower end resting on a horizontal frame member 16. 
The horizontal frame members 16 are supported on guidable, moveable, 
wheels 18 so that a unitary gantry structure is provided which may move 
along the ground in any desired direction. Self-contained power means (not 
shown) such as a diesel engine are provided for powering the wheels 18 for 
movement, as well as for operating hoisting wenches and for other power 
requirements for the gantry crane. 
A moveable trolley 20 is positioned on top of the transverse beam 12. The 
trollery 20 is mounted on four rollers or wheels 22 which travel along two 
rails 24 fixed to the upper outer edges of the transverse beam 12. Lower 
wheels 26 on the trolley engage the undersides of the rails to prevent the 
trolley from being tipped over by uneven loading. 
The trolley 20 may be powered for movement longitudinally of the beam 12 
and rails 24 in any desired manner. Preferably, the trolley is powered by 
a flexible cable 28 extending generally parallel to the beam 12 and driven 
by a powered wench 30 on the trolley about which the cable is wound. The 
cable 28 is attached to the transverse beam 12 at each outer end by means 
of brackets 32, so that the trolley, and the load suspended therefrom, 
will move to the right or left across the beam 12 depending upon the 
direction of rotation of the wench 30. 
A load carrying body, or lifting frame 34, is suspended from the trolley 20 
by means of flexible cables 36 attached at their outer ends to the trolley 
20, reeved about idler sheaves 38 on the lifting frame 34 and then about a 
pair of cable reels 40 on the trolley. An electric motor 42 is adapted to 
drive the cable reels to reel in or pay out additional lengths of the 
cable 36 to thereby raise or lower the lifting frame relative to the 
transverse gantry beams 12. 
Preferably, two control booths are provided on the gantry crane 10. The 
upper booth 43 is suspended from, and moves with, the trolley 20. The 
lower booth 45 is suspended from one of the horizontal frame members 16. 
All functions of the gantry crane may be controlled from either booth so 
that only a single operator is needed for the crane under most 
circumstances. The dual operating booths merely provide a choice of 
vantage points, depending upon the work being done. 
The lifting frame 34 is provided with load engaging means including four 
corner latches 44 adapted to engage latch receiving recesses (not shown) 
in the upper surface of cargo containers 46. The lifting frame also 
includes four pivoted lifting arms 48 adapted for bottom lifting of loads, 
such as truck trailer bodies 50 or cargo containers or other loads not 
provided with special latch receiving recesses. When not in use, the 
bottom lifting load arms 48 may be pivoted into a raised position (FIG. 4) 
where they will not interfere with the operation of the corner latches 44. 
The construction and operation of the corner latches 44 and the lifting 
arms 48 are conventional and are shown, for example, in U.S. Pat. No. 
3,558,172. 
Since the lifting frame 34 and any load carried by it are suspended by the 
flexible cables 36, movement of the frame and load, either longitudinally 
of the beam 12 by movement of the trolley 20, or by moving the entire 
gantry crane structure on its wheels 18, tends to cause sway of the 
lifting frame 34 and its load, Sway inducing forces are generated by 
inertia of the cargo and lifting frame and also may be exerted by wind, 
gravity, or other means. Sway in a direction generally parallel to the 
transverse beam 12 tends to be minimized because of the angles at which 
the suspending cables 36 extend between the idler sheaves 38 on the 
lifting frame and the cable reel 40 on the trolley. However, sway in a 
direction generally perpendicular to the transverse beam 12 still may 
occur. Therefore, a separate stabilizing means is desirable to prevent 
sway of the lifting frame and load in a direction generally perpendicular 
to the gantry beam 12. 
The stabilizing means of the present invention comprise a stabilizing beam 
52 extending between the legs 14 of the gantry crane. At opposed ends of 
the beam 52 are guide members 54 received on vertical guide bars 56 
mounted on the gantry legs 14. The beam 52 thus may more freely in a 
vertical direction but is guided against displacement in other than a 
vertical direction. Preferably, a pair of such stabilizer beams 52 are 
provided, one disposed on each side of the legs 14, although the objects 
of the invention may be accomplished by a single beam. 
The guide beams 52 preferably are idler beams and are adapted, when in an 
unlatched position, to rest on the top of the lifting frame 34. The idler 
beams 52 are not provided with independent means for raising and lowering, 
but will rise and fall automatically as the lifting frame 34 is raised and 
lowered by means of the flexible cables 36. 
Channel members 58 on the top of the lifting frame are adapted to 
selectively engage the stabilizing beams 52 to prevent the lifting frame 
and the load carried thereby from moving perpendicularly to the 
stabilizing beam 52. Appropriate antifriction means such as wheels or 
rollers (not shown) are provided in the channel members 58 so that the 
lifting frame 34 may move freely in a directly parallel to the transverse 
beam 12 while the stabilizing beams 52 are resting thereon. 
Means also are provided for assuring that the stabilizer beams 52 remain 
always in a horizontal position, parallel to the top beam 12, regardless 
of the transverse position of the lifting frame 34. These means comprise a 
pair of double idler sheaves 60 and 62 rotatably mounted adjacent opposed 
ends of the idler beam 52 and a pair of flexible cables 64 and 68 reeved 
about the sheaves 60 and 62 and dead-ended on the structure of the gantry 
frame 10. As shown in FIG. 1 and in the sketch, FIG. 3, one flexible cable 
64 is dead-ended at bracket 70 on one leg 14 of the gantry frame, is 
reeved about the top of the front sheave on double sheave 60, extends 
across the beam 52, is reeved about the lower portion of the back sheave 
of double sheave 62 and then is dead-ended at the bracket 72 on the 
opposite leg 14 of the gantry frame. The second cable 68 is dead-ended at 
bracket 74 on the gantry frame leg 14, is reeved about the top of the 
front sheave of double sheave 62, extends across the gantry frame, is 
reeved about the bottom of the back sheave of double sheave 60 and extends 
up to and is dead-ended at bracket 76 on the opposite leg 14 of the gantry 
frame. Since the cables 64 and 68 are of the same length and are taut, it 
will be apparent to those skilled in the art that the beam 52 always will 
remain horizontal and parallel to the transverse beam 12, regardless of 
the position of the lifting frame 34 which is used to support, raise and 
lower the beam 52. 
The cable and reeving arrangement for retaining the stabilizing beam 
horizontal preferably is duplicated for both of the stabilizing beams 52. 
With the apparatus as described, it will be apparent that when the idler 
stabilizing beams 52 are engaged by the channel members 58, the lifting 
frame 34 and the load carried thereby will be stabilized against sway in a 
direction perpendicular to the transverse gantry beams 12, while the 
trolley 20 and lifting frame 34 will be free to move longitudinally of the 
beam 12. As the lifting frame 34 and the load carried thereby are raised 
relative to the gantry structure by shortening the suspension cables 36, 
the stabilizing beams 52 resting on top of the lifting frame 34 and 
engaged with the channel members 58 automatically will be raised. As the 
lifting frame 34 and load are lowered by lengthening the suspension cables 
36, the stabilizing beams 52 will be lowered along therewith, under the 
influence of gravity. 
With the stabilizing beams thus engaged with the lifting frame 34, the 
bottom lifting load arms 48 may be used to lift a truck body 50 and 
accurately position it above the rail flatcar 72 without the trailer 50 
tending to sway relative to the flatcar. Once the truck trailer is 
accurately positioned on the flatcar, the entire gantry frame may be 
advanced on its wheels 18 in order to stab the "fifth wheel" on the 
flatcar (not shown) into a corresponding latch (not shown) in the truck 
trailer body. 
Referring to FIG. 4, there is shown the hoisting apparatus of the present 
invention being utilized to handle cargo containers 46. When the 
containers 46 include latch receiving recesses in the upper corners 
thereof, the bottom lifting load arms 48 may be pivoted into a raised 
position, as illustrated in FIG. 4, and the container may be engaged by 
means of corner latches 44 on the lifting frame 34. 
The legs of the gantry frame preferably are positioned far enough apart so 
that the gantry frame may be received over a plurality of rows of cargo 
containers. As shown, the containers may be stacked higher in one row than 
in another. If it is desired to lift or lower a container in one of the 
lower rows, then it may be necessary of the lifting frame 34 to extend 
below the top of the containers in an adjacent row. In this case, the 
stabilizing beams 52 would be obstructed by the top of the highest row of 
containers between the gantry legs, thus interfering with the operation of 
the gantry. To avoid this problem, there preferably are provided means for 
selectively retaining the stabilizer beams in a raised, inoperative, 
position. As illustrated, these comprise latches which may be engaged with 
opposed ends of the lifting beams. As shown in FIG. 4, a solenoid 74 is 
disposed near the upper end of each of the gantry legs 14 and a plunger 
76, actuated by the solenoid, is adapted to support the bottom of the 
guide members 54 on each end of the stabilizing beams. When it is desired 
to latch the stabilizer beams in an inoperative position, the solenoids 74 
are actuated to retract the plungers 76, the lifting frame 34 is raised by 
the cables 36 so as to place the stabilizing beams and guide members above 
the level of the plungers, and the solenoids are deactivated to permit the 
plungers 76 to be extended responsive to resilient means such as springs 
(not shown) internally of the solenoids. The lifting frame 34 then may be 
lowered free of engagement with the stabilizer beams 52, which will rest 
on the plungers 76. When it is desired again to use the stabilizer beams 
52, they are lifted by means of the frame 34, the plungers 76 are 
retracted and the lifting frame and stabilizer beams are lowered below the 
level of the plungers 76. 
From the foregoing, it will be apparent that the desired objects and 
advantages of the invention are accomplished by the apparatus as 
disclossed. The foregoing disclosure and description of the invention is 
illustrative only and various changes may be made in the size, shape, 
materials of construction and arrangement of parts, within the scope of 
the appended claims, without departing from the spirit of the invention.