Crane attachment for a front end loader

A crane attachment for a front end loader includes arm members pivotally attached to a central portion of a forward each end of loader arm. Remote ends of the arms are joined together to form a triangular boom or truss structure. A cable or a chain extends from each arm of the loader to the remote ends of the arm members to support the truss structure. The length of the cable or chain can be adjusted, with a "come-along" or the like, to provide desired leverage and extension of the truss structure. A pulley is attached to the remote ends of the arm members and a winch cable runs through the pulley to permit an object to be lifted with the winch cable. The crane attachment can be used for lifting large objects, in place of a small crane. Also, the crane attachment can be laid back toward the operator cockpit to permit the loader bucket to be used without removing the crane attachment and the bucket need not be removed when using the crane attachment.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to crane attachments for construction equipment. In 
particular, the invention is a crane attachment for a front end loader 
that is easily installed and does not interfere with the normal operation 
of the front end loader. 
2. Description of the Related Art 
In the construction industry, labor and capital equipment costs are the 
primary variables that effect the cost of a particular project. Of course, 
in order to remain competitive, a construction contractor must minimize 
the cost of a project while meeting predetermined specifications. To this 
end, large machinery has been used to more efficiently handle tasks that 
were originally accomplished by hand, such as digging, lifting, and moving 
objects. For example, bulldozers (or graders) have been used to push large 
amounts of earth for grading and other tasks. 
A bulldozer is typically a tractor-like machine having a blade mounted on a 
frame that extends forward of the tractor body of the bulldozer. The blade 
is used to push dirt or other objects that need to be moved. The blade can 
be moved up and down slightly relative to the body to compensate for 
slopes and other irregularities in the ground. However, a bulldozer is 
limited to pushing dirt or the like along the ground. In order to lift and 
move large amounts of dirt or the like, other machinery is necessary. Of 
course, construction machinery is expensive and is often rented by the 
hour or by the day. Therefore, limiting the amount of machinery used on a 
particular project, and making constant use of the available machinery is 
desirable to limit costs. 
In view of this, a device known as a "front end loader" has been developed. 
A front end loader is the most versatile piece of construction machinery 
and thus has become the most widely used piece of construction machinery. 
A front end loader is capable of doing much of the work of a bulldozer and 
much more. A typical backhoe includes a basic 4-wheel tractor, an 
articulating arm (sometimes referred to as a backhoe) and a loader 
pivotally mounted to the tractor. The loader includes a pair of extending 
loader arms pivotally connected to the tractor, and a bucket pivotally 
mounted on free ends of the loader arms. Hydraulic cylinders, or the like, 
are mounted on the loader arms and controlled to cause the bucket to be 
positioned in various desired positions. The bucket can be lifted high 
over the tractor or placed on the ground. Further, the orientation of the 
bucket can be controlled to hold dirt or the like or to dump the same. 
However, a front end loader does have some limitations. In particular, a 
conventional front end loader cannot easily lift large relatively fragile 
objects, such as HVAC (heating, ventilation, and air conditioning) units 
or the like. Also, a conventional backhoe cannot lift objects higher than 
the maximum height of the bucket of the loader and when objects are lifted 
high, the objects are dangerously positioned over the backhoe operator. 
Therefore, conventional front end loaders are not suitable for lifting 
large poles, prefabricated walls, HVAC units, septic tanks, other vehicles 
or equipment, large trees, or the like. Often such objects must be lifted 
on a construction sight and thus a crane is also necessary. Of course, the 
need for a crane increases the cost of the construction project. 
To avoid the need for a separate crane, it is known to provide crane 
attachments for various construction machinery to increase the lifting 
versatility of the machinery. For example, U.S. Pat. No. 2,301,888 issued 
to Mosher discloses a crane attachment for a bulldozer. The crane 
attachment disclosed in Mosher is pivotally attached to the frame which 
supports the bulldozer blade. However, Mosher does not relate to front end 
loaders and thus the construction disclosed in Mosher does not address the 
complexities associated with mounting a crane attachment to a front end 
loader. In fact, the crane attachment disclosed in Mosher is not suitable 
for use on a front end loader for several reasons. Specifically, the crane 
attachment disclosed in Mosher has a curved lower portion that must be 
mounted on a substantially horizontal member, such as the frame of a 
bulldozer. This type of mounting cannot be accomplished on a front end 
loader because the hydraulics, muffler pipe, and other elements of a front 
end loader would interfere with a crane attachment mounted on a horizontal 
member. Since Mosher is directed to a bulldozer it does not address this 
problem. As noted above, bulldozers are not as versatile as front end 
loaders and are not as prevalent at construction sites. Therefore, Mosher 
falls short of providing a versatile machine for various lifting and 
moving tasks. 
There have been several attempts at adapting a crane attachment for use 
with a backhoe. For example, U.S. Pat. No. 3,527,362 issued to Allen 
discloses a crane attachment for a backhoe that attaches to each end of 
the secondary arms through a complex set of arms and levers. Also, the 
crane attachment disclosed in Allen requires that the bucket of the 
backhoe be removed when the crane attachment is mounted on the secondary 
arms. Removal of the bucket is not easily accomplished in the field and, 
at best, is very time consuming. Also, because the crane attachment 
attaches to the secondary arms through a complex structure and must be 
coupled to the hydraulic system of the backhoe, each crane attachment must 
be specifically designed for a particular backhoe. Accordingly, the crane 
attachment disclosed in Allen cannot be readily deployed in the field and 
does not permit normal operation of the backhoe. Therefore, Allen falls 
short of providing a versatile machine for moving and lifting tasks. 
U.S. Pat. No. 3,812,979 issued to Leihgeber discloses a crane attachment 
for a front end loader that does not require removal of the bucket. 
However, the crane attachment disclosed in Leihgeber mounts on the bucket 
and is fixed to the bucket. Therefore, the crane attachment must be 
removed to use the bucket. While the crane attachment disclosed in 
Leihgeber may be easier to deploy than the crane attachment disclosed in 
Allen, Leihgeber still falls short of providing a versatile machine for 
moving and lifting tasks because it does not permit normal operation of 
the front end loaders without removal of the crane attachment. 
In summary, attempts have been made to increase the versatility of front 
end loaders by providing crane attachments. In attempting to adapt a crane 
attachment, such as that disclosed in Mosher, prior inventors have found 
it necessary to use complex connections between the crane attachment and 
the machinery which interfere with normal use of the machinery. Therefore, 
the prior art crane attachments introduce limitations. In particular, 
prior art crane attachments for front end loaders do not provide easy 
switching between use of the crane attachment and use of the front end 
loader in a conventional manner. 
SUMMARY OF THE INVENTION 
It is an object of the invention to overcome the limitations of the prior 
art discussed above. 
It is another object of the invention to increase the versatility of a 
front end loader. 
It is another object of the invention to permit a front end loader to lift 
large objects. 
It is another object of the invention to permit a front end loader to 
safely lift objects high in the air. 
It is another object of the invention to attach a crane attachment to a 
front end loader without significantly modifying the front end loader. 
It is another object of the invention to allow a single crane attachment 
configuration to be readily attached to any front end loader. 
It is another object of the invention to permit a crane attachment to be 
easily broken down and transported to a work site for attachment to a 
front end loader. 
It is yet another object of the invention to permit selective use crane 
attachment of a and the loader bucket without the need to remove or attach 
any structural elements. 
The objects above are attained by the invention which is a crane attachment 
for a front end loader, the crane attachment having arm members pivotally 
attached to a central portion of a forward portion of a loader arm of the 
front end loader. Remote ends of the arms are joined together to form a 
triangular boom or truss structure. A cable or a chain extends from each 
loader arm to the remote ends of the arm members to support the boom 
structure. The length of the cables or chains can be adjusted, with a 
"come-along" or the like, to provide desired leverage and extension of the 
boom structure. A pulley is attached to the remote ends of the arm members 
and a winch cable runs through the pulley to permit an object to be lifted 
with the winch cable. The crane attachment can be used for lifting large 
objects, in place of a small crane, without removing the loader bucket. 
Also, the crane attachment can be laid back toward the operator cockpit to 
permit the loader bucket to be used without removing the crane attachment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
A preferred embodiment of the invention is illustrated in FIG. 1 and is 
shown attached to a conventional front end loader, such as a JD410.TM. 
sold by John Deere Co. However, the invention can be adapted to any front 
end loader. If necessary, the dimensions or configuration of the invention 
can be changed to accommodate the dimensions of different backhoes. 
Crane attachment 10 includes a pair of arm members 12 extending 
respectively from loader arms 14 of front end loader 13. In particular, 
arm members 12 are pivotally connected to plates 16 that are fixed to a 
central portion of a forward section of loader arms 14 respectively. This 
is best illustrated in FIG. 3 which is a top view. Plates 16 can be 
welded, bolted, or otherwise affixed to loader arm 14 by any material with 
adequate strength characteristics. In the case of arm members 12 being 
made of pipe or tubing as in the preferred embodiment, an end of each arm 
member 12 can be flattened and a hole can be formed in the flattened 
portion. Each flattened portion is secured to a respective one of plates 
16 by pin 18 extending through a hole formed in plate 16 and the flattened 
portion of the corresponding one of arm members 12. Pins 16 can be secured 
by a cotter pin or the like. Of course, arm members 12 can be secured to a 
central portion of the forward section of loader arms 14 in any manner 
that will achieve a pivotal mount with adequate strength, such as with a 
bolt or the like. Free ends of arm members 12 are secured to one another 
in the manner described below. Arm members 12 thus define a boom 
consisting of a triangular truss structure, with front end loader 13 
constituting one of the truss members, when attached to loader arms 14 as 
illustrated in FIG. 3. 
Pulley arrangement 20 is pivotally mounted between the free ends of arm 
members 12 as illustrated in FIG. 5. Cable 26 extends from winch 28 
mounted on front end loader 13 and extends through pulley arrangement 20 
to hang from a free end of the truss structure where arm members 12 are 
joined together. A shackle, hook, magnet, or the like can be attached to 
the free end of cable 26 to permit attachment of cable 26 to an object to 
be lifted. 
In particular, threaded fastener 30 passes through holes formed in 
connecting member 32 and through a hole formed in connecting member 34 as 
shown in FIG. 5. Nut 40 is disposed on one end of threaded fastener 30 and 
cotter pin 42 is disposed on the other end of threaded fastener 30. Pulley 
21 is attached to connecting member 34 by shackle 33. Also, cable 22 
passes through slots formed in connecting members 32. Guiding members 35 
are disposed on connecting members 32 to prevent cable 22 from being 
damaged due to being bent sharply. 
A connecting member in the form of a cable 22 extends from eyelet 24 on one 
loader arm 14 of backhoe 13, passes through connecting members 32 and 
terminates at eyelet 24 on the other loader arm 14. An adjustment device, 
such as a "come-along" or a turnbuckle, can be provided along the length 
of cable 22 to adjust the length of cable 22. Cable 22 supports the truss 
structure at a desired position, just above loader bucket 11 of front end 
loader 13 in the preferred embodiment. The leverage of crane attachment 10 
can be adjusted according to practical considerations such as the size and 
weight of the object to be lifted, the lifting height, the amount of any 
movement after lifting, and the terrain, by adjusting the length of cable 
22 which changes the angle of the truss structure with respect to cable 
22. An angle .alpha. of 5.degree. to 15.degree. between cable 22 and the 
truss structure is preferable for most applications. An angle .alpha. of 
11.degree. has been found to be optimal. 
Any front end loader can be retrofitted with crane attachment 10. 
Initially, plates 16 must be welded, or otherwise attached, to loader arms 
14. This is most readily done in the shop with conventional welding 
techniques but can be accomplished in the field if necessary because a 
welder is available at most construction sites. Once plates 16 are 
attached to loader arms 14, plates 16 can remain thereon without 
interfering with operation. 
When crane attachment 10 is to be coupled to front end loader 13 loader, 
bucket 11 is placed on the ground and crane attachment 10 is laid on the 
ground in front of bucket 11 with the flattened portions of arms 12 close 
to loader bucket 11. In this position, two human operators can lift the 
flattened portions up to plates 16 to align holes in the flattened 
portions with holes in plates 16 respectively. Pins 18 can then be 
inserted through the holes to pivotally fix arm members 12 to loader arms 
14. In this state, the free end of the truss structure rests on the 
ground. Cable 22 is then attached to eyelets 24 and run through connecting 
members 32 to lift the free end of the truss structure and position arms 
12 at the desired angle with respect to secondary arms 14. 
The precise angle can be predetermined or adjusted at the work site based 
on the particular application by adjusting the length of cable 22 with a 
come-along or other adjusting device. Alternatively, a chain can be used 
in place of cable 22 and adjustment can be accomplished by placing hooks 
on the end of the chain, passing the hooks through eyelets 24 and then 
hooking the hooks on the chain itself at the desired position. 
Cable 26 is then run from winch 28 to pass over pulley 21 of pulley 
arrangement 20 to permit the truss structure to be attached to an object 
by a hook, shackle, or the like, on the end of cable 26. Winch 28 is 
disposed on front end loader 13 directly in front of the driver in the 
preferred embodiment. However, winch 28 can be moved to increase 
visibility. For example, winch 28 can be disposed on one of the primary or 
secondary arms or on the roof of backhoe 13. Of course, controls for the 
winch should be placed within the operator's reach to permit a single 
operator to control front end loader 13 and crane attachment 10. 
After the above-assembly procedure, which can be accomplished by two people 
in about 10 minutes, crane attachment 10 is ready for use. The hook on the 
end of cable 22 is attached to the object to be lifted, such as a 
prefabricated wall, a large pole, or any other object. Winch 28 is then 
operated to remove slack from cable 22. In this state, crane attachment 10 
can be moved to the raised state illustrated in FIG. 2 merely by operating 
controls of front end loader 13 to raise bucket 11 in the conventional 
manner. It can be seen that raising the bucket causes loader arms 14 to be 
raised while cable 26 maintains the angle between loader arms 14 and arm 
members 12 thus causing crane attachment 10 to be moved to a raised 
position in which the object is raised off of the ground. The object can 
be raised or lowered merely by operating the controls of the front end 
loader in a conventional manner. This allows an operator to use crane 
attachment 10 without additional training. Alternatively, crane attachment 
10 can be moved to a raised position with slack in cable 26 and winch 28 
can be used to lift the object. 
With the object raised, front end loader 13 can be moved in a conventional 
manner to move the object and the object can be lowered when the proper 
location is reached. The object can be raised or lowered by raising or 
lowering crane attachment 10 or by operating winch 28. Note that winch 28 
should be rated for overhead use for safety. For example, the RE 10,000 
manufactured by RAMSEY.TM. can be used as winch 28. When use of crane 
attachment 10 is no longer needed, arm members 12 can be pivoted back 
against loader arms 14 as illustrated in FIG. 4. Arm members 12 can be 
fixed in this position by shortening cable 22 or by additional cables, 
chains, or the like tied around arm members 12 and secondary arms 14. 
Alternatively, crane attachment 10 can be detached from plates 16 and can 
be laid on a rack formed on the roof of front end loader 13, or stored on 
the ground or any other desired location, when not in use. 
It can be seen that the invention provides a crane attachment for a front 
end loader that has very few parts and is easy to assemble and attach. 
Also, the invention allows the conventional controls of the front end 
loader to be used for lifting with the crane attachment. Further, the 
crane attachment is easily moved to and from a stowed position to permit 
the front end loader to be used in a conventional manner. The loader 
bucket need not be removed and the loader bucket can be used without 
removing the crane attachment. Also, virtually any front end loader can be 
retrofitted with the crane attachment of the invention merely by welding 
plates or other attaching means to central portions of the forward section 
of the loader. The connection to the central portion of the forward 
section of the loader arms permits the crane attachment to be attached to 
the front end loader without interfering with the normal operating 
components of the front end loader and without reducing the structural 
strength of the front end loader. 
While the preferred embodiment has arm members that are connected 
essentially in the center of the forward portion of the loader arms, the 
arm members can be connected to virtually any portion of the forward 
portion of the loader arms that is far enough away from the ends of the 
forward portion of the loader arms to avoid interference with the 
operating components of the front end loader. Therefore, the phrase 
"central portion" as used herein is intended to mean any portion of the 
forward portion of the loader arms other than the very ends of the forward 
portion of the loader arms that are attached to the rear portion of the 
loader arms or the loader bucket. Also, the preferred embodiment has a 
connecting member constituted of a flexible member such as a cable or 
chain that extends from a top portion of the secondary arms to a pulley at 
the free end of the secondary arms. However, the connecting member can be 
any connecting member extending from a portion of the loader arm to a 
portion of the arm member remote from the loader arm. Also, the connecting 
member can be attached in any known manner. Of course, if the connecting 
member extends from a portion of the secondary arms that is below the 
central portion, the connecting member must be rigid in order to maintain 
the relative angle between the arm members and the loader arms. 
Alternatively, the arm members can be coupled to the loader arms in a 
non-pivotal manner and the connecting member can be omitted. Finally, 
there can be any number of arm members and the arm members can be 
connected in any configuration that provides adequate strength. 
The pulley arrangement and associated connection of free ends of the arms 
can be varied. For example, the free ends can be welded together. Also, 
any means for attaching and positioning the various cables can be used. 
Inasmuch as the present invention is subject to many variations, 
modifications and changes in detail, it is intended that all subject 
matter discussed above or shown in the accompanying drawings be 
interpreted as illustrative only and not be taken in a limiting sense.