Abstract:
A fork lift attachment for multi-purpose buckets that is easily installed and secured. The mechanism fits under the bucket and is supported by a slot on the top side of the tine and a latch at the heel of the tine. The latch is tightened causing the fork lift attachment to be cinched onto the bucket. A security chain readily and visibly secures the latch so as to prevent the fork lift attachments from being dislodged even if the hydraulics open the bucket.

Description:
RELATED APPLICATIONS  
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/386,288, filed on Jun. 5, 2002, which is incorporated herein by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention relates generally to the field of fork lift attachments to convert a multi-purpose bucket of a loader into a fork lift and more particularly to the field of doing so in a removable manner that is easy to install and does not damage the bucket.  
           [0004]    2. Discussion of the Background  
           [0005]    In the construction and agriculture industries loaders are often used as multi-functional pieces of equipment. Some of these loaders make use of a multi-purpose bucket in order to be more versatile and have one piece of equipment able to perform many tasks. These multi-purpose buckets are also referred to as 4-in-1 buckets or clam shell buckets. The bucket has two jaws that are pivotally mounted to each other with their positions relative to each other being controlled by hydraulic cylinders. The bucket is then otherwise operated and moved as any regular bucket would be on a loader.  
           [0006]    There have been fork lift attachments for regular buckets, such as U.S. Pat. No. 6,022,184 to Friedland, wherein the attachments allow for the temporary conversion of a regular bucket to perform fork lift jobs. This conversion ability is very advantageous in that it allows a single piece of equipment to be used for different functions without a major investment in separate specialized equipment.  
           [0007]    For multi-purpose buckets, prior fork lift attachments have relied upon cumbersome and sometimes unsecured means of attachment. Examples are illustrated by U.S. Pat. No. 3,667,633 to Cappella and U.S. Pat. Nos. 6,287,070, 6,527,497 and 6,547,508 to Perry. These designs have serious drawbacks. In practice the tips of the fork lift tine often are pushed upward, intentionally or unintentionally, creating forces that may dislodge the fork lift attachments. The result may be an insecure fork lift or dropped or damaged cargo which may cause personal injury or property damage. Inadvertent dropping of the fork lift attachment from the bucket can also occur if the jaws of the multi-purpose bucket open, even if only partially.  
           [0008]    A second shortcoming of these prior designs is the components that are used. Some, such as in the Perry design, have large steel plates that must be placed in the bucket with attached T or I beams. These can weigh a significant amount, thus reducing the useable payload weight. In addition the large, heavy components necessarily cannot be easily installed by an individual and can pose difficulties in field installations. Further, the Perry design has an expensively fabricated tine component which is necessary in order to have the front of the tines be at ground level. The fabrication to obtain such a configuration while maintaining strength is very expensive and involved.  
           [0009]    Another shortcoming of some designs is the use of semi-permanent bolts or other fasteners to secure the fork lift attachments to the bucket. Placement of holes or other similar permanent alterations to the bucket are not advisable, as it diminishes the integrity of the bucket and can initiate degradation or shortening of the life of the bucket. If the machine is a rental or loaned piece of equipment, such alterations are normally not permitted.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention involves the easy mounting of the within fork lift attachment to convert the multi-purpose bucket of a loader into a fork lift. The attachment is very secure and reduces the risk of slippage or movement of the fork lift attachment while in operation, even if the multi-purpose bucket opens partially or is reverse loaded. The design is simple and the location of the tines on the underside of the bucket allows for easy mounting and use. The fork tines can be set on the ground and the bucket attached and secured by only a single person. There is no need to manually lift the attachment or any of its parts into or over the bucket for installation.  
           [0011]    The attachment includes a security latch that is easily placed and readily visible to check for secure installation. Further, the latch acts to tighten the integration of the fork lift attachment to the bucket. The latch also acts as a load bearing structure to transfer forces to the most sturdy and rigid portions of the bucket, which are the leading edge of the upper jaw and rear and leading edge of the lower jaw of the bucket.  
           [0012]    The installation does not damage the bucket as there are no holes or mounting plates required. Further the fork lift attachment can be easily moved and stored as its parts are compact. The fork lift attachment components themselves are simple in design and relatively inexpensive with no massive, heavy components, thus allowing for easy installation and maintenance.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 illustrates a loader with a clamped multi-purpose bucket attached as it would essentially appear when being used as a loader bucket. FIG. 1 also illustrates the fork lift attachment of the present invention secured to the bucket.  
         [0014]    [0014]FIG. 2 illustrates a multi-purpose bucket opened showing the two major portions or jaws of this type of bucket.  
         [0015]    [0015]FIG. 3 illustrates one fork lift attachment with three alternative latch components that would be selected to be used with different types or brands of buckets.  
         [0016]    [0016]FIG. 4 illustrates a side view of a fork lift attachment along with the two jaws of the multi-purpose bucket as it is being positioned for installation.  
         [0017]    [0017]FIG. 5 as in FIG. 4 is a side view showing the installation process as the upper jaw of the bucket is first brought into contact with the latch of the fork lift attachment.  
         [0018]    [0018]FIG. 6 like in FIG. 5 is a side view with the top jaw being closed onto the latch thus securing the fork lift attachment.  
         [0019]    [0019]FIG. 7 illustrates two fork lift attachments with links or chains as visible safeties holding the latches in the position of installation as they would be in FIG. 6.  
         [0020]    [0020]FIG. 8 illustrates a perspective view of two fork lift attachments installed on a multi-purpose bucket with the links in place as shown in FIG. 7.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]    [0021]FIG. 1 illustrates a multi-purpose bucket  2  on a typical loader  1 . The bucket  2  as a whole is moveable on arms  4  as in such loaders  1 . The bucket  2 , as better seen in FIG. 2, has two major portions or jaws  6  and  8  that are pivotally mounted to each other at  7  and moveable relative to each other. In an opened position, the lower jaw  8  when raised allows the upper jaw  6  to be useable as a grader blade. The two jaws  6  and  8  in cooperation can also act as a claw for grasping and lifting and moving items in the field. In another configuration, the lower jaw  8  can act as a scraper for earth surface treatment. When the two jaws are closed without the fork attachment, it operates as a regular bucket. This versatility of such a typical multi-purpose bucket  2  is well known. However, the function that is not present without an attachment is the fork lift function. In the clamped position of FIG. 1, the rear edge  10  (see FIG. 2 again) of the lower jaw  8  meets the bottom edge  12  of the upper jaw  6  to form the bucket with the fork attachment  20  in FIG. 1 clamped between the two jaws of the bucket. The methods and attachments herein accomplish this extra functionality by the addition of a fork lift attachment  20  to the multi-purpose bucket  2  in an easy and secure manner that does not damage the bucket  2 .  
         [0022]    [0022]FIG. 3 illustrates the fork lift attachment  20  of the present invention which can be installed on the multi-purpose bucket  2  and are usually installed in pairs. Each fork lift attachment  20  is comprised of a tine  22  that has a tip  24  and a heel  26 . The fork lift attachment  20  also has a vertical extension  50  whose function as a cargo barrier will be more fully explained below. On the top side of the tine  22  is a slot  30  formed in part by member  32  positioned between the tip  24  and the heel  26 . The slot  30  is also preferably formed in part by a base  28  which is on the top side of the tine  22  and below a portion of the member  32 . A rear bearing point  35  is also provided on the top side of the tine  22  between the slot  30  and the heel  26  with a hinge point  33  being located on the heel  26  of the tine  22 . A latch  36  is rotatably attached to the hinge  33  on the tine  22  and as shown in FIG. 3 may have different configurations including those of  36   a ,  36   b  and  36   c .  36   a  is useable for John Deere multi-purpose buckets and Gannon Buckets.  36   b  is useable for Caterpillar and Komatsu multi-purpose buckets and  36   c  is useable for Case buckets. Most other multi-purpose buckets will use one of these three styles.  
         [0023]    [0023]FIG. 4 represents a side view of the fork lift attachment  20  resting on a surface, such as the ground. As the tine  22  nests on the bottom of the bucket when installed, there is no need to manually lift the tine  22  onto or into the bucket.  
         [0024]    [0024]FIG. 4 further illustrates that when initially joining the bucket  2  and fork lift attachment  20 , the jaws  6  and  8  of the bucket  2  are opened and the entire bucket  2  is rotated forward. This allows the bottom jaw  8  to engage the fork lift attachment  20  (similar to slipping a foot into a slipper). The operator places the leading edge  14  of the bottom jaw  8  in the slot  30  between the top member  32  and the base  28 . The bottom surface  13  of the bottom jaw  8  of the bucket  2  rests on the rear bearing point  35 . The rear edge  10  of the bottom jaw  8  when in place is approximately even with the hinge  33  on the heel  26  of the tine  22 .  
         [0025]    In the preferred embodiment, there are multiple hinge points such as  33  and  33   a  as in FIG. 3 to allow different locations of the latch  36   a ,  36   b , or  36   c  and the adjustment of the fork lift attachment  20  to fit the length of the bottom surface  13  of the bottom jaw  8  from the leading edge  14  to the rear edge  10 . In FIGS. 4, 5 and  6 , the more rearward hinge point  33  is shown being used. In FIG. 4 a front bearing point  34  on the slot forming member  32  is illustrated which interacts with the top of the leading edge  14  of the bottom jaw  8  to transmit forces. Thus the downward forces transmitted to the bucket  2  during loading of the tines  22  are localized by the front bearing point  34  on the leading edge  14 , where there is the greatest reinforcement and weight bearing ability.  
         [0026]    The latch  36  in each of the preferred embodiments (e.g., see version  36   c  in FIG. 3) is composed of a steel flat  37  with a hinge collar  38  at one end. The flat  37  must be thick and strong enough to withstand bending forces that will occur when the leading edge  12  in FIG. 6 is forced against the rear contact point  42 , which in turn will force the front surface of the flat  37  of the latch  36  to contact the rear edge  10  of the jaw  8 . In the preferred embodiment, the rear contact point  42  in FIG. 6 is located farther from the hinge  33  than the front contact point between the flat  37  and the edge  10 . This creates a fulcrum at the front contact point. By a lever action at the fulcrum point when the rear contact point is forced forward, the hinge  33  will be forced rearward. Also the latch  36  when forced upward will pull the attachment  20  and force the rear bearing point  35  against the bottom  13  of the bucket  2 . This action cinches the attachment  20  to the bucket  2  and concentrates the forces at the bearing points  34  and  35 .  
         [0027]    On the front side of the latch  36  (see again as an example  36   c  in FIG. 3) is a safety stop  40 . In the preferred embodiment the safety stop  40  is a rod or round stock welded on the front of the flat  37  of the latch  36 . The stop may also be an extension  41 , such as in version  36   a  in FIG. 3 designed for a specific bucket. Similarly the rear contact point  42  in the preferred embodiment is a rod or round stock welded on the rear face of the flat  37  of the latch  36 . The rear contact point  42  interfaces with the leading edge  12  (see FIG. 6) so as to create a vector force generally forward on the flat  37 .  
         [0028]    A wedge piece  44  in the latch versions  36   a ,  36   b  and  36   c  of FIG. 3 is a flat piece welded to rear contact point  42  and to and extending beyond the top  43  as shown. The top  43  in this regard is the end of the flat  37  away from the hinge  38  of the latch  36 . A hole  45  is broached into the end of the wedge  44  piece to accommodate the hook  62  (as shown in FIG. 7) on the safety link  60  as will be described in more detail below. This wedge  44  (see again FIG. 5) operates to allow the leading edge  12  of the top jaw  6  to smoothly engage the latch  36  and get into position against the rear contact point  42 . As an alternative, the purpose and safety feature of the latch  36  may be accomplished by a single fabrication piece or a different configuration understood to accomplish the same or some of the functions described herein.  
         [0029]    The installation of the fork lift attachment  20  onto a multi-purpose bucket  2  is progressively illustrated in FIGS. 4, 5 and  6  with FIG. 4 being a starting position.  
         [0030]    [0030]FIG. 5 is a side view with the top jaw  6  of the bucket  2  closing on the bottom jaw  8  and first engaging the latch  36 . As illustrated, leading edge  12  contacts the wedge  44  on the latch  36 . This causes the latch  36  to rotate, clockwise in this view, about the hinge  33  and a front contact point of the flat  37  to move towards contact with edge  10 .  
         [0031]    [0031]FIG. 6 illustrates the latch  36  rotated about the hinge  33  as the front of the latch  36  at a front contact point on the flat  37  is forced against the rear edge  10  in response to the top jaw  6  forcing the rear contact point  42  forward. In FIG. 6 the latch  36  is held in this configuration by hydraulic forces causing the leading edge  12  of the top jaw  6  to contact the rear contact point  42  of the latch  36 .  
         [0032]    In FIG. 6 the latch  36  has a safety stop  40 . The stop  40  acts as a safety to prevent the latch  36  from slipping down and out from the clamp of edge  12  and edge  10 , due to any reverse loading on the tip  24  of the tines  22 .  
         [0033]    The rear contact point  42  by way of the hydraulic force through edge  12  causes rotational forces in the latch  36  about the fulcrum point of the front contact point of the flat  37  and edge  10 . The force of edge  12  pushes against the rear contact point  42  and forces latch  36  forward. Since the latch  36  is attached to the heel  26  of the tine  22  at the hinge  33 , the heel  26  of the tine  22  is pulled rearward with the rear bearing point  35  pressing against the bucket bottom surface  13  of the bucket  2 . This, in turn, puts pressure on the fork lift attachment  20  to move the slot  30  backward against the leading edge  14  of the bucket  2 . The force of the backward movement at the slot  30  is opposed by the edge  14  of the bottom jaw  8  of the bucket  2  against the top member  32  of the slot  30  and against the front bearing point  34 . This series of actions acts as a cinch of the fork attachment  20  around the bottom surface  13  of the bucket  2  thus stabilizing the fork lift attachment  20 .  
         [0034]    The connection of the fork lift attachment  20  with the bucket  2  thus is accomplished with multiple securing techniques to stabilize the fork lift attachment  20  and form a rigid union between the fork lift attachment  20  and the multi-purpose bucket  2 . The hydraulic controls of the multi-purpose bucket  2  cinch the connection and insure a rigid interaction between the components. The result is an efficient force transfer between the components during loading. The tight connection, forced by the hydraulics and the bearing points  34  and  35  and the rear contact point  42 , insures that there is a rigid connection without any easy freedom of movement of the fork lift attachment  20  relative to the bucket  2 . All of the benefits result without heavy or cumbersome plates or cross pieces, and without bolts or permanent alterations to the bucket  2 .  
         [0035]    Further, the installation can readily be accomplished by the operator as no parts of the fork lift attachment  20  need to be manually lifted into or onto the bucket  2 . The tines  22  merely rest on the ground or platform and the bucket  2  by hydraulics is placed on the top side of the tines  22  to engage the slot  30  by the leading edge  14  of the bucket  2 . The closing of the latch  36  and the cinching of the connection occurs by hydraulically controlling the closure of the multi-purpose bucket  2 . The attachment is thus easily accomplished without any holes, bolts or heavy components.  
         [0036]    A further improvement with added safety includes the adjustable link or chain  60  (see FIG. 7) from the slot forming member  32  to the latch  36 . The link  60  in this embodiment is attached to the top of the slot forming member  32  and acts as another safety to prevent the latch  36  from moving open on the hinge  33  and thus, loosen or disengage from the rear edge  10  of the bucket  2 . This could occur if the clamping action or hydraulic forces are lost or weak or unintentionally released allowing edge  12  to move away from the latch  36  or if the tines are reverse loaded. In the preferred embodiment, the adjustment at  64  is a bolt  66  welded to the end of the link  60  opposite the end with the hook  62  (in the illustration the link  60  is a chain). The bolt extends through the slot forming member  32  and is attached thereto with a nut that is used to shorten the total length of the link  60 . The adjustment at  64  allows the link  60  to be attached to the latch  36  and then adjusted by shortening to provide a taut link. This minimizes any freedom in the attachment cinch. In the preferred embodiment the adjustment is a bolt, though any suitable adjuster could be used.  
         [0037]    Another feature of the fork lift attachment  20  aids the fork lift function. In this regard vertical extensions  50  of the fork lift attachment  20  extend upward from the front of the slot  30 . The extensions  50  operate as a load or cargo barrier or backstop to prevent loads, such as round stock or pipes and similar items from sliding or rolling into the bucket  2  when picked up and the fork lift tines  22  are rotated upward as is illustrated in FIG. 1. It also, at a suitable height, serves to allow the operator of the loader to see the location of the tine  22 . This is necessary when the ends  24  of the tines  22  are not visible over the bucket  2  and load or other parts of the machine. The extensions  50  also have lifting aids  52  (see FIGS. 6 and 7) so that the extension  50  may be clamped and moved by the bucket  2  or moved by chains, ropes or by hand for positioning using handles  54 .  
         [0038]    While several embodiments of the present invention have been shown and described in detail, it is to be understood that various changes and modifications could be made without departing from the scope of the invention.