Abstract:
In some embodiments, a post puller may include one or more of the following features: (a) a frame capable of being coupled to a vehicle, (b) first and second post removal doors having an open side facing each other and an opposite end coupled to the frame, (c) a V-shaped opening located on the open side of the doors, (d) butt hinges along which couple the doors to the frame along a hinge axis, (e) a blade located on the open side of each door, and (f) a fork aperture for receiving a fork.

Description:
BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     Embodiments of the present invention relate to devices for removing materials from the ground. Particularly, embodiments of the present invention relate to post pullers. More particularly, embodiments of the present invention relate to post pullers operated by and/or controlled by powered vehicles. 
     II. Discussion of Related Art 
     There are countless applications for a grasping and lifting apparatus for heavy or awkward work pieces. One example is a post puller grasping an elongated object such as a fence post or a telephone pole and lifting it out of a post hole or positioning it in a post hole or simply moving it about from place to place. A typical post puller consists of some type of clamp attached to a machine with lifting power, for example a tractor or a skid-steer loader. The clamp may be nothing more complex than a length of heavy chain wrapped tightly around the post, securing the post to the lifting machine. Such a clamp enables a remotely located worker such as a farmer with no power machinery other than a tractor to use the power lifting capacity of the tractor to place and remove fence posts or other awkward or heavy objects including brush and trees. 
     A chain used as a clamp may require a person to hold the chain securely around the post during the lifting and moving operation. If the chain is attached to a tractor with lifting capability, it may be possible for one person to simultaneously hold the chain and operate the tractor, but at best this is clumsy, and it often poses safety issues, so a second person may be needed. Lifting machines such as tractors or skid-steer loaders generally lift by pivoting about a point, and this results in the lifting motion being arcuate rather than linear. When inserting a post into, or removing it from, a deep post hole, an arcuate lifting motion can cause the post to bind against the walls of the hole, damaging the hole or the post, or rendering the lifting operation impossible. 
     Accordingly, there has been a need for a lifting apparatus easily attached to a lifting machine in a remote location, safely and conveniently operated by a sole worker, and can lift clumsy or heavy objects. It would be desirable for such an apparatus to lift an object through a linear rather than an arcuate range of motion. 
     SUMMARY OF THE INVENTION 
     In some embodiments, an apparatus for pulling posts may include one or more of the following features: (a) a frame having a first fork aperture and a second fork aperture coupled by a support member, (b) a first post removal door coupled to the first fork aperture and a second post removal door coupled to the second fork aperture, the doors coupled with a butt hinge, (c) a V-shaped opening on an end opposite the support member, and (d) a blade coupled to the first post removal door. 
     In some embodiments, a method of removing a post may include one or more of the following steps: (a) positioning a post puller, having fork apertures coupled together by a support member, around a post, (b) elevating the post puller to pinch the post between post removal doors, (c) pulling the post from the ground, (d) coupling the post puller to a vehicle, (e) transporting the post puller to the post, (f) driving the vehicle to a drop location, (g) lowering the post puller, and (h) releasing the post. 
     In some embodiments, a post puller may include one or more of the following features: (a) a frame capable of being coupled to a vehicle, (b) a first and second post removal doors having an open side facing each other and an opposite end coupled to the frame, (c) a V-shaped opening located on the open side of the doors, (d) butt hinges along which couple the doors to the frame along a hinge axis, (e) a blade located on the open side of each door, and (f) a fork aperture for receiving a fork. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  shows a side profile of a forklift as in embodiments of the present invention; 
         FIG. 2  shows a front elevated profile view of a post puller coupled to a forklift in an embodiment of the present invention; 
         FIG. 3  shows a flow process diagram of the operation of a post puller in an embodiment of the present invention; and 
         FIG. 4  shows a post puller in operation in an embodiment of the present invention. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     The following discussion is presented to enable a person skilled in the art to make and use the present teachings. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein may be applied to other embodiments and applications without departing from the present teachings. Thus, the present teachings are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the present teachings. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of the present teachings. 
     In embodiments of the present invention, a post puller can mount on a skid loader, a three-point hitch on a tractor, a tractor front end loader, an industrial wheel loader and a fork lift. The post puller operates by allowing an operator to place the post puller around a post or tree. The jaws of the post puller swing upward (depending on the size of the post or tree) as the post or tree push against the jaws to accommodate the post or tree. When the post or tree is in the post puller, the operator would then raise the post puller upward. As the post puller rises, the jaws of post puller pinch together, “bite into the post”. By raising the post puller upward the post or tree is pulled from the ground. To release the post or tree, the operator would simply lower the post puller until the post or tree hit the ground, which would push upward on the jaws, thus opening the jaws and releasing the post or tree. 
     As stated above, embodiments of the present invention can incorporate a skid loader. A skid loader or skid-steer loader is a rigid frame, engine-powered machine with lift arms used to attach a wide variety of labor-saving tools or attachments. Skid-steer loaders are four-wheel drive vehicles with the left-side drive wheels independent of the right-side drive wheels. By having each side independent of the other, wheel speed and direction of rotation of the wheels determine the direction the loader will turn. Skid-steer loaders can turn in their own tracks which make them extremely maneuverable and valuable for applications requiring a compact, agile loader. Unlike conventional front loaders, the lift arms in these machines are alongside the driver with the pivot points behind the driver&#39;s shoulders. Because of the operator&#39;s proximity to moving booms, early skid loaders were not as safe as conventional front loaders, particularly during entry and exit of the operator. Modern skid loaders have fully-enclosed cabs and other features to protect the operator. Like other front loaders, it can push material from one location to another, carry material in its bucket or load material into a truck or trailer. Most owners of skid steer loaders have a fork lift attachment also, making the post-puller easy to mount. 
     Embodiments of the present invention can incorporate a three-point hitch. The three-point hitch is made up of several components working together. These include the tractor&#39;s hydraulic system, attaching points, the lifting arms, and stabilizers. Three-point hitches are composed of three movable arms. The two outer arms—the hitch lifting arms—are controlled by the hydraulic system, and provide lifting, lowering, and even tilting to the arms. The center arm—called the top link—is movable, but is usually not powered by the tractor&#39;s hydraulic system. Each arm has an attachment device to connect implements to the hitch. Each hitch has attachment holes for attaching implements, and the implement has posts fitting through the holes. The implement is secured by placing a pin on the ends of the posts. The hitch lifting arms are powered by the tractor&#39;s own hydraulic system. The hydraulic system is controlled by the operator, and usually a variety of settings are available. There are several different hitch systems, called categories. Category Zero hitches are used with small farm or garden tractors. Category III hitches are found on the larger farm tractors, or those above 90 hp. The primary benefit of the three-point hitch system is to transfer the weight and stress of an implement to the rear wheels of a tractor. 
     With reference to  FIG. 1 , a side profile of a forklift  10  as in embodiments of the present invention is shown. Forklift  10  is used for the discussion below in regards to the post puller for ease of understanding by the reader. However, most any vehicle which projects force upwards, such as a skid loader or a three-point hitch, can be used without departing from the spirit of the invention. 
     A forklift  10  can have a frame  12  which is the base of forklift  10  to which the mast, axles, wheels, counterweight, overhead guard and power source are attached. Frame  12  may have fuel and hydraulic fluid tanks constructed as part of the frame assembly. A counterweight  14  is a heavy cast iron mass attached to the rear of the forklift frame  12 . The purpose of counterweight  14  is to counterbalance the load being lifted. In an electric forklift  10  the large lead-acid battery itself may serve as part of the counterweight. Cab  16  is the area containing a seat for the operator along with the control pedals, steering wheel, levers, switches, and a dashboard containing operator readouts. Cab  16  may be open air or enclosed, but it is covered by cage-like overhead guard assembly  18 . Overhead guard  18  is a metal roof supported by posts at each corner of cab  16  helping protect the operator from any falling objects. On some forklifts  10 , overhead guard  18  is part of frame assembly  12 . Power source  20  may consist of an internal combustion engine powered by LP gas, CNG gas, gasoline or diesel fuel. Electric forklifts  10  are powered by either a battery or fuel cells providing power to electric motors. The motors may be either DC or AC types. Tilt cylinders  22  are hydraulic cylinders mounted to the frame  12  and the mast  24 . Tilt cylinders  22  pivot the mast  24  to assist in engaging a load. 
     Mast  24  is the vertical assembly raising and lowering the load. It is made up of interlocking rails providing lateral stability. The interlocking rails may either have rollers or bushings as guides. Mast  24  is either hydraulically operated by one or more hydraulic cylinders or it may be chain operated with a hydraulic motor providing motive power. It may be mounted to the front axle or frame  12  of forklift  10 . Carriage  26  is the component to which forks  28  or other attachments mount. Carriage  26  is mounted into and moves up and down the mast rails by means of chains or by being directly attached to the hydraulic cylinder. Like mast  24 , carriage  26  may have either rollers or bushings to guide it in the interlocking mast rails. 
     With reference to  FIG. 2 , a front elevated profile view of a post puller coupled to a forklift in an embodiment of the present invention is shown. Post puller  30  is shown coupled to forks  28  of forklift  10 . Post puller  30  has a frame  32  with a pair of fork apertures  34  coupled by a tractor side support member  36 . Coupled by butt hinges  38  to fork apertures  34  are post removal doors  40 . Located on the interior of post removal doors  40  are metal blades  42 . Removal doors  40  present a V-shaped opening  44  at an opposite end  46  from support member  36 . V-shaped opening  44  allows for posts to be directed towards blades  42  should the operator not center the post within post puller  30  exactly. Post puller  30  is shown made of steel, however, it is fully contemplated post puller  30  could be made from most any material, such as iron, stainless steel, and plastic, without departing from the spirit of the invention. 
     With reference to  FIGS. 3 and 4 , the operation of post puller  30  in an embodiment of the present invention is shown. Upon discovery of a post, tree, or most any other object embedded in the ground, the operator could begin the post removal process  100  by coupling post puller  30  to vehicle  10  by simply driving up to post puller  30  and carefully inserting forks  28  into fork apertures  34  at state  102 . The operator would then lift forks  28  and post puller  30  off the ground slightly to transport post puller  30  at state  104 . The operator could then drive vehicle  10  over to post  50  placing post  50  directly in front of opening  44 . The operator could then drive vehicle  10  forward allowing post  50  to enter opening  44  at state  106 . 
     As post  50  moves towards blades  42  and begins to contact doors  40 , doors  40  will move upward along butt hinges  38 , thus allowing post  50  to travel back to blades  42 . Butt hinges  38  allow small posts and large posts to enter into post puller  30  by rotating along hinge axis  48 . Doors  40  can rotate 90° allowing very small to very large posts  50 . Once post puller  30  is moved completely around post  50  and post  50  is engaged by blades  42 , the operator can begin to lift forks  28  and thus post puller  30  at state  108 . As post puller  30  elevates, blades  42  engage post  50  and pinch it between blades  42 . The upward force of forks  28  places a large pinching force on post  50  and, thus, post  50  is held securely. The operator continues to elevate post puller  30  with post  50  until post  50  is pulled from the ground at state  110 . The operator can then drive vehicle  10  to a desired location to drop off post  50  at state  112 . Once at a drop site, the operator could simply move forks  28  downward at state  114 . This action causes post  50  to lower until post  50  touches the ground. After this, the continued downward motion of post puller  30  causes doors  40  to move upward thus releasing post  50  at state  116 . Post  50  will fall to the ground or the operator can slide post  50  out of post puller  30 . The operator can now move to the next post for removal at state  118  repeating the prior steps as necessary. 
     Thus, embodiments of the POST PULLER are disclosed. One skilled in the art will appreciate the present teachings can be practiced with embodiments other than those disclosed. The disclosed embodiments are presented for purposes of illustration and not limitation, and the present teachings are limited only by the following claims.