Abstract:
A self-propelled post driving apparatus includes a frame; a post driving mechanism including a post stabilizer and a post ram; a stabilizer and ram control assembly; a driving assembly including a first driving wheel; a second driving wheel; a first wheel driving assembly for driving the first driving wheel; a second wheel driving assembly for driving the second driving wheel; a power assembly including at least one machine for supplying power to at least one of the post driving mechanism, the first driving wheel and the second driving wheel; and a driving control assembly for selectively applying power to at least one of the first driving assembly and the second driving assembly for at least one of individual and simultaneous operation of the first driving wheel and the second driving wheel for selective directional movement of the post driving apparatus for selectively positioning the apparatus at a post driving location.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention is related broadly to powered implements including powered farm implements and, more particularly, to a self-propelled post driving apparatus that includes a steering apparatus. 
         [0002]    During fence building or mending operations, driving fence posts into the ground can be a time-consuming operation for farmers and others who must essentially plant wooden fence posts in the ground. Over a large farm, or other broad expanse, the total number of posts required to make a full-sized fence can make fencing operation a long process. 
         [0003]    Accordingly, over the years automatic or powered fence post drivers have been developed. Some of the post drivers have taken the form of an attachment for a tractor or truck while others are in the form of a trailer which may be towed behind a tractor or other vehicle. Still other post drivers are self-propelled. Some of the self-propelled post drivers are steerable and include a seat for a driver. Others are merely self-propelled to follow or lead a walking operator who is not positioned on the device itself. With the operator positioned on the ground, it becomes easier than with prior apparatus to maneuver a power driver to accurately position and drive a fence post. 
         [0004]    The positioning operation is a precise maneuver, given a margin of error for pole location on the order of several inches when compared to the size of a field. Therefore, in order to properly position a post driver, some form of steering is desired. In order to more precisely place the fence post for driving, a versatile steering system could enhance the operator&#39;s ability to properly position the driving apparatus over the desired post location. 
       SUMMARY OF THE INVENTION 
       [0005]    It is accordingly it is an object of the present invention to provide a self-propelled post driving apparatus that is highly maneuverable. 
         [0006]    It is another object of the present invention to provide a post driving apparatus that includes a zero turning radius steering system. 
         [0007]    It is another object of the present invention to provide such a post driver that also includes enhanced mobility of the ram in order to precisely position the post driver over a desired post location. 
         [0008]    To those ends, the present invention is directed to a self-propelled post driving apparatus including a frame and a post driving mechanism mounted to the frame including a post stabilizer and a post ram. A stabilizer and ram control assembly is provided for controlling operational movement of the post stabilizer and the post ram. Also included is a driving assembly including a first driving wheel mounted to the frame at a first position; a second driving wheel mounted to the frame at a second position oppositely from the first driving wheel; a first wheel driving assembly for driving the first driving wheel; and a second wheel driving assembly for driving the second driving wheel. A power assembly is included, with the power assembly having at least one machine for supplying power to at least one of the post driving mechanism, the first driving wheel and the second driving wheel. A driving control assembly is provided for selectively applying propulsion power to at least one of the first driving assembly and the second driving assembly for at least one of individual and simultaneous operation of the first driving wheel and the second driving wheel for selective directional movement of the post driving apparatus for selectively positioning the post driving mechanism at a post driving location. 
         [0009]    Preferably, the power assembly includes a liquid-fuel engine. It is further preferred that the power assembly include a working fluid compressor and fluid distribution system operatively associated therewith, the compressor being operatively associated with the liquid-fuel engine. 
         [0010]    It is preferred that the present post driving apparatus include an assembly for selectively engaging said first driving wheel and sand second driving wheel from said power assembly, thereby allowing selective free rotation of said first driving wheel and said second driving wheel. 
         [0011]    It is preferred that the first driving assembly includes a first fluid-driven motor operatively associated with the first driving wheel and the second driving assembly includes a second fluid-driven motor operatively associated with the second driving wheel for applying propulsion power to at least one of the first driving wheel and the second driving wheel, and wherein the first driving assembly and the second driving assembly are each operatively associated with the compressor using the fluid distribution system for applying propulsion power to the first driving assembly and the second driving assembly. 
         [0012]    It is further preferred that the first fluid-driven motor and the second fluid-driven motor are each formed as a hydraulic motor and the working fluid compressor is a hydraulic compressor. Preferably, the first driving assembly includes a first motor operatively associated with the first driving wheel for propulsion thereof and the second driving assembly includes a second motor operatively associated with the second driving wheel for propulsion thereof. 
         [0013]    It is preferred that the first driving assembly includes a first fluid-driven motor operatively associated with the first driving wheel and the second driving assembly includes a second fluid-driven motor operatively associated with the second driving wheel for applying driving power to at least one of the first driving wheel and the second driving wheel. Preferably, the power assembly includes a liquid-fuel engine, a working fluid compressor and fluid distribution system operatively associated therewith, the compressor being operatively associated with the liquid-fuel engine, wherein the first driving assembly and the second driving assembly are each operatively associated with the compressor using the fluid distribution system for applying propulsion power to the first driving assembly and the second driving assembly. 
         [0014]    Preferably, the stabilizer and ram control assembly is operatively associated with the compressor using the fluid distribution system for applying power selectively to the post stabilizer and the post ram. It is preferred that the present invention further includes an assembly for extending the ram laterally away from the frame and a control assembly associated with the ram extending assembly for selectively moving the ram laterally away from the frame. 
         [0015]    The present invention can also be described as a self-propelled post driving apparatus including a frame and a post driving mechanism mounted to the frame including a post stabilizer and a post ram. The present invention also includes a stabilizer and ram control assembly for controlling operational movement of the post stabilizer and the post ram. Also provided is a propulsion assembly including at least one apparatus mounted to the frame for propelling the post driving apparatus along a support surface; and a zero turning radius control assembly for controlling the apparatus during movement thereof including at least two drive wheels, with the drive wheels being selectively individually drivable in either direction of rotation to attain zero turning radius movement for selectively positioning the post driving mechanism at a post driving location. 
         [0016]    It is preferred that the propulsion assembly includes a power assembly including at least one machine for supplying power to at least one of the post driving mechanism and the at least two drive wheels. It is further preferred that wherein the power assembly includes a liquid-fuel engine. Preferably, the power assembly includes a working fluid compressor and fluid distribution system operatively associated therewith, the compressor being operatively associated with the liquid-fuel engine. 
         [0017]    It is preferred that the propulsion assembly includes a first driving assembly for driving the first driving wheel; a second driving assembly for driving the second driving wheel; and a power assembly including at least one machine for supplying power to at least one of the post driving mechanism, the first driving wheel and the second driving wheel. 
         [0018]    Preferably, the zero turning radius assembly includes a driving control assembly for selecting at least one of the first driving assembly and the second driving assembly for at least one of individual and simultaneous operation of the first driving wheel and the second driving wheel for selective directional movement of the post driving apparatus for selectively positioning the post driving mechanism at a post driving location. 
         [0019]    It is further preferred that the first driving assembly includes a first fluid-driven motor operatively associated with the first drive wheel and the second driving assembly includes a second fluid-driven motor operatively associated with the second drive wheel for applying propulsive power to at least one of the first driving wheel and the second driving wheel. 
         [0020]    Preferably, the first fluid-driven motor and the second fluid-driven motor are each formed as a hydraulic motor and the working fluid compressor is a hydraulic compressor. It is preferred that the present invention further include an assembly for extending the ram laterally away from the frame and a control assembly associated with the ram extending assembly for selectively moving the ram laterally away from the frame. 
         [0021]    It is further preferred that the present post driving apparatus include comprising an assembly for selectively engaging and disengaging said first driving wheel and said second driving wheel from said at least one apparatus mounted to the frame for propelling the post driving apparatus along a support surface, thereby allowing selective free rotation of said first driving wheel and said second driving wheel. 
         [0022]    The present invention is also directed to a method for driving a post into the ground. The present method includes the steps of: 
         [0023]    a. providing a self-propelled post driving apparatus including a post stabilizer; 
         [0024]    a post ram; a stabilizer and ram control assembly for controlling operational movement of the post stabilizer and the post ram; propulsion assembly including an apparatus mounted to the frame for propelling the post driving apparatus along a support surface; and a zero turning radius control assembly for controlling the apparatus during movement thereof including at least two drive wheels, with the drive wheels being selectively individually drivable in either direction of rotation to attain zero turning radius movement; and an assembly for selectively engaging and disengaging said first driving wheel and said second driving wheel from said apparatus mounted to the frame for propelling the post driving apparatus along a support surface; 
         [0025]    b. determining a post driving location; 
         [0026]    c. maneuvering the post driving apparatus using the control assembly to selectively operate the wheels assemblies individually, simultaneously or both to position the post ram over the predetermined location; 
         [0027]    e. removing a post from the post magazine; 
         [0028]    f. positioning the post over the predetermined driving location; 
         [0029]    g. stabilizing the post using the stabilizer arms; and 
         [0030]    h. ramming the post into the ground using the control assembly to selectively operate the ram to repeatedly pound the post into the ground at the predetermined location. 
         [0031]    Preferably, the method further includes the steps of providing a post driving apparatus having an assembly for extending the ram laterally away from the frame and a control assembly associated with the ram extending assembly for moving the ram laterally away from the frame; and moving the ram laterally away from the frame a predetermined distance using the ram extending control assembly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]      FIG. 1  is a diagrammatic side view of a self-propelled post driving apparatus according to one preferred embodiment of the present invention; 
           [0033]      FIG. 2  is a front view of the post driving apparatus illustrated in  FIG. 1 ; and 
           [0034]      FIG. 3  is a diagrammatic view of the hydraulics system of the post driving apparatus illustrated in  FIG. 1 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0035]    Turning now to the drawings and, more particularly, to  FIG. 1  a self-propelled post driver is illustrated generally at  10  and includes a generally skeletal frame structure  12  for supporting the various systems as will be explained in greater detail hereinafter. The frame  12  is ground supported by spaced, opposing left and right wheels  14 ,  16  as seen in  FIG. 2 . Further, a caster  18  is mounted to the frame  12  at a spaced relationship from both the left wheel  14  and the right wheel  16 . The caster  18  along with the wheels  14  and  16  provide a 3-point stance and a balanced structure for the post driver  10  of the present invention. 
         [0036]    A ram assembly  20  is provided for final positioning and driving a positioned post into the ground. The ram assembly  20  is mounted to the frame and includes an upright ram support  22  and a generally rectangular ramming head  24  which is configured for generally vertical movement along the ram support  22  as will be seen in greater detail hereinafter. The ramming head  24  is formed as a generally hollow body with a rectangular cross section that is fitted around the ram support  22  for telescoping movement therealong. A pair of gripping members  28  is pivotably mounted to the ram support  22  for operator-controlled movement toward and away from one another. The gripping members  28  are intended to guide and position a post for ground insertion by the ramming assembly  20 . A ramming surface  26  is mounted to the ramming head  24  for movement therewith for repeatedly ramming a fence post to drive the fence post into the ground at a predetermined location under the control of an operator. 
         [0037]    In order to enhance the precision with which the present apparatus can position itself for post-driving, the ram assembly  20  is laterally, reciprocally extendable, toward and away from the frame  12 . With reference to  FIG. 2 , a horizontal drive member  42  is mounted to the ram support  22  and projects laterally away therefrom. The drive member  42  projects away from a rear portion of the ram support  22 . The drive member  42  is fitted within a linear drive receiver  44  for telescoping movement in a reciprocating manner to allow the ram assembly  20  to be extended laterally away from the apparatus  10  for positioning the ram surface  26  over a post location, and back toward the apparatus for travel. 
         [0038]    As stated earlier herein, the present apparatus  10  is self-propelled and in that regard, includes a propulsion system. The primary operational system of the present apparatus  10  is a hydraulic system which will be discussed in greater detail hereinafter. The hydraulic system is configured for providing and controlling the propulsion, steering, positioning and ramming operation of the present apparatus  10 . The propulsion system includes a gasoline motor  30  on order of a large lawn tractor motor. The gasoline motor  30  is mechanically linked to a hydraulic compressor  32  which in turn is linked hydraulically and operatively to a control box  34 . For propulsion, the present invention includes a pair of hydraulic motors  46 ,  48  attached individually to the left wheel  14  and the right wheel  16  respectively. The hydraulic motors  46 ,  48  are individually operable or they may be simultaneously operated. 
         [0039]    In order to provide a zero turning radius and the enhanced positioning ability of the present invention, and as stated above, the wheels  14 ,  16  are individually drivable by hydraulic motors  46 ,  48 . By driving one wheel faster than the other wheel, steering can be accomplished. For example, if the left wheel  14  is driven clockwise, while the right wheel  16  is held stationery, the apparatus  10  will pivot about the right wheel  16 , steering to the right, causing the apparatus to pivot about a central axis toward the operator. In other words, the apparatus will tend to move counterclockwise when viewed from above about its own central axis. 
         [0040]    Similarly, if the right wheel  16  is held stationery and the left wheel  14  is driven counterclockwise, the turn will be to the right except the apparatus  10  will tend to pivot in a clockwise manner about its central axis when viewed from above. If both wheels are driven in opposite directions, i.e. the left wheel is driven counterclockwise and the right wheel is driven clockwise at the same speed, the apparatus will spin in place about its central axis. Direction of the spin is dependent on the respective directions of rotation of the left wheel  14  and the right wheel  16 . When positioning the apparatus, the operator can use controls  36  to throttle the wheels individually or can drive the wheels simultaneously for straight line movement along the fence line. For more precision movement, throttling the wheels individually can move the apparatus through a series of curves of increasing, decreasing or constant radius in order to position the ram surface  26  over the intended post location. The zero turning radius aspect of the present invention provides the operator with precision control to quickly and accurately position the ram  26  over the intended fence post location. 
         [0041]    With reference to  FIGS. 2 and 3 , the present post driving apparatus  10  is configured for towing by a tractor, truck or other towing vehicle, reducing the need to load the post driving apparatus  10  onto a carrying vehicle. With reference to  FIGS. 2 and 3 , each hydraulic motor  46 ,  48  is connected to its respective driving wheel  14 ,  16  by an assembly for selectively engaging and disengaging each driving wheel from its respective hydraulic motor. The engaging and disengaging assembly includes a manual clutch  62 ,  64  operatively associated with each hydraulic motor  46 ,  48  and each driving wheel  14 ,  16 . Each clutch includes a manually operative engagement/disengagement handle  66 ,  68 . By disengaging the driving wheels  14 ,  16  from their respective hydraulic motor  46 ,  48 , the post driving apparatus can move about under a free-rolling condition for towing from one job site to another, for example. Although a clutch is preferred at each wheel with manual operation, it is well within the scope and spirit of the invention to use other means for engaging and disengaging the driving wheels  14 ,  16  form the hydraulic motors  46 ,  48  for free-wheeling operation. 
         [0042]    Turning now to  FIG. 3 , a diagrammatic representation of the hydraulic system of the present driver apparatus  10  is illustrated. It should be noted that while a hydraulic system is referred, the present invention can be assembled and function with a pneumatic system, or with electrical drive. With continued reference to  FIG. 3 , the hydraulic system includes a motor  30  in mechanical operative association with a compressor  32  that provides the hydraulic fluid for the system. Conventional hydraulic tubing  52  transmits the hydraulic working fluid to a control box  34  for distribution to various hydraulic utilities. Conventional hydraulic tubing  54  transmits working fluid to the ram assembly  20  for movement of the ram head  24  in a reciprocating ramming manner. 
         [0043]    The working fluid also is used to operate the grips  28  and the ram extender  40  as seen in  FIG. 2 . The control box  34  also distributes working fluid to the individual hydraulic motors  46 ,  48  through conventional hydraulic tubing  56 ,  58  respectively. The hydraulic motors  46 ,  48  are used to individually drive the wheels  14 ,  16  in a manner that allows a zero turning radius as discussed above. A group of control rods  36  or other control elements is provided at the control box  34  so that an operator can effectively operate the apparatus  10  in a manner to be described hereinafter. Notably, there are enough controls to individually extend the ram, grip a post, and cause reciprocating motion of the ram to drive the post. Further, there are sufficient controls to allow for individual left wheel  14  and right wheel  16  operation as well as simultaneous wheel operation. As shown, the controls are illustrated as moveable rods which will operate selectively operable valves to route the hydraulic fluid where it needs to go for the chosen operation. It should also be understood that other valve operators may be provided to create the necessary valve lineup to perform the desired function. 
         [0044]    In operation and according to the method of the present invention, the present post driving apparatus  10  is provided with a series of fence posts P in the hopper  38  for use as the fence is constructed or mended. One of the advantages of the present invention is that one person can move a load of fence posts along a fence line and plant each post where it needs to be without further assistance. To that end, the operator engages the controls  36  to cause the apparatus  10  to move under its own power by applying working fluid in a controlled manner to the individual hydraulic motors  46 ,  48 . If working fluid is applied simultaneously to both motors, they respond simultaneously and the apparatus  10  tracks a straight line. If one or the other wheels is sped up or slowed down or even caused to stop, the apparatus  10  will be steered in a direction in accordance with the stopped wheel. For example, if the operator stops the right wheel  16 , while the left wheel  14  is allowed to operate, the device will be steered to the right and if the right wheel  16  is completely stopped, the apparatus  10  will essentially pivot on the stopped wheel to make a 90-degree right turn. If the left wheel  14  is stopped, the apparatus may be pivoted on that wheel by propelling the right wheel  16  and a 90-degree left turn is executed. If one wheel is driven clockwise and the other wheel is driven counter-clockwise, the device  10  will pivot about a central axis. With experimentation and practice, an operator can achieve precise positioning of the apparatus  10  with respect to the ramming surface  26  and a desired fence location. It may be useful for the operator to put a small stake in the ground where the fence post should go and use the stake as a reference point for positioning the apparatus  10  using the controls  36  and individually selectively driving the wheels  14 ,  16  until proper positioning has been achieved. 
         [0045]    Once the apparatus  10  has been positioned, the operator selects a post P, removes the stake from the ground and positions the post P where the stake used to be and, at this point, the operator may use the controls  36  to maneuver the grips  28  into position to stabilize the post P during driving operation. Once the post P is positioned and stabilized, the operator uses the controls  36  to cause reciprocating movement of the ram head  24  to thereby cause the ram surface  26  to drive the post into the ground at the desired location. Once the post is in position, the operator uses the controls  36  to retract the ram from its extended position and to place the ram in a traveling position. Once this is achieved, the operator can cause the wheels  14 ,  16  to move simultaneously to cause the apparatus  10  to travel along the fence line to the next driving post-driving location. 
         [0046]    By the above, the present invention provides a post-driving apparatus that can be precisely and effectively positioned for driving a post into the ground at a desired location and is configured for use by a single operator. Accordingly, the process of installing fence along a fence line can be greatly shortened and performed with greater efficiency. 
         [0047]    It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. While the present invention is described in all currently foreseeable embodiments, there may be other, unforeseeable embodiments and adaptations of the present invention, as well as variations, modifications and equivalent arrangements, that do not depart from the substance or scope of the present invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.