Patent Publication Number: US-9416514-B2

Title: Post driver with limited movement floating post anvil

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     No related application. 
     BACKGROUND OF THE DISCLOSURE 
     1. Field of Disclosure 
     This disclosure relates generally to a post driver with a floating post anvil, and more particularly, to a post driver with a floating post anvil that has limited movement to facilitate ease of operation and maximize the amount of available energy to be applied to the post driving process. 
     2. Background Art 
     Post Drivers that utilize the pile driving principle of raising a weight to some distance above a post and then dropping the weight in order to drive the post rely heavily upon the skill of the operator to properly position the post driver at the correct height before every cycle of the driver. Such post drivers rely on a post being present to dissipate the energy of the falling weight. When a post is properly positioned within the post driver, the kinetic energy of the falling weight is transferred into the post, pushing it into the ground. However, when a post is not properly positioned within the post driver, the weight may fail to contact the post upon falling, and may instead impact upon the frame of the post driver. Such a so-called “dry fire” can damage the post driver apparatus. 
     Many post drivers all work on the pile driving principle of raising a weight to some distance above a post and then dropping the weight in order to drive the post. Some such drivers utilize a floating post anvil that rests on the top of the post and is allowed to move up or down in relation to the vertical position of the driver. The anvil is designed to protect the post so that the post is not damaged by the falling weight. Generally, the post is positioned within the post driver such that the anvil rests on top of the post. When the weight falls, it impacts the anvil rather than directly striking the post. The kinetic energy is still transferred into the post, pushing it into the ground, but through the intermediary of the anvil so as to protect the post. This type of design relies heavily upon the skill of the operator to properly position the post driver at the correct height. If the driver is positioned too high and the anvil is not in contact with the post and/or is already resting at the bottom of the post driver frame, a dry firing situation may occur, causing damage to the driver. If the driver is positioned too low such that the post extends too far up into the post driver, the overall driving performance is diminished due to the shorter stroke length. 
     Further, during the operation of the post driver, the operator must lower the driver as the post is driven into the ground in order to prevent dry firing of the driver. This lowering of the driver can be a difficult process depending upon the skill of the operator thus increasing the time required to drive a post. It is common for the driver to be lowered too far which greatly reduces the performance of the driver due to the shorter distance the weight is dropped. Thus, a driver with limited movement floating post anvil would solve these issues. 
     BRIEF SUMMARY OF DISCLOSURE 
     The post driver with limited movement floating post anvil does not rely heavily upon the skill of the operator to efficiently drive posts. The post anvil is allowed to move up and down in relation to the driver, but its movement is limited by both lower and upper fixed barriers. Since the movement is limited, the operator can position the driver upon the post allowing the full weight of the driver framework/carrier machine to rest upon the post. The post would push the floating post anvil upward only to the point at which the upper fixed barrier prevents further upward movement of the floating post anvil. Thus, once the floating post anvil abuts the upper fixed barrier, substantially the entire weight of the post driver is resting on the post. This added weight put on the post increases driving force and prevents the post from “walking” around during driving. Due to the limited movement of the post anvil, the operator can place the carrier machine into the hydraulic float position and the driver will follow the post as it is driven into the ground without the operator needing to lower the driver to prevent dry firing. The limited movement of the post anvil also allows the weight to be dropped the maximum allowable distance every cycle thus maximizing the post driver&#39;s performance. 
     Accordingly, an aspect of the present disclosure is a post driver comprising a weight with a protrusion member, a fixed upper barrier with an opening for the protrusion member of the weight, a floating anvil that sits on a post, wherein movement of the floating anvil is limited, and a fixed lower barrier with an aperture for an insertion of the post. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
       For a better understanding of the present disclosure, reference may be made to the accompanying drawings in which: 
         FIG. 1  is an illustration of a post driver mounted in front of a mobile vehicle or equipment, such as a skid-steer, 
         FIG. 2  is a front-side illustration of a post driver, 
         FIG. 3  is an oblique illustration of a post driver. 
         FIG. 4  is an illustration of a post driver with a floating anvil of limited movement. 
     
    
    
     While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawing and will herein be described in detail. It should be understood, however, that the drawings and detailed description presented herein are not intended to limit the disclosure to the particular embodiment disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims. 
     DETAILED DESCRIPTIONS OF THE DISCLOSURE 
     Referring to  FIG. 1 , an embodiment of the present post driver  1  is shown as connected to a skid-steer loader  2 , in position to drive a post  3  into the ground. Post driver  1  may instead be adapted for attachment to and operation via a front-end loader or any other suitable vehicle. As shown in  FIG. 2 , post driver  1  includes an outer housing  5  which contains the internal workings of the post driver  1 . 
     As shown in  FIG. 3 , the internal workings of post driver  1  include a weight (or hammer)  10  with a protrusion member  12  extending from the bottom thereof. The weight  10  and protrusion member  12  are preferably comprised of a heavy, durable material as would be known to one of ordinary skill in the art. Below the weight  10  is positioned a fixed upper barrier  14  which includes a through hole  16 . Hole  16  is sized and shaped to allow the protrusion member  12  of the weight  10  to pass therethrough when the weight  10  is allowed to fall for each stroke of the post driver  1 . Preferably, the protrusion member  12  is long enough to impact substantially all of the kinetic energy from the falling weight  10  into the post  3  before the weight  10  impacts the fixed upper barrier  14 . 
     Residing below the fixed upper barrier  14  and within a guide  18  is a floating anvil  20 . Floating anvil  20  is designed to be positioned between the weight  10  and the post  3  during operation of the post driver  1 . When the weight  10  falls, the protrusion member  12  falls through the hole  16  in fixed upper barrier  14 , and strikes the floating anvil  20 . In normal operation, floating anvil  20  would be positioned so as to rest on top of a post  3 , such that the kinetic energy from the weight  10  and protrusion member  12  pass through the floating anvil  20  and into the post  3 . This protects the post  3  from damage from the falling weight  10 , but still drives the post  3  into the ground. For this reason, floating anvil  20  is preferably comprised of a durable material as would be known to one of ordinary skill in the art. In other embodiments, the weight  10  need not include a protrusion member  12 , and the hole  16  in the fixed upper barrier  14  may simply be sized to allow the striking end of the weight  10  to directly impact the floating anvil  20  therebelow. 
     As noted above, floating anvil  20  is positioned within guide  18 , and is bounded on the top by the fixed upper barrier  14 . Floating anvil  20  is also bounded on the bottom by fixed lower barrier  22 , visible in the cross-sectional view of  FIG. 4 . Thus, although floating anvil  20  is allowed to float, its movement is constrained on at least the top and bottom by the fixed upper and lower barriers  14 ,  22 . Preferably, the floating anvil  20  is also constrained against lateral movement by guide  18 . The floating anvil  20 , guide  18  and fixed upper and lower barriers  14 ,  22  form the limited anvil movement portion of the post driver  1 . 
     In operation, the floating anvil  20  initially rests on the fixed lower barrier  22  when no post  3  is within the post driver  3 . An operator places the post driver  1  over the top of a post  3 , such that the top of the post  3  enters the post driver  1  via the fixed lower barrier  22 . As the post  3  enters the post driver  1 , it encounters the floating anvil  20 , pushing the floating anvil  20  up. At this point in the process, the lowering of the post driver  1  has applied little weight to the post  3  itself, as there is little resistance to the post  3  pushing the floating anvil  20  upwardly as the post  3  enters the post driver  1 . However, eventually, the floating anvil  20  moves upward to the point that it contacts the fixed upper barrier  14 , at which point further upward movement of the floating anvil  20  is prevented by the fixed upper barrier  14 . 
     Once the floating anvil  20  is pressed upwardly against the fixed upper barrier  14 , any additional lowering of the post driver  1  applies additional weight on top of the post  3 . The weight of the post driver  1  is now resting on top of post  3 , through the floating anvil  20  and fixed upper barrier  14 . This additional weight helps to drive the post  3  into the ground, and can help to keep the post  3  from “walking” or moving during the driving process. 
     Once the post driver  1  is properly positioned over the post  3  so as to press the floating anvil  20  into the fixed upper barrier  14 , the weight  10  is dropped. The protrusion member  12  passes through the hole  16  in the fixed upper barrier  14  and impacts the floating anvil  20 , which impacts the force of the falling weight  10  into the post  3 , beginning to drive the post into the ground. The weight  10  is then lifted up again to prepare for another stroke of the post driver  1 . At this point, the post  3  has been driven partially into the ground, such that it no longer extends as far up into the post driver  1  and no longer presses the floating anvil  20  into the fixed upper barrier  14 . An operator therefore must lower the post driver  1 , as before, until the top of the post  3  again presses the floating anvil  20  up into contact with the fixed upper barrier  14 , so that another stroke can occur and the process can be repeated until the post  3  is sufficiently driven into the ground. In one embodiment, the operator may place the skid-steer  2  or other carrier machine into a “hydraulic float” position, in which the post driver  1  will follow the post  3  into the ground, keeping the floating anvil  20  pressed against the fixed upper barrier  14  through the process. 
     The fixed upper barrier  14  thereby prevents an operator from lowering the post driver  1  too far over a post  3 , and thereby prevents inefficient short strokes of the weight  10 . Additionally, the operator is no longer forced to guess when the post driver  1  has been lowered over the post  3  enough to prevent a dry-fire. Instead, the operator needs only to lower the post driver  1  over the post  3  until the post  3  presses the floating anvil  20  into the fixed upper barrier  14 , which signals to the operator that additional lowering is unnecessary. In fact, the operator will be unable to lower the post driver  1  any farther, and attempts to lower the post driver  1  any farther will simply exert beneficial weight onto the top of the post. The fixed upper barrier  14  also assists with subsequent strokes of the weight  1 , as the operator can merely continue to lower the post driver  1  so that it comes to rest on the top of the post  3  after each stroke, taking much of the difficulty out of driving posts. The post driver  1  can be lowered only to the point of a proper weight strike, and the lowering of the post driver  1  to that point is clearly indicated to the operator by the failure of the post driver  1  to lower any farther. 
     In one embodiment, the vertical position of the fixed upper and/or lower barriers  14 ,  22  may be adjustable. Similarly, the fixed upper and/or lower barriers  14 ,  22  may be replaceable with fixed barriers  14 ,  22  having differently sized thicknesses and/or through-holes  16  for differently sized weights  10  and/or protrusion members  12 . The protrusion member  12  may also be replaceable bottom of weight  10 . 
     As is evident from the foregoing description, certain aspects of the present disclosure are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. It is accordingly intended that the claims shall cover all such modifications and applications that do not depart from the spirit and scope of the present disclosure. Moreover, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure belongs. Although any methods and materials similar to or equivalent to or those described herein can be used in the practice or testing of the present disclosure, the preferred methods and materials are described above. Other aspects, objects and advantages of the present disclosure can be obtained from a study of the drawings, the disclosure and the appended claims.