Patent Publication Number: US-11643839-B2

Title: Systems and methods for pulling and installing posts

Description:
TECHNICAL FIELD 
     The present disclosure relates to systems and methods for pulling and installing posts, and more specifically to highway guardrail posts. 
     BACKGROUND INFORMATION 
     Various problems are associated with known post pullers. For example, the post puller described in U.S. Pat. No. 6,398,188 requires a large operating space around the post to accommodate a base and two lateral hydraulic cylinders. This post puller also involves a large number of components, thus increasing complexity, risk of failure, and cost. 
     SUMMARY 
     A system for pulling posts comprises a mast extending along a direction having a vertical component, an elongated arm rotatably and pivotably supported by the mast and extending at an angle relative to the mast, a pusher with first and second opposite ends, the first end of the pusher being configured to support the elongated arm at a first location of the elongated arm, and the second end of the pusher being configured to contact a ground surface, the pusher being configured to increase in length to drive the first location of the elongated arm away from a ground surface and thereby change the angle relative to the mast, and a pole attachment site at a second location of the elongated arm. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages disclosed herein will become more apparent from the following detailed description of exemplary embodiments when read in conjunction with the attached drawings. 
         FIG.  1    shows a side view of an exemplary embodiment of a system for pulling and installing posts. 
         FIG.  2    shows a perspective view of the exemplary embodiment of a system for pulling and installing posts. 
         FIG.  3    shows a perspective view of the exemplary embodiment of a system for pulling and installing posts. 
         FIG.  4    shows an exploded view of a portion of the exemplary embodiment of a system for pulling and installing posts. 
         FIG.  5    shows a side view of a portion of the exemplary embodiment of a system for pulling and installing posts. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS.  1 - 5    show an exemplary embodiment of a post pulling and installing system  300 . However, the present invention is not limited to the details of the exemplary embodiment. 
     The system  300  includes, in the embodiment, a pulling mechanism  100  for pulling posts, mounted to a trailer  200 . The pulling mechanism  100  comprises a mast  110 , an elongated arm  120 , and a pusher  130  (in the embodiment, a hydraulic cylinder). The mast  110  is fixed to the trailer  200 , for example, by bolting or other suitable means for handling mechanical stresses associated with pulling and/or installing posts. The mast  110  extends in the vertical direction in the embodiment, but can extend in a direction having a horizontal component and a vertical component in alternative embodiments. The elongated arm  120  is rotatably and pivotably supported by the mast  110  and extending at an angle relative to the mast  110 . 
     As shown in more detail in  FIGS.  4  and  5   , the pusher  130  of the pulling mechanism  100  includes first and second opposite ends  132 ,  134 . The first end  132  of the pusher  130  is configured to support the elongated arm  120  at a first location  122  of the elongated arm  120 , and the second end  134  of the pusher  130  is configured to contact a ground surface (e.g., the ground close the location of the post to be pulled and/or installed). The pusher  130  is configured to increase in length to drive the first location  122  of the elongated arm  120  away from a ground surface and thereby change the angle relative to the mast. 
     In the exemplary embodiment, the rotational support of the elongated arm  120  by the mast  110  is provided by being mounted to a beam  175  which is configured to rotate around the mast  110  without moving axially relative to the mast  110 . In particular, in the exemplary embodiment, the beam  175  is fixed, such as by welding, between bushings  170  and  172  that extend at least partially around the mast  110  and are configured to rotate around the mast  110  without moving axially relative to the mast  110 . 
     The elongated arm  120  can be configured to be hand-powered to rotate around the mast  110 , or to be driven by a motor to rotate around the mast  110 . Such a motor can be electrically powered, hydraulically powered, pneumatically powered, gas powered, or powered in any other suitable manner known in the art. In the exemplary embodiment, a hydraulic motor  121  is configured to rotate the elongated arm  120 . In particular, a gear fixed to the output shaft of the hydraulic motor  121  meshes with a gear  123  fixed to the bushing  170 /bushing  172 /beam  175  assembly, so that actuation of the hydraulic motor  121  in a forward or reverse direction will cause the gear  123 , along with the bushing  170 /bushing  172 /beam  175  assembly and the elongated arm  120 , to rotate in a clockwise or counterclockwise direction. Alternatively, the gear  123  can be fixed to the mast  110  and the hydraulic motor  121  configured to rotate with the bushing  170 /bushing  172 /beam  175  assembly, so that actuation of the hydraulic motor  121  in a forward or reverse direction will cause the hydraulic motor  121 , along with the bushing  170 /bushing  172 /beam  175  assembly and the elongated arm  120 , to rotate in a clockwise or counterclockwise direction. 
     In the exemplary embodiment, the pivotable support of the elongated arm  120  is provided by a hinge mechanism  171 , by which the elongated arm  120  is mounted to the beam  175 , and which is configured to allow the angle of the elongated arm  120  relative to the mast  110  to vary. In the exemplary embodiment, a hydraulic cylinder  150  is configured to pivot the elongated arm  120  relative to the mast  110 . The hydraulic cylinder  150  in the embodiment is mounted at one end, by a hinge mechanism  173 , to the beam  175 , and at the other end to the elongated arm  120  by a hinge mechanism  174 . The hydraulic cylinder  150  therefore rotates with the elongated arm  120  about the mast  110  as the structure including the beam  175  and bushings  170  and  172  is rotated about the mast  110 . The elongated arm  120  and hydraulic cylinder  150  can alternatively be rotatably supported about the mast by roller bearings or other types of bearings. Furthermore, instead of the hydraulic cylinder  150 , the elongated arm  120  can be configured to be hand-powered to pivot relative to the mast  110 , or to be driven by a motor to pivot relative to the mast  110 . Such a motor can be electrically powered, hydraulically powered, pneumatically powered, gas powered, or powered in any other suitable manner known in the art. 
     Furthermore, a pole attachment site  140  is provided at a second location  124  of the elongated arm  120 . In the exemplary embodiment, the pusher  130  is a hydraulic cylinder. The pusher  130  can be hinged to the elongated arm  120  at the first location  122 . The second end  134  of the pusher  130  can include a plate  136  configured to contact a ground surface or any other surface against which the pusher  130  is arranged to push. The plate  136  can be pivotably fixed to other portions of the pusher  130 , for example by a hinge as shown in the exemplary embodiment, or by a universal joint or a ball joint. 
     In the exemplary embodiment, the pole attachment site  140  includes one or more openings, and a chain  160  is coupled to the pole attachment site  140 . In the exemplary embodiment, the chain  160  is a grade  100  chain, which may be more suitable for pulling highway guardrail posts. Alternatively, the chain  160  can be a grade  70  chain, or other grades of chains, depending on the application. The chain  160  is configured to be wrapped around a post. During operation of the pulling mechanism  100 , as the pusher  130  increases the distance between the first and second ends  132 ,  134  of the pusher  130  and the elongated arm  120  is thereby pivotably raised, friction between the chain  160  and the post causes pulling of the post relative to a ground surface or other pushing surface. The pole attachment site  140  can be alternatively fitted with any other pole attachment/coupling mechanism, including mechanical arms such as cam pinchers and scissor pinchers, etc. Other connection devices could include cable, rope, sling or mechanical linkage such as a bar with socket ends to allow for movement. Chain allows reasonable freedom of movement along with relative high strength and abrasion resistance. Cable could also be used while maintaining strength and some abrasion resistance, although at somewhat of a loss of freedom of motion. Likewise, a rope or sling could be used with excellent freedom of movement, but a loss of abrasion resistance and strength. Lastly, a mechanical arm provides excellent strength and abrasion resistance, but would require the pole attachment site  140  to be more precisely located relative to the post. The mass of the trailer  200  to which the pulling mechanism  100  is fixed supports the mast  110  against reactive movement due to the forces from the elongated arm  120  as the post is extracted from the ground. 
     In the exemplary embodiment, the first location  122  is closer to the mast  110  than is the second location  124 , to allow for a greater vertical range of the post attachment site  140 . In the exemplary embodiment, the chain  160  can be selectively coupled to any of the one or more openings of the post attachment site  140  to vary the pulling power and/or the vertical range of the chain  160 . In other exemplary embodiments, the second location  124  is closer to the mast  110  than is the first location  122 , to provide greater torque. 
     In the exemplary embodiment, as discussed above, the pulling mechanism  100  is mounted to a trailer  200 , with the mast  110  of the pulling mechanism  100  being fixed to the trailer  200 . Fixing the pulling mechanism  100  to a trailer  200  may be advantageous over fixing the pulling mechanism  100  to a truck, as a trailer  200  can allow for a setup which is lower to the ground. However, the pulling mechanism  100  can be mounted to a truck in alternative embodiments. 
     In the exemplary embodiment, the system  300  further includes an installing mechanism  400  for installing posts which includes a second elongated arm  310  rotatably and pivotably supported by the mast  110  and extending at a second angle relative to the mast. Alternatively, the second elongated arm  310  is rotatably and pivotably supported by a second mast (not shown) separate from the mast  110 . The installing mechanism  400  of the exemplary embodiment also includes a hydraulic cylinder  320 , an extender  330 , and a post driver  220 . 
     In the exemplary embodiment, the second elongated arm  310  is rotatably supported by the mast  110  by being mounted to a beam  185  which is configured to rotate around the mast  110  in the same manner as the beam  175 . In particular, in the exemplary embodiment, the beam  185  is fixed, such as by welding, between bushings  180  and  182  that extend at least partially around the mast  110  and are configured to rotate around the mast  110  without moving axially relative to the mast  110 . In the exemplary embodiment, the beam  185  is provided higher on the mast  110  than the beam  175 . 
     The second elongated arm  310  can be configured to be hand-powered to rotate around the mast  110 , or to be driven by a motor to rotate around the mast  110 . The motor can be electrically powered, hydraulically powered, pneumatically powered, gas powered, or powered in any other suitable manner known in the art. In the exemplary embodiment, a hydraulic motor  125  is configured to rotate the second elongated arm  310 . In particular, in the embodiment, a gear fixed to the output shaft of the hydraulic motor  125  meshes with a gear  127  fixed to the mast  110 . The hydraulic motor  125  is configured to rotate with the bushing  180 /bushing  182 /beam  185  assembly, so that actuation of the hydraulic motor  125  in a forward or reverse direction will cause the hydraulic motor  125 , the bushing  180 /bushing  182 /beam  185  assembly and the second elongated arm  310 , to rotate in a clockwise or counterclockwise direction. Alternatively, the gear  127  can be fixed to the bushing  180 /bushing  182 /beam  185  assembly and the hydraulic motor  125  fixed to the mast  110 , so that actuation of the hydraulic motor  125  in a forward or reverse direction will cause the gear  127 , along with the bushing  180 /bushing  182 /beam  185  assembly and the second elongated arm  310 , to rotate in a clockwise or counterclockwise direction. 
     In the exemplary embodiment, the second elongated arm  310  is pivotably supported by a hinge mechanism  181 , by which the second elongated arm  310  is mounted to the beam  185 , and which is configured to allow the second angle of the elongated arm  310  to vary relative to the mast  110 . In the exemplary embodiment, a hydraulic cylinder  320  is configured to pivot the second elongated arm  310  relative to the mast  110 . The hydraulic cylinder  320  in the embodiment is mounted at one end, by a hinge mechanism  183 , to the beam  185 , and at the other end to the elongated arm  310  by a hinge mechanism  184 . The hydraulic cylinder  320  therefore rotates with the second elongated arm  310  about the mast  110  as the structure including the beam  185  and bushings  180  and  182  is rotated about the mast  110 . The second elongated arm  310  and hydraulic cylinder  320  can alternatively be rotatably supported about the mast by roller bearings or other types of bearings. Furthermore, instead of the hydraulic cylinder  320 , the second elongated arm  310  can be configured to be hand-powered to pivot relative to the mast  110 , or to be driven by a motor to pivot relative to the mast  110 . Such a motor can be electrically powered, hydraulically powered, pneumatically powered, gas powered, or powered in any other suitable manner known in the art 
     In the exemplary embodiment, the post driver  220  is a compressed air operated post driver unit mounted to the second elongated arm  310 . In the exemplary embodiment, the post pulling and installing system  300  further comprises an extender  330  (in the embodiment, a hydraulic cylinder) configured to extend the second elongated arm  310  as the post driver  220  hammers a post during installation, thereby extending the range at which the post driver  220  can be positioned away from the trailer  200 . 
     In the exemplary embodiment, the trailer  200  includes support posts  230  configured to secure the elongated arms  120  and  310  during transport of the trailer  200 . 
     In an exemplary embodiment, the trailer  200  includes a hydraulic pump configured to power any or all of the hydraulic cylinders of the post pulling and installing system  300 . In the exemplary embodiment, a valve assembly  128  mounted to the housing of the hydraulic pump can selectively supply hydraulic positive or negative pressure to the hydraulic cylinders and hydraulic motors of the system. The trailer  200  can also include an electrical battery configured to power any or all of the electric motors of the post pulling and installing system  300 , a combustion engine configured to power any or all driving systems of the post pulling and installing system  300 , and/or a pneumatic pump configured to power any or all pneumatic cylinders of the post pulling and installing system  300 , including the post driver  220 , which can be advantageously a pneumatic hammer having a pneumatically driven hammer inside a relatively heavy (e.g. over 100 lbs.) housing to keep the hammer positioned on a post during the hammering operation. The post driver  220  can be a commercially available pneumatic hammer such as the Rhino air driver PD-140 manufactured by Rhino Tool Company, Kewanee, Ill., USA (shown). 
     It will be appreciated by those skilled in the art that the disclosure herein can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently-disclosed embodiments are therefore considered in all respects to be exemplary and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.