Abstract:
An apparatus and methods for limiting the return stroke and modifying the extension stroke of a log splitter. A control rod is translated in the direction of the return stroke of the log splitter. An effort end of a trip arm coupled to the control rod is moved in the direction of the translation and a load end of the trip arm is moved in the opposite direction. The rotation of the load end causes a control lever of the log splitter to move from its rearward position to an intermediate position thereby stopping the return stroke.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/148,374, filed Apr. 16, 2015, the entire contents of which are hereby incorporated by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    This disclosure relates to powered log splitters, and more particularly, to an adjustable return stroke limiter for a powered log splitter. 
       BACKGROUND 
       [0003]    Powered log splitters are used to save time and labor in performing a longitudinal splitting operation on a log. Many of these log splitters include a frame supporting a splitting assembly with a wedge and a footplate, and a ram assembly that actuates the splitting assembly. 
         [0004]    The ram assembly typically includes a double acting linear actuator fixed to the frame, and a manually operated control lever operatively coupled to the linear actuator to activate its extension stroke and return stroke. Either the wedge or the footplate is fixed to the linear actuator, and the other of the wedge and the footplate is fixed, in opposition, to the frame. With the linear actuator having previously completed a return stroke, the wedge and the footplate are in an open configuration accommodating the placement of a longitudinally oriented log between them. Then, an extension stroke and a return stroke of the linear actuator together correspond to a work cycle for the log splitter. During the extension stroke, a longitudinal splitting operation is performed on the log. At the end of the return stroke, the wedge and the footplate are once again left in an open configuration accommodating the removal of the split log and the placement of another longitudinally oriented log between them. 
         [0005]    In the typical log splitter, the stroke of the linear actuator is long enough to allow for the open configuration of the wedge and the footplate to accommodate the placement of longer length, longitudinally oriented logs between them. However, for shorter length logs, the full stroke of the linear actuator is unnecessary. 
       SUMMARY 
       [0006]    Disclosed herein are methods and apparatuses for limiting the return stroke of a log splitter. 
         [0007]    One aspect of the disclosed embodiments is a stroke-limiting apparatus for a log splitter, including a trip arm with a load end and an effort end, wherein rotation of the load end causes movement of a control lever of the log splitter, wherein the control lever has a forward position activating an extension stroke of the log splitter, a rearward position activating a return stroke of the log splitter, and an intermediate position stopping the extension stroke or the return stroke. The apparatus also includes a control rod coupled to the effort end of the trip arm, the control rod including a first rod end, wherein translation of the first rod end causes the effort end of the trip arm to move in a direction of the translation and causes the load end of the trip arm to move in a direction opposite the direction of the translation, and wherein movement of the load end of the trip arm in the direction opposite the direction of the translation during the return stroke causes the control lever to move from the rearward position to the intermediate position. 
         [0008]    Another aspect is a method for limiting the return stroke of a log splitter, including: using a wedge of the log splitter, engaging a push block coupled to a first end of a control rod to translate the first end of the control rod in a direction of the return stroke; using the translation of the first end of the control rod rotating an effort end of a trip arm coupled to the control rod in a direction of the translation; using the rotation of the effort end of the trip arm, rotating a load end of the trip arm in a direction opposite the translation to move the trip arm to a trip position; and using the rotation of the load end of the trip arm, moving a control lever of the log splitter from a rearward position to an intermediate position to limit a length of the return stroke of the log splitter. 
         [0009]    Another aspect is a method for modifying an extension stroke of a log splitter, including: in response to a control lever of the log splitter moving to a forward position, disengaging a push block connected to a first end of a control rod in a stroke-limiting apparatus from a wedge of the log splitter, wherein disengaging the push block causes the first end of the control rod to translate in the direction of the extension stroke and the log splitter to perform the extension stroke; using the translation of the first end of the control rod, rotating an effort end of a trip arm of the stoke-limiting apparatus in the direction of the translation; and using the rotation of the effort end of the trip arm, rotating a load end of the trip arm in a direction opposite the translation to move the trip arm to a clear position, wherein the clear position allows the control lever to move to a rearward position activating a return stroke and an intermediate position stopping the return stroke or the extension stroke. 
         [0010]    These and other aspects will be disclosed in additional detail below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The various features, advantages and other uses of the present apparatus will become more apparent by referring to the following detailed description and drawings in which like reference numbers refer to like elements. 
           [0012]      FIG. 1  is a perspective view of a powered log splitter including a frame, a double acting linear actuator fixed to the frame, a wedge fixed to the linear actuator, a footplate fixed to the frame in opposition to the wedge and a manually operated control lever operatively coupled to the linear actuator to activate and deactivate its extension stroke and its return stroke. 
           [0013]      FIGS. 2A-D  include perspective views of the log splitter, showing the operation of the control lever and the corresponding activation and deactivation of the linear actuator&#39;s extension stroke and return stroke. 
           [0014]      FIG. 3A  is a perspective view of an example of an adjustable return stroke limiter that is configured for installation to the log splitter, and that includes a mounting bracket supporting a trip arm for operating the control lever to deactivate the linear actuator&#39;s return stroke, and a control rod for actuating the trip arm in response to the linear actuator. 
           [0015]      FIG. 3B  is a perspective view of an example of an adjustable return stroke limiter installed to the log splitter. 
           [0016]      FIGS. 4A-C  include perspective views of the return stroke limiter installed to the log splitter, showing the operation of the return stroke limiter during the commencement of an extension stroke at the beginning of the log splitter&#39;s work cycle. 
           [0017]      FIGS. 5A-5C  include additional perspective views of the return stroke limiter installed to the log splitter, showing the operation of the return stroke limiter to deactivate a return stroke before its otherwise normal completion and thereby end the log splitter&#39;s work cycle. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    An example of an accessory for a powered log splitter is described below that limits a linear actuator&#39;s return stroke by deactivating the return stroke before its otherwise normal completion. 
         [0019]    An example of a typical powered log splitter  10  is shown in  FIG. 1 . The log splitter  10  includes an elongate frame  12  that supports a splitting assembly  20  and a ram assembly  30 . 
         [0020]    In the illustrated example of the log splitter  10 , the frame  12  is horizontally oriented, and in this example, the frame  12  further supports an elevated loading platform  14 . The loading platform  14  may be, or include, any surface or combination of surfaces suitable for supporting a log  16  (shown on  FIG. 3B ) in a longitudinal orientation along the frame  12 . In other examples of the log splitter  10 , the frame  12  may be vertically oriented or subject to selective vertical orientation. In these examples, it will be understood that the loading platform  14  may optionally be eliminated. 
         [0021]    The splitting assembly  20  and the ram assembly  30  collaboratively support the performance of a longitudinal splitting operation on a log  16  supported on the loading platform  14 . 
         [0022]    The splitting assembly  20  includes a wedge  22  and a footplate  24 . The wedge  22  is generally configured to penetrate one end of the log  16  when engaged with the end of the log  16  under force. This penetration initially creates a longitudinal split in the log  16 , which is propagated with further penetration by the wedge  22  until the log  16  is ultimately substantially or wholly split. The footplate  24  opposes the wedge  22 , and is generally configured to engage the other end of the log  16  and oppose the forces acting on the log  16  during engagement and penetration by the wedge  22 . 
         [0023]    The ram assembly  30  actuates the splitting assembly  20  by selectively moving the wedge  22 , the footplate  24 , or both between an open configuration and a closed configuration through an intermediate configuration. In the illustrated log splitter  10 , the ram assembly  30  includes a double acting linear actuator  32  longitudinally oriented along the frame behind the wedge  22 . The linear actuator  32  may be a hydraulic cylinder, as shown, or a pneumatic cylinder or an electric linear actuator, for example. As shown, the linear actuator  32  and the footplate  24  are fixed to the frame  12 , and the wedge  22  is fixed to the linear actuator  32  in opposition to the footplate  24 . It will be understood that the wedge  22  may alternatively be fixed to the frame  12 , with the footplate  24  fixed to the linear actuator  32 . 
         [0024]    The linear actuator  32  has an extension stroke and a return stroke. The ram assembly  30  further includes a manually operated, multiple position control lever  34  operatively coupled to the linear actuator  32  to activate and deactivate its extension stroke and its return stroke. 
         [0025]    As shown with additional reference to  FIGS. 2A-D , in the illustrated log splitter  10 , the control lever  34  is mounted atop the linear actuator  32 , and its positions are aligned in the direction of the longitudinal orientation of the linear actuator  32 . As shown, the control lever  34  has a forward position F/E that activates the extension stroke of the linear actuator  32 , a rearward position R/R that activates the return stroke of the linear actuator  32  and an intermediate position I/D that deactivates the stroke of the linear actuator  32 . Where the linear actuator  32  is, as shown, a hydraulic cylinder, the control lever  34  may, for example, activate a control valve  36  operatively coupled between the linear actuator  32  and a hydraulic oil pump (not shown), an engine (not shown) and other componentry powering the stroke of the linear actuator  32 . As explained below, in the illustrated example of the log splitter  10 , the control valve  36  may have an outer surface defining a number of exposed threaded holes  44 . 
         [0026]    In the log splitter  10 , an extension stroke and a return stroke of the linear actuator  32  together correspond to a work cycle for the log splitter  10 . As shown in  FIG. 2A , initially, with the stroke of the linear actuator  32  deactivated after having completed a return stroke in a previous work cycle, the control lever  34  is positioned in its intermediate position I/D, and the wedge  22  and the footplate  24  are in an open configuration accommodating the placement of the longitudinally oriented log  16  between them on the loading platform  14 . 
         [0027]    As shown in  FIG. 2B , to begin a new work cycle, the control lever  34  is positioned in its forward position F/E to commence an extension stroke of the linear actuator  32 . During the extension stroke, the linear actuator  32  advances the wedge  22  through an intermediate configuration in which the wedge  22  and the footplate  24  are in relatively closer proximity. This engages the wedge  22  with the end of the log  16  facing the wedge  22  and the footplate  24  with other end of the log  16 , and initiates penetration by the wedge  22  to create a longitudinal split in the log  16 . As the extension stroke continues, the linear actuator  32  further advances the wedge  22  to propagate the longitudinal split in the log  16  until the log  16  is ultimately substantially or wholly split. 
         [0028]    As shown in  FIG. 2C , at the completion of the extension stroke, the control lever  34  is repositioned in its intermediate position I/D to deactivate the stroke of the linear actuator  32 , leaving the wedge  22  adjacent to the footplate  24  in a closed configuration. This positioning of the control lever  34  may occur manually or automatically by operation of the control valve  36 , for instance. Then, as shown in  FIG. 2D , the control lever  34  is positioned in its rearward position R/R to commence a return stroke of the linear actuator  32 . At the end of the return stroke, the control lever  34  is positioned in its intermediate position I/D, as shown in  FIG. 2A , to deactivate the stroke of the linear actuator  32 , once again leaving the wedge  22  and the footplate  24  in an open configuration accommodating the removal of the split log  16  and the placement of another longitudinally oriented log  16  between them on the loading platform  14 . This positioning of the control lever  34  may occur manually or automatically by operation of the control valve  36 , for instance. The end of the return stroke completes the work cycle. 
         [0029]    It can be seen that the time it takes to complete a work cycle for the log splitter  10  is the product, among other things, of the stroke of the linear actuator  32 . In the typical log splitter  10 , the stroke of the linear actuator  32  is long enough to allow for the open configuration of the wedge  22  and the footplate  24  to accommodate the placement of longer length, longitudinally oriented logs  16  between them on the loading platform  14 . The stroke of the linear actuator  32  may, for example, be approximately 25 inches. However, for shorter length logs  16 , for instance, 12-18 inch logs  16  commonly used in household fireplaces, the full stroke of the linear actuator  32  is unnecessary. With shorter length logs  16 , both time and energy are wasted at the beginning of a work cycle, during the extension stroke, to engage the wedge  22  with the end of the log  16  facing the wedge  22  and the footplate  24  with other end of the log  16 , and at the end of the work cycle, during the return stroke, to fully complete the return stroke even after the wedge  22  and the footplate  24  are far enough apart to accommodate the removal of the split log  16  and the placement of another longitudinally oriented log  16  between them on the loading platform  14 . 
         [0030]      FIG. 3A  shows an example of an adjustable return stroke limiter  100  that reduces or eliminates the wasted time and energy associated with the work cycle of the log splitter  10  with shorter length logs  16 .  FIG. 3B  shows a perspective view of an example of an adjustable return stroke limiter  100  installed to log splitter  10 . 
         [0031]    The return stroke limiter  100  is an accessory that, as explained below, installs to the log splitter  10  and, in operation, limits the return stroke of the linear actuator  32 . 
         [0032]    The return stroke limiter  100  includes a mounting bracket  110  supporting a trip assembly  120 . The mounting bracket  110  is generally configured for installation to the log splitter  10 . With the illustrated example of the log splitter  10 , the mounting bracket  110  may, as shown with additional reference to  FIGS. 4A-C  and  5 A-C, be configured for installation to the control valve  36  activated by the control lever  34 . According to this example, the mounting bracket  110  defines a number of apertures  112  that are spaced to align with the threaded holes  44  of the control valve  36 , with each sized to receive a threaded fastener  114  for a respective threaded hole  44 . 
         [0033]    The mounting bracket  110  can be attached to the control valve  36  by aligning its apertures  112  with the threaded holes  44  of the control valve  36 , and by engaging the threaded fasteners  114  with the threaded holes  44  through the apertures  112 . In this manner, the existing configuration of the control valve  36  may be used to implement the installation of the mounting bracket  110 . With either the illustrated or other examples of the log splitter  10 , it will be understood that the log splitter  10 , the mounting bracket  110  or both may be differently configured to support the installation of the mounting bracket  110  to the control valve  36  or otherwise to the log splitter  10 . In an embodiment, a spacer (not shown), with apertures aligning with the apertures of mounting bracket  110 , can be inserted between mounting bracket  110  and control valve  36  to provide, for example, more clearance to pivot  130 . In another embodiment, mounting bracket  110  can define apertures (not shown) to, for example, reduce the weight of apparatus  100 , remove sharp corners from apparatus  100 , and enable a less obstructed view of components of log splitter  10 . 
         [0034]    Once installed, the mounting bracket  110  operably supports the trip assembly  120  with respect to the linear actuator  32  and the control lever  34 . The trip assembly  120  is responsive to the linear actuator  32  during its return stroke to operate the control lever  34  to deactivate the return stroke before its otherwise normal completion. In the illustrated example, the trip assembly  120  includes a trip arm  122  for operating the control lever  34  to deactivate the return stroke of the linear actuator, and a control rod  124  responsive to the linear actuator  32  during its return stroke for actuating the trip arm  122 . 
         [0035]    In the illustrated implementation, the trip arm  122  generally functions as a lever that is actuated by the control rod  124  to operate the control lever  34 . As shown, the trip arm  122  is supported by the mounting bracket  110  on a pivot  130 , and includes a load end  132  and an effort end  134  opposed about the pivot  130 . With the trip arm  122  supported on the pivot  130 , the load end  132  is positioned to operate the control lever  34 , and the effort end  134  is positioned for coupling to the control rod  124  to subject the trip arm  122  to actuation by the control rod  124 . The pivot  130 , as generally shown, may be implemented in whole or in part by bolting the trip arm  122  to the mounting bracket  110 . 
         [0036]    As shown throughout  FIGS. 4A-C  and  5 A-C, the trip arm  122  is supported on the pivot  130  for pivotal movement between a trip position T and a clearance position C. The movement of the load end  132  with movement of the trip arm  122  is generally aligned with the positions of the control lever  34  in the direction of the longitudinal orientation of the linear actuator  32 . With the trip arm  122  in its clearance position C, the load end  132  occupies a space behind the positions of the control lever  34 . With the trip arm  122  in its trip position T, the load end  132  still occupies a space still behind the forward position F/E and the intermediate position I/D of the control lever  34 , but shared with the rearward position R/R that activates the return stroke of the linear actuator  32 . 
         [0037]    Thus, with the trip arm  122  in its clearance position C, the control lever  34  may be positioned in its intermediate position I/D, forward position F/E or rearward position R/R. However, with the trip arm  122  in its trip position T, the control lever  34  may no longer take its rearward position R/R. If the control lever  34  is positioned in its rearward position R/R, with movement of the trip arm  122  from the clearance position C to the trip position T, the load end  132  will engage the control lever  34  and reposition the control lever  34  to its intermediate position I/D that deactivates the stroke of the linear actuator  32 . 
         [0038]    In the illustrated implementation, the control rod  124  is supported by the mounting bracket  110  in the direction of the longitudinal orientation of the linear actuator  32 . With the control rod  124  supported by the mounting bracket  110 , the control rod  124  is coupled between the linear actuator  32  and the effort end  134  of the trip arm  122  to subject the trip arm  122  to actuation in response to the linear actuator  32  during its return stroke. The control rod  124  may be supported by the mounting bracket  110  in any manner for axial movement, and optionally, rotational movement. The mounting bracket  110  may, for example, include spaced eye bolts  140  and  142  for supporting the control rod  124 . 
         [0039]    The control rod  124 , at one end, includes a radially extending push block  150 . The push block  150  is suspended by the control rod  124  in an operative position. To reduce stress on push block  150 , a reinforcement, such as a gusset  151 , may be added between control rod  124  and push block  150 . In its operative position, the push block  150  occupies a space that is behind the wedge  22  fixed to the linear actuator  32 , but that would be shared with the wedge  22  during the return stroke of the linear actuator  32  before the return stroke&#39;s otherwise normal completion. Thus, with the push block  150  in its operative position, the wedge  22  will engage the push block  150  during the return stroke of the linear actuator  32  and axially move the control rod  124  in the direction of the return stroke. 
         [0040]    At its other end, the control rod  124  may optionally include a radially extending handle  152  adapted to support manual rotational movement of the control rod  124  that swings the push block  150  out of its operative position. As generally shown, the orientation and position of the handle  152  may be selectively fixed by a set screw, for example, according to clearance requirements or other design considerations. 
         [0041]    Behind the push block  150 , the control rod  124  crosses the effort end  134  of the trip arm  122 , and is coupled to the effort end  134  to subject the trip arm  122  to actuation. In the illustrated example of the control rod  124 , the control rod  124  includes structure defining longitudinally spaced radially extending shoulder surfaces  160  and  162  cradling the effort end  134  of the trip arm  122 . 
         [0042]    Thus, with the trip arm  122  supported on the pivot  130 , the shoulder surface  160  will engage the effort end  134  of the trip arm  122  with axial movement of the control rod  124  against the direction of the return stroke of the linear actuator  32  to move the trip arm  122  to its clearance position C. Optionally, a spring  164  may be coupled between the mounting bracket  110  and the control rod  124  to bias the control rod  124  against axial movement in the direction of the return stroke. As explained above, the wedge  22  will engage the push block  150  during the return stroke of the linear actuator  32  and axially move the control rod  124  in the direction of the return stroke. With axial movement of the control rod  124  in the direction of the return stroke of the linear actuator  32 , the shoulder surface  162  will engage the effort end  134  of the trip arm  122  to move the trip arm  122  to its trip position T. 
         [0043]    As shown, the shoulder surfaces  160  and  162  may be defined by respective collars  170  and  172  positioned on the control rod  124  between the eye bolts  140  and  142  supporting the control rod  124 , for example. According to this example, the spring  164  may be a coil spring positioned on the control rod  124  and engaged between the eye bolt  140  and the collar  170 , with abutment between the eye bolt  142  and the collar  172  operating to limit the permissible axial movement of the control rod  124  against the direction of the return stroke of the linear actuator  32 . As generally shown, the axial position of the control rod  124  in relation to the collars  170  and  172  may be selectively fixed by set screws, for example. It will be understood that the specific operative position of the push block  150  behind the wedge  22  fixed to the linear actuator  32 , and by extension, the point at which the wedge  22  will engage the push block  150  during the return stroke of the linear actuator  32 , may be adjusted to suit a particular length log  16 . 
         [0044]    The work cycle for the log splitter  10  as modified by the installed return stroke limiter  100  is shown in  FIGS. 4A-C  and  5 A-C. As shown in  FIG. 4A , initially, with the wedge  22  having engaged the push block  150  during a return stroke of the linear actuator  32  in a previous work cycle, the control rod  124  is axially moved in the direction of the return stroke, the shoulder surface  162  of the collar  172  is engaged with the effort end  134  of the trip arm  122  to move the trip arm  122  to its trip position T and the load end  132  is engaged the control lever  34  to position the control lever  34  to its intermediate position I/D. The stroke of the linear actuator  32  is consequently deactivated. Further, the spring  164  is compressed between the eye bolt  140  and the collar  170  by the axial movement of the control rod  124  in the direction of the return stroke to bias the control rod  124  against axial movement in the direction of the return stroke. 
         [0045]    As shown in  FIG. 4B , to begin a new work cycle, the control lever  34  is positioned in its forward position F/E to commence an extension stroke of the linear actuator  32 . During the extension stroke, the linear actuator  32  advances the wedge  22  and the wedge  22  disengages the push block  150 . Concurrently, the decompression of the spring  164  between the eye bolt  140  and the collar  170  axially moves the control rod  124  against the direction of the return stroke, and the shoulder surface  160  will engage the effort end  134  of the trip arm  122  to move the trip arm  122  to its clearance position C, as shown in  FIG. 4C . 
         [0046]    With the trip arm  122  in its clearance position C, the control lever  34  may be positioned in its intermediate position I/D or its rearward position R/R. At the completion of the extension stroke, the control lever  34  is repositioned in its intermediate position I/D to deactivate the stroke of the linear actuator  32 . Then, as shown in  FIG. 5A , the control lever  34  is positioned in its rearward position R/R to commence a return stroke of the linear actuator  32 . 
         [0047]    As shown in  FIG. 5B , the wedge  22  engages the push block  150  during the return stroke of the linear actuator  32 . Consequently, the control rod  124  is axially moved in the direction of the return stroke. Responsive to the axial movement of the control rod  124  in the direction of the return stroke, the shoulder surface  162  of the collar  172  engages with the effort end  134  of the trip arm  122  and the spring  164  is compressed between the eye bolt  140  and the collar  170  to bias the control rod  124  against axial movement in the direction of the return stroke. 
         [0048]    As shown in  FIG. 5C , the engagement of the shoulder surface  162  of the collar  172  with the effort end  134  of the trip arm  122  moves the trip arm  122  to its trip position T. The trip arm  122  is thereby actuated, and the load end  132  of the trip arm  122  engages the control lever  34  to position the control lever  34  to its intermediate position I/D. The stroke of the linear actuator  32  is consequently deactivated before its otherwise normal completion, thus completing the work cycle. With the work cycle of the log splitter  10  completed, the wedge  22  and the footplate  24  are left in an open configuration accommodating the removal of the split log  16  and the placement of another longitudinally oriented log  16  between them on the loading platform  14 . 
         [0049]    With the limitation of the return stroke of the linear actuator  32  by the return stroke limiter  100 , both time and energy are saved in association with the work cycle of the log splitter  10  with shorter length logs  16 . These savings can be achieved over a variety of shorter length logs  16  by adjusting the specific operative position of the push block  150  behind the wedge  22  fixed to the linear actuator  32  to, in turn, adjust the point at which the wedge  22  will engage the push block  150  during the return stroke of the linear actuator  32  to cause its deactivation. 
         [0050]    While recited characteristics and conditions of the invention have been described in connection with certain embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.