Forward impacted plow for trenchers

Abstract

A plow trenching apparatus for a vehicle having a raisable boom and a trenching plow pivotally mounted at a distal end of the boom in a plow holder, to extend rearwardly and downwardly therefrom. The plow has an upper portion and a lower portion, with a forwardly protruding toe portion, and a forward facing cutting portion. The plow is pivotable in the holder about a pivot axis located behind the holder and behind the plow, as seen in the travel direction of the plow during operation. A pivoting motion is imparted to the plow by a vibrator arranged at the upper portion. The vibrator is arranged to impart vibrations generally in a vertical plane, so that the lower portion is pivoted generally back and forth in the travel direction. The vibrator can be located behind or in front of the upper portion. The vibrator can have two eccentric weights, each being rotatable around its axis in a plane, the two weights being synchronized in their rotation so that they pass and are 180 degrees apart at two points during the rotation. This arrangement creates a straight line oscillating motion in the plane. A hydraulic cylinder is connected between the blade holder and the plow blade to set the depth of the plow.

What is claimed as the invention is:  
     
         1 . A plow trenching apparatus comprising: 
 a vehicle having a raisable and lowerable boom;    a trenching plow pivotally mounted at a distal end of said boom in a plow holder, to extend rearwardly and downwardly therefrom,    said plow having an upper portion and a lower portion with a forwardly protruding toe portion and a forward facing cutting portion, wherein said plow is pivotable in said holder about a pivot bar located on said holder behind said plow as seen in the travel direction of the plow during operation, a pivoting motion being imparted to said plow by a vibrator arranged at said upper portion, said vibrator being arranged to impart vibrations generally in a vertical plane, so that said lower portion is pivoted generally back and forth in the travel direction.    
     
     
         2 . The plow trenching apparatus as recited in  claim 1 , wherein said pivot bar is located substantially at the middle of the plow, i.e. the length of the upper portion being substantially equal to the length of the lower portion of the plow.  
     
     
         3 . The plow trenching apparatus as recited in  claim 1 , wherein said vibrator is arranged behind said upper portion.  
     
     
         4 . The plow trenching apparatus as recited in  claim 1 , wherein said vibrator is arranged in front of said upper portion.  
     
     
         5 . The plow trenching apparatus as recited in  claim 1 , wherein said vibrator has two eccentric weights, each weight being rotatable around its axis in a plane, said two weights being synchronized in their rotation so that they pass and are 180 degrees apart at two points during the rotation, thereby creating a straight line oscillating motion in said plane.  
     
     
         6 . The plow trenching apparatus as recited in  claim 2 , wherein said vibrator has two eccentric weighs each being rotatable around its axis in a plane, said two weights being synchronized in their rotation so that they pass and are 180 degrees apart at two points during the rotation, thereby creating a straight line oscillating motion in said plane.  
     
     
         7 . The plow trenching apparatus as recited in  claim 3 , wherein said vibrator has two eccentric weighs each being rotatable around its axis in a plane, said two weights being synchronized in their rotation so that they pass and are 180 degrees apart at two points during the rotation, thereby creating a straight line oscillating motion in said plane.  
     
     
         8 . The plow trenching apparatus as recited in  claim 4 , wherein said vibrator has two eccentric weights, each weight being rotatable around its axis in a plane, said two weights being synchronized in their rotation so that they pass and are 180 degrees apart at two points during the rotation, thereby creating a straight line oscillating motion in said plane.  
     
     
         9 . The plow trenching apparatus as recited in  claim 1 , wherein an actuation means is connected between said blade holder and said plow blade for varying the position of said plow blade within said blade holder and thereby varying the depth of said blade.  
     
     
         10 . The plow trenching apparatus as recited in  claim 9 , wherein said actuation means comprises at least one hydraulic cylinder connected between said blade holder and said plow blade.