Pengo corp11/24/2023 Mounting expansion holders displaced relative to the cutting holders in accordance with the present invention keeps the auger on center and maintains a more accurate grade. One of the problems of existing expansion head augers is that elliptic holes are cut because the expansion tooth holders are mounted on the same arms as the cutting tooth holders. The four point contact results in more true alignment of the hole being dug and also a more precise diameter. The expansion holder has expansion teeth which are pivotally mounted thereon, so that when the head is rotated in normal cutting direction the expansion holder and the teeth carried thereby pivot outwardly to dig out the perimeter of the hole, but when the direction of rotation is reversed, the holders pivot inwardly to permit retraction of the head within the casing after excavation is completed.Īccordingly, a principal purpose of the present invention is to provide a self-expanding, self-retracting clearance cutter, or expansion cutter, which is adjustable in the extent of expansion thereof.Īnother and very important feature of the invention is the fact that the expansion tooth holders are displaced approximately 90° from the cutting tooth holders and this provides four point contact of the head with the ground being excavated. Rearwardly, the head has a second part having expansion holders with teeth to dig out the perimeter of the holes thereby cutting clearance for the casing. The forward portion has conventional earth boring teeth which dig out the largest area of the hole being bored. More particularly, the invention relates to a head which has essentially two parts - one displaced approximately 90° relative to the axis of rotation of the head from the other. This invention relates to a new and improved head for horizontal earth boring. A boring head according to claim 3 in which one said abutment is adjustable in position to adjust the size of said outside diameter. An earth auger head according to claim 1 which further comprises a first abutment on each said second arm and a second abutment on each said expansion holder, said abutments coming into contact with each other to limit outward pivotal movement of said holder as said head is turned about its axis of rotation in first direction to limit the outside diameter of the hole being bored.Ĥ. A boring head according to claim 1 in which one said spacer is located adjacent the outer end of said second arm and is formed with an abutment and each said holder has a set screw engaging said abutment to limit the outward extension of the second tooth held in said holder.ģ. An earth auger head having an axis of rotation comprising a shaft, a plurality of first arms each carrying a plurality of first tooth holders, first teeth in said first tooth holders, said first teeth positioned to bore earth at the end of a hole substantially transverse to said axis of rotation, a plurality of second arms spaced rearwardly of said first arms and disposed substantially midway between said first arms, said second arms comprising diametrically disposed, parallel, thin, narrow front and rear expansion arms, each said expansion arm transverse to said axis and spaced relative to each other along said axis, said first and second arms fixed to said shaft, an expansion holder mounting means on the outer end of each said second arm disposed between said front and rear expansion arms, a pair of spacers between said front and rear expansion arms spacing said expansion arms apart, an expansion holder pivotally mounted in each said mounting means about a second axis parallel to said axis of rotation, a second tooth in each said expansion holder pivoting about said second axis between a retracted position inside the perimeter of the hole bored by said first teeth and an extended position outside said perimeter, said second teeth positioned to dig the outside of said hole when in extended position, said second teeth when in extended position being substantially midway between the two adjacent outermost first teeth when viewed in a direction parallel to said axis of rotation, said expansion holders pivoting to extended position when said head is rotated in one direction of rotation and to retracted position in reverse direction of rotation of said head.Ģ.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |