US3026953A - Earth auger tip - Google Patents

Description

March 27, 1962 H. B. PETTEE 3, 6, 3

EARTH AUGER TIP Filed July 21, 1959 INVENTOR. F I 2 HERBERT B. PETTEE ATTORN as ilnited dtates atent @iiice 3,026,953 E RTH. AUG 1 Herbert B. Pettee, Allenton Road, RED. 1, Hamilton, R1.

Filed July 21, 1959, er. No. 828,658. 2 Claims. (Cl. 175-385) This invention relates to a power operated earth auger which is useful for digging holes particularly for nursery seedlings.

Most of the earth angers that have been designed in the past have many disadvantages when they are attempted to be used in connection with nursery seedlings or transplants. First, most of the prior art augers have been designed with a view of digging a hole for a post. The digging of a hole for a post is an entirely different operation than that required for digging a hole for a nursery transplant or the like. In post hole digging, it is advantageous to have the walls of the hole for a post smooth. Further the auger should be designed in such a way that it will throw the dirt a sufficient distance from the hole so that the withdrawn dirt material will not accidentally fall back into the hole, thus disturbing the post insertion. Also to provide atrue circular hole, a centering pilot tip should be used. The auger for planting seedlings or the like must of necessity operate in just about the diverse manner for the hole should have a rough wall and there should be left in the hole bottom a soft base of loose dirt in order that the hair roots may start immediate growth, thus producing sturdier plants and the shortening of the time for the seedlings to reach salable size. Furthermore, the dirt brought upon from the hole should be left immediately around the rim thereof where it can be easily pushed back in and tamped down.

It is therefore an object of this invention to provide an earth auger which functions to drill a hole in the earth that will have a somewhat ragged wall and leave loose fill at the bottom thereof.

A further object of the invention is the provision of an earth auger having an earth cutting means at its lower end which cooperates with a second means for elevating the earth to the top of the hole being cut.

A still further object of the invention is to provide a tip for an earth auger which will cooperate with the spiral blade, the tip being fastened to the assembly so that should it become jammed as might happen when encountering a rock or stone, its driving connection will be severed.

A still further object of the invention is to provide an earth auger which will have the characteristics of nonclogging when used in the damp soil which clogging is prevented by the provision of the special tip cooperating with the flight of the auger.

With these and other objects in view, the invention consists of certain novel features of construction as will be more fully described and particularly pointed out in the appended claims.

FIGURE 1 is a perspective view of the earth anger of the invention;

FIGURE 2 is a bottom plan view of the auger of FIG. 1; and

FIGURE 3 is a perspective view of the tip constructed in accordance with the invention.

Referring now to the drawings, the auger comprises a spindle which is tubular in form and has a bore 11. Suitably secured to the periphery of the cylinder 10 are a pair of auger flights 12 and 14 of helical form which are both substantially coextensive with the length of the spindle 10 and are secured thereto by welding or in other fashions. The lower end of the flight 12 terminates in a lineal edge 15 While the lower end of the flight 14 terminates in a linear edge 16. The edges 15 and 16 may be provided with a knife-like edge and it will be noted that these edges are oriented (see FIG. 2) actuallyon a line which is offset from a true radius of the spindle 10, a slight amount indicated by the distance A for a purpose which will hereinafter appear.

Mounted at the lower endof the spindle 10 is atip generally designated 18, which tip has a central shaft portion 19 that is received within the bore 11 of the spindle l0 and is secured therein by a bolt or other fastening means 29 that passes through a bore 21 in the shaft 19. A bar perpendicularly extends from the lower end of the shaft 19 to form two radial cutters 22 and 23 which extend radially outward from the shaft 19 and its central axis of rotation. These cutters 22 and 23 are formed from a rectangular bar or block and are provided with an inclined relief portion 24, 25 which form cutting edges 26, 27 respectively. Vertical faces 28, 29 extend from the cutting edges 26, 27 which faces are shown as being substantially in line with the cutting edges 15, 16 but slightly advanced therefrom so as to form a lead as best shown in FIG. 2 of the drawing.

In operation a shaft of suitable construction is inserted into the bore 11 at the upper end thereof and pinned to the spindle 10 through the hole 30. The auger then rotates in a clockwise direction as viewed in FIG. 1 and the tip member 18 first penetrates the earth and serves to loosen the earth in a central zone. Then the two flights l2 and 14 enter the earth at their lower or cutting edges 15 and 16. At this point of entry the tip member 18 has already loosened the earth in a small hole and thus the radially outer portions of the edges 15 and 16 are the only ones that really go into working position. As the bit proceeds downwardly under slight pressure being exerted by the mechanism associated with the drive, the tip 13 continues to loosen earth in its path, the faces 28, 29 continually cutting away to provide a zone of loosened earth below the leading edges # 15 and 16 of the two flights l2 and 14. Thus, the earth as it first loosened by the tip 18 in a substantial central zone is further out by the leading edges of the two flights and then carried up the two flights to the top of the hole where by virtue of centrifugal force the earth is thrown off the top ends of the flights to area immediately surrounding the hole being dug. Due to the particular configuration of the tip 18, there is aiforded easy and rapid initial and continued penetration of the auger into the earth, and of course, the portion 24 and 25 which are cut back from the cutting edges 26 and 27 of the tip allow a relief for the earth being initially bored into by the tip. When boring stops at the depth desired, it will be obvious that the area between the lowermost point of penetration of the tip 18 and the leading edges of the flights 12 and 14 will be left ground up by the penetration of the tip and will remain in the hole when the anger is withdrawn. It will further be apparent that the effectiveness of such an arrangement in a sticky or packed earth digging operation is facilitated since the earth is initially allowed to loosen and separate before being elevated by the two flights.

It should also be pointed out that the wall of the hole will be left rough since there is no smoothing action taking place between the wall of the hole and the bit proper. Thus, the only action on the wall of the hole manifests itself in the outermost edge of the flights which are constantly revolving and which also will tend to leave a rough edge, as the bit is generally withdrawn while it is still rotating.

I claim:

1. An earth auger comprising a tubular spindle at least one auger flight fixed to and extending helically about said spindle and terminating with a radially extending lower cutting edge spaced longitudinally from the end of said spindle, a tip afiixed to the end of said spindle, said tip 2. An earth auger as in claim 1 wherein said tip has a comprising a bar extending generally perpendicular to the radius less than the radius of said auger flight. axis of said spindle, said bar having a length greater than References Cited in the file of this patent the diameter'of the spindle and having a pair of face portions located on opposite sides of the spindle axis and in 5 UNITED STATES PATENTS a plane parallel thereto, the lower edge of each said face 591,204 Bittenbender Oct. 5, 1897 portions extending beyond said spindle, said bar having 945,016 Caldwell J an. 4, 1910 relief portions leading upwardly and away from the lower 1,086,748 Braasch Feb. 10, 1914 edge of the face portions whereby the earth is loosened 1,206,488 Weathersby Nov. 28, 1916 in a substantial central zone below the lower edge of 10 2,591,233 Browne Apr. 1, 1952 the flight. 2,890,860 Smith Apr. 1, 1955

Images