US2591233A - Earth auger - Google Patents

Description

K. J. EROWNE April 1, 1952 EARTH AUGER Filed Jan. 2l, 1947 JNVENTOR.

ai! I lei n i MM Patented Apr. l, 1952 UNITED STATES PATENT OFFICE EARTH AUGER Kenneth J. Browne, Huntington Park, Calif.

Application January 21, 1947, Serial No. 723,368

Claims. (Cl. Z55-69) My invention relates to power operated earth augers of the rotary type used for digging holes for posts and the like.

Such augers as heretofore designed have many disadvantages the most outstanding of which are as follows: They require repeated full length earth penetrating operations to form a hole of their own length. The hole formed is not of uniform diameter, and frequently the walls of the hole cave in or the earth is not completely removed, requiring additional boring `operations to produce a hole acceptable to a post. Particularly in sticky formations, do they bog up and jam,

and many mechanisms have been designed forV automatically disconnecting the auger from its driving means to prevent breaking of the parts of the driving means incident to jamming of the auger. Lastly, the earth loosened by the auger constantly tends to fall back into the hole during the boring operation, and, in consequence, requires a longer period of operation to bore a hole devoid of loose earth.

It is a purpose of my invention to provide an earth auger which overcomes the disadvantages of prior augers and particularly those above mentioned, and functions in only a single and continuous operation to bore in the earth a hole of uniform diameter throughout its length, thereby greatly reducing the boring time to form a complete hole, and regardless of the stickiness of the formation; conveys all earth from and clear of the top of the hole to prevent it from falling back into the hole; and at the same time rmly packs the walls of the hole to preclude possible cavein.

A further purpose of my invention is the provision of an earth auger having an earth cutting means at its lower end, a second means for gradually elevating the earth as so cut, and a of thicker metal than the remaining convolutions.

It is also a purpose of my invention to provide an earth auger having means for so connecting it to a drive shaft, that should the auger become jammed in the earth against rotation, as when encountering a rock or stone, its driving connection with the shaft is automatically severed to prevent breaking or other injury to the shaft or the auger, but the auger will remain so connected to the shaft that it can still be withdrawn from the hole by the shaft.

I will describe only one form of earth auger embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings:

Fig. l is a view showing in side elevation one form of earth auger embodying my invention.

Fig. 2 is a view showing the auger of Fig. 1 in vertical section.

Fig. 3 is a bottom plan View of the auger.

Fig. 4 is a `fragmentary sectional view taken on the line 4-4 of Fig. 1.

With specific reference to the drawings, my auger in its present embodiment comprises a spindle A tubular in form, and to the outerside of which is welded or otherwise secured an auger night B of spiral formy and substantially coextensive in length with the spindle. The lower end of the flight B terminates in a lineal edge l5 extending radially from the spindle A, and inclined downwardly (see Fig. 4) with a cutting blade IS secured thereto by bolts Il or other means, and so that the cutting edge Ilia of the blade is disposed radially of the spindle.

Welded or otherwise secured to the lower end of the spindle A is a member i8 preferably of flat triangular forni, with one pointed end disposed axially of the spindle so as to center the lower end of the auger in its digging operation.

The structure and functions of the auger Hight B are paramount features of my invention because by reason thereof are accomplished the advantages of extremely rapid and complete dig# ging of a hole in a single operation, and of throwing the earth clear of the hole so as to avoid the falling of the earth back into the hole and thus requiring further digging operations.

These advantages are attained by forming the auger night B so that the lowermost convolution i9 has only a slight degree of inclination, while at the upper terminus of the flight convolution indicate-cl at 2t, the flight is abruptly increased in its upward inclination to a much greater degree preferably three feld, so that the remaining convolutions 2! are at a pitch greatly in excess of the convolution is.

It will be noted that the convolution I9 is of a metal thickness considerably greater ,than that of the convolutions 2 l. This not only gives added weight to the lower end of the boring blade, to increase its boring abilityat this point, but it gives added strength to withstand shocks when striking rocks or stones.

For rotating the auger in the digging of a hole, any conventional driving means may be employed including a shaft 22 which extends into the spindle A. The shaft is drivingly fixed to the spindle through the medium of a relatively long and thick metal sleeve 23 which receives the lower end of the shaft, and is secured thereto by a bolt 24 or other means, which extends through the spindle, sleeve and shaft. The sleeve 23, in turn, is fixed to the spindle at its lower end by welding, which operation may be performed simultaneously with welding of the centering member i8 to both the spindle and sleeve, and so that the sleeve is closed with the welding metal.

The bolt 24 is designed to shear when the auger becomes jammed in the digging of a hole, such as by a rock or stone, and whereby the auger is no longer drivingly connected to the shaft so that the latter may continue to rotate without injury to the auger or the shaft.

To prevent complete disconnection of the auger from the shaft so that it may be recovered from a hole in the event of the bolt 2d being sheared, a relatively short sleeve 25 is secured in the upper end of the spindle, and through which the shaft extends, with a pair of diametrically disposed set screws 2S extending through the spindle and threaded in the sleeve. These screws are provided with lock nuts 2'! for securing them in adjusted position to cause their inner pointed ends 28 to bite into the shaft and thus hold the shaft against withdrawal from the spindle.

Another structural and functional feature of Vmy invention. is a means for pressing the wall of the hole as it is dug by the auger, to prevent the earthY from caving in, and thus requiring rebori'ng operations to produce a clean hole of the desired depth. This means may comprise an arcuate iiange 23 xed on and depending from the edge of blade convolution i9 and disposed opposite the cutting blade i6.

In operation the shaft 22 drives the auger a clockwise direction as when viewed in Fig. 3, the member i8 rst penetrating the earth to center the auger, and then the cutting bladeY IS cutting the earth to dig the hole. The earth as out by the blade I6 passes onto the lower end of the auger flight B and is thus moved progressively upward of the flight. Due to the low degrec of pitch ofthe lowermost convolution 9 of the flight, there is relatively a gradual elevation of the earth at this point. This affords easy and rapid initial and continued penetration of the auger into the earth.

The cutting action of the blade i6 is made positive by the sleeve 23 because of the added weight it lends to the lower portion of the auger.

Once the loosened earth leaves the blade convolution IS, its elevation is greatly accelerated by reason of the increased pitch of the convolutions 2 I resulting in a continuous and rapid rise of the earth to the top of the auger, and finally throw- Y ing it clear of the hole to prevent it from falling the rate at which the earth is fed to the auger flight.

Particularly is my auger effective in diggingk result an increased earth elevating speed is produced which conveys the earth away from the lower convolutions with such rapidity that the lower convolutions and the cutting blade l5, can at all times perform their digging functions. In consequence, the earth is allowed to loosen and separate as it is elevated to prevent packing thereof and causing it to jam the auger in the hole, as is the case in augers where the convolutions are spaced uniformly from end to end.

In loose formations my auger is also particularly successful by virtue of the member 29, for in operation of the augerfthe cutting blade I6 produces a lateral thrust of theV auger which forces the member against the wall of the hole and thereby presses the earth sufliciently to prevent it from falling into the hole. Thus the auger is not only operable to form av hole in much less time than is possible with prior augers, but one which is devoid of loose earth as a result of cave Vin so that a post can without diniculty, be extended into the hole. i

Although I have herein shown and described only one form ofV earth auger embodying my invention, it is to be understood that various changes and modications may be made therein Without departing from the spirit of my invention and the spirit and scope of the appended claims.

Iclaim: Y

1. An earth auger comprising: a tubular spindle; a centering sleeve xed in the upper end portion of said spindle; a second sleeve fixed in the lower portion of said spindle, and relatively heavy to lend additional weight to the lower portion of said spindle; a centering member fixed to and projecting axially from the lower end of said spindle; a boring blade secured to and extending spirally of the outer side of said spindle; a

driving shaft for said spindle extending through the upper sleeve and into the second sleeve; Va shearable element extending through said spindle and said second sleeve and said shaft for operatively connecting the spindle to the shaft for rotation thereby; and set screws adjustabley in said spindle and centering sleeve for engaging the driving shaftV to maintain a connection of the spindle with the shaft should said element shear.

2. An earth auger having a spindle; and-an auger ight fixed to and extending in a continuous spiral about the spindle and being of substantially the same diameter throughout, the lowermost convolution of the flight having a smaller pitch than the pitch of the convolutions thereabove, and a cutting blade fixed to the lower end of said flight and disposed laterally of said spindle. Y

3. An earth auger having aV spindle; and an auger flight fixed to and extending in a continuous spiral about the spindle and being of substantially the same diameter throughout,V the loW- ermost convolution of the flight having a smaller` pitch than the pitch of theV convolutions thereabove, and of? thicker material to give added strength thereto and added weight at the lower end of the auger, and a cutting blade fixed to the lower end'of said night and disposed laterally of said spindle.

4. An earth auger, including: a spindle, an auger flight fixed to and extending in a continuous spiral about the spindle and being of substantially the same diameter throughout, the lowermost convolution of the ght having a smaller pitch than the pitch of the convolutions thereabove, and of thicker material than the convolutons thereabove; a cutting bladefixed to the lower end of the flight and disposed laterally of the spindle; and an arcuate element on and de- 10 pending from the edge of the lowermost convolution of the flight substantially diametrioally opposite the cutting blade.

5. An earth auger having a spindle; and an auger ight lixed to and extending in a continuous spiral about the spindle and being of substantially the same diameter throughout, the low ermost convolution of the flight having a smaller pitch than the pitch of the convolutions thereabove, and a cutting blade xed to the lower end of said liight and disposed laterally of said spindle, said blade extending from the spindle to the edge of the flight.

KENNETH J. BROWNE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date A 228,044 Dine May 25, 1880 732,479 Wheeler et al June 30, 1903 785,302 Fullard Mar, 21, 1905 919,595 Kessler Apr. 27, 1909 1,010,314 Popky Nov. 28, 1911 1,116,154 Stowers Nov. 3, 1914 1,554,160 Howlett et al Sept. 15, 1925 1,789,399 Bartenbach et al. Jan. 20, 1931 1,990,341 Meyer l Feb. 5, 1935 2,107,958 `Pribyl Feb. 8, 1938 2,221,680 Parrish Nov. 12, 1940 2,320,612 Kandle June 1, 1943 2,453,204 Dobbs Nov. 9, 1948

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