US 3382935 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
May 14, 1968 .J. P. WATTS EARTH DRILLING AUGER Filed June 28, 1966 VII/TV R mm A ww w.
R S E M A IU ATTORNEY United States Patent Office 3,382,935 Patented May 14, 1968 3,382,935 EARTH DRILLING AUGER James P. Watts, 6930 E. Pinchot, Scottsdale, Ariz. 85251 Filed June 28, 1966, Ser. No. 561,114 1 Claim. (Cl. 175313) This invention relates to improved earth drilling augers.
More particularly, the invention concerns earth drilling augers especially adapted to drilling in wet or loosely packed earth.
In a particular aspect, the invention concerns an improved earth drilling auger which is capable of boring a cylindrical hole of substantially uniform cross-section.
In boring holes in the earth for the purpose of pouring concrete foundation piers, such as are required for heavy building construction and the like, it is highly desired that the bored holes be of substantially uniform crosssection. In this way, the building contractor can pour only the amount of concrete required to achieve the minimum necessary structural strength and avoid waste of concrete due to irregularly shaped holes.
Holes bored by the use of apparatus commonly known and used in the prior art were often irregularly shaped due to the fact that the walls tended to collapse into the hole as the drilling auger was removed for cleaning. The collapse of the walls was primarily due to suction effects created when the auger was lifted from the hole. This problem was especially acute in drilling wet soil as the mud encountered functioned as an effective air seal, thus increasing the vacuum created in the hole when the auger was lifted.
It would be highly advantageous to provide a drilling auger especially adapted to prevent collapse of the walls of the bore hole when the auger is lifted from the hole. In this way, the cross-section of the hole is maintained substantially uniform along its length and the amount of concrete required to fill the hole is limited to just that required to produce a pier having the required structural strength.
Accordingly, it is a principal object of the present invention to provide an improved drilling auger;
Another object of the invention is the provision of a drilling auger especially adapted for use when boring holes in wet or moist earth;
A further object of the invention is the provision of an improved drilling auger assembly which is conveniently and economically emptied of earth, mud, etc., during the drilling operation;
Yet another object of the invention is the provision of an improved drilling auger assembly which is economically and conveniently fabricated and which is adapted for easy maintenance;
These and other, further, and more specific objects and advantages of the invention will become apparent from the following detailed description of the invention taken in conjunction with the drawings in which:
FIG. 1 is a sectional view of an anger assembly embodying the present invention and in which the presently preferred embodiment is shown and described;
FIG. 2 is a partial perspective view of the auger assembly of FIG. 1 showing the hinged cover member displaced from its normally closed position;
FIG. 3 is a perspective view illustrating the bottom portion of the auger assembly and showing the arrangement and operative relationship of the various cutter elements.
Briefly, in accordance with my invention, I provide an earth drilling auger comprising a rotatable central vertical shaft having a cutter bar extending radially outwardly from the shaft adjacent the lower end thereof, a spiral screw flight carried by the shaft and extending upwardly from the cutter bar, a cylindrical casing coaxially disposed around and enclosing the screw flight, the interior vertical surfaces of the casing slidably frictionally engaging the periphery of the screw flight, cutter elements carried by the lower edge of the casing and extending outwardly therefrom, and a cover member normally closing the top of the cylindrical casing, the cover member having a perforated hinged portion adapted to be displaced from the normally closed position of the cover.
Referring now to the drawings, in which like numerals identify the same elements in the various figures, FIG. 1 illustrates an auger assembly embodying the present invention and shows a rotatable central vertical shaft 1 having a cutter bar 2 extending radially outwardly from the shaft adjacent the lower end 3 thereof. A spiral screw flight 4 is carried by the shaft 1 and extends upwardly from the cutter bar 2. A cylindrical casing 5 is disposed coaxially with the shaft 1 and the screw flight 4, enclosing the screw flight. The interior vertical surfaces 5a of the casing 5 slidably frictionally engage the periphery 4a of the screw flight forming points of contact 4b between the interior surface 5a of the casing 5 and the periphery 4a of the screw flight 4. These points of contact 4b cause the casing 5 to rotate more or less concurrently with the shaft 1 and screw flight 4, but provide for slippage between the casing 5 and the screw flight 4, providing a freewheeling effect.
The casing 5 is provided with cutter elements 6 extending radially outwardly from the casing a short distance. These cutter elements 'provide a clearance between the exterior of the casing 5 and the side of the bore hole permitting passage of air and water between the casing 5 and the bore hole wall. This clearance reduces to a minimum the vacuum created in the bottom of the bore hole when the auger assembly is lifted from the hole. The bottom of the shaft 1 is provided with a pilot auger 7 which positions the auger laterally within the bore hole and provides an initial entry into the earth to be drilled. The top of the vertical shaft 1 is provided with suitable means for connecting the auger to the rotating driving shaft of a drilling rig (not shown). In the device of FIG. 1, the means for connecting the auger to the drilling rig shaft comprises a female socket 8 having a square cross section and suitable holes 8a for inserting keys to lock the apparatus to the bottom of the drilling rig shaft.
The casing 5 is provided with a cover member 9 which is provided with a central aperture 9n, within which the vertical shaft 1 rotates freely. Vertical movement of the casing 5 is limited by a collar 91) extending upwardly from the central aperture 911 and bearing upon the lower shoulder 3b of the socket 8.
Referring to FIG. 2, it will be seen that the cover memher 9 is provided with a perforated hinged portion 9c which is adapted to be displaced, as shown in FIG. 2, from its normally closed position. The hinged portion may be conveniently secured in its normally closed position by means of a latch assembly comprising a swing C washer 10 which engages stud 11 located on the stationary portion of the cover 9.
In operation, the improved drilling auger operates as follows.
Downward pressure in the direction of the arrow A of FIG. 1 is exerted by the drilling rig shaft seated in the socket 8 and the device is rotated in the direction of the arrow B of FIG. 2. The pilot auger 7 initially penetrates the earth to provide lateral stability for the main drilling elements. The cutter bar 2 engages the earth and displaces it upwardly onto the spiral screw flight 4 which carries the displaced and comminuted earth, mud, etc., upwardly into the interior of the casing 5. Frictional engagement between the casing 5 and the periphery 4a of the screw flight 4 causes rotation of the casing 5 in the same direction. The cutter elements 6 located on the bottom edge of the casing 5 enlarge the hole slightly to provide clearance between the casing 5 and the walls of the bore hole. When the casing 5 is filled with earth, mud, etc., as evidenced by discharge of some of the material through the perforations 9d in the cover member 9, the entire assembly is withdrawn from the bore hole and, still connected to the rotatable shaft of the drilling rig, it is positioned at a location remote from the bore hole preparatory to discharging the contents of the casing.
The contents of the casing are dischar ed by immobilizing the casing from rotation. This can be accomplished in any suitable manner, such as, for example, by placing several turns of a cable or a rope around the casing or by clamping the casing to some stationary object. The hinged portion of the cover member is then opened and the anger is rotated in the same direction as when drilling, thereby discharging the contents of the casing through the opened cover member. After the casing is emptied, the cover member is closed and latched, the apparatus is reinserted into the bore hole and the operation is repeated.
The apparatus of the present invention is therefore to be clearly distinguished from prior art augers employing a casing which is afiixed to the auger and which must be removed from the auger, as by lifting clear of the screw flight, before the discharging operation can be commenced.
Various changes in the devices chosen for purposes of illustration in the drawings will readily occur to persons skilled in the art having regard for the disclosure hereof. To the extent that such modifications and variations do not depart from the spirit of the invention, they are intended to be included within the scope thereof which is not limited to the devices specifically illustrated in the drawings but, rather, only by a just interpretation of the following claim.
Having fully described the invention in such manner as to enable those skilled in the art to understand and practice the same, the invention claimed is:
1. An earth drilling auger especially adapted for boring holes in wet soil comprising:
(a) a rotatable central vertical shaft;
(0) a cutter bar extending radially outwardly from said shaft adjacent the lower end thereof;
(0) a spiral screw flight carried by said shaft and extending upwardly from said cutter bar;
(d) a cylindrical casing coaxially disposed around and enclosing said screw flight, the interior vertical surfaces of said casing slidably frictionally engaging the peripheiy of said screw flight;
(e) cutter elements carried by the lower edge of said casing and extending outwardly therefrom;
(f) a cover member normally closing the top of said cylindrical casing, said cover member having a perforated hinged portion adapted to be displaced from said normally closed position.
References Cited UNITED STATES PATENTS 1,519,132 12/1924 Grothe 313 1,616,666 2/1927 Nebergall 175-323 FOREIGN PATENTS 123,009 1/ 1901 Germany.
CHARLES E. OCONNELL, Primary Examiner.
N. C. BYERS, Examiner.