US2883223A - Screw anchor adapter - Google Patents

Description

G. A. M. PETERSEN 2,883,223

SCREW ANCHOR ADAPTER April 21, 1959 2 Shets-Sheet 1 Filed July 15. 1954 FIEI 3 IN V EN TOR. GERALD AM PETERSEN Ap 1, 1959 G. A. M. PETERSEN 2,883,223

SCREW ANCHOR ADAPTER Filed July 15, 1954 2 Sheets-Sheet 2 INVENTOR. GERALD AM PETERSEN 24MMM United rates Patent 2,883,223 SCREW ANCHCR ADAPTER Gerald A. M. Petersen, Santa Clara, Calif. Application July 15, 1954, Serial No. 443,633 Claims. (Cl. 287-408) This invention relates to an adapter for drivingly connecting a screw anchor rod to the tip of an earth boring tool for driving the screw anchor into earth.

Screw anchors as such are not new, since it has long been a practice to drive these anchors by screw action into earth to provide anchorage for guy wires or cables. These screw anchors in general consist of an elongated rod having an eye formed on its upper end and its opposite end pointed and provided with a double helix blade which is relatively fiat but will screw into earth, sand or clay in auger fashion. The general purpose is to screw the blade well into earth to obtain anchorage of the rod therein to withstand direct pull thereagainst by guy wires connected to the eye of the rod.

Heretofore it has been the practice to drive the screw anchor into earth by either hand operaion or by leverage, but preferably by some form of power drive means. Since these screw anchors are usually employed in conjunction with power poles and installed by the same crew it has been the custom to use the same power drive as is used for the earth boring auger by which the holes are dug for reception of the power poles. While this practice is satisfactory insofar as driving the anchor rod into earth by power means is concerned, much time and loss of man hours is incurred by reason of the fact that the earth boring auger has to be removed from the power drive and another adapter or fitting secured to the drive means for coupling the same to the eye of the anchor rod.

The present invention has as its object the provision of I These and other objects of the present invention will become more apparent from a reading of the following description together with the drawings in which:

Fig. 1 is a side elevational view of a screw anchor coupled to an earth boring auger by an adapter fitting; i

embodying the present invention.

Fig. 2 is a vertical section through the adapter seen in Fig. 1.

Fig. 3 is a bottom plan view of the adapter of Fig. l. as seen from line 3--3 therein.

Fig. 4 is a side view of the adapter only of Fig. 1 as: seen from line 44 therein.

Fig. 5 is a top plan view of the adapter only as seen. from above in Fig. 4.

Fig. 6 is a front side View of the adapter as seen in Fig. 1 but at larger scale with respect thereto.

Fig. 7 is a horizontal section through the adapter of Fig. 4 and taken along line 77 therein.

Referring now to Figs. 1 and 2, the screw anchor rod generally designated 10 is shown coupled to an earth boring auger 11 by means of the adapter fitting 12 of the the present invention. As shown in Fig. 1, the screw anchor has its double helix blades 13 embedded in earth E and its eye portion 14 above the surface S of the earth for connection with the adapter fitting 12.

The earth boring auger 11 comprises a drill shaft 15 having its upper end suitably connected to a power drive means (not shown) in any conventional manner. In this connection the drill shaft 15 is considered a power driven shaft insofar as the description of this invention is concerned. The driven drill shaft 15 is provided with the usual helical blades 16 which may be of the single or double helix of conventional design in earth boring tools. The earth engaging end of the driven drill shaft 15 is provided with a pilot bit 17 usually consisting of a fiat triangular starting tip for entering earth and breaking the way for the larger radial helical blades 16 of the auger.

For purposes of the present disclosure I have shown a fish-tail type pilot bit having helical blades 18 of the double helix type. More particularly, the pilot bit 17 in the present disclosure has features and characteristics more specifically defined and claimed in my copending application, Serial No. 414,007 filed March 4, 1954, and issued December 11, 1956, as Patent No. 2,733,673 from the United States Patent Office. For purposes of this disclosure sulfice it to say that the pilot bit 17 preferably has diammetrically extending blades to present a tip of triangular shape, i.e., tapering toward an apex at from a base end of substantially the same diameter as the drill shaft 15. In the present disclosure the pilot bit 17 has a pair of diammetrically disposed fins 1919 extending beyond its apex a in the form of what I prefer to call a fish tail 20. It should here be understood that the helical blades 18 of the pilot bit may be relatively fiat diamrnetrically opposed radial blades which serve to chew into earth to break up the solid pack thereof.

With the foregoing in mind refer now to the screw anchor adapter 12 of the present invention as shown in Fig. 2 which consists of a unitary casting 21 formed with a relatively hollow core 22 divided between its upper and lower ends 23 and 24, respectively, by a reinforcing web or webs 26-26'. In the preferred embodiment, the reinforcing webs 26 and 26 are formed integrally with a cross brace 25 (see also Fig. 7).

The upper end 23 of the adapter 12 is formed by upper walls 2727 diametrically opposite and spaced from each other (Fig. 5) to provide a space 28 for receiving the radial blades 18 of the pilot bit 17. In this simplified form the tip of the pilot bit is stabilized relative to the casting 21 by engagement with the reinforcing webs 26--26 and the key-like connection of the diametrically extending blade 18 with the slot or space 28 between the walls 27-27 affords a driving connection between the pilot bit and the adapter fitting 12. More specifically and in connection with cone type pilot hits, the upper walls 27-27' are outwardly flared as shown in Fig. 4-. Each wall 27 and 27 is provided with a lip 29 and 29', respectively, on their trailing edges for hearing relation with the spirally extending, blades 18 of the pilot bit 17. In conjunction with the foregoing, each side wall 27-27 is provided with an inset or recess 30-30 in the direction of turning of the pilot bit under the influence of the drill shaft 15. These recesses 30-30 afford passage of the downwardly extending helical margins M of the blades 18 which diminish in radial extension from the axis of the pilot hit. As best illustrated in Figs. 2 and 6, cross brace 25 is of a contour to be received in the crotch formed between the fins 19-19 of the fish tail tip 20 of the pilot bit. In this manner the apex at of the pilot bit is disposed on the upper ridge r of the cross brace and the fins 19--19' straddle the latter for transmitting turn.- ing movement from the pilot bit to the adapter fitting 12. From the foregoing it will be seen that the insertion of the pilot bit 17 into a socket 31 afforded in the upper end of the adapter fitting drivingly couples the bit and adapter together for rotation in unison. If desired, a bolt 32 may be inserted through aligned bores 33--33' in the upper flared walls 2727' and through a hole through the base of the pilot bit 17. The bolt 32 thereby serves to maintain the pilot bit within the socket 31 particularly during reverse turning of the latter and drill shaft should it be desirable to withdraw the screw anchor from the earth E.

The opposite or lower end 24 of the unitary casting 21 is key like in that it is a flange of relatively ovoid shape 34 having its long dimension suitable to receive the eye 14 of the anchor rod but its narrower dimension less than the diameter of the eye 14 for hearing relation therewith during turning of the adapter, see Fig. 3. The upper end of the eye 14 normally bears against the reinforcing diaphragm or webs 26-26' during axial pressure from the drill shaft 15 through the adapter 12 and against the anchor rod eye 14. In this manner, the turning of the adapter 12 by action of the pilot bit 17 and drill shaft 15 is transmitted to the eye 14, anchor rod 10, and its helical blades 13 to drive the latter in screw fashion into the earth E. For the same reasons as stated in connection with the pilot bit 17, a bolt 35 extended through aligned openings 36-46 in the ovoid flange 34 at the lower end 24 of the casting 21 and through the eye 14 serves to maintain these parts together.

From the foregoing it will be apparent that I have provided a simple yet effective adapter fitting 12 for drivingly coupling a screw anchor to the lead end or pilot bit of a conventional earth boring auger 11. Moreover, since the adapter casting 21 has a dual ended female core for the reception of the pilot bit and anchor rod 10 at its opposite ends, it will be apparent that the anchor rod 10 is thereby maintained in driving alignment with the driven drill shaft. It should be noted further that the gradually diminishing triangular or conical pilot bit has a tendency to seek bottomed relation in the socket 31 provided in the adapter casting. Moreover, by reason of the recess formations 3030' in the flared walls of the upper end 23 of this casting clearance is afforded spiral blades when used. On the other hand, since the eye 14 of the screw rod 10 fits up into the ovoid flange 34 the latter confines the eye 14 even though it may be canted within the ovoid flange. The foregoing is true although the screw anchor is to be driven into earth at an angle as illustrated in Fig. 1. That is to say, the anchor rod is maintained insubstantial axial alignment with the driven drill shaft 15 during turning of the latter and descent of the helical blades 13 into the earth E.

While I have described my new screw anchor adapter in specific detail, it will be apparent that the same is susceptible of variations, alterations and/ or modifications without departing from the spirit of this invention. I therefore, desire to avail myself of all variations, alterations and/or modifications as fairly come within the purview of the appended claims.

What I claim as new and desire to protect by Letters Patent is:

1. In earth boring equipment an adapter for coupling the looped eye end of a screw anchor to a cone-shaped pilot bit having a spirally extending blade terminating in a fish-tail tip; comprising a unitary casting having an ovoid socket at one end for receiving the looped eye end of said screw anchor, a cross brace midway the ends of said casting adapted to bear against the looped eye end of said screw anchor and having an upwardly facing rib adapted to receive and be straddled by the fish-tail tip of said pilot bit, and a pair of side walls on said casting above said cross brace spaced from each other transversely of said cross brace and configurated to receive the spirally extending blade of said cone-shaped pilot bit for driving connection therewith.

2. In earth boring equipment an adapter for coupling the looped eye end of a screw anchor to a dual helix pilot bit; in which each helix has a downwardly spiral trend toward an apex, comprising a unitary casting having an ovoid socket formed in its lower end for receiving the looped eye end of said screw anchor rod, a diaphragm between the upper and lower ends of said casting, the upper end of said casting comprising a pair of side walls spaced from each other to facilitate the reception of the dual helix of said pilot bit therebetween, each of said side walls having one edge thereof disposed to bear against the leading face of one helix of said pilot bit and recessed adjacent said diaphragm to conform to the downwardly spiral trend of the helix of said pilot bit.

3. In an earth boring auger an adapter fitting for coupling the looped eye end of a screw anchor to a coneshaped pilot bit provided with symmetrical spirally extending helical blades; the combination with-a unitary casting having its lower end formed to receive the looped eye end of said screw anchor, of outwardly flared opposite side walls on the upper end of said casting conforming to the cone shape of said pilot bit and spaced from each other to receive said cone-shaped pilot bit, said opposite side walls each having a lip spaced from the adjacent edge of the other side wall and configurated to rest against the leading face of a respective one of said spirally extending helical blades of said pilot bit for driving connection therewith.

4. ,In an earth boring auger an adapter fitting for coupling the looped eye end of a screw anchor to a pilot bit provided with spirally extending radial blades terminating in a fish-tail tip; the combination with a unitary casting having an ovoid socket formed in its lower end to receive the looped eye end of said screw anchor in key-like fashion, of a cross brace midway the upper and lower ends of said casting for hearing relation with the looped eye end of said screw anchor and adapted to be straddled by the fish-tail tip of said pilot bit, a pair of side walls on the upper end of said casting spaced from each other for receiving the spirally extending radial blades of said pilot bit between them, each said side wall having a recess formed on its trailing edge conforming in contour to the leading faces of said spirally extending blades for driving engagement therewith during turning of said pilot bit with said auger.

5. In an auger an adapter fitting for coupling the looped eye end of a screw anchor to a cone-shaped pilot bit provided with spirally extending helical blades terminating in a fish-tail tip; the'combination with a unitary casting having its lower end formed to provide an ovoid socket for receiving the looped eye end of said screw anchor in key-like fashion, of an integral cross brace midway the ends of said casting adapted to be straddled by the fishtailed tip of said pilot bit, the upper end of said casting having outwardly flared opposite side walls for receiving said cone-shaped pilot bitbetween them, and the trailing edge of each of said side walls conforming to the downward spiral trend of said spirally extending helical blades for bearing relation therewith upon turning of said pilot bit.

References Cited in the file of this patent UNITED STATES PATENTS 200,203 Knox Feb. 12, 1878 1,114,723 Berry Oct. 27, 1914 1,158,895 Clark Nov. 2, 1915 1,349,428 Marshall, Ir. Oct. 10, 1920 1,532,662 Risser Apr. 7,1925 1,824,892 Hoke a- Sept. 29, 1931 2,099,921 Becker Nov. 23, 1937 2,248,733 Anderson July 8, 1941 2,569,528 Kandle Oct. 2, 1951 FOREIGN PATENTS 10,743 Great Britain 1913 137,771 Sweden Oct. 28, 1952

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