US3828562A

US3828562A - Method and apparatus for installing anchors

Info

Publication number: US3828562A
Application number: US00307548A
Authority: US
Inventors: S Petres
Original assignee: Joslyn Manufacturing and Supply Co
Current assignee: Joslyn Corp
Priority date: 1972-11-17
Filing date: 1972-11-17
Publication date: 1974-08-13
Anticipated expiration: 1991-08-13
Also published as: CA986739A

Abstract

A method and apparatus for installing an anchor utilize the rotational power and the axial thrust from a mechanical power source. The novel method and apparatus are particularly adapted for installing an earth anchor of the type having at least one helical screw portion attached to a polygonally shaped hub portion and having an elongated portion extending from the hub portion and include the placement of an elongated drive tube for telescopically receiving the elongated portion extending from the hub portion of the anchor in engagement with the hub portion. An elongated shear pin is utilized to securely retain the anchor in the installation apparatus. An adapter for connecting the drive tube to the mechanical power source includes a force transducer comprising a spring and spline assembly for measuring and indicating the axial thrust applied to the anchor by the mechanical power source and for transmitting the axial thrust through the installation apparatus to the anchor. After the earth anchor is installed to a desired depth, the installation apparatus is removed from the anchor merely by a reverse axial thrust from the mechanical power source sufficient to shear the shear pin.

Description

Petres Aug. 13, 1974 METHOD AND APPARATUS FOR INSTALLING ANCHORS [75] Inventor: Stephen Anthony Petres, Forest Park, Ill.

[73] Assignee: Joslyn Manufacturing and Supply Company, Chicago, Ill.

[22] Filed: Nov. 17, 1972 [21] Appl. No.: 307,548

[52] US. Cl 61/535, 61/5358, 52/157, 73/84, 73/136 A, 175/40 [51] Int. Cl. E02d 5/80, G011 3/02 [58] Field of Search 61/5368, 53.5, 53; 52/157; 73/136 A, 84; 175/40, 50; 279/1 [56] References Cited UNITED STATES PATENTS 2,758,891 8/1956 Kammerer 287/53 X 2,775,889 1/1957 Decker 73/136 A 3,148,510 9/1964 Sullivan 61/5368 3,377,077 4/1968 Hollander et a 52/157 3,525,225 8/1970 Yager et al. 61/535 3,529,460 9/1970 Marcus 73/136 A FOREIGN PATENTS OR APPLICATIONS 3,666 4/1898 Great Britain 61/53 Primary Examiner-Jacob Shapiro Attorney, Agent, or FirmMason, Kolehmainen, Rathburn & Wyss 57 ABSTRACT A method and apparatus for installing an anchor utilize the rotational power and the axial thrust from a mechanical power source. The novel method and apparatus are particularly adapted for installing an earth anchor of the type having at least one helical screw portion attached to a polygonally shaped hub portion and having an elongated portion extending from the hub portion and include the placement of an elongated drive tube for telescopically receiving the elongated portion extending from the hub portion of the anchor in engagement with the hub portion. An elongated shear pin is utilized to securely retain the anchor in the installation apparatus. An adapter for connecting the drive tube to the mechanical power source includes a force transducer comprising a spring and spline assembly for measuring and indicating the axial thrust applied to the anchor by the mechanical power source and for transmitting the axial thrust through the installation apparatus to the anchor. After the earth anchor is installed to a desired depth, the installation apparatus is removed from the anchor merely by a reverse axial thrust from the mechanical power source sufficient to shear the shear pin.

17 Claims, 17 Drawing Figures PATENIEU we 1 3 E174 SHEET 2 BF 5 F/G.5A 9O PATE auslsmu MED saw 3 or 5 3328562 PATENTEB we 1 31974 3'. 828 562 SHEET '4 OF 5 METHOD AND APPARATUS FOR INSTALLING ANCHORS BACKGROUND OF THE INVENTION A. Field of the Invention The present invention relates generally to earth anchors and, more particularly, to a method and apparatus for installing such anchors in the earth.

B. Description of the Prior Art Anchors installed in the earth are commonly utilized to provide anchorage for supporting in tension or in compression electrical or mechanical hardware or equipment. For example, e'arth anchors are commonly utilized to provide anchorage for guy lines used to support electrical transmission, distribution and communication equipment. Further, earth anchors are used to provide support in compression for electrical and mechanical equipment, such as street lighting poles and other similar equipment. As the electrical transmission, distribution and communication equipment has increased in size, more forces are encountered on the guy lines; and, thus, a need for greater anchorage has arisen. To provide greater anchorage, earth anchors have been developed which include helical screw portions having very large screw flange areas. Further, greater anchorage is achieved by providing a plurality of such helical screw portions on a single anchor. As the anchorage capacity of earth anchors is increased, their installation becomes more difficult.

At one time, earth anchors were manually installed However, as anchors have been improved and their size increased, their manual installation has become increasingly difficult and, in some cases, impossible. Thus, in most cases, earth anchors are presently installed by the utilization of the rotational power and the axial thrust from a mechanical power source. Typically, the mechanical power source comprises the power digging machines traditionally used in the construction of electrical transmission, distribution and communication equipment for boring comparatively large diameter holes in the earth by means of auger type drill bits.

Several methods and apparatus have been devised for utilizing these power digging machines to install screw anchors in the earth. One such method and apparatus are disclosed in US. Pat. Nos. 3,148,5l and 3,3 13,058. The method and apparatus of these patents utilize an elongated tube for telescopically receiving a guy rod of a screw anchor and for transmitting the axial thrust and the rotational power from the power digging machine to the anchor for installing the anchor in the earth. While the method and apparatus'of these patents are improvements over the installation of an earth anchor by hand, they have several serious disadvantages.

One such disadvantage is that the mechanism for securely retaining an earth anchor within the installation apparatus is mechanically complex and has a tendency to jam under stress or continuous use. This jamming tendency renders the task of removing the installation apparatus from the installed earth anchor timeconsuming-and arduous.

Another such disadvantage is that after installing an earth anchor by the use of the method and apparatus of the above-mentioned patents, an operator is required to approach the equipment and physically release the mechanism for retaining the earth anchor within the installing device. Such a procedure proves to be time-consuming, expensive due to the added manual labor involved and hazardous in that under certain circumstances, the safety of the operator may be imperiled by his presence in the vicinity of the installation apparatus and by the necessity for him to physically handle the installation apparatus.

Another major disadvantage in the above-mentioned prior art method and apparatus is that in order to remove the installation apparatus from an installed earth anchor, an operator, on occasion, is required to rotate the installed anchor clockwise and counterclockwise and to apply a forward and reverse axial thrust in order to disengage the mechanism for retaining the earth anchor within the installation apparatus to thereby permit the separation of the installation apparatus from the installed earth anchor. Such a removal procedure seriously disturbs the soil around the helical screw portion of an installed earth anchor and thereby reduces the anchorage capacity or holding strength of the installed anchor.

Another serious disadvantage in the use of the abovementioned prior art method and apparatus is the possibility that an operator of the installation apparatus may remove an installed earth anchor, especially those anchors having relatively small helical screw portions, from the earth by inadvertently failing to disengage the mechanism used to securely retain the earth anchor within the installation apparatus.

Another major disadvantage is that, since the telescoping tube of the above-mentioned prior art apparatus contacts an earth anchor merely over the hub portion, in the presence of high installation rotational power or torque, the hub portion may shear separating the helical screw portion from the remaining portions of the earth anchor, thereby preventing the installation of a unitary anchor in the earth.

A further serious disadvantage of the abovementioned prior art method and apparatus is the inability of the installation apparatus to provide an easy and rapid test of the holding strength of an installed earth anchor.

Another major disadvantage of the above-mentioned prior art method and apparatus is the use of a substantially square end on a drive tube for engaging the polygonally shaped hub portion of an earth anchor during the installation procedure. With the use of such a drive tube, the helical screw portion of an earth anchor is engaged at one point on the trailing edge of the helical screw portion. During the application of the forward axial thrust required to install the earth anchor, such a drive tube concentrates the forward axial thrust at that one point of engagement on the trailing edge of the helical screw portion, thereby occasionally damaging the trailing edge of the helical screw portion. This damaged trailing edge of the helical screw portion has been found on many occasions to tear under loading in tension or compression thereby reducing the anchorage capacity of the installed earth anchor.

Another serious disadvantage of the abovementioned prior art method and apparatus also results from the use ofa square drive end for engaging the hub portion of an earth anchor during the installation procedure. Since such a drive end is capable of engaging the earth anchor only in its polygonally shaped hub portion, the earth anchor is able to withstand without damage only a relatively limited amount of torsional and bending stresses. The torsional and bending stresses to which the earth anchor is subjected during the installation procedure are concentrated at the point of engagement of the polygonally shaped hub portion of the earth anchor with the square drive end. If the bending stress to which the earth anchor is subjected during the installation procedure is increased, for example, by the engagement of the forward end of the earth anchor with a relatively fixed object, the amount of torsional stress able to be withstood by the earth anchor is correspondingly reduced. Therefore, the'ability of earth anchors to withstand large amounts of tor- I sional and bending stresses during the installation procedure is rather limited by the use of the abovementioned prior art method and apparatus.

Further, another major disadvantage of the abovementioned prior art method and apparatus is the inability of an operator of the installation apparatus to continuously measure and-monitor the applied forward axial thrust required to install an earth anchor. The continual measuring and monitoring of the applied forward axial thrust is desirable in order to avoid the churning of the soil which would result in a reduced anchorage capacity or holding strength of the installed earth anchor.

Finally, another serious disadvantage of the abovementioned prior art method and apparatus results from the varying soil conditions that may be encountered during an installation procedure which may cause the rotating helical screw portion of an anchor to provide a forward axial thrust much greater than that provided by the power digging machine to thereby pull the anchor, the installation device, the power'digging machine and the supporting mechanism of the power digging machine, typically a boom arm, rapidly forward, thereby damaging or destroying the power digging machine and its supporting mechanism. Thus, the installation of earth anchors by prior art methods and apparatus has proved to be, in many cases. expensive and time-consuming.

SUMMARY OF THE INVENTION An object of the present invention is the provision of a new and improved method and apparatus for installing earth anchors.

Another object of the present invention is the provision of a new and improved method and apparatus for rapidly installing earth anchors and especially adapted for rapidly installing earth anchors of the type having at least one helical screw portion attached to a polygonally shaped hub portion and having an elongated portion extending from the hub portion.

Another object of the present invention is the provision of a new and improved method and apparatus for installing earth anchors of the type having at least one helical screw portion attached to a polygonally shaped hub portion and having an elongated portion extending from the hub portion by the utilization of the rotational i for measuring and indicating the axial thrust from the mechanical power source.

Another object of the present invention is the provision of a new and improved method and means for rapidly disengaging an installation device from an earth anchor after the anchor has been installed in the earth.

Another object of the present invention is the provision ofa new and improved method and means for rapidly testing the holding strength of an earth anchor immediately after installation in the earth.

Another object of the present invention is the provision ofa new and improved method and means for easily and rapidly consolidating the soil normally disturbed around the helical screw portion of an earth anchor during the installation procedure.

Another object of the present invention is the provision ofa new and improved method and means for protecting power equipment used in installing an anchor in the earth from damage caused by a sudden, severe, forward thrust transmitted to the power equipment by the anchor.

Briefly, the above and other objects ofthe present invention are achieved by a new and improved method and apparatus for installing anchors in the earth by the utilization of the rotational power and the axial thrust from a mechanical power source and especially adapted for installing anchors of the type having at least one helical screw portion attached to a polygonally-shaped hub portion and having an elongated portion extending from the hub portion. The installation apparatus preferably includes an elongated drive tube connected to the mechanical power source and adapted to telescopically receive the elongated portion extending from the hub portion of the anchor.

An elongated shear pin held in place by a spring plunger and passing through an aperture in the elongated portion extending from the hub portion of the anchor is utilized to securely retain the anchor in the installation apparatus. The shear pin is further utilized to perform several other important functions during the installation procedure.

After the anchor is installed to a desired depth in the earth, the installation apparatus may be removed from the anchor merely by an axial thrust from the mechanical power source in a direction opposite to that utilized to install the anchor in the earth. The axial thrust must be of an amount sufficient to shear the shear pin. The shearing of the shear pin upon removal of the installation apparatus from the installed anchor provides a proof test for the installed anchor and further sets each installed anchor by compacting and consolidating the soil disturbed around the helical screw portion of the anchor during the installation procedure.

The use of a shear pin eliminates the requirement of an operator to approach the installation apparatus after an earth anchor has been installed to release the locking mechanism for holding the earth anchor within the installation apparatus. Further, the shear pin eliminates the inadvertent removal of small earth anchors after their installation by eliminating the requirement for an operator to disengage a locking mechanism. The shear pin further protects the mechanical power source and its supporting apparatus from damage by shearing in an overload situation.

The installation apparatus further includes an adapter for connecting the drive tube to the mechanical power source. The adapter advantageously includes a force transducer comprising a spring and spline assembly for measuring and indicating the axial thrust applied to the anchor by the mechanical power source and for transmitting the rotational power and the axial thrust through the installation apparatus to the anchor. The force transducer includes visual means for indicating when the preferred axial thrust is being applied by the mechanical power source to thereby enable the installation apparatus to be operated by relatively inexperienced and unskilled personnel.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and advantages and novel features of the present invention will become apparent from the following detailed description of a preferred embodiment of the invention as illustrated in the accompanying drawings wherein:

FIG. 1 is a front, elevational view of a preferred embodiment of a novel apparatus for installing an earth anchor embodying features of the present invention;

FIG. 2 is a fragmentary, front, elevational view of the separation of the novel installation apparatus of FIG. 1 from an installed earth anchor in accordance with the principles of the present invention;

FIG. 3 is a front, elevational view of an earth anchor installed in accordance with the principles of the present invention;

FIG. 4 is an enlarged, cross-sectional view of a portion of the novel apparatus of FIG. 1 taken along line 44 of FIG. 1;

FIG. 5A is an enlarged, fragmentary, partially crosssectional and partially elevational view of a portion of the novel apparatus of FIG. 1 taken along line 55 of FIG. 4;

FIG. 5B is an enlarged, fragmentary, partially crosssectional and partially elevational view of the lowermost portion of the novel apparatus of FIG. 1 taken along line 55 of FIG. 4;

FIG. 6 is an enlarged, cross-sectional view of a portion of the novel apparatus of FIG. 1 taken along line 6-6 of FIG. 5A;

FIG. 7 is an enlarged, cross-sectional view of a portion of the novel apparatus of FIG. 1 taken along line 77 of FIG. 5A;

FIG. 8 is an enlarged, cross-sectional view of a portion of the novel apparatus of FIG. 1 taken along line 8-8 of FIG. 5A;

FIG. 9 is an enlarged, cross-sectional view of a portion of the novel apparatus of FIG. 1 taken along line 9-9 of FIG. 5B; 1

FIG. 10 is an enlarged, fragmentary, elevational view ofa portion of the novel apparatus of FIG. 1 taken from line 10-10 of FIG. 9; g

FIG. 11 is an enlarged, fragmentary, elevational view of a portion of the novel apparatus of FIG. 1 taken from line 11-11 of FIG. 9;

FIG. 12 is an enlarged, fragmentary, elevational view I of a portion of the novel apparatus of FIG. 1 taken from line l2-12 of FIG. 9;

FIG. 13 is an enlarged, fragmentary, exploded, perspective view of a portion of the novel apparatus of FIG. 1;

FIG. 14 is an enlarged, fragmentary, partially cutaway, partially cross-sectional and partially elevational view of an alternate embodiment of a portion of the 6 novel apparatus of FIG. 1 taken along line 55 of FIG.

FIG. 15 is an enlarged, cross-sectional view of a por tion of the device of FIG. 14 taken along line 1515 of FIG. 14; and

FIG. 16 is an enlarged, fragmentary, detail view in cross-section of a portion of the device of FIG. 14 taken along line 1616 of FIG. 15.

DESCRIPTION OF THE PREFERRED EMBODIMENT I. General Description Referring to the drawings and initially to FIG. 1, there is illustrated a new and improved apparatus for installing anchors into the earth generally designated as 20 and constructed in accordance with the principles of the present invention. The installation apparatus 20 serves to rapidly install an anchor into the earth and thereafter to rapidly separate the installation apparatus 20 from the installed anchor.

In accordance with an important advantage of the present invention, the installation apparatus 20 is especially adapted for installing an anchor 22 into the earth or ground 24 by the utilization of the rotational power and the axial thrust from a mechanical power source 26. As used herein, the word earth is intended to des ignate any substance or medium into which an anchor 22 may be placed. For example, the word earth would include an ice layer, an ocean bed or one or more soil layers. The mechanical power source 26 preferably includes a boom arm 28 for supplying the forward axial thrust required to install an anchor 22 into the earth 24 and for supplying the reverse axial thrust required to separate the installation apparatus 20 from an installed earth anchor 22. The mechanical power source 26 in a preferred embodiment further includes a source of rotational power 29. The source of rotational power 29 may be a hydraulic, pneumatic or electrical torque motor. The boom 28 conventionally extends from a truck (not shown) to provide the desired mobility for the mechanical power source 26.

The anchor 22 in the embodiment depicted in FIG. 1 includes a helical screw portion 30 attached to a polygonally shaped hub portion 32 and an elongated portion 34 extending from the hub portion 32. In the embodiment of FIG. 1, the elongated portion 34 comprises a guy rod.

' The installation apparatus 20 includes an elongated drive tube 36 adapted to telescopically receive the elongated portion 34 extending from the hub portion 32 of theanchor 22. In accordance with an important advantage of the present invention, the drive tube 36 preferably includes a wrench engaging first end 38 complementarily shaped to securely engage the polygonally shaped hub portion 32 of the anchor 22 at least partially in the area of attachment40 of the helical screw portion 30 to the hub portion 32 to thereby more effectively transmit the rotational power from the mechanical power source 26 to the anchor 22. By engaging the anchor 22 in the area of attachment 40, the installation apparatus 20 utilizes the increased crosssectional area of that specific portion of the anchor 22 to enable the anchor 22 to withstand the application of a very high rotational power or torque from the me chanical power source 26 without shearing. Since the anchor 22 is adapted to withstand the application of very high rotational power or torque from the mechanical power source 26, the anchor 22 may thus be installed in mediums which previously caused the shearing of anchors 22 at their hub portions 32.

Furthermore, it is occasionally found that during an installation procedure the hub portion 32 may tend to radially deform or twist in response to torsional stresses. In accordance with an important feature of the present invention, under such circumstances, the wrench engaging first end 38 engages the surface of the trailing edge of the helical screw portion 30 lying generally parallel to the longitudinal axis of the anchor 22 to positively engage and rotatably drive the helical screw portion 30 in addition to engaging and driving the hub portion 32. By such a novel engagement, the torsional stresses in the hub portion 32 are relieved and the installation of the anchor 22 into mediums which previously may have caused the shearing of the hub portion 32 is accomplished.

In accordance with an important feature of the present invention, by engaging the polygonally shaped hub portion 32 of the anchor 22 in the area of attachment 40 of the helical screw portion 30 to the hub portion 32, the capacity of an anchor 22 to withstand severe torsional and bending stresses during an installation procedure is greatly increased. By such an engagement of an earth anchor 22 by the installation apparatus 20, the torsional and bending stresses arising during an installation procedure are concentrated at an increased cross-sectional area of an earth anchor 22, that is, throughout the cross-sectional area of the polygonally shaped hub portion 32 and of the helical screw portion 30 of the anchor 22. Thus, an earth anchor 22 installed in accordance with the principles of the present invention is capable of withstanding torsional and bending stresses which formerly would have damaged or destroyed by shearing the hub portion 32 of an anchor 22.

In accordance with a further important feature of the present invention, the wrench engaging first end 38 of the drive tube 36 is complementarily shaped to the pitch of the helical screw portion 30 to engage the helical screw portion 30 along a portion of its surface. By so engaging the helical screw portion 30, the drive tube 36 distributes the applied forward axial thrust required to install an anchor 22 into the earth 24 along a portion of the surface 30 rather than concentrate the applied forward axial thrust at a single point of the surface of the helical screw portion 30. Thus, the possibility of damage to the trailing edge of the helical screw portion 30 during an installation procedure is greatly reduced and, in most cases, eliminated.

In accordance with a further advantage of the present invention, the installation apparatus 20 includes an adapter 50 for connecting the drive tube 36 to the mechanical power source 26. In accordance with an important feature of the present invention, the adapter 50 includes a force transducer 52 comprising a spring and spline assembly for measuring and indicating the axial thrust applied to the anchor 22 by the mechanical power source 26 and for transmitting the rotational power and axial thrust from the mechanical power source 26 to the drive tube 36 for application to the anchor 22. The force transducer 52 preferably includes visual means or designations 54 for indicating when the preferred axial thrust is being applied by the mechanical power source 26 through the installation apparatus 20 to the anchor 22 to thereby aid an operator in the proper installation of an anchor 22 into the earth 24. The visual means or designations 54 may comprise peripherial, colored bands or numerical designations or, preferably, a combination of both. Such visual designations 54 enable the installation apparatus 20 to be operated by relatively inexperienced and unskilled personnel.

The adapter 50 further includes an adapter portion 56 for connecting the installation apparatus 20 to a polygonally shaped rotatable output shaft 58 of the mechanical power source 26. The adapter 50 also includes an adapter portion 60 for connecting the drive tube 36 to the force transducer 52. The adapter portion 60 is designed to receive and securely retain a second, longitudinal end 62 of the drive tube 36. The adapter portion 60 further includes a pair of bolts 64 receivable through a pair of apertures in the end 62 of the drive tube 36 for lockingly engaging and securely retaining the drive tube 36 within the adapter portion 60. The adapter portion 60 also includes an aperture 66 for receiving a shear pin 67 used to retain the anchor 22 within the installation apparatus 20.

The anchor 22, illustrated in FIG. 1, is positioned at a desired angle with respect to the surface of the earth 24 for installation by the installation apparatus 20. In order to install the anchor 22 into the earth 24, an operator energizes the mechanical power source 26 to provide the required rotational power and axial thrust. The required rotational power and axial thrust for installing the anchor 22 into the earth 24 will vary depending upon the particular constituency of the earth 24 at a particular installation location. During the installation procedure, the operator monitors the visual designations 54 of the force transducer 52 to insure that the proper axial thrust is being provided by the mechanical power source 26. In the event of a deviation from the proper axial'thrust, the operator may increase or decrease the axial thrust from the mechanical power source 26 as required to maintain the proper amount of axial thrust during the installation procedure.

After the anchor 22 has been inserted to a desired depth in the earth 24, the installation apparatus 20 may be removed from the anchor 22 by an axial thrust from the mechanical power source 26 in a direction opposite to that utilized to install the anchor 22 into the earth 24 (FIG. 2). This axial thrust in a opposite or reverse di- V rection must be of a sufficient magnitude to shear the shear pin 67 in the aperture 66 of the adapter portion 60. The shearing of the shear pin 67 releases a shear pin coupling 68 attached to the anchor 22 from its position within a complementarily shaped recess 70 in the adapter portion 60 freeing the anchor 22 for removal from the installation apparatus 20. Alternately, after the installation of the anchor 22 into the earth 24, an operator could simply remove the shear pin 67 from the shear pin coupling 68 to permit the simple subsequent separation and removal of the installation apparatus 20 from the installed earth anchor 22.

After the installation apparatus 20 has been removed from the installed anchor 22, the shear pin coupling 68 may be removed and replaced by a suitable eyelet 72 (FIG. 3) to which a guy wire may then be attached.

2. Installation Energy Flow As is apparent from the embodiment of FIG. I, the energy for installing an anchor 22 into the earth 24 is supplied by the mechanical power source 26 and includes the rotational power from the power source 29 and the axial thrust from the boom 28. The rotational power and axial thrust flow from the mechanical power source 26 through the adapter portion 56, the force transducer 52, the adapter portion 60, and the drive tube 36 to the hub portion 32 of the anchor 22. The rotational power and axial thrust are transferred from the installation apparatus 20 to the anchor 22 at the hub portion 32 to enable the anchor 22 to be installed to a desired depth in the earth 24.

As illustrated in FIG. 4, the installation apparatus 20 is connected to the mechanical power source 26 through the adapter portion 56. The adapter portion 56 includes a longitudinally extending, tubular wall portion 74 complementarily shaped to the polygonallyshaped rotatable output shaft 58 of the power source 29 to thereby receive and securely engage'the output shaft 58. The wall portion 74 and the output shaft 58 include aligned, transverse apertures 78 for receiving a bolt or pin coupling 80 used to lock the output shaft 58 and the wall portion 74 together. Preferably, the bolt 80 includes an aperture 82 for receiving a hitch pin clip or a cotter pin to thereby securely retain the pin 80 in the apertures 78.

Although the output shaft 58 has been illustrated as a male shaft and the wall portion 74 illustrated as a female receptacle, the output shaft 58 of the power source 29 may, in a particular embodiment, comprise a female receptacle for receiving a complementarily polygonally shaped male coupling of the adapter portion 56. Further, although the output shaft 58 and wall portion 74 are illustrated as being hexagonally shaped, other polygonally shaped output shafts 58 and wall portions 74 may be utilized.

The adapter portion 56 further includes a plurality of bolts 90 for fastening the adapter portion 56 to the force transducer 52. Other suitable fastening means may be used to couple the adapter portion 56 to the force transducer 52. Alternately, the adapter portion 56 may be integrally formed with the force transducer 52.

From the adapter portion 56, the rotational power and axial thrust required to install an anchor 22 into the earth 24 flows into and through a force transducer 52 (FIG. A). In accordance with animportant advantage of the present invention, the force transducer 52 includes a spring assembly 92 and a spline assembly 94. The spring assembly 92 comprises an elongated spring member 96 restrained between an upper, transverse wall portion or shoulder 98 and a similar, lower, transverse wall portion or shoulder 100, Attached to the shoulder 98 is an elongated, movable, tubular wall portion or housing 102 having one longitudinal end portion 104 movable within an elongated, fixed, tubular wall portion or housing 106 attached to the shoulder 100. As the axial thrust is applied by the mechanical power source 26, the spring member 96 (FIG. 5A) is compressed between the

shoulders

98 and 100 and the housing 102 is telescopically received within the housing 106 in an amount proportional to the applied axial thrust. The outer surface of the housing 102 includes the visual designations 54 (FIG. 1) to indicate the amount of applied axial thrust. After being compressed in an amount proportional to the applied axial thrust, the spring member 96 (FIG. 5A) transfers the applied axial thrust through the shoulder 100 to the adapter portion 60. The spring assembly 92 further functions as a shock absorber for dampening the axial thrust spikes normally arising during a typical installation procedure to thereby achieve a smooth installation of the anchor 22 (FIG. 1) in the earth 24.

The rotational power from the mechanical power source 26 is transferred through the force transducer 52 (FIG. 5A) to the adapter portion 60 by the spline assembly 94. The spline assembly 94 includes an elongated shaft or plunger 108 having a plurality of splines 110 (FIGS. 5A and 6). The specific number of splines 110 will depend upon the rotational power or torque capacity required or to be transferred through the installation apparatus 20. The elongated shaft 108 is movable within a chamber 112 formed by an elongated, tubular member or spline housing 114. One end 116 of the tubular member 114 formes a splined shoulder portion complementarily shaped to the shaft 108 to securely engage the shaft 108 upon the application of rotational power to the force transducer 52 to enable the tubular member 114 to rotate with the shaft 108.

The shaft 108 is terminated at one end by a shoulder portion 118 for retaining the shaft 108 within the chamber 112. Preferably, resilient members 120 are positioned on either side of the shoulder portion 118 to absorb the shock resulting from the shoulder 118 arriving at its upper and lower limit positions, formed, respectively, by the end 116 of the elongated, tubular member 114 and the lower shoulder 100.

Since the elongated, tubular member 114 and the adapter portion 60 are securely attached to the lower shoulder 100 of the force transducer 52 through a bolt assembly 122, the rotational power passing through the force transducer 52 is applied to the adapter portion 60.

The adapter portion 60 includes an elongated recess or chamber complementarily shaped to and securely retaining the longitudinal end 62 of the drive tube 36. The end 62 of the drive tube 36 includes a plurality of apertures 132 for receiving one or more bolts 64 to lockingly engage and securely retain the drive tube 36 within the adapter portion 60. By this engagement, the adapter portion 60 transfers to the drive tube 36 the rotational power and axial thrust from the mechanical power source 26, the adapter portion 56 and the force transducer 52.

As is apparent from FIGS. 1 and 5A, the

adapter portions

56 and 60 could, in an alternate embodiment, be directly connected together should the force transducer 52 not be required or desired during a particular installation of an anchor 22 into the earth 24. Also, as is obvious, in a further alternate embodiment, the

adapter portions

56 and 60 could be formed as an integral unit in the absence of the force transducer 52.

The adapter portion 60 further includes an aperture 66 for receiving the shear pin 67. In accordance with an important feature of the present invention, the shear pin 67 is utilized to retain the anchor 22 within the installation apparatus 20 during the installation procedure. The shear pin 67 is received in an aperture 66 of the adapter portion 60 and an axially aligned aperture 136 in the shear pin coupling 68. Since the shear pin coupling 68 is securely attached to the elongated portion 34 of the anchor 22, the anchor 22 will be held in place within the installation apparatus 20 upon the re ceipt of the shear pin 67 through the

apertures

66 and 136. The shear pin 67 may be utilized in either a single shear mode or in a double shear mode. That is, by inserting only one end of the shear pin 67 into the shear pin coupling 68, the single shear mode of the shear pin 67 is utilized in that the shear pin 67 is required to be severed at only one point in order to release the shear pin coupling 68 from the installation apparatus 20. If the shear pin 67 is positioned in the installation apparatus so that it passes completely through the shear pin coupling 68, the double shear mode of the shear pin 67 is utilized in that, in order to release the shear pin coupling 68 from the installation apparatus 20, the shear pin 67 must be sheared at two points. When used in its double shear mode, approximately twice the amount of energy in the form of reverse axial thrust is required from the mechanical power source 26 in order to completely shear the shear pin 67 than is required if the shear pin 67 are utilized in its single shear mode.

The shear pin 67 may be held securely in place within the

apertures

66 and 136 by any suitable means. For example, a retaining bolt or spring plunger 138 (FIG. 7) may be screwed into engagement with the shear pin 67 through a threaded recess 140 in the adapter portion 60.

The shear pin 67 performs other functions besides merely retaining the anchor 22 within the installation equipment 20. In accordance with an important advantage of the present invention, the shear pin 67 is designed to shear in an overload situation during an anchor installation procedure to thereby protect the power source 29 (FIG. 1) and the boom 28 from damage or destruction.

Anchors 22 occasionally encounter varying soil conditions during their installation in the earth 24. When this occurs, a situation may arise wherein the rotating helical screw portion 30 may provide a forward axial thrust much greater than that provided by the mechanical power source 26 to thereby pull the anchor 22, the installation apparatus 20, the power source 29 and the boom 28 rapidly forward towards the earth 24, possibly damaging or destroying the power source 29, the boom 28 or both. To prevent this situation from occurring, the shear pin 67 shears when the forward axial thrust provided by the rotating helical screw portion 30 exceeds the axial thrust provided by the mechanical power source 26 by an amount equal to or greater than the shear strength of the pin 67. When the shear pin 67 shears in such a situation, the anchor 22 is released from the installation apparatus 20 to prevent the forward axial thrust provided by the rotating helical screw portion 30 of the anchor 22 from being transmitted to the installation apparatus 20, the power source 29 and the boom 28.

In accordance with a further important feature of the present invention, the installation apparatus 20 may be easily and rapidly removed from an installed anchor 22 by a reverse axial thrust from the mechanical power source 26 in a direction opposite to that of the forward axial thrust used to install the anchor 22 into the earth 24. The reverse axial thrust from the mechanical power source 26 must be of an amount equal to or greater than the shear strength of the shear pin 67. This rapid and easy separation of the installation apparatus 20 from an installed earth anchor 22 greatly reduces the time formerly required to complete the installation of an anchor 22 into the earth 24.

Further, the use of the shear pin 67 to retain the anchor 22 in the installation apparatus 20 eliminates the requirement for an operator to approach and physically contact the installation apparatus 20 in order to disengage the locking mechanism conventionally utilized in the prior art to retain the anchor 22 within the installation apparatus 20. In addition, the use of a shear pin 67 eliminates the possibility of an inadvertent removal of an installed earth anchor 22 from the earth 24 by the failure of an operator to release the locking mechanism conventionally used in the prior art. Also, by merely requiring a reverse axial. thrust from the mechanical power source 26 to shear a shear pin 67 to separate the installation apparatus 20 from an installed earth anchor 22, the procedure occasionally required by the use of prior art installation devices of alternately rotating an installed earth anchor 22 clockwise and counterclockwise and of alternately applying a forward and reverse axial thrust in order to disengage the mechanism for retaining the earth anchor 22 within the installation device is eliminated. Thus, the reduction in the anchorage capacity or holding strength of an installed earth anchor 22 by the disturbance of the soil around the helical screw portion 30 of an earth anchor 22 during such a removal procedure is eliminated.

The separation of the installation apparatus 20 from an installed earth anchor 22 accomplishes at least two other important functions. First, by requiring the shear pin 67 to be sheared before the separation of the installation apparatus 20 from an installed anchor 22 can occur, the installed anchor 22 is thereby tested for its holding strength. Due to the inability of installers to accurately predict the precise holding strength of an anchor 22 in every installation location, a test of the holding strength of an installed anchor 22 is usually required after the installation procedure. This test, in accordance with the principles of the present invention, is easily and rapidly performed during the separation of the installing apparatus 20 from an installed anchor 22. Since the particular holding strengths required for different installed anchors 22 may vary depending upon the loads to which the anchors 22 are expected to be subjected, the shear pins 67 utilized to retain the anchors 22 within the adapter portions (FIG. 5A) should be chosen so that their shear strengths are sufficient to provide an adequate test of the holding strengths of the installed anchors 22.

During a particular installation procedure, it may be found necessary or desirable to use a different shear pin 67 to test the holding strength of an installed anchor 22 than the shear pin 67 utilized to install the anchor 22 into the earth. In such a situation, after the installation of an anchor 22 into the earth 24, an operator may release the retaining bolt or spring plunger 138, remove the shear pin 67 used during the installation procedure and substitute therefor a different shear pin 67 for testing the holding strength of an installed anchor 22. Alternately, in such a situation, it may be sufficient for an operator to merely change the shear pin 67 from its use in its single shear mode of operation to a position in the adapter portion 60 in which its double shear mode of operation is utilized.

Secondly, since an installed anchor 22 is tensioned by the reverse axial thrust applied to shear the shear pin 67 during the separation of the installation apparatus 20 from the installed anchor 22, each installed anchor 22 is thereby set in the earth in that the soil normally disturbed around the helical screw portion 30 during the installation procedure is consolidated and comits receipt in the recess 70.

pacted by the tensioning of the installed anchor 22 during the separation procedure.

As illustrated in FIGS. A, 7 and 8, the recess 70 is of a smaller cross-sectional area than the recess or chamber 130. The inner dimensions of the recess or chamber 130 are designed to closely correspond to and just slightly exceed the outer dimensions of the end 62 of the drive tube 36 so as to reduce any movement or play of the drive tube 36 within the adapter portion 60 to a minimum. The drive tube 36 further includes a plurality of transverse, radially aligned apertures 132 to thereby enable the elongated tube 36 to be securely engaged by the bolts 64 notwithstanding the radial orientation of the drive tube 36 upon its receipt within the adapter portion 60.

Similarly, 'the inner dimensions of the recess 70 closely correspond to and are just slightly greater than the outer dimensions of theshear pin coupling 68 to thereby reduce any movement or play of the shear pin coupling 68 within the adapter portion 60 to a minimum. The shear pin coupling 68 further similarly includes a plurality of transversely aligned apertures 136 positioned so as to enable the shear pin coupling 68 to receive the shear pin 67 and to thus be securely retained within the adapter portion 60 notwithstanding the radial orientation of the shear pin coupling 68 upon The recess 70 further includes at its lower end tapered wall portions 142 to aid in the easy insertion of the shear pin coupling 68 in the recess 70. The tapered wall portions 142 act as a guide. to direct the leading edges of the shear pin coupling 68 easily into the recess 70. The recess 70 in the adapter portion 60 further includes at its lower extremity shoulder portions 144 to act as stops in limiting the upward movement of the drive tube 36 within the aperture portion 60. As illustrated in FIG. 5A, the shear pin coupling 68 may include threaded recesses 146 of different diameters at opposite ends of the shear pin coupling 68 to enable the shear pin coupling 68 to accommodate elongated portions 34 of different diameters.

The rotational power and axial thrust required to install an anchor 22 (FIG. 1) into the earth 24 passes from the adapter portion 60 (FIG. 5A) to the drive tube 36 for application to the anchor 22 at its hub portion 32 (FIG. 5B). In accordance with an important advantage of the present invention, the wrench engaging end 38 of the drive tube 36 is complementarily shaped to securely. engage the polygonally shaped hub portion 32 of the anchor 22 at least partially in the area of attachment 40 of the helical screw portion 30 to the hub portion 32 to more effectively transmit the rotational power from the mechanical power source 26 to the anchor 22. This novel engagement of a polygonally shaped hub portion 32 of an anchor 22 by the drive tube 36 of the present invention may be readily appreciated by reference to the several views of this engagement depicted in FIGS. 5B and 9 through 12.

By engaging the anchor 22 in the area of attachment of the helical screw portion 30 to the hub portion 32, the drive end 36 of the installation apparatus takes advantage of the increased mechanical stiffness of the anchor 22 due to the increased cross-sectional area at that specific portion of the anchor 22 to enable the anchor 22 to withstand the application ofa very high rotational power or torque from the mechanical power source 26 without shearing.

Further, since the engagement of the installation apparatus 20 with the anchor 22 takes place at an increased cross-sectional area of the anchor 22, the anchor 22 is able to withstand much greater torsional and bending stresses without shearing than earth anchors 22 installed according to conventional prior art methods and devices.

Also, in accordance with an important feature of the present invention and as clearly illustrated in FIGS. 5B and 9 through 12, the wrench engaging first end 38 of the drive tube 36 advantageously is complementarily shaped to follow the pitch of the helical screw portion 30 and to engage the helical screw portion 30 along a portion of its surface to thereby distribute the forward axial thrust required to install the anchor 22 into the earth along a portion of the surface of the helical screw portion 30. This novel engagement reduces the possibility of damaging the trailing edge of the helical screw portion 30 by the conventional engagement of the helical screw portion 30 by a square drive end at one point of the trailing edge of the helical screw portion 30 in accordance with prior art methods and devices.

Further, as is clearly illustrated in FIGS. 58 and 12, the wrench engaging end 38 of the drive tube 36 may, on occasion, engage a surface 147 of the helical screw portion 30 to apply the rotational power from the power source 29 directly to the helical screw portion 30 and to thereby relieve a portion of the torsional stress in the hub portion 32 of an anchor 22 during an installation procedure.

The wrench engaging first end 38 is further graphically illustrated in FIG. 13 wherein an enlarged, fragmentary, exploded, perspective view of several of the individual components of the installation apparatus 20 described above is set forth. In assemblying the component parts of the installation apparatus 20 in accordance with the principles of the present invention, the drive tube 36 is inserted into the recess or chamber 130 until the longitudinal end 62 of the drive tube 36 is stopped by the shoulder portions 144. In this position, 7

two of the apertures 132 in the drive tube 36 are aligned with a plurality of apertures 148 in the adapter portion for receiving the bolts 64. The bolts 64 are inserted in the apertures 148 until two end portions 150 of the bolts 64 are received within two of the apertures 132 of the drive tube 36 to thereby securely retain the drive tube 36 within the recess or chamber 130.

In order to insert and securely retain the anchor 22 within the installation apparatus 20, the shear pin coupling 68 is attached to one end of the elongated portion 34 of the anchor 22. One suitable manner of attachment is by the reception of a threaded end 152 of the elongated portion 34 of th anchor 22. within the threaded recess 146 in one longitudinal end of the shear pin coupling 68. After the shear pin coupling 68 is attached to the anchor 22, the anchor 22 is inserted into the installation apparatus 20 by passing the shear pin coupling 68 and the end portion 34 through the drive tube 36 and into the adapter portion 60. The shear pin coupling 68 is guided into its at rest position within the recess 70 by the tapered wall portions 142. In this position, the shear pin 67 is inserted through the

apertures

66 and 136 and is securely retained in its normal operating position (FIG. 5A) by the retaining bolt or spring plunger 138 (FIG. 13).

The apertures 136 in the shear pin coupling 68 are elongated axially in order 'to enable the shear pin 67 to be received therethrough irrespective of slight differences in the lengths of different anchors 22. The coupling 68 is preferably designed so as not to engage the closed longitudinal end of the recess 70. Such an engagement would in many cases, cause the elongated portion 34 to buckle in the drive tube 36. Thus, the distance between each longitudinal end of the elongated aperture 136 (FIG. 13) and the more distant end of the two longitudinal ends of the shear pin coupling 68 is less than the distance between the elongated aperture 66 in the adapter portion 60 and the closed longitudinal end of the recess 70. By maintaining these dimensional relationships, the axial force from the mechanical power source 26 (FIG. 1) is applied by the drive tube 36 to the helical screw portion 30 of the anchor 22 to thereby drive the anchor 22 into the earth 24.

3. Modifications Obviously, many modifications and variations of the present invention are possible in light of the above teachings. For example, an alternate embodiment of the force transducer 52 (FIG. SA) constructed in accordance with the principles of the present invention is a force transducer 158 (FIGS. 14 through 16). The force transducer 158 may be used for those installation procedures in which the forward axial thrust applied to an anchor 22 must be precisely controlled and monitored. The force transducer 158 effectively reduces the loss ofa portion of the forward axial thrust in overcoming the friction forces present in the transducer 52 (FIG. 5A) and thus enables the visual designations 54 (FIG. 14) to more accurately indicate the forward axial thrust being applied to the anchor 22.

The force transducer 158 includes a spring assembly 92 and a spline assembly 160. The spring assembly 92 of FIG. 14 differs from the spring assembly 92 of FIG. 5A only in that the elongated spring member 96 (FIG. 14) is compressed between a shoulder 98 and a spline housing flange 162 preferably integrally attached to an elongated, tubular member or spline housing 164.

In accordance with an important feature of the present invention, the spline. assembly 160 includes a ball bearing spline 166 securely fastened to one end or a shoulder portion 168 ofthe housing 164. The ball bearing spline 166 reduces to a minimum the amount of the forward axial thrust lost through the frictional engagement ofthe shaft 108 (FIG. 5A) with the end 116 ofthe tubular member or spline housing 114. Thus, the ball bearing spline 166 (FIG. 14) permits the forward axial thrust to be monitored quite closely and to be quite accurately indicated by the visual designations 54 (FIGS. 1 and 14).

The spline assembly 160 includes an elongated shaft or plunger 170 having a plurality of splines 172. The shaft 170 preferably includes a plurality of inner concave races 174 for receiving a plurality of ball bearings 176 positioned in a plurality of outer concave races 178 that mate with the races 174 and are positioned within the spline 166. Preferably, the ball bearings 176 provide the only contact between the shaft 170 and the spline 166. An unlimited amount of rolling travel is provided for the ball bearings 176 by providing a return path 180 for the ball bearings 176 which may be entered at the extremities of the outer concave races 178. The return path 180 provides a closed circuit or loop through which the ball bearings 176 recirculate when the shaft 170 and the spline 166 are axially displaced relative to each other.

Preferably, the shaft 170 is terminated at one end by a member or shoulder portion 182 for retaining the shaft 170 within a chamber 184 of the housing 164. Resilient members 186 are positioned on either side of the shoulder portion 182 to absorb the shock resulting from the shoulder portion 182 arriving at its upper and lower limit positions, formed, respectively, by the end 168 of the tubular member or housing 64 and the lower shoulder 100. Further, a thin metallic or hard nylon washer 188 may be utilized to reduce the wear on the upper resilient member 186 in contacting the shoulder portion 168 at the upper limit position of the shaft 170.

At the other end of the shaft 170, a polygonally shaped, longitudinally extending portion 190 integrally connected to the shaft 170 is provided for mating with and reception in a complementarily shaped recess 192 in the shoulder 98 for transferring the rotational power from the shoulder 98 to the shaft 170. Further, the shaft 170 may include a threaded, longitudinally extending portion (not shown) integrally attached to the portion 190 and received within a complementarily shaped and threaded recess (not shown) in the adapter portion 56 f0 securely retaining the portion 190 in the recess 192 to thereby maintain the shaft 170 in engagement with the shoulder 98. In assembling the shaft 170, the shoulder 98 and the adapter portion 56, one longi tudinal end of the splined portion of the shaft 170 is brought into engagement with the shoulder 98 such that the portion 190 is fully received within the recess 192. The threaded, longitudinally extending portion of the shaft 170 may then be received within the complementarily shaped and threaded recess of the adapter portion 56 by rotating the adapter portion 56, the shaft 170 and the shoulder 98 or the force transducer 158, until the threaded portion of the shaft 190 is fully received within the complementarily shaped and threaded recess of the adapter portion 56. The bolt assembly may then be secured in place to retain the adapter portion 56, the shoulder 98 and the shaft 170 in a secure engagement.

Preferably, the flange 162 is securely fastened to the shoulder by a bolt assembly 194. The shoulder 100 may be attached to the adapter portion 60 by means of a bolt assembly 196. The housing 106 may be securely fastened to the flange 162 by a set screw assembly 197.

The ball bearing spline 166 may be securely attached to the end 168 of the housing 164 by means of a set screw assembly or a key and set screw assembly 198. A bolt assembly 199 may be utilized to secure the shoulder portion 182, the upper resilient member 186 and the washer 188 to the shaft 170. Finally, a recessed bolt assembly 200 is preferably utilized to secure the lower resilient member 186 to the shoulder portion 182.

Further, a particular earth anchor 22 (FIG. 1) may include a plurality of helical screw portions 30 longitudinally disposed in a spaced relation along an elongated polygonally shaped hub portion 32. The elongated portion 34 of such an anchor 22 may in many cases merely comprise an integral, similarly polygonally shaped extension of the hub portion 32.

To install such an anchor 22, the drive tube 36 of the present invention may be rather short in length and include an end 62 receivable within the adapter portion 60 for securely retaining the drive tube 36 as an integral part of the installation apparatus and a wrench engaging first end 38 for engaging the hub portion 32 of such an anchor 22 in the area of attachment 40 of the uppermost helical screw portion to the hub portion 32. I

Also, instead of merely providing anchorage for a guy line, the anchor 22 (FIG. 1) may be utilized as a support for street lighting poles or other similar equipment. In such an application, the elongated portion 34 may comprise a hollow or solid, tubular, elongated member extending from the hub portion 32. The uppermost end of such an elongated member would be modified, for example, by the attachment thereto of a support plate, to serve as an attachment and support means for a street lighting pole or other similar equipment.

Furthermore, the elongated portion 34 of an anchor 22 and the drive tube36 may in a particular embodiment be required to be extended in length by including a plurality of similar such elements suitably coupled together in order to install the anchor 22 to a desired depth in the earth 24. Thus, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed and desired to be secured by Letters Patent of the United States is:

l. A device for installing an anchor of the type having at least one helical screw portion, a polygonally shaped hub portion and an elongated portion extending from said hub portion, in the earth by the utilization of rotational power and axial thrust from a mechanical power source comprising an elongated tubular means for housing said elongated portion of said anchor and having a first end adapted to securely en gagesaid polygonally shaped hub portion of said anchor and means for connecting said elongated tubular means to said mechanical power source, said connecting means including means for measuring and indicating said axial thrust from said mechanical power source.

2. A device as defined in claim 1 wherein said measuring and indicating means includes a spline assembly for transmitting said rotational power from said mechanical power source through said measuring and indicating means to said tubular means for application to said anchor.

3. A device as defined in claim 2 wherein said measuring and indicating means further includes an elongated resilient means adapted to be compressed in response to the application of said axial thrust to thereby measure and provide and indication of said axial thrust and to thereby also transmit said axial thrust from said mechanical power source through said measuring and indicating means for application to said anchor.

4. A device for installing an anchor of the type having at least one helical screw portion, a polygonally shaped hub portion and an elongated portion extending from said hub portion, in the earth by the utilization of rotational power and axial thrust from a mechanical power source comprising an elongated tubular means for housing said elongated portion of said anchor and having a first end adapted to securely engage said polygonallyshaped hub portion of said anchor and means for connecting said elongated tubular means to said mechanical power source, said connecting means including means for measuring and indicating said axial thrust from said mechanical power source, said measuring and indicating means including I a spline assembly for transmitting said rotational power from said mechanical power source through said measuring and indicating means to said tubular means for application to said anchor,

an elongated resilient means adapted to be compressed in response to the application of said axial thrust to thereby measure and provide an indication of said axial thrust and to thereby also transmit said axial thrust from said mechanical power source through said measuring and indicating means for application to said anchor,

first and second shoulder portions positioned transverse to the longitudinal direction of said resilient means and engaging the opposite longitudinal extremities of said resilient means to thereby contain said resilient means between said first and second shoulder portions,

an elongated tubular member having a first longitudinal opening corresponding to a first inner diameter of said tubular member, a first end fixedly attached to said first shoulder'portion and a sec: ond longitudinal opening at a second end of said tubular member corresponding to a smaller inner diameter of said tubular member than said first inner diameter to thereby form a third shoulder portion,

an elongated plunger having a first end fixedly attached to said second shoulder portion, having a fourth shoulder portion attached to a second end of said plunger and being movable within said elongated tubular member,

said first shoulder portion and said third shoulder "portion being oppositely disposed stops for said fourth shoulder portion to prevent further movement of said plunger within said elongated tubular member, and

resilient members positioned between said first shoulder portion and said fourth shoulder portion and between said third shoulder portion and said fourth shoulder portion to absorb the physical shock resulting from the prevention of further movement of said fourth shoulder means by said first and third shoulder means. 5. A device as defined in claim 1 wherein said connecting means further includes first means for receiving and securely retaining said elongated tubular means and second means for lockingly engaging said mechanical power source, said measuring and indicating means being positioned between said first and second means and being adapted to be securely interconnected with said first means and with said second means.

6. In combination, an anchor of the type having at least one helical screw portion, a polygonally shaped hub portion and an elongated portion extending from said hub portion and a device for installing said anchor in the earth by the utilization of rotational power and axial thrust from a mechanical power source, said device comprising an elongated tubular means for housing said elongated portion of said anchor and having a first end adapted to securely engage said polygonally shaped hub portion of said anchor and means for connecting said elongated tubular means to said mechanical power source, said connecting means including means for measuring and indicating said axial thrust from said mechanical power source. 7. The combination as defined in claim 6 wherein said measuring and indicating means includes a spline assembly for transmitting said rotational power from said mechanical power source through said measuring and indicating means to said tubular means and said anchor.

8. The combination as defined in claim 7 wherein said measuring and indicating means further includes an elongated resilient means adapted to be compressed in response to the application of said axial thrust to thereby measure and provide an indication of said axial thrust and to thereby also transmit said axial thrust from said mechanical power source through said measuring and indicating means to said tubular means and said anchor.

9. The combination as defined in claim 6 wherein said connecting means further includes first means for receiving and securely retaining said elongated tubular means and second means for lockingly engaging said power source, said measuring and indicating means being positioned between said first and second means and being adapted to be securely interconnected with said first means and with said second means.

10. A device for installing an anchor of the type having at least one helical screw portion, a polygonally shaped hub portion and an elongated portion extending from said hub portion, in the earth by the utilization of rotational power and axial thrust from a mechanical power source and having an elongated tubular means for housing said elongated portion of said anchor including a first end adapted to securely engage said polygonally shaped hub portion of said anchor, wherein the improvement comprises means for connecting said elongated tubular means to said mechanical power source, said connecting means including means for measuring and indicating said axial thrust from said mechanical power source.

11. A device as defined in claim 10 wherein said measuring and indicating means includes a spline assembly for transmitting said rotational power from said mechanical power source through said measuring and indicating means to said tubular means for application to said anchor.

12. A device as defined in claim 11 wherein said spline assembly includes a ball bearing assembly.

13. A device as defined in claim 10 wherein said measuring and indicating means includes an elongated resilient means adapted to be compressed in response to ace 4;

the application of said axial thrust to thereby measure and provide an indication of said axial thrust and to thereby also transmit said axial thrust from said mechanical power source through said measuring and indicating means for application to said anchor.

14. A device for installing an anchor of the type having at least one helical screw portion, a polygonally shaped hub portion and an elongated portion extending from said hub portion, in the earth by the utilization of rotational power and axial thrust from a mechanical power source and having an elongated tubular means for housing said elongated portion of said anchor including a first end adapted to securely engage the polygonally shaped hub portion of said anchor, wherein the improvement comprises a shear pin assembly for retaining said elongated portion of said anchor within said elongated tubular means during the installation of said anchor into the earth.

15. A device as defined in claim 14 wherein said shear pin assembly includes a shear pin and means for retaining at least a portion of said shear pin within said device during the installation of said anchor into the earth.

16. A method of installing an anchor of the type having at least one helical screw portion, a polygonally shaped hub portion and an elongated portion extending from said hub portion, in the earth by the utilization of rotational power and axial thrust from a mechanical power source comprising the steps of engaging said hub portion of said anchor with an anchor installing device,

securely retaining said anchor in engagement with said anchor installing device by means of an elongated shear pin,

connecting said anchor installing device to said mechanical power source and energizing said source to install said anchor in the earth.

17. A method ofinstalling an anchor of the type having at least one helical screw portion, a polygonallyshaped hub portion and an elongated portion extending from said hub portion, in the earth by the utilization of rotational power and axial thrust from a mechanical power source comprising the steps of engaging said hub portion of said anchor with an anchor installing device,

connecting said anchor installing device to said me chanical power source,

energizing said source to install said anchor in the earth and separating said anchor after installation in the earth from said anchor installing device by shearing said shear pin.

Claims

1. A device for installing an anchor of the type having at least one helical screw portion, a polygonally shaped hub portion and an elongated portion extending from said hub portion, in the earth by the utilization of rotational power and axial thrust from a mechanical power source comprising an elongated tubular means for housing said elongated portion of said anchor and having a first end adapted to securely engage said polygonally shaped hub portion of said anchor and means for connecting said elongated tubular means to said mechanical power source, said connecting means including means for measuring and indicating said axial thrust from said mechanical power source.

4. A device for installing an anchor of the type having at least one helical screw portion, a polygonally shaped hub portion and an elongated portion extending from said hub portion, in the earth by the utilization of rotational power and axial thrust from a mechanical power source comprising an elongated tubular means for housing said elongated portion of said anchor and having a first end adapted to securely engage said polygonally-shaped hub portion of said anchor and means for connecting said elongated tubular means to said mechanical power source, said connecting means including means for measuring and indicating said axial thrust from said mechanical power source, said measuring and indicating means including a spline assembly for transmitting said rotational power from said mechanical power source through said measuring and indicating means to said tubular means for application to said anchor, an elongated resilient means adapted to be compressed in response to the application of said axial thrust to thereby measure and provide an indication of said axial thrust and to thereby also transmit said axial thrust from said mechanical power source through said measuring and indicating means for application to said anchor, first and second shoulder portions positioned transverse to the longitudinal direction of said resilient means and engaging the opposite longitudinal extremities of said resilient means to thereby contain said resilient means between said first and second shoulder portions, an elongated tubular member having a first longitudinal opening corresponding to a first inner diameter of said tubular member, a first end fixedly attached to said first shoulder portion and a second longitudinal opening at a second end of said tubular member corresponding to a smaller inner diameter of said tubular member than said first inner diameter to thereby form a third shoulder portion, an elongated plunger having a first end fixedly attached to said second shoulder portion, having a fourth shoulder portion attached to a second end of said plunger and being movable within said elongated tubular member, said first shoulder portion and said third shoulder portion being oppositely disposed stops for said fourth shoulder portion to prevent further movement of said plunger within said elongated tubular member, and resilient members positioned between said first shoulder portion and said fourth shoulder portion and between said third shoulder portion and said fourth shoulder portion to absorb the physical shock resulting from the prevention of further movement of said fourth shoulder means by said first and third shoulder means.

5. A device as defined in claim 1 wherein said connecting means further includes first means for receiving and securely retaining said elongated tubular means and second means for lockingly engaging said mechanical power source, said measuring and indicating means being positioned between said first and second means and being adapted to be securely interconnected with said first means and with said second means.

6. In combination, an anchor of the type having at least one helical screw portion, a polygonally shaped hub portion and an elongated portion extending from said hub portion and a device for installing said anchor in the earth by the utilization of rotational power and axial thrust from a mechanical power source, said device comprising an elongated tubular means for housing said elongated portion of said anchor and having a first end adapted to securely engage said polygonally shaped hub portion of said anchor and means for connecting said elongated tubular means to said mechanical power source, said connecting means including means for measuring and indicating said axial thrust from said mechanical power source.

7. The combination as defined in claim 6 wherein said measuring and indicating means includes a spline assembly for transmitting said rotational power from said mechanical power source through said measuring and indicating means to said tubular means and said anchor.

13. A device as defined in claim 10 wherein said measuring and indicating means includes an elongated resilient means adapted to be compressed in response to the application of said axial thrust to thereby measure and provide an indication of said axial thrust and to thereby also transmit said axial thrust from said mechanical power source through said measuring and indicating means for application to said anchor.

16. A method of installing an anchor of the type having at least one helical screw portion, a polygonally shaped hub portion and an elongated portion extending from said hub portion, in the earth by the utilization of rotational power and axial thrust from a mechanical power source comprising the steps of engaging said hub portion of said anchor with an anchor installing device, securely retaining said anchor in engagement with said anchor installing device by means of an elongated shear pin, connecting said anchor installing device to said mechanical power source and energizing said source to install said anchor in the earth.

17. A method of installing an anchor of the type having at least one helical screw portion, a polygonally-shaped hub portion and an elongated portion extending from said hub portion, in the earth by the utilization of rotational power and axial thrust from a mechanical power source comprising the steps of engaging said hub portion of said anchor with an anchor installing device, securely retaining said anchor in engagement with said anchor installing device by means of an elongated shear pin, connecting said anchor installing device to said mechanical power source, energizing said source to install said anchor in the earth and separating said anchor after installation in the earth from Said anchor installing device by shearing said shear pin.