US3709464A - Device for imbedding and removing elongated members - Google Patents

Abstract

This device for driving or forcing elongated members such as electrical ground rods into a penetrable solid such as the subsoil comprises a supporting frame which is releasably anchored in relation to the penetrable solid, the frame having mounted thereon a reciprocating driving means such as a double-acting hydraulic cylinder. The driving means reciprocates gripping jaws linked thereto. The linkage is such that the gripping jaws engage and grip the elongated member upon movement in one direction and release it in the opposite direction. Means are provided for readily adapting the device for reversal of the direction of the gripping and release movements.

Description

United States Patent [1 1 Johnson et al.

[4 1 Jan. 9, 1973 [54] DEVICE FOR IMBEDDING AND REMOVING ELONGATED MEMBERS 2,683,019 7/1954 Saunders ..254/29 R Primary Examiner--Othell M. Simpson Attorney-Pendleton, Neuman, Williams & Anderson [57] ABSTRACT This device for driving or forcing elongated members such as electrical ground rods into a penetrable solid such as the subsoil comprises a supporting frame which is releasably anchored in relation to the penetrable solid, the frame having mounted thereon a reciprocating driving means such as a double-acting hydraulic cylinder. The driving means reciprocates gripping jaws linked thereto. The linkage is such that the gripping jaws engage and grip the elongated member upon movement in one direction and release it in the opposite direction. Means are provided for readily adapting the device for reversal of the direction of the gripping and release movements.

PATENTEDJMI 9 ms 3.7093164 SHEET 1 BF 3 g l 56 FIG. 4

WZWNW HNVENTORS CHARLES D. JOHNSON JAMES 7. DROEGEMUELLER BY wimmmm ATTORNEYS FIG.5

PATENTEUJAH 9 I975 SHEET 2 OF 3 INVENTORS CHARLES 0. uomvso/v ATTORNEYS JAMES FDAVOEGEM ELLE BY m/4M,

PATENTEDJAN 9 I973 52 ill FIE! SHEET 3 OF 3 INVENTORS CHARLES D. JOHNSON ATTORNEYS DEVICE FOR IMBEDDING AND REMOVING ELONGATED MEMBERS BACKGROUND OF THE INVENTION l. Field ofthe Invention This invention relates to a power-actuated device for imbedding elongated members such as electrical ground rods into penetrable solids or substrates such as the surrounding soil or subsoil. More particularly, it re- '0 lates to a versatile, low cost, power-actuated, impactfree rod driver which requires but a single operator and is capable of driving or removing rods of any desired length with a minimum of physical damage.

While the present invention will be described with particular reference to an embodiment designed specifically for imbedding electrical ground rods in soil, it should be understood that the invention is not limited thereto. It can also be adapted for driving or imbedding any elongated member including fence posts and sign posts in various penetrable solids, as those skilled in the art will recognize in the light of the present disclosure.

2. Description of the Prior Art Various techniques are employed for installing electrical ground rods, e.g., copper-coated steel rods, at substations and the like, ranging all the way from manually pounding the rod into the ground with a hammer or lightweight sledge to the use of various power-actuated devices for such purposes. Hand driving is time-consuming, inconvenient, and difficult to accomplish, particularly in the case of ground rods of extreme length, e.g., multi-section rods which may go down as much as 30 to 100 feet or more to reach and penetrate the strata of better conducting soils. The pounding may also damage the rod, and the whipping and bending of the rod as it is progressively hammered enlarges the hole, thereby decreasing contact area and interfering with the desired electrical grounding. These problems and the attendant high cost has led to the development of devices for rendering the manual technique more convenient or otherwise mechanizing the operation.

One crude approach is to apply a driving head to the rod at an intermediate point whereby the rod is gripped for convenient manual driving. A specific embodiment employed for post driving is illustrated, for example, in US. Pat. No. 2,330,360. The tediousness and inefficiencies associated with such hand-driven devices are manifest, as outlined above. In addition, in the case of extremely long posts or rods, the driving head must be repeatedly and manually removed and moved along the rod for an additional bite, as insertion proceeds.

The mechanization of the operation has included rod grippers which are pounded by air hammers or the like, the grippers being progressively moved along the rod by means of quick release handles and the like. Illustrative of such devices is the rod driver of US. Pat. No. 3,034,588. Such device is cumbersome, and, as a practical matter, requires two people to operate, one to hold and operate the air hammer or other impact means and the other to progressively position the rod gripper along the rod as it is progressively inserted. In addition, the device relies upon substantially sharp teeth to achieve the requisite grip on the rod: resulting in excessive physical damage, marring of any surface coating and the like. Moreover, while the device is intended for both rod driving and rod removal, the rod removal technique requires removal and reversal of the device on the rod and is otherwise awkward and incon' venient. It is also sometimes inoperative when only a small portion of the rod protrudes above the ground, leaving insufficient space for application of the air hammer.

Still other techniques include the erection of stands or guide rigs so that the rod can be pounded from the top using various power-actuated hammers, including air hammers, electrical hammers and selficontained gasoline powered hammers. Such alternatives are cumbersome, time-consuming and expensive. Such equipment is also very heavy and difficult to maneuver and requires more than one man to operate. In many instances it can not be readily adapted for rod removal purposes. Adjustments must be made to accommodate rods or couplings of different diameters and lengths. In addition, such techniques require special adapters to prevent damage to the rod, particularly at the top, as the result of the impact forces. As aforementioned, the high impact forces also may cause excessive whipping or bending of the rod and undesired hole enlargement.

OBJECTS OF THE INVENTION It is therefore a general object of the present invention to copewith these and other problems associated with prior art devices. It is another general object to provide a power-actuated, impact-free device for imbedding elongated members in penetrable solids, which device can be readily adapted for removal purposes also.

It is a more specific object to provide a fast-acting, rod driving and rod removal device which can be efficiently operated by a single operator. It is another specific object to provide a power-actuated rod driving and rod removal device which may be powered by conventional hydraulic systems. It is still another specific object to provide a power-actuated driving and removal device wherein the insertion and removal forces are substantially uniformly and smoothly applied without impact forces and without excessive hole enlargement.

It is still another specific object to provide a smoothacting rod driver wherein the insertion forces are applied adjacent the penetrable body with a minimum of rod whipping or bending. It is a still further object to provide a rod driving device wherein the driving forces enhance the gripping forces, whereby the greater the driving force the greater the gripping action. It is a still further object to provide a rod driving and removal device which does not excessively mar the surface or otherwise damage the rod. It is a still further object to provide a rod driving and removal device which can accommodate rods of varying or different diameters and lengths without complicated adjustment.

These and other objects of the present invention will become apparent as the detailed description thereof proceeds.

SUMMARY OF THE INVENTION These objects are achieved in a particular embodiment by a driver comprising a supporting frame which is releasably anchored to an adjacent, substantially immovable, structure. The frame supports a reciprocating drive means such as a double-acting hydraulic cylinder which carries a jaw support head at the end of the reciprocating piston rod. The jaw support head has spaced parallel arms pivotally mounted and extending outwardly therefrom so as to straddle the elongated member to be imbedded.

Outer and inner gripping jaws are pivotally mounted at spaced intervals on the parallel arms. As will become apparent from the drawings hereinafter, the linkage of the grippingjaws and parallel arms is such that the jaws grip the red when the driving means moves in one direction and releases the rod on the return stroke. The linkage is also readily adjustable whereby the gripping and release action may be reversed without physically removing and reversing the device. Thus, the rod may be pushed or pulled in either direction, as desired, the two modes of operation being referred to hereinafter as the insertion mode and the removal mode, respectively.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more clearly understood from the following detailed description of a specific embodiment, read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of the device of the present invention anchored to a utility pole and in the process ofinserting an electrical ground rod;

FIG. 2 is a fragmentary side elevation view of the device on an enlarged scale with the rod gripping jaws in the insertion mode but manually depressed to the open position;

FIG. 3 is a fragmentary front elevation view with the rod grippingjaws in the same position as in FIG. 2;

FIG. 4 is an exploded perspective view on a further enlarged scale of the rod gripping jaws and associated linkage;

FIG. 5 is an enlarged fragmentary section view on the line 5-5 of FIG. 2;

FIG. 6 is a fragmentary side elevation view on a scale somewhat larger than FIG. 2 and, as in FIG. 2, showing the rod gripping jaws in the insertion mode and depressed to the open position;

FIG. 7 is a fragmentary side elevation view similar to FIG. 6 but showing the rod gripping jaws closed on a ground rod preparatory to rod insertion;

FIG. 8 is similar to FIGS. 6 and 7 but depicting the gripping jaws in the rod removal mode; and

FIG. 9 is an enlarged fragmentary plan view in partial section showing the adjustable handle means for anchoring the device to a utility pole or the like.

It should be understood that graphic symbols are employed in the drawings and that the drawings are not necessarily to scale. It should also be understood that details shown in some figures may be omitted in other figures for simplicity and to facilitate illustration of still other details. Thus the drawings may depart in certain respects from actual appearances when visually observed. lt should also be understood, of course, that the invention is not necessarily limited to the particular embodiment illustrated.

DETAILED DESCRIPTION OF THE DRAWINGS,

INCLUDING PREFERRED EMBODIMENT Referring to FIG. I, apparatus 10 of the present invention is releasably anchored to utility pole 12 ad- LII jacent the ground 14 by means of chain loops 16 and 18, which are tightened by chain tighteners 20 and 22, respectively. Apparatus 10 is thus disposed in its insertion mode to force ground rod 24 to the desired depth in ground 14. While ground rod 24 is depicted as a single rod, it may in fact be a multi-sectioned rod having threaded ends which are coupled together by means well known to those skilled in the art.

Apparatus 10 in the present exemplar is hydraulically actuated by means of hydraulic fluid, e.g., compressed air, hydraulic oil, or the like, introduced and returned to a source (not shown) by means of hydraulic lines 26 and 28. One of the advantages of the present invention is that it may be hooked up to already existing hydraulic systems, thus avoiding the expense of specially designed systems.

Referring to FIGS. 2 and 3, apparatus 10 comprises upright frame or stand 30 which is supported on the ground by horizontal portion 32 which is welded and otherwise secured thereto. Frame 30 is held against the anchoring structure, such as utility pole 12 (FIG. 1 by the aforementioned chain loops l6 and 18. One end of each of these chains is linked or pinned to chain tighteners 20 and 22, respectively, the chain tighteners in turn being pivotally mounted on side brackets 34 and 36, respectively, of stand 30. A remote link of each of the chains is inserted into slots 38 and 40 formed between the upper and lower portions of side brackets 42 and 44, respectively. The chains are tightened by chain tighteners 20 and 22 as described in greater detail hereinafter in connection with FIG. 9. Since chains 16 and 18 may be of any selected length, it is apparent that the apparatus may be secured to anchoring structures of almost any girth.

Double-acting hydraulic cylinder 46, having pads 47 and 48 welded thereto, is immovably secured to frame 30 by the indicated bolts which pass through corresponding apertures in pads 47 and 48 and frame 30. These bolts also pass through aligned apertures in brackets 49 and 50, which support upper hollow cylindrical rod guide 52, and thereby similarly secure the latter to frame 30. Guide 52 is disposed above and in general alignment with the outer and inner jaws 54 and 56 of the gripping mechanism. Guide 52 is also aligned with the lower hollow cylindrical rod guide 58, which is mounted on and through the horizontal portion 32 of stand 30, adjacent the ground line.

The piston rod 60 of hydraulic cylinder 46 is reciprocated by conventional hydraulic circuitry (not shown) whereby rod 60 is reciprocally extended and retracted in vertical orientation when the apparatus is operated. Secured to the end of rod 60 is jaw support head 62, which is in sliding engagement with stationary vertical backing bar 64 on stand 30.

As shown in FIGS. 2-5, lateral linkage plates 66 and 68 are pivotally mounted adjacent the sides of support head 62 by means of stripper bolts 70 and 72, respectively, which are threaded into the threaded apertures of the support head. While a separate support head at the end of cylinder rod 60 is employed in this exemplar, it should be understood that the support head could be omitted and the structures modified so that the linkage plates could be pivotally'secured to the rod itself. Such alternative is considered an equivalent of the structure depicted and claimed hereinafter.

Linkage plates 66 and 68 pivotally support outer and inner jaws 54 and 56 by means of bolt and nut combination 74 and 75 and removable pin 76, respectively. Removable pin 76 is held in position by means of detent means 77 adjacent the entering end thereof. As will become apparent hereinafter, in the insertion mode removable pin 76 is inserted in the lower intermediate apertures of linkage plates 66 and 68 and the aligned lower aperture of inner jaw 56. In the removal mode it is inserted in the upper intermediate apertures of linkage plates 66 and 68 and the aligned upper aperture of innerjaw 56.

As viewed in FIGS. 6 and 7, which depict the insertion mode, outer and inner jaws 54 and 56 and linkage plates 66 and 68 are biased in a clockwise direction by means of compressed springs 78 and 80. The end-adjacent portions of springs 78 and 80 are housed in sideby-side cylindrical recesses in the lower surface of inner jaw 56 and aligned cylindrical recesses in the upper surface of bracket 82.

Springs 78 and 80 are retained by means of bolt and nut combinations 84 and 86 and 88 and 90, respectively, the elongated shanks of which slidingly pass through concentric cylindrical apertures in the recesses of bracket 82. Bracket 82 is removably secured to support head 62 by means of removable pin 91, which passes through aligned apertures in the upstanding arms of bracket 82 and the lower portion of support head 62. Removable pin 91 is retained in its inserted position by detent means 92 (FIG. 4). As will become apparent hereinafter, bracket 82 is removed to convert the device-from its insertion mode to the removal mode.

As shown in FIGS. 2, 3, 5 and 6, wherein the jaw linkage is counterbiased in a counterclockwise direction by finger pressure resulting in force F, jaws 54 and 56 are widely spaced so as to receive rods or couplings of various diameters. When counter-biasing is removed, the jaws close, as shown in FIG. 7, so as to incipiently grip rod 24. The are of movement of the inner jaw between the open and closed positions in the insertion mode is indicated in FIG. 6 by are A. It will be noted that the inner jaw initially moves away from and then back towards support head 62 as the jaws close.

When piston rod 60 is extended downwardly, the linkage is such that jaws 54 and 56 tightly grip the rod and smoothly force it downwardly without jolting impact. The greater the required insertion forces, the greater the gripping action. As piston rod 60 reaches the end of its downward travel and commences the return stroke, the linkage is such that the jaws release rod 24 and slidingly return along the rod to the upper position for another grip on a higher portion of rod 24 preparatory to the next insertion stroke. This operation is repeated until the rod is inserted to the depth desired.

The removal mode of the present invention is illustrated in FIG. 8. In this mode, pin 91 is removed, as aforementioned, so as to release bracket 82 with springs 78 and 80 and retainer bolt and nut combinations 84-86 and 88-90. To minimize the chances of misplacing or losing bracket 82 and associated parts when removed, it may be pinned by means of pin 91 to the retainer bracket 93 on the side of stand 30 (FIG. 3).

Also, as aforementioned, in the removal mode pin 76 is removed from the lower intermediate apertures in linkage plates 66 and 68. The upper intermediate apertures are then aligned with the upper aperture on inner jaw 56, and the pin reinserted in the aligned apertures.

Thus, in the removal mode, the pivotal axis of inner jaw 56 is now above, instead of below, a plane through the pivotal axes of linkage plates 66 and 68 and outer jaw 54. The relationship of these parallel axes determines the direction of movement of the rod. In the insertion mode, the pivotal axis of inner jaw 56 is below a plane through the pivotal axes of linkage plates 66 and 68 and outer jaw 54. In the removal mode it is above. In other words, the pivotal axis of the inner jaw is disposed, in relation to the other axes, in the direction of desired movement.

In the removal mode of FIG. 8, the gripping jaws 54 and 56 are gravitationally biased in a counterclockwise direction whereby they incipiently grip rod 24. When piston rod is retracted upwardly, the linkage is such thatjaws 54 and 56 grip rod 24 and pull it upwardly. At the end of the upward stroke, jaws 54 and 56 release their grip on rod 24 and slide downwardly on the rod as piston rod 60 is again extended. On the next upward stroke, the gripping action is repeated. The operation is continued until the rod is completely removed or removed to the extent desired.

In an illustrative specific embodiment, the piston of cylinder 46 has an effective area of about three square inches in the downward direction and the hydraulic system is capable of supplying hydraulic oil up to about 2,000 psi. Thus, a force of as much as three tons is available at the gripping jaws for red insertion. The effective piston area on the upstroke is less, but this presents no difficulty because requisite rod removal forces are usually substantially less than rod insertion forces.

The operation of chain tightener 20 (and identical chain tightener 22) is illustrated in FIG. 9. U-shaped bracket 94 is pivotally bolted to bracket 34 of stand 30 by bolt and nut combination 96 and. 98 (FIG. 3). Square-shaped shaft 100 with threaded cylindrical extremity 102 extends from bracket 94 and telescopes within hollow square shaft 104 having rotatable fluted handle 106 with mating threaded interior. Conventional ball bearings 108 and thrust bearing 110 permit fluted handle 106 to be rotated under load and to move shaft 104 with chain connector bracket 112 relative to shaft 100 and thus stand 30.

When anchoring the device to a utility pole or the like, stand 30 is placed against the pole as illustrated in FIG. 1 and fluted handle 106 is rotated so that shaft 100 extends substantially from shaft 104. Chain 16 is looped around the pole and a link (the closest link possible) inserted in slot 38 (FIG. 3). Fluted handle is then rotated to tighten chain 16 to the desired extent, thereby anchoring the device. Chain tightener 22 is similarly utilized to tighten chain 18.

From the above description and drawings, it is apparent that the objects of the present invention have been achieved. While only certain embodiments have been described or illustrated, many alternative modifications and equivalents will be apparent from the above description to those skilled in the art. These and other alternatives and equivalents are considered within the spirit and scope of the present invention and coverage thereof is intended by the claims of any patents based on this application and any continuations or divisions thereof, even though not necessarily encompassed by the strict verbiage thereof.

Having described the invention, what is claimed is:

l. A device for imbedding elongated members in, or removing the same from, a penetrable solid, said device comprising in combination:

a. a supporting frame;

b. means for releasably anchoring the frame in substantially fixed relation to the penetrable solid;

c. reciprocating driving means mounted on said frame;

d. jaw support means disposed to be reciprocated by said reciprocating driving means;

e. spaced, parallel arms pivotally mounted on said jaw support means and extending outwardly therefrom and disposed to receive the elongated member therebetween;

f. an outer gripping jaw pivotally supported by and between said parallel arms adjacent the outer extremities and having an inner gripping surface disposed upon reciprocation to grip the elongated the pivotal axes of said parallel arms and said outer jaw member, in the direction of desired movement of said elongated member.

2. The device of claim 1 including means for interchangeably pivotally mounting said inner jaw on either side of said plane so as to adjust the direction of the gripping action.

Claims (2)

1. A device for imbedding elongated members in, or removing the same from, a penetrable solid, said device comprising in combination: a. a supporting frame; b. means for releasably anchoring the frame in substantially fixed relation to the penetrable solid; c. reciprocating driving means mounted on said frame; d. jaw support means disposed to be reciprocated by said reciprocating driving means; e. spaced, parallel arms pivotally mounted on said jaw support means and extending outwardly therefrom and disposed to receive the elongated member therebetween; f. an outer gripping jaw pivotally supported by and between said parallel arms adjacent the outer extremities and having an inner gripping surface disposed upon reciprocation to grip the elongated member; and g. an inner gripping jaw pivotally supported by and between said parallel arms in inwardly spaced relationship from said outer jaw whereby the elongated member may be disposed therebetween, said inner gripping jaw having a frictional gripping surface on the outer surface thereof disposed upon reciprocation to grip the elongated member in opposed relationship to the outer gripping jaw; the pivotal axes of said parallel arms and said gripping jaws being parallel and the pivotal axis of said inner jaw being spacedly disposed, in relation to a plane through the pivotal axes of said parallel arms and said outer jaw member, in the direction of desired movement of said elongated member.

2. The device of claim 1 including means for interchangeably pivotally mounting said inner jaw on either side of said plane so as to adjust the direction of the gripping action.

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