GB2108419A - Rod driver - Google Patents

Abstract

A rod driver includes an elongate body having a longitudinal bore (30) defined therethrough. A driver head (40) has a curved cutout portion (60) defined therein to cover the bore so the bore has a concave blind end. A rod aft end (12) is impacted by the surface defining the cutout so that any deformation of the rod does not inhibit operation of the rod driver. <IMAGE>

Description

SPECIFICATION Rod driver The present invention relates to ground embedded rods, and, more particularly, to a means for driving such rods into the ground.

Many rods must be driven into the ground to carry out the function of those rods. An electrical grounding rod is such a rod. Many electrical grounding rods are formed of a material which can be deformed by impacts delivered thereto. Often, these rods must be driven into ground which is very hard, and thus must be given a large number of extremely forceful impacts to set the rod to the prescribed depth. Such impact setting often distorts the rod aft end into a mushroom shape, and a frayed end results. Such frayed ends are not only aesthetic drawbacks, they may be hazardous as well. There are many known devices which can be used to drive a rod into the ground. Examples of such devices range from the common hammer to devices such as disclosed in U.S. Patents Nos. 2,145,420, 1,693,848, 1,661,712 and 2,147,828.However, none of these devices can accommodate a wide variety of grounding rod sizes while permitting the deformation of the grounding rod during the driving process to occur in a manner which facilitates operation of the device.

Accordingly, there is need for a ground rod driving device which can accommodate a wide variety of grounding rod sizes and which facilitates further and continued operation of the device during the driving process.

The grounding rod driving device embodying the teachings of the present invention accommodates a wide variety of rod sizes, and causes the grounding rod to deform in a manner which facilitates the further and continued operation of the device.

The driver includes a tubular body having an axial bore defined therethrough. A head is connected to the tubular body and has a cutout region defined therein which is parabolic in shape, and is oriented to be aligned with the tubular body bore. The cutout region is upwardly converging with respect to the bore, and the longitudinal surface of the aft end of the grounding rod contacts the inner surface of the head which defines the cutout region during the driving process. The aft end of the grounding rod is planar and circular in shape, and thus the outer circumferential edge thereof contacts the cutout inner surface which is upwardly converging.

During the driving process, the rod is accommodated within the bore of the tubular body, and the drive is reciprocated up and down on the rod while delivering impacts to the aft end of the rod via the cutout inner surface.

The rod may deform due to the aforementioned impacts. However, due to the upwardly curving convergent nature of the cutout, the rod aft end will not mushroom, but instead, will curve inwardly toward the centerline of that rod. This upward and inward curving of the rod aft end moves that rod out of the way of the rod driver, and thus facilitates further operation of the driver.

Furthermore, the cutout is smoothly curved, and thus can accommodate a wide range of rod outer diameters. The smaller the rod outer diameter, the closer to the heel of the cutout the rod will intersect the cutout surface. The only limitation of rod size is thus the size of the tubular body bore, and the ability of the rod to withstand the impacts of the driver.

The invention is described further, by way of illustration, with reference to the accompanying drawings, in which: Figure lisa perspective of a rod driver embodying the present invention; Figure 2 is a sectional view taken along line 2-2 of Figure 1; Figure 3 is a side elevational view of the rod driver of Figure 1, inverted from the Figure 1 position; and Figure 4 is a sectional view of another rod driver embodying the present invention.

Referring to the drawings, shown in Figure lisa slender rod, such as an electrical grounding rod 10, or the like, which is to be embedded in ground G.

The rod has a leading end (not shown) and a following end 12, and is driven into the ground to a prescribed distance. Preferably, the rod 10 is set in the ground by driving.

A hand-held rod driver 20 is shown in the Figures, and is the subject of the present invention. As shown, the driver 20 includes a tubular body 22 having a fore end 26 and an aft end 28 and a bore 30 defined axially thereof. The bore 30 has a diameter greater than the diameter of the rod 10 so that any expected size rod can be received within the bore 30 in a free sliding accommodation. Knurling 32 and 34 is located on the outside surface of the tubular body for providing a secure grip. Preferably, the bands of knurling are each four inches wide and are equidistant from the fore and aft ends of the body.

A driver head is affixed to the aft end of the body, and has an outer diameter essentially matching the outer diameter of the tubular body. One embodiment of the device is shown in Figure 2, and includes a head 40 which has a boss 42 having external threads 44 defined thereon. The end of the bore 30 adjacent the aft end of the body 22 has internal threads 46 defined on the inner surface 48 thereof for cooperable association with the threads 44 of the head boss. The head is thus threadably attached to the body in the Figure 2 embodiment.

The boss 42 has a lowermost end 50 which is located within the bore 30 to close off that bore. A parabolic cupola 60 is defined in the boss to open into the bore 30. The bore 30 is thus a blind-ended bore with a concave blind end. The cupola has a heel 62 which is an axial alignment with the longitudinal centerline of the bore so that the cupola has an inner surface 64 which is symmetric with respect to that centerline. The cupola intersects the surface of the boss lowermost end, and is upwardly convergent therefrom. Thus, a continuously converging bore end is defined by the cupola forming cutout portion The drawing(s) originally filed was/were informal and the print here reproduced is taken from a later filed formal copy. ofthe drive head.

The aft end of the rod 10 is contacted by the cupola inner surface 64 during an embedding process. The rod 10 is formed of a deformable material which is deformed from the initially planar shape shown for the aft end thereof in Figure 1 to the bullet shape shown for the aft end 28' in Figure 3. The planar end 28 has a circular periphery which corresponds to longitudinal surface L of the rod, and this periphery contacts the inner surface of the cupola during the driving process to force the rod aft end into the cupola. The metal of the rod deforms due to the malleable nature thereof and due to the repeated impacts delivered thereto. However, the cupola serves as a guide to form the deformed rod into a shape which is not only aesthetically pleasing, but which will not inhibit further operation of the head during the driving process.The final configuration of the aft cnd 28' thus conforms to the shape of the cupola and is accordingly a truncated paraboloid, and can be described, as above, as being bulletshaped. The end 28' is truncated because the rod 10 contacts the cupola inner surface 64 at a location spaced from the heel 62. The amount of spacing between the heel 62 and the rod aft end is determined by the outer diameter of the rod and the amount of deformation undergone by the rod during the driving process.

The driver head 40 includes an aft end 7G located remote from the boss 42 which is conical in shape.

The apex 72 of the cone-shaped end 70 is located within the head 40 so that the cone is inwardly convergent of the head 40. The preferred angle of the cone is with respecttowall 74ofthe head 40.

Once the rod is driven into the ground a prescribed distance, the rod driver 20 is removed from the rod and inverted as shown in Figure 3. The conical end of the driver is then used to impact the rod end 28' to complete the driving process.

As above-discussed, the inwardly convergent nature of the cupola prevents the rod aft end from mushrooming out during the driving process. Indeed, the opposite effect occurs, the rod end is deformed inwardly toward a position out of the way of the bore inner surface. Thus, free movement of ti ìe rod driver is not im peded by the deformed rod aft end.

Another embodiment of the driver head is shown in Figure 4 and is indicated by the reference nurneral 40t. The rod head 40' is attached to the tubular body 22 by welds 80, or the like. The head 40' has a fore end 82 in abutting contact with the aft end 84 of the tubular body, and an aft end 86 which is preferably planar, but can have a conical shape similar to aft end 70 of the head 40 if so desired.

A cupola 60' is defined in the head 40' and includes a parabolic end 90 which intersects a tubular bore 92 at a location spaced from the heel 62' of the cupola.

The bore 92 is sized and located to be a smooth continuation of the bore 30 of the driver body 22 when the head is mounted on that body.

The cupola 60' operates and functions in a manner similar to the cupola 60, and thus, such operation will not be described.

Other embodiments of the driver head can include a plurality of telescoping sections which change the length of the cupola as measured from the heel section thereof. By moving the telescoping sections, the overall length of the cupola can be changed. Due to the parabolic nature of the cupola, rods having various sizes can be accommodated.

The preferred form of the rod driver 20 accommodates at least three sizes of rods as indicated in Figure 4. These preferred sizes are 3J4 inch for rod 10', 5/s inch for rod 10", sAs inch for rod 10"' and 1H2 inch for rod 1 0:V. These rods are shown in Figure 4 for convenience, and it is to be understood that the Figure 3 embodiment of the rod driver accommodates the same rod sizes which are not shown in Figure 3 only for the sake of clarity, and no limitation is intended. Other rod sizes can also be accommodated, if so desired.

The driver head is preferably an alloy hardened to a Rockwell hardness of 50-53, and the tubular body is preferably cold rolled steel.

In summary of this disclosure, the present invention provides a novel rod driver. Modifications are possible within the scope of the invention.

Claims (3)

1. A rod driver, comprising an elongate body having a rod receiving bore defined longitudinally therethrough, a driving head threadably mounted on the aft end of the body and having a boss projecting into and covering the rod receiving bore, and a cutout portion defined in the boss and curved outwardly of the bore.

2. A rod driver as claimed in claim 1 in which the cutout portion is conical in shape and has the apex thereof located inwardly of the driving head.

3. A rod driver substantially as hereinbefore described with reference to, and as illustrated in, Figure 1 to 3 of the accompanying drawings.