Patent Application
20150152620
The present invention is directed to a ground anchor having a blade extending axially from the ground anchor and a radially outwardly extending helical plate. The invention is particularly directed to a ground anchor having a ground engaging blade that is bent outwardly with respect to a longitudinal axis of the ground anchor and has a rotational twist or spiral.
Ground anchors are commonly used to support various structures and for use by utilities for anchoring supports, utility poles, and the like. The anchors often have an elongated shaft with a square or round cross-section. A top end of the shaft has a drive connection for coupling to a rotating drive assembly. The bottom, ground engaging end has one or more helical outwardly extending load bearing plates fixed to a hub.
U.S. Pat. No. 4,981,000 to Hamilton et al. discloses an earth anchor having a helical plate and a flattened lead tip. The center of the lead tip as shown appears to be aligned with the center axis. The angle of the cutting edge is positioned such that the apex leads the point at the intersection between the second cutting edge and the helical blade to facilitate movement of the soil around the hub.
One example of a screw anchor is disclosed in U.S. Pat. No. 4,334,392 to Dziedzic. This device is a modular screw anchor having an elongated rod with one or more specialized anchor members. The shaft also includes an obliquely oriented beveled earth penetrating lead to facilitate installation in rock soils. The anchor has a tubular, rod-receiving hub having a polygonal cross-section. An outwardly extending helical blade is fixed to the hub.
U.S. Pat. No. 5,408,788 to Hamilton et al. discloses a screw anchor having a hollow hub for receiving a wrench. A helical, load bearing element projects outwardly from the hub. An elongated, pointed spade extends from the end away from the hub. The spade has two diametrically opposed angular cutting margins on opposite sides of the hub.
U.S. Pat. No. 4,617,692 to Bond et al. discloses a drilling tip and expansion anchor for drilling a hole in a wall. The threaded shaft is rotated in a first direction to expand the anchor with a drill tip attached to the end of the shaft. The shaft is then rotated in the opposite direction to unscrew the shaft from the tip.
U.S. Pat. No. 4,750,571 to Geeting discloses a drilling apparatus having a disposable tip. A disposable cutting tip is attached to the auger section which is positioned within the ground screen. The tip is attached to the auger by a shear pin or bolt. The shear pin breaks when the auger is removed from the ground thereby leaving the drill tip in the ground.
U.S. Pat. No. 4,898,252 to Barr discloses a cutting tip for a rotary drill bit. The drill bit includes a wear surface attached to a plurality of plates forming the carrier for the cutting element. As the cutting edge wears, the plates break away to increase the clearance of the rear portion of the cutting edge and reducing the size of the wear surface to reduce the resistance to drilling.
U.S. Pat. No. 5,899,123 to Lukes discloses a threaded fastener having a drill point connected to the threaded fastener by a frangible line. The drill tip drills a hole through the work piece until the drill tip engages an inclined surface thereby causing the drill tip to break away from the threaded fastener.
U.S. Pat. No. 6,588,515 to Wentworth et al. discloses a rock drilling bit with a plurality of cutting teeth raked into the cut of the drilling bit. The teeth are angled at about 30° to provide the shear cutting force. The arrangement of the teeth reduces shock and vibration applied to the housing.
U.S. Pat. No. 7,182,556 to Takiguchi et al. discloses a drill with a disposable insert tip. The drill has a drill main body and an insert that is attached to the main body. The end of the main body has a plurality of guiding grooves shown in
U.S. Pat. No. 8,109,700 to Jordan et al. discloses a replaceable tip for a bit or auger. As shown in
While these prior devices have generally been suitable for their intended purpose, there is a continuing need in the industry for improved ground anchors.
The present invention is directed to a screw ground anchor and assembly for driving the ground anchor into the ground. The invention is particularly directed to a screw ground anchor having a ground engaging blade at a distal end of the ground anchor that extends along an axis formed at an incline with respect to the longitudinal axis of rotation of the ground anchor.
The ground anchor of the invention has a ground engaging end forming a pointed blade or spade tip that is able to stabilize the anchor and to penetrate the ground by a drive assembly in the ground. The ground anchor also includes a hub with a helical load bearing screw for supporting a load and/or for anchoring cables, guy wires or other structures. The ground engaging end with the pointed blade has angled faces that are able to penetrate the ground in various soil and rock conditions while directing the loosened soil directly to the helical plate.
Accordingly, one aspect of the invention is to provide a ground anchor that is able to penetrate the ground to support a load or anchor a structure where the ground anchor can be used in hard and soft soils. The blade at the ground engaging end of the ground anchor is oriented at an angle to assist in penetrating the ground and loosening the soil to allow the helical plate to penetrate the ground.
The invention is also directed to a ground anchor that can be used with a conventional driving apparatus without the need to modify the existing drive or drilling apparatus.
Another feature of the invention is to provide a ground anchor having a blade that can be used in soft and hard soils and is also able to efficiently penetrate the harder subsoil without the need to replace the drilling tip or to remove the assembly from the ground to change the assembly or anchoring members.
The screw ground anchor assembly of the invention has a hub with a load bearing helical screw plate and a ground engaging blade end that is able to penetrate the ground to assist in driving the load bearing screw into the ground to a depth necessary to support the desired load or anchor the intended structure.
The ground anchor of the invention has a blade extending axially from the hub where the blade has inclined side faces that converge to a tip forming a ground engaging axial face. The axial face can have a blunt, flat surface extending substantially perpendicular to a longitudinal axis of the ground anchor. In one embodiment, the blade has at least two opposing spiral major faces that converge toward the axial face at an inclined angle with respect to the longitudinal axis of the ground anchor. The base portion of the blade has a substantially trapezoidal shape while the axial face has a substantially rectangular shape.
The side faces of the blade preferably have a spiral curvature that occurs in the direction of rotation of the ground anchor when driven into the ground. The spiral surface forms the blade with a twisting, spiral configuration. The leading cutting edge of the blade is oriented in front of the leading edge of the helical plate to direct the loosened soil toward the leading edge of the helical plate. The leading cutting edge extends in a spiral from the ground engaging axial face of the blade to a point above and forward of the leading edge of the helical plate.
The side faces of the blade are twisted and spiral in an axial and longitudinal direction with respect to the blade to provide the blade with a spiral shape that complements the spiral of the helical plate. The spiral side faces extend in a longitudinal direction with respect to a longitudinal axis of the blade. The longitudinal axis of the blade preferably is oriented at an incline with respect to the longitudinal center axis of the ground anchor which defines the axis of rotation of the ground anchor. The major side faces of the blade spiral about 25° to about 35° and typically about 30° along the longitudinal length of the blade between a respective edge at a base portion of the blade and side edge of the axial face. The side edges of the axial face along the major faces of the blade are rotated about 25°-35° and typically about 30° from the corresponding bottom edge of the major faces at the base portion of the blade in a direction of rotation of the ground anchor when penetrating the ground.
In one embodiment of the invention, the blade has a base portion coupled to the body of the ground anchor with a substantially trapezoidal shape and an outer axial face with a substantially rectangular shape. The distal edges of the side faces are not parallel to the edges of the base portion of the blade to form the spiral shaped side surfaces. In one embodiment, the distal edges of the major side faces are at an angle of about 30° with respect to the respective edge at the base portion of the blade. The longitudinal axis of the blade is oriented at an angle of about 15°-25° and preferably about 20° from the longitudinal center axis of the ground anchor and the axis of rotation of the ground anchor.
These and other aspects of the invention are basically attained by providing a ground anchor comprising a body having a top face and a ground engaging bottom face and a center longitudinal axis defining an axis of rotation of the ground anchor. A blade extends from the bottom face of the body. The blade has a first major face, a second major face opposite the first major face, a first minor face extending between the first and second major faces, and a second minor face extending between the first and second major faces. Each of the major faces and minor faces converge to a ground engaging axial face. The blade has a longitudinal center axis extending from a base of the blade to the axial face and is oriented at an inclined angle with respect to the longitudinal axis of the body to orient at least a portion of the axial face radially outward from the first and second major faces with respect to the center longitudinal axis.
The various features and advantages of the invention are also attained by providing a ground anchor comprising a hub having a ground engaging helical plate with a leading edge for penetrating the ground and a trailing edge. The helical plate has a dimension for supporting a load in the ground. A body having a top face is coupled to the hub and has a ground engaging bottom face. The body has a center longitudinal axis extending through the ground anchor. A blade extends from the bottom face of the body where the blade has a base portion with a center axis aligned with the center axis of the body and a plurality of spiraling side surfaces converge into a ground engaging axial face. The blade has a longitudinal axis extending at an incline with respect to the longitudinal axis of the body.
The objects and advantages of the invention are further attained by providing a ground anchor comprising a body having a top face with a shaft for coupling with a rotary drive and a ground engaging bottom face. The body has a center longitudinal axis extending through the ground anchor defining an axis of rotation of the ground anchor. A ground engaging blade extends from the bottom face of the body. The blade has a plurality of spiraling surfaces that converge into a ground engaging substantially flat axial face. The blade has a longitudinal center axis extending between the center axis of the body and a center of the axial face where the longitudinal axis of the blade extends at an inclined angle with respect to the longitudinal axis of the body. The axial face has an outermost edge that is substantially axially aligned with an outer edge of the body.
The various objects, advantages and salient features of the invention will become apparent from the annexed drawings and detailed description of the invention which form part of the original disclosure.
The following is a brief description of the drawings, in which:
The present invention is directed to a spade point screw ground anchor for penetrating the ground for anchoring or supporting a structure. As shown in
Referring to the drawings, the ground anchor 10 includes a ground engaging spade point lead 18 and a hub 20. The lead 18 and hub 20 are coupled together as shown in
The ground engaging lead 18 of the ground anchor 10 has a body portion 34 with a top face 36 and bottom face 38. The top face 36 of body portion 34 includes a shaft 40 extending axially in an upward direction as shown in
As shown in
A ground engaging blade 46 extends axially from the bottom face 38 of the body 34. As shown in the drawings, blade 46 has tapered sides that converge to an axial end face 48 at a bottom or distal end of the blade 46. A base portion 50 at a top end defining a proximal end of the blade 46 is integrally formed with the body 34.
Blade 46 has a first major face 52 and a second opposing major face 54 that converge toward the axial end face 48. A first minor face 56 and a second minor face 58 converge to the axial end face 48. The first minor face 56 extends between the first major face 52 and the second major face 54 and along a first side edge of the major faces. The second minor face also extends between the first major face 52 and the second major face 54 along an opposite side edge of the major faces. Each of the major faces and minor faces define a spiral surface extending along the longitudinal axis of the blade 46 so that the blade 46 has a twisted or spiral configuration for penetrating the ground. The axial end face 48 typically has a flat surface lying in a plane perpendicular to the longitudinal axis of the ground anchor and the body. In the embodiment shown, the axial end face 48 has a substantially rectangular configuration defined by the bottom edges of the major faces 52 and 54 and minor faces 56 and 58.
The blade 46 has a substantially trapezoidal shaped cross-section at a base portion 50 of the blade joining the body 34. As shown in the embodiment of
The first major face 52 and the first minor face 56 converge to form a leading cutting edge 62. The leading cutting edge 62 has a curved spiral shape extending from the base portion 50 of the blade 46 to the axial face 48. The leading cutting edge 62 defines the radially outermost edge of the blade 46. In the embodiment shown, the first major face 52 is inclined at an angle extending radially away from the center axis 64. As shown in the drawings, the leading cutting edge 62 and the first major face 52 extend above the top surface of the leading edge 30 of the helical plate 28. In a preferred embodiment, the entire cutting edge 62 and the first major face 52 are oriented in front of the leading edge 30 of the helical plate as shown in
The body 34 has a central longitudinal axis 64 that extends through the central axis of the hub 20 and the longitudinal axis of the ground anchor 10. The axis 64 corresponds to the longitudinal axis of rotation of the ground anchor 10 when the ground anchor it is driven into the ground. The blade 46 has a longitudinal axis 66 that extends at an inclined angle with respect to the longitudinal axis 64 of the ground anchor 10 so that the blade 46 extends in a radially outward and axial direction with respect to the body 34 and the longitudinal axis 64. The longitudinal axis 66 of the blade 46 intersects with the longitudinal axis 64 as depicted in
In the embodiment shown, the axial end face 48 of the blade 46 has a substantially flat surface extending in a plane substantially perpendicular to the center axis 64 to form a blunt end face. As shown in
In the embodiment shown, each of the contiguous spiral faces of the blade 46 form a spiral edge between the faces. As shown in the drawings, the first minor face 56 joins the second major face 54 to define a spiral edge 68 that trails the leading cutting edge 62 with respect to the direction of rotation of the ground anchor 10 indicated by arrow 69 in
The blade 46 is oriented with its longitudinal axis 66 at an inclined angle with respect to the longitudinal axis 64 of the ground anchor and body so that the leading cutting edge 62 and axial face 48 travel in the circular path 60 spaced radially outward from the longitudinal center axis 64. The blade 46 can be oriented with the longitudinal axis of the blade intersecting with the center longitudinal axis and oriented at an angle of about 15° to 25° and preferably about 20° with respect to the longitudinal center axis 64. In the embodiment shown in
In one preferred embodiment, the leading cutting edge 62 forms the circular cutting path 60 so that at least a portion of the circular cutting path 60 is spaced radially outward from an outer edge 35 of the body 34 as shown in
The first and second major faces 52 and 54 spiral about 25° to about 35° along the longitudinal dimension of the respective face of the blade 46. The first major face 52 forms a first edge 74 at the axial face 48 and the second major face 54 forms a second edge 90 at the axial face 48. The first edge 74 and second edge 90 are substantially parallel to each other and form an angle of about 25°-35° with respect to the corresponding bottom edge of the respective face at the base 50 of the blade 46. In the embodiment shown, the edges 74 and 90 of the axial face 48 are at an angle of about 30° with respect to the bottom edge of the respective face at the base 50 of the blade. The minor faces 56 and 58 spiral in a similar manner between the bottom edge of the respective face at the base 50. The respective edges 76 and 94 of the axial face 48 are angled at about 50°-70° with respect to the bottom edge of the respective face. In the embodiment shown, the edges 76 and 94 are at an angle of about 60° with respect to the respective bottom edge of the respective face at the base of the blade 46.
As shown in
During use, the ground anchor 10 is connected to a rotary drive assembly as in the previous embodiment and driven into the ground by the rotational driving force of the drive apparatus. The blunt axial end 48 initially penetrates the soil at the surface for driving the ground anchor 10 into the ground. As the ground anchor 10 is driven into the ground, the spiral faces of the blade direct the soil toward the helical plate 28. The helical plate 28 penetrates the ground to a desired depth for anchoring or stabilizing the intended structure. The blade 48 is oriented with the body 34 and the helical plate 28 so that the leading cutting edge 62 and the first major face 52 are inclined to direct the soil upwards along a major face 52 to the leading edge of the helical plate 28 as indicated by lines 84 in
While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention as defined in the appended claims.
