Ground anchors with compression plates
Ground anchors, in particular tent stakes (100), comprise one or more inherently flexible tines (110), a ground compression plate (160), and various tie points (420, etc.) for attaching a guy rope or the like to the top of anchor. The compression plate extends perpendicularly or at a large angle to the tine so that when the guy rope pulls on the anchor, the tine will tend to rotate about an underground fulcrum so that the compression plate will press against the ground and help the anchor resist pullout. The anchors are preferably driven into the ground with a hammer or mallet. The tie points include hooks (420), closed holes (520), and swivel types comprising vertical members (810) with restraining, bulbous tops (820). An additional spring tie point (1600) can be inserted into optional lugs (1094, 1096) in the compression plate. The stakes can be driven into the ground vertically, or at an angle for additional holding force in some situations. They can also incorporate angled compression plates (160H, 160I). The stakes can be manufactured by a variety of means in various materials such as glass-reinforced plastic and forged or stamped metal.
This is a continuation-in-part (CIP) of parent application Ser. No. 10/989,960, Filed Nov. 15, 2004, which in turn is a CIP of grandparent application Ser. No. 08/923,443, Filed Sep. 4, 1997, now abandoned. The grandparent application claims priority of Australian application Ser. No. 36,761/97, filed Sep. 4, 1996.
BACKGROUND1. Field of Invention
This invention relates generally to ground anchors and in particular to tent pegs or stakes that are used to anchor tents and guy ropes to the ground.
2. Prior-Art
Tent Stakes
Prior-art tent and guy rope stakes have generally taken the shape of large nails or pegs. They normally secure a tent at two or more places. Some hold the edges of the tent against the ground, and others anchor guy ropes attached to poles at distal ends of the tent. The stakes at the tent's edge are driven nearly vertically into the ground. The guy anchor stakes are driven into the ground at an angle roughly perpendicular to the axis of the rope, typically about 45 degrees. While these stakes successfully secure a tent in mild weather conditions, they are easily dislodged if the tent is exposed to wind or other disturbances. The force of the wind or other disturbance can reverse the insertion path of stakes at the tent's edge and pull them out of the ground. Guy ropes produce a moment of torque around the guy anchor stake's upper end, causing it to rotate and/or bend and tear through the ground. This occurs because, although the lower end of the stake is generally buried in solid soil, the top end, which bears the majority of the load or pull, is in less compacted soil. As the size and weight of the tent increases, wind load and other forces render the holding force of prior-art stakes insufficient.
Tray and Beverage Container Holder
In U.S. Pat. No. 5,713,546 (1998), Auspos teaches a foldable holder for beverage containers and other items. The holder comprises a horizontal tray pivotally attached to a stake. In use, the tray is raised to a level position, and the stake is driven vertically into the ground. The tray remains supported above the ground at a convenient height for temporary storage of drinks and other items. For carrying and storage, the tray is folded to a position against the stake.
While this apparatus is useful, it has no structure intended for securing a tent edge or guy rope. It is intended only for holding drinks and other items.
Various other ground anchors are known, but these also have poor holding power and other disadvantages, including large size, unwieldiness due to plural tines, and/or a complicated construction.
OBJECTS AND ADVANTAGESAccordingly, one object and advantage of the present invention is to provide an improved method and apparatus for anchoring objects to the ground. Other objects and advantages are to provide an inexpensive and simple apparatus, which is compact, and which resists pull-out and tearing of the ground.
Additional objects and advantages will become apparent from a consideration of the drawings and ensuing description.
SUMMARYIn accordance with the present invention, a method and apparatus are described that provide a simple and sturdy ground anchor. In the preferred embodiment the ground anchor has a single narrow tine with a compression plate attached orthogonally to the upper part of the tine. The tine is driven into the ground until the plate contacts the ground. When the top of the tine is under load, e.g., due to pull from a guy line or a tent canvas, the plate compresses the ground around the anchor, limiting movement of the top of the anchor. In response to this limited movement, the upper portion of the anchor flexes slightly due to the inherent springiness of the tine and the depth-limited movement of the lower part of the tine. When the load is removed, the anchor springably returns to its original condition. The lower portion remains secured in the ground, thus reducing the anchor's tendency to slip out or tear the ground into which it is inserted. The narrow tine, and its inherent flexability, combine to ensure that any stiffness or rigidity, two attributes that cause a prior-art stake to fail, are not present in this novel design.
DRAWINGS—FIGURES
Stake 100 is formed into an inverted “J” shape comprising an ascending portion or tine 110, a bend or bight loop or portion 120, and first and second coaxial descending portions 130 and 135, respectively. Portions 110, 130, and 135 are preferably straight. A first elongated tine, comprising ascending portion 110 has a first sharpened tip 140 that facilitates insertion into the ground (not shown). Tip 140 can be wedge-shaped with a single flat side as shown in
Descending portion 135 forms a second shortened tine, generally contiguous with portion 130, below plate 160. Portion 135 terminates in a second sharpened tip 150. When inserted into the ground (not shown), portion 135 prevents rotation of stake 100 around the axis of tine 100.
Tine 100 is preferably round in cross-section, although elliptical, square, rectangular, star-shaped, and other cross-sections will work as well. The diameter of tine 100 is preferably 8 mm and its length from tip 140 to bend 120 is 30 cm. The lengths of descending portions 130 and 135 are 5 cm. Stake 100 and plate 160 are made of steel, aluminum, glass-reinforced plastic (GRP), or another structural material.
A compression plate (plate) 160 is secured about half-way down descending portions 130 and 135 (if present, see below) by a weld, adhesive joint, or similar attachment 170. The plane of plate 160 is perpendicular to the axis of ascending portion 100. Plate 160 is preferably about 8 cm by 2 mm thick. As with tine 100, plate 160 is made of steel, aluminum, GRP, or another structurally strong material which can be bonded to portion 130. Plate 160 and bight loop or portion 120 of the stake above plate 160 form a closed attachment loop, eye, or noose.
Tine 110 is preferably straight, or it may be curved. The inherent flexibility of tine 110 is determined by its diameter, its length, and the material of which it is made. The material of which tine 110 is made is normally stiff. The relatively long length and small diameter results in a structure which is springable under heavy load, but returns to its original shape when the load is removed.
The embodiments in
The user normally inserts tine 110 (
Because of its relatively small diameter, stake 100 is slightly flexible. When a load force is applied to stake 100 in the direction shown by the arrow, stake 100 attempts to rotate clockwise in response to the torque around a fulcrum point 300. The upper portion of tine 110 deviates from its previously straight condition, indicated by the dashed line extending upward from fulcrum 300. When surrounded by tightly compacted soil, any movement of stake 100 is limited to a compaction region 310 above fulcrum point 300. Tine 110 preferably flexes as much as five degrees under extreme-pull load conditions, and then springably returns to its original condition when the load is removed. Thus two factors (compaction area 310 and the springiness of the tine) combine to increase the efficiency of stake 100 over prior-art designs.
Plate 160 also compresses the soil to limit movement, while inherently flexible tine 110 allows whatever movement is induced by the load force to be dissipated above fulcrum point 300. Shaded areas 310 and 320 respectively indicate first and second compressed regions of soil beneath plate 160, and behind tine 110 which resist the torque around fulcrum point 300. The portion of tine 110 lying below fulcrum point 300 does not move or flex under normal load conditions. Stake 100 is thus rendered immobile in the direction of the applied load.
If present, descending portion 135 lying beneath plate 160 is also forced into the ground, and acts to prevent rotation of stake 100 about the axis of tine 110.
Stake 100 can be used to prevent fly-away of a tent edge (not shown). Stake 100 is inserted into the ground approximately 15 cm from the tent edge. A rope or line (not shown) is attached to each generally available grommet or tab on the tent edge. The other end of the rope is secured to stake 100. In this configuration, the load on stake 100 is nearly horizontal. A secure tether results.
If stake 100 is used to secure a guy or hawser (not shown), the rope is passed through the eye of stake 100. Stake 100 is oriented so that the axis of the guy rope lies in the plane containing tine 110 and descending portion 130 of stake 100. The rope is arranged to pull in a direction away from tine 110 and toward descending portion 130. The tension in the rope creates a clockwise moment of torque centered near fulcrum 300. This torque acts to force the outermost edge of plate 160 downward, thereby compressing the ground below plate 160 in region 310. The torque also forces tine 110 against the ground in region 320 in a direction away from the rope's pull. Alternatively the rope can be hooked over hook 200 of
For acute vertical angle loads, tine 110 can be inserted into the ground at an angle such that tip 140 lies closer to the anchoring force, and bend 120 lies farther away. Stake 100 is still fully inserted into the ground, up to the bottom of plate 160.
In this position, plate 160 is forced downward into the ground and plate 160 and tine 110 compress the ground in the direction of the applied force. The result is a stronger anchorage than would be obtained with a vertical insertion of tine 110 in this situation.
DESCRIPTION AND OPERATION—FIRST ALTERNATIVE EMBODIMENT—FIG. 4 A first alternative embodiment, stake 100C, is shown in
The top portion of stake 100C above plate 160B includes tie points comprising one or more hooks 410, 420, and 430. The top 440 of stake 100C is flat to accommodate striking of stake 100A by a hammer or mallet. The top 440 of stake 100C optionally includes a hole 450 for insertion of a rod, for example a flag mast. The diameter and depth of hole 450 are preferably 0.5 cm and 2 cm, respectively. The bottom end of stake 100C terminates in a sharpened tip 140B.
The embodiment of
This embodiment is preferably made of GRP. It is best used for tent staking in sand or friable soil.
DESCRIPTION AND OPERATION—SECOND ALTERNATIVE EMBODIMENT—FIG. 5 A second alternative embodiment, stake 100D, is shown in
As in the first alternative embodiment, stake 100D can be driven into the ground by force applied by the user's foot, or by hammer blows to top 440 of stake 100D. As above, the top 440 of stake 100D optionally includes a hole 442 for insertion of a mast such as a flag support. The diameter and depth of hole 442 are preferably 0.5 cm, and 2 cm, respectively.
The embodiment of
A third alternative embodiment, stake 100E, is shown in
In
Top 610 in
Stake 100E can be used to secure an animal (not shown), for example. A rope (not shown) is looped around neck 600 and tied. The other end of the rope is attached to the animal's collar (not shown). The animal is free to move within its prescribed radius without winding the rope around the stake. The presence of tie point 700 in
This embodiment is particularly well-suited to manufacture by molding in GRP, or forged or cast aluminum or other metal. It is best suited for staking out most tent bases.
In lieu of a circular plate 160D, the plate can be oval, triangular, square, rectangular, hexagonal, etc.
DESCRIPTION AND OPERATION—FOURTH ALTERNATIVE EMBODIMENT—FIG. 8
This embodiment is best suited to heavy duty anchoring in sand or friable soil. For example, it can be used for securing a beach umbrella from fly-away.
DESCRIPTION AND OPERATION—FIFTH ALTERNATIVE EMBODIMENT—FIG. 9 A fifth alternative, industrial-grade embodiment is shown in
A rectangular plate 160F incorporates a right-angle bend 930, and includes further tie point holes 940 and 950. Plate 160F is preferably 6 cm wide and extends about 8 cm away from tine 110D. The upper portion of plate 160F is about 3 cm high. Plate 160F is affixed to tine 110D by a weld or other attachment (not shown). Plate 160F is supported from below by a gusset 960 secured to tine 110D by an attachment or weld 970, and further attached to the bottom of plate 160F by another weld or attachment (not shown).
Tine 100D is driven into the ground by hammer blows to top 900 until plate 160F is in contact with the ground. One or more hawsers are tied through one or more of holes 910, 920, 940, and 950.
This embodiment is intended for heavy duty applications such as support for vineyard “straining posts”, for example. It is preferably made of mild steel.
DESCRIPTION AND OPERATION—SIXTH ALTERNATIVE EMBODIMENT—FIG. 10
Plate 160G further includes optional lugs 1094 and 1096 for securing a spring, as described below. Plate 160G can be stamped in a single operation.
The presence of two parallel tines 1000 and 1010 ensures that stake 100H will not rotate. The addition of a second tine also increases the holding power of stake 100H over one with a single tine.
This embodiment is preferably used for heavy duty tent, tarpaulin, or similar staking in sand, friable soil, or firm ground, particularly in windy conditions.
DESCR. & OPERATION—SEVENTH ALT. EMBOD.—EXPANSION PLATE—FIGS. 11 & 12 In loose or friable soil a larger-than-normal compression plate will function better. A separate metal or plastic plate is attached to the existing, smaller plate.
Plate 1100 includes lugs 1105 and 1110, stops 1115, 1120, 1125, and 1130, and an optional notch 1135. Stops 1115 and 1120 normally project a small distance above the plane of plate 1100.
Plate 1100 slidably mounts under plate 160 as shown in
Notch 1135 permits insertion of plate 1100 past descending portion 135 (if present) of stake 100 (
This embodiment provides improved stake performance, specifically of the stakes shown in
The above embodiments show compression plates fixedly attached to tines. Fixed attachment requires the tine to be driven into the ground a predetermined distance to seat the plate on the ground.
Plate 1300 comprises a circular foot plate 1315, and a star-shaped, tubular support 1320. Support 1320 is secured to foot 1315 by welds, other attachments, or thickly cast regions 1325. This combined structure is strengthened by gussets 1330 which are attached to foot 1315 and support 1320.
The cross-section of stake 1310 is star-shaped, comprising three sections oriented at 120-degree increments about the axis.
Support 1320 incorporates one or more holes 1340. Stake 1310 also incorporates a plurality of holes 1350. If support 1320 contains two or more holes 1340, then their spacing optionally matches the spacing of holes 1350 on stake 1310.
Stake 1310 is first driven the desired distance into the ground (not shown). Then tubular support 1320 is made to engage stake 1310 and is slidably moved downward until the underside of foot 1315 rests on the ground. One or more holes 1340 are then aligned with one or more holes 1350. Finally, one or more bolts, pins, screws, cotter pins, dowel pins, clevis pins, etc. (not shown) are inserted through the aligned holes. Plate 1300 is thus rigidly secured to stake 1310.
A minor upward adjustment in the position of plate 1300 may be required if holes 1340 and 1350 are not aligned while foot 1315 rests on the ground. If so, the nearest holes can be pinned, and stake 1310 can later be driven a small distance farther into the ground.
The central openings of plates 1300A and 1300B in
Stakes 1310, 1310A, and 1310B optionally incorporate tie point holes 1355, 1355A, and 1355B, respectively. They can also include hooks (not shown), if required.
This embodiment features attachment collars for fitting to pickets to improve performance in sand, friable soil, or firm ground. It is used for temporary or permanent fencing and military purposes. The stakes are preferably made of square timber, plastic, or steel.
DESCR. & OPERATION—NINTH ALTERNATIVE EMBOD.—INCORP. SPRING—FIGS. 16-20
Spring 1600 is shown in more detail in
Spring 1600 is held in place by lugs 1094 and 1096 (
Spring 1600 is shown in use in
The reader will see that the present stake system provides novel methods and apparatuses for anchoring articles firmly to the ground. When the stake is fully inserted, the compression plate first compresses the soil around the stake. When a load pulls against the stake, the compression plate further compresses the soil beneath, thereby strengthening the holding power of the stake. Numerous configurations of the stake accommodate a wide variety of soils. A narrow, inherently flexible stake secures objects in sand, for example. Multiple tines prevent rotation of the stake. Tine cross-sections other than circular reduce the tendency of the stake to rotate. Stakes can be driven into hard soil with a hammer or mallet. A variety of tie point configurations secure ropes for various needs. Some tie points are open, others are closed. A swivel design permits free-swiveling motion of a tie-off rope.
While the above description contains many specificities, these should not be considered limiting but merely exemplary. Many variations and ramifications are possible. For example instead of metal or GRP, the stakes can be made of wood or rigid plant shoots. More or fewer, larger and smaller tie points can be used. Although use with tents and the like is described, many other uses are possible including providing ground anchors for boats and other vehicles, balloons, and so forth. The parts can be attached together by means other than lugs or welds, such as staking, adhesive, integral forming, etc. The plate can be attached to the tine at an angle of 90 degrees or an acute angle. The spring (
While the present system employs elements which are well known to those skilled in the art of ground anchor design, it combines these elements in a novel way which produces new results not heretofore discovered. Accordingly the scope of this invention should be determined, not by the embodiments illustrated, but by the appended claims and their legal equivalents.
Claims
1. A ground anchor stake, comprising:
- a. at least one elongated tine with top and bottom ends and a tip at said bottom end,
- b. a compression plate fixed near said top end of said tine, said plate being oriented at an angle to said tine, said angle being 90 degrees or acute,
- c. at least one tie point near said top of said tine,
- whereby said tip of said tine can be driven into the ground until said plate contacts said ground, so that said plate will aid said stake in resisting pullout from said ground.
2. The anchor of claim 1 wherein said tip is selected from the group consisting of pointed and wedge-shaped members.
3. The anchor of claim 1 wherein a second shortened tine extends beneath said plate.
4. The anchor of claim 1 wherein said angle is 90 degrees.
5. The anchor of claim 1 wherein the said angle is acute.
6. The plate of claim 5 wherein said compression plate includes a portion that lies in a plane perpendicular to the axis of said tine.
7. The anchor of claim 1 further including an expansion plate affixed to said compression plate, said expansion plate being larger than said compression plate.
8. The anchor of claim 7 wherein said expansion plate is made of a material selected from the group consisting of metal and plastic.
9. The anchor of claim 1, further including a spring affixed to said compression plate.
10. The anchor of claim 1 wherein said stake is made of a material selected from the group consisting of metal and plastic.
11. The anchor of claim 1 further including a bight loop formed in the intersection between said compression plate and said top of said tine.
12. The anchor of claim 1 further including at least one hook extending from a position near said top end of said tine, and lying above said compression plate.
13. The anchor of claim 1 wherein said tie point comprises a neck and a top, both lying above said compression plate.
14. The anchor of claim 13 wherein said tie point further includes a second tie point extending from said top downward to said compression plate.
15. The anchor of claim 1 wherein said tie point comprises at least one hole.
16. The anchor of claim 15 wherein said hole is located in said compression plate.
17. The anchor of claim 15 wherein said hole is located in said tine, above said compression plate.
18. The anchor of claim 1 wherein said tie point is a tie-off bar.
19. The anchor of claim 1 wherein said tie point is a hook extending from the top surface of said compression plate.
20. The anchor of claim 1 wherein said tine further includes at least one first hole into which a pin can be inserted, said compression plate further includes a tubular portion attached to a top side of said compression plate and provided with at least one second hole for accommodating said pin so that said pin attaches said compression plate to said tine yet can be slidably moved up and down on said tine, whereby said tine can be driven a variable distance into the ground and said compression plate slidably moved downward on said tine until said compression plate contacts said ground, and said pin is inserted into said first and second holes, thereby holding said compression plate against said ground.
21. The anchor of claim 20 wherein the cross-section of said tine is selected from the group consisting of star-shaped, round, and square.
22. A method for anchoring a pull load to the ground, comprising:
- providing a stake with at least one elongated tine with a tip, providing a compression plate attached to said tine near the top of said tine, said compression plate forming an angle of 90 degrees or an acute angle with said tine, providing at least one tie point near the top of said tine, driving said tip into the ground until said plate contacts said ground, attaching a pull load to said tie point, whereby said plate will aid said stake in resisting pullout from said ground.
23. The method of claim 22 wherein said tip is selected from the group consisting of pointed and wedge-shaped members.
24. The method of claim 22, further including a second shortened tine extending beneath said compression plate.
25. The method of claim 22 wherein said angle is 90 degrees.
26. The method of claim 22 wherein said angle is acute.
27. The plate of claim 26 wherein said compression plate includes a portion that lies in a plane perpendicular to the axis of said tine.
28. A ground anchor comprising:
- a. a stake including at least one elongated tine having bottom and top ends with a tip at said bottom end,
- b. ground compression means attached to said tine for compressing said ground adjacent said tine, said plate forming an angle of 90 degrees or acute with said tine,
- c. tie point means near said top end of said stake,
- whereby when said tip of said tine is driven into said ground, said plate will aid said stake in resisting pullout from said ground.
Type: Application
Filed: May 13, 2005
Publication Date: Oct 6, 2005
Inventor: Peter Burns (Moonee Ponds)
Application Number: 11/129,177