The technology described herein generally relates to augers for drilling ground wells.
Various method are used for drilling wells for ground water monitoring for environmental and geotechnical applications. One method uses a hollow stem auger which not only bores the well hole, but can also be used to obtain soil samples. Hollow stem auger drilling uses a large diameter (up to 14 inch outside diameter) continuous flight augers which mechanically excavate and continuously transport cuttings to the surface. A center bit, which is attached to the drill rod and bolted to the auger drive cap, is inserted through the cutter head to excavate the center of the boring. As the boring is advanced by adding sections of auger, sections of drill rod are added, maintaining the center bit at the face of the cutter bit.
Another method uses a solid stem auger uses a claw bit to advance sections of solid stem augers into the ground. The drilling equipment applies pressure and rotation against the top of the stem of the upper-most auger section while turning the sections into the ground. The claw bit displaces the soil and moves it up the helical flights of the auger sections as the drill bores deeper into the ground. The solid stem auger is inserted in sections that are several feet long and from 6 to 12 inches in diameter and 4-6 feet long, with 4-6 flights of a helical blade that spirals around the center shaft. Each auger section is assembled in-hole by disconnecting the drilling apparatus from the top end of an in-ground auger section that is partly into the ground, and attaching a bottom end of a next auger section onto the top end of an in-ground auger section that is partly into the ground. The drilling apparatus is the reconnected to the top end of the next auger section, and the drilling continues until the next auger section becomes the in-ground auger section, and the next auger section is added in the same way.
A typical solid stem auger section is shown in
Once a well hole W has been drilled with a solid stem auger, the series of auger sections 80 are withdrawn from the well hole. During withdrawal of the auger sections, the drilling equipment 70 raises the series of auger sections, typically while also rotating to help move soil and mud within the helical flights. To disassemble the upper auger section 80a from the in-ground auger section 80b, the drilling rotation of the series of auger sections is stopped, and a brace is placed around the shaft 82 and between the flights of blades 84 of the in-ground auger section 80b, at ground level. In the illustrated embodiment shown in
The use of the fork brace 90 is satisfactory but has several drawbacks. First, it must be inserted between the helical blades 84 by hand, before lowering the series of auger sections so that the drilling equipment can be detached from an auger section and the withdrawn auger section removed from the remaining series of auger sections, and also withdrawn by hand from between the helical blades after the withdrawn auger section is removed and the drilling equipment reattached. Also, since mud and water are commonly withdrawn from the well hole along with the auger sections, the area of ground surrounding the well hole W can become deep in mud, making handling of the fork brace 90 difficult and uncertain.
Notwithstanding, there is a continuing need for an improved method for bracing the series of auger sections during their withdrawal, which is easier to work with, safer, and avoids the problems described herein above.
The present invention provides a ratcheting auger bracing device, comprising: (a) a support frame comprising a peripheral tubular assembly, having an interior area bounded by the peripheral tubular assembly; (b) a first pivotable brace, including a proximal hinge end secured pivotally to and around the first end bar of the support frame, a distal elongated end bar having opposed lateral ends, and a pair of opposed arms, each having a distal end rigidly connecting to the respective opposed lateral ends of the distal end bar, and a proximal end rigidly connecting to the proximal hinge end; and (c) a second pivotable brace, including a proximal hinge end secured pivotally to and around the second end bar of the support frame, a distal elongated end bar having opposed lateral ends, and a pair of opposed arms, each having a distal end rigidly connecting to the respective opposed lateral ends of the distal end bar, and a proximal end rigidly connecting to the proximal hinge end.
In some embodiments, the pair of opposed arms of the first pivotable brace and the pair of opposed arms of the second pivotable brace are linear and straight. In some embodiments, the pair of opposed arms of the first pivotable brace and the pair of opposed arms of the second pivotable brace are angled, and each of the arms includes a proximal arm member and a distal arm member joined at an elbow at an angle.
In some embodiments, each of the first pivotable brace and the second pivotable brace further includes an outer cylindrical bar surrounding coaxially, and rotatable freely around, the fixed distal elongated end bar.
In some embodiments, the proximal hinge end comprises one or more outer cylindrical bar surrounding coaxially, and rotatable freely around, the respective the first and second end bars of the support frame.
In some embodiments, the peripheral tubular assembly includes a pair of spaced-apart elongated side bars, a first elongated end bar connecting the pair of side bars at a first end, and a second elongated end bar connecting the pair of side bars at a second end opposite the first end.
Typically, the peripheral tubular assembly has an undersurface that is planar to rest upon a flat ground surface without rocking. In some embodiments, the peripheral tubular assembly includes a tubular member in the shape of an oval.
The present invention also provides an elevated ratcheting auger bracing device, comprising the ratcheting auger bracing device described herein, which is elevated by including an elevating frame that rests upon the surface of the ground surrounding a well hole, for raising or elevating the support frame and the opposed pair of pivotable braces a distance above the ground level. The elevating frame positions the hinged ends of the pivotable braces a distance above the ground level that avoids or prevents a pooling of mud that may be raised out of the well hole and may accumulate on the ground surrounding the well hole.
In some embodiments of the elevated ratcheting auger bracing device, the pair of opposed arms of the first pivotable brace and the pair of opposed arms of the second pivotable brace are linear and straight. In some embodiments thereof, the pair of opposed arms of the first pivotable brace and the pair of opposed arms of the second pivotable brace are angled, and each of the arms includes a proximal arm member and a distal arm member joined at an elbow at an angle.
In another embodiment of the invention, an elevated ratcheting auger bracing device can include an elevating frame that rests upon the surface of the ground surrounding a well hole, for raising or elevating the support frame and the opposed pair of pivotable braces a distance above the ground level. The elevating frame positions the hinged ends of the pivotable braces a distance above the ground level that avoids or prevents a pooling of mud that may be raised out of the well hole and may accumulate on the ground surrounding the well hole. The raising of the hinge ends of the pivotable braces minimizes or eliminates their soiling and fowling by the accumulated mud, and increases the time and the amount of mud that can accumulate around the well hole before the need to halt the auger withdrawal process and clear away accumulated mud. In some embodiments and circumstances, the accumulated mud can be pulled away from the area around the well hole, and from within the space confined by the elevating base, that avoids the need for halting the auger withdrawal process.
The present invention also includes a method for using the ratcheting auger bracing device for extracting sections of an auger from a well hole. The method can include the steps of positioning a support brace substantially symmetrically around a well hole in which sections of an auger are disposed. After positioning the support brace, the two opposed braces are pivoted inwardly toward a section of the auger extending upward from the well hole, until a distal bar at the end of the arms of each brace contact the shaft and/or helical blade of the auger section, whereby gravity pulls the pivoted braces against the auger section. As a section of auger is pulled upward out of the well hole, the successive rising helical blades of the auger section lifts upward and pivots outward the two opposed braces in alternating sequence. After a brace clears the rising edge of a helical blade, the distal bar of the brace falls by gravity against the shaft of the auger section. Further rising of the auger section repeats the action of the brace pivoting outwardly and falling back against the shaft. An auger section is raised sufficiently out of the well hole to cause the opposed braces of the ratcheting auger bracing device to come to rest under the helical blade of the next auger section below. This allows the raised auger section to be disconnected from the remaining auger sections below, while the weight of the remaining sections below are supported by the braces of the ratcheting auger bracing device. The auger hoist used to raise the auger sections is disconnected from the raised auger section, which is set aside. Once disconnected, the auger hoist is attached to the upper end of the next auger section, and the extracting of the next auger section from the well proceeds.
As the ratcheting auger bracing device can be used to support the auger sections without a human user needing to manipulate (insert and withdraw) a support fork, one can consider the ratcheting auger bracing device as a “smart fork” or a “Smart fork”.
These and other features and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
The support frame comprising a peripheral tubular assembly, having an interior area bounded by the peripheral tubular assembly. The shape of the outer peripheral tubular assembly can be square, rectangular, round, oval, and even triangular, provided it has a periphery shape that provides for support for the pivotable braces described below.
In the illustrated embodiment, the support frame 11 includes a pair of spaced-apart and substantially parallel side bars 14. A first elongated end bar 16a connects rigidly the pair of side bars 14 at a first end, and a second elongated end bar 16b connects rigidly the pair of side bars 14 at a second end opposite the first end. Typically, the sides bars 14 are rectangular cylinders, while the first and second end bars 16a,16b are round cylinders. The support frame 11 is configured in length along the side bars 14, and laterally along the end bars 16, to provide an interior area 12, bounded by the pair of side bars 14, the first end bar 16a and the second end bar 16b, that is sufficiently long and laterally broad to accommodate the full diameter of a well hole W and an auger section 80 there within.
The first pivotable brace 2 and the second pivotable brace 3 are similar in configuration, and the description below for the first pivotable brace 2 applies as well for the second pivotable brace 3 except as indicated.
The first pivotable brace 2 includes a proximal hinge end, a pair of arms 4, and a distal end bar 7. The proximal hinge end secures pivotally the first pivotable brace 2 to the first end bar 16a of the support frame 11. The hinge end can comprise one or more outer tubular cylinders, illustrated as a pair of axially-aligned and axially-spaced-apart circular cylinders 6, that are concentrically and pivotally around the first end bar 16a of the support frame 11. The inner diameter of the circular cylinders 6 is sufficient to rotatable freely around the first end bar 16a, with only minimal frictional interference therebetween.
A pair of opposed arms 4 have a proximal end at which the arms 4 are fixed to and extend from the pair of hinged-end outer cylinders 6, and extend distally to a distal end. In the illustrated embodiment, the arms 4 are made of a rectangular cylinder.
The distal end bar 7 is elongated and extends between and is secured to the distal ends of the pair of arms 4. The distal end bar 7 extends substantially parallel to the hinge end circular cylinders 6, and perpendicular to the arms 4. In the illustrated embodiment, the first pivotable brace 2 (and the second pivotable brace 3) further includes an outer cylindrical bar 8 surrounding coaxially, and rotatable freely around, the fixed, distal end bar 7. The outer cylindrical bar 8 is illustrated as a circular cylinder that surrounds coaxially the distal end bar 7. The inner diameter of the circular cylinder 8 is sufficient for the circular cylinder 8 to rotatable freely around the distal end bar 7, with only minimal frictional interference therebetween.
In this embodiment shows the pair of opposed arms 4 of the first pivotable brace and the pair of opposed arms 5 of the second pivotable brace as linear and straight rectangular, cylindrical bars. The pair of arms 4 of the first pivotable brace is configured in distal length to extend from the plane of the support frame 11 at an angle α of about 20° to 60° when the distal elongated end bar thereof rests against the outer surface of the shaft, between flights of the helical blade, and pair of arms 5 of the second pivotable brace is configured in distal length to extend from the plane of the support frame 11 at an angle β of about 20° to 60° when the distal elongated end bar 7 (or outer cylindrical bar 8) thereof rests against the outer surface of the shaft 82, between successive flights of the helical blade 84. To account for the downward spiral of the helical blade 84 along the outer surface of the shaft 82, the pair of arms 4 of the first pivotable brace 2 are slightly longer than the pair of arms 5 of the second pivotable brace 3, such that the respective distal end bar 7 of the first pivotable brace 2 and the second pivotable brace 3 contacts the shaft 82 in approximately the same height between successive flights of the helical blade 84 when the support frame 11 is positioned symmetrically about the shaft 82 and the well hole W. As the shaft 82 of the auger section 80 is typically vertical within the well hole W, and the support frame 11 is typically horizontal resting on the surface of the ground G, the distal ends of the respective pairs of opposed arms 4,5 likewise extend from a horizontal line perpendicular to the axis of the shaft 82 at a similar angle α,β of about 20° to 60°, depending upon the positioning of the support frame 11 around the shaft 82.
The first pivotable brace 20 includes a proximal hinge end, a pair of arms 23,24, and a distal end bar 28. The proximal hinge end secures pivotally the first pivotable brace 20 to the first end bar 16a of the support frame 11. The hinge end can comprise one or more outer cylinders, illustrated as a pair of axially-aligned and axially-spaced-apart circular cylinders 22, that are concentrically and pivotally around the first end bar 16a of the support frame 11. The inner diameter of the circular cylinders 22 is sufficient to rotatable freely around the first end bar 16a, with only minimal frictional interference therebetween. It can be understood that the single outer cylinder can be used in place of the pair of spared-apart outer cylinder 22, as shown by outer cylinder 122 in
The second pivotable brace 40 includes a proximal hinge end, a pair of angular arms 43,44, and a distal end bar 48. The proximal hinge end secures pivotally the second pivotable brace 40 to the second end bar 16b of the support frame 11. The hinge end can comprise one or more outer cylinders, illustrated as a pair of axially-aligned and axially-spaced-apart circular cylinders 42, that are concentrically and pivotally around the first end bar 16b of the support frame 11. The inner diameter of the circular cylinders 42 is sufficient to rotatable freely around the first end bar 16b, with only minimal frictional interference therebetween. It can be understood that the single outer cylinder can be used in place of the pair of spared-apart outer cylinder 42, as shown by outer cylinder 142 in
The first pivotable brace 20 also includes a pair of opposed, angular arms 23, 24, each having a proximal end at which the angular arms 23,24 are fixed to and extend from the respective hinged-end outer cylinders 22, and extend distally to a distal end. The angular arms 23,24 include respectively a proximal member 25 and a distal member 26 that are fixed angularly at a joint 27. In the illustrated embodiment, the lengths of the proximal member 25 and the distal member 26 are the same, and the joint 27 is in the middle of the length of each angular arm 23,24. In some embodiments, the length of the proximal member 25 can be 10%-100% longer than the length of the distal member 26, while in other embodiments, the length of the distal member 26 can be 10%-100% longer than the length of the proximal member 25. The angle π1 of the joint 27 can be from about 10° to about 50°, In some embodiments, the angle π1 is at least about 15°, for example, at least about 20°, at least about 25°, or at least about 30°, and up to about 45°, for example, up to about 40°, up to about 35°.
The second pivotable brace 40 has a pair of opposed angular arms 43,44, including proximal member 45 and distal member 46 fixed angularly at a joint 47, which are similar in configuration to such features of the first pivotable brace 20, and the description for such features of the angular arms 23,24 of the first pivotable brace 20, including that of the angle π2 of the joint 47, applies as well for such features of the angular arms 43,44 of the second pivotable brace 40, except as indicated.
It can be understood that the pair of opposed, angular arms 23, 24 can be fixed to and extend from a single outer cylinder, that the second pair of opposed, angular arms 43, 44 can be fixed to and extend from a single outer cylinder, as shown by outer cylinders 122 and 142 in
The first pivotable brace 20 also includes a distal end bar 28 that is elongated and extends between and is secured to the distal ends of the pair of angular arms 23,24. The distal end bar 28 extends substantially parallel to the hinge end circular cylinders 22, and perpendicular to the angular arms 23,24. Similarly, the second pivotable brace 40 also includes a distal end bar 48 that is elongated and extends between and is secured to the distal ends of the pair of angular arms 43,44. The distal end bar 48 extends substantially parallel to the hinge end circular cylinders 42, and perpendicular to the angular arms 43,44.
In the illustrated embodiment, the first pivotable brace 20 and the second pivotable brace 40, respectively, further include an outer cylindrical bar 30,50 surrounding coaxially, and rotatable freely around, the fixed, distal end bars 28,48, respectively. The outer cylindrical bars 30,50 are illustrated as circular cylinders that surround coaxially the distal end bars 28,48. The inner diameter of the circular cylinders 30,50 are sufficient for the circular cylinder 30,50 to rotatable freely around the distal end bars 28,48, with only minimal frictional interference therebetween.
In another embodiment, the distal end bars 28,48 each can comprise solid bars, rather than hollow cylinder bars, to increase the weight at the distal end of the arms, to improve the torque resulting from gravity to pull the distal ends of the arms back toward the shaft of the 82 of the auger section 80.
In this second embodiment, the pair of angular arms 23,24 of the first pivotable brace is configured in distal length to extend from the plane of the support frame 11, from the hinge end circular cylinders 22 to the distal end bar 28, at an angle α of about 20° to 60° when the distal elongated end bar 28 (or outer circular cylinders 30) thereof rests against the outer surface of the shaft 82, between flights of the helical blade 84. Likewise, the pair of angular arms 43,44 of the second pivotable brace 40 is configured in distal length to extend from the plane of the support frame 11, from the hinge end circular cylinders 42 to the distal end bar 48, at an angle β of about 20° to 60° when the distal elongated end bar 48 (or outer circular cylinders 50) thereof rests against the outer surface of the shaft 82, between flights of the helical blade 84.
To account for the downward spiral of the helical blade 84 along the outer surface of the shaft 82, the pair of angular arms 23,24 of the first pivotable brace 20 are slightly longer, from the hinge end circular cylinders 42 to the distal end bar 48, than the pair of angular arms 43,44 of the second pivotable brace 40, such that the respective distal end bars 28,48 of the first pivotable brace 20 and the second pivotable brace 40 contact the shaft 82 in approximately the same height between successive flights of the helical blade 82 when the support frame 11 is positioned symmetrically about the shaft 82 and the well hole W. This also has the advantage that the distal end bars 28,48 of the opposed pair of pivotable braces 20,40 engage the helical blade 84 from the underside 86 at the same time when the lengths of auger sections are lowered onto the ratcheting auger bracing device 10 during withdrawal of the auger sections, as described herein later, which maintains opposite and balanced forces upon the two opposed pivotable braces 20,40.
However, because the respective angular arms 23,24 of the first pivotable brace 20 are angled downwardly, when the first pivotable brace 20 is in contact with the surface of the shaft 82, the angle κ1 formed by the proximal member 25 of the angular arms 23,24 from the horizontal plane of the support frame 11, is larger than the angle α, typically larger by about 5°, and up to about 25°, In some embodiments, the angle κ1 is larger than angle α by at least about 10°, for example, at least about 15°, and up to about 20°. Conversely, the angle κ2 formed by the distal member 26 of the angular arms 23,24 from a horizontal line perpendicular to the axis of the shaft 82, is smaller than the angle α, typically also smaller by about 5°, and up to about 25°. In some embodiments, the angle κ2 is smaller than angle α by at least about 10°, for example, at least about 15°, and up to about 20°.
Similarly, the respective angular arms 43,44 of the second pivotable brace 40 are angled downwardly, and when the second pivotable brace 40 is in contact with the surface of the shaft 82, the angle λ1 formed by the proximal member 45 of the angular arms 43,44 from the horizontal plane of the support frame 11, is larger than the angle α, typically larger by about 5°, and up to about 25°. In some embodiments, the angle λ1 is larger than angle α by at least about 10°, for example, at least about 15°, and up to about 20°. Conversely, the angle λ2 formed by the distal member 46 of the angular arms 43,44 from a horizontal line perpendicular to the axis of the shaft 82, is smaller than the angle α, typically also smaller by about 5°, and up to about 25°. In some embodiments, the angle λ2 is smaller than angle α by at least about 10°, for example, at least about 15°, and up to about 20°.
The increase in the angle λ1 of the proximal member 25 of the angular arms 23,24, and λ2 of the of the proximal member 45 of the angular arms 43,44, is significant when the ratcheting auger bracing device 10 is used on a daily operating basis in the field. As noted in the background description, the mud and water withdrawn from a well hole in the area of ground surrounding the well hole can become deep in thick, sticky mud (M), as shown in
The drilling equipment then begins to raise the lengths of auger sections out of the completed well hole W, typically while rotating the lengths of auger sections, as shown by the vertical and rotational arrows of
At this point, as shown in
The material of the support frame and pivotable braces is typically metal, and in particular is steel, aluminum, iron, or other metal or alloy, and is typically in a cylindrical form, including either a round cylinder or a square cylinder, with rigid joints secured by welding.
In another embodiment of the invention, an elevated ratcheting auger bracing device can include an elevating frame that rests upon the surface of the ground surrounding a well hole, for raising or elevating the support frame and the opposed pair of pivotable braces a distance above the ground level. The elevating frame positions the hinged ends of the pivotable braces a distance above the ground level that avoids or prevents a pooling of mud that may be raised out of the well hole and may accumulate on the ground surrounding the well hole. The raising of the hinge ends of the pivotable braces minimizes or eliminates their soiling and fowling by the accumulated mud, and increases the time and the amount of mud that can accumulate around the well hole before the need to halt the auger withdrawal process and clear away accumulated mud. In some embodiments and circumstances, the accumulated mud can be pulled away from the area around the well hole, and from within the space confined by the elevating frame, that avoids the need for halting the auger withdrawal process.
A third embodiment of a ratcheting auger bracing device 101 illustrated in
The elevating frame 111 also includes a plurality of legs that elevate the support frame 11 and the hinged pair of pivotable braces. The legs include a plurality of legs that elevate the support frame 12 above and relative to the lower base 113, in an embodiment of the invention, a first pair of upright, vertical legs 117a and 117b connects between the upper side bar 14a with the lower side bar 114a, and supports and raises the upper sides bar 14a above the lower side bar 114a. A second pair of upright, vertical legs 118a and 118b connects the opposite upper side bar 14b with the opposite lower side bar 114b, and supports and raises the upper side bar 14b above the lower side bar 114b. Typically legs are typically vertical, though the set of legs can alternatively be diagonal between the lower base 113 and the support frame 12. In the illustrated embodiment, the vertical legs 117 and 118 are positioned at the corners formed by the respective side bars and end bars of the support frame 12 and lower base 113, The length of the vertical legs should be as long as possible to maximize the space below the pivotable braces, though the vertical legs should not be so long that limits the drilling equipment 70 from raising an uppermost auger section 80m well up and out of the well hole, while allowing the distal end bars, for example end bars 28 and 48 shown in
The support frame 111 is configured in length along the side bars 14,114, and laterally along the end bars 16,116, and vertically along the vertical legs 117, 118, to provide an interior volume 112, bounded by the side bars 14,114, the end bars 16,116, and the vertical legs 117,118, that is sufficiently long, laterally broad, and vertically tall, to accommodate the full diameter of a well hole W and an auger section 80 there within, and an accumulation of mud (M) brought up out the well hole during the extraction of the lengths of auger sections 80.
In the third embodiment of a ratcheting auger bracing device, shown in
In the fourth embodiment of a ratcheting auger bracing device; shown in
To commence withdrawing of the auger sections, the ratcheting auger bracing device 110, is opened by folding the two pivotable braces 20,40 away from the center, as shown in the dashed-line features of
The drilling equipment 70 then begins to raise the lengths of auger sections 80 out of the completed well hole W, typically while rotating the lengths of auger sections 80, as shown by the vertical and rotational arrows of
At this point, as shown in
As shown in
The separate elevating frame 311 also includes a plurality of legs that elevate the support frame 12 above and relative to the lower base 113, and elevate the support frame 11 of the ratcheting auger bracing device 10. An example of such upright, vertical legs is shown and described in
An embodiment can also include a means for preventing horizontal movement of the support frame 11 relative to the elevating frame 311 in the lateral direction (side to side), transverse to the length parallel with the side bars 14. One such means can include a pin 65 that is inserted through a through hole 61 in the side bar 14, and through a through hole 62 in the base sides bars 114 that align with the through hole 61 in the side bar 14. Typically two or more pairs of aligned holes 61,62 and respective pins 65 are used in each side bar 14 and base side bar 314.
Another means for preventing horizontal movement in the lateral direction can be a one or more raised wall sections secured to either the inner side surface of the base side bars 314, or the outer side surface of the base side bars 314, that extend vertically above the upper surface of the base side bars 314.
In another embodiments, a means for preventing horizontal movement can include a fastener, such as a threaded bolt, cotter pin, or other fastener to not only prevent lateral (or longitudinal) horizontal movement, but also to fix the bracing device to a separate elevating frame, to prevent lifting of the bracing device off of the elevating frame, and form a unified elevated bracing device. This arrangement allows for the two separate devices the bracing device and the elevating frame—to be handled separately, yet secured together into one unit.
The elevating frame 411 also includes a means for preventing horizontal movement of the support frame 11, after mounting the support frame 11 upon the elevating frame 411, in both the longitudinal direction and the lateral direction. One or more raised wall sections can be secured to either the inner side surface of the base side bars 414, or the outer side surface of the base side bars 414, that extend vertically above the upper surface of the base side bars 414.
A pair of elongated walls 420a and 420b secured to the inner side surface of the base side bars 414a,414b extend vertically above the upper surfaces of the base side bars. It can be understood that two or more raised wall sections can be secured to the base side bars, spaced apart by some distance. The lengths and heights of the raised wall sections can be selected to ensure restraining of the lateral, horizontal movement, and to prevent the side bars 14 from too easily “jumping” over the raised wall sections.
In addition, the raised end edges 421a and 422a at opposite ends of the first elongated wall 420a are position longitudinally inward from the ends 415a,415b of the first base side bars 414a, and the raised end edges 421b and 422h at opposite ends of the second elongated wall 420b, are position longitudinally inward from the ends 416a,416b of the second base side bar 414b. These raised end edges 421,422 are configured to contact the interior sides of the lateral base end bars 16a,16b of the or bracing device 10, which is illustrated in
In other embodiments, the elongated walls 420 can be secured to the outer side surface of the base side bars 414, or on both the inner side surface and the outer side surface of the base side bars 414.
As shown in
The material of the support frame, elevating frame, and pivotable braces is typically metal, and in particular is steel, aluminum, iron, or other metal or alloy, and is typically in a cylindrical form, including either a round cylinder or a square cylinder, with rigid joints secured by welding.
This application claims the benefit of U.S. Provisional Application No. 62/926,762 filed Oct. 28, 2019, and also U.S. Provisional Application No. 62/980,688 filed Feb. 24, 2020, the disclosures of which are hereby incorporated by reference in their entireties.
Number | Date | Country | |
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62926762 | Oct 2019 | US | |
62980688 | Feb 2020 | US |