Abstract:
Disclosed is a two-part caisson-clamp, wherein each half of the caisson-clamp contains only one jaw face. The two half caisson-clamps together pinch the top of a pile between them. The jaw faces may have a concave curve to secure the pile between them. The pile extends up between the two caisson-clamps to contact the caisson-beam. Horizontal forces on the two caisson-clamps, which would otherwise drive the two caisson-clamps apart, are resisted by mechanical stop(s). A mandril may be inserted into the pile to reinforce the top of the pile relative to the forces applied and transferred by the half-caisson clamps.

Description:
BACKGROUND 
     In construction projects, rigid members, such as piles, sheet piles, poles, caissons, or other vertically oriented piles (hereinafter referred to as “piles”) must sometimes be inserted into and/or withdrawn from the earth. Piles may be made out of wood, steel, reinforced and/or prestressed concrete, or other materials. Piles may have a square, rectangular, circular, “H” or other cross-section when viewed through a horizontal cross-section. 
     Pile insertion and extraction techniques typically involve applying a static force in conjunction with a dynamic, often vibrating force, both forces typically applied at or near the top of a pile. In pile insertion contexts, the static force is commonly provided by the weight of the pile and pile driving equipment while the dynamic force may be provided by i) a diesel, steam, or hydraulic drop hammer which raises a weight and drops it onto the upper end of the pile, ii) a hydraulic, gear, or roller-drive system which presses-in or crowds the pile into the earth, and/or iii) a vibratory system which, for example, may use a pair of balanced, counter-rotating eccentric weights (often obtaining power through a hydraulic connection to a remote power system) to vibrate the pile, which liquefies the earth in contact with the pile and allows the static force to push the pile into the earth (or withdraw it from the earth, in the case of extraction and application of a static lifting force). 
     Existing pile driving equipment typically includes a caisson-clamp attached to the top of the pile. An example of an existing clamp is shown in  FIG. 1 .  FIG. 1  shows a caisson-beam  1001  and two caisson-clamps  1017  and  1013 . The clamps  1017 / 1013  each comprise an adjustment mechanism  1005 , a fixed jaw face  1011 , an adjustable jaw face  1009 , a pile guide  1007 , and caisson-beam track  1015 . In use, the distance between two such caisson-clamps is adjusted by sliding the clamps along the caisson-beam through the caisson-beam tracks. The distance between the caisson-clamps is first roughly selected to allow the fixed jaw face  1011  and adjustable jaw face  1009  to be lowered onto a pile. The adjustable jaw face  1009  may have a roughly flat face, as shown in the detail view in  FIG. 1 , while the fixed jaw face  1011  may have a convex curve, generally with a tighter arc angle than the interior of the pile into which the caisson-clamps are to be lowered. The adjustable jaw face  1009  may be tightened (via the adjustment mechanism  1005 ) against the outside of the pile, causing the clamp to adjust its position relative to the pile  1000  and causing the fixed jaw face  1011  to tighten against the inside of the pile  1000 . The top of the pile  1000  is then pinched at two locations  1019  and  1021  by the jaw faces. Wedges  1020  may then be tightened to secure the position of the caisson-clamps  1013 / 1017  on the caisson-beam  1001 . 
     As shown in  FIG. 1 , two caisson-clamps are shown at the approximate center of a caisson-beam, with the caisson-clamps having a left- and right-sided orientation as viewed in the figure (so that the adjustable jaw side of both clamps is on the exterior of the pile). Two caisson-clamps are also shown at opposite ends of the caisson-beam, caisson-clamps  1013  and  1017 , both of which clamps are shown with a left-sided orientation. In use, caisson-clamp  1017  would be removed from the caisson-beam, rotated 180 degrees, and re-inserted onto the caisson-beam with a right-sided orientation. 
     The existing prior-art caisson-clamps require placement and replacement of four jaw faces and often require clamps and/or jaw faces sized to specific piles or narrow ranges of piles. Existing caisson-clamps often require that the pile be machined, welded, cut, ground, or otherwise modified prior to and/or after insertion or extraction, procedures which take time, expertise, and which may add cost, time, and complexity to a pile insertion and/or extraction procedure as well as to utilization of the pile after the insertion and/or extraction procedure. The pile used in prior-art systems must be hollow to accommodate the caisson-clamps or must be modified to accommodate the caisson-clamps. Needed is a pile clamp which addresses these shortcomings. 
     SUMMARY OF THE INVENTION 
     Disclosed is a two-part caisson-clamp, wherein each half of the caisson-clamp contains only one jaw face. The two half caisson-clamps together pinch the top of a pile between them. The jaw faces may have a concave curve to secure the pile between them. The pile extends up between the two caisson-clamps to contact the caisson-beam. Horizontal forces on the two caisson-clamps, which would otherwise drive the two caisson-clamps apart, are resisted by mechanical stop(s). A mandril may be inserted into the pile to reinforce the top of the pile relative to the forces applied and transferred by the half-caisson clamps. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts a prior art set of caisson-clamps in an elevation view and a plan view of a prior art set of caisson-clamps clamped to a pile. 
         FIG. 2  depicts an elevation view of an embodiment of a caisson-clamp according to this disclosure. 
         FIG. 3.A  depicts an elevation view of an embodiment of a mechanical stop according to this disclosure. 
         FIG. 3.B  depicts an elevation view of an embodiment of a mechanical stop according to this disclosure. 
         FIG. 4  depicts an elevation view of an embodiment of a caisson-clamp as clamped to 4″ and 6″ piles, according to this disclosure. 
         FIG. 5  depicts an elevation view of an embodiment of a caisson-clamp as clamped to 8″ and 10″ piles, according to this disclosure. 
         FIG. 6  depicts elevation and plan views of an embodiment of a pile jaw to be attached to a moveable jaw holder. 
         FIG. 7  depicts elevation and plan views of an embodiment of a pile jaw to be attached to a fixed jaw holder. 
         FIG. 8  depicts an elevation view of a mandril. 
         FIG. 9  depicts an elevation view of an embodiment of a mechanical stop. 
         FIG. 10  depicts an elevation view of an embodiment of a mechanical stop. 
     
    
    
     DETAILED DESCRIPTION 
     The following description of the drawings and detailed description refers to the accompanying drawings. The reference numbers generally begin with a numeral which identifies the figure, followed by another numeral which identifies the feature. The same feature number in different drawings generally identify the same or similar elements and/or components. The following detailed description is for the purpose of illustrating embodiments of the invention only, and other embodiments are possible without deviating from the spirit and scope of the invention, which is limited only by the appended claims. Certain of the figures are discussed in this specification using certain terms. The following discussion uses these terms and related terms as examples and not as limitations. The components depicted in certain of the figures represent functional groups; it should be understood that such functional groupings need not exist as discrete hardware devices and that the functions described as occurring within, comprising, or being provided by a grouping may be provided within or by common or separate physical devices. The functions within and comprising any of the function groupings may be regrouped in other combinations and certain of the components may be omitted or added without deviating from the spirit of the disclosed invention. Certain of the groupings depict components which are included together in the illustration for the sake of convenience. Certain of the figures depict components in isolation; the components from different figures may be combined and/or regrouped. As used herein, “releasable,” “releasably” and similar shall mean being able to repeatedly connect/disconnect (or engage/disengage) through the use of hands, feet, or human appendage with or without use of a tool (including power tools), and without the need for removal of material or application of a high temperature (greater than approximately 150 degrees Fahrenheit). Examples of “releasable” components include nuts and bolts, screws and a threaded receptacle, friction locking cams or chocks or wedges (female and male), hydraulic pistons and straps and tensioning levers. Not considered “releasable” are components attached to another component by chemical bonding or welding or which are removed from another component through use of a saw, drill, grinding tool, other material removal tool, or high intensity heat source (such as a welder or high-temperature cutting tool). 
       FIG. 2  depicts an elevation view of an embodiment of a caisson-clamp according to this disclosure. A caisson-beam  2001  is shown with two attached half-caisson clamps  2030  and  2032 . Half-caisson clamp  2030  comprises a caisson-beam track  2015 , a wedge  2016 , moveable jaw holder connecting bolts  2036 , and moveable jaw holder comprising a piston  2037 , a connecting rod  2038 , a guide fin  2035 , and a moveable pile jaw face  2041 . Details of an embodiment of a moveable pile jaw face  2041  are shown in  FIG. 6 . 
     The caisson-beam track  2015  is an example of means to connect the half caisson-beam clamp to the caisson-beam. Alternative means to secure the half caisson-beam clamps along the length of the caisson-beam are possible; examples include a caisson-beam comprising an opening (or other geometry) into which the caisson-beam clamp may be inserted (or otherwise may be coupled with). The moveable jaw holder and components thereof are examples of means for a moveable jaw holder; the piston  2037  may be powered by a hydraulic power system attached to hoses on or in the vicinity of the piston  2037 ; the moveable jaw holder may, for example, provide a horizontal movement range of 2¼″; a jack screw or similar is an example of an alternative to the components for the moveable jaw holder. 
     The wedge  2016  may comprise components such as bolts attached to at least one threaded chock in a set of metal chocks, which chocks are in a wedge relationship (at least two of the chocks having overlapping sides with an angle greater or less than horizontal); such that when the bolt(s) are turned to tighten the wedge  2016 , the threaded chock(s) slides along the other, forcing both chocks outward, generally perpendicular to their non-horizontal overlapping side, against the interior of the caisson-beam track  2015  and against the caisson-beam  2001 , thereby wedging the half-caisson clamp against the caisson-beam. The wedge  2016  holds the half-caisson clamp in a relationship with the caisson-beam, but is not expected to secure the half-caisson clamp against horizontal forces experienced during use. The wedge  2016  may be powered by a human-powered tool, such as a wrench, or by a power tool, or by a hydraulic power source. 
     Half-caisson clamp  2032  comprises a caisson-beam track  2015 , a wedge  2016 , and a fixed jaw holder comprising a fixed jaw face  2039 , fixed jaw face attachment bolts  2042 , and fixed jaw holder attachment bolts  2043  and  2045 . Details of an embodiment of a fixed pile jaw face  2039  are shown in  FIG. 7 . 
     Also shown in  FIG. 2  is a mechanical stop  2031  comprising a plate with holes drilled in it as well as holes drilled in the caisson-beam  2033 . A detailed plan view of the plate-based mechanical stop and caisson-beam are shown in  FIGS. 3.A  and  3 .B., while an alternative is shown in  FIG. 9 . Discussing  FIGS. 2 ,  3 , and  9 , the illustrated mechanical stop is an example of means to secure the half-caisson clamps against the horizontal forces experienced during use. With respect to  FIG. 2 , the holes in the mechanical stop  2031  as well as in the caisson-beam  2033  are chosen to allow a pile to be inserted between the half-caisson clamps taking into consideration factors such as i) that piles tend to have standard diameters, typically, for example, between 4″ and 12″; ii) taking into consideration the horizontal offset created by the width of the half-caisson clamp and the width of the mechanical stop; and iii) taking into consideration the horizontal movement range of the moveable jaw holder (approximately 2¼″). 
     As shown in  FIG. 3.A  as an example, the set of holes  3032 .A (in the mechanical stop  3031 ) and  3033 .A (in the caisson-beam  3001 ) and the set of holes  3032 .G (in the mechanical stop  3031 ) and  3033 .E (in the caisson-beam  3001 ) line up and may receive bolts, thereby securing the mechanical stop  3031  to the caisson-beam  3001 , which secured mechanical stop  3031  may secure a half-caisson clamp against horizontal forces experienced during use. As shown in  FIG. 3.B  as an example, the set of holes  3032 .D (in the mechanical stop  3031 ) and  3033 .B (in the caisson-beam  3001 ) and the set of holes  3032 .G (in the mechanical stop  3031 ) and  3033 .D (in the caisson-beam  3001 ) line up and may receive bolts, thereby securing the mechanical stop  3031  to the caisson-beam  3001 , which secured mechanical stop  3031  may secure a half-caisson clamp against horizontal forces experienced during use. The holes and relative hole-spacing in  FIGS. 3.A  and  3 .B are shown as examples. 
       FIG. 9  depicts an alternative mechanical stop in which the caisson-beam  9001  (shown as a partial view) has holes  9065 .A,  9065 .B,  9065 .C,  9065 .D, and  9065 .E. In this example, half-caisson clamp  9030  (also shown as a partial view) has hole  9067 . When, as shown in  FIG. 9 , hole  9067  is lined up with one of the holes in the caisson-beam, hole  9065 .D, a bolt, rod, pin or similar may be passed through the lined up holes, thereby releasably securing the half-caisson clamp  9030  against horizontal forces. The bolt, rod, pin, or similar may be secured with a nut, with a cotter pin, or similar. The holes in  FIG. 9  are shown with a horizontally oriented central axis; it would be appreciated that a vertically oriented central axis may be used, in which case the holes may pass through the bottom portion of the caisson-beam or another portion of the caisson-beam with a suitable orientation. 
       FIG. 10  depicts an alternative mechanical stop in which the half-caisson clamps  10030  and  10032  are secured by mechanical stop  10067 , comprising a bolt, rod, or similar. The mechanical stop  10067  may pass through a hole, channel, grove, or notch in the half-caisson clamps provided for this purpose. The ends of the mechanical stop  10067  may comprise one or more nuts, bolt-heads, or similar. Alternative mechanical stops not shown in the drawings include a belt, U-shaped bracket, or similar going around or attaching to one half-caisson clamp and going around or attaching to the other half-caisson clamp and/or the caisson-beam. 
     To clamp a different sized pile between the half-caisson clamps, the piston  2037  (if extended) may be withdrawn, the mechanical stop  2 / 3031  (if attached) may be unbolted from the caisson-beam  2 / 3001 , the wedges  2016  may be loosened (if required), the half-caisson clamps  2030  and  2032  may be relocated along the caisson-beam  2001 , the wedges  2016  may be tightened, the mechanical stops  2 / 3031  may be bolted to a new position, the new pile may be inserted into the space between the half-caisson clamps  2030  and  2032 , and the piston  2037  may extended to clamp the pile between the moveable pile jaw face  2041  and the fixed pile jaw face  2039 . One or more of these steps may be performed in another order. 
       FIG. 4  depicts an elevation view of an embodiment of a caisson-clamp as clamped to 4″ and 6″ piles, according to this disclosure. 
       FIG. 5  depicts an elevation view of an embodiment of a caisson-clamp as clamped to 8″ and 10″ piles, according to this disclosure. 
       FIG. 6  depicts elevation and plan views of an embodiment of a pile jaw to be attached to a moveable jaw holder, moveable pile jaw face  6041 . The depicted moveable pile jaw face  6041  has a concave portion  6053  to receive a pile. Shown is a moveable pile jaw face bracket  6051 , drilled to receive a bolt, rod, or similar to secure the moveable pile jaw face  6041  to the connecting rod  2038 . 
       FIG. 7  depicts elevation and plan views of an embodiment of a fixed jaw face  7039  to be attached to a fixed jaw holder. The fixed jaw face  7039  is depicted as having holes  7053  to receive fixed jaw face attachment bolts  2042 . The fixed jaw face  7039  has a concave portion  7057  to receive a pile. 
     The arc radius of the pile jaw face may be selected to approximate and/or be slightly larger than the arc radius of the pile to which the system is to be clamped. 
     Unlike the prior art, in which the jaw faces are flat or convex and in which two sets of jaw faces are required in each caisson-clamp, one set on each side of the pile (see  1021  and  1019 —a total of four jaw faces), the present invention utilizes two jaw faces, one per caisson-clamp, both of which jaw faces are concave. Unlike the prior art—in which the pile contacts the top of the caisson-clamps, in which the pile must be modified or reinforced to be driven into or extracted from the ground—in the demonstrated system, the pile contacts the caisson-beam, the pile does not need to be modified or reinforced, resulting in less damage to both the half-caisson clamps, the jaw faces, and the pile. Horizontal forces experienced by the half caisson-clamps during use are resisted by a mechanical stop. 
       FIG. 8  depicts an elevation view of a mandril  8061 . The mandril  8061  may have a hole  8063  to receive a bolt or similar to facilitate utilization of the mandril. The mandril  8061  may optionally be inserted into the pile to reinforce the pile against deforming forces which may be experienced during insertion or extraction of the pile. A mandril may not be used with the prior art.