Abstract:
A structural crack repair apparatus is disclosed. The apparatus includes at least one staple having an elongated torque plate, a pair of reinforcing rods and a pair of rotatable cam members provided on the torque plate and engaging the respective cam members. According to the method, the reinforcing rods are inserted in rod apertures provided in the surface on opposite sides of the crack. The cam members are selectively rotated to cause radial displacement of the reinforcing rods with respect to a geometric center of the cam members to cause tight engagement of the reinforcing rods with the interiors of the rod apertures.

Description:
RELATED APPLICATIONS 
       [0001]    This is a divisional of application Ser. No. 10/882,573, filed on Jul. 1, 2004, the entire contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to apparatus for repairing cracks in floors, walls and other surfaces. More particularly, the present invention relates to a novel structural crack repair apparatus and method which facilitates the repair of cracks in walls, floors and surfaces of a variety of above-ground structures as well as various subterranean structures such as swimming pools. 
       DESCRIPTION OF THE PRIOR ART 
       [0003]    A variety of structures such as houses, buildings, walls, fences and swimming pools, for example, have concrete surfaces. Concrete elements in such structures not only provide substantial reinforcement to the structures but also impart a pleasing aesthetic appearance to the structures. However, one of the problems associated with concrete structures is that cracks frequently form in the surfaces of the structures after a prolonged period of time. Therefore, a variety of techniques have been developed to repair cracks in concrete and other surfaces. 
         [0004]    U.S. Pat. No. 4,360,994 describes a concrete crack sealing system, which includes injecting a liquid latex into a crack, covering the exposed surface of the crack with an impermeable barrier, and injecting a low-viscosity liquid latex through the barrier into the crack. The liquid latex cures into a solid, elastomeric state. However, the system disclosed in the &#39;994 patent does not include heavy-duty mechanical elements which engage the concrete on opposite sides of the crack to prevent widening of the crack over time. 
         [0005]    U.S. Pat. No. 5,063,006 discloses methods for repairing cracks in concrete structures by attaching over a crack a series of cutoff agent-sealing members. A blowing resin is introduced under pressure into internal chambers of the members to elevate the pressure within the members. Inlet and outlet valves of the chambers are closed, causing elevated pressure in the chambers to push the cutoff agent deeply into the interior of the crack and seal the crack. However, the method disclosed in the &#39;006 patent lacks the use of mechanical elements to engage the concrete on opposite sides of the crack and prevent further widening of the crack. 
         [0006]    U.S. Pat. Nos. 5,476,340 and 5,771,557 each disclose an internal metal stitching method for stitching a crack in a concrete surface. Slots are cut in the concrete on opposite sides of the crack every two feet, and metal brackets are installed in the slots at alternating angles to the crack. The slots containing the brackets are then filled with a resin material and then smoothed out to the level of the concrete surface. However, because the brackets must be installed every two feet, the stitching method is time- consuming, laborious and requires a large number of brackets. Furthermore, the disclosed methods do not compress, and thereby stabilize, the crack. 
         [0007]    Another method of repairing cracks is detailed in U.S. Pat. No. 6,212,750. The method includes a plurality of drilling fixtures, which facilitate the creation of one or more lock-receiving recesses positioned generally transverse to the casting crack. The lock-receiving recesses are formed of a single-sized circular bore combination having alternating double and single circular portions to maximize strength. A plurality of correspondingly-shaped metal locks are inserted into the lock-receiving recesses to provide transverse metal locks which draw the casting portions on each side of the crack together. The method further includes inserting a plurality of stitching pins in threaded bores in overlapping relationship formed along the remainder of the crack. However, the method is laborious and time-consuming since the lock-receiving recesses must be cut to the same configuration and dimensions as the metal locks. 
         [0008]    Additional crack-repairing methods and apparatus are detailed in U.S. Pat. Nos. 2,838,145 and 3,168,941 and suffer from one or more disadvantages of the prior art. 
         [0009]    Accordingly, there is a well-established need for a structural crack repair apparatus and method which is simple in construction and is characterized by ease of installation and structural strength to prevent the further widening of a crack in a concrete surface. 
       SUMMARY OF THE INVENTION 
       [0010]    The invention is directed to a structural crack repair apparatus and method which is suitable for repairing cracks in surfaces, particularly the cracked concrete surfaces of walls, floors, fences and swimming pools, for example. The structural crack repair apparatus is characterized by structural simplicity, ease of installation and imparts considerable structural strength to a cracked surface to prevent further widening and/or propagation of the crack along the surface. The structural crack repair apparatus is applicable to repairing structural cracks in a wide variety of surfaces, structural bodies and the like having various configurations and compositions. 
         [0011]    In one general aspect of the present invention, a structural crack repair apparatus is provided for engaging a cracked concrete surface on opposite sides of a crack to be repaired. The structural crack repair apparatus comprises at least one staple, each of which includes: 
         [0012]    an elongated torque plate; 
         [0013]    a pair of spaced-apart cam members rotatably carried by the torque plate; and 
         [0014]    a pair of spaced-apart reinforcing rods engaged by the cam members, respectively, for insertion in respective rod openings extending into the surface on opposite sides of the crack to be repaired. 
         [0015]    In a further aspect of the present invention, multiple staples are provided in spaced-apart relationship to each other along the crack to be repaired to prevent further widening and propagation of the crack along the surface. 
         [0016]    In still a further aspect of the present invention, the torque plate has an elongated shaft and cam-receiving apertures provided in respective ends of the shaft for receiving the respective cam members. 
         [0017]    In yet another aspect of the present invention, each cam member includes a circular cam body having an offset aperture for receiving the corresponding reinforcing rod and a pair of spaced-apart pegs which are engaged by a cam-driving tool to rotate the cam member in the corresponding cam-receiving aperture of the torque plate and cause tight engagement of the attached reinforcing rod against the interior of the corresponding rod opening. 
         [0018]    In another aspect of the present invention, the torque plate has an elongated plate member and a pair of spaced-apart cam-receiving apertures provided in the plate member for receiving cam members, respectively. 
         [0019]    In still another aspect of the present invention, the staple is characterized by a unique low profile, facilitating a crack repair method requiring a relatively shallow excavation into the repair surface. 
         [0020]    In a still further aspect of the present invention, a method of repairing a crack in a surface is provided. The method includes: 
         [0021]    providing an excavation cavity in the surface in transverse relationship to the crack to be repaired; 
         [0022]    providing a pair of spaced-apart rod apertures extending from the rear or bottom of the excavation cavity into the surface; 
         [0023]    assembling a staple having an elongated torque plate, a pair of spaced-apart cam members rotatably carried by the torque plate and a pair of reinforcing rods engaged by the cam members, respectively; 
         [0024]    inserting the reinforcing rods into the respective rod apertures; and 
         [0025]    rotating the cam members with respect to the torque plate, such that the reinforcing rods are moved inwardly toward each other and against the interior walls of the respective rod apertures. 
         [0026]    In yet another aspect of the method of the present invention, an epoxy is applied to the reinforcing rods or the rod apertures to secure the reinforcing rods in the respective rod apertures. 
         [0027]    These and other aspects, features, and advantages of the present invention will become more readily apparent from the attached drawings and the detailed description of the preferred embodiments, which follow. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    The preferred embodiments of the invention will hereinafter be described in conjunction with the appended drawings provided to illustrate and not to limit the invention, where like designations denote like elements, and in which: 
           [0029]      FIG. 1  is a perspective view of a drained swimming pool, partially in section, with a fracture line or crack to be repaired in the side and bottom surfaces of the pool; 
           [0030]      FIG. 2  is a perspective view of the drained swimming pool of  FIG. 1 , with excavation cavities provided in the side and bottom surfaces of the pool in transverse relationship to the crack as a first step according to the crack repair method of the present invention; 
           [0031]      FIG. 3  is a perspective view of the pool of  FIG. 2 , illustrating a pair of rod apertures drilled from the rear or bottom of each excavation cavity into the surface as a second step according to the crack repair method of the present invention; 
           [0032]      FIG. 4  is a perspective view of the pool, illustrating in exploded view multiple, assembled staples of the structural crack repair apparatus of the present invention positioned for insertion into each corresponding pair of rod apertures as a third step according to the method of the present invention; 
           [0033]      FIG. 5  is a perspective view of the pool, illustrating in exploded view application of an epoxy to the reinforcing rods of each staple prior to insertion of the reinforcing rods into each corresponding pair of rod apertures as a fourth step according to the method of the present invention; 
           [0034]      FIG. 6  is a perspective view of the pool, illustrating the staples inserted in each corresponding pair of reinforcing rods in each excavation cavity as a fifth step according to the method of the present invention; 
           [0035]      FIG. 7  is a perspective view of the pool, illustrating in exploded view removable engagement of a cam-driving tool, ratchet and handle assembly (shown in phantom) with the cam member of each staple to facilitate rotation of the cam member and engagement of the reinforcing rods against the interiors of the rod cavities as a sixth step according to the method of the present invention; 
           [0036]      FIG. 8  is a perspective view of a staple, illustrating in exploded view a cam-driving tool (in solid lines) and a ratchet and handle assembly (in phantom) which may be conventional and is used to rotate each cam member on the torque plate element of the staple and cause secure engagement of the reinforcing rods against the interior surfaces of the rod apertures; 
           [0037]      FIG. 9  is a front view of a staple inserted in an excavation cavity in a surface, illustrating clockwise rotation of the cam members on the torque plate to cause rotation and radial displacement of the reinforcing rods into tight engagement with the interior surfaces of the respective rod apertures in which they are inserted; 
           [0038]      FIG. 10  is a top view of the staple of  FIG. 9 , prior to rotation of the cam members and reinforcing rods; 
           [0039]      FIG. 11  is a front view of the staple of  FIG. 9 , after rotation of the cam members on the torque plate and engagement of the reinforcing rods with the interior surfaces of the respective rod apertures; 
           [0040]      FIG. 12  is a top view of the staple of  FIG. 11 , after rotation of the cam members and reinforcing rods; 
           [0041]      FIG. 13  is a perspective view of an assembled staple of the structural crack repair apparatus according to the present invention; 
           [0042]      FIG. 14  is an exploded, perspective view of the staple of  FIG. 13 ; and 
           [0043]      FIG. 15  is a perspective view of an assembled staple according to an alternative embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0044]    Shown throughout the Figures, the present invention is generally directed to a structural crack repair apparatus and method for repairing cracks in a surface. The apparatus incorporates a simple, low profile, and yet heavy-duty, design that facilitates ease of installation and prevents or minimizes the widening or propagation of cracks in a variety of surfaces. 
         [0045]    Referring initially to  FIG. 6 , an illustrative embodiment of the structural crack repair system of the present invention is generally indicated by reference numeral  1 . In an exemplary application of the invention, the system  1  includes at least one staple  5 , and typically multiple staples, which span a crack  35  in the wall  33  and floor  34  of a swimming pool  32 . The staples  5  prevent further widening and propagation of the crack  35  along the wall  33  and floor  34 . While application of the invention will be hereinafter described with respect to repair of the crack  34  in the swimming pool  32 , it is understood that the system  1  can be used to repair cracks in a wide variety of surfaces, structural bodies and the like having various configurations and compositions. The structural details of each staple  5 , as well as a typical manner of installation, will be hereinafter further described. 
         [0046]    Referring next to  FIGS. 13-15 , each staple  5  typically includes a torque plate  2  having an elongated shaft  4 . A circular cam-receiving aperture  3  extends through each end portion of the shaft  4 . Accordingly, each cam-receiving aperture  3  is adapted to receive a cam member  7  in such a manner that the cam member  7  can rotate freely in the corresponding cam-receiving aperture  3 . In an alternative embodiment of the staple  5   a  illustrated in  FIG. 15 , the torque plate  2   a  includes an elongated, rectangular plate member  4   a  and the cam-receiving apertures  3  extend through the respective end portions of the plate member  4   a.    
         [0047]    As particularly illustrated in  FIG. 14 , each cam member  7  typically includes a circular cam body  10 . A pair of spaced-apart cam tool apertures  9  extend through the cam body  10  for purposes which will be hereinafter described. An offset aperture  8  extends through each cam body  10  in offset or eccentric relationship with respect to the geometric center of the cam body  10 . As illustrated in  FIG. 12 , in the assembled staple  5 , each offset aperture  8  receives the reduced diameter tip  13  of an elongated reinforcing rod  12 , which is typically steel. Accordingly, as illustrated in  FIG. 13 , the reinforcing rods  12  extend from the respective cam members  7 , in spaced-apart relationship to each other. 
         [0048]    Referring next to  FIGS. 1-12 , in typical application of the system  1  according to the structural crack repair method of the present invention, multiple staples  5  are used to repair a fracture line or crack  35  in the wall  33  and floor  34  of a swimming pool  32 . The crack  35  is shown in the untreated condition in  FIG. 1 . As illustrated in  FIG. 2 , in a first step according to the method of the invention, multiple excavation cavities  36 , each of which typically has an elongated, rectangular shape, are cut in the wall  33  and floor  34  in spaced-apart relationship to each other and in transverse and intersecting relationship to the crack  35 . The dimensions of each excavation cavity  36  depend on the length of the staples  5  which are to be used in the repair process. For example, in the event that the length of each of the staples  5  is 3.0 inches, each excavation cavity  36  has dimensions of typically 5.0×2.5 inches; if the length of each staple  5  is 6.0 inches, then each excavation cavity  36  has dimensions of typically 8×2.5 inches. The depth of each excavation cavity  36  is greater than the thickness of the torque plate  2  of each staple  2 . Each excavation cavity  36  is thoroughly cleaned to remove debris therefrom. 
         [0049]    As illustrated in  FIG. 3 , a pair of spaced-apart rod apertures  38  is next drilled into rear surface of each excavation cavity  36  cut in the swimming pool wall  33  and the bottom surface of each excavation cavity  36  cut in the swimming pool floor  34 . The locations of the rod apertures  38  may first be marked by using the assembled staple  5 , with the cam members  7  inserted in the respective cam-receiving apertures  3 , as a template. Accordingly, with the cam members  7  positioned in the respective cam-receiving apertures  3  in such a manner that the cam tool apertures  9  located at the inside position and the offset aperture  8  located at the outside position of each cam member  7 , as illustrated in  FIG. 13 , the rod apertures  38  correspond to the locations of the respective offset apertures  8 . Alignment means (not illustrated), such as indentations or markings, for example, may be provided in the torque plate  2  and circular cam members  7  to ensure proper orientation of the staple  5  prior to marking the locations of the rod apertures  38 . The rod apertures  38  may be formed using a 0.75 inch masonry bit, for example. A typical depth for each rod aperture  38  is at least 3.25 inches for a 3.0 inch reinforcing rod and at least 6.25 inches for a 6.0 inch reinforcing rod  12 . After drilling, debris is cleaned from the rod apertures  38  using compressed air, a brush or the like. 
         [0050]    As illustrated in  FIG. 4 , the reinforcing rods  12  are next assembled on each staple  5 . As illustrated in  FIG. 14 , this is facilitated by inserting the reduced-diameter tip of each reinforcing rod  12  in the offset aperture  8  of each cam member  7 , as heretofore described. As illustrated in  FIG. 5 , a two-part, free-flowing, non-sag epoxy  17  is then applied from an epoxy container  16  to each reinforcing rod  12 . Alternatively, the epoxy  17  may be applied directly to each rod aperture  38 . A small quantity of epoxy  17  may be used to secure the reduced-diameter tip  13  of each reinforcing rod  12  in the corresponding offset aperture  8  of the cam member  7 . 
         [0051]    As illustrated in  FIGS. 6 and 10 , the reinforcing rods  12  of each staple  5  are next inserted into the respective rod apertures  38  of each excavation cavity  36  until the torque plate  2  is flush with the rear or bottom wall of the excavation cavity  36 . The epoxy  17  is then allowed to cure for a period of time, depending on the particular epoxy used. 
         [0052]    As illustrated in  FIGS. 7 and 8 , the reinforcing rods  12  of each staple  5  are next forced inwardly toward each other by rotation of the cam members  7  in the respective cam-receiving apertures  3 . As illustrated in  FIG. 8 , this is carried out using a cam-driving tool  20 , which may be conventional. Such a cam-driving tool  20  typically includes a pair of spaced-apart pegs  21  and an offset or eccentric rod aperture  22 . A nut  23  is provided on the cam-driving tool  20  for engagement by the socket  27  of a ratchet  26 . A handle  28  engages the ratchet  26  for rotation of the cam-driving tool  20 . 
         [0053]    The cam-driving tool  20  engages each cam member  7  by inserting the pegs  21  of the cam-driving tool  20  in the respective cam tool apertures  9  of the cam member  7  and inserting the reduced-diameter tip  13  of the reinforcing rod  12 , which protrudes from the offset aperture  8 , into the rod aperture  22  of the cam-driving tool  20 . As illustrated in  FIGS. 9 and 10 , the cam tool apertures  9  of each cam member  7  are initially located at the inside position and the offset aperture  8  of each cam member  7  is located at the outside position. By operation of the cam-driving tool  20 , each cam member  7  is rotated in the clockwise direction, as indicated by the curved arrows in  FIG. 9 . This causes rotation of the offset aperture  8  of each cam member  7  from the outside position of  FIG. 9  to the upper position of  FIG. 11 , thereby facilitating radial displacement of the reinforcing rods  12  toward each other in the respective rod apertures  38 . Accordingly, prior to rotation of the cam members  7 , the reinforcing rods  12  are positioned in approximately the center of each rod aperture  38 , as illustrated in  FIG. 10 . After rotation of the cam members  7 , the reinforcing rods  12  engage the inner surface of the respective rod apertures  38  at a force of approximately  60  torque-pounds of resistance, as illustrated in  FIG. 12 . This substantially reinforces each staple  5  in the corresponding excavation cavity  36 . 
         [0054]    A light coating of epoxy (not illustrated) is then coated over the entire surface of the torque plate  2  and cam members  7  of each staple  5 . Finally, each excavation cavity is filled in using a non-shrinking cement (not illustrated), thereby covering the torque plate  2 , cam members  7  and reduced-diameter rod tips  13  of each staple  5 . 
         [0055]    While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications can be made in the invention and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention.