Abstract:
A wall straightening apparatus provides multiple independently controllable jacking members pressing outward on diagonal braces to push those braces against the wall to move the wall into a vertical alignment. Feedback control of the jacking members provides coordinated straightening of large wall sections with lessened cracking and distortion.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. provisional patent application 61/442,374 filed Feb. 14, 2011 and hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a method of straightening a foundational wall and in particular for use in the repair and reinforcement of basement walls comprised of blocks or other materials. 
       BACKGROUND OF THE INVENTION 
       [0003]    Below ground walls, such as those which provide for the walls of the basement, must be able to support the weight of a structure resting thereon and to resist lateral forces associated with the surrounding soil and hydrostatic pressure from water in the soil. 
         [0004]    Particularly when a basement wall is constructed of masonry block, lateral pressure may cause the wall to deflect inwardly and cracks to appear on the inner surface of the wall as mortar joints yield to a tensile force component. If such deflection continues unabated, the entire wall may buckle and collapse with damage to the supporting structure. 
         [0005]    A number of methods of straightening walls experiencing initial stages of deflection employ applying a counterbalancing force on the inner surface of the basement wall by means of cables or a threaded rod passing from a plate on the inner surface of the basement wall through the wall and anchored at a position outside the wall, for example, in a trench. Tightening the cable or threaded rod may then pull the wall back into alignment. A system of this type is taught by U.S. Pat. No. 4,189,891. 
         [0006]    In a different approach, U.S. Pat. No. 4,353,194 teaches applying force by means of an ellis jack braced between the floor of the basement and the wall suffering from deflection. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention provides an improved method of straightening walls that coordinates multiple jacks simultaneously with monitoring of the wall alignment during the jacking operation. In this way, a faster and more uniform straightening process may be obtained, the latter minimizing wall damage. Further, the wall may be straightened substantially immediately, and not over a lengthy period of time as required of other more gradual processes. 
         [0008]    Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a side elevational view of a hydraulic jack mounted on a fixture for attachment to a concrete slab basement floor in one embodiment of the invention; 
           [0010]      FIG. 2  is a side elevational view of the hydraulic jack of claim  1  positioned with a bracing system against a foundational wall shown in cross-section; 
           [0011]      FIG. 3  is a top plan view of multiple braces of  FIG. 2 , each with a hydraulic jack; 
           [0012]      FIG. 4  is a fragmentary elevational view showing the interconnection of an electronic level-sensor to a control valve of the hydraulic cylinder of  FIG. 1 ; 
           [0013]      FIG. 5  is a figure similar to that of  FIG. 4  showing an alternative mechanical implementation of the present invention; 
           [0014]      FIG. 6  is a plot of data that may be sensed by the level-sensor of  FIG. 4  to control hydraulic fluid gated to the cylinders to minimize wall damage; 
           [0015]      FIG. 7  is a perspective view of a foot bracket used to prevent push-out of the basement wall near the floor. 
       
    
    
       [0016]    Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    Referring now to  FIG. 1 , a hydraulic cylinder  10  of the type known in the art may receive hydraulic fluid through electronically controllable valve  12  from hydraulic hose  14 . As is understood in the art, hydraulic cylinders provide for an enclosed chamber that may be pressurized with a hydraulic fluid to apply force to a shaft communicating with the enclosed chamber through a piston or the like. 
         [0018]    The hydraulic cylinder  10  may provide for a piston driven shaft  15  having a portion extending from an end of the hydraulic cylinder  10  along an axis  16  tipped at approximately 45 degrees with respect to a plane of the floor  20  on which the hydraulic cylinder  10  rests. The end of the shaft  15  may connect with one end of a diagonal brace  22  also extending along the axis  16 . 
         [0019]    A base of a hydraulic cylinder  10  may be attached to and supported by a bracket  24  orienting the shaft  15  along axis  16 , for example, the bracket  24  being fabricated of welded steel plate having a base plate  26  that may rest against the floor  20  with holes receiving anchor screws  28  or the like therethrough to anchor the bracket  24  to the floor  20 . The bracket  24  further provides an angled steel plate against which the base of the hydraulic cylinder  10  may rest so that the piston driven shaft  15  extends along the axis  16 . In an alternative embodiment, (not shown) the bracket  24  may provide a hinge plate allowing flexible adjustment of the angle of the base of the hydraulic cylinder  10  as required. 
         [0020]    Referring now to  FIG. 2 , the diagonal brace  22  may extend toward a basement wall  30  and be aligned to abut at a hinge  23  an upright brace  32  between the ends of the upright brace  32 . The upright brace  32  may fit against an inner surface of the wall  30  extending approximately vertically by about four feet so that pressure can be directed to a specific spot on the wall  30 . The position of the upright brace  32  is moved up or down the wall  30  depending on where the deflection is. For example, if the wall  30  is bowed at the center then that is where the center of the upright brace is located, if the wall  30  is tipped but essentially flat, then the upright brace is put as high as possible. In the case of severely bowed walls, this fitting against the inner surface may only contact portions of the inner surface. The lower end of the upright brace  32  will generally be above the floor  20 . The diagonal brace  22  and the upright brace  32  may be, for example, rectangular steel pipes or other steel shape including angles, tubes, or I-beams . . . . 
         [0021]    Referring now to  FIG. 7 , the foot bracket  39  may provide for an L-shaped bracket having a first face that may be attached to the floor  20  with anchor bolts and a second face extending vertically therefrom adjacent to the wall  30  to be anchored thereto. The foot bracket  39  prevents the base of the wall  30  from separating from the floor  20  and moving outward as the wall  30  is straightened. A similar top bracket may be used when it is desired to prevent movement of the top of the wall  30  with respect to the house joists. 
         [0022]    Soil  34  outside of the wall  30  may be excavated to provide for a trench  36  on the outside of the wall  30  allowing the wall  30  to be pushed outward into alignment. This trenching operation may be used to replace a drain  33  placed at the bottom of the trench  36 . 
         [0023]    A tilt sensor  37  may be attached to the top of the upright brace  32  (or other convenient location) to provide an indication of whether the brace  32  is level and/or to detect movement or acceleration of the top of the upright brace  32 . Typically before the straightening process, the brace  32  will not be vertical but will lean toward the cylinder  10  caused by inward deflection of the wall  30 . 
         [0024]    Referring now to  FIG. 3 , multiple brace systems comprised each of a cylinder  10 , a diagonal brace  22 , and an upright brace  32  (here shown as cylinders  10   a - d , diagonal braces  22   a - d , and upright braces  32   a - d ) may be simultaneously applied against the wall  30  with the cylinders  10   a - d  connected to a common hydraulic pressure source  40 , for example an electric pump. 
         [0025]    Referring now to  FIG. 4 , in a first embodiment, an electronic control system  42 , for example a microcontroller or programmable logic controller, may receive a signal from tilt sensor  37 , for example a mercury switch, a pendulum and angle sensor (for example a potentiometer) combination, or a solid-state accelerometer, providing an indication of the vertical orientation of the upright brace  32 . In the case of the accelerometer, an angular deviation of a gravitational vector from the axis of the upright brace  32  may be determined as well as acceleration of the top of the upright brace  32 . It will further be appreciated that the indication of vertical orientation of the upright brace may be detected by measuring displacement of the shaft  15  (using a displacement sensor) and trigonometric formulae, for example using known positioning of the bracket  24  with respect to a base of the wall and the height of the hinge  23 . 
         [0026]    The electronic control system  42  also provides electrical signals controlling valves  12 , one for each cylinder  10   a - d . Generally, during operation, the electronic control system  42  may, in a first embodiment, allow all valves  12  to be open and the cylinders  10   a - d  to extend their shafts  15  outward to press upward on the brace  22  straightening the wall until a signal from the tilt sensor  37  of any upright brace  32  indicates that the upright brace  32  is vertical at which time the electronic control system  42  may shut the valve  12  associated with that upright brace  32  only. In this way each of the brace systems of  FIG. 3  may operate simultaneously to bring the wall back into alignment. 
         [0027]    Referring now to  FIG. 6 , the ability to monitor the orientation of the braces  32  permits more sophisticated control strategies where a most out of alignment section of the wall  30 , indicated by signal  50   a  from a tilt sensor  37 , is moved first during time terminating at t 1  and the other sections of the walls indicated by signals  50   b - c  from corresponding tilt sensors  37  are moved only after time t 1  is passed. Upon completion of time t 1 , the other sections of the wall may be moved, for example the upright brace  32  associated with signal  50   b  being moved after time t 1 , and the upright brace  32  associated with signal  50   c  being moved after time t 2  is complete, and the upright brace  32  associated with signal  50   d  being moved after time t 3  is complete. Using this technique, the amount of distortion of the wall  30  during this alignment may be significantly reduced thereby reducing additional damage from the alignment process. 
         [0028]    Another possible control strategy moves the upright braces  32  at substantially constant angular rates that are different in proportion to the misalignment of the wall associated with that upward brace so that all upward braces move to reach alignment with vertical at substantially the same time. 
         [0029]    It will be appreciated that even more sophisticated control algorithms may be developed that look at acceleration to control the valves  12  to reduce or warn of sudden acceleration, or that detect overcenter travel where the wall moves beyond vertical to provide warnings of this situation, or that monitor pressure differentials using pressure gauges (not shown) on each hydraulic hose  14 . 
         [0030]    Referring now to  FIG. 5 , the present invention contemplates that the sensing of the orientation of the upright braces  32  may be performed mechanically, for example, by attaching a pivot point  60  to the upper end of the upright brace  32  communicating via tie arm  62  to a lever-operated valve  12 ′ with a turnbuckle or other length adjusting mechanism used to cause movement of the upright brace  32  to shut off the valve  12  when the upright brace  32  is in the vertical position. In this case, the tie arm  62  provides a tilt sensor based on a known geometry of the system. 
         [0031]    It will also be appreciated that the hydraulic cylinders may be replaced with, for example, electric screw jacks or the like. Further, it will be understood that the present invention is applicable to a wide variety of different types of walls beyond the block walls depicted but also including poured walls. 
         [0032]    Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “left”, “right”, “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence, or order unless clearly indicated by the context. 
         [0033]    References to an electronic control system can be understood to include one or more processors that can communicate in a stand-alone and/or a distributed environment(s), and can thus be configured to communicate via wired or wireless communications with other processors, where such one or more processor can be configured to operate on one or more processor-controlled devices that can be similar or different devices. 
         [0034]    When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0035]    Various features of the invention are set forth in the following claims. It should be understood that the invention is not limited in its application to the details of construction and arrangements of the components set forth herein. The invention is capable of other embodiments and of being practiced or carried out in various ways. Variations and modifications of the foregoing are within the scope of the present invention. It also being understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention.