Patent Publication Number: US-11643805-B2

Title: Hydraulic expandable connector

Description:
RELATED APPLICATION 
     This is a divisional application of Nonprovisional application Ser. No. 16,176,869, filed Oct. 31, 2018, claiming the priority of Provisional Application Ser. No. 62/580,065, filed Nov. 1, 2017, both applications hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention is generally directed to a tension hold-down system used in walls in light frame construction to resist uplift and to compensate for wood shrinkage in wood frame construction and compression loading. 
     SUMMARY OF THE INVENTION 
     The present invention provides a hydraulic expandable connector for taking up a slack in a tie rod in a hold-down system, comprising an inner cylindrical body disposed within an outer cylindrical body; a first actuation spring operably attached to the inner cylindrical body and the outer cylindrical body to urge relative motion between the inner cylindrical body and the outer cylindrical body such that the connector expands axially to take up the slack; a first chamber and a second chamber disposed between an outer wall surface of the inner cylindrical body and an inner wall surface of the outer cylindrical body; a first passageway communicating between the first chamber and the second chamber; and a valve operably disposed in the first passageway, the valve having a closed position and an open position, the valve is in the open position when the connector expands to allow fluid from the first chamber to flow to the second chamber, the valve is in the closed position when the connector is subjected to an axial load to pressurize the fluid in the second chamber and absorb the load. 
     The present invention further provides a hydraulic expandable connector for taking up a slack in a tie rod in a hold-down system, comprising an inner cylindrical body disposed within an outer cylindrical body; a first piston slidable between the inner cylindrical body and the outer cylindrical body; a first spring operably attached to the outer cylindrical body to push the first piston axially; a first chamber and a second chamber disposed between an outer wall surface of the inner cylindrical body and an inner wall surface of the outer cylindrical body; a first passageway communicating between the first chamber and the second chamber; a valve operably disposed in the first passageway, the valve having a closed position and an open position, the valve is in the open position when the connector expands to allow fluid from the first chamber to flow to the second chamber, the valve is in the closed position when the connector is subjected to an axial load; and the first spring pressurizes the fluid in the first chamber to cause the fluid to flow into the second chamber through the passageway and axially move the inner cylindrical body away to expand the connector. 
     The present invention still further provides a hydraulic expandable connector for taking up a slack in a tie rod hold-down system, comprising an inner cylindrical body disposed within an outer cylindrical body; a first piston slidable between the inner cylindrical body and the outer cylindrical body; a first spring operably attached to the outer cylindrical body to push the first piston axially; a first chamber and a second chamber disposed between an outer wall surface of the inner cylindrical body and an inner wall surface of the outer cylindrical body; a first passageway communicating with the first chamber and the second chamber; a valve operably disposed in the first passageway, the valve having a closed position and an open position, the valve is in the open position when the connector expands to allow fluid from the first chamber to flow to the second chamber, the valve is in the closed position when the connector is subjected to an axial load; and the first spring pressurizes the fluid in the first chamber to cause the fluid to flow into the second chamber through the passageway. 
     The present invention provides a hydraulic expandable connector for taking up a slack in a tie rod in a hold-down system, comprising an inner cylindrical body disposed within an outer cylindrical body; a first spring operably attached to the inner cylindrical body and the outer cylindrical body to urge relative motion between the inner cylindrical body and the outer cylindrical body such that the connector expands axially to take up the slack; a first chamber and a second chamber disposed between an outer wall surface of the inner cylindrical body and an inner wall surface of the outer cylindrical body; a passageway communicating between the first chamber and the second chamber; a valve operably disposed in the passageway, the valve having a closed position and an open position, the valve is in the open position when the connector expands to allow fluid from the first chamber to flow to the second chamber, the valve is in the closed position when the connector is subjected to an axial load; and the valve including a deformable wall portion that deforms into an inner wall of the outer cylindrical body when the connector is subjected to an axial load to lock the inner cylindrical body with the outer cylindrical body. 
     The present invention still further provides a reinforced building wall, comprising a reinforced building wall, comprising a horizontal wall framing member; a bearing plate supported by the wall framing member; a tie rod operably attached to a foundation of the wall and extending through the bearing plate; a hydraulic expandable connector for taking up a slack in the tie rod, the connector being disposed on the bearing plate, the tie rod extending through the connector; and the hydraulic expandable connector including an inner cylindrical body disposed within an outer cylindrical body, the inner cylindrical body is operably attached to the tie rod, the outer cylindrical body is operably attached to the wall framing member, a first chamber and a second chamber disposed between an outer wall surface of the inner cylindrical body and an inner wall surface of the outer cylindrical body, a passageway communicating between the first chamber and the second chamber, a valve operably disposed in the passageway, the valve having a closed position and an open position, the valve is in the open position when the connector expands to allow fluid from the first chamber to flow to the second chamber, the valve is in the closed position when the connector is subjected to an axial load to pressurize the fluid in the second chamber and absorb the load. 
     The present invention provides a reinforced building wall, comprising a horizontal wall framing member; a first bearing plate supported by the wall framing member and a second bearing plate disposed vertically spaced above the first bearing plate; a tie rod operably attached to a foundation of the wall and extending through the first and second bearing plates, the tie-rod dividing the first and second bearing plates into a first lateral section on one side of the tie-rod and a second lateral section on a diametrically opposite side of the tie-rod; first and second hydraulic expandable connectors disposed between the first and second bearing plates, the first hydraulic expandable connector being disposed in the first lateral section, the second hydraulic expandable connector being disposed in the second lateral section; each of the hydraulic expandable connectors including an inner cylindrical body disposed within an outer cylindrical body, the inner cylindrical body is operably attached to the tie rod, the outer cylindrical body is operably attached to the wall framing member, a first chamber and a second chamber disposed between an outer wall surface of the inner cylindrical body and an inner wall surface of the outer cylindrical body, a passageway communicating between the first chamber and the second chamber, a valve operably disposed in the passageway, the valve having a closed position and an open position, the valve is in the open position when the connector expands to allow fluid from the first chamber to flow to the second chamber, the valve is in the closed position when the connector is subjected to an axial load to pressurize the fluid in the second chamber and absorb the load; and the tie rod is operably attached to the second bearing plate. 
     The present invention further provides a reinforced building wall, comprising a horizontal wall framing member; a bearing plate supported by the wall framing member; a tie rod operably attached to a foundation of the wall and extending through the bearing plate; a first hydraulic expandable connector for taking up a slack in the tie rod, the first hydraulic expandable connector being disposed on the bearing plate, the tie rod extending through the first hydraulic expandable connector; a second hydraulic expandable connector for taking up a slack in the tie rod, the second hydraulic expandable connector being disposed above the first hydraulic expandable connector, the tie rod extending through the second hydraulic expandable connector, the tie rod being operably connected to the second hydraulic expandable connector; the first hydraulic connector including first inner cylindrical body disposed within a first outer cylindrical body, a first chamber and a second chamber disposed between an outer wall surface of the first inner cylindrical body and an inner wall surface of the first outer cylindrical body, a first passageway communicating between the first chamber and the second chamber, a first valve operably disposed in the first passageway, the first valve having a closed position and an open position, the first valve is in the open position when the first hydraulic connector expands to allow fluid from the first chamber to flow to the second chamber, the first valve is in the closed position when the connector is subjected to an axial load; the second hydraulic expandable connector including a second inner cylindrical body disposed within a second outer cylindrical body, a first spring operably attached to the second inner cylindrical body and the second outer cylindrical body to urge relative motion between the second inner cylindrical body and the second outer cylindrical body such that the second hydraulic expandable connector expands axially, a third chamber and a fourth chamber disposed between an outer wall surface of the second inner cylindrical body and an inner wall surface of the second outer cylindrical body, a second passageway communicating between the third chamber and the fourth chamber, a second valve operably disposed in the second passageway, the second valve having a closed position and an open position, the second valve is in the open position when the second hydraulic expandable connector expands to allow fluid from the third chamber to flow to the fourth chamber, the second valve is in the closed position when the second hydraulic expandable connector is subjected to an axial load; the tie rod is threaded to the second inner cylindrical body, the first inner cylindrical body is receivable within the second outer cylindrical body to push the second inner cylindrical body upwardly; and a third passageway communicating with the third chamber and the fourth chamber, the third passageway is open all the time to allow fluid to flow between the third chamber and the fourth chamber even when the second passageway is closed. 
     The present invention further provides a reinforced building wall, comprising a wall including a first section, the first section including a horizontal framing member; a first bearing plate disposed below and engaging the wall framing member; a tie rod operably attached to a foundation of the wall and extending through the bearing plate, the tie rod is operably attached to the wall above the framing member; a first hydraulic expandable connector for taking up a slack in the tie rod, the first hydraulic expandable connector being disposed below and engaging the bearing plate, the tie rod extending through the first hydraulic expandable connector; the hydraulic expandable connector including a first inner cylindrical body disposed within a first outer cylindrical body, a first chamber and a second chamber disposed between an outer wall surface of the first inner cylindrical body and an inner wall surface of the first outer cylindrical body, a piston portion attached to the first inner cylindrical body, the piston portion separating the first chamber from the second chamber, a first passageway through the piston portion communicating between the first chamber and the second chamber, the first passageway allowing fluid from the first chamber to flow to the second chamber when the hydraulic expandable connector is subjected to an axial load to pressurize the fluid in the second chamber and absorb the load; and the tie rod is threaded to the inner cylindrical body. 
     The present invention still further provides a coupling for attaching one end of a rod to another end of another rod, comprising a housing including a chamber inside the housing, the housing including first and second opposite end portions; a piston inside the chamber, the piston being slidable between the first and second end portions of the housing, the piston including a rod portion extending outside the housing through the first end portion for attachment to a tie rod; the piston dividing the chamber into a first chamber on one side of the piston and a second chamber on another side of the piston, the piston including an opening communicating with the first chamber and the second chamber to allow fluid to flow from the first chamber to the second chamber; and the second end portion of the housing for attachment to another tie rod. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view, shown partly in cross-section, of a hold-down device, embodying the present invention. 
         FIG.  2 A  is a side elevational view of  FIG.  1   , in cross-section. 
         FIG.  2 B  is an enlarged view of a portion of the hold-down device shown in  FIG.  2 A . 
         FIG.  3    is a perspective view of a wall structure incorporating the device shown in  FIG.  1   . 
         FIG.  4 A  is a side elevational view of  FIG.  2 A , showing the hold-down device in operation. 
         FIG.  4 B  is an enlarged view of a portion of the hold-down device shown in  FIG.  4 A . 
         FIGS.  5 A- 5 F  are side elevational and cross-sectional views of the hold-down device shown in  FIG.  1   , depicting an initial set position ( FIGS.  5 A and  5 B ), a middle travel position ( FIGS.  5 C and  5 D ) and a fully expanded position ( FIGS.  5 E and  5 F ). 
         FIG.  6 A  is a side elevational view, shown in cross-section of another embodiment of a hold-down device, embodying the present invention. 
         FIG.  6 B  is an enlarged view of a portion of the hold-down device shown in  FIG.  6 A . 
         FIG.  7 A  is a side elevation view, shown in cross-section, of the hold-down device shown in  FIG.  6 A , showing the device in operation. 
         FIG.  7 B  is an enlarged view of a portion of the hold-down device shown in  FIG.  7 A . 
         FIG.  8    is a perspective view, shown partly in cross-section, of another embodiment of a hold-down device, embodying the present invention, using the displacement of the wall to which it is attached to actuate the device. 
         FIG.  9    is a cross-sectional view of another embodiment of a hold-down device, embodying the present invention, showing a bearing plate integrated with the device. 
         FIG.  10    is a cross-sectional view of another embodiment of a hold-down device, embodying the present invention. 
         FIGS.  11 A- 11 B  are enlarged perspective views, partly shown in cross-section, of portions of the hold-down device shown in  FIG.  10   , showing an embodiment of the one-way valve shown in  FIG.  10   . 
         FIG.  12    in an enlarged perspective view, with portions shown in cross-section, of portions of the hold-down device shown in  FIG.  10   , showing an embodiment of the one-way valve. 
         FIG.  13    is an enlarged perspective view, with portions shown in cross-section, of portions of the hold-down device shown in  FIG.  10   , showing an embodiment of the one-way valve. 
         FIGS.  14 A- 14 B  are enlarged perspective views, with portions shown in cross-section, of portions of the device shown in  FIG.  10   , showing an embodiment of attaching the one-way valve. 
         FIGS.  15 A- 15 B  are enlarged perspective views, with portions shown in cross-section, of portions of the device shown in  FIG.  10   , showing an embodiment of the one-way valve. 
         FIG.  16    is cross-sectional view of a hold-down device, embodying the present invention. 
         FIG.  17    is cross-sectional view of a hold-down device, embodying the present invention. 
         FIG.  18    is cross-sectional view of a hold-down device, embodying the present invention. 
         FIG.  19    is cross-sectional view of a hold-down device, embodying the present invention. 
         FIG.  20     FIG.  19    is cross-sectional view of a hold-down device, embodying the present invention. 
         FIG.  21    is cross-sectional view of a hold-down device, embodying the present invention. 
         FIG.  22    is a perspective view with portions shown in cross-section of a hold-down device, embodying the present invention. 
         FIG.  23    is a perspective view with portions shown in cross-section of a hold-down device, embodying the present invention. 
         FIG.  24    is a cross-sectional view of the hold-down device shown in  FIG.  1    shown installed inside a building wall. 
         FIGS.  25 A- 25 B  are perspective views with portions shown in cross-section of the hold-down device shown in  FIG.  1    shown installed inside a building wall over a cross-member. 
         FIG.  26    is a perspective view with portions shown in cross-section of the hold-down device shown in  FIG.  9    shown installed over a top plate of a building wall. 
         FIG.  27    is a cross-sectional view of two hold-down devices shown in  FIG.  1    installed in tandem inside a building wall. 
         FIG.  28 A  is cross-sectional view of a three-level building wall incorporating multiple hold-down devices shown in  FIG.  1   . 
         FIGS.  28 B- 28 C  are enlarged views in cross-section of portions taken from  FIG.  28 A . 
         FIG.  29 A  is cross-sectional view of a three-level building wall incorporating the hold-down devices shown in  FIGS.  1  and  6 A . 
         FIGS.  29 B- 29 C  are enlarged views in cross-section of portions taken from  FIG.  29 A . 
         FIG.  30    is a cross-sectional view of the hold-down device shown in  FIG.  6 A  disposed on top of another hold-down device. 
         FIG.  31    is cross-sectional view of an inverted hold-down device attached below a wall structure. 
         FIG.  32    is a cross-sectional view of an inverted hold-down device attached below a wall structure. 
         FIG.  33    is a cross-sectional view an inverted hold-down device similar to the device shown in  FIG.  32   . 
         FIG.  34    is a cross-sectional view an inverted hold-down device similar to the device shown in  FIG.  33   . 
         FIG.  35    is cross-sectional view of a three-level building wall incorporating multiple hold-down devices shown in  FIG.  1   . 
         FIGS.  36 - 37    are enlarged views in cross-section of portions taken from  FIG.  35   . 
         FIG.  38    is cross-sectional view of a three-level building wall incorporating multiple hold-down devices shown in  FIG.  1   . 
         FIG.  39    is an enlarged view in cross-section of portions taken from  FIG.  38   . 
         FIG.  40    is cross-sectional view of a three-level building wall incorporating multiple hold-down devices shown in  FIG.  1   . 
         FIG.  41    is an enlarged view in cross-section of portions taken from  FIG.  40   . 
         FIG.  42    is perspective cross-sectional view of a damping coupling embodying the present invention. 
         FIG.  43    is perspective cross-sectional view of a damping coupling similar to the damping coupling of  FIG.  42   , embodying the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS.  1 ,  2 A and  2 B , a hydraulic expandable connector  2  embodying the present invention is disclosed. The connector  2  includes an inner cylindrical body  4  disposed within an outer cylindrical body  6 . The inner cylindrical body  4  is slidable relative to the outer cylindrical body  6  during operation. An actuation spring  8  is operably attached to the inner cylindrical body  4  and the outer cylindrical body  6  to cause relative motion of the inner cylindrical body  4  with the outer cylindrical body  6  during use. The inner cylindrical body  4  has a central opening  9  through which a tie rod is extended in a typical installation. 
     A retainer ring  10  is removably attached to an upper portion of the inner cylindrical body  4  to capture the upper end portion of the spring  8 . The retainer ring  10  has a plurality of resilient fingers  12  disposed around the periphery of an opening  14  that are received in a circumferential groove  16 , which holds the retainer ring  10  attached to the inner cylindrical body  4 . The retainer ring  10  has a circumferential portion  11  that extends outwardly to capture the upper end of the spring  8 . The retainer ring  10  is further described in application Ser. No. 15/265,613, filed Sep. 14, 2016, hereby incorporated by reference. The outer cylindrical body  6  has a reduced diameter portion  18  to capture the lower end portion of the spring  8 . The spring  8  urges relative sliding movement between the inner cylindrical body  4  and the outer cylindrical body  6 . 
     The inner cylindrical body  4  has a reduced diameter portion  20  and another reduced diameter portion  22  with a smaller diameter than the reduced diameter portion  20 . The reduced diameter portions  20  and  22  are axially adjacent to each other. A piston member  24  in the form of a ring or sleeve is disposed within the portion  22 . A seal  25  disposed within an annular groove  27  in the piston  24  seals the piston to the outer cylindrical body  6 . A spring  26  urges the piston  24  against a seat  28  on the portion  22 . Fluid chambers  30  and  32  are disposed on either side of the piston  24 . A passageway  34  communicates between the chambers  30  and  32 . The passageway  34  is a gap between the piston  24  and the reduced diameter portion  22  of the inner cylindrical body  2 . A retainer ring  36  holds the spring  26  in place. An endcap  38  is threaded to the outer cylindrical body  6 . A seal  40  within an annular groove  43  in the endcap  38  seals the fluid chamber  32 . A seal  42  within an annular groove  45  in the outer cylindrical body  6  seals the fluid chamber  30 . The upper chamber  30  is bounded by the bottom of the endcap  38 , the portion  33  and top of the piston  24  and inner cylindrical body  4 . The lower chamber  32  is bounded by the portion  33 , a shoulder  41  extending radially toward the inner cylindrical body  4 , the bottom of the piston  24  and the inner cylindrical body  4 . The upper chamber  32  and the lower chamber  30  are filled with hydraulic fluid, such as mineral oi, water, etc. The piston member  24  functions as a valve, opening or closing the passageway  34 . 
     Referring to  FIG.  3   , the connector  2  is attached to a stud wall by means of a tie rod  44  with a nut  46 . The tie rod  44  is attached to a wall foundation with an anchor and an anchor rod (see  FIG.  28 A ). A bearing plate  48  may be used to effectively transfer the forces on the connector  2  onto the stud wall. A clip  50  is removed after the connector  2  is installed to release the inner cylindrical body  4  relative to the outer cylindrical body  6  so that the spring  8  can move the inner cylindrical body  4  when the stud wall settles downwardly. The connector  2  is shown installed inside a floor system comprising floor joists  52  (one shown) supported on a horizontal framing member, such as a top plate  54  of the stud wall below. A sub-floor  56 , supported by the floor joist  52 , supports a bottom plate  58  of the stud wall above. Support blockings  60  provides additional rigidity to the space adjacent the connector  2 . 
     The connector  2  shown in  FIG.  3    may also be replaced by the connector  64  shown in  FIG.  6 A- 7 B . 
     Referring to  FIGS.  4 A and  4 B , when the inner cylindrical body  4  moves upwardly from the action of the spring  8  due to the settlement of the stud wall, the piston  24  also moves but lags behind due to the pressurization of the fluid in the upper chamber  32 . The spring  26  is compressed by the higher pressure of the fluid in the upper chamber  32 , creating a gap  62  that communicates with the passageway  34 . The gap  62  serves as an entrance to the passageway  34 . Fluid from the chamber  32  flows to the lower chamber  30 . The upward movement of the inner cylindrical body  4  increases the volume of the lower chamber  30 , creating a lower pressure that causes the pressurized fluid from the upper chamber  32  to flow through the gap  62 . After the inner cylindrical body  4  has come to a rest, the spring  26  will push the piston  24  toward the seat  28  to close the gap  62 . 
     When an axial downward load is applied to the inner cylindrical body  4  when the stud wall tries to lift up during a windstorm, hurricane, earthquake, etc., the downward load is resisted by the piston  24  pressing on the fluid in the lower chamber  30  to a higher pressure than in the upper chamber  32 . Since the fluid, such as oil, is incompressible, and the passageway  34  is closed at the gap  62  by the piston  24  contacting the seat  28 , the connector  2  is able to hold the wall down. The piston  24  acts as a valve, opening or closing the passageway  34  at the gap  62  as the connector  2  reacts to a load. 
     Referring to  FIGS.  5 A- 5 B , the connector  2  is shown in an initial set position, prior to expanding to take up a slack in the tie rod  44 . The upper chamber  32  and the lower chamber  30  are shown in their initial volumes. 
     Referring to  FIGS.  5 C- 5 C , the connector has expanded to take the slack in the tie rod  44 . The inner cylindrical body  4  has moved upwardly, decreasing the volume of the upper chamber  32  while increasing the volume of the lower chamber  30 . The expansion of the connector  2  compresses the fluid in the upper chamber  32 , causing the fluid to flow through the gap  62  and the passageway  34  into the lower chamber  30 . 
     Referring to  FIGS.  5 E- 5 F , the connector  2  has expanded to its fully expanded position. The volume of the upper chamber  32  is reduced to zero, with the top end of the piston  24  butting against the bottom end of the endcap  38 . The volume of the lower chamber  30  is at maximum. 
     The actuation spring  8  may be made so that when compressed, it will have enough stored energy to cause upward movement of the inner cylindrical body  4  when a slack develops in the tie rod  44 . The actuation spring  8  may also be made so that in addition to the energy to expand the connector  2  when a slack develops in the tie rod  44 , the spring  8  will have sufficient stored energy to tension the tie rod  44  extending below the connector  2 . 
     Referring to  FIGS.  6 A and  6 B , another embodiment of a hydraulic expandable connector  64  is disclosed. The connector  64  is the same as the connector  2 , except the piston  24  is modified as piston  66 . The piston  66  includes a plurality of passageways  68  in the form of holes arranged around the piston  66  that communicate with the upper chamber  32  and the lower chamber  30 . When a downward load is imposed on the inner cylindrical body  4 , fluid from the lower chamber  30  flows through the passageways  68 , allowing the piston  66  to move downwardly in a controlled manner, creating a dampening effect. 
     Referring to  FIGS.  7 A and  7 B , as the connector  64  expands to take up a slack that develops in the tie rod  44 , the inner cylindrical body  4  moves upwardly under the action of the actuation spring  8 . The piston actuation spring  26  is compressed by the piston  66 , causing the top end of the piston  66  to separate from the seat  28  to create the gap  62  that communicates with the passageway  34 . The upper chamber  32  decreases in volume, pressurizing the fluid in the chamber while the lower chamber  30  increases in volume, creating a vacuum that causes the fluid from the upper chamber  32  to flow into the lower chamber  30 . Some fluid also flows through the passageways  68 . When the entire slack has been taken up, expansion stops and the piston  66  moves to engage the seat  28  under the action of the spring  26 . The connector  64  at this position is ready to absorb a downward load when the stud wall tries to lift up during a storm, hurricane, earthquake, etc. 
     The connectors  2  and  64  are actuated by the spring  8  when the stud wall moves downwardly due to settlement. The spring  8  is disposed outside the connectors  2  and  64 . 
     Referring to  FIG.  8   , an embodiment of a hydraulic expandable connector  70  is disclosed that uses the building wall displacement for its actuation rather than the spring  8 . The connector  70  works the same way as the connector  2 , except that the inner cylindrical body  4  is threaded to the tie rod  44  and the outer cylindrical body  6  is attached to the wall structure. The inner cylindrical body  4  includes an inner threaded portion  72  attached to the tie rod  44 . The outer cylindrical body  6  is attached to a bearing plate  74  with screws  76 . The bearing plate  74  is in turn attached to a horizontal framing member or wall structure  78 , such as a bottom plate or a cross-member, with screws  80 . Although not shown, the connector the connector  64  without the spring  8  may be modified as shown for the connector  70  for attachment to the building wall structure. 
     When the wall structure  78  moves downwardly due to settlement, the outer cylindrical member  6  moves with it, while the inner cylindrical body  4  stays stationary with respect to the tie rod  44  but moves upwardly relative to the outer cylindrical body  6 . The chamber  30  will expand in volume, creating a lower pressure than in the chamber  32 . The piston  24  will separate from the seat  28  to open the passageway  34  (see  FIG.  2 B ) between the chambers  30  and  32 . Fluid will flow from the upper chamber  32  into the lower chamber  30  to equalize the pressure between the chambers. The passageway  34  will close when the piston  34 , under the action of the spring  26 , engages the seat  28 . The connector  70  is now ready to resist any downward load on the inner cylindrical body  4 . A downward load will be resisted by the fluid in the lower chamber  30  as the fluid is pressurized by the piston  24 . 
     Referring to  FIG.  9   , an embodiment of a hydraulic expandable connector  82  is disclosed. The connector  80  is the same as the connector  70  and works the same way, except that the bearing plate  74  has been integrated into the outer cylindrical body  6  as a flange  84  attached to the wall structure  78 . Although not shown, the connector  64  without the spring  8  may be modified as shown for the connector  82  for attachment to the building wall structure. 
     Referring back to  FIG.  8   , the piston  24  is sealed to the outer cylindrical body  6  with a plurality of O-ring seals  86  disposed in respective circumferential grooves  88 . Similarly, the inner cylindrical body  4  is sealed to the outer cylindrical body  6  with a plurality of O-ring seals  90  disposed in respective circumferential grooves  92 . 
     Referring to  FIG.  10   , another embodiment of a hydraulic expandable connector  94  is disclosed. The connector  94  includes an inner cylindrical body  96  disposed inside the outer cylindrical body  6 . The inner cylindrical body  96  has a piston portion  98  extending radially and sealed to the outer cylindrical body  6  with the seal  25 . The piston portion  98  is preferably integral with the rest of the inner cylindrical body  96 . A piston  100  in the form of a ring is disposed between the inner cylindrical body  96  and the outer cylindrical body  6 . Seals  101  in annular grooves  103  in the piston  100  seal the space  108  from the upper chamber  102 . An upper chamber  102  is bounded by bottom of the piston  100 , the top of the piston portion  102 , the inner cylindrical body  4  and the portion  33 . A lower chamber  104  is disposed below the piston portion  98  and bounded by the bottom of the piston portion  98 , the portion  33 , the inner cylindrical body  96  and the shoulder  41 . A plurality of openings  105  communicate with the upper chamber  102  and the lower chamber  104 . The upper chamber  102  and the lower chamber  104  are filled with hydraulic fluid, such as mineral oi, water, etc. A one-way valve  107  is associated with each of the openings  105  to allow flow of the fluid from the upper chamber  102  to the lower chamber  104  but not in the opposite direction. The endcap  38  includes openings  106  that communicates with the outside and the space  108  to equalize the pressure inside the space  108  when the spring  110  expands to push the piston  100  downwardly when the connector  94  expands in response to the settlement of the building wall in which the connector  94  is installed. 
     The fluid in the upper chamber  102  is constantly pressurized by the spring  110 . When slack develops in the tie rod  44  due to building settlement, the pressure from the upper chamber  102  pushes the fluid into the lower chamber  104  through the openings  105  and the one-way valves  107 , pushing the inner cylindrical body  96  upwardly to take up the slack. When a downward load is applied to the inner cylindrical body  96  due to wall uplifting during a storm, earthquake, etc., the fluid in the lower chamber  104  is pressurized, closing the one-way valves  107  to prevent fluid flow into the upper chamber  102 . Accordingly, the fluid in the lower chamber  104  stops the inner cylindrical body  96  from moving downwardly from the load. 
     The principle of operation of the connector  94  may be used for the connector  64 , wherein the spring  110  and the air inlet openings  110  are used to actuate the connector. 
     Referring to  FIGS.  11 A and  11 B , the one-way valve  107  may be made of a ring plate  112  made of a single piece material, such as plastic. Reed portions  114  are cut into the plate  112  on three sides. The reed portions  114  are disposed below the respective openings  105 . The reed portions  114  when subjected to fluid pressure from the upper chamber  102  via the openings  105  are configured to separate from the plate  112  along the three cut sides to an open position, as shown in  FIG.  11 B , to allow the fluid to flow into the lower chamber and close position when the lower chamber  104  is pressurized by a downward load on the inner cylindrical body  96 . A retainer ring  116  held in a circumferential groove  118  supports the ring plate  112 . A spring  120  is disposed outside the outer cylindrical body  6  in the manner shown for the connectors  2  and  64 . 
     Referring to  FIG.  12   , the plate  112  may be installed into a circumferential groove  122  in the piston portion  98 . The plate  112  has a radial cut-out  124  to facilitate insertion of the plate  112  into the groove  122 . The plate  112  has an inside diameter larger than the outside diameter of the cylindrical portion  126  to facilitate insertion of the plate  112  into the groove  122 . To install the plate  112 , the ends at the cut-out  124  are brought together to temporarily reduce the outside diameter of the plate  112  to clear the inside diameter of the outer edge of the groove  122 . The ends at the cut-out  124  are released, allowing the plate  112  to spring back to its original size inside the groove  122 . 
     Referring to  FIG.  13   , the reed portions  114  may be attached directly to the underside of the piston portion of the piston portion  98  along one side  128  with standard fastener, such as screws. Each of the reed portions  114  has enough flexibility at the respective side  128  to open or close from the action of the fluid from the upper chamber  102  and the lower chamber  104 , respectively. Each of the reed portions  114  is disposed a respective opening  105  (see  FIGS.  11 B and  12   ). 
     Referring to  FIGS.  14 A and  14 B , the reed portions  114  may be attached to a ring plate  130 . The ring plate  130  has holes  132  aligned with the respective openings  105  in the piston portion  105 . Each of the reed portions  114  is attached to the ring plate  130  along the side  128 , allowing each of the reed portions  114  to away from or toward the respective openings  132  under the action of the fluid from the upper chamber  102  or the lower chamber  104 , respectively. The ring plate  130  is attached to the underside of the piston portion  98  by standard means, such as screws, adhesives, etc. 
     Referring to  FIGS.  15 A and  15 B , the one way valve  107  may be implemented by a flat washer  134  held against the underside of the piston portion  98  by a spring  136  held by a retainer ring  138  in a circumferential groove  140 . The flat washer  134  is urged against the underside of the piston portion  98  by the spring  136 , closing the openings  105 . When the inner cylindrical body  4  moves upwardly to take up the slack in the tie rod  44  due to the building wall&#39;s shrinkage, pressure in the upper chamber  102  builds up and pressure in the lower chamber  104  decreases. The pressure changes occur due to the decrease in volume of the upper chamber  102  and increase in volume in the lower chamber  104 . Fluid from the upper chamber  102  is then forced through the openings  105 , pushing the flat washer  134  away from the underside of the piston portion  98  and compressing the spring  136 . Fluid will continue to flow until the pressure in the upper chamber  102  and the lower chamber  104  are equalized. The spring  136  then pushes the flat washer against the piston portion  98 , thereby closing the openings  105 . When the inner cylindrical body  4  is subjected to a downward load, the fluid in the lower chamber  104  resists the load since the fluid is incompressible. Fluid cannot flow to the upper chamber  102  since the openings  105  are closed by the flat washer  134  being pushed by the pressure in the fluid and the spring  136 . 
     Referring to  FIG.  16   , another embodiment of a hydraulic expandable connector  142  is disclosed. The connector  142  includes the inner cylindrical body  4  disposed inside the outer cylindrical body  6 . The retainer ring  10  shown in  FIG.  1    is modified. Removable attachment of the retainer ring  10  to the inner cylindrical body  4  is implemented with a circular spring  144  that is received in both the retainer ring  10  and the inner cylindrical body  4  in cooperating circumferential grooves  146  and  148 . The spring  144  locks the retainer ring  10  in the upward direction but allows the retainer ring  10  to be slipped downwardly. The operation of the spring  144  and the grooves  146  and  148  is further described in several patents, such as U.S. Pat. Nos. 6,951,078, 7,762,030 and 8,136,318, hereby incorporated by reference. The spring  8  is retained around the outer cylindrical body  6  by a retainer ring  150  and the projecting portion  11 . The spring  8  urges the inner cylindrical body  4 , via the retainer ring  10 , in the upward direction to take up any slack that may develop in the tie rod  44  (see  FIG.  3   ) due to the building wall shrinkage. 
     A deformable seal or piston  152  is disposed between the inner cylindrical body  4  and the outer cylindrical body  6 . The deformable seal  152  includes a plate portion  154  that opens and closes the passageway  34  between the upper chamber  32  and the lower chamber  30 , functioning as a valve as described above in connection with the connector  2 . The deformable seal  152  also includes a deformable wall portion  156  made of a thin wall section disposed between the top end and the bottom end of the deformable seal  154 . The inner portion of the deformable seal  154  has a hollowed concave portion  158  to form the deformable wall portion  156  and provides an opening  160  that connects the lower chamber  30  with the hollowed portion  158  and the deformable wall portion  156 . The upper chamber  32  and the lower chamber  30  are filled with hydraulic fluid, such as mineral oi, water, etc. 
     The engagement of the top surface of the plate portion  154  against the seat  28  and the seal  40  seal the upper chamber  32  from the lower chamber  30 . Seals  162  and  164  within annular grooves  165  in the inner cylindrical body  6  seal the lower chamber  30  from the upper chamber  32 . 
     The connector  142  when taking up the slack that develops in the tire rod  44  works the same way as the connector  2 . However, when under load, the operation is different. When the inner cylindrical body  4  is subjected to an axial downward load, the seat  28  will press on the plate portion  154 , sealing the upper chamber  32  from the lower chamber  30 . The fluid in the lower chamber  30  is subjected to high pressure when the connector  142  is subjected to an axial downward load, deforming the thin and deformable wall portion  156 . The deformation occurs toward the outer cylindrical body  6 , forcing the deformable wall portion  156  into the wall of the outer cylindrical body  6  into a locking engagement. The gap  62  (see  FIG.  4 B ) is closed off by the pressure in the lower chamber  30  pushing the plate portion  154  against the seat  28  (see  FIG.  4 B ) and the higher the pressure the tighter the seal becomes. The seal  162  advantageously keeps the high pressure fluid in the lower chamber  30  from leaking into the abutting surfaces between the outer cylindrical body  6  and the deformable seal  152  so that pressure behind the deformable wall portion  156  is less than the pressure in the hollowed portion  158 . 
     The deformation of the deformable wall portion  156  advantageously provides a permanent seal that becomes tighter as more load is exerted on the inner cylindrical body  4 . The deformable seal  152  advantageously makes the connector  142  fail-safe under load. In the event the seals  164  fail, the inner cylindrical body  4  will hold the load due to the locking engagement of the deformable seal  152  with the wall of the outer cylindrical body  6 . 
     Referring to  FIG.  17   , another embodiment of a hydraulic expandable connector  1  is disclosed. The connector  166  is similar to the connector  142 , except that the seals  164  have been replaced by a deformable seal  168  similar in construction to the deformable seal  152 . The deformable seal  168  has a base portion  170  engaged against an inner shoulder  172  of the outer cylindrical body  6 . The deformable seal  168  has a deformable wall portion  174  abutting the inner cylindrical body  4 . A retainer ring  176  in a circumferential groove  178  holds a spring  180  that urges the base portion  170  against the should  172 . A lower chamber  182  filled with hydraulic fluid is bounded by the deformable seals  152  and  168  and the inner cylindrical body  4  and outer cylindrical body  6 . The upper chamber  32  is also filled with hydraulic fluid. 
     When an axial downward load is imposed on the inner cylindrical body  4 , the fluid in the lower chamber  182  is placed under high pressure. The inner cylindrical body  4  pushes down on the deformable seal  152 . The high pressure causes the deformable wall portions  156  and  174  to deform outwardly from the lower chamber  182  and onto the respective walls of the inner cylindrical body  4  and the outer cylindrical body  6 , providing a strong seal. Seals  183  in annular grooves  185  in the deformable seals  152  and  168  advantageously isolate the high pressure lower chamber  182  from the rest of the connector. 
     Referring to  FIG.  18   , another embodiment of a hydraulic expandable connector  184  is disclosed. The connector  184  is identical to the connector  166  except that the springs  26  and  180  are replaced with a single spring  186 . The spring  186  pushes the upper deformable seal  152  as the inner cylindrical body  4  moves upwardly to take up slack in the tie rod  44  caused by the building wall settlement. The spring  186  also keeps the lower deformable seal  168  in contact with the shoulder  172 . Seals  188  in annular grooves  189  in the upper and lower deformable seals  152  and  168  are disposed outside the high pressure fluid (under load) lower chamber  182 . 
     Referring to  FIG.  19   , another embodiment of a hydraulic expandable connector  190  is disclosed. The connector  190  is similar to the connector  184  except that the lower deformable seal  168  has been integrated into the outer cylindrical body  192 . The outer cylindrical body  192  has a deformable wall portion  194  extending from a shoulder  196 . The connector  190  works in the same way as the connector  184  during expansion and under load. 
     Referring to  FIG.  20   , another embodiment of a hydraulic expandable connector  198  is disclosed. The connector  198  is similar to the connector  2 , except that the inner cylindrical body  4  is provided with internal threads  200  for threading to the tie rod  44  and the retainer ring  10  has been replaced with a washer  202 . The tie rod  44  is attached to a wall foundation with an anchor and an anchor rod (see  FIG.  28 A ). A nut  204  compresses the spring  8  via the washer  202  and retainer ring  206  held in a circumferential groove  208  in the outer cylindrical body  6 . The spring  8  is compressed during installation. A bearing plate  210  is disposed on a horizontal metal framing member  220  (part of the building wall) to advantageously distribute the load over a larger area than the footprint of the connector  198 . Hydraulic seal  221  in annular groove  27  in the piston  24  is used instead of an O-ring for greater sealing power. Hydraulic seal  223  in annular groove  45  in the outer cylindrical body  6  is also used instead of an O-ring for greater sealing power. Hydraulic seals are typically used in reciprocating motion applications, such as piston-cylinder assemblies. 
     When the building wall shrinks, the outer cylindrical body  6  moves downwardly from the action of the spring  8  while the inner cylindrical body  4  stays attached to the tie rod  44 . The spring  8  may be configured with sufficient force to tension the tie rod  44 . The connector  198  works the same way as the connector  2  when subjected to a downward load. 
     Referring to  FIG.  21   , another embodiment of a hydraulic expandable connector  222  is disclosed. The connector  222  is similar to the connector  198 , except that the spring  8  is replaced with a conical spring  224  and the washer  202  is not used. The conical spring  224  is compressed by the nut  204  and presses on the outer cylindrical body  6  via the endcap  38 , which has been provided with a collar portion  226  to center the bottom end of the spring  224  over the endcap  38 . 
     When the building wall shrinks, the outer cylindrical body  6  moves downwardly from the action of the spring  224  while the inner cylindrical body  4  stays attached to the tie rod  44 . The connector  222  works the same way as the connector  2  when subjected to a downward load. 
     Referring to  FIG.  22   , another embodiment of a hydraulic expandable connector  228  is disclosed. The connector  228  is similar to the connector  2 , except that the inner cylindrical body  4  is modified to accept a split cylindrical nut  230  threadedly attached to the tie rod  44 . The tie rod  44  is attached to a wall foundation with an anchor and an anchor rod (see  FIG.  28 A ). The inner cylindrical body  4  an enlarged opening  232  that narrows into a conical opening  234 . 
     The cylindrical split nut  230  is made up of preferably four equal segments  236  with inner threads that mate with the threads of the tie rod  44 . The segments  236  are bundled together by a circular spring  235 . The cylindrical split nut  230  has conical portions  237  that mate with the conical opening  234 . A retainer ring  238  is threaded to a threaded portion  240  of the opening  232 . The retainer ring  238  compresses a spring  242  to urge the cylindrical split nut  230  downwardly into the conical opening  234 . The retainer ring  238  has an unthreaded opening  244  allows the tie rod  44  to move axially through the opening  244 . The clip  50  is removed after the connector is installed to allow the inner cylindrical body  4  to move relative to the outer cylindrical body  6 . 
     When the building wall in which the connector  228  is installed shrinks, the outer cylindrical body  6  moves downwardly with the wall from the action of the spring  8 . The inner cylindrical body  4  urges the cylindrical split nut  230  upwardly through the action of the spring  8 . The cylindrical split nut  230  advantageously reduces the amount of time of installation since the segments  236  are simply dropped into the opening  232  instead of being screwed down from the end of the tie rod  44  as with a standard nut. The opening  232  is larger than the diameter of the cylindrical portion of the cylindrical split nut  230  so that the segments  236  can radially expand and disengage from the threads of the tie rod as the connector  228  is slid down the tie rod during installation. Split nuts are disclosed in U.S. Pat. Nos. 9,303,399 and 9,222,251 and application Ser. No. 15/265,613, all of which are hereby incorporated by reference. 
     Referring to  FIG.  23   , the conical opening  234  in the inner cylindrical body  4  of the connector  228  is modified to work with a hexagonal split nut  246 . A washer  248  distributes the force of the spring  242  over the segments  250  of the split nut  246 . The opening  232  has a rounded outer edge  252  that cooperates with a complementarily rounded surface  254  that serve to draw the segments  250  into threaded engagement with the threads of the tie rod  44 . 
     Referring to  FIG.  24   , the connector  2  or the connector  64  (see  FIG.  6 A ) is shown installed inside a wall. The connector  2  is shown in the unactuated state since the locking clip  50  has not been removed yet. The clip  50  is removed to activate the spring  8  and hence the connector  2 . The tie rod  44  is cut at the end  256  just above the nut  46  to facilitate installation of the connector  2 , which is slid down the tie rod  44  at the end  256 . A coupling  258  joins the tie rod  44  to another tie rod  260  to continue the run. The bearing plate  48  sits on top of a horizontal framing member, such as a base plate  262  supporting a plurality of studs  264 . A sub-floor sheet  266  is below the top plate  258 . The tie rod  44  is attached to a wall foundation with an anchor and an anchor rod (see  FIG.  28 A ). 
     Referring to  FIGS.  25 A and  25 B , the connector  2  or the connector  64  (not shown but see  FIG.  6 A ) is shown installed over a horizontal framing member, such as a wood bridge member  268  or a metallic bridge member  270  supported on top of jack or reinforcement studs  272  attached to king studs  274 . The inner cylindrical body  4  is threadedly attached to the tie rod  44 . The tie rod  44  is attached to a wall foundation with an anchor and an anchor rod (see  FIG.  28 A ). The spring  8  moves the outer cylindrical body  6  as the wall shrinks or settles downwardly. The clip  50  is removed to activate the connector  2 . 
     Referring to  FIG.  26   , the connector  82  (see  FIG.  9   ) is attached to a horizontal framing member, such as a double top plate  276  supported by a plurality of studs  278 . A plurality of roof rafters  280  (one shown) is supported by the double top plate  276 . It should be understood that other connectors disclosed herein may also be installed in lieu of the connector  82 . The tie rod  44  is attached to a wall foundation with an anchor and an anchor rod (see  FIG.  28 A ). 
     Referring  FIG.  27   , two connectors  2  are shown attached in tandem inside a wall over the bottom plate  262 . The connectors  2  are installed on either side of the tie rod  44 . The tie rod  44  is attached to a wall foundation with an anchor and an anchor rod (see  FIG.  28 A ). Threaded rods  282  attached to a base plate  284  guide the respective connectors  2  as they expand. A top plate  286  distributes the load from the tie rod  44  over the two connectors  2 . Use of the tandem arrangement advantageously allows the use of the connectors  2  with smaller axial openings than the diameter of the tie rod  44 . With smaller axial openings, the overall outside diameter of the connectors  2  is advantageously reduced to fit in smaller spaces. The load is also distributed over the two connectors  2 , advantageously requiring less load capability for each connector. Swivel washers  288  with complementary concave surface  290  and convex surface  292  advantageously allow the tie rod  44  to be misaligned from the vertical while keeping the contact surface  294  of the swivel washers flat on the contact surface  296  of the top plate  286 . The nut  46  holds applies tension on the tie rod  44 . The swivel washers  288  and the tandem arrangement of the connectors  2  are also disclosed in application Ser. No. 15/265,613, filed Sep. 14, 2016, hereby incorporated by reference. It should be understood that other embodiments of the connector disclosed herein, such as the connector  64 ,  70 ,  82 ,  94 ,  142 ,  166 ,  184 ,  190 ,  222 ,  228 , etc., may be used in the tandem configuration. 
     Referring to  FIGS.  28 A,  28 B and  28 C , a three-level wall  297  is shown anchored to a foundation  298  with two connectors  2 . The wall is standard construction. Each section  299  of the wall includes a bottom plate  300 , a plurality of studs  302  and a double top plate  304 . Floor joists  306  between the lower wall section and the upper wall section are supported on the respective double top plates  304 . Roof rafters (one shown)  306  are supported by the top plates of the top wall section. 
     An anchor rod  308  is attached to an anchor  310  embedded in the foundation  298 . A tie rod  320  with threaded end portions and an unthreaded portion in between is attached to the anchor rod with a coupling  322 . The unthreaded portions of the tie rods  302  are disposed in the openings in the double top plates  304  and bottom plates  300  to advantageously allow the floors to shrink downwardly without snagging and bowing the tie rods. In this manner, the tie rods  320  will have no slack. 
     The upper connector  2  as shown in  FIG.  28 B  has a longer travel length of expansion than the lower connector  2  as shown in  FIG.  28 C , since the upper connector  2  is to accommodate the cumulative shrinkage of the floors below. The inner cylindrical body  4  of the connector  2  of  FIG.  28 B  has a convex upper edge surface  323  that cooperates with a swivel washer with a complementary shaped bottom surface  325  to advantageously allow the misalignment from the vertical of the tie rod  320 . Since the connector  2  of  FIG.  28 B  is located furthest from the foundation  298 , small misalignment or displacement as measured in arc length from the vertical of the tie rod  320  grows by the time it reaches to the position of the connector  2  on the third level of the wall  297 . 
     Referring to  FIGS.  29 A,  29 B and  29 C , the upper connector  2  shown in  FIG.  28 A  is replaced with the connector  64  (see  FIG.  6 A ). 
     Referring to  FIG.  30   , the connector  64  is disposed on top of a connector  324 , which is similar to the connector  70 , except that the outer cylindrical body  326  is not attached to the bearing plate  48 . The bearing plate  74  is also not attached to the wall structure  78 . The inner cylindrical body  328  is threaded to the tie rod  77  and extends into the connector  64 , engaging the inner cylindrical body  4  of the connector  64 . The outer cylindrical body  6  of the connector  64  engages the endcap  38  of the connector  324 . The nut  46  attaches the connector  64  to the tie rod  44 . The tie rod  44  is attached to a wall foundation with an anchor and an anchor rod (see  FIG.  28 A ). The spring  8  is used to actuate both connectors  4  and  64 . When the building wall shrinks, the inner cylindrical body  328  moves upwardly relative to the wall structure  78 , pushing the inner cylindrical body  4  upwardly. The spring  8  then pushes the outer cylindrical bodies  6  and  326  downwardly to take up the amount of shrinkage. Even after the lower connector  324  has bottomed out or failed, the upper connector  64  will still function to dampen any load on the tie rod  44 . 
     Referring to  FIG.  31   , another embodiment of a hydraulic expandable connector  330  is disclosed. The connector  330  is disposed inverted below and hanging from the wall structure  78 . The connector  330  has an inner cylindrical body  332  within an outer cylindrical body  334 . A piston portion  336 , preferably integral with the inner cylindrical body  332 , extends radially outwardly and slidably engages an inner wall  338  of the outer cylindrical body  334 . The piston portion  336  defines an upper chamber  340  and a lower chamber  342  between the inner wall  338  and the inner cylindrical body  332 . The chambers  340  and  342  are filled with hydraulic fluid, such as mineral oi, water, etc. A plurality of openings  344  communicate with upper chamber  340  and the lower chamber  342 . A seal  346 , preferably an O-ring, disposed within an annular groove  347  in the piston portion  336 , seals the piston portion  336  with the inner wall  338 . Another outer cylindrical body  348  is threaded to the other cylindrical body  334 . Seals  350 , preferably O-rings, seal the inner cylindrical body  332  to the outer cylindrical bodies  334  and  348 . The inner cylindrical body  332  is threaded to the tie rod  44 . The tie rod  44  is attached to a wall foundation with an anchor and an anchor rod (see  FIG.  28 A ). A spring  352  disposed within the upper chamber  340  pushes the outer cylindrical bodies  334  and  348  against the bearing plate  48 . The spring  352  prevents the outer cylindrical body  334  and the bearing plate  48  from falling downwardly due to gravity. 
     As the building wall shrinks downwardly, the wall structure  78  moves with the wall, pushing the outer cylindrical body  334  downwardly, thereby pressurizing the fluid in the upper chamber  340 . The fluid then flows through the openings  344  in a predetermined rate, depending on the size and number of the openings  344 . A smaller size of the opening  344  will cause the fluid to flow slower than a larger size. A greater number of the openings  344  will cause the fluid to flow faster than a lesser number of the openings  344 . Accordingly, the rate of downward movement of the wall may be predetermined. 
     When there is an uplift force on the wall, the tie rod  44  is pulled upwardly (tension force), causing the inner cylindrical body  332  to move upwardly, thereby pressurizing the upper chamber  340 . The fluid in the upper chamber  340  flows through the openings  344  in a predetermined rate to dampen the upward movement of the tie rod  44 . Accordingly, the wall cannot move faster than the rate of movement of the outer cylindrical body  334  or the inner cylindrical body  332 . 
     Referring to  FIG.  32   , the connector  330  shown in  FIG.  31    is modified as connector  354  wherein the seals  344  and  350  are replaced with standard hydraulic seals  356  and  358 , also known as rod seals. Hydraulic seals are typically used in reciprocating motion applications, such as piston-cylinder assemblies. The hydraulic seals  356  and  358  can withstand higher pressures than a typical O-ring seal. 
     Referring to  FIG.  33   , the connector  354  shown in  FIG.  32    is modified as a hydraulic expandable connector  360  wherein the spring  352  is not used. The friction between the inner cylindrical body  332  and the seals  358  is sufficient to keep the outer cylindrical bodies  334  and  348  and the bearing plate  48  from falling under their own weight. The force applied to the outer cylindrical bodies  334  and  348  as the wall shrinks is enough to overcome the friction of the seals  358  and move the outer cylindrical bodies  334  and  348 . 
     Referring to  FIG.  34   , the connector  360  is modified as a hydraulic expandable connector  362  wherein the outer cylindrical body  334  and the other outer cylindrical body  348  are modified as outer cylindrical bodies  364  and  366 , respectively. The outer cylindrical body  366  has a cylindrical portion  368  disposed between the inner cylindrical body  332  and the outer cylindrical body  365 . A seal  370 , preferably an O-ring, seals the cylindrical portion  368  against the outer cylindrical body  364 . The outer cylindrical body  366  has a threaded cylindrical portion  372  that mates with a corresponding threaded cylindrical portion  374  of the outer cylindrical body  364 . The threaded cylindrical portions  372  and  374  are advantageously disposed below the lower chamber  342  to provide a stronger connection between the outer cylindrical bodies  364  and  366 . 
     Referring to  FIG.  35   , the building wall  297  shown in  FIG.  28 A  is further equipped with the connectors  330 . A person of ordinary skill in the art will understand that the connectors  354  or  362 , which are variants of the connectors  330 , may also be used. The connectors  330  are designed to move downward slowly to allow for shrinkage/settling of the wall  397 . If the wall  297  attempts to move downward faster than the speed the connectors  330  are designed for, the connectors  330  will slow down the downward movement of the wall. The connectors  330  are mounted in the downward orientation as shown to slow down or resist the downward/compressive forces in the structure and channel those forces to the tie rods  320 , turning the tie rods into both a tension and compression member instead of a tension member only. 
     Referring to  FIGS.  36  and  37   , the upper connector  330  shown in  FIG.  36    has a greater travel length than the lower connector  330  shown in  FIG.  37    to account for the cumulative shrinkage of the floors below. 
     Referring to  FIGS.  38  and  39   , the upper connector  2  shown in  FIG.  39    is disposed on a cross member  376  supported on top of a pair of reinforcement studs  380 . The connectors  330  function in the same way as those shown in  FIG.  35   , slowing down or resisting the downward/compressive forces in the structure and channel those forces to the tie rods  320 , turning the tie rods into both a tension and compression member instead of a tension member only. 
     Referring to  FIGS.  40  and  41   , the upper connector  330  is installed directly below the cross member or bridge member  376 . The connectors  330  function to dampen the downward movement of the wall  297  as it shrinks. The cross member  376  is operably sandwiched between the reinforcement studs  380  and  379 . The reinforcement studs  380  and  379  are operably attached to the studs  302  to help transfer the load from the tie rod  320  to the cross member  376  and the studs. 
     Referring to  FIG.  42   , a damping coupling  378  is disclosed. The coupling  378  has a housing  381  with a closed internal chamber  382  filled with hydraulic fluid, such as mineral oi, water, etc. The housing  380  is preferably made of one body  384  threaded to another body  386 . A piston  388  is disposed inside the chamber  382  and slidable between one end of the chamber  382  to the other end. The chamber  382  is divided into one chamber  390  on one side of the piston  388  and another chamber  392  on the other side of the piston  388 . Passageways  394  allow the fluid in the chamber to flow from one chamber  390  to the other chamber  392  or vice versa. The piston  388  includes a rod portion  396  extending outside the housing  380  and threadedly attached to the tie rod  44  through a threaded opening in the rod portion  396 . The other body  386  is threadedly attached to another tie rod  44  through a threaded opening in the body  386 . A seal  398 , such as an O-ring disposed inside an annular groove  400  in the body  384 , seals the chamber  390  between the rod portion  396  and the body  384 . A seal  402 , such as an O-ring disposed in annular groove  404  in the piston  388 , seals the chamber  390  from the other chamber  392  so that fluid flow is restricted only through the passageways  394 . 
     The damping coupling  378  is a non-rigid coupling joining two tie rods  44  together. The tie rods  44  are allowed to move axially at a controlled rate within a designed maximum distance dictated by the length of the chamber  382 . When the designed maximum distance is reached, when the piston  388  reaches the upper wall or bottom wall of the chamber  382 , the coupling  378  becomes rigid in one direction. The passageways  394  allow the piston  388  to move through the fluid no faster than the fluid flow through the passageways  394 , thereby providing a damping effect on the compressive or tensile forces acting on the tie rods  44 . Damage due to excessive forces is advantageously avoided or lessened. 
     Referring to  FIG.  43   , the damping coupling  378  is modified as damping coupling  404  with the addition of a spring  406  disposed within the chamber  390 . The spring  406  advantageously generates a force to pull the two tie rods  44  together. The spring  406  further provides additional tensioning in the tie rods  44  as the wall shrinks. 
     While this invention has been described as having preferred design, it is understood that it is capable of further modification, uses and/or adaptations following in general the principle of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as may be applied to the essential features set forth, and fall within the scope of the invention or the limits of the appended claims.