Patent Description:
A hydraulic fluid power linear actuator employing a cylinder and combined piston and piston-rod assembly of elements to convert a supply of pressurized hydraulic fluid to linear mechanical force or motion is known from <CIT>.

<CIT> discloses a take up device for a building structure, e.g. hold-down for securing the building structure to a foundation, has a housing secured by fasteners to the building structure, the housing defining a cylindrical chamber containing a piston and fluid, with a piston rod projecting from the housing. The piston rod is connected to a foundation anchor, and a fluid passage interconnects portions of the cylindrical chamber at opposite sides of the piston. The fluid passage is provided with a one-way valve, which allows the housing to move upwardly relative to the piston, to maintain the tightness of the connection to the anchor bolt, but resists opposite movement of the housing.

<CIT> discloses a fastener assembly comprising a first cylindrical member disposed within a second cylindrical member. One is movable relative to the other one in a first direction, and locked in a second direction opposite the first direction. A spring is operably attached to the members to urge the one in the first direction.

The present invention provides a hydraulic expandable connector for taking up a slack in a tie rod in a hold-down system with the features of claims <NUM> and <NUM>, respectively, as well as a reinforced building wall with the features of claim <NUM>.

Referring to <FIG>, a hydraulic expandable connector <NUM> is disclosed. The connector <NUM> includes an inner cylindrical body <NUM> disposed within an outer cylindrical body <NUM>. The inner cylindrical body <NUM> is slidable relative to the outer cylindrical body <NUM> during operation. An actuation spring <NUM> is operably attached to the inner cylindrical body <NUM> and the outer cylindrical body <NUM> to cause relative motion of the inner cylindrical body <NUM> with the outer cylindrical body <NUM> during use. The inner cylindrical body <NUM> has a central opening <NUM> through which a tie rod is extended in a typical installation.

A retainer ring <NUM> is removably attached to an upper portion of the inner cylindrical body <NUM> to capture the upper end portion of the spring <NUM>. The retainer ring <NUM> has a plurality of resilient fingers <NUM> disposed around the periphery of an opening <NUM> that are received in a circumferential groove <NUM>, which holds the retainer ring <NUM> attached to the inner cylindrical body <NUM>. The retainer ring <NUM> has a circumferential portion <NUM> that extends outwardly to capture the upper end of the spring <NUM>. The retainer ring <NUM> is further described in application serial No. <CIT>. The outer cylindrical body <NUM> has a reduced diameter portion <NUM> to capture the lower end portion of the spring <NUM>. The spring <NUM> urges relative sliding movement between the inner cylindrical body <NUM> and the outer cylindrical body <NUM>.

The inner cylindrical body <NUM> has a reduced diameter portion <NUM> and another reduced diameter portion <NUM> with a smaller diameter than the reduced diameter portion <NUM>. The reduced diameter portions <NUM> and <NUM> are axially adjacent to each other. A piston member <NUM> in the form of a ring or sleeve is disposed within the portion <NUM>. A seal <NUM> disposed within an annular groove <NUM> in the piston <NUM> seals the piston to the outer cylindrical body <NUM>. A spring <NUM> urges the piston <NUM> against a seat <NUM> on the portion <NUM>. Fluid chambers <NUM> and <NUM> are disposed on either side of the piston <NUM>. A passageway <NUM> communicates between the chambers <NUM> and <NUM>. The passageway <NUM> is a gap between the piston <NUM> and the reduced diameter portion <NUM> of the inner cylindrical body <NUM>. A retainer ring <NUM> holds the spring <NUM> in place. An endcap <NUM> is threaded to the outer cylindrical body <NUM>. A seal <NUM> within an annular groove <NUM> in the endcap <NUM> seals the fluid chamber <NUM>. A seal <NUM> within an annular groove <NUM> in the outer cylindrical body <NUM> seals the fluid chamber <NUM>. The upper chamber <NUM> is bounded by the bottom of the endcap <NUM>, the portion <NUM> and top of the piston <NUM> and inner cylindrical body <NUM>. The lower chamber <NUM> is bounded by the portion <NUM>, a shoulder <NUM> extending radially toward the inner cylindrical body <NUM>, the bottom of the piston <NUM> and the inner cylindrical body <NUM>. The upper chamber <NUM> and the lower chamber <NUM> are filled with hydraulic fluid, such as mineral oil, water, etc. The piston member <NUM> functions as a valve, opening or closing the passageway <NUM>.

Referring to <FIG>, the connector <NUM> is attached to a stud wall by means of a tie rod <NUM> with a nut <NUM>. The tie rod <NUM> is attached to a wall foundation with an anchor and an anchor rod (see <FIG>). A bearing plate <NUM> may be used to effectively transfer the forces on the connector <NUM> onto the stud wall. A clip <NUM> is removed after the connector <NUM> is installed to release the inner cylindrical body <NUM> relative to the outer cylindrical body <NUM> so that the spring <NUM> can move the inner cylindrical body <NUM> when the stud wall settles downwardly. The connector <NUM> is shown installed inside a floor system comprising floor joists <NUM> (one shown) supported on a horizontal framing member, such as a top plate <NUM> of the stud wall below. A sub-floor <NUM>, supported by the floor joist <NUM>, supports a bottom plate <NUM> of the stud wall above. Support blockings <NUM> provides additional rigidity to the space adjacent the connector <NUM>.

The connector <NUM> shown in <FIG> may also be replaced by the connector <NUM> shown in <FIG>.

Referring to <FIG>, when the inner cylindrical body <NUM> moves upwardly from the action of the spring <NUM> due to the settlement of the stud wall, the piston <NUM> also moves but lags behind due to the pressurization of the fluid in the upper chamber <NUM>. The spring <NUM> is compressed by the higher pressure of the fluid in the upper chamber <NUM>, creating a gap <NUM> that communicates with the passageway <NUM>. The gap <NUM> serves as an entrance to the passageway <NUM>. Fluid from the chamber <NUM> flows to the lower chamber <NUM>. The upward movement of the inner cylindrical body <NUM> increases the volume of the lower chamber <NUM>, creating a lower pressure that causes the pressurized fluid from the upper chamber <NUM> to flow through the gap <NUM>. After the inner cylindrical body <NUM> has come to a rest, the spring <NUM> will push the piston <NUM> toward the seat <NUM> to close the gap <NUM>.

When an axial downward load is applied to the inner cylindrical body <NUM> when the stud wall tries to lift up during a windstorm, hurricane, earthquake, etc., the downward load is resisted by the piston <NUM> pressing on the fluid in the lower chamber <NUM> to a higher pressure than in the upper chamber <NUM>. Since the fluid, such as oil, is incompressible, and the passageway <NUM> is closed at the gap <NUM> by the piston <NUM> contacting the seat <NUM>, the connector <NUM> is able to hold the wall down. The piston <NUM> acts as a valve, opening or closing the passageway <NUM> at the gap <NUM> as the connector <NUM> reacts to a load.

Referring to <FIG>, the connector <NUM> is shown in an initial set position, prior to expanding to take up a slack in the tie rod <NUM>. The upper chamber <NUM> and the lower chamber <NUM> are shown in their initial volumes.

Referring to <FIG>, the connector has expanded to take the slack in the tie rod <NUM>. The inner cylindrical body <NUM> has moved upwardly, decreasing the volume of the upper chamber <NUM> while increasing the volume of the lower chamber <NUM>. The expansion of the connector <NUM> compresses the fluid in the upper chamber <NUM>, causing the fluid to flow through the gap <NUM> and the passageway <NUM> into the lower chamber <NUM>.

Referring to <FIG>, the connector <NUM> has expanded to its fully expanded position. The volume of the upper chamber <NUM> is reduced to zero, with the top end of the piston <NUM> butting against the bottom end of the endcap <NUM>. The volume of the lower chamber <NUM> is at maximum.

The actuation spring <NUM> may be made so that when compressed, it will have enough stored energy to cause upward movement of the inner cylindrical body <NUM> when a slack develops in the tie rod <NUM>. The actuation spring <NUM> may also be made so that in addition to the energy to expand the connector <NUM> when a slack develops in the tie rod <NUM>, the spring <NUM> will have sufficient stored energy to tension the tie rod <NUM> extending below the connector <NUM>.

Referring to <FIG>, another embodiment of a hydraulic expandable connector <NUM> is disclosed. The connector <NUM> is the same as the connector <NUM>, except the piston <NUM> is modified as piston <NUM>. The piston <NUM> includes a plurality of passageways <NUM> in the form of holes arranged around the piston <NUM> that communicate with the upper chamber <NUM> and the lower chamber <NUM>. When a downward load is imposed on the inner cylindrical body <NUM>, fluid from the lower chamber <NUM> flows through the passageways <NUM>, allowing the piston <NUM> to move downwardly in a controlled manner, creating a dampening effect.

Referring to <FIG>, as the connector <NUM> expands to take up a slack that develops in the tie rod <NUM>, the inner cylindrical body <NUM> moves upwardly under the action of the actuation spring <NUM>. The piston actuation spring <NUM> is compressed by the piston <NUM>, causing the top end of the piston <NUM> to separate from the seat <NUM> to create the gap <NUM> that communicates with the passageway <NUM>. The upper chamber <NUM> decreases in volume, pressurizing the fluid in the chamber while the lower chamber <NUM> increases in volume, creating a vacuum that causes the fluid from the upper chamber <NUM> to flow into the lower chamber <NUM>. Some fluid also flows through the passageways <NUM>. When the entire slack has been taken up, expansion stops and the piston <NUM> moves to engage the seat <NUM> under the action of the spring <NUM>. The connector <NUM> 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 <NUM> and <NUM> are actuated by the spring <NUM> when the stud wall moves downwardly due to settlement. The spring <NUM> is disposed outside the connectors <NUM> and <NUM>.

Referring to <FIG>, an embodiment of a hydraulic expandable connector <NUM> is disclosed that uses the building wall displacement for its actuation rather than the spring <NUM>. The connector <NUM> works the same way as the connector <NUM>, except that the inner cylindrical body <NUM> is threaded to the tie rod <NUM> and the outer cylindrical body <NUM> is attached to the wall structure. The inner cylindrical body <NUM> includes an inner threaded portion <NUM> attached to the tie rod <NUM>. The outer cylindrical body <NUM> is attached to a bearing plate <NUM> with screws <NUM>. The bearing plate <NUM> is in turn attached to a horizontal framing member or wall structure <NUM>, such as a bottom plate or a cross-member, with screws <NUM>. Although not shown, the connector <NUM> without the spring <NUM> may be modified as shown for the connector <NUM> for attachment to the building wall structure.

When the wall structure <NUM> moves downwardly due to settlement, the outer cylindrical member <NUM> moves with it, while the inner cylindrical body <NUM> stays stationary with respect to the tie rod <NUM> but moves upwardly relative to the outer cylindrical body <NUM>. The chamber <NUM> will expand in volume, creating a lower pressure than in the chamber <NUM>. The piston <NUM> will separate from the seat <NUM> to open the passageway <NUM> (see <FIG>) between the chambers <NUM> and <NUM>. Fluid will flow from the upper chamber <NUM> into the lower chamber <NUM> to equalize the pressure between the chambers. The passageway <NUM> will close when the piston <NUM>, under the action of the spring <NUM>, engages the seat <NUM>. The connector <NUM> is now ready to resist any downward load on the inner cylindrical body <NUM>. A downward load will be resisted by the fluid in the lower chamber <NUM> as the fluid is pressurized by the piston <NUM>.

Referring to <FIG>, an embodiment of a hydraulic expandable connector <NUM> is disclosed. The connector <NUM> is the same as the connector <NUM> and works the same way, except that the bearing plate <NUM> has been integrated into the outer cylindrical body <NUM> as a flange <NUM> attached to the wall structure <NUM>. Although not shown, the connector <NUM> without the spring <NUM> may be modified as shown for the connector <NUM> for attachment to the building wall structure.

Referring back to <FIG>, the piston <NUM> is sealed to the outer cylindrical body <NUM> with a plurality of O-ring seals <NUM> disposed in respective circumferential grooves <NUM>. Similarly, the inner cylindrical body <NUM> is sealed to the outer cylindrical body <NUM> with a plurality of O-ring seals <NUM> disposed in respective circumferential grooves <NUM>.

Referring to <FIG>, another embodiment of a hydraulic expandable connector <NUM> is disclosed. The connector <NUM> includes an inner cylindrical body <NUM> disposed inside the outer cylindrical body <NUM>. The inner cylindrical body <NUM> has a piston portion <NUM> extending radially and sealed to the outer cylindrical body <NUM> with the seal <NUM>. The piston portion <NUM> is preferably integral with the rest of the inner cylindrical body <NUM>. A piston <NUM> in the form of a ring is disposed between the inner cylindrical body <NUM> and the outer cylindrical body <NUM>. Seals <NUM> in annular grooves <NUM> in the piston <NUM> seal the space <NUM> from the upper chamber <NUM>. An upper chamber <NUM> is bounded by bottom of the piston <NUM>, the top of the piston portion <NUM>, the inner cylindrical body <NUM> and the portion <NUM>. A lower chamber <NUM> is disposed below the piston portion <NUM> and bounded by the bottom of the piston portion <NUM>, the portion <NUM>, the inner cylindrical body <NUM> and the shoulder <NUM>. A plurality of openings <NUM> communicate with the upper chamber <NUM> and the lower chamber <NUM>. The upper chamber <NUM> and the lower chamber <NUM> are filled with hydraulic fluid, such as mineral oil, water, etc. A one-way valve <NUM> is associated with each of the openings <NUM> to allow flow of the fluid from the upper chamber <NUM> to the lower chamber <NUM> but not in the opposite direction. The endcap <NUM> includes openings <NUM> that communicates with the outside and the space <NUM> to equalize the pressure inside the space <NUM> when the spring <NUM> expands to push the piston <NUM> downwardly when the connector <NUM> expands in response to the settlement of the building wall in which the connector <NUM> is installed.

The fluid in the upper chamber <NUM> is constantly pressurized by the spring <NUM>. When slack develops in the tie rod <NUM> due to building settlement, the pressure from the upper chamber <NUM> pushes the fluid into the lower chamber <NUM> through the openings <NUM> and the one-way valves <NUM>, pushing the inner cylindrical body <NUM> upwardly to take up the slack. When a downward load is applied to the inner cylindrical body <NUM> due to wall uplifting during a storm, earthquake, etc., the fluid in the lower chamber <NUM> is pressurized, closing the one-way valves <NUM> to prevent fluid flow into the upper chamber <NUM>. Accordingly, the fluid in the lower chamber <NUM> stops the inner cylindrical body <NUM> from moving downwardly from the load.

The principle of operation of the connector <NUM> may be used for the connector <NUM>, wherein the spring <NUM> and the air inlet openings <NUM> are used to actuate the connector.

Referring to <FIG>, the one-way valve <NUM> may be made of a ring plate <NUM> made of a single piece material, such as plastic. Reed portions <NUM> are cut into the plate <NUM> on three sides. The reed portions <NUM> are disposed below the respective openings <NUM>. The reed portions <NUM> when subjected to fluid pressure from the upper chamber <NUM> via the openings <NUM> are configured to separate from the plate <NUM> along the three cut sides to an open position, as shown in <FIG>, to allow the fluid to flow into the lower chamber and close position when the lower chamber <NUM> is pressurized by a downward load on the inner cylindrical body <NUM>. A retainer ring <NUM> held in a circumferential groove <NUM> supports the ring plate <NUM>. A spring <NUM> is disposed outside the outer cylindrical body <NUM> in the manner shown for the connectors <NUM> and <NUM>.

Referring to <FIG>, the plate <NUM> may be installed into a circumferential groove <NUM> in the piston portion <NUM>. The plate <NUM> has a radial cut-out <NUM> to facilitate insertion of the plate <NUM> into the groove <NUM>. The plate <NUM> has an inside diameter larger than the outside diameter of the cylindrical portion <NUM> to facilitate insertion of the plate <NUM> into the groove <NUM>. To install the plate <NUM>, the ends at the cut-out <NUM> are brought together to temporarily reduce the outside diameter of the plate <NUM> to clear the inside diameter of the outer edge of the groove <NUM>. The ends at the cut-out <NUM> are released, allowing the plate <NUM> to spring back to its original size inside the groove <NUM>.

Referring to <FIG>, the reed portions <NUM> may be attached directly to the underside of the piston portion <NUM> along one side <NUM> with standard fastener, such as screws. Each of the reed portions <NUM> has enough flexibility at the respective side <NUM> to open or close from the action of the fluid from the upper chamber <NUM> and the lower chamber <NUM>, respectively. Each of the reed portions <NUM> is disposed a respective opening <NUM> (see <FIG> and <FIG>).

Referring to <FIG>, the reed portions <NUM> may be attached to a ring plate <NUM>. The ring plate <NUM> has holes <NUM> aligned with the respective openings <NUM> in the piston portion <NUM>. Each of the reed portions <NUM> is attached to the ring plate <NUM> along the side <NUM>, allowing each of the reed portions <NUM> to away from or toward the respective openings <NUM> under the action of the fluid from the upper chamber <NUM> or the lower chamber <NUM>, respectively. The ring plate <NUM> is attached to the underside of the piston portion <NUM> by standard means, such as screws, adhesives, etc..

Referring to <FIG>, the one way valve <NUM> may be implemented by a flat washer <NUM> held against the underside of the piston portion <NUM> by a spring <NUM> held by a retainer ring <NUM> in a circumferential groove <NUM>. The flat washer <NUM> is urged against the underside of the piston portion <NUM> by the spring <NUM>, closing the openings <NUM>. When the inner cylindrical body <NUM> moves upwardly to take up the slack in the tie rod <NUM> due to the building wall's shrinkage, pressure in the upper chamber <NUM> builds up and pressure in the lower chamber <NUM> decreases. The pressure changes occur due to the decrease in volume of the upper chamber <NUM> and increase in volume in the lower chamber <NUM>. Fluid from the upper chamber <NUM> is then forced through the openings <NUM>, pushing the flat washer <NUM> away from the underside of the piston portion <NUM> and compressing the spring <NUM>. Fluid will continue to flow until the pressure in the upper chamber <NUM> and the lower chamber <NUM> are equalized. The spring <NUM> then pushes the flat washer against the piston portion <NUM>, thereby closing the openings <NUM>. When the inner cylindrical body <NUM> is subjected to a downward load, the fluid in the lower chamber <NUM> resists the load since the fluid is incompressible. Fluid cannot flow to the upper chamber <NUM> since the openings <NUM> are closed by the flat washer <NUM> being pushed by the pressure in the fluid and the spring <NUM>.

Referring to <FIG>, another embodiment of a hydraulic expandable connector <NUM> is disclosed. The connector <NUM> includes the inner cylindrical body <NUM> disposed inside the outer cylindrical body <NUM>. The retainer ring <NUM> shown in <FIG> is modified. Removable attachment of the retainer ring <NUM> to the inner cylindrical body <NUM> is implemented with a circular spring <NUM> that is received in both the retainer ring <NUM> and the inner cylindrical body <NUM> in cooperating circumferential grooves <NUM> and <NUM>. The spring <NUM> locks the retainer ring <NUM> in the upward direction but allows the retainer ring <NUM> to be slipped downwardly. The operation of the spring <NUM> and the grooves <NUM> and <NUM> is further described in several patents, such as <CIT>, <CIT> and <CIT>. The spring <NUM> is retained around the outer cylindrical body <NUM> by a retainer ring <NUM> and the projecting portion <NUM>. The spring <NUM> urges the inner cylindrical body <NUM>, via the retainer ring <NUM>, in the upward direction to take up any slack that may develop in the tie rod <NUM> (see <FIG>) due to the building wall shrinkage.

A deformable seal or piston <NUM> is disposed between the inner cylindrical body <NUM> and the outer cylindrical body <NUM>. The deformable seal <NUM> includes a plate portion <NUM> that opens and closes the passageway <NUM> between the upper chamber <NUM> and the lower chamber <NUM>, functioning as a valve as described above in connection with the connector <NUM>. The deformable seal <NUM> also includes a deformable wall portion <NUM> made of a thin wall section disposed between the top end and the bottom end of the deformable seal <NUM>. The inner portion of the deformable seal <NUM> has a hollowed concave portion <NUM> to form the deformable wall portion <NUM> and provides an opening <NUM> that connects the lower chamber <NUM> with the hollowed portion <NUM> and the deformable wall portion <NUM>. The upper chamber <NUM> and the lower chamber <NUM> are filled with hydraulic fluid, such as mineral oil, water, etc..

The engagement of the top surface of the plate portion <NUM> against the seat <NUM> and the seal <NUM> seal the upper chamber <NUM> from the lower chamber <NUM>. Seals <NUM> and <NUM> within annular grooves <NUM> in the inner cylindrical body <NUM> seal the lower chamber <NUM> from the upper chamber <NUM>.

The connector <NUM> when taking up the slack that develops in the tire rod <NUM> works the same way as the connector <NUM>. However, when under load, the operation is different. When the inner cylindrical body <NUM> is subjected to an axial downward load, the seat <NUM> will press on the plate portion <NUM>, sealing the upper chamber <NUM> from the lower chamber <NUM>. The fluid in the lower chamber <NUM> is subjected to high pressure when the connector <NUM> is subjected to an axial downward load, deforming the thin and deformable wall portion <NUM>. The deformation occurs toward the outer cylindrical body <NUM>, forcing the deformable wall portion <NUM> into the wall of the outer cylindrical body <NUM> into a locking engagement. The gap <NUM> (see <FIG>) is closed off by the pressure in the lower chamber <NUM> pushing the plate portion <NUM> against the seat <NUM> (see <FIG>) and the higher the pressure the tighter the seal becomes. The seal <NUM> advantageously keeps the high pressure fluid in the lower chamber <NUM> from leaking into the abutting surfaces between the outer cylindrical body <NUM> and the deformable seal <NUM> so that pressure behind the deformable wall portion <NUM> is less than the pressure in the hollowed portion <NUM>.

The deformation of the deformable wall portion <NUM> advantageously provides a permanent seal that becomes tighter as more load is exerted on the inner cylindrical body <NUM>. The deformable seal <NUM> advantageously makes the connector <NUM> fail-safe under load. In the event the seals <NUM> fail, the inner cylindrical body <NUM> will hold the load due to the locking engagement of the deformable seal <NUM> with the wall of the outer cylindrical body <NUM>.

Referring to <FIG>, another embodiment of a hydraulic expandable connector <NUM> is disclosed. The connector <NUM> is similar to the connector <NUM>, except that the seals <NUM> have been replaced by a deformable seal <NUM> similar in construction to the deformable seal <NUM>. The deformable seal <NUM> has a base portion <NUM> engaged against an inner shoulder <NUM> of the outer cylindrical body <NUM>. The deformable seal <NUM> has a deformable wall portion <NUM> abutting the inner cylindrical body <NUM>. A retainer ring <NUM> in a circumferential groove <NUM> holds a spring <NUM> that urges the base portion <NUM> against the should <NUM>. A lower chamber <NUM> filled with hydraulic fluid is bounded by the deformable seals <NUM> and <NUM> and the inner cylindrical body <NUM> and outer cylindrical body <NUM>. The upper chamber <NUM> is also filled with hydraulic fluid.

When an axial downward load is imposed on the inner cylindrical body <NUM>, the fluid in the lower chamber <NUM> is placed under high pressure. The inner cylindrical body <NUM> pushes down on the deformable seal <NUM>. The high pressure causes the deformable wall portions <NUM> and <NUM> to deform outwardly from the lower chamber <NUM> and onto the respective walls of the inner cylindrical body <NUM> and the outer cylindrical body <NUM>, providing a strong seal. Seals <NUM> in annular grooves <NUM> in the deformable seals <NUM> and <NUM> advantageously isolate the high pressure lower chamber <NUM> from the rest of the connector.

Referring to <FIG>, another embodiment of a hydraulic expandable connector <NUM> is disclosed. The connector <NUM> is identical to the connector <NUM> except that the springs <NUM> and <NUM> are replaced with a single spring <NUM>. The spring <NUM> pushes the upper deformable seal <NUM> as the inner cylindrical body <NUM> moves upwardly to take up slack in the tie rod <NUM> caused by the building wall settlement. The spring <NUM> also keeps the lower deformable seal <NUM> in contact with the shoulder <NUM>. Seals <NUM> in annular grooves <NUM> in the upper and lower deformable seals <NUM> and <NUM> are disposed outside the high pressure fluid (under load) lower chamber <NUM>.

Referring to <FIG>, another embodiment of a hydraulic expandable connector <NUM> is disclosed. The connector <NUM> is similar to the connector <NUM> except that the lower deformable seal <NUM> has been integrated into the outer cylindrical body <NUM>. The outer cylindrical body <NUM> has a deformable wall portion <NUM> extending from a shoulder <NUM>. The connector <NUM> works in the same way as the connector <NUM> during expansion and under load.

Referring to <FIG>, another embodiment of a hydraulic expandable connector <NUM> is disclosed. The connector <NUM> is similar to the connector <NUM>, except that the inner cylindrical body <NUM> is provided with internal threads <NUM> for threading to the tie rod <NUM> and the retainer ring <NUM> has been replaced with a washer <NUM>. The tie rod <NUM> is attached to a wall foundation with an anchor and an anchor rod (see <FIG>). A nut <NUM> compresses the spring <NUM> via the washer <NUM> and retainer ring <NUM> held in a circumferential groove <NUM> in the outer cylindrical body <NUM>. The spring <NUM> is compressed during installation. A bearing plate <NUM> is disposed on a horizontal metal framing member <NUM> (part of the building wall) to advantageously distribute the load over a larger area than the footprint of the connector <NUM>. Hydraulic seal <NUM> in annular groove <NUM> in the piston <NUM> is used instead of an O-ring for greater sealing power. Hydraulic seal <NUM> in annular groove <NUM> in the outer cylindrical body <NUM> 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 <NUM> moves downwardly from the action of the spring <NUM> while the inner cylindrical body <NUM> stays attached to the tie rod <NUM>. The spring <NUM> may be configured with sufficient force to tension the tie rod <NUM>. The connector <NUM> works the same way as the connector <NUM> when subjected to a downward load.

Referring to <FIG>, another embodiment of a hydraulic expandable connector <NUM> is disclosed. The connector <NUM> is similar to the connector <NUM>, except that the spring <NUM> is replaced with a conical spring <NUM> and the washer <NUM> is not used. The conical spring <NUM> is compressed by the nut <NUM> and presses on the outer cylindrical body <NUM> via the endcap <NUM>, which has been provided with a collar portion <NUM> to center the bottom end of the spring <NUM> over the endcap <NUM>.

When the building wall shrinks, the outer cylindrical body <NUM> moves downwardly from the action of the spring <NUM> while the inner cylindrical body <NUM> stays attached to the tie rod <NUM>. The connector <NUM> works the same way as the connector <NUM> when subjected to a downward load.

Referring to <FIG>, another embodiment of a hydraulic expandable connector <NUM> is disclosed. The connector <NUM> is similar to the connector <NUM>, except that the inner cylindrical body <NUM> is modified to accept a split cylindrical nut <NUM> threadedly attached to the tie rod <NUM>. The tie rod <NUM> is attached to a wall foundation with an anchor and an anchor rod (see <FIG>). The inner cylindrical body <NUM> an enlarged opening <NUM> that narrows into a conical opening <NUM>.

The cylindrical split nut <NUM> is made up of preferably four equal segments <NUM> with inner threads that mate with the threads of the tie rod <NUM>. The segments <NUM> are bundled together by a circular spring <NUM>. The cylindrical split nut <NUM> has conical portions <NUM> that mate with the conical opening <NUM>. A retainer ring <NUM> is threaded to a threaded portion <NUM> of the opening <NUM>. The retainer ring <NUM> compresses a spring <NUM> to urge the cylindrical split nut <NUM> downwardly into the conical opening <NUM>. The retainer ring <NUM> has an unthreaded opening <NUM> allows the tie rod <NUM> to move axially through the opening <NUM>. The clip <NUM> is removed after the connector is installed to allow the inner cylindrical body <NUM> to move relative to the outer cylindrical body <NUM>.

When the building wall in which the connector <NUM> is installed shrinks, the outer cylindrical body <NUM> moves downwardly with the wall from the action of the spring <NUM>. The inner cylindrical body <NUM> urges the cylindrical split nut <NUM> upwardly through the action of the spring <NUM>. The cylindrical split nut <NUM> advantageously reduces the amount of time of installation since the segments <NUM> are simply dropped into the opening <NUM> instead of being screwed down from the end of the tie rod <NUM> as with a standard nut. The opening <NUM> is larger than the diameter of the cylindrical portion of the cylindrical split nut <NUM> so that the segments <NUM> can radially expand and disengage from the threads of the tie rod as the connector <NUM> is slid down the tie rod during installation. Split nuts are disclosed in <CIT> and <CIT> and application serial No. <CIT>.

Referring to <FIG>, the conical opening <NUM> in the inner cylindrical body <NUM> of the connector <NUM> is modified to work with a hexagonal split nut <NUM>. A washer <NUM> distributes the force of the spring <NUM> over the segments <NUM> of the split nut <NUM>. The opening <NUM> has a rounded outer edge <NUM> that cooperates with a complementarily rounded surface <NUM> that serve to draw the segments <NUM> into threaded engagement with the threads of the tie rod <NUM>.

Referring to <FIG>, the connector <NUM> or the connector <NUM> (see <FIG>) is shown installed inside a wall. The connector <NUM> is shown in the unactuated state since the locking clip <NUM> has not been removed yet. The clip <NUM> is removed to activate the spring <NUM> and hence the connector <NUM>. The tie rod <NUM> is cut at the end <NUM> just above the nut <NUM> to facilitate installation of the connector <NUM>, which is slid down the tie rod <NUM> at the end <NUM>. A coupling <NUM> joins the tie rod <NUM> to another tie rod <NUM> to continue the run. The bearing plate <NUM> sits on top of a horizontal framing member, such as a base plate <NUM> supporting a plurality of studs <NUM>. A sub-floor sheet <NUM> is below the top plate <NUM>. The tie rod <NUM> is attached to a wall foundation with an anchor and an anchor rod (see <FIG>).

Referring to <FIG> and <FIG>, the connector <NUM> or the connector <NUM> (not shown but see <FIG>) is shown installed over a horizontal framing member, such as a wood bridge member <NUM> or a metallic bridge member <NUM> supported on top of jack or reinforcement studs <NUM> attached to king studs <NUM>. The inner cylindrical body <NUM> is threadedly attached to the tie rod <NUM>. The tie rod <NUM> is attached to a wall foundation with an anchor and an anchor rod (see <FIG>). The spring <NUM> moves the outer cylindrical body <NUM> as the wall shrinks or settles downwardly. The clip <NUM> is removed to activate the connector <NUM>.

Referring to <FIG>, the connector <NUM> (see <FIG>) is attached to a horizontal framing member, such as a double top plate <NUM> supported by a plurality of studs <NUM>. A plurality of roof rafters <NUM> (one shown) is supported by the double top plate <NUM>. It should be understood that other connectors disclosed herein may also be installed in lieu of the connector <NUM>. The tie rod <NUM> is attached to a wall foundation with an anchor and an anchor rod (see <FIG>).

Referring <FIG>, two connectors <NUM> are shown attached in tandem inside a wall over the bottom plate <NUM>. The connectors <NUM> are installed on either side of the tie rod <NUM>. The tie rod <NUM> is attached to a wall foundation with an anchor and an anchor rod (see <FIG>). Threaded rods <NUM> attached to a base plate <NUM> guide the respective connectors <NUM> as they expand. A top plate <NUM> distributes the load from the tie rod <NUM> over the two connectors <NUM>. Use of the tandem arrangement advantageously allows the use of the connectors <NUM> with smaller axial openings than the diameter of the tie rod <NUM>. With smaller axial openings, the overall outside diameter of the connectors <NUM> is advantageously reduced to fit in smaller spaces. The load is also distributed over the two connectors <NUM>, advantageously requiring less load capability for each connector. Swivel washers <NUM> with complementary concave surface <NUM> and convex surface <NUM> advantageously allow the tie rod <NUM> to be misaligned from the vertical while keeping the contact surface <NUM> of the swivel washers flat on the contact surface <NUM> of the top plate <NUM>. The nut <NUM> holds applies tension on the tie rod <NUM>. The swivel washers <NUM> and the tandem arrangement of the connectors <NUM> are also disclosed in application serial No. <CIT>. It should be understood that other embodiments of the connector disclosed herein, such as the connector <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, etc., may be used in the tandem configuration.

Referring to <FIG>, a three-level wall <NUM> is shown anchored to a foundation <NUM> with two connectors <NUM>. The wall is standard construction. Each section <NUM> of the wall includes a bottom plate <NUM>, a plurality of studs <NUM> and a double top plate <NUM>. Floor joists <NUM> between the lower wall section and the upper wall section are supported on the respective double top plates <NUM>. Roof rafters (one shown) <NUM> are supported by the top plates of the top wall section.

An anchor rod <NUM> is attached to an anchor <NUM> embedded in the foundation <NUM>. A tie rod <NUM> with threaded end portions and an unthreaded portion in between is attached to the anchor rod with a coupling <NUM>. The unthreaded portions of the tie rods <NUM> are disposed in the openings in the double top plates <NUM> and bottom plates <NUM> to advantageously allow the floors to shrink downwardly without snagging and bowing the tie rods. In this manner, the tie rods <NUM> will have no slack.

The upper connector <NUM> as shown in <FIG> has a longer travel length of expansion than the lower connector <NUM> as shown in <FIG>, since the upper connector <NUM> is to accommodate the cumulative shrinkage of the floors below. The inner cylindrical body <NUM> of the connector <NUM> of <FIG> has a convex upper edge surface <NUM> that cooperates with a swivel washer with a complementary shaped bottom surface <NUM> to advantageously allow the misalignment from the vertical of the tie rod <NUM>. Since the connector <NUM> of <FIG> is located furthest from the foundation <NUM>, small misalignment or displacement as measured in arc length from the vertical of the tie rod <NUM> grows by the time it reaches to the position of the connector <NUM> on the third level of the wall <NUM>.

Referring to <FIG>, the upper connector <NUM> shown in <FIG> is replaced with the connector <NUM> (see <FIG>).

Referring to <FIG>, the connector <NUM> is disposed on top of a connector <NUM>, which is similar to the connector <NUM>, except that the outer cylindrical body <NUM> is not attached to the bearing plate <NUM>. The bearing plate <NUM> is also not attached to the wall structure <NUM>. The inner cylindrical body <NUM> is threaded to the tie rod <NUM> and extends into the connector <NUM>, engaging the inner cylindrical body <NUM> of the connector <NUM>. The outer cylindrical body <NUM> of the connector <NUM> engages the endcap <NUM> of the connector <NUM>. The nut <NUM> attaches the connector <NUM> to the tie rod <NUM>. The tie rod <NUM> is attached to a wall foundation with an anchor and an anchor rod (see <FIG>). The spring <NUM> is used to actuate both connectors <NUM> and <NUM>. When the building wall shrinks, the inner cylindrical body <NUM> moves upwardly relative to the wall structure <NUM>, pushing the inner cylindrical body <NUM> upwardly. The spring <NUM> then pushes the outer cylindrical bodies <NUM> and <NUM> downwardly to take up the amount of shrinkage. Even after the lower connector <NUM> has bottomed out or failed, the upper connector <NUM> will still function to dampen any load on the tie rod <NUM>.

Referring to <FIG>, another embodiment of a hydraulic expandable connector <NUM> is disclosed. The connector <NUM> is disposed inverted below and hanging from the wall structure <NUM>. The connector <NUM> has an inner cylindrical body <NUM> within an outer cylindrical body <NUM>. A piston portion <NUM>, preferably integral with the inner cylindrical body <NUM>, extends radially outwardly and slidably engages an inner wall <NUM> of the outer cylindrical body <NUM>. The piston portion <NUM> defines an upper chamber <NUM> and a lower chamber <NUM> between the inner wall <NUM> and the inner cylindrical body <NUM>. The chambers <NUM> and <NUM> are filled with hydraulic fluid, such as mineral oil, water, etc. A plurality of openings <NUM> communicate with upper chamber <NUM> and the lower chamber <NUM>. A seal <NUM>, preferably an O-ring, disposed within an annular groove <NUM> in the piston portion <NUM>, seals the piston portion <NUM> with the inner wall <NUM>. Another outer cylindrical body <NUM> is threaded to the other cylindrical body <NUM>. Seals <NUM>, preferably O-rings, seal the inner cylindrical body <NUM> to the outer cylindrical bodies <NUM> and <NUM>. The inner cylindrical body <NUM> is threaded to the tie rod <NUM>. The tie rod <NUM> is attached to a wall foundation with an anchor and an anchor rod (see <FIG>). A spring <NUM> disposed within the upper chamber <NUM> pushes the outer cylindrical bodies <NUM> and <NUM> against the bearing plate <NUM>. The spring <NUM> prevents the outer cylindrical body <NUM> and the bearing plate <NUM> from falling downwardly due to gravity.

As the building wall shrinks downwardly, the wall structure <NUM> moves with the wall, pushing the outer cylindrical body <NUM> downwardly, thereby pressurizing the fluid in the upper chamber <NUM>. The fluid then flows through the openings <NUM> in a predetermined rate, depending on the size and number of the openings <NUM>. A smaller size of the opening <NUM> will cause the fluid to flow slower than a larger size. A greater number of the openings <NUM> will cause the fluid to flow faster than a lesser number of the openings <NUM>. Accordingly, the rate of downward movement of the wall may be predetermined.

When there is an uplift force on the wall, the tie rod <NUM> is pulled upwardly (tension force), causing the inner cylindrical body <NUM> to move upwardly, thereby pressurizing the upper chamber <NUM>. The fluid in the upper chamber <NUM> flows through the openings <NUM> in a predetermined rate to dampen the upward movement of the tie rod <NUM>. Accordingly, the wall cannot move faster than the rate of movement of the outer cylindrical body <NUM> or the inner cylindrical body <NUM>.

Referring to <FIG>, the connector <NUM> shown in <FIG> is modified as connector <NUM> wherein the seals <NUM> and <NUM> are replaced with standard hydraulic seals <NUM> and <NUM>, also known as rod seals. Hydraulic seals are typically used in reciprocating motion applications, such as piston-cylinder assemblies. The hydraulic seals <NUM> and <NUM> can withstand higher pressures than a typical O-ring seal.

Referring to <FIG>, the connector <NUM> shown in <FIG> is modified as a hydraulic expandable connector <NUM> wherein the spring <NUM> is not used. The friction between the inner cylindrical body <NUM> and the seals <NUM> is sufficient to keep the outer cylindrical bodies <NUM> and <NUM> and the bearing plate <NUM> from falling under their own weight. The force applied to the outer cylindrical bodies <NUM> and <NUM> as the wall shrinks is enough to overcome the friction of the seals <NUM> and move the outer cylindrical bodies <NUM> and <NUM>.

Referring to <FIG>, the connector <NUM> is modified as a hydraulic expandable connector <NUM> wherein the outer cylindrical body <NUM> and the other outer cylindrical body <NUM> are modified as outer cylindrical bodies <NUM> and <NUM>, respectively. The outer cylindrical body <NUM> has a cylindrical portion <NUM> disposed between the inner cylindrical body <NUM> and the outer cylindrical body <NUM>. A seal <NUM>, preferably an O-ring, seals the cylindrical portion <NUM> against the outer cylindrical body <NUM>. The outer cylindrical body <NUM> has a threaded cylindrical portion <NUM> that mates with a corresponding threaded cylindrical portion <NUM> of the outer cylindrical body <NUM>. The threaded cylindrical portions <NUM> and <NUM> are advantageously disposed below the lower chamber <NUM> to provide a stronger connection between the outer cylindrical bodies <NUM> and <NUM>.

Referring to <FIG>, the building wall <NUM> shown in <FIG> is further equipped with the connectors <NUM>. A person of ordinary skill in the art will understand that the connectors <NUM> or <NUM>, which are variants of the connectors <NUM>, may also be used. The connectors <NUM> are designed to move downward slowly to allow for shrinkage/settling of the wall <NUM>. If the wall <NUM> attempts to move downward faster than the speed the connectors <NUM> are designed for, the connectors <NUM> will slow down the downward movement of the wall. The connectors <NUM> 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 <NUM>, turning the tie rods into both a tension and compression member instead of a tension member only.

Referring to <FIG>, the upper connector <NUM> shown in <FIG> has a greater travel length than the lower connector <NUM> shown in <FIG> to account for the cumulative shrinkage of the floors below.

Referring to <FIG>, the upper connector <NUM> shown in <FIG> is disposed on a cross member <NUM> supported on top of a pair of reinforcement studs <NUM>. The connectors <NUM> function in the same way as those shown in <FIG>, slowing down or resisting the downward/compressive forces in the structure and channel those forces to the tie rods <NUM>, turning the tie rods into both a tension and compression member instead of a tension member only.

Referring to <FIG>, the upper connector <NUM> is installed directly below the cross member or bridge member <NUM>. The connectors <NUM> function to dampen the downward movement of the wall <NUM> as it shrinks. The cross member <NUM> is operably sandwiched between the reinforcement studs <NUM> and <NUM>. The reinforcement studs <NUM> and <NUM> are operably attached to the studs <NUM> to help transfer the load from the tie rod <NUM> to the cross member <NUM> and the studs.

Referring to <FIG>, a damping coupling <NUM> is disclosed. The coupling <NUM> has a housing <NUM> with a closed internal chamber <NUM> filled with hydraulic fluid, such as mineral oil, water, etc. The housing <NUM> is preferably made of one body <NUM> threaded to another body <NUM>. A piston <NUM> is disposed inside the chamber <NUM> and slidable between one end of the chamber <NUM> to the other end. The chamber <NUM> is divided into one chamber <NUM> on one side of the piston <NUM> and another chamber <NUM> on the other side of the piston <NUM>. Passageways <NUM> allow the fluid in the chamber to flow from one chamber <NUM> to the other chamber <NUM> or vice versa. The piston <NUM> includes a rod portion <NUM> extending outside the housing <NUM> and threadedly attached to the tie rod <NUM> through a threaded opening in the rod portion <NUM>. The other body <NUM> is threadedly attached to another tie rod <NUM> through a threaded opening in the body <NUM>. A seal <NUM>, such as an O-ring disposed inside an annular groove <NUM> in the body <NUM>, seals the chamber <NUM> between the rod portion <NUM> and the body <NUM>. A seal <NUM>, such as an O-ring disposed in annular groove <NUM> in the piston <NUM>, seals the chamber <NUM> from the other chamber <NUM> so that fluid flow is restricted only through the passageways <NUM>.

The damping coupling <NUM> is a non-rigid coupling joining two tie rods <NUM> together. The tie rods <NUM> are allowed to move axially at a controlled rate within a designed maximum distance dictated by the length of the chamber <NUM>. When the designed maximum distance is reached, when the piston <NUM> reaches the upper wall or bottom wall of the chamber <NUM>, the coupling <NUM> becomes rigid in one direction. The passageways <NUM> allow the piston <NUM> to move through the fluid no faster than the fluid flow through the passageways <NUM>, thereby providing a damping effect on the compressive or tensile forces acting on the tie rods <NUM>. Damage due to excessive forces is advantageously avoided or lessened.

Referring to <FIG>, the damping coupling <NUM> is modified as damping coupling <NUM> with the addition of a spring <NUM> disposed within the chamber <NUM>. The spring <NUM> advantageously generates a force to pull the two tie rods <NUM> together. The spring <NUM> further provides additional tensioning in the tie rods <NUM> as the wall shrinks.

Claim 1:
A hydraulic expandable connector (<NUM>; <NUM>) for taking up a slack in a tie rod in a hold-down system, comprising:
a) an inner cylindrical body (<NUM>) disposed within an outer cylindrical body (<NUM>), the inner cylindrical body (<NUM>) including first and second outer cylindrical wall surfaces spaced and opposite from first and second inner cylindrical wall surfaces, respectively, of the outer cylindrical body (<NUM>);
b) a first actuation spring (<NUM>) operably attached to the inner cylindrical body (<NUM>) and the outer cylindrical body (<NUM>) to urge relative motion between the inner cylindrical body (<NUM>) and the outer cylindrical body (<NUM>) such that the connector (<NUM>; <NUM>) expands axially to take up the slack;
c) a first chamber (<NUM>) and a second chamber (<NUM>) disposed, respectively, between the first and second outer cylindrical wall surfaces of the inner cylindrical body (<NUM>) and the first and second inner cylindrical wall surfaces of the outer cylindrical body (<NUM>);
d) a first passageway (<NUM>) communicating between the first chamber (<NUM>) and the second chamber (<NUM>); and
e) a valve (<NUM>; <NUM>) operably disposed in the first passageway (<NUM>), the valve (<NUM>; <NUM>) having a closed position and an open position, the valve (<NUM>; <NUM>) is in the open position when the connector (<NUM>; <NUM>) expands to allow fluid from the first chamber (<NUM>) to flow to the second chamber (<NUM>), the valve (<NUM>; <NUM>) is in the closed position when the connector (<NUM>; <NUM>) is subjected to an axial load to pressurize the fluid in the second chamber (<NUM>) and absorb the load.