US 5,219,372 AGranted

Door accessory with a hydraulic retarding device

OwnerSimpson Leeinventor

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Abstract

A door accessory, such as a door hinge or a door check, includes a hydraulic retarding device for cushioning the closing action of a door. The hydraulic retarding device has a cylinder body which confines a fluid receiving space to receive hydraulic fluid therein. One end of a piston rod extends into the fluid receiving space and has a valve unit provided thereon. The valve unit includes a piston which is formed with perforations and which forms a clearance with the cylinder body and a valve ring which is loosely sleeved on the piston rod. The piston rod is operably associated with the door movement so that the valve ring does not block the perforations on the piston during a door opening action, thereby permitting faster fluid flow inside the fluid receiving space and providing little or no resistance to the movement of the piston rod, and so that the valve ring blocks the perforations on the piston during a door closing action, thereby permitting fluid to flow only through the clearance so as to retard the movement of the piston rod.

Claims15

Dependent claims

A door accessory, comprising:

a hinge pin;
a stationary hinge leaf fixed to said hinge pin and adapted to be fixed to a door frame;
a rotatable hinge leaf rotatably mounted to said hinge pin and adapted to be fixed to a door;
a static gear mounted axially and being stationary relative to said hinge pin;
a torsion spring assembly mounted on said hinge pin and being wound when the door is moved from a closed position to an open position relative to the door frame so as to provide a force for automatically returning the door back to the closed position;
a rod driving unit including:
a gear means meshing with and rotating in a first direction relative to said static gear when the door moves toward the open position and in a second direction when the door moves toward the closed position;
and an upright rack engaging said gear means and moving in a vertical upward direction when said gear means rotates in the first direction and in a vertical downward direction when said gear means rotates in the second direction;
and
a hydraulic retarding device provided below said rod driving unit and including:
a cylinder body confining a fluid receiving space to receive hydraulic fluid therein;
a piston rod having a lower end extending into said fluid receiving space;
a compression spring biasing said piston rod outwardly of said cylinder body;
a piston mounted on said piston rod inside said cylinder body and being formed with perforations, said piston forming a clearance with said cylinder body;
and a valve ring loosely sleeved on said piston rod below said piston;
said compression spring expanding to move said piston rod upward so that said hydraulic fluid flows through said clearance and through said perforations to separate said valve ring from said piston when said upright rack moves in the upward direction and ceases to apply a downward pushing force on said piston rod;
movement of said upright rack in the downward direction causing said upright rack to contact and apply a downward pushing force on said piston rod, thereby causing said piston to move downward and said valve ring to block said perforations to permit said hydraulic fluid to flow only through said clearance to retard downward movement of said piston rod.

14 more elements

A door accessory, comprising:

a hinge pin;
a stationary hinge leaf fixed to said hinge pin and adapted to be fixed to a door frame;
a rotatable hinge leaf rotatably mounted to said hinge pin and adapted to be fixed to a door;
a static gear mounted axially and being stationary relative to said hinge pin;
a torsion spring assembly mounted on said hinge pin and being wound when the door is moved from a closed position to an open position relative to the door frame so as to provide a force for automatically returning the door back to the closed position;
a rod driving unit including:
a gear means meshing with and rotating in a first direction relative to said static gear when the door moves toward the open position and in a second direction when the door moves toward the closed position;
a sheave rotated by said gear means;
and a cable having one end connected to said sheave;
and
a hydraulic retarding device provided below said rod driving unit and including:
a cylinder body confining a
fluid receiving space to receive hydraulic fluid therein;
a piston rod having a lower end extending into said fluid receiving space and an upper end connected to the other end of said cable;
a compression spring biasing said piston rod inwardly into said cylinder body;
a piston mounted on said piston rod inside said cylinder body and being formed with perforations, said piston forming a clearance with said cylinder body;
and a valve ring loosely sleeved on said piston rod above said piston;
rotation of said gear means in the first direction causing said cable to unwind from said sheave and further causing said compression spring to expand and move said piston rod downward so that said hydraulic fluid flows through said clearance and through said perforations to separate said valve ring from said piston;
rotation of said gear means in the second direction causing said cable to wind on said sheave and further causing said piston rod to move upward, thereby causing said piston to move upward and said valve ring to block said perforations to permit said hydraulic fluid to flow only through said clearance so as to retard upward movement of said piston rod.

16 more elements

Dependencies are inferred from the claim text.