Door closer for left-hand side openable door and right-hand side openable door

Abstract

 A door closer (10) includes a housing (20) having a longitudinal chamber (22) and a through hole (26) in communication with the longitudinal chamber (22). A spring member (30) is mounted in the longitudinal chamber (22) inside the housing (20). A piston rod (40) is mounted in the longitudinal chamber (22) inside the housing (20), stopped against the spring member (30) and provided with an elongated slot (42) and two racks (44, 46) in the elongated slot (42) at two opposite sides. A transmission shaft (50) is rotatably mounted in the through hole (26) of the housing (20) and provided with a transmission gear portion (54) alternatively engaged with one of the two racks (44, 46).

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention relates generally to a door closer in which a rebound force is accumulated in a door closing direction and a damping force is provided in a door opening direction at the time of opening a door and more particularly, to a door closer, which can be driven by a left-hand side openable door as well as a right-hand side openable door.

2. Description of the Related Art

[0002] In order to buffer the closing action of a door after it has been opened, a door closer is commonly used.

[0003] A conventional door closer generally comprises an elongated housing affixed to the door panel, a piston rod slidably mounted in the housing, a spring member mounted in the housing and stopped between one end of the piston rod and one end of the housing, a rack fixedly provided at the periphery of the piston rod, and a transmission shaft perpendicularly and rotatably inserted into the housing and having a transmission gear meshed with the rack at the piston rod, and a link coupled between one end of the transmission shaft outside the housing and a sliding way in the door frame. When the door panel is opened, the link is moved to rotate the transmission shaft to cause the transmission gear to move the rack and the piston rod, such that a rebound force provided by the spring is accumulated in a door closing direction and a damping force will be provided when the door panel is closed, i.e. when the transmission shaft is reversely rotated by the reversed motion of the piston rod.

[0004] Further, a door may be built for swinging in left-hand side or right-hand side. Since the rack of the piston rod of the aforesaid door closer is designed to match the transmission gear, the engagement arrangement between the rack at the piston rod and the transmission gear is generally designed subject to the swinging direction of the door. The engagement arrangement between the rack at the piston rod and the transmission gear for a left-hand side openable door is reversed to the engagement arrangement between the rack at the piston rod and the transmission gear for a right-hand side openable door. During installation of a door closer, the user must make sure that the engagement arrangement between the rack at the piston rod and the transmission gear fits the swinging direction of the door. An installation mistake results in functional failure of the door closer. If the installation mistake is not founded, the door or the door closer may be damaged as the door is opened. Because of the aforesaid drawback, a conventional door closer is not convenient in use.

SUMMARY OF THE INVENTION

[0005] The present invention has been accomplished in view of the above-noted circumstances. It is therefore one objective of the present invention to provide a door closer, which can be used with/driven by a left-hand side openable door as well as a right-hand side openable door.

[0006] To achieve this objective of the present invention, the door closer comprises a housing having a longitudinal chamber and a through hole in communication with the longitudinal chamber. A spring member is mounted in the longitudinal chamber inside the housing. A piston rod is mounted in the longitudinal chamber inside the housing and stopped against the spring member. The piston rod has an elongated slot and two racks in the elongated slot at two opposite sides. A transmission shaft is rotatably mounted in the through hole of the housing and provided with a transmission gear portion alternatively engaged with one of the two racks.

[0007] In a preferred embodiment of the present invention, the transmission shaft has a shaft body rotatably inserted into the elongated slot of the piston rod. The transmission gear portion extends partially around a periphery of the shaft body in a semicircular manner. Therefore, when the transmission gear portion engages one of the racks, it is disengaged from the other. As a result, the door closer provided by the present invention can be used with a left-hand side openable door as well as a right-hand side openable door, so that the user needs not to worry about the door open direction matching problem during installation of the door closer of the present invention.

[0008] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

FIG 1 is an exploded view of a door closer in accordance with a preferred embodiment of the present invention;

FIG 2 is a sectional assembly view of the door closer in accordance with the preferred embodiment of the present invention;

FIG. 3 a schematic drawing showing that the door closer according to the preferred embodiment of the present invention is installed in a left-hand side openable door panel;

FIG 4 is a sectional view of the preferred embodiment of the present invention, showing the transmission gear portion of the transmission shaft in engagement with the first rack of the piston rod;

FIG 5 is a schematic drawing showing that the door closer according to the preferred embodiment of the present invention is installed in a right-hand side openable door panel, and

FIG 6 is a sectional view of the preferred embodiment of the present invention, showing the transmission gear portion of the transmission shaft in engagement with the second rack of the piston rod.

DETAILED DESCRIPTION OF THE INVENTION

[0010] As shown in FIGS. 1 and 2, a door closer 10 in accordance with a preferred embodiment of the present invention comprises a housing 20, a spring member 30, a piston rod 40, a transmission shaft 50, a first adjustment valve 60a, and a second adjustment valve 60b.

[0011] The housing 20 is used for installing in a door panel. The housing 20 has a longitudinal chamber 22 extending through the two opposite ends thereof, two sealing caps 24 that seal the two ends of the longitudinal chamber 22 after filling of a hydraulic fluid in the longitudinal chamber 22, and a through hole 26 with internal thread perpendicularly extending from the longitudinal chamber 22 at the top.

[0012] The spring member 30 is mounted in the longitudinal chamber 22 inside the housing 20 and stopped with its one end against one end edge of the housing 20.

[0013] The piston rod 40 is slidably mounted in the longitudinal chamber 22 inside the housing 20 and stopped against the other end of the spring member 30. The piston rod 40 has an elongated slot 42, a first rack 44 in the elongated slot 42 at one side, and a second rack 46 in the elongated slot 42 at the opposite side.

[0014] The transmission shaft 50 has a shaft body 52 and a transmission gear portion 54 at the shaft body 52. The shaft body 52 is inserted into the through hole 26 of the housing 20 into the elongated slot 42 of the piston rod 40 and provided with a rectangular top connection portion 522 connected to one end of a link 70, as shown in FIG 3, which has its opposite end slidably coupled to a door frame. By means of the connection of the link 70 with the rectangular top connection portion 522 of the transmission shaft 50, the link 70 can drive the transmission shaft 50 to rotate. The transmission gear portion 54 is fixedly mounted on the shaft body 52 and extending partially around the periphery of the shaft body 52 in an arched manner. According to the present preferred embodiment, the transmission gear portion 54 shows a semicircular shape. By means of rotating the shaft body 52, the transmission gear portion 54 is forced into engagement with the first rack 44 or the second rack 46.

[0015] The first adjustment valve 60a is mounted in the top side of the housing 20 in communication with the longitudinal chamber 22 for adjusting the pressure of the hydraulic fluid in the housing 20 to buffer the thrust force of the spring member 30 against the piston rod 40. According to the present preferred embodiment, the first adjustment valve 60a is adapted to control the speed of the closing action of the door panel from 90° through 15°.

[0016] The second adjustment valve 60b is mounted in the top side of the housing 20 in communication with the longitudinal chamber 22 for adjusting the pressure of the hydraulic fluid in the housing 20 to buffer the thrust force of the spring member 30 against the piston rod 40. According to the present preferred embodiment, the second adjustment valve 60b is adapted to control the speed of the closing action of the door panel from 15° through 0°.

[0017] FIG 3 shows the door closer 10 installed in a left-hand side openable door panel 80. When opening the door panel 80, the link 70 drives the shaft body 52 to rotate, forcing the transmission gear portion 54 to engage the first rack 44 (see FIG 4) and to further move the piston rod 40 against the spring member 30, so that a rebound force is accumulated in a door panel closing direction for automatically closing the door panel 80 when the external force acting on the door panel 80 for opening the door panel 80 is released from the door panel 80.

[0018] FIG 5 shows the door closer 10 installed in a right-hand side openable door panel 90. When opening the door panel 90, the link 70 drives the shaft body 52 to rotate, forcing the transmission gear portion 54 to engage the second rack 46 (see FIG. 6) and to further move the piston rod 40 against the spring member 30. As shown in FIG 6, the transmission gear portion 54 extends around the periphery of the shaft body 52 in a semicircular manner. When the transmission gear portion 54 engages the first rack 44, it is disengaged from the second rack 46. On the contrary, when the transmission gear portion 54 engages the second rack 46, it is disengaged from the first rack 44. Therefore, when the transmission gear portion 54 engages one rack 44 or 46, the other rack 46 or 44 does not interfere with the rotation of the transmission gear portion 54.

[0019] By means of the aforesaid features, the door closer 10 can be selectively used in a left-hand side openable door or right-hand side openable door as desired.

[0020] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims

1. A door closer (10), characterized in that the door closer (10) comprises:

a housing (20) having a longitudinal chamber (22) and a through hole (26) in communication with the longitudinal chamber (22);

a spring member (30) mounted in the longitudinal chamber (22) of the housing (20);

a piston rod (40) mounted in the longitudinal chamber (22) of the housing (20) and stopped against the spring member (30), the piston rod (40) having an elongated slot (42) and two racks (44, 46) in the elongated slot (42) at two opposite sides; and

a transmission shaft (50) rotatably mounted in the through hole (26) of the housing (20), the transmission shaft (50) having a transmission gear portion (54) alternatively engaged with one of the two racks (44, 46).

2. The door closer (10) as claimed in claim 1, characterized in that the transmission shaft (50) comprises a shaft body (52) inserted into the elongated slot (42) of the piston rod (40); the transmission gear portion (54) extends partially around a periphery of the shaft body (52) in an arched manner.

3. The door closer (10) as claimed in claim 2, characterized in that the transmission gear portion (54) has a semicircular shape extending partially around the periphery of the shaft body (52).

Drawing