Hydraulic door closer capable of reducing oil-pressure therein in high temperature

Abstract

A hydraulic door closer capable of reducing oil-pressure therein at high temperature, comprises a housing with an oil chamber, an oil storage cavity, and a piston in the housing of the hydraulic door closer. The oil storage cavity is in communication with the oil chamber; when the oil temperature increases, hydraulic oil in the oil chamber and oil storage cavity generates an increased oil pressure move the piston, whereby volume of the oil storage cavity is enlarged, such that oil from the chamber will flow into the cavity, to reduce the oil pressure of the chamber and cavity. When the oil temperature decreases, the oil pressure in the chamber and cavity is reduced, whereby the storage piston restores its original position, whereby volume of the cavity will be reduced, and the oil in the cavity flows back into the chamber. The pressure in the oil chamber is reduced when the hydraulic oil expands due to increased temperature to prevent failure of the seal and to avoid hydraulic oil leakage.

Claims

1. A hydraulic door closer mounted between a door and a door frame, comprising: a housing; a fluid compartment in the housing for holding hydraulic fluid and having a variable volume; the fluid compartment including first, second and third cavities; the hydraulic fluid pressure changing in response to ambient temperature changes; a piston slidably mounted in the compartment and adapted to move within the compartment in response to changes in the ambient temperature and resulting hydraulic fluid pressure changes in the compartment; and the hydraulic fluid residing only on one side of the piston during operation of the door closer.

2. The hydraulic door closer of claim 1 wherein the piston moves in one direction in response to increased fluid pressure thereby increasing the volume of the compartment and moves in a opposite direction in response to decreased fluid pressure thereby reducing the volume of the compartment.

3. The hydraulic door closer of claim 1 wherein the first, second and third cavities have increasing volumes.

4. The hydraulic door closer of claim 1 wherein the first, second and third cavities have successively increasing diameters.

5. The hydraulic door closer of claim 1 wherein the piston is mounted in the third cavity.

6. The hydraulic door closer of claim 1 further comprising a spring in the compartment to bias the piston to a first position.

7. The hydraulic door closer of claim 6 wherein the piston moves to a second position when the fluid pressure compresses the spring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram illustrating an embodiment where a hydraulic door closer of the present invention is used.

(2) FIG. 2 is a schematic diagram of the hydraulic door closer of the present invention.

(3) FIG. 3 is an exploded view of the hydraulic door closer components of the present invention.

(4) FIG. 4 is a sectional view of the hydraulic door closer of the present invention when the oil temperature increases.

(5) FIG. 5 is an enlarged view of portion 5-5 of FIG. 4.

(6) FIG. 6 is a sectional view of the hydraulic door closer of the present invention when the oil temperature decreases.

(7) FIG. 7 is an enlarged view of portion 7-7 of FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(8) The present invention will be described hereinafter in details with reference to the FIGS. 1-7.

(9) As shown in FIG. 1, a hydraulic door closer 100 of the present invention capable of reducing oil-pressure therein at high temperature is mounted on the top of the door 300. The hydraulic door closer 100 includes a driving member connected to a transmission mechanism 400, which is connected to a slider mounted in the door frame 200.

(10) When opening the door 300, the transmission mechanism 400 is driven to move under the movement of the door 300.

(11) When the external force to the door 300 disappears, the transmission mechanism 400 is driven to move with the effect of the driving member, whereby the door 300 will be closed. The transmission mechanism 400, preferably, is in the form of a transmission rod. It should be noted that, without inducing any understanding problem, the driving member in the inside of the hydraulic door closer 100 and the slider configured on the door frame are not shown in FIG. 1.

(12) It should be noted that it is just a preferable embodiment to arrange the hydraulic door closer 100 on the top of the door 300 and the door frame 200 in the present invention, instead of a restriction for the position of hydraulic door closer 100 of the present invention. Thus, the door closer 100 may also be mounted at the bottom of the door 300 and the door frame 200.

(13) As shown in the figures, the hydraulic door closer 100 of the present invention comprises a housing 110 and an oil chamber 130 configured therein. One end of the transmission mechanism 400 is received in the housing 110, and the other end is connected to the door frame 200. The driving member is configured in the housing 110. It should be noted that without inducing any understanding problem, the connection between the transmission mechanism 400, the driving member and the hydraulic door closer 100 of the present invention is not shown in the figures.

(14) An oil storage cavity 140, configured with an oil storage apparatus 120, is provided in the housing 110. The oil storage cavity 140 is in communication with the oil chamber 130 and they are filled fully with hydraulic oil.

(15) As shown in FIGS. 5 and 7, the storage cavity 140 comprises a first oil storage cavity 141 in communication with the oil chamber 130, a second oil storage cavity 142 in communication with the first oil storage cavity 141, and a third oil storage cavity 143 in communication with the second oil storage cavity 142. The first oil storage cavity 141 has a diameter smaller than the diameter of the second oil storage cavity 142, and the second oil storage cavity 142 has diameter smaller than the diameter of the third oil storage cavity 143. The second oil storage cavity 142 and the third oil storage cavity 143 form a step in their junction.

(16) The oil storage apparatus 120 is configured in the third oil storage cavity 143, and comprises a piston 121 in airtight connection with the third oil storage cavity 143 of the oil storage cavity 140, and a blocker or plug 122 threadably-connected to the oil storage cavity 140, specifically to the third oil storage cavity 143. A spring 123 is configured between the piston 121 and the plug 122. One end of the spring 123 is sleeved on the piston 121, and the other end is connected to the plug 122.

(17) The piston 121 comprises a piston body configured with a first convex ring 1211 and a second convex ring 1212 (FIG. 3) having the same diameter, which is smaller than the diameter of the oil storage cavity 140, specifically the diameter of the second oil storage cavity 141. A seal ring 124 is provided in a groove formed between the first convex ring 1211 and the second convex ring 1212.

(18) When the oil temperature is normal, the oil chamber 130, the first oil storage cavity 141 and the second oil storage cavity 142 are all filled fully with hydraulic oil, and the spring 123 of the oil storage apparatus 120 is in a natural state, while the piston 121 of the oil storage apparatus 120 bears against the step formed by the second and third oil storage cavities.

(19) As shown in FIGS. 4 and 5, when the oil temperature increases, the hydraulic oil in the oil chamber 130 and oil storage cavity 140 expands and generates an increased oil pressure to squeeze and compress the oil storage apparatus 120, whereby the storage volume of the oil storage cavity 140 will be enlarged. As seen from arrows shown in FIGS. 4 and 5, the hydraulic oil from the oil chamber 130 will flow into the oil storage cavity 140, to reduce the oil pressure of hydraulic oil in the oil chamber 130 and oil storage cavity 140. Specifically, the spring 123 is compressed, the oil storage apparatus 120 moves rightwards to make more volume of the third oil storage cavity available, which results in the flow of hydraulic oil into the third oil storage cavity under effect of oil pressure.

(20) As shown in FIGS. 6 and 7, when the oil temperature decreases, the oil pressure of the hydraulic oil in the oil chamber 130 and oil storage cavity 140 is reduced, whereby the oil storage apparatus 120 restores its original position before compression, and whereby the oil storage volume of the oil storage cavity 140 will be reduced. As seen from arrows shown in FIGS. 6 and 7, the hydraulic oil in the oil storage cavity 140 flows back into the oil chamber 130. Specifically, the spring of the oil storage apparatus 120 restores to its original position before compression, the hydraulic oil will be expelled out by the oil storage apparatus 120 from the third oil storage cavity 143 into the oil chamber 130 through the second and first oil storage cavities.

(21) The present invention provides a hydraulic door closer capable of reducing oil-pressure therein at high temperature, wherein an oil storage cavity, configured with an oil storage apparatus, is provided in the housing of the hydraulic door closer, thereby the oil pressure in the oil chamber will be reduced effectively when the hydraulic oil expands due to increased temperature. The door closer prevents the sealing element from being squeezed and destroyed, avoids the situation that the hydraulic oil may leak, the door closer may be destroyed even possible, and people will be bumped while closing the door, etc.

(22) The embodiments described hereinbefore are merely preferred examples of the present invention, without any form of restriction for the present invention. So contents without departing from the technical solution of the present invention, any simple changes, equivalent variation and modifications based on the technical essence of the present invention fall into the protection scope of the present invention.