Description

FREE HINGE FOR OPENING AND CLOSING DOOR

Technical Field

[1] The present invention relates to a free hinge for opening and closing a door, and more particularly to a free hinge for opening and closing a door, in which the elastic force of each spring more positively acts on the door, to which a spring type free hinge is installed, the moment the door is finally closed, thereby causing the door to be completely closed. Background Art

[2] In general, a door hinge is classified into a manual hinge causing a door to be manually operated, and a free hinge forcing an opened door to be automatically closed by means of a spring, a hydraulic mechanism, or their combination.

[3] Such a free hinge is designed to maintain constant force by means of hydraulic pressure or spring's elasticity after the door is opened, thereby allowing the door to be slowly closed.

[4] However, friction between the door and its framework increases just before the door is nearly closed, and thus the elasticity or hydraulic pressure of the free hinge is relatively lowered step by step. Hence, the door is not completely closed, and that very often.

[5] To cope with this drawback, the elasticity or hydraulic pressure of the free hinge is increased so as to allow the door to operate with the greater force when the door is closed. For this reason, the long-term use of the door accumulates stress to the free hinge. As a result, the free hinge is shortened in lifetime. In addition, due to rapid closure of the door, it is difficult to obtain a desired safe closure speed of the door.

[6] Above all, in the spring type free hinge, these problems become more serious.

Furthermore, the door having the spring type free hinge gives inconvenience of use to the weak such as an old person and a child, and even causes an injury accident. Disclosure of Invention Technical Problem

[7] Accordingly, the present invention has been made to solve these problems occurring in the prior art, and an objective of the present invention is to provide a free hinge for opening and closing a door, in which an opened door moves at a safe speed which a user wants when being closed, and the elastic force of each spring efficiently acts on the door the moment the door is finally closed, so that the door is completely closed to improve reliability of a product.

Technical Solution

[8] In order to accomplish this objective, there is provided a free hinge for opening and closing a door. The free hinge includes: a shaft assembly installed in an upper housing and protruding downwardly through the center of a lower fixture fixed to an upper portion of a lower housing so as to rotate; a rotation cap cooperatively coupled to the protruded lower end of the shaft assembly, and formed with an operation space having a catch step on an inner circumferential surface thereof; an actuator fixed to the lower housing under the rotation cap, coupling an eccentric cam located in the operation space on an upper surface thereof, and formed with an cutaway space cut out by a rotation angle; and a torsion spring installed in the lower housing, and having an upper end coupled to the eccentric cam of the actuator. Advantageous Effects

[9] According to the present invention, the free hinge for opening/closing a door includes: upper and lower housings 110 provided with right and left plates 111 for coupling the door 1 and its framework; a shaft assembly 120 inserting a main shaft 121 in the upper housing 110, coupling a auxiliary shaft 125 to a lower end of the main shaft 121, and interposing a compression spring 124 between the main shaft 121 and auxiliary shaft 125 to allow the shaft assembly 120 to resiliently move up and down; an elastic module 130 inserting a torsion spring 131 around an outer circumferential surface of the shaft assembly 120 to fix upper and lower ends of the torsion spring 131, wherein the lower end of the torsion spring 131 is fixed to a lower fixture 132 having a center through-hole 133; a first elasticity adjustor 140 rotatably coupled to an upper side of the shaft assembly 120 and coupled with the torsion spring 131 of the elastic module 130; a rotation cap 150 cooperatively coupled to the lower end of the shaft assembly 120 passing through the lower fixture 132 of the elastic module 130, and formed with an operation space 152 having a catch step 153 on an inner circumferential surface thereof; an actuator 160 fixed to the lower housing 110 under the rotation cap 150, coupling the eccentric cam 163 on an upper surface thereof, and formed with an cutaway space 162; a torsion spring 170 having an upper end coupled to the eccentric cam 163 of the actuator 160 and a lower end coupled; a second elasticity adjustor 180 coupled with the lower end of the torsion spring 170; and upper and lower closure caps 190 coupled to the first and second elasticity adjustors 140 and 180, and fixed to the upper and lower housings. With this construction, the opened door moves at a safe speed which a user wants when being closed. Further, the restoration force of each torsion spring efficiently acts on the door the moment the door is finally closed, so that the door is completely closed. Thus, reliability of the product can be improved. Brief Description of the Drawings

[10] The above and other objectives, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[11] FIG. 1 is a sectional view illustrating a free hinge for opening and closing a door according to the present invention;

[12] FIG. 2 is an exploded perspective view illustrating a free hinge for opening and closing a door according to the present invention;

[13] FIG. 3 is a partially exploded perspective view illustrating a free hinge for opening and closing a door according to the present invention; and

[14] FIG. 4 is a sectional view for explaining an operation state of a free hinge for opening and closing a door according to the present invention, wherein:

[15] FIG. 4A is for explaining an opened state;

[16] FIG. 4B is for explaining an operation state just before the door is closed; and

[17] FIG. 4C is for explaining a closed state.

Best Mode for Carrying Out the Invention

[18] Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention unclear.

[19] FIG. 1 is a sectional view illustrating a free hinge for opening and closing a door according to the present invention, FIG. 2 is an exploded perspective view illustrating a free hinge for opening and closing a door according to the present invention, FIG. 3 is a partially exploded perspective view illustrating a free hinge for opening and closing a door according to the present invention, and FIG. 4 is a sectional view for explaining an operation state of a free hinge for opening and closing a door according to the present invention, wherein FIG. 4A is for explaining an opened state, FIG. 4B is for explaining an operation state just before the door is closed, and FIG. 4C is for explaining a closed state.

[20] As illustrated in FIGS. 1 through 4, the free hinge 100 for opening and closing a door according to the present invention is comprised of: upper and lower housings 110 provided with right and left plates 111 for coupling the door 1 and its framework; a shaft assembly 120 inserting a main shaft 121 in the upper housing 110, coupling a auxiliary shaft 125 to a lower end of the main shaft 121, and interposing a compression spring 124 between the main shaft 121 and auxiliary shaft 125 to allow the shaft assembly 120 to resiliently move up and down; an elastic module 130 inserting a torsion spring 131 around an outer circumferential surface of the shaft assembly 120 to fix upper and lower ends of the torsion spring 131, wherein the lower end of the

torsion spring 131 is fixed to a lower fixture 132 having a center through-hole 133; a first elasticity adjustor 140 rotatably coupled to an upper side of the shaft assembly 120 and coupled with the torsion spring 131 of the elastic module 130; a rotation cap 150 cooperatively coupled to the lower end of the shaft assembly 120 passing through the lower fixture 132 of the elastic module 130, and formed with an operation space 152 having a catch step 153 on an inner circumferential surface thereof; an actuator 160 fixed to the lower housing 110 under the rotation cap 150, coupling the eccentric cam 163 on an upper surface thereof, and formed with an cutaway space 162; a torsion spring 170 having an upper end coupled to the eccentric cam 163 of the actuator 160 and a lower end coupled; a second elasticity adjustor 180 coupled with the lower end of the torsion spring 170; and upper and lower closure caps 190 coupled to the first and second elasticity adjustors 140 and 180, and fixed to the upper and lower housings.

[21] In the shaft assembly 120, the main shaft 121 has a key hole 122 upwardly formed at a lower end thereof, and the auxiliary shaft 125 has a key 126 formed at an upper end thereof. The key 126 of the auxiliary shaft 125 is jointed into the key hole 122 of the main shaft 121. The compression spring 124 is inserted into the key hole 122 and compressed by the key 126, so that the main shaft 121 is installed so as to resiliently move up and down.

[22] Further, an upper portion 123 of the main shaft 121 and a lower portion 127 of the auxiliary shaft 125 are preferably formed with splines on their outer circumferential surfaces.

[23] In the elastic module 130, the lower fixture 132, to which the torsion spring 131 is fixed, is fixed at an upper side of the lower housing 110. The center through-hole 133 of the lower fixture 132 has an inner diameter larger than an outer diameter of the splined upper portion 127 of the auxiliary shaft 125, so that the auxiliary shaft 125 passing through the center through-hole 133 is smoothly rotated.

[24] The first elasticity adjustor 140, in which a bore is vertically drilled, is formed with a boss 141 at a lower side thereof, a key hole 142 at an upper side thereof, and a clutch toothing 143 at an upper end thereof.

[25] The rotation cap 150 is preferably provided at an upper portion thereof with a boss

151, into which the splined upper portion 127 of the auxiliary shaft 125, which passes through the lower fixture 132 of the elastic module 130, is fitted and fixed, so as to cooperate with the shaft assembly 120.

[26] The actuator 160 is fixed to an upper side of the lower housing 110 by means of a fixing pin 161, and rotatably fixes the eccentric cam 163 to one side of an upper surface thereof by means of a rotation pin 164.

[27] Here, the eccentric cam 163 is so coupled that its rotation can cause its distal end to be firmly caught by a catch step 153 within the operation space 152 of the rotation cap

[28] Moreover, the cutaway space 162 of the actuator 160 is preferably formed so that an upper end of the torsion spring 170, which is fixed to the eccentric cam 163, moves up to an angle slightly larger than the maximum rotation angle of the door 1.

[29] The second elasticity adjustor 180 is formed with a key hole 181 at an upper central portion thereof in a vertical direction, and a clutch toothing 182 at a lower end thereof.

[30] The upper and lower closure caps 190 are formed with clutch toothings 193, which correspond to the clutch toothings 143 and 182 of the first and second elasticity adjustors 140 and 180, and with through-holes 191 having inner diameter greater than those of the key holes 142 and 181 of the first and second elasticity adjustors 140 and 180. The upper and lower closure caps 190 are coupled and fixed to the upper and lower housings 110 by means of fixing pins 192, respectively.

[31] The operation of the present invention will be described below.

[32] When the door 1 is opened, the torsion springs 131 and 170 are wound in the same direction as the opened direction, and thus the door 1 is opened at a predetermined angle.

[33] At this time, the lower housing 110 is fixed, while the upper housing 110 rotates as the door 1 is opened. Thus, the shaft assembly 120 rotates, and at the same time, the torsion spring 131 is rotated and wound.

[34] Further, the rotation of the shaft assembly 120 causes the rotation cap 150, which is coupled with the splined lower portion of the shaft assembly 120, to rotate in the lower housing 110 at the same time.

[35] In this manner, when the rotation cap 150 rotates, the eccentric cam 163 of the actuator 160 fixed to the lower housing 110 is pushed to move away from the catch st ep 153. As a result, the eccentric cam 163 rotates to a certain degree along an inner circumferential surface of the rotation cap 150.

[36] Therefore, the torsion spring 170, the upper end of which is fixed to the eccentric cam 163, is rotated and wound to a certain degree.

[37] In this state, when the door 1 gets free, the wound torsion springs 131 and 170 are restored. Thereby, the door 1 returns in situ and is closed.

[38] Here, when the torsion springs 131 and 170 are restored, restoration force of the torsion spring 131 in the upper housing 110 is directly transmitted to the door, while restoration force of the torsion spring 170 in the lower housing 110 is indirectly transmitted from the eccentric cam 163 through the inner circumferential surface of the rotation cap 150 to the door. As a result, the door 1 is slowly closed.

[39] Just before the door 1 closed, the eccentric cam 163 is located within the operation space 152 of the rotation cap 150, and simultaneously caught by the catch step 153, so that the restoration force of the torsion spring 170 is directly transmitted to the rotation

cap 150. At this time, the restoration force of the torsion spring 170 is momentarily accumulated, which allows the door 1 to be completely closed.

[40] Meanwhile, the torsion springs 131 and 170 press and push down the first and second elasticity adjustors 140 and 180 through the through-holes 191 of the closure caps 190, so that the clutch toothings 143 and 182 are released from the clutch toothings 193. At this time, the first and second elasticity adjustors 140 and 180 are forwardly or backwardly rotated to wind or unwind the torsion springs 131 and 170, so that the torsion springs 131 and 170 are adjusted in elasticity. Therefore, the restoration force required to close the door 1 can be readily obtained. Industrial Applicability

[41] As described above, according to the present invention, the free hinge for opening/ closing a door includes: upper and lower housings 110 provided with right and left plates 111 for coupling the door 1 and its framework; a shaft assembly 120 inserting a main shaft 121 in the upper housing 110, coupling a auxiliary shaft 125 to a lower end of the main shaft 121, and interposing a compression spring 124 between the main shaft 121 and auxiliary shaft 125 to allow the shaft assembly 120 to resiliently move up and down; an elastic module 130 inserting a torsion spring 131 around an outer circumferential surface of the shaft assembly 120 to fix upper and lower ends of the torsion spring 131, wherein the lower end of the torsion spring 131 is fixed to a lower fixture 132 having a center through-hole 133; a first elasticity adjustor 140 rotatably coupled to an upper side of the shaft assembly 120 and coupled with the torsion spring 131 of the elastic module 130; a rotation cap 150 cooperatively coupled to the lower end of the shaft assembly 120 passing through the lower fixture 132 of the elastic module 130, and formed with an operation space 152 having a catch step 153 on an inner circumferential surface thereof; an actuator 160 fixed to the lower housing 110 under the rotation cap 150, coupling the eccentric cam 163 on an upper surface thereof, and formed with an cutaway space 162; a torsion spring 170 having an upper end coupled to the eccentric cam 163 of the actuator 160 and a lower end coupled; a second elasticity adjustor 180 coupled with the lower end of the torsion spring 170; and upper and lower closure caps 190 coupled to the first and second elasticity adjustors 140 and 180, and fixed to the upper and lower housings. With this construction, the opened door moves at a safe speed which a user wants when being closed. Further, the restoration force of each torsion spring efficiently acts on the door the moment the door is finally closed, so that the door is completely closed. Thus, reliability of the product can be improved.

[42] Although exemplary embodiments of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications,

additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.