Description

FREE HINGE FOR OPENING AND CLOSING DOOR

Technical Field

[1] The present invention relates, in general, to free hinges for opening and closing doors and, more particularly, to a free hinge for opening and closing a door which has a spring type free hinge structure such that the door, which has been opened, can be smoothly and stably closed, and such that at the final moment of closing the door, a force for closing the door is effectively applied to the door, thus perfectly completing the operation of closing the door. Background Art

[2] Generally, door hinges are classified into a manual hinge, which requires a door to be manually operated, and a free hinge, which automatically closes an open door by means of a spring, a hydraulic mechanism, or a combination thereof.

[3] Typically, such a conventional free hinge is constructed such that the door is closed by the elastic force of the spring after the door is opened. At this time, the elastic force of the spring remains constant due to hydraulic pressure, thus allowing the door to be slowly closed.

[4] In the conventional spring type free hinge, when the door is opened, the spring installed in the hinge is wound. When the door is released, the spring, having been wound, is released to its original state, which closes the door.

[5] Particularly, when the door is closed by the elastic force of the spring after it is opened, the elastic force of the spring is maintained constant using hydraulic pressure, thus allowing the door to be slowly closed.

[6] However, the conventional free hinge is relatively expensive because a hydraulic device is incorporated therein. If the free hinge is designed such that it comprises no hydraulic device and the door is thus closed only by the force of the spring, because the elastic force of the spring is directly applied to the door, the door is abruptly closed, thus increasing the risk of an accident.

[7] Furthermore, the hydraulic device must be very elaborate, and must be airtight. In addition, there is a likelihood of malfunction attributable to the leakage of hydraulic pressure after use for a long period, thus reducing the lifetime of the free hinge, and increasing the maintenance costs thereof.

[8] As well, just before the door is finally closed, resistance is increased by friction between the door and a door frame. Thereby, the effective elastic force of the spring and the hydraulic pressure are relatively reduced, with the result that the door may be incompletely closed.

[9] To avoid this disadvantage, in the case where the hydraulic pressure and the elastic force of the spring are increased such that the door is actuated by a relatively strong force when it closes, there is a problem in that stress is accumulated in the free hinge during use for a long period, so that the lifetime of the free hinge is reduced, and the door is closed too rapidly, that is, it cannot be closed at a safe speed.

[10] Particularly, in the case of the conventional spring type free hinge, this problem becomes more acute, and, as well, due to the increased speed at which the door is closed, it is inconvenient for the old and the weak to use, and safety hazards may result.

Disclosure of Invention Technical Problem

[11] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a free hinge for opening and closing a door which is constructed such that the door, which has been opened, can be closed at a safe speed desired by a user using only a mechanical structure, without additionally requiring a hydraulic device, thus minimizing the cost of the free hinge, and ensuring superior quality despite the relatively low cost.

[12] Another object of the present invention is to provide a free hinge for opening and closing a door which is constructed such that the door, which has been opened, can be closed at a safe speed desired by a user, and, such that at the final moment of closing the door, the elastic force of a spring is effectively applied to the door, thus perfectly completing the operation of closing the door, thereby enhancing the reliability of the product. Technical Solution

[13] In order to accomplish the above objects, the present invention provides a free hinge for opening and closing a door which is coupled to a door frame and the door and is constructed such that the door, which has been opened, is automatically closed by the elastic force of a torsion spring, wherein, when the door is closed by the release of the torsion spring from the wound state, the rotational motion of the torsion spring is converted into vertical linear motion and the motion of the torsion spring is damped by a shock absorption member, so that the torsion spring is prevented from being abruptly actuated, thus making it possible to close the door slowly, and, just before the door is finally closed, the shock absorbing operation of the shock absorption member is momentarily converted into an expansion operation, so that the door can be completely closed.

Advantageous Effects

[14] A free hinge for opening and closing a door according to the present invention includes: a coupling unit (110), having coupling plates (11 Ia) and (11 Ib), which are respectively fastened to a door frame and the door to support the door; a rotating housing unit (120), having a main housing (121) and upper and lower housings (124a) and (124b), which are provided between the coupling plates (11 Ia) and (11 Ib) of the coupling unit (110) to allow the coupling plates (11 Ia) and (11 Ib) to rotate with respect to each other; a main elastic unit (130), having a torsion spring (131) installed in the rotating housing unit (120) such that the coupling plates (110) are rotatable based on the rotating housing unit (120) using the elastic force of the torsion spring (131); a vertical actuating unit (140), which is provided below the main elastic unit (130) and has a vertical actuating member (141) which is actuated upwards or downwards depending on the rotation of the coupling plates (11 Ia) and (11 Ib); and a shock absorption unit (150), which is provided below the vertical actuating member (141) of the vertical actuating unit (140), so that the shock absorption member (150) is compressed by downward movement of the vertical actuating member (141). Therefore, the free hinge of the present invention enables the door, which has been opened, to move at a safe speed desired by a user when being closed. Furthermore, in the present invention, at the final moment of closing the door, elastic force of the spring is effectively applied to the door, thus perfectly completing the operation of closing the door, thereby enhancing the reliability of the product. Furthermore, the present invention can smoothly and stably control the door even though hydraulic pressure is not used, thus markedly reducing production costs. Brief Description of the Drawings

[15] Fig. 1 is an exploded perspective view illustrating a free hinge for opening and closing a door according to the present invention;

[16] FIG. 2 is a sectional view illustrating the state of the free hinge when the door is in an opened state according to the present invention;

[17] FIG. 3 is a sectional view illustrating the state of the free hinge just before the door is closed according to the present invention;

[18] FIG. 4 is a sectional view illustrating the state of the free hinge when the door is in a closed state according to the present invention;

[19] FIG. 5 is a displacement diagram of a guide slot to illustrate the operation of the free hinge according to the present invention;

[20] FIG. 6 is an exploded perspective view illustrating a free hinge for opening and closing a door according to the present invention;

[21] FIG. 7 is a sectional view illustrating the state of the free hinge when the door is in an opened state according to the present invention;

[22] FIG. 8 is a sectional view illustrating the state of the free hinge just before the door is closed according to the present invention;

[23] FIG. 9 is a sectional view illustrating the state of the free hinge when the door is in a closed state according to the present invention;

[24] FIG. 10 is an exploded perspective view illustrating a free hinge for opening and closing a door according to the present invention;

[25] FIG. 11 is a sectional view illustrating the state of the free hinge when the door is in an opened state according to the present invention;

[26] FIG. 12 is a sectional view illustrating the state of the free hinge just before the door is closed according to the present invention;

[27] FIG. 13 is a sectional view illustrating the state of the free hinge when the door is in a closed state according to the present invention;

[28] FIG. 14 is a displacement diagram of a cam to illustrate the operation of the free hinge according to the present invention;

[29] FIG. 15 is an exploded perspective view illustrating a free hinge for opening and closing a door according to the present invention;

[30] FIG. 16 is a sectional view illustrating the state of the free hinge when the door is in an opened state according to the present invention;

[31] FIG. 17 is a sectional view illustrating the state of the free hinge just before the door is closed according to the present invention; and

[32] FIG. 18 is a sectional view illustrating the state of the free hinge when the door is in a closed state according to the present invention. Best Mode for Carrying Out the Invention

[33] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[34] Fig. 1 is an exploded perspective view illustrating a free hinge for opening and closing a door according to the present invention. FIG. 2 is a sectional view illustrating the state of the free hinge when the door is in an opened state according to the present invention. FIG. 3 is a sectional view illustrating the state of the free hinge just before the door is closed according to the present invention. FIG. 4 is a sectional view illustrating the state of the free hinge when the door is in a closed state according to the present invention. FIG. 5 is a displacement diagram of a guide slot to illustrate the operation of the free hinge according to the present invention. FIG. 6 is an exploded perspective view illustrating a free hinge for opening and closing a door according to the present invention. FIG. 7 is a sectional view illustrating the state of the free hinge when the door is in an opened state according to the present invention. FIG. 8 is a sectional view illustrating the state of the free hinge just before the door is closed

according to the present invention. FIG. 9 is a sectional view illustrating the state of the free hinge when the door is in a closed state according to the present invention. FIG. 10 is an exploded perspective view illustrating a free hinge for opening and closing a door according to the present invention. FIG. 11 is a sectional view illustrating the state of the free hinge when the door is in an opened state according to the present invention. FIG. 12 is a sectional view illustrating the state of the free hinge just before the door is closed according to the present invention. FIG. 13 is a sectional view illustrating the state of the free hinge when the door is in a closed state according to the present invention. FIG. 14 is a displacement diagram of a cam to illustrate the operation of the free hinge according to the present invention. FIG. 15 is an exploded perspective view illustrating a free hinge for opening and closing a door according to the present invention. FIG. 16 is a sectional view illustrating the state of the free hinge when the door is in an opened state according to the present invention. FIG. 17 is a sectional view illustrating the state of the free hinge just before the door is closed according to the present invention. FIG. 18 is a sectional view illustrating the state of the free hinge when the door is in a closed state according to the present invention.

[35] As shown in FIGS. 1 through 5, the free hinge for opening and closing the door according to the present invention includes a coupling unit 110, which has coupling plates I l ia and 11 Ib, which are respectively fastened to a door frame and the door to support the door, and a rotating housing unit 120, which has a main housing 121 and upper and lower housings 124a and 124b between the coupling plates I l ia and 11 Ib of the coupling unit 110 to allow the coupling plates I l ia and 11 Ib to rotate with respect to each other. The free hinge further includes a main elastic unit 130, which has a torsion spring 131, which is installed in the rotating housing unit 120 such that the coupling plate 110 is rotatable based on the rotating housing unit 120 using the elastic force of the torsion spring 131, and a vertical actuating unit 140, which is provided under the main elastic unit 130 and has a vertical actuating member 141, which is actuated upwards or downwards depending on the rotation of the coupling plates I l ia and 11 Ib. The free hinge further includes a shock absorption unit 150, which is provided under the vertical actuating member 141 of the vertical actuating unit 140 and is compressed by downwards movement of the vertical actuating member 141.

[36] The coupling unit 110 includes the coupling plates I l ia and 11 Ib, which are respectively disposed at left and right positions and have respective fastening holes 112a and 112b. The coupling plates I l ia and 11 Ib are respectively fastened to the door frame and the door using the fastening holes 112a and 112b.

[37] The rotating housing unit 120 includes the main housing 121, which is provided on one edge of the right coupling plate 11 Ib, and the upper and lower housing 124a and 124b, which are provided on one edge of the left coupling plate I l ia and are disposed

above and below the main housing 121. Here, a pin hole 122, into which a setting pin 123 is inserted, is formed through the circumferential outer surface of the main housing 121. Pin holes 125a and 125b, into which setting pins 126a and 126b are inserted, are formed through the circumferential outer surfaces of the upper and lower housings 124a and 124b, respectively.

[38] The main elastic unit 130 includes a support member 136, which is disposed at a medial position in the main housing 121 and is stopped by the setting pin 123, and the torsion spring 131, the lower end of which is fitted into a coupling hole 136c of the support member 136.

[39] Here, a lower clutch 132, which has a coupling hole 132b therein, is disposed above the torsion spring 131, and the upper end of the torsion spring 131 is fitted into the coupling hole 132b. The lower clutch 132 is placed such that the upper end thereof is disposed at the junction between the upper end of the main housing 121 and the lower end of the upper housing 124a.

[40] Furthermore, an upper clutch 133 is provided on the upper end of the lower clutch

132 and is fastened to the upper housing 124a using a setting pin 126a, which is inserted into the pin hole 125a that is formed in the upper housing 124a.

[41] The lower clutch 132 has a shaft 134, which extends downwards from the central portion thereof and is placed through a through hole 136a that is formed through the central portion of the support member 136. A key 134a is provided under the lower end of the shaft 134, which passes through the through hole 136a in the support member 136. An insert hole 133a is formed through the central portion of the upper clutch 133. A key hole 132a, corresponding to the insert hole 133a, is formed in the lower clutch 136.

[42] In addition, a locking hole 136b is formed in the circumferential outer surface of the support member 136, so that the setting pin 123, which is inserted into the pin hole 122 in the main housing 121, is fitted into the locking hole 136b to lock the support member 136.

[43] The torsion spring 131 may be embedded in a shock absorption member 135. In this case, preferably, a through hole 135a is formed through the shock absorption member 135 along the longitudinal axis thereof to prevent interference with the shaft 134.

[44] In the vertical actuating unit 140, a guide member 142 is disposed in the lower housing 124b and the lower end of the main housing 121 and is caught by a setting pin 126b, which is inserted into a pin hole 125b formed through the lower housing 124b. An actuating space 142a is formed in the guide member 142 along the longitudinal axis thereof. A threaded hole 142b is formed in the lower end of the actuating space 142a. A locking hole 142c is formed in the circumferential outer surface of the guide member 142, so that the setting pin 126b, which is inserted into the pin hole 125b in

the lower housing 124b, is fitted into the locking hole 142c to lock the guide member

142. [45] Here, an adjustment screw 144 is inserted upwards into the threaded hole 142b in the actuating space 142a. [46] Furthermore, a guide slot 143 is formed through the circumferential surface of the guide member 142. The guide slot 143 has a first spiral slot 143a, a horizontal slot

143b and a reverse spiral slot 143c, which are contiguous. [47] The vertical actuating member 141 is inserted into the actuating space 142a of the guide member 142. A protrusion pin 141b is provided on the circumferential outer surface of the vertical actuating member 141. The protrusion pin 141b is inserted into the guide slot 143 and is guided by the first spiral slot 143a, the horizontal slot 143b and the reverse spiral slot 143c. [48] Furthermore, a key hole 141a, which extends a predetermined length downwards, is formed in the central portion of the upper end of the vertical actuating member 141.

The key 134a of the shaft 134 is inserted into the key hole 141a, so that the vertical actuating member 141 is rotated in conjunction with the rotation of the shaft 134. [49] Therefore, when the vertical actuating member 141 is rotated, it moves upwards or downwards under the guidance of the protrusion pin 141b, which moves along the first spiral slot 143a, the horizontal slot 143b and the reverse spiral slot 143c. [50] The shock absorption unit 150 includes a shock absorption member 151, and upper and lower covers 152a and 152b, which cover the shock absorption member 151. [51] The shock absorption member 151 is preferably made of elastic rubber, polyester, nonflammable rubber or synthetic resin, but the material thereof is not limited to any special material. [52] The upper and lower covers 152a and 152b must be coupled to each other at a position at which they do not interfere with the compression or expansion of the shock absorption member 151. [53] As shown in FIGS. 6 through 9, it is more preferable that a key 137, which extends a predetermined length downwards, be provided under the lower surface of a support member 136, which is fastened to the main housing 121, and that the key 137 be inserted into the key hole 141a in the vertical actuating member 141, because the elastic force of the torsion spring 131 can be easily adjusted. [54] In this case, the support member 136 has no through hole 136a, and a lower clutch

132 has no shaft 134 provided with the key 134a. [55] Meanwhile, as shown in FIGS. 10 through 14, the free hinge of the present invention may be constructed such that a cam unit 160 is coupled to the lower end of a shaft 134 which passes through a through hole 136a in a support member 136, so that the free hinge is actuated along a cam displacement path.

[56] In this case, the cam unit 160 includes an upper cam 161, which is coupled to the lower end of the shaft 134, and a lower cam 162, which is provided under the upper cam 161. The lower cam 162 has a first inclined surface 162a, a horizontal surface 162b, and a reverse inclined surface 162c, which are continuously formed.

[57] Furthermore, preferably, a compression rod 163 extends from the central portion of the lower surface of the lower cam 162 downwards. The lower end of the compression rod 163 is inserted into an actuating space 142a of a guide member 142, so that the compression rod 163 can compress a shock absorption member 151 along the cam displacement path. A compression spring 164 is provided between the lower cam 162 and the guide member 142, so that the lower cam 162 is elastically biased upwards.

[58] In addition, a guide slot 162d is formed in the circumferential outer surface of the lower cam 162. A pin hole 122a is formed in the main housing 121, and a setting pin 123 a is inserted into the pin hole 122a such that the end of the setting pin 123 a is inserted into the guide slot 162d, so that rotational motion can be converted into vertical linear motion along the cam displacement path.

[59] In this case, there is no vertical actuating member 141, and the guide member 142 has no guide slot 143.

[60] As shown in FIGS. 15 through 18, it is more preferable that an upper cam 138 be integrally provided under the lower surface of a support member 136, which is fastened to the main housing 121, and that it be coupled to a lower cam 162, because the elastic force of the torsion spring 131 can be easily adjusted.

[61] Here, a compression rod 163 extends from the central portion of the lower surface of the lower cam 162 downwards. A key 163a is provided in the lower end of the compression rod 163, and a key hole 142d is formed in the actuating space 142a of a guide member 142, so that the key 163a is inserted into the key hole 142d, such that a shock absorption member 151 is compressed along a cam displacement path.

[62] In this case, the support member 136 has no through hole 136a, a lower clutch 132 has no shaft 134, the lower cam 162 has no guide slot 162d, and the main housing 121 has neither a pin hole 122a nor a setting pin 123a.

[63] The operation of the present invention will be explained herein below.

[64] When the door is opened, the lower clutch 132 is rotated, so that the torsion spring

131 is wound and the shaft 134 is simultaneously rotated.

[65] Then, the vertical actuating member 141, which is coupled to the key 134a of the shaft 134, is also rotated. Thereby, the vertical actuating member 141 is moved upwards under the guidance of the protrusion pin 141b of the vertical actuating member 141, which is moved along the guide slot 143 of the guide member 142.

[66] Simultaneously, the shock absorption member 151 is gradually released from the state of having been compressed by the vertical actuating member 141, and, when the

door is completely opened, the shock absorption member 151 is completely released from the compressed state after the above-mentioned operation is continuously conducted.

[67] In this state, when the door is released, the door is automatically closed by the restoring force of the torsion spring 131, which has been wound.

[68] At this time, the lower clutch 132 is rotated in reverse, so that the shaft 134 is also rotated in reverse. Thereby, the vertical actuating member 141 is also rotated in reverse in conjunction with the shaft 134.

[69] While the vertical actuating member 141 is rotated in reverse, it is moved downwards under the guidance of the guide slot 143 of the guide member 142, thus compressing the shock absorption member 151.

[70] Therefore, the restoring force of the torsion spring 131, which is abruptly generated, is controlled by the shock absorption member 151, so that the torsion spring 131 is smoothly actuated. As a result, the door is closed at an appropriate speed.

[71] In detail, the protrusion pin 141b of the vertical actuating member 141 is guided by the first spiral slot 143a, the horizontal slot 143b and the reverse spiral slot 143c of the guide slot 143 of the guide member 142, so that the vertical actuating member 141 is moved downwards.

[72] Therefore, when the door is closed from the completely opened state, in the initial stage, the vertical actuating member 141 is guided by the first spiral slot 143a, and the restoring force of the torsion spring 131, which is abruptly generated, is controlled by the shock absorption member 151. Hence, the door can be smoothly closed at an appropriate speed.

[73] When the door is partially closed, in other words, when the torsion spring 131 is partially released and the restoring force thereof is reduced, the vertical actuating member 141 is guided by the horizontal slot 143b, so that it no longer compresses the shock absorption member, and all of the remaining restoring force of the torsion spring 131 is applied to the door, thus closing the door continuously and smoothly.

[74] Just before the door is finally closed, because the vertical actuating member 141 is guided by the reverse spiral slot 143c, the shock absorption member 151 is returned partway to its original state, that is, it is moved slightly upwards. Therefore, the restoring force of the shock absorption member 151 is applied to the door in conjunction with the reduced restoring force of the torsion spring 131, thus completely closing the door.

[75] Meanwhile, in the present invention, the restoring force of the shock absorption member 151 can be adjusted by setting the position of the shock absorption member 151 using the adjustment screw 144, which is inserted into the threaded hole 142b in the guide member 142.

[76] Furthermore, because the torsion spring 131 is molded in the shock absorption member 135, the elastic force of the torsion spring 131 can be controlled somewhat, thus making the motion of the door smooth.

[77] The elastic force of the torsion spring 131 can be adjusted by inserting a tool into the key hole 132a in the lower clutch 132 through the insert hole 133a of the upper clutch 133 and by rotating the lower clutch 132 after decoupling the upper and lower clutch 133 and 132 from each other by applying pressure thereto using the tool.

[78] Meanwhile, as shown in FIGS. 6 through 9, the above-mentioned closing operation may be realized through a construction in which the key 137 extends downwards from the lower surface of the support member 136, which is fastened in the main housing 121, and the key 137 is fitted into the key hole 141a in the vertical actuating member 141.

[79] Particularly, this construction does not require that the vertical actuating unit 140 be set again when it is desired to adjust the elastic force of the torsion spring 131, thus being more convenient.

[80] Alternatively, as shown in FIGS. 10 through 14, the above-mentioned closing operation may be realized through a construction such that the cam unit 160 is coupled to the lower end of the shaft 134, which passes through the through hole 136a in the support member 136, and is actuated along the cam displacement path.

[81] That is, the upper cam 161 is coupled to the lower end of the shaft 134, and the lower cam 162 is in contact with the lower surface of the upper cam 161. The first inclined surface 162a, the horizontal surface 162b and the reverse inclined surface 162c are continuously formed on the lower cam 162, thus realizing the above- mentioned continuous motion of the free hinge.

[82] In this case, the compression rod 163 extends downwards from the central portion of the lower surface of the lower cam 162 and is configured such that the compression rod 163 can compress the shock absorption member 151 along the cam displacement path. The guide slot 162d, which extends in the vertical direction, is formed in the circumferential outer surface of the lower cam 162. The pin hole 122a is formed in the main housing 121, and the setting pin 123a is inserted into the pin hole 122a, so that the end of the setting pin 123a is fitted into the guide slot 162d, such that rotational motion can be converted into vertical linear motion along the cam displacement path.

[83] Here, the compression spring 164 is provided between the lower cam 162 and the guide member 142, so that the lower cam 162 is elastically biased upwards. Just before the door is finally closed, the restoring force of the compression spring 164 and the restoring force of the shock absorption member 151 are added to the reduced restoring force of the torsion spring 131. Therefore, it is preferable that the compression spring be selectively installed in consideration of the size of the door.

[84] Meanwhile, as shown in FIGS. 15 through 18, the above-mentioned closing operation may be realized through a construction in which the upper cam 138 is integrally provided under the lower surface of the support member 136, which is fastened to the main housing 121, and in which the lower cam 162 is operated in conjunction with the upper cam 138 in the same manner as that in the above description.

[85] Here, the key 163a is provided under the compression rod 163 of the lower cam

162, and the key hole 142d is formed in the actuating space 142a of the guide member 142, so that the shock absorption member 151 is compressed along the cam displacement path in the same manner as that in the above description, thus making the operation of closing the door smooth.

[86] Particularly, this construction does not require that the vertical actuating unit 140 be set again when it is desired to adjust the elastic force of the torsion spring 131, thus being more convenient. Industrial Applicability

[87] As described above, the present invention provides a free hinge for opening and closing a door, which is constructed such that the door, which has been opened, can move at a safe speed desired by a user when being closed, and, such that at the final moment of closing the door, the elastic force of a spring is effectively applied to the door, thus perfectly completing the operation of closing the door, thereby enhancing the reliability of the product. Furthermore, the present invention can smoothly and stably control the door even though no hydraulic pressure is used, thus markedly reducing production costs.