Butterfly Hinge

Abstract

A butterfly hinge is disclosed comprising a first bracket with an index pin, a second bracket pivotally connected to the first bracket and provided with a pin shaft, and a lever rotatably mounted on the second bracket via the pin shaft. One end of the lever features several inclined first gear notches, while the other end is connected to the second bracket by a spring so that a first gear notch snap-fits onto the index pin under the spring's force. The lever also includes an extension piece slidably movable along its length, with an end extending beyond the lever and provided with an inclined extension slot adapted to mate with the index pin. The second bracket rotates relative to the first up to or near 180 to allow the sofa back to fold onto or near the sofa base's top surface, thus reducing sofa volume for compact packaging and transportation.

Claims

1. A butterfly hinge, comprising: a first bracket (1) provided with an index pin (11); a second bracket (2) pivotally connected to the first bracket (1) and provided with a pin shaft (21); and a lever (3) rotatably mounted on the second bracket (2) via the pin shaft (21), the lever (3) having a plurality of inclined first gear notches (31) formed at one end and with another end of the lever (3) connected to the second bracket (2) via a spring (4) so that, under the elastic force of the spring (4), the first gear notch (31) can be snap-fit onto the index pin (11); wherein the lever (3) is further provided with an extension piece (5) that is slidably movable relative to the lever (3) along the longitudinal direction of the lever (3), the end of the extension piece (5) extending beyond one end of the lever (3) and being provided with an inclined extension slot (51) adapted to mate with the index pin (11).

2. The butterfly hinge according to claim 1, wherein the lever (3) is provided with a sliding pin (32), and the extension piece (5) is provided, in a central portion of the extension piece (5), with a first linear sliding groove (52) extending along the length of the extension piece (5), the sliding pin (32) being received in the first linear sliding groove (52) to enable the extension piece (5) to be slidably mounted within the lever (3).

3. The butterfly hinge according to claim 2, wherein the lever (3) is further provided with a blocking plate (6) that is slidably movable along the longitudinal direction of the blocking plate (6) and configured to block the first gear notch (31), the blocking plate (6) having a second gear notch (61) adapted to mate with the first gear notch (31) and a sealing portion (62) positioned adjacent to the second gear notch (61), such that when the blocking plate (6) is slid relative to the lever (3) so that the second gear notch (61) is offset from the first gear notch (31), the sealing portion (62) is positioned adjacent to an opening of the first gear notch (31) to prevent the first gear notch (31) from being snap-fit onto the index pin (11).

4. The butterfly hinge according to claim 3, wherein the blocking plate (6) is provided, in a central portion of the blocking plate (6), with a second linear sliding groove (63) extending along the length of the blocking plate (6), the sliding pin (32) being received in the second linear sliding groove (63) to enable the blocking plate (6) to be slidably mounted within the lever (3), and wherein the end of the blocking plate (6) and the end of the extension piece (5) are respectively provided with a first positioning hole (64) and a second positioning hole (53) that are mutually adapted, so that when a positioning member (7) is inserted through the first positioning hole (64) and the second positioning hole (53), the blocking plate (6) and the extension piece (5) are fixed together, with the rear side of the first linear sliding groove (52) contacting the index pin (11) and the front side of the second linear sliding groove (63) contacting the index pin (11), thereby fixing both the blocking plate (6) and the extension piece (5) to the lever (3) with the sealing portion (62) positioned adjacent to the opening of the first gear notch (31).

5. The butterfly hinge according to claim 4, wherein the blocking plate (6) is provided with an inclined edge (65) at the front end of the blocking plate (6), the inclination angle of the inclined edge (65) being the same as that of the extension slot (51).

6. The butterfly hinge according to according to claim 1, wherein the first bracket (1) is provided with a bent first limiting plate (8) that, together with the first bracket (1), forms a limiting space (81), the index pin (11) being fixedly connected at both ends, one end to the first bracket (1) and the other end to the first limiting plate (8), and the lever (3) passing through the limiting space (81) and being slidably mounted therein.

7. The butterfly hinge according to claim 6, wherein the edge of the first limiting plate (8) is further provided with a clearance groove (82).

8. The butterfly hinge according to claim 6, wherein the inner surface of the first limiting plate (8) is provided with a first protrusion (83) for reducing a contact area and protruding inwardly, and the outer surface of the first bracket (1) is provided with a second protrusion (12) for reducing a contact area and protruding outwardly, the first protrusion (83) and the second protrusion (12) being disposed on opposite sides of the lever (3), with the lever (3) contacting at least one of the first protrusion (83) or the second protrusion (12).

9. The butterfly hinge according to claim 1, wherein the other end of the lever (3) is provided with a hook hole (33), a first hook portion (41) at one end of the spring (4) is engaged with the hook hole (33), and the second bracket (2) is further bent to form a hook rod (23), with a second hook portion (42) at the other end of the spring (4) engaged with the hook rod (23).

10. The butterfly hinge according to claim 9, wherein the hook rod (23) is provided on the outer side of the hook rod (23) with a hook slot (231) into which the second hook portion (42) is engaged.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a perspective view of the first state of the present invention;

[0019] FIG. 2 is another perspective view of the first state of the present invention;

[0020] FIG. 3 is an exploded perspective view of the first state of the present invention;

[0021] FIG. 4 is a third perspective view of the first state of the present invention;

[0022] FIG. 5 is a diagram illustrating the assembly state of the lever with the extension piece and the blocking plate after they have been relatively positioned;

[0023] FIG. 6 is a diagram illustrating the assembly state of the lever with the extension piece and the blocking plate when in a free state;

[0024] FIG. 7 is a perspective view of the second state of the present invention;

[0025] FIG. 8 is another perspective view of the second state of the present invention;

[0026] FIG. 9 is a perspective view of the third state of the present invention.

[0027] Below is the English translation formatted according to USPTO requirements:

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] The present invention will be further described in detail with reference to the embodiments and the accompanying drawings (see FIGS. 1-9). As shown in FIGS. 1-9, a butterfly hinge is provided, comprising: a first bracket (1) provided with an index pin (11); a second bracket (2) pivotally connected to the first bracket (1), the second bracket (2) being provided with a pin shaft (21); and a lever (3) rotatably mounted on the second bracket (2) via the pin shaft (21). One end of the lever (3) is provided with a plurality of inclined first gear notches (31), and the other end of the lever (3) is connected to the second bracket (2) via a spring (4) so that, under the elastic force of the spring (4), the first gear notch (31) can snap-fit onto the index pin (11).

[0029] In use, the first bracket (1) is fixed to the sofa base, and the sofa back is fixed to the second bracket (2) so that the back is rotatably adjustable relative to the sofa base. At this time, once one of the first gear notches (31) of the lever (3) is engaged with the index pin (11), the sofa back is no longer moved; that is, when the first bracket (1) and the second bracket (2) are not rotated relative to each other, the first gear notch (31) remains stably engaged with the index pin (11) under the elastic force of the spring (4). In one embodiment, the second bracket (2) is rotated relative to the first bracket (1) until both are parallel, as shown in FIG. 9, so that the sofa back and the sofa base lie in the same plane to form a sofa bed; alternatively, the second bracket (2) may be rotated relative to the first bracket (1) to an angle approaching 100, so that the sofa back is inclined relative to the sofa base to form a conventional sofa. As shown in FIGS. 1-2, when it is necessary to adjust the angle between the back and the base, the first bracket (1) on the back is rotated relative to the second bracket (2) in the direction toward the base. At this time, the first bracket (1) pulls the lever (3) in the direction away from the second bracket (2), causing the first gear notch (31) to disengage from the index pin (11). The first bracket (1) on the back is then rotated relative to the second bracket (2) in the direction away from the base until the desired angle is reached, at which point another one of the first gear notches (31) is stably engaged with the index pin (11) under the elastic force of the spring (4), thereby securing the back relative to the base. The foregoing describes the conventional technology of sofa hinges in the art.

[0030] In order to allow the relative rotation angle between the second bracket (2) and the first bracket (1) to exceed 100 and to enable the sofa back to be folded onto or near the upper end surface of the sofa base, the following design is provided: the lever (3) is further provided with an extension piece (5) that is slidably movable relative to the lever (3) along its longitudinal direction. The end of the extension piece (5) extends beyond one end of the lever (3), and the end of the extension piece (5) is formed with an inclined extension slot (51) adapted to mate with the index pin (11). When the second bracket (2) is rotated relative to the first bracket (1) to its maximum angle, the end of the lever (3) completely disengages from the index pin (11). At this time, the extension slot (51) at the end of the extension piece (5) hooks onto the index pin (11), and the extension piece (5) is slidably movable relative to the lever (3) along its longitudinal direction, thereby extending outward as an extension arm of the lever (3). This configuration prevents the structure formed by the combination of the lever (3) and the extension piece (5) from disengaging from the index pin (11), thereby increasing the relative rotation angle between the second bracket (2) and the first bracket (1). In one embodiment, the minimum angle between the second bracket (2) and the first bracket (1) is 0 or nearly 0, and the maximum angle is 180 or nearly 180. This design meets the objective of allowing the sofa back to be folded onto or near the upper end surface of the sofa base, thereby reducing the overall volume of the sofa and minimizing the space occupied for packaging and transportation.

[0031] The assembly structure of the extension piece (5) with the lever (3) is as follows:

[0032] The cross-section of the lever (3) is in the shape of a downwardly open square frame, and the extension piece (5) is disposed within the lever (3). A sliding pin (32) is provided within the lever (3), and the central portion of the extension piece (5) is provided with a first linear sliding groove (52) extending along its length. The sliding pin (32) is received in the first linear sliding groove (52), thereby enabling the extension piece (5) to be slidably mounted within the lever (3).

[0033] The lever (3) is further provided with a blocking plate (6) that is slidably movable along its longitudinal direction and is used to block the first gear notch (31). The blocking plate (6) has a second gear notch (61) adapted to mate with the first gear notch (31) and a sealing portion (62) positioned adjacent to the second gear notch (61). When the blocking plate (6) is slid relative to the lever (3) such that the second gear notch (61) is misaligned with the first gear notch (31), the sealing portion (62) is positioned adjacent to the opening of the first gear notch (31), thereby preventing the first gear notch (31) from snap-fitting onto the index pin (11). When the extension slot (51) at the end of the extension piece (5) hooks onto the index pin (11), the blocking plate (6) is fixedly assembled with the extension piece (5), and with the second gear notch (61) misaligned with the first gear notch (31), the sealing portion (62) remains adjacent to the opening of the first gear notch (31) so that the first gear notch (31) cannot engage with the index pin (11).

[0034] The assembly structure of the blocking plate (6) with the lever (3) is as follows:

[0035] The central portion of the blocking plate (6) is provided with a second linear sliding groove (63) extending along its length. The sliding pin (32) is received in the second linear sliding groove (63), thereby enabling the blocking plate (6) to be slidably mounted within the lever (3). In addition, the end of the blocking plate (6) and the end of the extension piece (5) are respectively provided with a first positioning hole (64) and a second positioning hole (53) that are mutually adapted. When a positioning member (7) is inserted through the first positioning hole (64) and the second positioning hole (53), the blocking plate (6) and the extension piece (5) are fixed together. In this configuration, the rear side of the first linear sliding groove (52) contacts the index pin (11), and the front side of the second linear sliding groove (63) contacts the index pin (11), thereby fixing both the blocking plate (6) and the extension piece (5) to the lever (3), with the sealing portion (62) positioned adjacent to the opening of the first gear notch (31).

[0036] The blocking plate (6) is provided at its front end with an inclined edge (65), the inclination angle of which is the same as that of the extension slot (51).

[0037] The first bracket (1) is provided with a bent first limiting plate (8), forming a limiting space (81) between the first bracket (1) and the first limiting plate (8). The two ends of the index pin (11) are fixedly connected to the first bracket (1) and the first limiting plate (8), respectively, and the lever (3) passes through the limiting space (81) and is slidably mounted therein.

[0038] The second bracket (2) is provided with a bent second limiting plate (9), with both ends of the pin shaft (21) being fixedly connected to the second limiting plate (9) and the second bracket (2), respectively, and the lever (3) is also received in an interval formed between the second limiting plate (9) and the second bracket (2).

[0039] A clearance groove (82) is provided at the edge of the first limiting plate (8). The clearance groove (82) is mainly provided to accommodate the positioning member (7) while ensuring that the positioning member (7) positions the extension piece (5) and the blocking plate (6) so that they cannot retreat relative to the first limiting plate (8). When the device is in normal use (i.e., when a sofa or a sofa bed is to be formed), the positioning member (7) is removed, allowing the extension piece (5) and the blocking plate (6) to freely slide relative to the lever (3). For example, in the use state, the blocking plate (6), under its own weight, slides downward relative to the lever (3) so that the second gear notch (61) and the first gear notch (31) become aligned; consequently, both the second gear notch (61) and the first gear notch (31) can subsequently snap-fit onto the index pin (11), thereby ensuring the proper function of the lever (3).

[0040] The inner surface of the first limiting plate (8) is provided with a first protrusion (83) that serves to reduce the contact area and protrudes inwardly, while the outer surface of the first bracket (1) is provided with a second protrusion (12) that serves to reduce the contact area and protrudes outwardly. The first protrusion (83) and the second protrusion (12) are distributed on the outer sides of the lever (3), and the lever (3) contacts at least one of the first protrusion (83) or the second protrusion (12). This configuration minimizes the contact area between the lever (3) and the first limiting plate (8) and the first bracket (1) during sliding, thereby reducing wear and improving the smoothness of the lever's (3) movement.

[0041] The other end of the lever (3) is provided with a hook hole (33). A first hook portion (41) at one end of the spring (4) is engaged with the hook hole (33); the second bracket (2) is further bent to form a hook rod (23), and a second hook portion (42) at the other end of the spring (4) is engaged with the hook rod (23), thereby stably connecting the spring (4) to both the lever (3) and the first bracket (1). The outer side of the hook rod (23) is provided with a hook slot (231), into which the second hook portion (42) is engaged, further ensuring the stability of the assembly and preventing the second hook portion (42) from accidentally disengaging from the hook rod (23).

[0042] In summary, when the second bracket (2) is rotated relative to the first bracket (1) to its maximum angle, the end of the lever (3) completely disengages from the index pin (11). At this time, the extension slot (51) at the end of the extension piece (5) hooks onto the index pin (11), and the extension piece (5) is slidably movable relative to the lever (3) along its longitudinal direction, thereby extending outward as an extension arm of the lever (3). This configuration prevents the structure formed by the lever (3) and the extension piece (5) from disengaging from the index pin (11), thereby increasing the relative rotation angle between the second bracket (2) and the first bracket (1). In one embodiment, the minimum angle between the second bracket (2) and the first bracket (1) is 0 or nearly 0, and the maximum angle is 180 or nearly 180. This design fulfills the purpose of allowing the sofa back to be folded onto or near the upper end surface of the sofa base, thereby reducing the overall volume of the sofa and minimizing the space occupied for packaging and transportation.

[0043] Of course, the above-described embodiments are provided merely as examples of the present invention and are not intended to limit the scope of the invention. Any equivalent variations or modifications based on the structure, features, or principles recited in the appended claims are intended to be encompassed within the scope of the present patent application.