Patent Application
20120139318
1. Field of the Invention
The invention relates to a chair, more particularly to a chair that has an inclination-adjustable backrest.
2. Description of the Related Art
Referring to
When the positioning pin. 14 is biased by the compression spring 15 to be inserted into the selected one of the positioning holes 122, the backrest plate 13 is positioned at an inclination relative to the base plate 11. To adjust the inclination of the backrest plate 13 relative to the base 11, the handling lever 16 is pulled for driving the torsion spring 17 to bias the positioning pin 14 away from said one of the positioning holes 121 against a biasing force of the compressions spring 15, thus enabling inclination adjustment of the backrest plate 13. After the backrest plate 13 is moved to another inclination relative to the base plate 11 and the positioning pin 14 is aligned with another one of the positioning holes 122, the handling lever 16 is released and the positioning pin 14 is biased to be inserted into the one of another positioning holes 121 by a restoring force of the compression spring 15 and the torsion spring 17.
However, the configuration of the above-mentioned backrest adjusting device is relatively complicated. Moreover, the backrest plate 13 can not be positioned at any desired angle relative to the base plate 11 due to the limitation of the number of the positioning holes 122, thereby resulting in a relatively low flexibility of the backrest adjusting device during use. Furthermore, since most elements that are included in the backrest adjusting device are rigid elements, the position where the handling lever 16 is mounted to the base plate 11 as well as the direction that the handling lever 16 is allowed to pivot are limited, thus resulting in inconvenience during use.
Therefore, the object of the present invention is to provide a chair capable of alleviating the above drawbacks of the prior art.
Accordingly, a chair of the present invention includes a seat assembly, a backrest assembly, a support assembly, and an actuating mechanism. The seat assembly includes a leg unit and a seat plate mounted to the leg unit. The backrest assembly includes a backrest plate and an engaging frame that interconnects pivotally the backrest plate and the seat assembly. The support assembly includes at least one telescopic rod that interconnects the engaging frame of the backrest assembly and the leg unit of the seat assembly. The actuating mechanism includes at least one actuating member that corresponds in position to the telescopic rod, and a drawing unit coupled to the actuating member and operable for driving the actuating member to actuate length adjustment of the telescopic rod so as to adjust inclination of the backrest assembly relative to the seat assembly.
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:
Before the invention is described in greater detail with reference to the accompanying embodiments, it should be noted herein that like elements are denoted by the same reference numerals throughout the disclosure.
As shown in
The seat assembly 2 includes a leg unit 21 and a seat plate 22 mounted to the leg unit 21. The leg unit 21 includes a seat-supporting member 211 disposed under and mounted to the seat plate 22, and a leg member 212 disposed under and connected fixedly to the seat-supporting member 211. The seat-supporting member 211 further includes a handle mounting wall 213 at a front part of the seat-supporting member 211, and spaced-apart backrest assembly mounting walls 214 at a rear part of the seat-supporting member 211. The backrest assembly mounting walls 214 extend in a front-rear direction.
The backrest assembly 3 includes a backrest plate and an engaging frame 32 that interconnects pivotally the backrest plate 31 and the seat assembly 2. The backrest plate 31 has a backrest segment 311 and an engaging segment 312 that is disposed under and forms a predetermined angle relative to the backrest segment 311. The engaging frame 32 includes an engaging wall 321 that is connected fixedly to the engaging segment 312 of the backrest plate 31, and two pivot mounting walls 322 that extend perpendicularly and respectively from opposite lateral ends of the engaging wall 321 and that are connected pivotally and respectively to the backrest assembly mounting walls 214 of the leg unit 21.
In this embodiment, the support assembly 4 includes two telescopic rods 41 that are spaced apart from each other, first and second positioning seats 42, 44, and first and second pivot rods 43, 45. The telescopic rods 41 interconnect the engaging frame 32 of the backrest assembly 3 and the leg unit 21 of the seat assembly 2. The first positioning seat 42 is mounted to a bottom surface of the seat plate 22 adjacent to the backrest assembly mounting walls 214, and is spaced apart from the engaging frame 32 of the backrest assembly 3. The first pivot rod 43 is for coupling pivotally the telescopic rods 41 to the first positioning seat 42. The second positioning seat 44 is mounted to the engaging wall 321 of the engaging frame 32. The second pivot rod 45 is for coupling pivotally the telescopic rods 41 to the second positioning seat 45.
In this embodiment, the actuating mechanism includes two actuating members 50, a coupling rod 51, a supporting frame 53, a handling device 54, and a drawing unit 56. Each of the actuating members 50 corresponds in position to a respectively one of the telescopic rods 41. The supporting frame 53 is secured to the telescopic rods 41. Each of the telescopic rods 41 is provided with a trigger member 412 operable to enable length adjustment of a corresponding one of the telescopic rods 41 and a protruding plate 413 disposed adjacent to a respective one of the actuating members 50. In this embodiment, the telescopic rods 41 are pneumatic cylinders, and the trigger members 412 are configured as valves for enabling and disabling the length adjustment of the pneumatic cylinders, i.e., the telescopic rods 41.
Each of the actuating members 50 has a spring-abutting portion 502 corresponding in position to the protruding plate 413 of the respective one of the telescopic rods 41, and a controlling portion 501 corresponding in position to the trigger member 412 of the respective one of the telescopic rods 41. The actuating mechanism 5 further includes two springs 52, each of the springs 52 having opposite ends abutting respectively against the spring-abutting portion 502 of the respective one of the actuating members 50 and the protruding plate 413 of the respective one of the telescopic rods 41.
The coupling rod 51 is connected co-movably to the spring-abutting portions 502 of the actuating members 50. The handling device 54 is mounted to the handle mounting wall 213 of the seat assembly 2 and includes a handle 541. The drawing unit 56 includes a connecting member 563 that is connected to the coupling rod 51, a flexible drawing strip 561 that has an end connected to the connecting member 563 and an opposite end connected to the handling device 54, and a bushing 562 that is sleeved on the drawing strip 561 and mounted to the supporting frame 53 to ensure that the part of the drawing strip 561 which is sleeved in the bushing 562 is only movable in a direction parallel to the telescopic rods 41.
Further referring to
After inclination of the backrest plate 31 relative to the seat plate 21 is adjusted to a desired position, the handle 541 is released and the spring-abutting portion 502 of each actuating member 50 is biased away from the respective protruding plate 413 by a restoring force of the respective spring 52. Consequently, the controlling portions 501 of the actuating members 50 are moved away from the trigger members 412 so as to permit the trigger members 412 to move from the open position to the close position, thereby positioning once again the backrest plate 31 relative to the seat plate 22.
To sum up, the advantages of the present invention are as follows. The chair according to the present invention has a relatively simple configuration compared to the conventional backrest adjusting device that is illustrated in
Referring to
The handling device 54 includes a main body 542, an elongated groove 543 formed in the main body 542, and an L-shaped handle 541 that is connected pivotally to the main body 542 at a corner portion 546 of the handle 541, and that has a grip portion 545 disposed distal from the main body 542 and a connecting portion 544 engaging slidably the elongated groove 543 of the main body 542. The drawing strips 561 are connected co-movably to the connecting portion 544 of the handle 541. When the grip portion 545 of the handle 541 is pulled, the connecting portion 544 of the handle 541 is moved along the groove 543, such that the actuating members 50 are driven to enable length adjustment of the telescopic rods 41 through the drawing strips 561. Therefore, the inclination of the backrest plate 31 relative to the seat plate 22 can be adjusted to a desired position. The second preferred embodiment has the same advantages as those of the first preferred embodiment.
While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
