Patent Publication Number: US-9414684-B2

Title: Tilting type chair

Description:
CROSS REFERENCE TO PRIOR APPLICATIONS 
     The present application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2013-0120455 (filed on Oct. 10, 2013), which is hereby incorporated by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a tilting type chair, and more particularly, to a tilting type chair in which a seat of the chair is movable up and down depending on a direction of a load or movement applied to a back support of the chair by a user and tilting is capable of being limited as needed. 
     2. Description of the Prior Art 
     Conventionally, comfort is considered to be one of the most important factors in a chair because a user should be able to be seated thereon for a long time. However, because a place in which such a chair is used may be changed due to, for example, frequent removal, portability and lightweight are recently preferred. Thus, simple chairs are in the spotlight of consumers. However, apart from excellence in portability and lightweight, such a simple chair such has a problem in that it is poor in comfort as compared to a large chair. Whereas, in large chairs, a seat, a back rest and/or arm rests have been provided with a soft cushion for the user&#39;s comfort, and the seat and the back rest are configured to be capable of rotating integrally in a state where the legs of the chair are fixed, and thus, the large chairs have been remarkably improved in comfortability. 
     Many large chairs are provided with a tilting function such that, when a user bends his/her upper body backwards on a large chair, the back rest of the chair is bent backwards in a state where the center of gravity of the chair is maintained, and when the external force applied by the user is removed again, the back rest is returned to its original position. 
     However, in order to ensure that the tilting function can be executed in a large chair, a means for providing a restoring force, such as a coil spring, is essential for the chair, and the configuration thereof is very complicated. Thus, it is not easy for a person to assemble the chair when the person is not skilled in assembly. 
     When the tilting means applied to a large chair as described above is applied to a simple chair, a complicated configuration is applied to the simple chair. As a result, the versatility of the simple chair is degraded and the weight of the simple chair is increased, which makes it difficult to adopt the tilting means in the simple chair. Even if the tilting means is applied to the simple chair in such a manner as to suppress an increase of the weight of the simple chair, the tilting function cannot be properly performed because it is not easy to maintain the center of gravity. Further, when the chair is tilted, a seating feeling on the seat is degraded so that the user may feel uncomfortable. 
     Meanwhile, Korean Laid-Open Patent Publication No. 2003-0059582 discloses a tilting type chair applied to a simple chair, which has been made so as to solve a problem that a user&#39;s entire upper body cannot be supported uniformly since a space is produced between a back rest and the user&#39;s lumbar vertebrae when the back rest is tilted. For this purpose, the chair disclosed in Korean Laid-Open Patent Publication No. 2003-0059582 is designed such that when the user bends his/her back backwards to tilt the back rest frame, the back rest frame can be deformed to fully support the lumbar vertebrae. However, the chair disclosed in Korean Laid-Open Patent Publication No. 2003-0059582 has a problem in that a separate complicated link structure should be provided in order to allow the back rest frame to be deformed. 
     PRIOR ART DOCUMENT 
     Patent Document 
     Korean Laid-Open Patent Publication No. 2003-0059582 (published on Jul. 10, 2003) 
     SUMMARY OF THE INVENTION 
     The present invention has been made in order to solve the above-described problems in the art, and an object of the present invention is to provide a tilting type chair in which a seat of the chair is movable up and down depending on a direction of a load or movement applied to a back support of the chair by a user so as to improve the user&#39;s comfortability. 
     According to an exemplary embodiment of the present invention, there is provided a tilting type chair including: a seat on which a user is seated; a back support configured to support a back portion of the user seated on the seat; and a tilting section interposed between the back support and the seat to couple the seat to the back support. When the user applies a load to bend the back support backward, the tilting section moves the seat upward in proportion to the load applied by the user, and, when the load applied to the back support by the user is removed, the tilting section moves the seat downward in proportion to the removed load. 
     In addition, the tilting section may include: a tilting body disposed between the back support and the seat; a pair of first connecting blocks configured to connect both sides of a rear end of the tilting body and both sides of a lower end of the back support as well as to connect both sides of a middle lower portion of the seat and both sides of the lower end of the back support; and a pair of second connecting blocks configured to connect both sides of the front end of the tilting body and both sides of a front lower portion of the seat. 
     In addition, the pair of first connecting blocks may include hinge connecting ends formed to protrude upward and connected by hinge to the both sides of the middle lower portion of the seat, respectively. 
     The pair of first connecting blocks may be provided with rotation center protrusions, respectively, which are inserted into the inside of the tilting body, and a torsion bar may be provided within the tilting body. Both ends of the torsion bar are inserted into the torsion bar fastening recesses formed in the rotation center protrusions of the pair of first connecting blocks, respectively, so as to interconnect the pair of first connecting blocks. 
     In addition, a fixing block formed with a through-hole may be fixedly disposed within the tilting body, in which the torsion bar is inserted through the through-hole. The torsion bar fastening recesses, the through-hole, and the torsion bar may be formed to have a square cross-section. 
     In addition, when the pair of first connecting blocks are rotated in relation to the tilting body in cooperation with the back support, the torsion bar may convert the load of the back support into a torsional force. 
     The tilting type chair may further include a tilting adjusting lever disposed at a side of the seat to be rotatable forward and backward. The tilting body may include a body portion including an installation space formed therein, and a tilting limit locking section disposed in the installation space of the body portion. The tilting adjusting lever and the tilting limiting locking section is connected so that the tiling may be adjusted by the tilting limiting locking section when the tilting adjusting lever is rotated. 
     The tilting limit locking section may include: a guide block fixed in the installation space and including a forward-backward sliding hole formed to be opened in a forward and backward direction and a left-right sliding hole formed to be opened in a left and right direction; a locking sliding block configured to be slid along the forward-backward sliding hole; and a tilting locking block configured to be slid along the left-right sliding hole. The tilting locking block may be slid in cooperation with the locking sliding block. 
     The forward-backward sliding hole and the left-right sliding hole may be provided one on another to be partly overlapped, the locking sliding block may be formed with a guide pin protruding into the left-right sliding hole, and the tilting locking block may be formed with a guide slot into which the guide pin is inserted. 
     The forward-backward sliding hole may be provided at a position lower than the left-right sliding hole. 
     The guide slot may be formed to be inclined so that the tilting locking block is slid to a position where a tip end of the tilting locking block protrudes to the outside of the body portion. 
     A locking knob may be formed on the tip end of the tilting locking block to protrude in a longitudinal direction. Here, a locking recess into which the locking knob protruding to the outside of the body portion is inserted may be formed in the first connecting blocks. 
     The body portion may be formed with a locking hole through which the locking knob may be inserted to be exposed to the outside of the body portion. 
     A wire position changing protrusion may be formed in the seat to change a position of the wire. 
     According to the exemplary embodiment of the present invention, a tilting type chair is configured such that the seat of the chair may be moved up and down in response to the tilting operation of the back support of the chair. As a result, a more comfortable seating feeling may be provided to the user seated on the seat of the chair. 
     In addition, the tilting may be limited as needed by the user. Thus, the tilting type chair of the present invention may further improve the user&#39;s convenience. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, 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: 
         FIG. 1  is a perspective view illustrating an exemplary embodiment of a tilting type chair according to the present invention; 
         FIG. 2  is an exploded perspective view of  FIG. 1 ; 
         FIG. 3  is a cross-sectional view taken along line A-A of  FIG. 1 ; 
         FIG. 4  is a side view illustrating a tilting state of the tilting type chair according to the present invention; 
         FIG. 5  is an exploded perspective view illustrating a state in which a tilting section among components in  FIG. 1  is installed on a back support; 
         FIG. 6  is a perspective view illustrating a pair of first connecting blocks among components of the tilting section; 
         FIG. 7  is an enlarged view illustrating a “B” portion in  FIG. 5  in an enlarged scale; 
         FIG. 8  is a cross-sectional view taken along line C-C in  FIG. 7 ; 
         FIG. 9  is a plan view illustrating an operation of a tilting limit locking section by the tilting adjusting lever, among the components of the tilting section; 
         FIG. 10  is a perspective view illustrating the operation of the tilting limit locking section of  FIG. 9 , 
         FIG. 11  is a perspective view illustrating a configuration of the tilting limit locking section illustrated in  FIGS. 9 and 10 . 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     Hereinafter, an exemplary embodiment of a tilting type chair according to the present invention will be described in detail. 
       FIG. 1  is a perspective view illustrating a tilting type chair according to an exemplary embodiment of the present invention,  FIG. 2  is an exploded perspective view of  FIG. 1 ,  FIG. 3  is a cross-sectional view taken along line A-A of  FIG. 1 , and  FIG. 4  is a side view illustrating a tilting state of the tilting type chair according to the present invention. 
     As illustrated in  FIGS. 1 to 4 , a tilting type chair  1  according to an exemplary embodiment of the present invention includes a seat  30  on which a user is seated, a back support  10  that supports a back portion of the user who is seated on the seat  30 , and a tilting section  100  interposed between the back support  10  and the seat  30  to interconnect the back support  10  and the seat  30 . 
     The tilting section  100  is configured to perform the following action: when the user applies a load to the back support  10  so as to bend the back support  10  backward, the tilting section  100  moves the seat  30  upward in proportion to the applied load, and when the load applied to the back support  10  by the user is removed, the titling section  100  moves the seat  30  downward in proportion to the removed load. A more specific tilting state of the seat  30  will be described in more detail below. 
     The back support  10  that supports the user&#39;s back portion is disposed to extend vertically, an opening  11  opened in a forward and backward direction is formed in the back support. An arm support  20  is provided at a middle portion of the back support  10  in the vertical direction. A cushion made of a foam or mesh material or a non-cushion material is installed in the opening  11  opened in the forward and backward direction so as to comfortably support the user&#39;s back. The lower end portion of the back support  10  is formed to be curved substantially to the front side. 
     As illustrated in  FIG. 3 , the seat  30  includes a lower frame  31 , and a cushion  33  assembled to the top of the lower frame  31 . The lower frame  31  and the cushion  33  may be fastened to each other via fastening members  35 . 
     As illustrated in  FIGS. 1 and 2 , the seat  30  may further include a tilting adjusting lever  505  so as to limit the tilting performed by the tilting section  100 . The tilting adjusting lever  505  protrudes outward from a side portion of the lower frame  31  in which the tilting adjusting lever  505  may be configured such that one end portion protruding outward (hereinafter, referred to as “outward protruding end”) may be rotated forward or backward by a predetermined angle around an internal hinge connection point (see  FIG. 11  in which no reference numeral is assigned). The tilting adjusting lever  505  is connected, via a wire  800 , with a locking sliding block  530 , which is one of the components of a tilting limit locking section  500 , which is one of the components of the tilting section  100  to be described later. Thus, the tilting adjusting lever  505  may be configured such that when the outwardly protruding end of the tilting adjusting lever  505  is rotated forward, the tilting of the seat  30  performed by the tilting section  100  is limited, and when the outwardly protruding end of the tilting adjusting lever  505  is rotated backward, the seat  30  may be tilted. This will be described in detail below. 
     As illustrated in  FIGS. 2 and 3 , the tilting section  100 : includes a tilting body  200  disposed between the back support  10  and the seat  30 ; a pair of first connecting blocks  300  configured to connect both sides of a rear end of the tilting body  200  and both sides of a lower end of the back support  10  as well as to connect both sides of a middle lower portion of the seat  30  and both sides of the lower end of the back support  10 , and to transfer a backward load (backward bending force) applied by the user and provided from the back support  10 ; and a pair of second connecting blocks  400  configured to connect both sides of the front end of the tilting body  200  and both sides of a front lower portion of the seat  30 . 
     Coupling recesses  13  are formed at the both sides of the lower end of the back support  10 , respectively, and a pair of first connecting blocks  300  are shape-matched and coupled to the coupling recesses  13 , respectively. The pair of first connecting blocks  300  may be fastened to the coupling recesses  13  by fastening members (not illustrated) to be shape-matched to the coupling recesses  13 , respectively. 
     The pair of first connecting blocks  300  are rigidly fixed to the both sides of the lower end of the back support  10  so that the backward load provided by the user through the back support  10  may be efficiently transferred to the tilting section  100  and the seat  30  connected thereto. 
       FIG. 5  is an exploded perspective view illustrating a state where the tilting section is installed on the back support among of the components illustrated in  FIG. 1 , and  FIG. 6  is a perspective view illustrating one of a pair of first connecting blocks among the components of the tilting section. 
     As illustrated in  FIGS. 5 and 6 , the pair of first connecting blocks  300  may include hinge connecting ends  320 , respectively, which protrude upward and are connected by hinge with the both sides of the middle lower portion of the seat  30 . Each of the hinge connecting end  320  may be formed with a hinge fastener  321 . 
     In addition, the pair of first connecting block  300  are formed with rotation center protrusions  310  which penetrate side portions of the tilting body  200  such that tip ends thereof are exposed to the inside of the tilting body  200 , respectively, and a torsion bar fastening recess  311  having a rectangular shape may be formed on the tip end of each of the rotation center protrusions  310 . One end of a torsion bar  110  to be described later may be inserted into and fastened to the torsion bar fastening recess  311 . 
     Further, each of the pair of first connecting blocks  300  may have a locking recess  330  formed on a side portion which is plane-contacted with a side surface portion of the tilting body  200 . A locking knob  540  is inserted into the locking recess  330 . The locking knob  540  will be described later. 
     The pair of first connecting blocks  300  are connected with the middle lower portion of the seat  30  to be relatively rotated through the hinge fasteners  321  provided in the hinge connecting ends  320 , and connected with the tilting body  200  when the torsion bars  110  are fastened to the torsion bar fastening recess  311  formed in the rotation center protrusions  310 . 
     Meanwhile, as illustrated in  FIGS. 2 and 3 , each of the pair of second connecting blocks  400  is connected by hinge to a front end of the tilting body  200  at the rear end thereof and connected by hinge to the front lower portion of the seat  30  at the front end thereof. Hinge insertion holes  410  and  420  may be formed in the pair of second connecting blocks  400  and hinges (not illustrated) may be inserted into and fastened to the hinge insertion holes  410  and  420  for hinged connection of each of the second connecting blocks  400 . In addition, connection recess portions  210  cut to have an L-shaped cross-section are formed on the front end portions of the tilting body  200 , respectively, so that the connection recess portions  210  are shape-matched and coupled with the pair of second connecting blocks  400 , respectively. 
     As illustrated in  FIG. 4 , the tilting section  100  configured as described above is operated as follows: when the user bends his/her back backward ({circle around (1)}), a load is applied to the pair of first connecting blocks  300  connected to the lower end of the back support  10 , the pair of first connecting blocks  300  receives a rotation force for rotating the hinge connecting ends  320  are rotated about the rotation center protrusions  310  extending to the inside of the tilting body  200  ({circle around (2)}), the rotation force is converted into a moving force for moving the rear end of the seat backward ({circle around (3)}), and the front end of the seat  30  is moved backward by the backward moving force of the seat  30  to move the seat  30  upward entirely ({circle around (4)}). 
     The conventional tilting type chair exhibits a poor seating feeling on the seat when the chair is tilted, which causes a user to feel inconvenience. However, according to the tilting type chair of the present exemplary embodiment, the user seated on the seat  30  feels comfortable and the seating feeling on the seat  30  is also improved due to the tilting of the back support  10 . 
     On the contrary, when the user bends his/her back forward, the load applied to the back support  10  is removed and thus, the tilting section  100  is operated in the following manner: the upper ends of the hinge connecting ends  320  of the pair of the first connecting blocks  300  connected to the lower end of the back support  10  are rotated around the rotation center protrusions  310  to the original positions thereof and the rear end of the seat  30  is moved forward, so that the seat  30  is entirely moved down to its original position. 
     As described above, the tilting operation of the back support  10  is performed when a load is applied to or removed from the back support  10 , and the seat  30  is moved up or down in response to the tilting operation of the back support  10 , a more comfortable seating feeling may be provided to the user seated on the seat  30 . 
       FIG. 7  is an enlarged perspective view illustrating the “B” portion in  FIG. 5  in an enlarged scale, and  FIG. 8  is a cross-sectional view taken along line C-C in  FIG. 7 . In addition,  FIG. 9  is a plan view illustrating an operation of a tilting limit locking section by the tilting adjusting lever, among the components of the tilting section,  FIG. 10  is a perspective view illustrating the operation of the tilting limit locking section of  FIG. 9 , and  FIG. 11  is a perspective view illustrating a configuration the tilting limit locking section illustrated in  FIGS. 9 and 10 . 
     As illustrated in  FIGS. 7 to 11 , the tilting body  200  may include a body portion  200 A formed with an installation space therein, and a body cover  200 B coupled to cover the top side of the body portion  200 A. 
     In the installation space in the body portion  200 A, a torsion bar  110  may be disposed in the left and right direction to interconnect torsion bar fastening recesses  311  formed in the rotation center protrusions  310  of the pair of first connecting blocks  300  described above, and the above-described tilting limit locking section  500 , and a height adjusting section  600  operated by a height adjusting lever (not illustrated) may also be disposed in the installation space in the body portion  200 A. 
     As illustrated in  FIG. 8 , one end of the torsion bar  110  is inserted into and fixed to a torsion bar fastening recess  311  formed in a rotation center protrusion  310  of one of the pair of the first connecting blocks  300  and the other end of the torsion bar  110  is inserted into and fixed to a torsion bar fastening recess  311  formed in a rotation center protrusion  310  of the other of the pair of the first connecting blocks  300 . Each of the torsion bar fastening recesses  311  may be formed to have a square cross-section so as to prevent the relative rotation of the torsion bar  110  therein, and the torsion bar  110  may also be formed to have a square cross-section. However, the torsion bar  110  and the torsion bar fastening recess  311  may have the same cross-sections other than the square cross-section. 
     Meanwhile, a fixing block  120  is provided in the installation space in the body portion  200 A at a portion corresponding to the middle portion of the torsion bar  110  disposed in the left and right direction, and is fixed to the body portion  200 A so as to fix the body portion  200 A such that the body portion  200 A cannot be rotated in relation to the torsion bar  110 . The fixing block  120  is rigidly fixed to the body portion  200 A by fastening members (which are not assigned with reference numerals), and a through-hole  121  is formed in the fixing block  120 . The torsion bar  110  is installed through the through-hole  121 . Like the torsion bar fastening recesses  311 , the through-hole  121  may be formed to have a square cross-section which is the same as that of the torsion bar  110 . 
     In addition to interconnecting the pair of first connecting blocks  300 , the torsion bar  110  also serves to transfer user&#39;s load provided thereto from the back support  10  to the seat  30 . That is, because the middle portion of the torsion bar  110  penetrates through the through-hole  121  of the fixing block  120  fixed to the installation space of the body portion  200 A, the torsion bar  110  converted the user&#39;s load (bending-back force) provided through the back support  10  into a torsional force so that the lower end of the back support  10  is rotated in relation to the tilting body  200  and at that time, the upper end of the hinge connecting end  320  is rotated backward, thereby moving the seat  30  upward. 
     As described above, because the torsional force by the torsion bar  110  may rotate the lower end of the back support  10  in relation to the tilting body  200 , the seat  30  may be tilted. According to an exemplary embodiment of the present invention, the tilting type chair  1  may be provided with a tilting limit locking section  500  in the installation space of the body portion  200 A so that the tilting is not performed as needed by the user. 
     As illustrated in  FIGS. 7 to 9 , the tilting limit locking section  500  may include: a guide block  510  fixed in the installation space of the body portion  200 A and provided with a forward-backward sliding hole  512  formed to be opened in a forward and backward direction and a left-right sliding hole  511  formed to be opened in a left and right direction; a locking sliding block  530  arranged to be slidable back and forth within the forward-backward sliding hole  512  by an external force; and a tilting locking block  520  arranged to be slidable within the left-right sliding hole  511  and sliding in the left and right direction in cooperation with the sliding movement of the locking sliding block  530 . 
     As illustrated in  FIG. 10 , the front end of the locking sliding block  530  is connected with the tilting adjusting lever  505  via the wire  800 , and when the tilting adjusting lever  505  is rotated forward, the locking sliding block  530  is slid forward. An elastic member installation groove (which is assigned with no reference numeral) is formed on the locking sliding block  530 , and the elastic member  550  is installed in the elastic member installation groove such that one end of the elastic member  550  is fixed to the guide block  510  and the other end of the elastic member  550  is supported on the locking sliding block  530  which is slid. Here, the elastic member  550  may be a coil spring. 
     When the locking sliding block  530  is slid forward, the elastic member  550  is compressed, and then, when the pulling force of the wire  800  of the tilting adjusting lever  505  is released, the elastic member  550  is returned to its original position so as to cause the locking sliding block  530  to be slid backward. 
     The tilting adjusting lever  505  is positioned above the front portion of the tilting limit locking section  500 , in which, when the tilting adjusting lever  505  and the tilting limit locking section  500  are arranged to have a rapid inclination, the operation of the tilting limit locking section  500 , which is induced by the rotation of the tilting adjusting lever  505 , may not be smooth. According to an exemplary embodiment of the present invention, as illustrated in  FIG. 10 , the tilting type chair  1  may be provided with a wire position changing protrusion  900  at a portion of the seat  30  corresponding to a side of the tilting adjusting lever  505  and the wire  800  may be disposed to surround the wire position changing protrusion  900  so as to continuously maintain the tension of the wire  800  interconnecting the tilting adjusting lever  505  and the tilting limit locking section  500  and the problem of non-smooth operation. 
     Meanwhile, the rear portion of the forward-backward sliding hole  512  in which the locking sliding block  530  is inserted may be formed to be partially overlapped with the left-right sliding hole  511  in which the tilting locking block  520  is inserted with the forward-backward sliding hole  512  being provided at a position lower than the left-right sliding hole  511 . Here, at an upper side of the rear end of the locking sliding block  530 , a guide pin  531  protruding into the left-right sliding hole  511  may be integrally formed, and the tilting locking block  520  may be formed with a guide slot  521  into which the guide pin  531  is inserted upwardly from a position below the guide slot  521 . 
     Assuming that tilting limit locking section  500  is provided at a rear left side in the installation space of the body portion  200 A, the guide slot  521  may be formed to be inclined to the left toward the rear side, as illustrated in  FIG. 10 . When the guide slot  521  is formed to be inclined to the left toward the rear side, while the locking sliding block  530  is slid forward, the guide pin  531  is moved forward, which causes the tilting locking block  520  to be moved to the left. 
     Meanwhile, a locking knob  540  may be formed on a left tip end of the tilting locking block  520  to protrude in a longitudinal direction, and a locking hole  210  communicated with the outside may be formed in the body portion  200 A adjacent to the locking knob  540 . When the tilting locking block  520  is slid leftward, the locking knob  540  is inserted, through the locking hole  210 , into a locking recess  330  formed in one of the pair of the first connection blocks  300  which is positioned adjacent to the locking knob  540 , thereby performing a locking function that prevents further tilting. That is, when the tip end of the locking knob  540  is inserted into the locking recess  330 , the relative rotation of the tilting body  200  and the pair of the first connecting blocks  300  is restricted so that further tilting cannot be performed. 
     According to the exemplary embodiment of the present invention, a height adjusting section  600  configured to adjust the height of the tilting type chair  1  may be provided at a rear central portion in the installation space of the body portion  200 A. A configuration already known in the art may be employed in the height adjusting section  600  as it is. However, a main feature is that constituent parts are installed in the tilting body  200  for the purpose of intensive installation of the constituent parts. Since the specific operating relationship of the height adjusting section  600  is not closely related to the contents of the tilting type chair  1  according to the present invention, descriptions thereof will be omitted. 
     Meanwhile, a rotating tube  700  may be provided at a rear lower side of the body portion  200 A, and a rotation shaft of legs (not illustrated) provided to be rotated in relation to the body portion  200 A may be inserted into the rotating tube  700  (see  FIG. 3 ). 
     Next, the operation state of the tilting type chair  1  configured as described above according to an exemplary embodiment of the present invention will be described briefly with reference to the accompanying drawings (in particular,  FIG. 4 ). 
     First, when the user is seated on the seat  30  and leans his/her back against the back support  10  to bend the back support  10  backward, the lower end of the back support  10  is rotated downward by a predetermined angle using the rotation center protrusion  310  as a rotation center ({circle around (1)}), and the hinge connecting ends  320  of the pair of first connecting blocks  300  are rotated upward by a predetermined angle using the rotation center protrusion  310  as a rotation center ({circle around (2)}). 
     When the hinge connecting ends  320  of the pair of first connecting blocks  300  are rotated, the seat  30  is moved backward ({circle around (3)}). At this time, the pair of second connecting blocks  400  are rotated so that the seat  30  is moved upward by a predetermined height ({circle around (4)}). 
     In particular, the downward rotation of the lower end of the back support  10  by the predetermined angle ({circle around (1)}) and the upward rotation of the hinge connecting ends  320  of the pair of the first connecting blocks  300  ({circle around (2)}) are performed since the load applied to the back support  10  is converted into a torsional force by the torsion bar  110  provided through the through-hole  121  of the fixing block  120  rigidly fixed in the installation space of the body portion  200 A. 
     In addition, the tilting may be limited as needed by the user in the following manner. When the tilting adjusting lever  505  protruding to a side of the seat  30  in a state where the tilting is not executed is rotated forward, the locking knob  540  of the tilting limit locking section  500  provided within the tilting body  200  is inserted into the locking recess  330  of the first connecting block  300 . As a result, the tilting can be limited. 
     Next, when the user separates his/her back forward from the back support  10 , the back support  10  is returned forward depending on the reduced extent of the load applied to the back support  10  by the user. This is because the torsional force generated by the torsion bar  110  acts as a restoration force of the back support  10 . 
     According to the present invention configured as described above, tilting is executed depending on a direction of a load or movement applied to the back support of the chair by the user and the vertical height of the seat  30  is adjusted in response the tilting, which improves the user&#39;s comfortability. 
     In the foregoing, a tilting type chair according to exemplary embodiments of the present invention has been described with reference to the accompanying drawings. However, it is evident that the present invention is not necessarily limited to the above-described exemplary embodiments and various modifications and equivalents may be made by a person ordinarily skilled within the scope of the present invention. Thus, the true scope of the present invention to be protected should be determined based on the accompanying claims.