Two-Stage Adjusting Member for Adjusting Slope of Seat Back

Abstract

A two-stage adjusting member for adjusting slope of a seat back formed by a first stage adjusting member and a second stage adjusting member is disclosed. A user operates the first stage adjusting member so that the seat back reclines from 90 degrees to 70 degrees to the horizontal. Then the users operates the second stage adjusting member so as to make the seat back further incline backward such as 10 degrees more to another slope. Thus the seat back slope is adjusted in two stages and such design is much more safer for users and can prevent danger or harm caused by suddenly reclining.

Description

BACKGROUND OF THE INVENTION

The present invention relates to an adjusting member for adjusting seat back slope, especially to a two-stage adjusting member for adjusting seat back slope that the user can operate a first stage adjusting member to make the seat back recline a certain angle. Then by a second stage adjusting member, the seat back further reclines such as 10 degrees more and becomes more close to a horizontal position. Thus the adjustment of the seat back is more safer.

There are various designs of adjustment mechanisms on office chairs such as height adjustment mechanism for armrests, height adjusting member for seats, seat slope adjusting member, seat back slope adjusting member, height adjusting member for seat backs, or waist support adjusting member, as prior arts disclosed in Taiwanese patent M321261, M326807, M308687, M3281531, M272463, M270739, M244008, M244006, M244008, 1227118, Taiwanese publication No. 00480961, 00312709, 00219466, 00148174, 00051473, 0578518, 00444555, 306219, 296582, Chinese patent No. ZL99235672.5 and U.S. Pat. No. 6,994,400 etc. The seat height adjustment mechanism and/or seat back slope adjustment mechanism are/is disposed in a main frame (first frame) of a base on bottom surface of the seat. Then by a control rod extending from the base to the edge of the bottom surface of the seat and on the left/right sides of the seat, the user can operates the mechanisms by left or right hand according to their needs.

Now the reclining function of the office chair is getting more important for users, especially for persons who sit on the seat for long period of time such as computer users. The office chair is not only a task chair but also for multiple purposes such as lounge chairs and recliner chairs. Thus the seat back of the office chair requires at least two kinds of slopes for users to choose. Generally, most of the seat back slope adjusting member available now is one-stage adjustment. That means the user adjusts the slope of the seat back only once. While adjusting the chair, the users recline and decide which slope of the seat back they require. However, the base of the office chair is disposed with rolling wheels. Thus the user may recline suddenly a large angle or to an almost flat position, fall backward and get hurts.

SUMMARY OF THE INVENTION

Therefore it is a primary object of the present invention to provide a two-stage adjusting member for adjusting seat back slope that includes a first frame whose top surface is fastened on the bottom surface of the seat, a second frame, a first stage adjusting member and a second stage adjusting member. A bottom surface of the first frame connects with a supporting mount. The rear end of the first frame is pivoted and connected with the second frame. The first stage adjusting member in the two-stage adjusting member for adjusting seat back slope is used to adjust the slope of the seat back to a first stage slope. The front end of the second frame is pivoted and connected with the first frame while the rear end of the second frame is fastened and connected with the seat back. The second stage adjusting member is disposed between the first frame and the second frame. The user operates the first stage adjusting member so as to make the seat back recline an angle for users to lie face up. Furthermore, the user operates the second stage adjusting member so that the seat back reclines from the first stage slope to the second stage slope. Thus the two-stage adjustment of the seat back is much more safer for users.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an embodiment of the present invention assembled on an office chair;

FIG. 2 is a perspective view of an embodiment according to the present invention;

FIG. 3 is a partial enlarged view of the embodiment in FIG. 2;

FIG. 4 is an explosive view of an embodiment according to the present invention;

FIG. 5 is an explosive view of a seat back depth adjusting member of an embodiment according to the present invention;

FIG. 6 is a schematic drawing showing a usage of an embodiment according to present invention;

FIG. 7 shows an embodiment of the present invention recline to a first stage slope;

FIG. 8 shows an embodiment of the present invention recline to a second stage slope;

FIG. 9 shows a user lying face up in the embodiment in FIG. 8;

FIG. 10 shows a status before adjustment of an embodiment according to the present invention;

FIG. 11 shows a status after adjustment of the embodiment in FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Refer from FIG. 1 to FIG. 4, a two-stage adjusting member for adjusting seat back slope 1 according to the present invention includes a first frame 20, a second frame 30 and a second stage adjusting member 40. The two-stage adjusting member for adjusting seat back slope 1 is disposed on a bottom surface 11 of a seat 10 and a rear end thereof extends to and fastened with a seat back 13 so that a certain angle formed between the seat 10 and the seat back 13, as shown in FIG. 6.

A top surface of the first frame 20 is fastened on the bottom surface 11 of the seat 10 while a bottom surface of the first frame 20 connects with a supporting mount 12 standing on the ground. By a pivot 50, the first frame 20 is pivoted with the second frame 30. A first stage adjusting member 21 is disposed on the first frame 20 and the second frame 30 is pivoted backward to a certain angle (about 20 degrees) around the pivot 50 by operation of a first adjustment rod 211. Thus the seat back 13 on top of the second frame 30 also reclines an angle A, as shown in FIG. 7. This is the first stage adjustment.

A front end of the second frame 30 is pivoted and connected with the first frame 20 by the pivot 50 while a rear end of the second frame 30 is fastened with the seat back 13. Refer from FIG. 6 to FIG. 10, an elastic device 14 is formed by a spring and is used to adjust supporting strength of the seat back 13 while the seat back reclining. That's elastic returning strength of the seat back 13 that enables the seat back 13 to turn back. Moreover, a seat back depth adjusting member 60 is disposed on the second frame 30. The seat back depth adjusting member 60 makes the seat back 13 move from an anterior position, as shown in FIG. 10, to a rearward position, as shown in FIG. 11. In this embodiment, the seat back depth adjusting member 60 is formed by an upper housing and a lower housing (60). A top surface 61 thereof is disposed with two vertical serrated slots 62 and stopping surfaces 63, as shown in FIG. 4 & FIG. 5. The seat back depth adjusting member 60 corresponds to a stage control device 64. The stage control device 64 includes an adjusting rod 65 that inserts through and locates between two holes 33 of the second frame 30. Two sets of positioning rings 66 and cams 67 are arranged on the adjusting rod 65, respectively and symmetrically on the right and left sides. That means each one side of the adjusting rod 65 is disposed with one positioning ring 66 and one cam 67. Through an insertion hole 34 on the second frame 30, the positioning ring 66 and one cam 67 correspond to and work with the serrated slots 62 and the stopping surface 63. When the positioning ring 66 and one cam 67 are respectively released from the serrated slot 62 and the stopping surface 63, the seat back 13 is able to be adjusted forward or backward for changing depth. After moving to a certain depth, rotate the adjusting rod 65 so that the two sets of positioning rings 66 and cams 67 rotate synchronously and the positioning ring 66 locks into one of the serrated slots 62 while the cam 67 presses against on the stopping surface 63 so as to finish operation of the seat back depth adjusting member 60. Thus the space for seating or reclining of the seat is adjusted for improving comfort of the chair. Furthermore, a fixing member 68 is further disposed between the upper and the lower housing (60), as shown in FIG. 5. Thus the fastening strength of the seat back depth adjusting member 60 with the seat back 13 is improved.

Refer to FIG. 4, the second stage adjusting member 40 is arranged between the first frame 20 and the second frame 30. As shown in FIG. 7, when the seat back 13 reclines a certain angle A by the adjustment of the first stage adjusting member 21, the seat back 13 can recline a further angle B such as 10 degrees, as shown in FIG. 8. Thus the user can lie face up and take a good rest, as shown in FIG. 9. The second stage adjusting member 40 includes a pin 41 formed by an inner end 411 and an outer end 412 and being disposed between left and right holes 23 of the first frame 20. The second frame 30 includes left and right holes 31a-31b corresponding to the left and right holes 23 of the first frame 20.

Moreover, the inner end 411 of the pin 41 connects to a handle 42 while the handle 42 is connected with a guide pin 46 which is disposed in a guiding hole 32 of the second frame 30 moveably. The pin 41 is arranged with an elastic member 43 such as spring and is restricted by a stopping block 44 so that the pin 41 can turn back automatically by elasticity of the elastic member 43 after movement. Furthermore, a projective rod 45 on the pin 41 moves freely inside the hole 31a of the second frame 30. Thereby, when the handle 42 is pulled outward horizontally by guiding of the guide pin 46, the outer end 412 of the pin 41 and the projective rod 45 synchronously move outward and release from the hole 31b and the hole 31a of the second frame 30 respectively. Now the second frame 30 further reclines an angle such as ten degrees from the slope of the first stage so that the slope of the second stage is achieved. In comparison, the conventional adjusting member only has one stage adjustment and the chair may recline from a vertical position to almost a flat position suddenly. This may cause danger or harm to users. Instead, the present invention adjusts the slope of the seat back 13 in two stages. By two-stage adjustment, the chair becomes much more safer. In addition, the second-stage slope can automatically turn back by elasticity of the spring of the elastic member 14, as shown from FIG. 6 to FIG. 10. Thus it's convenient for users to adjust the slope of the chair from the second stage back to the first stage. And the pin 41 also turns back to the original position-into the holes 31b, 31a automatically by the elasticity of the elastic member 43.

Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, and representative devices shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

Claims

1. A two-stage adjusting member for adjusting seat back slope comprising a first frame, a second frame and a second stage adjusting member; wherein

a top surface of the first frame is fastened on a bottom surface of a seat while the bottom surface of the first frame connects with a supporting mount; the first frame is pivoted and connected with the second frame by a pivot on rear end thereof; a first stage adjusting member in the first frame is used to adjust a seat back reclining to a first stage slope;

the second frame is pivoted and connected with the first frame by a pivot on front end thereof while a rear end thereof is fastened and connected with the seat back;

the second stage adjusting member is disposed between the first frame and the second frame so as to make the seat back further reclines a certain angle after being adjusted by the first stage adjusting member;

wherein the seat back reclines backward a certain angle by adjustment of the first stage adjusting member and then further reclines backward a further angle to a second stage slope so as to achieve safer adjustment of the seat back in two-stages.

2. The device as claimed in claim 1, wherein the second stage adjusting member having a pin moveably disposed between left and right holes of the first frame and also between left and right holes of the second stage adjusting member while the left and right holes of the second stage adjusting member are corresponding to the left and right holes of the first frame.

3. The device as claimed in claim 2, wherein the second stage adjusting member is disposed with a guide pin that guides the pin moving in parallel between the left and right holes of the first frame and the corresponding left and right holes of the second stage adjusting member.

4. The device as claimed in claim 3, wherein one end of the pin connects to a handle.

5. The device as claimed in claim 1, wherein the second stage adjusting member enables the seat back reclining backward ten degrees more.

6. The device as claimed in claim 1, wherein the second frame is disposed with a seat back depth adjusting member formed by an upper housing and a lower housing; a top surface of the seat back depth adjusting member is disposed with two vertical serrated slots and two stopping surfaces; a stage control device is arranged on the second frame while the stage control device includes an adjusting rod that inserts through and locates between two holes of the second frame and two sets of positioning rings and cams are arranged on the adjusting rod, respectively and symmetrically on the right and left sides of the adjusting rod; through an insertion hole on the second frame, the positioning ring and one cam correspond to and work with the serrated slots and the stopping surface; when the positioning ring and one cam are respectively released from the serrated slot and the stopping surface, the seat back is able to be adjusted forward or backward; after moving to a certain depth, the adjusting rod is rotated so that the two sets of positioning rings and cams rotate synchronously and the positioning ring locks into one of the serrated slots while the cam presses against and fixes on the stopping surface.