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.

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.