Headrest Adjusting Structure for Office Chair

Abstract

A headrest adjusting structure for an office chair includes a headrest member having a first pivot portion, a first adjusting lever having a second pivot portion and a third pivot portion, a holding unit having an upper jaw with a slideway, a lower jaw with a slide slidably mounted in the slideway, and an adjusting bolt extending through the upper jaw and the lower jaw, a second adjusting lever having a fourth pivot portion, a first locking member extending through the first pivot portion and the second pivot portion, a second locking member extending through the third pivot portion and the fourth pivot portion, and a third locking member extending through the passage of the upper jaw and rests on the second adjusting lever.

1 . A headrest adjusting structure for an office chair, comprising:
 a headrest member, a first adjusting lever, a holding unit, a second adjusting lever, a first locking member, a second locking member, and a third locking member;   wherein:   the headrest member is provided with a first pivot portion;   the first adjusting lever has a first end provided with a second pivot portion and a second end provided with a third pivot portion;   the holding unit includes an upper jaw, a lower jaw, and an adjusting bolt;   the upper jaw is provided with a slideway and a passage;   the lower jaw is provided with a slide;   the slide is inserted into and slidably mounted in the slideway so that the upper jaw and the lower jaw are moved relative to each other;   the adjusting bolt extends through the upper jaw and the lower jaw to lock the upper jaw and the lower jaw;   the second adjusting lever has a first end provided with a fourth pivot portion and a second end passing through the passage of the upper jaw;   the first locking member extends through the first pivot portion and the second pivot portion, so that the headrest member and the first adjusting lever are connected pivotally and are pivoted about the first locking member;   the first locking member positions the headrest member in place;   the second locking member extends through the third pivot portion and the fourth pivot portion, so that the first adjusting lever and the second adjusting lever are connected pivotally and are pivoted about the second locking member;   the second locking member positions the first adjusting lever in place; and   the third locking member extends through the passage of the upper jaw and rests on the second adjusting lever, so that the second adjusting lever is positioned by the third locking member.   
     
     
         2 . The headrest adjusting structure for an office chair as claimed in  claim 1 , wherein:
 the upper jaw and the lower jaw are moved relative to each other in parallel with a first direction, and   the adjusting bolt extends through the upper jaw and the lower jaw in parallel with the first direction.   
     
     
         3 . The headrest adjusting structure for an office chair as claimed in  claim 2 , wherein the second adjusting lever has a lengthwise direction in parallel with the first direction. 
     
     
         4 . The headrest adjusting structure for an office chair as claimed in  claim 2 , wherein the first locking member extends through the first pivot portion and the second pivot portion in a direction perpendicular to the first direction. 
     
     
         5 . The headrest adjusting structure for an office chair as claimed in  claim 4 , wherein:
 the second locking member extends through the third pivot portion and the fourth pivot portion in a direction perpendicular to the first direction; and   the direction of the second locking member is in parallel with that of the first locking member.   
     
     
         6 . The headrest adjusting structure for an office chair as claimed in  claim 4 , wherein:
 the third locking member extends through the passage of the upper jaw in a direction perpendicular to the first direction; and   the direction of the third locking member is perpendicular to that of the second locking member.   
     
     
         7 . The headrest adjusting structure for an office chair as claimed in  claim 1 , wherein the upper jaw and the lower jaw are made of plastic material with a hardness. 
     
     
         8 . The headrest adjusting structure for an office chair as claimed in  claim 1 , wherein the first pivot portion is located at a back of the headrest member.