Adjustable backrest

An adjustable backrest for a seating structure comprising:

• an upright comprising a rack;
• said backrest moveably mounted on said upright;
• a pawl pivotally mounted to said backrest about a pivot axis, wherein said pawl is pivotable between an engaged position wherein said pawl is engaged with said rack and a disengaged position wherein said pawl is disengaged from said rack, wherein said pawl is further translatably mounted to said backrest, wherein said pawl is translatable relative to said backrest between at least a disabled position and an operative position;
• and
• a spring biasing said pawl into said engaged position when said pawl is in said operative position;
• wherein said upright comprises a first upright, wherein said pawl comprises a first pawl and wherein said spring comprises a first spring, and further comprising a second upright comprising a second rack, wherein said backrest is moveably mounted on said first and second uprights, a second pawl pivotally mounted to said backrest about a second pivot axis, wherein said second pawl is pivotable between a second engaged position wherein said second pawl is engaged with said second rack and a second disengaged position wherein said second pawl is disengaged from said second rack, wherein said second pawl is further translatably mounted to said backrest, wherein said second pawl is translatable relative to said backrest between at least a second disabled position and a second operative position, and a second spring biasing said second pawl into said second engaged position when said second pawl is in said second operative position.

A method for adjusting the height of a backrest on a seating structure comprising:

• moving a backrest in a first direction on an upright to a desired height, wherein said backrest comprises an elongated first track and a second track having a first portion substantially parallel to said first track and a second portion communicating with said first portion and extending transverse to said first portion;
• engaging a rack on said upright with a pawl moveably mounted to said backrest and thereby releasably securing said backrest at said desired height, wherein said pawl and said rack permit movement of said backrest in only said first direction, wherein said pawl comprises a guide member traveling within said first and second portions of said second track;
• releasably securing said pawl in a disabled position by pivoting said pawl relative to said backrest in said first track while moving said guide member in said second portion in said second track, and thereafter translating said pawl in said first track in a first direction and translating said guide member in said first portion of said second track in said first direction;
• moving said backrest in a second direction opposite said first direction to a release position;
• and
• releasing said pawl from said disabled position when said backrest is in said release position.