Foldable and adjustable frame

A frame, including:

• a middle unit including a first supporting member, a second supporting member, a first coupler and a second coupler, wherein
• proximal ends of the first and second supporting members are pivotally connected to each other;
• a distal end of the first supporting member is pivotally connected to the first coupler such that the first supporting member is rotatable relative to the first coupler around a first lateral axis;
• and
• a distal end of the second supporting member is pivotally connected to the second coupler such that the second supporting member is rotatable relative to the second coupler around a second lateral axis;
• a first unit disposed at a first side of the middle unit when the frame is unfolded, the first unit including a first leg, a first longitudinal member, a second longitudinal member, a first lateral member and a second lateral member, wherein:
• proximal ends of the first and second longitudinal members are pivotally connected to each other;
• a distal end of the first lateral member is pivotally connected to the first longitudinal member;
• a distal end of the second lateral member is pivotally connected to the second longitudinal member;
• and
• a proximal end of the first lateral member is pivotally connected to the first coupler and a proximal end of the second lateral member is pivotally connected to the second coupler such that the first unit is rotatable relative to the first and second couplers around a first longitudinal axis;
• and
• a second unit disposed at a second side of the middle unit when the frame is unfolded, the second unit including a second leg, a third longitudinal member, a fourth longitudinal member, a third lateral member and a fourth lateral member, wherein:
• proximal ends of the third and fourth longitudinal members are pivotally connected to each other;
• a distal end of the third lateral member is pivotally connected to the third longitudinal member;
• a distal end of the fourth lateral member is pivotally connected to the fourth longitudinal member;
• and
• a proximal end of the third lateral member is pivotally connected to the first coupler and a proximal end of the fourth lateral member is pivotally connected to the second coupler such that the second unit is rotatable relative to the first and second couplers around a second longitudinal axis;
• wherein:
• (i) the first and second supporting members of the middle unit, the first and second longitudinal members of the first unit, the first and second lateral members of the first unit, the third and fourth longitudinal members of the second unit, and the third and fourth lateral members of the second unit are foldable onto each other,
• (ii) each of the first and second lateral members of the first unit is adjustable in length, thereby allowing the frame when unfolded to adjust its size in a lateral direction of the frame,
• (iii) each of the first longitudinal member of the first unit and the third longitudinal member of the second unit comprises a proximal longitudinal segment and a distal longitudinal segment telescopically connected to each other and selectively movable relative to each other in a longitudinal direction of the frame, the proximal longitudinal segment of the first longitudinal member is fixedly coupled to the first leg, and the proximal longitudinal segment of the third longitudinal member is fixedly coupled to the second leg, and
• (iv) the distal end of the first lateral member is pivotally connected to the proximal longitudinal segment of the first longitudinal member and remains stationary relative to the distal longitudinal segment of the first longitudinal member during selective movement of the distal longitudinal segment of the first longitudinal member, such that the selective movement of the distal longitudinal segment of the first longitudinal member is independent of the first lateral member and independent of the first leg, and the distal end of the third lateral member is pivotally connected to the proximal longitudinal segment of the third longitudinal member and remains stationary relative to the distal longitudinal segment of the third longitudinal member during selective movement of the distal longitudinal segment of the third longitudinal member, such that the selective movement of the distal longitudinal segment of the third longitudinal member is independent of the third lateral member and independent of the second leg, thereby allowing the frame to adjust its size in the longitudinal direction of the frame by moving only the distal longitudinal segment segments of the first longitudinal member and the third longitudinal member.