Seatbelt-adjusting device

A seatbelt-adjusting device comprising:

• a frame unit having top and bottom surfaces, and left and right sides that extend from said top surface to said bottom surface, and defining an opening that extends between said left and right sides and that has left and right ends disposed respectively adjacent to said left and right sides of said frame unit, and front and rear ends;
• an elongated belt-holding piece mounted slidably on said top surface of said frame unit, spanning said left and right ends of said opening, and slidable on said top surface of said frame unit between a rear position, in which, said belt-holding piece is disposed adjacent to said rear end of said opening, and a front position, in which, said belt-holding piece is disposed adjacent to said front end of said opening;
• and
• a positioning member disposed rearwardly of said belt-holding piece, and having left and right end portions and a bridge portion extending between and interconnecting said left and right end portions, said left and right end portions of said positioning member being respectively pivoted to said left and right sides of said frame unit so as to be pivotable about a rotating axis parallel to said top surface of said frame unit between a first position, in which, said bridge portion of said positioning member is spaced apart from said belt-holding piece, and a second position, in which, said bridge portion of said positioning member abuts against said belt-holding piece when said belt-holding piece is disposed at said front position;
• wherein said frame unit includes a U-shaped base member having a rear portion and left and right portions extending frontwardly and respectively from two opposite ends of said rear portion to serve respectively as said left and right sides of said frame unit, said rear, left and right portions defining a recess thereamong, said frame unit further including a mounting frame fixed on said base member and formed with a through-hole that is registered with said recess in said base member so as to define said opening in said frame unit, said through-hole in said mounting frame being confined by an opening-defining wall having a large-width portion adjacent to said rear portion of said base member and a small-width portion with a width smaller than that of said large-width portion, said belt-holding piece including a sliding block disposed slidably on said mounting frame and spanning said through-hole, and two engaging legs extending downwardly from said sliding block, through said through-hole in said mounting frame and into said recess in said base member.