Articles of unitary moulded-plastics sheet construction

Abstract

A foldable-box container is formed by injection moulding to have its side-walls ( 1,2 ) joined to one another and to its base ( 3 ) by integrally-formed membrane hinges ( 21 - 23 ). Membranes ( 24 ) divide the sides ( 2 ) to enable hinging of halves ( 2 a ,2 b ) of the side ( 2 ) onto one another back to back between the sides ( 1 ). The base ( 3 ) folds outwardly on diagonal membranes ( 26, 29 ) and inwardly on membranes ( 28 ) bringing parts ( 3 a ) back to back between parts ( 3 b ); the folding of the base ( 3 ) may be inverted to fold it inside the sides ( 1 ). A hinged lid ( 31 ) with hinged-down rim ( 34 ) may be formed integrally with the box.

1 . An article of unitary moulded-plastics sheet construction which is convertible between a three-dimensional erect state and a substantially-flat, folded state, the sheet incorporating a multiplicity of flexible membrane portions located between and integral with spaced parts of the sheet to define hinges for enabling those parts to be deflected angularly with respect to one another in conversion between the two states.  
     
     
         2 . An article according to  claim 1  wherein each membrane portion is defined by a channel in one of the two faces of the sheet leaving a thin web or membrane contiguous with the two parts of the sheet located either side of the channel, for hinging those two parts to one another.  
     
     
         3 . An article according to  claim 2  wherein the flanks of said channel are inclined away from one another outwardly of the channel.  
     
     
         4 . An article according to  claim 3  wherein the angle between the flanks when the two parts located either side of the respective channel are coplanar, is substantially a right angle.  
     
     
         5 . An article according to any one of  claims 2  to  4  wherein a first plurality of said membrane portions are defined as aforesaid by channels in one face of the sheet and a second-plurality of said membrane portions are defined as aforesaid by channels in the other face of the sheet.  
     
     
         6 . An article according to any one of  claims 1  to  5  wherein the article in the erect state has the form of a container having at least four walls, each said wall being individually hinged to three said walls by respective ones of said hinges.  
     
     
         7 . An article according to  claim 6  wherein one of said walls forms a base of the container and the other walls form sides of the container, and the base and one or more of the side-walls each individually incorporates a said hinge to enable that wall to fold onto itself in said folded state of the article.  
     
     
         8 . An article according to  claim 7  wherein the container is defined by a rectangular base and first and second pairs of opposite side-walls hinged by respective ones of said hinges to the base, each side-wall of the first pair being hinged by respective ones of said hinges to the two side-walls of the second pair, and wherein each side-wall of the second pair of side-walls incorporates a further respective one of said hinges to enable that side-wall to fold onto itself between the side-walls of the first pair of side-walls, in said folded state.  
     
     
         9 . An article according to  claim 8  wherein a plurality of said hinges are incorporated in the base for enabling the base to fold onto itself in said folded state.  
     
     
         10 . An article according to  claim 9  wherein an elongate flexible-membrane portion is incorporated in the base to extend substantially parallel to the side-walls of said first pair, and six of said hinges are incorporated in the base, four to extend from said flexible membrane portion to the four corners respectively of the base, and two to extend substantially-aligned with and in opposite directions from said flexible membrane portion.  
     
     
         11 . An article according to any one of  claims 7  to  10  wherein the sheet incorporates a part defining a lid to said container, the lid being hinged to one of said side-walls by a flexible membrane portion which is integral with that side-wall and the lid.