Panel interlocking device

Abstract

Aspects of the disclosure relate to a panel interlocking device, a carton, and a blank for forming the carton. The carton blank incorporating a panel interlocking device for securing together a first and a second panel in overlapping relationship. The panel interlocking device comprises a locking tab struck from the first panel, and a retaining tab defining a locking aperture struck from the second panel. In use the retaining tab is displaced out of the plane of the second panel to receive said locking tab through the locking aperture to be engaged therewith. The retaining tab has opposing side edges each concavely curved as viewed from the outside of the retaining tab.

1 - 24  (canceled) 
     
     
         25 . A panel interlocking device for joining a first panel and a second panel, the panel interlocking device comprising:
 a male tab on the first panel; and   a female tab having opposing side edges on the second panel,   wherein each of the opposing side edges of the female tab is formed by a curved cut line of continuous length such that each of the opposing side edges of the female tab is concavely curved as viewed from outside of the female tab.   
     
     
         26 . A panel interlocking device according to  claim 25  wherein the curved cutline of continuous length is configured to separate the female tab from the second panel along each of the opposing side edges. 
     
     
         27 . A panel interlocking device according to  claim 25  wherein the male tab comprises a single-position tab comprising:
 a main portion; 
 a neck portion; and 
 a shoulder portion; 
 wherein the neck portion is narrower in width than the shoulder portion to define at least one locking edge formed along a lower part of the shoulder portion, and 
 wherein a maximum width F 2  of the female tab is greater than a maximum width M 2  of the single-position tab, (F 2 >M 2 ). 
 
     
     
         28 . A panel interlocking device according to  claim 25  wherein a distal end of the female tab having a width F 5  is less than the maximum width M 2  of the single-position tab, (F 5 <M 2 ). 
     
     
         29 . A panel interlocking device according to  claim 25  wherein the female tab is connected to a mother panel by a non-linear fold line. 
     
     
         30 . A panel interlocking device according to  claim 29  wherein the non-linear fold line comprises a curved fold line, 
     
     
         31 . A panel interlocking device according to  claim 29 , wherein a center of curvature of the curved fold line is located at a position closer to a distal end of the female tab than to the curved fold line. 
     
     
         32 . A panel interlocking device according to  claim 30  wherein the non-linear fold line has a length F 1  which is: (i) less than a maximum width F 2  of the female tab, (F 1 <F 2 ), or (ii) less than a minimum width F 4  of the female tab, (F 1 <F 4 ), or (iii) is generally equal to a minimum width M 1 /M 4  of the male tab, (F 1 =M 1 ), (F 1 =M 4 ). 
     
     
         33 . A panel interlocking device according to  claim 25  wherein the male tab comprises a multi-position tab comprising a plurality of recesses along at least one side edge thereof, each recess providing an engagement edge for abutment with a panel portion of a mother panel from which the female tab is struck and wherein a maximum width F 2  of the female tab is greater than a maximum width M 5  of the multi-position tab. 
     
     
         34 . A panel interlocking device according to  claim 25  wherein a distal end of the female tab having a width F 5  is less than a maximum width M 5  of the multi-position tab, (F 5 <M 5 ). 
     
     
         35 . A panel interlocking device according to  claim 25  wherein the female tab has a distal end edge convexly curved as viewed from outside of the female tab, wherein a center of curvature of the distal end edge is located at a position closer to a proximal end of the female tab than to a distal end of the female tab. 
     
     
         36 . A panel interlocking device according to  claim 35  wherein a radius r 2  of curvature of the distal end edge is greater than a radius r 3  of curvature of each of the opposing side edges, (r 2 >r 3 )., wherein the radius of curvature r 2  of the distal end edge is generally equal to a maximum width F 2  of the female tab, (r 2 ≅F 2 ). 
     
     
         37 . A panel interlocking device for securing together a first panel and a second panel in overlapping relationship, said panel interlocking device comprising:
 a locking tab struck from the first panel, and   a retaining tab defining a locking aperture struck from the second panel,   wherein the retaining tab is displaced out of plane of the second panel to receive the locking tab through the locking aperture to be engaged therewith,   wherein at least one of the locking aperture and the retaining tab has opposing side edges, at least one of the opposing side edges being defined by a curvilinear cut line that is concavely curved toward its oppositely disposed side edge along its length,   wherein a minimum width (F 4 ) of the locking aperture is located between distal and proximal ends of the locking aperture.   
     
     
         38 . A panel interlocking device according to  claim 37  wherein a center of curvature of the at least one of the opposing side edges that is concavely curved is disposed outside the at least one of the locking aperture and the retaining tab. 
     
     
         39 . A panel interlocking device according to  claim 38  wherein the minimum width F 4  of the locking aperture is located between a distal end of the locking aperture having a width F 5  and a proximal end of the locking aperture having a width F 2  such that both the width F 5  at the distal end and the width F 2  at the proximal end is greater than the minimum width F 4 , (F 5 >F 4 ), (F 2 >F 4 ). 
     
     
         40 . A panel interlocking device according to  claim 39  wherein the width F 2  at the proximal end is the maximum width of the female tab and is greater than the width F 5  at the distal end. 
     
     
         41 . A panel interlocking device according to  claim 40  wherein a radius r 3  of curvature of each of the opposing side edges is generally equal to two-thirds of the maximum width F 2  of the female tab, (r 3 ≅⅔ F 2 ). 
     
     
         41 . A panel interlocking device according to  claim 38 , wherein at least one of the opposing side edges being defined by a curvilinear cut line that is concavely curved toward its oppositely disposed side edge along its entire length, wherein a minimum width of the locking aperture is located between distal and proximal ends of the locking aperture. 
     
     
         42 . A carton blank incorporating panel interlocking device having a first panel and a second panel, said panel interlocking means comprising a male tab on the first panel; and a female tab having opposing side edges on the second panel, wherein each of the opposing side edges of the female tab is formed by a curved cut line of continuous length such that each of the opposing side edges of the female tab is concavely curved as viewed from outside of the female tab.