ES344458A1 - Rotary locking mechanism for wrapper-type cartons - Google Patents

Abstract

Mechanism for interlocking a locking tab 59 in one panel with a retaining tab 63 in another panel, e.g. in securing wrap-around cartons, comprises means for moving the panels along a predetermined path and a rotary element having radial tab-engaging elements 98 arranged to engage the locking tab 59 and drive it against the retaining tab 63 and through the opening defined by said retaining tab, the rotary element being mounted for rotation about an axis 94 which is angularly disposed to the planes of said panels so that the locking tab is caused to swing through a predetermined angle whilst causing said retaining tab to swing through a smaller angle during a locking operation, the two angles being such that the free end of the locking tab is caused to swing past the free end of the retaining tab, so that the locking tab is braced at an angle to the panels by the retaining tab when the radial element is withdrawn from engagement with said tabs. In the embodiment suitable carton blanks as shown in Fig. 2 and comprising a panel 25 having fingergripping apertures 26, 27 and article-engaging apertures 28-33 sloping corner-forming panels 34, 35 side walls forming panels 38, 40 and bottom-forming panels 48, 51 having apertures 46 for locating the bottoms of said articles and retaining tabs 60-63 and locking elements 56-59 respectively, are removed singly from hopper 7 by a reciprocable suction plunger 14 and placed over a group of articles, e.g. bottles fed into the machine by suitable conveyer means. Each blank is supported on and transported by hooks 20 on an endless conveyer 15, in synchronism with a group of articles such as B1, B2 &c. urged along by plungers 13 on a conveyer 8. Each assembly of articles and associated carton blank, are then conveyed past suitable folding mechanism (plough 66 only shown) to wrap the blank around the articles in known manner. The bottom panels are brought into overlapping relationship and with the respective retaining tabs and locking elements in register. The blank is tightened around the articles by tightening elements such as 83, 84 engaging tightening apertures 52, 55 and the locking elements (59 shown) are pushed past the retaining tabs (63 shown) by a rotating element having a number of tab-engaging elements 98. The rotating element is driven by a chain 103 and is mounted on an axis 94 angularly disposed to the plane of movement of the bottom panels so that the locking elements are pushed through an angle in excess of 90 degrees whilst the retaining tabs are pushed through an angle of less than 90 degrees so that as the tab-engaging element 98 is withdrawn the elements and tabs spring together and positively engage. The pitch circle point on each tab engaging element 98 at which the instantaneous velocity is substantially equal to the velocity of the panels is arranged to be about half-way between point of maximum penetration and the plane of the tabs.