| 摘要 |
The invention relates to a process and apparatus for pre-folding and unfolding of a closure on a folding box of rectangular cross-section, which closure is formed of the creased unslotted end portion of the walls of the box of which two opposite closure panels are each provided with a pair of creases running from the corners and converging toward the center of the margin so as to form triangular pockets upon folding. The device comprises two pairs of folding tools at 90 DEG to one another and means for displacing them. One of the pairs corresponding to the creased panels each is bifurcated with a folding tine which engages its panel at substantially one location during folding while the other tine in inactive and an unfolding tine which engages the opposite face of the same panel during unfolding while the folding tine is inactive. A plunger is moved into the box prior to folding to serve as a backing means and, by unfolding as described, the panels are restored to a position where they are at most only minimally contacted by the plunger during withdrawal from the box. Thus, if the end portion of the box carries an adhesive material for later closure, the adhesive will not be removed by sliding of the plunger therealong. |
