GB640685A - Improvements in or relating to devices for shifting two superposed wrapping members in an automatic folder - Google Patents

Abstract

640,685. Feeding webs. SAPAL SOC. ANON. DES PLIEUSES AUTOMATIQUES. Dec. 29, 1947, No. 34395. Convention date. March 22, 1946. [Class 100 (i)] A device for shifting two superposed wrapping strips in an automatic folder wherein the strips are cut simultaneously into superposed sections comprises a mobile shifting gripper whose jaws execute a relative sliding motion while gripping the strips so as to make one strip overlap the other for a certain distance. The jaw 3 is secured to an arm 10 pivoted at 11 to a carriage 1 sliding in a slipper-guide 2, and is opened at predetermined times by a camactuated member 8 acting on a roller 9 and closed by spring action. The jaw 4 is secured to an arm 12 attached at 15 to an arm 16 pivoted at 17 to the carriage and having a stud 13 sliding in an arcuate guide 14 on the carriage. At predetermined times, the jaw 4 is reciprocated horizontally relative to the jaw 3 by means of a cam-actuated member 19 acting on a roller 18 and a return spring 20, the guide 14 being arranged to maintain the clamping pressure constant meanwhile. In operation, the ends of two wrapping strips are gripped and drawn to the right, the jaw 4 moving also to the right relatively to the jaw 3 so as to draw forward a greater length of the upper strip, both strips then being severed. On further movement of the gripper to the right, the upper jaw moves relatively leftward, to centre the strips over the object to be wrapped. The jaws then open and move further to the right to be detached from the severed strips, and the gripper returns to its initial position while the upper jaw again moves relatively leftward into alignment with the lower jaw. The first relative leftward movement of the upper jaw may be half the first such rightward movement or less, or may not take place.