This invention relates to apparatus for closing containers formed from a flexible material, such as plastic bags. With the widespread usage of such containers for handling a wide variety of materials, various machines have been proposed to eliminate the necessity of hand sealing of the containers. Such machines have typically employed a pair of gathering arms movable between an open position and a closed position in which the flexible material of the container is gathered and compressed. With the flexible material in that gathered and compressed condition, a sealing device (a device for applying a staple, a wire twist, etc.) is actuated to firmly seal the container. Examples of such devices can be found in Neidecker U.S. Pat. No. 3,717,972; Tipper U.S. Pat. No. 3,293,736; and Russel et al, U.S. Pat. No. 2,733,442.
Experience has proven, however, that it is not always easy to rapidly feed containers to such machines and the machines have often caused damage to the container material, especially when it was relatively thin. Additionally, some machines themselves had a relatively short usable lifetime when used for sealing flexible containers used to package an abrasive material.
USPTO Backgrounds
USPTO Backgrounds