초록 ▼

An automatic strapping apparatus is disclosed which forms a small primary loop from strap; expands the primary loop to a larger predetermined diameter loop which can be placed about a package to be strapped; and tensions, friction fuses, and severs the strap. The small primary strap loop is formed b

An automatic strapping apparatus is disclosed which forms a small primary loop from strap; expands the primary loop to a larger predetermined diameter loop which can be placed about a package to be strapped; and tensions, friction fuses, and severs the strap. The small primary strap loop is formed by feeding a free end of a length of strap into a circular cup through a slot in the cup sidewall so that the free end is guided by the inner periphery of the cup to form a loop with the strap free end overlapping a portion of the loop. The cup is moveable from an upper position around the formed primary loop to a position out of contact with, and below, the loop. A cylindrical gripper is provided inside the loop and a smooth-surfaced anvil is provided on the exterior of the loop for engaging the overlapped portion of the loop therebetween so that the strap free end is restrained by the gripper while the overlapped portion of the loop can be continued to be fed to expand the loop to a larger predetermined diameter. The strap free end remains restrained by the gripper as the strap is tensioned to tighten the loop about the package. The gripper is then rotatably oscillated at a high frequency to cause the strap free end to slide against the overlapped portion of the loop thereby generating heat and fusing the strap free end to the overlapped portion of the strap loop. A cutter is provided to sever the tightened and fused loop from the standing length of strap.

대표청구항 ▼

[An]In an apparatus for forming, tensioning, and securing a strap loop about a package, said apparatus comprising: means for [feeding]guiding a length of strap [in a path]to form a primary strap loop with a portion of the strap loop overlapped by the free end of the length of strap; means for restr

[An]In an apparatus for forming, tensioning, and securing a strap loop about a package, said apparatus comprising: means for [feeding]guiding a length of strap [in a path]to form a primary strap loop with a portion of the strap loop overlapped by the free end of the length of strap; means for restraining said free end of the strap from movement while feeding the standing length of the strap to expand the loop to a predetermined size; means for tensioning the strap to tighten the loop about said package; and means for joining said free end of the strap and an adjacent overlapped portion of the loop; the improvement in the apparatus characterized in that said means for guiding the strap to form a primary loop is free of guides for acting on the inside of the loop but includes an arcuate guide member having an inner surface for acting on the outside of the loop for guiding only one surface of the strap along the inner surface of the guide member to form said primary strap loop, said guide member defining a slot and being positionable to receive said length of a strap through said slot, said slot being open to one edge of said guide member; the improvement further characterized in that said guide member is movable relative to said restraining means; and the improvement further characterized in that said apparatus includes means for moving said guide member relative to said restraining means between a first position wherein said primary strap loop is formed and a second position spaced away from said first position to allow said primary strap loop to be expanded to said predetermined size out of contact with said guide member. [2. The apparatus in accordance with claim 1 in which said means for feeding said length of strap in a path to form a primary loop includes a guide member for guiding said length of strap in a closed path.] [3. The apparatus in accordance with claim 1 in which said means for feeding said length of strap in a path to form a primary loop includes a circular band member having a slot, said band member being positioned to receive said length of a strap through said slot and being designed to guide the strap along the inner surface of the band to form said primary strap loop.] [4. The apparatus in accordance with claim 3 in which said slot is open to one edge of said band member and including means for moving said band member between a first position wherein said primary strap loop is formed and a second position parallel to, and spaced away from, said first position to allow said primary strap loop to be expanded to said predetermined size out of contact with said band member.]