Abstract:
A method and apparatus particularly suited for cutting continuously moving thermoplastic film such as linear low density polyethylene and includes a stationary anvil, preferably a roller of tool steel and a tungsten carbide die mounted for rotation along a circular arc intersecting the anvil. In an embodiment for punching holes in the film, the apparatus includes a saddle shaped hollow tungsten carbide die projecting slightly above the cylindrical surface of a roll passing under a spring biased tool steel roller for cutting a semicircular hole in a continuously moving continuous plastic film web for the manufacturer draw tape bags. A vacuum is supplied to the center of the die for removing the segment of plastic film cut out by the apparatus. In an alternate embodiment, the rotary cutting apparatus includes a tungsten carbide plate member having a straight cutting edge is rotated along a circular arc at the end of support mounted to a shaft to intersect a spring biased roller supported along the arc to cut a perforation in a continuous plastic film passed between the straight cutting edge and roller. The alternate embodiment is suited for employing a plurality of the rotary cutting devices at spaced stations for cutting perforations across a moving film web.
Abstract:
A draw band bag made from polyethylene film providing a bag body having side seals and a mouth at one end of the body defined by a lip portion. A draw band extends along the lip portion of the bag and is secured at the opposite ends to the side seals of the bag. The body has an opening therethrough adjacent the lip portion and intermediate the side seals through which the draw band is adapted to be pulled for closing the mouth. The draw band covers the openings through the bag body prior to being pulled therethrough. After the draw band is pulled through the openings to close the mouth, it is used to make a half hitch around the top of the bag and pulled tight.
Abstract:
A method of and apparatus for feeding a continuous thin film plastic tape or like, pliable, foldable strip in an oscillatory fashion, which may be random, from a feed surface having a width many times greater than the width of said tape to a receiving surface having a width at least as great as a tape width and many times narrower than the width of the feed surface by spacing and positioning the feed and receiving surfaces with respect to one another to limit the maximum angle between a transverse plane bisecting the receiving surface and extending towards the approaching tape and the centerline of the tape. The maximum value of this angle, in degrees, is about 6.5 times the inverse of the tape width expressed in inches. The invention is illustrated with an apparatus which converts the oscillatory motion of a tape fed from a roll many times wider than the tape over an equally large roller surface to a pulley only slightly wider than the tape and many times smaller than the roller surface.
Abstract:
A method is described for making a fiber-reinforced composite film sheet (fiber/film laminate) by continuously forming a first planar lap from a plurality of machine-direction (MD) fibers, continuously forming a second planar lap from a single fiber as transverse-direction (TD) reaches which are connected by 180.degree. loops by stretching the fiber between a horizontally diverging pair of chain assemblies, continuously straddling both laps with a pair of co-extruded films which extend sidewardly beyond the loops, vertically converging the films and fibers to form a sandwich, edge sealing the sandwich within strips close to its side edges but inwardly of the loops, lifting the loops from the chain assemblies, sidewardly smoothing and tautening the sandwich, and laminating the sandwich with heat and pressure to form the composite film sheet and application for carrying out this method.
Abstract:
A flexible coupling of the light weight, low inertia spring plate type having a central disk which through flex provides for angular misalignment and four supporting side leaf springs which provide for parallel misalignment. Bolted on exterior drive lugs transmit the torque to the central disk. Bronze guides provide for attachment of the leaf springs to the center disk. The drive and driven plates are connected to hubs which are split so they can be clamped onto the input and output shafts which are subject to alternating torque loads.
Abstract:
A tarpaulin incorporating a novel and structure which will enable the tarpaulin to be readily utilized as an outdoor cover, drop cloth, lawn cleanup sheet and numerous other applications even under relatively adverse environmental conditions. The tarpaulin is preferably constituted of a fiber-reinforced thermoplastic film material, which incorporates corner or edge grommet structure; which enables staking or weighted components to be detachably fastened to the structure so as to ensure that the tarpaulins will not be displaced or carried off in response to extraneous forces caused by the elements, while concurrently allowing for the easy handling thereof during use, particularly when employed for outdoor purposes, such as the accumulation and removal of lawn trash constituted of leaves, grass or shrubbery cuttings and the like.
Abstract:
An assembly for thermoplastic shoppings bags which are adapted for employment as containers for grocery and produce items when they are employed in conjunction with a novel loading system for retail food market check-out counters. A novel method and apparatus are also provided for opening successive bags for filling and, when a bag is fully loaded, its removal from the filling station causes opening of an adjacent bag to a loading position.
Abstract:
Apparatus particularly suited for cutting continuously moving thermoplastic film such as linear low density polyethylene and includes a stationary anvil, preferably a roller of tool steel and a tungsten carbide die mounted for rotation along a circular arc intersecting the anvil. The roller is positioned at a stationary location along a circular arc for cyclicly contacting and rolling across the cutting surface for cutting the plastic film web passing between the roller and the cutting surface at the predetermined locations in the web. The roller is mounted on a support member by an assembly including a bracket mounting a shaft supporting the roller. The bracket is attached to one end of a rocker arm and the other end of the rocker arm is pivotally carried by the support member. A housing for a loading spring is carried by the support member adjacent the rocker arm. The housing has a tubular opening therethrough having an axial extending transversely to the axis of the shaft supporting the roller. A helical loading spring is disposed within the tubular opening of the housing and has one end engaging the rocker arm. A spring adjusting screw is carried in one end of the tubular opening in the housing for engaging the opposite end of the helical spring to adjust the load pressure of the spring applied to the roller. A stop member is carried by the support member on the opposite side of the rocker arm to limit movement of the roller in the direction of the cutting surface.
Abstract:
A mechanical folding device fires a multiplicity of pins through an air table and a multiplicity of parallel endless belts forming the conveyor to lift a flexible foldable length of material, such as a plastic film bag body, into a catching device such as a pair of nip conveyors carrying sets of folding belts for completing the fold and carrying the length of material away from the first conveyor. The pins are fired through the air table and conveyor belts by means of a torsion bar coupled by means of lever arms to a carriage carrying the pins. The torsion bar is mechanically loaded by a first air cylinder while the carriage is locked in a lowered position. When the carriage is released by a second air cylinder, the torsion bar first accelerates the carriage upward then decelerates the carriage during the upper half of the extension of the pins. The bar forces the pins to return to a retracted position within the air table.
Abstract:
An hydraulic index drive system including a variable displacement pump closely coupled to a fixed displacement motor through an adaptor which feeds oil to and returns oil from the motor. A lever on the pump controls the position of a swash plate which determines the pump displacement. The lever is positioned by a cam which makes one revolution per cycle. The cam is designed such that for 40% of the cycle there is no pump output which is the dwell portion of the cycle and for 60% of the cycle the output rises to a set maximum and returns to zero output which is the index portion of the cycle. The pump is driven by a variable speed motor. The system is particularly suited for use with a vacuum conveyor on a bag machine line for transfer of plastic bags to a bag folder.