Abstract: The present invention describes an improved grip belt drive system for use in sealing machines used to wrap articles in thermoplastic film. Briefly, a timing belt is used in place of the traditional flat or V belt. The presence of teeth on the pulleys, coupled with the use of a timing belt eliminates the possibility of slippage between the belt and the pulleys. To protect the system in the case of a film jam or misplaced article, a torque-limiting mechanism is included, which disengages the drive system if there is excessive counterforce. Furthermore, the outer surface of timing belt contains a pattern, which when mated with a second belt having the same or a complementary pattern, meshes in such a way so that the two belts are positively locked in both the longitudinal and transverse directions.

Abstract: The present invention describes a blade assembly for use with side-sealing and lap-sealing machines, which are used to seal thermoplastic film. Briefly, the cutting element is oval in shape, and has its entire outer edge profiled. This provides four distinct cutting surfaces, depending on the mounting orientation of the cutting element in the machine. This cutting element is held against a heating block, and its temperature is continuously monitored by a temperature sensor. The sensor is spring-loaded to insure solid contact with the cutting element, and thus, accurate temperature measurements. This entire assembly is then encased in insulation. Additionally, the cutting element is mounted on an adjustable platform, which permits vertical adjustments relative to the film. Thus, the specific portion of the cutting element which actually engages the film can be adjusted to improve the cutting quality or further extend the useful life of the cutting element.

Abstract: A sealing jaw apparatus for a plastic film wrapping machine has essentially spaced heated sealing jaws with a reciprocal knife located therebetween. The jaws operate against a heated elastomeric bed that has a longitudinal slot to receive the knife during the cutting operation. The arrangement provides a sealing of thermoplastic film and a severing thereof at a considerably lower temperature then the melting point of the film.

Abstract: A controlled product feed system for delivering discrete products at high speed to a downstream industrial operation which requires accurate speed and position of delivery. A retarding force is applied to the product stream to accumulate an abutting sequence of products with means controlling the rate of package release to correspond to the downstream operation and timing the release to obtain a predetermined phase of arrival of products at the point of delivery.

Abstract: A form fill seal type wrapping machine uses equal speed conveyors which are start/stop controlled to accept randomly fed packages and uniformly space them for wrapping and sealing in a roll fed wrapping material such as thermoplastic film. Different length packages can be wrapped without adjustment. One embodiment uses a traveling transverse seal mechanism so the machine can run continuously. Machine speed is enhanced by controlling dwell time for the transverse seal and time of travel for the transverse seal mechanism to be no longer than required to make the seal. A fast return mechanism for the transverse seal mechanism operates at a speed independent of machine speed.

Abstract: Apparatus for loading rolls of sheet material wound on cores into automatic wrapping machines wherein spindles are employed to support the rolls on overhead bearings for unwinding comprising a support upon which one end of the roll of sheet material to be loaded onto the bearings can be lifted and slid thereonto below the bearings, a hinge support mounting one of the bearings so that it can be moved from its operative position in alignment with the other bearing to an out-of-the-way position, and whereupon the ends of the roll spindle are centered over the bearings and the lift is retracted to lower the roll onto the aligned bearings.

Abstract: An automatic high-speed wrapping machine for wrapping packages in heat sealable thermoplastic film is disclosed wherein the film seal at the side and ends of the packages is made at a high rate of speed as the packages travel through the machine. The packages travel continuously in a straight line through the machine and are delivered at the input end of the machine by a flighted infeed conveyor into a film inverting head where the packages are surrounded by the film, thence to the side sealing mechanism which forms a seal while severing the selvage from the packages, then into an end sealing mechanism where both ends of the packages are sealed and the film web connecting succeeding packages is severed. The machine produces packages which have a sealed film wrap around the entire package which is then in condition for subsequent shrinking of the film if desired to provide a package having a tight film overwrap.

Abstract: An automatic L-sealer is arranged to pass product, including fragile items and loose piles of stacked paper, tiles or similar flat articles, through the machine without abrupt drops or changes in support level for the product to avoid breakage or upsetting of the pile. In the case of stacked loose flat articles an infeed conveyor deposits a package on an air table and an insertion arm progresses the package through the overwrap station to a sealing area where the L-seal completes and separates the overwrapped package. The sealing area includes a discharge conveyor pivoted at its discharge end and elevated at the end adjacent the air table to transfer the overwrapped package without an abrupt drop but is thereafter lowered during the sealing cycle to permit the seals to be made midway of the height of the package. The insertion arm retracts out of the path of package flow during its return stroke permitting infeeding of the next package to be initiated prior to the completion of the return stroke.