Abstract: A seal wire heat control system adapted to record in memory the immediate history of the operation of the seal wire and to adjust the time duration of the application of voltage to the seal wire in accordance with a predetermined program. The application of heat is controlled according to the running history of the machine. At start up, a relatively long pulse of power is sent through the wire to make a seal for a predetermined number of times. When the count is reached, an intermediate pulse is provided to the wire for a predetermined number of times. When this count is reached, a short pulse is provided to the wire. A reset timer monitors idle time. If no seal is executed after a predetermined time, the entire system, including counters, resets to prepare for delivery of a long pulse to the wire. A safety timer is also provided for limiting the duration of power to the wire within the wire's safety threshold value.

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: A pneumatic-electromagnetic latch is disclosed as applied to bring the sealing jaws of an L-sealer into pressure engagement without impact. An electromagnet mounted on a piston rod of a pneumatic actuator attracts and retains an armature attached to the sealing jaws when the jaws are brought close to the sealing bed. The cylinder of the actuator is attached to the frame and when actuated it draws the sealing jaws into smooth pressure contact with the sealing bed. Upon deenergization of the electromagnet the jaws are released to open for the next sealing cycle and the release of fluid pressure in the actuator extends the piston rod to position for the next operation.

Abstract: A static sealer for causing overlapping portions of film to adhere to each other preparatory to shrink-wrapping in an automatic wrapping machine comprising a grounded support having a planar surface and a charging head for generating an electrostatic field between the gounded support and charging head through which the overlapping portions of the film are moved rectilinearly to charge the latter oppositely, said grounded support being so designed as to reduce frictional resistance of the overlapping portions of the film to rectilinear tracking, said charging head being provided with discharge electrodes arranged with at least one electrode positioned medially of the path of travel of the seam and two other transversely-spaced electrodes downstream of the medially-positioned electrode.

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.