Title of Invention

"AN IMPROVED IMPLUSE SEALING SYSTEM"

Abstract

An improved sealing system comprising an upper and lower jaws pivotly secured with the respective shafts of the carrier block at the non sealing ends thereof, the upper jaw being connected to a cam lever through a flexible link to be actuated in the upper and downword directions characterized in that a piston cylindrical means is provided to push the said jaw in the semi-closed position towards the material provided in the packet to provide a tight seal of the wrapped packet and silicon rubber lips are provided at both the sides of the sealing rollers to stop damage to the sealing wrapper at the nip point.

Full Text

This invention relates to an improved impluse sealing system for use with a horizontal form fill and seal machine. In particular this invention relates to ^an improved in or relating to the impuls sealing machanism disclosed and described in the patent application no. 2659/DEL/97.%/ The impuls sealing machanisam of the patent application no. 2659/DEL/97 comprises an upper and lower jaw pivotly secured with the respective shafts at the non sealing end thereof. The upper jaw is connected to a cant lever through a flexible link such that to be actuated in the upper and downward directions. Gears are mounted on the shafts of said upper and lower jaws to provide actuating motion through the lower jaw. A heating wire is provided at the sealing surface of the upper jaw such that to be heated by providing power supply for a particular time pulse through a cam operated limit switch for sealing wrapping material. A heat registant pad is provided on the contact surface of the lower jaw. There are certain disadvantages associated with the sealing machanism known in the art. One of the main disadvantage is that enough clearance is provided between the sealing jaws to take care of any variation in packet length. Therefor, sometime the sealing of the packet is very loose. Another disadvantage is that the wrapping film is preferably of plane polypropylene, the risk of the film rupture at the stressed point of the film exists. Therefore, the main object of this invention is to provide an improved sealing system which obviate the disadvantages associated with the prior art. Another object of this invention is to provide an improved sealing system having means to seal the packet always in a tight position. According to this invention there is provided An improved sealing system comprising an upper and lower jaws pivotly secured with the respective shafts of the carrier block at the non sealing ends thereof, the upper jaw being connected to a cam lever through a flexible link so as to be actuated in the upper and downword directions characterized in that hydraulic piston cylindrical means being provided to push the jaw in the semi-closed position towards the packing material 8 provided in the packet so as to provide a tight seal of the wrapped packet and silicon rubber lips are provided at both the sides of the sealing rollers to stop damage to the sealing wrapper at the nip point. A sealing system according to a prefered embodiment is herein described and illustrated in the accompanying drawings wherein: Fig. 1 shows the plane view of the sealing machanism system in the open position. Fig. 2 shows the sealing system in the sealing semi closed position; Fig.3 shows the sealing system in the semi closed position of the jaws towards the packet; Fig,4 shows the sealing machanism in the closed/sealed position; Fig.5 shows the plan view of the leaver operating cam; and Fig.6 shows the sectional view of the roller sealing means having silicon rubber lip provided at the ends thereof. Referring to the drawings, particularly fig- 1 the sealing machanism has an upper jaw i and lower jaws 2 secured pivotly to a carrier block 3. The pivolted end of upper jaw 1 is connected to a cam operated lever 4 provided for opening and closing the upper and lower jaws 1 and 2 during the sealing operation by the sealing machanism. Carrier block 3 is mounted slidably on a guid bar 5 on both the ends thereof for sealing the packet at bogh sides thereof. Guid ways 6 are provided in the bottom portion of the carrier block 3 for guiding the movement of the carrier block 3 on the guiding bar 5. The carrier block 3 is connected to the hydraulic piston cylinder means 7 provided for pushing the carrier block 3 towards the packing 8, to be sealded, for providing tight sealing of the packet. A cam operative microswitch (not shown ) is provided for operating the hydraulic means 7 when the upper and lower jaws 1 and 2 cones into the semi closed position as shown in fig. 2. The jaws 1 and 2 comes in the semi closed position by the cam operater lever 4 and at the same time the hydraulic means 7 is switched on by the microswitch and starts working and the carrier block 3 is pushed towards trie packet as shown in fig.3. Finally the packet is tightly sealed by the upper and lower jaws as shown in fig. 4. The cam that operates the lever 4 to close the upper and lower jaws 1 and 2 has two rise parts AB and CD as shown in fig. 5. The first rise portion AB is provided to bring the jaws into the semi closed position, and the second rise portion CD closes the jaws completly and as shown in fig.4. The? sequence of the operation of the cam is as follows: Whenever product arrives into the sealing machanism the rise AB of the cam closes the jaws 1 & 2 partially and the solenoid , value, of the pneumatic cylinders 9 & 10 gets actuated at point L and the cylinder complets its stroke during L—M portion/part of the displacement diagram of the linear stroke 5. The rise CD of the sealing jaws 1 and 2. closes the jaw completly for starting sealing operation. At the point E on the displacement diagram (fig.5) of sealing jaws I and 2, operation cam starts opening the jaws and the jaws are completly open during the fall period EF of the cam. The pnewmatic cylinders 9 and 10 executes backward stroke during the NP part of the cycle. Reference is now made to fig.6, the silicon rubber lips 11 are provided at either end of sealing roller 12 to stop the transfer of heat from the roller 12 to the lip portion 11 and thus stops damage to the sealing wrapper during the sealing operation. Rest of the construction of the roller sealing means is the same as such known in the art. Thus it is seem that by providing hydraulic means 7 with the carrier block 3 the carrier block 3 is made to move towards the packet 8 to be sealed so as to provided a tight seal of the packet by the sealing means. Further by providing silicon rubber lip 11 at the ends of the roller 12 of the roller sealing means the damage at the nip portion of the sealing wrapper is stoped. I CLAIM; 1. An improved sealing system comprising an upper and lower jaws (1 and 2) pivotly secured with the respective shafts of the carrier block (3) at the non sealing ends thereof, the upper jaw being connected to a cam lever (4) through a flexible link so as to be actuated in the upper and downword directions characterized in that hydraulic piston cylindrical means (7) being provided to push the jaw in the semi- closed position towards the packing material 8 provided in the packet so as to provide a tight seal of the wrapped packet and silicon rubber lips (11) are provided at both the sides of the sealing rollers (12) to stop damage to the sealing wrapper at the nip point. 2. An improved sealing system as claimed in claim 1 wherein said means to push the block comprises preferably hydraulic means. 3. An improved sealing system substantially as herein described and illustrated.

Documents:

1625-del-1998-abstract.pdf

1625-del-1998-claims.pdf

1625-del-1998-correspondence-others.pdf

1625-del-1998-correspondence-po.pdf

1625-del-1998-description (complete).pdf

1625-del-1998-drawings.pdf

1625-del-1998-form-1.pdf

1625-del-1998-form-19.pdf

1625-del-1998-form-2.pdf

1625-del-1998-form-3.pdf

1625-del-1998-gpa.pdf

1625-del-1998-petition-others.pdf