Lockseaming process and apparatus for the same

Abstract

The present invention provides a method and apparatus for forming thin wall sheet into a mechanically locked shell by providing a Mandrel that is shaped the same as the required shell and a set of forming rollers that forms the said sheet around the said mandrel. And providing gathering and forming and center bares that are parallel to the horizontal axis of the said mandrel and are moved to form the two edges of the said sheet over the said center bar. And wherein the said gathering and forming and center bars are moved to open or up position. And providing Lockseaming rollers that are moved along the axis of the said mandrel such that the said Lockseaming rollers will progressively form the said two edges into the said mechanical lock commonly known to those who are skilled in the art as a Lockseam.

1 . A method for forming thin wall sheet into a mechanically locked shell comprising the steps off: 
 providing a Mandrel that is shaped the same as the required muffler shell which can be Round or Oval or irregular shape    providing a set of forming rollers mounted on arms and a platform that moves up and down such that the said thin wall sheet is placed over the said forming rollers when the said platform is in the down position and the said platform is moved up such that the said forming rollers will partially form the said thin wall sheet around the said mandrel    providing a set of gathering and vertical and Lockseaming rollers that are mounted on a roll carriage and is allowed to travel on top of the said mandrel and along the horizontal axis of the said mandrel such that the two edges of the said thin wall sheet are gathered together by the said rollers and progressively formed into a mechanical lock commonly known to those who are skilled in the art as a Lockseam    And by eliminating the gathering and vertical rollers.    providing gathering and forming bars that replaces the gathering rollers and are placed parallel to the horizontal axis of the said mandrel and allowed to rotate or slide or move between an open and closed position    providing a centre bar that replaces the vertical rollers and is placed parallel to the horizontal axis of the said mandrel and allowed to move between an up and down positions    wherein the said centre bar will have a right hand shape that matches the shape of the said right hand form bar and the said centre bar will have a left hand shape that matches the shape of the said left hand form bar and by placing said centre bar in the said down position before the said platform is moved up such that the said forming rollers will partially form the said thin wall sheet around the said mandrel and such that said centre bare is placed between the said two sheet edges and by moving the said gathering bars to close position such that the said gathering bars will further form the said sheet around the said mandrel and partially form the said sheet edges over the said centre bar and by moving the said forming bars to a closed position such that the said forming bars will form the said sheet edges to match the shape of the said centre bar and by moving the said forming bars to open position and the said centre bar to upper position and by moving the said roll carriage with the said Lockseaming rollers sets along the axis of the said mandrel such that the said Lockseaming rollers sets will progressively form the said two edges into the said mechanical lock commonly known to those who are skilled in the art as a Lockseam.    
   
   
       2 . The method according to  claim 1  where the said sheet is formed around the said mandrel using other means such as forming shoes or horizontal rollers or other means that are obvious to those who are skilled in the art.  
   
   
       3 . An apparatus for forming thin wall sheet into a mechanically locked shell comprising the steps off: 
 providing a Mandrel that is shaped the same as the required muffler shell which can be Round or Oval or irregular shape and by providing a set of forming rollers mounted on arms and a platform that moves up and down providing gathering and forming bars that are placed parallel to the horizontal axis of the said mandrel and allowed to rotate or slide or move between an open and closed position    providing a centre bar that is placed parallel to the horizontal axis of the said mandrel and is allowed to move between an up and down positions Wherein the said centre bar will have a right hand shape that matches the shape of the said right hand form bar and the said centre bar will have a left hand shape that matches the shape of the said left hand form bar wherein the said platform and the said form rollers are moved to a down position and a thin sheet is placed over the form rollers and the centre bar is placed in the down position and by moving the platform and form rollers to up position such that the said sheet is partially formed around the said mandrel and wherein the said gathering bars are moved to close position such that the said gathering bars will further form the said sheet around the said mandrel and partially form the said sheet edges over the said centre bar and wherein the said forming bars are moved to a closed position such that the said forming bars will form the said sheet edges to match the shape of the said centre bar and wherein the said forming bars are moved to open position and the said centre bar is moved to upper position and wherein the said roll carriage and the said Lockseaming rollers sets are moved along the axis of the said mandrel such that the said Lockseaming rollers sets will progressively form the said two edges into the said mechanical lock commonly known to those who are skilled in the art as a Lockseam.    
   
   
       4 . An apparatus according to  claim 3  where the said sheet is formed around the said mandrel using other means such as forming shoes or horizontal rollers or other means that are obvious to those who are skilled in the art.  
   
   
       5 . A method according to  claim 1  wherein the said centre bar will have a shape different from the said forming bars.  
   
   
       6 . An apparatus according to  claim 3  wherein the said centre bar will have a shape different from the said forming bars.  
   
   
       7 . A process according to  claim 1  where the said gathering bars are returned to the said open position before the said roll carriage and the said Lockseaming rollers are moved along the axis of the said mandrel such that the said Lockseaming rollers sets will progressively form the said two edges into the said mechanical lock.