Method and apparatus for forming a metallic container

Abstract

A method of forming a metallic container by placing body and lid portions together, keeping parts of the body and lid portions in contact with one another, and vibrating the lid with respect to the body, thereby generating frictional heat to form a friction metallic weld therebetween. Apparatus for attaching the lid and body portions of the metallic container includes a body supporting base, an assembly to support a flange of the body, a sonotrode to contact a flange of the lid so that wherein the flanges of the lid and body are held together between the support assembly and the sonotrode. A motor vibrates the sonotrode relative to the support assembly to thereby move the flanges relative to one another generating sufficient frictional heat to create a friction metallic weld therebetween.

1 . An apparatus for attaching a lid portion of a metallic container to a body portion of the container, the container body portion including a flange having an inner surface and an outer surface, the apparatus comprising: 
 a base, and a support assembly movable relative to the base, the support assembly including a support surface for engaging the flange outer surface of the metallic container body portion,    a sonotrode having a friction surface, the sonotrode being movable relative to the base between a retracted position, wherein the friction surface is spaced from the metallic container, and an engaged position, wherein the friction surface engages the lid portion, and    a motor for vibrating the sonotrode relative to the support assembly when situated in the engaged position to move the lid portion relative to the body portion such that frictional heat generated from the vibrational motion welds together the lid portion and the flange of the metallic container body.    
   
   
       2 . The apparatus of  claim 1 , wherein the sonotrode is moved in the engaged position to confront the support surface so that portions of the lid and the body of the metallic container are held in contact with one another between the support surface of the support assembly and the friction surface of the sonotrode.  
   
   
       3 . The apparatus of  claim 1 , wherein the motor is adapted to reciprocally move the sonotrode at a rate of between 15 KHz and 25 KHz.  
   
   
       4 . The apparatus of  claim 3 , wherein the motor is adapted to reciprocally rotate the sonotrode around a longitudinal axis of the metallic container.  
   
   
       5 . The apparatus of  claim 1  or  4 , wherein the motor is adapted to reciprocally vibrate the sonotrode longitudinally relative to the metallic container longitudinal axis.  
   
   
       6 . The apparatus of  claim 1 , further including an actuator for advancing and retracting the sonotrode between the engaged position and the retracted position, wherein when the sonotrode is moved to the engaged position, the actuator moves the sonotrode toward the base such that the sonotrode exerts a force to hold portions of the lid portion and the body portion of the metallic container in contact with one another between the support surface of the support assembly and the friction surface of the sonotrode, the actuator being adapted to provide a force between approximately 1300 N and approximately 7200 N.  
   
   
       7 . The apparatus of  claim 1 , wherein the support assembly includes a frame, and a clamshell anvil, the clamshell anvil comprising two halves that are pivotally mounted onto opposing portions of the frame for pivotal movement between an open position and a closed position, and springs biasing the two halves of the clamshell anvil to the open position.  
   
   
       8 . The apparatus of  claim 7 , wherein the sonotrode is supported on a shaft, the shaft having a cammed outer surface, portions of the pivotally mounted clamshell anvil halves engaging the cammed outer surface, such that when the sonotrode is in the retracted position, the pivotally mounted clamshell anvil halves engage the shaft at a point where the shaft allows the clamshell anvil halves to pivot to the open position, and when the shaft and the sonotrode begin to move downward, the cammed outer surface of the shaft forces the clamshell anvil halves to pivot to the closed position wherein the support surface engages the flange of the body portion of the metallic container.  
   
   
       9 . The apparatus of  claim 8 , wherein the cammed outer surface of the shaft is shaped such that the clamshell anvil halves are forced to pivot to the closed position prior to the sonotrode reaching the engaged position.  
   
   
       10 . The apparatus of  claim 9 , wherein at least one of the clamshell anvil halves includes a stop extending from an inner surface of the clamshell anvil half, positioned vertically above the support surface, such that when the sonotrode retracts from the lid portion of the metallic container after welding, if the lid portion sticks to the friction surface of the sonotrode, the stop will contact the lid portion, thereby holding the metallic container down as the sonotrode retracts upward.  
   
   
       11 . The apparatus of  claim 1 , wherein the support surface of the support assembly has a textured surface such that the support surface will frictionally engage the outer surface of the flange portion of the body of the metallic container to prevent sliding movement of the flange of the body portion relative to the support assembly.  
   
   
       12 . The apparatus of  claim 1 , wherein the friction surface of the sonotrode has a textured surface such that the friction surface will frictionally engage the lid portion of the metallic container to prevent sliding movement of the lid relative to the sonotrode.  
   
   
       13 . The apparatus of  claim 1 , wherein at least one of the support surface of the support assembly and the friction surface of the sonotrode has a knurled pattern formed therein.  
   
   
       14 . The apparatus of  claim 13  wherein the knurled pattern comprises a triangular knurl pattern.  
   
   
       15 . The apparatus of  claim 1 , wherein at least one of the support surface and the friction surface are grit blasted.  
   
   
       16 . The apparatus of  claim 1 , wherein at least one of the support surface and the friction surface each have a raised ridge in a serpentine pattern.  
   
   
       17 . The apparatus of  claim 1 , wherein an interior surface of the body portion and the lid portion of the metallic container include a coating applied thereto, wherein when the sonotrode is moved to the engaged position, the sonotrode exerts a downward force to hold portions of the lid portion and the body portion of the metallic container in contact with one another between the support surface of the support assembly and the friction surface of the sonotrode, the downward force of the sonotrode and the frequency of vibration of the sonotrode provided by the motor being such that the frictional heat generated from the relative motion between the lid portion and the body portion is sufficient to create a friction weld between the lid portion and the body portion of the metallic container.  
   
   
       18 . The apparatus of  claim 1 , wherein at least one of the friction surface of the sonotrode and the support surface of the support assembly are angled relative to the longitudinal axis of the apparatus.  
   
   
       19 . A method of forming a metallic container comprising: 
 providing a pre-formed body portion;    providing a pre-formed lid portion;    placing the lid portion onto the body portion and applying a force to keep portions of the lid portion and the body portion held in contact with one another;    vibrating the lid portion with respect to the body portion to generate frictional heat between the lid portion and the body portion such that a friction weld is formed therebetween.    
   
   
       20 . The method of  claim 19 , further comprising the steps of 
 providing the pre-formed body portion with a generally cylindrically shape open at one end, the open end having an angled flange extending circumferentially therearound,    providing the pre-formed lid portion with a generally disk shape including an angled flange extending circumferentially therearound, the angle of the flange on the body portion being approximately equal to the angle of the flange on the lid portion.    
   
   
       21 . The method of  claim 20 , wherein said step of placing the lid portion onto the body portion and applying a force to keep portions of the lid portion and the body portion held in contact with one another includes 
 placing the lid portion onto the body portion such that an inner surface of the flange of the lid portion contacts an inner surface of the flange on the body portion and    applying a force to keep the inner surface of the flange on the lid portion held in contact with the inner surface of the flange on the body portion.    
   
   
       22 . The method of  claim 21 , wherein said step of applying a force to keep the inner surface of the flange on the lid portion held in contact with the inner surface of the flange on the body portion includes applying a force of between approximately 1300 N and 7200 N.  
   
   
       23 . The method of  claim 19 , wherein said step of vibrating the lid portion with respect to the body portion includes reciprocally rotating the lid portion with respect to the body portion at a rate between 15 KHz and 25 KHz.  
   
   
       24 . The method of  claim 19 , wherein said step of vibrating the lid portion with respect to the body portion includes longitudinally reciprocating the lid portion with respect to the body portion at a rate between 15 KHz and 25 KHz.  
   
   
       25 . The method of  claim 19 , wherein said step of vibrating the lid portion with respect to the body portion includes orbitally moving the lid portion with respect to the body portion at a rate between 15 KHz and 25 KHz.  
   
   
       26 . The method of  claim 19 , wherein said step of vibrating the lid portion with respect to the body portion includes randomly moving the lid portion with respect to the body portion at a rate between 15 KHz and 25 KHz.  
   
   
       27 . The method of  claim 23 , wherein the step of contacting the lid portion with a sonotrode that is movable with respect to the support assembly comprising the steps of: 
 moving the sonotrode into an initial engagement a first downward force, such that the motor reciprocally rotates the sonotrode at a first frequency for a predetermined amount of time; and    increasing the downward force to a second downward force, larger than the first downward force, and increasing the rate of reciprocal rotation of the sonotrode to a second rate, larger than the first rate, after the predetermined amount of time has passed; and    holding the sonotrode in the engaged position, at the second downward force, and maintaining the reciprocal rotation of the sonotrode, at the second frequency for a second predetermined amount of time.    
   
   
       28 . The method of  claim 27 , wherein the step of moving the sonotrode into an initial engagement a first downward force, such that the motor reciprocally rotates the sonotrode at a first frequency for a predetermined amount of time includes the step of wiping out any coating material on confronting surfaces of the body portion and lid portion to expose a weld zone.  
   
   
       29 . The method of  claim 28 , wherein said steps of increasing the downward force to a second downward force, larger than the first downward force, and increasing the rate of reciprocal rotation of the sonotrode to a second rate, larger than the first rate, after the predetermined amount of time has passed; includes the step of: 
 maintaining the reciprocal rotation of the sonotrode, at the second frequency until a friction weld has been formed in the weld zone.    
   
   
       30 . The method of  claim 27 , wherein the first frequency and the first downward pressure are between approximately sixty percent and approximately seventy percent of the second frequency and the second downward pressure.