US20060016063A1 - Lockseaming process and apparatus for the same - Google Patents

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.

Description

• This application Claims the benefits of prior filing date of provisional application number US60/590,950-Filing date Jul. 26, 2004-Applicant Mohamed T. Gharib, Brantford, Canada
BACKGROUND AND SUMMARY OF THE INVENTION
• Silencer shells (mufflers) such are the ones used in the automotive industries are formed by wrapping a thin sheet around a mandrel that have the same shape as the desired silencer (muffler) shell, then mechanically locking the two sheet edges using a process called Lockseaming. The Lockseaming process involves the use of gathering and Lockseaming rollers and produces drag on the sheet edges. This drag forces sheet material away from the Lockseam and causes the trailing end of the Lockseamed shell to be larger than the leading end. And causes the Lockseam to deteriorate at the trailing end of the Lockseamed shell.
• The current invention uses gathering bars and forming bars to gather the two sheet edges and perform the two edges at the correct location before Lockseaming. This greatly reduces the drag on the sheet edges and keeps the difference between the circumference of the trailing end of the Lockseamed shell and the leading end to a minimum and maintains the quality of the Lockseam along the entire Silencer shell length.
BRIEF DESCRIPTION OF THE DRAWINGS
• The present invention will become more fully understood from the detailed description and the accompanying drawings wherein:
• FIG. 1 is sectional view of Lockseaming apparatus according to current invention showing forming rollers in upper position, gathering and forming bars in the closed position and centre bar in the down position
• FIG. 1aand1bare sectional views of forming bars and centre bar showing two different shapes.
• FIG. 2 is showing a Lockseaming apparatus according to prior art showing forming rollers in the down position
• FIG. 3 is showing a Lockseaming apparatus according to prior art showing forming rollers in the up position and the sheet is partially formed around the mandrel.
• FIG. 4 is showing a Lockseaming apparatus according to prior art showing forming rollers in the up position and the roll carriage and gathering rollers are pre forming the two sheet edges.
• FIG. 5 is showing a Lockseaming apparatus according to prior art showing forming rollers in the up position and the roll carriage and gathering rollers are in advanced position of the pre-forming process.
• FIG. 6 is showing a Lockseaming apparatus according to prior art showing forming rollers in the up position and the roll carriage and Lockseaming rollers are Lockseaming the two sheet edges.
• FIG. 7 is showing a typical roll carriage with gathering and Lockseaming rollers.FIG. 8 is showing an enlargement of the finished Lockseam of an oval and a round Silencer (Muffler) shell.
• FIG. 9 is showing a Lockseaming apparatus according to prior art when Lockseaming large diameter Silencer (Muffler) shell.
• FIG. 10 is showing a Lockseaming apparatus according to prior art when Lockseaming large diameter Silencer (Muffler) shell and the forming rollers are raised higher to form a larger section of the sheet around the mandrel.
• FIG. 11 is sectional view of Lockseaming apparatus according to current invention showing forming rollers in down position, gathering and forming bars in the open position and centre bar in the down position
• FIG. 12 is sectional view of Lockseaming apparatus according to current invention showing forming rollers in upper position, gathering and forming bars in the open position and centre bar in the down position
• FIG. 13 is sectional view of Lockseaming apparatus according to current invention showing forming rollers in upper position, gathering bars in the closed position, forming bars in the open position and centre bar in the down position
• FIG. 14 is sectional view of Lockseaming apparatus according to current invention showing forming rollers in upper position, gathering and forming bars in the closed position and centre bar in the down position
• FIG. 15 is sectional view of Lockseaming apparatus according to current invention showing forming rollers in upper position, gathering bars in the closed position, forming bars in the open position and centre bar in the up position.
• FIG. 16 is sectional view of Lockseaming apparatus according to current invention showing forming rollers in upper position, gathering bars in the closed position, forming bars in the open position and centre bar in the up position while roll carriage and Lockseaming rollers are performing the Lockseaming operation
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• With reference toFIGS. 2, 3,4,5,6 and7adescription of the prior art technique for forming thin wall sheet into an Automotive Muffler Shell will be described. The forming technique according to the prior art includes providing aMandrel1 that is shaped the same as required muffler shell which can be Round or Oval or irregular shape.
• Asheet2 is placed under the saidmandrel1 and above Formingrollers3 and4 andpressure bar12. The saidrollers3 and4 are mounted onarms5 and6 and allowed to rotate aroundcentres7 and8 that are mounted onplatform11. Springs9 and10 are acting as to apply force against the saidarms5 and6.
• The saidpressure bar12 is mounted onpneumatic cylinder13 and is allowed to move up and down
• The saidplatform11 is moved up and down by the use of hydraulic cylinders or other means. As the saidplatform11 moves up, the said formingrollers3 and4 along with the saidarms5 and6 are rotated around the saidcentres7 and8 allowing the forces of the saidsprings9 and10 to be exerted on the saidsheet2 such that the saidsheet2 is partially formed around the saidmandrel1 as shown inFIG. 3.
• A set ofgathering rollers15 and16 andvertical rollers17 are mounted onroll carriage14 and is allowed to travel on top of thesaid mandrel1 and along the horizontal axis of the saidmandrel1 such that the two edges of the saidsheet2 are gathered together by the said rollers sets15 and16 and formed against the said vertical rollers set17 as to formedges39 and40.
• As the saidroll carriage14 travels along the axis of the saidmandrel1, the said set ofrollers15 and the said set ofrollers16 having different shapes will progressively form thesaid edges39 and40 closer as shown inFIG. 5.
• Following the said sets ofgathering rollers15 and16 and17 is two sets of Lockseamingrollers18 and19. Each of the said sets ofrollers15,16,17,18 and19 consists of a number of rollers of different shapes and will progressively form the said twoedges39 and40 into aLockseam41 as shown inFIG. 8
• The number or rollers in the said sets ofrollers15 and16 is different depending on design and preference. Typically design includes7 to9 rollers in each of the said sets ofrollers15 and16. The number or rollers in the said set ofrollers17 is different depending on design and preference. Typically design includes3 rollers in the said set ofrollers17.
• Similarly the number or rollers in the said sets ofLockseaming rollers18 and19 is different depending on design and preference. Typically design includes7 to9 rollers in each of the said sets ofrollers18 and19.
• FIG. 7 is showing a typical roll carriage arrangement.
• The means of mounting and moving the saidroll carriage14 will vary and is obvious to those skilled in the art.
• The saidsprings9 and10 can be replaced by hydraulic or pneumatic cylinders or other means that are obvious to those skilled in the art.
• According to prior art the saidplatform11 is moved to down position along with the saidrollers3 and4 and the saidarms5 and6 and the saidpressure bar12. The saidsheet2 is placed on top of the said formingrollers3 and4 and the saidpressure bar12.
• The saidplatform11 is moved up such that the said formingrollers3 and4 will partially form the saidsheet2 around the saidmandrel1.
• The saidpressure bar12 will hold the saidsheet2 firmly against the saidmandrel1 such that the saidsheet2 will not move in horizontal plane relative to the saidmandrel1 while the saidplatform11 is moving upward and the saidrollers3 and4 are forming the saidsheet2 around the saidmandrel1.
• The saidroll carriage14 with the said gathering rollers sets15 and16 and the said vertical rollers set17 and the said Lockseaming rollers sets18 and19 will travel along the axis of the saidmandrel1. The said gathering roller set will progressively bring thesaid sheet edges39 and40 together and form thesaid sheet edges39 and40 over the said vertical roller set17. Furthermore, the saidLockseamer rollers18 and19 will progressively form the said twoedges39 and40 into the said Lockseam41 as shown inFIG. 8
• Other means of forming the saidsheet2 around the saidmandrel1 provide forming shoes or horizontal rollers or other means that are obvious to those who are skilled in the art.
• Other means of gathering the said twosheet edges39 and40 and progressively forming the said twosheet edges39 and40 into the said Lockseam41 provide perform rollers to formsaid sheet edges39 and40 followed by gathering rollers or gathering bars followed by a set of Lockseaming Rollers or other means that are obvious to those who are skilled in the art.
• The process of gathering thesaid sheet edges39 and40 together causes drag on the saidmuffler sheet2 and causes the trailing end of the said muffler shell to be larger in circumference that the starting end. This problem is increased when forming large muffler cross-sections such as large round muffler and asymmetric shapes as illustrated inFIG. 9.
• As shown inFIG. 9 the said formingrollers3 and4 are placed at larger distance from the saidgathering rollers15 and16 and from the said Lockseamingrollers18 and19. That cusses alarge section42 and43 of the saidsheet2 to be unsupported between the said gathering andLockseaming rollers15,16,17,18 and19 and the said formingrollers3 and4. The drag on the saidmuffler sheet edges39 and40 will force the said sheet material into the saidareas42 and43 causing the trailing end of the said muffler to be larger than the said start end and will cause deterioration of the said Lockseam41 at the said trailing end.
• By forming a larger section of the saidsheet2 around the saidmandrel1 as shown inFIG. 10, the said formingrollers3 and4 are closer to the saidgathering rollers15,16 and17 and the said Lockseamingrollers18 and19, however thesaid sheet edges39 and40 are folded over each other making it impossible for the said vertical roller set17 to separate the said twosheet edges39 and40 and to form the said twosheet edges39 and40 as shown inFIG. 5.
• Present Invention
• The present invention provides aMandrel1 that is shaped the same as required muffler shell which can be Round or Oval or irregular shape.
• Asheet2 is placed under the saidmandrel1 and above formingrollers3 and4 andpressure bar12. The said formingrollers3 and4 are mounted onarms5 and6 and are allowed to rotate around centres7 and8 that are mounted onplatform11.Springs9 and10 are acting as to apply force against the saidarms5 and6.
• The saidpressure bar12 is mounted onpneumatic cylinder13 and is allowed to move up and down
• The saidplatform11 is moved up and down by the use of hydraulic cylinders or other means. As the saidplatform11 moves up, the said formingrollers3 and4 along with the saidarms5 and6 are rotated around the said centres7 and8 allowing the forces of the said springs9 and10 to be exerted on the saidsheet2 such that the saidsheet2 is partially formed around the saidmandrel1 as shown inFIG. 1.
• The said springs9 and10 can be replaced by hydraulic or pneumatic cylinders or other means that are obvious to those skilled in the art.
• The present invention also provides for gatheringbars20 and21 that are placed parallel to the horizontal axis of the saidmandrel1. Further, the said gathering bars20 and21 are mounted onarms22 and23. The saidarms22 and23 are allowed to swivel aroundaxis30 and31. Further, the said gathering bars20 and21 and the saidarms22 and23 are powered bycylinders32 and33 such that the saidarms22 and23 along with the said gathering bars20 and21 are rotated between an open and closed position.
• The invention also provides for formingbars24 and25 that are placed parallel to the horizontal axis of the saidmandrel1 and mounted onarms26 and27 that swivel around the saidaxis30 and31 and powered by atoggle34 and35 andslide38. The saidslide38 is powered bycylinder36 such that the saidarms26 and27 along with the said formingbars24 and25 are rotated between and open and closed position.
• The saidarms24 and25 can have same saidaxis30 and31 as the saidarms22 and23 or can have different axis.
• The saidarms24 and25 can be powered directly or through a toggle.
• The invention also provides forcentre bar28 mounted onrods29 and powered bycylinder37 such that the saidcentre bar28 is moved between an upper and down position.
• The said formingbar24 will further have ashape44 that matches theshape45 of the right hand side of the saidcentre bar28. The said formingbar25 will further have ashape46 that matches theshape47 of the left hand side of the saidcentre bar28 as illustrated inFIGS. 1aand1b.
• According to the current invention as shown inFIG. 11, the saidplatform11 is moved to down position along with the saidrollers3 and4 and the saidarms5 and6 and the saidpressure bar12. The said gathering bars20 and21 and the said formingbars24 and25 along with the saidarms22,23,26 and27 are rotated to an open position. The saidcentre bar28 and the saidrod29 are moved to down position. The saidsheet2 is placed on top of the said formingrollers3 and4 and the saidpressure bar12.
• As shown inFIG. 12, the saidplatform11 is moved up such that the said formingrollers3 and4 will partially form the saidsheet2 around the saidmandrel1 and such that said centre bare28 is placed between the said twosheet edges39 and40.
• The saidpressure bar12 will hold the saidsheet2 firmly against the saidmandrel1 such that the saidsheet2 will not move in horizontal plane relative to the saidmandrel1 while the saidplatform11 is moving upward and the saidrollers3 and4 are forming the saidsheet2 around the saidmandrel1.
• As shown inFIG. 13, the said gathering bars20 and21 along with the saidarms22 and23 are rotated to a closed position such that the said gathering bars20 and21 further form the saidsheet2 around the saidmandrel1 and partially form the said sheet edges39 and40 over the saidcentre bar28.
• As shown inFIG. 14, the said formingbars24 and25 along with the saidarms26 and27 are rotated to a closed position such that the said formingbar24 forms the saidsheet edge39 to match the said shapes44 and45 of the said formingbar24 and the saidcentre bar28. Similarly, the said formingbar25 forms the saidsheet edge40 to match the said shapes46 and47 of the said formingbar25 and the saidcentre bar47.
• As shown inFIG. 15 the said formingbars24 and25 along with the saidarms26 and27 are rotated around the said centres30 and31 to open position and the saidcentre bar28 and the saidrod29 are moved to upper position. The saidsheet2 will spring back between the said gathering bars20 and21 however the said sheet edges39 and40 will maintain its form as illustrated inFIG. 15.
• As shown inFIG. 16 the saidroll carriage14 with the said Lockseaming rollers sets18 and19 will travel along the axis of the saidmandrel1. Each set of the said Lockseaming rollers sets18 and19 consists of a number of rollers of different shapes and will progressively form the said twoedges39 and40 into the saidLockseam41 as shown inFIG. 8
• The means of mounting and moving the saidroll carriage14 will vary and is obvious to those skilled in the art.
• The motion of the said gathering bars20 and21 and the said formingbars24 and25 can be a sliding motion or any other motion that is obvious to those skilled in the art.
• As shown inFIG. 16, the saidparts44 and45 of the saidsheet2 between the said gathering bars20 and21 and the said Lockseaming rollers sets18 and19 are much smaller than the said parts between the saidrollers3 and4 and the said Lockseaming rollers sets18 and19. Hence the saidsheet2 is better supported and the circumference difference between the said trailing end of the muffler and the said leading end is kept to a minimum.
• And hence the said sheet edges39 and40 are formed using the said formingbars24 and25, there is no need for the saidgathering rollers15 and16 and the saidvertical rollers17, hence the said drag on the said sheet edges39 and40 is kept to a minimum, hence the circumference difference between the said trailing end of the muffler and the said leading end is kept to a minimum.
• As a result the saidLockseam41 remain consistent along the entire said muffler length.
• The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of this invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims (7)

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 toclaim 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 toclaim 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 toclaim 1 wherein the said centre bar will have a shape different from the said forming bars.

6. An apparatus according toclaim 3 wherein the said centre bar will have a shape different from the said forming bars.

7. A process according toclaim 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.

Images