US2929914A

US2929914A - Apparatus for fabricating tubular shells

Info

Publication number: US2929914A
Application number: US663919A
Authority: US
Inventors: Walter J Ely
Original assignee: OLDBERG Manufacturing CO
Current assignee: OLDBERG Manufacturing CO
Priority date: 1957-06-06
Filing date: 1957-06-06
Publication date: 1960-03-22
Anticipated expiration: 1977-03-22

Description

4 Sheets-Sheet 1 JNYENTUH; ML T512 J ELY.

W. J. ELY

March 22, 1960.

APPARATUS FOR FABRICATING TUBULAR SHELLS Filed June 6, 1957 www March 22, 1960 w. J. ELY 2,929,914

APPARATUS FOR FABRICATING TUBULAR SHELLS Filed June 6, 1957 4 Sheets-Sheet 2 II .J

I llllll I h -p l I INK/ENTER. I/I/I IL m2 JELK March 22, 1960 w. J. ELY

APPARATUS FOR FABRICATING TUBULAR SHELLS 4 Sheeis-Sheet 3 Filed June 6, 1957 YENTUJZ LTEH JZ'LY.

.ATTY'.

March 22, 1960 w. J. ELY 2,929,914

APPARATUS FOR FABRICATING TUBULAR SHELLS Filed June 6, 1957 4 Sheets-Sheet 4 INK/ENTER I I Im T21: JIELY. .IBY

United States Patent APPARATUS FOR FABRICATING TUBULAR SHELLS Walter J. Ely, Grand Haven, Mich., assignor to Oldberg Manufacturing Company, Grand Haven, Mich, a corporation of Michigan Application June 6, 1957, Serial No. 663,919 8 Claims. (Cl. 219-78) This invention relates to a method of and apparatus for forming or ccnfigurating metal sheets into tubular or shell formation and more especially to the processing of metal sheets into configurations of noncircular crosssectional contour such as an intermediate sheet metal bafiie or shell construction for a sound attenuating means or muffler for use with the exhaust gas system of an internal combustion engine.

In the utilization of sound attenuating mufilers for use with the exhaust system of an internal combustion engine of an automotive vehicle it is desirable to dispose the muffier construction as close to the floor of the vehicle as possible to secure adequate road clearance especially in view of the trend in design to lower the components of the vehicle as much as possible. The chassis construction of a vehicle necessarily includes cross frame members to provide adequate support for the vehicle floor and body construction. To adapt mufilers for installation close to the vehicle floor, the inlet and outlet gas passage tubes are disposed near a lower wall of the mufiier in order to provide clearance for the frame cross members.

Such mufiier constructions include an intermediate shell or bafile means of pear-shaped cross section embracing an inlet or exhaust conveying duct so as to form sound resonating compartments or chambers for attenuating high frequency sound waves.

The present invention has for an object the provision of a method for forming a tubular shell of this character from sheet metal involving the steps of configurating a substantially flat sheet into a tubular configuration of noncircular cross section and permanently maintaining such configuration.

An object of the invention is the provision of an apparatus for performing steps in the method of configurating a metal sheet into a tubular configuration of generally tear drop shape in cross-sectional contour and securing overlapping regions of the sheet together in order to maintain the tear drop configuration.

Another object of the invention is the provision of an apparatus equipped with a nipping station and a tube forming station in which a movable component preforms a nip or bend in a metal sheet and another portion of the movable component engages the sheet at the tube forming station to complete the formation of the tube.

Another object of the invention is the provision of a simple yet effective apparatus for automatically forming a metal sheet into noncircular shell configuration wherein overlapping regions of the configurated sheet are welded together and the operations of forming the shell configuration performed in rapid sequence whereby high production is attained.

Further objects and advantages are within the scope of this invention such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economics of manufacture and numerous other features as will be apparent from a consideration of the specification and drawing of a form of the invention, which may be preferred, in which:

Figure 1 is a front elevational view illustrating a form of apparatus of the invention; 7

Figure 2 is a top plan view of the apparatus illustrated in Figure 1;

Figure 3 is a side elevational view with certain parts shown in section of the apparatus illustrated in Figures 1 and 2;

Figure 4 is an isometric view of a mandrel construction forming a component of the apparatus;

Figure 5 is an isometric view of a forming die and blank holding means of the invention;

Figure 6 is a schematic view illustrating the position of a blank at the nipping station prior to the nipping operation;

Figure 7 is a view similar to Figure 6 illustrating the method of forming a nip or bend in the end region of a blank;

Figure 8 is a schematic view illustrating the relation of the blank configurating means and the position of a blank just prior to its delivery to shell forming position;

Figure 9 is a semi-diagrammatic view illustrating the step of folding the nipped region of the blank into contiguous relation with a mandrel;

Figure 10 is a view similar to Figure 9 showing the blank in fully configurated position;

Figure 11 is a semi-diagrammatic view illustrating the step of fastening overlapping regions of the blank together; and

Figure 12 shows the completed tubular shell being ejected from a mandrel.

While the form of apparatus of the invention is especially adapted for carrying out the method of forming tubular bafile means or shells for installation on the interior of sound attenuating mufilers or silencers for exhaust gas systems, it is to be understood that the method and apparatus of the invention may be utilized for forming articles of similar configuration or shape from sheet metal blanks.

The method of the invention involves a series of steps or operations which are performed in definite sequence at timed intervals to attain high production of the sheet metal shells. The method steps and operations involve consecutive placement of sheet metal blanks at a nipping station wherein an end region of the blank is nipped, bent or curved to the extent equivalent to about onequarter of a circle, the blank being then transferred to a forming station. The nipped blank at the feeding station is automatically moved into a position adjacent a mandrel and is held in fixed relation adjacent the mandrel while die means configurates or bends the blank into contiguous relation with certain planar surfaces of the mandrel and immediately thereafter another portion of the blank is curled or bent about a curved region of the mandrel to form the shell configuration.

Overlapping regions of the shell configuration are engaged by means adapted to secure the overlapping regions together so as to maintain the proper shape of the shell. The shell is removed from the mandrel automatically to complete the cycle of operations. The several steps or functions in the method are carried on automatically by means correlated to obtain maximum production of the shell units. I

Referring to the drawings in detail and initially to Figures 1, 2 and 3, the apparatus is inclusive of a frame structure 10 which includes horizontal channel members 11 supporting upwardly extending struts or uprights 12 joined together by substantially

parallel frame plates

14 and 16 secured thereto by bolts or other suitable means. Angularly arranged struts are welded to the channel members and to the vertical struts 12.

The arrangement is inclusive of a blank receiving and nipping station 20 at which a substantially flat blank B is received and an end region bent or' nipped into a generally arcuate configuration as shown in Figure 7. The arrangement includes a relatively movable blank support or uniplanar platenv 22 which is secured. to a shaft 24 which is suitably journalled in bearings carried by the

plates

14 and 16, the platen 22 being thus pivotally mounted for oscillatory movement about the axis of the shaft 24.

Secured to the shaft 24 isa downwardly extending pin 26 which is connected by a contractile coil spring 28 with a block 30 or othermeans for anchoring the opposite end of the spring 28 in the manner illustrated in Figure 1'.

Mounted upon the extremities of the cross members or plates 14 and16 is a bar or member 32 which, as shown in Figure 2, extends forwardly of the-frame structure and beneath an end portion of a sheet metal blank B. Secured to the distal end of the. movable platen or work support 22 is one leg 34 of an S-shaped member 36, another leg portion 37 of which engages a lower surface of the bar-32 to limit the uppermost position of the platen 22.

The apparatus includes a means for nipping or bending an end region of a blank at the'nipping station 20 to form an arcuate shape or bent configuration'to the end region of a blank. This arrangement is inclusive of a shaft 40 journalled in suitable bearings contained within

housings

42 and 43 which are secured respectively to the

frame plates

14 and 16 by means of bolts 45 which pass through flange portions 46 formed on each of the bearing housings. V

Mounted upon the shaft 40 at the region thereof extending forwardly of the frame plate 14 is a member or block 41 which is secured to the shaft by a key 44. Secured to the member 41 is an arm or extension plate 48. Welded to the plate 48 and extending substantially at right angles thereto is a strut or member 50. The members 48 and 50 are also joined by a wall 52 which is welded or otherwise secured to the plates 48 and 50.

A second member or strut 55 is arranged in parallel relation with the strut or plate 50, the member 55 having an extending portion 57 which rests upon an upper surface region of the plate 48. The portion 57 is secured to member 41 by means of bolts 58 While the strut portion 55 is secured to the plate 50 by means of bolts 66 or other suitable means. The distal end or extremity of the stnlt or member 55 is provided with a cylindrically shaped member 62 or a member of suitable curvature for imparting a curved shape to the blank.

Rotation of the shaft 40 in a counterclockwise direction as viewed in Figure 1 swings the assemblage of

plates

48, 50, 52 and the strut member 55 in a position wherein the cylindrical member or nipping means 62 engages a sheet metal blank B disposed upon the platen 22, the blank being properly positioned on the platen by means of pins 64 and an abutment block 65. The end portion of the blank B extends over the nip bar 32 and as the cylindrical member 62 engages the blank, the platen 22 is'swung downwardly about the axis of the shaft 24while the end region of the blank remains in engagement with the nip bar 32. During downward movement of the cylindrical member 62, a region'of the blank is' bent around a por tion of the periphery of the member 62 by reason of the adjacentv end of the blank remaining in engagement with the nip bar. The curved or arcuately shaped portion of the blank is shown at 68 in Figures 7, 8 and 9.

The plate or arm'48 is equippedat its distal end with a-curling or bending die 70:which is secured to the :plate 48 by means of bolts 72. When the strut construction 55 is moved into the blank-nipping position, the plate 48 and 7 section as illustrated in Figure 12.

4 the curling die 70 are in the position shown in broken lines in Figure 1.

Means are provided for rotating the shaft 40 to effect the changes in position of the nipping member 62 and the forming die 70 in carrying on the sequenceof operations. Secured to a portion of the shaft 4iladjacent the bearing member 43 is an arm provided with a pin 76 upon which is journally supported a cam roller or follower 78.

Disposed transversely of the frame construction is a member or plate 80 which is slidably supported in suitable recesses fashioned in

members

81 and 82, the plate being held therein by plates or members 83. As shown in Figure 1, the slidable plate 80 is formed with a cam slot accommodating the cam roller 78, the cam slot being fashioned with an arcuately contoured portion 84 and a horizontal portion or dwell 86. The cam slot is of a width to accommodate or receive the roller or follower 82 carried by the arm 75. Reciprocation of the plate or slidable member 80 moves the roller 82 in the cam slot to control the movement of the nip forming roll 62 and the bending die 70.

The apparatus for operating the slide or cam plate 80 is shown in Figure 2. Secured to the plate 80 is a wrist pin which receives one end of a connecting rod or pitman 92, the opposite end being connected with a crank pin 94 which is associated with one of the links of a roller chain 98.

The roller chain 98 takes over a driving sprocket 100 and an idler sprocket 102. The driving sprocket'100 is mounted upon a shaft 104 journalled within a housing 106.

Mounted on the shaft 104 within the housing 106 is a worm wheel 108 which is in constant mesh with a worm 110 mounted upon a shaft 112 journalled in a hub portion 114 formed on the housing 106. Mounted upon the shaft 112 is a pulley 116 which is connected by means of a driving belt 118 with a pulley 120 carried by the shaft 121 of a motor 122 shown in Figure 3. The motor 122 is bolted or otherwise secured to a frame member 124. The idler sprocket 102 is .carried upon a shaft 126 journalled in spaced bearing means 127 carried by spaced plates 128. V

Rotation of the motor shaft 121 causes rotation of pulley 116 and shaft 112 and, through the gear reduction provided by the worm 110 and the worm wheel 108, the sprocket 100 is rotated at a comparatively slow speed and moves the roller chain at the same speed. Movement of the roller chain causes the pin 94 to move in the same path of traverse as the roller chain 98 and through the medium of the pitman 92 effects slidable reciprocatory movements of the slidable member or plate 80. Thus the slidable reciprocatory movements of the plate 80 control the movement of the cylindrically shaped member 62 and the bending'die 70 through the medium of the cam 78 traversing the cam slot 84.

In the operation of one phase of the apparatus, the cylindrically shaped member 62 is moved to the position illustrated in Figure 7 and in a broken line position as shown in Figure 1. When a blank B is supported at its end region by a bar 32, movement of the cylindrically shaped member 62 into engagement with the blank B 'as shown in Figure 7 forms the arcuate or curved configuration 68 in an end region of the blank The arrangement or apparatus is inclusive of a structural combination for forming the blank B into tubular configuration of generally tear drop shape in cross- The blank is adapted to be wrapped around a mandrel construction 74 which in the embodiment illustrated is fashioned 'of three components or elements .132, .133 and 134. As shown in Figure? the mandrel construction 74 is supported by the frame and is clamped in position by means of a saddle or,cap,136 held in place by suitable screws .138.

The mandrel construction illustrated is of generally tear drop shape in cross-section, the upper surface 140 of the mandrel component 132 being of semi-cylindrical shape as particularly shown in Figures 9 through 12. The side walls of the

mandrel components

133 and 134 are generally convergently arranged to form convergent side walls in the tubular shell S, which are joined with a comparatively short connecting wall formed around the lower surface 145 of the mandrel component 134.

Disposed adjacent the mandrel 74 is a means for receiving the blank B from the blank nipping station 20 and for conveying the blank into a position to be formed or wrapped around the mandrel 74. Extending forwardly of the frame is a plurality of ways 147 upon which is slidably supported a table, plate or platen 148 for conveying the blank having a curved end region into a position adjacent the mandrel whereby the blank may be folded, bent or formed around the mandrel. Secured to the slidable table or platen 148 is a rod or member 150 which is guided through suitable bushings 152 supported by the

frame members

14 and 16 as shown in Figure 2. Positioned on the rear of a frame member 154 is a fluid actuated means for reciprocating the table or platen 148.

As shown in Figure 2, the fluid actuator is inclusive of a cylinder 156 supported upon a bracket 158 which is mounted upon the frame member 154. The rod 150 extends into the cylinder and is equipped with a piston 159. The admission of pressure fluid such as compressed air or oil under pressure into the rear end of the cylinder 156 moves the piston 159 forwardly in the cylinder, and through the medium of the rod 150 the table 148 is moved forwardly of the machine to the position indicated in broken lines in Figure 2. The fluid flow to the cylinder 156 is controlled by solenoid actuated valve means (not shown).

The table 148 in its extended position is adapted to receive a partially formed or nipped blank which has been transferred from the pivotally supported platen 22 onto the slidable table 148. The platen 148 is equipped with pins or abutments 162 adapted for engagement with the edge of the blank to properly position the same on the platen. The blank is properly positioned in a lengthwise direction by engaging an end edge of the blank with an abutment 164 as shown in Figure 1.

The abutment 164 is supported upon a member 165 which is bolted or otherwise secured to a plate 166 by means of bolts 167. The surface region of the table 148 is provided with inserts 148, being magnetic in character to assist in retaining the blank on the table.

When the table 148 moves a blank beneath the mandrel 74, the inner edge of the blank contacts a spring-biased plunger 149, shown in Figure 1, which maintains the blank in engagement with the pins 162 to properly position the blank beneath the mandrel.

Means are provided for cooperation with the mandrel construction 74 for forming a blank to a generally U or V-shaped configuration of the contour provided by the exterior surfaces of the

mandrel components

133 and 134. Carried by the frame member 14 and a frame member 170 is a supplemental frame construction 171 which slidably supports a forming die 172 as shown in Figure 3.

The forming die 172 is coextensive with the mandrel 74 and is arranged for vertical movement relative to the mandrel. The forming die 172 consists of spaced

portions

173 and 174, each formed with a tapered surface 175. The tapered surfaces 175 are of the same angularity as the tapered sides of the mandrel component 134.

The supplemental frame construction 171 is formed with a vertically disposed wall 176, a second vertically disposed wall 177 and transversely extending members 166 and 178, the latter connecting the lower extremities of the

walls

176 and 177. The wall portion 177 is secured to the wall plate or member 14 as shown in Figure 3. Secured to the wall portion 14 and the wall 176 are guides or ways 180 and slidably disposed between the walls is the forming die 172 which is guided for vertical slidable movements by the ways 180.

The central region of the forming die 172 is provided with vertically arranged openings adapted to receive or accommodate vertically disposed rods or shafts 184. The cross member 178 is also provided with openings through which extend the lower regions of the rods 184.

The upper ends of the rods 184 are provided with tenon portions 186 which snugly fit into sockets or bores formed in a blank holding member or pad 187, the rods being secured to the pad 187 by means of pins 188. The rods 184 are arranged for slidable vertical movement relative to the forming die 172.

Mounted on each of the rods or shafts 184 is a collar 190 and disposed between each collar 190 and the cross member 178 is an expansive coil spring 192 which urges or biases the shafts 184 and the blank holding pad or member 187 toward the mandrel 74. The blank holding member 187 is coextensive with the lower component 134 of the mandrel 74, the expansive pressure of the springs 192 functioning to secure the blank in engagement with the lower surface of the mandrel component 134 during movement of the forming die to bend the blank into generally U-shaped configuration provided by the contour of the lower region of the mandrel 74.

Means is provided for vertically reciprocating the forming die 172, which means in the present embodiment is cam actuated. Disposed beneath and secured to the forming die 172 is a member 195. The member 195 is provided with recesses 197 adapted to receive and accommodate projections or furcations 199 formed on a member 200 particularly shown in Figure 1.

Mounted upon plate 14 is a bearing support or journal 202 and mounted upon plate 16 is a second journal 204 as shown in Figure 2. Rotatably mounted in bearings carried by the

journal members

202 and 204 is a shaft 206.

Secured to the forward end region of shaft 206 is a member or block 208 provided with a recess snugly receiving the member or block 200, the latter being securely held in the block 208 by means of screws 210. A key 212 secures the block 208 to the shaft 206 whereby the block 208 and the projecting member 200 are rotated with the shaft.

Fixedly mounted upon the rear end region of the shaft 206 is an arm or member 214 equipped with a roller 216 which traverses a cam slot 218 formed in the slidable or plate member 80. The cam slot 218 is fashioned with

horizontal portions

220 and 222 and an angularly arranged portion 224 connecting the horizontal portions of the cam slot 218. The slot 218 controls the vertical reciprocatory movements of the forming die 172. Thus, as shown in Figure 1, the cam roller 216 is in the horizontal portion or dwell 220 maintaining the forming die 172 to its uppermost position forming the blank around the lower region of the mandrel 74.

When the slidable member 80 moves in a right-hand direction as viewed in Figure l, the roller 216 traverses the angular portion 224 of the slot, causing rotation of shaft 206 in a clockwise direction as viewed in Figure l, wherebythe projections 199 move the forming die 172 downwardly to its lowermost position determined by the presence of the roller 216 in the horizontal dwell portion 222 of the cam slot 218.

In the lowermost position of the forming die 172, the lower surface 224 engages the collars or abutments 190 on the shafts 184 to lower the blank-retaining pad or member 187 a sufficient distance to enable the finished shell to be stripped from the mandrel 74 and to facilitate insertion of a blank beneath the mandrel. The arrangement is inclusive of means for welding or joining overlapping regions of the formed shell while the same is held in engagement with the mandrel by means V v tam-14.

7 of the bending die 70' and the forming die 172 as shown in Figure'IO. Y

The overlapping regions of the shell blank are joined together by a series of spaced spot welds 227 shown in Figure 12 through the engagement of a plurality of electrodes or welding tips brought into engagement with the overlapped portions. A mounting plate 228 shown in Figure 1 is secured to the frame of the machine. Disposed adjacent the mounting plate is a plurality of cylinders 230, and disposed in each cylinder is a piston 231 connected with a welding electrode 232. The Welding electrodes may be formed of copper or other suitable metal. having high current conducting characteristics.

Secured to the rear end of each of the cylinders 230 is a. tube 234 connected with a header or manifold 236 which. is connected by means of a tube 238 with an air operated hydraulic actuator 239. The fluid for actuating the pistons 231 in the cylinders 230 is preferably oil and is associated with an air actuator 239' whereby air pressure in the actuatoris effective on the oil to move the electrodes 232 into impinging engagement with the overlapping portions of the shell blank on the mandrel Electrical energy is supplied to the electrodes 232 by means of insulated conductors 240 connected with

buss bars

241 or 242, there being five electrodes illustrated, two of whichqare connected with the buss bar 241 and the remaining three with the buss bar 242. The buss bars are connectedwith a power transformer contained within a housing 245 which is connected with a current supply.

The regions of the electrodes spaced from the tips thereof are surrounded by jackets 247 adapted to receive a coolant fluid for reducing the temperature of the electrodes.

The cooling jackets are connected together by means of. tubes 248 and with a source of coolant, such as water or other suitable fluid, continuously circulated through the cooling jackets. The actuator for the electrodes is set into operation by means of a switch 290 operated upon'movement of the arm 48 to a position indicated in Figure l at the completion of the bending of the blank around the upper region of the mandrel by means of the bending die 70. 7

After the weld ng operations have been completed by the electrodes 232 in engagement with the overlapped regions of the shell blank, the air pressure on the oil or other fiuid in the cylinders 230 is released. Disposed in each of the cylinders is an expansive coil spring 250 which acts against the piston 231 in each of the cylinders to return the electrodes to a position out of engagement with the welded shell S.

The central component 133 of the mandrel construction 74 is provided with a recess in a region thereof adjacent the overlapping portions of a shell, said recess adapted to accommodate a bar 254 formed of copper or the like which forms a backing electrode as shown in Figure 11. The mandrel component 133 is also formed with recesses to accommodate a generally U-' shaped tube or pipe 256 as shown in Figures 4 and 8. The

leg portions

257 and 258 of the tube are disposed in the recesses and extend full length of the mandrel construction, the extremities of the tube being provided with fittings 259 for connecting the tube with a source of coolant fluid such as water for conducting-away excess heat resulting from the welding operations.

The arrangement includes means for effectively stripping a finished shell S from the mandrel 74. As particularly shown in Figures 4 and 8. the upper and lower surface regionsof the mandrel 74. are provided with lo'ngitudinally extending recesses'262 and 263 which are of semicircular cross-section. These recesses are; adapted'to accommodateand form guiding means forfstripper rods or bars-255 and 266 shown in Figure 3. 'The forward extremities-267 of the rods engage the rear upper and lower. edge regions of a stripped shell S as shown in Figure 12.

In Figure 1, a formed shell S is shown embraced by the bending and forming dies 70 and 172. p

The

shell stripping rods

265 and 266 are carried by a crosshead or member 268 mounted upon the forward extremity of a piston rod 270 carrying a piston 272 reciprocably mounted within a cylinder 274.

The cylinder 274 is provided adjacent its end regions with air inlet and outlet pipes (not shown) for conveying air or other fluid into the cylinder to effect longitudinal movements of the piston, piston rod and the stripper bars or

rods

265 and 266.

The admission of air or other fluid under pressure to the cylinder 274 is controlled by a multi-way valve (not shown) controlled by an electrically operated solenoid or other suitable means which is energized after the bending die 73, forming die 172 and retaining pad 87, are moved out of engagement with the finished shell S.v Fluid is ad mitted to the right-hand end of the cylinder 274 as viewed in Figure 3 'to move the piston 272 and stripper rods 255 and 256 in a left-hand direction to engage the shell S to remove the same from the mandrel.

The operations of the several components of the apparatus and their proper sequence of operation are initiated and controlled through electrically actuated components of conventional construction and hence the electrical con trol components are not shown in detail herein. With particular reference to Figure 1, there is illustrated a switch 285 supported by the plate 14 equipped with a movable arm 286 carrying a roller 287, the roller projecting into the path of the edge region of a blank during traverse of the portion thereof being formed around the mandrel 74.

Thus, as the left-hand region'o'f the blank, as viewed in Figure l, swings upwardly under the influence of the forming die 172, the edge region of the blank engages the roller 237 actuating the switch 235 which prepares the electrical circuit for subsequent welding operations. If there is no blank disposed on the table or slide 148, the switch 235 will not be actuated and the welding operations will not take place.

A switch 2%, shown in Figure 2, is equipped with a pivotally supported arm 292 which is adapted to be engaged bv an arm 293 secured upon the shaft 40. The switch 290 is connected in circuit with a solenoid actuating means for an air control valve (not shown) for initiating the movement of the welding electrodes 232 into engagement with the overlapping portions of the blank in the manner shown in Figure 11. is actuated by the arm 293 when the shaft 4% is rotated to'its extreme clockwise position shown in Figure 1 to initiate the welding operation.

With part cular reference to Figure 2, there is illustrated a bracket 298 which supports a switch 299 equipped with a pivoted arm 39% su porting a roller 381. Secured to the slidable cam plate 8% is a lug 303. Subsequent to the performance of the Welding operations and after the cam plate is moved a substantial distance in a right-hand direction. as viewed in Figure 1, during which movement the bending die 76 is traversing its stroke away from the mandrel 74 and the blank holding pad 187 and die 172 are retracted from the mandrel, thecam or lug 303 on the plate 80 engages the roller 301 to actuate the switch 299.

The switch 299 is in circuit with a solenoid actuated valve means (not shown) for admitting air to the rear end of the cylinder 274 shown in Figures 2 and-3 to move the

shell ejector rods

265 and 266 in a direction to eject the finished shell S from the mandrel 74 to the dotted position indicated at S' in Figure 3. Also dis posed adjacent the cam plate 80 is a switch 395 provided with the arm 396 and a roller 307, and cam plate 33 is provided with a second lug 309 for actuating the switch 305; v r

The switch roller 3%? is engaged by the lug 309 to operate a solenoid actuated valve means (not shown) for Thus, the switch 29% admitting air to the air or other pressure fluid to the inner end of the cylinder 156 to move the piston 159, rod 150 and the slide 148 from the broken line position shown in Figure 2 to its full line position, carrying with it a blank B to a position beneath and adjacent the mandrel 74.

The operation of the switch 305 occurs in advance of the operation of switch 299 whereby the slide or table 148 moves a blank beneath the mandrel just prior to the ejection of the finished shell S from the mandrel, the latter operation being initiated through actuation of the switch 299 by the lug 309. Through this sequence of operations, the blank supporting slide or member 148 and the blank carried thereby are moved beneath the mandrel so as to be out of the path of the ejected finished shell S discharged from the mandrel.

The operation of the apparatus in carrying out or performing a complete cycle of operation to form or configurate a fiat, rectangular sheet metal blank to a finished welded shell or tube of pear-shaped cross-section is as follows: The motor 122 is first energized. A stack 23 of sheet metal blanks, shown in Figure 1, of proper length and Width, are disposed upon a suitable support near the blank receiving station 20. The blanks may be delivered onto the swingable platen or table 22 manually or they may be successively delivered automatically if desired.

A blank B shown in Figure l is delivered onto the table or platen 22 while the member 41 and cylindrical member 62 are in the position shown in Figure l. Rotation of the shaft 40 in a counterclockwise direction, ef-

fected by slidable movement of plate 80 in a right-hand direction as viewed in Figure l, swings the member 41 in a counterclockwise direction.

As the cam plate 80 approaches its extreme position of slidable movement in a right hand direction, as viewed in Figure 1, the cylindrical member 62 engages a region of a blank B on the platen 22, the end of the blank projecting beyond the platen onto a block or member 32. Further downward movement of the cylindrical member 62 forms a portion of the blank with an arcuate curvature of approximately one-quarter of a circle or ninety degrees.

Figure 6 is illustrative of the flat sheet metal blank and its position relative to the bar 32 prior to the formation of the arcuate curvature in the blank.

Figure 7 illustrates the position of the cylindrical member 62, its supporting arm 55 and the blank 13 at the completion of the curved configuration imparted to the blank through engagement of the cylindrical member 62 therewith. A blank B with the curved configuration h s been transferred by the operator onto the slide or table .148 and has been moved by the actuator 156 to a position beneath the mandrel 74 by previous movement of the cam plate through actuation of the switch 305.

The motor 122, shown in Figure 3, continuously rotates the pulley 116 by means of the driving belt 118 rotating a worm 110 in the housing 106. The worm 110 rotates the worm wheel 108 to impart rotation to the shaft 104 at a greatly reduced speed in order to provide ample power for operating the various components of the shell forming apparatus. The shaft 104 drives a sprocket 100 supporting a roller chain 98 which takes over a second sprocket 102 carried by shaft 126.

One of the roller supports of the chain 98 is equipped with a projecting pin 94 and through the medium of the connecting rod 92 connected with the cam plate 80 reciprocates the cam plate in the direction of its length by the continuous rotation of the chain 98. When the cam plate 80 is at its extreme position of movement in a right-hand direction as viewed in Figure 1, the cylindrical member 62 is in its lowermost position completing the curvature imparted to the blank B as in Figure 7.

As the cam plate 80 initiates its return movement in a left-hand direction as viewed in Figure 1, the curvature of the slot 84, acting on the arm 75 through the roller 10 82, effects clockwise rotation of the shaft 40, moving the arm 48 and the bending die 70 toward the mandrel 74.

When the cam plate reaches an intermediate position, with the cam roller 216 traversing the angular portion 224 of the slot 218, the angular walls 24 cause rotation of the shaft 206 in a clockwise direction and projections 199 cooperate with member 195 to move the forming die 172 and the blank gripping pad or member 187 downwardly away from the region of the mandrel 74, the components moving against the compressive pressure of springs 192 shown in Figure 3. The lug 309 engages the switch 307 through the movement of the cam plate 80, the operation of switch 305 actuating a solenoid operated air valve to directcompressed air into the inner end of the cylinder 156 causing the piston 159 and rod to move rearwardly as viewed in Figure 2. The operator, during the formation of the curvature at the end of a blank by member 62, has removed the previous blank from the platen 22 and deposited it on the slide or table 148 while in its forwardmost position indicated in broken lines in Figure 2. The blank B with a curved end region is shown in such position in Figure l. The blank is positioned lengthwise by the engagement of the end of the blank with the abutment 164 shown in Figures 1 and 2. The pins 162 engage the edges of the blank to properly locate the blank on the table 148 in the direction of its width.

As the slide or table 148 is moved rearwardly by the air pressure in cylinder 156, an edge of the blank en gages a spring biased plunger 149 which resiliently urges the blank into engagement with the pins 162 to resiliently position the blank in condition to be engaged by the shell forming components.

In the .cycle of operations, a finished shell S is disposed on the mandrel 74, and movement of the cam plate 80 engages the lug 303 with the switch 299, the switch actuating a solenoid operated valve means admitting compressed air into the rear end of the cylinder 274 so as to move the

shell stripping bars

265 and 266 lengthwise in the recesses 262 and 263 in the mandrel engaging and ejecting the shell S lengthwise from the mandrel in the manner shown in Figure 12.

Movement of the cam plate 80 in a left-hand direction traverses the roller 78 in the slot 84 in the cam plate and moves the bending die 70 in an arcuate path toward the mandrel 74. Such. movement of the cam plate rotates the shaft 206 in a counterclockwise direction as viewed in Figure 1 and causes the projections 199 to move upwardly to move the forming die 172 upwardly. During the initial upward movement of the bifurcated portions 199 of the block 200, the expansive pressure of the coil springs 192 also moves the blank holding pad or member 187 upwardly and into engagement with that portion of the blank B in registration with the lower surface of the mandrel component 134 to resiliently yet securely clamp the blank B in engagement with the mandrel component 134.

Further upward movement of the projections or furcations 199 moves the forming die 172 upwardly causing the

wall portions

173 and 174 thereof to bend the portions of the blank at each side of the mandrel in an upward direction to form a U-shaped configuration to the blank of the general character shown in Figure 9. At the completion of this operation, the horizontal portion 220 of the cam slot 218 provides a dwell period during which time the projections 199 are in their uppermost positions with the blank retainer 187 and the forming die 172 maintained in engagement with the blank as shown in Figure 9. Continuing movement of the cam plate 80 in a left-hand direction brings the bending die 70 nearer to the mandrel 74, the bending die engaging the curved configuration of the blank B in the manner shown in Figure 9. During the succeeding movement of the bending die 70 it configurates, shapes, or bends the curved region of the blank into the position shown in drel.

Figures to and ll'with the end tenant of the blank in 7 290, the actuation of switch 290 operating or activating a solenoid controlled air valve of conventional construc- 'tion (not shown) for establishing air pressure ina fluid reservoir (not shown) containing oil or other fluid which 1s del vered to the manifold or header 236 shown in Figure 1, the 011 under pressure flowing into the cylinders 23p supporting the several welding electrodes 232, and :mov ng the electrodes into engagement with the overlapping regions of the blank as shown in Figure 11.

I The welding current is supplied from the transformer 245 to the electrodes through the conductors 240. A

cooling fluid, such as water, is continuously circulated through the'cooling' jackets 247 to carry away excess heat generated by'the welding operations. A coolant fluid,

such as water, is continuously circulated through the U-shaped tube 256 associated with the intermediate mandrel section 133 to convey away heat generated by the welding operations. shown) is incorporated in the circuit of the switch 292 A time delay switch means (not to relieve the air pressure on the oil or fluid actuating the welding electrodes 232 so that after a predetermined penod of time the electrodes 232 are moved away from engagement with the overlapping regions of the shell to' the position indicated in broken lines in Figure 11 under the influence of the springs 25%. During this period the cam plate has begun its return stroke in a right-hand direction as viewed in Figure l and hence the arcuate portion 84 engages the cam roller 82 and the angular walls 224 of the cam slot 218 engage the'cam roller 216, the,

bending die 70 swings upwardly and away from the manfdrel 74 and the forming die 172 and blank retainer or holding pad 187 move downwardly away from the blank on the mandrel. While the blank is being formed around the mandrel 74 and the overlapping portions of the blank welded together. the table or slide 148 is returned to its outermost position by compressed air introduced into the rear end of the cylinder 156 by solenoid operated air valve means controlled through a time delay switch (not shown After the slide or table 148 is in its outermost position, the operator manually transfers a blank formed with a eur'ved e'nd region on the pivoted table 22 onto the table 148 which has been moved to the broken line position shown in Figure 2. Thereafter the cam plate 80,

moving in a right-hand direction as viewed in Figure 1,

brings the lug 309 into contact with the switch 3%7 to move the'table 148 and curved blank thereon to its innermost position with the blank disposed beneath the man- Subsequent actuation of the switch 299 by the lug 303 actuates solenoid operated valve means to direct air into the rear end of the cylinder 274 moving the

s'trippin'gshaftsor rods

265 and 266 lengthwise of the mandrel 74 to strip the finished'shell 'S from the mandrel as shown in Figure 12.

In the event that during theroperations of the apparatus a blank is not properly positioned beneath the mandrel 74, or in the absence of a blank in this position, the switch 285 will not be actuated and hence a welding operation will not take place until a blank is formed-around the mandrel. t

From the foregoing description of the operation of the apparatus it' will be seen that a flat blank of sheet metal is completely formed into a finished pear-shaped tubular shell automatically with the exception of the .operationof manually transferring the blank from the pivoted. platen or table. 22 onto the s lide or table 148.

V Itfis'appare'nt that, Within the scope of the invention,

'modiiications and different arrangements may be made 'otherthari is herein disclofid', and the present disclosure ,member movably supported upon the framer a tions, one of said portions being provided at a distal end with a curved portion, a bending die carried by another of said portions, a mandrel provided with planar surfaces and a curved surface, a relatively movable forming die disposed adjacent the mandrel, a relatively movable cam plate formed with cam configurations, means for actuating the cam plate, cam followers cooperating with the cam configurations for actuating said member and said forming die, said cam configurations being shaped to sequentially actuate the member to engage the curved portion with a blank to form a curved region in the blank, to actuate the forming die to fold a blank into contact with the planar surfaces of the mandrel and actuate the member to bend the curved portion of the blank around the curved surface of the mandrel and overlap the end regions of the blank, and'means for securing the overlapping regions together to form a shell.

2. Apparatus for forming tubular shells from sheet metal blanksincluding, in combination, a frame, a relatively movable platen adapted to support a sheet metal blank, a shaft journally supported on the frame, a member secured on the shaft provided with radially extending portions, one of said portions being formed with a curved surface, a bending die carried by the other of said portions having planar surfaces and a curved surface, a relatively movable forming die disposed adjacent the mandrel, a second shaft journally supported on the frame, means associated with the shaft for actuating said forming die, a relatively movable element formed with cam configurations, roller means associated with each of said shafts cooperating with the cam configurations for controlling rotation of the shafts during relative movement of the element, said cam configurations being shaped to sequentially rotate the member to engage the curved surface thereof with a blank to form a curved region in the blank, to rotate the second mentioned shaft to actuate the forming die to fold a blank partially around the mandrel into contact with the planar surfaces and rotate the first mentioned shaft whereby the bending die forms the curved region of the blank around the curved surface of the mandrel and overlaps the end regions of the blank, electrode means engageable with the overlapping regions to weld the same to form a tubular shell, and means for ejecting the welded shell from the mandrel.

3. Apparatus for forming tubular shells from sheet metal blanks, in combination, a frame, a pair of shafts journalled on the frame, a stationary mandrel, blank supporting means disposed adjacent the mandrel, a cam sprockets supporting the chain, means for driving the chain, a reciprocable cam plate, means connecting the chain with the cam plate to reciprocate the plate, cams formed in the plate, an arm carried by each of said shafts provided with a cam engaging means, said cam engaging means cooperating with the cams for controlling the rotation of the shafts, a bending die supported on one of said shafts, a relatively movable forming die, means carried-by the other of the shafts arranged to actuate the forming die to fold a portion of the blank partially aroundrthe mandrel upon rotation of "the said shaft, the shaft carryingthe bending die being adapted to be rotated by inseam means for bending the remaining-portion of the blank around the mandrel; and overlapping portions of the blank, and means for Welding the overlapping portions together to form ashell. 7 V

4;. Apparatus" for forming t'ubular shells from sheet chain,

13 metal blanks, in combination, a frame, a pair of shafts journalled on the frame, a stationary mandrel, blank receiving means disposed adjacent the mandrel, means for moving the blank receiving means to convey a blank to a position adjacent the mandrel, a cam plate slidably supported upon the frame, means for reciprocating the plate, a. pair of cam slots formed in the plate, an arm carried by each of said shafts provided with a roller, said rollers cooperating with the cam slots for controlling the rotation of the shafts, a bending die supported on one of said shafts, a slidably mounted forming die, means carried by the other of the shafts arranged to actuate the forming die to fold the blank partially around the mandrel upon rotation of the said shaft, the shaft carrying the bending die being adapted to be rotated by the cam slot and roller means for bending the partially formed blank around the mandrel and overlapping portions of the blank, a. plurality of welding electrodes, means adapted to engage the electrodes with the blank on the mandrel at the region of overlap to weld the overlapping portions together to form a shell, said mandrel being formed with a. longitudinally arranged grove, a shell ejector rod, and means for moving the rod in the groove to discharge the shell from the mandrel.

5. Apparatus for forming tubular shells from sheet metal blanks, in combination, a frame, a pair of shafts journalled on the frame, a stationary mandrel provided with planar surfaces and a curved surface, blank receiving means disposed adjacent the mandrel, means for moving the blank receiving means to convey a blank to a position adjacent the mandrel, a cam plate slidably supported upon the frame, means for reciprocating the plate, a pair of cam slots formed in the plate, an arm carried by each of said shafts provided with a roller, said rollers cooperating with the cam slots for controlling the rotation of the shafts, a bending die supported on one of said shafts, a slidably mounted forming die, means carried by the other of the shafts arranged to actuate the forming die to fold the blank into contact With the planar surfaces of the mandrel upon rotation of the said shaft, the shaft carrying the bending die being adapted to be rotated by the cam slot and roller means for bending a portion of the partially formed blank around the curved surface of the mandrel and overlappingportions of the blank adjacent one of the planar surfaces, a plurality of welding electrodes disposed adjacent and lengthwise of the mandrel, fluid pressure means adapted to engage the electrodes with the formed blank at the region of overlap to weld the overlapping portions together to form a shell, a pair of longitudinally arranged grooves formed in the mandrel, a pair of shell ejector rods, and means for moving the rods in the grooves to discharge the shell from the mandrel.

6. Apparatusfor forming tubular shells from sheet metal blanks including, in combination, a frame, a man drel formed with planar surfaces and a curved surface, a forming die, a bending die, a slidably mounted plate, means for reciprocating said plate, a pair of shafts journally supported on the frame, an arm supported on each of the shafts, cam slots formed in said plate, rollers car ried by said arms and cooperating with the slots in the plate, the contours of the cam slots being shaped to effect rotation of said shafts, a member carried by one of said shafts provided with a cylindrically shaped element and a bending die, means mounted on the other of said shafts for actuating the forming die, a blank supporting means, the member provided with the cylindrically shaped element being movable to a position to form a curve in an end region of a blank, means for supporting a blank formed with a curved end region adjacent the mandrel, said forming die actuating means being movable to a position to form the planar portion of the curved blank into the shape of the planar surfaces of the mandrel, said member carrying the bending die being mova le to a position to bend the curved portion of the blank around the curved surface of the mandrel with the ends of the blank in adjacent relation, and means for welding the adjacent portions of the blank together to form a tubular shell.

7. Apparatus for forming tubular members from sheet metal blanks including, in combination, a frame, a mandrel mounted on the frame provided with planar surfaces and a curved surface, a slidable table adapted to support a blank, means for moving the table to convey a blank adjacent the mandrel, a forming die adapted to engage and fold a portion of the blank to the configuration of the planar surfaces of the mandrel, a bending die adapted to engage the blank to form the remaining portion thereof around the curved surface of the mandrel with the end regions in overlapping relation, means for sequentially actuating the forming die and the bending die, a plurality of welding electrodes, means for engaging said electrodes with the overlapping regions of the blank on the mandrel to weld the said regions together to form a tubular member, and a tube extending through passages formed in the mandrel adapted to contain circulating cooling fluid to convey away heat generated by the welding operation.

8. Apparatus for forming tubular shells from blanks of sheet material including, in combination, a frame, a member pivotally mounted on the frame, said member having a portion engageable with an end region of a fiat blank adapted to impart a curve to the said end region, a mandrel having planar surfaces and a curved surface, a bending die carried by said pivotally mounted member, a forming die, means for moving the forming die toward the mandrel to fold a flat portion of the blank partially around the mandrel at the planar surfaces, means for moving the member about its pivotal axis to engage the bending die carried thereby with the curved portion of the blank to fold the curved portion over the curved surface of the mandrel whereby the edge regions of the blank are brought into overlapping relation, a plurality of welding electrodes, means for engaging the electrodes with the overlapping regions of the blank on the mandrel to weld the overlapping regions together to form a tubular shell, and e ecting means engagable with the tubular member for removing the same from the mandrel.

References Cited in the file of this patent UNITED STATES PATENTS 606,213 Higgins June 28, 1898 1,167,073 House Ian. 4, 1916 1,330,782 Brown Feb. 17, 1920 1,359,001 tesau Nov. 16, 1920 1,663,970 Brenzinger Mar. 27, 1928 1,879,078 Carlsen Sept. 27, 1932 2,066,025 Zublin et al Dec. 29, 1936 2,139,771 Riemenschneider Dec. 13, 1938 2,251,218 Borton July 29, 1941 2,333,997 Glans Nov. 9, 1943 2,357,170 Burggraf Aug. 29, 1944 2,358,960 Cleve Sept. 26, 1944 2,395,723 Chmielewski Feb. 26, 1946 2,443,596 Cahill June 22, 1948