Claims
- 1. An apparatus for forming a blank of sheet material into a container, said apparatus comprising:
- (a) a die set including a female die being segmented and having bottom, lower radius, side wall, rim and downturned lip-forming surfaces generally defining the shape of said container;
- (b) draw pad means disposed to engage the outer peripheral edge of said blank placed in an initial plane during formation of said container for applying tension to said blank, said draw pad means including two opposite draw pad surfaces disposed to engage the opposite outer peripheral surfaces of said blank;
- (c) said die set further including a segmented male die member axially movable into mating relationship with said female die wherein said segments of said male die member engage said blank on the surface of said female die sequentially, said segmented male die member comprising:
- first forming means axially movable into mating relationship with said bottom and lower radius surfaces of said female die for forming said bottom and lower radius of said container;
- second forming means axially movable separately from said first forming means into mating relationship with said side wall surfaces and rim of said female die for forming the side wall and rim of said container;
- lip-forming means axially movable into mating relationship with said downturned lip-forming surface of said female die;
- (d) means for sequentially moving said first forming means and second forming means axially to form the bottom, lower radius, side wall and rim of said container prior to said lip-forming means engaging said blank;
- (e) first resilient means interconnecting said first and second forming means for allowing initial axial movement of said first and second forming means together, and for delaying application of forming pressure on said side wall surface until after application of forming pressure on said bottom and lower radius surfaces; and,
- (f) means for resiliently biasing said draw pad surfaces axially to engage said blank and maintain the peripheral edge of said blank in said initial plane during formation of the bottom, lower radius, side wall and rim of said container.
- 2. The apparatus of claim 1 wherein said draw pad means comprise a lower annular draw pad member surrounding said female die, said lower draw pad member having an upper draw pad surface, said upper draw pad surface having an indentation therein disposed to receive the outer peripheral edge of said blank.
- 3. The apparatus of claim 2 wherein said draw pad means includes resilient means disposed between said lower draw pad member and a portion of said female die.
- 4. The apparatus of claim 1 wherein said draw pad means includes an upper draw pad member; said upper draw pad member being an annular member surrounding said first and second forming means; said upper draw pad member having a blank engaging surface disposed to be moved axially into engagement with said blank.
- 5. The apparatus of claim 4 wherein said die set includes resilient means disposed between said upper draw pad member and a platen located above said second forming means.
- 6. The apparatus of claim 4 wherein said upper draw pad member includes at least a portion of said lip-forming means.
- 7. The apparatus of claim 4 wherein said upper draw pad means moves axially to engage with the upper surface of said blank at a blank engaging position, wherein said blank engaging position is above the rim surface of said lower die.
- 8. The apparatus of claim 1, further comprising second resilient means extending between said second forming means and platen located above said second forming means.
- 9. The apparatus of claim 2 wherein said die set includes means for maintaining said lower draw pad surfaces and said blank at an axial position at a level with the surface of said rim of said female die prior to engagement of said first forming means with said female die.
- 10. The apparatus of claim 1 wherein said female die includes, at said bottom surface, means for moving a portion of said bottom surface axially.
- 11. The apparatus of claim 10 wherein said movable portion of said bottom surface of said female die may be disposed at an axial position level with the surface of said rim of said female die.
- 12. A method of forming a blank of sheet material into a container utilizing a sequentially engageable segmented female die including bottom, lower radius, side wall rim and downturned lip-forming surfaces and a segmented male die including a first forming means and a second forming means, wherein said container includes a bottom, a lower radius, a side wall, a rim and a lip, said method comprising the steps of:
- (a) holding the outer peripheral surface of said blank between two opposing surfaces such that said blank can retract radially upon application of a predetermined radial force on said blank;
- (b) engaging said first forming means with said bottom and lower radius surfaces to form the bottom and lower radius of said container while said outer peripheral surface is radially restrained;
- (c) engaging said second forming means with said side wall and rim surfaces to form the side wall and rim of said container subsequent to forming the bottom and lower radius of said container while said outer peripheral surface of said blank is radially restrained; and,
- (d) releasing radial restraint on said blank and thereafter forming said lip portion.
- 13. The method of claim 12 wherein said two opposing surfaces maintain tension on said blank during a least a portion of said forming steps.
Parent Case Info
This application is a continuation of U.S. patent application Ser. No. 06/938,858 filed on Jan. 8, 1986 and now abandoned.
US Referenced Citations (8)
Continuations (1)
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Number |
Date |
Country |
Parent |
938858 |
Dec 1986 |
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