Claims
- 1. An apparatus for making bags from an elongated tube of thin synthetic-resin film, said apparatus comprising:
- an endless conveyor having a stretch defining a transport path extending in a transport direction from an upstream cutting/welding station through a stacking station and a flattening station, to a downstream punching station, said conveyor having an endless support element and a plurality of groups of transverse rigid bars forming along said path a plurality of respective platforms having predetermined lengths in said direction and spaced apart by gaps, the bars of each platform engaging one another in said direction;
- means for feeding said tube generally continuously in said direction to said upstream cutting/welding station;
- cutting/welding means in said cutting/welding station for periodically transversely cutting through said tube and generally simultaneously forming upstream of each cut a transversely throughgoing weld for subdividing said tube into a succession of bag blanks each having, as viewed in said transport direction, an unsealed upstream or trailing edge and a sealed downstream or leading edge;
- stacking means in said stacking station including a transversely reciprocal needle bar provided with a plurality of needles adapted to engage said bag blanks and including at least one heated blocking needle, said needles being located downstream of and in close proximity to the cutting portion of said cutting/welding means, and a transversely reciprocal stripper bar through which said needles extend toward said path;
- control means for synchronously operating said conveyor, said cutting/welding means, and said stacking means for (a) advancing said needles to pierce through the unsealed upstream edge region of each of said bag blanks as same is cut free from said tube, (b) intermittently immobilizing said conveyor to dispose a respective one of said platforms in a position just downstream of said cutting/welding station to enable that platform to support a plurality of said bag blanks in a stack as same are cut free from said tube, (c) after a predetermined number of operations of said cutting/welding means, stripping the accumulated stack of said bag blanks off said needles with said stripper bar, and (d) operating said conveyor to displace the stack of bag blanks stripped from said needles downstream along said transport path to said punching station;
- flattening means in said flattening station having a plurality of flattening elements for engaging each of said bag blanks as same is cut free from said tube and pressing same flatly down against the platform supporting that bag blank and any others previously cut from said tube;
- a gripper carriage displaceable in and against said direction and having a holding element displaceable vertically toward and away from said stretch, said control means being connected to said carriage to press said holding element down against each stack of bag blanks as same are stripped from said needle bar and for thereafter displacing said carriage synchronously and codirectionally with the platform supporting that stack downstream to said punching station; and
- punching means at said punching station for punching a section out of said unsealed upstream edge region of each of said stacks of bag blanks as same arrive, said punching station being spaced in said direction downstream of said welding/cutting station by a distance substantially greater than said predetermined length of said platforms.
- 2. The apparatus defined in claim 1 wherein said transverse rigid bars are releasably secured to said support element, whereby the length of each of said platforms can be varied.
- 3. The apparatus defined in claim 1 wherein said flattening means includes at least one disk rotatable about an axis transverse to said direction and parallel to said platforms, said disk carrying said flattening elements and being rotatable about said axis by said control means.
- 4. The apparatus defined in claim 1 wherein said punching means is provided with vertically reciprocal holding bars engageable with a stack of bag blanks in said punching station to hold same during punching.
- 5. The apparatus defined in claim 1 wherein said predetermined length of each platform is shorter than the corresponding dimension of each bag blank.
- 6. The apparatus defined in claim 1 wherein said control means includes means to operate said conveyor step-wise.
Priority Claims (1)
Number |
Date |
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Kind |
3020009 |
May 1980 |
DEX |
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Parent Case Info
This application is a continuation of application Ser. No. 265,547 filed May 20, 1981, now U.S. Pat. No. 4,395,252 issued July 26, 1983.
US Referenced Citations (9)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2059630 |
Jul 1979 |
GBX |
Continuations (1)
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Number |
Date |
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Parent |
265547 |
May 1981 |
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