US3855037A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture or closing of sacks by welding cut lengths of tube of thermoplastics
Assignee: BASF SE
•
Filing: 1970-07-30
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Granted: 1974-12-17
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Expires: 1990-07-30
Abstract
Abstract Apparatus which welds cut lengths of a thermoplastic film-tube in the manufacture of sealed sacks, said apparatus including: motor-driven guide members such as a pair of metal bands which grip a flat length of the tube transversely just below a cut open end thereof to provide front and rear side edges of the tube projecting from the guide members a distance approximately equal to the intended breadth of the weld, said guide members being arranged to advance the resulting projecting or exposed two-layer strip of tube end-face edges through the welding apparatus; a resistance member to contact the advancing strip to fold open its front side edge or leading edge as it is being advanced; knife means in the path of the advancing strip to cut it first at its front side edge and subsequently at its rear side edge; guide plate means to then fold apart the advancing strip; heating means to heat the inner surfaces of the folded apart strip to a fusing temperature; and finally means to press the two-layer strip back together to complete the weld.
Inventors
- 👤 K Imhagen
- 👤 W Weidner
- 👤 W Kasper
- 👤 G Manhart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:49
CPC Classifications
B; B65; B65B; B65B51/00; B65B51/10; B65B51/20; B29; B29C; B29C65/00; B29C65/02; B29C65/10; B29C65/103; B29C65/74; B29C65/749; B29C65/78; B29C65/7858; B29C65/7861; B29C65/787; B29C65/7873; B29C66/00; B29C66/01; B29C66/05; B29C66/10; B29C66/11; B29C66/112; B29C66/1122; B29C66/348; B29C66/349; B29C66/3492; B29C66/40; B29C66/41; B29C66/43; B29C66/431; B29C66/4312; B29C66/43121; B29C66/432; B29C66/4322; B29C66/70; B29C66/73; B29C66/739; B29C66/7392; B29C66/73921; B29C66/80; B29C66/81; B29C66/818; B29C66/8181; B29C66/83; B29C66/834; B29C66/8341; B29C66/83411; B29C66/83413; B29C66/836; B65B51/18; B29C2793/00; B29C2793/0081; B29C66/71; B29L; B29L2031/00; B29L2031/712; B29L2031/7128; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1026; Y10T156/1052; Y10T156/1062; Y10T156/1067; Y10T156/1069; Y10T156/108; Y10T156/12; Y10T156/13
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
261 words
Apparatus for welding cut lengths of a thermoplastic film tube in the manufacture of sealed sacks which comprises: motor-driven guide members facing one another to grip a flat length of the tube, which is cut open at one end transversely to the front and rear side edges thereof, in such a way that said front and rear side edges project from the guide members by an amount approximately equal to the intended breadth of the weld, said guide members being adapted to advance the resulting projecting two-layer strip formed by the exposed end-face edges through the welding apparatus; a resistance member mounted laterally in the path of the projecting two-layer strip to contact the front side edge thereof as the strip is being advanced by said guide members and to fold open said front side edge of said strip; knife means mounted next to the resistance member in the path of the advancing strip with its point of cutting engagement set at a position between said resistance member and said guide members to first cut the projecting two-layer strip at its folded open front side edge and subsequently at its rear side edge; guide plate means following said knife means iN the path of the advancing strip to fold apart the two-layer strip; heating means following said guide plate means in the path of the advancing strip to heat the inner surfaces thereof after they are folded apart to a fusing temperature; and means to press the heated two-layer strip back together and to cool and strip to complete the weld.
Claim 2
Dependent Claim
261 words
Apparatus for welding cut lengths of a thermoplastic film tube in the manufacture of sealed sacks which comprises: motor-driven guide members facing one another to grip a flat length of the tube, which is cut open at one end transversely to the front and rear side edges thereof, in such a way that said front and rear side edges project from the guide members by an amount approximately equal to the intended breadth of the weld, said guide members being adapted to advance the resulting projecting two-layer strip formed by the exposed end-face edges through the welding apparatus; a resistance member mounted laterally in the path of the projecting two-layer strip to contact the front side edge thereof as the strip is being advanced by said guide members and to fold open said front side edge of said strip; knife means mounted next to the resistance member in the path of the advancing strip with its point of cutting engagement set at a position between said resistance member and said guide members to first cut the projecting two-layer strip at its folded open front side edge and subsequently at its rear side edge; guide plate means following said knife means iN the path of the advancing strip to fold apart the two-layer strip; heating means following said guide plate means in the path of the advancing strip to heat the inner surfaces thereof after they are folded apart to a fusing temperature; and means to press the heated two-layer strip back together and to cool and strip to complete the weld.
Claim 3
Dependent Claim
18 words
Apparatus as claimed in claim 1 wherein said guide plate means includes a holder for said knife means.
Claim 4
Dependent Claim
64 words
Apparatus as claimed in claim 1 wherein said heating means comprises a heatable hollow welding prism mounted to project into the space between the folded apart layers of the strip and support jaws having cooling channel means to receive and guide the folded apart layers of the strip on their outer surfaces as heat is applied by the welding prism to their inner surfaces.
Claim 5
Dependent Claim
53 words
Apparatus as claimed in claim 3 wherein said means to press the heated two-layer strip back together comprises a pair of knurled rollers and said means to cool the strip to complete the weld comprises a second set of jaws with slits to supply cooling air on both sides of the two-layer strip.
Claim 6
Dependent Claim
33 words
Apparatus as claimed in claim 3 wherein the flanks of the welding prism are positioned at a small distance of about 0.5 to 20 mm. from the folded apart layers of the strip.
Claim 7
Dependent Claim
67 words
Apparatus as claimed in claim 3 wherein said welding prism includes a barrier ridge extending longitudinally parallel to the prism tip on each side of the prism and projecting into a gap space formed between the outer walls of the prism and opposing parallel supporting walls of said jaws, said ridges being placed outside of the region occupied by the two folded apart layers of the strip.
Claim 8
Dependent Claim
45 words
Apparatus as claimed in claim 3 wherein said heating means includes a supply conduit for hot air into the interior of the hollow welding prism which is provided with perforations for the discharge of hot air onto the two folded apart layers of the strip.
Claim 9
Dependent Claim
30 words
Apparatus as claimed in claim 7 wherein said perforations for the discharge of hot air are arranged along the welding prism tip and also distributed over the welding prism flanks.
Claim 10
Dependent Claim
35 words
Apparatus as claimed in claim 8 wherein the total cross-sectional area of the perforations provided along the welding prism tip is greater than the total cross-sectional area of the perforations distributed over the prism flanks.
Claim 11
Dependent Claim
66 words
Apparatus as claimed in claim 3 wherein said support jaws extend longitudinally beyond the end of the welding prism in the path of the advancing strip and include means to direct compressed air through perforations in the supporting surfaces of the jaws to straighten and guide together the heated layers of the strip where they rest on said jaws in the region adjacent the welding prism.
References Cited (Backward Citations)
US2678679A
Cited
US2997098A
Cited
GB1003203A
Cited
US3461017A
Cited
US3580788A
Cited
US3481051A
Cited
US3591908A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |