US3916148A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat sealing head for plastic films
Assignee: Square Bag-It Corp
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Filing: 1974-05-22
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Granted: 1975-10-28
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Expires: 1994-05-22
Abstract
Abstract For a device producing heat seals in lapped portions of plastic film a sealing head having a bar with a longitudinally extending free edge for bearing on the plastic film to transfer heat thereto. An electrical resistance heating element extends generally longitudinally of an exterior surface of the bar and a strip of an insulating material overlies the heating element and is wrapped around the bar. The bar, heating element, and strip of insulating material are frictionally received between a pair of carrier plates releasably secured to a mounting bracket.
Inventors
- 👤 Arthur E Lafleur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:26
CPC Classifications
B; B29; B29C; B29C65/00; B29C65/02; B29C65/18; B29C65/24; B29C65/30; B29C65/305; B29C66/00; B29C66/004; B29C66/0042; B29C66/80; B29C66/81; B29C66/812; B29C66/8126; B29C66/81261; B29C66/814; B29C66/8141; B29C66/81427; B29C66/816; B29C66/8161; B29C66/8167; B29C66/818; B29C66/8182; B29C66/81821; B29C66/8187; B29C66/81871; B29C66/90; B29C66/91; B29C66/912; B29C66/9121; B29C66/91211; B29C66/91212; B29C66/91213; B29C66/91231; B29C66/914; B29C66/9141; B29C66/91421; H; H05; H05B; H05B3/00; B29C66/0044; B29C66/01; B29C66/05; B29C66/10; B29C66/11; B29C66/112; B29C66/1122; B29C66/40; B29C66/41; B29C66/43; B29C66/8122; B29C66/83; B29C66/832; B29C66/8322
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
139 words
A heat sealing head comprising a bar having high thermal conductivity, said bar having a free edge for conducting heat to lapped portions of plastic film to form a heat seal therein, an electrical resistance heating element for supplying heat to said bar, said heating element extending generally longitudinally of said bar exteriorly thereof in heat conducting relation with an exterior surface thereof, said heating element being spaced from said free edge of said bar such that said heating element does not contact any portion of said plastic film as said free edge is conducting heat to lapped portions of plastic film, heat insulating means overlying that side of the heating element opposite said exterior surface of the bar, whereby heat produced by said heating element is conducted primarily into and through said bar to said free edge thereof.
Claim 2
Dependent Claim
139 words
A heat sealing head comprising a bar having high thermal conductivity, said bar having a free edge for conducting heat to lapped portions of plastic film to form a heat seal therein, an electrical resistance heating element for supplying heat to said bar, said heating element extending generally longitudinally of said bar exteriorly thereof in heat conducting relation with an exterior surface thereof, said heating element being spaced from said free edge of said bar such that said heating element does not contact any portion of said plastic film as said free edge is conducting heat to lapped portions of plastic film, heat insulating means overlying that side of the heating element opposite said exterior surface of the bar, whereby heat produced by said heating element is conducted primarily into and through said bar to said free edge thereof.
Claim 3
Dependent Claim
49 words
The heat sealing head of claim 1 wherein said heating element has multiple interconnected legs overlying the exterior surface of the bar throughout substantially the entire length thereof such that the length of said heating element is a multiple of the length of said exterior surface of the bar.
Claim 4
Dependent Claim
64 words
The heat sealing head of claim 1 wherein said electrical resistance heating element comprises an alloy, the electrical resistance of which varies with and is proportional to the temperature thereof such that said element will function to both supply heat to said bar and to indicate a change in the temperature of said bar by a change in the electrical resistance of said element.
Claim 5
Dependent Claim
16 words
The heat sealing head of claim 3 wherein said element has a posItive coefficient of temperature.
Claim 6
Dependent Claim
43 words
The heat sealing head of claim 1 wherein said heat insulating means extends closely adjacent but spaced from said free edge of the bar, whereby heat radiated to the atmosphere by said bar is radiated predominantly by said free edge of said bar.
Claim 7
Dependent Claim
64 words
The heat sealing head of claim 5 wherein said electrical resistance heating element comprises an alloy, the electrical resistance of which varies with and is proportional to the temperature thereof such that said element will function to both supply heat to said bar and to indicate a change in the temperature of said bar by a change in the electrical resistance of said element.
Claim 8
Dependent Claim
49 words
The heat sealing head of claim 1 which also comprises a carrier having a generally longitudinally extending cavity receiving said bar therein and said heat insulating means includes an elastic material received in said cavity between said bar and said carrier to frictionally retain said bar in said cavity.
Claim 9
Dependent Claim
64 words
The heat sealing head of claim 7 wherein said carrier comprises a pair of separate plates forming generally opposed longitudinally extending side walls of said cavity, said plates being dimensioned with respect to each other, said elastic material and said bar such that when said plates are secured in assembly they compress said elastic material to firmly frictionally retain said bar in said cavity.
Claim 10
Dependent Claim
51 words
The heat sealing head of claim 7 wherein said elastic material has a coefficient of thermal conductivity which is less than one-tenth of the coefficient of thermal conductivity of said bar such that heat radiated to the atmosphere by said bar is radiated predominantly by said free edge of said bar.
Claim 11
Dependent Claim
35 words
The heat sealing head of claim 1 which also comprises a film of a plastic material carrying said element thereon, said film lying adjacent said exterior surface of said bar and extending generally longitudinally thereof.
Claim 12
Dependent Claim
64 words
The heat sealing head of claim 10 wherein said electrical resistance heating element comprises an alloy, the electrical resistance of which varies with and is proportional to the temperature thereof such that said element will function to both supply heat to said bar and to indicate a change in the temperature of said bar by a change in the electrical resistance of said element.
Claim 13
Dependent Claim
38 words
The heat sealing head of claim 10 wherein said electrical resistance heating element comprises a flat ribbon carried by said film and said flat ribbon has an average thickness which does not exceed one thousandth of an inch.
Claim 14
Dependent Claim
27 words
The heat sealing head of claim 12 wherein said flat ribbon carried by said film has an average width which does not exceed one-sixteenth of an inch.
Claim 15
Dependent Claim
76 words
The heat sealing head of claim 1 wherein said bar has first and second generally opposed generally longitudinally extending exterior surfaces thereon and said electrical resistance heating element has a plurality of traverses lying closely adjacent to each one of said first and second exterior surfaces in heat conducting relation with said bar, each traverse of said ribbon extending generally longitudinally of said bar exteriorly thereof and being spaced from said free edge of said bar.
Claim 16
Dependent Claim
64 words
The heat sealing head of claim 14 wherein said electrical resistance heating element comprises an alloy, the electrical resistance of which varies with and is proportional to the temperature thereof such that said element will function to both supply heat to said bar and to indicate a change in the temperature of said bar by a change in the electrical resistance of said element.
Claim 17
Dependent Claim
16 words
The heat sealing head of claim 15 wherein said element has a positive coefficient of temperature.
Claim 18
Dependent Claim
43 words
The heat sealing head of claim 14 wherein said heat insulating means extends closely adjacent but spaced from said free edge of said bar, whereby heat radiated to the atmosphere by said bar is radiated predominantly by said free edge of said bar.
Claim 19
Dependent Claim
57 words
The heat sealing head of claim 17 which also comprises a film of a plastic materiaL carrying thereon said electrical resistance heating element, said film being interposed between said bar and said heat insulating means, said film extending at least generally longitudinally of said bar and lying closely adjacent said generally opposed exterior surfaces of said bar.
Claim 20
Dependent Claim
34 words
The heat sealing head of claim 18 wherein said electrical resistance heating element comprises a printed circuit on said plastic film having an average thickness which does not exceed one thousandth of an inch.
Claim 21
Dependent Claim
21 words
The heat sealing head of claim 19 wherein said printed circuit has an average width not exceeding one-sixteenth of an inch.
Claim 22
Dependent Claim
28 words
The heat sealing head of claim 1 wherein said heat insulating means extends to within at least one-eighth of an inch of said free edge of said bar.
Claim 23
Dependent Claim
46 words
The heat sealing head of claim 1 wherein said free edge of said bar in transverse cross section has a width not greater than one-fourth of the dimension of the bar in cross section in a direction perpendicular to said width of said free edge thereof.
Claim 24
Dependent Claim
40 words
The heat sealing head of claim 1 wherein said bar in transverse cross section has a width not greater than one-fourth of the dimension of the bar in cross section in a direction perpendicular to said width of said bar.
Claim 25
Dependent Claim
58 words
The heat sealing head of claim 1 wherein said bar has opposed exterior side faces spaced apart a distance not more than one-fourth of the height of said side faces in a direction transverse to the length of said side faces and said heating element overlies said opposed exterior side faces in heat conducting relation with said bar.
Claim 26
Dependent Claim
25 words
The heat sealing head of claim 5 wherein said electrical resistance heating element is closely adjacent but spaced from said free edge of said bar.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |