Patent US4523752A successfully refreshed from Google Patents.
Patent US3754489A successfully refreshed from Google Patents.
US3754489A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Smokeless cut-off blade for plastic wrapping film
Assignee: DOVE J B Inc
•
Filing: 1971-06-02
•
Granted: 1973-08-28
•
Expires: 1991-06-02
Abstract
Abstract In wrapping machinery for wrapping articles in heat-sealable plastic film, such as polyvinylchloride (PVC), a web of film is drawn from a supply roll and is severed by pulling the film under tension downwardly onto the narrow edge of an electrically heated blade to melt the film material along a thin transverse line, and permit severance thereof by pulling, without generating toxic fumes. The blade has sufficient width and sufficient crosssectional area to store a quantity of heat capable of replenishing instantly the heat lost at the narrow edge of the blade when the film is contacted and melted, thereby maintaining substantially constant the temperature at the blade edge. The temperature at the blade edge is sufficiently high to melt the film material but not high enough to decompose the film and generate toxic fumes.
Inventors
- 👤 H Carver
- 👤 O Hansen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:40
CPC Classifications
B; B65; B65B; B65B61/00; B65B61/04; B65B61/06; B65B61/10; B26; B26F; B26F3/00; B26F3/06; Y; Y10; Y10T; Y10T83/00; Y10T83/04; Y10T83/0405; Y10T83/041; Y10T83/0414; Y10T83/283; Y10T83/293
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
127 words
A method of severing an end section of heat-sealable plastic web film from a supply after overwrapping an article in an end section thereOf, said method including the steps of: a. holding the film under longitudinal tension between the overwrapped article and a restraining line located a short distance from the article toward the film supply; and b. subjecting said tensioned web of film to a sufficient supply of heat to maintain substantially constant temperature along a thin line transverse of said web during the entire severing operation, said thin transverse line being located between said restraining line and said overwrapped article, said substantially constant temperature being sufficiently high to melt said film to allow parting thereof under said tension but not sufficiently high to create fumes.
Claim 2
Independent Claim
127 words
A method of severing an end section of heat-sealable plastic web film from a supply after overwrapping an article in an end section thereOf, said method including the steps of: a. holding the film under longitudinal tension between the overwrapped article and a restraining line located a short distance from the article toward the film supply; and b. subjecting said tensioned web of film to a sufficient supply of heat to maintain substantially constant temperature along a thin line transverse of said web during the entire severing operation, said thin transverse line being located between said restraining line and said overwrapped article, said substantially constant temperature being sufficiently high to melt said film to allow parting thereof under said tension but not sufficiently high to create fumes.
Claim 3
Dependent Claim
227 words
In wrapping machinery for wrapping articles in heat-sealable film, the combination of: a. a supply of plastic web film; and b. means for severing an end section of film from the supply without generation of objectionable fumes by melting said film along a thin line transverse to the web while said web is under longitudinal tension to cause said web to part along the melt line, said means including: b-1. a fixed heater blade of electrical resistance material, said blade being rectangular in cross section having a width at least five times its thickness, to provide a storage body for storing a quantity of heat to replenish instantly heat removed when the film is moved into contact with the edge of the blade to melt the film; b-2. a film restraining rod located on the film supply side of said heater blade and spaced a short distance therefrom, said film restraining rod having a frictional surface adapted to offer substantial resistance to movement of the web of film thereacross, thereby to place in tension the film beyond the restraining rod in the direction of movement of the film; and b-3. means for heating said heater blade to a temperature sufficiently high to melt said film but not sufficiently high to cause the film material to decompose and emit fumes, said temperature being not in excess of 350*.
Claim 4
Dependent Claim
227 words
In wrapping machinery for wrapping articles in heat-sealable film, the combination of: a. a supply of plastic web film; and b. means for severing an end section of film from the supply without generation of objectionable fumes by melting said film along a thin line transverse to the web while said web is under longitudinal tension to cause said web to part along the melt line, said means including: b-1. a fixed heater blade of electrical resistance material, said blade being rectangular in cross section having a width at least five times its thickness, to provide a storage body for storing a quantity of heat to replenish instantly heat removed when the film is moved into contact with the edge of the blade to melt the film; b-2. a film restraining rod located on the film supply side of said heater blade and spaced a short distance therefrom, said film restraining rod having a frictional surface adapted to offer substantial resistance to movement of the web of film thereacross, thereby to place in tension the film beyond the restraining rod in the direction of movement of the film; and b-3. means for heating said heater blade to a temperature sufficiently high to melt said film but not sufficiently high to cause the film material to decompose and emit fumes, said temperature being not in excess of 350*.
References Cited (Backward Citations)
US3043071A
Cited
US3047991A
Cited
US3452511A
Cited
US3367589A
Cited
US3579949A
Cited
US3465627A
Cited
US3570215A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |