US3779838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat sealing head
Assignee: FMC Corp
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Filing: 1971-11-12
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Granted: 1973-12-18
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Expires: 1991-11-12
Abstract
Abstract A heat sealing head eliminates the detrimental effects of thermal expansion by providing a construction accommodating longitudinal expansion and minimizing the effects of lateral expansion. A heater element is held to a sealing bar by spaced spring biased clamp blocks. Intermediate the clamp blocks, support bars cover the heater and are resiliently clamped to the sealing bar. A central post of each support bar connects to a rigid support beam which reciprocates to actuate the sealing bar. The heater element expands linearly under its clamp blocks, and the support bars expand linearly between the clamp blocks, thus eliminating warping stress and maintaining the active face of the sealing bar flat for optimum sealing, and in the illustrated embodiment, parallel to an oppositely disposed cooperating sealing bar having the same construction.
Inventors
- 👤 R Wech
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:28
CPC Classifications
B; B29; B29C; B29C65/00; B29C65/02; B29C65/18; B29C65/24; B29C65/30; B29C65/305; B29C65/74; B29C65/745; B29C66/00; B29C66/004; B29C66/0042; B29C66/0044; B29C66/00441; B29C66/80; B29C66/81; B29C66/812; B29C66/8122; B29C66/814; B29C66/8141; B29C66/81411; B29C66/81425; B29C66/816; B29C66/8161; B29C66/8167; B29C66/818; B29C66/8181; B29C66/8185; B29C66/83; B29C66/832; B29C66/8322; B29C66/84; B29C66/851; B29C66/8511
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
164 words
In a heating sealing head including a sealing bar having a heating element and a beam supporting said sealing bar, wherein thermal expansion and contraction tends to warp the sealing surface of said sealing bar, the improvement of means for preventing warpage of said sealing bar comprising an elongate support bar engaged with said sealing bar, a post connecting said support bar to said support beam, and clamp means holding each end portion of said support bar to said sealing bar to maintain interengagement of said support and sealing bars while allowing end to end and lateral thermal expansion of said support bar independent of said sealing bar, each of said clamp means including two vertically aligned clamp plates extending across said support bar, a pair of compression springs intermediate said clamp plates, and a bolt extending through each of said springs and said clamp plates with threaded engagement with saId sealing bar to resiliently clamp said support bar and said sealing bar together.
Claim 2
Dependent Claim
28 words
Apparatus according to claim 2, wherein said support bar is notched to clear each of said bolts and allow unrestrained thermal expansion and contraction of said support bar.
Claim 3
Dependent Claim
89 words
A heat sealing head comprising an elongate rigid support beam reciprocable toward and away from a web to be heat sealed, an elongate heated sealing bar substantially parallel to said support beam, a plurality of spaced support bars engaged with said sealing bar and confronting said support beam, a post connecting each support bar to said support beam, and a clamp resiliently gripping each support bar to said sealing bar for maintaining the interengagement of said sealing bar and said support bars without restricting the thermal expansion of either.
Claim 4
Dependent Claim
99 words
A heat sealing head comprising an elongate rigid support beam reciprocable toward and away from a web to be heat sealed, a sealing bar substantially coextensive with said support beam, a plurality of spaced support bars engaged with said sealing bar and confronting said support beam, a post connecting each support bar to said support beam, a tubular heater loosely mounted in complementary recesses of said support bars and said sealing bar, a spring holding each support bar to said sealing bar, a clamp block intermediate adjacent support bars, and a spring holding each clamp block against said heater.
Claim 5
Dependent Claim
117 words
A heat sealing head comprising an elongate rigid support beam reciprocable toward and away from a web to be heat sealed, an elongate sealing bar substantially parallel to said support beam, a plurality of spaced support bars engaged with said sealing bar and confronting said support beam, and axially adjustable post connecting each support bar to said support beam, a tubular heater loosely gripped between said support bars and said sealing bar and having one end portion anchored to said support beam, a clamp resiliently gripping each support bar to said sealing bar, a clamp block intermediate adjacent support bars, and a clamp connected to said sealing bar and resiliently holding each clamp block against said heater.
Claim 6
Dependent Claim
150 words
A heat sealing head comprising an elongate rigid support beam reciprocable toward and away from a web to be heat sealed, a sealing bar substantially coextensive with said support beam, a plurality of spaced support bars engaged with said sealing bar and confronting said support beam, a central post connecting each support bar to said support beam, a tubular heater extending along said sealing bar and loosely mounted in complementary recesses of said support bars and said sealing bar, a heater clamp securing one end portion of said heater to said support beam, a spring clamp mounted on said sealing bar and gripping each end portion of each support to said sealing bar, a clamp block intermediate the ends of adjacent support bars and having an arcuate recessed surface engaged with said heater, and a spring clamp mounted on said sealing bar and gripping each clamp block to said heater.
References Cited (Backward Citations)
US2589756A
Cited
US2663353A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |