Patent US4756299A successfully refreshed from Google Patents.
US4756299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemical heating pad with differing air-admitting perforation sets for different heat-generation levels
Assignee: Hypertherm Technologies Inc
•
Filing: 1987-11-18
•
Granted: 1988-07-12
•
Expires: 2007-11-18
Abstract
Abstract A heating pad of the type having a particulate chemical mixture, which is exothermically reactive in the presence of air, and a pair of opposed panels forming an envelope containing the mixture and admitting air to support the reaction. Differing perforation sets in the opposed panels allows the pad to generate two levels of heat and allows opposed body-contact surfaces of the pad to apply two different heat conditions to the human body.
Inventors
- 👤 Carl W. Podella
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:02
CPC Classifications
A; A61; A61F; A61F7/00; A61F7/02; A61F7/03; A61F7/032; A61F7/034
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
141 words
In a heating pad of the type having a particulate chemical mixture which is exothermically reactive in the presence of air and having first and second opposed panels forming an envelope which contains the mixture while admitting air, the improvement comprising: the first panel having a first body-contact surface and a first set of air-admitting perforations extending from the first body-contact surface to inside the envelope; the second panel having a second body-contact surface and a second set of air-admitting perforations extending from the second body-contact surface to inside the envelope; and the second set of perforations differing structurally from the first set of perforations thereby to provide different air-admission properties supporting differing reaction characteristics, whereby two different heat conditions may be applied to the human body by the two body-contact surfaces with the opposite body-contact surfaces exposed to the atmosphere.
Claim 2
Dependent Claim
141 words
In a heating pad of the type having a particulate chemical mixture which is exothermically reactive in the presence of air and having first and second opposed panels forming an envelope which contains the mixture while admitting air, the improvement comprising: the first panel having a first body-contact surface and a first set of air-admitting perforations extending from the first body-contact surface to inside the envelope; the second panel having a second body-contact surface and a second set of air-admitting perforations extending from the second body-contact surface to inside the envelope; and the second set of perforations differing structurally from the first set of perforations thereby to provide different air-admission properties supporting differing reaction characteristics, whereby two different heat conditions may be applied to the human body by the two body-contact surfaces with the opposite body-contact surfaces exposed to the atmosphere.
Claim 3
Dependent Claim
22 words
The heating pad of claim 1 wherein each of the panels, except for the perforations, comprises a substantially air- and moisture-impermeable material.
Claim 4
Dependent Claim
28 words
The heating pad of claim 2 wherein the at least one of the panels comprises a laminate, including at least one layer of the air- and moisture-impermeable material.
Claim 5
Dependent Claim
17 words
The heating pad of claim 3 wherein the laminate includes a layer of air- and moisture-permeable material.
Claim 6
Dependent Claim
32 words
The heating pad of claim 4 wherein the air- and moisture-permeable material is an outer layer to form one of the body-contact surfaces, whereby such body-contact surface has a good tactile quality.
Claim 7
Dependent Claim
36 words
The heating pad of claim 1 wherein the chemical mixture comprises a moist particulate mixture comprising carbon powder, iron powder, vermiculite, and a salt-water solution selected and in amounts to provide an exothermic reaction in air.
Claim 8
Dependent Claim
51 words
The heating pad of claim 1 wherein the chemical mixture, the first and second panels, and the perforation sets are selected to provide temperatures within a range of about 57.5-65 degrees C. at the first body-contact surface and within a range of about 50-57.5 degrees C. at the second body-contact surface.
Claim 9
Dependent Claim
22 words
The heating pad of claim 1 wherein the first and second panels differ in thickness, thereby contributing to the different heat conditions.
Claim 10
Dependent Claim
22 words
The heating pad of claim 8 wherein each of the panels, except for the perforations, comprises a substantially air- and moisture-impermeable material.
Claim 11
Dependent Claim
28 words
The heating pad of claim 9 wherein the at least one of the panels comprises a laminate, including at least one layer of the air- and moisture-impermeable material.
Claim 12
Dependent Claim
17 words
The heating pad of claim 10 wherein the laminate include a layer of air- and moisture-permeable material.
Claim 13
Dependent Claim
44 words
The heating pad of claim 1 wherein the perforations of the first set are of greater size than the perforations of the second set, allowing greater air flow through the first panel than through the second panel, thereby contributing to the different heat conditions.
Claim 14
Dependent Claim
22 words
The heating pad of claim 12 wherein each of the panels, except for the perforations, comprises a substantially air- and moisture-impermeable material.
Claim 15
Dependent Claim
28 words
The heating pad of claim 13 wherein the at least one of the panels comprises a laminate, including at least one layer of the air- and moisture-impermeable material.
Claim 16
Dependent Claim
17 words
The heating pad of claim 14 wherein the laminate includes a layer of air- and moisture-permeable material.
Claim 17
Dependent Claim
40 words
The heating pad of claim 1 wherein the first set of perforations has a greater number of perforations than the second set of perforations, allowing better access of air to the chemical mixture, thereby contributing to the different heat conditions.
Claim 18
Dependent Claim
22 words
The heating pad of claim 16 wherein each of the panels, except for the perforations, comprises a substantially air- and moisture-impermeable material.
Claim 19
Dependent Claim
28 words
The heating pad of claim 17 wherein the at least one of the panels comprises a laminate, including at least one layer of the air- and moisture-impermeable material.
Claim 20
Dependent Claim
17 words
The heating pad of claim 18 wherein the laminate includes a layer of air- and moisture-permeable material.
References Cited (Backward Citations)
US1620581A
Cited
US3736769A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-07-12 | 1992-01-11 | 1992-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-12 | 1996-01-11 | 1996-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-12 | 2000-01-11 | 2000-07-12 | $7700.00 | Window Closed / Lapsed |