US4200169A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stethoscope
Assignee: 3M Co
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Filing: 1978-10-16
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Granted: 1980-04-29
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Expires: 1998-10-16
Abstract
Abstract This invention relates to a stethoscope having improved acoustical properties. The improvement comprises twin, smooth-walled sound pathways extending from the chestpiece to the ear tips which are free of sound leakage and each pathway has a constant diameter along its entire length.
Inventors
- 👤 Robert D. MacDonald, III
- 👤 Frederick W. Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:55
CPC Classifications
A; A61; A61B; A61B7/00; A61B7/02; A61B7/026
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
169 words
In a stethoscope comprising a pair of elongated rigid ear tubes each having an upper end suitably curved for insertion into the ear of the wearer, a lower end for attaching to flexible tubing and a central passageway extending lengthwise therethrough having a diameter, at least one chestpiece having an adapter for attachment to flexible tubing, flexible tubing acoustically connecting the at least one chestpiece to said ear tubes and spring means attached to said lower end of said ear tubes for biasing said ear tubes toward each other, the improvement wherein said flexible tubing defines separate twin passages extending between the at least one chestpiece and said ear tubes, each of said passages being connected to and continuous with one of said ear tube passageways by a leak-free junction and the diameter of said passages being equal to the diameter of said ear tube passageways thereby forming twin air columns having constant diameters extending between the at least one chestpiece and the upper ends of said ear tubes.
Claim 2
Dependent Claim
169 words
In a stethoscope comprising a pair of elongated rigid ear tubes each having an upper end suitably curved for insertion into the ear of the wearer, a lower end for attaching to flexible tubing and a central passageway extending lengthwise therethrough having a diameter, at least one chestpiece having an adapter for attachment to flexible tubing, flexible tubing acoustically connecting the at least one chestpiece to said ear tubes and spring means attached to said lower end of said ear tubes for biasing said ear tubes toward each other, the improvement wherein said flexible tubing defines separate twin passages extending between the at least one chestpiece and said ear tubes, each of said passages being connected to and continuous with one of said ear tube passageways by a leak-free junction and the diameter of said passages being equal to the diameter of said ear tube passageways thereby forming twin air columns having constant diameters extending between the at least one chestpiece and the upper ends of said ear tubes.
Claim 3
Dependent Claim
23 words
The stethoscope according to claim 1 wherein said twin passages are side-by-side in a common structure for a major portion of their length.
Claim 4
Dependent Claim
21 words
The stethoscope according to claim 2 wherein said twin passages diverge along their length from said chestpiece to said ear tubes.
Claim 5
Dependent Claim
16 words
The stethoscope according to claim 1 wherein said flexible tubing is attached to a single chestpiece.
Claim 6
Dependent Claim
16 words
The stethoscope according to claim 1 wherein the at least one chestpiece consists of two chestpieces.
Claim 7
Dependent Claim
23 words
The stethoscope according to claim 1 wherein said diameter of said bore through said ear tubes has a circular cross-section throughout its length.
Claim 8
Dependent Claim
37 words
The stethoscope according to claim 1 wherein said spring means comprises at least one elongated leaf spring prestressed to form a U-shaped arc and securing means interengaging said leaf spring at its ends to said ear tubes.
Claim 9
Dependent Claim
60 words
The stethoscope according to claim 7 wherein the portion of the surface of said lower end of said ear tube which interengages said leaf spring is smooth and flat and contains a pin therein for aligning with a hole in said leaf spring so that when so aligned, rotation of ear tubes with respect to said leaf spring is prevented.
Claim 10
Dependent Claim
13 words
The stethoscope according to claim 8 wherein said securing means comprises a bushing.
Claim 11
Dependent Claim
33 words
The stethoscope according to claim 1 further comprising flexible earpieces attached to the upper end of said ear tubes to provide a cushion between said ear tubes and the ears of the wearer.
References Cited (Backward Citations)
US1847607A
Cited
US3168161A
Cited
US3108652A
Cited
US3437172A
Cited
US3504760A
Cited
US3570625A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-04-29 | 1983-10-29 | 1984-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-29 | 1987-10-29 | 1988-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-29 | 1991-10-29 | 1992-04-29 | $7700.00 | Window Closed / Lapsed |