Patent US3855874A successfully refreshed from Google Patents.
US3855874A
Expired / Lapsed
US
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Double mesh type w-n gear
Assignee: HASEGAWA HAGURUMA KK
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Filing: 1973-07-12
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Granted: 1974-12-24
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Expires: 1993-07-12
Abstract
Abstract So-called ''''initial pitting'''' conventionally unavoidable with some sorts of this type of gears can be effectively prevented by increasing the clearance between the intermediate portions of the mating tooth surfaces and this can be attained by shifting the two points of meshing contact from their normal position respectively in a direction away from the pitch line or by arranging the meshing gears at a center distance slightly smaller than normal. Among additional advantanges are: reduced contamination of lubricating oil, smoother operation and increase in durability.
Inventors
- 👤 S Honma
- 👤 Y Fujii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:18
CPC Classifications
F; F16; F16H; F16H55/00; F16H55/02; F16H55/08; F16H55/0826; Y; Y10; Y10T; Y10T74/00; Y10T74/19; Y10T74/19949; Y10T74/19963; Y10T74/19972
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
143 words
A double mesh type W-N gear with a basic rack on a transverse plane or on a normal plane characterized in that modifications are introduced so that the two points of contact between the mating tooth surfaces are shifted respectively in a direction away from the pitch line so as to give a pressure angle of not less than 30* thereby to obtain an increased clearance between intermediate straight portions of the mating profiles, the gear teeth profiles each including circular addendum and dedendum arcs connected by an intermediate straight line segment at the pitch line area, the arcs being of different radii centered on the pitch line or on points adjacent thereto, the two points of contact on one gear tooth being one on the addendum and one on the dedendum arc for contact with a gear tooth on the other gear.
Claim 2
Dependent Claim
143 words
A double mesh type W-N gear with a basic rack on a transverse plane or on a normal plane characterized in that modifications are introduced so that the two points of contact between the mating tooth surfaces are shifted respectively in a direction away from the pitch line so as to give a pressure angle of not less than 30* thereby to obtain an increased clearance between intermediate straight portions of the mating profiles, the gear teeth profiles each including circular addendum and dedendum arcs connected by an intermediate straight line segment at the pitch line area, the arcs being of different radii centered on the pitch line or on points adjacent thereto, the two points of contact on one gear tooth being one on the addendum and one on the dedendum arc for contact with a gear tooth on the other gear.
Claim 3
Dependent Claim
39 words
A double mesh type W-N gear as claimed in claim 1, having a tooth profile modified by spacing the center of the circular dedendum arc (BC) from the pitch line by a distance of not less than 0.1 module.
Claim 4
Dependent Claim
55 words
In a double mesh type W-N gear as in claim 1 where the gear teeth profiles each include said circular addendum and dedendum arcs that merge smoothly into the intermediate straight line segment, the center of the circular dedendum arc being spaced from the pitch line by a distance of not less than 0.1 module.
Claim 5
Dependent Claim
22 words
In a double mesh type W-N gear as in claim 3 where the circular addendum arc is centered on the pitch line.
Claim 6
Dependent Claim
63 words
A gear device including a pair of double mesh type W-N gears, characterized in that the two gears are held in mesh with each other at a center distance slightly smaller than the normal center distance so that the two points of contact between the mating tooth surfaces are shifted from their normal position respectively in a direction away from the pitch line.
Claim 7
Dependent Claim
63 words
A gear device including a pair of double mesh type W-N gears, characterized in that the two gears are held in mesh with each other at a center distance slightly smaller than the normal center distance so that the two points of contact between the mating tooth surfaces are shifted from their normal position respectively in a direction away from the pitch line.
Claim 8
Dependent Claim
82 words
In a double mesh type W-N gear as in claim 5 where the gear teeth profiles each include circular addendum and dedendum arcs that merge smoothly into an intermediate straight line segment, the arcs having radii of curvature different from each other, the pitch lines of the gear teeth of the two gears being spacEd from each other by a distance of 0.015 to 0.06 module to provide increased tooth clearance between mating tooth surfaces in the vicinity of the pitch lines.
Claim 9
Dependent Claim
28 words
In a double mesh type W-N gear as in claim 6 where the mating tooth surfaces at the contact point have a pressure angle of at least 30*.
References Cited (Backward Citations)
US3756091A
Cited
US3709055A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |