Patent US4099329A successfully refreshed from Google Patents.
US4099329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arch forms and a method of moulding same
Assignee: Lucas Electrical Co Ltd
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Filing: 1976-04-21
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Granted: 1978-07-11
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Expires: 1996-04-21
Abstract
Abstract An arch form comprises a tooth portion including a plurality of integral teeth injection moulded in pastics material and arranged in a curved row, and a gum portion in situ injection moulded onto the tooth portion so as to overlie an upper surface thereof. An undulating ridge extends along the upper surface of the tooth portion and is surrounded by the gum portion. Front teeth of the tooth portion have a substantially natural inclination with respect to the general plane of the tooth portion, whereas rear teeth thereof are inclined towards the front teeth such that their direction of extent is angled at 10° to 20° with respect to their counterparts in a natural set of teeth. A method of moulding the arch form requires the provision of a two-part mould defining the shape of the tooth portion, and a further mould part defining the shape of the gum portion. One part of the two-part mould includes a curved row of interconnected cavities defining the shapes of the individual teeth of the tooth portion: the other part thereof defines the upper surface of the tooth portion and the undulating ridge. Substantially white plastics material is injected into the two-part mould so as to form the tooth portion. The said other part of the two-part mould is then removed and is replaced by the further mould part. Red or pink plastics material is then injection into further mould part so as to mould the gum portion in situ on the tooth portion. The further mould part is withdrawn, and the completed arch form is removed. The arch form can be produced in an economic manner and in a form which facilitates mass production.
Inventors
- 👤 Horace Stanley Hawthorne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:16
CPC Classifications
A; A61; A61C; A61C13/00; A61C13/08; A61C13/081; A61C13/10; A61C13/1003; A61C13/1013
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
90 words
An arch form comprising a tooth portion including a plurality of integral teeth of a first plastics material, each tooth having a base portion, an integral fillet between said base portions at each pair of adjacent teeth, at least one integral projection provided on said tooth portion, and a gum portion of a second plastics material, said second plastics material being of a different color than said first plastics material, and said gum portion surrounding said at least one projection and meeting said tooth portion at least at said fillet.
Claim 2
Dependent Claim
90 words
An arch form comprising a tooth portion including a plurality of integral teeth of a first plastics material, each tooth having a base portion, an integral fillet between said base portions at each pair of adjacent teeth, at least one integral projection provided on said tooth portion, and a gum portion of a second plastics material, said second plastics material being of a different color than said first plastics material, and said gum portion surrounding said at least one projection and meeting said tooth portion at least at said fillet.
Claim 3
Dependent Claim
36 words
An arch form as claimed in claim 1 wherein said at least one projection is in the form of a ridge extedning over said tooth portion in spaced relationship to said base portions of said teeth.
Claim 4
Dependent Claim
26 words
The arch form according to claim 2 wherein said ridge has a part which extends to a surface of said gum portion remote from said teeth.
Claim 5
Dependent Claim
34 words
The arch form according to claim 1, wherein said rear teeth are inclined with respect to their said counter parts in a natural set of teeth at an angle of between 10° and 20°.
Claim 6
Dependent Claim
12 words
The arch form according to claim 4, wherein said angle is 14°.
Claim 7
Independent Claim
224 words
A method of moulding an arch form comprising the steps of: providing a two-part mould defining the shape of a tooth portion of said arch form, one part of said two-part mould including a row of interconnected cavities defining individual teeth of said tooth portion arranged in the manner in which they are to appear in the completed arch forms, the other part of said two-part mould defining a part of said tooth portion which is to be covered by a gum portion and also defining at least one projection on said part of said tooth portion; injecting plastics material into said two-part mould thereby forming said tooth portion; withdrawing said other part of said two-part mould from said one part thereof; providing a further mould part defining said gum portion; placing said further mould part over said part of said tooth portion to be covered by said gum portion when said tooth portion is in said one part of said two part mould; injecting plastics material into said further mould part, thereby in situ moulding said gum portion onto said tooth portion so as to overlie said part thereof and surround said at least one projection; withdrawing said further mould part from said one part of said two-part mould and removing the resultant moulded arch from said one part of said two-part mould.
Claim 8
Independent Claim
224 words
A method of moulding an arch form comprising the steps of: providing a two-part mould defining the shape of a tooth portion of said arch form, one part of said two-part mould including a row of interconnected cavities defining individual teeth of said tooth portion arranged in the manner in which they are to appear in the completed arch forms, the other part of said two-part mould defining a part of said tooth portion which is to be covered by a gum portion and also defining at least one projection on said part of said tooth portion; injecting plastics material into said two-part mould thereby forming said tooth portion; withdrawing said other part of said two-part mould from said one part thereof; providing a further mould part defining said gum portion; placing said further mould part over said part of said tooth portion to be covered by said gum portion when said tooth portion is in said one part of said two part mould; injecting plastics material into said further mould part, thereby in situ moulding said gum portion onto said tooth portion so as to overlie said part thereof and surround said at least one projection; withdrawing said further mould part from said one part of said two-part mould and removing the resultant moulded arch from said one part of said two-part mould.
Claim 9
Dependent Claim
42 words
The method according to claim 6, wherein said tooth portion is injection moulded by injecting said plastics material into said two-part mould through a gate disposed substantially midway along the rear of said cavities in said one part of said two-part mould.
Claim 10
Dependent Claim
79 words
The method according to claim 6 wherein cavities in said one part of said two-part mould which define rear teeth of said tooth portion are inclined towards cavities in said one part of said two-part mould which define front teeth of said tooth portion, such that there are no undercut surfaces in said mould with respect to a predetermined direction, and said moulded tooth portion is removed from said one part of said two-part mould in said predetermined direction.
Claim 11
Dependent Claim
140 words
An arch form comprising a tooth portion including a plurality of integral teeth injection moulded in a plastics material and arranged in a row in the manner in which they are to appear in the complete arch form, front teeth of said plurality of integral teeth having a substantially natural inclination with respect to a general plane of said tooth portion, rear teeth of said plurality of integral teeth being inclined towards said front teeth such that their direction of extent is angled with respect to their counterparts in a natural set of teeth, the arch form further comprising a gum portion in situ injection moulded onto said tooth portion so as to overlie a part thereof, and at least one integral projection provided on said part of said tooth portion, said gum portion surrounding said at least one projection.
Claim 12
Dependent Claim
140 words
An arch form comprising a tooth portion including a plurality of integral teeth injection moulded in a plastics material and arranged in a row in the manner in which they are to appear in the complete arch form, front teeth of said plurality of integral teeth having a substantially natural inclination with respect to a general plane of said tooth portion, rear teeth of said plurality of integral teeth being inclined towards said front teeth such that their direction of extent is angled with respect to their counterparts in a natural set of teeth, the arch form further comprising a gum portion in situ injection moulded onto said tooth portion so as to overlie a part thereof, and at least one integral projection provided on said part of said tooth portion, said gum portion surrounding said at least one projection.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-10 | 1982-01-09 | 1982-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-10 | 1986-01-09 | 1986-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-10 | 1990-01-09 | 1990-07-11 | $7700.00 | Window Closed / Lapsed |