US4440392A
Expired / Lapsed
US
⏱️ 0.0 years remaining
One piece molded games racket
Assignee: Dunlop Ltd
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Filing: 1981-01-29
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Granted: 1984-04-03
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Expires: 2001-01-29
Abstract
Abstract The invention relates to games racket frames which are made from reinforced plastics material and have a hollow construction. The particular construction and method of the invention enable a satisfactory hollow product to be made by an injection moulding technique instead of the more laborious technique of building a suitable reinforced hollow construction around a mandrel. The frame is a hollow injection moulding of reinforced thermoplastics material in which the walls (21A and 21B) at the outer and inner circumference of the head (21) are joined by supports (25) through which the stringing holes (23) pass. The supports are integrally formed during the moulding.
Inventors
- 👤 Frank W. Popplewell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:35
CPC Classifications
A; A63; A63B; A63B49/00; A63B49/02; B; B29; B29C; B29C45/00; B29C45/17; B29C45/40; B29C45/44; B29C45/4457; A63B49/10; A63B60/00; B29C33/00; B29C33/44; B29C33/52; A63B2049/103; A63B49/11; A63B60/50; A63B60/54; B29L; B29L2031/00; B29L2031/52; B29L2031/5245; Y; Y10; Y10S; Y10S273/00; Y10S273/23
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
132 words
A games racket frame comprising a head and a shaft, in which at least said head is in the form of a hollow injection moulding of thermoplastics material reinforced with short filament reinforcing material, said moulding having walls formed by a first wall portion which lies at an outer circumference of said head, a second wall portion which lies at an inner circumference of said head and sidewall portions which connect with said first and second wall portions to complete the walls of the head of said frame, said first wall portion being connected to said second wall portion by an internal support means, said head having holes for stringing and said stringing holes passing through said internal support means, said moulding, including said internal support means, being an integrally-formed, seamless construction.
Claim 2
Dependent Claim
132 words
A games racket frame comprising a head and a shaft, in which at least said head is in the form of a hollow injection moulding of thermoplastics material reinforced with short filament reinforcing material, said moulding having walls formed by a first wall portion which lies at an outer circumference of said head, a second wall portion which lies at an inner circumference of said head and sidewall portions which connect with said first and second wall portions to complete the walls of the head of said frame, said first wall portion being connected to said second wall portion by an internal support means, said head having holes for stringing and said stringing holes passing through said internal support means, said moulding, including said internal support means, being an integrally-formed, seamless construction.
Claim 3
Dependent Claim
26 words
A games racket frame according to claim 1, in which said internal support means is in the form of a centrally-disposed row of seamless hollow pillars.
Claim 4
Dependent Claim
50 words
A games racket frame according to claim 2, in which the head is of generally oval shape and in which the axis of each pillar lies in the plane of the strings of the racket and is normal to the tangent to the circumference of said head at that point.
Claim 5
Dependent Claim
29 words
A games racket frame according to claim 2 in which the axis of the pillar is aligned with the plane of the stringing when said stringing is in place.
Claim 6
Dependent Claim
36 words
A games racket frame according to claim 1, in which said internal support means is in the form of a series of pillars, said pillars being abutments extending inwardly from the sidewall portions of said frame.
Claim 7
Dependent Claim
20 words
A games racket frame according to claim 5, in which alternate pillars extend from opposite sidewall portions of said frame.
Claim 8
Dependent Claim
19 words
A games racket frame according to claim 1, in which the frame is of rectangular shape in transverse section.
Claim 9
Dependent Claim
34 words
A games racket frame according to claim 1, in which the outer face of the first wall portion of said frame contains a groove or channel to recess strings used with the racket frame.
Claim 10
Dependent Claim
19 words
A games racket frame according to claim 1, in which said short filament reinforcement material is of carbon fibres.
Claim 11
Dependent Claim
24 words
A games racket frame according to claim 9, in which said thermoplastics material contains from 10% to 40% by weight of said carbon fibres.
Claim 12
Dependent Claim
35 words
A games racket frame according to claim 1, in which a transverse cross section of said frame is larger in areas of said head adjacent to said shaft than in other areas of said head.
Claim 13
Dependent Claim
133 words
A games racket frame comprising a head and a shaft, in which at least said head is in the form of a hollow injection moulding of thermoplastics material reinforced with short, discrete lengths of fiber, said moulding having walls formed by a first wall portion which lies at an outer circumference of said head, a second wall portion which lies at an inner circumference of said head and sidewall portions which connect with said first and second wall portions to complete the walls of the head of said frame, said first wall portion being connected to said second wall portion by an internal support means, said head having holes for stringing and said stringing holes passing through said internal support means, said moulding, including said internal support means, being an integrally-formed seamless construction.
Claim 14
Dependent Claim
133 words
A games racket frame comprising a head and a shaft, in which at least said head is in the form of a hollow injection moulding of thermoplastics material reinforced with short, discrete lengths of fiber, said moulding having walls formed by a first wall portion which lies at an outer circumference of said head, a second wall portion which lies at an inner circumference of said head and sidewall portions which connect with said first and second wall portions to complete the walls of the head of said frame, said first wall portion being connected to said second wall portion by an internal support means, said head having holes for stringing and said stringing holes passing through said internal support means, said moulding, including said internal support means, being an integrally-formed seamless construction.
Claim 15
Dependent Claim
19 words
A games racket according to claim 12, which has the size, weight and configuration suitable for a tennis racket.
Claim 16
Dependent Claim
34 words
A games racket according to claim 12, in which said moulding is of rectangular shape in transverse cross-section and said internal support means is in the form of a centrally-disposed row of hollow pillars.
Claim 17
Dependent Claim
177 words
A games racket frame comprising a head and a shaft, in which at least said head is in the form of a hollow injection moulding of thermoplastics material reinforced with short filament reinforcing material, said moulding having walls formed by a first wall portion which lies at an outer circumference of said head, a second wall portion which lies at an inner circumference of said head and sidewall portions which connect with said first and second wall portions to complete the walls of the head of said frame, said first wall portion being connected to said second wall portion by an internal support means in the form of a centrally disposed row of seamless hollow pillars, said head having holes for stringing and said stringing holes passing through said internal support means, said moulding, including said internal support means, being an integrally-formed, seamless construction, said frame having a rectangular transverse sectional shape and the outer face of the first wall portion of said frame containing a groove or channel for recessing strings used with the racket frame.
Claim 18
Dependent Claim
177 words
A games racket frame comprising a head and a shaft, in which at least said head is in the form of a hollow injection moulding of thermoplastics material reinforced with short filament reinforcing material, said moulding having walls formed by a first wall portion which lies at an outer circumference of said head, a second wall portion which lies at an inner circumference of said head and sidewall portions which connect with said first and second wall portions to complete the walls of the head of said frame, said first wall portion being connected to said second wall portion by an internal support means in the form of a centrally disposed row of seamless hollow pillars, said head having holes for stringing and said stringing holes passing through said internal support means, said moulding, including said internal support means, being an integrally-formed, seamless construction, said frame having a rectangular transverse sectional shape and the outer face of the first wall portion of said frame containing a groove or channel for recessing strings used with the racket frame.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-04-03 | 1987-10-03 | 1988-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-03 | 1991-10-03 | 1992-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-03 | 1995-10-03 | 1996-04-03 | $7700.00 | Window Closed / Lapsed |