US4742890A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Work platform
Assignee: Protective Plastics Ltd
•
Filing: 1987-10-22
•
Granted: 1988-05-10
•
Expires: 2007-10-22
Abstract
Abstract A work platform comprising a moulded polymeric resin fibre-reinforced generally channel-section shell having a lip flange extending inwardly from each channel side, and comprising tensile elongation resisting reinforcement comprising fibres extending longitudinally at least along marginal zones of the channel base and of the lip flanges adjacent the channel sides, and said channel sides comprising fibrous reinforcement resisting tensile elongation of said sides in the direction perpendicular to said marginal zones, whereby said platform is rendered substantially rigid to bending about axes transverse of said channel structure.
Inventors
- 👤 Jakob de Blauw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:38
CPC Classifications
E; E04; E04G; E04G3/00; E04G3/28; E04G3/30; E04G1/00; E04G1/15; E04G1/153
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
87 words
A work platform comprising a moulded polymeric resin fibre-reinforced generally channel-section shell having a lip flange extending inwardly from each channel side, and comprising tensile elongation resisting reinforcement comprising fibres extending longitudinally at least along marginal zones of the channel base and of the lip flanges adjacent the channel sides, and said channel sides comprising fibrous reinforcement resisting tensile elongation of said sides in the direction perpendicular to said marginal zones, whereby said platform is rendered substantially rigid to bending about axes transverse of said channel structure.
Claim 2
Dependent Claim
87 words
A work platform comprising a moulded polymeric resin fibre-reinforced generally channel-section shell having a lip flange extending inwardly from each channel side, and comprising tensile elongation resisting reinforcement comprising fibres extending longitudinally at least along marginal zones of the channel base and of the lip flanges adjacent the channel sides, and said channel sides comprising fibrous reinforcement resisting tensile elongation of said sides in the direction perpendicular to said marginal zones, whereby said platform is rendered substantially rigid to bending about axes transverse of said channel structure.
Claim 3
Dependent Claim
20 words
Platform according to claim 1 wherein said longitudinally extending fibrous reinforcement has a tensile modulus approximately that of aramid polymer.
Claim 4
Dependent Claim
15 words
Platform according to claim 2 wherein said longitudinally extending reinforcement comprises KEVLAR (trade mark) fibres.
Claim 5
Dependent Claim
14 words
Platform according to claim 1 wherein said longitudinally extending reinforcement comprises substantially continuous fibres.
Claim 6
Dependent Claim
17 words
Platform according to claim 1 including tensile elongation resisting tie means connecting transversely between said channel sides.
Claim 7
Dependent Claim
43 words
Platform according to claim 1 wherein said tie means comprise moulded polymeric resin fibre-reinforced elongate elements having longitudinally extending fibrous reinforcement, said elements being spaced longitudinally along the platform and each being connected at each end to said marginal zones of said flanges.
Claim 8
Dependent Claim
22 words
Platform according to claim 1 comprising a core of lightweight substantially non-absorbent rigid material embedded in the resin comprising the channel base.
Claim 9
Dependent Claim
18 words
Platform according to claim 7 wherein said sheet material comprises balsa or a closed cell rigid plastics foam.
Claim 10
Dependent Claim
17 words
Platform according to claim 7 wherein said sheet material generally tapers in thickness toward each longitudinal edge.
Claim 11
Dependent Claim
29 words
Platform according to claim 7 comprising longitudinal and transverse elongation resisting fibre embedded in the resin composition of the shell adjacent the upper and lower surfaces of said core.
Claim 12
Dependent Claim
30 words
Platform according to claim 1 wherein said shell comprises a raised portion projecting upwardly in the direction opposite to said channel sides along each longitudinal edge of the channel base.
Claim 13
Dependent Claim
19 words
Platform according to claim 1 wherein the outer side of said channel base has anti-slip particulate material embedded therein.
Claim 14
Dependent Claim
21 words
Platform according to claim 1 wherein said shell comprises end walls integral with and closing the ends of said channel section.
Claim 15
Dependent Claim
15 words
Platform according to claim 1 wherein each end portion has a hand hold hole therethrough.
Claim 16
Dependent Claim
41 words
Platform according to claim 1 wherein said channel section shell comprises embedded therein over substantially its entire area at least one layer of a woven fabric reinforcement comprising aramid fibre or fibre of tensile modulus at least equal to aramid fibre.
Claim 17
Dependent Claim
23 words
Platform according to claim 15 wherein inwardly from said woven fabric reinforcement said shell comprises embedded therein a layer of glass fibre reinforcement.
Claim 18
Dependent Claim
14 words
Platform according to claim 16 wherein said glass fibre reinforcement comprises glass fibre mat.
Claim 19
Dependent Claim
12 words
Platform according to claim 1 wherein said reinforcement comprises electrically non-conductive fibres.
References Cited (Backward Citations)
US2225737A
Cited
US3260522A
Cited
US3744591A
Cited
CA1029163A
Cited
US4029172A
Cited
US4349297A
Cited
US4496029A
Cited
CH660391A5
Cited
US4520897A
Cited
US4683981A
Cited
US4655321A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-10 | 1991-11-09 | 1992-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-10 | 1995-11-09 | 1996-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-10 | 1999-11-09 | 2000-05-10 | $7700.00 | Window Closed / Lapsed |