Patent US4917554A successfully refreshed from Google Patents.
US4917554A
Expired / Lapsed
US
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Screw unit to join semi-rigid mats together
Assignee: Cryotherm Ltd
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Filing: 1989-03-29
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Granted: 1990-04-17
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Expires: 2009-03-29
Abstract
Abstract A screw unit with a shaft (1) and an enlargement at one end, to join together semi-rigid mats, consisting for example of mineral fibers or foam material, has the shaft (1) consisting of a wire helix (W) wound in corkscrew fashion and continuing at the one end as a spiral winding forming the headpiece (2), with the helical slope (α) of the wire helix (W) adjacent the headpiece (2) being smaller than the helical slope (β) in the region of a point (5) at the other end of the shaft (1).
Inventors
- 👤 Walter Bronn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:03
CPC Classifications
F; F16; F16B; F16B25/00; F16B25/0005; E; E04; E04B; E04B1/00; E04B1/38; E04B1/41; E04F; E04F13/00; E04F13/07; E04F13/08; E04F13/0801
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
140 words
A screw unit for joining together semi-rigid mats, consisting for example of mineral fibers or foam material, comprising a shaft and an enlargement at one end of said shaft, with said shaft consisting of a wire helix wound in corkscrew fashion, having a longitudinal axis, and continuing at said one end into said enlargement as a spiral winding forming a headpiece, with the helix angle of said wire helix adjacent said headpiece and with respect to said longitudinal axis being smaller than the helix angle of said wire helix in the region of the other end of said shaft, and with at least a portion of said enlargement extending orthogonally with respect to said longitudinal axis and having a relatively short axial length such that said enlargement is prevented from projecting beyond an adjacent surface of one of said mats.
Claim 2
Dependent Claim
140 words
A screw unit for joining together semi-rigid mats, consisting for example of mineral fibers or foam material, comprising a shaft and an enlargement at one end of said shaft, with said shaft consisting of a wire helix wound in corkscrew fashion, having a longitudinal axis, and continuing at said one end into said enlargement as a spiral winding forming a headpiece, with the helix angle of said wire helix adjacent said headpiece and with respect to said longitudinal axis being smaller than the helix angle of said wire helix in the region of the other end of said shaft, and with at least a portion of said enlargement extending orthogonally with respect to said longitudinal axis and having a relatively short axial length such that said enlargement is prevented from projecting beyond an adjacent surface of one of said mats.
Claim 3
Dependent Claim
42 words
A screw unit according to claim 1, wherein said end of said wire helix adjacent said headpiece passes over via an outwardly-directed intermediate portion into the headpiece, and the said winding spiral extends from the outside to the inside of said spiral.
Claim 4
Dependent Claim
101 words
A screw unit for joining together semi-rigid mats, consisting for example of mineral fibers or foam material, comprising a shaft and an enlargement at one end of said shaft, with said shaft consisting of a wire helix wound in corkscrew fashion and having a longitudinal axis, continuing at said one end into the helix angle of said wire helix adjacent said headpiece and with respect to said longitudinal axis being smaller than the helix angle of said wire helix in the region of the other end of said shaft wherein said headpiece is fashioned as a frustrum of a shallow cone.
Claim 5
Dependent Claim
101 words
A screw unit for joining together semi-rigid mats, consisting for example of mineral fibers or foam material, comprising a shaft and an enlargement at one end of said shaft, with said shaft consisting of a wire helix wound in corkscrew fashion and having a longitudinal axis, continuing at said one end into the helix angle of said wire helix adjacent said headpiece and with respect to said longitudinal axis being smaller than the helix angle of said wire helix in the region of the other end of said shaft wherein said headpiece is fashioned as a frustrum of a shallow cone.
Claim 6
Dependent Claim
33 words
A screw unit according to claim 1, wherein at least one abutment surface is provided on said spiral winding for engagement by a tool to apply a fastening torque to said screw unit.
Claim 7
Dependent Claim
143 words
A screw unit for joining together semi-rigid mats, consisting for example of mineral fibers or foam material, comprising a shaft and an enlargement at one end of said shaft, with said shaft consisting of a wire helix wound in corkscrew fashion and having a longitudinal axis, continuing at said one end into said enlargement as a spiral winding forming a headpiece, with the helix angle of said wire helix adjacent said headpiece and with respect to said longitudinal axis being smaller than the helix angle of said wire helix in the region of the other end of said shaft, wherein at least one abutment surface is provided on said spiral winding for engagement by a tool to apply a fastening torque to said screw unit and said headpiece is wound from outside to inside and said abutment surface is provided at said inside.
Claim 8
Dependent Claim
143 words
A screw unit for joining together semi-rigid mats, consisting for example of mineral fibers or foam material, comprising a shaft and an enlargement at one end of said shaft, with said shaft consisting of a wire helix wound in corkscrew fashion and having a longitudinal axis, continuing at said one end into said enlargement as a spiral winding forming a headpiece, with the helix angle of said wire helix adjacent said headpiece and with respect to said longitudinal axis being smaller than the helix angle of said wire helix in the region of the other end of said shaft, wherein at least one abutment surface is provided on said spiral winding for engagement by a tool to apply a fastening torque to said screw unit and said headpiece is wound from outside to inside and said abutment surface is provided at said inside.
Claim 9
Dependent Claim
142 words
A screw unit for joining together semi-rigid mats, consisting for example of mineral fibers or foam material, comprising a shaft and an enlargement at one end of said shaft, with said shaft consisting of a wire helix wound in corkscrew fashion and having a longitudinal axis, continuing at said one end into said enlargement as a spiral winding forming a headpiece, with the helix angle of said wire helix adjacent said headpiece and with respect to said longitudinal axis being smaller than the helix angle of said wire helix in the region of the other end of said shaft, wherein at least one abutment surface is provided on said spiral winding for engagement by a tool to apply a fastening torque to said screw unit and an innermost turn of said spiral winding is constructed as an engagement opening for said tool.
Claim 10
Dependent Claim
142 words
A screw unit for joining together semi-rigid mats, consisting for example of mineral fibers or foam material, comprising a shaft and an enlargement at one end of said shaft, with said shaft consisting of a wire helix wound in corkscrew fashion and having a longitudinal axis, continuing at said one end into said enlargement as a spiral winding forming a headpiece, with the helix angle of said wire helix adjacent said headpiece and with respect to said longitudinal axis being smaller than the helix angle of said wire helix in the region of the other end of said shaft, wherein at least one abutment surface is provided on said spiral winding for engagement by a tool to apply a fastening torque to said screw unit and an innermost turn of said spiral winding is constructed as an engagement opening for said tool.
Claim 11
Dependent Claim
13 words
A screw unit according to claim 6, wherein said engagement opening is circular.
Claim 12
Dependent Claim
19 words
A screw unit according to claim 1, wherein said wire helix has a diameter of 0.5 to 5.0 mm.
Claim 13
Dependent Claim
19 words
A screw unit according to claim 8, wherein said wire helix has a diameter of 1.0 to 2.5 mm.
Claim 14
Dependent Claim
19 words
A screw unit according to claim 1, wherein said wire helix has a length of 20 to 500 mm.
Claim 15
Dependent Claim
19 words
A screw unit according to claim 10, wherein said wire helix has a length of 40 to 100 mm.
Claim 16
Dependent Claim
18 words
A screw unit according to claim 1, wherein said headpiece has a diameter of 10 to 100 mm.
Claim 17
Dependent Claim
18 words
A screw unit according to claim 12, wherein said headpiece has a diameter of 20 to 50 mm.
Claim 18
Dependent Claim
27 words
A screw unit according to claim 1, wherein the ratio of the length of said wire helix to the diameter of said headpiece is 2:1 to 10:1.
Claim 19
Dependent Claim
27 words
A screw unit according to claim 14, wherein the ratio of the length of said wire helix to the diameter of said headpiece is 3:1 to 8:1.
Claim 20
Dependent Claim
16 words
A screw unit according to claim 1, wherein said wire helix consists of galvanised steel wire.
Claim 21
Dependent Claim
16 words
A screw unit according to claim 1, wherein said wire helix consists of stainless steel wire.
References Cited (Backward Citations)
GB280648A
Cited
US2138919A
Cited
US2391792A
Cited
US2755699A
Cited
US4437286A
Cited
US4762453A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-16 | 1993-10-16 | 1994-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-16 | 1997-10-16 | 1998-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-16 | 2001-10-16 | 2002-04-17 | $7700.00 | Window Closed / Lapsed |