US3830581A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Green wood joint
Assignee: CUSTODIS-ECODYNE Inc
•
Filing: 1972-05-26
•
Granted: 1974-08-20
•
Expires: 1992-05-26
Abstract
Abstract A method and apparatus for lengthening green wood structural members by joining the ends of at least two members in an end to end relationship in a manner which compensates for the shrinkage as the wood dries. The method includes the step of applying and retaining a compressive force of sufficient magnitude to the adjacent ends to compress the ends a distance greater than the joined members shrink during drying, the compressive force being of a magnitude less than the fiber stress at the proportional limit of the members at their initial moisture content. The apparatus includes a scarf joint having a plurality of transversely extending V-shaped teeth milled in the scarf surfaces and positioned in a meshing relationship. These V-shaped teeth in combination with the application of the compressive force results in a unique scarf joint which compensates for the shrinkage of the wood as it dries so as to substantially retain the axial and flexural strength of the joint. A plurality of tubular inserts pass through holes in the scarf surfaces and are flared at their respective ends to retain the compressive force applied to the scarf surfaces.
Inventors
- 👤 D Furlong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:09
CPC Classifications
E; E04; E04B; E04B1/00; E04B1/18; E04B1/26; E04B1/2604; E04B1/38; E04B1/48; F; F16; F16B; F16B7/00; F16B7/22; E04B2001/262; E04B2001/2652; E04B2001/2692; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826; Y10T29/49863; Y10T29/49908; Y10T29/49938; Y10T29/4994; Y10T29/49947; Y10T29/49954; Y10T29/49966; Y10T29/4997; Y10T403/00; Y10T403/65; Y10T403/655; Y10T403/71; Y10T403/7123
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
167 words
A method of joining together the adjacent ends of first and second structural green wood members to form a single structural member of increased length, said structural members having an initial moisture content when joined together and a final moisture content after the members have been allowed to dry; comprising the steps of: a. forming cooperating scarf surfaces at said adjacent ends of said first and second members; b. positioning said scarf surfaces relative to each other in a facing relationship; c. applying a compressive force of sufficient magnitude to said adjacent ends to compress said adjacent ends by an amount at least equal to the amount that said joined members shrink as the moisture content of said members goes from said initial to said final moisture content, said compressive force additionally being of a magnitude less than the fiber stress at the proportional limit of said members at said initial moisture content; and d. securing said adjacent ends together while retaining said adjacent ends in compression.
Claim 2
Independent Claim
167 words
A method of joining together the adjacent ends of first and second structural green wood members to form a single structural member of increased length, said structural members having an initial moisture content when joined together and a final moisture content after the members have been allowed to dry; comprising the steps of: a. forming cooperating scarf surfaces at said adjacent ends of said first and second members; b. positioning said scarf surfaces relative to each other in a facing relationship; c. applying a compressive force of sufficient magnitude to said adjacent ends to compress said adjacent ends by an amount at least equal to the amount that said joined members shrink as the moisture content of said members goes from said initial to said final moisture content, said compressive force additionally being of a magnitude less than the fiber stress at the proportional limit of said members at said initial moisture content; and d. securing said adjacent ends together while retaining said adjacent ends in compression.
Claim 3
Dependent Claim
35 words
The method of claim 1 wherein said compressive force is of a magnitude less than the perpendicular to grain fiber stress at the proportional limit of the species of wood at said initial moisture content.
Claim 4
Dependent Claim
36 words
The method of claim 1 wherein said scarf surfaces have shear resistance means formed thereon and said scarf surfaces are positioned relative to each other such that said shear resistance means are in an interlocking relationship.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein said compressive force is substantially evenly distributed over the entire extent of said adjacent ends.
Claim 6
Dependent Claim
35 words
The method of claim 1 further including the steps of: a. drilling a plurality of holes through said adjacent ends; and b. inserting fastening means within said holes to retain said adjacent ends in compression.
Claim 7
Dependent Claim
65 words
The method of claim 1 further including the steps of: a. drilling a plurality of holes through said adjacent ends; b. inserting tubular inserts within and substantially filling said holes having opposite ends projecting therethrough; and c. flaring said ends of said tubular inserts while simultaneously compressing said adjacent ends so as to retain said adjacent ends in compression upon removal of said compressive force.
Claim 8
Independent Claim
219 words
A method of joining together the adjacent ends of first and second structural green wood members in an end to end relationship to form a single structural member of increased length, said structural members having an initial moisture content when joined together and a final moisture content after the members have been allowed to dry; comprising the steps of: a. forming cooperating scarf surfaces at said adjacent ends of said first and second members; b. positioning said scarf surfaces relative to each other in a facing relationship; c. determining the distance said adjacent ends will shrink while going from said initial moisture content to said final moisture content; d. determining the magnitude of the compressive force which must be applied to said adjacent ends to compress said adjacent ends at least the distance that they will shrink; e. determining the fiber stress at the proportional limit of said adjacent ends at their initial moisture content; f. applying a compressive force of sufficient magnitude to said adjacent ends to compress said adjacent ends a distance that said joined members shrink as determined by step (d), said compressive force additionalLy being of a magnitude less than the fiber stress at the proportional limit as determined by step (e); g. securing said adjacent ends together while retaining said adjacent ends in compression.
Claim 9
Independent Claim
219 words
A method of joining together the adjacent ends of first and second structural green wood members in an end to end relationship to form a single structural member of increased length, said structural members having an initial moisture content when joined together and a final moisture content after the members have been allowed to dry; comprising the steps of: a. forming cooperating scarf surfaces at said adjacent ends of said first and second members; b. positioning said scarf surfaces relative to each other in a facing relationship; c. determining the distance said adjacent ends will shrink while going from said initial moisture content to said final moisture content; d. determining the magnitude of the compressive force which must be applied to said adjacent ends to compress said adjacent ends at least the distance that they will shrink; e. determining the fiber stress at the proportional limit of said adjacent ends at their initial moisture content; f. applying a compressive force of sufficient magnitude to said adjacent ends to compress said adjacent ends a distance that said joined members shrink as determined by step (d), said compressive force additionalLy being of a magnitude less than the fiber stress at the proportional limit as determined by step (e); g. securing said adjacent ends together while retaining said adjacent ends in compression.
Claim 10
Dependent Claim
180 words
A scarf joint for joining together the adjacent ends of first and second structural green wood members to form a single structural member of increased length, said structural members having an initial moisture content when initially joined together and a final moisture content after the members have been allowed to dry; said scarf joint comprising: a. a first wooden member having a first scarfed end portion associated therewith; b. a second wooden member having a second scarfed end portion associated therewith; c. said first scarfed end portion being positioned in a facing relationship to said second scarfed end portion; and d. means for compressing and securing said first and second scarfed end portions together with a compressive force of sufficient magnitude to compress and retain said end portions at a distance greater than the distance said joined members shrink as the moisture content of said members goes from said initial to said final moisture content, said compressive force additionally being of a magnitude less than the fiber stress at the proportional limit of said members at said initial moisture content.
Claim 11
Dependent Claim
180 words
A scarf joint for joining together the adjacent ends of first and second structural green wood members to form a single structural member of increased length, said structural members having an initial moisture content when initially joined together and a final moisture content after the members have been allowed to dry; said scarf joint comprising: a. a first wooden member having a first scarfed end portion associated therewith; b. a second wooden member having a second scarfed end portion associated therewith; c. said first scarfed end portion being positioned in a facing relationship to said second scarfed end portion; and d. means for compressing and securing said first and second scarfed end portions together with a compressive force of sufficient magnitude to compress and retain said end portions at a distance greater than the distance said joined members shrink as the moisture content of said members goes from said initial to said final moisture content, said compressive force additionally being of a magnitude less than the fiber stress at the proportional limit of said members at said initial moisture content.
Claim 12
Dependent Claim
35 words
The invention of claim 8 wherein said compressive force is of a magnitude less than the perpendicular to grain fiber stress at the proportional limit of the species of wood at said initial moisture content.
Claim 13
Dependent Claim
36 words
The invention of claim 8 wherein said scarf surfaces have shear resistance means formed thereon and said scarfed surfaces are positioned relative to each other such that said shear resistance means are in an interlocking relationship.
Claim 14
Dependent Claim
20 words
The invention of claim 10 wherein said shear resistance means include V-shaped transversely extending teeth formed on said scarf surfaces.
Claim 15
Dependent Claim
30 words
The invention of claim 11 wherein said teeth have inclined faces such that the faces of adjacent teeth have an included angle therebetween in the range of 45* to 90*.
Claim 16
Dependent Claim
21 words
The invention of claim 8 wherein said compressive force is substantially evenly distributed over the entire extent of said end portions.
Claim 17
Dependent Claim
70 words
The invention of claim 8 wherein said means for compressing and securing said first and second scarfed end portions together includes; a. a plurality of holes passing through said end portions; and b. a plurality of tubular inserts positioned within and substantially filling said holes having opposite ends projecting therethrough; c. said holes being flared so as to retain said end portions in compression upon removal of said compressive force.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |