CA2512042C - A screw with a double thread and a recess in the side of the shank - Google Patents
A screw with a double thread and a recess in the side of the shank Download PDFInfo
- Publication number
- CA2512042C CA2512042C CA 2512042 CA2512042A CA2512042C CA 2512042 C CA2512042 C CA 2512042C CA 2512042 CA2512042 CA 2512042 CA 2512042 A CA2512042 A CA 2512042A CA 2512042 C CA2512042 C CA 2512042C
- Authority
- CA
- Canada
- Prior art keywords
- screw
- recesses
- shank
- approximately
- tapered
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 229920002522 Wood fibre Polymers 0.000 claims description 9
- 239000002023 wood Substances 0.000 claims description 8
- 239000002025 wood fiber Substances 0.000 claims 2
- 230000037431 insertion Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B25/00—Screws that cut thread in the body into which they are screwed, e.g. wood screws
- F16B25/001—Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by the material of the body into which the screw is screwed
- F16B25/0015—Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by the material of the body into which the screw is screwed the material being a soft organic material, e.g. wood or plastic
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B25/00—Screws that cut thread in the body into which they are screwed, e.g. wood screws
- F16B25/0036—Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw
- F16B25/0042—Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw characterised by the geometry of the thread, the thread being a ridge wrapped around the shaft of the screw
- F16B25/0047—Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw characterised by the geometry of the thread, the thread being a ridge wrapped around the shaft of the screw the ridge being characterised by its cross-section in the plane of the shaft axis
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B25/00—Screws that cut thread in the body into which they are screwed, e.g. wood screws
- F16B25/0036—Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw
- F16B25/0042—Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw characterised by the geometry of the thread, the thread being a ridge wrapped around the shaft of the screw
- F16B25/0068—Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw characterised by the geometry of the thread, the thread being a ridge wrapped around the shaft of the screw with multiple-threads, e.g. a double thread screws
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B35/00—Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws
- F16B35/04—Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws with specially-shaped head or shaft in order to fix the bolt on or in an object
- F16B35/041—Specially-shaped shafts
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Geometry (AREA)
- Physics & Mathematics (AREA)
- Dispersion Chemistry (AREA)
- Wood Science & Technology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Dowels (AREA)
- Transmission Devices (AREA)
- Mutual Connection Of Rods And Tubes (AREA)
- Joining Of Building Structures In Genera (AREA)
Abstract
A screw (1, 2) includes two recesses (5, 6) in the side of the shank, said recesses being arranged diametrically opposite one another, where each recess is shaped as two plane segments extending substantially parallel to the axis of the screw and along a portion of the shank length.
Description
Title: A screw with a double thread and a recess in the side of the shank Technical Field 5. The invention relates to a screw with a double thread and a recess in the side of the shanl~.
Back.g_round Art It is a well-known fact that screws have a tendency to spread the wood fibres instead j of cutting said wood fibres, especially when said screws are used close to a side of a piece of wood, and accordingly said screws leave a tendency to split said wood on both sides of the screw. As a result, not ozaly the wood is destroyed, but the tighten-i . ing grip of the screw in the wood is much too poor. When the fibres are not cut up during the insertion of the' screw, said fibres are arranged as a bow surrounding the 1 core of the screw. As a result, the screw is subjected to an intense pressure, which in turn involves a high fziction oaunteractir~g the screwing movement.
; . In addition, it is known to provide screws with a recess leaving a portion of the j ZO ' screw without threads an,d extending into the shank of said screw. Such a single re-cess does not ensure the ndcessary cutting up of the wood fibres duriztg the screwing movement.
Disclosure of Izivention The object of the invention is to provide a screw which efficiently cuts up the wood fibres during the screwing ri~ovement, and which avoids a splitting of said wood dur-ing the screwing movement.
Back.g_round Art It is a well-known fact that screws have a tendency to spread the wood fibres instead j of cutting said wood fibres, especially when said screws are used close to a side of a piece of wood, and accordingly said screws leave a tendency to split said wood on both sides of the screw. As a result, not ozaly the wood is destroyed, but the tighten-i . ing grip of the screw in the wood is much too poor. When the fibres are not cut up during the insertion of the' screw, said fibres are arranged as a bow surrounding the 1 core of the screw. As a result, the screw is subjected to an intense pressure, which in turn involves a high fziction oaunteractir~g the screwing movement.
; . In addition, it is known to provide screws with a recess leaving a portion of the j ZO ' screw without threads an,d extending into the shank of said screw. Such a single re-cess does not ensure the ndcessary cutting up of the wood fibres duriztg the screwing movement.
Disclosure of Izivention The object of the invention is to provide a screw which efficiently cuts up the wood fibres during the screwing ri~ovement, and which avoids a splitting of said wood dur-ing the screwing movement.
The above object is obtained by the screw including two recesses arranged diametrically opposite one another, where each recess is shaped as two plane segments extending substantially parallel to the axis of the screw and along a portion of the shank length.
As a result two cut surfaces are provided, where the two cutting edges thereof are arranged diagonally opposite one another while a clearance is simultaneously established, said clearance being positioned ahead of the cutting edges during the screwing movement. As a result, the wood fibres have a tendency to nestle against the plane surfaces of the recesses between the thread-cutting edges prior to meeting the succeeding two cutting edges which efficiently cut up the wood fibres in such a manner that the risk of a splitting of the wood has been minimized.
The recesses are suitably of such a length that they extend from the tapering portion of the screw and a short distance over a portion where the root diameter of the screw presents the same size everywhere. A double thread renders it possible to keep the length of the recess relatively short in such a manner that the strength and retaining force of the screw are not significantly reduced.
According to a particularly advantageous embodiment of the invention, each recess can cut off from approximately 0.15 mm to approximately 0.5 mm of the core diameter extending perpendicular to the plane side of the recess farthest away from the tapered end of the screw.
Finally, the recesses may extend up to a distance of from approximately 6.0 mm to approximately 14.0 from the tapered end of the screw, whereby it is ensured that a suitably good result is obtained in connection with most screw dimensions.
Brief Description of the Drawing The invention is explained in detail below with reference to the drawing, in which FIG. 1 is a front view of a portion of a screw according to the invention, and FIG. 2 is a side view of the portion of FIG. 1.
Best Mode for Carrying out the Invention The screw shown in the drawing includes two threads 1 and 2 extending in parallel and around the core 3 of the screw from a tapered end 4.
A plane recess 5, 6 is provided on each side of the screw, said recesses extending parallel to one another and parallel to the axis of the core. The recesses extend at such a distance from the axis of the core 3 that a segment of the core is cut off, said segment being of a maximum height a in the range from approximately 0.15 mm to approximately 0.5 mrn. The plane recesses 5 and 6 extend from the tapered area of the screw in such a manner that the end adjacent the tapered end 4 also extends through the portions of the threads 1 and 2 within this axea. Subsequently, the recesses 5 and 6 extend upwards to a length b of from approximately 6.0 mm to approximately 14.0 mm from the tapered end of the screw. As a result, two threaded cutting edges 7, 7 are provided along the sides of the recesses 5 and 6, said threaded cutting edges cutting up the wood fibres during the screwing movement of the screw.
The above ranges of the lengths a and b depend on the dimension of each screw, as two threaded cutting edges 7 and 8 should, if possible, always be provided along the rirn of the recess.
As a result two cut surfaces are provided, where the two cutting edges thereof are arranged diagonally opposite one another while a clearance is simultaneously established, said clearance being positioned ahead of the cutting edges during the screwing movement. As a result, the wood fibres have a tendency to nestle against the plane surfaces of the recesses between the thread-cutting edges prior to meeting the succeeding two cutting edges which efficiently cut up the wood fibres in such a manner that the risk of a splitting of the wood has been minimized.
The recesses are suitably of such a length that they extend from the tapering portion of the screw and a short distance over a portion where the root diameter of the screw presents the same size everywhere. A double thread renders it possible to keep the length of the recess relatively short in such a manner that the strength and retaining force of the screw are not significantly reduced.
According to a particularly advantageous embodiment of the invention, each recess can cut off from approximately 0.15 mm to approximately 0.5 mm of the core diameter extending perpendicular to the plane side of the recess farthest away from the tapered end of the screw.
Finally, the recesses may extend up to a distance of from approximately 6.0 mm to approximately 14.0 from the tapered end of the screw, whereby it is ensured that a suitably good result is obtained in connection with most screw dimensions.
Brief Description of the Drawing The invention is explained in detail below with reference to the drawing, in which FIG. 1 is a front view of a portion of a screw according to the invention, and FIG. 2 is a side view of the portion of FIG. 1.
Best Mode for Carrying out the Invention The screw shown in the drawing includes two threads 1 and 2 extending in parallel and around the core 3 of the screw from a tapered end 4.
A plane recess 5, 6 is provided on each side of the screw, said recesses extending parallel to one another and parallel to the axis of the core. The recesses extend at such a distance from the axis of the core 3 that a segment of the core is cut off, said segment being of a maximum height a in the range from approximately 0.15 mm to approximately 0.5 mrn. The plane recesses 5 and 6 extend from the tapered area of the screw in such a manner that the end adjacent the tapered end 4 also extends through the portions of the threads 1 and 2 within this axea. Subsequently, the recesses 5 and 6 extend upwards to a length b of from approximately 6.0 mm to approximately 14.0 mm from the tapered end of the screw. As a result, two threaded cutting edges 7, 7 are provided along the sides of the recesses 5 and 6, said threaded cutting edges cutting up the wood fibres during the screwing movement of the screw.
The above ranges of the lengths a and b depend on the dimension of each screw, as two threaded cutting edges 7 and 8 should, if possible, always be provided along the rirn of the recess.
Claims (7)
1. A screw comprising:
a double thread; and two recesses arranged diametrically opposite one another on a radial side portion of a shank of the screw, each of the two recesses being shaped as two plane segments extending substantially parallel to an axis of the screw and along a portion of the shank and located so that a portion of the double thread in which the recesses are formed divides the remainder of the double thread into first and second uninterrupted portions one of which extends from the recess to a tip of the screw.
a double thread; and two recesses arranged diametrically opposite one another on a radial side portion of a shank of the screw, each of the two recesses being shaped as two plane segments extending substantially parallel to an axis of the screw and along a portion of the shank and located so that a portion of the double thread in which the recesses are formed divides the remainder of the double thread into first and second uninterrupted portions one of which extends from the recess to a tip of the screw.
2. The screw according to claim 1, wherein a depth of each of the said two recesses is approximately 0.15 mm to approximately 0.5 mm taken along a core diameter the screw shank.
3. The screw according to claim 1, wherein each of the said two recesses extend along the screw shank to a location which is approximately 6.0 mm to approximately 14.0 from the tip of the screw.
4. The screw according to claim 2, wherein each of the said two recesses extend along the screw shank to a location which is approximately 6.0 mm to approximately 14.0 from the tip of the screw.
5. The screw according to claim 1, wherein the screw has a tapered shank portion and a non-tapered shank portion, the tapered shank portion extending from the tip of the screw to the non-tapered shank portion, and wherein the two recesses are formed in at least the non-tapered shank portion so that a root diameter of the screw presents the same size along the non-tapered portion of the shank in which the two recesses are formed.
6. The screw according to claim 1, wherein the screw comprises a wood screw.
7. The screw according to claim 1, wherein the two recesses interrupt the double screw thread in a manner wherein a plurality of cutting edges, which are configured to cut wood fibers, are formed on the interrupted portion of the double screw thread and which provides a space in which wood fibers can nestle against plane surfaces of the two recesses in a manner that attenuates a tendency for the wood into which the screw is screwed, to split.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2512042 CA2512042C (en) | 2005-07-14 | 2005-07-14 | A screw with a double thread and a recess in the side of the shank |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2512042 CA2512042C (en) | 2005-07-14 | 2005-07-14 | A screw with a double thread and a recess in the side of the shank |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2512042A1 CA2512042A1 (en) | 2007-01-14 |
| CA2512042C true CA2512042C (en) | 2009-04-07 |
Family
ID=37663402
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2512042 Expired - Fee Related CA2512042C (en) | 2005-07-14 | 2005-07-14 | A screw with a double thread and a recess in the side of the shank |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2512042C (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102023110239A1 (en) * | 2023-04-21 | 2024-10-24 | Berner Omnichannel Trading Holding Se | wood screw |
-
2005
- 2005-07-14 CA CA 2512042 patent/CA2512042C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2512042A1 (en) | 2007-01-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |