WO2011111022A1 - Threaded device, particularly for self-threading and coupling thermoplastic materials and the like - Google Patents
Threaded device, particularly for self-threading and coupling thermoplastic materials and the like Download PDFInfo
- Publication number
- WO2011111022A1 WO2011111022A1 PCT/IB2011/051017 IB2011051017W WO2011111022A1 WO 2011111022 A1 WO2011111022 A1 WO 2011111022A1 IB 2011051017 W IB2011051017 W IB 2011051017W WO 2011111022 A1 WO2011111022 A1 WO 2011111022A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- threading
- thread
- angle
- self
- thermoplastic materials
- Prior art date
Links
- 230000008878 coupling Effects 0.000 title claims abstract description 9
- 238000010168 coupling process Methods 0.000 title claims abstract description 9
- 238000005859 coupling reaction Methods 0.000 title claims abstract description 9
- 239000012815 thermoplastic material Substances 0.000 title claims abstract description 8
- 239000000463 material Substances 0.000 description 9
- 229920003023 plastic Polymers 0.000 description 9
- 239000011295 pitch Substances 0.000 description 5
- 238000012360 testing method Methods 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 239000004917 carbon fiber Substances 0.000 description 3
- 239000003365 glass fiber Substances 0.000 description 3
- 238000013021 overheating Methods 0.000 description 3
- 239000004033 plastic Substances 0.000 description 3
- 238000005096 rolling process Methods 0.000 description 3
- 229920000049 Carbon (fiber) Polymers 0.000 description 2
- 230000032683 aging Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 230000000670 limiting effect Effects 0.000 description 2
- 229910052623 talc Inorganic materials 0.000 description 2
- 239000000454 talc Substances 0.000 description 2
- 238000007669 thermal treatment Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- -1 for heavy use Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 239000002023 wood Substances 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
- F16B37/00—Nuts or like thread-engaging members
- F16B37/002—Nuts or like thread-engaging members cutting threads during screwing; removing paint or dirt layers covering threaded shanks
-
- 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
Definitions
- the present invention relates to a threaded device, particularly for self-threading and coupling thermoplastic materials. More specifically, the invention relates to a device that is adapted to form threads and couple various types of technopolymers, in particular technopolymers with carbon or glass fibers or loaded with various inert materials (talc, carbon, glass), for heavy use, wood and agglomerates thereof and with appropriate thermal treatments, composite materials with other hardening elements, with holes made by mechanical processing or injection molding, with exceptionally low screwing torque and high resistance to thread-stripping and with an exceptionally low thread formation load and high thread-stripping and unscrewing load, without generating overheating of the female screw when used on technopolymers.
- technopolymers in particular technopolymers with carbon or glass fibers or loaded with various inert materials (talc, carbon, glass), for heavy use, wood and agglomerates thereof and with appropriate thermal treatments, composite materials with other hardening elements, with holes made by mechanical processing or injection molding, with exceptionally low screwing torque and high resistance
- threadings of the known type have drawbacks which are due to the fact that they cause phenomena of radial precompression owing to their profile having broad angles and high threading pitches, which cause high thread-formation loads, with low resistance to unscrewing and to thread-stripping.
- the threadings currently used are double-threaded or single-threaded screws, with symmetric profiles at 30°- 40°- 50° which create phenomena of creep, breakage over time of the studs, caused by the ageing of the technopolymers, with consequent easy thread-stripping and unscrewing. Disclosure of the Invention
- the aim of the present invention is provide a threaded device, particularly for self-threading and coupling thermoplastic materials and the like, which makes it possible to overcome the drawbacks of the background art, and which makes it possible to have an extremely low screwing torque and a high resistance to thread-stripping.
- an object of the present invention is to provide a threaded device, particularly for self-threading and coupling thermoplastic materials, which does not generate overheating of the female screw when used on thermoplastic polymers.
- Another object of the present invention is to provide a threaded device that is highly reliable, relatively easy to implement and low-cost.
- a threaded device particularly for self- threading and coupling thermoplastic materials, that comprises a cylindrical body provided, at one end, with a head, said body being providing with a threading, characterized in that the thread of said threading is angled toward said head, with an angle that is comprised between 3° and 6° with respect to an axis perpendicular to the longitudinal axis of said cylindrical body.
- Figure 1 is a schematic plan view of the device according to the invention.
- Figure 2 is a side view of the device according to the invention.
- Figure 3 is a detailed cross-sectional view of the thread of the device according to the invention.
- Figure 4 is a view of a rolling comb used to produce the device according to the invention.
- Figure 5 is a view of the bending sequence made by the comb in Figure 4.
- the device comprises a cylindrical body 1 made of metal in the natural state or hardened by means of thermal treatment, and provided, at one end, with a head 3, and along the body 1 , with a thread 2.
- the device is especially adapted for self- threading or for coupling two parts made of plastic material and the like.
- a rolling comb P Figure 4 which is constituted by two sections, one that threads the device without negative inclination of the thread and a final part A which creates the negative inclination of the thread.
- the thread 2 is inclined gradually by the action of the comb P (a, b, c, d, e, f, g).
- the end part of the comb is negatively inclined and during the threading it transforms the face of the thread, i.e. the part of the thread facing the head 3, from a right angle to a negative angle with an inclination of 3°- 6°.
- Thread-forming, unscrewing and thread-stripping properties are
- the device according to the invention can be used in the manufacturing industry where use is made of technopolymers of various types, glass or carbon fibers, polymers loaded with talc, carbon and other inert elements.
Abstract
The present invention relates to a threaded device, particularly for self-threading and coupling thermoplastic materials, that comprises a cylindrical body (1) provided, at one end, with a head (3), the body being providing with a threading (2), the distinctive characteristic of which consists in the fact that the thread of the threading is angled toward the head, with an angle that is comprised between 3° and 6° with respect to an axis perpendicular to the longitudinal axis (5) of the cylindrical body.
Description
THREADED DEVICE, PARTICULARLY FOR SELF-THREADING AND COUPLING THERMOPLASTIC MATERIALS AND THE LIKE
Technical Field
The present invention relates to a threaded device, particularly for self-threading and coupling thermoplastic materials. More specifically, the invention relates to a device that is adapted to form threads and couple various types of technopolymers, in particular technopolymers with carbon or glass fibers or loaded with various inert materials (talc, carbon, glass), for heavy use, wood and agglomerates thereof and with appropriate thermal treatments, composite materials with other hardening elements, with holes made by mechanical processing or injection molding, with exceptionally low screwing torque and high resistance to thread-stripping and with an exceptionally low thread formation load and high thread-stripping and unscrewing load, without generating overheating of the female screw when used on technopolymers.
Background Art
As is known, in order to couple parts made of plastic material, threadings are sometimes used in an improper manner.
However, threadings of the known type have drawbacks which are due to the fact that they cause phenomena of radial precompression owing to their profile having broad angles and high threading pitches, which cause high thread-formation loads, with low resistance to unscrewing and to thread-stripping.
Furthermore, because of the friction produced for the reasons mentioned above, surface melting of the female screw occurs, which is caused by the high speed of modern screwing tools.
The threadings currently used are double-threaded or single-threaded screws, with symmetric profiles at 30°- 40°- 50° which create phenomena of creep, breakage over time of the studs, caused by the ageing of the technopolymers, with consequent easy thread-stripping and unscrewing.
Disclosure of the Invention
The aim of the present invention is provide a threaded device, particularly for self-threading and coupling thermoplastic materials and the like, which makes it possible to overcome the drawbacks of the background art, and which makes it possible to have an extremely low screwing torque and a high resistance to thread-stripping.
Within this aim, an object of the present invention is to provide a threaded device, particularly for self-threading and coupling thermoplastic materials, which does not generate overheating of the female screw when used on thermoplastic polymers.
Another object of the present invention is to provide a threaded device that is highly reliable, relatively easy to implement and low-cost.
This aim, as well as these and other objects which will become more apparent hereinafter, are achieved by a threaded device, particularly for self- threading and coupling thermoplastic materials, that comprises a cylindrical body provided, at one end, with a head, said body being providing with a threading, characterized in that the thread of said threading is angled toward said head, with an angle that is comprised between 3° and 6° with respect to an axis perpendicular to the longitudinal axis of said cylindrical body.
Brief description of the drawings
Further characteristics and advantages of the invention will become clearer from an embodiment of the device according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:
Figure 1 is a schematic plan view of the device according to the invention;
Figure 2 is a side view of the device according to the invention;
Figure 3 is a detailed cross-sectional view of the thread of the device according to the invention;
Figure 4 is a view of a rolling comb used to produce the device
according to the invention;
Figure 5 is a view of the bending sequence made by the comb in Figure 4.
Ways of carrying out the invention
With reference to the figures, the device according to the invention comprises a cylindrical body 1 made of metal in the natural state or hardened by means of thermal treatment, and provided, at one end, with a head 3, and along the body 1 , with a thread 2. The device is especially adapted for self- threading or for coupling two parts made of plastic material and the like.
Experimental research and studies and technical and practical tests carried out by the applicant have surprisingly ascertained that, with a shape of the profile of the thread 2 having:
- an angle a less than or equal to 18° (see in particular Figure 3, the angle a being the angle defined by the extensions of the two faces 2a and 2b of the thread 2);
- a side toward the head 3, i.e. the side of the thread facing the head 3 of the device, with an inclination of δ -3°-6° with respect to the axis 5 of the device;
- an angle ω, defined as the angle defined between the surface of the point or cusp of the thread 2 and an imaginary line parallel to the axis 5, of 10°
(Figure 3);
- anti-tearing connections 4 at the base of the threading, defining an angle of 45°-50° γ with respect to an imaginary line parallel to the axis 5 of the thread 2 (Figure 3).
With these characteristics of the thread 2 we obtain a low thread formation load, since the friction is considerably reduced and no radial precompression and overheating is generated, which in plastic materials generates phenomena of immediate stress-cracking or stress relaxation, and later on, owing to ageing, creep phenomena with loosening of the screw.
With the side toward the head 3 of the device at a negative angle, the
effusion of the material of the female screw is prevented.
With a careful study of the pitches (Figure 2) to give to the threading, it was ascertained after innumerable tests on different types of material that, contrary to what was always believed, i.e. that high pitches with consequently a large amount of material between the spires of the screw improve the hold against thread-stripping, in reality the unscrewing coefficient deteriorates considerably, thus rendering the gained resistance to thread-stripping useless.
On the contrary, by using these suitably reduced pitches the thicknesses of the elements to be connected are reduced, thus saving on raw materials.
With a ratio of the outer diameter of the threading (dl) to the pitch of the screw, dl/p (which in general in threads of the known type is 1.5 - 2 times the diameter of the screw, with an inclination of the thread of 40°-50°) of 3 - 3.5 times dl , with an inclination δ comprised between 3° and 6°, in tests a high unscrewing coefficient was obtained with materials, i.e. technopolymers with glass and carbon fibers in constructions that support considerable forces, with tightening and loosening maneuvers for an undefined number of times, with an improved thread-stripping load. This is due to the compression exerted by the thread with negative inclination δ (Figure 3) which ensures that the female screw behaves like an elastic washer, thus improving the hold against unscrewing and making it possible to tighten elements even if they have thin cross-sections.
With the inclined plane ω (Figure 3) on the summit of the thread, radial compression is also prevented for thin studs (i.e. cast parts where the screw is screwed and which have their own hole so as to allow the insertion of the screw) and the profile of the resistant section is strengthened.
Industrial production of the device according to the invention, once the machine tools with the profile adapted for this purpose have been made, is possible with common machinery (rolling screw-cutting machines, die-
stamping machines and the like).
For example, it is possible to use a rolling comb P, Figure 4, which is constituted by two sections, one that threads the device without negative inclination of the thread and a final part A which creates the negative inclination of the thread. From Figure 2 it can be seen that the thread 2 is inclined gradually by the action of the comb P (a, b, c, d, e, f, g). The end part of the comb is negatively inclined and during the threading it transforms the face of the thread, i.e. the part of the thread facing the head 3, from a right angle to a negative angle with an inclination of 3°- 6°.
The technological improvements of the invention over other systems of threading are made clear by the comparative tests between one type of screws currently in use and the threaded device described herein, as illustrated in the table below.
Thread-forming, unscrewing and thread-stripping properties.
In practice it has been found that the device according to the invention fully achieves the intended aim and objects.
Advantageously, the device according to the invention can be used in the manufacturing industry where use is made of technopolymers of various types, glass or carbon fibers, polymers loaded with talc, carbon and other inert elements.
The device, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.
In practice the materials employed, as well as the contingent dimensions and shapes, may be any according to requirements and to the state of the art.
The disclosures in Italian Patent Application No. PV2010A000003 from which this application claims priority are incorporated herein by reference.
Where the technical features mentioned in any claim are followed by reference numerals and/or signs, those reference numerals and/or signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference numerals and/or signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference numerals and/or signs.
Claims
1. A threaded device, particularly for self-threading and coupling thermoplastic materials, that comprises a cylindrical body (1) provided, at one end, with a head (3), said body being providing with a threading (2), characterized in that the thread of said threading is angled toward said head, with an angle that is comprised between 3° and 6° with respect to an axis perpendicular to the longitudinal axis of said cylindrical body.
2. The device according to claim 1 , characterized in that said threading has a pitch with a ratio given by the diameter (dl) of the device to the pitch (p) which is less than 3.0-3.5 times said diameter (dl).
3. The device according to claim 1 , characterized in that said threading (2) has an angle (a), defined as the angle between the extensions of the two opposite faces of the thread, less than or equal to 18°.
4. The device according to claim 1 , characterized in that said threading (2) has an inclined plane at the summit of the thread with an angle comprised between 10° and 15° with respect to an imaginary line parallel to said longitudinal axis (5) of the cylindrical body (2).
5. The device according to one or more of the preceding claims, characterized in that it is a screw.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP11717747A EP2545290A1 (en) | 2010-03-11 | 2011-03-10 | Threaded device, particularly for self-threading and coupling thermoplastic materials and the like |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
ITPV2010A000003 | 2010-03-11 | ||
IT000003A ITPV20100003A1 (en) | 2010-03-11 | 2010-03-11 | ANTIBIDDING THREAD AND RELATED THREAD TOOL, FOR THERMOPLASTIC MATERIALS, COMMON THERMO-HARDENERS AND LOADED WITH INERT MATERIALS, CARBON AND GLASS FIBERS, WOOD AND ITS COMPOUNDS, CONCRETE, PLASTER, INSULATING MATERIALS, WITH R |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2011111022A1 true WO2011111022A1 (en) | 2011-09-15 |
Family
ID=42989280
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/IB2011/051017 WO2011111022A1 (en) | 2010-03-11 | 2011-03-10 | Threaded device, particularly for self-threading and coupling thermoplastic materials and the like |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP2545290A1 (en) |
IT (1) | ITPV20100003A1 (en) |
WO (1) | WO2011111022A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102020106119B3 (en) | 2020-03-06 | 2021-09-09 | Günter Weippert | screw |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5605458A (en) * | 1995-03-06 | 1997-02-25 | Crystal Medical Technology, A Division Of Folsom Metal Products, Inc. | Negative load flank implant connector |
DE20316200U1 (en) * | 2003-10-22 | 2003-12-18 | Böllhoff GmbH | Connecting arrangement has metal fastening element with threaded shank with thread of saw-tooth profile with fine pitch and conical outer contour, and plastic component with conical smooth-walled bore |
US20080260495A1 (en) * | 2007-04-19 | 2008-10-23 | Illinois Tool Works Inc. | Threaded screw fastener with multiple characteristic threads |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4334814A (en) * | 1978-10-02 | 1982-06-15 | Microdot Inc. | Self-tapping screw for use in plastics |
US6923611B2 (en) * | 2002-06-13 | 2005-08-02 | Illinois Tool Works Inc. | Self-drilling fastener |
DE102007023735A1 (en) * | 2007-05-22 | 2008-11-27 | Fischerwerke Gmbh & Co. Kg | Thread-cutting concrete screw and arrangement with such a concrete screw |
-
2010
- 2010-03-11 IT IT000003A patent/ITPV20100003A1/en unknown
-
2011
- 2011-03-10 WO PCT/IB2011/051017 patent/WO2011111022A1/en active Application Filing
- 2011-03-10 EP EP11717747A patent/EP2545290A1/en not_active Withdrawn
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5605458A (en) * | 1995-03-06 | 1997-02-25 | Crystal Medical Technology, A Division Of Folsom Metal Products, Inc. | Negative load flank implant connector |
DE20316200U1 (en) * | 2003-10-22 | 2003-12-18 | Böllhoff GmbH | Connecting arrangement has metal fastening element with threaded shank with thread of saw-tooth profile with fine pitch and conical outer contour, and plastic component with conical smooth-walled bore |
US20080260495A1 (en) * | 2007-04-19 | 2008-10-23 | Illinois Tool Works Inc. | Threaded screw fastener with multiple characteristic threads |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102020106119B3 (en) | 2020-03-06 | 2021-09-09 | Günter Weippert | screw |
Also Published As
Publication number | Publication date |
---|---|
ITPV20100003A1 (en) | 2011-09-12 |
EP2545290A1 (en) | 2013-01-16 |
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