US3479921A - Non-circular screws - Google Patents

Non-circular screws Download PDF

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US3479921A
US3479921A US653713A US3479921DA US3479921A US 3479921 A US3479921 A US 3479921A US 653713 A US653713 A US 653713A US 3479921D A US3479921D A US 3479921DA US 3479921 A US3479921 A US 3479921A
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thread
crest
screw
screws
circular
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US653713A
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Seiji Omoto
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    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21H—MAKING PARTICULAR METAL OBJECTS BY ROLLING, e.g. SCREWS, WHEELS, RINGS, BARRELS, BALLS
    • B21H3/00—Making helical bodies or bodies having parts of helical shape
    • B21H3/02—Making helical bodies or bodies having parts of helical shape external screw-threads ; Making dies for thread rolling
    • B21H3/027—Rolling of self-tapping 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
    • F16B33/00—Features common to bolt and nut
    • F16B33/02—Shape of thread; Special thread-forms
    • 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
    • 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

Definitions

  • NON-CIRCULAR SCREWS Filed July 17', 1967 2 Sheets-Sheet l Nov. 25,1969 sraul oMoTo NON-CIHCULAR SCREWS 2 Sheets-Sheet 2 Filed July 17, 1967 United States Patent O 3,479,921 NON-CIRCULAR SCRIEWS Seji Omoto, Tokyo, Japan, assignor of one-half to Hideo Osawa, Toyokawa-machi, Toyokawa-shi, Aichi-ken,
  • This invention relates to screws, and more particularly to non-circular screws of the self-tapping or thread forming type.
  • Non-circular screws have hitherto been proposed in which not only the crest portions of thread are at gradually varied radii but its root portions are also at correspondingly varied radii.
  • the crest portions of thread have been blunted or attened at spaced circumferential intervals about the thread to provide for radial reliefs.
  • These screws may well be adapated for being produced by a shaving or grinding operation, but are rather troublesome to make by a rolling process. They are not strong enough to be driven forcibly into the stock.
  • the present invention aims to eliminate these drawbacks.
  • the present invention resides in the provision of noncircular screws in which the thread is continuous but is gradually reduced in height at suitably spaced intervals along the thread to provide for reliefs while the root of the thread is kept at a constant radius throughout.
  • the reduction in height of the thread is effected in such a manner that (l) the crest of the thread is gradually lowered with the crest angle remaining the same as the original one, (2) the crest of the thread is gradually lowered by a constant crest angle which is greater than the original one but is the same as the crest angle at the lowest thread, or (3) the crest of thread is gradually lowered with gradually increasing angle till the lowest thread is reached where the crest angle is the largest.
  • non-circular refers to a form of a screw in which the surafce defined by the tops of the threads is of a noncircular conguration.
  • circular screw refers to an ordinary screw which has a ridge of uniform section in the form of a helix on the external surface of a cylinder.
  • without lead refers to an imaginary thread which would have no lead or in other word which would not advance axially Iwith respect to a fixed mating thread in one revolution.
  • non-cricular screws may be grouped into three types, namely (I) a screw in which the crest of the thread and also the root of the thread are both varied in height; that is the cross-sectional shape both at the crest of the thread (without lead) and at the root are such that any radius is not of the same length, (II) a screw in which the cross-sectional shape at the crest of the thread is such that any radius is of the same length while at the root of the thread any radius is not of the same length, and (III) a screw in Vwhich the crosssectional shape at the crest of the thread is such that any radius is not of the same length while at the root of the thread any radius is of the same length.
  • Non-circular screws which have hitherto been proposed belong to said type (I).
  • the present invention is primarily concerned with non-circular screws of type (III), while at the same time the invention is intended to include noncircular screws of type (II) which are exactly the reverse con-formation of type (III).
  • FIGURE l is a perspective view of a cylinder shown as a base surface from which the thread according to this invention is to project.
  • FIGURE 2 is a diagrammatic perspective view, on an enlarged scale, of a fraction of thread, straightened and developed on a plane, showing the thread formation of one embodiment of this invention.
  • FIGURES 3 and 4 are similar to FIGURE 2 but showing second and third embodiments of this invention.
  • FIGURES 5, 6, and 7 are end views .of the threads illustrated in FIGURES 2, 3 and 4, respectively.
  • FIGURE 8 is a transverse sectional view of a screw, on a reduced scale, through the root of thread showing the thread outline of both the first and second embodiments but without lead.
  • FIGURES 9 and 10 are similar to FIGURE 8 but showing the third and fourth embodiments, respectively.
  • FIGURE 1 the numeral 10 designates a right circular cylinder having a longitudinal axis at O O. It is obvious that any point on its surface is equi-distant from said axis. Now if one or more threads of uniform section are Wound on the external surface of said base cylinder consecutively and on a constant pitch in the form of helix, then a normal screw will be obtained. According to the present invention, the thread is not of uniform section but is gradually varied in height and form in such fashion as will fully be explained in connection with FIGURES 2 to 7.
  • FIGURE 2 a fraction of thread 21 according to one embodiment of the invention is diagrammatically shown as developed on a plane.
  • a triangular shape shown at the left end is a lateral section of the thread at its highest portion 22.
  • Straight line designates a base line which, in the case of a screw without lead, coincides with a generating line of the surface of cylinder 10 shown in FIGURE l.
  • the crest height of the thread gradually decreases from the highest thread portion 22 to the lowest thread portion 23 and then increases from that portion to the next highest portion 22 and so on, longitudinally of the thread.
  • the manner in which the crest height is changed is illustrated more clearly in FIGURE 5.
  • the crest angle of the perfect thread or the highest thread portion 22 is kept constant throughout the change of height until the lowest thread portion 23 is attained.
  • the crest angle along crest line 24 is constant and is nowhere flattened theoretically. Reference is made to theoretically because no crest has a sharp apex in actual practice.
  • the root of the thread has a fiat part 25 in the region of lowered thread portion, said fiat part 25 resembling something like a half of a leaf as in FIGURE 2. Actually this part 25 is not fiat but is a part of a cylindrical surface.
  • the numeral 31 indicates a modified form of thread, in which crest line 34 is gradually varied in height in the manner similar to crest line 24 of FIGURE 2, but the crest angle is also varied increasingly from the highest thread portion 32 to the lowest thread portion 33 as is more clearly illustrated in FIGURE 6.
  • the numeral 41 designates another modification of thread, in which crest line 44 is gradually varied in height in the manner similar to FIGURES 2 and 3, but the crest angle, except at the highest thread portion 42, is made throughout the same as that of the lowest thread portion 43 which is greater than the former, as is more clearly illustrated in FIGURE 7.
  • a lateral section at any point longitudinally along the thread is of the shape of gambrel roof with the exception of both at the highest portion 42 and at the lowest portion 43 where it is a triangle.
  • This form of thread may be made in practice by a tool or grinding wheel formed with a V-shaped cutting edge.
  • a thread of uniform section having 60 degree crest angle may be changed into the form of FIGURE 4 by shaving off the top gradually from the perfect thread portion or the highest portion 42 toward the lowest portion 43 with the use of a V-shaped tool of 90 degree cutting edge.
  • crest nor root of thread in this embodiment has any flat part theoretically, but a second ridge line 44 is formed on the ank on either side of crest line 44. Said ridge line 44' is the line of junction between the flank of the original thread and the shaved surface of the finished thread.
  • the lowest thread portions 23, 33 and 34 are disposed substantially at mid-point between two adjacent perfect thread portions 22, 32 and 42 of threads 21, 31 and 41, respectively.
  • the fashion in which the crest height changes along with its angle is shown in FIGURES 5, 6 and 7 which correspond to FIGURES 2, 3 and 4, respectively.
  • the form of thread 21 illustrated in FIGURE 2 has fiat part 25 at the root of thread.
  • this form is utilized as a tap for swaging a mating female screw or as a bolt for self tapping, there occurs no interference of thread in said flat part 25 and no disturbance is observed to lessen the efficiency of the thread.
  • this type of screw is produced by a rolling process, sometimes fine-grained material is observed to peel off in this fiat area though it does not seriously affect the swagng action of thread. Therefore, it is preferred in practice to utilize such patterns as threads 31 and 41 illustrated in FIGURES 3 and 4.
  • a non-circular screw according to this invention has such configuration as may be obtained by closely winding a thread or threads of varying crest height (21, 31 or 41) in the form of helix around a cylinder 10 of the same radius. It should, however, be understood that said cylinder 10 can easily be substituted by a cone or frustum of a cone and the same undulating thread or threads may be closely wound thereon substantially in the same manner as above stated.
  • the resulting type of screw will be a tapered one of a non-circular configuration. In practice this type will be formed on a tapered portion of a screw, an entering end of a tap, or a tapered portion of a back-taper screw. This type of screw configuration having a conical base may be made without departing from the inventions fundamental theme.
  • the screw according to this invention is characterized in that the sectional shape thereof through a plane perpendicular to the axis is a circle at the root of thread (without lead), the crest of thread has theoretically no flat part, and the crest line of the thread is of a wavy formation. It is. therefore, fundamentally different from such forms of screw as have hitherto been proposed, for example, in connection with a fluteless swaging tap in which the crest angle of the thread is constant throughout while the crest and root are both varied in height circumferentially to provide radial reliefs so that cross-sectional shapes of the tap (without lead) at crest and root may both be of a noncircular configuration.
  • applicants screw has no recess at the root of the thread, and accordingly it is stronger than any other non-circular screws of prior art.
  • the strength of the thread per se can also be increased.
  • the number of highest crest or perfect thread portions 22, 32 or 42 must be more than one per one revolution of threads 21, 31 or 41 (FIGURE 2, 3 or 4) around the base cylinder (FIGURE 1) in the form of a helix. It is preferable to provide, per one revolution of the thread, two to six highest portions (22, 32 or 42) appropriately spaced from one another circumferentially as seen in FIGURES 8 to l0.
  • the arrangement of said highest portions longitudinally of the screw may be such that they are disposed on lines either parallel or obliquely to the axis of the screw. If the lines are oblique, then they will become helical lines which, however, are quite different from those of thread formation and may be referred to as helical lines of highest portions.
  • the highest portions on such helical lines which may be either right-handed or left-handed, though it is possible in the invention to arrange them on parallel lines to the axis of the screw as previously stated.
  • the helical arrangement is preferred to the parallel one because the working faces of dies for the former are easy to make, and furthermore mating screw threads rolled by such dies are better than the latter.
  • non-circular screws according to the invention comprise such threads as are shown in FIG- URES 2 to 7, whose crests are gradually reduced in height from perfect thread portions 22, 32 or 42 to lowest portions 23, 33 or 43 in such a manner that the lateral sectional shape at any point along the thread is (l) of analogous form, (2) of gambrel roof form, or (3) of increasing crest angle.
  • the work in die making is facilitated if the above three forms of thread are properly mixed into one variety. Therefore such a mixed form of thread is generally used in practice rather than utilizing the three forms separately.
  • FIGURES 8 to l0 lateral sections at the root of thread (Without lead) are shown as having the thread outline of a non-circular configuration according to the invention.
  • each of the embodiments is shown as having six highest crest portions per one revolution of thread.
  • the root outline is shown as a circle 11.
  • FIGURE 8 shows a non-circular screw which has a thread of the form illustrated either in FIGURE 2 or in FIGURE 3.
  • the outline of the lowered crest portions of the thread is shown approximately as a straight line.
  • This line may be changed in any manner unless it departs from the idea of the invention. It is, however, preferable to make it in the form of a straight line or a line as nearly as straight but slightly curved inwardly or outwardly.
  • This form of screw can be obtained by a rolling process with the use of such dies as prepared by the methods disclosed in the specifications of Japanese Patent Nos. 440,387 and 172,758, said dies being provided with exactly reversed unevenness to that of the non-circular screw which is desired to produce.
  • FIGURE 9 shows a non-circular screw which has a thread of the form illustrated in FIGURE 4, the outline of the lowered crest portions of the thread being shown similarly as a straight line. Between the thread outline and the root circle 11, there appears a Second ridge line.
  • the perfect thread portion 42 is within range A
  • portion 43 where the crest is lowered with a constant angle greater than that of perfect thread portion 42r is within range C
  • portion in the form of mixture of the two is within range B where a second ridge line appears.
  • FIGURE 10 shows a non-circular screw of this invention, which is not produced by a rolling operation but worked out of an ordinary circular screw by a shaving or grinding operation.
  • This form. has also six perfect thread portions 52 left unground and uniformly spaced circumferentially, the remaining thread portions having been ground olf by a grinder having a V edge of an angle greater than the crest angle of portion 52.
  • the numeral 53 indicates the lowered thread portions which are formed by feeding the grinder along the root circle 11. If desired, the grinder may be moved along a straight line or even along an excentric curve. However, the thread outline of portions 53 must always be inside a circumscribed circle of perfect thread portion 52, and the lowest position of the tool path should be limited by the root circle 11.
  • the form illustrated in FIGURE 10 cannot be manufactured elficiently when compared with those illustrated in FIG- URES 8 and 9, and therefore this form is mainly utilized to make only a master screw for manufacturing rolling dies.
  • Non-circular screws of the form as heretofore stated are used mainly in the threaded portions of taps and self-tapping screws. Screws having exactly reversed thread formation are used in the threaded portions of rolling dies.
  • non-circular screws of this invention are constructed as above set forth, they are stronger than prior art non-circular screws, without injuring the relieving function.
  • female thread forming tools such for example as taps, self-tapping screws or the like, driving torque is minimized and thread forming by plastic deformation is enhanced.
  • these non-circular screws have particularly suitable formations for being rolled, they can be effectively and advantageously used in mass production.
  • screws of such a form .as may be obtained when a continuous thread having a crest progressively varying in height is closely formed around the external surface of a cylinder at a constant pitch in the form of a helix; a non-circular screw characterized in that said continuous thread has, in one turn thereof, a plurality of highest portions where the pattern of the perfect thread formation and the desired size thereof are maintained while the portions other than said highest ones are all reduced gradually in height, and the crest of said continuous thread is practically sharp and has no flat part thereon, the prole, in planes perpendicular to the longitudinal axis of the screw without lead, being a circle at the roots of the thread, but nearly a polygon at the crests, said continuous thread has an undulating crest line and the lateral section between the highest and lowest points are a series of sections each with a different shape Whose sides have two slopes, the upper and lower ones corresponding to those of the lateral sections, respectively, of the triangular shapes at the lowest and highest points, and

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
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US653713A 1967-07-17 1967-07-17 Non-circular screws Expired - Lifetime US3479921A (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
US65371367A 1967-07-17 1967-07-17
GB50542/68A GB1245618A (en) 1967-07-17 1968-10-24 Improvements in and relating to screws and taps
DE19681809094 DE1809094A1 (de) 1967-07-17 1968-11-15 Schraube
CH6669A CH496903A (de) 1967-07-17 1969-01-06 Schraube
AT699469A AT315584B (de) 1967-07-17 1969-07-21 Schraube mit unrundem Gewindeumriß

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US653713A Expired - Lifetime US3479921A (en) 1967-07-17 1967-07-17 Non-circular screws

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AT (1) AT315584B (de)
CH (1) CH496903A (de)
DE (1) DE1809094A1 (de)
GB (1) GB1245618A (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3742541A (en) * 1970-12-10 1973-07-03 S Ohmoto Tool for forming internal screw-threads and method of making the same
US5842923A (en) * 1995-06-14 1998-12-01 Minebea Kabushiki-Kaisha Screw and method for its production
US20080219800A1 (en) * 2007-03-06 2008-09-11 Van Cor Dale E Threaded fastener and fastener system
CN100482957C (zh) * 2004-02-25 2009-04-29 A-Z装备与配件股份有限及两合公司 形成螺纹的螺丝紧固件
US20110280685A1 (en) * 2010-05-13 2011-11-17 Taiwan Shan Yin Int'l Co., Ltd. Screw with low drilling resistance
US20160138639A1 (en) * 2013-10-03 2016-05-19 Aoyama Seisakusho Co., Ltd. Bolt
US9822810B2 (en) * 2015-12-08 2017-11-21 Taiwan Shan Yin International Co., Ltd. Fastener

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3046692C2 (de) * 1980-12-11 1986-01-23 Kamax-Werke Rudolf Kellermann Gmbh & Co Kg, 3360 Osterode Gewindefurchende Schraube
JPS57110812A (en) * 1980-12-26 1982-07-09 Nissan Motor Clamp and its manufacture
DE3335092C2 (de) * 1983-09-28 1985-08-08 Rommel, Erwin, 4320 Hattingen Gewindeformende Schraube
DE3926951C2 (de) * 1989-08-14 1995-11-16 Wakai Sangyo Kk Klemmschraube
FR2683275B1 (fr) * 1991-11-06 1995-03-03 Itw De France Element d'assemblage.
US7101134B2 (en) 2001-06-19 2006-09-05 Illinois Tool Works Inc. Fastener having multiple lobed thread
AU2004202642B2 (en) * 2002-03-12 2007-04-26 Illinois Tool Works Inc. Fastener having multiple lobed thread
FR2930803B1 (fr) * 2008-04-30 2013-02-08 Bol Fm Internat Bfmi Cheville filetee utilisable pour la fixation d'objets a un support en materiau tendre et/ou friable
DE102016120106A1 (de) * 2016-10-21 2018-04-26 Sfs Intec Holding Ag Befestigungselement mit wellengewinde

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1428792A (en) * 1921-07-11 1922-09-12 Lysiak Antoni Joint or connection
US1876796A (en) * 1931-03-02 1932-09-13 Trbojevich Nikola Screw thread
US2336570A (en) * 1941-11-27 1943-12-14 Gen Motors Corp Shielded spark plug for aircraft engines
AT210236B (de) * 1958-07-29 1960-07-25 Strojirny A Slevarny Bohumira Gewindebohrer
US3180202A (en) * 1963-05-28 1965-04-27 Gen Am Transport Fluteless thread-forming tools
US3200691A (en) * 1962-08-06 1965-08-17 Neuschotz Robert Threaded elements with self-tapping peaks and recesses
GB1004883A (en) * 1962-03-20 1965-09-15 Res Eng & Mfg Improvements in self-tapping screws

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1428792A (en) * 1921-07-11 1922-09-12 Lysiak Antoni Joint or connection
US1876796A (en) * 1931-03-02 1932-09-13 Trbojevich Nikola Screw thread
US2336570A (en) * 1941-11-27 1943-12-14 Gen Motors Corp Shielded spark plug for aircraft engines
AT210236B (de) * 1958-07-29 1960-07-25 Strojirny A Slevarny Bohumira Gewindebohrer
GB1004883A (en) * 1962-03-20 1965-09-15 Res Eng & Mfg Improvements in self-tapping screws
US3200691A (en) * 1962-08-06 1965-08-17 Neuschotz Robert Threaded elements with self-tapping peaks and recesses
US3180202A (en) * 1963-05-28 1965-04-27 Gen Am Transport Fluteless thread-forming tools

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3742541A (en) * 1970-12-10 1973-07-03 S Ohmoto Tool for forming internal screw-threads and method of making the same
US5842923A (en) * 1995-06-14 1998-12-01 Minebea Kabushiki-Kaisha Screw and method for its production
CN100482957C (zh) * 2004-02-25 2009-04-29 A-Z装备与配件股份有限及两合公司 形成螺纹的螺丝紧固件
US20080219800A1 (en) * 2007-03-06 2008-09-11 Van Cor Dale E Threaded fastener and fastener system
US8858144B2 (en) * 2007-03-06 2014-10-14 Dale E. Van Cor Threaded fastener and fastener system
US20110280685A1 (en) * 2010-05-13 2011-11-17 Taiwan Shan Yin Int'l Co., Ltd. Screw with low drilling resistance
US8864430B2 (en) * 2010-05-13 2014-10-21 Taiwan Shan Yin Int'l Co., Ltd. Screw with low drilling resistance
US20160138639A1 (en) * 2013-10-03 2016-05-19 Aoyama Seisakusho Co., Ltd. Bolt
US9903405B2 (en) * 2013-10-03 2018-02-27 Aoyama Seisakusho Co., Ltd. Bolt
US9822810B2 (en) * 2015-12-08 2017-11-21 Taiwan Shan Yin International Co., Ltd. Fastener

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Publication number Publication date
DE1809094A1 (de) 1970-05-21
GB1245618A (en) 1971-09-08
CH496903A (de) 1970-09-30
AT315584B (de) 1974-05-27

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