US20010015088A1 - Screw-thread forming apparatus, screw-thread forming method and fuel supply pipe assembly therewith - Google Patents
Screw-thread forming apparatus, screw-thread forming method and fuel supply pipe assembly therewith Download PDFInfo
- Publication number
- US20010015088A1 US20010015088A1 US09/819,537 US81953701A US2001015088A1 US 20010015088 A1 US20010015088 A1 US 20010015088A1 US 81953701 A US81953701 A US 81953701A US 2001015088 A1 US2001015088 A1 US 2001015088A1
- Authority
- US
- United States
- Prior art keywords
- forming
- screw
- punches
- forming punches
- thread
- 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.)
- Granted
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D17/00—Forming single grooves in sheet metal or tubular or hollow articles
- B21D17/04—Forming single grooves in sheet metal or tubular or hollow articles by rolling
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D17/00—Forming single grooves in sheet metal or tubular or hollow articles
- B21D17/02—Forming single grooves in sheet metal or tubular or hollow articles by pressing
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21K—MAKING FORGED OR PRESSED METAL PRODUCTS, e.g. HORSE-SHOES, RIVETS, BOLTS OR WHEELS
- B21K1/00—Making machine elements
- B21K1/56—Making machine elements screw-threaded elements
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S220/00—Receptacles
- Y10S220/33—Gasoline tank cap
Definitions
- the present invention relates to an apparatus for forming a screw-thread(s) on or around a metal pipe (such as a steel pipe) and a method for forming the screw-thread(s) on or around the metal pipe using such an apparatus, and further relates to a fuel supplying pipe assembly being assembled with the metal pipe, on which is formed the screw-thread(s) being obtained by the described screw-thread forming apparatus and method therefor.
- a metal pipe such as a steel pipe
- a fuel supplying pipe assembly being assembled with the metal pipe, on which is formed the screw-thread(s) being obtained by the described screw-thread forming apparatus and method therefor.
- a metal pipe 101 is introduced to cover on a core metal 100 , around which is formed a forming groove 100 a , and as shown in FIG. 11( b ), a protruded or convex forming portion 102 a of a forming roller 102 is pushed on the metal pipe 101 when the metal pipe 101 begins rotation together with the core metal 100 , so as to deform a threaded portion 103 following the forming groove 100 a.
- the present invention can be classified as a punch forming method, and one such method is already known as is disclosed in Japanese Laid-Open Patent No. Sho 61-253140 (1986).
- a plurality of forming punches 104 are provided, each having a forming edge portion 104 a of curvature corresponding to that of concave portion of the desired screw-thread , being freely movable in a direction toward one point (i.e., a central portion of a set) back and forth, and a metal pipe 101 is set or fixed at the center of the plural forming punches 104 . Then, the plural forming punches 104 are shifted toward the central portion of the set to give pressure on the metal pipe 101 at the forming edge portion 104 a of the punches, thereby forming the threaded portion by deforming the pipe 101 plastically.
- the roll forming method is not appropriate in particular in a case when forming double threading, or wherein the threaded portions are not formed more than one turn around the outer periphery of the pipe (i.e. wherein threaded length-wise portions of the pipe 3 are formed, the threads not being physically continuous on the circumference of the pipe 3 ).
- the curvature of the thread-forming portion of the forming punch is set to be equal to that of the convex curvature of the threaded portion to be formed, but it is smaller than that of the outer periphery on the metal pipe before the forming thereof. Therefore, as shown in FIG. 12( b ), in initial steps of the machining process, the forming punches abut on the outer periphery of the metal pipe only at both ends p of each forming portion 104 a thereof, and the forming is started from those portions. The material between the forming punches is not moved nor extended into such direction that it forms the threaded portion, however, as shown in FIG. 12( c ), it rather extends or bulges outward in the radial direction.
- an apparatus for forming a screw thread on a metal pipe comprising:
- a plurality of main forming punches being disposed radially with respect to a center of the metal pipe which is set therein, and being movable back and forth in a direction to the center of the metal pipe;
- a plurality of auxiliary forming punches being disposed between or among said plurality of main forming punches, wherein a pit forming portion in each of said plurality of main forming punches is made equal to concave portion of the screw-thread to be formed in radius of curvature thereof, and said plurality of auxiliary forming punches are made smaller than said plurality of main forming punches in sizes along with outer periphery of the metal pipe, as well as movable back and forth independent upon said main forming punches.
- main forming punches are provided four (4) in number thereof, and said auxiliary forming punches are provided two (2) in number thereof, being disposed between a pair of said main forming punches among said four (4) main forming punches.
- FIG. 1 is a view showing a screw-thread forming apparatus according to the present invention, in particular showing the condition before the forming operation thereof;
- FIG. 2 is a view showing the same screw-thread forming apparatus in the condition during the forming operation thereof;
- FIG. 3 is a view showing the same screw-thread forming apparatus in the condition when completing the forming operation thereof;
- FIG. 4 is a view for explaining a forming method according to another embodiment of the present invention, in a manner similar to that in FIG. 2;
- FIG. 5 is a plain view of a pipe on which is formed double screw-threads obtained according to the present invention.
- FIG. 6 is a vertical cross-sectional view of the pipe on which is formed the double screw-threads
- FIG. 7 is a cross-sectional view of a fuel supply pipe assembly formed with a cap and the double screw-threads which are obtained according to the present invention
- FIG. 8 is a view of the cap taken in the direction indicated by arrows A-A in FIG. 7;
- FIG. 9 is a view of the cap taken in the direction indicated by arrows B-B in FIG. 7;
- FIG. 10 is a view for explaining the function of an idling mechanism of the cap
- FIGS. 11 ( a ) and ( b ) are views for explaining a roll forming method according to the conventional art.
- FIGS. 12 ( a ) to ( c ) are views for explaining a punch forming method according to the conventional art.
- FIG. 1 is a view of showing a screw-thread forming apparatus according to the present invention, in particular in the condition before the forming operation thereof;
- FIG. 2 is a view of showing the same screw-thread forming apparatus in the condition during the forming operation thereof;
- FIG. 3 is a view of showing the same screw-thread forming apparatus in the condition when completing the forming operation thereof;
- FIG. 4 is a view for explaining a another forming method, according to another embodiment of the present invention, in a manner similar to that in FIG. 2;
- FIG. 5 is a plain view of a pipe on which is formed double screw-threads obtained according to the present invention;
- FIG. 6 is a vertical cross-sectional view of the pipe on which is formed the double screw-threads.
- the screw-thread forming apparatus for forming double screw-threads on a metal pipe comprises main forming punches 1 and auxiliary forming punches 2 .
- the main forming punches 1 are disposed four in number thereof in the present embodiment, however, the number can be any other arbitrarily.
- the main forming punches 1 are movable back and forth toward a center of the metal pipe 3 which is set at a forming position, wherein radius of curvature at each thread-forming portion la thereof is selected to be equal to that at a concave portion of the screw-thread to be formed therewith.
- the main forming punches 1 are in condition of being open when they are away from the center, while they are in a closed condition when the main forming punches 1 , forming a pair or group with one another, are moved toward the center so as to abut on one another at the ends thereof.
- the auxiliary forming punches 2 are disposed between the main forming punches 1 forming opposing pairs, receptively. Those auxiliary forming punches 2 are also movable back and forth but independent from the main forming punches 1 , and a forming (tip) portion 2 a of each is rounded in shape.
- each of the auxiliary forming punches 2 is provided only between the main forming punches 1 together comprising the pair being opposite to another pair of punches but not between the forming punches 1 which do not form the pair.
- the auxiliary forming punches 2 are disposed among each of main forming punches 1 .
- a plurality of forming portions la are provided on each main forming punch 1 at a predetermined pitch therebetween.
- the plurality of forming portions la are shown lying on top of one other in the direction being vertical to the surface of the figure.
- the auxiliary forming punches 2 are advanced from the condition shown in FIG. 1, while leaving the main forming punches 1 as they are, so as to perform a preliminary forming in which a portion 3 a of the metal pipe 3 is slightly recessed in the radial direction thereof (toward the center of the radius thereof).
- the auxiliary forming punches 2 are moved back or receded and at the same time the main forming punches 1 are moved ahead or advanced, thereby forming the threaded portions (screw-threaded portions of pipe 3 ) 4 and 4 on outer periphery of the metal pipe 3 with shifting 1800 in the phase thereof, as shown in FIGS. 5 and 6.
- unfinished portions 5 , 5 remain between each ends of the threaded portions 4 and 4 , respectively.
- FIG. 7 shows a cross-sectional view of a fuel supplying assembly assembled with a cap 10 and the metal pipe 3 having the double screw-threads thereon, which are formed by the above-mentioned method according to the present invention.
- FIG. 8 is a view taken in the direction indicated by arrows A-A in FIG. 7
- FIG. 9 is a view taken in the direction indicated by arrows B-B in FIG. 7.
- the fuel supplying assembly comprises the metal pipe 3 and the cap 10 , wherein the above-mentioned threaded portions 4 and 4 are formed on the metal pipe 3 , and further the cap 10 comprises an insertion portion 11 , a handle portion 12 and an idling mechanism 13 which makes the handle portion 12 run idle with respect to the insertion portion 22 when a predetermined force is applied thereto.
- a middle plate 14 is fixed rotatably. On an outside of the middle plate 14 on the reverse side of the handle 12 is fixed a circular limit member 15 , and further a convex portion 17 of the above middle plate 14 is located at a cutoff portion 16 of the circular limit member 15 .
- the middle plate 14 is rotatable within a region where the convex portion 17 can be shifted within the cutoff portion 16 of the circular limit member 15 .
- the convex portion 17 is biased by means of a spring 18 so that it touches on the cutoff portion 16 at one end thereof.
- an elastic stopper piece 19 is provided therein, thereby forming a hook 20 at the tip of this elastic stopper piece 19 .
- a concave and convex portion 21 of a saw tooth-like shape is formed on the portion opposing to the above-mentioned elastic stopper piece 19 of insertion portion 11 .
- convex portions 22 for hooking them on the above threaded portion 4 .
- the idling mechanism 13 should not limited only to such the structure as mentioned above, but also it may be structured by forming the middle plate 14 on the side of the insertion portion 11 while the saw tooth-like concave and convex portions 21 on the reverse side surface of the handle 12 .
- FIG. 8 is a view showing the handle from a lower position, therefore in this figure, an anti-clockwise direction is that for closing the cap.
- the closure of the cap 12 is completed when the handle 12 is rotated by a half-turn (180°) or a quarter-turn (90°).
- the angle may be selected so that the closure is completed when the handle 12 is rotated by up to one-turn (360°), if the purpose is to prevent the user from forgetting to close the cap.
- portions are formed preliminarily by the auxiliary forming punches, in particular on the outer periphery surface of the metal pipe which are located between or among the plurality of the main forming punches when forming it, in advance of or at the same time as forming by the main forming punches, so as to recess the portions located between or among the plurality of the main forming punches inwards in the radial direction, thereby enabling the forming of a uniform threaded portion without clipping or pinching the material between the main forming punches.
- the threaded portions are formed with 4.0 mm in width between the convex (or concave) portions thereof and with 3.18 mm in height thereof, the sizes of the convex portions are equal or less than 0.5 mm in width and equal or less than 0.2 mm in height, being left after the forming process of the portions where they are located between the main forming punches in the initial steps thereof. Accordingly, they cause no problem with the function of the threaded portions thereof.
- the strength or durability can be improved greatly, such as against cracking and damage thereof.
- the cap can be closed with the predetermined sealing force by turning it within one-turn, thereby dissolving a chance of incomplete closure as may be caused by a user forgetting the necessary number of turns of the cap for proper, sealed closure.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Forging (AREA)
- Shaping Metal By Deep-Drawing, Or The Like (AREA)
Abstract
In an apparatus and a method for forming threaded portions around a metal pipe with accuracy and ease, a preliminary forming is performed so as to recess portions of the metal pipe a little bit inwardly in the radial direction thereof by advancing auxiliary forming punches while keeping main forming punches as they are. Thereafter, by receding the auxiliary forming punches back, while advancing the main forming punches, simultaneously, the threaded portions are formed on outer periphery of the metal pipe 3 shifted by 180° in phase thereof.
Description
- 1. Field of the Invention
- The present invention relates to an apparatus for forming a screw-thread(s) on or around a metal pipe (such as a steel pipe) and a method for forming the screw-thread(s) on or around the metal pipe using such an apparatus, and further relates to a fuel supplying pipe assembly being assembled with the metal pipe, on which is formed the screw-thread(s) being obtained by the described screw-thread forming apparatus and method therefor.
- 2. Description of Prior Art
- Conventionally, a roll forming method and a punch forming method are known for forming a screw-thread(s) on a metal pipe.
- In the roll forming method, as shown in FIG. 11(a), a
metal pipe 101 is introduced to cover on acore metal 100, around which is formed a forminggroove 100 a, and as shown in FIG. 11(b), a protruded or convex formingportion 102 a of a formingroller 102 is pushed on themetal pipe 101 when themetal pipe 101 begins rotation together with thecore metal 100, so as to deform a threadedportion 103 following the forminggroove 100 a. - On the other hand, the present invention can be classified as a punch forming method, and one such method is already known as is disclosed in Japanese Laid-Open Patent No. Sho 61-253140 (1986).
- Namely, as shown in FIG. 12(a), a plurality of forming
punches 104 are provided, each having a formingedge portion 104 a of curvature corresponding to that of concave portion of the desired screw-thread , being freely movable in a direction toward one point (i.e., a central portion of a set) back and forth, and ametal pipe 101 is set or fixed at the center of theplural forming punches 104. Then, theplural forming punches 104 are shifted toward the central portion of the set to give pressure on themetal pipe 101 at the formingedge portion 104 a of the punches, thereby forming the threaded portion by deforming thepipe 101 plastically. - In the roll forming method, pressure is applied to the metal pipe at the summit of the
convex forming portion 102 a of the forming roller so as to perform machining plastically with continuity. In other words, the summit of theconvex forming portion 102 a and themetal pipe 101 are contact with each other under a condition of point contact or a form of contact similar thereto, as can be seen from FIG. 11(b), especially in a direction C thereof. Therefore, the material is extended (deformed) only in the portion where the summit of theconvex forming portion 102 a contacts with it, and the threaded portion is formed by the material being extended. As a result of this, the threaded portion is extremely reduced in the thickness thereof. - It is noted that the roll forming method is not appropriate in particular in a case when forming double threading, or wherein the threaded portions are not formed more than one turn around the outer periphery of the pipe (i.e. wherein threaded length-wise portions of the
pipe 3 are formed, the threads not being physically continuous on the circumference of the pipe 3). - On the other hand, in the punch forming method, the curvature of the thread-forming portion of the forming punch is set to be equal to that of the convex curvature of the threaded portion to be formed, but it is smaller than that of the outer periphery on the metal pipe before the forming thereof. Therefore, as shown in FIG. 12(b), in initial steps of the machining process, the forming punches abut on the outer periphery of the metal pipe only at both ends p of each forming
portion 104 a thereof, and the forming is started from those portions. The material between the forming punches is not moved nor extended into such direction that it forms the threaded portion, however, as shown in FIG. 12(c), it rather extends or bulges outward in the radial direction. - And, as the material of the portion being expanded outward is finally protruding among or between the forming punches, it is therefore impossible to form the threaded portion uniformly.
- According to the present invention, for dissolving such problems as mentioned above there is provided an apparatus for forming a screw thread on a metal pipe, comprising:
- a plurality of main forming punches, being disposed radially with respect to a center of the metal pipe which is set therein, and being movable back and forth in a direction to the center of the metal pipe; and
- a plurality of auxiliary forming punches being disposed between or among said plurality of main forming punches, wherein a pit forming portion in each of said plurality of main forming punches is made equal to concave portion of the screw-thread to be formed in radius of curvature thereof, and said plurality of auxiliary forming punches are made smaller than said plurality of main forming punches in sizes along with outer periphery of the metal pipe, as well as movable back and forth independent upon said main forming punches.
- Further, in a case where, for example, double screw-threads are formed by use of the screw-thread forming apparatus mentioned above said main forming punches are provided four (4) in number thereof, and said auxiliary forming punches are provided two (2) in number thereof, being disposed between a pair of said main forming punches among said four (4) main forming punches.
- Also, in a case of forming the screw-thread by use of the screw-thread forming apparatus as described in the above, a forming method is disclosed, comprising the following steps of:
- setting a metal pipe at a center of the plurality of main forming punches in a condition of being open;
- confronting auxiliary forming punches between main forming punches at a same time of said setting step;
- performing preliminary forming with said auxiliary forming punches; and thereafter,
- forming the screw-thread by moving said main forming punches to shrink in the diameter thereof.
- In this manner, by recessing inwardly the portions which would otherwise be extended outwardly according to the conventional art, prior to the forming by means of the main forming punches, it is possible to make the projections occurring between or among the main forming punches as small as possible.
- As another method for forming a screw-thread on the metal pipe by using the apparatus for forming a screw-thread as described in the above, according to the present invention, there is provided a method, comprising the following steps of:
- setting a metal pipe at the center of the plurality of main forming punches in a condition of being open;
- confronting the auxiliary forming punches disposed between the main forming punches at a same time of said setting step;
- forming convex portion of the screw-thread to a certain extent, by suppressing the tip forming portions of said main forming punches and said auxiliary forming punches on outer periphery of the metal pipe, as well as advancing said main forming punches and said auxiliary forming punches at the same time; and thereafter,
- forming the screw-thread into a final shape thereof only by the action of said main forming punches while receding said auxiliary forming punches back from the screw-thread.
- Also, it is possible to achieve a fuel supply pipe assembly by combining a cap together with a metal pipe on which are formed the double screw-threads, being obtained by the screw-thread forming apparatus and the forming method according to the present invention.
- In this instance, by selecting an inclination angle of the double screw-threads, it can be so structured that the cap is closed completely when it rotates less than 360° or 180° in rotation angle and a handle begins to run idle at this time point due to the function of an idling mechanism.
- FIG. 1 is a view showing a screw-thread forming apparatus according to the present invention, in particular showing the condition before the forming operation thereof;
- FIG. 2 is a view showing the same screw-thread forming apparatus in the condition during the forming operation thereof;
- FIG. 3 is a view showing the same screw-thread forming apparatus in the condition when completing the forming operation thereof;
- FIG. 4 is a view for explaining a forming method according to another embodiment of the present invention, in a manner similar to that in FIG. 2;
- FIG. 5 is a plain view of a pipe on which is formed double screw-threads obtained according to the present invention;
- FIG. 6 is a vertical cross-sectional view of the pipe on which is formed the double screw-threads;
- FIG. 7 is a cross-sectional view of a fuel supply pipe assembly formed with a cap and the double screw-threads which are obtained according to the present invention;
- FIG. 8 is a view of the cap taken in the direction indicated by arrows A-A in FIG. 7;
- FIG. 9 is a view of the cap taken in the direction indicated by arrows B-B in FIG. 7;
- FIG. 10 is a view for explaining the function of an idling mechanism of the cap;
- FIGS.11(a) and (b) are views for explaining a roll forming method according to the conventional art; and
- FIGS.12(a) to (c) are views for explaining a punch forming method according to the conventional art.
- Hereinafter, embodiments according to the present invention will be fully explained by referring to the attached drawings, wherein, FIG. 1 is a view of showing a screw-thread forming apparatus according to the present invention, in particular in the condition before the forming operation thereof; FIG. 2 is a view of showing the same screw-thread forming apparatus in the condition during the forming operation thereof; FIG. 3 is a view of showing the same screw-thread forming apparatus in the condition when completing the forming operation thereof; FIG. 4 is a view for explaining a another forming method, according to another embodiment of the present invention, in a manner similar to that in FIG. 2; FIG. 5 is a plain view of a pipe on which is formed double screw-threads obtained according to the present invention; and FIG. 6 is a vertical cross-sectional view of the pipe on which is formed the double screw-threads.
- The screw-thread forming apparatus for forming double screw-threads on a metal pipe, as shown in the figure, comprises main forming punches1 and auxiliary forming
punches 2. - The main forming punches1 are disposed four in number thereof in the present embodiment, however, the number can be any other arbitrarily. The main forming punches 1 are movable back and forth toward a center of the
metal pipe 3 which is set at a forming position, wherein radius of curvature at each thread-forming portion la thereof is selected to be equal to that at a concave portion of the screw-thread to be formed therewith. - The main forming punches1 are in condition of being open when they are away from the center, while they are in a closed condition when the main forming punches 1, forming a pair or group with one another, are moved toward the center so as to abut on one another at the ends thereof.
- The auxiliary forming
punches 2 are disposed between the main forming punches 1 forming opposing pairs, receptively. Those auxiliary formingpunches 2 are also movable back and forth but independent from the main forming punches 1, and a forming (tip)portion 2 a of each is rounded in shape. - Further, in the example shown in the figure, for the purpose of forming the double screw-threads, each of the auxiliary forming
punches 2 is provided only between the main forming punches 1 together comprising the pair being opposite to another pair of punches but not between the forming punches 1 which do not form the pair. However, in the case of forming a normal spiral screw-thread, the auxiliary formingpunches 2 are disposed among each of main forming punches 1. Further, in the case of forming the normal spiral screw-thread, a plurality of forming portions la are provided on each main forming punch 1 at a predetermined pitch therebetween. However, the plurality of forming portions la are shown lying on top of one other in the direction being vertical to the surface of the figure. - Also, as mechanisms for back and forth moving the main forming punches1 and the auxiliary forming
punches 2 back and forth are used know means, such as a fuel pressure cylinder unit, etc., not shown in the figure. - For forming the double screw-threads on or around the
metal pipe 3 with use of the screw-thread forming apparatus mentioned above, first of all, theauxiliary forming punches 2 are advanced from the condition shown in FIG. 1, while leaving the main forming punches 1 as they are, so as to perform a preliminary forming in which aportion 3 a of themetal pipe 3 is slightly recessed in the radial direction thereof (toward the center of the radius thereof). - Thereafter, as shown in FIG. 3, the
auxiliary forming punches 2 are moved back or receded and at the same time the main forming punches 1 are moved ahead or advanced, thereby forming the threaded portions (screw-threaded portions of pipe 3) 4 and 4 on outer periphery of themetal pipe 3 with shifting 1800 in the phase thereof, as shown in FIGS. 5 and 6. - In the present embodiment,
unfinished portions portions - However, in the process of the forming, as shown in FIG. 4, it is also possible to form the concave portion of the screw-thread to a certain extent by advancing both the main forming punches1 and the
auxiliary forming punches 2 simultaneously, and thereafter, only the auxiliary formingpunches 2 are receded while advancing the main forming punches 1 further, thereby forming the screw-thread into the final shape thereof. - FIG. 7 shows a cross-sectional view of a fuel supplying assembly assembled with a
cap 10 and themetal pipe 3 having the double screw-threads thereon, which are formed by the above-mentioned method according to the present invention. FIG. 8 is a view taken in the direction indicated by arrows A-A in FIG. 7, and FIG. 9 is a view taken in the direction indicated by arrows B-B in FIG. 7. - The fuel supplying assembly according to the present invention comprises the
metal pipe 3 and thecap 10, wherein the above-mentioned threadedportions metal pipe 3, and further thecap 10 comprises aninsertion portion 11, ahandle portion 12 and anidling mechanism 13 which makes thehandle portion 12 run idle with respect to theinsertion portion 22 when a predetermined force is applied thereto. - On the reverse side of the
handle 12 mentioned above, amiddle plate 14 is fixed rotatably. On an outside of themiddle plate 14 on the reverse side of thehandle 12 is fixed acircular limit member 15, and further aconvex portion 17 of the abovemiddle plate 14 is located at acutoff portion 16 of thecircular limit member 15. - Therefore, the
middle plate 14 is rotatable within a region where theconvex portion 17 can be shifted within thecutoff portion 16 of thecircular limit member 15. However, in the present embodiment, theconvex portion 17 is biased by means of aspring 18 so that it touches on thecutoff portion 16 at one end thereof. - Also, with forming a cut portion of a “L” shape on the outer periphery of the
middle plate 14, anelastic stopper piece 19 is provided therein, thereby forming ahook 20 at the tip of thiselastic stopper piece 19. - A concave and
convex portion 21 of a saw tooth-like shape is formed on the portion opposing to the above-mentionedelastic stopper piece 19 ofinsertion portion 11. - Further, on a side surface of the
insertion portion 11 are formedconvex portions 22 for hooking them on the above threadedportion 4. - However, the idling
mechanism 13 should not limited only to such the structure as mentioned above, but also it may be structured by forming themiddle plate 14 on the side of theinsertion portion 11 while the saw tooth-like concave andconvex portions 21 on the reverse side surface of thehandle 12. - In the above, for closing the
cap 10 completely, first letting theconvex portions 22 which are formed on the side surface of theinsertion portion 11 pass through theunfinished portion 5 defined between the threadedportions cap 10 is inserted into themetal pipe 3, and then the handle is rotated in a clockwise direction. It is noted, however, that FIG. 8 is a view showing the handle from a lower position, therefore in this figure, an anti-clockwise direction is that for closing the cap. - Next, since the
convex portions 22 abut on the belly of the threadedportions 4, thecap 10 enters into themetal pipe 3 while shifting along the inclination of the threadedportions 4, thereby pushing a packing 23 toward the open end of themetal pipe 3. - When the force pushing down the packing23 is great enough to ensure airtightness therethrough, a resistance becomes large against the rotation of the
cap 10. Then, as shown in FIG. 10, theelastic stopper piece 19 is deformed upwardly, and the tip of thehook 20 climbs over the saw tooth-like concave andconvex portion 21, thereby causing the portion of the handle to run idle with respect to theinsertion portion 11. - By the clicking sound or action occurring in this instance, a user can notice with ease the completion of the closing operation of the cap.
- In the present embodiment, by selecting the inclination angle θ of the threaded
portions 4 appropriately, the closure of thecap 12 is completed when thehandle 12 is rotated by a half-turn (180°) or a quarter-turn (90°). - In explanation, if the inclination angle θ of the threaded
portions 4 is too small, the handle will not come into the idling condition when rotating it more than one round, while contrarily if it is too large thehandle 4 is brought into the idling condition by rotating it a little bit but comes off easily as only a small portion of threaded contact is employed. Accordingly, it is important to select the inclination angle θ at an appropriate angle. - The angle may be selected so that the closure is completed when the
handle 12 is rotated by up to one-turn (360°), if the purpose is to prevent the user from forgetting to close the cap. - When external force is applied to the
handle 12 in the open direction after completing the closure thereof, themiddle plate 14 is rotated in that direction (i.e., the anti-clockwise direction in FIG. 8), thereby making possible loosening of the cap. - However, according to the present embodiment, in the case where the external force is applied to the
handle 12 in the open direction, only thehandle 12 is rotated in the anti-clockwise direction against thespring 18 while themiddle plate 14 remains as it is, therefore there is no chance that thecap 10 is loosened. - When the user intends to take off the cap, he must rotate it by making an
end 16 a of thecutoff portion 16 push on theconvex portion 17 of themiddle plate 14. - As is fully explained in the above, according to the present invention, in the method for forming the threaded portion(s) on the metal pipe by using the plurality of main forming punches, portions are formed preliminarily by the auxiliary forming punches, in particular on the outer periphery surface of the metal pipe which are located between or among the plurality of the main forming punches when forming it, in advance of or at the same time as forming by the main forming punches, so as to recess the portions located between or among the plurality of the main forming punches inwards in the radial direction, thereby enabling the forming of a uniform threaded portion without clipping or pinching the material between the main forming punches.
- Showing in more detail with numerical values thereof, in a case where the threaded portions are formed with 4.0 mm in width between the convex (or concave) portions thereof and with 3.18 mm in height thereof, the sizes of the convex portions are equal or less than 0.5 mm in width and equal or less than 0.2 mm in height, being left after the forming process of the portions where they are located between the main forming punches in the initial steps thereof. Accordingly, they cause no problem with the function of the threaded portions thereof.
- In particular, by forming the threaded portion not on the article formed of resin material but that of the metal, the strength or durability can be improved greatly, such as against cracking and damage thereof.
- Further, with the fuel supply pipe assembly in the conventional art, since the closure of the cap is so designed to be completed by turning it two or three-turns, it sometimes happens that the closure is still incomplete although the user believes the closure to have been properly completed. However, with the fuel supply pipe assembly according to the present invention, the cap can be closed with the predetermined sealing force by turning it within one-turn, thereby dissolving a chance of incomplete closure as may be caused by a user forgetting the necessary number of turns of the cap for proper, sealed closure.
Claims (6)
1. An apparatus for forming a screw-thread on a metal pipe, comprising:
a plurality of main forming punches, being disposed radially with respect to a center of the metal pipe which is set therein, and being movable back and forth in a direction to the center of the metal pipe; and
a plurality of auxiliary forming punches being disposed among said plurality of main forming punches, wherein a pit forming portion of each of said plurality of main forming punches is made equal to concave portion of the screw-thread to be formed in radius of curvature thereof, and said plurality of auxiliary forming punches are smaller than said plurality of main forming punches in sizes along with outer periphery of the metal pipe, and are movable back and forth independent from said main forming punches.
2. An apparatus for forming a screw-thread as described in , wherein said apparatus is for forming circumferentially separate screw-thread portions, and wherein said main forming punches are provided four (4) in number thereof, and said auxiliary forming punches are provided two (2) in number thereof, each being disposed between a different pair of said main forming punches among said four (4) main forming punches.
claim 1
3. A method for forming a screw-thread by using the apparatus for forming a screw-thread as described in the or , comprising the steps of:
claim 1
claim 2
setting a metal pipe at the center of said plurality of main forming punches in a condition of being open;
confronting said auxiliary forming punches each disposed between said main forming punches at the same time as carrying out said setting step;
performing preliminary forming by said auxiliary forming punches; and thereafter,
forming the screw-threads by advancing said main forming punches.
4. A method for forming a screw-thread by using the apparatus for forming a screw-thread as described in or , comprising the steps of:
claim 1
claim 2
setting a metal pipe at the center of said plurality of main forming punches in a condition of being open;
confronting said auxiliary forming punches each disposed between said main forming punches at the same time as carrying out said setting step;
forming convex portion of the screw-thread to a certain extent, by advancing the tip forming portions of said main forming punches and said auxiliary forming punches upon outer periphery of the metal pipe, as well as by advancing said main forming punches and said auxiliary forming punches, simultaneously; and thereafter,
forming the screw-thread into a final shape thereof only by advancing said main forming punches while withdrawing said auxiliary forming punches.
5. A method for forming a screw-thread described in or , wherein double screw-threads are formed on the outer periphery of said metal pipe, separated from each other by 180°.
claim 3
claim 4
6. A fuel supplying assembly comprising:
a metal pipe connected to a fuel tank; and
a cap attached on an opening end portion of said metal pipe, wherein on said metal pipe double screw-threaded portions are formed, and further, said cap comprises:
an insertion portion;
a handle portion; and
an idling mechanism for idling said handle portion with respect to said insertion portion when a predetermined force is applied thereto, wherein an angle of said double screw-threads is so selected that said handle portion runs idle due to said idling mechanism when said cap rotates within 360° or 180°.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/819,537 US6412651B2 (en) | 1999-05-27 | 2001-03-28 | Screw-thread forming apparatus, screw-thread forming method and fuel supply pipe assembly therewith |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11-147806 | 1999-05-27 | ||
JP14780699A JP3462427B2 (en) | 1999-05-27 | 1999-05-27 | Screw forming apparatus, screw forming method and oil supply pipe assembly |
US09/417,972 US6237389B1 (en) | 1999-05-27 | 1999-10-13 | Apparatus and method for forming screw-thread on a pipe |
US09/819,537 US6412651B2 (en) | 1999-05-27 | 2001-03-28 | Screw-thread forming apparatus, screw-thread forming method and fuel supply pipe assembly therewith |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/417,972 Division US6237389B1 (en) | 1999-05-27 | 1999-10-13 | Apparatus and method for forming screw-thread on a pipe |
Publications (2)
Publication Number | Publication Date |
---|---|
US20010015088A1 true US20010015088A1 (en) | 2001-08-23 |
US6412651B2 US6412651B2 (en) | 2002-07-02 |
Family
ID=15438645
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/417,972 Expired - Lifetime US6237389B1 (en) | 1999-05-27 | 1999-10-13 | Apparatus and method for forming screw-thread on a pipe |
US09/819,537 Expired - Fee Related US6412651B2 (en) | 1999-05-27 | 2001-03-28 | Screw-thread forming apparatus, screw-thread forming method and fuel supply pipe assembly therewith |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/417,972 Expired - Lifetime US6237389B1 (en) | 1999-05-27 | 1999-10-13 | Apparatus and method for forming screw-thread on a pipe |
Country Status (2)
Country | Link |
---|---|
US (2) | US6237389B1 (en) |
JP (1) | JP3462427B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140116668A1 (en) * | 2012-10-31 | 2014-05-01 | GM Global Technology Operations LLC | Cooler pipe and method of forming |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003054614A (en) * | 2001-08-13 | 2003-02-26 | Toyoda Gosei Co Ltd | Cap device |
JP2003154430A (en) * | 2001-11-19 | 2003-05-27 | Sankyo Seiki Mfg Co Ltd | Rotary shaft with screw, and manufacturing method thereof |
DE102004038864B4 (en) * | 2003-08-11 | 2010-05-12 | Toyoda Gosei Co., Ltd., Nishikasugai-gun | cap device |
US7281640B2 (en) * | 2003-09-29 | 2007-10-16 | Toyoda Gosei Co., Ltd. | Cap device |
JP5049787B2 (en) * | 2004-11-04 | 2012-10-17 | マイクロチップス・インコーポレーテッド | Cold pressure sealing method and apparatus |
ATE359895T1 (en) * | 2004-12-01 | 2007-05-15 | Erowa Ag | CLAMPING DEVICE FOR REleasably FIXING A PALLET WITH A DAMPING ELEMENT |
US9192738B2 (en) * | 2012-04-25 | 2015-11-24 | Medtronic Vascular Galway | Devices and methods for crimping medical devices |
US11260522B2 (en) * | 2015-12-07 | 2022-03-01 | Patrick H. Monahan | Multi-section quick assembly handle and method of making same |
US10177517B1 (en) * | 2018-05-15 | 2019-01-08 | Aptiv Technologies Limited | Ferrule crimping tool |
CN112893585B (en) * | 2021-01-30 | 2022-04-26 | 余姚市恒辉仪表有限公司 | Dotting machine |
WO2023007997A1 (en) * | 2021-07-27 | 2023-02-02 | 日鉄ステンレス株式会社 | Device for manufacturing fuel filler pipe and method for manufacturing fuel filler pipe |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE453363C (en) * | 1926-08-27 | 1927-12-05 | C & F Schlothauer Metallwarenf | Process for the production of screw threads in thin-walled metal bushings |
CH144361A (en) * | 1930-01-31 | 1930-12-31 | Hardmeyer Robert | Process for the production of inwardly directed approaches on cylindrical hollow bodies, in particular on pipes. |
US3382699A (en) * | 1965-03-11 | 1968-05-14 | Continental Can Co | Method and apparatus for threading closure caps |
JPS5225666B2 (en) * | 1972-05-31 | 1977-07-08 | ||
US3986634A (en) | 1974-06-05 | 1976-10-19 | General Motors Corporation | Torque limiter mechanism |
US4142648A (en) * | 1978-06-19 | 1979-03-06 | General Motors Corporation | Cap assembly for a fuel tank |
US4416142A (en) * | 1981-08-31 | 1983-11-22 | Olin Corporation | Apparatus for simultaneously forming a cap member with internal threads |
JPH0790321B2 (en) | 1985-05-02 | 1995-10-04 | 松下電器産業株式会社 | Welding nozzle manufacturing method |
US4678097B1 (en) * | 1986-07-09 | 1999-09-07 | Stant Mfg Co | Breakaway gas cap |
US4765505A (en) * | 1986-07-22 | 1988-08-23 | Stant Inc. | Delayed actuation fuel cap |
US4768677A (en) * | 1986-10-21 | 1988-09-06 | Nihon Radiator Co., Ltd | Fuel tank cap |
SU1486256A1 (en) | 1987-09-07 | 1989-06-15 | Uk G Pt Exi Ukrorgstankinprom | Radial forging die set |
US5110003A (en) * | 1990-06-28 | 1992-05-05 | Stant Inc. | Torque-override cap |
US5638975A (en) * | 1994-05-06 | 1997-06-17 | Stant Manufacturing Inc. | Lost motion fuel cap with cap closure indicator |
US6079584A (en) * | 1997-01-16 | 2000-06-27 | Stant Manufacturing Inc. | Quick-on filler neck cap |
DE69929348T2 (en) * | 1998-10-06 | 2006-07-27 | Stant Manufacturing Inc., Connersville | cap |
-
1999
- 1999-05-27 JP JP14780699A patent/JP3462427B2/en not_active Expired - Lifetime
- 1999-10-13 US US09/417,972 patent/US6237389B1/en not_active Expired - Lifetime
-
2001
- 2001-03-28 US US09/819,537 patent/US6412651B2/en not_active Expired - Fee Related
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140116668A1 (en) * | 2012-10-31 | 2014-05-01 | GM Global Technology Operations LLC | Cooler pipe and method of forming |
Also Published As
Publication number | Publication date |
---|---|
US6237389B1 (en) | 2001-05-29 |
US6412651B2 (en) | 2002-07-02 |
JP3462427B2 (en) | 2003-11-05 |
JP2000334521A (en) | 2000-12-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6412651B2 (en) | Screw-thread forming apparatus, screw-thread forming method and fuel supply pipe assembly therewith | |
US4744480A (en) | Tamper-evident container-closure | |
US3186464A (en) | Thread forming screw and method and apparatus for making the same | |
US4701088A (en) | Undercut sealing threaded fastener | |
JP5887340B2 (en) | Threaded bottle can manufacturing method and manufacturing apparatus | |
JP5857038B2 (en) | Threaded bottle can manufacturing method | |
US3929246A (en) | Plastic container cap unit with integral sealing ring | |
CA2118732C (en) | Method of manufacturing tee nut | |
US4610834A (en) | Apparatus and method for installing internal annular rings in tubular box members | |
GB2113791A (en) | Blind fastener and method and apparatus for making same | |
JPH0757405B2 (en) | Thread forming screw | |
US4691550A (en) | Method and apparatus for making a pressure hose socket | |
US4688315A (en) | Screw extractor and method of using same | |
US7591054B2 (en) | Insertion die tooling for flange installation and the method of use | |
JP5090290B2 (en) | Bottle can | |
JP4680976B2 (en) | Bottle can body and bottle | |
US4904435A (en) | Method for making tamper-evident container closure | |
JP2019182443A (en) | Bottle type can with cap | |
US3405596A (en) | Self-tapping threaded part | |
EP0450820A1 (en) | Fastener | |
US3934444A (en) | Method and apparatus for forming vibration-resistant thread-forming screw | |
JP4570838B2 (en) | Method of forming a cap part of a bottle can body and screw forming apparatus | |
US3443713A (en) | Cornered blanks for closure caps,liners,washers,etc.,plus method of blanking and forming the blanks and utilizing the corners thereof | |
US3452694A (en) | Containers and method of making same | |
JP2004148403A (en) | Method for manufacturing metallic container and metallic container |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
REMI | Maintenance fee reminder mailed | ||
LAPS | Lapse for failure to pay maintenance fees | ||
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20140702 |