Variable-pitch bottle cap

Abstract

A varying-pitch bottle cap is characterized in that varying-pitch threads are arranged on a bottle opening, corresponding threads are arranged in the bottle cap, and the length of each thread of the corresponding threads is shorter than the length of the circumference of the threads divided by the number of thread lines. When the bottle cap is sleeved on the bottle opening, due to the fact that the screw pitch of the front end of the internal thread of the bottle cap is large, the same twisting angle is achieved, the twisting distance is large, and the screw pitch of the rear end is small, locking is easy. The bottle cap and the bottle opening can be tightly matched, contents are not prone to overflowing, the bottle cap can be screwed in rapidly and is not prone to loosening, and the use convenience of the bottle cap is improved.

Description

Technical Field

[0001] This invention relates to a cylindrical spiral fastening structure, and more particularly to a variable pitch bottle cap. Background Technology

[0002] Bottle caps widely employ a cylindrical screw-on fastening structure. Examples include toothpaste bottle caps, plaster bottle caps, and cosmetic bottle caps. The screw-on fastening structure of a bottle cap consists of matching internal and external threads, usually with equal pitch. Equal pitch allows the cap and bottle neck to be easily screwed in. With an equal pitch, each turn of the screw advances the cap by one pitch distance. For example, a toothpaste cap typically requires two turns to advance twice the pitch, ensuring the toothpaste tube tip penetrates the cap sufficiently to prevent toothpaste spillage. Under the same diameter conditions, increasing the pitch and the number of thread lines can speed up the screwing process, but it is less effective at final tightening and makes the cap more prone to loosening.

[0003] This invention provides a variable pitch spiral fastening structure that, when used in bottle cap structures, allows for quick screwing in and reliable fastening. Summary of the Invention

[0004] A cylindrical helical fastening structure is composed of mating internal and external threads. The threads on the internal or external threads are variable-pitch threads, and the length of each thread line on the corresponding external or internal thread is shorter than the thread circumference divided by the number of thread lines. This invention defines the starting end where the external and internal threads come into contact as the front end and the corresponding ending end as the rear end. By making the pitch larger at the front end and smaller at the rear end, a variable-pitch thread is formed. The thread circumference is the outer diameter circumference of the thread. For ease of description, the threads on the external or internal threads corresponding to the variable-pitch thread are simply referred to as the corresponding threads. To enable the corresponding threads to engage with the variable-pitch thread, the length of each thread line of the corresponding thread is limited to be shorter than the thread circumference divided by the number of thread lines. For example, for a single-start variable-pitch thread, the corresponding thread is shorter than one circumference; for a double-start variable-pitch thread, the length of each thread line is shorter than half the circumference; for a triple-start variable-pitch thread, the length of each thread line is shorter than one-third of the circumference, and so on.

[0005] Preferably, the variable pitch thread is a gradually decreasing pitch thread. For example, by making the pitch larger at the beginning of the thread and then gradually decreasing it until the pitch is smallest at the end, a gradually decreasing pitch thread is formed.

[0006] Preferably, the variable pitch thread is a segmented unequal pitch thread. For example, the thread front end maintains a segment with a larger pitch for easy and rapid turning; the rear end maintains a segment with a smaller pitch for easy locking and preventing disengagement. The pitch of the corresponding thread is consistent with the pitch of the rear end.

[0007] Preferably, the variable pitch thread is grooved, and the corresponding thread on the external or internal thread is dotted. For example, a grooved variable pitch thread is provided inside the internal thread, and the thread on the external thread is dotted. When the internal thread is fitted onto the external thread, the dotted threads on the external thread engage with the grooved thread inside the internal thread and slide along the grooved thread. Because the pitch at the front end of the grooved thread is larger, the distance it twists in is greater when twisting at the same angle, while the rear end, due to its smaller pitch, is easier to lock and less likely to come out.

[0008] The aforementioned spiral fastening structure is applied to bottle caps.

[0009] The variable pitch bottle cap of the present invention, due to its variable pitch structure, allows for a larger twisting distance when the same angle is initially turned, making it easy for the bottle mouth to penetrate the cap more deeply, preventing contents from overflowing. Furthermore, the cap can be fully locked in the end, making it less prone to loosening, thus improving the ease of use of the bottle cap.

[0010] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of a bottle neck with rectangular threaded segments of unequal spacing.

[0012] Figure 2 To and Figure 1 The diagram shows the bottle cap that matches the bottle opening.

[0013] Figure 3 This is a schematic diagram of a bottle cap with a groove-shaped variable pitch thread.

[0014] Figure 4 To and Figure 3 The diagram shows the bottle opening that matches the bottle cap.

[0015] In the diagram, 1 is the bottle mouth, 2 is the bottle cap, 31 is the first segment of the rectangular threaded segmented non-uniform pitch thread, 32 is the second segment of the rectangular threaded segmented non-uniform pitch thread, 33 is the third segment of the rectangular threaded segmented non-uniform pitch thread, 4 is the corresponding thread inside the bottle cap, 5 is the second bottle cap, 6 is the groove-shaped variable pitch thread inside the second bottle cap, 7 is the second bottle mouth, and 8 is the dotted thread on the second bottle mouth. Detailed Implementation Example 1

[0016] Figure 1 The image shows a bottle neck 1 with a three-line rectangular threaded segmented unequal-pitch thread. The unequal-pitch thread is divided into three segments. The first segment 31 at the front end of the bottle neck 1 is rotated 120 degrees, with a constant pitch and the largest pitch. The second segment 32 in the middle is rotated 120 degrees, with a constant pitch, but its pitch is half that of segment 31. The third segment 33 at the rear end is rotated 60 degrees, with a constant pitch, but its pitch is the smallest, half that of segment 32. Figure 2 Is with Figure 1 The matching bottle cap 2 has a three-line rectangular thread 4 on its inner side. The diagram shows that the length of each thread line is less than 1 / 3 of the outer diameter circumference of the thread, while the pitch is equal to the pitch of the third segment 33 at the rear end of the bottle opening. When the bottle cap 2 is placed on the bottle opening 1, because each thread line on the inner side of the bottle cap is less than 1 / 3 of the thread circumference, there is space for the rectangular threads on the bottle opening to enter, allowing it to be fitted and twisted. Since the pitch at the front end of the bottle opening is larger, the distance twisted is greater for the same angle. The third segment 33 at the rear end, with its smaller pitch that matches the pitch of the corresponding thread on the bottle cap, is easier to lock and less prone to loosening.

[0017] This embodiment has been tested through actual modeling and 3D printing. The original constant pitch toothpaste cap required two full rotations (720 degrees) to screw the toothpaste bottle opening in by 10 millimeters. The redesigned variable pitch screw cap only requires a little over half a rotation to screw in 10 millimeters, and it is less prone to coming loose. Example 2

[0018] Figure 3 This shows a bottle cap 25 with a grooved variable pitch thread. Inside the bottle cap 25, there is a 3-line grooved variable pitch thread 6. Figure 4 The bottle neck 7 corresponds to the bottle cap 2 5 and has three dot-shaped threads 8. When the bottle neck 2 is fitted onto the bottle cap 2, the dot-shaped threads on the bottle neck 2 engage with the grooved threads inside the bottle cap 2 and slide in along the grooved threads. Because the pitch of the front end of the grooved thread is larger, the distance it can be turned in is greater when the same angle is turned, while the rear end, due to its smaller pitch, is easier to lock and less likely to loosen.

[0019] This embodiment has been tested through actual modeling and 3D printing, and can be easily and quickly screwed in and locked. Another advantage of the groove-shaped variable pitch thread is that the inner diameter of the cap and the outer diameter of the bottle mouth can be fitted more tightly, making it less likely for the contents of the bottle to spill out. Example 3

[0020] In some applications, it's necessary to further prevent bottle caps from loosening. A recess matching the corresponding dot-shaped thread can be created at the rear end of the threaded section where the groove shape changes pitch. When the dot-shaped thread engages in the corresponding recess, it further prevents the bottle cap from loosening. This recess matching the corresponding dot-shaped thread constitutes a locking structure to prevent the bottle cap from loosening. Example 4

[0021] This is a screw and nut locking device. A variable pitch thread is set on the screw, and the matching nut has a thread length per thread line shorter than the outer diameter circumference of the thread divided by the number of thread lines. This screw and nut structure allows for easy and quick tightening, and can be used in scenarios where high tightening force is not required.

[0022] The embodiments described above are merely examples of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. For those skilled in the art, any modifications, improvements, and applications made without departing from the concept of this application are all within the protection scope of this application.

Claims

1. A cylindrical spiral fastening structure, comprising mutually matching inner and outer threads, characterized in that, The threads on internal or external threads are variable pitch threads. The length of each thread line on the corresponding external or internal thread is shorter than the circumference of the thread divided by the number of thread lines.

2. The spiral fastening structure as described in claim 1, characterized in that, The variable pitch thread is a gradually changing pitch thread.

3. The spiral fastening structure as described in claim 1, characterized in that, The variable pitch thread is a segmented, unequal-pitch thread.

4. The spiral fastening structure as described in claim 1, characterized in that, The variable pitch thread is groove-shaped, and the corresponding thread on the external or internal thread is dot-shaped.

5. The spiral fastening structure as described in claim 1, applied to a bottle cap.

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