Cylindrical spiral fastening structure

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] The invention relates to a cylindrical spiral bottle cap fastening structure, in particular to a variable pitch bottle cap. Background Art

[0002] Bottle caps widely utilize a cylindrical spiral fastening structure. Examples include toothpaste bottle caps, plaster bottle caps, and cosmetic bottle caps. The spiral fastening structure of a bottle cap consists of matching internal and external threads, typically with equal pitch. This equal pitch facilitates the screwing of the bottle cap and bottle neck together. Each turn of a bottle cap with equal pitch results in a screw tightening distance of one pitch. For example, a toothpaste cap typically requires two turns, a screw tightening distance of two times the pitch, to ensure the tube is inserted far enough into the cap to prevent spillage. While increasing the pitch and number of threads for the same diameter can speed up screwing, it can compromise the final tightening of the cap and make it more prone to loosening.

[0003] The invention provides a variable pitch spiral bottle cap fastening structure, which can be quickly twisted in and finally reliably fastened when used in a bottle cap structure. Summary of the Invention

[0004] A cylindrical spiral bottle cap fastening structure is composed of an inner screw and an outer screw that match each other. The thread on the inner screw or outer screw is a variable pitch thread in which the front pitch is greater than the rear pitch. The corresponding thread on the outer screw or inner screw has a thread length per line shorter than the thread circumference divided by the number of thread lines. The present invention defines the starting end where the outer screw and the inner screw are in contact as the front end, and the corresponding end end as the rear end. By making the pitch at the front end of the thread larger and the pitch at the rear end smaller, a variable pitch thread is formed. The thread circumference is the circumference of the outer diameter of the thread. For the sake of convenience, the thread on the outer screw or inner screw corresponding to the variable pitch thread is referred to as the corresponding thread. In order to enable the corresponding thread to be twisted into the variable pitch thread, the thread length per 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-line variable pitch thread, the corresponding thread is shorter than one circumference; for a double-line variable pitch thread, the length of each thread line is shorter than 1 / 2 of the circumference; for a three-line variable pitch thread, the length of each thread line is shorter than 1 / 3 of the circumference. And so on.

[0005] Preferably, the variable pitch thread is a gradual pitch thread. For example, the pitch of the thread is larger at the front end, then gradually decreases, and the pitch is smallest at the rear end, thus forming a gradual pitch thread.

[0006] Preferably, the variable pitch thread is a segmented unequal pitch thread. For example, the front end of the thread maintains a uniform pitch with a larger pitch for rapid threading, while the rear end maintains a uniform pitch with a smaller pitch for easy locking and preventing backing out. The pitch of the corresponding thread is then consistent with the pitch of the rear end.

[0007] Preferably, the variable-pitch threads are groove-shaped, and the corresponding threads on the external or internal thread are dot-shaped. For example, the internal thread is provided with a groove-shaped variable-pitch thread, while the threads on the external thread are provided with dot-shaped threads. When the internal thread is fitted onto the external thread, the dot-shaped threads on the external thread engage with the grooved threads inside the internal thread and slide along them. Because the front end of the grooved threads has a larger pitch, the same angle of twisting allows for a greater distance of twisting. However, the rear end, with a smaller pitch, is easier to tighten and less likely to come out.

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

[0009] The variable pitch bottle cap of the present invention adopts a variable pitch structure. When twisting at the same angle at the beginning, the twisting distance is large, so the bottle mouth can be easily inserted deeper into the bottle cap, and the contents are not easy to spill. At the rear end, due to the smaller pitch, the bottle cap can be fully locked and is not easy to loosen, thereby improving the convenience of using the bottle cap.

[0010] The present invention will be further described below through embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Schematic diagram of a bottle mouth with rectangular thread segments and unequal distances.

[0012] Figure 2 For Figure 1 Schematic diagram of the bottle cap matching the bottle mouth shown.

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

[0014] Figure 4 For Figure 3 Schematic diagram of the bottle mouth matching the bottle cap shown.

[0015] In the figure, 1 is the bottle mouth, 2 is the bottle cap, 31 is the first section of the rectangular screw thread segmented unequal distance thread, 32 is the second section of the rectangular screw thread segmented unequal distance thread, 33 is the third section of the rectangular screw thread segmented unequal distance thread, 4 is the corresponding thread inside the bottle cap, 5 is the bottle cap 2, 6 is the groove-shaped variable pitch thread inside the bottle cap 2, 7 is the bottle mouth 2, and 8 is the dot-shaped screw thread on the bottle mouth 2. DETAILED DESCRIPTION

[0016] Example 1

[0017] Figure 1A bottle mouth 1 is shown, featuring a three-line rectangular thread with segmented, unequal pitch. The unequal pitch thread is divided into three segments. The first segment 31 at the front of the bottle mouth 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 half that of segment 31. The third segment 33 at the rear is rotated 60 degrees, with a constant pitch, but the smallest pitch, half that of segment 32. Figure 2 is with Figure 1 The matching bottle cap 2 has three lines of rectangular threads on its inner side, corresponding to the threads 4. The figure shows that the length of each line of the corresponding threads is less than 1 / 3 of the circumference of the thread's outer diameter, and the pitch is equal to the pitch of the third section 33 at the rear end of the bottle mouth. When the bottle cap 2 is placed on the bottle mouth 1, because each line of the thread on the inner side of the bottle cap is less than 1 / 3 of the circumference of the thread, there is space for the rectangular threads on the bottle mouth to enter, allowing the bottle cap 2 to be inserted and twisted. Because the pitch at the front end of the bottle mouth is larger, the same twist angle can be twisted a greater distance. Since the pitch of the third section 33 at the rear end is smaller and consistent with the pitch of the corresponding thread of the bottle cap, it is easy to lock and difficult to loosen.

[0018] This embodiment was tested through actual modeling and 3D printing. The original constant-pitch toothpaste cap required two full turns (720 degrees) to tighten the bottle opening 10 mm. The redesigned variable-pitch screw cap only requires a little more than half a turn to tighten 10 mm and is less likely to come loose.

[0019] Example 2

[0020] Figure 3 Show a bottle cap 2 5 with a groove-shaped variable pitch thread. Inside the bottle cap 2 5, 3 lines of groove-shaped variable pitch threads 6 are provided. Figure 4 The bottle opening 7, corresponding to the bottle cap 5, is shown with three lines of dotted threads 8. When the bottle opening 7 is attached to the bottle cap 5, the dotted threads on the bottle opening 7 engage with the grooved threads inside the bottle cap 5 and slide along them. Because the grooved threads have a larger pitch at the front end, they advance farther for the same angle. However, the smaller pitch at the rear end allows for easy tightening and prevents loosening.

[0021] 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 bottle cap and the outer diameter of the bottle mouth can be more closely matched, making it more difficult for the contents of the bottle to spill.

[0022] Example 3

[0023] In some applications, further protection against loosening of the bottle cap is required. A recess that matches the corresponding dot-shaped thread can be provided at the rear end of the variable-pitch thread. When the dot-shaped thread engages with the corresponding recess, the cap can be further protected from loosening. This recess, which matches the corresponding dot-shaped thread, forms a locking mechanism to prevent the cap from loosening.

[0024] Example 4

[0025] Used in screw and nut locking devices. The screw features a variable-pitch thread, and the matching nut has a thread length shorter than the thread's outer diameter divided by the number of threads. This screw and nut structure allows for quick and easy tightening, making it suitable for applications requiring less demanding tightening force.

[0026] The above-described embodiments merely represent several implementation methods of the present application, and their descriptions are relatively specific and detailed, but 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 the present application are all within the scope of protection of the present application.

Claims

1. A cylindrical spiral fastening structure, consisting of an inner screw and an outer screw that match each other, characterized in that: The thread on the internal or external thread is a variable pitch thread in which the front pitch is greater than the rear pitch. The length of each thread 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 according to claim 1, wherein: The variable pitch thread is a gradually variable pitch thread.

3. The spiral fastening structure according to claim 1, wherein: The variable pitch thread is a segmented unequal pitch thread.

4. The spiral fastening structure according to claim 1, wherein: The variable pitch thread is in the shape of a groove, and the corresponding thread on the external thread or internal thread is in the shape of a dot-shaped thread.

5. The spiral fastening structure according to claim 1, wherein: Apply on bottle cap.

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