JP4719634B2 - Diagonal cover prevention screw structure - Google Patents

Description

  The present invention relates to an oblique covering prevention screw structure that can prevent, for example, the occurrence of oblique covering (screwing failure) generated between a cap formed with a double thread and a container mouth portion.

  Since the cap formed with a double thread can be quickly opened and closed with a so-called one-touch sensation, it is used in bottles for various drinks such as sports drinks. However, there is a problem that oblique covering tends to occur in the process of attaching the cap in the filling line. In the cap mounting process, the cap is tightened by applying a predetermined tightening torque to the cap under the condition that a predetermined top load is applied by the cap tightening machine. If the correspondence between the bottle mouth and the cap does not match due to the swinging of the conveyor, etc., perfect screwing may not be possible, and so-called diagonal caps may occur, resulting in poor sealing. It was. In addition, oblique covering may occur due to slight molding errors or deformation of the container mouth or cap.

  In view of this, a cap mounting apparatus has been proposed that can prevent the occurrence of poor screwing due to such oblique covering (see, for example, Patent Document 1). This device suppresses the swinging of the plastic container by supporting the bottom part of the plastic container held by the suspension mechanism with a cushion base, thereby causing the swinging of the container when the cap is screwed. It is said that it is possible to prevent problems such as insufficient closing torque and oblique covering phenomenon.

In addition, an oblique fitting prevention mechanism for multi-threaded screws that can prevent such an oblique covering phenomenon has been proposed (for example, see Patent Document 2). This cap has a threaded tip of at least one thread in the multi-thread thread removed, so that it will accidentally engage the next thread groove beyond the normal thread groove of the container male thread. However, it is not possible to engage and oblique covering does not occur.
Registered Utility Model No. 3003750 Japanese Patent Laid-Open No. 11-247818

  However, in the above conventional cap mounting apparatus, even if it is possible to prevent the occurrence of poor screwing due to the swinging of the container, for example, the container is inclined, the container mouth, a slight molding error or deformation of the cap, etc. It is not possible to eliminate a screwing failure caused by the above. In addition, in the conventional multi-thread screw diagonal fitting prevention mechanism, a part of the multi-thread screw (screwed tip) is only a single thread to prevent diagonal covering, and prevents oblique covering. Therefore, in the cap mounting process, the top load that is normally applied to the cap by the cap tightening machine is not effectively used, and there is no description suggesting it in the publication.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an oblique covering prevention screw structure capable of preventing oblique covering by effectively utilizing a top load acting on a cap.

The present invention includes a male thread formed on the mouth portion side of the container, the internal thread is respectively formed on the cap side, has a double threaded screw starting from the opposite position, acts on the cap in the mounting process of the cap An oblique covering prevention screw structure that can prevent the cap from being obliquely covered using a top load, and the cap is pushed down by the top load acting on the cap so that the screw thread of the cap Over the predetermined range from the thread formation start end of all of the two threads on the cap side, so that the male thread of the mouth is screwed into the female thread of the cap over the thread. Forming the height lower than the other part, and gently forming a chamfered shape so that the shape of the hem side edge of the thread formed in the lower part is easy to screw, Constant range, characterized in that it is set in a range of 1/4 lap to 1/3 laps from the thread formation starting end.

According to such a configuration, in the cap mounting process, even if the correspondence between the mouth portion of the container and the cap may be somewhat inconsistent, the screw thread over the predetermined range from the thread formation start end of the double thread screw. Is formed lower than the other parts, and the shape of the hem side edge of the thread formed in the lower part is gently chamfered so that it can be easily screwed together. The cap is pushed down by the top load applied to the cap by the cap tightening machine at the initial stage of the process, and the screw thread (female thread) of the cap is forcibly screwed into the normal state with respect to the screw thread (male thread) of the mouth. Can be made.

In this way, by effectively utilizing the pressing force of the cap by the top load, the container mouth is not limited to a slight molding error or deformation of the container mouth, but is caused by the inclination or swinging of the container being conveyed. Even if the corresponding state of the part and the cap may not match somewhat, the cap thread (female thread) can be forcibly screwed into the normal state with respect to the screw thread (male thread) of the mouth, Ru it is possible to prevent the occurrence of sealing failure effectively.

Before SL predetermined range, Ru is set from the thread-forming starting end in the range of laps 1/4 lap to 1/3. In this way, even if there is a slight misalignment between the mouth portion and the cap, it becomes easy to screw the cap into the normal state with respect to the mouth portion by the action of a predetermined top load (15 to 20 kg).

The height of the thread is formed lower than the other part over a predetermined range from the thread formation start end, and the shape of the hem side edge of the thread formed in the lower part is easily screwed together. A double thread that is gently formed in a chamfered shape may be formed on the cap side. If it does in this way, diagonal covering of a cap can be prevented, without giving any processing to the double thread of a container mouth part (it is a regular double thread). Moreover, the height of the low-formed thread may be set in the range of 6/10 to 8/10 of the height of other portions.

The oblique covering prevention screw structure according to the present invention is formed such that the height of the thread is lower than the other parts over a predetermined range from the thread formation start end of the double thread, and the thread formed in the lower part is formed. Since the shape of the hem side edge is gently chamfered so that it can be easily screwed together, even if the container mouth and the cap may not match slightly in the cap mounting process, By pushing down the cap with the acting top load, the cap thread (female thread) can be forcibly screwed into a normal state with respect to the thread (male thread) of the mouth.

Hereinafter, an embodiment of an oblique covering prevention screw structure of the present invention will be described in detail with reference to the drawings.
FIG. 1A is a cross-sectional view of a cap to which the oblique covering prevention screw structure of the present invention is applied, FIG. 1B is a bottom view, FIG. 2 is a view corresponding to assembly of the cap, and FIGS. It is explanatory drawing of the operation | movement of prevention. As shown in these drawings, a male screw 3 formed in the mouth portion 2 of the container 1 and a female screw 5 formed on the inner side of the peripheral wall 4 in which the knurled groove of the cap C is formed are formed into two threads, The height H2 of the thread T is formed to be lower than the height H1 of the other part over the range from 1/4 turn to 1/3 turn from the thread formation start end st of the double thread on the cap C side, In addition, the shape of the hem side edge portion Tm of the thread T of the lower portion is gently formed in a chamfered shape so as to be easily screwed together.

  Specifically, for example, as shown in an enlarged view in FIG. 1, the inner diameter D1 of the regular screw thread indicated by the alternate long and short dash line is 35.25 mm, which is 1/4 turn to 1/3 turn from the thread formation start end st. The inner diameter D2 of the thread T over the range = 35.75 mm, the height H1 of the regular thread H = 0.7 mm to 1.0 mm, and the height H2 of the thread T formed low = (6/10) H1 to (8 / 10) H1, normal thread R1 = 0.3 mm, and low thread T T2 = 0.8 mm. A cleaning gap s is formed at predetermined intervals on the female screw 5 formed inside the cap C. Further, a tamper evidence band 6 is connected to the skirt portion of the peripheral wall 4 of the cap C via a breakable bridge, and a ring-shaped medium that fits into the mouth portion 2 of the container 1 is provided inside the top plate 7. A foot 8 (see FIG. 2) protrudes downward.

  According to such a configuration, there is a case where the correspondence state between the mouth portion 2 of the container 1 and the cap C is somewhat inconsistent in the initial stage of the cap C mounting process shown in FIGS. In the initial stage of the process, the cap C is pushed down by the top load TL (15 to 20 kg) acting on the cap C by the cap tightening machine. The female screw 5) can be forcibly screwed into a normal state. That is, even when the cap C is obliquely covered at the stage of FIG. 3B, the cap C is pushed down by the top load TL, and as shown in FIG. 3, the screw thread (female screw) 5 of the cap C can be forcibly screwed into a normal state. In the subsequent process (not shown), the cap C is further screwed so that the middle leg 8 of the cap C is fitted into the mouth 2 of the container 1, and the locking member 6 a of the tamper evidence band 6 is The fastening operation is completed by engaging with the portion 9.

  As described above, by effectively using the pressing force of the cap C by the top load TL, not only a slight molding error or deformation of the cap C or the mouth portion 2 of the container 1, but also the inclination of the container 1 to be conveyed, Even if the correspondence state between the mouth 2 and the cap C may be somewhat inconsistent due to rocking or the like, the screw thread (female screw) 5 is connected to the thread ( It is possible to forcibly engage with the male thread 3) in a regular state, and to effectively prevent the occurrence of poor sealing. In addition, such a double thread may be formed in the cap C side as mentioned above, and may be formed in the container 1 side. Moreover, you may form in both.

  It should be noted that the present invention is not limited to the embodiment, and can be freely modified and improved as necessary, for example, as long as it does not depart from the gist of the invention. The screw thread T may be appropriately selected and set according to the inner diameter of the cap C or the like. Further, the multi-thread screw may be a triple thread.

(A) is sectional drawing of the cap provided with the diagonal covering prevention screw structure which concerns on embodiment of this invention, (b) is the bottom view. It is the assembly | attachment corresponding | compatible figure of the same cap and a container. (A)-(c) is explanatory drawing of the initial state in the mounting process of a cap, (a) is the state which covers a cap on a mouth part, the state which starts mounting | wearing work, (b) is the state which the diagonal covering produced, c) shows a state where the screw has been corrected to the normal screwing state by the action of the top load TL.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Mouth part, 3 ... Male screw, 5 ... Female screw, C ... Cap, TL ... Top load, st ... Screw thread formation start end, T ... Screw thread, Tm ... Bottom edge

Claims (2)

Use a male thread formed on the mouth portion side of the container, the internal thread is respectively formed on the cap side, has a double threaded screw starting from the facing position, the top load acting on the cap in the mounting process of the cap An oblique covering prevention screw structure that can prevent oblique covering of the cap,
When the cap is pushed down by the top load acting on the cap, the screw thread of the cap crosses over the screw thread of the mouth and the male screw of the mouth engages with the female screw of the cap. The height of the thread is formed lower than the other parts over a predetermined range from the thread formation start end of all the threads of the double thread, and the hem side edge of the thread formed in the lower part is formed. The shape is smoothly formed in a chamfered shape so as to be easily screwed, and the predetermined range is set to a range of ¼ to ３ from the thread formation start end. Diagonal cover prevention screw structure.   2. The oblique heading prevention screw structure according to claim 1, wherein a height of the low-formed screw thread is set in a range of 6/10 to 8/10 of a height of other portions.

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