JPS60215163A - Boot - Google Patents

Abstract

PURPOSE:To give a thick part corresponding to a pitch variation to each part of bellows structure, by varying a pitch between crest parts of the bellows structure whose crest and root parts have a constant diameter. CONSTITUTION:Pitches a, b,...h, and i between crest parts 1-1', 1'-1''... of a bellows structure are varied on the whole and be degrees. In this case, on the assumption that there is no draw-down in time of hollow molding, thickness becomes thin at the small side (a side) in the pitch but it becomes thick at the large side (i side) in the pitch. Therefore, in case of operating a boot, for example, when the boot is contracted, this contraction starts from the thinner side, and conversely when the boot is expanded wide, this expansion also starts from the thinner side. Even in the case where the boot is bent, no only operations for expansion or contraction, also this bending starts from the thinner side, yet larger bending takes place.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to boots. More specifically, the present invention relates to a boot having a bellows structure formed by a blow molding method.

Boots formed by the blow molding method are formed into a bellows structure by expanding a cylindrical molding material (parison) in a mold and pressing it against the inner surface of the mold to copy its shape. However, since the mold used for molding has only an outer mold and no inner mold, it is generally difficult to freely control the wall thickness.

That is, in the blow molding method, drawdown of the parison causes variations in wall thickness (gradient) in the longitudinal direction of the molded product, and the upper portion during molding tends to be thinner, and the lower the part, the thicker it becomes. Therefore, although parison control has been used to partially control these wall thicknesses, there are limits to this, and it is difficult to create large or accurate wall thickness differences at specific locations. Have difficulty.

In view of the above-mentioned current situation, in a boot that has a bellows structure formed by the hollow molding method and whose peaks and valleys have a constant diameter, if the pitch between the peaks of the bellows structure is equal intervals. However, it has not been possible to make the rocking, sliding, or both of these operations of specific parts of the boot easier or harder to operate in stages or locally.

The present inventor has proposed a boot having a snakeskin structure formed by a hollow molding method, in which the peaks and valleys have a constant diameter, and the pitch between the peaks of the bellows structure can be adjusted wholly or partially. It has been found that by setting the actuators at irregular intervals, it is possible to easily control the ease or difficulty of the operation as described above. The invention therefore relates to such a boot.

As a method for setting the pitch between the peaks of the bellows structure to be entirely or partially unequal, there may be a method of changing the pitch stepwise or a method of locally changing the pitch.

Figure 1 of the drawings shows the peaks 1-f, 1' of the bellows structure.
-1#, ...... pitch a, b, ......
A cross-sectional view shows a mode in which h, 1 is changed overall and in stages. In this case, assuming that there is no drawdown during blow molding, the wall thickness will be thinner on the smaller pitch side (& side) and thicker on the larger pitch side (1 side). Therefore, when the boot is operated, for example - when the boot is retracted, it starts to shrink from the thinner side, and conversely, when the boot is extended, it starts to expand from the thinner side.

Furthermore, when bending something other than a simple expansion/contraction operation, the bending starts from the thinner part and bends more.

Figure 4 shows how the boots will shrink (&
) , (b) , and (0) are shown in this order, that is, the operation when the pitch is small and the thinner wall starts to be compressed, and the operation sequentially spreads to the side with a larger pitch. It is shown.

The stepwise change in pitch can also be made partially, as shown in FIG. In this embodiment, a
A plurality of the same pitches are set in the portion , the portion b, the portion C, and the portion d.

Further, the pitch between the peaks of the bellows structure can be changed partially and locally, and an example of such a mode is shown in FIG. That is, in general, in a bellows structure having a pitch of a, parts with a pitch of blcSc,b are partially provided, and this can be said to be local with respect to c and a, but with respect to 'b, o, o, and d. Then, it can be said that the change is made in stages starting from a. The way the boots with this kind of bellows structure shrink is 5th F! i!
It is shown in J and 2. Similarly, the operating states in which the pitch is small and the line is gradually drawn from the thinner wall are (a) and (b).
), (0).

In the boot according to the present invention, by changing the pitch between the peaks of the bellows structure in which the peaks and valleys have a constant diameter, each part of the bellows structure is given a wall thickness corresponding to the pitch, so for example, Blue boots used as covers for automobile racks and pinions, which have a uniform wall thickness, may interfere with the housing due to rocking or sliding, so by varying the pitch, the operation can be localized. to prevent such interference.

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[Brief explanation of the drawing]

1 to 3 are half-cut sectional views of one embodiment of the boot according to the present invention. Moreover, FIGS. 4 and 5 are state diagrams showing how these boots are contracted. (Explanation of symbols) 1... Yoshi Yamabe, patent attorney representing the bellows structure 1) Toshio Figure 1 Figure 2 Figure 3 Figure 4 ((]) (b) 1 Figure 5 ( 0) Procedural amendment (own ship April 12, 1985 Patent Application No. 6951, Title of invention Relationship to the boot amendment case Name of patent applicant Nippon Mectron Co., Ltd. Agent (〒105) Address 1-2-7 Shiba Daimon, Minato-ku, Tokyo Contents of the detailed description of the invention column and drawing amendments in the specification subject to amendment (1) IrbJln ``d'' in the first line of page 5 of the specification. ( 2) Correct Figure 3 of the drawings to look like the attached drawing. 7. Corrected drawings for catalog of attached documents (Figure 3) 1 copy Figure 3

Claims (1)

[Claims] 1. In a boot having a bellows structure formed by a blow molding method and having peaks and valleys of a constant diameter, the richness between the peaks of the bellows structure is reduced entirely or Boots partially spaced unevenly. 2. The boot according to claim 1, wherein the pitch between the crests is changed in stages. & The boot according to claim 1, wherein the pitch between the crests is locally changed.