Patent Description:
The conventional hinge cap includes a cap body attached to a container body, a hinge portion, and a sealing portion connected to the cap body to open and close the container body (<CIT>). This hinge cap is configured such that a closed state of the hinge cap is held by engaging a locking portion formed on the cap body and a claw portion formed on the sealing portion.

The claw portion is formed by a concave portion and a convex portion formed on an inner surface of a tubular object. In addition, the claw portion is formed on an opposite side of the hinge portion in the circumferential direction of the tubular object. The convex portion of the claw portion is an undercut portion that becomes a mold release resistance when releasing the claw portion from a mold in injection molding.

The terms used in the conventional hinge cap, such as the cap body, the sealing portion, the locking portion, and a portion facing the claw portion are referred to, in the present disclosure, as an inner lid, an outer lid, a claw portion, and an engaging portion, respectively. <CIT> describes a hinge cap including a cap main body fixedly held at a mouth portion of a container and a lid body connected to the cap main body via a hinge, and particularly, an under cap for locking the lid body in a closed posture. <CIT> describes a container with a cap. The container comprises a container main body further comprising an opening at the top, a top portion, and a cylindrical torso portion, and is further configured from a cap unit that is housed in an elastic ring body, further comprising a push button that is formed upon the exterior peripheral surface of the elastic ring body and is exposed from the interior direction of the cylindrical torso portion toward the exterior direction thereof, a conical surface portion that expands downward upon, at a minimum, one side of the container main body and the elastic ring body, hooking portions that hook the cylindrical torso portion and the container main body together at prescribed locations, and fitting portions that fit the elastic ring body with the container main body, wherein, when pressing the push button when the cap portion is in an attached state, the elastic ring body contracts and deforms, causing the conical surface portion to raise gradually, thereby lifting the cap portion, the lifting whereof disengages the hooking portions, and the contracting deformation of the elastic ring body disengages the fitting portions. <CIT> describes a cap detachably attached to an upper end of a container body for housing contents. A lid part is joined to a cap body by a hinge. The cap body includes an upper plate part where a spout is formed in a central part, an inner cylindrical part protruding downward from the upper plate part, and an outer cylindrical part protruding downward from the outside of the inner cylindrical part in the upper plate part. In an inner peripheral surface of the inner cylindrical part, an engaging part which engages the side of the container body in attaching the cap to the container body is formed. The outer cylindrical part includes a circular wall part and a non-circular wall part in a circumferential direction. In the circular wall part, a slit extending in an axial direction from an end part on the side of the container body is formed in a region on the side of the non-circular wall part. <CIT> describes a synthetic resin cap that includes an inner stopper fitted in a mouth of a bottle , and a spout fitted on the inner stopper. The inner stopper has a plate-like overhanging portion to cover part of the mouth of the bottle, an opening which includes the edge of the overhanging portion as part of its inner peripheral edge to have a wide open area greater than the area of the overhanging portion, and a film sealing up the opening. The inner stopper allows a bar-like object to be inserted therein through the opening, hooked on the lower surface of the overhanging portion, and swung on the upper edge of the fitting portion serving as a fulcrum that is opposite to the overhanging portion. This releases the fitting portion from its engagement with the mouth of the bottle to remove the inner stopper.

For removing the molded piece with an undercut portion from the mold of the injection molding, <NUM>) a forcible removal from a mold and <NUM>) a slide core in the mold are known.

The mold using the technique <NUM>) is more complicated and more expensive than the mold using the technique <NUM>).

In the case of the technique <NUM>), when performing forcible removal, the undercut portion is sometimes partially chipped or damaged so that the shape as designed may be deformed to an undesirable shape. In addition, if the engaging portion is formed on the opposite side of the hinge, that is, on a part in the circumferential direction of the tubular object, the mold release resistance is concentrated on the undercut portion of the engaging portion during mold release, and the undercut portion may be easily damaged. If the undercut portion is damaged, the closed state of the hinge cap becomes unstable.

The present invention has been created in consideration of the above circumstances, and an object thereof is to provide a hinge cap that makes an engaging portion (an undercut portion), which is a portion of an inner surface of a tubular object that contributes to the stability of a closed state of the hinge cap, less likely to be damaged during mold release in injection molding and stabilizes an engaging state. Another object of the present invention is to provide a hinge cap set capable of improving airtightness using this hinge cap.

The present invention presumes an injection-molded hinge cap including: an inner lid attached to a container body; a hinge; and an outer lid connected to the inner lid by the hinge to open and close the cap.

The inner lid includes: a tubular inner wall portion that is attached to a mouth portion of the container body; an inner closing plate portion which protrudes from an inner surface of the inner wall portion in a state of closing the inner side thereof and in which a passage port for contents is formed; and a claw portion that protrudes outward in a radial direction from a surface of the inner closing plate portion.

The outer lid includes: an outer wall portion having a tubular configuration; an outer closing plate portion protruding from an inner surface of the outer wall portion in a state of closing the inside thereof; and a plurality of convex portions, as undercut portions, and a plurality of concave portions which are arranged side by side in an axial direction on the inner surface of the outer wall portion.

One convex portion and a concave portion adjacent to the one convex portion on an inner side of the outer wall portion form an engaging portion which fits to the claw portion in a closed state of the outer lid. A convex portion adjacent to the engaging portion in the axial direction of the outer wall portion (at least one side of the inner side and an open end side) and a concave portion adjacent to the adjacent convex portion on the inner side of the outer wall portion form a mold pressing portion.

The engaging portion may include any convex portion of the plurality of convex portions. However, if another convex portion is arranged on the open end side of the outer lid with respect to the engaging portion, the claw portion is likely to come into contact with the another convex portion in an opening/closing operation of the outer lid. The contact corresponds a case where the claw portion is located on a locus of the another convex portion during the opening/closing operation of the outer lid. In such a case, it is difficult to open or close the outer lid unless the claw portion gets over not only the convex portion of the engaging portion but also the another convex portion during the opening/closing operation of the outer lid. In order to enable the outer lid to be opened or closed only by causing the claw portion to get over one convex portion, the following configuration is desirably adopted.

That is, the engaging portion includes a convex portion on the most open end side among the plurality of convex portions. If the engaging portion includes the convex portion on the most open end side, the mold pressing portion is adjacent to the engaging portion on the inner side of the outer wall portion.

In addition, a row formed by the concave portions and the convex portions of the engaging portion and the mold pressing portion is not limited in number and position with respect to a circumferential direction of the outer wall portion, but the following configuration is desirably adopted when considering the ease of opening and closing the outer lid, the ease of releasing a mold, and the stability of the outer lid in the closed state.

That is, the number of the rows formed by the concave portions and the convex portions of the engaging portion and the mold pressing portion is one with respect to the circumferential direction of the outer wall portion, and the row is formed on the opposite side of the hinge.

In accordance with the present invention, the outer wall portion includes through-holes formed on both sides of the outer wall portion in the circumferential direction with respect to the engaging portion, and the following configuration is adopted in order to stabilize an engaging state between the claw portion and the engaging portion while facilitating the opening/closing operation.

That is, the outer wall portion has the through-holes formed on both the sides of the outer wall portion in the circumferential direction with respect to the engaging portion.

The through-hole may have any shape, but the following configuration is desirably adopted in order to facilitate the opening/closing operation of the outer lid.

That is, the through-hole is an elongated hole extending in the axial direction of the outer wall portion.

In the hinge cap, the passage port for the contents may adopt any configuration. The hinge cap may be used alone or used in combination with other parts. However, a hinge cap set in which the hinge cap and a packing sheet are combined desirably adopts the following configuration in order to improve airtightness in a closed state.

That is, the hinge cap set includes the hinge cap and the packing sheet that enhances the airtightness in the closed state of the hinge cap. The inner closing plate portion includes: an inner closing plate body protruding inward in the radial direction from the inner surface of the inner wall portion over the whole circumference in a circumferential direction; and a nozzle serving as the passage port for the contents, which is formed on an inner peripheral portion of the inner closing plate body, and protruding from the inner peripheral portion of the inner closing plate body to the opposite side of the container body. The outer lid includes a packing sheet support portion inside. The packing sheet has elasticity to be recessed in a state of being in close contact with a distal end of the nozzle.

Note that opening force acts on the outer lid due to restoring force of the packing sheet, and thus, the outer lid is likely to be opened by the restoring force of the packing sheet, for example, unless engaging force between the claw portion and the engaging portion is stronger than that in a hinge cap without the packing sheet. In order to strengthen the engaging force such that the outer lid is not opened by the restoring force of the packing sheet, for example, it is necessary to make a dimension in the radial direction in the engaging state between the claw portion and the engaging portion larger than that in the hinge cap without the packing sheet. Even with such a configuration, a shape of the engaging portion can be brought closer to a shape as designed by the plurality of undercut portions configured to disperse a mold release resistance, and thus, the hinge cap stabilizes the engaging state between the claw portion and the engaging portion, and the packing sheet improves the airtightness.

A modification of an embodiment of the invention has the following structure.

A hinge cap (not according to the invention) with a body formed by an injection-molding comprises: a body having an open end with a claw portion provided on a rim of the open end; a hinge provided on the rim at a position opposite to the claw portion; and a lid connected to the body through the hinge to open and close the open end of the body. The lid includes: a tubular outer wall portion; an outer closing plate portion for closing one side of the outer wall portion; and a plurality of convex portions as undercut portions and a plurality of concave portions which are aligned alternately in an axial direction of the tubular outer wall portion on an inner surface of the outer wall portion, one convex portion and a concave portion adjacent to the one convex portion form an engaging portion capable of being engaged with the claw portion in a closed state of the outer lid, and an adjacent convex portion adjacent to the engaging portion and a concave portion adjacent to the adjacent convex portion form a mold pressing portion.

In the hinge cap of the present invention, the plurality of convex portions as the undercut portions are arranged side by side in a straight line in the axial direction of the tubular outer wall portion. Thus, the mold release resistance when the outer wall portion is released from the portion of the injection-molding mold that forms the inner surface of the outer wall portion is dispersed to the plurality of undercut portions, and the shape of the engaging portion can be brought closer to a shape as designed, and an engaging state between the engaging portion and the claw portion is stable as compared with, for example, a hinge cap in which one convex portion as an undercut portion is arranged on the outer wall portion.

In the hinge cap of the present invention, the claw portion does not have to get over another convex portion during the opening/closing operation of the outer lid when the engaging portion includes the convex portion on the most open end side among the plurality of convex portions so that the opening/closing operation becomes easy.

In the hinge cap, in a case where the row formed by the concave portions and the convex portions of the engaging portion and the mold pressing portion with respect to the circumferential direction of the outer wall portion is single and formed on the opposite side of the hinge, the outer lid can be easily opened and closed and the mold can be easily removed during injection molding as compared with a case where there are a plurality of the rows, and the closed state of the outer lid is more stable than that in a case where the row is formed in the vicinity of the hinge.

In the hinge cap of the present invention, the outer wall portion is easily deformed elastically by the amount of the through-hole when the through-holes are formed on both the sides of the outer wall portion in the circumferential direction with respect to the engaging portion. Thus, the opening/closing operation of the outer lid becomes easy, and the shape of the outer lid does not change by the presence or absence of the through-hole unless external force is applied, so that the engaging state between the claw portion and the engaging portion is stable.

In the hinge cap of the present invention, the opening/closing operation of the outer lid becomes easy when the through-hole is the elongated hole extending in the axial direction of the outer wall portion.

In the hinge cap set of the present invention, the shape of the engaging portion can be brought closer to the shape as designed by the plurality of undercut portions configured to disperse the mold release resistance, and thus, the engaging state between the claw portion and the mating portion can be held even if the packing sheet has the restoring force, and the airtightness is improved by the close contact between the packing sheet and the nozzle.

A hinge cap set of a first embodiment of the present invention shown in <FIG>, <FIG> includes: a hinge cap <NUM> attached to a container body <NUM> shown by the dotted line in <FIG>; and a packing sheet P that enhances airtightness in a closed state of the hinge cap <NUM> and is supported inside the hinge cap <NUM>.

The hinge cap <NUM> includes: an inner lid <NUM> attached to the container body <NUM>; two hinged wings <NUM>; an outer lid <NUM> that is connected to the inner lid <NUM> by the two hinged wings <NUM> to open and close the cap; and an L-shaped elastic plate <NUM> that applies opening force and closing force between the inner lid <NUM> and the outer lid <NUM>. The hinge cap <NUM> is made of resin and is formed by an injection-molding, and the inner lid <NUM>, the hinge <NUM>, the outer lid <NUM>, and the elastic plate <NUM> are configured as an integrated object. An axis of the container body <NUM>, an axis of the inner lid <NUM>, and an axis of the outer lid <NUM> are common in a state in which the container body <NUM> is assembled with the inner lid <NUM> and the outer lid <NUM> is closed by the inner lid <NUM>.

The inner lid <NUM> includes: a tubular inner wall portion <NUM> attached to a mouth portion of the container body; an inner closing plate portion <NUM> having a nozzle <NUM> protruding from a top surface thereof; and a claw portion <NUM> protruding outward in a radial direction from the top surface of the inner closing plate portion <NUM>.

Hereinafter, the hinge cap <NUM> is assumed to be in a state immediately after injection molding. The state immediately after injection molding is a state in which the outer lid <NUM> is open and the outer lid <NUM> is arranged on the right side of the inner lid <NUM> as shown in <FIG> and <FIG>.

Directions are defined as follows except for the above-described left-right direction.

A "container body side" is referred to as the lower side of an object (for example, the inner closing plate portion <NUM>) in <FIG>. An "opposite side of the container body" is referred to as the upper side in <FIG>.

An "axial direction" of a tubular object is referred to as an up-down direction in <FIG> in the case of the inner wall portion <NUM>.

A "front-back direction" is referred to as a direction orthogonal to both the up-down direction and the left-right direction.

The "radial direction" is referred to as a direction of a straight line that extends radially from a center of a tubular object in a direction perpendicular to the axial direction.

As shown in <FIG>, the inner wall portion <NUM> extends towards the container body side from the inner closing plate portion <NUM>. In addition, the inner wall portion <NUM> includes first, second, and third inner wall portions <NUM>, <NUM>, and <NUM> arranged in said order with intervals in the radial direction. The first, second, and third inner wall portions <NUM>, <NUM>, and <NUM> are each tubular, more specifically cylindrical, and have a common centerline. That is, the inner wall portions <NUM>, <NUM> and <NUM> have a common axis. The common axis is also the same as the axis of the container body <NUM>. The first, second, and third inner wall portions <NUM>, <NUM>, and <NUM> have one side (lower side) in the axial direction as an open end, and is connected to the inner closing plate portion <NUM> at the other end (upper side end). The first, second, and third inner wall portions <NUM>, <NUM>, and <NUM> have longer cylinder lengths in said order, and lower ends thereof terminate at lower levels in said order.

The first inner wall portion <NUM> is arranged inside the mouth portion of the container body <NUM>. The third inner wall portion <NUM> covers the second inner wall portion <NUM> from the outside in the radial direction. A female screw 15a is formed on an inner peripheral surface of the second inner wall portion <NUM>. The female screw 15a engages with a male screw formed on an outer peripheral surface of the mouth portion of the container body <NUM>.

The inner closing plate portion <NUM> includes: an inner closing plate body <NUM> covering the upper sides of the inner wall portions <NUM>, <NUM> and <NUM>; and a nozzle <NUM> at the center of the inner closing plate body <NUM> as a passage port for contents in the container body <NUM>.

The nozzle <NUM> has a tapered shape that protrudes from the inner peripheral portion of the inner closing plate body <NUM> to the opposite side (upper side) of the container body <NUM>, and has a shape whose inner and outer diameters decrease toward the upper side. More specifically, the nozzle <NUM> has the shape of a funnel including a tapered nozzle body portion <NUM> and a cylindrical discharge port portion <NUM> protruding upward from a distal end portion of the nozzle body portion <NUM>.

The inner closing plate body <NUM> is annular, more specifically, toroidal when viewed in a plan view. In addition, the inner closing plate body <NUM> includes a raised portion <NUM> in which a portion inside an outer peripheral portion of the surface of the inner closing plate body <NUM> is raised. When viewed from the top, an outer shape of the raised portion <NUM> fits to an open end portion of an outer wall portion <NUM>, which will be described later, of the outer lid <NUM>. The raised portion <NUM> includes two semi-circular portions <NUM> facing each other at opposite sides, one on the side with hinge <NUM> and the other one on the side away from the hinge <NUM>, while two parallel linear portions <NUM> connecting the ends of the two semi-circular portions <NUM>. Both the two semi-circular portions <NUM> have a shape that follows the circle which is the outer shape of the inner closing plate body <NUM>. When the open end portion of the outer wall portion <NUM> is fitted to the raised portion <NUM>, the outer wall portion <NUM> is placed on a portion of the inner closing plate body <NUM> located outside the raised portion <NUM> in the radial direction, that is, on the outer peripheral portion of the inner closing plate body <NUM>. Note that the claw portion <NUM> protrudes upwardly from the surface of the raised portion <NUM>. The claw portion <NUM> will be described in detail later.

In addition, an extension wall <NUM> extending from the inner wall portion <NUM> (third inner wall portion <NUM>) to the other side in the axial direction is formed on the hinge <NUM> side of the inner closing plate body <NUM>.

The outer lid <NUM> includes: the tubular outer wall portion <NUM>; an outer closing plate portion <NUM> covering the tubular outer wall portion <NUM> to close the inside thereof; and a packing sheet support portion <NUM> on an inner surface of the outer closing plate portion <NUM>, such that the packing sheet support portion <NUM> supports a packing sheet P, which will take a tight contact with a distal end of the nozzle <NUM>; a plurality of convex portions <NUM>, serving as mountains or protruding undercut portions on the inner surface of the outer wall portion <NUM>; and a plurality of concave portions <NUM>, serving as valleys or concaved areas between the plurality of convex portions <NUM> on the inner surface of the outer wall portion <NUM>. The convex portions <NUM> and the concave portions <NUM> are aligned alternately in the direction parallel to the axial direction.

The outer closing plate portion <NUM> includes: an outer closing plate body portion <NUM> which closes one side of the tubular outer wall portion <NUM> in the axial direction; and a pedestal portion <NUM>, which protrudes from an inner surface of the outer closing plate body portion <NUM>, for placing the packing sheet P.

As shown in <FIG>, the pedestal portion <NUM> is formed in a "cross" shape when viewed from the top.

Note that the packing sheet P placed on the pedestal portion <NUM> has a disk shape, and is a circle having a diameter larger than a dimension of the cross of the pedestal portion <NUM> in a crossing direction. The packing sheet P is made of a resin that is softer than the hinge cap <NUM>, and has elasticity enough soft to be slightly recessed when the distal end of the nozzle <NUM> is pressed, so as to ensure tight contact.

The packing sheet support portion <NUM> includes a pair of support arms 33a that hold the packing sheet P in between from opposite sides in a direction that intersects (more specifically, is orthogonal to) with the packing sheet P in the up-down direction.

The pair of support arms 33a protrude from an inner surface of the outer closing plate portion <NUM> and extend from the inner surface of the outer wall portion <NUM> to reach the periphery of the pedestal portion <NUM>.

The support arm 33a includes: an arm portion body 33b that extends from the hinge <NUM> side toward the pedestal portion <NUM> on the inner surface of the outer wall portion <NUM>; and a curved support portion body 33c that extends in a state of partially covering the periphery of the pedestal portion <NUM> from a distal end of the arm portion body 33b on the pedestal portion <NUM> side. When viewed from the top, the curved support portion body 33c is formed in an arc shape so as to follow an outer shape of the packing sheet P placed on the pedestal portion <NUM>. In addition, a diameter of the arc formed inside the pair of support portion bodies 33c is formed to be slightly smaller than a diameter of the packing sheet P.

The outer wall portion <NUM> has a curved concave surface 31a, which is concaved in an arc shape when viewed from the side, on its outer surface on the side opposite to the hinge <NUM>. The curved concave surface 31a is formed on the outer closing plate portion <NUM> side in the axial direction of the outer wall portion <NUM> to be easily touched by a finger during an operation of opening the outer lid <NUM>. As shown in <FIG>, the curved concave surface 31a includes a rounded upper edge 31b, left and right side edges 31c each extending linearly, and a lower edge 31d extending between the side edges 31c.

As shown in <FIG>, the outer wall portion <NUM> includes a recessed portion 31v, which is formed by a slope face slanted from the open end (upper end) of the outer wall portion <NUM> towards the other end, (lower end) at a position adjacent the hinge <NUM>. A shape of the recessed portion 31v corresponds to the shape of the extension wall <NUM> of the inner lid <NUM>. In addition, an end on the outer closing plate portion <NUM> side, which is a closed end (lower end) of the outer wall portion <NUM>, is formed in a state of being inclined so as to be located on the one side (lower side) in the axial direction as proceeding from the hinge <NUM> side to the opposite side of the hinge <NUM>.

The outer closing plate body portion <NUM> has a shape that is inclined so as to be directed to the one side in the axial direction of the outer wall portion <NUM> as proceeding from the hinge <NUM> side to the opposite side of the hinge <NUM> in accordance with the shape of the outer wall portion <NUM>. In addition, the outer closing plate body portion <NUM> has a shape that extends to the opposite side of the hinge <NUM> as compared with a case where the outer wall portion <NUM> does not have the curved concave surface 31a, for example. An upper surface of the outer closing plate body portion <NUM> is inclined to be farther from the inner lid <NUM> as being separated from the hinge <NUM> with respect to a plane orthogonal to the axis of the outer lid <NUM>, that is, the axis that coincides with the common axis in the closed state of the outer lid <NUM>. The outer closing plate body portion <NUM> is provided with an eaves portion 31e on the opposite side of the side on which the hinge <NUM> is provided. The eaves portion 31e protrudes further outward from an outer tubular surface of the outer wall portion <NUM>. This facilitates an operation of opening and closing the outer lid <NUM> in combination with the curved concave surface 31a.

The inner surface of the outer wall portion <NUM> is formed so as to be larger from the outer closing plate portion <NUM> side (lower side), which is the one side in the axial direction, to the open end side (upper side), which is the other side in the axial direction in consideration of easy removal of a convex-shaped portion of an injection-molding mold that forms the inner surface of the outer wall portion <NUM>. That is, the inner surface of the outer wall portion <NUM> is widened outward in the radial direction as proceeding toward the open end (upward).

More specifically, the inner surface of the outer wall portion <NUM> is a tapered slope except for a part thereof, and is inclined by an angle θ with respect to the up-down direction. Such a part of the inner surface of the outer wall portion <NUM> is a portion of the inner surface of the outer wall portion <NUM> corresponding to the curved concave surface 31a, and includes a slope portion <NUM> that is inclined in a state of being slightly widened to the right side, which is the outer side in the radial direction, as proceeding upward from the outer closing plate portion <NUM>, and a curved convex surface 31f that is curved in a state of being directed to the right side as proceeding upward from an upper end of the slope portion <NUM>. An angle of the slope portion <NUM> is smaller than the angle θ of the inner surface of the outer wall portion <NUM>. The angle θ is preferably <NUM> to <NUM> degrees.

As shown in <FIG>, the outer wall portion <NUM> is formed with a pair of through-holes <NUM> each penetrating in the radial direction at an interval in the circumferential direction. The pair of through-holes <NUM> are formed in a portion of the whole circumference corresponding to the curved concave surface 31a, in other words, on the opposite side of the hinge <NUM> in the circumferential direction. That is, the pair of through-holes <NUM> are elongated holes formed in the outer wall portion <NUM> and extending in parallel with the axis of the outer lid <NUM>, extend to both sides of a plurality of convex portions 34a and 34b, which will be described later, and exist so as to sandwich the plurality of convex portions 34a and 34b. Further, the pair of through-holes <NUM> are formed in a range extending over a part of the curved concave surface 31a.

As shown in <FIG> and <FIG>, the outer wall portion <NUM> includes a pair of grooves <NUM>, each extending from the open end (upper end) to reach the pair of through-holes <NUM>, on the inner surface. Since the groove <NUM> has a bottom and does not penetrate, the open end side of the outer wall portion <NUM> is an annular shape connected in the circumferential direction. In addition, the groove <NUM> and the through-hole <NUM> are connected in the axial direction (up-down direction) of the outer wall portion <NUM>. The plurality of convex portions <NUM> and the plurality of concave portions <NUM> are arranged between the pair of grooves <NUM> and between the pair of through-holes <NUM> in the circumferential direction of the outer wall portion <NUM>.

As shown in <FIG>, the plurality of convex portions <NUM> and the plurality of concave portions <NUM> are arranged alternately side by side in the axial direction of the outer wall portion <NUM>. The number of rows in which the convex portions <NUM> and the concave portions <NUM> are arranged side by side is one in the circumferential direction of the outer wall portion <NUM>. The concave portion <NUM> is located closest to the open end side among the plurality of convex portions <NUM> and the plurality of concave portions <NUM>.

The concave portion <NUM> is concaved with respect to the inner surface of the outer wall portion <NUM>. The concave portion <NUM> is concaved in a stepped manner with respect to the circumferential direction of the outer wall portion <NUM>. In addition, the number of the concave portions <NUM> is three in the present embodiment, which are from the open end side, the first concave portion 35a, the second concave portion 35b, and the third concave portion 35c, in <FIG>. The reference sign with a number and an alphabet is used when referring to a particular concave portion, and the reference sign with only a number is used when referring to the concave portions in general.

The convex portion <NUM> protrudes from the inner surface of the outer wall portion <NUM>, and forms the undercut portion in injection molding. In addition, the number of the convex portions <NUM> is two in the present embodiment, which are from the open end side, the first convex portion 34a and the second convex portion 34b in <FIG>. The reference sign with a number and an alphabet is used when referring to a particular convex portion, and the reference sign with only a number is used when referring to the convex portions in general.

The concave portion 35a on the most open end side among the plurality of concave portions <NUM>, that is, the first concave portion 35a from the open end side, is inclined in a state of being directed outward in the radial direction toward the open end. In addition, the convex portion 34a on the most open end side among the plurality of convex portions <NUM>, that is, the first convex portion 34a from the open end side, and the concave portion 35b (that is, the second concave portion 35b from the open end side) adjacent to the first convex portion 34a on the inner side of the outer wall portion <NUM> form an engaging portion <NUM> that fits to a distal end portion of the claw portion <NUM> of the inner lid <NUM> in the closed state of the outer lid <NUM>.

The claw portion <NUM> includes: a claw neck portion 13a protruding upward from the surface of the raised portion <NUM> of the inner closing plate portion <NUM> on the opposite side of the hinge <NUM>; and a claw distal end portion 13b extending outwardly in the radial direction from an upper end portion of the claw neck portion 13a.

In addition, the convex portion 34b adjacent to the engaging portion <NUM> on the inner side of the outer wall portion <NUM> is the second convex portion 34b from the open end side. The concave portion 35c adjacent to the adjacent convex portion 34b on the inner side of the outer wall portion <NUM> is the third concave portion 35c from the open end side. The second convex portion 34b from the open end side and the third concave portion 35c from the open end side each have a shape similar to that of the engaging portion <NUM>, and form a mold pressing portion <NUM> that does not fit to the distal end portion of the claw portion <NUM> in the closed state of the outer lid <NUM>. In addition, the mold pressing portion <NUM> is adjacent to the engaging portion <NUM> on the inner side of the outer wall portion <NUM>. Note that there is only the first concave portion 35a on the open end side of the outer wall portion <NUM> with respect to the engaging portion <NUM>, and thus, the mold pressing portion <NUM> is formed only on the inner side of the outer wall portion <NUM> with respect to the engaging portion <NUM> in the present embodiment. The engaging portion <NUM> and the claw portion <NUM> constitute an engaging mechanism.

In <FIG>, a protrusion amount L3 of the convex portion 34b with respect to the concave portion 35c of the mold pressing portion <NUM> is smaller than a protrusion amount L1 of the convex portion 34a with respect to the concave portion 35b in the engaging portion <NUM> in the present embodiment. Thus, a resistance force received from a mold <NUM> is smaller in the convex portion 34a than in the convex portion 34b when forcibly removing the mold <NUM> as shown in <FIG>, and thus, any damages received from the resistance force is smaller in the convex portion 34a than in the convex portion 34b. In addition, a height H3 of the convex portion 34b from an outer peripheral surface of the outer wall portion <NUM> is larger than a height H1 of the convex portion 34a. Further, a wall thickness (H1 - L1) of the outer wall portion <NUM> between the convex portion 34a and the convex portion 34b is thinner than a wall thickness (H3 - L3) on the lower side (opposite side of the convex portion 34a) from the convex portion 34b. Thus, the portion with the wall thickness (H1 - L1) can be easily bent than the portion with the wall thickness (H3 - L3), as clear from <FIG>. Thus, the resistance force received from the mold <NUM> can be released by bending at the wall thickness (H1 - L1) portion when the mold <NUM> is forcibly removed as shown in <FIG>. Further, the outer wall portion <NUM> facing the convex portion 34a is partially not existing due to the recessed portion 31v. Thus, the mold <NUM> can be easily inclined with respect to the outer wall portion <NUM> toward the recessed portion 31v during the removal of the mold <NUM> forcibly.

An engaging slope 41a and a pressing slope 43a, each is slanted with respect to the axial direction of the outer wall portion <NUM>, are formed on the inner side of each of the convex portion 34a of the engaging portion <NUM> and the convex portion 34b of the mold pressing portion <NUM>, respectively. Both the engaging slope 41a and the pressing slope 43a are slanted inwardly in the radial direction from the inner side of the outer wall portion <NUM> to the open end side. In addition, an angle Θ3, which is an acute angle formed by the pressing slope 43a and a straight line in the axial direction, is smaller than an angle Θ1 which is an acute angle formed by the engaging slope 41a and a straight line parallel to the axial direction in the present embodiment. Thus, the pressing slope 43a is more easy to slip than the engaging slope 41a with respect to the mold <NUM> when the mold <NUM> is forcibly removed.

Note that the engaging portion <NUM> and the mold pressing portion <NUM> are arranged on the front side, which is the opposite side of the hinge side where the hinge <NUM> is located, in the circumferential direction of the outer wall portion <NUM>. Furthermore, portions <NUM> and <NUM> are arranged between the pair of grooves <NUM>, and also between the pair of through-holes <NUM>. In addition, the engaging portion <NUM> and the mold pressing portion <NUM> are arranged in the axial direction of the outer lid <NUM> to form a single row, and the row exists only one when viewed in the circumferential direction.

A reason why the mold pressing portion <NUM> is provided will be described with reference to <FIG> and <FIG>. <FIG> shows a state in which the outer wall portion <NUM> and the mold <NUM> are tightly attached, and the mold <NUM> is about to be forcibly removed from the outer wall portion <NUM> by an external force F0. <FIG> shows a state immediately after the forcible removal starts and the outer wall portion <NUM> is released from the mold <NUM>. As shown in <FIG>, the external force F0 is dispersed into action and reaction forces F1 and F2 generated at the slope 41a and the slope 43a, where the plurality of undercut portions exist. At the places where the slope 41a and the slope 43a face the corresponding surfaces of the mold <NUM>, sliding forces are generated at such slopes. With the dispersion into the forces F1 and F2, a mold release resistance is dispersed, and any damages to the engaging slope 41a can be mitigated/prevented. Further, when the outer wall portion <NUM> is separated from the mold <NUM> as shown in <FIG>, the recessed portion 31v is formed on the hinge side, which is the opposite side of the front side (the side where the engaging portion <NUM> and the mold pressing portion <NUM> exist) where the slope 41a and the slope 43a of the outer wall portion <NUM> are provided, and thus, the mold <NUM> can escape while being tilted toward the hinge side, only the pressing slope 43a is in contact with the mold <NUM>, the engaging slope 41a can be kept in the state of being separated from the mold <NUM>, and the engaging slope 41a will not be damaged. Even if the engaging slope 41a is in contact with the mold <NUM> immediately after the outer wall portion <NUM> being separated from the mold <NUM>, the engaging slope 41a can be prevented from being damaged by bending, because the wall thickness of the outer wall portion <NUM> between the convex portion 34a and the convex portion 34b is thin.

Next, the hinge <NUM> will be described. The hinge <NUM> is joined to the outer wall portion <NUM> of the outer lid <NUM> and the inner wall portion <NUM> (third inner wall portion <NUM>) of the inner lid <NUM>, and includes: a first wing 3a protruding outward in the radial direction from the outer wall portion <NUM>; a second wing 3b protruding outward in the radial direction from the inner lid <NUM>; and a portion that is joined to the first wing 3a and the second wing 3b and is thinner than both the first wing 3a and the second wing 3b, that is, a hinge body 3c which is a rotation axis portion. The hinge body 3c is the center when the outer lid <NUM> is opened (performs an axis of rotating motion), and thus, is also called the hinge rotation axis 3c. The elastic plate <NUM> is located between the pair of hinged wings <NUM>. In the closed state of the outer lid <NUM>, as shown in <FIG>, the hinge rotation axis 3c is at a level above an upper surface of the inner closing plate portion <NUM>. As a result, the upper surface of the inner closing plate portion <NUM> and a lower surface of the outer wall portion <NUM> can abut on each other reliably and stably as compared with a case where the hinge rotation axis 3c is included on the same level as the upper surface of the inner closing plate portion <NUM>.

The elastic plate <NUM> has a plate shape and functions as a so-called leaf spring. The elastic plate <NUM> has a cross-sectional shape that is bent in a V shape, and has opposite ends joined, respectively, to the outer wall portion <NUM> of the outer lid <NUM> and the inner wall portion <NUM> of the inner lid <NUM>. More specifically, the elastic plate <NUM> includes a first pivotable portion (connected to the inner lid <NUM> side) 5a that is freely bendable, a leaf spring portion 5c that has a configuration of a V shape, and a second pivotable portion (connected to the outer lid <NUM> side) 5b that is freely bendable. The first pivotable portion 5a and the second pivotable portion 5b are thinner than the leaf spring portion 5c. That is, the thickness of the elastic plate <NUM> has a tapered thickness that is the thickest in the central portion (leaf spring portion 5c) and becomes thinner toward the first and second pivotable portions 5a and 5b. A spring effect is stronger than a plate that has a uniform thickness. Both the first pivotable portion 5a and the second pivotable portion 5b are located away from the hinge rotation axis 3c. In the open state of the outer lid <NUM> as shown in <FIG> and in the closed state of the outer lid <NUM> as shown in <FIG>, the V-shaped leaf spring portion <NUM> takes such a state that both ends 5a and 5b are spaced but at a closest possible distance, at which the V-shaped leaf spring portion <NUM> is in a stable state. As the outer lid <NUM> rotates about the hinge rotation axis 3c by about <NUM> degrees from the open state (<FIG>) to the closed state (<FIG>) or vice versa, the second pivotable portion 5b takes a motion of a semi-circle indicated by the dotted line in <FIG>. In a state where the outer lid <NUM> is rotated about <NUM> degrees, i.e., a halfway, the V-shaped leaf spring portion <NUM> opens to take such a state that both ends 5a and 5b are spaced apart at a furthest possible distance producing a biasing force acting towards the closing/opening direction. When the outer lid <NUM> passes through a position rotated <NUM> degrees while operating in the closing direction, the biasing force in the closing direction is applied automatically to complete the closing operation. When the outer lid <NUM> passes through a position rotated <NUM> degrees while operating in an opening direction, the biasing force in the opening direction is applied automatically to complete the opening operation. Therefore, the outer lid <NUM> can be held in the open state or the closed state. The V-shaped leaf spring portion <NUM> applies snap action to the outer lid <NUM> in both the opening direction and the closing direction. As a result, the outer lid <NUM> can be comfortably opened and closed. The above-described engaging mechanism is provided in order to hold the outer lid <NUM> in the closed state more firmly.

In the hinge cap <NUM> of the first embodiment of the present invention, the two convex portions <NUM> as the undercut portions are arranged side by side in a straight line in the axial direction of the tubular outer wall portion <NUM>. Thus, the mold release resistance when the outer wall portion <NUM> is released from the portion of the injection-molding mold that forms the inner surface of the outer wall portion <NUM> is dispersed to the plurality of undercut portions. For example, in comparison with a case where a hinge cap has only one convex portion as an undercut portion on the outer wall portion <NUM>, it is possible to design the shape of the engaging portion <NUM> freely and nearly the same as a preferred shape as designed. Also, an engaging state between the engaging portion <NUM> and the claw portion <NUM> can be made very stable. Moreover, the concave portion 35b of the engaging portion <NUM> has the shape that is concaved with respect to the inner surface of the outer wall portion <NUM>, and thus, the claw portion <NUM> is positioned in the circumferential direction with respect to the concave portion 35b of the engaging portion <NUM> in the closed state of the outer lid <NUM>. Thus, the engaging state between the engaging portion <NUM> and the claw portion <NUM> is stable.

In the hinge cap <NUM> of the first embodiment of the present invention, the engaging portion <NUM> includes the convex portion 34a on the most open end side among the plurality of convex portions <NUM>, and thus, the claw portion <NUM> does not have to get over another convex portion during the opening/closing operation of the outer lid <NUM> so that the opening/closing operation becomes smooth.

In the hinge cap <NUM> of the first embodiment of the present invention, there is only one row formed by the concave portions <NUM> and the convex portions <NUM> of the engaging portion <NUM> and the mold pressing portion <NUM> along the circumferential direction of the outer wall portion <NUM>. Thus, the outer lid <NUM> can be easily opened and closed and the mold can be easily removed during injection molding as compared with a case where there are a plurality of the rows. Moreover, the row is formed on the opposite side of the hinge <NUM>, and thus, the closed state of the outer lid <NUM> is more stable than that in a case where the row is formed in the vicinity of the hinge <NUM>.

In the hinge cap <NUM> of the first embodiment of the present invention, the through-holes <NUM> are formed on both sides of the outer wall portion <NUM> along the circumferential direction with respect to the engaging portion <NUM>. A portion between the through-holes <NUM> in the outer wall portion <NUM> can be easily deformed. Thus, the opening/closing operation of the outer lid <NUM> becomes easy. Also, the shape of the outer lid <NUM> does not change regardless of the presence or absence of the through-hole <NUM>, unless external force is applied. Thus, the engaging state between the claw portion <NUM> and the engaging portion <NUM> is stable. That is, since the through-holes <NUM> are formed on both sides of a row of the engaging portion <NUM> and the mold pressing portion <NUM> aligned in the axial direction, the row of the engaging portion <NUM> and the mold pressing portion <NUM> can be easily displaced outward in the radial direction. Thus, engaging portion <NUM> can be easily pressed by the claw portion <NUM>.

In the hinge cap <NUM> of the first embodiment of the present invention, the through-hole <NUM> is the elongated hole extending in the axial direction of the outer wall portion <NUM>, and thus, the opening/closing operation of the outer lid <NUM> becomes easier depending on the length of the through-hole <NUM>, and the mold release resistance during injection molding also becomes smaller. Moreover, since the through-holes <NUM> as the elongated holes are arranged not only in the engaging portion <NUM> but also on both the sides of the mold pressing portion <NUM> in the circumferential direction, the opening/closing operation of the outer lid <NUM> becomes easy and the mold release resistance becomes small.

The hinge cap <NUM> of the first embodiment of the present invention is provided with the groove <NUM> extending from the open end to the through-hole <NUM> in the inner surface of the outer wall portion <NUM>, but provided with no cutout portion along the circumferential direction in the open end portion side of the outer wall portion <NUM>. Thus, the engaging state between the claw portion <NUM> and the engaging portion <NUM> is stable even when external force is applied to the outer lid <NUM>.

The hinge cap <NUM> of the first embodiment of the present invention is provided with the raised portion <NUM> which is raised from the surface of the inner closing plate portion <NUM> and is fitted to the open end portion of the outer wall portion <NUM>, and thus, the closed state of the outer lid <NUM> is stable.

In the hinge cap set of the first embodiment of the present invention, the shape of the engaging portion <NUM> can be brought closer to the shape as designed by the plurality of undercut portions (convex portions <NUM>) configured to disperse the mold release resistance, and thus, the engaging state between the claw portion <NUM> and the engaging portion <NUM> can be held even if the packing sheet P has restoring force, and the airtightness is improved by the close contact between the packing sheet P and the nozzle <NUM>.

The present invention is not limited to the above embodiment, and can be appropriately modified. For example, the number of the mold pressing portions <NUM> is one in the above embodiment, but may be plural without being limited thereto in the present invention.

In addition, as compared with the protrusion amount L1 of the convex portion <NUM> with respect to the concave portion <NUM> of the engaging portion <NUM>, the protrusion amount L3 of the convex portion <NUM> with respect to the concave portion <NUM> of the mold pressing portion <NUM> is smaller in the above embodiment, but may be desirably equal to or more than, or more desirably larger without being limited thereto in the present invention. As a result, the surface of the engaging portion <NUM> can be prevented from being damaged as much as possible at the time of mold release, and the engaging state between the engaging portion <NUM> and the claw portion <NUM> can be stabilized.

In addition, as compared with the angle Θ1 which is the acute angle formed by the engaging slope 41a and the straight line parallel to the axial direction, the angle Θ3, which is the acute angle formed by the pressing slope 43a and the straight line parallel to the axial direction, is smaller in the above embodiment, but may be desirably the same, or more desirably larger without being limited thereto in the present invention. As a result, the surface of the engaging portion <NUM> can be prevented from being damaged as much as possible at the time of mold release, and the engaging state between the engaging portion <NUM> and the claw portion <NUM> can be stabilized.

Since the mold pressing portion <NUM> is provided in order to disperse the mold release resistance as described above, the mold release resistance applied to the mold pressing portion <NUM> increases as the angle Θ3 becomes larger, and the damage to the surface of the engaging portion <NUM> can be mitigated. As for the angle Θ1 of the engaging portion <NUM>, the engaging with the claw portion <NUM> is stronger as the angle is larger, and a click feeling is improved, for example, but the surface of the engaging portion <NUM> is easily damaged because the resistance at the time of mold release increases. In addition, the mold release resistance itself between the mold <NUM> and a molded product increases as the angles Θ1 and Θ3 become larger. Thus, it is necessary to appropriately adjust the respective angles in accordance with the shape of the outer wall portion <NUM>, which is the molded product, in order to smoothly release the mold <NUM> from the molded product. It is desirable that an apex 50b of the mold <NUM> (facing the concave portion 35c) be equal to or lower than an apex 50a of the mold <NUM> (facing the concave portion 35b) when viewed from a central axis of the mold. As a result, the contact of the mold <NUM> with the engaging slope 41a other than the pressing slope 43a at the time of releasing the mold <NUM> is reduced (see <FIG>), and the damage to the surface of the engaging portion <NUM> can be prevented. A height of the apex 50b is preferably equal to or lower by <NUM> than that of the apex 50a, and more preferably lower by <NUM> to <NUM> than that of the apex 50a.

Claim 1:
A hinge cap formed by an injection-molding comprising:
an inner lid (<NUM>) capable of being attached to a container body (<NUM>);
a hinge (<NUM>); and
an outer lid (<NUM>) that is connected to the inner lid by the hinge to open and close the cap, wherein
the inner lid (<NUM>) includes: a tubular inner wall portion (<NUM>) capable of being attached to a mouth portion of the container body; an inner closing plate portion (<NUM>) which protrudes from an inner surface of the inner wall portion for closing one side of the inner wall portion and is formed with a passage port; and a claw portion (<NUM>) protruding outwardly in a radial direction from a surface of the inner closing plate portion,
the outer lid (<NUM>) includes: a tubular outer wall portion (<NUM>); an outer closing plate portion (<NUM>) for closing one side of the outer wall portion; and a plurality of convex portions (<NUM>,34a, 34b) as undercut portions and a plurality of concave portions (<NUM>,35a, 35b, 35c) which are aligned alternately in an axial direction of the tubular outer wall portion on an inner surface of the outer wall portion,
one convex portion (34a) and a concave portion (35b) adjacent to the one convex portion (34a) form an engaging portion (<NUM>) capable of being engaged with the claw portion (<NUM>) in a closed state of the outer lid, and
an adjacent convex portion (34b) adjacent to the engaging portion (<NUM>) and a concave portion (35c) adjacent to the adjacent convex portion (34b) form a mold pressing portion (<NUM>),
characterized in that the outer wall portion (<NUM>) has through-holes (<NUM>) formed on both sides of the engaging portion (<NUM>)..