Tongue for seat belt device, and seat belt device

A tongue for a seat belt device is provided with a tongue main body that is insertable within a buckle, and a train-around portion through which an intermediate portion of a webbing is inserted. The train-around portion includes a first shaft is fixedly mounted between a pair of opposing walls, and a second shaft that is movably mounted between the walls. The webbing is slidably bent 180° around the first fixed shaft. When tension of the webbing exceeds a predetermined magnitude or greater, the movable second shaft engages the webbing and increases a bending angle of the webbing around the first shaft to an angle greater than 180° thereby increasing frictional resistance between the webbing and the train-around portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 USC 119 from Japanese Patent Application No. 2011-199899 filed Sep. 13, 2011, the disclosure of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a tongue for a seat belt device that structures a seat belt device of a vehicle, and to a seat belt device that is equipped with this tongue.

2. Related Art

At a tongue for a seat belt device that is disclosed in Japanese Patent Application National Publication No. 2009-525909 (Patent Document 1) (this tongue is called the “belt tongue portion” in Patent Document 1), the main body portion thereof (called the “tongue portion main body portion” in Patent Document 1) is curved around an axis whose axial direction is the width direction of a webbing (called “belt webbing” in Patent Document 1), and a curved, plate-shaped bending-and-fastening element is provided at the inner side of this main body portion.

When, due to the vehicle rapidly decelerating, the body of the vehicle occupant pushes the webbing forward, and, due thereto, the tension of the webbing increases, the bending-and-fastening element slides along the inner side of the main body portion of the tongue due to this tension. The bending-and-fastening element that slides in this way pushes the webbing from a thickness direction one side thereof, and, due thereto, the bending-and-fastening element, together with an upper bar of the main body portion at the tongue, clamps the webbing. Due to the webbing being clamped in this way, the portion of the webbing, which portion is further toward the proximal end side than the tongue, moving further toward the distal end side than the tongue is suppressed.

However, when tension is applied to the webbing in the state in which the webbing is clamped, localized load is applied to the clamped portion at the webbing. Therefore, the webbing must be endowed in advance with strength that is able to withstand such load.

SUMMARY OF THE INVENTION

In consideration of the above-described circumstances, the present invention is to provide a tongue for a seat belt device and a seat belt device that can prevent or suppress movement of a webbing from a shoulder side to a lap side, and further, at which localized load is not applied to the webbing in this state in which movement is prevented or suppressed.

A tongue for a seat belt device relating to a first aspect of the present invention has: a tongue main body that is provided at an intermediate portion of a webbing in a longitudinal direction of the webbing, and at which the webbing is folded over in a state in which the tongue main body is inserted in a buckle; a train-around portion that is provided at the tongue main body, and at which the webbing is bent due to the webbing being trained therearound; and a bending angle increasing section that includes a movable portion provided so as to be apart from the train-around portion by more than a thickness dimension of the webbing, and that, in a case in which tension of the webbing is a predetermined magnitude or greater, moves the movable portion in a predetermined direction to cause the movable portion to push the webbing, and trains the webbing around the train-around portion and increases a bending angle of the webbing in a state in which the movable portion is apart from the train-around portion by more than the thickness dimension of the webbing.

In the tongue for a seat belt device relating to the first aspect of the present invention, for example, when a vehicle occupant who is seated in a seat, while pulling the tongue main body, places the webbing around his/her body and attaches the tongue main body to the buckle, there becomes a state in which the webbing is applied to the body of the vehicle occupant. In this state, the webbing is folded over at the tongue main body. The portion of the webbing, which portion is further toward the longitudinal direction proximal end side than this folded over portion, is the shoulder webbing and restrains the shoulder portion and the chest portion of the vehicle occupant. The portion of the webbing, which portion is further toward the longitudinal direction distal end side than the folded over portion, is the lap webbing and restrains the waist portion of the vehicle occupant.

On the other hand, for example, due to the vehicle rapidly decelerating, the body of the vehicle occupant attempts to inertially move toward the vehicle front side. When, due thereto, the tension of the webbing becomes greater than or equal to a predetermined magnitude, the movable portion of the bending angle increasing section is moved in a predetermined direction. The movable portion that has moved in this way pushes the webbing, and trains the webbing around the train-around portion that is provided at the tongue main body. Due to the webbing being trained-around the train-around portion in this way, the portion of the webbing, which portion is further toward the distal end side than the train-around portion, bends with respect to the proximal end side of the webbing. Due to the bending angle of the webbing increasing in this way, the frictional resistance between the train-around portion and the webbing increases. The webbing moving further toward the distal end side than the folded over portion of the webbing at the tongue main body, i.e., the length of the lap webbing increasing, can be prevented or suppressed.

Further, in the tongue for a seat belt device relating to the present invention, from the state before movement of the movable portion to after the end of the movement, the interval between the movable portion and the train-around portion is longer than the thickness dimension of the webbing. Therefore, the webbing is not clamped by the movable portion and the train-around portion. As a result, when movement of the webbing is prevented or suppressed, localized load being applied to the webbing can be prevented even more effectively.

Note that, in the present invention, it suffices for the train-around portion to be a structure around which the webbing is trained at least due to the webbing being pushed by the movable portion. Accordingly, the webbing does not have to be trained-around the train-around portion in the state before the movable portion moves. Further, even in a structure in which the webbing is trained-around the train-around portion and is bent in the state before the movable portion moves, it suffices for the train-around portion to be a structure in which, due to the movable portion moving, the webbing is further trained-around the train-around portion and the bending angle of the webbing increases.

Further, in the present invention, there may be a single or plural train-around portions. Moreover, this train-around portion may include the fold-over portion that is the portion at which the webbing is folded over at the tongue main body, and/or may include the movable portion of the bending angle increasing section.

In a tongue for a seat belt device relating to a second aspect of the present invention, the present invention relating to the first aspect has a restricting portion, the tongue further has a restricting portion that restricts movement of the movable portion in the predetermined direction by the restricting portion engaging with the movable portion that has moved in the predetermined direction with respect to the tongue main body, at a position at which a gap between the train-around portion and the movable portion is greater than or equal to the thickness dimension of the webbing.

In accordance with the tongue for a seat belt device relating to the second aspect of the present invention, when the tension of the webbing becomes greater than or equal to a predetermined magnitude, and, due thereto, the movable portion of the bending angle increasing section moves in a predetermined direction, the movable portion pushes the webbing. Further, when the movable portion moves in this way, the restricting portion engages with the movable portion. In the state in which the restricting portion is engaged with the movable portion, the interval between the movable portion and the train-around portion is in a state of being greater than or equal to the thickness of the webbing, and moreover, further movement of the movable portion in the predetermined direction is restricted. Accordingly, due to the restricting portion engaging with the movable portion, the interval between the movable portion and the train-around portion after the movable portion moves can be maintained in a state of being greater than or equal to the thickness of the webbing.

In the first aspect or the second aspect, it is possible that one of the train-around portion or the movable portion is a folded over portion at which the webbing is folded over, and the bending angle increasing section, in the case in which the tension of the webbing is the predetermined magnitude or greater, moves the movable portion in the predetermined direction such that a portion of the webbing at a side further toward a proximal end side than the folded over portion and a portion of the webbing at a side further toward a distal end side than the folded over portion approach or contact with each other in the vicinity of the folded over portion.

Further, it is possible that the movable portion is a folded over portion at which the webbing is folded over, and the movable portion is a slider member that can slide at the tongue main body.

Further, it is possible that the train-around portion is a folded over portion at which the webbing is folded over, and the movable portion is a rotating member that can rotate with respect to the tongue main body.

A seat belt device relating to a third aspect of the present invention has: a buckle that is provided at a side of a seat; a webbing that is shaped as an elongated strip; and a tongue that includes: a tongue main body that is provided at an intermediate portion of the webbing in a longitudinal direction of the webbing, and at which the webbing is folded over, the tongue main body being insertable into the buckle; a train-around portion that is provided at the tongue main body, and at which the webbing is bent due to the webbing being trained therearound; and a bending angle increasing section that includes a movable portion provided so as to be apart from the train-around portion by more than a thickness dimension of the webbing, and that, in a case in which tension of the webbing is a predetermined magnitude or greater, moves the movable portion in a predetermined direction to cause the movable portion to push the webbing, and trains the webbing around the train-around portion and increases a bending angle of the webbing in a state in which the movable portion is apart from the train-around portion by more than the thickness dimension of the webbing.

In the seat belt device relating to the third aspect of the present invention, for example, when a vehicle occupant who is seated in a seat, while pulling the tongue main body, places the webbing around his/her body and attaches the tongue main body to the buckle, there becomes a state in which the webbing is applied to the body of the vehicle occupant. In this state, the webbing is folded over at the tongue main body. The portion of the webbing, which portion is further toward the longitudinal direction proximal end side than this folded over portion, is the shoulder webbing and restrains the shoulder portion and the chest portion of the vehicle occupant. The portion of the webbing, which portion is further toward the longitudinal direction distal end side than the folded over portion, is the lap webbing and restrains the waist portion of the vehicle occupant.

On the other hand, for example, due to the vehicle rapidly decelerating, the body of the vehicle occupant attempts to inertially move toward the vehicle front side. When, due thereto, the tension of the webbing becomes greater than or equal to a predetermined magnitude, the bending angle increasing section moves the movable portion in a predetermined direction. The movable portion that has moved in this way pushes the webbing, and trains the webbing around the train-around portion that is provided at the tongue main body. Due to the webbing being trained-around the train-around portion in this way, the portion of the webbing, which portion is further toward the distal end side than the train-around portion, bends with respect to the proximal end side. Due to the bending angle of the webbing increasing in this way, the frictional resistance between the train-around portion and the webbing increases. The webbing moving further toward the distal end side than the folded over portion of the webbing at the tongue main body, i.e., the length of the lap webbing increasing, can be prevented or suppressed.

Further, in the seat belt device relating to the present invention, from the state before movement of the movable portion to after the end of the movement, the interval between the movable portion and the train-around portion is longer than the thickness dimension of the webbing. Therefore, the webbing is not clamped between the movable portion and the train-around portion. As a result, when movement of the webbing is prevented or suppressed, localized load being applied to the webbing can be prevented even more effectively.

Note that, in the present invention, it suffices for the train-around portion to be a structure around which the webbing is trained at least due to the webbing being pushed by the movable portion. Accordingly, the webbing does not have to be trained-around the train-around portion in the state before the movable portion moves. Further, even in a structure in which the webbing is trained-around the train-around portion and is bent in the state before the movable portion moves, it suffices for the train-around portion to be a structure in which, due to the movable portion moving, the webbing is further trained-around the train-around portion and the bending angle of the webbing increases.

Further, in the present invention, there may be a single or plural train-around portions. Moreover, this train-around portion may include the fold-over portion that is the portion at which the webbing is folded over at the tongue main body, and/or may include the movable portion of the bending angle increasing section.

As described above, in the tongue for a seat belt device and the seat belt device relating to the present invention, movement of the webbing from the shoulder side toward the lap side can be prevented or suppressed, and further, localized load is not applied to the webbing in a state in which such movement is prevented or suppressed.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention are described next on the basis of the respective drawings ofFIG. 1AthroughFIG. 12B. Note that, when explaining the following respective embodiments, regions, that are basically the same as those of embodiments and modified examples that were described before the embodiment or modified example that is being explained, are denoted by the same reference numerals, and detailed description thereof is omitted.

Further, among the following respective embodiments, the first embodiment is a basic embodiment for describing the principles, operation and effects of the present invention in an easily understood manner, and this basic embodiment is described with details of the structure omitted. Description that further concretizes this basic embodiment is given in the respective embodiments from the second embodiment on, and description is given hereinafter with the structures of the respective embodiments from the second embodiment on, and the structures of the first embodiment that is the basic embodiment, being set in correspondence with one another.

Structure of First Embodiment

Basic Embodiment

The structure of a tongue10for a seat belt device (hereinafter called tongue10) relating to a first embodiment (basic embodiment) is shown inFIGS. 1A and 1Bin a schematic front view (note that hatching of the cross-section is omitted fromFIGS. 1A and 1Bin order to make the structure and operation easy to understand). The structure of the tongue10is shown inFIG. 2in a schematic side view. Further, the overall structure of a seat belt device11that includes the tongue10is shown inFIG. 3in a schematic front view.

As shown in these drawings, the tongue10has a tongue main body12. An insertion portion14that is flat-plate-shaped is formed at the tongue main body12. As shown inFIG. 2, an engagement hole16is formed in the insertion portion14. When the insertion portion14is inserted into a buckle18that is shown inFIG. 3, a latch provided within the buckle18engages with the engagement hole16so as to be inserted therein. Due thereto, there becomes a state in which the tongue10is attached to the buckle18.

Further, a pair of supporting walls20, that oppose one another in the width direction of the insertion portion14, are provided at the tongue main body12. A first shaft22, that is a fold-over portion and serves as a train-around portion, is provided between these supporting walls20. In the present embodiment that is a basic embodiment, the first shaft22is formed in a solid-cylindrical shape having a round cross-section, and the both ends thereof are fixed to the supporting walls20. In the applied state of a webbing26to the body of a vehicle occupant24that is shown inFIG. 3, the webbing26is folded over at the first shaft22as shown inFIGS. 1A and 1B.

As shown inFIG. 3, a base (proximal) end side in the longitudinal direction of the webbing26is anchored on a spool of a webbing retractor30that is provided at the side of a seat28opposite the side at which the buckle18is provided. The webbing26, that is pulled-out toward the upper side of the vehicle from the spool of this webbing retractor30, is folded over downwardly at a shoulder anchor32that is provided, for example, in a vicinity of an upper end portion of a center pillar of the vehicle. At the webbing26, the portion between the shoulder anchor32and the first shaft22of the tongue10is a shoulder webbing34, and restrains the shoulder portion and the chest portion of the vehicle occupant24.

In contrast, the portion of the webbing26, which portion is further toward the tip (distal) end than the first shaft22, is anchored to an anchor plate36that is fixed to the vehicle body at the side of the seat28opposite the side at which the buckle18is provided, or to a skeleton portion of the seat28. At the webbing26, the portion between the anchor plate36and the first shaft22of the tongue10is a lap webbing38, and mainly restrains the waist portion of the vehicle occupant24from the front.

On the other hand, as shown inFIGS. 1A and 1B, a second shaft40that is a movable portion of a bending angle increasing section and that serves as a train-around portion, is provided between the both supporting walls20at the side of the first shaft22opposite the side at which the insertion portion14is provided. In this basic embodiment, the second shaft40is formed in a solid-cylindrical shape having a round cross-section. The second shaft40is provided at the side of the shoulder webbing34opposite the side at which the lap webbing38is provided, and further, the second shaft40is apart from the shoulder webbing34in an initial state.

This second shaft40can move in, for example, the thickness direction of the insertion portion14. When the tension of the webbing26becomes greater than or equal to a predetermined magnitude, the second shaft40approaches the shoulder webbing34and pushes the shoulder webbing34toward the lap webbing38side. Further, as shown inFIGS. 1A and 1B, the second shaft40is provided such that the outer peripheral surface thereof is apart from the outer peripheral surface of the first shaft22by greater than or equal to the thickness of the webbing26, and, even in the state in which the second shaft40is pushing the shoulder webbing34, the position of the second shaft40is set such that the outer peripheral surface of the second shaft40is apart from the outer peripheral surface of the first shaft22by greater than or equal to the thickness of the webbing26.

Note that, as described above, the present embodiment is a basic embodiment for easy understanding of the operation and effects thereof. Description of the structure for holding the second shaft40in the initial state, and of the concrete structure for operating the second shaft40, are omitted here. The structure that concretizes the bending angle increasing section, that corresponds to the second shaft40, is described from the second embodiment on.

Operation and Effects of First Embodiment

Basic Embodiment

Operation and effects of the present embodiment are described next.

At the present tongue10, due to the tip end side of the insertion portion14being inserted into the buckle18and the latch of the buckle18engaging with the engagement hole16, there becomes a state in which the tongue10is attached to the buckle18. If, in this state, the webbing26is placed around the body of the vehicle occupant24, there is a state in which the webbing26is applied to the body of the vehicle occupant24, and the body of the vehicle occupant24is restrained by the webbing26.

In this state, when the vehicle rapidly decelerates, the body of the vehicle occupant24attempts to move inertially toward the vehicle front side. In this case, the waist portion of the vehicle occupant24pushes the lap webbing38toward the vehicle front side, and the chest portion and the shoulder portion push the shoulder webbing34toward the vehicle front side. When the tension of the webbing26(the tension of the lap webbing38in particular) becomes greater than or equal to a predetermined magnitude due to the body of the vehicle occupant24pushing the webbing26in this way, the second shaft40operates to approach the shoulder webbing34along the thickness direction of the insertion portion14as shown inFIG. 1B.

When the second shaft40that approaches the shoulder webbing34press-contacts the shoulder webbing34, the second shaft40pushes the shoulder webbing34toward the lap webbing38side. Due thereto, as shown inFIG. 1B, the shoulder webbing34is trained around the second shaft40, and is trained around the first shaft22more so than in the state before the second shaft40operates (i.e., the state shown inFIG. 1A). Due thereto, the path of passage of the shoulder webbing34is changed.

Due to the shoulder webbing34being trained around the second shaft40in this way, the portion of the shoulder webbing34, which portion is further toward the distal end side than the second shaft40, bends around the central axis of the second shaft40at an angle of θ2(hereinafter called bending angle θ2) with respect to the proximal end side relative to the second shaft40. Further, due the webbing26being folded over at the first shaft22, the portion further toward the distal end side than the first shaft22bends at an angle of θ (hereinafter called bending angle θ) with respect to the proximal end side relative to the first shaft22. However, due to the shoulder webbing34being pushed by the second shaft40and the webbing26being further trained-around the first shaft22, the portion further toward the distal end side than the first shaft22bends at an angle of θ1(hereinafter called bending angle θ1), that is larger than the bending angle θ, with respect to the proximal end side relative to the first shaft22.

In other words, a portion of the webbing which is further toward the proximal end side than the folded over portion (the first shaft22) (a portion of the shoulder webbing34) and a portion of the webbing which is further toward the distal end side than the folded over portion (a portion of the lap webbing38) approach each other in the vicinity of the folded over portion (FIG. 1B).

Due to the bending angle of the portion of the webbing26, which portion is further toward the distal end side than the proximal end side of the first shaft22, being increased from θ to θ1, the frictional resistance between the first shaft22and the webbing26increases. Moreover, due to the bending θ2increasing due to the shoulder webbing34being trained-around the second shaft40as described above, the frictional resistance between the second shaft40and the webbing26further increases. Due thereto, the portion of the webbing26, which portion is further toward the distal end side of the webbing26than the first shaft22, moving, i.e., the shoulder webbing34moving further toward the distal end side of the webbing26than the first shaft22, so the length of the lap webbing38increasing, can be prevented or suppressed. By being able to prevent or suppress movement of the webbing26further toward the distal end side of the webbing26than the first shaft22, the lap webbing38effectively restrains the waist portion of the vehicle occupant24, and inertial movement of the vehicle occupant24toward the vehicle front side can be suppressed effectively.

Moreover, even in the state in which the second shaft40pushes the shoulder webbing34, the outer peripheral surface of the second shaft40is apart from the outer peripheral surface of the first shaft22by greater than or equal to the thickness of the webbing26. Therefore, the second shaft40merely press-contacts the shoulder webbing34(the webbing26), and the webbing26is not clamped by the second shaft40and the first shaft22. Thus, in the embodiment, a large load is not applied locally to the webbing26, which is different in a structure in which the webbing26is clamped so the shoulder webbing34side moving toward the distal end side of the webbing26is suppressed.

Note that, in this basic embodiment, the first shaft22and the second shaft40are shaped as solid cylinders having round cross-sections, for ease of comprehension of the concept of the bending angle. However, the shapes of the sliding-contact portion and the bending angle increasing section are not limited to shapes that are round in cross-section such as those of the first shaft22and the second shaft40, and these shapes may be non-round shapes such as polygonal or oval or the like.

Further, in this basic embodiment, the first shaft22that is the fold-over portion and the second shaft40that is the bending angle increasing section are structured as separate bodies. However, the present invention is not limited to such a structure.

For example, in a modified example shown inFIG. 4A, instead of the first shaft22and the second shaft40, there are provided a first shaft46that serves as a train-around portion, and a second shaft48that is a fold-over portion, and is a movable portion of a bending angle increasing section, and further, serves as a train-around portion. The axial direction both ends of the first shaft46are fixed to the supporting walls20, and the shoulder webbing34(the webbing26) is trained around the first shaft46in the state in which the webbing26is applied to the body of the vehicle occupant24. In the state in which the webbing26is applied to the body of the vehicle occupant24, the portion of the shoulder webbing34, which portion is further toward the distal end side than the first shaft46, bends at an angle of θ3(hereinafter called bending angle θ3) with respect to the proximal end side relative to the first shaft46.

On the other hand, in the state in which the webbing26is applied to the body of the vehicle occupant24, the webbing26is trained-around and folded over at the second shaft48that is provided further toward the insertion portion14side than the first shaft46, and the portion of the webbing26further toward the proximal end side than the second shaft48is the shoulder webbing34, and the distal end side is the lap webbing38. This second shaft48is structured such that, when the tension of the webbing26becomes greater than or equal to a given magnitude, as shown inFIG. 4B, the second shaft48moves away from the insertion portion14and approaches the first shaft46. In the state in which the webbing26is applied to the body of the vehicle occupant24, the portion of the webbing26, which portion is further toward the distal end side than the second shaft48, bends at an angle of θ4(hereinafter called bending angle θ4) with respect to the proximal end side relative to the second shaft48.

When the tension of the webbing26becomes greater than or equal to a given magnitude and the second shaft48moves toward the first shaft46side, as shown inFIG. 4B, the portion of the webbing26, which portion is further toward the distal end side than the second shaft48, bends, with respect to the proximal end side relative to the second shaft48, at an angle of θ5(hereinafter called bending angle θ5) that is greater than the bending angle θ4. Further, due to the second shaft48moving toward the first shaft46side, the shoulder webbing34(the webbing26) is trained further around the first shaft46.

Due thereto, the portion of the shoulder webbing34, which portion is further toward the distal end side than the first shaft46, bends, with respect to the proximal end side relative to the first shaft46, at an angle of θ6(hereinafter called bending angle θ6) that is greater than the bending angle θ3. In this way, the total sum (bending angle θ5+bending angle θ6) of the bending angles of the webbing26after the tension of the webbing26increases and the second shaft48operates increases to more than the total sum (bending angle θ3+bending angle θ4) of the bending angles of the webbing26before the second shaft48operates. In this way, this modified example as well exhibits operation that is similar to and achieves effects that are similar to those of the above-described first embodiment that is the basic embodiment.

Structure of Second Embodiment

A second embodiment is described next.

The overall structure of a tongue120for a seat belt device (hereinafter called tongue120), that is the structure of the main portion of a seat belt device121relating to the present embodiment, is shown inFIGS. 5A and 5Bin side views that correspond toFIG. 2. The structure of the tongue120is shown in sectional views inFIGS. 6A and 6B.

As shown in these drawings, the tongue120has a tongue main body122that is formed by the punching-out and bending-molding of a metal flat plate. The tongue main body122has the insertion portion14. A base portion124is formed in continuation from the proximal end portion of the insertion portion14. The base portion124is shaped as a rectangular (trapezoidal) flat plate whose width dimension is sufficient longer than width dimension of the insertion portion14. A through-hole126is formed in the base portion124.

The opening dimension of the through-hole126, along the width direction of the base portion124and at the portion of the through-hole126that is at the side opposite the insertion portion14, is set to be larger than the width dimension of the webbing26, and the webbing26can pass through the through-hole126. The portion of the base portion124, which portion is at the side of the through-hole126opposite the side at which the insertion portion14is provided, is a train-around portion125, and the webbing26is trained around the train-around portion125as described later. Moreover, vertical wall portions128are provided so as to stand from the width direction both end portions of the base portion124toward one side in the thickness direction of the base portion124. Top wall portions130extend from the distal (tip) ends of these vertical wall portions128(the end portions of the vertical wall portions128at the side opposite the base portion124) toward the width direction inner side of the base portion124.

On the other hand, the present tongue120has a slider132that is a fold-over portion, and is a train-around portion, and also serves as a movable portion that structures a bending angle increasing section. The slider132has a slider main body134. The slider main body134is formed in the shape of a plate that has a thin width and whose longitudinal direction is along the longitudinal direction of the base portion124. The longitudinal dimension of the slider main body134is set to be shorter than the interval between the one top wall portion130and the other top wall portion130, and is set to be longer than the opening width dimension of the through-hole126.

Leg plates136extend from the longitudinal direction both end portions of the slider main body134toward the base portion124side along the thickness direction of the slider main body134. Pushing pieces138extend from the end portions of the leg plates136at the side opposite the slider main body134, toward the outer sides in the longitudinal direction of the slider main body134. The thickness dimension of the pushing pieces138is slightly smaller than the interval between the top wall portions130and the base portion124, and the pushing plates138enter-in between the top wall portions130and the base portion124.

Due thereto, the slider132is guided by the vertical wall portions128and the top wall portions130and can slide toward the distal end side or the proximal end side of the present tongue120. Further, the shape and the like of the leg plates136are set such that, in the state in which the pushing pieces138have entered in between the top wall portions130and the base portion124, the interval between the surface of the base portion124, including the train-around portion125, at the slider132side, and the surface of the slider main body134at the base portion124side, is greater than the thickness of the webbing26.

Further, as shown inFIGS. 6A and 6B, at the present tongue120, the webbing26is folded over by being passed-through the through-hole126from the side of the base portion124opposite the slider132and being trained around the slider main body134, and the webbing26is again passed-through the through-hole126. Namely, in the present embodiment, the portion of the webbing26further toward the proximal end side than the slider main body134is the shoulder webbing34, and the portion of the webbing26further toward the distal end side than the slider main body134is the lap webbing38.

On the other hand, as shown inFIGS. 5A and 5B, shear pins140are formed at one surface in the thickness direction of the base portion124. The shear pins140are formed on the base portion124at the side of the slider132that is opposite the side at which the insertion portion14is provided, and face the pushing pieces138along the sliding direction of the slider132.

Operation and Effects of Second Embodiment

Operation and effects of the present embodiment are described next.

In the state in which the vehicle occupant24who is seated in the seat28places the webbing26around his/her body and attaches the insertion portion of the tongue120to the buckle18, the slider main body134of the slider132is pulled by the webbing26toward the proximal end side of the tongue120, but, as shown inFIG. 5AandFIG. 6A, the pushing pieces138are held at positions abutting the shear pins140.

In this state, the webbing26contacts one surface in the thickness direction of the slider main body134(the surface at the side opposite the base portion124), and the portion of the webbing26, which portion contacts the one surface in the thickness direction of the slider main body134, is bent at an angle of θ7(hereinafter called bending angle θ7) with respect to the portion of the webbing26that is further toward the proximal end side than this portion. Further, the portion of the webbing26, which portion is further toward the distal end side than the portion that contacts the one surface in the thickness direction of the slider main body134, contacts one width direction end of the slider main body134(the end portion at the insertion portion14side).

The portion of the webbing26, which portion contacts the one width direction end of the slider main body134, is bent at an angle of θ8(hereinafter called bending angle θ8) with respect to the portion that contacts the one surface in the thickness direction of the slider main body134. Further, the portion of the webbing26, which portion is further toward the distal end side than the portion that contacts the one width direction end of the slider main body134, is bent at an angle of θ9(hereinafter called bending angle θ9) with respect to the portion that contacts the one width direction end of the slider main body134.

When, in this state, the vehicle rapidly decelerates and the body of the vehicle occupant24pushes the lap webbing38of the webbing26toward the vehicle front side, the tension of the webbing26that increases due thereto pulls the slider main body134of the slider132. When the slider main body134is pulled in this way, the pushing pieces138push the shear pins140and break the shear pins140. Due thereto, the interference of the shear pins140with respect to the slider132is cancelled, and, as shown inFIG. 5BandFIG. 6B, the slider132slides toward the proximal end side of the tongue120(i.e., the side opposite the insertion portion14).

Due to the slider132sliding in this way, the other width direction end of the slider main body134(the end portion at the side opposite the insertion portion14) is positioned further toward the proximal end side of the tongue120(i.e., the side opposite the insertion portion14) than the end portion of the through-hole126at the side opposite the insertion portion14. Due thereto, as shown inFIG. 6B, the webbing26slidingly-contacts not only the slider main body134, but also the portion of the inner peripheral portion of the through hole126at the side opposite the insertion portion14. Further, the portion of the webbing26, which portion is further toward the proximal end side than the portion that slidingly-contacts the inner peripheral portion of the through-hole126, slidingly-contacts the surface of the train-around portion125at the side opposite the slider132.

In this state, the portion of the webbing26, which portion contacts the inner peripheral portion of the through-hole126, is bent at an angle of θ10(hereinafter called bending angle θ10) with respect to the portion that contacts the train-around portion125. Further, the portion of the webbing26, which portion is between the train-around portion125and the other width direction end of the slider main body134(the end portion at the side opposite the insertion portion14), is bent at an angle of θ11(hereinafter called bending angle θ11) with respect to the portion of the webbing26that contacts the inner peripheral portion of the through-hole126. Moreover, the portion of the webbing26, which portion contacts the other width direction end of the slider main body134, is bent at an angle of θ12(hereinafter called bending angle θ12) with respect to the portion of the webbing26which portion is between the train-around portion125and the other width direction end of the slider main body134.

Moreover, the portion of the webbing26, which portion contacts the one surface in the thickness direction of the slider main body134, is bent at an angle of θ13(hereinafter called bending angle θ13) with respect to the portion that contacts the other width direction end of the slider main body134. The portion of the webbing26, which portion contacts the one width direction end of the slider main body134(the end portion at the insertion portion14side), is bent at an angle of θ14(hereinafter called bending angle θ14) with respect to the portion that contacts the one surface in the thickness direction of the slider main body134. The portion of the webbing26, which portion is between the one width direction end of the slider main body134and the train-around portion125, is bent at an angle of θ15(hereinafter called bending angle θ15) with respect to the portion that contacts the one width direction end of the slider main body134. The portion of the webbing26, which portion is further toward the distal end side than the portion between the one width direction end of the slider main body134and the train-around portion125, is bent at an angle of θ16(hereinafter called bending angle θ16) with respect to that portion that is between the one width direction end of the slider main body134and the train-around portion125.

In other words, a portion of the webbing which is further toward the proximal end side than the folded over portion (the slider132) (a portion of the shoulder webbing34) and a portion of the webbing which is further toward the distal end side than the folded over portion (a portion of the lap webbing38) contact with each other in the vicinity of the folded over portion (FIG. 6B).

Due to the frictional resistance between the webbing26and the tongue120increasing in this way, movement of the webbing26along the longitudinal direction thereof is suppressed. Due thereto, the portion of the webbing26at the shoulder webbing34side passing-through the through-hole126and moving toward the lap webbing38side, i.e., the length of the lap webbing38increasing, can be prevented or suppressed, and the waist portion of the vehicle occupant24can be effectively restrained by the lap webbing38, and inertial movement of the vehicle occupant24toward the vehicle front side can be effectively suppressed.

Further, at the tongue120, the shape and the like of the leg plates136are set such that the interval between the surface of the base portion124, including the train-around portion125, at the slider132side, and the surface of the slider main body134at the base portion124side, is greater than the thickness of the webbing26. Therefore, the base portion124(including the train-around portion125) and the slider main body134do not clamp the webbing26. Thus, as described above, even in a state in which increasing of the length of the lap webbing38is prevented or suppressed, a large load is not applied locally to the webbing26.

Structure of Third Embodiment

A third embodiment is described next.

The overall structure of a tongue160for a seat belt device (hereinafter called tongue160), that is the structure of the main portion of a seat belt device161relating to the present embodiment, is shown in plan views inFIGS. 7A and 7B. The structure of the tongue160is shown in sectional views inFIGS. 8A and 8B.

As shown in these drawings, the tongue160has top wall portions162instead of the top wall portions130. Portions of the top wall portions162, which portions are at the proximal end side of the tongue main body122, are stoppers164, and extend further toward the width direction inner side of the tongue main body122than the portions of the top wall portions162, which portions are further toward the distal end side of the tongue main body122than the stoppers164.

On the other hand, the present tongue160has, instead of the slider132, a slider166that is a fold-over portion and is a train-around portion, and further, that serves as a movable portion that structures a bending angle increasing section. Differently than the slider132, the slider166is formed in the shape of a thin-width plate that does not have the leg plates136. The shear pins140stand from the base portion124at the portion further toward the proximal end side of the tongue160than the slider166(FIG. 7A). Due to the shear pins140interfering with the slider166, the slider166sliding toward the proximal end side of the tongue160is restricted.

Abutment projections168are formed from the longitudinal direction both end portions of the slider166so as to project toward the proximal end side of the tongue main body122. These abutment projections168face the stoppers164that serve as restricting portion and that are provided further toward the proximal end side of the tongue160than the shear pins140. Due to the abutment projections168, that are a portion of the slider166(i.e., a portion of the movable portion) abutting the stoppers164, further sliding of the slider166toward the proximal end side of the tongue main body122is restricted. The projecting dimensions of the abutment projections168, the shapes and positions of the stoppers164, and the like are set such that, in the state in which the abutment projections168abut the stoppers164, the interval, along the direction from the proximal end side toward the distal end side of the tongue main body122, between the end portion at the slider166, which end portion is at the proximal end side of the tongue main body122, and the end portion at the through-hole126, which end portion is at the proximal end side of the tongue main body122, is sufficiently larger than the thickness of the webbing26.

Operation and Effects of Third Embodiment

Operation and effects of the present embodiment are described next.

In the state in which the vehicle occupant24who is seated in the seat28places the webbing26around his/her body and attaches the insertion portion14of the tongue160to the buckle18, the slider166is pulled by the webbing26toward the proximal end side of the tongue160, but, as shown inFIG. 7AandFIG. 8A, the pushing pieces138are held at positions abutting the shear pins140.

In this state, the webbing26contacts one surface in the thickness direction of the slider166(the surface at the side opposite the base portion124), and the portion of the webbing26, which portion contacts the one surface in the thickness direction of the slider166, is bent at an angle of θ17(hereinafter called bending angle θ17) with respect to the portion of the webbing26that is further toward the proximal end side than this portion. Further, the portion of the webbing26, which portion is further toward the distal end side than the portion that contacts the one surface in the thickness direction of the slider166, contacts one width direction end of the slider166(the end portion at the insertion portion14side).

The portion of the webbing26, which portion contacts the one width direction end of the slider166, is bent at an angle of θ18(hereinafter called bending angle θ18) with respect to the portion that contacts the one surface in the thickness direction of the slider166. Further, the portion of the webbing26, which portion is further toward the distal end side than the portion that contacts the one width direction end of the slider166, is bent at an angle of θ19(hereinafter called bending angle θ19) with respect to the portion that contacts the one width direction end of the slider166.

When, in this state, the vehicle rapidly decelerates and the body of the vehicle occupant24pushes the lap webbing38of the webbing26toward the vehicle front side, the tension of the webbing26that increases due thereto pulls the slider166. When the slider166is pulled in this way, the slider166pushes the shear pins140and breaks the shear pins140. Due thereto, the interference of the shear pins140with respect to the slider166is cancelled, and, as shown inFIG. 7BandFIG. 8B, the slider166slides toward the proximal end side of the tongue160(i.e., the side opposite the insertion portion14) until the abutment projections168abut the stoppers164.

Due to the slider166sliding in this way, the other width direction end of the slider166(the end portion at the side opposite the insertion portion14) is positioned further toward the proximal end side of the tongue160(i.e., the side opposite the insertion portion14) than the end portion of the through-hole126at the side opposite the insertion portion14. Due thereto, as shown inFIG. 8B, the webbing26slidingly-contacts not only the slider166, but also the portion at the inner peripheral portion of the through hole126at the side opposite the insertion portion14. Further, the portion of the webbing26, which portion is further toward the proximal end side than the portion that slidingly-contacts the inner peripheral portion of the through-hole126, slidingly-contacts the surface of the train-around portion125at the side opposite the slider166.

In this state, the portion of the webbing26, which portion is between the train-around portion125and the other width direction end of the slider166(the end portion at the side opposite the insertion portion14), is bent at an angle of θ20(hereinafter called bending angle θ20) with respect to the portion of the webbing26that contacts the surface of the train-around portion125at the side opposite the slider166. Further, the portion of the webbing26, which portion contacts one surface in the thickness direction of the slider166(the surface at the side opposite the base portion124), is bent at an angle of θ21(hereinafter called bending angle θ21) with respect to the portion of the webbing26between the train-around portion125and the other width direction end of the slider166.

Moreover, the longitudinal direction of the portion of the webbing26, which portion contacts one width direction end of the slider166(the end portion at the insertion portion14side), is bent at an angle of θ22(hereinafter called bending angle θ22) with respect to the portion that contacts the one surface in the thickness direction of the slider166. The portion of the webbing26, which portion is between the one width direction end of the slider166and the train-around portion125, is bent at an of θ23(hereinafter called bending angle θ23) with respect to the portion of the webbing26that contacts the one width direction end of the slider166. The portion of the webbing26, which portion is further toward the distal end side than the portion between the one width direction end of the slider166and the train-around portion125, is bent at an angle of θ24(hereinafter called bending angle θ24) with respect to the portion between the one width direction end of the slider166and the train-around portion125.

The total sum (bending angle θ20+bending angle θ21+bending angle θ22+bending angle θ23+bending angle θ24) of the bending angles from the bending angle θ20to the bending angle θ24is greater than the total sum (bending angle θ17+bending angle θ18+bending angle θ19) of the bending angles from the bending angle θ17to the bending angle θ19before the slider166slides. Due thereto, the frictional resistance between the webbing26and the tongue160increases.

Due to the frictional resistance between the webbing26and the tongue160increasing in this way, movement of the webbing26along the longitudinal direction thereof is suppressed. Due thereto, the portion of the webbing26at the shoulder webbing34side passing-through the through-hole126and moving toward the lap webbing38side, i.e., the length of the lap webbing38increasing, can be prevented or suppressed, and the waist portion of the vehicle occupant24can be effectively restrained by the lap webbing38, and inertial movement of the vehicle occupant24toward the vehicle front side can be effectively suppressed.

Further, at the present tongue160, even though the abutment projections168abut the stoppers164, the interval between the end portion of the slider166at the proximal end side of the tongue main body122, and the end portion of the through-hole126at the proximal end side of the tongue main body122, is sufficiently larger than the thickness of the webbing26, and further, this state is maintained. Therefore, the base portion124(including the train-around portion125) and the slider166do not clamp the webbing26. Thus, as described above, even in a state in which increasing of the length of the lap webbing38is prevented or suppressed, a large load is not applied locally to the webbing26.

Structure of Fourth Embodiment

A fourth embodiment is described next.

The overall structure (appearance) of a tongue190for a seat belt device (hereinafter called tongue190), that is the structure of the main portion of a seat belt device191relating to the present embodiment, is shown in a perspective view inFIG. 9. The structure of the tongue190is shown in sectional views inFIGS. 10A and 10B.

As shown in these drawings, the tongue190has a tongue main body192that is formed by punching-out a metal flat plate. The tongue main body192has the insertion portion14. A base portion194is formed continuously from the proximal end portion of the insertion portion14. The base portion194is shaped as a rectangular (trapezoidal) flat plate whose width dimension is sufficiently longer than the width dimension of the insertion portion14. A through-hole196through which the webbing26passes is formed in the base portion194. The portion of the base portion194, which portion is at the side of the through-hole196opposite the side at which the insertion portion14is provided, is a fold-over/train-around portion197that serves as what are called the train-around portion (the fold-over portion) in the aspects of the invention. Further, shafts198are formed from the width direction both end portions of the base portion194so as to project-out, coaxially to one another, toward the width direction outer sides of the base portion194.

On the other hand, the present tongue190has a rotating member202that serves as a movable portion that structures a bending angle increasing section. The rotating member202has a pair of arms204that face one another in the width direction of the tongue main body192. Through-holes, into which the shafts198are inserted, are formed in longitudinal direction one ends of these arms204. The arms204are supported, so as to be rotatable around the shafts198, due to the shafts198being inserted in the through-holes. In contrast, the longitudinal direction other end portions of the arms204are connected integrally by a connecting portion206, and the rotating member202forms a concave shape that opens toward the distal end side of the tongue main body192in plan view.

A shaft208that serves as a train-around portion is provided at the longitudinal direction intermediate portions of the arms204at a position that is apart, by greater than or equal to the thickness of the webbing26, from the connecting portion206. The shaft208is formed in, for example, the shape of a round bar having a circular cross-section. One longitudinal direction end portion of the shaft208is supported at one of the arms204, and the other longitudinal direction end portion is supported at the other arm204. Note that, in the present embodiment, the shaft208is formed in the shape of a round bar having a circular cross-section, but the shape of the shaft208is not limited to a round bar shape, and may be a bar shape having an oval cross-section, or may be an angular bar shape having a polygonal cross-section.

Further, as shown inFIG. 10AandFIG. 10B, at the present tongue190, the portion of the webbing26, which portion is further toward the distal end side than the shoulder webbing34, passes-through the through-hole196from the other side in the thickness direction of the base portion194, and passes-through between the connecting portion206and the shaft208from the one side in the thickness direction of the tongue main body192. The portion of the webbing26, which portion is further toward the distal end side than the portion that passes-through between the connecting portion206and the shaft208, is the lap webbing38, and the portion of the webbing26, which portion is further toward the proximal end side than the pass-through hole196, is the shoulder webbing34.

On the other hand, shear pins210are formed to project-out at the width direction side end portions of the tongue main body192, further toward the distal end side of the tongue main body122than the shaft198. Pushing portion212are formed at the distal end portions of the arms204in correspondence with these shear pins210. The pushing portions212face the shear pins210around the shafts198. When the rotational force of the rotating member202, that is based on the tension of the webbing26, becomes greater than or equal to a given magnitude, the pushing portions212push and break the shear pins210.

Operation and Effects of Fourth Embodiment

Operation and effects of the present embodiment are described next.

In the state in which the vehicle occupant24who is seated in the seat28places the webbing26around his/her body and attaches the insertion portion14of the tongue190to the buckle18, due to the tension of the lap webbing38at the webbing26, the lap webbing38pushes the shaft208and rotates the rotating member202until the shear pins210interfere with the pushing portions212. In this state, as shown inFIG. 10A, the webbing26slidingly-contacts only a portion of the inner peripheral portion of the through-hole196, portions of the outer peripheries of the shaft208and the base portion194.

In this state, the portion of the webbing26, which portion is further toward the distal end side than shaft208, is bent at an angle of θ25(hereinafter called bending angle θ25) with respect to the longitudinal direction proximal end side. Further, the portion of the webbing26, which portion contacts the inner peripheral portion of the through-hole196, is bent at an angle of θ26(hereinafter called bending angle θ26) with respect to the portion between the shaft208and the inner peripheral portion of the through-hole196. Moreover, the portion of the webbing26, which portion is further toward the distal end side than the portion that contacts the inner peripheral portion of the through-hole196, is inclined at an angle of θ27(hereinafter called bending angle θ27) with respect to the portion that contacts the inner peripheral portion of the through-hole196.

When, in this state, the vehicle rapidly decelerates and the body of the vehicle occupant24pushes the lap webbing38of the webbing26toward the vehicle front, the tension of the webbing26that increases due thereto pushes the shaft208, and, due to the rotational force around the shafts198that arises due thereto, the arms204break the shear pins210. When the restriction on the rotation of the rotating member202is cancelled due to the shear pins210being broken, the rotating member202rotates until the longitudinal direction of the arms204are along the direction from the proximal end side to the distal end side of the tongue main body192. Due thereto, as shown inFIG. 10B, the webbing26slidingly-contacts the other surface in the thickness direction of the base portion194.

In this state, the webbing26slidingly-contacts the connecting portion206of the rotating member202, and the portion of the webbing26, which portion is further toward the distal end side than the connecting portion206, is bent at an angle of θ28(hereinafter called bending angle θ28) with respect to the longitudinal direction proximal end side. Further, the portion of the webbing26further toward the distal end side than the shaft208is bent at an angle of θ29(hereinafter called bending angle θ29) with respect to the portion of the webbing26between the connecting portion206and the shaft208.

Moreover, the portion of the webbing26, which portion slidingly-contacts the inner peripheral portion of the through-hole196, is bent at an angle of θ30(hereinafter called bending angle θ30) with respect to the portion of the webbing26that is between the shaft208and the inner peripheral portion of the through-hole196. The portion of the webbing26up until the lap webbing38overlaps the shoulder webbing34is bent at an angle of θ31(hereinafter called bending angle θ31) with respect to the portion of the webbing26that slidingly-contacts the inner peripheral portion of the through-hole196. Further, the portion, that is further toward the distal end side than the portion up until the lap webbing38overlaps the shoulder webbing34, is bent at an angle of θ32(hereinafter called bending angle θ32) with respect to the portion up until the lap webbing38overlaps the shoulder webbing34.

Due to the frictional resistance between the webbing26and the tongue190increasing in this way, movement of the webbing26along the longitudinal direction thereof is suppressed. Due thereto, the portion of the webbing26at the shoulder webbing34side passing-through the through-hole196and moving toward the lap webbing38side can be suppressed, and the waist portion of the vehicle occupant24can be effectively restrained by the lap webbing38, and inertial movement of the vehicle occupant24toward the vehicle front side can be effectively suppressed.

Moreover, the interval between the connecting portion206and the shaft208is larger than the thickness dimension of the webbing26, and, even if the rotating member202rotates, the interval between the connecting portion206and the shaft208does not change. Therefore, the webbing26is not clamped by the connecting portion206and the shaft208, and accordingly, a large load is not applied locally to the webbing26.

Structure of Fifth Embodiment

A fifth embodiment is described next.

The overall structure of a tongue240for a seat belt device (hereinafter called tongue240), that is the structure of the main portion of a seat belt device241relating to the present embodiment, is shown in a perspective view inFIG. 11. The structure of the tongue240is shown in sectional views inFIGS. 12A and 12B.

As shown in these drawings, the tongue240has a tongue main body242that is formed by punching-out and bending-molding a metal flat plate. The insertion portion14that is rectangular in plan view is formed at the tongue main body242. One of a pair of leg plates244is formed continuously from one width direction end side of the insertion portion14at one longitudinal direction end of the insertion portion14. Another of the pair of leg plates244is formed continuously from the other width direction end side of the insertion portion14at the one longitudinal direction end of the insertion portion14. The interval between the one leg plate244and the other leg plate244is made to be greater than or equal to the width dimension of the webbing26, and the webbing26can pass between the both leg plates244. Further, at the longitudinal direction intermediate portions thereof, these leg plates244are bent in the shapes of cranks around an axis whose axial direction is the width direction. Engaging pieces246extend toward the width direction outer sides of the insertion portion14from longitudinal direction one ends of the leg plates244.

On the other hand, the tongue240has a plate248that serves as a bending angle increasing section. The plate248has a base portion250that serves as a sliding-contact portion and is formed in the shape of a flat plate. The base portion250is formed in the shape of a flat plate that is a substantial rectangle whose longitudinal direction runs along the width direction of the insertion portion14. A through-hole252is formed in the base portion250. The through-hole252passes-through in the thickness direction of the base portion250. The opening shape of the through-hole252is a rectangle whose longitudinal direction runs along the longitudinal direction of the base portion250. The longitudinal direction dimension of the through-hole252is set to be larger than the width dimension of the webbing26. In the state in which the tongue main body242and the base portion250are assembled, the side of the base portion250, which side is further toward the insertion portion14side than the through-hole252, is a first train-around portion254that serves as a fold-over portion and a train-around portion, and the side of the base portion250, that is at the side of the through-hole252opposite the side at which the insertion portion14is provided, is a second train-around portion256that serves as a movable portion and a train-around portion.

As shown inFIGS. 12A and 12B, in the present exemplary embodiment, the webbing26is trained around the side of the first train-around portion254, which side is opposite the second train-around portion256, so as to circle-in from one side in the thickness direction of the base portion250, and the webbing26passes-through the through-hole252between the first train-around portion254and the second train-around portion256, and extends toward the one side in the thickness direction of the base portion250. Namely, in the present embodiment, the portion of the webbing26, which portion is further toward the proximal end side than the portion trained-around the first train-around portion254, is the shoulder webbing34, and the distal end side is the lap webbing38.

On the other hand, as shown inFIG. 11, vertical wall portions258stand from longitudinal direction both end portions of the base portion250toward the one side in the thickness direction of the base portion250. Guide holes260are formed in these vertical wall portions258so as to pass-through in the thickness directions of the vertical wall portions258. The opening shapes of the guide holes260are triangular or fan-shaped, and the engaging pieces246pass-through the guide holes260from the longitudinal direction inner side of the base portion250.

The shapes of the guide holes260are set such that, in the state in which the engaging pieces246are passed-through the guide holes260, the plate248can rotate, with respect to the tongue main body242, around an axis whose axial direction is the longitudinal direction of the base portion250. However, shear projections262are formed at the inner peripheral portions of the guide holes260, and, due to the shear projections262interfering with the engaging pieces246, rotation of the plate248with respect to the tongue main body242is restricted, and the engaging pieces246are held at positions of being set apart from the base portion250.

When the engaging pieces246of the tongue main body242break the shear projections262due to the tension of the webbing26, the plate248rotates until restricting portions264, that serve as restricting portions and are portions of the inner peripheral portions of the guide holes260, abut the engaging pieces246.

Operation and Effects of Fifth Embodiment

Operation and effects of the present embodiment are described next.

In the state in which the vehicle occupant24who is seated in the seat28places the webbing26around his/her body and attaches the insertion portion of the tongue240to the buckle18, the engaging pieces246of the tongue main body242interfere with the shear projections262as shown inFIG. 12A, and the engaging pieces246are held at positions of being set apart from the base portion250.

In this state, the webbing26is trained-around the first train-around portion254, and the portion of the webbing26, which portion is further toward the distal end side than the portion trained-around the first train-around portion254, passes-through the through-hole252. In this state, the portion of the webbing26, which portion contacts the first train-around portion254at the side opposite the second train-around portion256, is bent at an angle of θ33(hereinafter called bending angle θ33) with respect to the portion of the webbing26, which portion is further toward the proximal end side than the portion that contacts the first train-around portion254at the side opposite the second train-around portion256.

Further, further toward the distal end side than the portion that contacts the first train-around portion254at the side opposite the second train-around portion256, the webbing26contacts the other surface in the thickness direction of the first train-around portion254. The portion of the webbing26, which portion contacts the other surface in the thickness direction of the first train-around portion254, is bent at an angle of θ34(hereinafter called bending angle θ34) with respect to the portion that contacts the first train-around portion254at the side opposite the second train-around portion256. Further, the portion of the webbing26, which portion is further toward the distal end side than the portion that contacts the other surface in the thickness direction of the first train-around portion254, is bent at an angle of θ35(hereinafter called bending angle θ35) with respect to the portion that contacts the other surface in the thickness direction of the first train-around portion254.

When, in this state, the vehicle rapidly decelerates and the body of the vehicle occupant24pushes the lap webbing38of the webbing26toward the vehicle front, the tension of the webbing26that increases due thereto pulls the plate248. Due to the plate248being pulled in this way, the shearing projections262push the engaging pieces246and, due thereto, the shearing projections262deform or break due to the pushing reaction force that the engaging pieces246apply to the shearing projections262. The interference of the shearing projections262with respect to the engaging pieces246is cancelled, and rotation of the plate248with respect to the tongue main body242is permitted.

In this state, the plate248is pulled by the tension of the webbing26, and the plate248rotates around an axis, whose axial direction is the width direction of the base portion250, with respect to the tongue main body242until the restricting portions264of the guide holes260abut the engaging pieces246. When the plate248rotates in this way, as shown inFIG. 12B, the lap webbing38is pushed by one surface in the thickness direction of the second train-around portion256, and the path of passage of the lap webbing38, at the one side in the thickness direction of the second train-around portion256, is changed.

Further, the second train-around portion256pushes the shoulder webbing34via the lap webbing38that is pushed, and, due thereto, the path of passage of the shoulder webbing34, at the one side in the thickness direction of the second train-around portion256, is changed. The webbing26, whose path of passage is changed in this way, is trained-around, of the outer peripheral portion of the first train-around portion254, the portions other than the surface that structures the inner peripheral portion of the through-hole252, and is trained-around the second train-around portion256in a state in which the shoulder webbing34and the lap webbing38overlap.

In this state, the portion of the webbing26, which portion faces the one surface in the thickness direction of the second train-around portion256and the one surface in the thickness direction of the first train-around portion254, is bent at an angle of θ36(hereinafter called bending angle θ36) with respect to the portion of the webbing26that is further toward the proximal end side than the second train-around portion256. Further, the portion of the webbing26, which portion slidingly-contacts the end surface of the first train-around portion254at the side opposite the through-hole252, is bent at an angle of θ37(hereinafter called bending angle θ37) with respect to the portion of the webbing26which portion faces the one surface in the thickness direction of the second train-around portion256and the one surface in the thickness direction of the first train-around portion254. Moreover, the portion of the webbing26, which portion slidingly-contacts the surface at the other side in the thickness direction of the first train-around portion254, is bent at an angle of θ38(hereinafter called bending angle θ38) with respect to the portion of the webbing26which portion slidingly-contacts the end surface of the first train-around portion254at the side opposite the through-hole252.

The portion of the webbing26that is passed-through the through-hole252is bent at an angle of θ39(hereinafter called bending angle θ39) with respect to the portion of the webbing26which portion slidingly-contacts the surface at the other side in the thickness direction of the first train-around portion254. Further, the portion of the webbing26, which portion slidingly-contacts the one surface in the thickness direction of the second train-around portion256, is bent at an angle of θ40(hereinafter called bending angle θ40) with respect to the portion of the webbing26that is passed-through the through-hole252. Moreover, the portion of the webbing26, which is further toward the longitudinal direction distal end side than the portion thereof that slidingly-contacts the one surface in the thickness direction of the second train-around portion256, is bent at an angle of θ41(hereinafter called bending angle θ41) with respect to this portion of the webbing26that slidingly-contacts the one surface in the thickness direction of the second train-around portion256.

Due to the frictional resistance between the webbing26and the tongue240increasing in this way, movement of the webbing26along the longitudinal direction thereof is suppressed. Due thereto, the portion of the webbing26at the shoulder webbing34side passing-through the through-hole242and moving toward the lap webbing38side, i.e., the length of the lap webbing38increasing, can be prevented or suppressed, and the waist portion of the vehicle occupant24can be effectively restrained by the lap webbing38, and inertial movement of the vehicle occupant24toward the vehicle front side can be effectively suppressed.

Moreover, because the interval between the first train-around portion254and the second train-around portion256is greater than the thickness dimension of the webbing26, the first train-around portion254and the second train-around portion256do not clamp the webbing26. Further, even when the plate248rotates as described above, the plate248and the tongue main body242do not clamp the webbing26, and moreover, in the state in which the restricting portions264abut the engaging pieces246, further rotation of the plate248is restricted. Therefore, as described above, even in a state in which increasing of the length of the lap webbing38is prevented or suppressed, a large load is not applied locally to the webbing26.