WO2004110830A1

WO2004110830A1 - Buckle

Info

Publication number: WO2004110830A1
Application number: PCT/KR2003/001185
Authority: WO
Inventors: Jin-Hee Kang
Original assignee: Jin-Hee Kang
Priority date: 2003-06-17
Filing date: 2003-06-17
Publication date: 2004-12-23
Also published as: AU2003245063A1

Abstract

The present invention is related to a buckle of a seatbelt where in a buckle with the rocking obstructions of the control member passing through the side walls of the frame, and the latch plate is rotated by the retreating of the ejector, and the ejector spring and main spring is supported on the latch plate and frame is disclosed. According to the buckle of the present invention, there is no problem of the tongue falling out even in sudden impacts from vehicle collisions and thus securely maintaining the fastened state of the passenger is possible.

Description

Buckle

Technical Field

The present invention is related to a buckle for seatbelts provided for seats of vehicles and in particular, to a buckle in which the tongue does not fall out of the hooking protrusion of the latch plate, and the hooking of the tongue and the hooking protrusion of the latch plate is securely hooked when the tongue is inserted within the buckle, and in which the number of parts have been reduced.

Background Art

Generally, the buckle is classified by the way the release button is depressed largely into the depressing button type and the sliding button type. The depressing button type is generally installed in the rear seat of the vehicle, in which it is configured such that the hooking of the latch plate and tongue is released by the release button being depressed against the perpendicular direction of the insertion direction of the tongue. The sliding button type is generally installed in the front seat of the vehicle, in which it is configured such that the hooking of the latch plate and tongue is released by the release button sliding along the horizontal direction identical to the insertion direction of the tongue. Among the buckles of the sliding button type, the conventional buckle is depicted in figure 8 to figure 11. The buckle (A) into which the tongue (1) is inserted and separated is assembled by using a frame (4) as a reinforcement member, in which a latch plate (6), control member (7), release button (8), ejector spring (9), ejector (10), main spring (11), and spring supporting member (12) are installed within the frame (4).

The tongue (1) is generally provided with a belt insertion hole (2) on the end with the wide width, and a hooking hole (3) on the end with the narrow width. The end with the narrow width of the tongue (1) is inserted or separated from the buckle (A) .

The frame (4) is a thick metal plate with the lateral surface thereof formed in a ϋ shape by the side walls (4b, 4c) being bent by a predetermined bending means at the sides of the bottom plate (4a) .

Between the side walls (4b, 4c) of the frame (4) a latch plate (6) is installed. The width (W) of the latch plate (6) is slightly smaller than the space between the side walls (4b, 4c) of the frame (4), and in the lower surface center of the latch plate (6) a hooking protrusion (5) which is hooked within the hooking hole (3) of the tongue (1) is formed downward. The latch plate (6) is rotatively installed between the side walls of the frame (4) between the hooking location of the tongue (1) and the releasing location of the tongue (4). On the top surface of the latch plate (6) a control member (7) which limits the rotation of the latch plate (β) by relatively sliding in a predetermined length is fitted. The control member (7) is relatively slidably installed on the top surface of the latch plate (6), and the enabled sliding displacement is between the position which obstructs the upward movement of the latch plate (6) by elastically abutting the release button (8) and the position which allows the upward movement of the latch plate (6).

The release button (8 ) is received within the frame (4 ) such that it is parallel to the bottom plate of the frame (4) and that it is longitudinally depressed and elastically slid. On the side of the rear end of the release button (8) guide pins (23, 23') are formed and on the center of the rear end of the release button (8) a pair of spring receiving arms (32, 32') are formed. The ejector (10) is slidably installed along the bottom plate of the frame (4), and when the tongue (1) is released from the latch plate (6) , it functions in the direction in which the tongue (1) is pushed out of the buckle (A) by the ejector spring (9) . The main spring (11) biases the release button (8) in the return direction, namely, in the arrow ϋ direction of figure 9, and also biases the control member (7) to the direction which obstructs the upward movement of the latch plate (β). The spring support member (12) is fitted into the frame (4 ), and supports the fixed end side of the main spring (11) and the ejector spring (9).

The cover member (13) depicted in the imaginary line covers the above components. On the bottom plate (4a) of the frame (4) , a guide hole which guides the ejector (10) along the insertion and separation direction tongue (1) is formed. In addition, on the rear of the guide hole (14), a belt connection hole (15) is formed.

On the latch plate (6), side extensions (16, 16') which extend both sides' from the hooking protrusion (5) , and which both sides thereof approach and face the frame side walls (4b, 4c) are provided. On the interior surface of the side walls (4b, 4c) ^• of the frame (4) control protrusions (18 , 18') are installed in the vicinity of the insertion side of the tongue (1) . Also, on both ends of the side extensions (16, 16' ) , notches (17, 17' ) are formed to allow the latch plate (6) to pass by the control protrusions (18 , 18') of the frame (4) during the rotational operation of the latch plate (6). In addition, the width(W) of the side extensions (16, 16') is slightly smaller than the space between the frame (4) such that it is rotative between the side walls (4b, 4c) of the frame (4).

Meanwhile, on both ends of the control member (7), the notches (17, 17') of the latch plate (6) are closed and thus obstructs the notches (17, 17') from passing by the control protrusions (18, 18), and thereby rocking extensions (19, 19') which wholly obstruct the upward movement of the tongue (1) from the hooked position with the latch plate (6) to the release position. Also, the width of the rocking obstructions (19, 19')

^' is slightly smaller than the space between the side walls (4b, In addition, the main spring (11) intervenes between the spring support frame (12) fitted on the frame (4) and the spring reception arms (32, 32') of the release button (8) to constantly bias the release button (8) to the return direction , and also abuts the perpendicular arm (31) of the control member (7) and thereby the rocking obstructions (19, 19') bias the notches (17,

17') to the closing direction.

In addition, on the inner surface of the side walls (4b, 4c) of the frame (4) behind the control protrusions (18, 18') at a position that is spaced slightly longer than the length of the rocking obstructions (19, 19'), cam protrusions (20, 20') which position the control member (7) to the position that makes the same become distant to the frame bottom plate (4a) when the control member (7) moves toward the release side. The inclined cam protrusions (20, 20') are provided with an incline surface (B) which abuts the rear edge of the rocking obstructions (19, 19').

Meanwhile, on both sides of the rear end of the latch plate (6), support shafts (21, 21') are formed, and at the side walls (4b, 4c) of the frame (4) behind the inclined cam protrusions (20, 20') support ends (22, 22') which rotatively support the support shafts (21, 21') are wholly installed. Also, at the side walls (4b, 4c) of the frame (4) above the inclined cam protrusions (20, 20'), elongated holes (24, 24') are formed into which the guide pins (23, 23') on the rear end side of the release button (8) are guided and inserted.

On the side walls (4b, 4c) which interlock with the notches (17, 17') of the latch plate (6), fixed protrusions (25, 25') are formed, and these fixed protrusions (25, 25') disperses the load in the tensile direction of the belt which acts on the latch plate (6) and transmits the dispersed load to the frame (4) .

On the front end of the control member (7) slidably installed on the top surface of the latch plate (6), a concave portion (26) is formed, and on the rear end of the control member (7) a hook (28) is formed. In addition, on the front end of the latch plate (6), a T-shaped guide (27) is formed, and on the rear end of the latch plate (6) a rectangular hole (29) is formed.

By passing the concave portion (26) of the control member (7) through the lower portion of the horizontal arms of the T-shaped guide (27) of the latch plate (6), and making the hook (28) of the control member (7) pass through the rectangular hole (29) of the latch plate (6) and abut the bottom surface of the latch plate ( 6) , the control member (7 ) is assembled such that it is movably along the insertion and separation direction of the tongue (1) at a predetermined stroke range. Also, the front end of the horizontal arms (30, 30' ) of both sides of the concave portion (26) are arranged such that they abut the abutting portion (8b) of the rear surface of the depressed surface (8a) of the release button (8), as depicted in figure 11.

In addition, the control member (7) abuts the release button (8) and allows the rocking obstructions (19, 19') to simultaneously open and close the notches (17, 17') of the latch plate (6) while sliding in the forward and backward directions. The perpendicular arm (31) formed on the center portion of the control member (7) is received between the pair of spring reception arms (32, 32') formed on the rear end of the release button (8) .

In addition, regarding the inter-operation of the release button (8), control member (7) and the main spring (11), when the release button (8) is at the fully returned position to the front, the main spring (11) abuts the perpendicular arm (31) of the control member (7) with the far end thereof fitted into the spring reception arms (32, 32'), and biases the control member (7) such that it faces the shake-obstruction position. Also, when the release button (8) moves due to the operation of the buckle release actuation, the perpendicular arms (30, 30') of the control member (7) abuts the abutting portion (8b) and moves in the same direction and thereby the biasing force applied on the compressed control member (7) is released.

The control protrusions (18, 18') of the side walls (4b, 4c) forms an arch shape along the path of the notches (17, 17') when the latch plate (6) rotates. The bottom end of the control protrusions (18 , 18') is in a hooked state with the latch plate (6) and thus is at a height that allows interlocking with the top surface of the rocking obstructions (19, 19') formed on both sides of the control member (7).

The operation of this buckle of the conventional art is described with reference to figure 9 to figure 11.

Figure 9 depicts the state before the tongue (1) is inserted into the buckle (A) , where the latch plate (6) is rotational to the direction of arrow Y about the center of the support shafts (21, 21'), and the ejector (10) is positioned on the bottom -surface of the hooking protrusion (5) and thereby- restricting the rotation of the latch plate (6) to the direction of arrow X. Also, although here the control member (7) is biased to the tongue insertion opening (arrow U direction) by the main spring(ll) abutting the perpendicular arm(31), the control protrusions (18, 18') within the notches (17, 17') of the latch plate (6) are received and the rocking obstructions (19, 19') are abutting the rear surface of the control protrusions (18 , 18') and thus does not move forward but stays at a fixed state.

In this state, as depicted in figure 10, when the tongue (1) is inserted into the buckle (A) , the ejector(lθ) is depressed and pushed backwards by the far end of the tongue (1) and is pushed back on the lower portion of the hooking protrusion (5) . Therefore, the rocking obstructions (19, 19') of the control member (7) moves forward downwardly along the rear surface of the control protrusions (18 , 18') by the actuation of the main spring(ll), and accordingly the latch plate(6) rotates about the support shafts (21, 21') as center to the direction of arrow X, and thus the hooking protrusion (5) is hooked on the hooking hole (3) of the tongue and the tongue (1) is connected to the buckle (A) . In addition, the rocking obstructions (19, 19') of the control member (7) moves in the direction of arrow U by the actuation of the main spring (11) and closes the upper opening of the notches (17, 17') of the latch plate (6) and thus prevents the notches (17, 17') of the latch plate ( 6) from passing through the control protrusions (18, 18'). Accordingly, the latch plate (6) makes the top surface of the rocking obstructions (19, 19') and the bottom end of the control protrusions (18, 18') face each other and maintain the them in the bottom direction, and thus movement to the direction of arrow Y is obstructed and the interlocked state of the hooking protrusion (5) of the latch plate (6) and the tongue (1) is maintained.

Next, figure 11 depicts the state when the tongue (1) is separated from the buckle (A) , where when the depressed surface (8a) of the release button (8) is biased to the direction of arrow V, the release button (8) retreats while compressing the main spring (11), and biasing force of the main spring (11) against the control member (7) released, and arm portions (30, 30') and abutting portion (8b) abut, and thereby the control member (7) moves in the direction of arrow V. Here, the rocking obstructions (19, 19') are moved backwards to the rear of the notches (17, 17') of the latch plate (6), and thus enables the notches (17, 17') to pass through the control protrusions (18 , 18') . Further, when the release button (8) is depressed, because the control member (7) retreats and the rear end of the rocking obstructions (19, 19') abuts the inclined surface (B) of the inclined cam protrusions (20, 20') and retreats upwardly, the latch plate (6) moves upwardly in the direction of arrow Y with the control member (7) , and thus the tongue (1) is released from the hooking protrusion (5) . Here, the ejector (10) separates the tongue (1) from the buckle (A) by the elevation of the hooking protrusion (5) , and at the same time is positioned between the hooking protrusion (5) and the frame bottom plate (4a) and obstructs the rotation of the latch plate (6) . Also, when the biasing force on the release button (8) is relieved, the ejector (10) abuts the release button (8) and moves the release button (8) up to the original return position and maintains the elastic position as in the state of figure 9. However, in this conventional buckle, the control protrusions (18, 18 ') on the inner surface of the side walls (4b, 4c) of the frame (4) are installed protruding as a whole unit of which are formed by the pressing process and thus limiting the protruding amount. Also, in the interlocking state of the tongue and the buckle, the width of the rocking obstructions (19, 19') control member (7) which abut the bottom end of the control protrusions (18, 18') and obstruct the upward rotation of the latch plate (6) is set to be slightly smaller than the space between the side walls (4b, 4c) of the frame (4) such that it may slide and rotate between the side walls (4b, 4c) of the frame (4) . Namely, both ends of the rocking obstructions (19, 19') are configured to be spaced at a predetermined spacing from the side walls (4b, 4c) of the frame (4).

Therefore, during vehicle impact, in case heavy shock is applied between the tongue and the buckle, heavy shock is also applied to the control member (7), and in particular when this shocking force is applied at an angle to the longitudinal of the buckle and not along the longitudinal direction, the control member (7) leans to one side of the side walls (4b, 4c) of the frame (4), and accordingly one end of the rocking obstructions (19, 19') becomes spaced from the one side of the side walls (4b, 4c) of the frame (4) at twice the spacing than the predetermined, and thus there is the problem of the rocking obstructions (19, 19') which abut the bottom end of the control protrusions (18 , 18') separating from the control protrusions (18, 18')- If the rocking obstructions (19, 19') are separated from the control protrusions (18, 18'), the hooking protrusion (5) of the latch plate (6) also is separated from the hooking hole (3) of the tongue (1) and thus the tongue (1) falls out of the buckle (A) .

In addition, in the conventional buckle, when the tongue (1) is inserted into the buckle, the latch plate (6) is only moved downward by the gravitational inertia from the weight of the latch plate (6) and the control member (7), and therefore there is the possibility of the hooking protrusion (5) not being securely hooked into the hooking hole (3) of the tongue (1).

In addition, in the conventional buckle, the spring support frame (12), which is a plastic injection molding, is needed to support the ejector spring (9) and the main spring (11) , and thus not only requires numerous parts but also requires the spring support frame (12) to be assembled to the frame (4) and accordingly causes the problem of increased number of assemblers . Therefore, the object of the present invention is to provide a buckle with a configuration wherein the rocking obstructions of the control member passes through the side walls of the frame, the latch plate is rotated downwardly by the backward movement of the ejector, and the ejector spring and the main spring are supported on the latch plate and the bottom plate of the frame.

Disclosure of the Invention

To achieve the foregoing object, according to the present invention, in a buckle installed with a belt connection hole on the lateral surface U-shaped frame formed on the bottom plate of the buckle, to which the tongue is inserted and separated, between the side walls of said frame, a hooking protrusion is installed such that relative sliding is allowed with the latch plate which is rotative between the hooked position on said tongue and the separated position from the tongue and with the release button which is biased parallel to the bottom surface of said frame and slides elastically on the top surface of said latch plate, and provided with an ejector which is installed such that sliding is allowed with the control member enabled with sliding displacement between the position which obstructs upward movement of said latch plate by abutting said release button and the position which allows upward movement of said latch plate, and along the bottom surface of said frame, and which is biased to the direction where said tongue is pushed out from the buckle characterized in that, the width of the rocking obstructions of said control member is larger than that of said frame, on the side walls of said frame, rocking obstructions passing elongated holes for passing through the rocking obstructions of said control member are formed, on said rocking obstructions passing elongated holes a inclined hole which is inclined to the rear upward direction is formed, on the upper portion of said inclined holes insertion holes for inserting the rocking obstructions of said control member into the inclined holes are extended and formed, on the center of the rear- end of said latch plate a pair of downward legs which are bent and extended perpendicular to the rear direction are wholly formed, where the bottom ends of said downward legs are formed to abut the rear end of said ejector, on the rear direction of the guide hole of said frame is wholly formed an ejector spring support end protruding in the front direction, and at the end of the rectangular hole of said latch plate a main spring support end is wholly formed protruding in the front direction.

Brief description of the Drawings

Figure 1 is an exploded -perspective view of the buckle of the present invention, figure 2 is a rear view of the release button of the buckle, figure 3 is a cross-sectional view along line Et-III of figure 2, figure 4 is an assembled perspective view of the buckle of the present invention, figure 5 is a side cross-sectional view of the buckle of the present invention at a state prior to the tongue inserted into the buckle, figure 6 is a side cross-sectional view of the buckle of the present invention at a state where the tongue is inserted into the buckle and hooked on the hooking protrusion, figure 7 is a side cross-sectional view of the buckle of the present invention at a state where the tongue is released from the hooking protrusion and separated from the buckle, figure 8 is an exploded perspective view of the conventional buckle, figure 9 is a side cross-sectional view of the conventional buckle at a state prior to the tongue inserted into the buckle, figure 10 is a side cross-sectional view of the conventional buckle at a state where the tongue is inserted into the buckle and hooked on the hooking protrusion, figure 11 is a side cross-sectional view of the conventional buckle at a state where the tongue is released from the hooking protrusion and separated from the buckle.

Detailed description of the preferred embodiments

The buckle of the present invention is described hereinafter with reference to the attached figures. The buckle of the present invention is depicted in figure 1 to figure 4. Among the components used in the buckle (100) depicted in figure 1 to figure 4, for the components identical to those of the conventional components, the same numbers used in figure 8 will be applied. Also, description for the components identical to those in the conventional art will be omitted.

In the buckle (100) of the present invention, the width of the rocking obstructions (19, 19') of the control member (7) is formed wider than the width of the, and on the side walls (4b, 4c) of the frame (4) there are formed rocking obstructions passing elongated holes (41, 41') for passing through the rocking obstructions (19, 19') of the control member (7) . On the rocking obstructions passing elongated holes (41, 41') there are extendingly formed inclined hole (42, 42') which are inclined to the rear upwardly at a predetermined angle. It is preferable that the inclined angle of the inclined holes (42, 42') is from 40° to 50°. The rocking obstructions (19, 19') moves along the inclined surface of the inclined holes (42, 42 ' ) . On the top portion of the inclined holes (42, 42_.') there are extendingly formed insertion holes (42a, 42a') for inserting the rocking obstructions (19, 19') of the control member(7).

In addition, in the buckle (100) of the present invention, there are wholly formed a pair of downward legs (51, 51') which are bent extended downwardly perpendicular in the rear end center of the latch plate (6) . The bottom ends of the downward legs (51, 51') are formed to abut the rear end of the ejector (10) .

In addition, in the buckle (100) of the present invention, on the rear side of the guide hole (14) of the frame (4) an ejector spring support end (43) is protrudingly formed as a whole unit, and on the rear side of the rectangular hole (29) of the latch plate (6) a main spring support end (53) is formed protruding forward as a whole unit..

In addition, as a modification of the present of the invention, in this invention, on both sides of the rear end of the latch plate (6) hinge shafts (55, 55') are formed, and on the front location of the hinge shafts (55, 55' ) stop shafts (56, 56' ) are formed.

At the rear of the inclined hole (20, 20') on the side walls (4b, 4c) of the frame (4), stop grooves (46, 46') to which hinge grooves (45, 45') and stop shafts (56, 56') are mounted to rotatively support the hinge shafts (55, 55' ) are formed so that the hinge shafts (55, 55') of the latch plate (6) correspond to the stop shafts (56, 56').

On both sides of the rear of the release button (8) sliding holders (61, 61') are extendingly formed thereon, and on the center of the inner surface of these sliding holders (61, 61'), guide grooves (63, 63') are protrudingly formed. In addition, on the front half of the side walls (4b, 4c) of the frame (4), to guide longitudinal sliding of the release button (8), guide rails (47 , 47') which are formed outwardly bent perpendicular to the side walls (4b, 4c). On the front end of the guide rails (47, 47'), separation prevention projections (47a, 47a') protruding outwardly are formed to prevent separation of the release button(8).

The guide grooves (63, 63') of the release button (8s) are fitted into the guide rails (47, 47') of the frame (4) and guided while sliding on the guide rails (47, 47'). Because the guide grooves (63, 63') are protruding inward from the inner surface of the sliding holders (61, 61'), when the release button (8) is assembled to the frame (4), the separation prevention projections (47a, 47a') of the guide rails (47, 47') get hooked on the front end of the guide grooves (63, 63') and the release button (8) falls out of the frame (4).

In addition, in the center of the rear surface of the release button (8) , as depicted in figure 2 and figure 3, a pair of release protrusions (65, 65') which are provided with an inclined surface that abuts the front end of the horizontal arms (30, 30') are formed.

In the present invention, the main spring (11) intervenes between the main spring support end(53) of the latch plate (6) and the spring reception arms (32, 32') of the release button (8 ).

In addition, on the center of respective front ends of the side walls (4b, 4c) of the frame (4), a pair of guide tabs (49, 49' ) bent perpendicularly inward against the side walls (4b, 4c) to limit the upward movement of the inserted tongue while guiding it. In addition, on the bottom end of the release button (8), a pair of guide rods (67, 67' ) are formed at an identical height to the guide tabs (49, 49') of frame (4) to limit the upward movement of the inserted tongue while guiding it.

The operation of the buckle as the above is described with reference to figure 5 to figure 7. In figure 5 to figure 7, the cover member has been omitted.

Figure 5 is a view of the state prior to the insertion of the tongue (1) into the buckle (100) according to the present invention, where the latch plate (6) is rotative about the hinge shafts (55, 55') in the direction of arrow Y, and the ejector (10) is located on the bottom surface of the hooking protrusion (5) and regulates the rotation of the latch plate (6) in the direction of arrow X.

Also, although the control member (7) is biased to the side of the tongue insertion opening (arrow U direction) by the main spring (11) abutting the perpendicular arms (31), because the front edge of the rocking obstructions (19, 19') are abutting the front inclined surface of the inclined holes (42, 42') it does not move forward but stays at a standstill. ^• At this state, as depicted in figure 6, when the tongue (1) is inserted into the buckle (100), the ejector (10) is depressed by the far end of the and is moved back and thus moves back at the bottom portion of the hooking protrusion (5) . Therefore, the rocking obstructions (19, 19') of the control member (7) moves forward downwardly along the inclined holes (42, 42') by the actuation of the main spring (11), and accordingly the latch plate (6) rotates about the hinge shafts (55, 55') in the direction of arrow X, and thus the hooking protrusion (5) is hooked on the hooking hole (3) of the tongue (1) ahd the tongue (1) is connected to the buckle (100).

When the rocking obstructions (19, 19') of the control member (7) move along the inclined holes (42, 42') of the frame (4) and is positioned within the rocking obstructions passing elongated holes (41, 41') of the frame side walls (4b, 4c), because the rocking obstructions (19, 19') have passed through the rocking obstructions passing elongated holes (41, 41"), in the event of vehicle collision, even of substantial shock is applied between the tongue and the buckle, there is no concern for the rocking obstructions (19, 19') separating from the rocking obstructions passing elongated holes (41, 41' ). As such, if the rocking obstructions (19, 19') are not separated from the rocking obstructions passing elongated holes (41, 41'), the hooking protrusion (5) of the latch plate ( 6) also do not separate from the hooking hole (3) of the tongue (1), and thus the tongue (1) does not fall out of the buckle (100).

Next, figure 7 is a view of the state at which the tongue (1) is separated from the buckle (100), where when the biasing surface (8a) of the release button (8) is biased to the direction of arrow V, the release button (8 ) compresses the main spring (11) and reverses and thus the biasing force on the control member (7) from the main spring (11) is relieved, and by the abutting of the arms (30, 30') and the release protrusions ( 65, 65'), the control member (7) moves to the direction of arrow V. Here, because the control member (7) retreats and the rear end of the rocking obstructions (19, 19') abuts the rear inclined surface of the inclined holes (42, 42') which are extendingly formed on the rocking obstructions passing elongated holes (41, 41') and retreats upwardly, the latch plate (6) moves upward along with the control member (7) to the direction of arrow Y, and thus the tongue (1) is released from the hooking protrusion (5) .

Here, the ejector (10) separates the tongue (1) from the buckle (100) by elevation of the hooking protrusion (5) and at the same time, is positioned between the hooking protrusion (5) and the frame bottom plate (4a) and thus obstructs the rotation of the latch plate (6). Also, when the biasing force on the release button (8) is relieved, the ejector (10) abuts the release button (8) and moves the release button (8) all the way to its original position and maintains the elastic state of figure 5.

In addition, in the buckle of the present invention, when the tongue (1) is inserted into the buckle, as depicted in figure 6, when the ejector (10) retreats and the rear end thereof abuts the rear legs (51, 51') of the latch plate (6) and pushes backward, the latch plate (6) and the control member (7) rotates downwardly about the hinge shafts (55, 55') due to the leverage effect and secure hooking of the hooking protrusion (5) within the hooking hole (3) of the tongue (1) is enabled. Meanwhile, in the conventional buckle, the inner circumferential surface of the elongated hole described as the belt connection hole (15) is smoothly finished. However, because the inner circumferential surface area is small surface area pressure applied on the belt becomes high, and thus during vehicle collision if high tensile force is applied to the portion of the belt in contact with the elongated holes, there is the problem of the severing of the belt due to high surface pressure with the inner circumferential surface of the elongated holes. In the frame (4) of the present invention, through out the whole of the inner circumferential surface of the elongated hole (15) composed of a first elongated extension (15a) and a second elongated extension (15b) facing the first elongated extension (15a) and a arc shaped short extensions (15c, 15d) which smoothly extends the connecting portion of the first elongated extension (15a) and the second elongated extension (15b) , a first protrusion (71) which is rounded at the edges is formed from one side of the steel plate. Because the width of the inner circumferential surface of the elongated hole (15) is formed in a thick manner by the first protrusion (71) , the area of the first elongated extension (15a) which the belt comes into contact is formed with a large area. The first protrusion (71) is burring processed or drawing processed from one side of the steel plate to the other side and thereby is protruding from one side, and at the same time the edge is formed in a rounded manner along the direction where on the belt is depressed. In figure 1, for the convenience^' of illustration, the first protrusion (71) is depicted to project to the top side of the steel plate, but it does not matter if the first protrusion (71) is projected to ^'the bottom side of the steel plate.

Therefore, according to the present invention, because the pressure applied to the belt may be sufficiently decreased at the first elongated extension (15a) , even if sudden tensile force is applied to the belt during vehicle collision, severing of the belt may be prevented.

Generally, the elongated hole is an oval shape with the first and second elongated extension all in a linear line shape or is a half-moon shape where only the second elongated extension is a curve shape to facilitate the insertion of the belt. In the present invention, the among the inner circumferential surface of the elongated hole (15) where the belt is wrapped, the first elongated extension (15a) is formed such that it is elevated from both ends in the longitudinal direction to the center, and the second elongated extension (15b) facing the first elongated extension (15a) is also formed to correspond to the first elongated extension (15a) . The center of the first elongated extension (15a) is fully curved such that it is protruded in the opposite direction of the tensile force from the belt, and thus there are no instances where the first elongated extension (15a) is bent along the direction of tensile force application. Therefore, without instances where the belt converges on the first elongated extension (15a) , the width of the belt is always maintained in the normal state. Thereby, the tensile force of the belt is always distributed equally on the first elongated extension (15a) .

In addition, the second elongated extension (15b) is also fully curved as the first elongated extension (15a) , and thus in case the belt is fully curved along the center line of the longitudinal direction thereof to keep the flat state of the belt and inserting it into the elongated hole (15), the shape of the first elongated extension (15a) and the second elongated extension (15b) becomes identical to the shape of the fully curved shape of the belt. Therefore, the belt is easily inserted into the elongated hole (15). In addition, in the above configuration, although the protrusion is formed along the entire inner circumferential surface of the elongated hole, the protrusion may be formed on a portion of the inner circumferential surface of the elongated hole. Namely, the protrusion may be formed only on the first elongated extension (15a) of the elongated hole (15), and also the protrusion may be formed only on the first elongated extension (15a) and the first and second short extension (15c, 15d) .

In addition, in the above configuration, although protrusions are formed on the elongated hole having the first and second elongated extensions formed in a curved shape, it is obvious that the scope of the present invention includes configuration wherein the protrusions may be formed on the elongated hole having the first and second elongated extensions which are both formed as a linear line, or the protrusion may be formed on the elongated hole with only the second elongated extension in a curved shape.

The foregoing preferred embodiment is set forth as an exemplary description and should not be considered to be limited to the detailed description in anyway.

According to the buckle of the present invention, there are no instances where the tongue falls out even in sudden high impacts during vehicle collision, and thus may securely maintain the passenger of the vehicle in a fastened position.

In addition, according to the buckle of the present invention, when the tongue is inserted into the buckle, the hooking of the tongue and the hooking protrusion of the latch plate may be firmly secured. In addition, according to the buckle of the present invention, the spring support frame, which is a separate plastic injection molding, does not need to be provided, and thus manufacturing costs may be saved.

Claims

What is claimed is :

Claim 1. In a buckle installed with a belt connection hole (15) on the lateral surface U-shaped frame (4) formed on the bottom plate of the buckle, to which the tongue (1) is inserted and separated, between the side walls of said frame (4), a hooking protrusion (5) is installed such that relative sliding is allowed with the latch plate (6) which is rotative between the hooked position on said tongue (1) and the separated position from the tongue (1) and with the release button (8) which is biased parallel to the bottom surface (4a) of said frame (4) and slides elastically on the top surface of said latch plate (6), and provided with an ejector (10) which is installed such that sliding is allowed with the control member (7) enabled with sliding displacement between the position which obstructs upward movement of said latch plate (6) by abutting said release button (8) and the position which allows upward movement of said latch plate (6), and along the bottom surface (4a) of said frame (4), and which is biased to the direction where said tongue (1) is pushed out from the buckle characterized in that, the width of the rocking obstructions (19, 19') of said control member (7) is larger than that of said frame (4), on the side walls (4b, 4c) of said frame (4), rocking obstructions passing elongated holes (41, 41' ) for passing through the rocking obstructions (19, 19') of said control member (7) are formed, on said rocking obstructions passing elongated holes (41, 41') a inclined hole (42) which is inclined to the rear upward direction is formed, on the upper portion of said inclined holes (42, 42') insertion holes (42a, 42a') for inserting the rocking obstructions (19, 19') of said control member (7) into the inclined holes (42a, 42a') are extended and formed, on the center of the rear end of said latch plate (6) a pair of downward legs (51, 51') which are bent and extended perpendicular to the rear direction are wholly formed, where the bottom ends of said downward legs (51, 51') are formed to abut the rear end of said ejector (10), on the rear direction of the guide hole (14) of said frame (4) is wholly formed an ejector spring support end (43) protruding in the front direction, and at the end of the rectangular hole (29) of said latch plate (6) a main spring support end (53) is wholly formed protruding in the front direction.

Claim 2. The buckle of claim 1, wherein, on inner circumferential surface of said elongated hole (15), a first protrusion (71) which is rounded at the edges is formed from one side of the steel plate, and among the inner circumferential surface of said elongated hole (15) the first elongated extension (15a) , to which the connection belt is wrapped, is formed from both ends of the longitudinal direction thereof elevated facing the center portion, and the second elongated extension (15b) facing said first elongated extension (15a) is formed to follow said first elongated extension (15a) .

Claim 3. The buckle of claim 1, wherein, on both sides of the rear of the release button (8) sliding holders (61, 61') are extendingly formed thereon, on the center of the inner surface of these sliding holders (61, 61'), guide grooves (63, 63') are protrudingly formed. on the front half of the side walls (4b, 4c) of the frame (4 ) guide rails (47, 47') which are outwardly bent perpendicular to the side walls (4b, 4c) are formed, on the front end of the guide rails (47, 47') separation prevention projections (47a, 47a') protruding outwardly are formed, in the center of the rear surface of the release button (8) a pair of release protrusions (65, 65') which are provided with an inclined surface that abuts the front end of the horizontal arms (30, 30') of said control member (7) are formed, on the center of respective front ends of the side walls (4b, 4c) of the frame (4), a pair of guide tabs (49, 49') bent perpendicularly inward against the side walls (4b, 4c), and on the bottom end of the release button ( 8 ) , a pair of guide rods (67, 67') are formed at an identical height to the guide tabs (49, 49' ) .