ANCHOR DEVICE FOR SEAT BELTS

Abstract: A slide anchor is fixed to an elongated rail (11) attached to a chassis-fixing portion so that the height of the slide anchor can be regulated in the lengthwise direction. An anchor bolt (25) projecting into the interior of a vehicle body is secured to the slide anchor. A slip anchor (23) supporting an intermediate portion of a seat belt (80) is rotatably supported on the anchor bolt. A locking pin (27) is withdrawably passed through a bore (26) made through the anchor bolt. Locking holes (12) are provided in the portions of the rail which are opposed to an end of the locking pin so that the locking holes are aligned in the lengthwise direction of the rail. A spring (30) urges the locking pin in the direction in which the end portion of the locking pin is fitted in a locking hole. An operating portion (31) for withdrawing the locking pin from a locking hole is provided on the head portion.

Description: Technical Field The present invention relates to an anchoring device for supporting the upper end of the shoulder portion of a seat belt mounted in a vehicle, such as an automobile, in such a way that the height of the shoulder portion can be adjusted and, more particularly, to an anchoring device that is used with a seat belt and permits the point at which the belt is supported is moved over a wide range without the need to increase the whole length of a rail member. Background Art Some seat belts mounted in automobiles use connector belts wherein the belt holds both one shoulder and the loins of a passenger. Many of these seat belts have slip anchors through which the central portion of the seat belt passes to hold the central portion and correctly fasten one shoulder of a passenger in conformity with the sitting height and the physical make of the passenger. The anchor is mounted to a stationary portion of the automobile body, such as a center pillar, so as to be vertically adjustable. In the conventional seat belt-anchoring device of this kind, a slide anchor is movably mounted to a rail member extending vertically. The rail member is rigidly fixed to a stationary portion of the automobile body, such as a center pillar. An anchor bolt is firmly attached to the underside of the slide anchor. The slip anchor through which the seat belt passes and is guided is rotatably held by the anchor bolt. A retaining pin that is always urged to protrude by a leaf spring is mounted over the slide anchor so as to be capable of protruding rearward from the back surface of the slide anchor. A knob that can be operated by a person is formed integrally with the pin. Some holes are formed in the rail member longitudinally, and the front end of the pin can be inserted into any one of these holes so as to be withdrawable. If necessary, the knob is pulled to withdraw the pin integral with it from one hole in the rail member. Then, the slide anchor is free to move vertically. In this state, its height can be easily adjusted. A known seat belt anchoring device of this type is disclosed in US Patent No. 4577888. The device has a rail member on which a slider is movably mounted, to which an anchor bolt carrying a slip anchor ring is attached. A latch assembly comprising a spring-biased retaining pin is provided on the slider for selective engagement with holes in the rail member. In the conventional seat belt-anchoring devices constructed as described above, it is necessary to allow the slide anchor to move a long distance, for preventing the knob on the pin from interfering with the slip anchor. This narrows the range in which the height can be adjusted. Further, the weight of the assembly increases. If the whole length of the rail member is increased, then the range in which the height of the slide anchor can be adjusted is enlarged. However, the upper and lower points at which the rail member is fixed are spaced more widely and so the central portion bends easily. Elongating the rail member increases the weight and the space needed for installation accordingly. Disclosure of the Invention The present invention is intended to provide an anchoring device that is for use with a seat belt and enlarges the range in which a slide anchor can move, without increasing the whole length of a rail member. According to the present invention there is provided an anchoring device for use with a seat belt, comprising: a rail member for fixing to a stationary portion of the body of a vehicle, such as a center pillar, so as to extend vertically; a slide anchor slidably engaging the rail member so as to be movable longitudinally of the rail member; an anchor bolt mounted on the slide anchor so as to protrude inwardly of the passenger's compartment; a slip anchor adapted to hold the central portion of the seat belt; a retaining pin situated in a through hole so as to be movable along the axis of the through hole; a plurality of holes formed in the rail member and longitudinally spaced from each other for receiving the front end of the retaining pin; a spring to urge the front end of the retaining pin towards a hole of the rail member to engage therewith and to thereby fix the position of the slide anchor on the rail member; and an operation means disposed on the opposite side of the front end of the retaining pin, actuable to disengage the front end thereof from the hole to allow an adjustment of the position of the slide anchor on the rail member; characterised in that the slip anchor is rotatably mounted on the anchor bolt, and in that the through hole is provided in the anchor bolt and extends therethrough toward the rail member, and in that the spring is arranged on the anchor bolts. The operation means may comprise a knob fixed to the head of the retaining pin so as to be operable by a person. In the seat belt-anchoring device constructed as described above, the operation portion on the retaining pin is mounted in the center of the anchor bolt coaxially with the bolt. The front end of the pin can be withdrawn from the hole in the rail member simply by pulling the knob. The height of the slide anchor can be easily adjusted. The length of the slide anchor in the direction in which it can move is much shorter than that of the prior art slide anchor. Therefore, the slide anchor moves a long distance relative to the rail member. This enlarges the range in which the height of the slide anchor can be adjusted. Also, the upper end of the seat belt can be connected to a stationary portion of the automobile body at an appropriate height in conformity with the sitting height and the physical make of the passenger. Brief Description of the Drawings Fig. 1 is a side elevational view in cross section of a seat belt-anchoring device according to the invention; Fig. 2 is a front elevational view of the device shown in Fig. 1; Fig. 3 is a cross-sectional view taken on line 3-3 of Fig. 2; and Fig. 4 is a schematic perspective view of an operation portion on a retaining pin that can be used in the device shown in Fig. 1. Referring to Figs. 1-3, an elongated rail member 11 is fabricated from belt-like metal plate extending vertically by press working. This rail member 11 takes a shape as shown in horizontal cross section, and has jaws at its both fringes. A certain bending resistance is imparted to the member. A plurality of holes 12 extend through the rail member 11, and these holes are arranged longitudinally. The rail member 11 is also provided with holes 13 and 13′ at its upper and lower ends, respectively. Bolts 14 and 14′ pass through the holes 13 and 13′, respectively, and are screwed to a center pillar 16 via washers 15 and 15′, respectively. The pillar 16 constitutes one stationary portion of the body of an automobile. Thus, the rail member is firmly fixed to the stationary portion 16 of the body such that a given gap t is left between the rear surface of the rail member and the mounted surface of the stationary portion 16. An inclined guide surface 17 is formed on the front side of the opening of each hole 12 in the rail member 11 to facilitate insertion and withdrawal of a retaining pin 27 (described later). The rear side of the opening of each hole 12 is subjected to a press working, so that the fringe 18 of the hole 12 is slightly depressed from the rear surface of the rail member 11. The actual depth of each hole 12 is constant, irrespective of the thickness of the rail member 11. The corner of the fringe 18 of the opening forms a substantially right-angled edge. A slide anchor 19 is made of a metal plate and slidably connected to the jaws at both ends of the rail member 11 via sheets 20 made of a synthetic resin. These sheets 20 are used to reduce friction. The anchor 19 is mounted so as to be movable longitudinally of the rail member 11. The anchor 19 is centrally formed with a hole 19a on its front side. A nut 21 is rigidly attached within the hole 19a. An anchor bolt 25 is screwed to the nut 21. The base portion 24 of a slip anchor 23 is rotatably held by the anchor bolt 25 via a soundproof bush 22. The anchor 23 serves to guide the upper end of the shoulder portion of a seat belt 80 so as to be slidable. The slide anchor 19 has a length ℓ in the direction in which it can move. This length is set shorter than the length of the conventional anchoring device. The anchor 19 can move a longer distance relative to the rail member 11 than the conventional anchoring device. The anchor bolt 25 is centrally provided with a stepped hole 26. A cylindrical pin 27 is inserted in the hole 26 so as to be slidable in a direction perpendicular to the direction of movement of the slide anchor 19. The hole 26 has a step 29. The pin 27 has a step 28 at its center. A coiled spring 30 is compressed between the steps 28 and 29 to always bias the pin 27 in such a direction that the front end of the pin 27 is fitted in one of the holes 12 formed in the rail member 11. The head of the pin 27 has a peripheral groove 32. A knob 31 to be operated has claws 33 fitted in the groove 32 and so the knob is attached to the pin 27. The knob 31 has a skirt 34 on its outer periphery. The skirt 34 covers the outer periphery of the anchor bolt 25. The pin 27 is provided with a peripheral groove 36 at the location where the pin 27 is fitted in the hole 12 in the rail member 11. The groove 36 has a width greater than at least the depth of the hole 12 in the rail member 11 except for a given length of an engaging portion 35. An engaging step 37 is formed at the end of the groove 36 opposite to the fringe 18 of the opening in the hole 12. The step 37 can engage with the fringe 18. A resinous cylinder 38 is mounted in the groove 36 formed in the pin 27. The cylinder 38 possesses such rigidity that it does not deform when subjected to stresses produced during normal use of the belt, and that it is deformed or destroyed after pressed against the inner surface of the hole 12 if an impulsive load exceeding a given value acts on the belt. If the cylinder is deformed or destroyed in this way, then the engaging step 37 of the pin 27 is allowed to engage the fringe 18 of the opening in the hole 12. The cylinder 38 is provided with a slit extending along the axis of the cylinder. The cylinder 38 is assembled: (1) by fitting it into the groove 36 in the pin 27 by utilizing the resilience of the cylinder itself; (2) by inserting the pin 27 in a casting mold, introducing resinous material directly into the groove 36, and molding the cylinder; (3) or by shaping the cylinder 38 into a form conforming to the groove 36 and bonding the cylinder to the pin 27 with adhesive. The cylinder can be made of any resinous material, as long as it can satisfy the aforementioned mechanical characteristics, but usually it is preferably made of polyacetal resin, polyester resin, or other similar material. The cylinder 38 is designed so that when the pin 27 is inserted into or withdrawn from the hole 12, the outer surface of the cylinder 38 does not impede such an operation. A slide garnish 39 is fixed to the front side of the slide anchor 19 to conceal the rail member 11 and the slide anchor 19. The novel seat belt-anchoring device operates in the manner described below. When the seat belt is worn, the position of the slide anchor 19 is shifted upward or downward so that the height of the slip anchor 23 may match the physical make of the passenger. For this purpose, the knob 31 is pulled to withdraw the pin 27 from the hole 12 in the rail member 11. Then, the slide anchor 19 is permitted to move along the rail member 11. The passenger moves the anchor 19 into a desired position and releases the knob 31. The pin 27 is automatically fitted into the hole 12 by the biasing force of the spring 30. Subsequently, the slip anchor 23 is held at a desired height to locate the slide anchor 19 in position. The slide anchor 19 has the length ℓ in the direction in which it can move, and this length is shorter than conventional. The anchor 19 can move a longer distance relative to the rail member 11. Therefore, the range in which the height can be adjusted is substantially enlarged. Consequently, the belt can be better matched to the passenger's physical make. The resinous cylinder 38 mounted on the pin 27 is not deformed at all by stresses produced during normal use of the seat belt 80. In this state, the cylinder 38 prevents the engaging step 37 of the pin 27 from engaging the fringe 18 of the opening in the hole 12. This mitigates the collision between the outer surface of the pin 27 and the inner surface of the hole 12. Hence, generation of noise which would otherwise be caused by vibration during running of the vehicle is prevented. When the slide anchor 19 is fixed, if an impulsive load exceeding a given value, generally 200 Kg to 3 tons, is applied to the seat belt 80 as by collision of the vehicle, then a load is applied to the pin 27 in a direction perpendicular to the axis via the slip anchor 23 and the slide anchor 19. The resinous cylinder 38 is pressed against the inner surface of the hole 12, so that the cylinder is deformed. The engaging step 37 of the pin 27 comes into engagement with the fringe 18 of the opening in the hole 12, preventing the pin 27 from coming out of the hole 12. Also, they are connected together with a greatly increased strength. The slide anchor 19 is prevented from sliding downward. As a result, the passenger is maintained in a correct restrained state by the seat belt 80. Fig. 4 shows another seat belt-anchoring device according to the invention. It is to be noted that like components are indicated by like reference numerals throughout all the figures. The head of the retaining pin 27 has a small hole 41 extending perpendicular to the axis. A pull ring 42 rotatably passes through the hole 41. The pin 27 is inserted or withdrawn by pulling the ring 42 from inside the passenger's compartment. When the belt is not in use, the ring 42 of the device can be tilted downward to minimize the protrusion within the passenger's compartment. Hence, the device can be rendered more compact. The operation portion formed on the head of the pin 27 can be shaped differently from the foregoing. As an example, an appropriate positive cam mechanism is mounted between them to transmit the force applied to a button or lever by the user to the pin 27, for moving the pin 27 axially. In this way, the direction of the force applied by the operator can be changed by a suitable mechanism. Usually, a cover for protecting the passenger's head is mounted to the outside of the slip anchor 23 including these operation portions. In the above examples, the slip anchor is employed to support the seat belt. The seat belt 80 passes through the slip anchor and then its direction is changed. The invention is also applicable to an anchoring device in which the slip anchor takes the form of a buckle, and in which the device connects the buckle to the automobile body at a location above one shoulder of the passenger in such a way that the position of the buckle can be adjusted vertically. A tongue seamed to the front end of the seat belt is detachably connected to the buckle. Industrial Applicability As described above, if the novel anchoring device for use with a seat belt uses the same length of rail member as the prior art rail member, the slide anchor is able to move a longer distance relative to the rail member than heretofore. This enables the range in which the height of the slip anchor is adjusted to be enlarged. Also, the weight of the slide anchor can be reduced. Consequently, the device can be made lighter and more compact. Furthermore, in accordance with the invention, it is unlikely that the slip anchor interferes with the operation portion on the pin, because the operation portion is disposed at the protruding end of the anchor bolt within the passenger's compartment, the anchor bolt being rigidly fixed to the slide anchor. Additionally, the height of the shoulder portion can be easily and quickly adjusted.

Claims: 1. An anchoring device for use with a seat belt, comprising: a rail member (11) for fixing to a stationary portion of a body of a vehicle; such as a center pillar, so as to extend vertically; a slide anchor (19) slidably engaging the rail member (11) so as to be movable longitudinally of the rail member (11); an anchor bolt (25) mounted on the slide anchor (19) so as to protrude inwardly of the passenger's compartment; a slip anchor (23) adapted to hold the central portion of the seat belt; a retaining pin (27) situated in a through hole (26) so as to be movable along the axis of the through hole (26); a plurality of holes (12) formed in the rail member (11) and longitudinally spaced from each other for receiving the front end of the retaining pin (27); a spring (30) to urge the front end of the retaining pin (27) towards a hole (12) of the rail member (11) to engage therewith and to thereby fix the position of the slide anchor (19) on the rail member (11); and an operation means (31) disposed on the opposite side of the front end of the retaining pin (27), actuable to disengage the front end thereof from the hole (12) to allow an adjustment of the position of the slide anchor (19) on the rail member (11); characterised in that the slip anchor (23) is rotatably mounted on the anchor bolt (25), and in that the through hole (26) is provided in the anchor bolt (25) and extends therethrough toward the rail member (11), and in that the spring (30) is arranged on the anchor bolt (25). 2. An anchoring device for use with a seat belt as set forth in claim 1, wherein the operation means is a knob (31) fixed to the head of the retaining pin (27) so as to be operable by a person. 3. An anchoring device for use with a seat belt as set forth in claim 1, wherein the operation means is an annular pull ring (42) passing through a hole (41) that extends through the head of the retaining pin (27) in a direction perpendicular to the direction in which the pin (27) is inserted and withdrawn. 4. An anchoring device for use with a seat belt as set forth in claim 1, wherein the operation means comprises: a lever pushed in a direction perpendicular to the direction in which the retaining pin (27) is inserted and withdrawn; and a positive cam mechanism for converting the motion of the lever into an axial shift of the pin (27).

Inventors: TAKADA, JUICHIRO
Applicants: TAKATA CORPORATION
Application year: 1987
Main classification: B60R22
IPC codes: B60R22