Winding – tensioning – or guiding – Reeling device – With spring motor
Reexamination Certificate
2000-03-15
2001-11-20
Walsh, Donald P. (Department: 3653)
Winding, tensioning, or guiding
Reeling device
With spring motor
C242S379200, C280S806000
Reexamination Certificate
active
06318664
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a webbing retractor which takes up a webbing for restraining a vehicle occupant by winding the webbing in layers onto a winding shaft.
2. Description of the Related Art
A webbing retractor, which winds up in layers a webbing for restraining a vehicle occupant, is attached to a vehicle body through a frame which, when viewed from top, is formed in a substantial U-shape. A winding shaft (spool) for taking up the webbing in layers is rotatably supported between a pair of leg plates of the frame. A spring cover made of resin is attached to the outer side of one of the leg plates. An urging means (a power spring), which applies an urging force to the winding shaft such that the shaft is rotated in the direction in which the webbing is taken up, is provided between the leg plate and the spring cover. Further, a sensor cover made of resin is attached to the outer side of the other leg plate. A locking mechanism (including a sensor) for instantaneously preventing the winding shaft from rotating in the direction in which the webbing is drawn out when the vehicle decelerates suddenly, is provided between the leg plate and the sensor cover.
In conventional webbing retractors, plugs are used as a means for fixing a sensor cover or the like to a leg plate of a frame. However, in the process of improving webbing retractors, the functions and forms of the sensor cover and the like have been changing, and fixing a cover by plugs may not always be adequate.
SUMMARY OF THE INVENTION
In view of the aforementioned, an object of the present invention is to provide a webbing retractor in which a cover can be fixed to a leg plate of a frame without using plugs.
A webbing retractor relating to a first aspect of the present invention includes: a frame which is fixed to a vehicle body, and has a pair of leg plates which rotatably support therebetween a winding shaft for winding in layers a webbing for restraining a vehicle occupant, and which has one or more attachment holes in each of the leg plates; a first cover which is disposed at an outer side of the leg plate of the frame and is provided with one or more engaging pawls to be engaged with a peripheral portion of the attachment hole by deforming elastically within a range of an opening width of the attachment hole; and a second cover adapted to be secured to the leg plate so as to cover the first cover, and having one or more removal preventing portions to be inserted in the corresponding attachment holes to prevent the engaging pawl from coming out of the attachment hole.
A webbing retractor relating to a second aspect of the present invention is characterized in that, in the invention of the first aspect, the first cover includes a shaft-supporting portion which rotatably supports the winding shaft, and a sensor holding portion which holds a sensor section which detects a state of sudden deceleration of the vehicle; and the second cover includes a sensor protection portion which protects said sensor section.
According to the first aspect of the present invention, the one or more attachment holes are formed in the leg plate of the frame, and correspondingly, the one or more engaging pawls are provided at the first cover. First, while the first cover is being disposed at the outer side of the leg plate, the one or more engaging pawls of the first cover are inserted into the one or more attachment holes of the leg plate of the frame. The engaging pawl inserted into the attachment hole engages with the peripheral portion of the attachment hole by elastically deforming within the range of the opening width of the attachment hole.
Next, the second cover is fitted to the first cover so as to cover the first cover. The one or more removal preventing portions are provided at the second cover at such positions at which they can be inserted into the attachment holes. The removal preventing portion is inserted in the attachment hole such that the engaging pawl may not come out of the attachment hole. Then, the second cover is fixed to the leg plate of the frame. In the state in which the second cover is fixed to the leg plate, the engaging pawl cannot deform elastically toward the side in the direction in which the engaging pawl comes out since the removal preventing portion is placed at the side of the engaging pawl in the direction in which the engaging pawl comes out, as described above. Thus, removal of the first cover from the leg plate of the frame is prevented.
Thus, according to the present invention, at least the first cover can be fixed to the leg plate of the frame without using plugs.
According to the second aspect of the present invention, the first cover includes a shaft supporting portion which rotatably supports a winding shaft, and a sensor holding portion which holds a sensor section which detects a sudden deceleration state of a vehicle, and the second cover comprises a sensor protection portion which protects the sensor section. That is, in the present invention, two types of covers which have different functions from each other are provided at the sensor.
In such a case, if the first cover and the second cover were respectively fixed to the leg plate by plugs, many plugs would need to be hammered into the leg plate. This would cause various disadvantages such as, it would be difficult to secure the space for these plugs to be hammered, or the task of fitting the covers would be troublesome or time-consuming, or the like. However, all these problems are eliminated by applying the first aspect of the present invention.
Further, although the first cover is provided with the shaft-supporting portion which rotatably supports the winding shaft, if the first cover were fixed to the leg plate by using plugs, the attachment strength of the first cover to the leg plate in the direction of thrust (axial direction) would likely be low. Therefore, some device would be needed for preventing removal of the first cover from the leg plate when a load in a direction of thrust were applied from the winding shaft to the shaft-supporting portion of the first cover for a long time period. However, by applying the first aspect of the present invention, as long as the state of the second cover being attached to the leg plate is maintained, the first cover will not come off from the leg plate since the elastic deformation of the engaging pawl of the first cover in a direction of the engaging pawl coming put of the attachment hole is impeded by the removal preventing portion of the second cover.
In addition, if the first cover were fixed to the leg plate by using plugs, the positioning of the first cover with respect to the leg plate would be difficult. That is, accuracy in positioning the first cover with respect to the leg plate would likely be low. However, if the first aspect of the present invention is applied, by inserting the removal preventing portion into the attachment hole, the engaging pawl of the first cover is restrained by being engaged with the peripheral portion of the mounting hole. Thus, the position of the first cover with respect to the leg plate does not deviate. Namely, the precision of positioning the first cover with respect to the leg plate improves.
From the above, it can be seen that the present invention is a suitable attachment structure for attaching the first cover which functions as a shaft-supporting portion.
REFERENCES:
patent: 4204652 (1980-05-01), Cislak et al.
patent: 4285478 (1981-08-01), Stamboulian
patent: 4603819 (1986-08-01), Loose et al.
patent: 4607805 (1986-08-01), Burghardt et al.
patent: 4667893 (1987-05-01), Fohl
patent: 5484118 (1996-01-01), Fujimura et al.
patent: 5826813 (1998-10-01), Hibata
Cole Thomas W.
Jones David A
Kabushiki Kaisha Tokai-Rika-Denki-Seisakusho
Nixon & Peabody LLP
Walsh Donald P.
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