JPS6236899B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention generally relates to an emergency safety belt which allows freedom of movement of a passenger under the tension of a retraction spring of a retractor provided that the safety belt is secured in the event of an emergency situation. It relates to fixed safety belts, and more particularly to devices that reduce the tension exerted on the belt during use by the force of a retraction spring.

Various types of safety belt braces are currently used in automobiles and aircraft that utilize various safety belts to restrain passengers to their seats in the event of an emergency situation. Safety belt retraction devices are commonly used to cooperate with such belt appliances to stow the belt or strap when not in use. Since a retraction spring is used to retract the belt into the retractor, the retraction spring applies some tension to the belt when it is placed around a passenger during use. It has been recognized in the past that such tension is uncomfortable for passengers, and various devices have heretofore been used to relieve the tension of the retraction springs applied to the belt during use. One such prior attempt is disclosed in U.S. Pat. No. 3,834,646, in which a belt containing reel is provided with a belt-operated device for keeping the belt free of retraction. Belt tension is completely removed. However, if a low tension is applied to the belt in the retraction direction to avoid a loose belt condition, and the belt is simply disconnected when it is in the so-called "low tension range" of low tension, it will automatically It has been found desirable to use a retraction device.

The applicant's earlier patent application No. 130385 (Sho 51-130385)
59425), the applicant proposed a safety belt retractor strain relief device with an additional device for applying a low tension to the safety belt when the force of the retraction spring is prevented from acting on the belt. disclosed the device. Patent application No. 51-144864 of the applicant
No. 53-23428), the applicant disclosed a strain relief device that uses a single spring to rotate the reel in both the main retraction system and the low tension retraction system. The device, when the belt is put into service and operated in a predetermined manner, clearly produces a reduced torque on the belt, i.e., in response to a slight retraction movement of the belt after an initial extension. A device is included to selectively reverse a portion of the retraction torque of the safety belt retractor retraction spring onto the retractor spool in the direction of belt retraction to create a low tension condition.
With each of these previous retractors having a low tension effect, the range of motion of the belt while the tension was being reduced was somewhat limited.

A principal object of the present invention is to enable a greater amount of low-tension movement of the seat belt while the belt is in a low-tension state during belt retraction than previously available with prior art retractors; It is an object of the present invention to obtain and disclose a device that provides a low tension effect to a seat belt during use.

It is a further object of the present invention to provide a spool retraction spring of a retractor that rotates the spool one or more complete revolutions in the belt retraction direction while in a low tension condition before the full torque of the spool retraction spring is reapplied. It is an object of the present invention to provide and disclose a device for disabling a device that produces a torque reduction effect.

Generally stated, the present invention provides a device for imparting a reduced low tension motion to a seat belt and for rotation of a spool in the direction of belt retraction for more than one complete revolution under the influence of reduced tension. Accordingly, a device is obtained which deactivates devices that produce such low tensions. In an exemplary embodiment of the invention, the cam arrangement is placed between the gear members of the gear arrangement that rotate at different speeds during rotation of the spool, thereby positioning the cam to disable the arrangement creating low tension. To rotate the device,
More than one rotation of the spool is required.

In another exemplary embodiment, a cam device for disabling the tension reduction device is rotatably mounted inside the cover of the tension reduction device and is in a low tension condition and under the influence of the low tension. As the spool rotates in the belt retraction direction, the cam device cooperates with the tension reduction device to rotate the spool one or more full revolution before moving to a position that disables the tension reduction device.

An exemplary embodiment of an emergency fixed safety belt retractor is shown generally at 10 in FIGS. 1 and 2 and is generally U-shaped in conventional manner, including a side wall 11 integrally formed with the base. It has a frame. Spacer rods are provided to give structural stiffness to the frame, one of the rods also being in a known manner for actuating a cooperating fixed rod having teeth that mesh with a ratchet wheel mounted on a spool. A provided inertial response pendulum is rotatably mounted. The safety belt 20 is wound on a conventional spool, generally designated 21, to which a ratchet wheel 22 is secured. The frame of the retractor places the cooperating safety belt 20 in a position to be pulled by the retractor and is placed around the passenger in use when the belt cooperates with a conventional buckle provided on the vehicle. It is attached to the car frame in a conventional manner. As will be apparent to those skilled in the art, a retractor of the type shown generally at 10 in FIGS. The spool is fixed in the emergency state of engagement to prevent further belt withdrawal or extension. The retractor mechanism described so far is conventional. However, the present invention
An improved device for reducing the tension applied to belt 20 during use is contemplated and disclosed herein.

Referring now to Figures 1-4, a preferred exemplary embodiment of a device for reducing tension applied to a belt during use is a tension applied to the spool, typically by a retraction spring, to produce a net torque reduction effect on the spool. includes a device that selectively applies a portion of the retraction torque applied to the belt in the direction of belt withdrawal, and where the low-tension effect is such that 203 mm (8 in.) of
Extends up to two revolutions of the spool allowing belt movement of 1 to 305 mm (12 inches).

In this embodiment, the ring gear 232 is
33, and the cup 233 is connected to the shaft 2 of the spool.
The sleeve 225 is supported by its boss 234, which surrounds the sleeve 225 so as to rotate relative to the sleeve 225. The outer end 241 of the retraction or coil spring 240 is connected to the ring gear slot 23 for interconnecting the outer free end of the spring 240 and the ring gear.
It's in the middle of 6. Inner end 242 of spring 240
is usually a slot 24 at the end of the spool shaft 25 for turning the spool shaft 25 in the direction of belt retraction.
It is enshrined inside.

In this embodiment, the device for applying reverse torque to the spool includes the ring gear 232, the second gear 2
50, a torque reduction gearing interconnecting the gears, indicated generally at 260, and a torque reduction gearing, indicated generally at 260.
It includes a device, shown at 70, for selectively connecting the gear 250 to the spool. As best seen in FIGS. 1 and 2, gear 250 is generally cylindrical and has a body 2 integrally formed with sleeve 254.
51 and by the sleeve 254 the shaft 2
It is mounted to rotate relative to 5.
As can be seen in FIG.
is built around.

A torque reduction gearing, generally designated 260, is located between ring gear 232 and gear 250, and is made integral with the cover and has a gearing around shaft 263, as best seen in FIG. It is rotatably mounted by a central portion 261 that fits around portion 262. The torque reduction gear is made of plastic and cooperates with gears 232 and 250 to create a reaction torque that opposes the spring retraction torque, restoring 50-65% of the spring retraction torque. As can be seen in FIG. 2, the shape of the steps of the torque reduction gear include a small gear portion 263' having external teeth 264 that mesh with teeth 237 of gear 232, and a larger diameter portion 263' having teeth 266 that mesh with teeth 253 of gear 250. A gear portion 265 is provided.

Apparatus is provided for selectively connecting gear 250 to a spool, generally designated 21. In this example, such a device, indicated generally at 270, includes:
Gear 250 also includes a pawl 271 attached to gear 250 by a pivot pin 272.
It serves as a pawl carrier that supports pawl 271 to rotate about axis 25, as described below.
The pawl 271 is attached to the sleeve 22 fixed to the shaft 25.
5 and meshes with the teeth of a ratchet wheel 220 which is made integrally with the ratchet wheel 220. When pawl 271 engages the teeth of ratchet wheel 220, the outer end of spring 240 is connected to the spool through devices, gears 232, 260, and 250, for providing a reduced retraction force on the spool. A counter-torque is applied to the spool in a direction that counteracts the belt retracting action of the inner end of spring 240 on shaft 25, ie, promotes belt retraction movement of the spool.
However, as mentioned above, since gear 250 has a greater mechanical magnification than gear 232, the belt tension reduction effect is achieved when the belt is placed in use and pawl 271 is connected to ratchet 220. be able to.

In this exemplary embodiment, a cam arrangement including a first cam member or spring wire cam 280 connects the ratchet wheel 220 and the cover to rotate relative to the pawl 271 by frictional drive between the ratchet wheel and the ratchet wheel. 231, and are relatively rotatable. During normal withdrawal of the safety belt from the spool, one of the protrusions 281 and 282 of the cam lies beneath the pawl 271 and holds it out of engagement with the ratchet wheel 220. However, when the safety belt is extended to the use position and then retracted a little, the spool rotates and the cam 280 moves slightly due to the frictional force between the groove and the cam, and the recess 283 of the spring cam 280 engages the pawl 271. , and move it to the pawl wheel 22 as shown in Figure 1.
Engage with 0. A low tension state of the seat belt is thus brought about as described above. That is, when the belt is pulled out, the spring cam 280 rotates clockwise until the right end 286 of the spring cam abuts the stop member 285 (which is integrally provided with the gear 250) shown in FIG. The spring cam 280 stops. In this stopped state, the protrusion 281 of the spring cam lies beneath the pawl 271. When the next belt 20 is pulled in slightly,
The spring cam rotates in a counterclockwise direction so that the cam recess 283 is located below the pawl 271, creating a low tension condition, as shown in FIG. Thereafter, the left end 284 of the spring cam collides with the stop member 285 (FIG. 4), and the rotation of the spring cam is stopped.

As specifically contemplated in this exemplary embodiment of the invention, the device for disabling pawl 271 is capable of imparting large, low-tension travel to the belt corresponding to up to one revolution of the spool. There is. Essentially, in this embodiment the cam 290 that releases the pawl 271 is attached to a cup 233 that is made integral with the ring gear 232. ring gear 2
32 rotates in the same direction as the pawl catch gear 250, but at a different speed by the interconnecting gear 260, allowing up to two revolutions on the spool at low tension for the retractor, which is approximately
203 mm (8 inches) or 305 mm (12 inches)
corresponds to the movement of the belt.

The pawl release cam device of this exemplary embodiment, shown generally at 290 and best seen in FIGS. It includes a front cam ring 291 and an outer cam ring 292.
The gearwheel 232 thus serves as a carrier for the cam arrangement 290. Cam driven pin 294 pawl 271
and extends through a slot 295 in gear body 251 and rests on cam surface 296 of cam ring 291 . As best seen in FIG. 3, during the retraction movement of the extended low tension belt, the mutual rotation of gears 232 and 250 causes the pin 294 to move out of the cam as shown in FIG. When portion 297 is reached, the surface of portion 297 is shaped to cause cam follower pin 294 to raise pawl 271 and disengage pawl wheel 220 .

As best seen in Figure 3, the inner cam ring 2
91 has a radially inwardly extending sector 297' with a stop 298 adjacent thereto. The stop 298 is the body 2 of the ring gear 250.
It is made of a resilient rubber-like material that acts as a shock absorber for the contact 235 made integrally with the contact 51.
The contact 235 is located in an annular cavity 29 formed in the inner cam ring 291 adjacent the side wall of the cup 233.
8' limits mutual rotation of gears 232 and 250.

Because of the provision of the contact 235 and the shock absorber 298, the mutual rotation of the gears 232 and 250 is limited to rotation only during the retraction movement of the belt in the pleasure zone condition. During normal withdrawal of the belt, ring gear 232 is held against rotation by the outer end 241 of the retraction spring.
This is because the gear 23 is driven by the torque reduction gear 260.
2 and 250 prevent simultaneous clockwise rotation in FIG. However, when the safety belt is placed in service and retracted slightly so that pawl 271 engages ratchet wheel 220, the retraction movement of the belt under low tension will cause gears 232 and 250 to engage with gears 232 and 250 in FIGS. Rotate counterclockwise at the same time, but at different speeds due to gear connections. Thus, with the gear ratio described above, the shaft 25 of the spool and the gear 2 with the contact 235 rigidly attached.
50 rotates counterclockwise twice from the position shown in FIG. 3 to the position shown in FIG. This difference displaces contact 235 from the left side of bumper stop 298 in FIG. 3 to the right side of sector 297' as shown in FIG. At this point, the pawl 271 is disengaged from the ratchet wheel 220 by the cam surface 297, and the pawl 271 is then held out of engagement by the protrusion 281 of the cam spring during the full retraction action, while the gear 2
32 and 250 are returned to their original mutual arrangement as shown in FIG. The outer cam ring 292 is the inner surface 29
9, which prevents the pawl 271 from moving too much by engaging the pin 294.

5-9, another embodiment of the extended comfort zone creating apparatus of the present invention is shown therein, which provides safety during a low tension condition corresponding to one or more revolutions of the spool. Allows belt movement. This exemplary embodiment will be described in conjunction with the exemplary retractor of FIG. Referring first to FIG. 6, as in the previous embodiment, cup 3
A first member, such as a ring gear 332 shaped like 33, is rotatably mounted to the retractor frame around the sleeve 325 by a matte cup boss 334. The outer end of the coil spring 340 is connected to the ring gear 332, and the inner end 342 of the spring 340 is normally connected to the shaft 2.
5 and its cooperating spool are connected to a shaft for rotating in the direction of belt retraction.

As before, in this exemplary embodiment, the spool,
The device that provides reduced tension on the belt therefore includes a device that applies a counter-torque to the spool retraction spring 340. The second member, gear 350, is connected to gear 332 by a torque reduction device, such as a step gearing, generally designated 360, as in the previous embodiment. A second member or gear 350 can be connected to the spool by a connection device shown generally at 370. As best seen in FIGS. 5 and 6, the gear 350 is made integral with a body 351 which in turn is made integral with a sleeve 354 and is adapted for rotation relative to the shaft 25 by the sleeve 354. attached. As you can see in Figure 5,
External teeth 353 are made around gear 350. The first and second members, namely gears 332 and 3
50 are thus interconnected as in the previous embodiment.

Apparatus is provided to selectively connect the second member or gear 350 to the spool to place the mechanism in a low tension state. In this example, such a device, indicated generally at 370, includes a pawl 371 attached to a member 350 by a pin 372, and the member 350 rotates the pawl 371 about the axis 25 of the spool as described above. It acts as a pawl holder to support rotation. The pawl 371 is adapted to mesh with teeth 321 of a ratchet wheel 320 that is made integral with a sleeve 325 that is non-rotatably fixed to the shaft 25. When the pawl 371 meshes with the teeth of the ratchet wheel 320, the outer end of the spring 340 engages with the teeth of the ratchet wheel 320.
32, 360, and 350 to the spool in a direction that promotes the belt retracting movement of the spool, counteracting the belt retracting action of the inner end of the spring 340 on the shaft 25. Add to spool. However, since gear 350 has a greater mechanical magnification than gear 332 as mentioned in the previous embodiment, a tension reduction effect is achieved such that gears 350 and 332 move in the same direction during retraction when the spool is under low tension, but Rotate at different speeds as described above. In this embodiment, another low-tension extension is achieved by providing the detent cam arrangement in a novel manner that differs from that of the previous embodiment. It will be appreciated by those skilled in the art that spring wire cam 280 acts on pawl 371 with its protrusions 281 and 282 during belt extension and retraction as described above.

A pawl release cam device, generally designated 390 in this exemplary embodiment, includes a boss 33 integrally formed with a cover 331, as best seen in FIGS.
3' includes a cam disk 391 attached by a bore 392. Disc 391 is free to rotate relative to cover boss 333' and thus relative to ratchet wheel 320 and spool shaft 25. The cam disk has a cam surface around its outside, which includes a cam ramp portion 393. The pawl 371 includes a cam driven roller 375, which will be explained in more detail later, which causes the pawl teeth 373 to connect to the pawl wheel 3.
In order to remove it from the teeth 321 of No. 20, it rolls upward on a slope 393.

When a low tension condition is achieved by moving the spring wire cam 280 to the position of FIG.
and engage it with the wheel 320. As gears 332 and 350 rotate counterclockwise in FIG. 5 while the belt is retracting under low tension, such as when a passenger steps back in the seat, pawl 371 reaches the position of FIG. 8. The cam follower roller 375 moves freely around the cam 391 until it reaches the position where the cam follower roller 375 begins to rest on the sloped portion 393 of the cam. Cam disc 391
is the journal or cover boss 333'
It then engages pawl 371 until stop surface 394 of cam disk 391 engages cam stop 395 as shown in FIG.
and its receiving member or gear 350 rotate with continuous counterclockwise movement. As best seen in FIG. 7, a cam stop 395 is provided on and integrally formed with the cover 331. The body portion of the cam disk 391 is fixed to the stop 3 as shown in FIG.
95, but the protruding beveled portion 393 of the cam brings the stop surface 394 into contact with the stop 395 as shown in FIG. 9 to limit further counterclockwise movement of the detent cam.

As can be seen in FIG. 9, continuous counterclockwise movement of pawl 371, which rotates with receiver or gear 350 in the exemplary embodiment due to continuous spool retraction under low tension conditions, causes cam follower roller 375 to now remain stationary. The beveled portion 393 of the cam disengages the pawl teeth 373 from the teeth of the ratchet wheel 320, thus disabling the low-tension device and transferring the main retraction force of the spring 340 back to the spool through the shaft 25. Add.

A device is provided to return the pawl release cam, generally indicated at 390, to its initial starting position when the pawl catch or gear 350 rotates clockwise. As shown in FIG. 5, the gear 350 is connected to a cam disk 391
The contactor 356 is adapted to engage an arm 396 provided on the terminal. During operation under low tension as described above, gear 350 moves counterclockwise in FIG.
Move away from 96. As mentioned above, the cam driven roller 3
75 is a cam disc 391 that catches the cam disk 391, that is, the gear 3
50 from the position of FIG. 8 to the position of FIG. 9, thus maintaining the arcuate separation of contact 356 and arm 396 from each other as shown in FIG. . However, as shown in FIG. 9, when gear 350 continuously rotates counterclockwise, pawl 371 causes contact 356 to
It is removed before engaging the rear side of 6. Claw 37
1 is removed from the ratchet wheel 320, the pawl catch or gear 350 rotates clockwise, causing the contact 356 to complete one revolution as seen in FIG.
6 to the left hand side and rotate the arm clockwise as shown in FIG. 5 until the parts come around to the stop 395. From the foregoing, it can be seen that the pawl catch or gear 350 rotates approximately two complete revolutions between the initial pawl engagement with the ratchet wheel 320 and the disengaged pawl condition shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is a side view of an exemplary embodiment of a safety belt retractor having a device for reducing tension on a belt during use in accordance with the present invention; FIG.
A sectional view taken along plane 2-2 in the figure, FIG.
4 is a detailed view of the embodiment of FIG. 3 showing the beginning of the tension reduction effect; FIG. FIG. 6 is a side view of another exemplary embodiment of an apparatus for reducing tension applied to the plane 6 of FIG.
-6, Figure 7 is the plane 7 of Figure 5.
8 is a view similar to FIG. 5 showing the tension reduction condition, and FIG. 9 is a view similar to FIG. 5 showing the removal of the tension reduction effect. In FIGS. 1 to 9, reference numeral 10 is a "retractor," 20 is a "belt," 21 is a "belt storage spool," 220 is a "rattle device," and 232 is a "first 240 is a spool retraction spring,
241 is the "opposite end of the retraction spring", 242 is "one end of the retraction spring", and 250 is the "second member"
or “second ring gear”, 260 is “torque reduction device” or “reduction gear device”, 271,3
71 is a "claw", 280 is a "cam device", 290 is a "claw removal cam device", 291 is a "cam member",
294 is a "cam follower", 296 is a "cam surface", 3
31 is a "cover", 333' is a "boss", 350 is a "pawl attachment device", 375 is a "cam driven roller", 390 is a "cam device", 391 is a "cam disk", 392 is a "center hole" ”, 393 indicates a “cam slope portion”, 394 indicates a “stop surface”, and 395 indicates a “contact stop device”.

Claims (1)

[Scope of Claims] 1. A safety belt retractor, comprising: a spool 21 that accommodates the belt; a shaft 25 of the spool fixed to the spool and for belt withdrawal rotation and belt retraction rotation; connected to the spool shaft 25; a retraction spring 240 that is biased toward the spool in the direction of retracting the belt;
ring gears 232, 332 fitted into; second gears 250, 35 fitted into the shaft 25;
0; torque reduction gears 260, 360 interconnecting the ring gear and the second gear; pawls 271, 371 attached to the second gear; fixed to the shaft of the spool and reducing torque to the spool when engaged with the pawls; a first cam 280 that engages the pawl with the ratchet in response to rotation of the spool during the initial stage of belt retraction rotation; and a pawl that engages the pawl with the ratchet. a second cam 290, 390 driven by rotation of the spool for disengaging the pawl from engagement with the ratchet wheel in response to rotation of the spool one or more revolutions in the belt retraction direction when engaged;
The safety belt retractor has a.