Dual sensitive retractor

• US 4,148,446 A
• Filed: 12/08/1976
• Issued: 04/10/1979
• Est. Priority Date: 05/12/1976
• Status: Expired due to Term

• Current Assignee: American Safety Equipment Corp (Berkshire Hathaway Incorporated)
• Original Assignee: American Safety Equipment Corp (Berkshire Hathaway Incorporated)
• Inventors: Sugar, Joseph
• Primary Examiner(s): Hornsby, Harvey C.
• Assistant Examiner(s): Jillions, John M.
• Application Number:
  US05/748,655
• Time in Patent Office: 853 Days
• Field of Search: 242/107.4 R-107.4 E, 242/118.61, 297/388, 280/744-747, 403/359, 403/368, 403/370, 403/372
• US Class Current: 242/383.4
• CPC Class Codes: B60R 22/405 responsive to belt movement and vehicle movement
• CPC Class Codes: Y10T 403/7052 Engaged by axial movement

Abstract

A dual sensitive retractor prevents protraction of webbing when either a predetermined vehicle acceleration or webbing acceleration occurs. The reel includes a shaft which is rotatably mounted on a frame. Locking means, in the form of a lock cup, on the frame moves locking pawls into and out of the path of ratchet teeth on the reel. An inertia mass is mounted on the shaft for rotation with respect to the shaft, and an inertia weight is provided which is responsive to changes in the inertia of the vehicle. The invention includes the improvement of providing a latch and means for mounting the latch for engaging the locking means to prevent webbing protraction. Drive means, which in one embodiment is a cam fixed to the shaft contacting the latch generally is driven by the shaft and is connected to the latch to impart rotation from the shaft to the inertia mass and to move the latch into engagement with the locking means when the webbing acceleration rotates the shaft faster than the inertia mass. A gear and means mounting the gear on the shaft for rotation with respect to the shaft are provided. The gear is engageable by the inertia weight to prevent its rotation with the shaft. A gear connecting member is connected to the gear to impart rotary motion from the drive to the gear and operates the drive means to move the latch into engagement with the locking means when the inertia weight prevents rotation of the gear to lock the reel against further protraction. In one embodiment, the gear connecting member connects the gear to the latch to move the latch into engagement with the locking mens. Programming means initiates rotation of the lock cup when the vehicle or webbing acceleration is sensed when the locking pawl is in a predetermined position relative to any one of the ratchet teeth so that the locking pawls engage the ratchet teeth at a predetermined location on the tooth so the rotation of the lock cup drives the locking pawl. Alignment means may also be provided to align the pawl bounce prevention means during manufacture.

Claims

1. In a dual sensitive retractor for preventing webbing protraction when the webbing undergoes a predetermined acceleration and/or the vehicle on which the retractor is mounted undergoes a predetermined change in inertia, the retractor including a reel having a shaft mounted on a frame for rotation and locking means for locking said reel against protraction, the retractor including an inertia mass mounted on the shaft for rotation with respect to the shaft, and an inertia weight responsive to changes in the inertia of the vehicle, the improvement comprising the provision of:

latch means and means for mounting said latch means for engaging said locking means to prevent webbing protraction;

interconnecting means for connecting said latch means and said inertia mass for normally concurrent rotation;

drive means driven by said shaft and connected to said latch means for imparting rotation from the shaft to said latch means and through said interconnecting means to the inertia mass and for moving said latch means into engagement with said locking means when webbing acceleration rotates the shaft faster than the inertia mass;

gear means and means mounting said gear means on the shaft for rotation with respect to the shaft, said gear means being engageable by said inertia weight to prevent its rotation with the shaft; and

yielding means in a gear driving relation between said latch means and said gear means for imparting rotary motion from the latch means through the yielding means to the gear means and for moving said latch means into engagement with said locking means when said inertia weight prevents rotation of said gear means to lock said reel against further protraction.

2. The improvement of claim 1 further comprising:

said gear means having teeth thereon, and lever means including a tooth thereon movable into the teeth of the gear means in response to movement of said weight during acceleration of the vehicle, said teeth on said gear means and said tooth on said lever insuring positive engagement therebetween.

3. The improvement of claim 1 wherein the latch means is mounted on the inertia mass, the drive means comprises cam means fixed to the shaft and contacting the latch means for imparting rotation from the shaft to the inertia mass and for moving the latch means into engagement with the locking means when webbing acceleration rotates the shaft faster than the inertia mass, and wherein the gear connecting means connects the latch means with the gear means to impart rotary motion from the latch means to the gear means and for moving the latch means into engagement with the locking means.

4. The improvement of claim 3 wherein said latch means includes a latching portion which engages said locking means, a pivot connecting said latch means with said inertia mass, and connecting means opposite said pivot on said latch means for connecting said spring means to said latch means for pivoting the latching portion about said pivot when said gear means is stopped.

5. The improvement of claim 4 wherein said yielding means comprising spring means of resilient material in the shape of a C, said resilient material being located generally above at least part of the circumference of said inertia mass for pivoting said latch means.

6. In the retractor of claim 4, said reel including ratchet teeth and said locking means including a locking pawl movable into engagement with said ratchet teeth, the improvement further comprising said locking means including a lock cup with inwardly facing teeth thereon, means connected to said lock cup engaging said locking pawl whereby rotation of said lock cup drives said locking pawl into engagement with said ratchet wheel, said latch portion engaging said teeth on said lock cup to rotate the lock cup so that the lock cup positively moves said locking pawl into engagement with said ratchet wheel.

7. In a retractor for winding webbing thereon and preventing protraction of the webbing when the webbing protraction exceeds a certain acceleration including a reel having a shaft rotatably mounted on a frame, locking means for preventing protractive rotation of the reel, an inertia mass mounted on the shaft for rotation with respect to the shaft, latch means pivotally mounted on the inertia mass and pivotable into engagement with said locking means for locking said reel, and resilient means resiliently connecting said inertia mass to said shaft to rotate said inertia mass with said shaft permitting said shaft to rotate with respect to said inertia mass against said resiliency, the improvement comprising the provision of:

cam means fixed to the shaft including an arcuate slot and pin means extending from said latch means for engagement within said slot for lifting said pin means to pivot said latch means into engagement with said locking means when the inertia mass rotates slower than the shaft during acceleration of webbing protraction to lock said reel and vehicle inertia sensitive means responsive to acceleration of said vehicle and means for connecting the vehicle sensitive means to said latch means when a predetermined vehicle acceleration occurs to pivot said latch means into engagement with said locking means.

8. The improvement of claim 7 further including ratchet teeth on said reel, said locking means including locking pawl means engaging said ratchet teeth and programming means between said latch means and said locking pawl means to program the locking of said locking pawl means into the ratchet teeth at one of a plurality of predetermined locations so that the bounce of the locking pawl means from a tooth of said ratchet during locking of the retractor is prevented.

9. The improvement of claim 8 wherein said programming means comprises teeth on said locking means for being engaged by said latch means, said locking means and said reel having an equal number of teeth.

10. The improvement of claim 9 wherein said programming means comprises alignment means for aligning the latch driving means with respect to the ratchet teeth for driving the latch into engagement with the teeth on said locking means when any one of the ratchet teeth are at a predetermined location relative to the locking pawl.

11. The improvement of claim 10 further including alignment means insertable between said latch driving means and said shaft the first time the retractor is locked to prevent rotation of the latch driving means relative to the shaft after the latch driving means is positioned with respect to the ratchet teeth when the retractor is locked.

12. The improvement of claim 11 wherein said alignment means includes mounting means on the latch driving means to allow small amounts of rotation of the shaft with respect to the latch driving means, shaft gripping means on the shaft, latch driver gripping means on the latch driving means, and cap means insertable between the latch driver gripping means and the shaft gripping means to prevent rotation of the shaft relative to the latch driving means.

13. In a dual sensitive retractor for use in a vehicle which prevents protraction of webbing when either a predetermined vehicle acceleration or webbing acceleration occurs including a reel on a shaft rotatably mounted on a frame, locking means for locking the reel to prevent protractive rotation of said reel, an inertia mass mounted on the shaft for rotation therewith, resilient means associated with the shaft to drive said inertia mass in rotation with rotation of said shaft whereby constant speed rotation of the shaft causes constant speed rotation of the inertia mass and accelerating rotation of said shaft causes said inertia mass to rotate at a slower speed than the shaft, latch means pivotally mounted for engaging the locking means to lock the reel, the improvement comprising the provision of:

differential sensitive means responsive to a differential in rotational speed of the inertia mass and the shaft to pivot the latch means into engagement with said locking means; and

vehicle inertia sensitive means and means for operably connecting it to said latch means to pivot the latch means into engagement with the locking means on change of vehicle inertia.

14. The improvement of claim 13 wherein the vehicle inertia sensitive means comprises gear means mounted for rotation on said shaft, a weight sensitive to changes in the vehicle inertia and means for mounting the weight to intersect the gear means upon changes in the vehicle inertia to prevent rotation of the gear means, and gear connecting means connecting said gear means with the inertia mass for transmitting rotation of the inertia mass to the gear means and for moving the latch means into engagement with said locking means when the gear means is prevented from rotation by said weight.

15. The improvement of claim 14 wherein the gear connecting means is connected directly from the gear means to the inertia mass.

16. The improvement of claim 15 wherein the latch means is eccentrically mounted with respect to the shaft, the improvement further comprising linkage means pivotally mounted on the inertia mass and being connected to the latch means whereby when the inertia weight stops the gear means, the gear connecting means slows rotation of the inertia mass whereby the linkage means pivots the latch into engagement with the locking means.

17. The improvement of claim 14 wherein the latch means is pivotally mounted on the inertia mass.

18. The improvement of claim 17 wherein said latch means includes a latching portion which engages said locking means, and connecting means opposite said pivot on said latch means for connecting said gear connecting means to said latch means for pivoting the latch portion about said pivot when said gear means is stopped.

19. The improvement of claim 14 wherein said gear connecting means comprises resilient material in the shape of a C, said resilient material being locted generally above at least part of the circumference of said inertia mass for pivoting said latch means.

20. The improvement of claim 19 wherein said resilient material is of the same material and is a part of said gear means.

21. A method of programming a retractor so that the locking pawl is prevented from intersecting the edge of ratchet teeth, the retractor comprising a reel with ratchet teeth thereon a shaft rotatable on a shaft rotatably mounted on a frame, locking pawl means on the frame for engaging the ratchet teeth to prevent protractive rotation of the reel, a lock cup having teeth thereon mounted for rotation on the frame, means connecting the lock cup with the locking pawl such that rotation of the lock cup causes the locking pawl to engage the ratchet teeth, latch means which pivots into the teeth of the lock cup and latch drive means on the shaft for rotation therewith for pivoting the latch means into the lock cup and to rotate the lock cup to drive the locking pawl into the ratchet teeth, the method comprising the steps of:

providing teeth on the lock cup of a number equal to the number of ratchet teeth,

allowing the latch driving means to rotate with respect to the shaft,

orienting the latch driving means with respect to the shaft by rotating the shaft, engaging the lock cup with the latch, and continuing rotating the shaft until the lock cup drives the locking pawl into the path of the ratchet teeth to stop the rotation of the shaft whereby the latch drives the latch driving means about the shaft until the lock cup stops the latch from moving as the pawl fully engages the ratchet teeth to stop rotation of the lock cup,

then fixing the latch driving means to the shaft by inserting a member of resilient material between the shaft and the latch driving means whereby the resilient material is gripped by both the latch driving means and the shaft so that they can rotate together whereby the position of the lock cup is fixed with respect to each tooth of the ratchet teeth as each is engaged by the locking pawl.