Seat belt retractor having inertial device activated by two stimuli

• US 3,918,658 A
• Filed: 06/15/1973
• Issued: 11/11/1975
• Est. Priority Date: 06/15/1973
• Status: Expired due to Term

• Current Assignee: Herbert R. Beller
• Original Assignee: Herbert R. Beller
• Inventors: Beller, Herbert R.
• Primary Examiner(s): Taylor, Billy S.
• Application Number:
  US05/370,567
• Time in Patent Office: 879 Days
• Field of Search: 242/107.4,107.2,17SB 280/15SB 244/122
• US Class Current: 242/383.4
• CPC Class Codes: B60R 22/405 responsive to belt movement and vehicle movement

Abstract

A reel-type retractor for a safety belt incorporating a single inertial locking system responsive to two different stimuli for actuating a pawl to locking engagement with a ratchet wheel. A pendulum responds to a first stimulus resulting from acceleration, deceleration or roll-over of the vehicle. An inertia wheel responds to a second stimulus resulting from acceleration in withdrawal of the safety belt. The retractor includes: a movable plate; a driving gear fixed to the end of a reel shaft extending adjacent to the outside surface of the movable plate; and a driven gear fixed to a spindle mounted on the movable plate. The driven gear meshes with the driving gear. When accelerated rotation of the reel shaft and driving gear exceeds a predetermined rate, the driven gear moves around the driving gear, causing movement of the plate, which urges the pawl into locking engagement with the ratchet wheel. A lever is mounted above the pendulum. The pendulum is adapted to move the lever into contact with the inertia wheel, thereby inhibiting rotation of the inertia wheel. Thus, the pendulum does not directly affect the pawl, but rather places the inertia wheel in a condition wherein any pull on the safety belt causes the pawl to engage the ratchet instantly.

Claims

1. In a vehicle safety seat belt system the combination of a webbing retractor having a single inertial device responsive to two different stimuli to prevent pay-out of the safety belt webbing under emergency conditions, said combination comprising:

a. a support having a base and two walls extending therefrom;

b. a shaft journaled on the support adapted for connection to a seat belt, said shaft extending beyond the support wall;

c. a biasing member connected to the support and to the shaft, urging it to rotate in its winding direction;

d. a ratchet wheel fixed to the rotatable shaft;

e. a pawl mounted pivotally on the support for engagement with the ratchet wheel, said pawl being movable between a normally unlocked position and a locked position for engagement with the ratchet to stop rotation of the shaft in its unwind direction;

f. a normally stationary movable plate rotatable about the extending shaft for limited motion in a plane parallel to the outside surface of the support wall, said plate having an extension therefrom for urging the pawl into locking engagement with the ratchet wheel, said plate being biased to its normally stationary position;

g. a driving gear fixed to the end of the extending shaft, adjacent to the outside surface of the movable plate;

h. a driven gear concentrically fixed to a spindle, said spindle being perpendicular to the outer surface of the movable plate and rotatably supported thereon, said driven gear disposed to mesh with the driving gear;

i. an inertial wheel rotatable on the spindle and concentrically attached to the driven gear, whereby accelerated rotation of the shaft and attached driving gear exceeding a preselected rate induces movement of the driven gear around the driving gear, with consequent movement of the plate attached thereto, in opposition to its bias, with the extension of the plate urging the pawl into locking engagement with the ratchet;

j. a pendulum support fixed to a support wall, said pendulum support having an opening therein;

k. a free swinging pendulum comprising a pivoting member having a dimension greater than that of the opening in the support, a pendulum bob, and a rigid interconnecting shank, said pivoting member being disposed above the opening, with the shank terminating in the pendulum bob extending therethrough;

l. a lever pivotally mounted and disposed above the upper extension of the pendulum whereby movement of the pendulum will induce upward movement of the lever, urging it to contact and inhibit rotation of the inertial wheel, whereby rotation of the shaft and attached driving gear induces movement of the driven gear around the driving gear, moving the plate attached thereto in opposition to its bias, with the extension of the plate urging the pawl into locking engagement with the ratchet.

2. The combination of claim 1 wherein the attachment of the inertial wheel with the driven gear is a spring biased frictional attachment, in which the inertial wheel is adjacent to the driven gear on the spindle and rotatable thereon, and in frictional contact with a clutch plate slideably keyed to the spindle, and biased to the surfacE of the inertial wheel by a spring concentric to the spindle and retained thereon by a fastening member.

3. The combination of claim 1 wherein the attachment of the inertial wheel with the driven gear is a spring biased frictional attachment, in which the inertial wheel is adjacent to the driven gear on the spindle and rotatable thereon, said inertial wheel being recessed for receiving a spring concentrically disposed about the spindle and sandwiched between the inner surface of the recess and a clutch plate slideably keyed to the spindle, said clutch plate being retained on the spindle by a fastening member.

4. The combination of claim 1 wherein the inertial wheel has ratchet teeth on its periphery, disposed for locking engagement with the pivotally mounted lever.

5. The combination of claim 1 wherein the rotatable plate includes a rigid housing extending about the inertial wheel and its attached driven gear, said housing having parallel walls with opposing openings in each wall into which the spindle is journalled and supported.

6. The combination of claim 1 wherein the extension of the movable plate for urging the pawl into locking engagement with the ratchet wheel, is an arm terminating in a bifurcation, for biasing the extension of the pawl and the pawl of which it is a part, out of engagement with the ratchet wheel when the plate is in its normal stationary position and for urging the pawl into engagement with the ratchet wheel in response of the inertial device, to stimuli.

7. The combination of claim 1 wherein the ratio of the effective diameter of the driving gear to that of the driven gear lies within the range of 1.5:

1 to 10.0;

1.

8. The combination of claim 1 wherein the bias to the rotatable plate is supplied by a contraction spring fixed at one end to the support and at the other to the movable plate, to urge the extension thereto and the pawl with which the extension is in contact, out of engagement with the ratchet wheel.

9. The combination of claim 8 wherein there is provided adjustment means for varying the tension of the contraction spring.

10. The combination of claim 8 wherein the adjusting means comprises a tabular projection extending horizontally from the plate and substantially above the pawl, said tabular projection having a cylindrical opening perpendicular to the plate, said tabular projection also having a plurality of short equispaced channels in the surface of the side of the tabular projection facing the support wall, said channels radiating away from the axis of the cylindrical opening and each channel having a corresponding in-line channel on the opposite side of the cylindrical opening;

a cylindrical member rotatable and slideable within the cylindrical opening, said cylindrical member having at the end away from the support wall an enlarged portion contoured for receiving a tool for inducing rotary motion to the cylindrical member, said enlarged portion also having a perforate perpendicularly disposed extension for securing the end of the biasing contraction spring, the end of the cylindrical member toward the support wall having a transverse opening for the introduction of a short rod for engaging any selected two in-line channels;

a coiled compression spring disposed concentric to the cylindrical member between the enlarged portion of the cylindrical member and the tabular projection to thereby retain the short rod in engagement with any two in-line channels, whereby the application of force to rotate the enlarged portion of the cylindrical member changes the position of the perforate extension for the biasing contracting spring, to change its tension.

11. The combination of claim 1 wherein one ratchet wheel fixed to the shaft is disposed between the two support walls and adjacent to the wall, said inertial device being supported on the outside wall, and with the pawl extending pivotally between both walls for engagement with the ratchet wheel;

said pawl having a projecting member extending through the supporT wall for engaging the extension of the rotatable plate, said rotatable plate normally biasing the pawl to its disengaged position with the ratchet.

12. The combination of claim 1 wherein the pendulum pivoting member is a button-shaped disc, perpendicular to the shank from which the pendulum bob depends, so that angular displacement of the pendulum rocks the pivoting member toward its periphery and raises the pivotally mounted lever above it, to contact the inertial wheel and inhibit rotary motion.

13. The combination of claim 12 in which the disc has a centrally located depression in its upper surface corresponding to the protruding nodule beneath the pivoting lever, and the opening in the pendulum support has a raised collar extending upwardly from the plate, with the disc resting on the circular edge of this collar rather than directly on the surface of the pendulum support, said opening and surrounding collar being sized to permit the pendulum to swing through an arc of at least about 40*.

14. In a vehicle safety seat belt system, the combination of a webbing retractor having a single inertial device responsive to two different stimuli to prevent pay-out of the safety belt webbing under emergency conditions, said combination comprising:

a. a support having a base and two walls extending therefrom;

b. a shaft journaled on the support walls adapted for connection to a seat belt, said shaft extending beyond the support wall;

c. a biasing coiled spring connected to the support and to the shaft, urging the shaft to rotate in its winding direction;

d. at least one ratchet wheel fixed to the shaft and disposed between the two support walls, adjacent to the wall;

e. a pawl extending between both support walls for engagement with the ratchet wheel, said pawl being pivotable in the walls from a position of locking engagement with the ratchet wheel to a position of disengagement therewith, said pawl having additionally a projecting member extending through the support wall;

f. a normally stationary, movable plate rotatable about the extending shaft for limited motion in a plane parallel to the outside surface of the support wall, said plate having an arm extending therefrom for connection with the projecting member of the pawl, said movable plate being spring biased to its normally stationary position, with its extending arm biasing the pawl, with which it is in contact, into its disengaged position with the ratchet wheel;

g. a driving gear fixed to the end of the extending shaft adjacent to the outside surface of the movable plate;

h. a driven gear concentrically fixed to a spindle, said spindle being perpendicular to the outer surface of the movable plate and rotatably supported thereon, said driven gear disposed to mesh with the driving gear;

i. a clutch plate slideable longitudinally on the spindle and keyed thereto;

j. an inertial wheel rotatable on the spindle, said wheel having ratchet teeth on its periphery and having a circular concentric recessed clutch surface on its outer face;

k. a spring on the spindle with one end in the recess and compressed between the inertial wheel and the keyed clutch plate on the spindle, the components being retained under compression by means of a fastening member, at the end of the spindle opposite the driven gear;

l. a rigid housing about the inertial wheel and driven gear on the spindle, said housing extending from the movable plate and having an outer wall parallel to the surface of the movable plate with opposing openings, one opening in the plate and one in the outer parallel wall, into which openings the spindle is journaled and supported for rotation, whereby accelerated rotation of the shaft and attached driving gear exceeding a preselected rate, induces movement of the driven gear around the driving gear with consequent movement of the plate and extending arm attached thereto in opposition to the spring bias, with the arm urging the pawl into locking engagement witH the ratchet wheel;

m. a pendulum support fixed to a support wall, said pendulum support having an opening therein;

n. a free swinging pendulum comprising a button-shaped disc as a pivoting member, having a diameter greater than that of the opening in the support, a rigid shank perpendicular to the disc, extending downwardly therefrom through the opening in the pendulum support to terminate in a pendulum bob;

o. a lever, pivotally mounted, disposed above the button-shaped disc in a normally stationary position;

said lever being contoured for engaging the ratchet teeth of the inertial wheel when moved upwardly from its normally disengaged position, whereby movement of the pendulum will rock the button-shaped disc and lift the lever for engagement of the inertial wheel, whereupon minimal extension of the webbing will induce movement of the driven gear around the driving gear with consequent movement of the plate attached thereto, in opposition to its bias, with the arm extending from the plate urging the pawl into locking engagement with the ratchet wheel.

15. In a vehicle safety belt retractor having a shaft and belt webbing wound upon said shaft, wherein said retractor normally permits payout of the belt webbing and prevents payout of the webbing under emergency conditions, the improvement comprising:

a webbing-sensitive locking mechanism mounted on the retractor, responsive to withdrawal of the webbing at a pre-selected high rate of acceleration, and an independently mounted vehicle sensitive sensor which, in response to rapid acceleration or deceleration of the vehicle to which the retractor is attached, places said webbing sensitive locking mechanism in condition for actuation into locking engagement to prevent any further extension of the webbing;

said webbing sensitive locking mechanism including;

a plate, means mounting said plate on said retractor for movement between a stationary position and an actuated position, means biasing said plate to its normally stationary position, a driving member rotatably mounted on said shaft adjacent to said plate, a driven member, means for rotatably mounting said driven member on said plate, said driven member engaging said driving member, and an inertia wheel, means for rotatably mounting said inertia wheel on said plate, whereby acceleration in the payout of said webbing causes acceleration in rotation of said shaft and attached driving gear and induces movement of the driven member around the driving member, as a result of engagement between said driven member and said driving member, said movement of said driven member causing movement of the plate in opposition to its bias which actuates said locking mechanism to prevent further payout of the webbing;

said vehicle sensitive sensor including a pendulum and a lever movably mounted adjacent to said pendulum and said inertia wheel, whereby movement of said pendulum will induce movement of said lever, urging said lever into contact with said inertia wheel, thereby preventing further rotation of said inertia wheel, said vehicle sensitive sensor thereby placing said webbing sensitive locking mechanism in condition for actuation, said inertia wheel thereby being responsive to two different stimuli to prevent payout of the webbing under emergency conditions.

16. In a vehicle safety belt retractor having a shaft and belt webbing wound upon said shaft, wherein said retractor normally permits payout of the webbing and prevents payout of the webbing under emergency conditions, the improvement comprising:

a webbing-sensitive locking mechanism mounted on the retractor, responsive to withdrawal of the webbing at a pre-selected high rate of acceleration, and an independently mounted vehicle sensitive sensor which, in response to rapid acceleration or deceleration of the vehicle to which the retractor is attached, places said webbing sensitive locking mechanism in condition for actuation into locking engagement to prevent any further extension of the webbing;

said webBing sensitive locking mechanism including;

a movable means, means mounting said movable means on said retractor for movement between a stationary position and an actuated position, means biasing said movable means to its normally stationary position;

an inertia wheel, means for rotatably mounting said inertia wheel on said movable means;

gear means coupled to said shaft and to said movable means, said movable means responding to motion of said gear means, whereby acceleration in the payout of said webbing causes acceleration in rotation of said shaft and induces movement of the gear means as a result of said coupling between said gear means and said shaft, causing movement of the movable means to its actuated position in opposition to its bias, as a result of said coupling between said gear means and said movable means, said movable means actuating said locking mechanism to prevent further payout of the webbing;

said vehicle sensitive sensor including a pendulum means for locking said inertia wheel, preventing further rotation of said inertia wheel;

said vehicle sensitive sensor thereby placing said webbing sensitive locking mechanism in condition for actuation, said inertia wheel thereby being responsive to two different stimuli to prevent payout of the webbing under emergency conditions.