US3632057A

US3632057A - Time delay retractor

Info

Publication number: US3632057A
Application number: US34377A
Authority: US
Inventors: William L Pringle
Original assignee: Allied Chemical Corp
Current assignee: Allied Corp
Priority date: 1970-05-04
Filing date: 1970-05-04
Publication date: 1972-01-04
Anticipated expiration: 1989-01-04
Also published as: CA942269A

Abstract

A retracting reel assembly including a support means and a reel means which is rotatably supported by the support means and an elongated flexible seat belt connected to the reel means and adapted to be wound thereon and unwound therefrom. A locking bar is movable between a locked position engaging the reel means and an unlocked position for respectively preventing and allowing rotation of the reel means. There is also included time delay means for allowing the locking means to move to the locked position following the expiration of a predetermined period of time after the initial unwinding of the flexible element from the fully wound position. The time delay means includes a cup-shaped member and a flexible element which are connected together to define a closed chamber. A piston is movable in the chamber and is guided therein by a post and a flexible seal means coacts between the piston and the chamber. The seal means and the flexible wall of the chamber are an integral member and are disposed over an upwardly extending sleeve portion of the piston. The seal means is urged into sealing engagement with the chamber upon movement of the piston in the first direction and is freely movable out of its sealing engagement with the chamber upon movement of the piston in the second direction. The seal means has a passage therethrough to allow fluid flow or to meter fluid flow from one side of the piston to the other.

Description

United States Patent [72] Inventor William L. Pringle Grosse Pointe, Mich.

[21 Appl. No. 34,377

[22] Filed May 4, 1970 [45] Patented Jan. 4, 1972 [7 3] Assignee Allied Chemical Corporation Mount Clemens, Mich.

[54] TIME DELAY RETRACTOR 13 Claims, 6 Drawing Figs.

[52] US. Cl 242/1074, 188/317 [51] Int. Cl A62b35/02, B65h 75/48 [50] Field of Search 242/107 R,

107 SB, 107.4, 107.5, 107.6, 107.7;297/386, 388, 389; 280/150 SB ;188/316, 317; 16/66 Primary Examiner-Stanley N. Gilreath Assistant ExaminerWerner H. Schroeder AttorneysBamard, McGlynn & Reising and Jonathan Plaut ABSTRACT: A retracting reel assembly including a support means and a reel means which is rotatably supported by the support means and an elongated flexible seat belt connected to the reel means and adapted to be wound thereon and unwound therefrom. A locking bar is movable between a locked position engaging the reel means and an unlocked position for respectively preventing and allowing rotation of the reel means. There is also included time delay means for allowing the locking means to move to the locked position following the expiration of a predetermined period of time after the initial unwinding of the flexible element from the fully wound position. The time delay means includes a cup-shaped member and a flexible element which are connected together to define a closed chamber. A piston is movable in the chamber and is guided therein by a post and a flexible seal means coacts between the piston and the chamber. The seal means and the flexible wall of the chamber are an integral member and are disposed over an upwardly extending sleeve portion of the piston. The seal means is urged into sealing engagement with the chamber upon movement of the piston in the first direction and is freely movable out of its sealing engagement with the chamber upon movement of the piston in the second direction. The seal means has a passage 7 therethrough to allow fluid flow or to meter fluid flow from one side of the piston to the other.

PATENTEDJAH 4&572 3.432.057

SHEET 1 OF 2 I N VEN TOR. [MY/lam f. Hing/e ATTORNEYS PATENKU SHEET 2 or 2 TORNEYS TIME DELAY RETRACTOR This invention relates to safety seat belt assemblies of the type utilized in automobiles as restraining devices. It is common practice to utilize rollup or retracting assemblies which wind up at least one of the disconnected belt sections so that such sections do not remain loosely disposed on the seat when not in use. A deficiency in such devices is that the passengers rarely realize the amount of belt remaining in the retraction device once the belt is unwound therefrom. The biasing action, which tends to wind the seat belt onto the retraction device, is such that a passenger may buckle a seat belt believing that both sections of the seat belt are fully extended and are, therefore, taunt or tight. In actuality, however, and in many cases, the seat belt is not fully extended and in the event of a crash or sudden stop the seat belt will fully extend allowing the passenger to move a dangerous amount.

In order to alleviate this problem, there have been provided retracting assemblies wherein the retracting device is locked to prevent further extension of the seat belt once the seat belt has been partially extended and coupled about the passenger. Normally, a seat belt user will pull the two halves of the seat belt so that at least one-half is unwound from the retracting assembly to the point where the seat belt halves are coupled together at which time there occurs a slight bit of winding or retraction. To prevent further unwinding, retracting assemblies have been developed including a locking member which prevents further extension of the seat belt once the seat belt has been extended and is allowed to retract a slight amount. The problem with such devices is, however, that the passenger may extend the seat belt an amount which is not sufficient in the first instance and allow it to rewind a certain amount before buckling the seat belt halves together. This, of course, means that the seat belt cannot be extended further without allowing the entire belt to be retracted to the initial position before it may be extended or unwound the desired amount.

Further development work has overcome this problem by providing means for preventing movement of the locking means to the locked position until a predetermined time after the seat belt is initially unwound from the fully wound position. One type of such assembly is disclosed in US Pat. No. 3,193,327 wherein there is disclosed a closed fluid chamber or dashpot connected to the locking means to prevent the locking means from moving to the locked position until a predetermined time after the seat belt is initially moved from the fully wound position.

The problem with such prior art assemblies is that they either have fluid chambers open to atmosphere or are susceptable to leakage after use so that moisture may accumulate inside the chambers. If such moisture contains dissolved salt, it will crystalize and cause faulty operation. Also, dust seeping into the chambers can cause faulty operation. Additionally, many of the prior art fluid chamber time delay devices are comparatively expensive to manufacture and assemble.

Accordingly, it is an object and feature of this invention to provide a retracting reel assembly including a time delay means defined by a chamber and a flexible seal means for coacting between a piston and the chamber whereby the sealing means is urged into sealing engagement with the chamber upon movement of the piston is a first direction and is freely movable out of sealing engagement to allow fluid flow thereby upon movement of the piston in a second direction and wherein there is included passage means through the seal means for allowing fluid flow therethrough during movement of the piston in the first direction to control the length of time delay.

Other objects and attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. I is an exploded view of a preferred embodiment of the instant invention;

FIG. 2 is a plan view of the preferred embodiment of the instant invention;

FIG. 3 is a cross-sectional view taken substantially along line 3-3 of FIG. 2;

FIG. 4 is a view similar to FIG. 3 showing the locking means in the locked position to prevent further extension of the seat belt;

FIG. 5 is an enlarged cross-sectional view taken substantially along line 5-5 of FIG. 3; and

FIG. 6 is an enlarged cross-sectional view taken substantially along line 6-6 of FIG. 4.

Referring now to the drawings wherein like numerals indicate like or corresponding parts throughout the several views, a preferred embodiment of a retracting reel assembly constructed in accordance with the instant invention is generally shown at 10in FIGS. I and 2.

The reel assembly 10 includes a support means 12 comprising a U-shaped bracket having a base 14 and sidewalls I6 and 18.

The assembly 10 also includes a reel means generally in dicated at 20 and rotatably supported by the support means 12. The reel means 20 includes a shaft 22 which is rotatably supported by the

walls

16 and 18. A cylinder 24 is disposed concentrically about the shaft 22 and a pair of

circular ratchet members

26 and 28 are secured to the ends of the cylinder 24 and to the ends of the shaft 22. The cylinder 24 has a slot 30 extending therealong. The reel means 20 also includes first biasing means comprising the spiral spring 32 for urging the cylinder 24 and the

ratchet members

26 and 28 to rotate in a winding direction. The spring 32 has one end 34 disposed in a slot 36 in the shaft 22 and the other end 38 disposed in a slot 40 in the cover 42, the cover 42 being secured to the outside ofthe wall 18.

The assembly 10 also includes an elongated flexible element or a seat belt 44 which is connected to the reel means 20 and adapted to be wound thereon and unwound therefrom. More specifically, the seat belt is attached to the shaft 22 by being looped thereabout and extends through the slot 30 in the cylinder 24. A tongue 46 is attached to the seat belt 44, the tongue 46 being of the well-known type adapted to be inserted into a buckle.

The reel assembly 10 also includes a locking means comprising a pawl 48 which is movable between unlocked and locked positions as respectively shown in FIGS. 3 and 4. When the locking pawl 48 is in the locked position illustrated in FIG. 4, it engages the

ratchet members

26 and 28 to prevent rotation of the reel means in the unwinding direction. When the locking pawl 48 is in the unlocked position illustrated in FIG. 3 it allows free rotation of the reel means. A spring 50 urges the locking pawl 48 to rotate toward the locked position.

There is also included a means comprising the finger 52 for moving the locking pawl 48 from the locked to the unlocked position as the seat belt 44 is wound onto the reel means. As the seat belt 44 is wound upon the reel means 20, it engages the ginger 52 to move the finger 52 to the left, as shown in FIGS. 3 and 4, as additional seat belt webbing 44 is wound about the cylinder 24.

The reel assembly 10 also includes time delay means generally shown at 54 for allowing the locking pawl to move to the locked position shown in FIG. 4 following the expiration of a predetermined period of time after the initial unwinding of the seat belt 44 from the fully wound position illustrated in FIG. 3. More specifically, the time delay means includes a closed chamber which is in part defined by a cup-shaped member 56. The base 14 has a hole 58 therein and the cupshaped member 56 has a projection 60 extending into the hole 58 for positioning the time delay means 54. The cup-shaped member 56 may be secured to the base 14 by an adhesive or by any other appropriate means. The remainder of the closed chamber is defined by the flexible wall 62.

A piston 64 is movable within the chamber and includes a sleeve portion 66 and a disk portion 68.

Also included is a seal means 70 coacting between the piston 68 and the inner wall of the cup-shaped member 56. The seal means 70 is urged into sliding sealing engagement with the inner wall of the cup-shaped member 56 upon movement of the piston is a first upward direction from the position shown in FIG. 5. The seal means 70 however is freely movable out of sealing engagement with the inner wall of the cupshaped member 56 upon movement of the piston 68 in a second direction opposite to the first direction, i.e., downward from the position shown in FIG. 6. The seal means 70 has a passage 72 therethrough for fluid flow therethrough during sealing engagement with the inner wall of the cup-shaped member 56.

There is also included a biasing means comprising a spring 74 for urging the piston 68 to move upwardly in the first direction.

A guide means comprising the post 76 coacts with the sleeve portion 66 of the piston 64 for preventing movement of the piston 64 to that which is in the first and second up and down directions. The post 76 is integral with and extends upwardly from the base of the cup-shaped member 66.

The seal means 70 and the flexible wall 62 are defined by an integral member which includes a cover portion 78 disposed about and over the sleeve portion 66 of the piston 64. Thus, the flexible wall 62 is attached to the piston 64 for movement therewith. Preferably the integral member defining the seal means 70, the flexible wall 62 and the cover portion 78 is made of silicone rubber.

Further, the cup-shaped member 56 is preferably made of a plastic such as a polycarbonate resin, as for example, such a resin sold under the trademark Delrin by the Du Pont Company. The flexible wall 62 is secured to the cup-shaped member 56 by heat sealing whereby the upper rim 80 is bent over under heat and sealed about a lip 82 of the wall 62.

The seal means 70 extends radially outwardly from the cover portion 78 near the bottom thereof and overlies or rests upon the disk portion 68 of the piston 64. The seal means 72 terminates in an annular curled-up flap 84 which engages the inner wall of the cup-shaped member 56 so as to be in sealing engagement therewith during upward movement. The disk portion 68 of the piston 64 terminates in spaced relation to the inner wall of the cup-shaped member 56. In other words, the outer periphery of the disk portion 68 is in spaced relation to the inner wall of the cup-shaped member 56. Disk portion 68 of the piston 64 is inclined upwardly toward the perimeter thereof beneath the seal means 70. Thus, as the piston 64 moves upwardly from the position shown in FIG. 5, the curledup flap 84 will be urged into sealing engagement with the inner wall of the cup-shaped member 56, but as the piston moves downwardly air or gases below the piston may move upwardly about the periphery of the' disk portion 68 of the piston, and move the curled-up flap 84 out of sealing engagement with the inner wall of the cup-shaped member 56.

To allow the free flow of air from the top side of the seal means 70 to the space therebelow, a groove 86 extends radially inwardly from the perimeter of the disk portion 68 and beneath the seal means 70 to communicate with the passage means 72 in the seal means 70. When the piston moves upwardly from the position illustrated in FIG. 5, air flows through the passage 72 and through the groove 86 and the amount of air thus flowing will control the speed at which the piston moves upwardly.

The inner wall of the cup-shaped member 56 has a shoulder 88 defined by an enlarged portion of the chamber which does not seal with the curled-up flap 84 of the seal means 70 when the piston 64 has moved a predetermined amount in the first upward direction. Thus, once the curled-up flap 84 reaches the shoulder 88 air freely moves to the upper side of the seal means 70 whereby the piston 64 moves very rapidly upwardly under the energy or force of the spring 74.

A wire hook 90 is in mechanical interlocking engagement with a tab 92 extending from the locking pawl 48.

In operation, the assembly is normally in the fully wound condition illustrated in FIG. 3. If if is desirous to utilize the seat belt 44, the tongue 46 is grasped and the seat belt 44 is unwound from the reel means 20 as the shaft 22, the cylinder 24, and the

ratchet members

26 and 28 are rotated in the counterclockwise direction as illustrated in FIG. 3. When the seat belt 44 is fully wound on the reel means, as illustrated in FIG. 3, the time delay means 54 is in the position illustrated in FIG. 5. Upon unwinding of the seat belt 44, the finger S2 is free to move radially inwardly except that the time delay means 54 prevents the locking pawl 48 from moving to the fully locked position shown in FIG. 4 until the piston 64 has moved upwardly sufficiently that the curled-up flap 84 passes the shoulder 88. The amount of time that it takes for the piston to move this distance is controlled by the metering of gases through the passage 72 and the groove 86. During this predetermined period of time, however, the user of the seat belt may extend the seat belt and move the seat belt back and forth to the proper position before the locking pawl 48 is allowed to move to the fully locked position illustrated in FIG. 4. As the seat belt is rewound on the reel means, the finger 52 moves the locking pawl 48 rearwardly and turns the time delay means 54 from the condition shown in FIG. 6 to that shown in FIG. 5.

The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A retracting reel assembly comprising: support means; reel means rotatably supported by said support means; an elongated flexible element connected to said reel means and adapted to be wound thereon and unwound therefrom; locking means movable between locked and unlocked posi tions for respectively preventing and allowing rotation of said reel means; and time delay means for allowing said locking to move to said locked position following the expiration of a predetermined period of time after the initial unwinding of said flexible element from the fully wound position, said time delay means including a closed chamber, said chamber including a cup-shaped member, a piston movable in said chamber and flexible seal means for coacting between said piston and said chamber, said seal means being urged into sliding engagement with said chamber upon movement of said piston in a first direction, said seal means being freely movable out of said sealing engagement with said chamber upon movement of said piston in a second direction opposite to said first direction, said seal means having passage means therethrough for fluid flow therethrough during said sealing engagement, and guide means comprising a post extending upwardly from the base of said cup shaped member coacting with said piston for limiting movement of said piston to that in said first and second directions.

2. An assembly as set forth in claim 1 wherein said chamber includes a flexible wall attached to said piston for movement therewith.

3. An assembly as set forth in claim 2 wherein said seal means is made of silicone rubber.

4. An assembly as set forth in claim 2 including biasing means for urging said piston to move in said first direction.

5. An assembly as set forth in claim 1 wherein said piston includes a sleeve portion and a disk portion, said sleeve portion being disposed in sliding engagement about said post.

6. An assembly as set forth in claim 5 wherein said seal means and said flexible wall are defined by an integral member including a cover portion disposed about and over said sleeve portion of said piston.

7. An assembly as set forth in claim 6 wherein said seal means extends radially outwardly from said cover portion and overlaps said disk portion of said piston and terminates in an annular curled-up flap which engages the inner wall of said cup-shaped member so as to be in said sealing engagement.

8. An assembly as set forth in claim 7 wherein said disk portion of said piston terminates in spaced relation to said inner wall of said cup-shaped chamber.

9. An assembly as set forth in claim 8 including a groove extending radially inwardly from the perimeter of said disk portion and beneath said seal means to communicate with said passage means in said seal means.

10. An assembly as set forth in claim 9 wherein said disk portion of said piston is at least in part inclined upwardly toward the perimeter thereof beneath said seal means.

11. An assembly as set forth in claim 10 wherein said inner wall of said cup-shaped member has a shoulder defining an enlarged portion which does not seal with said seal means when said piston has moved a predetermined amount in said first direction.

12. An assembly as set forth in claim 11 wherein said reel means includes a shaft rotatably supported by said support means, a cylinder disposed concentrically about said shaft, a pair of circular ratchet members secured to the ends of said cylinder and to said shaft, said cylinder having a slot extending therealong and said flexible element being attached to said shaft and extending through said slot, and first biasing means for urging said cylinder and ratchet members to rotate in a direction to wind said flexible element onto said cylinder; and said locking means includes a pawl engageable with said ratchet members in said locked position, and second biasing means urging said pawl toward said locking position.

13. An assembly as set forth in claim 1 wherein said chamber includes an enlarged portion which does not seal with said seal means when said piston has moved a predetermined amount in said first direction.

Claims

1. A retracting reel assembly comprising: support means; reel means rotatably supported by said support means; an elongated flexible element connected to said reel means and adapted to be wound thereon and unwound therefrom; locking means movable between locked and unlocked positions for respectively preventing and allowing rotation of said reel means; and time delay means for allowing said locking to move to said locked position following the expiration of a predetermined period of time after the initial unwinding of said flexible element from the fully wound position, said time delay means including a closed chamber, said chamber including a cup-shaped member, a piston movable in said chamber and flexible seal means for coacting between said piston and said chamber, said seal means being urged into sliding engagement with said chamber upon movement of said piston in a first direction, said seal means being freely movable out of said sealing engagement with said chamber upon movement of said piston in a second direction opposite to said first direction, said seal means having passage means therethrough for fluid flow therethrough during said sealing engagement, and guide means comprising a post extending upwardly from the base of said cup shaped member coacting with said piston for limiting movement of said piston to that in said first and second directions.