US3603525A

US3603525A - Retracting reel assembly

Info

Publication number: US3603525A
Application number: US841310A
Authority: US
Inventors: William L Pringle; John S Cucheran
Original assignee: Jim Robbins Seat Belt Co
Current assignee: Jim Robbins Seat Belt Co
Priority date: 1969-07-14
Filing date: 1969-07-14
Publication date: 1971-09-07
Anticipated expiration: 1988-09-07

Abstract

A retracting reel assembly including a U-shaped support member rotatably supporting a reel means upon which a flexible belt element is wound and unwound. A locking pawl is supported by the support member for movement to and from a locking position for preventing rotation of the reel means in the unwinding direction. A clutch member engages the locking pawl and is rotated by the reel means for moving the locking pawl to the locking position. A cam operated stop member is movable to and from a position for preventing movement of the clutch member which would move the locking member to the locked position until a predetermined length of the flexible belt has been unwound from the reel means. There is also included a delay means comprising an electromagnet operable upon the locking pawl, and circuit means for controlling current flow to the electromagnet for preventing movement of the locking pawl to the locked position for a predetermined period following the initial portion of unwinding of the flexible belt from the reel means.

Description

United States Patent [72] Inventors William L. Pringle Grosoe Pointe;

John S. Cucheran, Pleasant Ridge, both of,

Mich. [2]] Appl. No. 841,310 [22] Filed July 14, 1969 [45] Patented Sept. 7, 1971 [73] Assignee Jim Robbins Seat Belt Co.

' Mt. Clemens, Mich.

[54] RETRACIING REEL ASSEMBLY 9 Claims, 7 Drawing Figs.

[52] US. Cl. 242/1074 [51] Int. CL B65h 75/48 [50] Field oiSeareh 242/107,

280/ l 50 SB [56] References Cited UNITED STATES PATENTS 3,l93,327 7/1965 Roe 297/388 3,343,764 9/1967 Webb, Jr. 242/l07.4 3,412,952 11/1968 Wohlert et a]. 242/l07.4 3,450;368 6/1969 Glauser et al... 242/1074 Primary Examiner-Stanley N. Gilreath Assistant ExaminerWerner H. Schroeder Attorneys-Marvin Bressler and Jonathan Plaut ABSTRACT: A retracting reel assembly including a U-shaped support member rotatably supporting a reel means upon which a flexible belt element is wound and unwound. A locking pawl is supported by the support member for movement to and from a locking position for preventing rotation of the reel means in the unwinding direction. A clutch member engages the locking pawl and is rotated by the reel means for moving the locking pawl to the locking position. A cam operated stop member is movable to and from a position for preventing movement of the clutch member which would move the locking member to the locked position until a predetermined length of the flexible belt has been unwound from the reel means. There is also included a delay means comprising an electromagnet operable upon the locking pawl, and circuit means for controlling current flow to the electromagnet for preventing movement of the locking pawl to the locked position for a predetermined period following the initial portion of unwinding of the flexible belt from the reel means.

RETRACTING REEL ASSEMBLY This invention relates to safety seatbelt assemblies of the type utilized in automobiles as restraining devices. It has been common practice to utilize rollup or retracting assemblies which wind up or retract at least one-half of the disconnected belt sections so that such sections do not remain loosely disposed on the seat when not in use. The 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 retract the seatbelt into the retraction device, is such that a passenger may buckle a seatbelt believing that both sections of the seatbelt are fully extended and are, therefore, taut or tight, i.e., cannot be extended further. In actuality, however, and in many cases, the seatbelt is not fully extended and in the event of a crash or sudden stop the seatbelt 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 seatbelt once the seatbelt has been partially extended and coupled about the passenger, Normally, a seatbelt used will pull the two halves of the seatbelt so that at least one-half is extended from the retracting assembly to the point where the seatbelt halves are coupled together at which time there occurs a slight bit of winding or retraction. To prevent further extension or unwinding retracting assemblies have been developed including a locking member which prevents further extension of the seatbelt once it has been extended and is allowed to retract or rewind a certain amount. The problem with such device is, however, that the passenger may extend the seatbelt an amount which is sufficient in the first instance and allow it to rewind or retract a certain amount before buckling the seatbelt halves together. This, of course, means that the seatbelt 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. To overcome this problem other retracting assemblies have been developed which include delay or timing means to prevent the locking pawl from moving to the locking position for a predetermined period so that the seatbelt may be extended and retracted for a predetermined period of time after the initial extension of the seatbelt. Such assemblies which have been developed thus far are, however, deficient in that the components utilized for providing the time delay are subject to malfunction. The resultof such a malfunction is that either the seatbelt cannot be extended at all or the locking member is rendered inoperative to prevent further extension of the seatbelt once in the proper position about an occupant.

Accordingly, it is an object and feature of this invention to provide a retracting assembly including locking means for preventing extension of the flexible belt element in response to a predetermined amount of extension followed by a predetermined amount of retraction and delay means responsive to a predetermined condition for rendering the locking means inoperative to prevent the extension and wherein the locking means is operative upon failure ofthe delay means.

In correlation with the foregoing object and feature, is another object and feature of this invention to provide such a retraction assembly wherein the locking means includes a locking pawl movable to and from a locked position for preventing unwinding rotation of a reel means and clutch means for moving the locking pawl and stop means for preventing movement of the locking pawl by the clutch means and wherein the delay means includes an electromagnet cooperable with the locking pawl to prevent movement of the locking pawl to the locked position and control means for rendering the electromagnet operable to retain the locking pawl in the locked position for a predetermined period after the initial portion of the unwinding of the flexible belt from the reel means.

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 accompany drawings wherein:

FIG. l is a perspective view of a preferred embodiment in the instant invention;

FIG. 2 is an exploded view of the preferred embodiment;

FIG. 3 is a fragmentary plan view of the preferred embodiment;

FIG. 4 is a cross-sectional view taken substantially along line 4-4 ofFIG. 3.

FIG. 5 is a cross-sectional view taken substantially along line 5-5 of FIG, 3.

FIG. 6 is a view similar to FIG. 5 but showing the locking pawl in the locked position; and

FIG. 7 is a schematic view of an electrical circuit which may utilized in the instant invention.

Referring now to the drawings wherein like numerals indicate like corresponding parts throughout the several views, a retracting reel assembly constructed in accordance with the instant invention is generally shown at 10.

Referring now to FIGS. l and 2, the retracting reel assembly 10 includes support means generally indicated at 12, reel means generally indicated at M and rotatably supported by said support means 12, and elongated flexible seatbelt element generally indicated at 16 and connected to said reel means 14 and adapted to be wound thereon and unwound therefrom, locking means generally shown at 18 for preventing unwinding ofthe flexible element 16 after a predetermined amount of unwinding followed by a predetermined amount of winding, and delay means generally indicated at 20 for rendering the locking means I8 inoperable to prevent the unwinding for a predetermined period following the initial portion of the unwinding.

The support means 12 includes a generally U-shaped bracket or support member having a base 22 and

parallel sidewalls

24 and 26. The base 22 of the support means 12 has a hold 23 extending therethrough whereby a fastening means may be utilized to secure the support member to a vehicle. The support means also includes a shaft 28 which is rotatably supported by and extends through the

sidewalls

24 and 26.

The reel means l4 includes a cylinder 30 disposed concentrically about the shaft 28. Circular platelike ratchet members 32 and 343 are secured to the ends of the cylinder 30 and to the shaft 28 so as to rotate with the shaft 28. The cylinder 3t) has a slot 36 (as shown in FIG. 5) extending therealong and the flexible belt element 16 is connected to or looped about the shaft 28 and extends through the slot 36 to be wound about and unwound from the cylinder 30. A tongue 17 is secured to the end of the flexible seatbelt element 16 and is adapted to be cou pled to a buckle (not shown). The reel means also includes biasing means comprising the spiral spring 38 for urging the shaft 28, and, therefore, the

ratchet members

32 and 34 and the cylinder 30, to rotate in the winding direction. One end of the spring 38 is disposed in a slot 39 in the shaft 28 and the other end of the spring 38 is disposed in a slot 40 in the housing 41, the housing 41 being secured to the outside of the wall 24 of the support member.

The locking means 18 includes a locking pawl 42 which is movable between an unlocked position for allowing rotation of the reel means, as illustrated in FIG. 5, and a locked position for preventing rotation of the reel means, as illustrated in FIG. 6. The locking pawl 42 is an elongated member having flanges at either end through which a pin 44 extends to rotatably support the locking pawl 42. The

ratchet

32 and 34 have teeth disposed thereabout which are engaged by the upper edge 46 of the locking pawl 42. The locking pawl also has an extension 48 extending from its upper edge 46, the purpose of which will become clear hereinafter. The locking means I8 also includes clutch means comprising a clutch plate 50, a friction member 52, and a spring or biasing means 54. The clutch means moves the locking pawl 42 between the locked and unlocked positions in response to rotation of the reel means 14. The clutch plate 50 is rotatably supported on the shaft 28 between the first of the ratchet members 32 and the adjacent sidewall 24. The friction member 52 is disposed between the clutch plate 50 and the first ratchet member 32. The spring 54 is disposed between the clutch plate 50 and the adjacent sidewall 24 for biasing the clutch plate 50 into engagement with the friction member 52. Upon rotation of the ratchet member 32, the clutch plate 50 will rotate unless prevented from doing so. The clutch plate 50 is operatively connected to the locking pawl 42 through a pin 56 and slot 58.

The locking means 18 further includes movable stop means comprising a stop member 60, a cam member 62, a cam follower 64, and linkage 66 interconnecting the cam follower 64 and the stop member 60. The stop means prevents movement of the locking pawl 42 to the locked position by the clutch plate 50 until a predetermined length of the flexible belt element 16 has been unwound from the reel means, i.e, the

ratchet members

32 and 34 have rotated a predetermined number of revolutions. The clutch plate 50 has a recess 68 which includes a shoulder 70. The stop member 60 is engageable with the clutch plate 50 and is movable to a stop position engaging the shoulder 70 for preventing rotation of the clutch plate 50 in the direction for moving the locking pawl 42 to the locked position The stop member 60 is movable to a release position disposed in the large part of the recess 68 for allowing the rotation of the clutch plate 50 to move the locking pawl 42 to the locked position. The stop member 60 is supported by a leaf spring type member 72 which is secured to the base 22 and urges the stop member 60 to move to the release position. During the initial unwinding, the clutch plate 50 is urged to rotated in the clockwise direction as viewed in FIG. 2 whereby the stop member 60 engages the shoulder 70 and is retained therein. Once extension or unwinding of the belt is sufficient and there occurs a slight rewinding or retracting movement, the clutch plate 50 rotates in the counterclockwise direction as viewed in FIG. 2 and the stop member 60 moves into the recess 68 whereupon further extension of the seatbelt rotates the clutch plate 50 in the clockwise direction to move the locking pawl 42 into the locked position due to the coaction between the pin 56 and the slot 58. The cam member 62 is secured to the second ratchet member 34 so as to be rotatable therewith and has a cam track 74 which is at least in part spirally disposed about an axis of the shaft, i.e., disposed in a plane substantially perpendicular to the shaft 28. The cam follower 64 is disposed in the cam track 74 at one end and is rotatably disposed about the wirelike member comprising the linkage means 66. The linkage means 66 has each end thereof rotatably disposed in the

sidewalls

24 and 26 and has an offset portion operatively connected to the stop member 60 and an irregular portion 76 which is engaged by the length of the cam follower 64. When the flexible seatbelt element 16 is in the fully retracted position, the end of the cam follower 64 which is disposed in the cam tract 74 is disposed radially outwardly of the cam member 62 and the length of the cam follower 64 engages the irregular portion 76 to rotate and maintain the stop member 60 in the stop position engaging the shoulder 70. Upon extension of the flexible seat element 16 the end of the cam follower 64 moves radially inwardly to allow the stop member 60 to move to the release position whereby the clutch plate 50 may move in a clockwise direction as viewed in FIG. 2. In other words, the linkage means 66 operatively interconnects the cam follower 64 and the stop member 60 so that the stop member 60 is prevented from moving from the stop position engaging the shoulder 70 until the cam follower 64 has been moved radially relative to the axis of the shaft 28 a predetermined amount as a result of the unwinding of the flexible seatbelt element 16 a predetermined length as the reel means is rotated.

The delay means includes a retention means comprising the electromagnet 80 which is engageable with the extension 48 of the locking pawl 42 for retaining the locking pawl 42 in the unlocked position illustrated in FIG. 5. The electromagnet is selectively operable to retain the locking pawl 42 in the unlocked position. The delay means 20 further includes control means comprising the switch 82 and the circuit breaker means 84. The control means renders the electromagnet 80 operable to retain the locking pawl 42 in the unlocked position for a predetermined period following the initial portion of the unwinding of the flexible seatbelt element 16 from the reel means. The switch 82 includes an arm 86 which engages the flexible belt element 16 as it is wound about the reel means. When the flexible seatbelt element 16 is unwound from the reel means, the arm 86 rotates from the position illustrated in FIG. 5 to the position illustrated in FIG. 6 to close the switch 82 thereby supplying current to the electromagnet 80. The switch 82 is, therefore, responsive to initial unwinding of the flexible seatbelt element 16 for activating the electromagnet 80 by supplying current thereto. Upon activation of the electromagnet 80 a magnetic force is created which acts upon the extension 48 of the locking pawl 42 to hold the locking pawl 42 in the unlocked position illustrated in FIG. 5. The magnetic force supplied by the electromagnet 80 is sufficient to prevent the clutch plate 50 from moving the locking pawl 42. The circuit breaker means 84 discontinues the current flow to the electromagnet 80 at the end of the predetermined period following the initial portion of unwinding of the flexible seatbelt element 16. The circuit breaker means 84 includes switch contacts 88 which are secured to the

strips

89 and 90. The strip 90 is a bimetallic strip with the coil 92 disposed thereabout, although this is not shown schematically in FIG. 7. The contact points 88 are normally closed and when the switch 82 is closed current passes through the electromagnet 80 and through the coil 92 which is disposed about the bimetallic strip 90. Current flows until the coil 92 heats the bimetallic strip 90 sufficiently that the contact points 88 move apart breaking the circuit. Upon breaking the circuit, the electromagnet 80 is rendered inoperative and the magnetic field is discontinued. Once the electromagnet 80 has been rendered inoperative and upon a slight rewinding of the flexible belt ele ment 16 followed by an extension of unwinding of the flexible belt element 16, the clutch plate 50 will move the locking pawl 42 into the locked position to prevent further unwinding or extension of the flexible seatbelt element 16.

In operation, the retracting assembly is normally in a stored condition wherein the flexible seatbelt element 16 is fully retracted as indicated in FIGS. 3 and 5. The assembly operates such that the flexible seatbelt element 16 may be unwound or extended and moved back and forth to the appropriate position for a predetermined period of time. Normally the tongue 17 will be coupled to a buckle within the predetermined period of time that the seatbelt element is allowed to move freely back and forth. After the predetermined period of time has expired, the winding of slight retraction of the seatbelt element 16 followed by an extension will move the locking pawl 42 into locking engagement with the reel means to prevent further extension of the seatbelt element 16. This is accomplished in that upon initial unwinding of the seatbelt element 16 the switch 82 is closed supplying current to the electromagnet 80 which in turn acts upon the extension 48 of the locking pawl 42 to hold the locking pawl 42 in the unlocked position. The locking pawl 42 will be retained in the unlocked position until the coil 92 heats up the bimetallic strip 90 sufficiently to move the contacts 88 apart discontinuing current flow through the electromagnet 80. At this time a slight retraction of the seatbelt element 16 followed by an extension thereof will rotate the clutch plate 50 in a clockwise direction as viewed in FIG. 2 to move the locking pawl 42 to the locked position engaging the teech on the

ratchet members

32 and 34 to prevent further extension of the seatbelt element 16. When the tongue 17 is disconnected from the buckle, the spring 38 effects a winding of the seatbelt element 16 onto the reel means and returns the assembly to the initial storage condition. Should the delay means 20 malfunction or fail, the seatbelt element 16 may be extended and buckled but will be prevented from further extension once it has retracted a slight amount because the clutch means and the step means will continue to operate without the locking pawl 42 being prevented from moving to the locked position for a predeterminedperiod.

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 and unwound therefrom;

a locking pawl;

a clutch means for moving said locking pawl, in response to rotation of said reel means, between an unlocked position for allowing rotation of said reel means and a locked position for preventing rotation of said reel means;

retention means engageable with said locking pawl for retaining said locking pawl in said unlocked position for a predetermined period following the initial portion of said unwinding.

2 An assembly as set forth in claim 1 including control means for rendering said retention means operable to retain said locking pawl in said unlocked position.

3. An assembly as set forth in claim 1 including movable stop means for preventing movement of said locking pawl to said locked position by said clutch means until a predetermined length of said flexible element has been unwound from said reel means.

4. An assembly as set forth in claim 3 wherein said clutch means and said stop means are mechanically connected to and operated by said reel means.

5. An assembly as set forth in claim 3 wherein said retention means comprises an electromagnet.

6. An assembly as set forth in claim 5 wherein said control means includes a switch responsive to initial unwinding of said flexible element for activating said electromagnet by supplying current thereto.

7. An assembly as set forth in claim 6 wherein said control means further includes circuit breaker means for discontinuing current flow to said electromagnet at the end of said predetermined period following the initial portion of said unwinding.

8. An assembly as set forth in claim 7 wherein said clutch means and said stop means are mechanically connected to and operated by said reel means.

9. An assembly as set forth in claim 8 wherein: said support means includes a generally U-shaped bracket having a base and parallel sidewalls, and a shaft rotatably supported by said sidewalls; said reel means includes a cylinder disposed concentrically about said shaft, a circular platelike ratchet member secured to each end of said cylinder and to said shaft, said cylinder having a slot extending therealong and said flexible element being connected to said shaft and extending through said slot to be wound and unwound about said cylinder, and biasing means for urging said rachet members and said shaft to rotate in the winding direction; said electromagnet is supported on said base and said locking pawl is supported by and extends between said walls and includes an extension engageable with said electromagnet; said clutch means comprises a clutch plate rotatably supported on said shaft between a first of said ratchet members and the adjacent sidewall, a friction member disposed between said clutch plate and said first ratchet member, and means biasing said clutch plate into engagement with said friction member, said clutch plate being operatively connected to said locking pawl through a pin and slot arrangement; and said stop means includes a stop member engageable with said clutch plate and movable between a stop position for preventing rotation of said clutch plate in the direction for moving said locking pawl to said locked position and a release position for allowing such rotation of said clutch plate, a cam member secured to the second of said ratchet members and having a cam track which is at least in part spirally disposed about the axis of said shaft, a cam follower disposed in said cam track, and linkage means operatively interconnecting said cam follower and said stop member so that said stop member is prevented from moving from said stop position until said cam follower has been moved radially relative to said axis a predetermined amount as a result of the unwinding of said flexible element said predetermined length to rotate said reel means.

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 and unwound therefrom; a locking pawl; a clutch means for moving said locking pawl, in response to rotation of said reel means, between an unlocked position for allowing rotation of said reel means and a locked position for preventing rotation of said reel means; retention means engageable with said locking pawl for retaining said locking pawl in said unlocked position for a predetermined period following the initial portion of said unwinding. CM,2Sembly as set forth in claim 1 including control means for rendering said retention means operable to retain said locking pawl in said unlocked position.