Winding – tensioning – or guiding – Reeling device – With spring motor
Reexamination Certificate
1999-09-28
2001-03-13
Walsh, Donald P. (Department: 3653)
Winding, tensioning, or guiding
Reeling device
With spring motor
C242S378100
Reexamination Certificate
active
06199785
ABSTRACT:
CROSS-REFERENCES TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the field of winding devices, and more particularly, to a ratchet mechanism for a retractor. Although the present invention is subject to a wide range of applications, it is especially suited for use as a small-card retraction device, and will be particularly described in that connection.
2. Description of the Related Art
A ratchet mechanism for a retractor prevents the retractor from retracting a cord into the housing of the retractor. Typically, ratchet mechanisms consist of a pawl which has a spring or gravity return and in the case of a mechanics rachet wrench the pawl can be “one direction” locking through a lever so that force can be applied in either a clockwise (CW) or counterclockwise (CCW) direction. Other similar devices, for example, spring-driven clock escapements, are intended to arrest a toothed gear from continuous movement to incremental rotation. All subject similar devices use a pawl which is fixed in the mechanism by a pivot pin. The pawl can be influenced in one direction by a spring or the force of gravity. The pawl is rendered inactive, or caused to be reversible, by a lever actuator.
In one example of a conventional retractor, U.S. Pat. No. 4,901,938 discloses an electrical cord retractor. A spiral spring biases a spool in the CW direction. A detent formed of a strip of springy metal is fixed at one of its ends to the inner surface of a base by a pin. Intermediate its ends, the detent presents a bulge adapted to engage indentations in a toothed wheel. When the bulge engages in one of the indentations, the detent prevents rotation of the spool under the influence of the spring.
An elongated actuator has one end located adjacent to the bulge and the other end extends through a hole in the base and carries a pushbutton. When the pushbutton is depressed, an end of the actuator pushes the bulge out of engagement with the indentations, thereby releasing the latching function of detent and wheel so as to free the spool for rotation by the spring. When the pushbutton is released, the resilience of the detent returns the actuator to its initial position and permits the bulge to engage one of the indentation to relatch the spool.
Although suitable for some applications, this retractor, however, does not allow the cord to be freely pulled out the ratchet wheel without actuating the lever and is an elaborate design requiring many parts that increases the cost of the retractor.
In another example of a conventional retractor, U.S. Pat. No. 5,509,616 discloses a retractable chalk line device. In particular, it discloses a thumb slide assembly for controlling the spool. The thumb slide assembly includes a thumb grip slidably mounted on a casing. A pair of opposed tabs project from the thumb grip and straddle the spool and engage associated teeth which are located on the opposing faces of the spool. When the grip is in a neutral position, the opposed tabs are disengaged from the spool teeth, allowing dispensing or retraction of the string. When the thumb grip is in a locked position, the opposed tabs are engaged with the spool teeth to restrict movement of the string.
Although suitable for some applications, this retractor, however, has the tabs in direct engagement with the teeth, which required the thumb assembly and teeth to be reinforced to handle the excessive wear and tear. Further, this retractor does not allow the cord to be freely pulled out without actuating the thumb assembly once it is in the locked position.
All of the above described devices require a number of expensive components, operate both above and to the side of the rotating member, take up an inordinate amount of space, and are typically reinforced to transmit torque from one rotating member to another.
A need therefore exists for a ratchet mechanism for a reel that provides the advantages of allowing the string to be freely pulled out the ratchet wheel without actuating the lever, simplifying the actuator design, and reducing the cost of the ratchet mechanism.
BRIEF SUMMARY OF THE INVENTION
The present invention, which tends to address this need, resides in an improved ratchet mechanism for a retractor. The ratchet mechanism described herein provides advantages over known ratchet mechanisms in that it allows the string to be freely pulled out and latched without actuating the lever, simplifies the actuator design, and reduces the cost of the ratchet mechanism. Further, the ratchet mechanism does not disturb the face of the reel, which leaves it available for decoration.
According to the present invention, a spring driven spool is prevented from rotation by a detent integrally formed on a flat spring disposed between a sidewall of the reel and the outside diameter surface of the spool. The detent engages a notch formed in the outside diameter surface when the notch rotates to the position of the detent, thus preventing the spool to rotate in a winding direction. The detent automatically disengages from the notch as the spool rotates in an unwinding direction. A thumb slide is mounted in the sidewall and engages the flat spring. The thumb slide acts on the flat spring to disengage the detent from the notch, thus allowing the spring-driven spool to rewind.
In accordance with one aspect of the present invention, the notch is right-triangle shaped and the the detent is isosceles-triangle shaped.
Other features and advantages of the present invention will be set forth in part in the description which follows and accompanying drawings, wherein the preferred embodiments of the present invention are described and shown, and in part become apparent to those skilled in the art upon examination of the following detailed description taken in conjunction with the accompanying drawings, or may be learned by practice of the present invention. The advantages of the present invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
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Pretty & Schroeder, P.C.
Rivera William A.
Walsh Donald P.
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