DESCRIPTION
HEADPHONE WITH CORD TAKE-UP DEVICE TECHNICAL FIELD
The present invention relates to a headphone with a cord take-up device, suitably applied to a headphone used for portable audio equipment, for example. BACKGROUND ART
Lately, with portable audio equipment and the like being developed, headphones have become frequently used outdoors as well. In the case where the headphones are carried, tangling of input cords and the like are problematic.
Accordingly, there has been proposed a headphone with a cord take-up device, incorporating a mechanism which winds and retracts an input cord of the headphone into a housing of the headphone. The input cord take-up mechanism of the headphone with the cord take-up device is configured to have take-up means provided in a headphone housing and forced to wind and retract an input cord into the housing and ratchet means interacting with the take-up means, including a ratchet wheel in the form of a metal plate and an engaging pawl that is provided at one end of a turning arm in the form of a metal plate and that is forced toward the side of the ratchet wheel, preventing the input cord from being wound and retracted by the take-up means and allowing the input cord to be pulled out of the housing.
Thus, when the input cord is pulled out of the housing,

there is an inconvenience that a harsh clicking sound is generated every time the engaging pawl in the form of a metal plate gets over a pawl portion of the ratchet wheel in the form of a metal plate.
Therefore, Patent Document 1 of related art proposes a structure in which such harsh clicking sound is reduced by providing a buffer material such as soft rubber or synthetic resin for a part of the engaging pawl in the form of a metal plate which comes in contact with the pawl portion each time the engaging pawl getting over the ratchet wheel in the form of a metal plate.
[ Patent Document 1] Japanese Published Patent Application No. 2000-253477 DISCLOSURE OF THE INVENTION
However, since most of the volume has to be used for the storage space for the input cord, the part of the pawl portion of the ratchet wheel, which is in contact with the engaging pawl in the form of a metal plate, is considerably thin; thus, the buffer material provided for the engaging pawl is required to have both flexibility with which sound is muffled efficiently in a narrow area and durability with which the pawl portion of the ratchet wheel moving frenetically and the engaging pawl withstand several tens of thousands or more of violent collisions, which is therefore extremely difficult to put into practice.

Further, the engaging pawl is also in the form of a thin metal plate, and so it is extremely difficult as well to arrange the buffer material not to be detached even after violent collisions of several tens of thousands times or more.
The present invention aims to have a structure which is put into practice relatively easily and with which a harsh clicking sound is prevented from being generated when an input cord is pulled out of a headphone housing.
A headphone with a cord take-up device according to the present invention includes: an input cord; take-up means provided in a housing and forced to wind and retract the input cord into the housing; ratchet means interacting with the take-up means, including a ratchet wheel and an engaging pawl provided at one end of a turning arm and forced toward the side of the ratchet wheel, preventing the input cord from being wound and retracted by the take-up means and allowing the input cord to be pulled out of the housing; and a. buffer material provided between the turning arm and the housing; wherein when the input cord is pulled out of the housing, movement of the engaging pawl at one end of the turning arm is restricted by the buffer material.
According to the present invention, since the buffer material is provided between the turning arm having the engaging pawl at one end thereof and the housing, therefore, the operation range of the engaging pawl is restricted by the buffer

material, and the engaging pawl is kept from hitting the pawl portion of the ratchet wheel to barely avoid collision, thereby preventing a collision sound from being generated.
The buffer material can be arranged in a free space inside the housing, which does not limit the cord storage space, so that a sufficient area can be secured and the buffer material can therefore be put into practice easily; and also, inexpensive materials having sufficient durability, such as neoprene sponge, can be selected for the buffer material, so that a sound-muffling effect can surely be obtained for a long time. BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a structural view showing a relevant part of a headphone with a cord take-up device according to an embodiment of the present invention;
FIG. 2 is a sectional view showing an example of a headphone with a cord take-up device;
FIGS. 3A to 3D are diagrams for explaining the present invention; and
FIG. 4 is a sectional view showing an example of a relevant part of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a headphone with a cord take-up device according to the present invention is explained with referring to FIGS. 1 to 4.
First, a headphone with a cord take-up device will be

schematically explained with referring to FIG. 2.
In FIG. 2, a reference numeral 10 denotes a headphone housing; in a front housing lOc of the headphone housing 10 are provided front opening holes lOd facing the external ear canal of a human ear, and a loudspeaker unit 21 is installed facing these front opening holes lOd.
Also, an ear pad 22 is attached to the periphery of the front of the front housing lOc; a take-up device board 23 is installed at the end of a prop lOe that is integrally formed with the front housing lOc and that extends toward the back, namely, in a direction away from the ear; a spindle 2 is planted in an upright position in the take-up device board 23; and a reel 1 is installed on the spindle 2 in a freely rotatable manner.
In the reel 1 are provided: a cord take-up portion la which winds and retracts an input cord 9 in a spiral manner; a cord slack portion Ib at the center of the cord take-up portion la; and a spring storage portion Ic divided on the opposite side to the cord slack portion Ib.
The input cord 9, one end of which is electrically connected to a terminal portion 21a of the loudspeaker unit 21 by soldering or the like, enters the cord slack portion Ib from a hole 23a provided in the take-up device board 23 and is loosely wound in the spiral manner several times there; further, the input cord 9 penetrates through the inside of the reel 1 and

is fixed to the reel 1 at this part, and it enters the cord take-up portion la and is wound thereon.
The headphone housing 10 covers a take-up device from behind, and a cord pullout hole lOa from which the input cord 9 is pulled out is provided at the bottom of the headphone housing 10; at the end of the input cord 9 pulled therefrom is provided a plug 9a to be connected to audio equipment or the like.
In this regard, take-up means is constructed, being forced in the direction of the arrow Rl in FIG. 1 by a spring 3, one end of which is fastened to the spindle 2 and the other end of which is fastened to the inner surface of the spring storage portion Ic of the reel 1.
Also, one of the flanges on both sides of the reel 1 is made a ratchet wheel 5 formed of a thin resin board (see FIG. 1); and the ratchet wheel 5 is provided with locking pawl portions 5a which are formed, for example, with four cuts made by equally dividing the perimeter of the ratchet wheel 5 by a certain integer, for example four, as shown in FIG. 1.
Also, as shown in FIGS. 1 and 3, an engaging pawl 7a is provided at one end of a turning arm 7 pivotally supported by a shaft 6 in a tamable manner. In order that the engaging pawl 7a at one end of the turning arm 7 is pressed to engage with a locking pawl portion 5a of the ratchet wheel 5, the engaging pawl 7a of the turning arm 7 is forced in the direction of the arrow R2, namely, in the direction of the ratchet wheel 5, by a

forcing spring 8 whose one end is joined to the turning arm 7 and whose other end is joined to the housing 10.
The relationship between the locking pawl portions 5a of the ratchet wheel 5 and the engaging pawl 7a at one end of the turning arm 7 is as follows: regarding the direction in which the input cord 9 is pulled out, in other words, when the ratchet wheel 5 rotates in the direction of the arrow R3, the engaging pawl 7a is made to proceed on the gentle slope side where it does not engage with the locking pawl portions 5a, so that it does not engage with these locking pawl portions 5a, and the input cord 9 can be pulled out (is allowed to be pulled out) from the housing 10 by applying force greater than that of the spring 3.
Also, regarding the direction in which the input cord 9 is wound and retracted, in other words, when the ratchet wheel 5 rotates in the direction of the arrow Rl, the engaging pawl 7a engages with a locking pawl portion 5a of the ratchet wheel 5 and is thus locked, preventing the input cord 9 from being wound and retracted.
The locking pawl portions 5a of the ratchet wheel 5 and the engaging pawl 7a at one end of the turning arm 7 constitute what is called ratchet means.
Also, a cancellation button Ib, with which the prevention of the winding and retracting of the input cord 9 by the ratchet means is canceled, is provided at the other end of the turning

arm 1, and the cancellation button 7b is made to protrude from an opening lOb of the headphone housing 10.
In this regard, when the cancellation button 7b at the other end of the turning arm 7 is operated, the engagement between a locking pawl portion 5a of the ratchet wheel 5 and the engaging pawl 7a at one end of the turning arm 7 is cancelled, so that the input cord 9 is wound and retracted into the headphone housing 10 by means of the force of the spring 3.
In this embodiment, as shown in FIGS. 1, 3 and 4, a wide portion of predetermined size is provided on the other end side of the turning arm 7 close to the cancellation button 7b at the other end; the wide portion is bent to form a parallel surface portion 7c which is parallel with the inner surface of the headphone housing 10; and a buffer material 11, made of neoprene sponge or the like, of predetermined size and predetermined height is provided using adhesion on the inner surface of the headphone housing 10 facing the parallel surface portion 7c of the turning arm 7.
The headphone with the cord take-up device according to this embodiment is constructed as described above; therefore, when the cancellation button 7b of the turning arm 7 is operated, the engagement between a locking pawl portion 5a of the ratchet wheel 5 and the engaging pawl 7a at one end of the turning arm 7 is canceled, so that the input cord 9 can be wound and retracted into the headphone housing 10 by means of the force of the

spring 3.
Also, when the input cord 9 is pulled out of the headphone housing 10, the input cord 9 is pulled out by applying force greater than that of the spring 3 thereto. On this occasion, as shown in FIGS. 3A, 3B and 3D, the ratchet wheel 5 rotates in the direction of the arrow R3; and regarding the locking pawl portions 5a, the gentle slope side, which does not engage with the engaging pawl 7a, is brought in contact with the engaging pawl la, so that the locking pawl portions 5a and the engaging pawl 7a do not engage with each other, and the input cord 9 can therefore be pulled out.
When the applied force with which the input cord 9 is pulled out is stopped after the input cord 9 has been extended to a desired position, the ratchet wheel 5 rotates in the direction of the arrow Rl by means of the force of the spring 3, and the engaging pawl 7a engages with a locking pawl portion 5a of the ratchet wheel 5 and is thus locked, making it possible to lock the input cord 9 with a desired length.
In this regard, according to this embodiment, the bent parallel surface portion 7c is formed on the other end side of the turning arm 7, which has the- engaging pawl 7a at one end thereof, and also the buffer material 11, made of neoprene sponge or the like, of predetermined size and predetermined height is provided on the inner surface of the headphone housing 10 facing the parallel surface portion 7c, so that the operation

range of the engaging pawl la is restricted by the buffer material 11, and as shown in FIG. 3C that is an enlarged view of FIG. 3B, the engaging pawl 7a is kept from hitting a locking pawl portion 5a of the ratchet wheel 5 in such a manner as to barely avoid collision, thereby preventing a collision sound from arising.
Therefore, a harsh clicking sound is not generated when the input cord 9 is pulled out of the headphone housing 10.
Also, according to this embodiment, the buffer material 11 can be arranged in a free space inside the housing 10, which does not limit the cord storage space inside the headphone housing 10, so that a sufficient area can be secured and the buffer material 11 can therefore be put into practice easily; also, inexpensive materials with excellent durability, such as neoprene sponge, can be selected for the buffer material 11, so that a sound-muffling effect can be obtained for a long time.
Furthermore, in this embodiment, since the parallel surface portion 7c is provided for the turning arm 7 at a position corresponding to the buffer material 11, a sound-muffling effect can surely be obtained for a long time.
It should be appreciated that although the number of locking pawl portions 5a of the ratchet wheel 5 is four in the above-mentioned example, the number may be different as long as it is two or more.
Also in the above embodiment, although an example in which

the present invention was applied to a headphone was described, it should be appreciated that the present invention can also be applied to what is called a headset in which headphones are provided with a microphone.
Also, the present invention is not limited to the above-mentioned example, it should be appreciated that various other
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structures can be employed without deviating from the gist of the present invention. INDUSTRIAL APPLICABILITY
According to the present invention, a buffer material is provided between a turning arm, which has an engaging pawl at one end thereof, and a housing; accordingly, the operation range of the engaging pawl is restricted by the buffer material, and the engaging pawl is kept from hitting a pawl portion of a
ratchet wheel in such a manner as to barely avoid collision, thereby preventing a collision sound from arising.

CLAIMS
1. A headphone with a cord take-up device, .comprising:
an input cord;
take-up means provided in a housing and forced to wind and retract said input cord into said housing; and
ratchet means interacting with said take-up means, including a ratchet wheel and an engaging pawl provided at one end of a turning arm and forced toward the side of said ratchet wheel, preventing said input cord from being wound and retracted by said take-up means and allowing said input cord to be pulled out of said housing.
2. A headphone with a cord take-up device according to
claim Ir wherein a buffer material is provided between said
turning arm and said housing.
3. A headphone with a cord take-up -de-vice according .to
claim 1, wherein movement of the engaging pawl at one end of
said turning arm is restricted'by said buffer material when said
input cord is pulled out of said housing.
4. A headphone with a cord take-up device according to
claim 1, wherein said buffer material provided between said
turning arm and said housing is a neoprene sponge.