Music Box Spring Winding Mechanism

The present invention relates to a music producing device for music boxes and the like and, more particularly, to a coiled spring winding mechanism in combination with a drive wheel for use in a music producing device for music boxes and the like.

One example of the prior art coiled spring winding mechanism comprises a toothed wheel having a beveled gear provided along the periphery thereof and a recess portion provided in the center thereof, a ratchet tooth being formed on the flat portion of the recess, an outwardly displacable metallic engaging member fitted into the recess, and a coiled spring axle provided through the engaging member and the toothed wheel so that the engaging member is capable of cooperating with the coiled spring axle.

In connection with this device, following drawbacks are pointed out as follows:

One is that when transmitting a power, the engagement between the ratchet tooth and the engaging member becomes unstable because of difficulties in forming the toothed wheel, dimension error of the ratchet, and a trouble between the coiled spring axle and the engaging member. Second, the metallic engaging member will not engage the ratchet teeth if the toothed wheel moves in an axial direction away from the metallic engaging member with. respect to the coiled spring axle. Third is that, when the coiled spring axle revolves, the contacting sound occuring when the engaging member is in engagement with or out of engagement with the ratchet tooth, echoes in a casing for accommodating the coiled spring winding mechanism.

Another prior art device is disclosd in U.S.Pat. No. 3,390,599. This prior art teaches a music producing device for music boxes and the like having a two-part housing which has interconnecting walls grooved to provide bearings for the axles of the drum, driving spring, governer, and associated transmission gears, the drum having cylindrical bearing portions projecting less than the drum pins and being engaged by the two end reeds of the reed plate, and the music box having bevel gears transmitting the force from the driving spring to the drum.

One object of the present invention is to provide a coiled spring winding mechanism for use in a music producing device capable of eliminating an instability between a ratchet tooth formed in the recess of the toothed wheel and an engaging member.

Another object of the present invention is to provide a coiled spring winding mechanism for use in a music producing device capable of rotating a spring axle in a soft touch.

Another object of the present invention is to provide a coiled spring winding mechanism for use in a music producing device designed so that the sound of contact between the ratchet tooth and the toothed wheel does not echo in the box.

Another object of the present invention is to provide a coiled spring winding mechanism for use in a music producing device capable of quickly engaging the teeth on the pawl with the ratchet teeth so that the arcuated portion of the pawl is in contact with each end of the ratchet tooth, thereby making it possible to disperse the return pressure of the pawl.

Another object of the present invention is to provide a coiled spring winding mechanism for use in a music producing device which makes it easy to simplify the structure to facilitate the assembling thereof.

Another object of the present invention is to provide a coiled spring winding mechanism for use in a music producing device capable for producing a soft contacting sound when the pawl is in engagement with or out of engagement with the ratchet teeth.

The features and advantages of the coiled spring winding mechanism for use in a music producing device according to the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic cross sectional and elevational view illustrating an one example of a music producing device;

FIG. 2 is an exploded perspective view illustrating a conventional coiled spring winding mechanism;

FIG. 3 is an exploded perspective view illustrating a coiled spring winding mechanism according to the present invention;

FIG. 4 is a view illustrating the pawl assembly and ratchet teeth on the drive wheel of the invention;

FIG. 5 is a schematic view illustrating an engagement relationship between an engaging member and ratchet teeth formed in a toothed wheel; and

FIG. 6 is a view illustrating each condition that the fitting portion of the engaging member is in engagement with or out of engagement with the ratchet tooth as shown in FIG. 5.

In these drawings, the same reference numerals indicate the same or similar elements of the coiled spring winding mechanism according to the present invention.

FIG. 1 is a schematic cross sectional and elevational view illustrating an example of a music producing device.

As understood from FIG. 1, the music producing device includes a coiled spring winding mechanism labeled M. This mechanism M comprises a base member 30, a spring winding axle drive wheel 32 rotatably mounted on the base member 30, a bevel gear 34 formed on the outer peripheral edge of wheel 32, a spring loaded axle 36 extending through the bevel gear 34 and the wheel 32, the top of the spring axle being mounted on the casing 38. The music producing device further comprises a transmission mechanism comprising a bevel gear 40, a flat toothed wheel 42, and a drum 44.

The wheel 32 is provided with an axially aligned recess in which is disposed a pawl device 15b. The axle 36 extends through the wheel 32 and the pawl device and is keyed to the pawl device so that the pawl device will rotate with the spring winding axle. The upper end of the spring winding axle (14) near the end 36 is provided with a spring drive means. One end of the spring is secured to the housing and fixed against movement while the other end of the spring is secured to the axle so that the spring end moves with the axle as the axle is rotated. Rotation of the axle winds the spring to make the spring tight so that a motive force is formed in the spring. The pawl is provided with teeth (15d) on the outer end so that when the pawl is rotated with the axle to wind the spring, the teeth do not engage teeth (16) on the wheel 32. The teeth (15d) on the pawl function to lock against the teeth of wheel 32 so that after the spring is wound by the spring winding axle, the pawl teeth will engage one tooth of the wheel and rotate the wheel when the spring winding axle is released. The wheel 32 then drives bevel gear 40 to rotate the music cylinder.

The present invention is concerned with the coiled spring winding mechanism.

Before proceeding with the explanation of the invention, reference is made to the concerned conventional coiled spring mechanism.

In the prior art, a coiled spring winding mechanism, labeled by M, for use in a musich producing device, as shown in FIG. 2, comprises a spring winding axle wheel 2 with a bevel gear 1 wherein the wheel 2 is provided with an annular recess 3 close to the periphery of the spring toothed wheel 2. Reference numeral 4 designates an annular inner wall. The ratchet teeth 5 are formed on the flat portion of the recess 3. The engaging member 7 having a contact plate 6 is fitted into the recess 3 so as to become in contact with the inner peripheral surface 4. The contact plate is capable of cooperating with a spring winding axle 8.

According to this construction, the pawl portion 9 integrally formed with the top of the engaging member is in contact with the ratchet toothed wheel 5 in the axial direction. It is required that the pressure of the pawl portion 9 of the engaging member 7 is exerted on the ratchet wheel 5.

In this case, the following drawbacks are pointed out.

That is, when transmitting a power, the engagement or disengagement between the ratchet tooth 5 and the engaging member 7 becomes unstable because of failure in the springforces required to press the engaging member against the ratchet teeth on wheel 2. Dimension error, such as thickness of the ratchet wheel 5, and an inconvenience occuring when the spring axle 8 is assembled into the engaging member are other drawbacks.

Further, a following disadvantage is pointed out; If wheel 2 is fixed to the spring axle 8 so that the wheel 2 cannot fluctuate in the axial direction with respect to the spring axle 8, it is difficult that the wheel 2 cannot smoothly mesh with the drum toothed wheel (not shown in FIG. 2). Furthermore, since the recess 3 is formed on the upper portion of the wheel 2, when the spring toothed engaging member 7 starts to revolve, the contacting sound of the pawl portion 9 of the engaging member 7 which is engaged with or out of engagement with the ratchet wheel 5 echoes in a casing (not shown). Since the engaging member 7 is formed with metal and the pawl portion 9 of the engaging member 7 is engaged with or out of engagement with the ratchet tooth 5 by one pitch, the revolution of the toothed wheel 8 cannot be smoothly effected. Thus, rotation action of the engaging member 7 is impressed to be heavy.

Moreover, in effecting such rotating action, there occurs hard sound, occuring when the metallic material strikes any material.

Reference is now made to the present invention.

The preferred embodiments according to the present invention will be explained with reference to the drawings.

In the embodiment shown in FIGS. 3 to 6, M' designates a spring winding mechanism for use in a music producing device. The spring winding mechanism M' comprises a ratchet drive wheel 13 having a bevel gear 11 formed along the periphery of the outer edge of the upper surface thereof and a recess 12 formed in the lower surface thereof, and pawl member 15 of synthetic resin which is fitted in the recess 12 and is adapted to cooperate with the spring winding axle 14. The ratchet wheel has teeth 16 formed along the inner peripheral surface of the recess 12. As shown in FIG. 3 the pawl member 15 comprises a body portion 15b having a central aperture 15a through which the spring winding axle 14 is fitted and secured thereto against rotation by a key that fits into a key-way 17, a resilient arcuated portion 15c integrally formed with the body portion 15b, and a portion 15d formed on the end of the arcuated portion 15c. The portion 15d, as shown in FIGS. 5 and 6, comprises a first contact portion a and a second contact portion b so that they are capable of being in contact with the ratchet tooth 16 when the pawl member 15 revolves together with the spring winding axle 14. The portion is made of synthetic resin. In this case, the thickness of the portion 15d is that of the recess 12 in order that the gap. between the recess 12 of the wheel 13 and the pawl member becomes small, as minimum as possible, in order to render the suitable strength. The angle of the ratchet teeth 16 formed along the inner peripheral surface of the recess 12 is about 90.degree. with respect to the spring axle 14.

Reference is made to the operation of this mechanism. Assuming that the spring tooth wheel 13 and the pawl member 15 are placed on the base member shown in FIG. 1. When the spring winding axle 14 revolves, the spring is wounded so that the arcuated portion 15c of the pawl member 15 is displaced inwardly because of the resilient force.

As understood from the engagement state shown in FIG. 5 to the out of engagement state shown in FIG. 6, when the engagement of the second contact portion b of the fitting portion 15d is released, under the condition that the fitting portion 15d is floated, the first contact portion a comes in contact with the top of the tooth of the ratchet tooth 16. Then, when starting to rotate, the contact condition of the first contact portion a is released. The fitting portion 15d becomes in contact with the adjacent portion of the second contact b. When the fitting portion 15d revolves, under the condition that the fitting portion 15d is placed in a floating condition the second contact portion b is in contact with the top of the adjacent tooth. When the revolution of the spring winding axle 14 is stopped, the fitting portion 15d is engaged with the ratchet tooth 16 as shown in FIG. 4, thereby preventing the axle 14 to be rotated in the opposite direction. Because returning force is applied to the arcuated portion 15c of the engaging member 15, the arcuated portion 15c is formed so that its width is enlarged.

Thus, the same action is repeated. That is, the fitting portion 15d rotates while resiliently contacting the top of the tooth of the ratchet wheel 16 by 1/2 pitch.

While this invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intented to embrace all alternatives, modifications and variations that fail within the spirit and broad scope of the appended claims.