Abstract:
An acoustic sound generating device comprises a base frame, at least one vibrating rod member composed of a base end portion secured to said base frame, an intermediate portion having a small diameter and a free end portion to be picked, and a pawl segment having at least one associated picking projection for picking the free end. The pawl segment is operatively movable with the free end picked to thereby produce acoustic sounds.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an acoustic sound generating device in which at least one vibrating member mounted on a substrate or base frame is picked by pawls to thereby generate acoustic sounds. 
     There has been heretofore provided a so-called music box as a sound generating device in which the vibrating members are picked by the pawls. However, since the vibrating member of the music box consists of a comb-shaped vibrating plate on one side thereof with a plurality of vibrating strip members, in order to manufacture such a vibrating plate it must pass through machining processes such as a press-punching process, a grooving process, a barrel process, a combing process, a tuning process and the like, which is very intricate and also time-consuming disadvantageously. 
     SUMMARY OF THE INVENTION 
     In order to eliminate the above noted defects, an object of the present invention is to provide a novel sound generating device which is simple in construction and may be miniaturized in size, the device being manufactured with ease. 
     This, as well as the other objects, is achieved by the acoustic sound generating device according to the present invention wherein an end base portion of each vibrating rod is fixed to the substance or frame, a member to be picked is provided at the other free end thereof, a small diameter portion is formed midway of the vibrating rod, and a pawl member to pick said member to be picked is rotatably or reciprocatingly supported at a position to confront said member to be picked. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
     FIG. 1 is an exploded view showing an acoustic sound generating device embodying the invention; 
     FIG. 2 is a side view showing the device shown in FIG. 1; 
     FIG. 3 is a cross-sectional view showing another embodiment according to the invention; 
     FIG. 4 is a plan view of the vibrating rods and the base frame shown in FIG. 3; 
     FIG. 5 is a plan view of the pawl segment shown in FIG. 3; and 
     FIG. 6 is a plan view of the casing shown in FIG. 3. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will now be described with reference to the accompanying drawings. A basic frame or substance 1 is angled in the form of an L letter to have an upright portion 1a with a pair of support holes 1b and 1c into which a pair of vibrating rods 2 and 3 are fixedly inserted. On the opposite side of the frame is formed an angled section or segment 1d. An opposing upright portion 1d&#39; and 1d&#34; are diametrically provided with a pair of bearing holes 1e and 1e&#39;. On one side of the upright portion 1d&#39; is provided a stopper engaging portion 1d&#34;. 
     The vibrating rods 2 and 3 include end base portions 2a, 3a, middle or intermediate portions 2b, 3b and free end portion 2c, 3c to be picked, respectively. Preferably, each portions may be manufactured by a turning lathe. The base end portions 2a, 3a have maximum diameters, the middle portions 2b, 3b have minimum diameters and the diameters of the free end portions 2c, 3c to be picked are smaller than those of the base end portions 2a, 3a and larger than those of the middle portions 2b, 3b. Accordingly, when the vibrating rods 2 and 3 are rigidly coupled to the base frame 1, the vibrating rods 2 and 3 are, as shown in FIG. 1, inserted in the arrow A directions whereby the base end portions 2a, 3a are pressingly fixed to the support holes 1b and 1c. 
     Tip ends of the picked portions 2c, 3c of the vibrating rods are formed in a conical shape by cutting whereby the vibrating characteristics are improved when the picked portions 2c, 3c are picked by the pawl 4. It has been found that the vibrating rods 2 and 3 are quenched or hardened after they are processed by the lathe, so that a tone or quality of a sound is further enhanced. 
     In a pair of opposing wall members 4a and 4b of the pawl section 4 are formed a pair of bearing holes 4a&#39; and 4b&#39;, and at the same time a stopper extension is formed in the wall member 4a. Furthermore, on the respective wall members 4a and 4b are formed respective projections 4a&#34;&#39; and 4b&#34; for picking, the two projections being positioned with a displacement in phase by a predetermined angle. 
     The pawl section or segment 4 is rotatably mounted on the angled section 1d of the base frame 1 and supported around a horizontal support shaft 5 through the bearing holes 1e, 1e&#39;, 4a&#39;, 4b&#39;. Between the pawl segment 4 and the base frame 1 is interposed a leaf spring member 6, and with the spring force of the member 6, the pawl segment 4 is at all times biased in a direction in which the stopper 4a&#34; is engaged with the engagement portion 1d&#34;. With such a structure, the original position of the pawl segment 4 is determined. 
     In operation, the pawl segment 4 is pushed down in the B direction shown in FIG. 2 to rotate, the first picking projection 4a&#34;&#39; picks the vibrating rod 2 to vibrate and then the second picking projection 4b&#34; picks the rod 3. When the depression force is released, the pawl segment 4 automatically returns in the B&#39; direction shown in FIG. 2 to the original position due to the spring force of the leaf spring member 6. At this time, the rods 3 and 2 are again picked by the picking projections 4b&#34; and 4a&#34;&#39; and thereafter, the pawl member 4 restores to the original position. 
     Referring now to FIGS. 3 to 6, another embodiment according to the present invention will be described, in which the pawl segment 4 is not secured to the base frame 1 but fixed to a casing or enclosure 10. In this embodiment, the same reference or primed characters are used to denote the like members or parts. 
     The above noted members are encased in the casing 10. The frame member 1 is secured to the bottom surface of the casing 10 through plural pins 14 and associated holes 14&#39;, for example, by welding. In the same manner as in the preceding embodiment, the vibrating members 2 and 3 are pressingly secured to the base frame 1 as shown in FIG. 4. A vertical extension rod 5&#39; corresponding to the horizontal shaft 5 is formed at a suitable position of the casing 10. 
     A modified pawl member 4&#39; having a pair of projections 4a&#34;&#39; and 4b&#34; for picking the vibrating members 2 and 3 is slidably mounted around the extension rod 5&#39;. The projections 4a&#34;&#39; and 4b&#34; are displaced to each other in the vertical direction. Between the bottom of the casing 10 and the pawl member 4&#39; is interposed a coil spring 6&#39; around the extension rod 5&#39; to thereby bias the pawl member 4&#39; upwardly. The spring 6&#39; is retained by cup means 6&#34; as shown in FIGS. 3 and 6. The movement of the pawl member 4&#39; is limited by an E-shaped ring or push nut 5&#34; secured to an upper portion of the extension rod 5&#39; and is also guided by a pair of vertical parallel guide grooves 42 formed in the side walls of the pawl member 4&#39;, the guide grooves being slidingly engaged with a pair of projections 16 formed in inner side walls of the casing 10. With such a structure, the pawl member may be smoothly reciprocated. 
     The operation of the thus constructed acoustic sound generating device is obvious from that of the foregoing embodiment. 
     It will be understood that the number and the length of the vibrating rods are not confined to those shown in the specific embodiments and various modifications are possible within the scope of the invention. 
     As mentioned above, according to the present invention, since the middle portion of the vibrating rod has a minimum diameter with the middle portion being formed only by the turning lathe, the control of the length of the middle portion leads to the control over the musical or acoustic interval. As a result, the manufacturing process may be simplified and at the same time the structure also be simplified. 
     Also, due to the fact that the vibrating rod is made up of large, intermediate and small diameter portions, the mount in the arrow A direction is possible, and the pressing mount portion is the large diameter portion whereby the fixing is positively achieved and the vibration of the vibrating rod is achieved under the optimum condition. 
     Furthermore, since the round rod is used as the vibration rod, the effective contact of the pressing part to the base frame is fully carried out to thereby enhance the transmission of vibration, and the free tip end of the vibrating rod is conically cut so that after the vibrating rod is picked by the pawl section, i.e., in returning, it does not contact against the other parts. 
     Also, since the stopper and the spring member for biasing the stopper in one direction are used, the pawl member is at all times biased to the original position, which requires only a depression operation to achieve the two rotational or reciprocative picks. 
     Also, when base end portion of the large diameter portion is inserted into the hole, the portion is used as a push portion in assembly to thereby prevent it from deforming and the rotational support portion for the pawl section is formed in the base frame so that the alignment between the vibrating rod and the pawl section is easily and correctly carried out.