Abstract:
A structure of speaker for ship having a base seat, a vibration board connected to a vibration shaft, and a coil seat containing a coil, characterized in that a coil housing enclosing an iron block therein, being made from iron is mounted in between the base seat and the coil seat so as to obtain the effect of magnetism concentration, the magnetism is formed when a current is passed through the coil and the magnetism is concentrated at the iron block which in turn attracts the vibration shaft to move downward, and drives, the vibration board to produce vibration, which produce sound.

Description:
BACKGROUND OF THE INVENTION 
     a) Technical Field of the Invention 
     The present invention relates to a structure of speaker for use on ship, and in particular, to speaker for which the majority of the parts forming the speaker are made from stainless steel, which is a good resistance against rust, and does not cause damages to speaker or loss of fidelity of sound. 
     b) Description of the Prior Art 
     A conventional type of speaker structure used on ship is shown in FIG. 1, which comprises a coil  4020  contained in an iron-made container  4020  in order to obtain magnetism concentration effect to allow a vibration board  4030  to vibrate and produce sound. The parts making up this conventional speaker are made from iron, and the speaker is functioned to provide information or warning to other ships. However, the environment of the ship is normally humid and the sea water is very corrosive to iron. As a result, the speaker rusts easily after a certain period of use on ship. 
     This will cause damages to the speaker and a loss of fidelity in sound production. If the rusty effect is too serious, the speaker may not produce any sound effect at all. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a structure of speaker for use on ship, which can prevent rust and does not easily damage when it is used on ship or used in outdoor. 
     An aspect of the present invention is to provide a structure of speaker for use on ship, having a base seat, a vibration board connected to a vibration shaft, and a coil seat containing a coil, characterized in that a coil housing enclosing an iron block therein, and being made from iron is mounted in between the base seat and the coil seat so as to obtain the effect of magnetism concentration, magnetism is formed when a current is passed through the coil, and the magnetism is concentrated at the iron block which in turn attracts the vibration shaft to move downward, driving the vibration board to produce vibrations, which produce a sound effect. 
     The foregoing objects and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective exploded view of a conventional speaker used on ships. 
     FIG. 2 is a perspective exploded view of a speaker structure used on ships in accordance with the present invention. 
     FIG. 3 is a sectional view of the speaker structure used on ships in accordance with the present invention. 
     FIG. 4 is a sectional views of the conductive shaft in accordance smith the present invention. 
     FIG. 5 is a sectional view of the structure of the speaker when the circuit is closed in accordance with the present invention. 
     FIG. 6 is a sectional view of the structure of the speaker when the circuit is opened in accordance with the present invention. 
     FIG. 7 is a perspective view of the speaker in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings. Specific language will be used to describe same. It will, nevertheless, be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated herein being contemplated as would normally occur to one skilled in the art to which the invention relates. 
     FIG. 1 is a perspective exploded view of a conventional speaker used on ship. As can be seen from the figure, water moisture enters the housing  4060  via a mounting rubber ring  4050 , which is used to hold a power source wire  4040 , and causes the bottom seat and other parts of the speaker to rust. Although the internal structure of the speaker is rustproof, such as a rubber ring  4070  being mounted at the connection of the vibration board  4030  and the iron-made container  4000  to prevent the entry of water moisture, and the pad at the vibration board  4030  and the speaker connection  4010  being painted, the strong corrosive of sea water, the layer of paint will cause to strip and the vibration board  4030  becomes rusty after sometime of use. 
     Referring to the drawings, and in particularly FIGS. 2 and 3. there is shown a structure of speaker for use on ship. The speaker employs a coil housing  1100  to be mounted at a base seat  1000  (stainless steel) to provide magnetism concentration. A combination peg  2200  (stainless steel) is mounted within an iron block  1200 . A pressing machine is used to cause the iron block  1200 , the coil housing  1100 , the base seat  1000  and the combination peg  2220  to form integrally as a unit. A coil seat  1300  is placed within the coil housing  1100  and a coil  1310  is wound around the coil seat  1300 . The coil housing ( 1100 ) includes a lower surface and a body portion. The body portion of the coil housing ( 1100 ) contacts the upper surface of the coil seat ( 1300 ), as shown in FIG.  3 . The coil seat ( 1300 ) includes an upper surface, a lower surface, and a body portion positioned between the upper surface and the lower surface of the coil seat ( 1300 ). The coil ( 1310 ) being would around the body portion of the coil seat ( 1300 ), as shown in FIG.  3 . The coil ( 1310 ) is totally enclosed by an enclosure formed from at least the body portion of the coil seat ( 1300 ), the upper surface of the coil seat ( 1300 ) and the body portion of the coil housing ( 1100 ). When a current passes to the coil  1310 , a magnet is formed and the iron block  1200  possesses magnetism. A mounting plate  1400  (stainless steel) is mounted onto the coil seat  1300 . The top and the bottom of the mounting plate  1400  are individually provided with a mounting peg  1410  which can be mounted at a peg seat  1010  of the base seat  1000 . The mounting peg  1410  can be connected at the base seat  1000  by means of the pressing machine. 
     The coil seat  1300  is rigidly mounted at the coil housing  1100 . A vibration shaft  1500  is mounted with an annular rim  1600  and a heavy weight  1700 , and a combination peg  2300  is used to combine a washer  1800  (stainless steel), a vibration board  2100  (stainless steel), a pad  1900  (stainless steel) and the vibration shaft  1500  together. 
     A pressing machine is used to combine all these parts into a unit. A screw  2900  (stainless steel) and a nut  2910  (stainless steel) are used to combine the vibration board  2100 , a rubber pad  2000 , the base seat  1000 , a connection board  2400  (stainless steel) and a top cover  3100  (stainless steel). The rubber pad  2000  is used to prevent water moisture from entering into the interior of the speaker. A flat screw  2800  (stainless steel) is used to mount the housing  3000  at the connection board  2400 . At the bottom of the housing  3000 , a mounting rubber ring  2700  is provided to allow the passage of the power source wire. 
     Referring to FIGS. 4,  5  and  6 , one end of the coil  1310  is connected to a conductive shaft  1350  and one end of the conductive shaft  1350  is connected to a power source wire  2600  via the base seat  1000  and an insulative blocking plate  2500 . The other end of the coil  1310  is connected to a conductive plate  1320 . A resistance coil  1330  is mounted to the conductive plate  1320  to prevent the current directly passes through the mounting plate  1340 . The mounting plate  1340  is connected to the power source wire  2600  by the conductive shaft  1360 , which passes through the insulative blocking plate  2500 . The other end of the conductive plate  1320  is connected to a conductive device  1370  which contacts with the mounting plate  1340  to form a closed circuit. When current passes to the coil  1310 , a magnetic field is formed at the coil  1310  and the iron block possesses magnetism to attract the vibration shaft  1500  to move downward. The heavy weight  1700  is used to increase attraction force by the iron block  1200  to cause the vibration board  2100  to move downward. When the vibration board  2100  mores downward, the annular rim  1600  contacts with the conductive plate  1320  which drives the conductive plate  1320  to press downward, and the conductive device  1370  is not in contact with the conductive device  1380  of the mounting plate  1340 , which causes an opened circuit, and the coil  1310  cannot produce a magnetic field. The iron block  1200  does not possess magnetism, and the vibration board  2100  has the elasticity to restore the vibration shaft  1500  to its original position. 
     The annular rim  1600  moves upward and the conductive plate  1320  is not pressed. The conducting device  1370  of the conductive plate  1320  and the conductive device  1380  of the mounting plate  1340  are in contact. A closed circuit is formed. The alternate attracting and releasing actions cause the vibration board  2100  to vibrate and produce sound. 
     In accordance with the present invention, the majority of the parts of the speaker which exposed in the air are made from stainless steel (SS  304 ). As the bottom seat  1000  is made from stainless steel, which does not concentrate magnetism as that made from iron, the coil housing  1100  is mounted in between the base seat  1000  and the coil seat  1300  such that a magnetism concentration effect is obtained. Then current passes to the coil  1310 , the coil  1310  produces a magnetic field. The coil housing  1100  allows the magnetism to concentrate on the iron block  1200 . The magnetism produced by the iron block  1200  attracts the vibration shaft  1500  to move downward which drives the vibration board  2100 . When the annular rim  1600  moves downward to press the conductive plate  1320 , the circuit is cut off, and the magnetism is lost, then, the vibration board  2100  moves upward. The repeating attracting and releasing actions of the vibration board  2100  produce vibration, which in turn, produce sound effect. 
     It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. 
     While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.