US2020768A - Electromagnet horn - Google Patents

Description

Nov. 12, 1935. R. M. CRlTCHFlELD ET AL 2,020,768

I ELECTROMAGNET HORN Filed May 31, 1930 2 Sheets-Sheet 1 Zlwmntoz:

c755 WH/ TE ROBERT/W. C/P/TCHF/ELD R. M. CRITCHFIELD ET AL 2,020,768

ELECTROMAGNET HORN Nov. 12, 1935.

Filed May 31, 1930 -2 Sheets-Sheet 2 JbE WHITE ROBERT M CR/TCHF/EL 0 Patented Nov. 12, 1935 UNITED STATES PATENT OFFICE ELECTROMAGNET HORN poration of Delaware Application May 31, 1930, Serial No. 458,610

15 Claims.

This invention relates to sound signal devices, and particularly to the vibratory type.

One of the objects of the invention is to provide a sound signal of the class described that will manifest in a clarity of tone. v

A further object of the invention is to provid adequate means of adjustment under various conditions of operation.

A further object of the invention is to provide means of varying the pitch of the sound product.

A further object of the invention is to improve generally sound signal devices of the class described.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a longitudinal sectional View of a sound signal device illustrating the preferred form, being a sectional view substantially as indicated by the line and arrows of Fig. 3.

Fig. 2 is a longitudinal sectional View similar to Fig. 1, but illustrating a modified form of the instant invention, and with the section through the magnet motor being taken substantially at right angles to that illustrated in Fig. 1, being substantially that indicated by the line and arrows 22 of Fig. 1 or 3.

Fig. 3 is a rear elevation of a power plant with a section through the housing substantially as indicated by the line and arrows 3-3 of Fig. 1.

Fig. 4 is a plan View of the modified form of mouth piece substantially as indicated by the line and arrows 44 of Fig. 2. v

Fig. 5 is a transverse sectional View of the same substantially as indicated by the line and arrows 5-5 of Fig. 2.

With particular reference to the drawings, 2|] indicates a mounting plate of a sound signal device to which is clamped a collar 2| by means of screw devices 22 that operate to rigidly secure a vibratory diaphragm 23 at its peripheral edge 24. The mounting plate 20 has provision for supporting a field frame 25 by screw studs 26 secured therein and in clamping engagement with brackets 21 and 28 by means of nuts 29 and 30. The

brackets 27 and 28 are secured to the field frame 25 in any desirable manner as is well known to those experienced in the art, and operates to adjustably support the field frame with respect to the foundation plate 20.

In proper magnetizable relation with the field frame 25, a field coil 35 is secured by clips 36 in the usual manner, and the windings of the coil have appropriate connection with the circuit breaker mechanism 31 supported by an appropriate lug 38 struck up from the foundation plate 5 20. The circuit breaker mechanism includes a fixed contact support 39 providing a contact 40 optionally engageable with and separate from a movable contact 4| carried by a leaf spring conductor 42, the end of said spring being disposed in the path of an actuating nut 42a carried by an armature rod 43 reciprocable through the central aperture 44 of the field frame 25. In the preferred form the magnet frame 25 carries a bushing or sleeve 45 through which the armature rod slides in its movement to the central aperture 44. Reciprocable movement of the armature rod 43 is accomplished by providing it with an armature 46 against which is disposed a spacer 41, and thence making engagement with the diaphragm 23 by aid of a pair of clamping washers 48 and 49 on either side of the diaphragm and secured thereto by the lock washer and nut device 50. To establish better operation and make the magnet motor more responsive to electrical impulses impressed thereon, a condenser 5| is provided with appropriate leads 52 and 53 making connection with the circuit breaker mechanism and is embraced by a clip 54 secured to the foundation plate 20 as by a screw 55. In Fig. 2, certain modifications of structure are illustrated, but in main the structure is essentially the same, in that the foundation plate 20 supports a field frame 25 operable upon an armature 46 carried by an armature rod 43 that actuates the circuit breaker mechanism 31 as does the structure of Fig. 1. In the form illustrated in Fig. 2, the armature rod 43 is supported at the contact breaker mechanism by a short spring member 56 secured to the bracket 38 and engaging the rod 43 through the agency of a clip 51 and nut 58. Since this structure is old in itself and is illustrated in copending applications, it is deemed that further illustrationis unnecessary. However, when a proper source of ourrent and a switch are connected with terminal members 60 and GI, energization of the field coil 35 will operate to draw the armature 46 against the field frame 25, and in doing so the engaging nut 42 will move the contact 4| away from the contact 4|], whereupon the field coil will be deenergized. Upon energization of the magnet mo.- tor the diaphragm 23 will be moved with the armature 46, and when the field coil is deenergized by breaking of the circuit through contacts 40 and 4| the diaphragm 23 will move backward along with the armature 46.

In the illustrated embodiment the sound signal device is provided with a trumpet or projector 65 that has connection with a mouth piece (it supported by the collar 2!, in close contiguous relation with the vibratory diaphragm 23. In the preferred form illustrated, the mouth piece 66 manifests in a Venturi portion 61 that has uninterrupted communication with the toe 68 of theprojector. From the venturi 6! the mouth piece 66 rapidly flares outwardly to present the sharpened lip 69 disposed in operable relation with the diaphragm 23. In practice it has been found desirable to form the mouth piece 66 as illustrated, with the cylindrical portion 10 threaded to cooperate with a central aperture H of the collar 2!, and a clamping nut 72 of desired form may be threaded upon the cylindrical extension fill and run up against the collarZl so as t hold the mouth piece fifi in the desired position. Means are thus also provided for supporting the trumpet 65 in definite relation with respect to the lip 69 oi the mouth piece so that an air column of definite length can be assured. The union of the trumpet 65 with the mouth piece is assured by securing to the toe 68 ofthe trumpet, a collar 13 about which is disposed a clamping nut 14 that operates to secure the trumpet firmly to the mouth piece 56 by threading the same upon the cylindrical extension Hl.

In the form illustrated in Fig. 2, that illustrating the modification, a collar member Zia is similarly secured to the foundation plate 26 by the screw devices 22' and operates to rigidly clamp adiaphragm 230. at its periphery as in the preferred form. The diaphragm ZShas connection with the armature rod 43 by the clamping discs 48 and 49 and the nut lockifl as in-the preferred form. While the diaphragm 23a, of Fig. 2 is flat as compared with the corrugated dia-. phragm 23 of Fig. 1, its operation is essentially the same, in that upon operation; of the magnet motor it functions to alternately open and stop the air column at the inner end or mouth piece of the trumpet.

The greatest difference-in the; structure of the two forms illustrated is in the form of the mouth piece, and is believed to be clear as illustrated. In the modified form the mouthpiece 66a is considerably greater in external diameter, but

like the mouthpiece B6 is threadedinto the front of the collar Zia as indicated at Tia. and is secured in'its adjusted position by a clamping nut or ring 12a, Here, the lip 69:; is not as sharply defined as the lip 59 of the preferred form, but

of the'collar 21a.

the wall of the mouth piece 66a rapidly diminishes to a venturi We as in the preferred form, and opens into the toe 68a. of the projector without interruption of the contour as does the preferred form. The terminating edge of the toe' 68a is flared outwardly into a flange at l5 where it is engaged by a packing nut 76 operating to secure the trumpet to the mouth piece 61a; by threaded engagement with an aperture ll coaxial with the venturi 61a. .About the aperture Tithe mouth piece 66a is providedwith a hexagon or otherwise angular boss l8 whereby provision is made for turning the same and out In either form the device whether it be'the preferredform illustrated in Fig. 1 orthe modified form illustrated in Fig. 2, the mouth piece rigidly supports the projector and is axially ad- I, nite length of the air column between the lip of the mouth piece and the bell of the trumpet is not disturbed, for as the lip moves inwardly so does the bell move inwardly.

In the operation of the magnet motor the diaphragm 23 or 2311, as the case may be, is pulled away from and allowed to slap back against the lip of the mouth piece in a rapid succession of blows, and this movement operates to suddenly open and stop the column of air present in the trumpet. Thus, a tone product of definite timber will be provided, the pitch of which depends mainly upon the length of the air column that is stopped. By joining the venturi of the mouthpiece with the toe of the trumpet without ma terial interruption of the continuity of surface interference of the sound product is therebysubstantially eliminated, and the tone product that results is substantially a true air tone.

While the form of embodiment of the present invention as herein disclosed, constitutes a pre ferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow. a

What is claimed is as follows:

l. A sound signal comprising in combination, a motor, a supporting plate for the same, a dished clamping collar secured to the plate, a vibrating diaphragm actuatable bythe motor and clamped between. the plate and collar to form an air chamber, with the dished member, a projector supported by the collar having a mouth piece within the air chamber closely continguous to the diaphragm, said mouth piece forming an inlet and outlet passage for said chamber, and means for varying the relative positionof the mouth piece with respect to said diaphragm so that the mouthpiece will be engaged by the diaphragm as the diaphragm is flexed toward the mouth piece.

2. A sound signal comprising in combination, a motor, a supporting plate for the same, a dished clamping collar secured to the plate, a vibrating diaphragm clamped between the plate and collar to. form an air chamber, with the dished member, a projector supported by the collar having a mouth piece projecting within the air chamber to form a fulcrum closely contiguous to the diaphragm, said mouth piece providing a'sole inlet and outlet passage for said chamber, said motor being operably connected with the diaphragm to alternately move the diaphragm from and to contact with the fulcrum,

and thereby adapted to open and stop the mouth piece at the lips thereof.

' 3. 'A sound signal comprising in combination, 8

ing the sole passage to said chamber, said motor a operable to move the diaphragm alternately into and out of contact with the fulcrum, and means for varying the relative position of the fulcrum With respect to the diaphragm without varying the length of the air column of said projector.

' 4. A sound signal comprising in combination; a motor; a supporting plate for same; a cupshaped clamping collar secured to said plate; a vibrating diaphragm clamped between the plate and collar to form an air chamber; a projector supported by said collar having a mouth piece closely contiguous to the diaphragm, said mouth piece forming an air inlet and outlet passage for said chamber, said motor having a positive connection with said diaphragm for vibrating the diaphragm alternately to move from and to contact with the mouth piece as a fulcrum whereby air is alternately drawn into and expelled from the chamber.

5. A sound signal comprising in combination; a motor; a supporting plate for same; a cupshaped member secured to said plate; a diaphragm clamped between the cup-shaped memher and plate to form a closed chamber, said diaphragm having a positive connection with said motor, a trumpet provided with a mouth piece to provide the sole opening to said chamber, means supporting the mouth piece in contiguous relation with the diaphragm so as to provide an annular fulcrum for the diaphragm, said motor actuating the diaphragm from and to contact with the fulcrum, whereby the air column through said mouth piece will be alternately opened and closed by the diaphragm and the major portion of diaphragm actuation will be confined to that portion within the bounds of the annular fulcrum.

6. In a sound signal, a casing comprising a cup shaped member, a diaphragm mounted on the rim of the cup shaped member, a mouth piece supported concentrically of the cup shaped memher and extending into the casing with its edges contacting the diaphragm so as to close the casing, and means for vibrating the diaphragm to move the diaphragm alternately from and to contact with the mouth piece whereby air is alternately drawn into and expelled from the casing.

'7. In a sound signal the combination comprising, a casing including a cup shaped member, a diaphragm mounted on the rim of the cup shaped member, a mouth piece supported concentrically of the cup shaped member and providing an annular fulcrum contacting the diaphragm so as to close the casing, and means including a vibration motor for vibrating the diaphragm to move the diaphragm alternately from and to contact with the fulcrum whereby the diaphragm is arrested at the fulcrum but the central portion of the diaphragm is permitted to continue its movement to a point substantially within the mouth piece.

8. In a sound signal the combination comprising, a casing including a cup shaped member, a diaphragm mounted on the rim of the cup shaped member, a mouth piece supported concentrically of the cup shaped member and extending into the casing with its edges contacting the diaphragm so as to provide an annular fulcrum for the same, and a motor for vibrating the diaphragm alternately from and to contact with the mouth piece, and for continuing movement of the central portion of the diaphragm to a point within the mouth piece after the diaphragm has engaged the annular fulcrum whereby an increased volume of air is moved through the mouth piece.

9. In a sounding signal of the class described the combination comprising, a chambered member opening into a trumpet and providing an offset rim, a diaphragm mounted on the rim of the chambered member providing a closed wall therefor, a mouth piece projecting within the chambered member and having a lip normally engaging the diaphragm to close off the chambered member, and a motor for vibrating the diaphragm from and to contact with the lip and for forcing a portion of the diaphragm within the mouth piece whereby air is alternately drawn into and expelled from the chambered member.

10. In a sounding signal the combination comprising, a trumpet, a chambered member provided with a rim, a concentrically corrugated diaphragm mounted on the rim of the chambered member, a mouth piece within the chambered member communicating with the trumpet and having a lip concentric with the rim and engaging the diaphragm along the juncture of two successive corrugations, and a motor for actuating the diaphragm from and to contact with the lip whereby the diaphragm when it approaches the lip will have an annular portion thereof arrested at the lip, and that portion within the boundary of the lip will move to a position substantially within the mouth piece,

11. In a sounding signal the combination comprising, a trumpet, a chambered member provided with a rim, a concentrically corrugated diaphragm mounted on the rim of the chambered member, a mouth piece communicating with the trumpet and having a lip within the chambered member intermediate the rim and diaphragm center, and a motor for oscillating the diaphragm from and to contact with the lip so that the diaphragm will move as a whole against the lip, and so that the central portion of the diaphragm within the lip will continue its movement toward the mouth piece.

12. In a sounding signal the combination comprising, a trumpet, a chambered member provided with a rim, a concentrically corrugated diaphragm mounted on the rim of the chambered member, a mouth piece within the chambered member providing an annular fulcrum intermediate the rim and diaphragm center so as to engage the diaphragm along the juncture of two successive corrugations, and a motor for actuating the diaphragm from and to contact with the fulcrum, and after moving the diaphragm into contact with the fulcrum to substantially rock the same over the annular fulcrum whereby the volume of air movement through the trumpet and mouth piece is increased.

13. In a sounding signal the combination comprising, a trumpet, a chambered member provided with a rim, a concentrically corrugated diaphragm mounted on the rim of the chambered member, means providing an annular fulcrum for the diaphragm intermediate the rim and diaphragm center and so as to engage the diaphragm at the juncture of two successive corrugations, and a motor to actuate the diaphragm from and to engagement with the said means and to bend the central portion of the diaphragm relative to the outer portion upon engagement with the fulcrum so as to increase the mass of air movement through the trumpet.

14. A sounding signal comprising, a housing, a diaphragm having concentric corrugations mounted in the housing and adapted for oscillation, a motor mechanism connectedto said diaphragm for flexing the same, a throat member supported by the housing to provide an opening therefor, and having a part disposed in engageable relation with the diaphragm along the juncture of two successive corrugations, said motor when flexing the diaphragm on thercompression stroke driving the diaphragm against the end of the throat member, and thence pushing the central portion of the diaphragm bounded by the throat engagement toward a point Within and at the axis of the throat member, whereby member su'pp'orted'by the housing to provide an opening therefor, and having a part disposed in engageable relation with the diaphragm, said motor when flexing the diaphragm on thelcoitnpression stroke causing the diaphragm to move as a whole against the end of the throat member, andthus causing the part of the diaphragm within the boundary of the throat member to continue its movement toward a point within the throat member while that part of the diaphragm without the boundary of the throat member is substantially arrested or caused to reverse its movement so that the diaphragm is flexed radially over the end of the throat member as a fulcrum.

JOE WHITE.

ROBERT M. CRITCHFIELD;

Images