US3656156A

US3656156A - D.c. vibrating horn

Info

Publication number: US3656156A
Application number: US53754A
Authority: US
Inventors: Charles Berns
Original assignee: Edwards Co Inc
Current assignee: Edwards Co Inc
Priority date: 1970-07-10
Filing date: 1970-07-10
Publication date: 1972-04-11
Anticipated expiration: 1989-04-11
Also published as: GB1344717A

Abstract

A D.C. horn apparatus has been provided including an open housing, a diaphragm mounted over the opening in the housing and an electromagnetic means including a circuit breaker contact for providing vibrating motion to the diaphragm when energized. The improvement includes a resilient vibrating contact mounted at one end to the housing having one contact thereon, a secondary contact arm mounted on the housing at one end and having a second contact engaging said first contact for closing the circuit of the electromagnetic means, and a resilient damper pad mounted on the free end of the vibrating arm for engaging the diaphragm and transferring motion of the diaphragm when activated by said electromagnetic means for opening the contacts and damping interaction of the vibrating arm and the diaphragm.

Description

United States Patent Berns [54] D.C. VIBRATING HORN [72] Inventor: Charles Berns, Brookfield, Conn.

[73] Assignee: Edwards Company, Inc., Norwalk, Conn.

[22] Filed: July 10, 1970 21 Appl. No.: 53,754

1151 3,656,156 1451 Apr. 11, 1972 FOREIGN PATENTS OR APPLICATIONS 511,295 10/1930 Germany ..340/403 Primary Examiner-Thomas B. Habecker AttorneyHarold S. Wynn and John P. De Luca [5 7] ABSTRACT A D.C. horn apparatus has been provided including an open housing, a diaphragm mounted over the opening in the housing and an electromagnetic means including a circuit breaker contact for providing vibrating motion to the diaphragm when energized. The improvement includes a resilient vibrating contact mounted at one end to the housing having one contact thereon, a secondary contact arm mounted on the housing at one end and having a second contact engaging said first contact for closing the circuit of the electromagnetic means, and a resilient damper pad mounted on the free end of the vibrating arm for engaging the diaphragm and transferring motion of the diaphragm when activated by said electromagnetic means for opening the contacts and damping interaction of the vibrating arm and the diaphragm.

2 Claims, 3 Drawing Figures PATENTEDAPR 1 1 912 FIG. 2

FIG. 1

D.C. VIBRATING HORN BACKGROUND OF INVENTION This invention relates to sound producing devices and in particular to a direct current actuated vibratory horn.

In the construction of fire alarm or intrusion warning systems for factories, schools or hospitals it is necessary to provide numerous audible warning devices in and about the structure. In general, these devices for providing audible alarm are uniformly constructed and are readily interchangeable at any of the warning locations. Generally, these devices are mass produced items and as such must be efficient in operation, simple in construction and economical in terms of manufacturing costs.

Generally in the construction of a D.C. bell or born there is a necessity for providing a device, for interrupting periodically the duty cycle of a driver means or that which actuates the sound producing diaphragm or bell clapper. Such an apparatus is generally a set of contacts in the energizing circuit of the driving means periodically actuated to an open condition for deenergizing the driving means and releasing the diaphragm or noise producing mechanism of the device. Such a mechanical arrangement must be capable of efficient operation and must also be durable to operate over many thousands of cycles. Vibratory characteristics of the diaphragm and the contact apparatus must be considered for the most efficient operating characteristics.

It is therefore an object of the present invention to provide an arrangement which substantially obviates one or more of the limitations and disadvantages of the prior arrangements.

It is another object of the present invention to provide a simplified audible D.C. horn.

It is another object of the present invention to provide a warning apparatus of moderate cost.

SUMMARY OF INVENTION There has been provided an electric horn including an open housing, a diaphragm mounted over the opening in the housing and an electromagnetic means including a circuit breaker contact for providing vibrating motion to said diaphragm when energized. The improved circuit breaker contact comprises; a resilient vibrating contact arm mounted at one end to the housing and having one contact thereon, a secondary contact mounted to the housing at one end and having a second contact thereon engaging said first contact for closing the circuit of the electromagnetic means, and a resilient damper pad mounted at the free end of the vibrating arm for engaging the diaphragm and transferring motion of the diaphragm when ac tivated by the electromagnetic means for opening the contacts and damping interaction of the vibrating horn and the diaphragm.

For a better understanding of the present invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawings, while its scope will be pointed out in the appended claims.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a partially rear elevation of the DC. hornv described in the present application.

FIG. 2 is a side section elevation of FIG. 1 along line 2-2. FIG. 3 is a detailed illustration of the contact assembly of the present invention along line 3-3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS about the coil 13 forconcentrating the magnetic field produced in the coil 13 when energized. An armature 16 mounted to the diaphragm 11 engaging the forward ends of the laminations 15 completes a magnetic circuit for the driving means 12. Each time the electromagnetic driving means 12 is energized, it draws the armature 16 towards the laminations and consequently moves the diaphragm 11. When the electromagnet 12 is deenergized, the resiliency of the diaphragm urges the armature away from the laminations l5 and produces a vibratory sound.

The contact mechanism shown in FIG. 3 is responsive to the motion of the diaphragm 11 drawn by the electromagnet 12. The contacts 16 complete a circuit for energizing the coil 13. Each time the diaphragm 11 is drawn towards the electromagnet 12, a vibratory member 17 fixed at one end to an insulated mounting bracket 18 engages the diaphragm 11 so that the contacts 16 open upon a sufficient motion of diaphragm 11 towards the electromagnet 12. The open circuiting of contact 16 consequently deenergizes the electromagnet and releases the diaphragm. Again, upon motion of the diaphragm 11 away from the electromagnet'lZ, the contacts 16 close again and complete the circuit for energizing the electromagnet l2 and the cycle is repeated .until the power source is disconnected from the inputs to the horn.

The horn also includes a baffiing plate 20 suitably mounted to the diaphragm for providing a resonant tone to the sound generated by the vibrating diaphragm 11. A front face plate 21 mounted over the diaphragm and the baffling plate assembly has holes therein 22 for providing a path for the generated sound and for protecting the diaphragm l1 and baffiing plate 20 assembly. The cover plate 21 also includes a noise control including a set screw 23 mounted through hole 24 in the front plate 21. The screw 23 engages with the baffiing plate 20 as it is moving and according to the position of the head of the screw 23 relative to the baffiing plate 20 noise is suppressed. That is, if the head of the screw 23 is relatively closely spaced with the baffiing plate 20, less sound is emitted because the throw of the diaphragm 11 and bafiling plate 20 is substantially reduced.

The configuration of the contact mechanism shown in FIG. 3 has been designed in order to provide ease of installation, reduce costs of components and easy adjustment of the tension of the contact mechanism. The mechanism shown in FIG. 3 is mounted on an extension 25 of the bracket 14. The extension 25 is. a tab having a second extension 26 thereon and a hole 27 for movable mounting by adjusting screw 28. The contacts 16 are mounted on the vibratory member 17 and contact arm 29 respectively and are held rigidly at one end by the insulative bracket members 18. A spring steel member 30 mounted directly below the vibratory member 17 provides resiliency to the vibratory member 17. The tension or the elasticity of the spring member 30 is chosen to be about 10 times that of the diaphragm so that upon initial actuation of the diaphragm 11, the vibratory member 17 and the spring 30 traveling together are substantially at rest each time the diaphragm 11 engages the vibratory member 17 for opening the contacts 16. Under these conditions, the diaphragm and vibratory arm 17 are substantially synchronized and a firm closure of contact 16 is maintained each time the vibratory member returns to the rest or initial position.

Vibratory member 17 also includes a damper pad 19 fixed to its free end. The damper pad 19 is formed of resilient material, preferably nylon, which insulates the metal vibratory arm 17 from the diaphragm electrically and also damps out secondary oscillations which might be present each time the diaphragm engages with the vibratory arm 17. This damping action tends to make the actuation of the contacts 16 more uniform and also suppress oscillations which would cause an undesired tone. In addition, the resiliency of the damper pad 19 tends to protect the diaphragm from damage by the constant mating of the vibratory member 17 and diaphragm l1.

Adjustment of the tension on the vibratory member 17 against the contact arm 29 is accomplished by the adjustment of the position of set screw 28. Set screw 28 engages with the lower tab 26. Disposed between the bracket 18 and the tab 26 is a spring 31 used to keep tension against the set screw to maintain its position. As the set screw 28 is turned in towards the diaphragm, bracket 18 upon which the contact arm 29 and vibratory member 17 are mounted, moves towards the diaphragm also. When the damper pad 19 engages with the diaphragm as the screw 28 is turned in, the contacts 16 tend to separate. Any vibration at all of the diaphragm therefore would also immediately disconnect the contact 16 and cause the armature to be released. If, however, it is desired to adjust the frequency of the diaphragm, the set screw 28 may be backed off until a substantial throw of the diaphragm causes a separation of the contacts 16. Actually, the farther the diaphragm must move to actuate the contacts, the lower the frequency of the horn will ultimately be. This feature adds versatility to the horn by permitting frequency variations in the tone of the horn output while providing a rather simple means for adjusting the tone quality of the device.

A capacitor 32, mounted adjacent to the assembly, is connected across the contact points 16 as shown and absorbs energy for suppressing the spark across the contacts 16 when they are opened by the influence of the diaphragm 11 against damper pad 19. Energy stored in the coil 13 tends to are across the contacts 16 when they are opened and the capacitor 32 absorbs this energy thus reducing any spark which might occur. Spark suppression serves two purposes; one of which is reduction in the wear of the contact points 16 caused by the constant arcing and also in certain areas, spark suppression is a requirement in respect to tire control regulations.

While there has been shown what is at present believed to be the preferred embodiment of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the true spirit and scope of the invention, and it is therefore aimed in the appended claims to cover all such changes and modifications that fall within the true spirit and scope of the invention.

What is claimed is:

1. An electric horn including an open housing, a diaphragm secured between at least one peripheral support and the housing over the opening in the housing and an electromagnet operating means including a circuit breaker for providing vibrating motion to the diaphragm when energized with direct current wherein the improvement comprises;

a. a circuit breaker supporting bracket formed integral with the peripheral support and having one leg extending inwardly over the diaphragm with a single opening formed therein for reception of a mounting and adjustment screw;

nection terminals extending laterally therefrom,

. the vibrating contact having a vibrating arm carrying a contact point extending parallel to the diaphragm and an actuating arm extending normal to the diaphragm and having a plastic tip disposed on the end thereof to be periodically contacted directly by a portion of the diaphragm upon operation of the horn, the vibrating arm having a single opening formed therein for passage of a mounting and adjustment screw,

2. the fixed contact having a contact point at one end for cooperating with the contact point of the vibrating contact and having a single opening at the other end for passage of a mounting and adjustment screw,

0. a plurality of spacers of insulating material for aligning, supporting and insulating the vibrating and fixed contacts one above the other, the spacers having a flat surface adjoining another leg of the supporting bracket to prevent rotation of the spacers and contacts and having a single central opening for an adjustment and mounting screw, and

. mounting and adjusting means for securing the contacts and the spacers to said one leg of the mounting bracket including,

1. a screw passing through the openings in the spacers and the contacts and threaded into the opening in said one leg of the bracket for adjustably mounting the contacts on the bracket, and v 2. a relatively stiff compressed spring disposed between the spacers and said one leg of the bracket for permitting adjustment of the spacing of the vibrating contact relative to the diaphragm upon turning the mounting and adjustment screw but maintaining the contacts firmly secured between the spacers.

2. An electric horn according to claim 1 wherein the plastic tip is formed of nylon and has a substantially broad flat surface for contacting the diaphragm.

. cooperating vibrating and fixed contacts having wire con-'

Claims

1. An electric horn including an open housing, a diaphragm secured between at least one peripheral support and the housing over the opening in the housing and an electromagnet operating means including a circuit breaker for providing vibrating motion to the diaphragm when energized with direct current wherein the improvement comprises; a. a circuit breaker supporting bracket formed integral with the peripheral support and having one leg extending inwardly over the diaphragm with a single opening formed therein for reception of a mounting and adjUstment screw; b. cooperating vibrating and fixed contacts having wire connection terminals extending laterally therefrom, 1. the vibrating contact having a vibrating arm carrying a contact point extending parallel to the diaphragm and an actuating arm extending normal to the diaphragm and having a plastic tip disposed on the end thereof to be periodically contacted directly by a portion of the diaphragm upon operation of the horn, the vibrating arm having a single opening formed therein for passage of a mounting and adjustment screw, 2. the fixed contact having a contact point at one end for cooperating with the contact point of the vibrating contact and having a single opening at the other end for passage of a mounting and adjustment screw, c. a plurality of spacers of insulating material for aligning, supporting and insulating the vibrating and fixed contacts one above the other, the spacers having a flat surface adjoining another leg of the supporting bracket to prevent rotation of the spacers and contacts and having a single central opening for an adjustment and mounting screw, and d. mounting and adjusting means for securing the contacts and the spacers to said one leg of the mounting bracket including, 1. a screw passing through the openings in the spacers and the contacts and threaded into the opening in said one leg of the bracket for adjustably mounting the contacts on the bracket, and 2. a relatively stiff compressed spring disposed between the spacers and said one leg of the bracket for permitting adjustment of the spacing of the vibrating contact relative to the diaphragm upon turning the mounting and adjustment screw but maintaining the contacts firmly secured between the spacers.

2. the fixed contact having a contact point at one end for cooperating with the contact point of the vibrating contact and having a single opening at the other end for passage of a mounting and adjustment screw, c. a plurality of spacers of insulating material for aligning, supporting and insulating the vibrating and fixed contacts one above the other, the spacers having a flat surface adjoining another leg of the supporting bracket to prevent rotation of the spacers and contacts and having a single central opening for an adjustment and mounting screw, and d. mounting and adjusting means for securing the contacts and the spacers to said one leg of the mounting bracket including,

2. a relatively stiff compressed spring disposed between the spacers and said one leg of the bracket for permitting adjustment of the spacing of the vibrating contact relative to the diaphragm upon turning the mounting and adjustment screw but maintaining the contacts firmly secured between the spacers.