US2301487A

US2301487A - Electric horn

Info

Publication number: US2301487A
Application number: US321177A
Authority: US
Inventors: White Joe
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1940-02-28
Filing date: 1940-02-28
Publication date: 1942-11-10
Anticipated expiration: 1959-11-10

Description

Nov. 10, 1942. J, WHITE 2,301,487

ELECTRIC HORN Filed Feb. 28, 1940 k &5 i.

' M M ATTORNEY? Patented Nov. 10, 1942 2,301,487 ELECTRIC HORN Joe White, Anderson, I nd., assignor to General Motors Corporation, Detroit, Mich-., a corporation of Delaware Application February 28, 1940, Serial No. 321,177

1 Claim.

This invention relates to horns operated by vibratory electric motors which comprise an electromagnet, a movable armature connected with the horn diaphragm and a circuit breaker controlled by movements of the armature for controlling the circuit of the electromagnet.

An object of the invention is to provide for the facile adjustment of the circuit breaker.

Another object of the invention is to provide for adjusting the frequency of vibration of removable parts including the diaphragm and diaphragm operating armature.

In carrying out these objects, I provide the circuit breaker with a leaf spring member, the free end of which is located in the path of movement of the armature. I also provide the frequency adjuster with a similar leaf spring member located diametrically opposite to the leaf spring member which forms a part of the circuit breaker. The leaf spring member of the frequency adjuster is likewise located in the path of movement of the armature. To a certain extent the pressure exerted upon the armature by the leaf spring member of the circuit breaker tending to unbalance the armature on one side is counteracted by a somewhat equal and opposite tendency to unbalance the armature on the other side due to its engagement with the leaf spring member of the frequency adjuster.

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

In the drawing:

Fig. 1 is a side View partly in section of a horn embodying the present invention, said section being taken on the line of Fig. 2.

Fig. 2 is a bottom plan view of an assembly of Y a frame and electromagnet structure shown in Fig, 1, together with a circuit breaker and an armature frequency adjuster.

Fig. 3 is a sectional View on the line 3-3 of Fig. 2.

Fig. 3a is a detail of structure on an enlarged scale.

Fig. 4 is a view of the circuit breaker disassembled from the frame of the horn motor, said view looking in the direction of arrow 4 of Fig. 3.

Fig. 5 is a view of the circuit breaker spring also looking in the direction of arrow 4 of Fig. 3.

Fig. 6 is a sectional view on the line 66 of Fig. 2.

Referring to Fig. 1, the horn comprises castings and 2|, which together provide a spiral 55 insulated contact 43.

passage 22 which starts from a throat 23 at the center of the horn and terminates in a bell-mouth at 24. The casting 20 cooperates with a movable steel diaphragm 25 to provide an air compression chamber 26. Diaphragm 25 supports an armature 3|! which, together with a. spacing washer 3| and a clamping washer 32 are secured to the diaphragm and to each other by a screw The armature 33 forms a part of the diaphragm-actuating vibratory motor which is housed by a stamped metal frame 34 which, together with the diaphragm 25 is secured to the base 20 by screws 35 and nuts 36. Frame 34 supports a central magnetizable core 31 and a magnetizable field member 38 which presents pole pieces 39 to the armature 30. The core 31 is surrounded by magnet coil 40.

The armature 3U cooperates with a circuit breaker which includes a leaf spring blade member 4| carrying a contact 42 normally engaging a contact 43 carried by a bracket 44. Bracket 44 is located between

insulating plates

45 and 45. The parts 4|, 44, 45 and 46 are attached to a hinge-plate 41 by rivets 49 insulated from part 44 by bushing 49a. (Fig. 6). The hinge-plate 47 is provided with a tapped hole 50 for receiving a screw 5| having a tapered head 52 received by a similarly tapered recess provided by a flange 53 struck inwardly from the frame 34. The flange 53 is received by a round hole 54 in the leaf spring member 48. 'The hinge-plate 41 provides an annular boss 41a surrounding the tapped hole 50. The boss 41a is received by a hole 55 in the leaf spring member 48, thus providing for the proper location of the leaf spring 48 relative to the hinge-plate 41. The contact bracket 44 is not in contact with the screw 5| since the screw 5| clears the edges of the hole in bracket 44 through which the screw passes.

The circuit of the horn is not illustrated, but it Will be understood that the horn carries an insulated terminal which is connected with the electromagnet 40 which in turn is connected with the The circuit of the horn is completed to ground through the non-insulated contact 42 having metallic electrical connection with the horn frame 34 which is grounded.

'I'he hinge-plate 41 is notched at 41b to provide separate feet 410 which engage an inner surface of the frame 34. When the'screw 5| is screwed into the tapped hole of the hinge-plate 41, the distance between this plate and the frame 34 is decreased against the action of the leaf spring 48. This causes the circuit breaker assembly to pivot counter-clockwise at the places where thefeet 410 of plate 41 engage the frame 34. The screwing of the screw into the hinge plate 41 therefore causes the blade 4| to move toward the armature 30. The unscrewing of the screw 5| will release the spring 48, thereby causing the blade 4| to move toward the right and away from the armature 30. In this way the instant of separation of the

circuit breaker contacts

42 and 43 relative to the armature 30 is adjusted.

The armature 3|) cooperates with a frequency adjuster formed'of several of the same kind of parts which are used to form the circuit breaker. The frequency interrupter comprises a hingeplate 41, a U-shaped leaf spring 48, a blade 4| and a plate 46 all riveted together by rivets 49. A screw 5| having a head 52 received by a recess provided by an annular flange 53 of the frame 34 cooperates with the hinge-plate 41, just as in thecase of thecircuit breaker, to adjust the free end of theleaf spring 4| relative tothearmature 3!]. The frequency of vibration of the armature 3D and of the diaphragm 25 depends upon the amount of pressure exerted by the blade 4| upon the armature. 3|! and this will depend upon the duration of contact between the blade 4| and the armature 30 during vibratory movement of the latter. Since the armature 30 is engaged by the ends of similar leaf spring members 4| and 4| which contact with the armature 3|! on diametrically opposite sides of the axis of core 31 and about, the same distance from the core axis the forces exerted by the spring 4| upon the armature 33. will be somewhat counter-balanced by the force, exerted by the spring 4|. There-. fore he Wfllb ubs ntial s mm t i al application of force to the armature and,

therefore, tendency to cook the diaphragm will be reduced.

The adjusting screws 5| are easily accessible since their heads are located on the outside of the frame 34 which provides an enclosure for the horn motor.

While the embodiment of the present invention constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claim which follows.

What is claimed is as follows:

In a vibrator motor having a frame wall and an oscillatable assembly spaced therefrom, an adjustable assembly adapted to be mounted on the frame wall and project into the path of movement of the oscillatable assembly, comprising in combination, a flat spring blade, an L- shaped hinge plate, a U-shaped leaf spring, and means securing them together each at one end and in stack assembly, and means for mounting the stack assembly on the frame wall, and for adjusting its relation to the oscillatable assembly comprising a single screw passing through the frame wall, the unsecured end of the leaf spring and threadedly engaging the secured ends of the stack assembly, said hinge plate embracing the leaf spring and engaging the frame wall at a point intermediate the mounting screw and the path of the oscillatable assembly to provide a fulcrum about which the adjustable assembly may be moved through actuation of the screw, said hinge plate acting as a thrust plate against which the spring blade tends to move whenit is engaged by the oscillatable assembly.