US2048984A

US2048984A - Electric horn

Info

Publication number: US2048984A
Application number: US639363A
Authority: US
Inventors: Zeininger Gustav
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch AG; Robert Bosch GmbH
Priority date: 1931-11-05
Filing date: 1932-10-24
Publication date: 1936-07-28
Anticipated expiration: 1953-07-28

Description

July28,1936;, G. ZE.N.NGER' 2,0 8,98

ELECTRIC HORN Filed Oct. 24, 19:52

Patented July 28, 1936 Gustav Zeininger, Obegen,

Bcsch er to Robert Stuttgart,

Application The present invention relates to electric horns, particularly for vehicles.

In electromagnetic horns for motor vehicles, the armature is rigidly secured, as a rule, to the diaphragm by a screwed bolt.

- The diaphragms are ordinarily of sheet metal and are rigidly clamped at their margins so that there exist always certain tensions or strains in the diaphragm and also in the rigid fastening .10 of the armature which tend to prevent the diaphragm from vibrating exactly axially or in a direction perpendicular to the plane of the diaphragm and the operation of the entire vibrating system is forced or constrained. Such dis- 15 placed and unequal vibration of the diaphragm and armature results in variations in the tone; anddiiierencesinthesizeoi theairgapwiliaffeet very materially the proper operation of the horn. Furthermore, the purity of the tone is impaired because such improper vibration increases the wear on the interrupter contacts and on the i 7 guide for the diaphragm and armature. The present invention has for its object to remove the drawbacks which result from the usual rigid fastening of the armature to the diaphragm.

For this purpose, according to the invention the armature is secured to the-diaphragm by a bolt or similar fastening means with the interposition of a resilient member mounted coaxially of said bolt and resilient uniformly to the axis thereof so as to press uniformly on the diaphragm, the said resilient member being tensioned to such an extent that it behaves like a rigid member in holding the armature and diaphragm together but is sufiiciently resilient to avoid or compensate for undesirable stresses consequent upon fastening with rigid means. 7

To employ nuts, together with a slotted washer, for securing the armature is not novel, but these slotted washers are not suitable for the present purpose, because they are not resilient uniformly to the axis of the fastening bolt and consequently only produce a very unilateral stifiening or stay- Y ing with resultant undesired tensions or strains. The invention is more particularly described with reference to the accompanying drawing in which three examples or construction of the invention are illustrated and in which:- Figure 1 is a longitudinal section through one 543 example.

Figure 2 a longitudinal section through the second example, and

Figure 3 a cross-section through a curved sprlngy disc for use in the third example of con- 55 structionctober 24, 1932, Serial No. 639,363

- November 5, 1931 In Figure 1, an electromagnet I has a plateshaped armature 2, which is secured by a bolt 3 to the diaphragm d.- A plate-shaped oscillator 5 is connected to the diaphragm A by the bolt 3,

which has a cylindrical enlarged part, which is 5 side of the diaphragm 4 is a disc I I which carries a pin 12 for centering the armature 2. Between the disc H and the oscillator 5 a distance disc I3 is arranged, which prevents the diaphragm 4 when oscillating from touching the oscillator 5. The free end of the bolt 3 is provided with a thread which carries a nut M which bears through a helical spring I5 against the oscillator 5. 4

The ball-joint mode of fastening the armature 2 enables an exact adjustment of the armature 2 in a plane parallel to its attraction face. The air gap between the armature 2 and its attraction time 'may, if desired, be adjusted by inserting a suitable washer between the armature 2 and the intermediate piece 8. The fastening nut it is finally tightened up and then again slackened by about a quarter turn. By this means undesired tensions in the diaphragm and armature fastening are compensated for. Consequently, the note produced is much more uniform than in the rigid screwing up of the oscillating system; also small difierences or variations in the exact size of, the air gap are compensated for so that such great care in adjusting the air gap as would otherwise be necessary need not be taken. The adjustment of the horn is thereby much less delicate than in the rigid fastening and the oscillating system works without constraint, whereby reliable operation is ensured even after long use.

It is not necessary that the springy member should be supported against the fastening nut. On the contrary, the springy member may, for example, be displaced even to the other end of the bolt 3, as shown in Figure 2. The construction therein shown is essentially the same as in the first example, except that the bolt 3 is carried through to a flange I1 and the ball end face of the intermediate piece I bears against the coneshaped recess 9 of an intermediate disc l8. The spiral spring, here marked I9, is compressed between this intermediate disc [8 and the flange l1, and the fastening nut I4 is tightened against instead of the spiral spring I5.

As will be seen from Figures 1 and 2, the airgap between the armature 2 and its attraction face is not appreciably varied by adjusting the spring l5 or I 9 by means of the bolt 3 in the manner described.

There is nothing to prevent the resilient fastening of the armature being also used in horns armature and said diaphragm, a ball and socket without an oscillator. In this case, the distance piece l3 and the oscillator 5 are simply omitted. The use of a ball-joint type of armature adjustment is also not necessary, and another mode of supporting the armature may be adopted than by the guide spring 6. I declare, that what I claim is: 1. An electromagnetic horn comprising a casing, an electromagnet mounted in said casing, an armature having an opening therein, an interrupter operated by said armature, a diaphragm secured at its periphery to said casing and having an opening therein, a bolt having an abutment thereon passing through the openings in said joint between said armature and said bolt, and a member resilient uniformly to the axis of said bolt coacting with the abutment on said bolt to exert a high tension on said diaphragm and said armature to resiliently clamp said armature and diaphragm together and to resiliently mount said armature on said diaphragm.

- 2. An electromagnetic horn comprising a casing, an electromagnet mounted in said casing,

' an armature having an opening therein, an interrupter operated by said armature, a diaphragm secured at its periphery to said casing and having an opening therein, a bolt having an abutment thereon passing through the openings in said armature and said diaphragm, and a member "resilient uniformly to the axis of said bolt and arranged co-axially on said bolt in the chamber formed by said casing and said diaphragm acting I on said diaphragm and said armature and coacting with the abutment on said bolt to resiliently clamp said armature and diaphragm together and to resiliently mount said armature on said diaphragm.

3. In an electromagnetic horn, the combination with a casing, a vibratory diaphragm secured at its periphery to said casing and an electromagnet secured to said casing, of an armature, fastening means carried by said diaphragm for securing said armature thereto, and resilient means-mounted coaxially of said fastening means andresilient uniformly to the axis thereof, said resilient means acting on said diaphragm and said armature and coacting with said fastening means to resiliently clamp said armature and diaphragm together and to resiliently mount said armature on said diaphragm, said resilient means being tensioned so highly that said mounting is to said casing and spaced from said armature, a

by said fastening member and acting on said armature and diaphragm and coacting with said fastening member to resiliently clamp said armature and diaphragm together and to resiliently l5 mount said armature on said diaphragm.

5. An electromagnetic horn comprising a casing, an electromagnet mounted in said casing, an armature, a diaphragm secured at its periphery bolt carrying said armature and passing through said diaphragm to secure said armature thereto, and resilient means carried by said bolt and-r'esilient uniformly to the axis thereof, said resilient means coacting with said bolt to resiliently clamp" said diaphragm and armature together andfto resiliently mount said armature on said diaphragm, said resilient means being tensioned so highly that said mounting is comparatively unyielding but is sufliciently resilient to compensate 3 for undesired tensions in ithe diaphragm and mounting.

6. An electromagnetic horn comprising 9. casing, an electromagnet mounted in said casing, an armature having an opening therein; a diaphragm secured at its periphery to said'casing and having an opening therein, a bolt" passing through the openings in said armature and said diaphragm, means spacing said. diaphragm from said armature on said bolt, and a resilient member carried by said bolt and resilientuniformly to the axis thereof acting on said armature and diaphragm to resilientlyurge them together against such spacing means and coacting with said bolt to resiliently fasten said armature to said diaphragm.

7. An electromagnetic horn comprising a casing, an electromagnet mounted 'in said'casing, an armature having an opening therein, "a dia; phragm secured at its periphery to the casing'"50 and having an opening therein, spacing means between said armature and diaphragm, a'bolt passing through said openings in said armature and diaphragm and having an adjustable nut co-. operating with said bolt to adjustably clamp said armature, spacing means and diaphragm together, and a. spring member mounted on said bolt between said nut and the head of the bolt and resilient uniformly to the axis thereof t0 resiliently urge said armature and diaphragm to-' gether, the tension of said spring member being adjustable by said nut without altering the spac: ing between said armature and diaphragm.

8. An electromagnetic horn as claimed in claim '7 in which the adjustable nut is arranged on the 65 end of the bolt towards the sound opening of the horn and the spring member is arrangedbetween the adjustable nut and the diaphragm.

9. An electromagnetic horn comprising a cas ing having an open end, a diaphragm, means securing the diaphragm to the open end of the casing, an electromagnet secured in the casing,'an armature for the electromagnet, ball and socket means between the armature and-diaphragm. clamping means for holding the armature, ball and socket means and diaphragm together wherebythearmatureissecuredtosaiddia, andspringmeansreaiiientuniiormlytotheaxis of said diaphragm and mounted between the clamping means and the armature, bail and 7 socket. and diaphragm '10. An electromagnetic horn comprising a cas- ,inghavinganopenendadiaphragmgmeansseeuringthediaphragmtotheopenendoitheeasing, an el In secured in the casing, an armature tor the e1eetromagnet,aball and socket joint between the armature-and diaphragm, a

- bolt for clamping the armature and diaphragm together whereby the armature is secured to said diaphragm.-a ball and socket joint between said bolt and said armature. and a spring resilient uniformly to the axis of said bolt and mounted onsaidboltandurgingsaidarmatureanddiaph aem to eth 20' lhanetiohornasinelaimlmin which one element of each of the and socket 7 joints is loosely mounted onsaid bolt. said loosely mounted elements mounting said armature on said bolt.

12. An electromagnetic horn comprising a easing having an open end, a diaphragm, means securing the diaphragm to the open end of the easing, an electromagnet secured in the casing, an

armature for the electromagnet, clamping means for holding said armature and diaphragm together and for mounting said armature on said diaphragm, and spring means resilient uniform- 1y to the axis 0! said diaphragm and mountedbetween the clamping means and the armature and