US2263342A - Horn device - Google Patents

Description

Nov. 18, 1941. N LEWI 2,263,342

HORN DEVICE Filed Oct. 51. 1940 INVENTOR NORMAN I-T LEWIS ATTORNEY Patented Nov. 18, 1941 UNITED STATES OFFI CE HORN DEVICE Norman F. Lewis, Wilkinsburg,":'Pa., sassignor to The'Westing'house Air Brake Company, Wilmerding, Pa.,.a 'corporationof Pennsylvania Application October 31, 1940, Serial 'N0.363,724

8 Claims.

This invention relates to horn. devicesand more particularly to the type embodying flexible .dia-

sound.

The principal object. of the invention is the provision of-an improved .horn device embodying a novel diaphragm .means or unit which, as compared to prior devices of this type, is more flexible,

is operative by fluidunder pressure over a greater rangeof pressures, .has longer..life,-and-does not' require rasflne adjustments or asgreat exactness in the-manufactureof the differentparts of the view of a portion of the horndevice shownin Fig.

l; and Fig. 3 is a plan view of one of the; diaphragm elements of the improved-horn device.

Description As shown in the drawing' the horn devicecomprises a body I and ahornibell 2 which.may be formed .integralwith said body and which projects from one end thereof. A flexible diaphragm unit 3 is disposed in the body I and at one face ofsaiddiaphragm unit the body is provided with anannular cavity 4. .The'horn bell 2 has a passage 5 open to the cavity 4 through an annular disposed a nut 8'having screw-threaded'engagement with the'body for movement relative thereto toward or away from said diaphragm unit. This nut has projecting from its inner face an annular shoulder I arranged in coaxial relation with shoulder I in the body-and adapted to engage the Z outer face of the diaphragm unit3 .oppos'itethat engaged by the shoulder l. -The diameter of the shoulder I9 .is less than-that of the shoulder I so as to engagethe diaphragm unit in an' annular region spaced radially inwardly from the shoulder l,- whereby upon screwing'thenut 8 into the body I the diaphragm unit may be deflected or flexed in the direction-of the seat ribiG. Between the nut 8- and diaphragm un'it13. is a chamher I I which'is.inconstantcommunication with the atmosphere through a breather port I2. I

In cavity 4 there is "disposed a laminated'valve I4 adapted to cooperate with the annular seat ribB for controlling communication between said :cavity and .thepassage S'in'the horn bell-2, said valve being'securedto' the'diaphra'gm' unit as will be "later described. The degree of 'flexingof the diaphragm unit 3" and thepressure" with which -10 the valve I 4 isnorm'ally'urg'edagainst the .seat

rib 6 is adaptedto'beadjusted to ades'ired degree "by rotation "ofthe nut 8 in the'horn'body 'I as will beapparent.

The cavity 4 is connected through achoke' or .5 restricted port formed inthe'bo'dy I to a pipe "I6 'which'is securedtto the" body. Through this pipe and Tchoke'fluidiunderpressure is adapted .to

be supplied'to 'the cavity 4. from any suitable source and under the control of any suitable'val ve ,20 means controlled manually or in any otherdesired'm'anner,forteifecting operation of'the horn device.

The diaphragm unit 3' which embodies the present invention "and provides 'for' attainment of 5 the objects hereinbefore. enumerated will'now be described in detail.

The preferred form of diaphragm unit 3 shown -in the "drawing comprises a'pluralitylof disks such as indicated by reference numerals'20, 2I and22, which are preferably struckfrom sheet metal and rigidly clamped together around their outer edges between the shoulders I and III as above dec'sribed. The disksand2l are provided centrally. with apertures 23 and 24 respectively, which are lpreferably of 'the same diameter, while the --disk .22 whichis disposed adjacent the valve- I4. is .provided centrallywith an aperture 25-of smaller diameter.

A bolt. 26" having. .a head '21. disposed .in- .the chamber I I has-ahmain body portion --28 '-which extends through and has substantially :a sliding .fit in the-aperture-ZEinediaphragm 22. rThe-bolt head Z'I' and body-portion2 8- are joined by-a .cylindrical portion 29 of intermediate diameter which extends through the apertures 23 and 24in the diaphragm idisksx20 and 2|. "Theidiameteri of this--cy1indrica1'portion.is preferably less than that of the -ap'ertures23 and" 24 so as not'to con- 50 tact the diaphragms and H.

' The body 'portion '28and' cylindrical portion "290i the bolt 26 are "joined by anannular shoulder 30 which tapers outwardly slightly in "the direction of the bolthead 21. Thistaperisprovided so that the diaphragm '22 will engage the 'bolt only at or adjacent to'the corner or edge of the aperture 25,'th'us' providing a substantial line contact only 'between the diaphragm 22 an d' the bolt 26.

Aiollow'er" 3I .is mounted. on the body. portion The valve I4 comprises a plurality of circular disks 33 which are provided centrally with aligned bores through which the body portion 28 of bolt 26 extends. One end of this pile of disks 23 is mounted against the face of follower 3| oppo- I site that engaging the diaphragm 22, while engaging the opposite face of this pile of disks is a nut 34 having screw-threaded engagement with the end of the bolt, this nut being tightened up againstthe disks'for securely clamping same against the follower 3| and for thereby clamping the diaphragm 22 between face 32 of said follower and the annular shoulder 30 on the bolt.

. With the, diaphragm. 22 thus rigidly secured 'to the bolt the space between said diaphragm and the innerface 35 of the head 28 on the bolt is slightly greater than the combined thicknesses of the diaphragms 20 and 2| so that with the 'parts of the diaphragm unit-in their normal positions, as shown in Fig, 2, there will be slight clearance space between the face 35 and the adjacent face of the diaphragm 20, it being understood that under this condition the several diaphragms are all urged into, contact with each other and against the diaphragm 22 due to the pressure exerted. by nut 8 against the diaphragm 20.

The diaphragm 22 is solid except for the central aperture 25, and since it is clamped around its periphery to the body and around the opposite ends of aperture 25 between the shoulder 3|J on bolt 26 and face 32 on follower 3| it provides a seal against leakage of fluid under pressure from cavity 4 to chamber II. This diaphragm is also relatively thin in order to provide long life without rupturing under repeated The diaphragm 2| is preferably made in a single pieceflfrom relatively thick sheet material and is provided with a plurality of slots 36 which are spaced from each other and extend radially through the diaphragm from the central aperture 24 to a point terminating short of the annular region clamped between the shoulders I and In. These slots separate the central portion of the diaphragm into a plurality of flexible spring-like sections 31 which are adapted to flex independently of each other upon vibration of the central portion of the diaphragm unit. These spring-like sections 31 also prevent the development of excessive internal forces in the diaphragm upon deflection thereof, such as are obtainedv in solid diaphragms, so that said diaphragm will be more flexible and thereby sensitive to variations in force which control the operation of the horn-device to produce sound, as will be later described.

The diaphragm 20 may be like the diaphragm 2| oras shown in the drawing, like the diaphragm. 22.

With'the, parts of the horn device assembled in their working relation shown in the drawing and as above described, the several diaphragms Under this condition the diaphragm 20 is out of contact with the bolt head 28 as shown in Fig. 2. The force of the diaphragms 20 and 2|, due to being flexed, is however applied to the diaphragm 22 which transmits same in addition ,to its own force to the follower 3| for seating the valve M, as just mentioned.

Operation I If it is desired to cause the horn device to operate to effect a signal, fluid under pressure is supplied to pipe l6 by any suitable means, and from said pipe flows through choke |5 at a restricted rate into cavity 4 at one side of the diaphragm unit 3, the opposite side of which is always at atmospheric pressure through breather port I2. When the pressure of fluid in cavity 4 is thus increased to a degree suiflcient to overcome the flexing force now acting on the diaphragm unit, said pressure starts flexing said unit. in the direction away from the valve seat 6. This flexing initially occurs in the diaphragm 22 in the region between the bolt 26 and the outer clamped peripheral edge of the diaphragm and will therefore cause deflection of the central portion of the diaphragms 2| and 20 relative to said bolt. This deflection is opposed as will be apparent by the initial stress in the diaphragms 22 and 20 and by the pressure of the spring sections3'l of diaphragm After a certain slight degree of flexing of the central portions of diaphragms 20 and 2|, the diaphragm 26 contacts the inner face 35 of the bolt head 2'! so that the pressure of fluid in cavity 4 applied through the diaphragm 22 to the diaphragms 2| and 2|! then becomes effective directly on the bolt 26 along with that applied to said bolt by diaphragm 22.

When the pressure in cavity 4 and thereby the force applied through the several diaphragms to the bolt 26 is then further increased to a suflicient degree, said diaphragm unit is operated to pull the valve 4 away from the seat rib 6. A vent communication from cavity 4 past valve I4 to passage 5 in the horn bell is thereby opened which has a flow capacity so in excess of the capacity of choke |5 to supply fluid under pressure to cavity 4, that a sudden reduction in pressure in cavity 4 occurs into the horn passage 5. This reduction in pressure on the diaphragm unit permits the forces in the several diaphragms, due to being flexed, to promptly return said diaphragm unit to its normal position for closing the valve I4. The pressure in cavity 4 then again increases through choke l5 and causes the diaphragm unit 3 to move through another cycle of vibration. This vibration of the diaphragm unit will continue as long as the supply of fluid under pressure to pipe I6 is maintained and will be at such a rate as to create vibrations of the air column in passage 5 within the horn bell which will cause the horn to emit an audible sound suitable for signal purposes.

From the above description it will now be apparent that in the normal position of the diaphragm unit shown in Fig. 2, the diaphragms 26 and 2| and particularly the diaphragm 2| acts merely like a resilient spring to oppose deflection of the relatively thin diaphragm 22 by fluid pressure supplied to cavity 4 whereby the diaphragm unit will promptly respond to a certain pressure in said cavity and start moving. After the unit is thus under motion the diaphragm 20 contacts the bolt head 26 whereby the presthe valve l4.

The valve l4 may become slightlyunseated by "diaphragm 22 before the diaphragm 20 engages the bolt head 21, but the degree 01' this .unseating must not be so great that the resultant loss of fluid pressure from said cavity past said valve will prevent the'pressure therein from building up through choke to the degree 're- -quired for causing the'diaphragm unit to operate the bolt 26 to fully .unseatthe valve M. It will thus beapparent that the clearance space provided between the :bolt head 21 and diaphragm '20, when in their normal positions-shown in Fig. :2, must not exceed a certain limit. Within this limit however this clearance space is not critical aslong as suflicient'is provided to get the several diaphragms under motion before the diaphragm 20 .contacts the bolt head 21.

It will be noted that the diaphragm 22 is the -only diaphragm which is rigidly secured to the bolt 26 and upon vibration of the diaphragm unit flexes about its substantial-lines of contact -with shoulder 30 on'bolt 26 and face 32 on follower 3|.

diaphragms 22 against being-"ruptured by the high operating pressure which may be obtained in cavity 4.

'In the normal position of thediaphragm unit shown in Fig. 2, and throughout a portion of the travel of the central portion thereof, the diaphragms 20 and 2| are substantially free of the bolt 26. 'The slots' 36 in the relatively thick diaphragm 3| prevent the development of disruptive internal forces therein upon deflection of thediaphragm, while the independent sections 310i the diaphragm act in'the capacity of springs to control vibration of the unit as well as to sup- "port the thinner diaphragm 22 against rupture as 'hereinbefore mentioned.

While it is di'fiicultto observe the action of the parts while in operation, the above description of operation'of the different parts of the improved diaphragm unit is believed to be correct. Re-

gardless of this however it has been found that "a diaphragm unit constructed as shown in the drawing and as abovedescribedaccomplishes all of the objects hereinbefore enumerated, and that horn devices equipped therewith have been surprisingly successful in service. More specifically, this improved diaphragm unit provides the required strengthtoprevent rupture thereof by the high pressures which may be supplied to cavity 4, and it has been found that, due it is believed to thegreaterflexibility of the unit, its useful lifeis indefinite and it will operate as desired over a wide range ofoperating pressures,

such as from seventy toone hundred and forty pounds per square inch. It has also been'found that great accuracy in the manufacture of the various parts of the horn device is not required .and. neither is-it necessary that the nut 8 be adjustediwith any great degree of accuracy.

The benefits to be-derived'fro'm this improved diaphragm unit may be realized in horn devices 5 already in use merely by'the'substitution' of the improved unit for the unit previously employed :and this substitution orreplacement of units may be eflected' without returning the device to the factory since any semi-skilled workman with a 10 -minimum of instruction willbe capableof effecting same.

While only one illustrative embodiment of the invention has been'shown and described in detail, it is not the intention to limit the scope to that embodiment or otherwise than by the-terms of the appended claims.

Having now described my invention, what I claim-as new and desire to secure by Letters Patent, is:

-1.i.A horn device comprising a body, a flexible :diaphragm unit in said body adapted to vibrate in response to variations in fluid pressure for producing sound, said unit comprising a flexible diaphragm clamped around its peripheral edge -and adapted to prevent leakage of fluid under pressure from one side to the opposite side thereof and other flexible diaphragm means also clamped around its peripheral edge and having a plurality of spring like sections projecting from the clamped portion thereof and bearing against the first named diaphragm for controlling vibra- "tion of said unit and for supporting the first named diaphragm against rupture by the pres- "sure of said fluid, and connecting means associated with said unit operative to provide a rigid connection between the central portions of said diaphragm and diaphragm means after a certain deflection of the'unit by" fluid pressure, the said diaphragm means being free of said go connecting means'prior'to said certain deflection.

2. A horn device comprising a body, a vibratory laminated diaphragm unit disposed in said body and clamped thereto around its peripheral edge, and a valve in said body, said diaphragm unit comprising one diaphragm having an operating connection with said valve for vibrating said valve with said'unit and another diaphragm which is normally independent of saidvalve, said diaphragm 'unit being normally deflected under stress in one direction for operating said valve to provide a differential of fluid pressures on opposite sides of saidunit and being deflectable in the opposite direction by said differential of 'fluid'pressure foroperating' said valve to destroy said differential, the second named diaphragm opposing movement of the unit in said opposite direction, and'means arranged to connect said second"nameddiaphragm with said valve after a certain initial movement of thediaphragm unit in said opposite direction.

7 35A horn device comprising a body, a valve in said body,.a vibratory laminated diaphragm unit idispose'd in said body and clamped thereto around its peripheral edge, said diaphragm 'unit being normally deflected under stress in one direction for operating said'valve to provide a difierential of fluid pressures on opposite faces of said unit i andbeing deflectable in the'opposite direction -by' said differential of fluid pressures for operating said valve to destroy'said difierential, said diaphragm unit comprising two flexible diaphragmaiza'bolt ccnnecting'said valve to one of said .-idiaphra'gms for vibratingi'said valve with issaid one'idiaphragm, said bolt'lhaving a shoulder arranged for engagement by the second named diaphragm after a certain initial deflection of said first named diaphragm in said opposite direction, said shoulder being disengaged from said second named diaphragm when said valve is in the position provided for obtaining said differential of fluid pressures.

4. A horn device comprising a body, a vibratory laminated diaphragm unit disposed in said body and clamped thereto around its peripheral edge, a valve in said body connected to said unit and adapted to vibrate therewith to alternately provide a differential of fluid pressures on opposite sides of said unit and to then destroy said differential for thereby causing vibration of said unit'and valve, the connection between said unit and valve comprising a member securing said valve to one diaphragm of said unit for movement therewith, said unit comprising another diaphragm cooperative with the first named diaphragm to oppose movement of said unit by said differential of fluid pressures, the second named diaphragm being free of said member when said difierential of fluid pressures is destroyed, and means arranged to connect said second named diaphragm and member after a certain initial movement of said unit under the influence of said differential of fluid pressures.

5. A horn device comprising a body, a vibratory laminated diaphragm unit disposed in said body and clamped thereto around its peripheral edge, a valve in said body connected to said unit and adapted to vibrate therewith to alternately provide a differential of fluid pressures on opposite sides of said unit and to then destroy said differential for thereby causing vibration of said unit and valve, the connection between said unit and valve comprising a bolt secured to said valve and extending through central aligned openings in the diaphragms of said unit, means rigidly clamping said bolt to one of said diaphragms at the opposite ends of the opening therethrough, another of said diaphragms being free of said bolt when said diiferential of fluid pressures is destroyed, and means associated with said bolt adapted to be engaged by said other diaphragm after a certain initial movement of said unit under the influence of said difierential of fluid pressures.

6. A horn device comprising a body, a vibratory laminated diaphragm unit disposed in said body and clamped thereto around its peripheral edge, a valve in said body connected to said unit and adapted to vibrate therewith to alternately provide a differential of fluid pressures on opposite sides of said unit and to then destroy said differential for thereby causing vibration of said unit and valve, the connection between said unit and valve comprising a bolt secured to said valve and extending through central aligned openings in the diaphragms of said unit, means rigidly clamping said bolt to one of said diaphragms at the opposite ends of the opening therethrough, another of said diaphragms being free of said bolt when said differential of fluid pressures is destroyed, and means associated with said bolt adapted to be en aged by said other diaphragm after a certain initial movement of said unit under the influence of said diflerential of fluid pressures, the second named diaphragm being provided with aplurality of slots spaced from each other and extending radially from the central opening in the diaphragm to near the clamped portion of the diaphragm thereby providing a plurality of resilient members which are independent of each other and operative to oppose deflection of the first named diaphragm by said differential of fluid pressure and to support said first named diaphragm against said differential of fluid pressures upon connection with said bolt after said initial deflection.

7. A horn device comprising a body, alaminated vibratory diaphragm unit disposed in said body and clamped thereto around its peripheral edge, a valve in said body connected to said unit and adapted to vibrate therewith to alternately provide a differential of fluid pressures on opposite sides of said unit and to then destroy said differential of fluid pressures for thereby causing vibration of said unit and valve, said diaphragm unit comprising two relatively thin outside diaphragms and a central diaphragm of greater thickness, all of said diaphragms having axially aligned openings, the central diaphragm being provided with a plurality of slots spaced from each other and extending radially from the central opening therein to near the clamped portion of the diaphragm, a bolt extending through the aligned openings in the several diaphragms and rigidly connected to said valve, means cooperative with said bolt rigidly clamping one of the outer diaphragms to said bolt at the opposite sides of the axial opening therethrough, the two other diaphragms being free of said bolt when the differential of fluid pressures on said unit is destroyed by said valve, and means on said bolt arranged to be engaged by the other outer diaphragm after a certain initial movement of said unit under the influence of said differential of fluid pressures.

8. A horn device comprising a body, a laminated vibratory diaphragm unit disposed in said body and clamped thereto around its peripheral edge, a valve in said body connected to said unit and adapted to vibrate therewith to alternately provide a differential of fluid pressures on opposite sides of said unit and to then destroy said differential of fluid pressures for thereby causing vi bration of said unit and valve, said diaphragm unit comprising at least three flexible diaphragms provided with axially aligned openings, a bolt extending through said openings and having a shoulder adapted to engage the inner face of one of the outer diaphragms and having a head spaced from said shoulder and adapted to engage the outer face of the other outer diaphragm, the distance between said shoulder and head exceeding the combined thicknesses of the diaphragms arranged therebetween, a member carried by said bolt arranged to engage the outer face of the diaphragm engaged on its inner face by said shoulder, means rigidly securing said member against the said one outer diaphragm and connecting said valve for movement therewith, said shoulder and the surface on said member engaging the opposite faces of said one outer diaphragm being tapered in an outwardly direction away from the diaphragm to thereby provide contact with the diaphragm only adjacent the opposite edges of the central opening therethrough, the said distance between said shoulder and head providing for engagement between said head and said other outer diaphragm after a certain initial deflection of said unit under the influence of said diflerential of fluid pressures for supporting said first named outer diaphragm, the said distance also rendering the said other outer diaphragm and the central diaphragm independent of said bolt at other times.

NORMAN F. LEWIS.

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