US2477427A - Pneumatic sounder - Google Patents

Description

Patented July 26, 1949 PNEUMATIC SOUNDER Walter siegerflwestchester, Ill., assignor to Howard Foundry Company, Chicago, 11]., a corporation of Illinois Application July 20, 1945, Serial No. 606,244

3 Claims. (01. 116- 142) This invention relates to a pneumatic sounder which is designed to produce a loud, clear signal such as is required in industrial plants, harbor installations, fast-moving trains, etc. In the accomplishment of my purposes, I utilize a wind chest having a discharge opening which is diaphragm-controlled, together with a screen for separating solid particles from the air in its movement through the wind chest, In such a construction, the screen may vibrate sympathetically with the diaphragm whereby the separated solid particles are dislodged to fall into a trap to be discharged through a blow-out port whenever a closure therefor is removed. In conjunction with the wind chest I also provide a resonator into Whose chamber is discharged the blasts or pulsations of air when and as released by the operation of the diaphragm.

A device of this kind is subjected to very rigorous service, and since it may be exposed also to any and all weather conditions, I prefer to employ bronze as the principal material for its construction. However, the diaphragm itself is preferably made from heat-treated beryllium copper to insure a life of maximum duration. A sounder embodying the features of my invention will produce a maximum of sound with a minimum of air volume and pressure. The resonator may be disposed with its axis horizontally whereby to facilitate drainage therefrom of any moisture collecting therein. The provision of a filter screen, which is self-operating to dislodge particles separated from the air, will prevent damage to the orifice seat whereon the diaphragm is rested. Morse code or other signals may also be emitted with a quick response, thereby adapting the sounder for specialized uses on trains, boats, and harbor installations.

A suggestive embodiment of my invention is set forth in the accompanying drawing wherein- Fig. 1 is a top plan view of the pneumatic sounder in its entirety; and

Fig. 2 is a central vertical section therethrough.

The main unit of my pneumatic sounder is a body B which is chambered to form a wind chest. For convenience and attainment of certain advantages the body may be provided with a separable end fitting flanged at 6 to abut a flange l on the body whereby to facilitate a union of one of the other as by means of cap screws 8. Between the flanges may be clamped in place a screen, here shown as a perforated disc Si which extends transversely across the wind chest.

Interiorly of the end fitting is a hollow central boss l0 through which is an inlet orifice II. A throttle-controlled connection (not shown) to the interior of this boss will serve to conduct air thereto for delivery to the wind chest within the body. Surrounding this boss is an annular channel l2 forming a trap from which a lateral passage l3 leads to a blow-out port I4 normally closed by a removable plug l5.

The opposite body end is provided with inner walls l6 which form a central discharge opening directly opposite the, inlet orifice. These walls, in conjunction with the outside walls of the body, define an annular chamber I! from which leads a lateral passage l8 extending through to the exterior of the body where I have provided a collar IS. The body walls continue on beyond the annular chamber to form a shoulder 20 and then a top ring 2| which is interiorly threaded for connection with the circular walls 22 of a cap 23 from whose top may rise a pair of lugs 24 to facilitate application of a wrench or other tool.

The inner walls It surroundin the central discharge opening form at the top an annular seat 25 which lies in a plane that is substantially coincident with the circular shoulder 20 that is spaced outwardly therefrom. A circular diaphragm 26, normally flat, is extended across this end of the body, its edge portion resting on the shoulder 20 to be, there held in a fixed position by engagement therewith of the bottom edges of the walls 22 of the cap 23 when the latter is rotatively advanced sufflciently for this purpose. When so secured the diaphragm is adapted to contact the annular seat, thereby closing off communication to the surrounding annular chamber.

The top ring 2| may be split at one point where a pair of outtumed ears 28 are provided, each formed with a transverse opening in register with the other to receive a bolt 29 whereby to contact and hold the ring tightly around the cap walls 22. In this way a secure friction lock is provided. Fixedly secured within the collar I9 is the cylindrical small end 30 of an outwardly tapering resonator R in the form of a horn. When so attached, perhaps with the aid of solder or other suitable connecting medium, the chamber 3| within the resonator will be in communication, via the lateral passage l8, with the annular chamber I! which is normally closed by the diaphragm. In operation, air which is compressed to say 50-100 lbs., is released through the inlet orifice to enter the wind chest. In passing throughthe screen, any solid particles suspended in the air are separated therefrom to fall down into the channel trap I2 from whence they may be blown out by removal of the plug l5 at any convenient time. The cleaned air is adapted to exert its pressure on the diaphragm, flexing it away from the annularseat sothat a blast or pufi of air is released into the resonating chamber 3|. This pulsation of air quickly exhausts itself by movement through the resonator out into the atmosphere, and in consequence produces a rare faction 1 3 V j at the ,underside of the diaphragm whereby to draw it back tightly against its seat. This com pletes one cycle or vibration of the sounder, the frequency of which isgoverned by the natural pitch of the resonating chamber. The air pulsations within the wind chest also produce vibrations of the screen 9 which are more or less sympathetic with those of the diaphragm, so'that any solid particles separated out by} the screen from the passing air will be constantly shaken off to fall into the trap therebelow. 'The vibration of the screen is due to the screerr'being sufiiciently flexible and to its ofiering sufiicient resistance to the passage of air through it to be flexed by the pulsations of the air jzolumn within the Wind chest.

Experience has demonstrated that the present sounder will operate to" produce with a minimum of .air volume and pressure a maximum of sound which is pure and free of disturbances and damping effects due to interfering vibrations or other causes. This efficiency may be attributed in. part to the special arrangement of the discharge opening opposite the inlet orifice, the space therebe= tween providing a wind chest wherein a static head will remain between pulsations which tegether produce each sound blast When the apparatus is in operation.

I claim: V 1. A pneumatic sounder comprising, in combination, a body defining a wind chest for a moving a air column, the wind chest having a circular shoulder at its upper end, a horizontal diaphragm arranged upon'the shoulder and extending transversely across the upper end of the body, an end fitting secured to the lower end of the body and having an inlet orifice, a horizontal screen extending across the wind chest and having its marginal portion clariiped between the body and the end fitting and vibrated with the diaphragm by pulsationsof the air column within the wind chest for disiodging any accumulation of particles separatedfrom saidair column, by said screen, a wall interiorly of the bodyat the upper end thereof defining with'the diaphragm an annular chamber and'fa discharge openin surrounded by the annular chamber, said wall having a passage extending laterally from the annular chamber to the body exterior, the upper edge of said wall forming a circular seat around the discharge opening with which the diaphragm contacts, a cylindrical cap secured to the body andclamping the diaphragm upon said shoulder and forming a closed air chamber above the diaphragm, and a horizontal resonator in connection with the sounder body opposite the lateral passage having its axis substantially parallel with the plane of the diaphragm.

2. A pneumatic sounder comprising, in combination, a body defining a wind chest for a moving air column, the wind chest having a circular shoulder at its upper end, a horizontal diaphragm arranged upon the shoulder and extending transversely acrossthe upper end of the body, an end fitting secured to 'the lower end of the body and provided with a hollow boss forming an inlet orifice, said end fitting'being provided adjacent the bottom with a normally closed blow-out-port, a horizontal screen extending across the wind chest and having its marginal portion clamped between the body and the end fitting and vibrated with the diaphragm by pulsations of the air column within the wind chest for dislodgingany accumulation of particles separated from said air column, by said screen, a wall interiorly of the body at the upper ,end thereof defining with the diaphragm an annular chamber and a discharge opening surrounded by the annular chamber, said wall having a passage extending laterally from the annular chamber to the body exterior, the upper edge of said wall forming a circular seat around; the discharge opening with which the diaphragm contacts, acylindrical cap secured to the body and clamping the diaphragm upon said shoulder and forming a closed air chamber above the diaphragm, and a horizontal resonator inconnection with the sounder body opposite the lateral passage having its axis substantially parallel with theiplane oi the. diaphragm.

3-. A pneumatic sounder comprising, in combination, a bedy defining a wind chest for a moving air column, the wind chest having a circular sioulder at its upper end and provided with an outer vertical wall rising from said shoulder and interiorly threaded and split at one side and provided at the split portion with spaced ears, a flexible horizontal diaphragm arranged upon said shoulder and extending transversely across the upper endof the body, an end fitting secured to the lower end of the body and provided with a hollow boss forming an inlet orifice, said end fitting being also provided with a normally closed blow-out port located at the bottom of the fitting, a horizontal screen extending across the wind chest andhaving its marginal portion clamped between the body and the end fitting and vibrated with the diaphragm by pulsations of the air column within the :wind chestfor dislodgin any accumulation of particles separated fromsaid air column, by said screen, a wall interiorly of the body defining with the diaphragm an annular chamber surrounding a discharge opening from which a passageextends to the exterior of the body, theupper edges of the inwardly extending wallforniing a circular valve seat around the discharge opening and with which the diaphragm contacts, a cylindrical cap threaded into said outer wall and clamping the diaphragm upon said shoulder and forming a closed air chamber above the diaphragm, fastening means piercin the ears of the split wall and securing the cap in its clamping engagement with'the diaphragm and a horizontal resonator in connection with the sounder body opposite the lateral passage having its axis substantially parallel with the plane of the dia phragm. w V WALTER SIEGERT.

REFERENCES CITED 7 The following reierences are of record in the file of this patent:

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