Having thus described my invention, I claim
1. A valve unit for use in a fluid-handling device, comprising a base element having its outer periphery turned up to define a cup, an intermediate portion of the bottom of said cup, in an annular area thereof, being depressed below the plane of the lower end of the cup rim as defined by the turned up periphery thereof, said annular depressed area having therein a circumferential series of apertures, a center portion of the bottom of said cup and an outer peripheral portion thereof spaced apart by said depressed annular area being substantially coplanar and in an elevated relation to said annular depressed area, flexible flapper means seating on said center and having peripheral portions in bridging relation to said depressed annular area in a normal disposition thereof, means for securing said flapper means to said base element at the center portion of the cup, and a body having a recess in which said base element is received, the bottom of said recess having, in an intermediate annular portion thereof, through openings communicating with the apertures in said base element, said openings surrounding a center hub portion and the depressed annular area of said base element fitting against said hub and against an outer peripheral portion of the bottom of said body recess to position said base element.
2. A valve unit according to claim 1, wherein said hub portion is formed with a stepped configuration at its upwardly projecting end to nest with the relatively elevated center portion of the bottom of said cup.
3. A valve unit according to claim 2, characterized by screw means extending axially through said flexible flapper means and through the relatively elevated center portion of said base element into the upwardly projecting end of said hub portion of said body to secure said flexible flapper means to said base element and to secure said base element to said body.
4. For use in combination with an apertured valve body in a fluid handling device, a valve unit comprising a separable base element having its outer periphery turned up to define a cup, an intermediate portion of the bottom of said cup, in an annular area thereof, being depressed below the plane of the lower end of the cup rim as defined by the turned up periphery thereof, said annular depressed area having therein a circumferential series of apertures, a center portion of the bottom of said cup and an outer peripheral portion thereof spaced apart by said depressed annular area being in an elevated relation to said annular depressed area, flexible flapper means seating on said center and having peripheral portions in bridging relation to said depressed annular area in a normal disposition thereof, said base element being arranged to seat to the valve body at its center portion and at its outer periphery at the lower end of the cup rim, the annular depressed area of said base element disposing in a bridging relation to an apertured portion of the valve body, and means for simultaneously securing the flapper means to said base element at the center portion of the cup and securing said cup at its center portion to said body, the outer periphery of said base element being turned upward a substantial distance fully to enclose and to relatively recess said flexible flapper means.
5. A valve unit according to claim 4, characterized by bleed means achieving an unloading through said flapper means of pressures trapped within the relatively recessed area cupped by said base element over said flapper means.
6. A valve unit according to claim 5, wherein said bleed means has the form of a bleed orifice in said flapper means overlying said annular depressed area and diametrally sized in a range between 0.010 and 0.020 inches to avoid affecting normal valve operation and yet to provide for relatively quick pressure unloading.
The invention subject of this application has particular reference to improvements in valve units. The invention unit is characterized by a particular advantage for application to air compressors and like structures. Therefore, to illustrate the character and effectiveness of the invention it is portrayed in its use in combination with an air compressor. However, it will be readily understood that neither the form nor the application of the invention as presented herein is so limited.
There have been evident limitations in prior art valves directed to similar applications. Their construction has been such that their reaction is characterized by undesirable delays in concluding sealing or opening functions, thereby seriously affecting the efficiency of the operating units in which they may be incorporated.
By contrast, the present invention provides a very simple valve embodiment having optimally related components so designed to enable its control element to function in a sensitive, rapidly responsive, positive and quiet fashion. As incorporated in an air compressor, pump or like fluid handling device, the construction and formation of the invention valve unit and the components thereof is such to enable the operating unit to start up against a substantially zero pressure head.
For purposes of illustration, the invention embodiment is shown herein in application to fluid-handling apparatus such as an air compressor to produce a relatively quiet, improved flow pattern and achieve a high working efficiency.
A primary object of the invention is to provide a valve unit, particularly advantageous for application to air compressors, fluid pumps or like operating structures, which may be economically fabricated, more efficient and satisfactory in use, adaptable to a wide variety of applications and unlikely to malfunction.
Another object of the invention is to provide for an air compressor or like structure to have means to automatically provide therein a zero pressure head on shutdown, facilitating thereby a rapid and effective starting operation.
A further object of the invention is to provide an improved intake valve having particular advantage for use in air compressors, fluid pumps and like structures.
An additional object of the invention is to provide valve means for use in fluid handling devices capable of enabling therein an unusually quiet operation and an improved flow pattern.
An additional object of the invention is to provide a valve unit possessing the advantageous structural features, the inherent meritorious characteristics and the means and mode of operation herein described.
With the above and other incidental objects in view as will more fully appear in the specification, the invention intended to be protected by Letters Patent consists of the features of construction, the parts and combinations thereof, and the mode of operation as hereinafter described or illustrated in the accompanying drawings, or their equivalents.
Referring to the accompanying drawing wherein is shown one but obviously not necessarily the only form of embodiment of the invention,
FIG. 1 is a perspective view of an air compressor embodying the various features of the present invention;
FIG. 2 is an exploded view of the compressor structure illustrated in FIG. 1;
FIG. 3 is a cross-sectional view taken on line 3--3 of FIG. 4;
FIG. 4 is a bottom view of the compressor base;
FIG. 5 is a view of the cuplike base of the unique intake valve employed in the compressor structure of FIG. 1; and
FIG. 6 is a view which illustrates the assembly of the aforementioned intake valve.
Like parts are indicated by similar characters of reference throughout the several views.
Referring to the drawings the air compressor there shown includes a base 10 comprising a generally rectangular plate 11 supported at each of its corners by a short cylindrical leg 12. The central portion 13 of the plate 11 is dished to assume the characteristic form of a segment of a generally spherical shell. This shell form produces a convexity on the plate bottom which depends intermediately of and in centered relation to the legs 12.
A boxlike enclosure 14 forming a chamber 15 is centered on and dependent from the apex of the convex surface 16 of the dished portion 13. One side of the enclosure 14 provides an inlet opening, which opening is bridged by an air filter 17.
A recessed shoulder 19 rims a central aperture 18 in the bowl-like surface produced by the plate portion 13. The aperture 18 provides an outlet from the chamber 15. The wall of aperture 18 is bridged by four integrally connected radial ribs 20 which are spaced at 90° intervals and joined at the center of the aperture by a hub 21. The latter has a threaded bore and projects slightly above the upper surface of the ribs 20 and the shoulder 19.
The shoulder 19 seats a valve unit 22 representing a preferred embodiment of the present invention. The valve 22 consists of a cup 23 nesting a flexible flapper element 25. Both valve elements are centrally apertured to accommodate the projection therethrough of the screw 27. Centered intermediate the radial limits of its dished base the cup 23 has formed therein an annular depression including six circularly arranged, equidistantly spaced apertures 24. The relatively elevated portions of the cup base which rim the annular depression and thereby the apertures 24 are offset to form radially spaced seats 24' for the peripheral skirt portions of the flexible flapper 25. The flapper 25 substantially fills the cup 23 and together therewith normally seals the aperture 18. The flapper 25 is centrally contained in a fixed relation to the base of cup 23 by means of a washer 26, which washer overlies the upper end of the hub 21 and a central portion of the flapper and is secured thereto by a screw 27 engaged in the threaded bore of the hub. Note that the upper end of hub 21 nests in an upwardly offset central portion of the cup base to which the central portion of the flapper is clamped by washer 26 and screw 27. Also, the free skirt of the flapper 25 has a uniformly balanced seat on the elevated base portions 24' . In thus bridging the relatively depressed apertures 24, one accomplishes an optimal seal thereof, avoiding leakage thereby.
The upper surface of the plate 11 is coextensively covered by a flexible diaphragm 28 which bridges the bowllike cavity formed by its dished portion 13. A centrally apertured spacer plate 29 is further superposed to overlie the peripheral portions of the diaphragm 28 which seat to the plate 11. Stacked on the plate 29 is a plate 30 having a central elliptical aperture 34. The major axis of the aperture 34 coincides, in a vertically spaced sense, with the transverse axis of the dished portion 13 of plate 11 and is equidistantly spaced from the front and rear edges of the plate 30. Formed integral with and rising vertically from the rear edge of plate 30 is a vertically disposed support plate 31. A bearing 32 having one end connected to form the uppermost extremity of the support 31 projects at right angles thereto and in a sense forwardly therefrom, in a vertically spaced alignment with the minor axis of the aperture 34. The cross-sectional area of the aperture 34 is smaller than that of the circular aperture in the plate 29 and the opening defined by the central depression in the plate 11.
The superposed parts 30, 29, 28 and 11 have aligned apertures in their respective corners which accommodate the projection therethrough of screws 33 which threadedly engage in the underlying leg supports 12.
Fixed to the rear of the bearing 32 and the rearmost face of the vertical support plate 31 is a vertically oriented motor mounting plate 35. The plate 35 has an opening which accommodates the projection therethrough of a drive shaft 36 housed in and projected through the bearing 32. The foremost extremity of the drive shaft 36 has connected thereto a projected, eccentrically disposed drive pin 37 which overlies a central portion of the aperture 34 in vertically spaced relation thereto. The opposite end of the shaft 36 mounts a large drive pulley 38 having a gearlike periphery.
A drive motor 39 is mounted to project perpendicular to the plate 35 above and in vertically spaced relation to the bearing 32. The motor drive shaft 40 projects through an aperture in the mounting plate 35 and has fixed thereto, at its outer end, a small drive pulley 41. The pulley 41 also has a gearlike periphery. The pulleys 41 and 38 are positively interconnected by a continuous drive belt 42, the inner engaging surface of which has gearlike formations complementary to those on the pulleys.
Accordingly, on energizing the motor 39, there is a drive of the shaft 36 by way of the motor drive shaft 40, pulley 41, belt 42 and pulley 38. This produces, of course, a corresponding circular movement of the eccentric drive pin 37.
The pin 37 projects through a bearing in the upper end of a connecting rod 43 which depends through the aperture 34 in the plate 30 to fixedly nest in the vertically projected tubular hub of a disc-shaped backing plate 44. The plate 44 depends within the aperture of the spacer plate 29 and has a through bore which aligns with a small central aperture in the diaphragm 28 as the base of the plate 44 seats to the center of the diaphragm. Fixed in relatively opposed relation to the plate 44, to the underside of the diaphragm 28, is a retainer element 45. The retainer 45 has its face most remote from the diaphragm 28 formed generally as the segment of a sphere which depends within the bowllike cavity defined by the dished portion 13 of the plate 11. A screw 46 is projected through a central aperture in the retainer 45 to extend upwardly through the central aperture in the diaphragm 28 and the through bore of the backing plate 44 to threadedly engage in the lower end of the connecting rod 43.
Thus, there is a fixed assembly of the diaphragm 28 to the connecting rod 43 by way of the backing plate 44 and the retainer element 45. The rod 43 is so connected to and eccentrically driven by the drive pin 37 to operate in the plane of the major axis of the elliptical opening 34. The drive of the rod 43 produces thereby an eccentric flexing of the diaphragm, in the same sense.
Observing the drawings, it will be noted that the diaphragm 28 seals the top of the bowllike cavity produced by the dished configuration of the portion 13 of the plate 11. Moreover, it will be seen that the configuration of the retainer 45 establishes between the retainer and diaphragm and the base of the cavity a thin generally spherically contoured shell-like space 47. The space 47 provides a fluid chamber coextensive with the base surface of the cavity. In this instance, the aperture 18 provides an inlet to said cavity by way of the normally closed valve 22. A relatively small outlet 48 from the chamber 47 is defined in the base surface of the cavity on a line which generally defines with the major axis of the elliptical aperture 34 a vertical plane including the central point of the inlet aperture 18. The outlet 48 is positioned to one side of the cavity base, on the upper wall portion thereof adjacent its peripheral limit.
Structure forming an integral appendage to the plate 11 provides below the outlet 48 a communicating chamber 49. The chamber 49 is defined by a tubular dependent portion 50 the lower end of which is closed by a screw plug 51. The plug 51 includes central vertically projected stud 52 which is surrounded by a coil spring 53. One end of the spring 53 abuts the body of the plug 51 and the other end biases a ball valve 54 into a normal sealing relation to the outlet 48 in the plate 11.
The uppermost extremity of the tube 50, adjacent the outlet 48, has a lateral aperture 55 which opens to a horizontally defined discharge passage 56. Formed integral with the plate 11, to one side thereof, is a cuplike projection 57 the base of which has a small opening 58 which communicates with the outermost end of the discharge passage 56. The cup 57 is adapted to threadedly receive the adapter of a pressure switch 59 the purpose of which shall be further described.
It is to be noted that the convex surface to the bottom of the plate 11 has integrally formed radially projected ribs 60. The ribs 60 not only provide rigidity to the base 10 as such but they also function to rapidly dissipate developed heat as will be further described. Moreover, in positioning the pump in any suitable location the legs 12 may be secured to a reference surface through the medium of right angled vibration pads 61 which are illustrated in FIG. 2 of the drawings. The pads 61 may be of any suitable vibration-dampening material.
Further, in respect to the flapper portion 25 of the valve 22, it should be noted that there is a very small bleed hole 62 adjacent and spaced inwardly of its outer peripheral edge.
In the unit illustrated, it is provided that the apertures 24 of the valve unit 22 afford a cross-sectional flow area which is considerably greater than that of the discharge outlet 48. In the preferred compressor here illustrated, the optimal ratio of these areas is about 8 to 1.
Further, it has been found, in the application here described, that the diameter of the bleed hole in the valve flapper 25 has an important optimal dimension of about 0.015 inches. For a proper operation of this bleed hole, in any event, its diameter should be between 0.010 and 0.020 inches.
Note further, viewing FIG. 3 of the drawings, the operating surface of the retainer 45 is formed on a lesser radius than the base surface of the related cavity.
In the use of the described device as an air compressor, as has been noted previously, the motor 39 is energized to drive the shaft 36 and thereby the connecting rod 43 through the medium of the eccentric pin 37. Resultingly, the connecting rod 43 will be eccentrically reciprocated in the plane of the major axis of the aperture 34 and the transverse axis of the plate 11. As here prescribed, the vertical extent of the reciprocation will be within vertical limits governed by the thickness of the spacer plate 29. As the diaphragm 28 and the retainer 45 is correspondingly eccentrically rocked, the upward travel thereof produces an insuction uniformly lifting the skirt of flapper 25 from the base seats 24' rimming the apertures 24. This causes air to be pulled through the air inlet to the chamber 15 and through the aperture 18 to the chamber 47 by way of the apertures 24. The spherical contour of the retainer 45 and the form of the chamber 47 is such that on rocking thereof the retainer 45 will pressure substantially the total air in advance thereof from the side portion of the shell-like chamber remote from the outlet 48 to move in a progressive smoothly developed fashion across to the outlet 48, to displace the ball check valve 54 and escape through the opening 55 and the discharge passage 56.
It is to be noted that the stud 52 on the adjustable screw plug 51 affords a limit for the displace on the ball check valve 54 against the bias of spring 53. By providing controlled travel of the ball 54 in this manner one may obtain an optimal operating efficiency. The pressure switch 59 may be appropriately set and arranged to cut off the motor 39 at a predetermined pressure level, in an obvious conventional manner.
It will thus be seen that there is a relatively large amount of air drawn to the chamber 47 by way of the intake valve 22 which air is efficiently and effectively compressed in discharge thereof through limited outlet 48 by means of the particularly formed retainer 45. The fact that the base of the valve unit 22 is so formed to essentially cup the flapper 25 and the flapper 25 is retained thereto only through the medium of an attachment at its center, there is a most effective and generally uniform lift of the flapper skirt to provide inflow to the chamber 47. Moreover, in the compression stroke the raised perimeters of the inlet apertures 24 facilitate an optimal seating of the flapper which inhibits loss of compression thereby. Again, the direct pressured movement of the air, in compression thereof, from one side to the other of the thin shell-like space affording the chamber 47 insures optimal compression effect on each stroke of the rod 43. The ribs 60 provide for rapid dissipation of the heat developed in the high-compression process. Their disposition at the base of the compressor facilitates a safe and effective transfer of this heat.
Referring to the flapper 25, the bleed hole 62 has been found to offer a uniquely effective medium for insuring, in the starting of the air compressors, a substantially zero pressure head in the chamber 47. It has been found, in the critical dimensioning of the bleed hole that with a shutdown of the compressor, for any reason, there is a relatively quick unloading of the air in the chamber 47. The air, under the existing pressure, is dumped through the bleed hole and back into the chamber 15. This leaves a pressure condition in the chamber 47 which is receptive to an immediate startup of the compressor without any back pressure to affect the operating efficiency. Thus, the air compressor provided by the present invention can reach a required operating pressure in a minimal interval of time.
It may be further seen that there is provided, in the invention structure, a uniquely improved valve unit which enhances the functional operation of the described structure as a compressor. The valve unit will, of course, have similar advantages in other fluid handling devices.
It has been further found in the case of an air compressor as above described that one can very economically obtain approximately double the operating pressure achieved in conventional units having approximately the same range of cost. It should be noted in this respect that losses are minimal due also to the contouring of the cooperating surfaces of the pumping elements and the thin shell-like, generally spherically contoured character of the chamber which is defined therebetween. By the rocking of the one spherical component on the other practically all the same in the chamber 47 is fully utilized. One obviates thereby the prevalent problem of locking and binding of parts and the resulting damage thereto in the operation of a normal air compressor. Of course, the operation of the invention embodiments is particularly enhanced by the nature of the inflow and outlet structure including the invention valve unit.
It is also important to note that the form of the intake valve utilized in this invention is such to avoid undue or uneven lift of the flapper 25 and the consequent slapping thereby of the base 23 on seating thereto. This is a factor in providing for a quieter and smoother operating air compressor as obtained by the present invention.
While the invention has been described in reference to the application of the invention valve unit to an air compressor, it should be readily obvious that with appropriate dimensioning a similarly constituted embodiment may be utilized with similar advantageous effects in other devices which operate on other types of fluids. Note that the invention valve unit can be equally used in a vacuum-type pump with excellent results. Of course, it should be obvious that in a vacuum application there would be no bleed hold in the flapper 25.
The invention has nevertheless been described in reference to its use in the air compressor embodiment because of the particularly unique results which may be illustrated in such use.
From the above description it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirably, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principal involved in sacrificing any of its advantages.
While in order to comply with the statute the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise but one of several modes of putting the invention into effect.