Abstract:
A pressure regulator housing assembly includes a lower housing and an upper housing; a plunger and diaphragm assembly supported within the lower and upper housings, the plunger movable toward and away from a valve seat. The diaphragm has a radially inner edge fixed to one end of the plunger and a radially outer edge clamped between an annular surface within said upper housing and a surface of a clamp ring locked against rotation relative to said upper housing thereby isolating said diaphragm from any contact with the lower housing. Upon assembly of the upper and lower housings requiring relative rotation therebetween, an upper edge of the lower housing is engaged by a lower surface of the clamp ring.

Description:
RELATED APPLICATION 
     Priority is claimed from provisional application Ser. No. 61/314,450, filed Mar. 16, 2010, the entirety of which is incorporated herein by reference. 
    
    
     This invention relates to valves and pressure regulators generally, and specifically, to a housing assembly for axial-flow fluid pressure regulators particularly suited for use in agricultural irrigation systems. 
     BACKGROUND OF THE INVENTION 
     It is well known to use pressure regulators in irrigation systems in order to provide substantially constant, regulated outlet pressure over a wide range of regulator inlet pressures, to thereby insure, for example, that a supply of water to a sprinkler or other irrigation device is maintained at a substantially uniform pressure. The need for such regulators is particularly acute in low pressure systems because even slight variations in pressure may cause much greater variations in water delivery than the same system operating at high pressure. 
     The assignee of this invention currently manufactures and sells fluid pressure regulators of the flow-through type, having an inlet at one end of a tubular housing and an outlet at the other end of the tubular housing. A valve or regulator seat is fixed within the housing and is adapted to be engaged by a tubular plunger which is spring-biased away from the seat (i.e., in the direction of fluid flow) so that under normal conditions, maximum flow through the regulator is permitted. In the event of a pressure surge, the plunger is moved by back pressure within a diaphragm chamber, against the action of an opposed coil spring (and against atmospheric pressure), toward the regulator seat to thereby decrease flow through the regulator until the pressure is reduced, at which point the plunger will stop or, if pressure decreases sufficiently, move upwardly away from the seat to thereby increase the flow. In this way, the regulator constantly seeks an equilibrium position to thereby maintain a substantially uniform outlet pressure. See, for example, U.S. Pat. Nos. 7,048,001; 5,875,815; and 5,257,646. 
     In a typical regulator assembly, the internal diaphragm is engaged and held in place by a cap (or components within the cap) or upper housing that is fastened to the housing body or lower housing. Typically, the cap is secured to the housing body (or lower housing) by four circumferentially-arranged screws. This method of fastening is advantageous in that the cap does not rotate relative to the housing during assembly, and thus, the exposed diaphragm edge is not disturbed. There is a disadvantage, however, in that assembly equipment designed to simultaneously apply and tighten plural screws is expensive and complex. There remains a need, therefore, for a pressure regulator housing coupling arrangement that is of relatively simple design which facilitates the assembly process without damaging the otherwise fragile regulator diaphragm. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Initially, it is noted that any reference herein to “upper”, “lower”, “vertical” or “horizontal” edges or other surfaces of the regulator cap and/or housing is made with respect to the orientation of the regulator as shown in  FIG. 1 , and is not intended to be limiting in any way, recognizing that the installed orientation of the regulator may be different from that shown in  FIG. 1 . 
     In one exemplary but nonlimiting example, the invention relates to a pressure regulator housing and internal stem and diaphragm assembly that eliminate the need for screws or other discrete fasteners in favor of a rotating bayonet-type attachment to secure the cap to the housing. At the same time, the diaphragm edge is supported in such a way that it rotates with the regulator cap on assembly, so that there is no relative rotation between the cap and the diaphragm, and no contact between the diaphragm and the housing, thus eliminating any concern for damage to the diaphragm during assembly. 
     More specifically, an internal regulator plunger or stem has an upper radial flange which supports a radially inner edge of the diaphragm, clamped between an annular, inner clamp ring and the flange. An annular outer clamp ring is adapted to be received over the plunger and engage the outer edge of the diaphragm. The outer clamp ring is formed with a plurality of relatively closely-spaced teeth projecting radially outwardly from its peripheral edge. An internal wall portion of the cap is formed with a plurality (six in the illustrated example) of relatively widely circumferentially spaced teeth or lugs that project radially inwardly, so that when the outer clamp ring is located over the outer edge of the diaphragm, the teeth on the internal cap wall will naturally “find” and engage selected ones of the teeth on the outer clamp ring. With the outer diaphragm edge sandwiched between an internal radially-oriented, annular surface of the cap and the outer clamp ring, the diaphragm is fixed relative to the cap so that on assembly, the diaphragm will rotate with the cap. In addition, the upper edge of the housing will engage a smooth underside of the outer clamp ring, such that no part of the diaphragm is engaged by the housing. In this way, no torque or twisting force is applied to the diaphragm during assembly of the cap to the housing. 
     The cap or upper housing and the regulator body or lower housing are formed with cooperating surface features that enable a bayonet-type attachment where the cap is axially-aligned with and telescoped over the upper edge of the housing, and then rotated into locking engagement. More specifically, in the illustrated embodiment, the lower skirt portion of the cap is formed to include on its interior peripheral surface a plurality of circumferentially-spaced locking pads. In the illustrated example, the locking pads are substantially square in shape with a relatively sharp edge on one vertical side thereof, and a sloped or ramped edge on the opposite vertical side thereof. The locking pads are flush with the lower edge of the cap skirt, and are generally axially-aligned with the lugs formed on the interior of the cap, although they need not be so aligned. 
     The outer peripheral surface of the housing at the upper edge thereof is formed with a plurality of circumferentially-spaced cam platforms, each defined by a cam surface that increases in diameter along a generally arcuate surface extending from a relatively flat base portion to a sharp axial alignment edge. A lower portion of the cam surface for each cam platform is cut out to form a locking recess, located proximate the sharp alignment edge, the locking recess sized and shaped to receive a corresponding locking pad on the inside of the cap as described above. There is a locking recess in the housing for each locking pad on the cap. The circumferential space between the edge of the locking recess and the sharp alignment edge associated with that cam surface is taken up by a relatively small, axially-extending, rib that has an axially-oriented ramped surface on one side, along the locking recess and a sharp vertical edge on its other side, in alignment with, and becoming part of the sharp alignment edge. The ramped surface on the rib may be included to permit an “over-ride” of the locked arrangement as described further herein. 
     When the cap and housing are ready for assembly, with the plunger, diaphragm and outer clamp ring properly located, the cap may be telescoped over the housing when the sharp edges of the locking pads are substantially aligned with (but slightly offset from) the sharp alignment edges of the plural cam platforms. Upon full insertion of the housing upper end into the cap, the cap may be rotated such that the locking pads ride over the cam surfaces of the cam platforms and snap or click into the corresponding locking recesses, with the sharp edges of the respective locking pads and locking recesses preventing any back-rotation of the cap. At the same time, the engagement of upper horizontal edges on the locking pads with upper horizontal edges of the locking recesses prevents relative axial movement between the cap and the housing. 
     As already mentioned, during this relative rotation of the cap and housing, no torque or twisting forces of any kind are exerted on the diaphragm. 
     Accordingly, in one exemplary but nonlimiting aspect, the invention provides a pressure regulator housing assembly comprising a lower housing and an upper housing; a plunger and diaphragm assembly supported within the lower and upper housings, the plunger movable toward and away from a valve seat, and the diaphragm having a radially inner edge fixed to one end of the plunger and a radially outer edge clamped between an annular surface within the upper housing and a surface of a clamp ring locked against rotation relative to the upper housing thereby isolating the diaphragm from contact with the lower housing; wherein, upon assembly of the upper and lower housings requiring relative rotation therebetween, an upper edge of the lower housing is engaged by a lower surface of the clamp ring. 
     In another exemplary but nonlimiting aspect, the invention provides a pressure regulator housing assembly comprising a lower housing and an upper housing adapted for assembly via axial engagement and relative rotation; a plunger and diaphragm assembly supported within the lower and upper housings, the plunger movable toward and away from a valve seat, and the diaphragm having a radially inner edge fixed to one end of the plunger and a radially outer edge clamped between an annular surface within the upper housing and a surface of a clamp ring; wherein an outer peripheral surface of the clamp ring is formed with a first plurality of vertically-oriented, tapered teeth and an inner peripheral wall portion of the upper housing adjacent the annular surface is formed with a second plurality of vertically-oriented teeth engageable, on assembly, with the first plurality of vertically-oriented teeth thereby locking the clamp ring against rotation relative to the upper housing; and further wherein an inner peripheral surface of the upper housing is formed with circumferentially-spaced locking pads and an outer peripheral surface of the lower housing is formed with circumferentially-spaced locking recesses which, on axial assembly of the upper housing over the lower housings, are offset from the circumferentially-spaced locking pads and which upon relative rotation between the upper and lower housings, are seated in the circumferentially-spaced locking recesses to thereby lock the upper housing to the lower housing, and wherein during the relative rotation, the diaphragm rotates with the upper housing and an upper edge of the lower housing is engaged by a lower surface of the clamp ring. 
     In still another exemplary but nonlimiting aspect, the invention provides a pressure regulator housing assembly comprising a housing including an upper housing portion and a lower housing portion configured for attachment by axial engagement and relative rotation; a plunger and diaphragm assembly supported within the housing, an outer rim of the diaphragm isolated from any torque forces applied during assembly of the upper and lower housing portions. 
     The invention will now be described in connection with the drawings identified below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross section of a pressure regulator assembly in accordance with an exemplary but nonlimiting embodiment of the invention; 
         FIG. 2  is an enlarged detail of the attachment between the regulator cap and housing portions of the assembly shown in  FIG. 1 ; 
         FIG. 3  is a top, right perspective view of a regulator plunger and diaphragm assembly removed from the regulator housing assembly of  FIG. 1 ; 
         FIG. 4  is a bottom left perspective view of the regulator plunger and diaphragm assembly shown in  FIG. 2 ; 
         FIG. 5  is a perspective view of an annular diaphragm clamp ring removed from the regulator housing assembly of  FIG. 1 ; 
         FIG. 6  is an exploded view, partially in section, of the regulator housing and cap, with the plunger-diaphragm assembly omitted; 
         FIG. 7  is a perspective view, partially cut away to show internal details of the regulator housing and cap fully assembled with the plunger-diaphragm assembly in place; 
         FIG. 8  is an exploded view, partially cut away, showing the cap and housing of the regulator assembly, with the plunger and diaphragm removed; 
         FIG. 9  is a section showing the initial attachment position of the cap and housing prior to being rotated to a locked position; and 
         FIG. 10  is a partial enlarged detail from a similar perspective as  FIG. 8 , but with the cap rotated to a locked position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIGS. 1 and 2 , a fluid pressure regulator housing assembly  10  in accordance with an exemplary but nonlimiting embodiment includes a hollow lower housing  12  and a hollow upper housing or cap  14 . Both housing and cap components are internally threaded at their respective inlet and outlet ends,  16 ,  18 , permitting the regulator to be secured in-line between, for example, a sprinkler at the outlet end and a supply hose at the inlet end. 
     The interior of the cap is counterbored to form a series of at least the annular shoulders  20 ,  22  and  24 , the purposes for which will be described further herein. It is noted initially that the shoulder  20  defines an internal diameter section  26  of the cap, adjacent the internal threads at the cap outlet  18 , which receives the upper end  28  of a plunger-diaphragm assembly  30 . 
     Before describing the manner in which the cap  14  and housing  12  are attached, a more detailed description of the plunger-diaphragm assembly  30  will be provided for ease of understanding. As best seen in  FIGS. 3 and 4 , the plunger-diaphragm assembly  30  includes a tubular plunger  32  having a tapered lower edge  34  ( FIGS. 1 and 4 ) forming a valve for interaction with a valve seat (not shown) supported in the housing  12 . The plunger  32  is provided adjacent the upper or outlet end  28  thereof (flow is from bottom to top as viewed in  FIG. 1 ) with a radial flange  36  ( FIGS. 1 and 4 ). A radially inner edge  38  of an annular “rolling” diaphragm  40  is supported on the flange  36  and is clamped between the flange and a rigid inner clamp ring  42  ( FIGS. 1 and 2 ) snap-fit over an array of upstanding spring fingers  44  that extend upwardly from the flange  36 , as best appreciated from  FIG. 1 . The inner clamp ring  42  is adapted to engage the shoulder  22  of the cap when the plunger  32  is in its fully raised position as shown in  FIGS. 1 and 2 . The intermediate portion of the diaphragm assumes a substantial U-shape ( FIG. 1 ) when the plunger  32  is in the raised position, and the radially outer edge  62  of the diaphragm  40  is held between shoulder  24  of the cap and an outer clamp ring  48  described further below. 
     While the operation of the regulator forms no part of this invention, it will be appreciated that the plunger  32  moves up and down within a limited range of movement as a function of outlet pressure (i.e., the pressure at the outlet end  18 ), noting that the inner clamp ring  42  and flange  36  are located in a diaphragm chamber  50  ( FIG. 2 ) which is exposed to outlet pressure due to the presence of radial slots or grooves  52  ( FIG. 2 ) formed in the shoulder  22  that connect to the diaphragm chamber  50 . When the outlet pressure is high, the pressure in the diaphragm chamber  50  causes the plunger  32  including the tapered lower edge or valve  34  to move downwardly toward the valve seat to restrict flow. As the outlet pressure decreases, the plunger  32  (under the action of a spring, not shown) will move upwardly, increasing flow past the valve seat. Thus, the plunger  32  is always seeking equilibrium as it maintains a substantially uniform outlet pressure. For more details regarding the operation of regulators of this type, see U.S. Pat. Nos. 7,048,001; 5,875,815; and 5,257,646. 
     With reference now to  FIG. 5 , the outer clamp ring  48  is formed with an upper flanged portion  54  having a plurality of axially-extending, upwardly tapered teeth  56  formed on the outer peripheral edge thereof. The teeth  56  taper in an upward direction for a purpose described further below. An inner skirt portion  58  extends downwardly from the upper flanged portion and is sized to help locate and center the outer clamp ring  48  ring within the upper end of the housing  12  on assembly. The upward-facing edge  60  of the flanged portion  54  is grooved at  61  ( FIGS. 1 and 2 ) to receive an increased thickness of the diaphragm outer edge  62 , thus facilitating the retention function of the outer clamp ring  48 . 
     With reference now to  FIG. 6 , an inner surface  64  of the cap  14 , adjacent the shoulder  24 , is provided with a first plurality (six in the illustrated example) of circumferentially-spaced teeth or lugs  66  that project radially inwardly and that are adapted to engage between respective pairs of the teeth  56  on the outer clamp ring  48 . During assembly, after locating the plunger-diaphragm assembly  30  in place within the cap  14  (this may be done with the cap inverted relative to its orientation in  FIG. 1 ), when the housing  12  is moved axially into telescoped engagement with the cap  14  as described in greater detail below, the outer clamp ring  48  will orient itself with certain of the teeth  56  engaged with the lugs  66  on the cap inner wall, thus preventing any relative rotation between the outer clamp ring  48  and the cap  14 . This meshing engagement is facilitated by the upward taper of the teeth  56 . Now, when so located, the outer clamp ring  48  will also seat on the outer peripheral edge  62  of the diaphragm  40  with the thickened diaphragm edge engaged in the groove formed in the upward-facing edge  60 . Thus, the outer peripheral edge  62  of the diaphragm  40  is clamped between the shoulder  24  and the outer clamp ring  48 , and both the outer clamp ring  48  and diaphragm  40  are prevented from relative rotation with respect to the cap  14 . Note also that it is the smooth annular surface  68  on the underside of the outer clamp ring  48  that is engaged by the upper edge  70  of the housing (best seen in  FIG. 2 ) i.e., no part of the diaphragm  40  is exposed to any contact with the housing  12  that, during the locking rotation described below, would otherwise cause torque or twisting action to be applied to the outer edge  62  of the diaphragm. 
     With reference now especially to  FIGS. 6-10 , the cap  14  and the housing  12  are formed with cooperating surface features that enable a bayonet-type attachment where the cap  14  is axially-aligned with, and telescoped over, the upper end of the housing  12 , and then rotated into locking engagement. More specifically, in the illustrated, nonlimiting embodiment, a lower skirt portion  72  of the cap  14  is formed to include on its interior surface a plurality of circumferentially-spaced and radially-inwardly projecting locking pads  74  (best seen in  FIGS. 6 and 8 ). In the illustrated example, the locking pads  74  are substantially square in shape with a relatively sharp edge  76  on one vertical side thereof, and a sloped or ramped edge  78  on the opposite vertical side thereof. The locking pads  74  are flush with a lower edge  80  of the cap ( FIG. 6 ), and are generally axially-aligned with the lugs  66 , although they need not be so aligned. 
     The outer surface of the housing  12  at the upper end thereof is formed with a plurality of circumferentially-spaced cam platforms  82  ( FIGS. 6 ,  7  and  8 ), each defined by a cam surface  84  that increases in diameter along a generally arcuate surface extending from a relatively flat base portion  86  to a sharp axial alignment edge  88 . These cam platforms are replicated about the circumference of the upper end of the housing  12 , thus forming a series of circumferentially-spaced, vertically-extending alignment edges  88 . A lower portion of the cam surface  84  for each ratchet tooth is cut out to form a locking recess  90 , located proximate the sharp alignment edge  88 , the locking recess  90  sized and shaped to receive a corresponding locking pad  74  on the inside of the cap  14  as described above. There is a locking recess  90  in the housing  12  for each locking pad  74  on the cap  14 . The circumferential space between the edge of the locking recess  90  and the sharp alignment edge  88  associated with that cam surface is taken up by a relatively small, axially-extending, rib  92  that may have an axially-oriented ramped surface  94  on one side, along the locking recess, and a sharp vertical edge  96  on its other side, in alignment with, and becoming part of the sharp alignment edge  88 . The ramped surface  94  on the rib may be included to permit an “over-ride” of the locked arrangement as described further herein. 
     When the cap  14  and housing  12  are ready for assembly, with the plunger-diaphragm assembly  30  and outer clamp ring  48  properly located, the cap  14  may be telescoped over the housing  12  when the sharp edges  76  of the locking pads  74  are substantially aligned with (but slightly offset from) the sharp alignment edges  88 . In this regard, it is noted that, for assembly purposes, the cap may be inverted from the orientation shown in  FIG. 1  to facilitate placement of the plunger-diaphragm assembly  30  into the cap. The outer clamp ring  48  can then be located over the outer edge of the diaphragm, with meshing engagement of teeth  56  and lugs  66 , followed by insertion of the housing into the cap. Alternatively, after placement of the plunger and diaphragm assembly into the cap, the outer clamp ring  48  can be seated in the housing, relying on the friction fit between the clamp ring skirt portion  58  and the interior surface of the housing to hold the clamp ring  48  as the cap and housing are brought together. 
     Upon full insertion of the upper end of the housing  12  into the cap  14  (see  FIGS. 7 and 9 ), the cap  14  may be rotated such that the locking pads  74  ride over the cam surfaces  84  of the cam platforms  82  and snap or click into the corresponding locking recesses  90 , with the sharp edges  76 ,  89  of the locking pads  74  and locking recesses  90 , respectively, preventing any back-rotation of the cap  14  (see  FIG. 10 ). At the same time, the engagement of upper horizontal edges  98  on the locking pads  74  with upper horizontal edges  100  of the locking recesses  90  prevents any further relative axial movement between the cap and the housing. 
     If the ramped surfaces  94  are employed, it is possible to exert a further rotation force on the cap to move the locking pads out of the locking recesses  90  to enable disassembly of the cap from the housing. On the other hand, if the assembly of the cap to the housing is to be permanent, the ramped surface  94  can be eliminated in favor of a sharp edge like the alignment edge  88 . With two sharp edges defining the opposite axial sides of the locking recesses  90 , further relative rotation between the cap and the housing is essentially precluded. 
     As already mentioned, during the relative rotation of the cap  14  and housing  12  during the assembly of one to the other, no torque or twisting forces of any kind are exerted on the diaphragm  40 , since the outer clamp ring  48  and diaphragm  40  are fixed relative to the cap  14  and rotational surface friction is established only between the annular surface  68  on the underside of the clamp ring  48  and the upper edge  70  of the lower housing  12 . 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements.