Abstract:
A nozzle assembly comprises a hollow nozzle body having a central bore and a plurality of ports extending through the body from the central bore; and a switching valve cartridge disposed in the central bore that directs fluid flow to ports upon application of fluid flow above a predetermined threshold to the inlet and direct fluid flow to different ports upon fluid flow having subsequently dropped below the predetermined threshold and then exceeding the predetermined threshold. The cartridge comprises a cylindrical cartridge case having a front portion and a cup shaped rear portion, a cylindrical poppet slidably disposed within the cup shaped rear portion of the cartridge case, and a biasing member within the cartridge case between the front portion of the case and the poppet urging the poppet away from the front portion of the cartridge case.

Description:
CROSS REFERENCE To RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 61/955,056, filed Mar. 18, 2014, having the same title. This application is related to U.S. patent application Ser. No. 13/367,080, filed Feb. 14, 2012, having the same title, now U.S. Pat. No. 8,863,775, issued Oct. 21, 2014, each of which is hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE DISCLOSURE 
       [0002]    Traction nozzles are used in sewer pipe lines and other piping systems to assist in pulling high pressure hose into the pipe to reach obstructions requiring removal. These traction nozzles have jet tips oriented at an angle rearward in order to generate thrust in the nozzle within the pipe to assist in pulling the hose through and along long stretches of pipe and around pipe bends. These nozzles have forward directed jet tips and may also have laterally directed tips to ablate the obstructions encountered. However, the forward directed jet tips produce a counter force against forward travel of the nozzle through the pipe. This counterforce hinders effective deployment of the high pressure hose and reduces the net pulling force produced by the traction nozzle on the high pressure hose. Thus there is a need for a switching mechanism that does not generate a counterforce during traction operation, yet facilitates operation of an effective fluid jet nozzle during actual cleaning operations. Furthermore, there is a need for a nozzle assembly incorporating a switching valve assembly that is replaceable and has a minimum number of component parts in order to simplify design and maintenance of such a nozzle assembly. 
       SUMMARY OF THE DISCLOSURE 
       [0003]    An exemplary embodiment of a nozzle assembly in accordance with the present disclosure includes a hollow nozzle head body containing a switching valve cartridge assembly captured in the body by an inlet nut fastened to the nozzle body. The cartridge assembly includes a generally cylindrical cartridge case slidably disposed in the nozzle body, a movable poppet disposed in the cartridge case, and a bias member resiliently biasing the poppet toward the inlet nut at a rear end of the cartridge case. 
         [0004]    This nozzle assembly more particularly includes a hollow nozzle body having a central bore and a plurality of ports extending through the body from the central bore. A switching valve cartridge is disposed in the central bore. This cartridge is operable to direct fluid flow from an inlet to at least one of the plurality of ports upon application of fluid flow above a predetermined threshold to the inlet and direct fluid flow from the inlet to at least a different one of the plurality of ports upon fluid flow having subsequently dropped below the predetermined threshold and then exceeding the predetermined threshold. 
         [0005]    The cartridge includes a cylindrical cartridge case having a front portion and a cup shaped rear portion, a cylindrical poppet slidably disposed within the cup shaped rear portion of the cartridge case, and a biasing member within the cartridge case disposed between the front portion of the case and the poppet. This biasing member is preferably a coil spring. The spring urges the poppet away from the front portion of the cartridge case. 
         [0006]    The cartridge preferably includes one or more of guide members engaging the poppet to alternatingly align the poppet with the at least one of the plurality of ports and the different one of the plurality of ports each time the poppet abuts the front portion of the case. The guide members are preferably pins through a side wall of the cartridge case projecting radially inward from the rear portion of the cartridge case that engage a corresponding feature on the poppet. 
         [0007]    The poppet has at least one through bore to permit fluid flow therethrough and the corresponding feature. This feature preferably is a peripheral zig-zag groove. Each transition below the predetermined threshold causes the poppet to rotate about its axis to permit fluid flow to alternate between the first and second set of ports. 
         [0008]    The front portion of the cartridge case has at least one bore therethrough leading to the first set of ports and at least one other bore therethrough leading to the second set of ports. The poppet has a front face and at least one lug protruding from the front face for selectively closing the at least one bore through the front portion of the cartridge case. The guide members rotate the poppet a predetermined amount, for example 22.5° each time the poppet moves toward or away from the front portion of the cartridge case. 
         [0009]    The cartridge case preferably has two or more axial bores through the front portion equally spaced about a central axis through the cartridge case and two or more angled bores through the front portion extending to an annular channel that extends around the front portion of the cartridge case. The poppet has a front face, at least two through bores spaced about the central axis, and at least two lugs protruding from the front face for selectively engaging the axial and angled bores through the front portion of the cartridge case depending on a rotational position of the poppet within the rear portion of the cartridge case. 
         [0010]    An embodiment of a nozzle assembly in accordance with the present disclosure includes a hollow nozzle body connectable to a high pressure fluid supply. The nozzle body has a central bore, a first plurality of ports extending out of the body from one end of the central bore and a second plurality of ports extending out of the body from a side of the central bore. A switching valve cartridge assembly is disposed in the central bore that is operable to direct fluid flow from an inlet to one or more of the first plurality of ports upon application of fluid flow above a predetermined threshold to the inlet and direct fluid flow from the inlet to one or more of the second plurality of ports upon fluid flow dropping below the predetermined threshold and then exceeding the predetermined threshold again. 
         [0011]    The cartridge assembly in this embodiment includes a cartridge case disposed in the central bore of the hollow body. The cartridge case has a front portion and a cup shaped rear portion. The front portion has a first plurality of bores therethrough for passage of fluid to the first plurality of ports and a second plurality of bores therethrough for passage of fluid to the second plurality of ports. 
         [0012]    A cylindrical poppet is slidably disposed in the rear portion of the cartridge case. This poppet has a plurality of axially extending poppet bores therethrough. A biasing member within the rear portion of the cartridge case extending between the front portion and the poppet urges the poppet away from the front portion of the cartridge case such that, absent fluid flow through the nozzle assembly, the poppet abuts against a retaining nut that captures the cartridge within the nozzle body. A guide member that extends between the rear portion of the cartridge case and the poppet engages a corresponding feature on the poppet to rotate the poppet as it slides forward and rearward within the rear portion of the cartridge case. 
         [0013]    The poppet has a front face and a plurality of lugs protruding from the front face each closing one of the bores through the cartridge case when the poppet abuts against front portion of the cartridge case. The poppet has a zig-zag peripheral annular groove engaging the guide member. This engagement causes the poppet to rotate in only one direction a predetermined amount about a central axis through the assembly each time fluid flow transitions above and below the predetermined threshold. The bores through the poppet align with one or more of the bores through the cartridge case when the poppet abuts against the front portion of the cartridge case. 
         [0014]    One embodiment of a switching valve cartridge for use in a nozzle body in accordance with the present disclosure includes a generally tubular cartridge case having a front portion and a cup shaped rear portion. The front portion has a peripheral annular channel and a first plurality of axial bores therethrough for axial passage of fluid out of the front end and a second plurality of bores therethrough for passage of fluid to the annular channel. The cartridge also includes a cylindrical poppet slidably disposed in the rear portion of the cartridge case. This poppet has a plurality of axially extending poppet bores therethrough. A biasing member is disposed within the rear portion of the cartridge case between the front portion and the poppet. This biasing member is preferably a coil spring that biases the poppet away from the front portion of the cartridge case absent sufficient fluid flow to overcome the spring force. A guide member extends between the rear portion of the cartridge case and the poppet and engages a corresponding feature on the poppet to rotate the poppet as it slides forward and rearward within the rear portion of the cartridge case. 
         [0015]    The poppet has a front face and a plurality of lugs protruding from the front face each closing one of the bores through the cartridge case when the poppet abuts against front portion of the cartridge case. The bores through the poppet align with one or more of the bores through the cartridge case when the poppet abuts against the front portion of the cartridge case. 
         [0016]    Further features, advantages and characteristics of the embodiments of this disclosure will be apparent from reading the following detailed description when taken in conjunction with the drawing figures. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a partial exploded view of a switching nozzle head assembly in accordance with present disclosure fastened to a cleaning hose. 
           [0018]      FIG. 2  is an enlarged exploded view of the switching nozzle head assembly shown in  FIG. 1 . 
           [0019]      FIG. 3  is an axial cross sectional view through an assembled switching nozzle head assembly in an unpressurized condition. 
           [0020]      FIG. 4  is an axial cross sectional view through the nozzle head assembly shown in  FIG. 3  in a pressurized condition with flow directed to cleaning ports. 
           [0021]      FIG. 5  is an axial cross sectional view through the nozzle head assembly rotated 45 degrees from that shown in  FIGS. 3 and 4 , with the poppet directing flow to tractor ports. 
           [0022]      FIG. 6  is an axial cross sectional view through the nozzle assembly as in  FIG. 4  with flow plugged from passage to the cleaning ports. 
           [0023]      FIG. 7  is an axial cross sectional view through the nozzle assembly as in  FIG. 5 , showing the poppet preventing fluid flow to the tractor ports. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    An exemplary embodiment of a nozzle assembly incorporating a switching valve assembly is shown in  FIGS. 1 through 7 . Note that the cross sectional views of  FIGS. 3 ,  4  and  6  are axial cross sectional views showing the cleaning nozzle ports passing out of the side of the nozzle head body.  FIGS. 5 and 7  are axial cross sectional views of the same assembly rotated 45 degrees, with the cut going through a pair of tractor nozzle ports. 
         [0025]    Turning now to  FIG. 1 , a partial exploded view of a pipe cleaning assembly with a nozzle assembly  102  incorporating a cartridge assembly  100  in accordance with an exemplary embodiment of the present disclosure is shown. The nozzle assembly  102  includes a hollow nozzle head body  104  that houses the cartridge assembly  100  captured within the nozzle body  104  by a threaded retainer nut  103 . The assembly  102  is in turn threaded or otherwise fastened via retainer nut  103  to a distal end of a rotating bearing coupling assembly  106  such as is disclosed in U.S. Pat. No. 6,059,202, which is, in turn, fastened to the distal end of a high pressure fluid hose  108 . 
         [0026]    A separate enlarged exploded view of the nozzle assembly  102  is shown in an exploded view in  FIG. 2 . The cartridge assembly  100  comprises a cartridge body  130 , a coil spring  134  and a poppet  132 . 
         [0027]    The nozzle head, or body,  104  in this exemplary embodiment, is generally symmetrical about its longitudinal axis “A” and has a set of four circumferentially spaced apart tractor ports  110 , a set of four cleaning ports  112 , and a front cleaning port  114 . Each of these ports  110 ,  112 , and  114  passes into a central blind bore  116  into which the cartridge  100  is installed. The ports  110  and  114  extend into a bottom annulus portion of the central blind bore  116 . The ports  112  intersect a side portion of the central blind bore  116 , spaced from the bottom annulus portion of the central blind bore  116 . 
         [0028]    Each of these ports is positioned/directed at an angle from, or displaced off center from the longitudinal axis A of the nozzle body  104  so as to impart a rotational moment to the nozzle body  104  during device operation. The angle from the axis causes forward traction, or neutral (no pulling), or retarding in the case of a forward cutting nozzle. It is only the radial offset that imparts a rotational moment to the nozzle body. As a result, during operation of the cartridge assembly  100 , the nozzle body  104  spins on the bearing assembly  106 . The bearing assembly  106  typically is designed to allow spinning of the nozzle assembly  102  at a controlled rate. 
         [0029]    The choice of and direction of ports  110 ,  112 , and  114  may be modified in different nozzle heads  104 , depending on the particular cleaning application for which the nozzle assembly  102  is designed. For example, the precise angular position, number and offset of each of the ports may be changed as well as the number of sets of ports depending on operational needs for a specific application. Provided the same radial spacing of the port openings into the central blind bore  116  remains the same, a variety of nozzle head configurations may utilize the same cartridge  100  as described below. Furthermore, all of the wear parts in the switching valve mechanism of the nozzle assembly  102  are contained in the cartridge  100  such that repair is simplified by simple cartridge replacement when required. 
         [0030]    The cartridge  100  comprises a cup shaped cartridge case  130 , a poppet  132 , and a biasing spring  134 . The cartridge  100  is assembled into the central blind bore  116  in the nozzle body  104  and captured therein via the threaded retainer nut  103 . The threaded retainer nut  103  has a peripheral face groove holding a seal O-ring  142  which engages a rear annular face of the cartridge case  130  to capture the cartridge case  130  within the nozzle body  104 . The cartridge case  130  carries a pair of spaced O-rings  142  in corresponding peripheral grooves to center and seal the cartridge  100  in place in the bore  116 . 
         [0031]    The cartridge case  130  has a cup shaped rear portion  131  and a solid front portion  133 . The front portion  133  has a distal end  143  for engaging the bottom of the central blind bore  116  in the nozzle body  104 , an annular rim  141 , and an annular channel  140  around the front portion  133  separating the front portion  133  from the rear portion  131 . The front portion  133  also has a central axial blind bore  135  for receiving therein one end of the spring  134 . The front portion  133  also preferably has four axially extending, equally spaced apart bores  137  alternating with four angled bores  139 . The four axially extending bores  137  are symmetrically spaced 90 degrees apart about the central axis A. The angled bores  139 , also 90 degrees apart, are symmetrically spaced between the four axially extending bores  137 . Thus there is a bore  137  or  139  every 45 degrees around the central axis A through the cartridge case  130 . 
         [0032]    Each of these angled bores  137  communicates with the annular channel  140  around the solid front portion  133  of the cartridge case  130 . The disc shaped rim  141  of the front portion  133  carries an O-ring  142  that isolates the annular channel  156  from the distal end  143 . The cartridge case  130  also has four equally spaced guide pins  136  that extend radially inward through the side wall of the cup shaped rear portion  131 . These guide pins are press fit through the side wall of the rear portion  131 , and are used to control position of the poppet  132  within the cartridge case  130  as explained further below. The cartridge case  130  requires no specific orientation about axis A when installed within the blind bore  116  of the nozzle body  104 . 
         [0033]    The poppet  132  is basically a solid cylindrical body having a front end  144  and a rear end  146 . The front end  144  has a flat radial face with four symmetrically spaced protruding lugs  148  spaced 90 degrees radially apart about the axis A. Between these lugs  148  are four equally spaced axially extending through bores  150 , again equally spaced 90 degrees apart about the axis A. Each of the lugs  148  acts as a valve disk to one of the bores  137  and  139  depending on the rotational position of the poppet  132  within the cartridge case  130 . 
         [0034]    The exemplary poppet  132  has an outer side wall  152  that has a zig-zag pattern annular cam groove  154  formed in the side wall  152  fully around the periphery of the poppet  132 . This cam groove  154  is sized complementary to the diameter and depth of the pins  136  that project radially inward from the side wall of the rear portion  131  of the cartridge case  130 . When the cartridge  100  is fully assembled, the pins  136  ride in the cam groove  154 . This cam groove  154  has forward notches or vertices  156  each rotationally spaced about 45° apart along the groove  154 . The cam groove  154  also has rear notches  158  spaced alternatingly with four axial grooves  160  spaced about 90° apart. These axial grooves  160  merge with the cam groove  154  at an angular rotation position between the rear notches  158  in the groove  154 . 
         [0035]    Each of the four guide pins  136  ride in the cam groove  154  when the valve cartridge  100  is fully assembled. The sides of the cam groove  154  are angled toward the sequential forward and rear notches or vertices  156  and  158  of the groove  154  such that when the poppet  132  moves forward and back as flow is applied or reduced, the poppet  132  has to rotate about 22.5° clockwise each time as it moves either forward or back with each change in flow above and below a predetermined threshold rate. 
         [0036]    When fluid flow is off, as is shown in  FIG. 3 , or at least reduced below the predetermined threshold, determined by the spring rate of the spring  134 , the poppet  132  is pushed by the spring  134  rearward so that it rests against the nut  103 . At the same time, the poppet  132  is rotated 22.5° clockwise. The guide pins  136  shown in  FIG. 3  are either resting against the forward notches  156  or riding within the axial grooves  160 . 
         [0037]    In this intermediate position, the poppet  132  rests against the nut  103 . In this position, the passages  150  through the poppet  132  are open to all the passages in the cartridge case  130 , i.e. the axial passages  137  and angled passages  139  to all the ports  110 ,  112  and  114 . However, fluid pressure is either off or low at this point. 
         [0038]    If the position of the poppet  132  before flow decrease had been as shown in  FIG. 4 , i.e., with flow through the angled passages  139  to the annular channel  140  to the cleaning nozzle ports  112 , then, when fluid flow is again turned on, the poppet  132  again is moved forward by the fluid flow against the inlet end portion of the poppet  132 , but this time moves the poppet  132  moves forward and rotates 22.5° clockwise to the position shown in  FIG. 5 . In this position, the passages  150  are aligned with the axial passages  137  to the tractor ports  110  and front cleaning port  114 . At the same time, the four lugs  148  on the poppet end  144  close the four angled bores  139  to the cleaning nozzles  112 , as is shown in  FIG. 6 . 
         [0039]    When flow is subsequently reduced below the predetermined threshold, such as by the operator turning off flow, the poppet  132  rotates about 22.5° as the spring  134  pushes the poppet  132  rearward, via engagement with the stationary guide pins  136  to cause rotation and axial movement to an intermediate position, again as is shown in  FIG. 3 , except rotated one notch  156  further by 22.5°. This rotation is caused by the interaction between the stationary guide pins  136  riding in the groove  154  forcing rotation of the poppet  132  as the spring  134  pushes the poppet rearward. 
         [0040]    Then, when flow is again increased above the predetermined threshold, the poppet  132  rotates about 22.5° again as fluid flow pushes the poppet  132  forward, to the position shown in  FIGS. 4 and 7 . When the poppet  132  is in this position, the passages  137  are plugged via the lugs  148 , and the passages  150  are directly aligned with the angled bores  139  to the annular channel  140  and the cleaning ports  112 . Since the ports  137  are plugged as is shown in  FIG. 7 , there is no flow available to the traction ports  110 . Thus, while flow is directed through the cleaning ports  112 , flow is positively prevented through the traction ports  110 . 
         [0041]    Each cycle of fluid flow/pressure application causes about a 45° rotation of the poppet  132  and hence an alternation between fluid flow being directed to forward port  114  and traction ports  110  and between cleaning ports  112 . Since all of these ports are preferably offset from a direct radial orientation, a rotational torque is applied to the nozzle body  104  to cause nozzle head rotation when fluid pressure is applied. Finally, each of the ports  110 ,  112  and  114  each preferably has a threaded jet tip  170  installed. These jet tips  170  may also be of different configurations depending on the task to be performed. 
         [0042]    It is to be understood that various changes can be made to the nozzle body  104  and to the switching valve cartridge  100  in accordance with the present disclosure. For example, the nozzle head body  104  may be configured with a different number of ports  110  and  112  and the corresponding poppet  132  and case  130  in the cartridge  100  would thus have a different number of openings and passages. The same cartridge  100  may be utilized in a variety of nozzle head bodies  104  each with a different set of angled ports. The angles and offsets utilized may be tuned to achieve specific rotational torques at designed pressures and flow rates. Additionally, the lugs  148  on the poppet  132  may be replaced with a flat face seal. The cartridge  100  could also be used in a non-rotary nozzle or flow diversion design in-line along a hose. All such changes, alternatives and equivalents in accordance with the features and benefits described herein, are within the scope of the present disclosure. Such changes and alternatives may be introduced without departing from the spirit and broad scope of my invention as defined by the claims below and their equivalents.