Patent Publication Number: US-9415410-B2

Title: Clog retarding filtering apparatus for inlet fluid into a pressure chamber of a sprayer

Description:
Priority is claimed to U.S. Provisional Application No. 61/799,737, filed Mar. 15, 2013, which is herein incorporated by reference. 
    
    
     DESCRIPTION 
     This invention relates to an apparatus for retardation of clogging in a filtering apparatus for inlet fluid into the pressure chamber of a sprayer, and more particularly to an improvement over the filtering apparatus illustrated in Klein, U.S. Pat. Nos. 7,789,329 (the Klein patent) and U.S. Pat. No. 8,622,323, which are incorporated herein by reference. 
     As shown in the Klein patent, the removable filter may be provided adjacent to the inlet port of the pressure chamber of the sprayer. The filter is manually removable and replaceable via the opening of the sprayer tank. The removal and replacement of the filter has engendered some difficulty, and from time to time, the filter has not been timely removed and some clogging of the filter has occurred. It has become desirable not to rely on the operator to remove the filter when necessary and to provide a separate means for preventing clogging of the filter. Merely providing agitation of the liquid at the bottom of the tank has found to be insufficient to avoid clogging of the filter. For apparatus&#39; for agitating the liquid at the bottom of the tank, see Luchsinger U.S. Pat. No. 4,768,714, issued Sep. 6, 1988, and Luchsinger U.S. Pat. No. 4,798,333, issued Jan. 17, 1989. 
     Accordingly, it is the principal feature of the present invention to provide an improved filtering apparatus for inlet fluid into the pressure chamber of a sprayer which facilitates the retardation of clogging of a filter which may be removably disposed over the inlet to the pressure chamber. 
     It is a more specific feature of this invention to provide clogging resistance for a filter, such as shown in the Klein patent, and to lengthen the time between removal and replacement of the filter and thereby reduce the need for operator assistance for maintaining the filter clear of debris. 
     Briefly described, the clogging retardation apparatus provided by the present invention includes a structure defining an auxiliary pumping chamber associated with the pump of the sprayer which pressurizes the liquid to be sprayed. Liquid enters the pressure chamber, via an inlet port from the tank of the sprayer. The auxiliary pumping chamber is connected via a hose in a position facing the filter which is removably disposed over the inlet port of the pressure chamber. This hose provides a jet of fluid directed against the filter for flushing the filter, thereby retarding the accumulation of sediment and other clogging materials at the filter. In addition, the hose provides a conduit for fluid from the tank into the auxiliary chamber so that it can be pumped and thrust outwardly through the hose to flush the filter and to prevent accumulation of material which may clog the filter. 
     The present invention also describes a method for retarding accumulation of clogging material on a filter of a sprayer pump having the steps of: providing a sprayer pump having a pressure chamber with an inlet for receiving fluid from a tank (or container) into which the pressure chamber is received, providing a filter in the tank adjacent such inlet, and providing an auxiliary pump having an auxiliary pressure chamber for directing fluid from the tank along a path from said second pressure chamber against the filter to flush such filter. The sprayer pump and the auxiliary pump are preferably coupled to a common actuator mechanism for simultaneous operation. 
     The foregoing and other objects, features and advantages of the invention will be more apparent from reading the following description in connection with the accompanying drawings in which: 
       FIG. 1  is a view looking upward from the bottom of the auxiliary pumping mechanism, the auxiliary pumping mechanism is connected to the bottom of the pressure chamber with the removable filter shown in place over the inlet to the pressure chamber from the tank, the tank not being shown but apparent from the drawings and description of the Klein patent; 
       FIG. 2  is a view looking downwardly to end of the flushing hose from the auxiliary pressure chamber showing the filter in place; 
       FIG. 3  is a view taken from the front showing the hose emanating from the chamber and extending into a flange at the bottom of the pressure chamber; 
       FIG. 4  is a view similar to  FIG. 3 , but with the filter removed; and 
       FIG. 5  is a partial exploded view of lower part of the pumping structure of  FIG. 1 . 
    
    
     Referring to  FIGS. 1-4 , a pressure chamber  10  is connected to the surrounding tank of the sprayer by a flange  12  extending from the bottom thereof. The general design of the pressure chamber  10  including its pressure relief valve  14  ( FIG. 1 ) at the top thereof and the connection to the tank will be apparent from the aforementioned Klein patent (see tank and pressure chamber referenced as elements  10  and  16 , respectively, in the incorporated Klein patent). The pressure chamber  10  has an inlet port assembly  16  having an inlet port  17  ( FIG. 2 ) to which is connected a removable filter  18  as described in the Klein patent (see inlet port and filter referenced as  34  and  30 , respectively, in the incorporated Klein patent). Entering into the tank is the pumping apparatus  20  of the sprayer which includes the pump piston, operated via a crank mechanism  22  (see pumping mechanism referenced as  22  in the incorporated Klein patent) with the improvement of the present invention having an auxiliary (or additional) pumping structure  24 . 
     The crank mechanism  22  has a crank arm  25  operative by cranking a lever manually, as shown for example in above-mentioned Luchsinger patents or the Klein patent. The mechanism  22  has another arm  27  which is connected to reciprocate the diaphragm  28   a  of the diaphragm pump  28  in the structure  24 . 
     The arm  27  is also coupled mechanically to the pump piston in the main pumping apparatus  20 . Crank arm  25  may be pivotally mounted to arm  27 , as shown in  FIG. 1 . The auxiliary pumping structure  24  is connected via clamping rings  26  to the pumping apparatus  20  of the sprayer. The auxiliary pumping structure  24 , as noted above, includes an auxiliary pressure chamber  29  ( FIG. 5 ) and a diaphragm pump  28 , the outside of which is shown in  FIG. 1 . This diaphragm pump  28  is driven together with the piston in the pumping apparatus  20  by means of the crank mechanism  22 , thereby providing a common actuator mechanism. 
     Referring to  FIG. 5 , the lower part of pumping apparatus  20  is shown disassembled at clamping rings  26  thereby enabling a better view of the auxiliary pumping structure  24  contained therein having diaphragm pump  28 . In the preferred embodiment, diaphragm pump  28  has a rigid outwardly flared upper section  28   b  extending from pump chamber  10 , and a lower dome-shaped diaphragm  28   a  which mates along the edges of upper section  28   b  to form auxiliary pressure chamber  29  there between. Diaphragm  28   a  may be made, for example, of plastic, rubber or other resilient material, so that it can move forward and back (e.g., between flexed and unflexed positions) with respect to upper section  28   b  when reciprocated by arm  27 , which is connected along the bottom of diaphragm  28   a . Further information as to the design of the diaphragm pump in the auxiliary or additional pumping structure reference is made to the above-mentioned Luchsinger patents. 
     One lower end  33  of a hose  30  is located in an opening in section  28   b  to extend into auxiliary pumping chamber  29 , while the upper end  32  of the hose is disposed in an opening in flange  12  (see  FIG. 2 ) residing in a tank into which the main pressure chamber  10  is located. Fluid can pass through hose  30  between such tank and auxiliary pumping chamber  29  during diaphragm pump  28  operation. A frustoconical cover  31  may be provided over diaphragm  28   a  when diaphragm  28   a  and upper diaphragm section  28   b  are clamped together by clamping rings  26 . Cover  31  has an opening  31   a  for arm  27  to extend there through. 
     The piston of the pump apparatus  20  draws fluid from the tank via the inlet port assembly/structure  16 , i.e., via inlet port  17 , pressurizing the pressure chamber  10  which supplies pressurized fluid out of the pressure chamber for spraying, as described in detail in the Klein patent. The auxiliary pressure chamber  29  is pressurized by the diaphragm  28   a  of diaphragm pump  28 . The diaphragm  28   a  of diaphragm pump  28  sucks liquid from the tank into the auxiliary chamber  29 , via the hose  30  (e.g., in a direction or path from hose end  32  to end  33 ), and pumps the liquid out of the auxiliary pressure chamber  29  through the hose  30  (e.g., in a direction or path from hose end  33  to end  32 ) in a stream or jet of fluid directed upon the filter  18  (i.e., filter screen  34 ). 
     The auxiliary pumping chamber  29  is connected via the hose  30  through the flange  12  to an outlet adjacent to the filter  18  of the filtering apparatus which is shown over the inlet port  17  to the pressure chamber  10 . The filter  18  presents a screen  34  over the openings in the inlet port  17 .  FIG. 2  shows the exit end  32  of the hose  30  extending through the flange  12  and adjacent to and in flushing relationship with the filter screen  34  of the removable filter  18 . The inlet structure  16  is shown with the filter  18  removed in  FIG. 4 . 
     The filter  16  and particularly the screen  34  thereof is subject to clogging by sediment and other components of the liquid in the tank as the liquid flows inwards and outwards of the inlet port. The provision of the hose  30  is to enable a jet directed towards the screen  34  of the filter  16 , or over the screen, to direct the jet to flush the filter  16  and to remove the material which may be clogging the filter screen  34 , thereby lengthening the time required for the filter  16  needing to be removed and replaced, and provides an operational advantage by reducing the need for supervision of the operator in so far as attendance to the removal and replacement of the filter  16 . 
     Although the pumping structure  20  is described as being that also shown in the Klein patent, the present invention may be utilized in other typical backpack sprayers having a pumping structure to pressurize fluid in a backpack sprayer tank. 
     One benefit of the present invention is with each manual pump of the tank, via crank arm  25 , to pressurize fluid therein, fluid also is simultaneously being directed against filter screen  34 , thus providing dual actions with each forward manual pump stroke. 
     It will be appreciated that the hose provides for flow of fluid into the auxiliary pressure chamber for pressurization by the diaphragm pump as well as for the delivery of the jet of fluid against or over the filter for flushing the filter thereby retarding the formation of clogging sediment or other material. 
     Variations and modifications in the herein described apparatus, method, and system will undoubtedly suggest themselves to those skilled in the art. Accordingly, the foregoing should be considered as illustrative and not in a limiting sense.