Patent Publication Number: US-2022228669-A1

Title: Pump for A System for Applying A Coating Product, and Use of Such A Pump

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit under 35 USC § 371 of PCT Application No. PCT/EP2020/063591 entitled PUMP FOR A SYSTEM FOR APPLYING A COATING PRODUCT, AND USE OF SUCH A PUMP, filed on May 15, 2020 by inventors Nicolas Plantard and Francois Morales. PCT Application No. PCT/EP2020/063591 claims priority of French Patent Application No. 19 05163, filed on May 16, 2019. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a pump for a system for applying a coating product and a use of such a pump. 
     BACKGROUND OF THE INVENTION 
     Pneumatic pumps for systems for applying a coating product, such as paints or varnishes, include an intake valve for the product, through which the product is discharged under high pressure, from a source containing the product and toward an application device. This valve is generally screwed to the pump body and ensures sealing relative to the outside and stopping of the flow of product during shut-down periods of the pump. 
     The passage of the product in the intake valve involves periodic cleaning. When the product cools, a deposit in skin form may appear, and over time the pump may no longer take up the product. 
     The valve must then be disassembled in order to clean its component parts, in particular the valve, the seat of the valve shutter, the components that ensure the sealing between the valve and the pump body, etc. These disassembly operations generally require a certain number of tools and quantity of time, whereas the operators who use the pumps do not necessarily have all of the necessary tools at their disposal, or work outdoors under conditions that are not favorable to maintenance. 
     Furthermore, on some pumps, the screw threads of the valve may be placed in contact with the product, which complicates the disassembly. 
     The invention aims to address these drawbacks by proposing a new pump for a coating product application system allowing simplified cleaning and maintenance operations. 
     SUMMARY OF THE DESCRIPTION 
     To this end, the invention relates to a pump for a system for applying a coating product, comprising a pump body, and an intake valve secured to the pump body, intended to be connected to a source of coating product, the intake valve comprising a valve body and a valve shutter. This pump is characterized in that the valve body comprises a first component secured to the pump body, and a second component screwed to the first component, said second component including a valve-shutter support, situated radially toward the inside of the first component and forming a seat of the valve which is intended to collaborate with the valve shutter in order to establish sealing, in that the second component also includes a nut, attached to the valve-shutter support, extending radially around an end part of the first component, this end part having an external screw thread cooperating with an internal screw thread of the nut, and in that after unscrewing of the nut from the first component, the second component and the valve shutter can be extracted from the first component. 
     Owing to the invention, the seat of the valve shutter and the valve shutter can be disassembled easily by unscrewing through the bottom of the pump. 
     According to advantageous but optional aspects of the invention, such a pump may incorporate one or more of the following features, considered in any technically allowable combination:
         The nut is provided with external disassembly shapes making it possible to unscrew or screw the second component in the first component using a nonspecific tool. The seat of the valve shutter and the valve shutter can therefore be disassembled without specific tooling.   The valve-shutter support includes a tubular part supporting the seat, said tubular part being inserted into an internal cavity of the first component. A maximum external diameter of the tubular part of the valve-shutter support and a maximum external diameter of the valve shutter are smaller than a minimum internal diameter of the internal cavity.   The external screw thread is fluidly insulated from the internal cavity by a tubular end part of the first component. The internal screw thread is fluidly insulated from an internal duct of the second component by the tubular part of the valve-shutter support.   The first component comprises a frustoconical internal bearing surface against which a corresponding external frustoconical surface of the valve-shutter support bears so as to create sealing between the valve-shutter support and the first component.   The seat of the valve is formed by a component attached on the valve-shutter support.   The nut and the valve-shutter support are attached so as not to be separable.   The nut is connected inseparably with a tool for unscrewing the second component.   The external shapes of the nut form radial protuberances extending in planes comprising a central axis of the pump, able to be actuated by percussion by a nonspecific tool for the unscrewing or the screwing of the second component.   The external shapes of the nut form a recess for accommodating a nonspecific unscrewing or screwing tool for the second component.       

     The invention also relates to a use of a pump as mentioned above, characterized in that it consists in using a nonspecific tooling to unscrew or to screw the second component with respect to the first component by action on the external shapes of the nut of the second component using said nonspecific tool. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood, and other advantages thereof will appear more clearly, in light of the following description of a pump and a use of this pump according to its principle, provided as a non-limiting example and in reference to the appended drawings, in which: 
         FIG. 1  is a sectional view in a longitudinal plane of a pump according to the invention, in a disassembled configuration; 
         FIG. 2  is a sectional view similar to  FIG. 1 , in an assembled configuration; 
         FIG. 3  is a perspective view of the pump of  FIG. 1  in the disassembled configuration; 
         FIG. 4  is a perspective view of the pump in the assembled configuration and during unscrewing of an intake valve of the pump; 
         FIG. 5  is a perspective view of the pump in the disassembled configuration, showing a variant embodiment of a nut of the intake valve; 
         FIG. 6  is a perspective view of the pump in the assembled configuration and during unscrewing, showing an unscrewing tool inseparably connected to the intake valve. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       FIG. 1  shows a pump  2  for a system for applying a coating product, for example a paint or a varnish. Such a pump is in particular intended for exterior uses, for example worksites, hulls of boats, coating metal frames, for applying paints or anticorrosion materials. For interior use, such a pump can be used in the automotive industry. 
     The invention applies to pumps using air as vector for the product to be applied, as well as airless pumps. 
     The pump  2  comprises a pump body  4 , and an intake valve  6  secured to the pump body  4 , intended to be connected to a source of covering product, not shown. The intake valve  6  comprising a valve body formed by a first component  8  secured to the pump body  4 , and by a second component  10  screwed to the first component  8 , and a valve shutter. The valve shutter is formed in this example by a ball  12 . The pump  2  defines a longitudinal central axis X 2 . 
     The longitudinal axis X 2  is a vertical axis, and hereinafter, the directions “top” and “bottom” are used in reference to the longitudinal axis X 2  relative to the orientation of  FIG. 1 . The pump body  4  is therefore located in the top part of the pump  2 , while the intake valve  6  is located in the bottom part. 
     The terms “inner,” “internal,” “outer,” “external,” “radial” or “axial” are used in reference to this axis X 2 . A radial surface is a curved surface surrounding the central axis X 2 , and an axial surface is a surface perpendicular to the axis X 2 . 
     The first component  8  is attached to the pump body  4  by any suitable means, for example by screwing. 
     The second component  10  includes a valve-shutter support  14 , situated radially inside the first component  8  and forming a seat  142  of the valve  6  which is intended to cooperate with the ball  12  in order to establish sealing between the first component  8  and the second component  10 . 
     The second component  10  can optionally comprise a tube, not shown, for connecting to a product suction tube. 
     The first component  8  has a globally cylindrical geometry centered on the central axis X 2  and defining an internal cavity  81 , in which the valve-shutter support  14  is received. The valve-shutter support  14  is globally cylindrical and centered on the central axis X 2 , and has a tubular part  141  which is received in the internal cavity  81 . The tubular part  141  has a maximum external diameter D 141  which is smaller than a minimum internal diameter D 81  of the internal cavity  81 . 
     The second component  10  also includes a nut  16 , attached to the valve-shutter support  14 , extending radially around an end part  80  of the first component  8 , this end part  80  having an external screw thread  82  cooperating with an internal screw thread  160  of the nut  16 . The end part  80  has a tubular shape centered on the central axis X 2  and extends downward while surrounding the internal cavity  81 . The external screw thread  82  is provided on an external radial surface of the end part  80 . 
     The external screw thread  160  is provided on an internal radial surface of a tubular part  161  of the nut  16 , centered on the central axis X 2 , and which forms an upward extension parallel to the tubular part  14  of the valve-shutter support  14 . The tubular parts  141  and  161  define an annular space  17  between them in which the end part  80  of the first component  8  is received. 
     The first component  8  comprises a frustoconical internal bearing surface  84  against which a corresponding external frustoconical surface  140  of the valve-shutter support  14  bears so as to create sealing between the valve-shutter support  14  and the first component  8 . The internal surface  84  is provided at an upper end of the internal cavity  81 , opposite a lower axial edge  86  of the end part  80 . The internal surface  84  forms an internal diameter reduction D 84 , smaller than the diameter D 81 , and converges toward the central axis X 2  toward the top part of the pump  2 . 
     The seat  142  of the valve  6  is formed by a component attached on the valve-shutter support  14 . The seat  142  is an annular component attached in an internal groove  144  of the tubular part  141 . The seat  142  has a frustoconical surface  142 A on which the ball  12  rests. 
     The ball  12 , and more generally the valve shutter, has a maximum external diameter D 12  smaller than the minimum internal diameter D 84  of the frustoconical surface  84 , and therefore also smaller than the internal diameter D 81 . The ball  12  is therefore capable of being partially inserted into the first component  8  higher than the frustoconical surface  84 , in an upper cavity  88  of the first component  8 . 
     Since the maximum external diameter D 141  of the tubular part  141  and the maximum external diameter D 12  of the ball  12  are smaller than the minimum internal diameter D 81  of the internal cavity  81 , the seat  142  and the ball  12  can be inserted into the cavity  81  and removed from the cavity  81  from the bottom. 
     The nut  16  and the valve-shutter support  14  are advantageously connected so as not to be separable. They form a secured assembly facilitating disassembly and preventing successively disassembling several components. For example, the nut  16  and the valve-shutter support  14  can be glued to one another. 
     The valve-shutter support  14  has a collar  146 , extending radially outward in the bottom part of the valve-shutter support  14 , and which comes into contact with the tubular part  161  of the nut  16 . The collar  146  has an axial surface  146 A oriented downward. The nut  16  defines an axial surface  164  extending radially inward from the tubular part  161 , and oriented upward. The surfaces  146 A and  164  bear against one another, and according to one embodiment can be glued to one another. 
     “Inseparably connected” also means that the valve-shutter support  14  and the nut  16  can form a single integral part, that is to say, a second monobloc component  10 . 
     The nut  16  is provided with external disassembly shapes making it possible to unscrew and disassemble the second component  10  from the first component  8 . 
     As shown in  FIG. 3 , the external shapes of the nut  16  can form a recess  162  for accommodating an unscrewing tool for the second component  10 , such as a wrench  18 . 
     In a variant shown in  FIG. 5 , the external shapes of the nut  16  can form radial protuberances  164  extending for example in planes P 164  comprising the central axis X 2 , and able to be actuated to unscrew the second component  10 . For example, the nut  16  can be of the “wing nut” type, that is to say, provided with radial protuberances  164  forming radial wings allowing it to be unscrewed. 
     According to an aspect showed in  FIG. 6 , the radial protuberances can also be formed by a wrench  19  attached inseparably on the nut  16 . “Attached inseparably” means that the wrench  19  or more generally the tool can be embedded, glued, or can even form a single monobloc component with the nut  16 . In other words, the tool or the wrench  19  can be a material protrusion from the external periphery of the nut  16  which will serve as lever arm to actuate the loosening or tightening of the nut  16 , for example respectively before and after a cleaning operation of the ball  12 . 
     Thus, the user of the pump  2  according to the invention does not have to think to take a specific tool at the beginning of a painting session. The pump  2  therefore does not involve additional integrated equipment for maintenance directly on the usage site. In such a case, the tool or the wrench  19  forms an inseparable whole with the nut  16 . 
     In such cases, an operator needs, in order to unscrew the nut  16 , to exert a pushing action on the or one of the radial protrusions. This can for example be done by striking a radial protuberance with a standard percussive tool of the mallet or hammer type. More generally, the external shapes of the nut form one or more surfaces able to be struck with any tool in order to unscrew the second component  10 . 
     It may also be considered for the valve-shutter support  14 , the nut  16  and the unscrewing tool  18  or the wrench  19  to form an inseparable whole, which is for example glued, welded, irreversibly attached or integral so as to form a monobloc assembly. 
     In the case where the tool and the nut  16  do not form an inseparable whole, the external recess  162  of the nut  16  is advantageously provided with material projections chosen so as to cooperate with any type of standard tools (crescent wrench, adjustable wrench, Allen wrench, etc.) so as to make the loosening or tightening operations not be limited to the use of a specific tool. 
     During a maintenance or cleaning operation, the valve  6  is disassembled as follows. Initially, the pump  2  and the valve  6  are assembled as shown in  FIGS. 2 and 4 . An operator positions the wrench  18  on the recess  162  and performs a rotation about the central axis X 2  along the arrow R 1  in  FIG. 4 , so as to unscrew the nut  16  from the first component  8 . After unscrewing the nut  16  from the first component  8 , the second component  10  and the ball  12  are able to be extracted from the first component  8  through the bottom, along arrow F 1  in  FIG. 4 . This disassembly maneuver is simple and fast and does not require elaborate tooling. The first component  8  of the valve  6  does not need to be disassembled. 
     Further, the screw threads  160  and  82  are constantly moved away from the flow of fluid, that is to say, the circulation zone of the product. The screw thread  82  is external and is therefore fluidly insulated from the flow of fluid, formed by the internal cavity  81 , by the end part  80 . The internal screw thread  160  is fluidly insulated from the flow of fluid, formed by an internal duct  148  of the valve-shutter support  14 , by the tubular part  141 , which extends axially higher than the screw thread  160 . The screw threads  160  and  82  therefore do not risk being exposed to the product and complicating the disassembly.