EP0802832A2 - Amortisseur pour admission de pistolet a pulverisation sans air et ressort pour soupape d'entree - Google Patents

Amortisseur pour admission de pistolet a pulverisation sans air et ressort pour soupape d'entree

Info

Publication number
EP0802832A2
EP0802832A2 EP95943761A EP95943761A EP0802832A2 EP 0802832 A2 EP0802832 A2 EP 0802832A2 EP 95943761 A EP95943761 A EP 95943761A EP 95943761 A EP95943761 A EP 95943761A EP 0802832 A2 EP0802832 A2 EP 0802832A2
Authority
EP
European Patent Office
Prior art keywords
check valve
inlet check
fitting
paint
spring
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP95943761A
Other languages
German (de)
English (en)
Other versions
EP0802832B1 (fr
Inventor
Roger Conatser
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Campbell Hausfeld LLC
Original Assignee
Campbell Hausfeld Scott Fetzer Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US08/370,159 external-priority patent/US5639219A/en
Application filed by Campbell Hausfeld Scott Fetzer Co filed Critical Campbell Hausfeld Scott Fetzer Co
Priority to EP98111118A priority Critical patent/EP0865829A3/fr
Publication of EP0802832A2 publication Critical patent/EP0802832A2/fr
Application granted granted Critical
Publication of EP0802832B1 publication Critical patent/EP0802832B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B23/00—Pumping installations or systems
    • F04B23/02—Pumping installations or systems having reservoirs
    • F04B23/025—Pumping installations or systems having reservoirs the pump being located directly adjacent the reservoir
    • F04B23/028—Pumping installations or systems having reservoirs the pump being located directly adjacent the reservoir the pump being mounted on top of the reservoir
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B1/00—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
    • B05B1/30—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to control volume of flow, e.g. with adjustable passages
    • B05B1/3006—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to control volume of flow, e.g. with adjustable passages the controlling element being actuated by the pressure of the fluid to be sprayed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B9/00—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour
    • B05B9/03—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material
    • B05B9/04—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material with pressurised or compressible container; with pump
    • B05B9/0403—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material with pressurised or compressible container; with pump with pumps for liquids or other fluent material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B9/00—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour
    • B05B9/03—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material
    • B05B9/04—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material with pressurised or compressible container; with pump
    • B05B9/0403—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material with pressurised or compressible container; with pump with pumps for liquids or other fluent material
    • B05B9/0413—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material with pressurised or compressible container; with pump with pumps for liquids or other fluent material with reciprocating pumps, e.g. membrane pump, piston pump, bellow pump
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B9/00—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour
    • B05B9/03—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material
    • B05B9/04—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material with pressurised or compressible container; with pump
    • B05B9/043—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material with pressurised or compressible container; with pump having pump readily separable from container
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B11/00—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation
    • F04B11/0008—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation using accumulators
    • F04B11/0016—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation using accumulators with a fluid spring
    • F04B11/0025—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation using accumulators with a fluid spring the spring fluid being in direct contact with the pumped fluid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
    • F04B53/10—Valves; Arrangement of valves
    • F04B53/102—Disc valves
    • F04B53/1032—Spring-actuated disc valves

Definitions

  • This invention relates to airless paint sprayers, and more particularly, to a mechanism for providing a more consistent spray of paint without a loss of pressure over a range of operating parameters.
  • a piston driven diaphragm pulls the paint from a supply line into a paint holding or diaphragm chamber.
  • a spray gun has a trigger which, when depressed, opens a valve to allow the pressurized paint in the chamber to flow to a gun nozzle and
  • Airless paint sprayers commonly include a suction tube inserted within a can of paint through which the paint is delivered to the diaphragm chamber. Suction is created in the suction tube by a deformable diaphragm which is secured around its perimeter. A central portion of the diaphragm is oscillated, by a piston-driven hydraulic system, for example, between a convex and a concave configuration to thereby pull the paint toward the diaphragm and hence force it outwardly to the spray gun.
  • a rotating eccentric cam drives a bearing which in turn drives a piston.
  • the piston is coupled to the diaphragm and the rotation of the cam drives the piston to thereby move the diaphragm to and between the convex and concave configurations.
  • the paint is drawn from the can through the suction tube and inlet valve toward the diaphragm and into the diaphragm chamber to be discharged through the spray gun.
  • sprayers include ineffective spraying of paint of a first type but efficient spraying of paint of a second type.
  • problems of this type have been proposed such as lack of consistent priming, paint buildup, clogged filters, paint viscosity, humidity, etc.
  • these problems occur even when a problem paint is thinned to the general consistency of water, the filters are clean, or the flow path of the paint
  • a preferred embodiment of the invention contemplates the use of a dampener on the spray liquid or paint intake side of the paint sprayer.
  • a dual spring inlet check valve is used in the inlet of the paint in conjunction with the dampener.
  • One aspect of the invention is the realization of the basic problem which is responsible for inconsistent paint spraying performance. According to the invention, that problem is the inconsistency of the system by which paint is delivered from an open container to the pumping or diaphragm chamber of the spraying apparatus.
  • the suction tube between the inlet check valve of the pumping chamber and the open paint container is vertically oriented and may be 1 to 2 feet long. Paint is sucked up from the container in this tube, through the inlet check valve and into the pumping chamber.
  • the diaphragm in order to suck the paint past the inlet check valve the diaphragm must create a pressure drop in the chamber and it does so by virtue of its eccentric drive or by the piston-driven hydraulic drive.
  • the nature of the diaphragm is cyclical; the diaphragm constantly accelerating and decelerating through each sucking and pumping direction.
  • the diaphragm As the diaphragm is moved to enlarge the chamber for sucking paint up the supply tube, it accelerates due to the eccentric action of the piston. It decelerates as it reaches its maximum stroke and the check valve closes. During this time, the paint in the tube is subjected to a pressure drop which first accelerates then decelerates to near equilibrium when the inlet check valve closes. Thereafter, the diaphragm is accelerated into the chamber to pump out the paint therein.
  • the diaphragm accelerates in a reverse direction to again open the inlet check valve and suck paint up from the tube.
  • the eccentric rotation of the cam drive and the acceleration/deceleration of the rod following the cam create acceleration spikes in the flow of the paint during each cycle.
  • the acceleration spikes correspond to specific points or areas on the drive cam which result in significant acceleration/deceleration of the rod.
  • These acceleration/deceleration forces are transferred from the rod to the diaphragm thereby resulting in acceleration spikes in the flow of the paint drawn into the diaphragm chamber through the inlet check valve and suction tube.
  • the paint is thus being accelerated and decelerated with each stroke of the diaphragm.
  • This invention is based, in part, upon the realization that the force required to accelerate the paint was
  • the dampener of one embodiment of the present invention comprises a generally T-shaped fitting connected to the suction tube leading to the inlet check valve of the pump or diaphragm chamber.
  • the T-shaped fitting includes a first leg having a port through which
  • a third leg of the T-fitting comprises a closed chamber which is
  • the above aspect of this invention solves a significant number of occurrences of the problem of pressure loss during the operation of the paint sprayer caused, in part, by acceleration spikes transmitted in the paint.
  • This is initially accomplished with the T-shaped fitting positioned in-line on the suction tube on the intake side of the inlet check valve.
  • the air trapped in one of the legs of the T-fitting dampens the acceleration spikes to thereby even the flow of the paint.
  • the paint in the discharge or second leg of the T-fitting is still subjected to some of the acceleration spikes and the acceleration/deceleration forces, the volume of paint which remains on the intake side or of the first leg of the T-fitting is isolated from the acceleration spikes.
  • a dampening chamber such as the T-fitting described is operatively connected to the paint supply path upstream of the inlet check valve.
  • the pump On start up, the pump is primed normally, however it will be appreciated a slight negative pressure is created in the dampening chamber.
  • the diaphragm On operation, when the diaphragm is pushed into the pumping chamber and the inlet check valve
  • the inlet check valve When the diaphragm starts its reciprocal motion and begins to accelerate, the inlet check valve is open. As the pressure drop increases
  • the suction on the paint supply increases to a peak.
  • the paint in the suction tube is subjected to this drop, but the paint in the dampening chamber is sufficient to feed the increased paint demand.
  • the intake paint is thus made up not only of paint from the supply can and in the tube above it, but also paint in the dampening chamber.
  • the pressure in the dampening chamber is greater than the pressure in the supply side of the fitting connected to
  • the inlet check valve As a result, the paint at the higher pressure in the dampening chamber feeds the supply side of the fitting during extreme acceleration of the diaphragm. Thus, the acceleration spikes applied to the supply side paint are reduced and are not excessive enough to cause
  • the pumping chamber is full and design pressure drop at the spray orifice is maintained sufficiently to support consistent atomization and paint spray performance.
  • closure of the inlet check valve allowed the now slight negative pressure in the dampening chamber to suck up a small amount of make-up paint from the suction tube in readiness for another dampening cycle.
  • the dampener of this invention thus solves a significant number of the problems identified hereinabove with airless diaphragm paint sprayers. With the inclusion of the dampener of this invention, the even flow of the paint from the tube to the spray gun without cavitation, loss
  • the inlet check valve spring of this invention also solves a large number of occurrences of paint cavitation and loss of pressure in paint spray, and very often more occurrences than the dampener fitting previously described. Prior to this invention, only about 10-15% of the maximum paint flow was passing through the paint sprayer due to the cavitation of the paint. For example, a paint sprayer pump capable of operating at a peak flow of about 1.2 gallons per minute (gpm) was only operating at approximately 0.1 to 0.19 gpm flow. It was discovered
  • the response time of the valve is the time for the valve to return from an open configuration to a closed position.
  • One way to increase the response time of the valve and maintain a longer travel distance was to increase the return spring preload or spring rate. However, increasing the spring preload or rate adversely effects the vacuum and priming
  • One way to increase the spring preload is to utilize a spring with a higher spring rate (i.e., a spring which requires more force for the same amount of deflection).
  • a spring with a higher spring rate i.e., a spring which requires more force for the same amount of deflection.
  • sensitivity to valve and component wear increases when utilizing a spring with a sufficiently high spring rate to maintain a sufficient response time for the system while providing increased inlet travel distance to avoid paint cavitation.
  • the inlet check valve spring of the present invention was discovered by taking into consideration the altitude, temperature, and pressure conditions that might occur at any given operating location, and
  • the pressure drop across various components of the airless paint sprayer and the total intake system were used to calculate the maximum pressure drop across the inlet check valve without paint cavitation.
  • a pressure drop of approximately 3.5 psi across the inlet check valve without cavitation is possible with a minimum design pressure of 10 psi absolute.
  • the inlet check valve of the present invention includes dual springs which in combination provide for maximum travel of the inlet check valve to avoid cavitation, sufficient response time of the inlet
  • the inlet check valve spring assembly includes a primary spring having a very low spring rate, approximately 1 Ibf/in (one pound force per inch) in a presently preferred embodiment, and a secondary spring having a much higher spring rate, approximately 6 Ibf/in in a preferred embodiment.
  • the primary spring is always engaged with the inlet check valve and reduces sensitivity to valve wear and dimensional variation because it has a low spring rate.
  • the secondary spring depending upon tolerance conditions, can be either nominally preloaded or disengaged from the valve when not in operation. If the secondary spring is engaged due to tolerance conditions, the combined preload of the secondary and primary springs does not exceed that of current single spring inlet check valve designs. As a result, the dual inlet check valve spring can be used in products
  • the secondary spring permits an increased response time of the valve due to the higher spring rate.
  • the primary spring maintains a low preload during priming operations.
  • the secondary spring provides little, if any, preload during priming operations, but provides the majority if not all of the preload during normal operation.
  • the dual spring of the inlet check valve of this invention avoids the cavitation of the paint and the problems associated therewith in an airless sprayer by permitting greater
  • the dual spring facilitates the greater flow without the disadvantages of reduced response time, increased sensitivity to component wear and loss of priming
  • dampener and inlet check valve spring of this invention solve most, if not all, the problems identified hereinabove with airless diaphragm paint sprayers.
  • the dampener and inlet check valve spring of this invention With the inclusion of the T-fitting dampener and inlet check valve spring of this invention, the even flow of the paint from the tube to the spray gun without cavitation, loss of pressure, or
  • Fig. 1 is a perspective view of an airless paint sprayer according to the invention
  • Fig. 2 is a cross-sectional view along line 2-2 of Fig. 1 of the T- shaped dampener fitting and inlet check valve according to this invention; and Fig. 3 is an enlarged cross-sectional view of the dual spring inlet check valve assembly of Fig 2.
  • An airless paint sprayer 10 as shown in Fig. 1 includes a mobile hand cart 12 supported on the ground by wheels 14 mounted upon an axle 16 for rotation.
  • the hand cart 12 includes a frame 18 to support
  • a pump 20 and a motor 22 which draws paint from a can 24 or other receptacle mounted on a generally L-shaped carriage 26 secured to a lower portion of the frame 18.
  • the paint sprayer 10 can be moved about by grasping an upper generally U-shaped handle 28 and tilting the unit backwards to thereby raise the carriage 26 and paint can 24 supported thereon upwardly to balance the sprayer 10 upon the wheels 14.
  • Other structure of carrying the pump and motor 20, 22 and for supporting them over a paint container or spray liquid container can be
  • the paint is drawn from the can 24 through a generally cup-shaped intake 30 having a plurality of cut-outs 32 through which the paint enters the intake 30 supported on a bottom wall of the can 24.
  • the paint is drawn from the can 24 through the intake 30 and into a suction tube 34.
  • the paint flows through the suction tube 34 and into the pump 20 for pressurized delivery to a supply line 35 and spray gun 37 through which the pressurized paint is sprayed out of the spray gun in the direction of a surface to be coated.
  • the route of the paint from the can 24 through the pump 20 is identified as a paint path P in
  • the T-shaped fitting 36 in one embodiment includes a first leg 38 which is inserted into the upper end of the suction tube 34 as shown in Fig. 2 and a first port 40 through which the paint is drawn from the suction tube 34.
  • a third leg 46 Perpendicular to the second leg 42 and generally in line with the first leg 38 of the fitting 36 is a third leg 46 which extends upwardly and includes a third port 48.
  • the third port 48 is closed by a cap 50 which is secured on an upper end of the third leg 46 by inter-engaging threads on the cap 50 and an outer surface of the third leg 46 or another appropriate fastening mechanism. The cap 50 secured to the third leg 46 closes the third port
  • the first leg 38 is approximately one inch in length and the first port 40 has an inner diameter of about 0.48 inches.
  • the second leg 42 is approximately 2.1 inches in length as measured from the centerline of the first leg 38 and the second port 44 has an inner diameter of 0.78 inches.
  • the third leg 46 is approximately 2.1 inches in length as measured from the centerline of the second leg 42 and the third port 48 has an inner diameter of approximately 0.9 inches.
  • the T-shaped fitting 36 is preferably manufactured from 10% glass-filled nylon.
  • the second leg 42 of the T-shaped fitting 36 is connected to an
  • inlet valve cartridge 54 by a coupling 56 or other appropriate mechanism as known in the art.
  • the inlet valve cartridge 54 is mounted to a pump housing 58 of the pump 20.
  • the housing 58 is secured to the pump 20 as shown in Fig. 2 by bolts 60 or other mechanical fasteners. Seated
  • an inlet check valve assembly 62 which includes an elongated valve stem 64 projecting axially within the inlet valve cartridge 54, and having a disk-shaped valve head 66 secured on one end opposite from another end 68 thereof.
  • the inlet check valve assembly 62 translates between open and closed positions to permit the flow of paint through the inlet valve cartridge 54 to the hose 35 and spray gun upon actuation by a trigger 39 or other appropriate mechanism as is well known by those of ordinary skill in the art.
  • the valve head 66 is positioned proximate a diaphragm chamber or pumping chamber 70 and is spaced from a deformable diaphragm 72.
  • the diaphragm 72 is secured around its perimeter so that a central portion of the diaphragm 72 can oscillate between convex and concave
  • the deformable diaphragm 72 has a stem 74 secured to a central portion 76.
  • the stem 74 is driven indirectly from a piston and eccentric cam (not shown) as is well known in airless paint sprayers of the type described
  • the inlet check valve assembly 62 is biased to a closed position in which the valve head 66 is in sealing contact with a surface 78 of an annular seat 81.
  • the seat 81 is juxtaposed to a limiter 80.
  • the inlet check valve assembly 62 is shown in Figs. 2 and
  • valve head 66 in contact with the surface 78 of the seat 81.
  • the valve stem 64 projects through a hole 82 in the center of the limiter 80.
  • the valve 62 is biased toward the closed position by a pair of nested helical compression springs 84, 86 according to a presently preferred embodiment of this invention.
  • the outer, primary spring 84 is mounted between the limiter 80 and an
  • the end coils of the primary spring 84 are seated on flanges 92 on the retainer 88 and on the limiter 80 as shown in Fig. 3.
  • the retainer 88 is juxtaposed to an annular push-on retainer 94 proximate the end 68 of the valve stem 64.
  • the primary spring 84 is preloaded to a partially compressed configuration thereby urging the retainer 88 and the limiter 80 apart and biasing the valve stem 64 into a closed configuration with the valve head 66 in sealing contact with the
  • the secondary spring 86 is nested within the primary spring 84 and around the valve stem 64.
  • the secondary spring 86 is seated within sockets 96 formed within the centers of the retainer 88 and the limiter
  • the secondary spring 86 may contribute to the preload of the valve 64 in the closed configuration or the secondary spring 86 may be offset within the sockets 96 from either or both of the retainer 88 and the limiter 80 so
  • valve stem 64 that it is not compressed while the valve stem 64 is in the closed configuration.
  • the primary spring 84 has a relatively low spring rate and the secondary spring 86 has a significantly larger spring rate.
  • the primary spring 84 has a rate of approximately 1 Ibf/in and the secondary spring 86 has a rate of 6 Ibf/in.
  • the primary spring 84 maintains engagement with both the retainer 88 and the limiter 80 and thereby remains in at least a partially compressed configuration.
  • the relatively low spring rate of the primary spring 84 reduces sensitivity to valve wear and dimensional variation of the inlet check valve assembly 62 components. With the valve 64 in the closed position, the secondary spring 86, depending on
  • tolerance conditions can range from being preloaded at approximately 0.01 inches of deflection to 0.20 inches of freedom in one particular embodiment of this invention. If the secondary spring 86 is engaged in the closed position, the combined preload of the primary and secondary
  • inlet check valve assembly 62 can be used in many standard airless paint sprayers without detriment to the system, vacuum or priming operations.
  • the deformable diaphragm 72 operates to draw paint into the diaphragm chamber 70 with the inlet check valve assembly 62 open and the head 66 spaced from the surface 78 of the limiter 80.
  • the primary and secondary springs 84, 86 are compressed and the retainer 88 and the limiter 80 are drawn closer together as a result of the travel or movement of the valve stem 64 so that the valve head 66 is spaced from the surface 78.
  • the primary and secondary springs 84, 86 of the inlet check valve assembly 62 according to this invention enable the
  • valve travel distance to be increased relative to known single spring inlet check valve assemblies The increased travel of the valve head 66 enables greater fluid flow through the valve 62 without cavitation or boiling of the paint over a wide range of operating conditions, barometric pressures, ambient temperatures, and altitudes.
  • the maximum fluid flow that can be achieved was raised from about 0.14- 0.19 gpm to 0.85-1.14 gpm with the increased travel distance of the valve and the dual spring assembly. This increased allowable fluid flow was achieved due to the increased travel distance of the valve.
  • the response time as used herein refers to the elapsed time for the inlet check valve 62 to move between opened and closed positions.
  • the inlet check valve 62 should have a response faster than 30 Hz in one preferred embodiment of the
  • the dual spring inlet check valve assembly 62 maintains a relatively low preload upon the valve stem 64 in the closed configuration and while priming the system and a much higher load when the valve 62 is in the open position.
  • the optimum combined spring preload for the inlet check valve assembly 62 with a maximum inlet check valve head 66 travel distance is approximately 0.83 pounds. This value will change based upon valve size, component geometry, maximum travel distance, and other paint sprayer parameters.
  • the optimum preload force upon the valve in the closed position is approximately 0.13 pounds.
  • the travel distance of the valve head 66 can be increased to thereby allow greater fluid flow through the inlet check valve 62 without cavitation of the paint while still maintaining an appropriate response time for the inlet check valve and minimizing the detrimental effects of component wear, diminished priming and vacuum performance of the system.
  • the T-shaped fitting 36 contributes to reducing cavitation in the paint by dampening the acceleration spikes transmitted in the fluid from the deformable diaphragm 72.
  • the paint level in the third leg 46 of the T- shaped fitting 36 is indicated by reference numeral 98.
  • the chamber 52 in the third leg 46 contains a trapped volume of air, preferably at a partial vacuum of greater then about 1.0 in-Hg and approximately 3.0 in- Hg in one preferred embodiment.
  • the air trapped within the chamber 52 in the third leg 46 of the T-shaped fitting 36 dampens the acceleration spikes being transmitted from the diaphragm 72 through the paint in the inlet valve cartridge 54 and second leg 42 of the T-shaped fitting 36 to thereby even the flow of the paint. While the paint in the discharge or second leg 42 of the T-shaped fitting 36 may be subjected to some of the acceleration spikes and acceleration/deceleration forces generated b ⁇
  • the deformable diaphragm 72 the volume of paint which remains on the intake side of the T-shaped fitting 36 or the first leg 38 is isolated from the acceleration spikes.
  • the volume of paint within the chamber 52 in the third leg 46 is drawn into the second leg 42 along with paint from the suction tube 34 and first leg 38 while the inlet check valve 62 is open and drawing paint therethrough.
  • the added supply of paint from the chamber 52 overcomes the acceleration spikes and inhibits cavitation in the paint path P. Therefore, the paint does not cavitate, boil, or breakdown thereby avoiding a significant number of occurrences of pressure loss in the paint sprayer 10 and other problems previously associated with airless diaphragm paint sprayers.
  • dampener and dual spring inlet check valve assemblies are shown and described herein, that either feature can be used alone to inhibit paint cavitation in the paint path of the airless sprayer.
  • Each of these features and inventions independently contribute to solving the above described problems and should not be considered to be mutually dependant upon each other to attain the goals and objectives of this invention.
  • use of the dampener and dual spring inlet check valve inventions in combination provide greater advantages by avoiding the most of the problems of cavitation than use of either invention individually.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Nozzles (AREA)
  • Reciprocating Pumps (AREA)
  • Catching Or Destruction (AREA)
  • Closures For Containers (AREA)
  • Spray Control Apparatus (AREA)
  • Compressor (AREA)

Abstract

Un pistolet à pulvérisation sans air (10) comporte un ensemble soupape d'aspiration (62) à double ressort qui permet d'allonger la course de la soupape d'aspiration (62), ce qui augmente le débit du fluide à travers la soupape sans diminuer le temps de réponse de celle-ci ni les opérations d'amorçage du système. Un amortisseur contribue également à réduire la cavitation et la chute de pression dans le pistolet à peinture (10) et comprend un raccord généralement en forme de T (36) dans lequel une section (46) dudit raccord (36) est fermée et renferme un volume d'air emprisonné (52) pour amortir les forces d'accélération-décélération et les brusques pointes d'accélération transmises depuis la pompe (20) jusqu'au fluide pompé à travers le raccord (36).
EP95943761A 1995-01-09 1995-12-13 Soupape d'entree pour admission de pistolet a pulverisation sans air Expired - Lifetime EP0802832B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP98111118A EP0865829A3 (fr) 1995-01-09 1995-12-13 Amortisseur pour admission de pistolet à pulvérisation

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
US37037795A 1995-01-09 1995-01-09
US08/370,159 US5639219A (en) 1995-01-09 1995-01-09 Airless paint sprayer intake dampener and inlet valve spring
US370159 1995-01-09
US370377 1995-01-09
PCT/US1995/016141 WO1996021519A2 (fr) 1995-01-09 1995-12-13 Amortisseur pour admission de pistolet a pulverisation sans air et ressort pour soupape d'entree

Related Child Applications (1)

Application Number Title Priority Date Filing Date
EP98111118A Division EP0865829A3 (fr) 1995-01-09 1995-12-13 Amortisseur pour admission de pistolet à pulvérisation

Publications (2)

Publication Number Publication Date
EP0802832A2 true EP0802832A2 (fr) 1997-10-29
EP0802832B1 EP0802832B1 (fr) 1999-06-09

Family

ID=27004843

Family Applications (2)

Application Number Title Priority Date Filing Date
EP95943761A Expired - Lifetime EP0802832B1 (fr) 1995-01-09 1995-12-13 Soupape d'entree pour admission de pistolet a pulverisation sans air
EP98111118A Withdrawn EP0865829A3 (fr) 1995-01-09 1995-12-13 Amortisseur pour admission de pistolet à pulvérisation

Family Applications After (1)

Application Number Title Priority Date Filing Date
EP98111118A Withdrawn EP0865829A3 (fr) 1995-01-09 1995-12-13 Amortisseur pour admission de pistolet à pulvérisation

Country Status (13)

Country Link
EP (2) EP0802832B1 (fr)
JP (1) JP3233409B2 (fr)
AT (1) ATE180993T1 (fr)
AU (2) AU693639B2 (fr)
BR (1) BR9510190A (fr)
CA (1) CA2208116C (fr)
DE (1) DE69510231T2 (fr)
FI (1) FI113017B (fr)
HU (1) HU221565B (fr)
NO (1) NO973105L (fr)
NZ (1) NZ300419A (fr)
PL (1) PL179315B1 (fr)
WO (1) WO1996021519A2 (fr)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5534796B2 (ja) * 2009-12-15 2014-07-02 キヤノン株式会社 電子写真感光体の製造方法
US9162866B2 (en) 2010-06-24 2015-10-20 Graco Minnesota Inc. Dual pump fluid proportioner with adjustable motor position
US20160023427A1 (en) * 2012-05-29 2016-01-28 Niles Nanofabrix Nanomaterial based fabric reinforced with prepreg methods, and composite articles formed therefrom

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US2290788A (en) * 1939-07-10 1942-07-21 Wilson John Hart Slush pump
FR1405442A (fr) 1964-05-30 1965-07-09 Perfectionnements aux appareils de distribution de liquides
US3447564A (en) * 1967-05-31 1969-06-03 Brunswick Corp Leakproof valve
SE368266B (fr) * 1969-12-16 1974-06-24 Danfoss As
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US3945767A (en) 1973-09-21 1976-03-23 Desoto, Inc. Damper apparatus
US4221437A (en) * 1977-05-06 1980-09-09 Kelsey Hayes Co. Brake proportioning apparatus
US4524947A (en) 1982-11-30 1985-06-25 The Cessna Aircraft Company Proportional solenoid valve
DE8810454U1 (de) * 1988-08-18 1988-09-29 Hoechst Ag, 6230 Frankfurt Vorrichtung zum Dämpfen von stoßweise fördernden Pumpen
FR2638812A1 (fr) * 1988-11-04 1990-05-11 Boisseau Rene Dispositif d'amortissement de pulsations de fluide pompe
US4896548A (en) * 1988-12-27 1990-01-30 Gilian Instrument Corp. Fluid sampler with miniature single-acting pump assembly
GB9304486D0 (en) * 1993-03-05 1993-04-21 Lucas Ind Plc Fuel injection nozzle

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See references of WO9621519A3 *

Also Published As

Publication number Publication date
ATE180993T1 (de) 1999-06-15
JPH10512186A (ja) 1998-11-24
EP0865829A2 (fr) 1998-09-23
WO1996021519A2 (fr) 1996-07-18
FI972904A7 (fi) 1997-07-08
HUT77145A (hu) 1998-03-02
EP0802832B1 (fr) 1999-06-09
NO973105D0 (no) 1997-07-03
EP0865829A3 (fr) 1998-12-02
AU693639B2 (en) 1998-07-02
AU700478B2 (en) 1999-01-07
NZ300419A (en) 1999-07-29
CA2208116A1 (fr) 1996-07-18
DE69510231D1 (de) 1999-07-15
AU6706198A (en) 1998-07-16
CA2208116C (fr) 2002-07-02
AU4515596A (en) 1996-07-31
FI972904A0 (fi) 1997-07-08
PL321137A1 (en) 1997-11-24
BR9510190A (pt) 1997-12-23
HU221565B (hu) 2002-11-28
JP3233409B2 (ja) 2001-11-26
MX9705080A (es) 1997-10-31
NO973105L (no) 1997-07-03
FI113017B (fi) 2004-02-27
DE69510231T2 (de) 1999-12-02
PL179315B1 (pl) 2000-08-31
WO1996021519A3 (fr) 1996-10-31

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