FR2525924A1 - AIR SPRAY GUN - Google Patents

Abstract

THE INVENTION RELATES TO AN AIR SPRAYING GUN INCLUDING A SPRAYING HEAD ASSEMBLY CONSISTING OF INDEPENDENT ELEMENTS, BUT CAN BE CONNECTED TO ONE TO THE OTHERS. THIS ASSEMBLY 46 IS MOUNTED ON A PROJECT 48, ORIENTED DOWN, OF THE BODY 50 OF THE GUN 20 BY SCREWING ON A FITTING 32 FOR INTAKE FLUID TO BE SPRAYED. THIS TIGHTENING CAUSES THE TIGHTENING OF THE PROJECTOR 48 BETWEEN THE FITTING 32 AND THE ASSEMBLY 46, WHICH AVOIDING THE NEED TO FORM THREADS ON THE BODY 50 OF THE GUN FOR THE ASSEMBLY OF THE SPRAY HEAD. FIELD OF APPLICATION: GUNS FOR SPRAYING FLUIDS BY AIR ATOMIZATION, ETC.

Description

The invention relates to spray guns

  in general, and more particularly

  an advanced air spray gun

  comprising a spray head assembly which

  takes separate elements mounted on a front end

  of the gun body, without screwing on this body.

  Fluid flow channels passing through the head of an air spray gun are often made of a corrosion resistant material to be protected from corrosion due to various types of

  coating materials Previous processes of

  protection against corrosion generally consisted of

  to use, with the pistol, a molded head resisting

  both corrosion-resistant, independent and removable, or to screw a stainless steel insert and a stainless steel fluid inlet fitting into the gun head, the fitting insert being oriented perpendicularly to each other. other, machining the inserts as they are mounted in the gun to form fluid flow channels, and then attaching the inserts to the position by means of

  of an epoxy resin A problem posed by the first pro-

  it is necessary to resolve a compromise concerning the

  weight and balance, which are important

  for the "sensation" given by a spray gun.

  veration, and a problem arising in the second process is the loss of the epoxy resin that occurs

  often when a gun is dipped in a solvent

  For a longer period of time, moreover, in the pistols

  spraying nets, nets intended to receive

  see a cap for mounting an air nozzle on the gun head are usually made on

  the body of the pistol This arrangement raises difficulties

  the fact that nets may be

  and, if so, the entire body of the pistol, which is essentially the entire pistol,

becomes unusable.

  Compared to previous spray guns

  type of air with corrosion-resistant fluid flow channels, the air gun

  according to the invention is improved by the fact that

  Apparently, the spraying head comprises independent elements which can be connected to each other and comprise a fluid nozzle, a fluid inlet connection and a nozzle retaining element. independent, the fluid inlet connection and the fluid nozzle can be

  made of corrosion-resistant material and the

  The elements can be easily assembled on the front end of the gun to form fluid flow channels, resistant corrosion, without the need to proceed

  machining operations or ocurcxoettre the "sensa-

  tion * offered by the gun, and the nozzle retainer itself, and not the gun body, has threads for mounting an air nozzle on the gun so that in case of deterioration of the nets, only the nozzle retainer, and not virtually the entire spray gun, should be

replaced.

  The invention will be described in more detail with reference to the accompanying drawings by way of non-limiting example and in which:

  FIG. 1 is an elevation with a sectional cut

  the air spray gun having an improved spray head assembly according to the invention; Figure 2 is a longitudinal section of the spray head assembly according to the invention; and FIG. 3 is an exploded longitudinal section of the sprayhead assembly shown in FIG.

in Figure 2.

  As shown in FIG. 1, the spray gun assembly according to the invention, indicated

  globally at 20, includes a spray gun 22

  paint composition comprising a handle 24 intended to be connected, by its lower end, to a source of compressed air (not shown) by means of a connector 26 The gun comprises an air nozzle 28 and means associated with this nozzle , indicated generally at 30, by which a fluid reaching the gun by means of an inlet fitting 32 connected to a source of this fluid (not shown) is dispensed in order to be atomized to form a spray and a fan-shaped beam, under the action of the air jets exiting the nozzle To control the spraying operation, an air valve 34 can be moved between positions

  opening and closing to control the flow of

  compressed air through the gun; a rod 36

  valve can be moved between

  opening and closing for controlling a flow of fluid through the means associated with the nozzle, and a trigger, which can be actuated manually, is connected to the valve and to the stem. The trigger is mounted by an upper end, on a pivot 40 and can be manually moved between a gun stop position, in which it is remote from the handle so that the air valve and the fluid valve are

  closed, and a running position of the pistol in the-

  it is close to the handle so that the air valve and the fluid valve are open and a material spray is emitted.

  performed by means of a button 42 for determining the air

  mine the amount of atomizing air emitted when the gun is running, and a setting made by means of a fluid control knob 44 determines the flow rate

material distribution.

  The spray gun assembly as heretofore described is known in the art and if it was conventional and had corrosion resistant fluid flow channels, it would usually be equipped with either a molded spraying head resistant to corrosion,

  fluid intake insert, of stainless steel

  and a fluid outlet insert, also of stainless steel, screwed perpendicularly to one another in the head, machined while in position in the gun to form the flow channel However, since the body of the gun is usually made of aluminum so as to be light, the problem encountered in the first case is that the weight and balance of the gun may being compromised, weight and balance being important points in the 'feel' or handling of such a gun, and a problem in the second case is that the epoxy is often lost when In addition, in the case of conventional guns, threads intended to receive an air cap for mounting an air nozzle are

  usually formed on the aluminum body of the pis-

  tolet, which presents difficulties because aluminum nets are relatively fragile and, if they are

  deteriorated, the entire body of the pistol becomes

tilisable.

  Compared to previous spray guns

  the gun according to the invention has for perfection-

  a spraying head assembly comprising independent, but connectable, elements having a fluid nozzle, a fluid inlet connector, and a nozzle retainer, these elements, because they are independent allowing the fluid nozzle and the fluid inlet fitting to be conveniently made of corrosion-resistant material. The elements can be easily mounted on the front end of the gun body without screwing onto the body, and they form corrosion-resistant and leak-proof fluid flow channels without the need for machining operations or compromising the "feel" of the gun At the same time, the retaining element of the fluid nozzle, itself, and not the body of the pistol, has threads allowing the mounting of an air cap so that, in case of deterioration of the threads, only the retaining element of the nozzle can be replaced, and not practically the entire body of the

gun.

  As also shown in FIGS.

  and 3, a spray head assembly, indicated globally

  46 is mounted on a downward protrusion 48 of a front portion 50 of the gun body. The spray head assembly, which includes the fluid nozzle, also includes the air nozzle 28 and the coupling 32. fluid inlet, as well as a fluid nozzle 52, a fluid nozzle retaining member 54 and an air cap 56 The inlet and the fluid nozzle are respectively traversed by channels 58 and 60 of the fluid nozzle. fluid flow and they are made of a material that is resistant to corrosion of fluids flowing through these channels, for example stainless steel or

hardened steel.

  The inlet fitting 32 is L-shaped and the projection 48 of the body 50 is traversed by a channel 62

  whose inner end has a relative diameter

  a small channel which increases towards an outer end, this channel having two shoulders 64 and 66. A branch of the inlet fitting comprises threads 68 and can

  be introduced into channel 62 to be connected to the

  54 to retain the fluid nozzle by means of corresponding threads 70 of this retaining element 54, so that the inlet connection and the retaining element of the fluid nozzle are mounted on the front end of the body When the two elements are tightly clamped against each other, shoulders 72 and 74 of the fluid nozzle retainer abut

  sealingly against the shoulders 64 and 66,

  tively. To connect the fluid nozzle 52 to the element 54 for retaining this nozzle, said nozzle is introduced into the retaining element and screwed to the latter by the respective threads 76 and 78 of the nozzle and the element.

  until a seat 80 at one end

  The inlet nozzle, the fluid nozzle retaining element and this nozzle are thus connected to a nozzle 82 at the outer end of the channel 58 passing through the inlet fitting 32. to each other and establish a sealed flow path through the fluid flow channels 58 and 60 in the fitting

intake and in the nozzle.

  To complete the set 46 at the head of spraying

  In this embodiment, the air nozzle 28 is glove over the outer end of the fluid nozzle 52 so that an outer end 84 thereof enters a channel 86 centrally traversing a front wall of the air nozzle. that a shoulder 88 of the latter door

  and is lodged against a shoulder 90 of the fluid nozzle.

  The air cap 56 is then placed around the air nozzle and screwed onto the fluid nozzle retainer 54 by means of inner threads 92 of the air cap and outer threads 94 of the retainer. until an annular rim 96, projecting radially inwards and located at the outer end of the air cap, bears against a rim

  ring 98, protruding radially outwards

  the air nozzle against the fluid nozzle to form a tight seal between the

shoulders 88 and 90.

  It should be noted that the entire

  A spray head, which includes the air nozzle 28, the inlet fitting 32, the fluid nozzle 52, the fluid nozzle retaining element 54 and the air cap 56, is mounted on the nozzle. the front end of the body 50 of the spray gun without being screwed on this body It should also be noted that, since all the elements of the spray head assembly are independent and distinct, they can be very conveniently made in any selected material and, if necessary, easily dismantled for repair or replacement without the need to repair or replace the entire assembly.

spray head.

  As shown in particular in FIG. 2, to supply atomizing air to the spray head assembly 46, the gun body 50 has an air flow channel 100 which receives compressed air during the opening of the air valve 34 and an air valve stem 102 passes in this channel to bear against a seat 104 located at a front end of said channel The valve stem is connected to the trigger 38 to be retracted when the gun is turned on, the amplitude of the withdrawal being determined by the positioning of the air adjusting knob 42 and, when the rod is retracted, it establishes a communication between the channel 100 and an annular channel 106 formed in the extension 48 of the body, this annular channel terminating at the same time to the air outlet orifices 108 forming a bundle, formed in

  opposed legs or wings of the air nozzle 28, and an opening

  An annular air outlet annulus 110 formed between the exterior extension 84 of the fluid nozzle 52 and the walls of the air nozzle channel 86. To establish a circuit between the channel 106 and the orifices 108, channels 112 are formed through the retaining member of the fluid nozzle and channels 114 are formed through the lugs of the air nozzle, and to supply air to the orifice 110, channels 116 are formed through the fluid nozzle Thus, when the trigger is depressed, the gun discharges air to atomize the dispensed material by forming a spray which

  constitutes a fan-shaped beam.

  To control the delivery of fluid or coating material, the valve stem 36 passes through an opening 118 formed in the rear end of the fluid inlet fitting 32 and then passes into the aligned fluid channels 58 and 60 until to a conical front seat 120 of a valve formed in the channel of the fluid nozzle

  valve in the opening 118 is provided by a press

  cable 122 and a compression coupling 124, and one end

  The front of the stem has a conical nose 126 for

  to come against the valve seat

  The back of the rod is connected to the trigger 38 so that actuation thereof to turn on the pistol retracts the valve seat stem to allow dispensing of the coating material from an exit port 128. at the end of the fluid nozzle 52 Therefore, when the trigger of the gun is retracted, fluid is discharged from the spray head assembly and atomized

  and put in the form of a fan spray.

  The invention therefore relates to a spray gun

  improved air-conditioning system comprising a spray head assembly consisting of separate elements,

  which facilitates the manufacture, assembly and replacement

  The entire spraying head assembly, including the air cap for the air nozzle, is mounted on the front end of the gun body without the need for any of these components. establish links by screwing with the body, so that the latter has no threading

  which can be damaged by the whole.

  It goes without saying that many modifications can be made to the gun described and represented

  without departing from the scope of the invention.

Claims (10)

  An air spray gun comprising a gun body (50) and a spray head assembly (46) mounted on a front end of the body for emitting therefrom an atomized fluid spray, characterized in that spray head assembly comprises a fluid inlet (32) through which a channel (58), one end of which can be connected to a fluid supply, a fluid nozzle (52) traversed by a channel (60) which terminates at a first end at a fluid outlet port (128), a fluid nozzle retaining member (54) removably connected to the fluid inlet fitting and the fluid nozzle for supporting fluid   opposite ends of the said communication channels   quent and that a fluid introduced into said first end of the channel of the inlet fitting flows through said channels to be emitted by the outlet orifice, the gun further comprising atomization air emission means at said first end of the fluid nozzle for emitting air for atomizing a spray of the emitted fluid through said outlet port.   2 air spray gun according to claim 1, characterized in that the fluid inlet connection is independent and can be separated from the fluid nozzle, each of these two parts can be detachably connected to said   retainer element of the fluid nozzle.   3 air spray gun according to claim 1, characterized in that the atomization air emission means are connected in a manner   removable to the retaining element of the fluid nozzle.   An air spray gun according to claim 1, characterized in that it comprises a member (48) projecting from said front end of the gun body, the inlet fitting and the nozzle retainer. fluid compressing and holding said protruding member together when removably connected to mount said spray head assembly to the front end of the gun body.  An air spray gun according to claim 4, characterized in that said projecting member comprises a circular member projecting downwardly at said front end of the body and traversed by a channel (62), the inlet fitting and the fluid nozzle retaining member, when removably attached, penetrating the opposite ends of the circular member channel and compressing and   squeezing this circular element between them.   6 air spray gun according to claim 1, characterized in that the atomization air emission means comprise an air nozzle (28) located at a front end of the fluid nozzle and traversed by a central channel (86) for receiving the outlet orifice of the fluid nozzle, said air nozzle having at least one air outlet port (108) for emitting atomizing air, and a cap (56) ) of air which is arranged around the air nozzle and which is removably connected to the fluid nozzle retaining element for mounting said air nozzle on the fluid nozzle, the body being traversed by an air flow channel (100) adapted to apply compressed air supply to said port of air outlet.   Air spray gun according to claim 1, characterized in that the fluid inlet connection, the fluid nozzle, the fluid nozzle retaining element and the atomizing air emission means. have threads (68, 76, 78) allowing them to be removably connected each other.   An air spray gun having a body (50) and a spray head assembly (46) mounted on a front end of the body for emitting therefrom an atomized fluid spray, characterized in that the body comprises a substantially annular, downwardly directed projection (48) at said front end, and that the spray head assembly comprises a fluid inlet fitting (32) traversed by a connectable channel (58) at a first end to a fluid supply, a portion of the inlet fitting having an opposite end of said forwardly extending channel and   penetrates into said annular projection, the gun com-   both also a fluid nozzle retaining element (54), a portion of which extends rearwardly and penetrates into said annular projection to removably connect to said portion of the fluid connector. inlet, the latter and the retaining element of the fluid nozzle maintaining and compressing between them said annular projection so that the latter carries the connection and the retaining element on the front end   of the gun body, a fluid nozzle (52) being   channel (60) which terminates, at a front end, at a fluid outlet port (128), said fluid nozzle being removably connectable by   screwing, to said restraint member so that one end   rear channel of the fluidic nozzle   with said opposite end of the intake connection channel   a circuit is thus established to allow the listening of   fluid from said first end of the inlet connection channel to and through said   outlet orifice of the fluid nozzle, means for emitting   atomizing air being located at said front end of the fluid nozzle to form a spray atomizing fluid flowing through said orifice Release.   9 air spray gun according to claim 8, characterized in that the atomizing air emission means comprise an air nozzle (28) removably mounted on the front end of the fluid nozzle and having at least one air outlet port (108) for emitting air to atomize a fluid flowing through the outlet port, and an air cap (56) mounted around it of the air nozzle and releasably connected by screwing to the fluid nozzle retaining element   in order to mount the air nozzle on the fluid nozzle, the   seems to spray head so being mounted on the front end of the gun body without it being   necessary to screw this set on the body.   10 Air spray gun according to   one of claims 1 and 8, characterized in that   the fluid inlet connection and the fluid nozzle are made of a material that is resistant to corrosion   due to the fluid flowing in their channels.