US2237842A

US2237842A - Spraying device

Info

Publication number: US2237842A
Application number: US246101A
Authority: US
Inventors: Harry M Reynolds
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-12-16
Filing date: 1938-12-16
Publication date: 1941-04-08
Anticipated expiration: 1958-04-08

Description

April 8, 1941.

i H. M. REYNOLDQ SPRAYING DEVICE Fild Dec. 16, 1958 5 Sheets-Sheet l INVENTOR Harry M. Reyna/d5.

ATTORNEYS April 8, 1941. H REYNQLDS 2.237.842

' SPRAEEING DEVICE Filed Dec. 16, l938 3 Sheets-Sheet 2 v75 52/ 2 II 45 Fly 7 IN VEN TOR. Har/y M Reyna/d5.

BY W M 7 ATTORNEYS.

atented Apr. 8, 1941 UNITED STATES. PATENT OFFICE 2,237,842 SPRAYING DEVICE Harry M. Reynolds, Columbus, Ohio Application December 16, 1938, Serial No. 246,101

3 Claims.

certain purposes where the spraying device must operate in a limited space, such as in spraying the interior of molds. Another disadvantage of the prior art devices resides in the fact that most oi them must be operated manually. They have not been constructed in such a manner that they could be operated quickly and automatically to atomize and spray the liquid and to interrupt the flow of liquid at the proper intervals. Furthermore, these prior art devices have not been constructed in such a maner that the quantity of the liquid sprayed could be adjusted efficiently and minutely.

in the following description I will refer to the liquidto be atomized and sprayed as oil and to v the fluid by means of-which it is atomized as air, but it is to be understood that I am not restricted to these particular fluids.

One of the objects of my invention is to provide a simple and compact device for atomizing oil by means of air under pressure, the device being composed of a minimum number of parts so that it can be manufactured cheaply.

Another object of my invention is to provide a spraying device which will operate automatically to atomize and spray the oil and to interrupt the spraying of the oil at the proper intervals.

Another object of my invention is to provide a spraying device which is of such a nature that it may be operated almost instantaneously to spray the oil or to interrupt the spraying of the oil and which is of such a nature that when it is rendered inoperative it will be completely sealed :0 that there will be no danger of leakage of fluid therefrom.

Another object of my invention is to provide a device of the type indicated which is of such a nature that the amount of oil sprayed therefrom may be minutely adjusted in an easy manner.

Various other objects and advantages will be apparent from the following description.

. forward portion of the device of Figure 3 show- In its preferred form my invention contemplates the provision of a spraying device having a passage for oil to be atomized and sprayed and a passage for air under pressure which is adapted to atomize and spray the oil at the proper instant. The two passages are so disposed that the stream of oil and the stream of air under pressure will be brought into cooperative relationship at the proper time. The device is liperated automatically to atomize and spray the oil by means of supplying the air under pressure thereto and to stop the atomizing and spraying of the oil by means of interrupting the how of air under pressure to the'device. The device is so constructed that it may be easily adjusted to vary the amount of oil sprayed.

The preferred embodiment of my invention is illustrated in the accompanying drawings wherein similar characters of reference designate corresponding parts and wherein:

Figure 1 is a longitudinal section taken through a spraying device made in accordance with my invention.

Figure 2 is a view partly in perspective and partly in longitudinal section showing the device of Figure 1 with the parts thereof disassembled.

Figure 3 is a longitudinal section taken along line 3-3 of Figure 4 through a somewhat different form of spraying device made in accordance with my invention.

Figure 4 is a transverse section taken substantially on line 4-4 of Figure 3.

Figure 5 is a transverse section taken substantially along line 5-5 of Figure 3.

Figure 6 is a longitudinal section through the ing the parts in operative position.

Figure 7 is a plan view partly broken away of the device of Figure 3. v

Figure 8 is a view similar to Figure 3 but showing a slightly different device.

Figure 9 is a detail of a portion of the device illustrated in Figure 8.

Figure 10 is a transverse section taken substantially along line Ill-l0 of Figure 8.

Figure 11 is a longitudinal section illustrating a spraying device associated with means to: projecting it into and withdrawing it Irom'the interior of an article to be sprayed such as a. mold.

Figure 12 is a section taken substantially along line I2-|2 of Figure 11.

Figure 13 is a section of the forward portion of a slightly modified form of my device.

With reference to the drawings, and particularly to Figures 1 and 2, I have illustrated my spraying device-as comprising a housing I which is preferably a machine casting. The housing is made in two pieces, namely, a forward portion 2 of substantially tubular form and an enlarged rear portion 3 of hexagonal form. The rear end of the portion 2 threads into the forward end of the portion 3, as at 4. A nut portion 5 is formed on the rear end of portion 2 to facilitate screwing of the rear end of the member 2 into the forward end of member 3. The member 3 has a threaded socket 3 formed in its rear end for receiving the threaded end of anoll conduit and also has a similar threaded socket 1 formed in its rear end for receiving the threaded end of an air conduit. Between the rear end of the member 2 and the base of the cooperating socket in the member 3 is disposed an annular member 3. A gasket 9 is disposed between member 8 and the inner end of the socket in member 3. The member 8 is of such shape that an annular passageway I is formed which is in communication with the bore II in which the socket 1 is formed. The member 8 is provided with a plurality of circumferentially spaced openings |2 establishing communication between the passageway I3 and the interior of member 2.

The member 8 has a central aperture l3 which is in communication with the inner end of the bor H in which the socket 8 is formed. Surrounding this opening l3 and extending forwardly is a collar portion l5. This collar'portion |5 receives the rear end of a bellows mem ber 5 which is suitably secured thereto. This bellows member l6 ay be made of copper or any other suitable fl xible material. The forward end of the bellows is connected to the rear end of a nozzle member H as at l8. This nozzle member is preferably of the shape shown and is provided with a central passageway IS. The forward end" of the nozzle member converges to form a nozzle portion as at and forms a valve seat with which the point 2| of a needle member 22 cooperates. This needle member is centrally disposed in the passageway IQ of nozzle II. It extends rearwardly through the bellows member |6, through opening l3 of member 8 and is threaded into member 3, as at 23. A small outlet passageway 24 is provided in the extreme forward end of the nozzle member H.

The forward end of the nozzle member I1 is carried by a piston 25 which is adapted to reciprocate longitudinally in the tubular member 2. This piston has a plurality of circumferential grooves 26 formed therein at spaced intervals to aid in preventing escape of air from the annular passageway 21 formed in member 2 around the bellows i6 and nozzle H. The grooves 23 may receive packing rings, if desired. The piston 25 I is of annular form and the nozzle member i1 is disposed centrally therewithin. The interior of the piston is threaded, as at 28, adjacent its rear end for receiving a correspondingly threaded portion on th nozzle member |1. This nozzle member has a nut portion 29 formed on its rear end to facilitate screwing of the nozzle into the piston. The piston and nozzle member are provided-with cooperating beveled seats 38 adjacent their rear ends. The forward end of the piston is provided with a reduced portion 3| within which an atomizing chamber 32 is formed. At its forward end the nozzle is provided with the enlarged portion 33 which converges at 20 as previously described. Between the portion 3| of the piston and the enlarged portion 33 of the nozzle is an annular inwardly directed space 34 which communicates at its forward end with the chamber 32. The space 34 gradually increases in width so that the air rapidly expands to its maximum velocity as it passes through this space. The rear end of the space 34 is in communication with longitudinally extending grooves 35 which are formed in the exterior of the nozzle member. These grooves are in communication at their rear ends with the annular space 21. The forward end of the member 2 is threaded on its exterior and receives a cap 38, having a threaded skirt 31. A compression spring 33 is disposed in surrounding relationship to the reduced portion 3| of the piston-25 and is located between the cap 36 and the piston proper. The reduced portion 3| of the piston has a further reduced portion 38 on its forward end which is adapted to be projected into the central opening 40 of the cap when the spraying device is operating. As indicated in Figure 2, the cap is knurled to facilitate rotation. It carries a rearwardly projecting leaf spring 4|. This spring 4| has a finger 42 on its inner end which is adapted to bear against a knurled or roughened portion 43 formed adjacent the forward end of member 2 and on the exterior thereof. The cap 36 may be adjusted to different positions on the member 2 and normally will be maintained in ad-' Justed position by means of the spring 42 cooperating with the roughened portion 43.

Oil will be supplied to this device through the line connectedto the socket 6, through bore I4, through opening l3, through the bellows I6, through the passageway I9 in nozzle H which will be normally closed at its forward end due to the fact that the portion 20 of nozzle U will be seated on the point 2| of needle 22. As long as the Piston 25 is held in its rearwardmost position by the spring 38, the oil will not escape. The bellows serves as eflfective means for preventing escape of oil into the air passageways and for preventing passage of air into the oil passageways.

When the device is to be operated to atomize and spray the oil, air under pressure is supplied thereto by means. of th line which is connected to the socket 1. Suitable means may be provided for controlling the supply of this air under pressure. The air under pressure passes through the bore around through the passageway ID, forwardly through openings l2 and forwardly through the annular chamber 21 within the member 2. This air will force the piston 25 forwardly unseating the forward end of the nozzle from the point 2| of the needle 22. Part of the air will also flow forwardly through the grooves 35 into the annular space 34 and then into the chamber 32 and outwardly through the opening in the cap. At the same time, the oil will flow between the point 2| and the converging portion 23 of the nozzle, being sucked forwardly through the outlet 24 by the air stream, and the oil will be atomized by the air flowing from the surrounding passageway 34. The air under pressure which moves the piston 25 is sufficient to overcome the resistance of the spring 38 and to compress it. Consequently, as soon as the flow of air under pressure through the device is interrupted, the spring 38 will expand, forcing the converging portion 23 of the nozzle against the point 2| and stopping the flow of oil. When the device is operating, the reduced portion 39 of v the piston will project into the opening 43 of the cap. The amount of oil atomized and sprayed from this device may be adjusted easily merely by turning the cap in order to vary the distance the piston must travel before striking the cap. This in turn will vary the size of the space between the portion 25 of the nozzie'and the point ll of needle 22 when the device is operating.

In Figures 3 to 7, I have illustrated a different form of my spraying device. It comprises a housing 44 which is preferably a machine casting. The main portion of this housing is of substantially tubular form. It has an enlarged rear portion 45 of hexagonal form. The portion 45 has a threaded socket 45 formed in its rear end for receiving the threaded end of an oil conduit and also has a similar threaded socket 41 formed in its rear end for receiving the threaded end of an air conduit. A centrally disposed bore M5 is also formed in the portion 45 of the housing. The rear end of this bore 55 is normally closed and sealed by means of ascrew 49 which is threaded in the rear end thereof and a cooperating gasket 55. The inner end of the socket M is in communication with the bore 55 by means of a passageway 5i. The inner end of the socket ll is in communication with the interior or the housing M by means of a passageway 52.

The forward end of the bore 45 receives the threaded rear end of an oil tube or needle 55. This tube or needle 55 extends forwardly through the tubular portion of the housing 45 substantially throughout the length thereof. It is centrally disposed therewithin. The forward end of the tube 55 is closed and has a point 54 formed thereon. However, transverse outlet openings 55 are provided in the wall of the tube" 55 just behind the point 54. A tube 55 is disposed in surrounding relationship to the tube 55 and is of somewhat larger diameter than the tube tit. A spacer washer 51 is provided between the tube 55 and the tube 55 and a shoulder 58 formed on the interior of tube 55 adjacent its forward end limits forward movement of this washer bl. Behind the washer 51 packing 55 is disposed in the space between the

tubes

55 and 55. The rear end of the tube 55 is threaded on its exterior and receives a threaded packing nut 55. This nut 50 abuts a sleeve 54 which extends into the annular space between the

tubes

55 and 55 and will serve to compress the packing 55. A lock nut 52 is disposed on the tube 55 for locking th gland 55 in adjusted position. As will be apparent hereinafter, the packing 55 will serve to prevent oil from escaping rearwardly along the tube 53 and air from entering the oil passageways.

The forward end of the tube 55 converges to form a nozzle portion, as at 55, and forms a valve seat against which the point 54 of tube 55 normally seats itself. A small outlet passageway 64 is provided in the extreme forward end of the tube 55. It will be noted that there is an annular chamber or space 55 formed between the forward end of the tube 55 and the tube 55 in front of the washer 51.

The forward end of the tube 55 is carried by a piston 55 which is adapted to reciprocate longitudinally in the tubular or cylindrical portion of the housing 44. This piston has a plurality of circumferential grooves 51 formed therein at spaced intervals, which may .receive packing rings, to aid in preventing escape of air from the interior of the housing 44 past the piston. The piston receives the enlarged exteriorly threaded portion 55 of the tube 55. It will be noted that the forward portion of the piston 55 has an inner surface which converges as indicated at 55 and an annular space 15 is formed between the converging portions of the piston and the corre spondingly converging portions 55 of the tube 55. A small annular passageway 1i surrounds the outlet passageway 54 of tube 55. A plurality of longitudinally extending grooves 12 are formed in the exterior of the threaded enlarged portion 55 of tube 55 in order to connect the space 15 behind the piston with the annular passageway 15.

The forward end of the housing 44 is threaded on its exterior and receives a cap 14 having-a threaded skirt 15. A compression spring 15 is disposed between the cap 14 and the piston 55. The spring 15 surrounds a reduced portion 11 of the piston. The. iston has a further reduced portion 15 which-is adapted to be projected into the central opening 15 in the cap when the spraying device is operated. As indicated in Figure the cap is knurled to facilitate rotation. It carries an inwardly projecting leaf spring 55. ihis spring has a finger 5| on its inner end which is adapted to bear against a knurled or roughened portion 82 formed adjacent the forward end of the housing 44 and on the exterior thereof. The cap 14 maybe adjusted to different positions on the housing and will be normally maintained in adjusted position by means of the spring 55 cooperating with the roughened portion 82.

\ Oil will be supplied to this device through the line connected to the socket 45, through passageway 5l, bore 45, to the tube 55. It will pass through this tube and will pass outwardly therefrom through the openings 55 into the annular space 55. The converging nozzle portion 55 of tube 55 will normally be seated on the point 54 of tube 55 by means of spring 15. This spring will normally force the piston 55 and the tube 55 which is carried thereby, rearwardly so that the portion 55 of tube 55 willseat on the point 55 of tube 55. It will be apparent that the unit comprising iston 55, tube 55 and packing nut 55 and associated parts may reciprocate in the housing 44 relative to the tube 55.

Thus, normally when the device is inoperative the oil will be in the tube 55 and in the annular chamber .55 surrounding its forward end. However, it cannot escape.

When the device is to be operated to atomize and spray the oil, air under pressure is supplied thereto by means of the line which is connected to the socket 41. Suitable means may be provided for controlling the supply of this air under pressure. The air under pressure passes through the passageway 53 into the chamber 15 within the tubular portion of the housing 44. This air will force the piston 55 forwardly unseating the nozzle portion 55 of the tube 55 from the point 54 of the tube 55, as indicated in Figure 6. Part of the air will flow forwardly through the grooves 12 into the annular space 15 and then outwardly through the annular passage 1|. At the same time the oil will flow between the point 54 and the portion 55 of tube 55 and will be sucked outwardly through the outlet 54 by the air stream. As it flows from the outlet 54, it will be atomized by the air flowing from the surrounding passageway 1|. The air under pressure which moves the piston 55 is suflicient to overcome the resistance of the spring 15 and to compress it. Consequently, as soon as the flow of air under pressure to the device is interrupted the spring 18 will expand forcing the nozzle portion 63 of tube 56 against the point 54 and stopping the flow of oil. When the device is operating, the reduced portion E8 of the piston will project into the opening E9 of the cap. The amount of oil atomized and sprayed from the device may be easily adjusted merely by turning the cap 14 in order to vary the distance the piston 66 and associated parts must move before the piston strikes the cap.

The nozzle portion 63 of the device just described is so formed that the spray will be merely directed forwardly. However, this nozzle may be varied in the manner illustrated in Figure 8 so that the air will spin as it issues from the nozzle in order that there will be a bushier spray or a spray that covers an angle of 360 degrees in a direction perpendicular to the axis of the spray.

Thus, the device illustrated in Figure 8 is exactly the same as that illustrated in Figure 3 with the exception that the nozzle portion 63a of the tube 66a has a spiral groove 12a formed in its exterior. The air will pass through the longitudinal grooves 12b and then through the spiral groove 12a. It will be caused to swirl as it passes through the outlet H and will consequently produce a swirling spray. The device of Figure 1 may also be provided with this type of nozzle portion, if desired.

In Figure 13 I show a slightly different form of nozzle structure for obtaining a different type of spray. In this instance the piston 66a is provided with a reduced extension 28a which always projects through the opening iii in the cap 1 3. The piston 66a and the extension We are pro vided with auxiliary Jets 72b which are directed inwardly at their outer ends. A chamber Fla is formed within the outer end of extension Tide. It will be apparent that when the piston is moved forwardly, in addition to the main stream of air and oil ejected from the nozzle, there will be auxiliary streams of air which 'pass forwardly through the jets lib. These auxiliary Jets are disposed diametrically opposite each other and will serve to flatten the main stream producing a fan shape spray. Different arrangements of auxiliary jets may be provided for producing sprays of different shape.

In Figure 11 I have illustrated means which I preferably provide for passing my spraying device into and withdrawing it from an object to be sprayed such as the interior of a mold. The spraying device shown is practically the same as that illustrated in Figures 3 to 8. However,

it may be the same as that shown in Figure 1 or Figure 3. The housing of the spraying device is changed somewhat.

The housing d ia does not have the enlarged hexagonal portion at its rear end but instead is continued rearwardly to form a long tubular portion 88 which constitutes a hollow piston rod.

This rod 83 projects into a cylinder 8 3. A packing gland 85 is provided at the forward end of the cylinder 86. The rod 83 and the spraying device are thus mounted for reciprocation relative to the cylinder fi l. The rear end of the rod 83 has a piston 86 formed thereon. This piston fits tightly within the cylinder 836.

The rear end of the tube 53 of the spraying de= vice is threaded, brazed or soldered into the forward end of a tube 63'. This tube 53 has its rear end threaded, brazed or soldered into a tubular portion 81 which is disposed within the piston rod 83 and piston 86 and is a part thereof. .i tube 88 is disposed within the tube as and is free to slide sure through the inlet 97.

therein. This tube has its rear end threaded. brazed or soldered into the head 88, as at 80. This head 89 closes the rear end of cylinder 84. A similar head 9! is provided at the forward end of the cylinder but is provided with an opening through which the rod 83 passes. The packing gland 88: is mounted on a threaded extension 83 of the head 9|. A packing gland as is provided within member 81 around the tube 88. The piston 88 is provided with a coil spring at its rear side which serves as a cushion to prevent the piston from striking the head 89. A compression spring 96 is provided in front of the piston 86 and in surrounding relationship to the rod 83 to prevent the piston from striking the head 8i.

An inlet ii! for air pressure is provided in the head SE. An inlet 98 for air under pressure is provided in the head 94. It will be noted that there is an annular chamber 99 formed between piston rod 83 and cylinder 3 It will also be noted that there is an annular chamber I00 formed between piston rod 83 and tube 53'. The forward end of this last chamber is in communication with the chamber 73 of the spraying device while the rear end of chamber iilil is in communication with the space behind piston 83 by means of passageway WI and holes (102 shown in Figures 11 and 13.

Air under pressure is normally supplied through the inlet 38 to the chamber 99. This will keep the piston 86 in its rearwardrnost position as indicated in Figure 11. If the device is bein used for spraying molds, it will be mounted over the mold cavity and the piston 86 will normally be in its uppermost position. When it is desired to spray the mold cavity, air is supplied under pres- The pressure of this air may be the same as that supplied through the inlet 95. Suitable means may be provided for supplying and interrupting the supply of air through the inlet 91. The air entering through opening fill will pass into the cylinder 86 behind the piston 86. Since it will act on a greater area of the piston than does the air within the chamber 98, it will force the piston 8i; outwardly. At the same time the air will flow through openings I62, passage idi, chamber iflil and into the chamber P3 of the spraying device and will operate the spraying device in exactly the same manner as previously described.

At the time that the piston 86 moves outwardly, the rod 83 which carries the spraying device slides outwardly through the forward end of the cylinder so as to project the spraying device into the mold cavity. When the rod 83 moves outwardly, the tube E33 moves therewith and slides longitudinally on the tube 88. The tube 38 is stationary since it is threaded into the head 89. The tube 53' and the tube 88 will always telescope with each other. The tube 88 receives the oil through an oil supply passageway 593 which is provided in the head 89.

When the spraying operation is completed, the supply of air through the inlet 9? is stopped and the air is permitted to exhaust through said opening. This will permit the air in chamber 91 to force the piston 86 rearwardly to the piston indicated in Figure 11. This will cause the spraying device to be withdrawn from the mold. Furthermore, the spraying operation will be simultaneously interrupted,

It will be apparent that with this device the spraying head may be caused to enter the mold and simultaneously the spraying operation will be initiated. When the spraying operation is completed, the sprayingdevice will be withdrawn from the mold cavity and simultaneously the spraying operation will be stopped.

From the above description it will be apparent that I have provided a device having many advantages. The device is very simple and compact. It can be used where space is limited. It will opcrate automatically to atomize and spray the oil and to interrupt the spraying of the oil at the proper intervals.

in the preceding description, I refer to oil as the fluid being atomized and air as the fluid which is used to atomize the oil. Also in the claims I use these terms. understood that I am not limited to oil and air but intend to cover other fluids which might be used.

Having thus described my invention, what I claim is: v

i. A spraying device of the type described comprising a substantially cylindrical housing, a stationary needle member centrally disposed within said housing, a nozzle member mounted on said needle member and being free to move longitudinally thereon, said nozzle member having a portion which fits tightly within said housing and However, it is to be surface of said orifice so that the needle will close said discharge orifice, said needle member having serves as a piston, said nozzle member having a tapered discharge orifice through which oil to be atomizedis adapted to be discharged, said needle member extending to the forward end of said housing and having a tapered portion normally projecting into the tapered discharge orifice of said nozzle member and contacting with the suriace thereof so that said orifice will be normally closed, said nozzle member having a passageway associated therewith for conducting oil into said nozzle member, said nozzle member having a passageway therein for receiving air under pressure and directing it adjacent said discharge oriflee to atomize oil discharged through "said orifice, means for supplying air under pressure to the interior of said housing, the air under pressure acting on said piston portion of said nozzle to move the nozzle forwardly on said needle and permitting the oil to issue through said discharge orifice, a portion of the air also passing through said passageway in said nozzle, a cap member threaded on the forward end of said housing and having an opening through which the fiuid passes, said cap member having a portion con tacted by said nozzle member when it moves to its forwardmost position, a compression spring disposed between said cap member and said nozzle member for resisting movement of said nozzle member on said needle member, and means for maintaining said cap in any position to which it is rotated to limit the movement of said nozzle member to a preselected degree and consequently to produce a predetermined spacing of the cooperating tapered surfaces of the nozzle member and the needle member.

2. A spraying device of the type described comprising a nozzle, a movable nozzle member disposed within said housing adjacent the forward portion thereof and having a piston portion thereon fitting tightly within the housing, said movable nozzle member having a discharge orifice through which oil to be atomized is adapted to be discharged. a stationary needle member mounted within the housing and having a portion which normally contacts with a cooperating a passageway for oil associated therewith, means for supplying oil to said passageway, said nozzle member being provided with a discharge orifice for air which is disposed adjacent said oil discharge orifice so that it will atomize any oil which issues through said orifice, means for supplying air under pressure into said housing behind the piston portion so that it will act on said piston portion to move the nozzle member relative to said stationary needle and will permit the oil to be discharged throughsaid oil discharge orifice and to cause air to be discharged through said air discharge orifice in the nozzle member to atomize the oil, a compression spring disposed within said housing and normally pressing against the forward end of said piston portion to resist movement of said nozzle member relative to said needle member, and means for varying the extent of movement of said nozzle member relative to said needle member to vary the space between the surface of said nozzle orifice and the cooperating portion of said needle and consequently to vary the amount of oil sprayed from the device, said means comprising an adjustable stop member with which said nozzle member contacts when it reaches its forwardmost position.

3. A spraying device of the type described comprising a substantially cylindrical housing, a stationary needle member centrally disposed within said housing, a nozzle member disposed in surrounding relationship to said needle member and being free to move longitudinally thereof, said nozzle member having a piston portion formed thereon which fits tightly within said housing and serves as a piston, said nozzle member having a discharge orifice through which the oil to be atomized is adapted to be discharged, said needle member extending to the forward end of said housing and normally projecting into the discharge orifice of said nozzle member so that said orifice will be normally closed, a bellows member disposed in surrounding relationship to said needle. said bellows being connected at its forward end to said nozzle member and being anchored. at its rear end to said housing, means for supplying oil into said bellows. said nozzle member having a passageway therein for receiving air under pressure and directing it adjacent said oil discharge orifice to atomize oil discharged through said orifice. means for supplying air under pressure to the interior of said housing behind said piston portion so that it will act on the piston portion to move the nozzle member relative to said stationary needle forwardly permitting the oil to issue through said oil discharge orifice and causing air to be discharged through said discharge orifice in the nozzle member to atomize the oil, a cap member threaded on the forward end of said housing and having an opening through which the fluid passes. a compression spring disposed between said cap member and the forward end of said piston portion for resisting movement of said nozzle member relative to said needle member, and means for maintaining said cap member in any position to which it is rotated to limit the movement of said noale member to a preselected degree.

HARRY M. ampms.