US3759449A

US3759449A - Device for producing coolant mist

Info

Publication number: US3759449A
Application number: US00121023A
Authority: US
Inventors: J Ruthman; W Smith; R Forte
Original assignee: RUTHMAN MACHINERY CO
Current assignee: RUTHMAN MACHINERY CO
Priority date: 1971-03-04
Filing date: 1971-03-04
Publication date: 1973-09-18
Anticipated expiration: 1990-09-18

Abstract

The mechanism herein disclosed provides a coolant mist for machine tools and the like and the intensity of which mist may be changed at the will of the user or operator. The machine tool with which the coolant mist is employed may be performing a drilling, reaming, tapping, grinding and the like operation and the nozzle for delivering coolant to said point of operation is controlled in the form of a stream of coolant, a coolant mist, or a continuous air stream operation. The mist producing mechanism may be readily adjusted for increasing or varying the amount and intensity of the coolant stream, the coolant mist, and the stream of air.

Description

United States Patent [1 1 Ruthman et al.

DEVICE FOR PRODUCING COOLANT MIST Inventors: Jerome E. Ruthman, Cincinnati,

Ohio; William L. Smith, Cold Spring; Robert A. Forte, Dayton, both of Ky.

The Ruthman Machinery Company, Cincinnati, Ohio Filed: Mar. 4, 1971 Appl. No.: 121,023

Assignee:

US. Cl 239/4l6.2,'239/4l6.4, 239/413 Int. Cl B05b 7/24 Field of Search 239/413, 416.2, 416.4, 239/4165, 417.5, 305

References Cited UNITED STATES PATENTS 7/1959 Harr 239/4173 X 10/1963 Thomas 239/4164 X 7/1968 Dasse et al..... 239/4175 X 1/1959 Faust 239/413 UX [451 Sept. 18, 1973 3,104,826 9/1963 Morris 239/4164 X 3,253,788 5/1966 McHugh et al. 239/434 X Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-John J. Love Attorney-James S. Hight et al.

[57] ABSTRACT The mechanism herein disclosed provides a coolant mist for machine tools and the like and the intensity of which mist may be changed at the will of the user or operator. The machine tool with which the coolant mist is employed may be performing a drilling, reaming, tapping, grinding and the like operation and the nozzle for delivering coolant to said point of operation is con trolled in the form of a stream of coolant, a coolant mist, or a continuous air stream operation. The 'mist producing mechanism may be readily adjusted for increasing or varying the amount and intensity of the coolant stream, the coolant mist, and the stream of air.

12 Claims, 13 Drawing Figures PATENTED SEN 8 I973 SHEH 2 [1F 4 INVENTORS JEROME E RUTH/WAN WILLIRM L,SM[TH By/ ROBERT A FORTE final pg ll DEVICE FOR PRODUCING COOLANT MIST This invention relates to a mechanism for effecting either a continuous liquid flood flow, or a mist flow of coolant, or at the desire of the operator, a stream of air, to a workpiece at the point where it is being operated upon by another tool such as a grinding wheel, drill, tap, reamer, or the like.

The principal object of the present invention is the provision of a mechanism wherein the motor and pump thereof may be mountable either remotely or on a machine tool and the nozzle thereof adjacent to a point of workpiece where another tool, such as a grinding wheel, drill, tap, or the like, is operating and which work must either have a flood of water or a mist surrounding the portion or other part of the work that is being formed so that the proper attitude between the work and the tool is maintained, that is, so that the work is not burnt or the tool having its temper removed due to excessive amount of heat.

Another object of this invention is the provision of a.

mechanism as above set forth and wherein the mechanism is reduced to its simplist form comprising, first, a means for adjusting the amount of the mist; second, a controldevice in the form of a push button for electrically opening a valve so as to switch from liquid flood flow to mist flow at a nozzle; and, third, a device that can be mounted directly on the machine or can be mounted remotely from the machine, as on tank so that the mist or coolant mechanism may be brought adjacent to the machine and the vicinityof the work being operated upon.

A further and specific object of this invention is the provision of a device as above set forth and wherein it is contained within a comparative compact body hav- FIG. 7 is a vertical sectional view through the device taken on a plane ahead of that of ,FIG. 5 on FIG. 6, namely, as seen from line 7-7 on said FIG. 6;

FIG. 8 is a transverse sectional view of the structure as seen from line 8-8 on FIG. 5;

FIG. 9 is a vertical transverse sectional view through the device of FIG. 1 taken in a plane to the right of that of FIG. 8 as seen from line 9-9 on said FIG. 1;

FIG. 10 is a vertical diagrammatic view of a mechanism including a pump and the device of the present invention, connected with the pump, it being understood, of course, that the FIG. 10 is of a much smaller scale of the other views;

FIG. 11 is an enlarged sectional view through the nozzle of the discharge tube taken on line 11-11 on FIG. 3;

FIG. 12 is a horizontal sectional view taken through the control operating valve and as seen from line 12-12 on FIG. 2 and illustrating the components of a solenoid valve; and

FIG. 13 is a sectional view of the control valve seat and taken on line 13-13 on FIG. 5.

Throughout the several views of the drawings, similar reference characters are employed to denote the same or similar parts.

As illustrated in FIG. 10, use is made of a tank 15 having therein the coolant such as oil, water, or water ing thereon a gauge to indicate the amount of pressure behind the mist or the stream, an electrical solenoid for opening the valve in accordance with the setting thereof by the said control mechanism and wherein the mist-producing mechanism body and its mechanism are of the simplist operation possible considering the fact that the results are relatively complex requiring the user to simply push a switch or operate a valve handle.

Other objects and advantages of the present invention should be readily'apparent by reference to-the following specification considered in conjunctionwith the accompanying drawings forming a part thereof and it is to be understood that any modifications may be made in the exact structural details there shown and described without departing from or exceeding the spirit of the invention.

In the drawings:

FIG. I is a front elevational view of the coolant control mechanism of the present invention; I

FIG. 2 is a top plan view of the mechanism as illustrated in FIG. 1;

FIG. 3 is a view longitudinally of the delivery hose and nozzle and which hose, obviously, could be of any desired length;

FIG. 4 is a horizontal sectional view taken in a plane above the center of the device as seen in FIG. 1, namely, on line 4-4 of said FIG. 1;

FIG. 5 is a sectional view vertically of the device as seen from line 5-5 on FIG. 6;

FIG. 6 is a bottom elevational view of the device of 7 FIG. 1;

with detergent or another liquid which acts as a coolant.

The. unit may also be, and is continuously, used as a compressed air unit for blowing away chips or the like, allas well known in the industry.

. The tank 15 has at its upper end a cover 16 through which an opening 17 is provided. for filling the tank and, as will presently be made clear, for connection with the machine tool or the like that is using the coolant or mist for maintaining the condition of the workpiece and too].

On the other side of the vertical center of the top or cover 16, there is provided a bracket 18 for a motor 19 having extended from its lower end a shaft 20 connected with the pump mechanism 21 fromwhich extends the delivery pipe 22 having at its upper end a. shut-ofi valve 23.

The shut-off valve 23 is connected by a nipple 24 with the coolant spray control mechanism of the present invention indicated in its entirety by the reference numeral 25.

' tends from any suitable or desirable source of compressed air, not shown in the drawings.

Referring now to FIGS. 5 and 9, it will be noted that the intake coupling 28 opening is connected into a cavity 30 in which is a strainer 31, and from which cavity 30 there extends a reduced opening 32 to a transverse opening 33. There is also a second passage or flow path from the chamber 30 by way of a duct or port 34 (FIG. 9) entering into a second duct or port 35 which extends parallel to the chamber 30.

The duct or port 35 extends through a metering valve 109 and connecting

passages

115, 38 to a metering opening or tapped bore 36 which in turn is connected with a larger opening or tapped aperture 37.

In operation, flow from the liquid inlet port 30a follows two paths; one through the metering valve 109 and the other through the passage 32 and a flow control valve 59 in the transverse bore 33. As explained more fully hereinafter, when the unit is operated in a liquid flood mode, liquid coolant flows through the unit along both paths; but when it is operated in a mist mode, the passage 32 is closed by the valve 59 and only a metered quantity of liquid reaches the outlet port 37 through the

passages

34, 35, 115, 38 and the metering valve 109.

By referring now to FIG. 3, it will be noted that the discharge nozzle or pipe, indicated in general by the reference numeral 40, has a flexible outer metal sleeve 41. This sleeve 41 has at its one end a pipe coupling 42 which is threaded into the threaded aperture 37 and at its other end a nozzle 43 through which liquid, mist or air may selectively be discharged.

Extending centrally of the flexible metallic tube, or sleeve hose, 41 is a plastic hose 44 which inherently can be flexed or twisted as determined by flexing, bending, or the like the outer flexible sleeve 41.

The inner end of the flexible tube 44 has connected therewith a member 45, which may be designated a coolant collector having a reduced portion 46 which is pressed into the inner end of the tube 44. The coupling or coolant collector 45 has intermediate its ends a hexagon-shaped section 47 to facilitate its being threaded into a small diameter threaded section 36 of the outlet port 37. It also has at its outer end a threaded nipple section 48 in which the threads are interrupted by an annular channel 49. A plurality of drilled holes or ports 49a extend between the channel 49 and the interior of the collector 45.

The nozzle per se comprises an outside body member 51 along with a meter 52 which may be called a mixer head, interiorly of the nozzle body member 51, and which mixer head is provided on its periphery with threads 52a which are threaded into a threaded axial passage 51a in the body 51. As illustrated more clearly in FIG. 11, the inner end threaded section of the mixer head 52 is square in cross section and thereby provides an area 53 on each side of the threaded portion of the mixer head through which air may pass to impact with the liquid stream. The outer end of the mixer head is cone-shaped and terminates in a circular collar 55. An axial aperture 55a through the mixer head communicates with the interior 50 of the tube 44 and provides for the flow therethrough of the coolant.

In order to adjust the fineness of themist when the unit is operated in a mist mode, an air flow adjustment member 56 is provided at the outer end of the nozzle body 51. This member 56 has external screw threads which screw into the same aperture 51a in which the mixer head 52 is screwed. That is, the outside body member 51 is threaded onto the mixer head 52 and the air flow adjustment member 56 is threaded into the outer end thereof.

The air flow adjustment member 56 and the cone portion of the mixer head or mist energizer are each provided with similar inclined or conical surfaces indicated at their line of contact by the reference numeral 57. By adjusting the clearance between these conical surfaces, the quantity of air passed through the nozzle passage 53 (FIG. 11) may be controlled and consequently the fineness of the mist or the degree of liquid atomization emitted from the nozzle when the unit is operating in the mist mode may be controlled and varied.

It should be here noted that the coolant passes down through the center 50 of the tube 44 and the air passes through the aperture or space 50a between the outer surface of the tube 44 and the inner surface of the flexible sheet-like metal pipe 41, as will be subsequently made clear.

The coolant from the pump 21 and through the pipe 22 and therefore through the unit of this invention is controlled through the valve 23; that is, the valve may be shut off to stop any flow through the mist unit or it may be partially open to permit a smaller amount of water than the full capacity of the pump.

Referring now to FIGS. 4 and 9, the chamber 33 through which the coolant flows is in reality a control valve for the flow of coolant and comprises a valve sleeve 58, pressed into the chamber 33 and having centrally thereof a spool type valve, indicated as a whole by the reference numeral 59, including lands 60 and 61 with the connecting'reduced diameter spool type portion 62 therebetween. The said valve 59 has projecting from its outer end or land 60 a reduced portion 63 around which is disposed a spring 64 for maintaining the spool type valve 59 in its proper position, as illustrated in the drawings.

The spring 64 has one end abutting against a cover plate 65 over the end of the valve chamber 33, and its other end abutting against the spool land or portion 60 of the valve. The land or spool-like portion 61 has projecting from its end a slightly reduced portion 66 which has supported thereby a diaphragm 67 which makes an air or water seal therearound by means of the projecting portion 68 of the diaphragm having its open or free end engaged with the valve sleeve 58.

As will later be made clear, the function of this spooltype valve is to permit the coolant to flow when it is desired to have a flood of coolant instead of a mist. As a matter of fact, the coolant is merely mixed with compressed air when a mist-type of a coolant is desired.

As noted above, the air intake tube 29 extends between a source of compressed air (not shown) and the housing 26 where it communicates with a chamber 69 (see FIGS. 5 and 12). The chamber 69 has a valve boyd 70 mounted therein which has an aperture 71 extending into a transverse aperture 72. The transverse aperture 72 terminates in an upstanding valve seat 73. The valve seat 73 is adapted to be closed by a relatively compressible valve 74 in a carrier 75 spring-loaded by means of a spring 76. The spring 76 abuts on one end with a plug 77 in a sleeve-like member 78 which has at its inner end a flange 79. This flange is secured within a counterbored chamber in the valve member body 70 by a screw threaded nut 81 threaded into a threaded section of the chamber.

The sleeve-like member or spring carrier 75 has surrounding it an electro-magnetic coil 82 of an electrically operated solenoid valve, indicated in its entirety by the reference numeral 83. The magnetic coil 82 is encased in a sheet metal open bottom end casing 84 which in turn has therearound an enclosing member 85. The outer enclosing casing member 85 is secured onto the sleeve-like member 78 by means of a spring clip 86 which is U-shaped in elevation and which is locked in position by entering a groove87 formed in the outer end of the sleeve 78.

As will be seen in FIGS. 12 and 13, there is a space or chamber 88 surrounding the outwardly projecting valve seat 73 which is connected with an outlet port 89 of the valve body 70 by two cross ports 91. By this constructqon compressed air enters the unit from any suitable source through the valve body 70 of the solenoid valve 83 so that opening of the valve closure 74 permits the air to flow through the

passages

69, 71, 91, and 89 to the system and subsequently to mix with the liquid coolant and form a mist or spray, as is explained more fully hereinafter.

Upon opening of the solenoid valve 83, compressed air from the port 89 enters the port 90 and follows the path of the air flow arrows indicated in FIGS. 4 and 5 by several short lines immediately behind the head of the arrow and is directed into a central air chamber 92 of the housing 26. When air enters the chamber 92, it immediately acts on the valve shifter diaphragm 67 to shift the spool valve 59 to the position in which the full flow port 36a is closed so that the liquid coolant is cut off from the free or flood flow.

At the same time the compressed air enters the chamber 92, it follows the path along dash line arrows indicated in FIGS. 4, 5, and 8 and passes through a conventional pressure regulator valve 1 16 to an outlet duct 103. As illustrated in FIG. 5, the unregulated compressed air enters the regulator 116 through inlet port 90 and operates against the inner end of the valve diaphragm 96a which is secured between

springs

97 and 98. An adjustment knob 1 l7 enables the tension of the spring 97 to be varied so as to control the air pressure of the regulated air emitted from the regulator 116 through an outlet port 118. The port 118 communicates with the passage 103 (FIG. 4) so that the pressure of the air stream passing through that passage is the air pressure determined by the adjustable air regulator l 16.

At the same time and as seen in FIGS. 1 and 2, the air pressure emitted from the pressure regulator valve 116 is measured by a standard air gauge 102 secured in a threaded aperture 119 (FIG. 4) of the housing 26 by a hollow threaded nipple 106. The aperture 119 communicates with the passage 103 so that the air gauge measures the regulated air pressure emitted from the pressure regulator 116.

When assembled,the discharge pipe 40 is secured to the housing 26 by threading the threaded section 48 of the coolant collector 45 into the small diameter threaded section 36 of the outlet port of the unit. The threaded section 42a of the outer flexible hose is then threaded into the large diameter section 37 of the outlet por't. When thus assembled, metered liquid coolant flow from the inlet port 30a of the unit may enter the coolant collector 45 either by flowing through the flow control valve 59 and the outlet port 36a of that valve through the axial passage of the coolant collector or, when the valve 59 is closed, a metered quantity of liquid may enter the coolant collector by flowing from the inlet port 30a through the

passages

34, 35, 115, and 38 into and through the annular recess 49 of the coolant collector and the radial passages 490 into the axial passage of the collector 45 and subsequently into and through the tube 44.

Operation The coolant control flow unit 25 heretofore described is operable in any of three modes. Specifically, it is operable (a) to direct air flow from the nozzle 43 onto a workpiece or (b) to supply flood liquid coolant to the workpiece through the nozzle 43 or (c) it is operable to supply a mist atomized liquid flow through the nozzle 43 onto the workpiece. Each of these three different modes of operation is selectable by control of the fluid flow control valve 23 (FIG. 10) and the solenoid operated air flow control valve 74 (FIG. 12. This latter valve may be actuated under the control of an electrical switch 93 located in an electrical flow control lead 94 to a plug 95.

Air Flow Mode When the spray control unit 25 is utilized in the air flow mode, as it might be to blow chips away from a workpiece, the valve 23 is closed and the switch 93 actuated to open the solenoid valve 74. In this mode of operation, air flow enters the unit through the coupling 27 from a source of pressurized air and flows through the solenoid valve 74 into and through the pressure chamber 92 via the passage 103 to the outlet port 37. At the outlet port 37, the flow enters the annular passageway 50a between the exterior of the tube 44 and the interior of the flexible metal tube 41 and flows through the passages 53 around the mixer head over the conical surface 57 and out the annular passage 55a around the exterior of the nozzle collar 55. The quantity of air and the pressure of the air stream may be adjusted by adjusting the pressure adjustment knob 117 of the pressure regulator and by varying the clearance between the mixer head 52 and the air flow adjustment member or collar 56. This last adjustment is made by unthreading the collar 56 from the interior of the nozzle body 51.

Liquid Flood Mode In the flood mode of operation, the unit operates to supply a heavy stream of liquid to a workpiece. When it is desired to operate the unit 25 in this mode and to supply a stream of liquid from the nozzle 43 to a workpiece, the valve 23 is opened and the switch 93 is deactuated so as to deenergize the solenoid of the solenoid controlled valve 74. In this condition of the solenoid,

the air flow control valve 74 is closed so that there isno air input into the unit 25 from the air inlet'port 27.

In this mode of operation, the spring 64 (FIG. 4) biases the coolant flow control valve 59 to an open position in which a stream of liquid is free to flow from the liq- ,uid intake port 30a through the liquid coolant flow contion, coolant flows both through the coolant flow control valve 59 and through the parallel coolant metering flow control passages 34-38 into and through the coolant flow tube 44 to and through the axial passage of the nozzle 43. I

Mist Flow Mode To convert from a flood coolant flow to a mist coolant flow, all that is required is to energize the electrical solenoid coil 82 of the solenoid valve 74. In the illustrated embodiment this is accomplished by the switch 93 in the electrical leads 94 to the solenoid coil. When the solenoid coil is energized, it has the dual effect of closing the liquid flow control valve 59 and simultaneously supplying air at a regulated pressure via the passage 103 and the annular passage 50a around the tube 44 to the annular passage 55a around the exterior of the collar 55 of the nozzle. This air flow impacts with the liquid emitted from the nozzle 43 and causes that liquid stream to be atomized, the degree of fineness of atomization being determined by the quantity and pressure of the air stream as determined by the setting of the flow control adjustment member 56 and the pressure of the stream as determined by the setting of the pressure regulator control knob 117.

In this mode of operation, the air flow is from the intake coupling 27 through the solenoid control body 70 of the valve 74 into the chamber 92 of the housing 26. Compressed air in the chamber 92 acts upon the bellows seal 67 to move the valve piston 62 against the bias of the spring 64 to a closed position in which a land 61 of the valve covers both the intake and

outlet ports

32 and 36a of the valve. When this valve is closed, a reduced quantity of liquid still flows from the liquid intake port 30a (FIG. 9) via the

passages

34, 35, the metering valve 109, the

passages

115, 38, the annular groove 49, the radial passages 49a, the interior 50 of the tube 44 and subsequently through the axial passage of the nozzle 43. Simultaneously, air flows from the air chamber 92 of the housing 26 via the pressure regulator 116 into the passage 103 (FIG. 4) and subsequently through the annular passage 50a surrounding the hose 44 through the passage 53 (FIG. 11) around the mixer head out through the conical passage indicated at 57 to impact with the liquid stream emitted through the interior of the nozzle member 56. When this air stream impacts with the liquid stream, it causes the air stream at be atomized. By adjusting the air flow control 56 in the nozzle and the pressure of the air stream at the regulator 116, the fineness of the mist may be controlled. The quantity of liquid or coolant contained in the mist may be varied by adjusting the knob 111 of the liquid flow control valve 109 (FIGS. 1, 2 and 7).

From the foregoing it will be noted that the device may be utilized as either a liquid coolant discharge mechanism (flood) at a full or normal speed and intensity or the liquid coolant may be cut ofi and the device operated to emit air alone from the nozzle 43 at a pressure which is adjustable and registerable on a .gauge. Alternatively, by operating both the air and the liquid coolant, a desired combination of both water and air mist may be ejected from the end of the nozzle 43.

What is claimed is:

1. In a device of the class described, the combination of a housing, a first inlet and an outlet into and from said housing, a first passageway within said housing between its inlet and outlet for conveying liquid coolant therethrough, a conveyor for said coolant from a source under pressure to the housing coolant inlet, a coolant flow control valve in said first coolant passageway, a second inlet into said housing, a second passageway within said housing for conveying compressed air between the said second inlet and the outlet from said housing, an electrically operated control valve carried by said housing within said compressed air passageway operable in one condition to prevent flow of air under pressure through the compressed air passageway, flow control means including said electrically operated control valve and said coolant flow control valve for supplying a large volume of coolant flow to said outlet in a flood mode of operation and for supplying a lesser volume of coolant flow together with air to said outlet in a mist mode of operation, discharge hose means for conveying said coolant and said air along separate flow paths from said housing outlet to a nozzle, and means at said nozzle for causing said air and said coolant to commingle and create an atomized mist when said device is operated in said mist mode.

2. The device of claim 1 in which said device includes a third passageway in said housing between said first inlet and said outlet for conveying coolant therethrough, said third passageway being operable to convey said lesser volume of coolant to said outlet when said device is operated in a mist mode of operation.

3. The device of claim 2 in which said third passageway includes a coolant flow adjustment control valve for varying the quantity of coolant in siad mist when said device is operated in said mist mode.

4. In a device of the class described as set forth in claim 1 characterized by said electrical control valve being operable to control flow of compressed air in said second passageway and also to control actuation of said coolant flow control valve in said first passageway.

5. In a device of the class described as set forth in claim 1 characterized by a pressure regulator in said air passageway within the housing for varying the pressure and strength of the air pressure flow therethrough and thereby the quality of the mist between a coarse and a fine mist.

6. in a device of the class described as set forth in claim 1 characterized by a third coolant flow passageway in said housing, said discharge hose means being in the form of a discharge hose having at its end adjacent to the body member a coolant collector for collecting coolant from said first and third passageways and directing the coolant through the hose to the outlet.

7. In a device of the class described as set forth in claim 1 characterized by said discharge hose means including a tube centrally of a hose which has an air flow space between the inner surface of the hose and the outer surface of the tube and collecting means for collecting and routing coolant into the tube at the end thereof adjacent the housing.

8. In a device of the class described as set forth in claim 1 characterized by said conveyor means for said coolant from the source thereof under pressure to the housing having exteriorly of said housing a valve for stopping the flow through the said conveyor and thereby, upon actuation of the electrically controlled valve, permitting only flow of air through the discharge means from the housing.

9. In a device of the class described as set forth in claim 1 characterized by said conveyor means for said coolant from the source thereof under pressure to the housing having exteriorly of said housing a valve for stopping the flow through the said conveyor and thereby, upon actuation of the electrically controlled valve, permitting onlyflow of air through the discharge hose means from the housing, and a pressure regulator in said second air passageway within the body for varying the pressure and strength of the air pressure flow therethrough and thereby the quality of the mist between a coarse and a fine mist.

10. In a device of the class described, the combination of a housing, a first inlet and an outlet into and from said housing, a first passageway within said housing between its inlet and outlet for conveyingliquid coolant therethrough, a coolant flow control valve in said first coolant passageway, a second inlet into said housing, a second passageway within said housing for conveying compressed air between the said second inlet and the outlet from said housing, an air flow control valve within said second passageway, and flow control means including said coolant flow control valve for supplying a large volume of coolant flow to said outlet in a flood mode of operation and for supplying a lesser volume of coolant flow together with air to said outlet in a mist mode of operation.

11. The device of claim 10 which further includes discharge hose means for conveying said coolant and said air along separate flows paths from said housing outlet to a nozzle, and means at said nozzle for causing said air and said coolant to commingle and create an atomized mist when said device is operated in said mist mode.

12. The device of claim 10 in which said air flow control valve is an electrically operated valve carried by said housing.

Claims

1. In a device of the class described, the combination of a housing, a first inlet and an outlet into and from said housing, a first passageway within said housing between its inlet and outlet for conveying liquid coolant therethrough, a conveyor for said coolant from a source under pressure to the housing coolant inlet, a coolant flow control valve in said first coolant passageway, a second inlet into said housing, a second passageway within said housing for conveying compressed air between the said second inlet and the outlet from said housing, an electrically operated control valve carried by said housing within said compressed air passageway operable in one condition to prevent flow of air under pressure through the compressed air passageway, flow control means including said electrically operated control valve and said coolant flow control valve for supplying a large volume of coolant flow to said outlet in a ''''flood'''' mode of operation and for supplying a lesser volume of coolant flow together with air to said outlet in a ''''mist'''' mode of operation, discharge hose means for conveying said coolant and said air along separate flow paths from said housing outlet to a nozzle, and means at said nozzle for causing said air and said coolant to commingle and create an atomized mist when said device is operated in said ''''mist'''' mode.

2. The device of claim 1 in which said device includes a third passageway in said housing between said first inlet and said outlet for conveying coolant therethrough, said third passageway being operable to convey said lesser volume of coolant to said outlet when said device is operated in a ''''mist'''' mode of operation.

3. The device of claim 2 in which said third passageway includes a coolant flow adjustment control valve for varying the quantity of coolant in siad mist when said device is operated in said ''''mist'''' mode.

9. In a device of the class described as set forth in claim 1 characterized by said conveyor means for said coolant from the source thereof under pressure to the housing having exteriorly of said housing a valve for stopping the flow through the said conveyor and thereby, upon actuation of the electrically controlled valve, permitting only flow of air through the discharge hose means from the housing, and a pressure regulator in said second air passageway within the body for varying the pressure and strength of the air pressure flow therethrough and thereby the quality of the mist between a coarse and a fine mist.

10. In a device of the class described, the combination of a housing, a first inlet and an outlet into and from said housing, a first passageway within said housing between its inlet and outlet for conveying liquid coolant therethrough, a coolant flow control valve in said first coolant passageway, a second inlet into said housing, a second passageway within said housing for conveying compressed air between the said second inlet and the outlet from said housing, an air flow control valve within said second passageway, and flow control means including said coolant flow control valve for supplying a large volume of coolant flow to said outlet in a ''''flood'''' mode of operation and for supplying a lesser volume of coolant flow together with air to said outlet in a ''''mist'''' mode of operation.

11. The device of claim 10 which further includes discharge hose means for conveying said coolant and said air along separate flows paths from said housing outlet to a nozzle, and means at said nozzle for causing said air and said coolant to commingle and create an atomized mist when said device is operated in said ''''mist'''' mode.