Technical Field

The present invention relates to assemblies used to spray coatings of > materials onto substrates, and in particular to such assemblies that provide rough surface textures on the materials sprayed on the substrates

Background

Various automobiles have chip resistant coatings on the lower portions of

10 their body panels that were applied over the primer layer and under the paint

These chip resistant coatings resist chipping of paint on the automobiles as a result of objects such as sti ikmg the panels during use of the automobile Such chip resistant coatings ali have outer surface textures that are generally rough when compared to the surface ot the paint on the rest ot the automobile, however the

1 ^" degree of outer surface roughness on such coatings is significantlv different on different makes and models ot automobiles When an automobile is repaired by re¬ surfacing or replacing a body panel (e g , a door a tender) it is desirable to apply chip resistant coating to that panel that has the same outer surface texture as that of the chip resistant coating on the rest of the automobile With the application

20 assemblies available heretotoie however, it has been difficult for the craftsman applying such a chip resistant coating to adjust its outer surface texture to match that ot the chip resistant coating on the rest of the automobile

Automobiles also typically have coatings of undercoating materials on the inner surfaces of their body panels to protect the sur faces of those panels from

25 corrosion and for sound deadening purposes Such coatings of undercoating materials also have outer surface textuies that are generally very rough, and differ in roughness between the diffei ent makes and models of automobiles When an automobile is repaired it mav be desirable to apply such coatings of undercoating material with the same outer surface texture as that of the undercoating material on

">o the rest of the automobile, particularly in areas that may be more readily observed, such as in the trunk or wheel wells of the automobile With the application

assemblies a* ailable heretofore however it has been difficult for the craftsman applying such a coating of undercoating material to adjust its outer surface texture to match that on the rest ot the automobile

Known devices used for applying chip resistant coatings or coatings of undercoating materials draw the coating materials through a dip tube from a container of the coating material carried on the applicator which adds bulk to the applying device This also requires the craftsman to only use the applicator with the container projecting genei alK downwardly so that the coating material in the container will be drawn into the dip tube, thereby limiting the positions from which

10 the coating material can be applied

Known devices used tor applying chip resistant coatings or coating of undercoating materials that are at least partially reusable have either been difficult to clean or purge, or ha\ e gone to the expense of using disposable parts so that clean up or purging is not required and totally disposable aerosol spi av devices are often i used

Disclosure of Invention

The present invention provides a spray assembly for applying coatings such as a chip resistant coating or a coating of undercoating material which spray

20 assembly ( 1 ) is easily adjustable to change the surface texture of the coating being applied to match that of other coatings on the automobile (2) does not need to earn,' the supply ot coating material being applied on the portion of the assembly being manipulated bv the operator, (3) allows the operator to use the portion of the assembly manipulated bv him in any orientation to apply the coating, and (4) is

25 easily purged after use so that disposable pans are not required

In the spray assembly according to the pi esent invention there is provided a sprav nozzle having an inlet end adapted to be coupled to a source of air under pressure, a through passageway between that inlet end and an outlet end which has a portion of reduced diameter and a suction passageway inter secting the through

30 passageway adiacent its portion of reduced diametei The assembly also includes a valve attached to the spray nozzle A valve bodv tor the valve has an outlet

passageway communicating between a socket and the suction passageway, and an inlet passageway also communicating with the socket A moveable member is mounted in the socket for movement between open and closed positions through intermediate positions The moveable member has a connectable passageway adapted to connect between the inlet and outlet passageways in the open and intermediate positions, and to be spaced from at least one of the inlet and outlet passageways in the closed position so that the moveable member blocks communication between those passageways Decreasing portions of the cross sectional areas of the passageways are connected at the interface between the valve body and the moveable member during movement of the moveable member through its intermediate positions from its open position toward its closed position The assembly also includes a reservoir adapter adapted to engage a reservoir containing a liquid coating material to be sprayed with the liquid material at an opening through the adapter, and a flexible hose connected between the through opening in the reservoir adapter and the inlet passageway in the valve body When the inlet end of the spray nozzle of this assembly is then attached to and supported on a hand held air gun attached bv a hose to a source of air under pressure (i e . an air supply gun sold under the trade designation "3M No Cleanup Applicator gun". "Part Number 051 135-08801 ' ^" by Minnesota Mining and Manufacturing Company, St Paul, Minnesota) it can be used to spray the coating material onto a surface The outer surface texture or roughness of the material being coated can be adjusted by moving the movable valve member to change the ratio between the air and the material being dispensed Because the material being coated is being drawn through a flexible hose, the operator can use the hand held air gun and the spray nozzle with the valve attached to it in any orientation to spray material onto a substrate This facilitates spraying many locations, such as the lower portions or undersides of panels or in wheel welis and trunks on automobiles

The surface texture of a coating of material applied by the spray assembly is primarily a result of the degree of atomization of the material at the time it impacts the surface being coated, with materials that are more finely atomized producing a coating with a smoother surface texture The degree of atomization produced by

the spray assembly is a result of several variables, including ( 1 ) the rheology of the material (e g , thinner materials are more easily atomized then thicker materials), (2) the inlet pressure of the air passing through the spray nozzle (i e , the higher the air pressure the finer the atomization), (3) the ratio between the volume of air and the volume of coating material being dispensed from the spray nozzle (the less material dispensed for a given volume of air the finer the atomization), and (4) the distance between the spray nozzle and the surface being coated (the greater the distance the finer the atomization) Known prior art spraying devices for coating materials have only had adiustments on the pressure and, thereby, the volume of air passing through the spray nozzle The present invention provides the valve assembly which can be used for adiusting the amount of material being drawn into the spray nozzle for anv setting of air pressuie to the nozzle T his valve assembly greatly facilitates the users ability to select the desired amount of atomization for the material being sprayed The valve assemblv used in the pi esent invention also has a novel structure that facilitates making tine adjustments in that amount of material being drawn into the sprav nozzle At the interface between the valve body and the moveable member the passageways have cross sectional shapes adapted to increase the angle of rotation required to rotate the rotary member from its open portion through its intermediate positions to its closed position, and to afford more accurate adjustment of the rotarv membei to allow small amounts of the material being spraved to pass through the valve than would be possible if those passageways had circular shapes of the same diameter at their interfaces T his adjustment of the material being spiayed together with the use of chip resistant coatings of two different viscosities (e g , the chip resistant coatings commercially designated "Part No 8447 Rockei Coating Smooth" and "Part No 8448 Rocker Coating Coarse" soon available from Minnesota Mining and Manufacturing Company (3M), St Paul, MN) affords duplicating the surface texture on the factory applied chip resistant of many different 1996 model automobiles including the "Corola" (T M ), "T ercel" (T M ), and "T-100 ^" (T M ) pickup models made by Toyota which have a very smooth surface texture, the "Trooper" (T M ) made by Isuzu and the "Impreza" (T M ) made by Suburu which have smooth, surface textures, the "Taurus" (T M )

sedan and wagon and the " ^' Escort" (T M ) sedan and wagon made by the Ford Motor Company which have medium surface textures, and the "B3000" (T M ) made by Mazada, the "Targa" (T M ) made by Porsche, the "Passat" (T M ) made by Volkswagon, and the "E300" (T M ) made by Mercedes which have coarse surface textures

Also, the spray assembly is easily purged of the material being sprayed after use The moveable member has an air inlet passageway having inlet and outlet openings through the surface of the moveable member positioned so that in the closed position of the moveable member the inlet opening is open to the atmosphere and the outlet opening communicates with the outlet passageway in the valve body Air under pressure moved thiough the spray nozzle will then pull air through the air inlet passageway, and expel anv material remaining in the outlet passageway so that the assemblv will be purge foi future use This air purging feature also makes the spray assembly useful to coat materials for which the sui face texture of the applied coating is unimportant, such as intercavity coatings, sprayable putties, weld through coatings, oversprav masking liquids, and the like

A plurality of the spiav assemblies can be supported on a carrying tray including a platform supporting reservoirs for the sprav assemblies, and a support member adapted to support their spray nozzles and valves The reservoirs of the sprav assemblies can contain any of the different coating materials that a craftsman mav use in repairing an automobile (e g , different chip resistant coatings which may be of different viscosities, different undercoating materials that may have solvent or water bases, an inter cavitv coating, a sprayable putty, a weld through coating, an overspray masking liquid, and/or a bumper coating) The craftsman can carry the carrying trav to his work place and have available those various coatings needed to complete repair of an automobile

Brief Description of Drawinu

The present invention will be further described with reference to the accompanying drawing wherein like reference numerals refer to like parts m the several views, and wherein Figure 1 is an exploded perspective view of a spray assembly according to the present invention.

Figure 2 is an exploded perspective view of a valve included in the spray assembly of Figure 1 .

Figure 3 is a front \ ιew of a valve body included in the valve illustrated in Figure 2,

Figure 4 is a side ol the valve body illustrated in Figure 3,

Figure 5 is a top iew ol a movable member included in the valve illustrated in Figure 2,

Figure 6 is a side v iew of the movable member illustrated in Figure 5 Figure 7 is a sectional \ lew taken approximately along line 7-7 of Figure 5,

Figure 8 is a i cai v iew of the valve illustrated in Figure 2 when the valve is assembled and the movable member is in an open position

Figure 9 is a top view of the valve as illustrated in F igure 8,

Figure 10 is a lear iew of the valve illustrated in Figure 2 when the valve is assembled and the movable member is in one of its intermediate positions.

Figure I 1 is a top view of the valve as illustrated in Figure 10

Figure 12 is a reai view of the valve illustrated in Figui e 2 when the valve is assembled and the movable member is in a closed position

Figure 1 3 is a top v iew of the valve as illustrated in Figure 12, Figure 14 is a Ci oss sectional view taken approximately aiong line 14-14 of

Figure 1.

Figure 15 is a fragmentary side view showing the spray assembly of Figure 1 coupled to an air gun and to a reservoir.

Figure 16 is a graph showing the results of an experiment performed with the spray assembly according to the present invention.

Figure 17 is a side view of a tray according to the present invention that can be used to support a plurality of the spray assemblies of Figure 1 after they have been attached to reservoirs.

Figure 18 is an end view of the tray of Figure 17, and s Figure 19 is a top view of the tray of Figure 17

Detailed Description

Referring now to Figure 1 of the drawing, there is shown a spray assembly according to the present invention generally designated bv the reference numeral 10 in Generally the spray assembly 10 comprises a ventuπ spray nozzle 1 1 having an inlet end 12 adapted to be coupled to a source of air under pressure an outlet end 1 3 and a thiough passagewav 14 between its ends 1 1 The through passagewav 14 has a portion 1 ^ of reduced passage diameter between the ends 12, 13 and the spiay nozzle includes a suction passagewav 16 intersecting the through is passagewav 14 adjacent that portion 1 S of reduced passage diameter in which a vacuum will be formed when air under pressure moves through the passageway 14 Also included in the sprav assembly 10 is a valve 18 comprising a valve body 19 attached to the sprav nozzle 1 1 that has a socket 20 and has separate inlet and outlet passageways 22 and 23 communicating with the socket 20, with the outlet 0 passagewav 23 communicating between the socket 20 and the suction passageway 16 A moveable or rotary member 24 is mounted in the socket 20 in the valve body 19 for rotational movement between open and closed positions through intermediate positions between those open and closed positions The rotary member 24 has a connectable passageway 26 adapted to connect between the inlet 5 and outlet passageways 22 and 23 m the open and intermediate positions, and to be spaced from the inlet and outlet passageways 22 and 23 m the closed position so that the rotary member 24 blocks communication between the inlet and outlet passageways 22 and 23 in the valve body 19, and to have deci easing portions of the cross sectional ai eas of the passageways 22, 23, 26 connected at the interface between the valve body 19 and the rotary member 24 during movement of the rotary member 24 through the intermediate positions from the open position toward

the closed positio The assembly 10 also includes a reservoir adapter 27 having a through opening that is adapted to engage a reservoir 29 (Figure 1 5) containing a liquid coating material to be sprayed with the liquid coating material at the through opening 28, and a flexible hose 30 having a through opening connected between the reservoir adapter 27 and the valve body 19 with the through opening in the hose 30 communicating between the through opening in the reservoir adapter 27 and the inlet passageway 22 in the valve body 19

The reservoir adapter 27, as illustrated, is adapted to engage a standard 1 and 3/4 inch diameter externally threaded collar 3 1 that forms an opening for the reservoir or one quart container 29. As is best seen in Figure 1 , the adapter 27 includes a main portion 32 including a first short hollow cylindrical tube 33 co- axially at its center, a radially outwardly projecting flange 34 about midway along the length of the first tube 33 that is adapted to rest on the distal end of the threaded collar 3 1 and has a radial vent slot 35 that provides a vent for the container 28, a hose bib 36 formed around the periphery of the first tube 33 at one end, and walls defining a socket 37 in the first tube 33 at it's other end Those walls have L- shaped slots 38 and are adapted to provide half of a bayonet coupling that releasably engages an end portion 40 of a second tube 4 1 That end portion 40 of the second tube 41 has radially outwardly projecting pins 42 adapted to engage surfaces of the walls defining the L-shaped slots 38 in a conventional manner by first sliding the pins 42 axially into axially aligned portions of the slots 38 and then rotating the first and second tubes 33 and 41 relative to each other to cause the pins 42 to firmly cam into circumferentially extending portions of the slots 38 at which they are retained by a detent between the pins 42 and the wails defining the slots 38, and the end portion 40 has a distal end formed with an annular radially outwardly projecting ridge 43 adapted to seal against the inner surface of the socket upon engagement of the pins 42 against the surfaces defining the L-shaped slots 38. A circular metal collar 44 included in the reservoir adapter 26 has an internally threaded cylindrical portion 45 adapted to engage the threads on the flange of the container, and a radially inwardly extending portion 46 adapted to bear against and press the flange 34 against the end of that collar 3 1 when the cylindrical portion 45

is so engaged The reservoir adapter 27 also includes a hollow cylindrical dip tube 48 adapted to reach to the bottom of the container 29 with which the reservoir adapter 27 is engaged, with one end portion of the dip tube 48 engaged over the hose bib 36 formed around the end of the tube 33 While the reservoir adapter 27 illustrated is preferred for manv purposes, the spray assembly 10 could alternatively include any reservoir adapter that serves to provide a supply of the liquid coating material to be spraved at the end of the hose 30 opposite the valve 18

One end of the hose 30 is engaged over a hose bib 50 formed around the end of the second tube 41 opposite its end portion 40 The end of the hose 30 opposite the second tube 41 is coupled to the valve 18 bv a coupler 52 that, to save making a different part has the same structure as the main portion 32 of the adapter 27 described above 1 he coupler 52 includes a first short hollow cylindrical tube 53 co-axiallv at its center a iadiallv outwardly projecting flange 54 about midway along the length of the first tube 53 that can be grasped to engage the coupler 52, a hose bib 55 formed around the periphery of the first tube 53 at one end, and a wall of the first tube 53 at it s other end that defines L-shaped slots 57 and a socket 56 opening through its distal end that provide half of a bavonet coupling that releasably engages an end portion of a tube 61 defining the inlet passageway 22 that is formed on the valve bodv 1 That end portion of the tube 61 on the valve body 19 has radially outwaidlv proiecting pins 62 adapted to engage surfaces of the walls defining the L-shaped slots 57 in a conventional manner as described above, and an annular radially outwardly pioiecting ridge 63 around its distal end that will seal against the inner surface of the socket 56 when the pins 62 engage the surfaces defining the L-shaped slots 7 Similarly, a tube 64 on the valve body 19 defining the outlet opening 23 includes a wall defining L-shaped slots 65 and a socket that open through its distal end to provide half of a bayonet coupling that releasably engages an end portion of a tube 66 formed on the spray nozzle 1 1 that defines the suction passagewav 16 That end portion of the tube 66 on the valve body 19 has radially outwardly proiecting pins 67 adapted to engage surfaces of the walls defining the L-shaped slots 65 in a conventional manner as described above, and has an annular radially outwardly proiecting ridge 68 at its distal end that is adapted to

seal against the inner sui face ot the socket when the pins 67 are engaged with the surfaces defining the L-shaped slots 65

The valve body 19 (see Figures 1 , 2, 3, and 4) and moveable or rotary member 24 (see Figures 1 , 2, 5, 6 and 7) of the valve 18 are both injection molded ^ of a polymeric material (e g , polypropylene) The valve body i 9 includes a hollow cylindrical portion 70 defining the socket 20 which is also generally cylindrical, a partial end wall 71 across one end of the socket 20, and the opposite outwardly projecting portions 61 and 64 which define the axially aligned inlet and outlet passageways 22 and 23 respectively The rotary member 24 includes a generally

10 cylindrical portion 80 including a central part 81 with a cylindrical peripheral surface adapted to tit closelv with a portion of the inner surface defining the socket 20 and through which the connectabie passagewav 26 radiallv extends The rotary member 24 has annular ui oov es 84 and 85 flanking the central part 81 around which O ring seals 86 and S7 extend to provide a seal with the inner surface of the

| ϊ cylindrical portion 70 and a ndge 88 at one end adapted to engage a recess around the surface defining the socket 20 to retain the rotary membei 24 in the socket 20 The rotary member 24 also has a radially proiecting ridge 90 around its end opposite the ridge 88 that is positioned along one end of the cylindrical portion 70 and a transverse handle portion 92 proiecting bevond the cvlmdrical portion 80 that

20 can be manually engaged to rotate the rotary member 24 with respect to the valve housing 19 between its closed and open positions T he r otarv member 24 also has radially extending ridges 93 disposed in a V-shaped pattern and projecting from its end opposite the handle 92 that are adapted to abut an edge of the partial end wall 71 and limit rotation of the l otarv member 24 between its open and closed

25 positions

At their interfaces between the valve bodv 1 and the t otary member 24 the inlet and outlet passageways 22 and 23 are circular, and the opposite ends of the connectabie passagewav 26 (see Figures 5 and 7) have non-circular elongated shapes tapered at one end that are adapted to increase the angle of rotation required

30 to rotate the rotary member 24 from its open portion through its intermediate positions to its closed position, and to afTord more accurate adjustment of the rotary

member to allow small amounts of the material being sprayed to pass through the valve than would be possible if the opposite ends of the connectabie passageway 26 had circular shapes of the same diameter as the inlet and outlet passageways 22 and 23 The opposite ends of the connectabie passagewav 26 have circular portions 95 of the same diameter as the inlet and outlet passageways 22 and 23 which align with the inlet and outlet passageways 22 and 23 when the rotary member 24 is in its open position with respect to the valve body 19 (see Figures 8 and 9) The opposite ends of the connectabie passagewav 26 also have V shaped portions 94 at the ends of V- shaped grooves similar in shape to the pour spout on a pitcher, which V-shaped grooves are on opposite sides at its opposite ends (see Figures 5 and 7) As the rotary member 24 is rotated through its intermediate positions toward its closed position first both a portion ot its cii cuiar portion 95 and its V-shaped portion 94 will be in communication with the circular inlet and outlet passageways 22 and 23 as can be seen in Figure 1 I Subsequently only the V-shaped portions 94 will be in communication with the cii culai ends of the inlet and outlet passageways 22 and 23, and the areas of the pans ot the V-shaped portions in communication will dimmish linearlv a the rotary member 24 is moved to its closed position The V-shaped portions 94 thus elongate the openings at the ends of the connectabie passageway 26 to extend the amount of rotation needed to move the rotarv member 24 to its closed position, and decrease the rate at which the ends of the connectabie passagewav 26 move out of alignment with the ends of the inlet and outlet passageways 22 and 23 compai ed to the use of a connectabie passageway 26 with circular ends of the same diameter as the ends of the inlet and outlet passageways 22 and 23 These V-shaped grooves 94 thus facilitate fine adiustment by the craftsman of the amount of material moving into the nozzle 1 ! , potentially resulting in a better match of the surface texture of the material being coated with the surface texture that the craftsman desnes to match While the V-shaped portions 94 illustrated are preferred because of their simplicity and ease of formation, other shapes could be used to replace the V-shaped portions 94, such a W shape or a half oval shape with a long width to height ratio Also, alternatively the opposite ends of the connectabie passageway 26 could be circular and the inlet and outlet

^■ I I -

passageways 22 and 23 could have non-circular elongated shapes tapered at one end at their interfaces with the rotary member 24 that are adapted to increase the angle of rotation required to rotate the rotary member 24 from its open portion through its intermediate positions to its closed position, and which afford more accurate adiustment of the lotary member 24 to allow small amounts of the material being spraved to pass through the valve 18 than would be possible if the inlet and outlet passageways 22 and 23 had circular shapes of the same diameter as the connectabie passageway 26 at those interfaces

Figure 16 graphs the results of an experiment comparing the use of the connectabie passagewav 26 that has ends of the shape described above with the use of a connectabie passagewav that has cncular ends of the same diameter as the ends of the inlet and outlet passageways 22 and 23 1 he ventuπ spray nozzle 1 1 used in the experiment which was shaped as illustrated in Figure 14, had a 2 068 inches or 5 253 centimetei s long passageway 14 which passagewav 14 had a cylindrical portion adiacent the inlet end 12 of the nozzle I 1 which had a diameter of 0 330 inch or 0 838 centimeter and a length of 0 544 inch or I 382 centimeters, and had a diameter of 0 347 inch or 0 88 i centimeter at the outlet end 1 3 of the nozzle 1 1 The portion 1 5 of leduced passagewav diameter in the passageway 14 had a diameter of 0 1 10 inch or 0 279 centimeter and a length of 0 238 inch or 0 605 centimeter, the suction passageway had a diameter of 0 149 inch or 0 378 centimeter and was spaced 0 793 inch or 2 014 centimeters from the outlet end of the nozzle 1 1 and 0 166 inch or 0 422 centimetei tiom the adiacent end of the portion 15 of reduced passagewav diameter The cylindrical portion 80 of the rotary member 24 had a diameter of 0 760 inch or 1 930 centimeters, the inlet and outlet passageways 22 and 23 both had diameters of 0 250 inch or 0 635 centimeter and the connectabie passageway 26 had, at each end, a circular portion 95 with a 0 250 inch or 0 635 centimeter diameter and a V-shaped portion 94 with an apex angle of 67 9 degrees that projected beyond the circular portion 95 The V-shaped portion 94 was at the end of a V-shaped groove, the apex or bottom 1 15 of which (see Figuie 7) had a 0 015 inch or 0 038 centimeter radius and was parallel to and spaced 0 050 inch oi 0 127 centimeter away from an imaginary line 1 16,

which imaginary line 1 1 passed thi ough the axis of the rotarv member 24 and was disposed at an angle 1 17 ot 24 degrees with respect to the centerhne or axis 1 18 of the connectabie passagewav 26 Air under 40 PSI pressure was blown through the passageway 14 and water was sucked through the suction passageway 16 as the 5 rotarv member 24 was moved in steps measured in degrees and plotted on the X axis from its open through its intermediate to its closed position Measurements were made of the rate of delivery of the water at various settings of the rotary member 24 and plotted on the Y axis, resulting in the plot line 1 12 in Figure 16 The same experiment was performed using a cylindrical portion that was the same lo as the cylindrical portion 80 desci ibed above except that its connectabie passageway had circular ends ot 0 250 inch or 0 635 centimeter diameter that did not have V- shaped portions resulting in the plot line 1 14 in Figure 1 As can be seen in Figure 16 the cylindrical portion that was the same as the cylindrical portion 80 described above except that its connectabie passagewav had circular ends was

| s rotated bv 45 degrees before it was in its closed position and delivered about 4 and 1/4 grams per second ot the material just prior to being placed in that closed position whereas the cvlindi ical portion 80 described above that had ends with both a circular and V-shaped portions was rotated by 50 degrees before it was in its closed position, and delivered about 3 and 1/4 grams per second of the material just

20 prior to being placed in that closed position

The v lve 18 includes means for allowing air to be drawn into the nozzle 1 1 through the outlet and suction passageways 23 and 16 to purge them ot the coating material after the lotary member 24 is moved to its closed position The rotary member 24 has an air inlet passageway (see Figure 7) having an inlet opening 96 5 through the end surface of the rotary member 24 opposite the handle portion 92, and an outlet opening 97 through the cential part 81 of the cylindrical portion 80 positioned to communicate with the outlet passagewav 23 in the valve body 19 in the closed position of the rotary member 24 (see Figures 12 and 13), and to be spaced from the outlet passagewav 23 in the valve body 19 in the intermediate and 0 open positions of the rotary membei 24 A projecting annular ring 99 around the inlet opening 96 to the air inlet passageway is positioned along the planar inner

-1 ^'

surface of the partial end wall 7 1 on the valve bodv 19 to seal it closed when the rotarv member 24 is in its open or intermediate positions (see Figures 8 and 10), whereas that inlet opening 96 moves into alignment with an opening along the edge of the partial end wall 71 when the rotary member 24 moves to its closed position (see Figure 12) so that air can then be drawn into the outlet passageway 23, suction passageway 16, and the nozzle 1 1 to purge it of coating material

The ventuπ sprav nozzle 1 1 , best seen in Figures 1 and 14, is molded of polymeric material (e g , polypropylene) The inlet end 12 is adapted to be coupled to an air supply gun 100 (see igure 15) sold under the trade designation "3M No Cleanup Applicator gun Part Number 051 135-08801 " by Minnesota Mining and Manufacturing Companv St Paul Minnesota) The air supply gun 100, when attached bv an an hose 101 to a source of air under pressui e can be manually manipulated bv a handle 1 2 and manually activated by pulling a trigger 103 to propel air undei pr essui e thunigh the passagewav 14 in the sprav nozzle 1 1 The suction passagewav \ ⁽ ι lntei sects the through passagewav 14 adiacent that portion 1 5 of reduced passage diametei between that portion 1 5 of reduced passageway diameter and the outlet end I 3 of the nozzle 1 1 , and bv ventun action will suck material thi ough the suction passagewav 16 into the air stream moving through the through passagewav 14 The portion of the nozzle s inlet end 12 adapted to be coupled to the an suppiv gun 100 includes wails 106 defining a socket 107 adapted to receive a cylindrical proiection 108 around an air outlet port on the air gun 100 The alls 106 hav e L-shaped slots 109 and ar e adapted to provide half of a bayonet coupling that reieasablv engages radially outwardlv proiecting pins 1 10 on the proiection 108 in the conventional manner described above for other bayonet couplings in the spiav assembly 10

If desired the l eservou adapter 27 with a container 29 filled with material to be spraved attached thereto can be attached directlv to the tube 61 on the valve body 19 bv engaging the pins 62 with the slots 38 Alternatively, a package of two part material of the type described in U S Patent No 4,971 ,251 can be attached directlv to the tube 61 oi to the tube 40 and used as the suppiv of the material to be sprayed Also, the spi ay nozzle 1 1 can have an extension tube (not shown )

attached to its outlet end to extend the through passageway 14, and that extension tube can be used in places such as between panels in an automobile to apply rust proofing materials, after which both the spray nozzle 1 1 and that extension tube can be purged of the material being applied by turning the rotary member 24 to its closed position

A plurality of the spray assemblies 10 can be supported on a carrying device such as a carrying tray 120 illustrated in Figures 1 7- 19 which could be made of wood or molded of polymeric material That carrying tray 120 includes a platform 121 from which side walls 122 and dividing walls 123 project upwardly to define open top compartments in which a plurality of the reservoirs 29 for the spray assemblies 10 can be received and supported The carrying tray 120 also includes a support assembly 125 that proiects upwardly centrally of the platform 121 The support assembly 125 includes a transverse handle portion 126 at its upper end adapted for manual engagement to carry the tray 120, and has two parallel support members 128 extending between the platform 121 and the opposite ends of the handle portion 126 The support members 128 each include two parts 130, 13 1 and are adμistable in length bv inserting fasteners 129 (e g , bolts or pins) through different pairs of openings 132 along the parts 1 30, 1 3 1 to provide different spacings between the handle portion 126 and the platform 121 that may be desirable to the workman for various reasons, such as to facilitate storage of the carrying tray 120 The support membei s 12S also include pioiecting portions adiacent the ends of the handle portion 126 that include notches 134 and proiections 135 adapted to receive and support the sprav nozzles 1 1 , valves 18. and hoses 30 of the spray assemblies 10 carried in the compartments on the platform 121 The reservoirs 29 to which the spray assemblies 10 carried in the carrying tray 120 are connected can contain difTerent coating materials that a craftsman may use in repairing an automobile and that can be applied using the sprav assemblies 10 (e g , difTerent chip resistant coatings which may be of different viscosities such as "Part No 8447 Rocker Coating Smooth" and "Part No 8448 Rocker Coating Coarse", both soon available from M, St Paul, MN, different undercoating materials such as "Part No 8449 Water Base Undercoat ^" and "Part No 8450 Solvent Base Undercoat", both

available from 3M, St Paul. MN, an inter cavity coating such as "Part No 8446 Cavity Coating ^" available from 3M, St Paul, MN, a sprayable putty, a weld through coating, an overspray masking liquid, and/or a bumper coating) The craftsman can carry the carrying tray 120 and spray assemblies 10 coupled to reservoirs 29 that are supported on it to his work place and have available those various coatings needed to complete the repair of an automobile

The present invention has now been described with reference to one embodiment and several modifications thereof It will be apparent to those skilled in the art that many changes can be made in the embodiment described without departing from the scope of the present invention Thus the scope of the present invention should not be limited to the structures described in this application, but only bv structures described bv the language of the claims and the equivalents of those structures