Ceramic Flat Spray Tip

The present invention relates to spraying tips used with a spraying device, for spraying a material, such as paint. In particular, the invention relates to a ceramic flat spray tip which produces a spray pattern of a generally oblong or flat shape, as opposed to a circular shape.

Flat tip nozzles have been used in connection with airless paint spraying equipment as evidenced by U.S. Pat. No. 4,025,045 assigned to the assignee of the present application. As disclosed in that patent, a discharge end of the spray pistol includes a tip nut which is threadingly received on the gun and which engages over a flange of a guard member which in turn has means for engaging a flange of the nozzle tip, thus, the nozzle tip which includes a noncircular orifice can be firmly held on the front of the spray gun to direct a relatively flat spray. The ledge on the outer diameter of the tip nut is generated as a circle which allows complete rotation of the guard member with respect to the tip nut. However, the inner diameter of the guard member which abuts the outer diameter of the nozzle tip has diametrically opposed flats thereon which mate with flats on the nozzle tip. In this manner, the nozzle tip is not rotatable independently of the guard member.

A flat spray tip producing a flat spray pattern, mounted to a spraying device such as a spray gun, is known to the art. A spray tip which produces a flat pattern must be held securely in the holder to prevent undesired axial rotation of the tip, which would change the orientation of an elongated axis of the flat spray pattern.

Ceramic material, providing excellent wear resistance to the erosive property of paint when sprayed, is an ideal material for use in a flat spray tip. A ceramic spray tip which produces a circular spray pattern is known to the art. However, tips which produce circular spray patterns need not be fixed against axial rotation and thus can be guided or closely captured rather than fixed. Securely holding flat spray tips composed of a non-brittle material such as carbide is known to the art. However, securely holding a brittle material such as a ceramic material is not known to the art and therefore the subject of the present invention.

It is therefore new to the art to provide a ceramic flat spray tip for a spraying device, such as a spray gun, which is securely held into a spray nozzle secured to the spray gun.

It is an object of the present invention to provide a flat spray tip for a spraying device such as a paint gun which exhibits excellent wear resisting properties; is held securely into a spray tip holder, preventing axial rotation during spraying; can be quickly and easily installed into the holder during manufacture; makes assembly relatively foolproof; and comprises a minimum of parts.

The object is accomplished in that a ceramic spray tip is utilized providing excellent wear resistance to spraying induced erosion; the ceramic spray tip can be glued into the holder and either the holder or the ceramic spray tip is provided with means to prevent glue from penetrating outward of the holder during installation, and possibly fouling a discharge orifice of the spray tip; the ceramic spray tip can be secured into the holder by providing the holder or the spray tip with integral ribs tightly engaged against the ceramic spray tip when inserted; the ceramic spray tip is fashioned of a shape which permits insertion into the holder from a rearward side only; a ledge is provided on either the ceramic spray tip or the holder which prevents the ceramic spray tip from being excessively inserted into the holder and thus protruding outward of the holder excessively; the ceramic spray tip can be provided with means to positively insure correct orientation of the ceramic spray tip with the holder, such as tabs; and minimum parts are utilized by securing the ceramic spray tip to the holder by an adhesive, or by ribs tightly engaging the ceramic spray tip.

FIG. 1 is a sectional view of a nozzle assembly.

FIG. 2 is an enlarged sectional view of a portion of the nozzle assembly depicted in FIG. 1, in particular a spray nozzle.

FIG. 3 is an elevational view of the spray nozzle depicted in FIG. 2, generally viewed along line III--III.

FIG. 4 is a sectional view of an alternate embodiment of the spray nozzle depicted in FIG. 2.

FIG. 5 is an elevational view of the alternate embodiment spray nozzle depicted in FIG. 4, generally viewed along line V--V.

FIG. 6 is a sectional view of an alternate embodiment of the nozzle assembly depicted in FIG. 1.

FIG. 7 is an enlarged sectional view of a portion of the nozzle assembly depicted in FIG. 6, in particular a spray nozzle.

FIG. 8 is an elevational view of the spray nozzle depicted in FIG. 7, generally viewed along line VIII--VIII.

FIG. 9 is an elevational view of the spray nozzle depicted in FIG. 7, generally viewed along line IX--IX.

FIG. 10 is an enlarged sectional view of a portion of spray nozzle depicted in FIG. 7, generally along line X--X.

FIG. 11 is an elevational view of an alternate annular engagement end of the actuating lever.

FIG. 12 is a sectional view generally along line XlI--XII of FIG. 11.

FIG. 13 is a second alternate embodiment of the nozzle assembly of FIG. 1.

FIG. 14 is an enlarged sectional view of a nozzle holder and a spray tip shown in FIG. 13.

FIG. 15 is an elevational view generally along line XV--XV of FIG. 14.

FIG. 16 is an elevational view generally along line XVI--XVI of FIG. 14.

FIG. 17 is a perspective view of the spray tip of FIG. 13 and FIG. 14.

FIG. 18 is an enlarged sectional view generally along line XVIII--XVIII of FIG. 14.

FIG. 1 shows a nozzle assembly generally at 20. The nozzle assembly 20 includes a safety barrier 22, a housing cylinder or retaining nut portion 24 and a rotatably movable actuating lever 26. Preferably, the safety barrier 22 and retaining nut portion 24 comprise an integral molded plastic item. An internally threaded insert 28 is molded inside the retaining nut portion 26. A paint conduit 30, such as a barrel of a paint spray cup gun, opened to an interior 31 of the insert 28, threadingly engages the threaded insert 28 at a threaded end 30a of the paint conduit 30 and engages a spray device at a remote end (not shown).

Residing interior of the retaining nut portion 26 is a spray nozzle 32 including a holder 34, and a spray tip 36. A swirl valve 38, and a retention spring 40 also reside therein. The swirl valve 38 abuts an open rear end 41 of spray nozzle 32, and is pressed thereagainst by the retention spring 40. The spray tip 36 resides interior of the holder 34. The spray tip 36 is composed of a ceramic material which provides excellent wear resistance to the erosive property of liquid being sprayed, such as paint. Spray tips 62, 108 described below are also composed of ceramic material. It has been determined that a preferred ceramic material, referred to as GTC-TA, manufactured by the Diamonite Products division of W. R. Grace & Co., being a transformation toughened aluminum oxide material, can be injection molded into the desired configuration described herein without requiring any further machining as required by conventional carbon tungsten spray tips, thus greatly reducing manufacturing costs. However, such material is more brittle, and, thus, has a greater susceptibility to fracture than does carbon tungsten, thereby requiring a unique mounting arrangement not necessary with conventional spray tips.

A spraying fluid such as paint enters the paint conduit 30 from the spraying device (not shown), moves into the swirl valve 38, passes from the swirl valve 38 through the spray tip 36, and thereupon exits the spray tip 36 in a selective spray pattern having an axial centerline generally collinear with an axis of the spray tip 36.

The spray tip 36 is secured to the holder 34, and the actuating lever 26 grips a perimeter of the holder 34 to prevent retraction of the holder 34 out of the retaining nut portion 24 towards the conduit 30 and providing that rotation of the actuating lever 26 about the axis of the spray tip 36, results in rotation of the holder 34 which rotates the spray tip 36. Rotation of the spray tip 36 causes rotation of the axial centerline of the spray pattern discharged from the spray tip 36. Where the spray pattern is unsymmetrical about the axial centerline such as a flat spray pattern, selective rotation causes an elongated axis of the flat spray pattern to rotate to a desired angular orientation.

FIG. 2 shows in sectional view, the preferred embodiment of the spray nozzle 32 gripped by an annular engagement end 26a of the actuating lever 26. The holder 34 comprises: an oblong barrel 42, a cylindrical barrel 43 and an outer ring portion 43a. The holder 34 is gripped by the engagement end 26a of the actuating lever 26 about the oblong barrel 42. The oblong barrel 42 provides two recesses 42a, 42b on opposing sides of an end of the oblong barrel 42 forward of a forward surface 24a of the retaining nut portion 24, when the holder 34 is in an installed position. The recesses 42a, 42b provide flat surfaces 42c, 42d, respectively. The engagement end 26a of the actuating lever 26 snaps into the recesses 42a, 42b and abuts the forward surface of the retaining nut portion 24. A central opening 26b of the engagement end 26a is sized to stretch over an extreme forward end 34a of the holder and spring back into the recesses 42a, 42b. Thus, the engagement end 26a of the actuating lever 26 prevents rearward retraction of the holder 34 toward the conduit 30, acting as lock ring.

The flat surfaces 42c, 42d provide a keying arrangement whereby the engagement end 26a can grip the holder 34 to be rotated by rotation of the actuating lever 26.

A front annular surface 43b of the outer ring portion 43a abuts a rear surface 28a (FIG. 1) of the insert 28, preventing forward removal of the holder 34 from the housing cylinder 24.

The spray tip 36 is engaged interior of the holder 34. The spray tip 36 comprises: a spray ball 44 having a spray orifice 46, a tip sleeve 48, and a collar 50. The tip sleeve 48 is fit tightly inside the oblong barrel 42 and the cylindrical barrel 43 at an interface 48a. The collar 50 resides interior of the outer ring portion 43a of the holder 34 and abutting a rearward facing step 54 of holder 34. Outer ring 43a and the step 54 provide stability to the spray tip 36 during operation, and alignment of the spray tip 36 during installation. The step 54 prevents forward travel of the spray tip 36 once installed. An attachment means such as glue is applied to a forward surface 56 of the collar 50 to secure the spray tip 36 in the holder 34. The interface 48a between the tip sleeve 48 and the oblong barrel 42 and the cylindrical barrel 43 provides a close fitting arrangement to prevent glue from forward travel during installation of the spray tip 36 into the holder 34, thus preventing fouling of the spray orifice 46 with glue.

FIG. 3 shows the annular engagement end 26a which surrounds the oblong barrel 42 in a close fit fashion. The oblong barrel 42 comprising the two flat surfaces 42c, 42d provide a grip for rotation of the oblong barrel 42 by rotation of actuating lever 26. Spray ball 44 comprises a generally hemispherical shape and has a spray orifice 46 opened to an interior of the spray tip 36. The spray orifice 46 in the preferred embodiment is an oblong opening which provides a flat shaped spray pattern.

Thus, the holder 34 provides an inventive means to secure the spray tip 36 composed of a brittle material, such as a ceramic material, and provides an arrangement to effectively rotate the spray tip 36 by rotating the holder 34. The spray tip 36, providing a flat spray pattern, is secured into the spray nozzle 32 and can be rotated by the actuating lever 26 to orient the elongated axis of the flat spray pattern. Holders 66, 100, described below, provide the same advantages.

FIG. 4 depicts an alternate embodiment of the present invention wherein a ceramic spray tip 62 comprises a straight cylindrical sleeve 64 without a collar. A holder 66 provides lateral and axial stability along an interface 68 between the holder 66 and the sleeve 64, and a retaining ring portion 70 of the holder 66 opposes forward movement of the spray tip 62 by abutting a rearward surface 72 of the ring portion 70 to a forward surface 74 of the sleeve 64. A means of attachment along the interface 68 can be glue or a frictional fit. The retaining ring portion 70 also acts to prevent glue from traveling forward of the interface 68 which could foul the spray orifice 46. Similar to FIG. 2, the engagement end 26a of the actuating lever 26 grips the holder 66 about an oblong barrel portion 72, to prevent retraction of the holder 66 toward the conduit 30 and for rotation of the holder 66. The engagement end 26a snaps into recesses 72a, 72b which function identically to recesses 42a, 42b, described above.

FIG. 5 shows the actuating lever 26 surrounding the oblong barrel portion 72 with the engagement end 26a to effectuate rotation and to prevent retraction of the holder 66 toward the conduit 30. The oblong barrel portion 72 comprises two flat surfaces 72c, 72d interior of recesses 72a, 72b providing a grip for rotation. The retaining ring portion 70 is shown. The spray ball 44 and the spray orifice 46 are otherwise identical to FIG. 3.

FIG. 6 shows an alternate embodiment of the nozzle assembly shown in FIG. 1. In this embodiment a longer holder 100 is utilized in conjunction with a separate lock ring 102 which prevents retractive movement of the holder 100 in a rearward direction towards the paint conduit 30. The holder 100 protrudes through the engagement end 26a of the actuating lever 26 to be gripped by the lock ring 102. The lock ring 102 can be a known lock ring, such as a Tinnerman lock ring.

FIG. 7 shows the longer holder 100 to be comprised of a formed barrel portion 104 and an extended casing portion 106. The formed barrel portion 104 surrounds a rearward portion of a ceramic spray tip 108 which comprises tabs 110a, 110b and a rear cylinder portion 112. The tabs 110a, 110b reside interior of recesses 113a, 113b of the formed sleeve 104. The recesses 113a, 113b serve to guide the spray tip 108 into position during installation, and also to prevent rotation of the ceramic spray tip 108 about its axis during operation. A front surface 116 of the tabs 110a, 110b and the cylinder portion 112 abuts a rear surface 118 of the formed barrel portion 104 thus preventing excessive forward movement of the spray tip 108. FIG. 6 shows extended casing portion 106 of the holder 100 extends forwardly from the formed barrel portion 104 to a position forward of the engagement end 26a of the actuating lever 26. In such a position the extended casing portion 106 can be gripped by the lock ring 102 to prevent retraction of the holder 100 toward the paint conduit 30. A forward annular surface 114 of the holder 100 abuts the rear surface 28a (FIG. 6) of the insert 28 preventing forward removal of the holder 100 from the housing cylinder 24.

FIG. 7 shows a longitudinal sleeve 120 of the spray tip 108. The extended casing portion 106 of the holder 100 provides on an interior circumference three longitudinal ribs 126 at approximately 120.degree. spacing. When the ceramic spray tip 108 is inserted into the holder 100 from a rearward opening, the tabs 110a, 110b align with the recesses 113a, 113b which guide and retain the ceramic spray tip 108 in a proper orientation to the holder 100. Proper projection of the ceramic spray tip 108 into the holder 100 tightly engages the ribs 126 against the sleeve 120 along a length of the ribs 126. The ribs 126, thus tightly compressed against the sleeve 120, provide a secure means of preventing retraction of the ceramic spray tip 108 toward the paint conduit 30, and provide a secure means of preventing axial rotation of the spray tip 108 with respect to the holder 100.

FIG. 8 shows the formed barrel portion 104 and particularly the recesses 113a, 113b wherein reside the tabs 110a, 110b. The cylinder portion 112 is also shown.

FIG. 9 shows the three ribs 126 compressed against the sleeve 120 at approximately 120.degree. spacing around the circumference of the sleeve 120. The extended casing portion 106 comprises at a forward end two flat surfaces 106a, 106b to facilitate gripping by the engagement end 26a of the actuating lever 26.

FIG. 10 shows an enlarged view of one of the ribs 126 compressed and deformed against the slots 124 of the longitudinal sleeve 120. The dashed FIG. 126a denotes the uncompressed configuration of the rib. The holder and ribs 126 can be made of a material suitable for compression of the ribs such as die-cast zinc.

FIG. 11 shows an alternate embodiment of the engagement end of the actuating lever 26: a gripper 26b. In this embodiment, a holder, such as holder 100 as shown in FIG. 7, is gripped interior of the gripper 26b. The gripper 26b provides a central opening 26c for receiving the holder 100. The casing portion 106 is gripped by fingers 130a, 130b along rounded sides 106c, 106d of the casing portion 106. Similar to the engagement end 26a, the gripper 26b provides flats 26d, 26e, which abut flat surfaces 106a, 106b to fix for rotation the casing portion 106 with the gripper 26b.

FIG. 12 shows that when the casing portion 106 is inserted into the housing cylinder 24, the gripper 26b is pushed onto the casing portion forward of forward surface 24a of the housing cylinder 24.

The fingers 130a, 130b extend inward of the central opening 26c a distance great enough to interfere with the casing portion 106. Thus, the fingers 130a, 130b bend forwardly as the casing portion 106 is being inserted, while still gripping the casing portion 106. A springing force from the fingers 130a, 130b caused a tight grip upon the casing portion, preventing rearward retraction of the holder 100 from the forward surface 24a.

FIG. 13 shows a second alternate embodiment of the nozzle assembly of FIG. 1. The assembly of FIG. 13 is similar to the assembly shown in FIG. 6. However, in this assembly of FIG. 13 the paint conduit 30 abuts the swirl valve 38 in sealing fashion. The swirl valve 38 sealingly abuts a fan spray tip 160 in sealing fashion such that paint passes from the paint conduit 30 through the swirl valve 38 and into the fan spray tip 160. The fan spray tip 160 is grippingly held in an alternate holder 150.

FIG. 14 shows the alternate holder 150 surrounding the fan spray tip 160. The arrangement of FIG. 14 is nearly identical to the arrangement of FIG. 7. The only substantial difference between FIG. 14 and FIG. 7 is the use of four engaging ribs 166 formed with the spray tip 160 and the elimination from the holder of the longitudinal ribs 126. Rather than forming the ribs 126 on the holder of FIG. 7, as shown in FIG. 14 the engaging ribs 166 are formed on the fan spray tip. FIG. 15 shows the rear view of the holder 150 and the spray tip 160 as being identical to the arrangement of FIG. 8. The fan spray tip 160 has formed thereon alignment tabs 126a, 162b, identical in function to the tabs 110a, 110b of FIG. 8, to align assembly of the spray tip 160 in a proper orientation to the holder 150.

FIG. 16 shows four engagement ribs 166 spaced apart at quarter points around the circumference of a sleeve portion 162 of the spray tip 160. The sleeve portion 162 inserts into a barrel portion 154 of the alternate holder 150.

FIG. 17 shows the spray tip separate form the holder. This elongated aperture 168 of the spray tip 160 for a flat spray pattern, as well as the engagement ribs 166 and the alignment tabs 162a, 162b.

FIG. 18 shows an enlarged sectional view of one engagement rib 166 gripping into or deforming the surface of the barrel portion 154 of the holder 150. The holder 150 is, in the preferred embodiment, formed of a relatively soft metal, such as zinc, which will slightly deform during gripping insertion of the ceramic spray tip 160, more particularly under pressure of the engaging ribs 166.

Thus a plurality of engaging ribs 166 spaced around a circumference of the spray tip engage the holder to prevent axial and rotational movement of the spray tip 160 with respect to the holder 150.

As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art.