US2388517A - Spray coating apparatus - Google Patents

Description

Nov. 6, 1945.

F. A. BAILEY ETAL SPRAY COATING APPARATUS Filed March '6, 1945 4 Sheecs-Sheet 1 FIG/i INVENTORS FRANK A. BAILEY GODFREY A. MILLER BY CURQW ATTORNEY Nov. 6, '1945. F, B L Y ET AL 2,388,517

' SPRAY COATING APPARATUS I Filed March 6, 1943 4 Sheets-Sheet 2 FIG.3

FIG 2 m L A m INVENTORS FRANK A. BAILE BYGODFREY A.MIL R ATTORNEY 1945- F. A. BAILEY ET AL 2,383,517

SPRAY COATING APPARATUS Filed March 6, 1943 4 Sheets-Sheet 5 FIG 5 I) Q U 8 IL i INVENTORS FRANK A. BAILEY G ODFREY A. MILLER 1945- F. A. BAILEY ET AL 2,333,517

SPRAY COATING APPARATUS Filed March 1943 4 Sheds-Sheet 4 I IF 1 i l I I l I l I I l j E 5 i 5 l E I. i 11;: I Q HE: J) 3 ii- 132;; N I7 I ll| F IT:

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-J 5" ||LAJ|\' I| l I ll u I i m f'i I p 9) In Q (0 10 m i 9 [L n 5; l l v 6 I F O P *1 0 0 1 INVENTORS FRANK A. BAILEY BY GODFREY A. MILLER Q m [B (/OPQAMJ ATTORNEY Patented'Nov. 6, 1945 UNITED" STATE s -PATENT OFFICE SPRAY COATING APPARATUQ m: Bailey and,Godfrey A. Miller, Toledo. ()hio, assignora to The DeVilbiss Company, Toledo, Ohio, a corporation of Ohio Application March 6, 1943, Serial No. 478,276

6 Claims. (01.299-62) such apparatus which includes a spraying nozzle designed to revolve while coating the hollow portion.

Another object of the invention is the provision of an inexpensiv and simple mechanism for revolving the nozzle and for moving it into and out of the cavity. It has been the general practice previously to revolve the article instead of the nozzle. This invention is particularly advantageous when the article is heavy and cumbersome to handle.

Another object of the invention is the provision of a revolving nozzle in which the inner liquid tube is stationary. This is desirable in view of the difficulty that is encountered in securing a leakproof seal at the joint between a revolvin liquid tube and an adjoining stationary supply part. I L Another object of the invention is the provision of means for revolving the nozzle ata con stant speed and having it revolve before the spray material is discharged.

Numerous other objects and advantages of the invention will be apparent from a study of the following description which taken in connection with the accompanying drawings, discloses sev- 'eral preferred embodiments.

In the drawings:

' Fig. 1 is a side elevation of a coating apparatus embodying the present invention;

' Fig. 2 is an end view thereof from theleft side of Fig. 1; r

Fig. 3 is atransverse vertical sectional view taken substantially along the lines 3'3' of Fig. 2;

Fig. 4 is a view mainly in section of a governing device for controlling the flow of air to an air motor driving the revolving nomle;

v nozzle of the spray device; and

Fig. 5 is a side elevation with parts broken away of an apparatus embodying the invention in which a different type of drive is used to revolve the nozzle;

Fig. 6 is a left shown in Fig. 5:

Fig. Us a side elevation of an apparatus embodying the invention in which a third type of revolving mechanism is utilized with the forward end of the nozzle being broken-away;

end view of the embodiment Fig. 8 is a left end view ofthe embodiment shown inl 'lg. 7; I

Fig. 9 is a sectional view showing details of the Fig. 10 is a plan view with parts broken away of'an apparatus embodying the invention having two spray guns, males of which are rotated by means of a single belt.

Referring particularly to Fig. 1, the article to be coated on the inside is a shell designated by the numeral I; a supporting means 2 may either be in a fixed position or it may be carried by or be a part of a .conveyer. The apparatus itself includes a supporting base 3 and an upright supporting structure 4. Rigidly fastened to the structure is platform 5 which has two parallel sections, one on either side with considerable space between them. Reciprocating table 8, upon which the spray device I is supported, is guided in channels 8 between the inside edges of the sections of platform 5 and 'gib members 9. The gibs are secured to the platform by studs l0.

On the base 3 is mounted an electric motor Ii, which, through belt connection l2 and a gear transmission box 13, drives a chain I 4 between a sprocket on a shaft of the transmission box and an idler sprocket mounted near the other end of the structure. Fastened to the chain It is a connecting rod l5 which has a connection through a stud IS with the bottom of the table 6 whereby the table is given a reciprocating motion and the spray nozzle I! is moved in and out of the cavity of shell l.

In the embodiment shown in Fig. 1, the nozzle I1 is revolved by means of an air motor I! through which the outer air tube 19 extends from spray gun I to the nozzle II.

The spray gun is an automatic type operated by an air piston, a. gun design which is well known in the art and forthat reasonis not shown here in greater detail. It has a hose 20 for supplying the liquid coating material and air hose 2| for supplying air for atomization. In the Particular embodiment of this invention shown in Fig. 1, part of the atomization air is utilized for driving the air motor ii. A third hose 22 supplies air for actuating the air piston which controls the liquid discharge valve. -Deta'ils of the driving connection between the air motor and the nozzle are shown in Fig. 3. g

The body of the air motor is rigidly supported between upright members 23 which are fastened to the table 8 by studs it. The air motor It has a cylindrical casing 25 which is held between the 56 end plates of the motor by bolts or studs which nicates with the air chamber 29 at the forward I end of the gun body.

Through member 30 the gun is connected to the air motor and supported with it by upright members 23. The tube l9 revolves in bearing 3 I. Lubricant filler openings are indicated at 32.

There is provided a dust cap 33 protecting the outer one of the bearings 31. It may be noted that the only rotating parts are the rotor 26 with its vanes 21, the air tube IS with the inner sections of th bearings 3|, and the discharge nozzle 11 carried by tube l9.

Between the inner end of the tube l9 and the surrounding part 30 is a seal 34. The spray liquid tube 35 is connected with the liquid passage of the spraygun through part 36.

The tube 35 carries a liquid discharge tip 38 at its forward end within the discharge nozzle I1 as shown in Fig. 9. The fluid needle valve 31, the movement of which is controlled by the air piston in the spray gun, when in its normal closed position seats in the liquid tip .38, preventing the flow therefrom of any of the liquid coating material. To keep the liquid tip 38 centered within the nozzle IT, a bearing 39 is located between the tubes 35 and I9 as close as possible to the discharge nozzle l1. The bearing must be ported laterally so as not to restrict the flow of air through the tube l9.

In Fig. 4 is illustrated a speed controlled air valve which may be used to govern the revolving speed of the nozzle. In this case an air suppiy independent of the spray gun is preferable. As shown this may be supplied through tube 40. A governor of standard design, indicated at 4|, mounted on and secured to the revolving tube is by a collar Me. A second collar 42 is free to slide longitudinally upon the tube Hi. This collar carries a valve, which when drawn to the left by an excessive speed of the tube 19, shuts off the air supply. After passing this valve, when it is in open position, the air goes through chamber 43 and connection 44 to operate the air motor l8.

By control of the piston air reaching the gun through hose 22, the discharge of the material from nozzle I1 may be synchronized with the movement of the nozzle into and from the cavity of shell I. It is found to be desirable to have the nozzle discharge during its withdrawal movement instead of while it is entering such a cavity. For this work the spray device can have a nozzle that sprays either directly forwardly in a cone pattern, or one that has an angular discharge. In either case the revolving movement results in a more uniform deposit of the coating upon the surface.

In Figs. 5 and 6 a modification is illustrated in which an electric motor is utilized to drivev the revolving nozzle, instead of an air motor as shown in the previous figures. It is believed that less trouble would be encountered with such a drive. The same means for reciprocating the table is utilized. As shown the electric motor may be supported on an upright member 45 which would replace one of the members 23 utilized in the embodiment in Fig. 1.

Bearings for the tube is are held by members 23 and 45. In this case the spray gun I is connected to and supported by upright 45. A V- pulley 46 is mounted directly on the tube It and is driven by belt 41 from driving pulley 43 mounted on the shaft of the electric motor 49.

A preferred embodiment of the invention is illustrated in Figs. 7 and 8. This is simpler than the other forms in that the same electric motor reciprocates the table and also provides the power for revolving the nozzle. A gear box 50, somewhat similar to that utilized in the other embodiments, is driven by motor II through pulleys 62 and 53. Through a similar chain, sprocket. and connecting rod arrangement the table in this embodiment is reciprocated as in the other embodiments. Instead, however, of sliding on flat surfaces, this table 44 is supported on rollers 56 extending inwardly from the inner side edges of the platform sections 51. Side and upward thrust of the table is prevented by the guidance of V rollers 53 which are on bearings supported by blocks 59.

As in the embodiment shown in Fig. 5, pulley 46 is fastened directly to the tube IS. A belt 41 drives this pulley through its riding contact over the roller-like pulley 60 which is an extension of the V pulley 53. The other end of this pulley 60 is supported in bearing member 6| on the other end of the base 3. The nozzle revolving speed is so high compared to its reciprocating speed that it has beenfound that belt 41 will travel along pulley 60 following the reciprocation movement of the spray device without difliculty.

The lengthwise central opening in the platform 51 provides space for belt 41 to pass on either side of the chain l4.

An idler sprocket for the chain is not shown in this view. It could either be supported from the base as was done in the other embodiments or be supported by table 51. In either ,case, of course, the support means must be located beyond the limit of the forward travel of belt 41 as otherwise it would be transverse the path of the belt.

The apparatus shown in Figure 10 has two revolving tubes IQ for coating the interior of two articles simultaneously. As indicated, these may be mounted side by side and on supports 23, and each have a driving pulley 46 mounted upon it as in the modification shown in Figs. 7 and 8. In this case, however, the belt 41 passes across both pulleys before returning to the driving pulley 44.-

Where a double arrangement like this is used, a wider reciprocating table 55 would have to be provided.

While this invention is designed primarily for treating articles that are brought to a fixed position, it also could be adapted for coating articles that are moving on a conveyer. In that case means would be provided for moving the spray device with the conveyer. This might be a platform on rollers which would follow the conveyor just long enough for the spray device to do its work and be moved back to start traveling again in synchronism with the conveyer for treatment of the succeeding article.

As many variations in the invention may suggest themselves to those skilled in the -art, without departing from the spirit of the following claims, it should be understood that this invention is not limited to any specific construction arrangement or form of parts.

What is claimed is:

1. In an apparatus of the type described, a spray gun, a reciprocable mounting for the spray gun, actuating means for reciprocating the spray gun on the mounting, a rotatable nomle on the spray gun, a pulley mounted on the nozzle, and a power driven belt running over the pulley acting to rotate the nozzle while the spray gun is being moved.

2. In an apparatus of the type described, a spray coating device, a slidable supporting table for the spray device, motivating means including a connecting rod for reciprocating the table, a rotatable nozzle on the spray device, and driving means traveling with the table for rotating the nomle.

3. In a coating'apparatus, a spray device, an extension nozzle therefor, a relatively stationary liquid tube within the extension nozzle, an outer rotatable air tube forming the principal outside portion of the extension nomle, a spray discharge tip on the outer end of the air tube, a bearing between the liquid tube and the air tube near their outer ends, and rotating means for the air tube having driving connection with it near its inner end.

4. In a coating apparatus, a spray device, a reciprocable mounting therefor, a rotatable nozzle on the spray device, a pulley associated with the noule, a belt over the pulley for rotating the nozzle, and a driving pulley for the belt supported in a stationary position relative to the reciprocable mounting and having an elongated cylindrical belt contacting surface over which the belt -may ride laterally in following the movement of the reciprocable mounting.

5. In a coating apparatus, a spray device, a reciprocable mounting therefor, associated sprockets positioned-below the mounting, a motor-driven chain running over the sprockets, a connecting rod, the rod connecting the chain and the mounting to give the latter reciprocable motion, a rotatable nozzle on the spray device, a pulley associated with the nozzle, a belt over the pulley for rotating the nozzle, and a driving pulley for the belt supported in a stationary position relative to the reciprocable mounting and having an elongated cylindrical belt contacting surface over which the belt may ride laterally in following the movement of the reciprocable mounting, the diameter of one of the belt pulleys being sufficiently large to permit the belt to travel on either side of the chain.

6. In a coating apparatus, a spray device, a reciprocable mounting therefor, associated sprockets positioned below the mounting, a motordriven chain running over the sprockets, a connecting rod, the rod connecting the chain and the mounting to give the latter reciprocable motion, a rotatable nomle on the spray device, a pulley associated with the nozzle, a belt over the pulley for rotating the nozzle, and a driving pulley for the belt supported in a stationary position relative to the reciprocable mounting and having an elongated cylindrical belt contactin surface over which the belt may ride laterally in following the movement of the reciprooable mounting, the total of the diameters of the belt pulleys being suihciently larger than that of the sprockets to permit the belt to travel on either side of the chain.

FRANK A. BAILEY. GODFREY A. MIILER.

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