US2403994A

US2403994A - Spraying machine

Info

Publication number: US2403994A
Application number: US540927A
Authority: US
Inventors: Horace J Paynter
Original assignee: American Can Co
Current assignee: Primerica Inc
Priority date: 1944-06-19
Filing date: 1944-06-19
Publication date: 1946-07-16
Anticipated expiration: 1963-07-16

Description

July 16, 1946. 4H. J. PAYNTERv SPRAYING MACHINE 5 Sheets-Sheet 1 Filed June 19, 1944 %W\ \\\\\\\\\\\\\\M\\MM\\\\\\\\\\\ \\\\\\\\\\\l\ w E w NYM w. N -l /Q Q QN m N S O O mm M\ io NIT mw mmm Q Q l INVENTo-R July 16, `1946. H. J. PAYNTER 2,403,994

SPRAYING MACHINE Filed June 19, 1944 5 sheets-sheet 2 IN VEN TOR.

@f5/bam@ A T Toe/Q5 x5 July 16,1946. H. J. PAYNTER SPRAYING MACHINE 5 Sheets-Sheet 3 Filed June 19, 19451j H. J; PAYNTER i 2,403,994

SPRAYING MACHINE July 16, 1946.

' 5 Sheets-Sheet 5 Filed June 19,

.llllllllfl JTTOE/YE'YS Patented July 16, 1946 2,403,994 n SPRAYING MAcHiNE Horace J. Paynter, Union, N. J., assignor to American CanCompany, New York, N. Y.,

corporation of New Jersey Application June 19, 1944, Serial No. 540,927

Claims.

This invention relates to a machine for spra ing surfaces of articles with a coating material and has particular reference to varying the quantity of coating material in the spray in accordance with a variation in the distance between the point of discharge and the surface being sprayed to provide an even coating of the material on such surface.

In the spray coating of articles, the spray gun used and the article being sprayed usually are moved relative to each other. When spray coating irregular shaped articles according to usual methods, portions of the article which are spaced farther away from the spray gun receive a thinner coating of the sprayed material than do portions closer to the gun. This results in uneven coating which in most instances is undesirable.

The present invention contemplates overcoming such difficulties by regulating the discharge from the gun in d1rect proportion to the distance of the sprayed surface from the point of discharge to control the quantity of coating material sprayed upon the surface.

An object of the invention is the provision of a machine for spraying surfaces with a coating material wherein the quantity of coating material discharged from the spraying devices for application onto the surfaces is controlled in accordance with the distance between the surface being sprayed and the spraying devices so that a lm of coating material of uniform thickness will be applied to all surfaces being sprayed.

Another object is the provision in such a machine cf devices for effecting relative movement between an irregular shaped article to be sprayed and a spray gun having an orifice controlled by a needle valve wherein the needle valve is operated in time with the movement and in accord'- ance with the distance between the gun and the varying surfaces of the article to insure the application to the surfaces of a film of coating material of uniform thickness.

Another object is the provision in a machine of this character of a valve controlled spray gun which is rotatable and insertableinto an article of irregular contour while the article is held stationary for spraying the inside surface of the article while varying the quantity of coating material discharged from the gun in accordance with the contour of the article so that a lm of coating material of uniform thickness maybe applied to the surfaces.

Another object is the provision in such a machine of control devices for the valve in the spray gun wherein quick opening, sensitive regulation,

and sharp cut-off of the the gun is rotating.

Numerous other objects and advantages of the invention will be apparent as it is better understoodfrom the following description, which, taken in connection With the accompanying drawings, discloses a preferred embodiment thereof.

Referring to thedrawings:

Figure 1 is a longitudinal sectional view of principal parts of a spraying machine embodying the present invention withv parts broken away and showing a spray gun in position prior to insertion into a can body;

Fig. 2 is a rear elevation of the machine shown in Fig'. 1, with partsbroken away;

Fig. 3 is an enlarged view similar to Fig, l showing the spray gun in spraying position Within the can body;

Figs; 4 and 5 are transverse sectional views valve may be had while taken substantially along the lines 4-4 and 5-5 in Fig. 1;

Fig. 6 is a perspective detail of parts shown in Fig. 3;

Figs. 7 and 8 are transverse sectional views taken substantially along the lines 1 1, 8-8 in Fig. 3; and

Fig. 9 is an end View of a rectangular can body indicating. diagrammatically several positions of the spray projected against the inside surface of the body as an incident to spray coating such a surface.

As a preferred embodiment of the instan-t invention the drawings illustrate a machine for spraying a uniform lrn of coating material onto the inside surfaces of oblong rectangular sheet metal can bodies. However,. the invention is equally well adapted' to spraying outer as well as other inner surfaces and to other articles having curved, irregular, or plane surfaces and a more or" a less elaborate machine can be used while fulfilling the same principles of invention.

In the instant machine the can bodies, indicated by the letter A,A are carried in a. horizontal positionfthroug'h a vertically disposed circular path of travel which extends through a spraying station' X (Figs. 1 and'2). The bodies are advanced in an intermittent or step-by-step man ner and come to rest individually at the spraying station for the spraying operation. While at the spraying station, a continuously rotating horizontally disposed spray gun B then in line with the middle of the can body at rest in the station, moves into and out of the body and sprays its interior' walls. Such a gun has a discharge nozzle arranged to direct a single spray against a side wall of the body. During this spraying operation the quantity of coating material discharged from the nozzle is controlled in accordance with the distance between the nozzle and the wall being sprayed, It is this controlled operation of the spray that results in the uniform application of the coating material. u

In the instant case where the can body has an oblong rectangular cross section, as best shown in'Fig. 9, the distance between the parts of the surface being sprayed and the nozzle varies as the spray gun rotates within the body. The far` ther away the surface is from the nozzle, the

greater will be the area of wall spacecovered by the spray from the nozzle and accordingly the less dense the spray will be. The diagrammatic showing of dierent locations of the spray stream in Fig. 9 graphically indicates this. With a constant spray as used in conventional practices, a thinner film of coating material will be applied to the more distant surface parts of the body since the spray stream is spread out over a greater surface.

In the instant invention this Variation in distance is utilized for controlling the nozzle discharge so that an increased quantity of coating material will be ejected from the nozzle as the distance between the nozzle and the area sprayed increases. In this manner a uniform film of even thickness of the coating material is applied to the body surface regardless of the contour of the body being sprayed.

Reference'will now be had to a more detailed description of the machine and its operation. Movement of the can bodies A through a circular path of travel toward and away from the spraying station is effected by a rotatable carrier turret 2| (Figs. 1, 3 and '1) having a plurality of pockets 22 which are spaced aroundthe periphery of the turret and in which the can bodies are carried. The bodies are deposited in the turret pockets and are ejected therefrom in any suitable manner.

The carrier turret 2| is mounted on the outer end of a horizontal turret shaft 23 (see also Fig. 2) which is carried in a pair of spaced

bearings

24, 25 formed in brackets 26 which extend up from opposite ends of a frame 21. This latter constitutes the main frame of the machine.

The turret shaft 23 and the turret 2| carried thereon are intermittently rotated by a conventional indexing device located at the end of 'the machine opposite the turret. The indexing device includes a Geneva wheel 28 (see also Fig. 5) and a cooperating Geneva actuating arm 29. The Geneva wheel is mounted on the turret shaft 23. The Geneva arm 29 is secured to one end of a drive shaft 3| journaled in spaced bearings 32, 33 (Fig. 1) formed in the main frame of the machine. The ydrive shaft may be driven from an outside source of power in any suitable manner, as for example through a gear 34 -mounted on the outer end of the shaft.

The spray gun B at the spraying station X of the machine is disposed in a horizontal position in line withvthe middleof a can body brought to rest at this station by the turret 2|. The gun at all times is parallel to the turret shaft 23. The gun in general is cylindrical in shape and vis mounted for rotation in a pair of longitudinally spaced split bearings 4| 42 formed in a horizontal slide bracket 45 (Figs. 1, 3 and 4). The slide bracket is formed with slide tongues 46 (see also Fig. 5) which operate in longitudinal slideways i1 in the main frame 21.

viding a. single outlet.

Rotation of the spray gun B is brought about by a spur gear 5| (Figs. 1 and 3) which surrounds the gun and which is keyed in place on the gun. This gear meshes with and is driven by a. gear 52 which is formed integrally with a wide driving gear 53 constituting a composite gear unit. This lcomposite gear unit is mounted loosely on the 'turret shaft 23 between a pair of retaining bearings 55, 56 formed on the slide bracket 45. The retaining `bearings provide support for` the turret shaft intermediate its main .

bearings

24, 25 and also retain the composite gear unit in place within the slide when the latter moves, as` will be hereinafter explained. The composite gear unit is .continuously rotated by a main driving gear 51 carried on the inner en-d of the drive shaft 3|.

The spray gun B is shifted into and out of the can body A for the spraying operation by movement of the slide bracket 45 along its slideways 41 while the body is at rest at the .spraying station. This movement of the slide bracket is brought about by cam action. For this purpose the slide bracket carries a cam roller 6| which operates in a cam groove 62 formed in a barrel cam 63 mounted on and continuously rotated by the drive shaft 3|. The cam shifts the slide bracket and the spray gun carried thereon when the carrier turret 2| is at rest.

Referring now to the details of the spray gun itself it will be observed that it is made up primarily of an outer cylindrical shell 65 (Figs. 3

rand 1) and an inner tube member 66 concentri- 4cally disposed within the shell and in spaced relation. This construction sets olf an annular air passageway 61 therebetween. The outer ends .of the shell and the tube member, i. e., the end adjacent theturret 2|, are secured in a, nozzle head 68. The nozzle head is formed with a, tapered valve seat embodied in Aa needle valve 1| which is located at the horizontal center of the tube member 66.

-l-Iead 68is formed with an L-shaped channel 12 adjacent to and on one side of the valve seat. The horizontal leg of the channel communicates lwith the annular air passageway 61 while the vertical leg of the channel terminates adjacent -the outer end of the tapered Valve seat and is disposed at right angles to the valve thus pro- The inner or opposite end of the shell 65 carries a stuffing box nut 15 which surrounds the tube member 66 and which holds a tapered sealing gasket 1G in place between the shell and the tube member. This seals the inner end of the passageway 61.

Compressed air is introduced into the air passageway 51 by way of a pipe 8| which leads from any suitable source of compressed air. The gun end of the pipe is threadedly connected into the upper half of the split bearing 42 and communicates with a recess 62 formed in the bearing. A port 83 in the gun shell 65 constitutes a connection from the bearing recess to the air passageway 61 and directs now of air from the recess into the passageway as the gun rotates.

A flexible ring stufn-g box device 64 is located in theV bearing recess 82 and surrounds the outer shell 65 of the gun. This prevents leakage of air pastthe bearing. The stuiiing box device is held in place by a collar nut 85 threadedly engaged in one end of the bearing 42.

Compressed air introduced into the circular air passageway 61 flows along the length of the gun and into the L-shaped channel 12 in the nozzle head 68. The air continually discharges from the outlet end of the channel in a single jet issuing in a cam groove |67 of a face cam |68 formed in the outer end of the slide bracket barrel cam 63. The timing of the face cam |68 is thus tied-in with the rotation of the barrel cam 63 and with the reciprocationof the slide bracket 45.

Hence on a forward stroke of the slide bracket 45 to insert the spray gun B into the can body A to be sprayed, the face cam |68 rocks the cam lever |55 and the arm |62 and thus lifts the foot |58 formed thereon. These parts remain in this position during the entire spraying operation. This lifting of the foot through the actuating roller |57 thus rocks the bell crank |53 in a clockwise direction (Fig. 3). This movement of the bell crank draws the plunger |45 outwardly and shifts the valve actuating sleeve outwardly through the yielding action of the spring |45.

The yielding action of the compression spring |46 compensates for any overthrow 0f the face cam |68 and permits full operation of the cam |68 even after the movement of the sleeve in its bearing H2 is arrested by the stopy screw |4l. This yielding feature permits of accurate adjustment for the amount of initial opening of the needle valve by utilizing the stop screw to regulate the travel of the sleeve.

The sleeve movement affects the movement of the valve rod Si to open the valve by the cam roller |36 moving with the sleeve, This roller presses against the valve control cam surface |35 on the rotating flange of the valve stem |0|. Movement is toward the right asin Fig 3. Spring |3| is compressed and the rotating disc H8 is pressed tightly against lthe stationary stop plate |2 The longitudinal movement imparted to the valve rod Eil withdraws the valve face Q6 from its seat and thus opens the discharge valve 1|. The coating material under pressure within the tube member 86 thus discharges from the valve.

The air issuing from the outlet end of the channel l2 adjacent the valve 1| blows the discharging coating material into a spray of finely divided particles and projects it at right angles to the nozzle and against the inside surface of the can body A. This spray continues while the gun moves forward (toward the left as in Fig. 3) into and through the body and also while the gun moves back in a return stroke. Thus the entire inner surface is covered with a lm of the coating material.

As the nozzle leaves the edge of the sprayed can body, on the return stroke of the gun, the valve il is immediately closed to prevent waste of coating material. This is brought about by a reverse Shifting of the actuating sleeve which now moves toward the left, as viewed in Fig. 3. This is brought about by lowering of the foot |58 which first relieves the pressure on the spring |45 whereupon the sleeve is free to move. The spring |3| now becomes thi prime mover and forces the valve rod 97 forward (left) first reseating the valve face 36. This closes the valve.

The description of the opening and closing of the discharge valve up to the present time has not included the further control of the discharge valve 'H to insure the discharge of the coating material in carefully measured amounts in accordance with the distance intervening between the nozzle head 68 and the wall of the can body being sprayed. This additional partial opening and closing of the discharge valve is brought about by cam surface |35 on the rotating fiange ||5 of the valve rod stem |01 operating over the roller |36 then rotating on a stationary axis.

This cam surface is shaped in accordance with the contour of the can body being sprayed, i. e., in accordance with the distance the spray stream must travel at any moment during the guns rotation.

Since the control cam is formed as a part of the valve rod and rotates with the spray gun it is always in time with the single jet of spray issuing from the gun nozzle and this insures accurate registration of the parts involved in spraying the irregular surface of the body. It is this control cam that insures the application to the inner surface of the can body, of a lm of coating material having a uniform thickness extending over the entire surface sprayed, as hereinbefore explained.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing al1 of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

l. In a machine for spraying a coating material on a surface, the combination of an elongated spray gun having a discharge orifice, said gun being rotatable on its longitudinal axis, the surface sprayed being stationary and said gun having longitudinal movement relative to said surface at different distances throughout a spraying operation, a valve rod located in said gun for controlling the effective size of said orifice, means mounted adjacent said gun for moving said valve rod in opposite directions respectively to open and close said orifice, and means operating adjacent said gun in accordance with the relative distances between the gun and the surface 'being sprayed for altering the position of said valve rod when said orifice is open to vary the size of said orifice and thus control the quantity of coating material passing through said orifice to insure a coating of even thickness on the said surface.

2. In a machine for spraying a coating material on the surface of an irregular shaped tubular article, the combination of an elongated spray gun having a discharge orifice, said gun being rotatable on its longitudinal axis, the tubular article being stationary While being sprayed and said gun being longitudinally movable relative to said article being sprayed at different distances from the gun, a valve rod located in said gun for rcontrolling the effective size of said orifice, means mounted adjacent said gun for moving said valve rod in opposite directions respectively to open and close said orifice, and devices disposed adjacent said gun and having a shape corresponding to the contour of the article surface being sprayed and operating in accordance with the relative distances between the gun and the surface being sprayed for altering the position of said valve rod when the orifice is open to control the quantity of coating material passing therethrough t0 insure a coating of uniform thickness on the said article.

3. In a machine for spraying a coating material on the interior surface of an irregular shaped tubular can body, the combination of an elongated spray gun having an orifice for discharging a coating material and an air orifice for ejecting a blast of air at an angle to said discharge orifice for spraying the discharged coating material laterally of said gun onto said can body While the 9T latter is stationary, said gun being movable into said can body and having rotation on its longitudinal axis throughout a spraying operation, a valve rod located in said gun for controlling the effective size of said orifice, `means mounted adjacent said gun for moving said valve rod to open and close said orifice, and devices connecting with said valve rod and rotatable with said gun and operating in accordance with the distance between the gun and that portion of the surface of the can body being sprayed for altering the size of said orifice to controlv the quantity of coating material discharging therefrom, whereby a uniform thickness of coating material is applied to the interior surface of the can body irrespective of the varying distances of the sprayed surfaces of the can body from said spray gun orifice.

4. In a machine for spraying a coating material on the interior surface of an irregular shaped tubular can body, the combination of an elongated spray gun having a discharge orifice, said gun being rotatable on its longitudinal axis and longitudinal movement into and out of the can body while the latter is held stationary for a spraying operation, a valve rod located in said gun for controlling discharge of coating material from said orifice, means disposed adjacent said gun for closing said valve rod against said orifice, a cam located adjacent said gun and rotatable therewith, said cam having a surface contour which is variable in accordance with the relative distances between the said orifice and the can body surface for preventing the operation of said valve closing means and for changing the position of said valve rod to vary the quantity of coating material discharging from said orifice so as to provide an even thickness of coating on said can body surface, and means for rendering said cam ineffective when said valve closing means becomes effective.

5. In a machine for spraying a coating material on the interior surface of an irregular shaped tubular can body, the combination of an indexing turret for advancing a can body through the machine and for holding the body in a stationary Aposition during a spraying operation, a slide having reciprocal movement adjacentsaid turret, a rotatable spray gun carried on said slide and having a discharge orifice, said gun being movable by said slide longitudinally of said held can body for spraying the interior surface thereof, avalve rod located in said gun for controlling the effective size of said oriiice, means mounted on said slide for moving said valve rod to open and close said orifice, and devices carried by said slide and having independent movement thereon in accordance with the distance between the gun and that portion of the interior surface of the held can body being sprayed for further moving said valve rod after the orifice has been opened for altering the size of said orifice to control the quantity of spraying niateriai discharging therefrom to provide an even thickness coating on the interior surface of the can body.

6. In a machine for spraying a coating material on the interior surface of an irregular shaped tubular can body, the combination of a support for holding a can body stationary during a sprayn ing operation, a slide having reciprocal movement adjacent said support, a sleeve carried on said slide and movable thereon, a rotatable spray gun carried on said slide and having a discharge oririce, said gun being movable by the slide longitudinally into the held can body for spraying the 10 interior surface thereof, a valve rod located in said gun for controlling the effective size of said orifice, means for shifting the ,sleeve independently of the slide to move said valve rod to open and close said orifice, and devices carried by said sleeve and operable in accordance with the distance between the gun and that portion of the interior surface of the stationary can body being sprayed for shifting the valve rod after the orifice is open for altering the size of said orifice to control the quantity of spraying material discharging therefrom to -provide an even thickness coating on the interior surface of the can body.

7. In a machine for spraying a coating material on the interior surface of an irregular shaped tubular can body, the combination of an intermittently rotatable support for holding a can body stationary during a spraying operation, an elongated rotatable spray gun having a discharge orifice and being movable longitudinally of its axis into the stationary can body for spraying the interior surface thereof, an elongated valve rod located in said gun and rotatable therewith on ieir longitudinal axes and for controlling the effective size of said orifice, a spring carried by said valve rod for moving the same to close said orifice, and a cam carried by said valve rod and rotatable therewith said cam having a surface of irregular contour for variably overcoming the action of said spring to alter the size of said orifice and thus regulate the quantity of spraying material discharging therefrom, the irregular contour of said cam surface constituting an increment of the distance between the gun and that portion of the interior surface of the can body being sprayed to provide an even thickness coating for the interior surface of the can body.

8. In a machine for spraying a coating material on the interior surface of an irregular shaped can body, the combination of an intermittently rotatable support for said can body, an elongated spray gun having a discharge orifice for spraying the interior surface of a can body while temporarily held stationary on said support, means for rotating said spray gun on its longitudinal axis, means connected with said rotating means for longitudinally reciprocating said gun into and out of said stationary can body during the spraying operation, a valve rod carried by and operated in said gun for controlling the effective size of said orifice, and devices actuated by said rotating means for longitudinally moving the valve rod to alter the size of said orifice and thereby vary the quantity of spraying material discharging therefrom to apply an even thickness coating to the interior surface of the can body, said variation of spraying material being dependent upon the distance between the gun and that portion of the interior surface of the can body being sprayed.

9. In a machine for spraying a coating material on the interior surface of an irregular shaped can body, the combination of a turret for presenting can bodies for a spraying operation, a spray gun having a discharge orifice, a valve rod carried by and operated in said gun for controlling the effective size of said orice, means for moving said turret intermittently and for holding a can body stationary, means for reciprocating said spray gun to move its discharge orifice into said stationary can for spraying, means for continuously rotating said spray gun to pass said discharge orifice along the interior surface of the irregular shaped can body, and devices for actuating the said valve rod in accordance with the distance between the gun and that portion of the interior surface of the can body being sprayed to regulate the quantity of spraying material discharged from said orifice to insure an even thickness coating on the interior surface of the can body.

l0. In a machine for spraying a coating material on the interior surface of an irregular shaped tubular can body, the combination of an intermittently rotatable turret for successively presenting can bodies for a spraying operation, a rotatable spray gun having a discharge nozzle, said gun being movable longitudinally into a stationary can body for spraying the interior surface thereof, means for intermittently rotating said turret for temporarily holding stationary a can 12 body to be sprayed, a valve rod movable Within said gun for controlling discharge of coating material from said orifice, a cam located adjacent said gun and having rotation therewith, said cam having a cam surface constituting an increment of the shape of said can body, a sleeve movable with and relative to said gun and enclosing said cam, an adjustable stop for limiting said sleeve movement, and means carried by said sleeve for engaging said cam surface to alter the position of said valve rod to vary the quantity of coating material discharging therefrom, whereby an even thickness coating is applied to the said surface.

HORACE J. PAYN'IER.