US2728322A - Ventilation system for automatic spraying machines - Google Patents

Description

es. 2?, 1955 5zz p Ns 2,728,322

VENTILATION SYSTEM FOR AUTOMATIC SPRAYING MACHINES Filed Feb. 15, 1952 4 Sheets-Sheet l INVENTOR. Ho/r r Szczepansh ,AZQAMK/Z Dec. 27, 1955 H. SZCZEPANSKI VENTILATION SYSTEM FOR AUTOMATIC SPRAYING MACHINES 4 Sheets-Sheet 2 Filed Feb. 15. 1952 INVENTOR. zepo'nsk/ Dec. 27, 1955 H. SZCZEPANSKI 2,728,322

VENTILATION SYSTEM FOR AUTOMATIC SPRAYING MACHINES Filed Feb. 15. 1952 4 SheetsSheet 3 INVENTOR.

Af/omez Dec. 27, 1955 H. SZCZEPANSKI 2,

VENTILATION SYSTEM FOR AUTOMATIC SPRAYING MACHINES Filed Feb. 15. 1952 4 Sheets-Sheet 4 LU BRICATOR INVEN TOR.

Horr Szcze ans/0' T Affornez VENTILATION SYSTEM FOR AUTOMATIC SPRAYING MACHINES Harry Szczepanski, Grand Rapids, Mich. Application February 15, 1952, Serial No. 271,741 6 Claims. (8. 118--326) The present invention relates to spraying machines, and particularly to ventilating systems associated therewith. This application is a continuation-in-part of my application Serial Number 137,390, filed January 7, 1950, now Patent Number 2,695,592. Preferably, this invention is used in conjunction with an automatic spraying machine adapted for the use of masks. A mask is similar to a stencil, and covers a portion of the workpiece that is not to receive paint. An opening is provided in the housing of the machine of such dimensions as to receive the mask, and articles to be painted are placed against it. With this arrangement, the mask in effect becomes a part of the housing, and paint is sprayed against it from the inside.

Practical considerations make it preferable to place work against the mask in a downward direction. Since it is preferable to project spray against the opposite side of the mask in a direction substantially perpendicular thereto, this orientation results in placing the spray guns underneath the mask with the spray directed upwardly. Droplets of wet paint have a tendency to accumulate on the mask, and to drop from it back onto thespraying equipment. It has been found possible to at least minimize this chest by tilting the plane of the mask from the horizontal a sufiicient amount so that the point or" the accumulation of the droplets of paint will be sufficiently offset from a vertical projection above the spraying equipment so that the paint will fall clear of the guns.

A ventilation system is also provided by the present invention in which a stream is established flowing preferably downward across the mask in a direction substantially perpendicular to the spray. The duct is so arranged as to receive most of the droplets that progressively accumulate on the mask, with the direction of normal free fall of the droplets substantially coincident with the direction of the flow in the ventilation duct. Dispersal of the droplets in the ventilation stream is accomplished by this arrangement, and the accumulation of them at any particular point is avoided. It may be noted that it is a great deal easier to clean removable portions of the ventilation duct than it is 'to laboriously remove the thicker accumulations of paint from the irregular contours of the spraying equipment. Dispersal of the paint throughout the ventilation duct makes the layers accumulated on the walls of sufficient thinness to be easily removable with suitable solvents.

The several features of the present invention will be discussed in detail through an analysis on the particular embodiments illustrated in the accompanying drawings. In these drawings,

Figure 1 is a perspective view showing the exterior of an automatic spraying machine embodying the present invention.

Figure 2 is a rear elevation of the portion of the machine in which the spraying apparatus is located.

Figure 3 is a section taken on the plane 33 of Figure 2.

States Patent O eliminate 'or present invention, and

on an enlarged scale on the adapted to receive masks of varying descriptions, and it will be noted that the plane of the opening 12 is slanted to the horizontal. When the machine is in use, masks are secured to the housing over the opening 1.2, and spray heads are reciprocated opposite the mask by automatic mechanism to be described herein.

Referring to Figure 3, a set of two parallel guide rods, 13 and 14, are mounted opposite the opening 12. These rods support the sliding spray-gun carrier unit generally designated at 15, which is actuated in a to-and-fro movement by the push-rod 16. The spray- guns 17 and 18 are supported on this mechanism, and project the spray at a mask covering the opening 12.

Referring to Figures 4 and 5, and also to Figure 3, the spray- guns 17 and 18 are provided with integral projecting bosses as indicated at 19 in Figure 3. These bosses are received within the clamps 20 mounted upon the rods 21 and 22. These rods, in turn, are received Within clamps in the oscillating member 23 pivotably.

34 in the carrier 15, and the mechanism previously described results in transmitting force to move the entire carrier assembly by way'of the oscillating member 23.

As indicated in Figure 4, force applied by the push rod 16 to move the carrier assembly to the left will first re sult in a clockwise rotation of the member 23 until the adjustable stop 31 is encountered by the depending arm 26. At the end of the stroke in that direction, a reversal of force (established by mechanism not related to the collected in the first result in applying a counterclockwise rotation to the member 23 until the stop 30 is encountered. This condition is illustrated in Figure 5. This arrangement results in altering the relative angle of the spray and the plane of the mask at each stroke of the spray gun equipment control air (serving as an oif-on control for the spray at the passages indicated, at 37, 38, 39, and 40; Associated with these various passages in the manifold 35 are the .flexible conduitsfl gun), and for gauge pressure Patented Dec. 27, s-v

The spray chamber 10 is'proat 28, and also 32 and 33 respecfor the connection of 41, 42', and 43, each of which lead to a suitable separate manifold on the carrier 15.. From each of the carrier manifolds, lines are connected to suitable points on the spray guns 17 and 18, and the gauge conduit 44 is associated with the carrier manifold in which spraying air pressure is distributed. With this arrangement, the gauge will read the actual pressure operative on the spray guns 17 and 18 without the necessity of allowing for line losses and other variable quantities.

Reference to Figure 4 will illustrate the manner in which the carrier manifolds are built into the carrier itself. The line 43 communicates with the manifold to supply pressure to the conduit 45 machined into the carrier member 15. The flexible lines 46 and 47 also communicate with the conduit 45, and these flexible lines conduct the pressure to the individual spray guns. A similar manifold construction is positioned on the opposite side of the carrier 15 to that shown in Figure 4, and an auxiliary manifold 48 (shown brokenaway in Figure 4) is secured to the central part of the carrier 15 as shown in Figure 3. With the three carrier manifolds available, one is used for paint, one for spray air, and one for needle-control air. The particular manifold which may be selected for any one of these functions is not of great importance. The spray guns 1'7 and 18 are of standard construction, and form no part of the present invention.

The arrangement of the conduits and the control systems associated with the machine is shown in the schematic diagram provided in Figure 6. In this figure, the carrier manifolds are designated generally at 15, with the push rod 16 shown operatively connected thereto. The push rod 16 is associated with the piston and cylinder assembly 49. The piston and cylinder assembly, together with the mechanism shown in Figure 6 upstream from the manifold 35 is preferably disposed within the housing 11 (refer to Figure 1). The various instruments appear on an instrument panel 50 which is conveniently disposed within the visual range of' the operator or maintenance man.

Air is admitted at the point indicated in Figure 6, and passes through a suitable filter into a manifold 51. This manifold acts as a distributing point, and air pressure passes from there into the lines 52, 53, 54, and 55. Pressure regulators as indicated at 56 and 57, respectively, are porvided in the lines 52 and 53, together with suitable gauges associated therewith. An off-on valve 58 is positioned to control the flow of air in line 52 which provides the atomizing air for the spray guns 17 and 18. A similar off-on valve 59 is positioned to control line 53, which supplies air pressure to the cylinder assembly 49 through the lubricator as shown.

The actual control of the spraying system is obtained through the control of the needles of the spray guns 17 and 18. The piston assembly 49 is in continuous reciprocating operation as long as the valve 59 is turned on. Actuation of the cycling mechanism merely operates to energize the spray guns for a selected length of time according to the setting of the timer 60. Line 54 is controlled by the timer 60, and a line connects a foot valve 61 with the timer to energize it in the conventional manner. A charge of air is supplied to the timer 60 at each actuation of the foot valve, and this charge results in opening the line 54 to the needle control for a specified length of time according to the setting of the timer 60.

Referring to Figure 3, the spray projected from the guns 17 and 18 is thrown across a moving stream of air designated generally at 62. It will be noted that the attitude of the guns a sprayed area on the mask covering the opening 12 at such a point that accumulations of wet paintrthereon' spray gun mechanism. The move-- will drop clear of the ment of the stream of air 52 in a downward direction across the opening 12 is such that thesedrops naturallyjoin the stream and 'are'dispersed through the'duct63,

17 and 18 results in establishing and are either carried by the air or impinged on the walls oftheduct- The housinglt) .is preferably formed .withthe various components of the duct 63 easily removable for purposes of cleaning.

Ventilation air enters the duct 63 from an opening 64 in the back 36 of the housing 10, and this opening is preferably covered by a screen 65. A panel 66 forms a part of the conduit 63, and the spray ejected from the nozzles 17 and 18 may be considered as being projected through an opening in the conduit 63 and across the stream 62 contained therein.

The flow of air in the conduit 63 is established by a suction fan (not shown) connected at the outlet 67. The generally rectangular conduit 63 passes through a transition after the point approximately indicated at 68, and becomes circular at the point of connection of the conduit 67.

The velocity of the stream 62 has the general effect of lowering the pressure in that area with respect to the static air in the chamber 69 containing the spray equipment. This condition results in inducing a small flow of air outwardly from the chamber 69 and into the stream 62, which tends to remove vapors from the chamber and also urges the particles of paint into the ventilation stream which may have spattered in a direction toward the spraying equipment. Small vents as indicated at 70 permit inflow into the chamber 69.

These vents need not always be specially formed in the housing. In the ordinary type of sheet-metal construe tion used with such housings, there will be enough leakage at the joints to serve as an adequate vent.

The particular embodiments of the present invention which have been illustrated and discussed herein are for illustrative purposes only and are not to be considered as a limitation upon the scope of the appended claims;

In these claims, it is my intent to claim the entire invention disclosed herein except as I am limited by the prior art.

1 claim:

1. A spraying machine, comprising: housing means having a work-receiving opening disposed in a plane inclined to the horizontal; ventilation duct means establishing a path for the flow of air having substantially all of the stream-lines thereof disposed in vertical planes and passing completely across said opening parallel to the plane thereof and directed downwardly immediately under said opening, said duct means having an aperture in the wall opposite the opening in said frame means; spraying means; and mounting means for said spraying means disposed to position said spraying means to project spray through said aperture in the direction of said the stream-lines thereof disposed in vertical planes and" passing completely across said opening parallel to the plane thereof, said duct means having an aperture in the wall opposite said opening; ing means for said spraying means disposed to position said spraying means to project spray through said aperture in the direction of said opening.

3. A spraying machine, comprising: housing means having a work-receiving opening disposed in a plane in clined to the horizontal; spraying means; and mounting means for said spraying means disposed to position said spraying means to project spray in the direction of said opening along a path inclined from the vertical toward a normal to the plane of said opening by an amount such that the intersection of said path with the plane of said opening is always outside the vertically-projected area of spraying means; and mount-' sition said spraying means to project spray upwardly in the direction of said opening along a pathinclined from the vertical by an amount such that the intersection thereof with the plane of said opening is always outside the vertically-projected area of said spraying means.

5. A spraying machine, comprising: housing means having a mechanism chamber provided with a vent, and also having a work-receiving opening; ventilation duct means establishing a path for the flow of air having substantially all the streamlines thereof passing completely across said opening parallel to the plane thereof, said duct means having an aperture in the wall opposite said opening; spraying means disposed in said mechanism chamber; and mounting means for said spraying means disposed to position said spraying means to project spray through said aperture in the direction of said opening.

6. A spraying machine, comprising: housing means having a work-receiving opening; ventilation duct means establishing a path for the flow of air having substantially all the streamlines thereof passing completely across said opening.

References Cited in the file of this patent UNITED STATES PATENTS 1,608,082 Curren Nov. 23, 1926 1,682,407 Nelson et al. Aug. 28, 1928 1,741,155 Hatch Dec. 31, 1929 2,106,187 Naugler Jan. 25, 1938 2,132,826 Ludwig Oct. 11, 1938 2,227,481 Bates Jan. 7, 1941 2,257,516 Roche et al. Sept. 30, 1941 2,310,205 Bell Feb. 9, 1943 2,350,708 Roselund Jan. 6, 1944 2,486,251 Braun Oct. 25, 1949 2,602,417 Medcalf July 8, 1952

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