US2695592A - Automatic spraying machine - Google Patents

Description

1954 H; SZCZEPANSKI AUTOMATIC SPRAYING MACHINE 3 Sheets-Sheet 1 Filed Jan. 7, 1950 IN V EN TGR.

//AR2Y $2 czzm NSKI BY 4?. i k: A TTOENE Y Nov. 30, 1954 H. SZCZEPANSKI 2,695,592

7 AUTOMATIC SPRAYING MACHINE Filed Jan. '7, 1950 3 Sheets-Sheet 2 INVENTOR. I fi/A/aev .SZCZ'PAIV-SKI ATTORNEY Nov. 30, 1954 H. SZCZEPANSKI 2,695,592

AUTOMATIC SPRAYING MACHINE Filed Jan. 7, 1950 3 Sheets-Sheet 3 IN V EN TOR. #4122 Y S: CZEPAMSK/ 2,695,592 AUTOMATIC SPRAYING MACHINE Harry Szczepanski, Grand Rapids, Mich. Application January 7, 1950, Serial No. 137,390

4 Claims. (Cl. 118-301) The present invention provides an automatic spraying machine. The preferred form of this machine is par ticularly well adapted to the application of paints or lacquers to recessed surfaces, or to flat surfaces covered by a mask or stencil.

It is a considerable problem to apply paint to a surface covered by a mask having one or more islands or sections which are not connected to the principal part of the mask. These areas have to be supported in some way, and it is conventional to provide a bridge of wire or similar material to secure the isolated portion in its proper location. When a spray-gun passes opposite such a section of the mask, there is a tendency for the bridge to shield a part of the area to be painted and to create a thin spot or shadow. Even where masks or their equivalent are not used at all, the painting of molded plastic surfaces renders it necessary to project paint into recesses or on either side of projections, and this operatign is subject to the same difficulties as are outlined a ove. r r The present invention provides a. machine capable of handling the most complex spraying problems with ease and efiiciency. Uniformity is assured, and the necessity of using skilled operators is completely removed since the application of the paint or lacquer is controlled by an entirely automatic sequence of operations. Means are provided for applying paint to recesses and semi-obstructed surfaces in a manner which reduces the waste involved in any of the methods involving manual operations or the projection of random sprays. Essentially, the solution of the problem of applying paint to these surfaces is obtained by providing a spray-gun carrier and an actuating mechanism which not only movesthe guns opposite the area to be painted, but causes the angular attitude of the guns to be altered during transit. The present invention provides an improvement in this general type of mechanism. This variation of angular attitude is a variation with respect to the surface receiving the paint, and of course results in the substantial removal of the effect of interfering surfaces. When bridges" are used with a mask, the variation of gun angle causes the spray to be projected around the structure and assures that a coating of paint is applied to all parts of the surface. When recesses or projections are involved on the painted surface, the variation in angular attitude assures that both the first surface to come opposite the gun and the succeeding edge are equally covered. To geometrically define the required movement of the spray-gun, it may be stated that the plane of at least a component of oscillation is substantially perpendicular to the surface being painted and is parallel to the line of movement of the spray-gun carrier. Preferably, the gun carrier may be provided with a plurality of spray-guns disposed at a lateral angle to generate a fan-type of spray which will have a tremendous covering power when coupled with the oscillating system outlined above.

The preferred; form of attitude-changing mechanism provided by the present invention involves an actuator adapted to move a spray-gun carrier along a particular guiding means. The attachment of the actuator to the carrier also controls the angular attitude of the carrier between suitable limit stops resulting in a characteristic attitude of the spray-guns for each direction of movement of the carrier along the guiding means. This arrangement is accomplished by pivotally mounting a set of gun clamps upon the carrier, and connecting the United States Patent 2,695,592 Patented Nov. 30, 1954 actuator to the carrier at an arm directly associated with the clamp structure. With this arrangement, a force applied by the actuator first causes a rotation about the hinge point which continues until a limit stop is engaged. The force applied than causes movement of the entire carrier until the direction of the application of force is reversed by the actuator.

A modified and slightly more complicated version of the present invention involves the use of a plurality of spray-guns or sets thereof each disposed at a characteristic angle with respect to the carrier and fixed in such position. The air pressure required to operate these guns is supplied thereto through a selector valve adapted to determine which of the sets of spray guns receives air at a given moment. provides the connection between the actuator and the carrier in a similar fashion to the preferred form of the invention described above. With such a system, the force first applied by the actuator causes the movement of the selector valve to a position permitting air to be applied to a particular set of spray-guns. When the limit of movement of the valve is reached, the movement of the carrier begins.

. The preferred form of the associated mechanism used in connection with the system outlined above involves a pneumatic or hydraulic actuator and suitable control valves accessible to the operator. The preferred form of the guiding means used to establish the path of the moving carrier involves a pair of parallel rods with which the carrier cooperates. The carrier may either surround the rods in the manner of a cross-head on a steam engine, or the carrier may be provided with a set of rollers for engagement with the rods if it is desired to minimize the friction involved.

It is definitely preferred to form the machine involving the above noted features in such a manner that the sprays are directed upwardly at an opening which may be covered by a mask, or by a workpiece alone if a mask is not to be used. It will be noted that this arrangement makes it possible for an operator to place a workpiece down upon the painting station in a manner similar to laying an article upon a table. The simplicity of this arrangement over a separate assembly of mask and workpiece is obvious. The mask is preferably semi-permanently attached to the machine opposite the opening, and suitable locating means are provided to establish the desired relative position of mask and workpiece. This general system permits entire concealment of the spray itself and the application of suitable ventilating and ducting systems capable of completely preventing the escape of vapors into the surrounding room.

The present invention also provides features which are very valuable in regard to the ventilation and removal of excess spray. The sprays from the gun are actually projected through a panel or diaphragm which is in spaced and generally parallel relationship with the workpiece. The chamber provided by this panel between it and the workpiece is equipped with suitable ventilation ducts capable of establishing a flow of air across the passage of the spray. The ventilating stream of air also passes across the opening in the diaphragm through which the spray is projected, and it is preferred to provide a pres sure differential in which the pressure in the chamber housing the spray-gun equipment is slightly in excess of the pressure in the ventilating chamber. A small aperture is then provided in the mechanism chamber permitting the inflow of air from the outer atmosphere resulting in a secondary ventilating flow from the mechanism chamber out through the spray aperture which merges with the ventilation flow and prevents the accumulation of particles or droplets of paint in the mechanism chamber and around the guns themselves.

The spray-guns preferably are so mounted with regard to the supply of paint that the normal level of paint without the urging of the air is just at or slightly below the point of ejection. This arrangement prevents the continued flow of the paint after the air is turned off, and also minimizes the amount of lift which the air must applyto the paint before the orifice is reached. This arrangement is of particular value when the spray- The selector valve preferably guns are not provided with a valve for controlling the flow of paint except as induced by the movement of arr.

The various features of the present invention Wlll be discussed in detail by an analysis of the particular embodiments illustrated in the accompanying drawings. in these drawings:

Fig. 1 shows a sectional elevation of a machine embodying the present invention.

Fig. 2 shows a plan View of the machine illustrated in Figure 1.

Fig. 3 shows an end-view section of the mechanism taken on the plane 33 of Figure 1.

Fig. 4 showsan end-view partially in section of a modified form of the spray-gun carrier from that shown in Figure 1 to 3.

Fig. 5 shows an elevation of the mechanism of Figure 4.

Fig. '6 presents a schematic diagram of the relative position of a paint supply system with the spray-guns.

Fig. 7 shows a modified form of the present invention with regard to the variation of spray angle.

Referring to Figures 1, -2, and 3, a machine is shown having a housin 10 surrounding the entirety of the mechanism. An opening 11 is provided at the top of the housing 10 opposite which it is intended that a workpiece or mask shall be placed. The guide rails 12 and 13 are fixed with respect to the housing 10 and establish a path of movement for the spray-gun carrier 14. The spray- guns 15 and 16 are pivotally mounted upon the carrier 14 to rotate about the axis 17. The

spray-guns themselves are supported upon the rods 18 and 19, as "is best indicated in Figure 3. The angular position of the rods 18 and 19 about the axis 17 is determined by the arm 20 attached thereto and extending downwardly through a suitable aperture in the carrier 14. Suitable stops (not shown in Figures 1, 2, and 3) limit the degree 'of rotation permitted to the arm 20, and thus establish the limiting angular attitudes of the spray- guns 15 and 16.

An actuating rod 21 is pivotally connected to the lower extremity of the 'arm 20, and transmits the driving force necessary to move the carrier 14 and to induce the rotation of the spray-gun assembly about theaxis 17. Rod 21 is associated with a piston and cylinder assembly 22 in which a suitable piston is positioned by the action of compressed air admitted at the points 23 or 24. A valve-control rod is indicated at 25, and moves axially with the push rod 21 through attachment at the endplate 26. The movement of the valve actuator 25 carries with it'the plate 27 which co-operates with the stops 28 and 29 attached respectively tothe positioning rods 30 and 31. The positioning rods 30 and '31 are associated withthe valve mechanism generally designated as 32, and determine whether air .is to be admitted to the line 23 or to the line 24. Pressure is supplied to the inlet 33 'ofthe valve mechanism from a line connected to a suitable off-on manually controlled valve (not shown) positioned by the operator of the machine.

Since thepush rod 21 moves along a definite axis, it is obvious that a small degree of lost motion must be provided "in the connection between this rod and the arm 20 which controls the position of the spray-guns, due to the fact that the arm moves along a radius and the point of connection has a small degree of vertical movement even though the angular movement is limited. With the mechanism outlined above, the admission of air to the point 33 will cause the carrier to move in whatever direction is determined "by the setting of the valve mechanism 32 under the action of the positioning rods 30 or 31, rod 25, plate 27, and the stops 28 and 29. As the carrier nears the extremity of its movement, either the stop 28 or 29 will be engaged and further movement of the carrier will cause the valve mechanism to be tripped and permit air to be inserted at the opposite end of the piston to begin the motion of the carrier in the opposite direction. Suitable exhaust circuits under the control'of the valve mechanism 32 are of course provided and are 'not shown in these figures. It will be noted that the amount and the location of the reciprocating path of the carrier 14 may be determined by the location of the stops 28 and 29 upon their associated rods and by varying the position of the plate 27 with respect to the rod 25 by the threaded engagement indicated at 34. The actuating cylinder and associated mechanism are securely supported upon the beam 4 35 rigidly attached at its ends to components of the housing 10.

To assure ventilation and remove the vapors and droplets of paint which remain suspended in the atmosphere after the projection of the spray, a suction duct 36 is preferably attached as shown in Figure 3. Openings to the surrounding atmosphere are provided at 37, 38, 39, 40, and at similar locations not shown on these particular views.

The spray-guns, carrier, and associated mechanism may be considered as being contained within a chamber 41. The sprays are projected from the guns through an aperture 42 in a diaphragm indicated at 43 (refer to Figure 3).

An opening is provided within the mechanism chamber 41 at 44, and the reduction in pressure generated by the suction duct 36 within the chamber defined by the diaphragm 43, the housing 11 and the workpiece or mask opposite the opening 11 draws a small quantity of air in through the hole 44 and thence through the opening 42 in the diaphragm 43 to prevent the accumulation of droplets of paint upon the mechanism. A cross flow of air is generated by the suction duct which tends to remove vapors and small particles of paint which are not deposited upon the mask or the workpiece during the operation of the machine.

When a mechanism is used which does not include a valve stopping the flow of paint instantly upon the interruption of the air pressure, the paint-supply arrangement of Figure 6 is preferred. A supply bottle 45 maintains the container 46 at a constant level due to the fact that the mouth of the bottle 45 is submerged .at which ever level may be desired. This level is established to be approximately at the point of ejection of the sprayguns 15 and 16. Paint is supplied from the container 46 to the guns by means of suitable tubes 47 and 48., and air is supplied to the guns by the similar tubes 49 and 50.

Referring to Figures 4 and 5, a modification of the previously-illustrated carrier mechanism is shown. The difference between the two mechanisms lies in the method of engagement between the carrier and the guide rods 12 and 13. In the modified form of the invention, sets of rollers 51 and 52 are arranged to engage the rods, and the carrier is supported against the action of vertical forces through the engagement of the grooved periphery of these rollers. As in the previous arrangement, the gun-supporting rods 53 and 54 are rotatably supported upon the carrier through being mounted upon a block 55 pivotally mounted upon the shaft '56. The angular position of the guns is limited by the presence of the stops 57 andSS.

Referring to Figure 7, a view is illustrated presenting a modified form of the means for varying the angle of paint spray with respect to the surface being painted. in this arrangement, the spray- guns 58 and 59 are firmly fixed in position upon the carrier '60, and are supplied with paint in a fashion similar to the connections shown in Figure 6. The supply of air, however, is provided through the selector valve mechanism indicated at 61. Suitable conduits 62, 63, connect the output ports of the valve mechanism to the spray-guns. Air pressure is .admitted to the selector valve by means of the flexible conduit 64, and 'the'position of the valve arm to the left or right will indicate which of the spray-guns 58 M59 is'to receive the required air pressure to generate a spray. With this mechanism, the movement of the .carrier .is affected by a pushrod similarto thatillustrated in Figures 1 to 3, the connection being made at the point 66. ltis necessary to either permit some degree of lost motion at this connection or to provide a link'connecting thepoint 66 to the end-of the actuator inorder to accommodate :the smaller degreeof'radial movement of the arm. With this arrangement it will be 'seen that the initial movement-of the actuating rod will first position the'selectorWalve and cause the operationo'f one of the sets of spray-guns '58 or 59. When the appropriate limit stop 67 or 68 is reached, the arm then ceases angular movement and forces are generated causing the carrie'r'60 to move along its associated guide rails.

The particular embodiments of the ,present invention which have been illustrated in the accompanying drawings and described herein-are'for illustrative purposes only and are not to be taken as limitations upon thescopeo'f appended claims. In these claims ibis-the intent-of the inventor to claim the :entire invention to whichhe is entitled in view of the prior art.

I claim:

1. A spraying machine comprising a housing having an opening adapted to receive a mask, nozzle means and nozzle carrier means therefor arranged in said housing, guide means for said carrier means establishing a path of movement for said nozzle means opposite said opening, means to reciprocate said carrier means longitudinally of said guide means, and nozzle controlling means mounted on said carrier means and movable relative thereto in a plane parallel to said guide means and perpendicular to said opening for periodically redirecting spray from said nozzle means, said carrier reciprocating means including actuating means connected to said nozzle controlling means and to said carrier means adapted to apply reciprocating forces parallel to said guide means to shift said nozzle controlling means with and with respect to said carrier means.

2. A spraying machine as set forth in claim 1 wherein means provide a pivotal mounting for said nozzle means on said carrier means, and said nozzle controlling means interconnects said nozzle means and actuating means and imparts periodic angular adjustment to said nozzle means.

3. A spraying machine as set forth in claim 1 wherein said nozzle means includes a plurality of nozzles directed at different angles towards said opening, and said nozzle controlling means includes valve means selectively 1eloniecting certain of said nozzles with a source of spray 4. A spraying machine as set forth in claim 1 wherein adjustable limiting means cooperate with said actuating means to control the application of said reciprocating forces.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,347,256 Davis July 20, 1920 1,529,134 Kelter Mar. 10, 1925 1,835,402 Juers Dec. 8, 1931 1,926,198 Guenst Sept. 12, 1933 1,932,215 Johnson et al Oct. 24, 1933 2,257,516 Roche et al. Sept. 30, 1941 2,342,375 Shurley Feb. 22, 1944 2,344,905 Short Mar. 21, 1944 2,345,834 Schweitzer Apr. 4, 1944 2,373,604 Schweitzer Apr. 10, 1945 2,397,482 rilfin Apr. 2, 1946 2,434,176 Potthofi June 6, 1948 2,488,519 Andrews et a1. Nov. 22, 1949

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