US2560745A - Paint spraying device - Google Patents

Description

July 17, 1951 A. w. SALSTROM PAINT SPRAYING DEVICE Filed July 13, 1948 2 Sheets-Sheet 1 1 fr 'rroRNYs 1 5 Iii y 17, 1951 A. w. SALSTROM 2,560,745

PAINT SPRAYING DEVICE Filed July 13, 1948 2 Sheets-Sheet 2 INVENTOR A AORN Patented July 17, 1951 UNITED STATES NT OFFICE 3 Claims.

1 My invention relates to a paint sprayer and more particularly to a machine for automatic or semi-automatic production sprayin of various articles.

It is common practice in the spraying of various articles to mount the article upon a rotatable support, and, while rotating the support by hand, to spray the article with paint by means of a spray gun held in one hand. That method of spraying is in many cases unsatisfactory since the quality of the work is dependent wholly upon the skill of the individual operator.

It is an object of my invention to provide a paint spraying machine, which is fully automatic or semi-automatic in operation, and in which variations due to the skill or lack of skill of the individual operator will be reduced to a minimum. 7

It is another object to provide a paint spraying machine which will either automatically or semi-automatically spray articles uniformly, or as desired, at a rapid rate, and, in general, the object is to provide an improved machine for the rapid spraying of articles.

In the drawings which show, for illustrative purposes only, preferred forms of the invention Fig. 1 is a side view in partial section of a machine illustrative of the invention, some parts being shown more or less schematically;

Fig. 2 is a top plan view of the machine shown in Fig. 1;

Fig. 3 is a detail view in elevation of a typical switch or valve and actuating cam used in the machine of Fig. 1;

Fig. 4 is a schematic view showing various connections and means for operating the same illustrated in Fig. 1; and

Fig. 5 is a fragmentary view illustrating a modification of the machine shown in Fig. 1 so as to render the operation of the machine substantially automatic.

Briefly stated, in a preferred form of the invention, I employ means for moving a spray gun and the article to be sprayed relatively to each other so as to spray the article in the desired manner or according to a desired pattern. Such relative movement may be effected by having the spray gun in fixed position adjacent to the article to be sprayed, and having the article mounted on a rotating support or turntable. The rotatable support is rotated by a suitable motor, and the motor may serve to automatically control the operation of a spray gun. After the article has been sprayed, it may be removed from the rotatable support either automatically,

by hand, or by means which may be manually actuated. For automatic operation, the motor may be kept in continuous operation and the spray gun operated intermittently so that during the time that the spray gun is shut down, a sprayed piece may be removed and a new work piece set in place on the rotatable support. For semi-automatic operation the motor may be set in operation by manual means, and if desired, continued in rotation by automatic means controlled by the rotation of the motor so that at the end of the desired time, the motor will be stopped and the rotatable support consequently brought to rest. In any event, it is preferred that the spray gun be controlled by or in accordance with the rotation of the rotatable support or by the motor and so timed with the rotation of parts that the article will be sprayed while in rotation and the spray gun cut off while the article is stopped or is being removed from the support and a new article is being set in place.

In the preferred form shown, the machine includes a table 5, which may carry a rotatable support 6, and secured thereto, or forming a part thereof, there may be an adapter 1 for suitably supporting any desired article, for example a jug 8 shown in place on the rotatable support. The rotatable support may be rotated by means of a suitable motor 9 which through means such as a worm Ill and worm wheel I I rotates a shaft l2. The shaft l2 may carry a bevel gear l3 for rotating the bevel pinion l4 carried by a pulley shaft IS. A belt l6, trained over a pulley I! on the shaft l5, and a pulley l8 on the rotatable work support serve to rotate the latter, as will be understood. The motor 9 is set in operation by manually controlled means, and after being set in motion may rotate continuously as heretofore indicated, or may, after a predetermined cycle, be stopped.

In the particular form shown, I employ a compressed air motor, which is set in motion by manually controlled means and continued in rotation for a predetermined cycle by means controlled by the rotation of the motor itself. As illustrated, I employ a manually controlled valve I9, between the compressed air main 26 and the motor. When the valve H) is actuated as by means of a foot pedal 2i, compressed air passes through the valve and through the conduit 22 to the motor 9 to set the latter in rotation. I preferably employ a second or automatically actuated valve 23, which is in a shunt line 24 connecting the main 20 and the motor line 22. The valve 23 (shown in side elevation in Fig. 3) is in position to be actuated by adjustable cam means 25 carried by the shaft l2. In the position of the valve 23 shown in Fig. 3, the valve is closed. When the valve I9 is opened as by means of the foot pedal 2|, compressed air passes to the motor and sets it in rotation, as heretofore noted. As soon as the shaft l2 rotates sufficiently, the valve 23 will be actuated by its adjustable cam so as to pass compressed air from the main 2|) directly to the motor and maintain it in operation. As soon as the valve 23 has been actuated to open position, the manual valve |9 may be released, but the motor will continue in operation. Operation of the motor, as heretofore described, will rotate the rotatable support 6'| and thus rotate the article to be sprayed.

A part of the machine, such as the table 5, has means such as one or more standards 26 for adjustably supporting one or more spray guns 21-21. The spray guns may have the usual paint and atomizing air connections 29, and the guns may be set in operation by air pressure admitted through a flexible hose 3!), as is common practice. A stop cock 3| may be provided in the actuating air connection. The spray guns may be put in operation automatically at intervals if the rotatable support is rotated continuously, and if the rotatable support is operated in a cycle, the spray guns are set to operate in timed relation with the rotation of the article to be sprayed, as will be described. In the form shown, I employ a spray control valve 32 which may be in all respects the same as the valve 23 shown in Fig. 3. The valve 32 is actuated by adjustable cam means 33, which may be the same or similar to the cam means 25 shown in Fig. 3.

The operation of the device as thus far described, for intermittent or cycle operation, is as follows:

The valve I9 is actuated by depressing the pedal 2| so as to admit compressed air to the motor 9 to initiate its rotation. Rotation of the motor through the worm and worm wheel connection rotates the cam shaft l2, and through the connections heretofore described rotates the rotatable support 6-1 and the article 8 previously placed thereon. As soon as the cam shaft |2 has rotated far enough, the adjustably set cam actuates the air valve 23 so as to admit air from the main 20 to the motor to continue the latter in operation. As soon as the air valve 23 has been cam actuated, the starting valve l9 may be released, but the motor will continue in operation. After the article 8 is in rotation, the adjustable cam 33 actuates the spray control air valve 32 so as to admit compressed air from the main 2!) to the control pipes to set the spray gun or guns 21-21 in operation, it being understood that the paint and air connections 29 are normally in connection with the paint and a source of compressed air. The article 8 is then sprayed while it is in rotation, thus providing for an even or any desired type of coating. The adjustable cam 33 is so set and timed in relation to the cam 25 that the valve 32 is released so as to stop the operation of the spray guns prior to the time that the cam 25 releases the valve 23. Thus, the spray is cut ofi before the rotation of the work piece is stopped, it being understood that when the cam 25 rotates so as to release the valve 23, air pressure to the motor will be cut off and rotation of the latter and the work piece will be stopped until the initiating valve I9 is again actuated. When the piece 8 has been sprayed, it is removed and a new piece inserted in its place.

In the preferred form, I provide manually controlled means for removing the work piece from the rotatable support 6-'|. Such means may take various forms, but when I employ an air motor, as heretofore described, I prefer to employ pneumatic means for removing the work piece. As illustrated, I may support an air cylinder 35 beneath the table 5, in which cylinder is mounted an air piston 36 having a long piston rod 31, which may extend centrally through the rotatable support 6'| and up into position to engage and raise the article 8 from its support from which raised position it may be easily grasped and removed. Normally, the piston will be in its depressed position, as shown in Fig. 1, so that the article 8 may be properly supported by the rotatable support. For intermittent or cycle operation, I prefer to control the article removing means by a manually actuated reversing air valve 38. When the pedal 39 is depressed, compressed air from the main 2D enters the valve through conduit 40 and passes through conduit 4| to the head end of the cylinder 36 so as to raise the piston and remove the article 8 from its support. When the pedal 39 is released the piston 36 returns to its lowermost position, if desired, under the influence of compressed air, through conduit 42, while the head end of the cylinder is exhausting through conduit 4| and the valve 33. If it is desired to remove the article 8 from its support automatically after the spraying has been completed, I may mount the valve 38 in position to be actuated by an adjustable cam 43 on the cam shaft |2. Thus, the adjustable cam 43 may be positioned so as to actuate the valve 30 to raise the article 8 from its support at any time after the paint spray has been shut off. The cam 43 may be positioned and proportioned so as to again depress the piston 36 after a specified time before the motor 9 stops its rotation, or the cam 43 may be proportioned and positioned so as to depress the piston 36 at the beginning of the cycle and before the paint spray is initiated.

For substantially continuous operation, the cam 25 may be set to keep the valve 23 open and keep the motor in continuous operation, Or instead of the valve 23 any hand-operated valve may be employed to merely turn on the air to the motor for putting it in operation. Thereafter, the cam 33 will intermittently actuate the paint sprays so as to start and stop the spray. During the time that there is no spray, the article may be removed either manually or by means of the pneumatic piston heretofore described and a new article set in place, after which the cam 33 will again set the spray in operation and the operation will be substantially continuous, the operator being called upon merely to remove sprayed articles and put on unsprayed articles.

It will be understood that the speed of any particular cycle of operations, whether of the automatic or semi-automatic type, may be controlled by the timing and placement of the cams, by change of gear ratios, or by change of motor speed, as by varying the air pressure.

It will be seen that I have provided a very simple paint spraying device, which may be operated on either an automatic or a semi-automatic cycle, which will greatly speed up the sprayin of article, with consequent reduction of unit costs.

While the invention has been described in considerable detail and a preferred form shown employing compressed air as the motive means, it is to be understood that other types of motive means may be employed, and that various changes and modifications may be made in the form and arrangement of parts, all within the scope of the invention as defined in the appended claims.

I claim: I

1. In a paint spraying device, a rotatable support for a piece to be sprayed, a fluid pressure actuated motor, a drive connection between said motor and support for rotating said support, a valve for controlling a spray gun, an actuating connection between said motor and said valve for controlling the latter, a pair of supply pipes for conducting fluid to said motor, a manual valve in one of said supply pipes, means for normally urging said manual valve toward closed position, whereby said manual valve may be moved against said urging means to admit fluid to said motor through said one of said supply pipes, a valve in the other of said supply pipes, means for urging said last valve toward closed position, and an actuating connection between said motor and said last valve for opening the latter upon operation of said motor to admit fluid to said motor through said last valve to maintain operation of said motor.

2. In a paint spraying device, a rotatabl support for a piece to be sprayed, a fluid pressure actuated motor, a drive connection between said motor and support for rotating said support, a shaft, and means connecting said motor and shaft for rotating said shaft by said motor, valve means for controlling a spray gun, means on said shaft for controlling the actuation of said valve, a pipe for conducting fluid to said motor and a manually operable motor valve in said pipe to control the supply of fluid to said motor, means for urging said motor valve toward closed position to tend to shut off the supply of fluid to said motor, a second pipe for conducting fluid to said motor and a second motor valve in said second pipe for controlling the supply of fluid to said motor, and means actuable by said shaft to control said second motor valve for shutting off the supply of pressure fluid to said motor after a predetermined movement of said shaft.

3. In a paint spraying device, a rotatable support for a piece to be sprayed, a fluid pressure actuated motor, a shaft and a drive connection between said motor and shaft for driving said shaft by said motor, cam means on said shaft for controlling valve means for a spray gun, a pressure fluid supply pipe to said motor and a manually operable motor valve in said supply pipe for controlling the supply of pressure fluid to said motor, a pressure fluid connection to said motor and located between said motor and said first motor valve, a second motor valve in said pressure fluid connection for controlling the supply of pressure fluid to said motor independently of said manually operable motor valve, and means actuated by said shaft for controlling the operation of said second motor valve to actuate the latter upon predetermined movement of said shaft.

ARTHUR W. SALSTROM.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 1,070,428 De Vilbiss Aug. 19, 1913 1,327,973 Allen Jan. 13, 1920 1,347,994 Day July 27, 1920 1,879,393 Miller Sept. 27, 1932 2,069,844 Paasche Feb. 9, 1937 2,088,542 Westin July 27, 1937 2,136,068 Allen Nov. 8, 1938 2,195,753 Paasche Apr. 2, 1940 2,342,307 Smith Feb. 22, 1944

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