US 3356069 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Dec. 5, 1967 c. G. MARTIN 3,356,069
SPRAY PAINTING APPARATUS INCLUDING A WORKHOLDER, MASK AND ALIGNING MEANS THEREFOR Filed May 16, 1966 2 Sheets-Sheet 1 MASK Dec. 5, 1967 c. G. MARTIN SPRAY PAINTING APPARATUS INCLUDING A WORKHOIJDER,
AND ALIGNING MEANS THEREFOR 2 Sheets-Sheet 2 Filed May 16, 1966 FOOT PEDAL INVENTOR. CLYDE G. MARTIN Wham United States Patent C) 3,356,069 SPRAY PAINTING APPARATUS INCLUDING A WORKHOLDER, MASK AND ALIGNING MEANS THEREFQR Clyde G. Martin, Toledo, Ghio, assignor to Conforming lllfitrix Corporation, Toledo, Ohio, a corporation of Filed May 16, 1966, Ser. No. 550,458 9 Claims. (Cl. 118-301) The invention relates to a multiple spray painting fixture for holding two or more interchangeable spray masks to be used in painting an article in two or more colors.
When it is necessary to paint a particular area of an article in a manufacturing operation, it is customary to employ a mask that fits the article closely, exposes the area to be painted and covers the remainder of the article. In the production of large quantities of articles that are so painted it is desirable to employ a fixture in which the spray mask and a work holder are mounted for relative movement so that the article to be painted can be positioned precisely on the Work holder and then can be brought into proper engagement with the mask by moving the work holder toward the mask.
When it is necessary to apply different colors to two or more areas on the surface of an article, the operation of painting the article is more cumbersome because it is necessary to employ a separate mask to define each area to which a particular color is to be applied. When a spray mask is used to apply paint of one color to an article and is then replaced by another spray mask for applying paint of another color to a different area on the article, it is necessary to position each mask with great precision to insure that in each painting operation. the paint will be applied to the desired area. The operation of precisely positioning a mask on a fixture is most difiicult in the case of a large mask which is used for applying paint to a relatively large area.
The principal object of the invention is to provide a spray painting fixture having a single work holder and having mountings for supporting a plurality of spray masks, which is of improved design to permit each of the spray masks selectively to be brought quickly into a precise position so that the work held by the work holder can be engaged with the mask for spray painting. More specific objects and advantages are apparent from the following description, in which reference is had to the.
accompanying drawings illustrating a preferred embodiment of the invention. In the drawings:
FIG. 1 is a side elevation of a preferred form of device embodying the invention.
FIG. 2 is an end elevation,
FIG. 3 is an exploded end elevation of the mounting for holding a mask.
FIG. 4 is a perspective view of a mask.
FIG. 5 is a perspective view of the mounting for holding a mask.
FIG. 6 is a diagram of the air piping and controls.
These specific drawings and the specific description that follows are intended to disclose and illustrate and not to limit the invention.
The multiple spray painting fixture shown in the draw ings is supported upon two leg members 10, each of which rides upon two casters 11. Each of the leg members 10 consists of an X-shaped frame made by welding pieces of angle and including a horizontal angle 12 welded across the top of the leg member. The base portion of the fixture includes an inverted channel 13 beneath the ends of which are welded two transverse plates 14. Each of these transverse plates 14 is bolted to the horizontal ment which might otherwise occur because of slight bend angle 12 which forms the top portion of one of the leg members 10.
Secured to and depending from the channel 13 are two air cylinders 15. The pistons 16 which extend upward from the air cylinders 15 support a work holder 17 that carries a work-supporting platform 18 provided with work-locating members which in the illustrated embodiment consist of four angles 13. Additional locating members may be provided when necessary to fit the article to be painted, so that when the article is placed upon the platform 18 it is held in a precise position. The platform 18 remains horizontal at all times, so that an article placed upon the platform is held in position by gravity.
Secured to and depending from the work holder 17 are a pair of racks 20. The racks 20 mesh with a pair of gears 21 fixed on the two ends of a shaft 22 which is mounted in two bearings 23 each of which is secured to a plate 24 welded across the bottom of the inverted channel 13. This arrangement of racks and gears keeps the work holder 17 horizontal and prevents either of the piston rods 16 from moving faster than the other piston rod.
The assembly that carries the spray masks includes a pair of discs 25. A bearing 26 is secured to the center of each of the discs 25, and each disc is pivoted by means of the bearing 26 upon a stud 27 which is provided with a flat head 28 and is secured in a bracket 29 welded on top of the inverted channel 13.
Bolted to the inner face of each of the discs 25 are three guideways 30, each of which is provided on its inner side with a longitudinally extending groove 31 (FIGS. 3 and 5 Each of the guideways 30 is connected at one end by means of an angle 32 to a guideway on the opposite disc 25. The three angles 32 which connect the three pairs of guideways 30. also form the connection between the two discs 25 to produce a single mask carrying assembly. Each angle 32 with its two guideways 30 constitutes a mounting for supporting a spray mask.
Each spray mask 33 (FIG. 4) consists of a relatively shallow channel including a front wall 34 to which are secured a pair of handles 35, and a rear wall 36 which has a portion cut away at each end to permit the edges at the two ends of the channel to be slid into the grooves 31 of the guideways 30. At the front end of each guideway 30, a portion of the guideway above the groove is cut away to leave an exposed ledge 37, so that the rear corners of the mask 33 can be dropped onto the ledges 37 to place the mask in a position such that it can be slid readily into the grooves 31.
Two blocks 38 are welded upon each of the angles 32, and a bushing 39 extends through each of the blocks 38. When a mask is mounted in the guideways 30 in proper position for painting, each bushing 39 and a corresponding hole 40 in the angle 32 are in alignment with a hole 41 in the mask 33. In order to secure the mask in position, a pin 42 is inserted by hand through each bushing 39 and the corresponding holes 40 and 41.
Also secured to each mask 33 are two plates 43, through each of which extends a relatively large bushing 44. The two bushings 44 constitute aligning apertures for receiving two aligning pins 45 which are mounted on the ends of the work holder 17 and which, when the work holder is raised by the air cylinders 15, enter the bushings 44 through relatively large holes provided in the mask 33 below the bushings 44.
The entry of the aligning pins 45 into the bushings 44 on the spray mask 33 performs the final precise alignment of the spray mask with the work on the platform 18 carried by the work holder 17. The final precise alignment performed by the aligning pins 45 corrects any misalign- Patented Dec. 5, 1967 ing or distortion of the assembly which carries the spray mask.
In accordance with the present invention it has been discovered that before the work holder is brought into engagement with a spray mask carried by the pivotally mounted assembly, causing the aligning pins to engage the aligning apertures in the spray mask, it is desirable to perform a rather precise preliminary alignment of the pivotally mounted assembly which carries the spray mask. A considerable amount of force must be employed to move the relatively heavy work holder into engagement with the spray mask, and it has been found that without a rather precise preliminary alignment of the pivotally mounted assembly to bring the spray mask into a substantially correct position, a slight misalignment of the spray mask may cause the mask to be damaged when the aligning pins attempt to enter the aligning apertures in the spray mask. Accordingly, an important feature of the present invention consists in the provision of at least one plot in pin which is slidably mounted on the base for longitudinal movement, and the provision of a plurality of apertures in the pivotally mounted assembly, each aperture being located to receive a pilot pin when the assembly is in an angular position in which an aligning aperture in a spray mask carried by the assembly is subtantially aligned with the corresponding aligning pin carried by the work holder.
In the specific embodiment shown in the drawings, each of the discs 25 is provided with three aligning apertures 46 for receiving a pilot pin 47 that is slidable in a bore provided in a block 48 secured to the side of the channel 13. Each of the pilot pins 47 forms an extension of the piston of an air cylinder 49 which also is secured to the side of the channel 13. Whenever each of the pilot pins 47 is engaged in one of the apertures 46, one of the spray masks carried by the pivotally mounted assembly is properly located in a position vertically above the work holder 17.
Each air cylinder 49 provides a separate drive for slidably moving the pilot pin, so that the pilot pin may be first engaged with one of the apertures 46, and the work holder then may be moved to engage the aligning pins 45 with the corresponding apertures in the spray mask.
As shown in FIG. 6, compressed air may be supplied to the system through two separate regulators 50 and 51 which may be set to maintain two different pressures. Compressed air is supplied through the regulator 51 to a foot pedal-operated valve 52. The valve 52 has two operating positions, in one of which it admits compressed air from the regulator 51 to the spaces below the pistons in the air cylinders 15. In its other operating position, the valve 52 shuts oif the supply of compressed air from the regulator 51 and vents the spaces below the pistons of the air cylinders to the atmosphere in order to permit the work holder 17 to move downward under the influence of gravity.
Compressed air from the regulator 51 also is supplied to a foot pedal-operated pilot valve 53. The pilot valve 53 has two operating positions, in one of which it supplies compressed air from the regulator 51 to a plenum chamber 54, and in the other of which it vents the plenum chamber 54 to the atmosphere. The pressure in the plenum chamber 54 controls a spring-biased reversing valve 55 which is connected to the regulator 50. The reversing valve 55 has two operating positions, one of which it assumes when compressed air from the regulator 51 is supplied to the plenum chamber 54, and the other of which it assumes when the plenum chamber 54, is vented to the atmosphere. In one of the operating positions of the reversing valve 55, the spaces at the left side of the pistons in the air cylinders 49 are supplied with compressed air from the regulator 50 and the spaces at the right side of the pistons are vented to the atmosphere. In the other position of the reversing valve 55, the spaces at the right side of the pistons in the air cylinders 49 are supplied with compressed air from the regulator 50 and the spaces at the left side of the pistons are vented to the atmosphere.
In the operation of the device illustrated in the drawings, the operator first places the article to be painted upon the platform 18 while the work holder 17 is in its lower most position. At this time the pivotally mounted assembly is so positioned that the desired one of the masks is located vertically above the platform 18, and the air cylinders 49 are operated by means of the pilot valve 53 to bring the pins 47 into engagement with the proper apertures 4-6. The operator then operates the valve 52 by means of the foot pedal to supply compressed air to the spaces below the pistons in the air cylinders 15, thus raising the work holder 17 until the aligning pins 45 enter the aligning apertures provided by the bushings 44 on the mask 33. When the work holder 17 is fully raised, the mask 33 is properly aligned with the work, and the work is tightly engaged with the mask. The operator then uses a spray gun to spray paint through the mask so as to apply paint to the proper area of the article.
When this painting operation has been completed, the operator places the valve 52 in its other operating position by means of the foot pedal, thus venting the spaces below the pistons in the air cylinders 15 to the atmosphere and permitting the work holder to settle into its lowermost position. He also places the pilot valve 53 in position to retract the pilot pins 47. Then the operator grasps hand rails 56 which are provided on the discs 25 and rotates the mask-carrying assembly to bring a different mask into a position vertically above the work holder 17. The pilot valve 53 is also reactuated by releasing the foot pedal to bring the pilot pins 47 into engagement with the pro-per apertures 46.
The work holder 17 is then raised in the manner previously described, and paint of another color is applied to the proper area of the article. Then if paint of a third color is to be applied, the illustrated device can be operated again in the manner described, to permit a third mask 33 to be employed in a third painting operation.
The pilot pins 47 are operated by the relatively small air cylinders 49 with a short stroke and with relatively little force. Thus the pilot pins 47 can be manipulated quickly and easily in performing the preliminary aligning operation. At the same time the preliminary alignment performed by the pilot pins 47 is precise, and it has been found that this preliminary alignment enables the aligning pins 45 to enter the bushings 44 provided on the spray mask to correct any deformation of the structure without any danger of damaging the spray mask.
The embodiment illustrated in the drawings may be varied when necessary to meet various requirements.
Having described the invention, I claim:
1. A multiple spray painting fixture comprising a base, an assembly which is pivotally mounted on the base and which carries a plurality of mountings for supporting a plurality of spray masks in positions that are angularly displaced from one another, a work holder which is slidably mounted on the base and which carries an aligning pin extending in the direction of the sliding movement of the work holder for engaging an aligning aperture in a spray mask carried by the pivotally mounted assembly, in order to align the mask with work which is to be spray painted through the mask and which is held on the work holder, and a pilot pin which is slidably mounted on the base for longitudinal movement, the pivotally mounted assembly having a plurality of apertures each of which is located to receive the pilot pin when the assembly is in an angular position in which an aperture in a spray mask carried by the assembly is substantially aligned with the corresponding aligning pin carried by the work holder.
2. A multiple spray painting fixture according to claim 1 that comprises a drive for slidably moving the pilot pin, and a separate drive for slidably moving the work holder to engage the aligning pin with the corresponding aperture in a spray mask after the pilot pin has been engaged with an aperture in the pivotally mounted assembly.
3. A multiple spray painting fixture according to claim 2 wherein the pivotally mounted assembly is mounted on a horizontal axis and the work holder is slidable vertically.
4. A multiple spray painting fixture according to claim 3 wherein the pivotally mounted assembly comprises a pair of side members carrying mountings for supporting a plurality of horizontally extending spray masks to permit each of the masks selectively to be brought to a position vertically above the work holder.
5. A multiple spray painting fixture according to claim 4 wherein the apertures for receiving the pilot pin are located in one of the side members, and the pilot pin is slidable horizontally.
6. A multiple spray painting fixture according to claim 1 wherein the pivotally mounted assembly is mounted on a horizontal axis and the work holder is slidable vertically.
7. A multiple spray painting fixture according to claim 6 wherein the pivotally mounted assembly comprises a pair of side members carrying mountings for supporting a plurality of horizontally extending spray masks to permit each of the masks selectively to be brought to a position vertically above the work holder.
8. A multiple spray painting fixture according to claim 7 wherein the apertures for receiving the pilot pin are located in one of the side members, and the pilot pin is slidable horizontally.
9. A multiple spray painting fixture according to claim 7 wherein apertures for receiving a pilot pin are located in both side members, and two horizontally slidable pilot pins are provided for engaging such apertures.
UNITED STATES PATENTS References Cited 2,475,434 7/1949 Moss 1l8503 XR 2,969,296 1/1961 \Valsh 1l738 3,117,025 1/1964 Learn et al. 118504 XR 3,205,855 9/1965 Ault ll8301 XR 3,207,126 9/1965 Byron 1l8504 XR 3,238,917 3/1966 Burns 118-38 XR 3,241,519 3/1966 Lloyd 1l849 3,302,609 2/1967 Walker et al. 101-50 XR CHARLES A. WILLMUTH, Primary Examiner.
R. I. SMITH, Assistant Examiner.