US2672121A - Spray coating machine - Google Patents

Description

March 16, 1954- D. J. PEEPS- 2,672,121 V SPRAY COATINQ MACHINE Filed Feb, 7, 1952 3 Sheets-Sheet 1 E JEVENTOR: UNALD EEPE' I151- CUFCW ATTORNEY March 16, 1954 D. J. PEEPS SPRAY COATING MACHINE 3 Sheets-$heet 2 Filed Feb. 7, 1952 INVENTOR Z .UUNALD JFBEPs.

CUPCW ATTORNEY March 16, 1954 D J PEEPS 2,672,121

SPRAY COATING MACHINE Filed Feb. '7, 1952 3 Sheets-Sheet 3 TIE-5 I INVENTOR: EDNA/:17 JPBzPs.

BY (,9, P001) ATTORNEY Patented Mar. 16, 1954 SPRAY COATING MACHINE Donald J. Peeps. Toled Ohio, assign r to The De vilhiss C mpany, T ed hio, :1 corp ration of Ohi Application February 7, 1952, Serial No. 270,441 4 Claims. (01. .1l8w32l) This invention relates to a spray coating machine in which a series of articles are conveyed through a coating station and particularly to such a machine in which one or more spray guns are moved in synchronism with the movement of the articles during the coating operation.

While machines of this type have usually included means for movement of the spray guns there have been shortcomings in the customary spring devices for returning the spray guns to their original or starting positions. When reliance for this action is placed upon a spring, the movement may be irregular, too sluggish or too jarring. Since no coating is being applied during this portion of the machine operation it is desirable in order to maintain highest production that the time involved be minimized and unvarying.

A primary object of the invention is the provision of means for steady following movement of the spray guns and positive rapid return movement of the spray guns to their starting posi-- tions.

This object is accomplished through having a pick-up arm for the following motion and a separate arm with a lever action for efiecting the return movement.

Other objects and advantages will become apparent on reading the following description with reference given the accompanying drawings in which:

Figure l a front elevation with parts broken away of a machine embodying my invention;

Figure 2 is a plan view of'the machine oi'Figurel;

Figure 3 is a vertical section taken on the line 3- of Fi ure 2; d

Figure 4 is a representation of the following arm and engaging dog mechanism.

Themachine embodying the invention as shown in the drawings is supported upon a square sided frame having uprights I joined by crossbeams 2.

An endles conveyor chain 3 follows an arcuate path above the frame. The chain is guided toward and away from the frame by straight track portions formed of two channel irons 4 in parallel spaced relation with their closed sides facing each other. The chain has laterally broadened upper links 5 which overlay the upper sides of the channel irons and suspend the chain between the channel irons. Intermediate it approaching and departing portions the chain engages teeth or lugs :on the periphery of the revo1ving circular table 6 and travels with it in a counterclockw direction as viewed in Figure While th table quite satisfactory following illustrated is in the form or a closed bowl it would be as efiective if shaped as a spoked wheel with a center hu b.

During the chains arcuate travel with the table the tableside of the broadened chain links .5 ride within a recess formed between the upper surface of a peripheral flange 1 of the table and a squaresectioned ring a secured around the table above the flange. The opposite lateral portions of the chain links 5 slide upon a semiscircular track 9 mounted upon the table. The track 9 has an inwardly turned lip forming a continuous slot for receiving the outer edge 'portions of the chain links 5.

The circular table 6 is fixed to and turns with a vertical shaft. 10.

The latter has a reduced lower end by which it is supported in a pillow block H mounted upon an angle iron brace l2. The upper end of the 20 shaft [0 extends into a hearing member 13. This is secured to the free end of a plate 14 extending over the center of the revolving table from the edge of the frame where it is attached to the upper end of a mounting post l5. The latter is welded to cross beams 2 of the frame.

Every fourth vertical pin 16 of the chain is elongated upwardly to receive a revolvable spindle ll. Over the latter is placed a workholder 18 designed to hold the articular article being coated. A shell casing to be coated exteriorly is shown in the drawings as indicated by the letter S. Each spindle I? has a. peripheral groove for momentary coaction with the two sided V belt 19. The belt is mounted on driving pulley 2B, and idler pulleys 2|. Through the contact of the driven V belt 19 with the spindles, the spin..- dles are rapidly revolved while passing the spray station. This station may involve a substantial portion of the arcuate path of the chain. In this manner the parts are rotated and all sides 01 the parts are thus presented toward the spray guns for efiective coating.

Two spray guns 22 are shown in the drawings.

somewhat figuratively These are supplied at..-

. omizing and motivating compressed air through conduits 23 and 24 and spray material through conduits 25. The guns are held to rods 26 by brackets 2'1. The rods extend from collars 28 fixed through set screws to the vertical shaft 29. There is a thrust bearing between the lower end of shaft 29 and the upper end of the larger shaft ill. The shaft 29 is retained in vertical position within the vertical bore 30 of bracket 3|. The bracket 3! is bolted to plate It.

The means provided for swinging the guns on shaft 29 in temporary synchronism with the movement of the articles being coated includes arm 32 of T cross section. This arm is firmly attached at its inner end to shaft 29. Pivotally mounted at nine spaced points on the inner periphery of the table 3 are dogs 33. These are angularly shaped and ordinarily hang downwardly as shown at the right of Figure 4. In this position they are below arm 32. As the table 6 is turned by the conveyor chain the dogs 33 are successively pivoted upwardly upon going over the end of cam segment 34. The upraised leg of each dog then contacts the end of arm 32 and through movement thereof swings the guns on shaft 29. This following movement is interrupted when each dog 33 reaches the end of cam segment 34 and pivots downwardly out of contact with the arm. Segment 34 is bolted to the outer side of stationary ring 35 which is suspended by a bracket 33 from plate l4.

Return movement of the spray guns to their starting position is accomplished through the engagement of a dog 33 with the end of a second arm 31. The latter is pivotally mounted near the mid point of its length on a vertical bearing stud 38 rising from stationary bracket 33 which in turn is bolted to plate l4. On the inner end of the second arm 31 is a roller 40 which extends into and has motivating contact with the sides of an elongated slot 4|. This slot is formed in an outwardly extending tongue 42 of a bracket 43 fixedly mounted on shaft 29.

As the outward end of the second arm 31 is picked up by a dog 33 and swung in the direction of rotation of the table 6 the inner end of the arm due to the center pivot mounting is moved counter to the table rotation. Consequently through the contact of the roller 43 with the sides of the slot 4| of the bracket 43, the shaft 23 is rotated and the spray guns mounted thereon are swung back to their original position.

The dogs 33 are raised to a position to engage the second arm 31 by a cam segment 44 generally similar to segment 34 but fastened to the opposite side of stationary ring 35.

The gun return movement is more rapid than the following movement due to the lever action of the arm 31. The return movement is cushioned through the compression of air in the shock absorber and movement stopping device 44 mounted at one end to plate 14 and at the other to an extension 45 of bracket 43.

To adjust and maintain arm 32 and the second arm 31 in position for desired working relation bracket 43 which controls the location and movement of arm 3? is bolted to arm 32 through a slot 41 therein.

With the mechanism provided by this invention it is possible to return the spray guns to their starting position in one half of the period or" time during which they are moving for spray coating purposes, in synchronism with the travel of the articles being coated. Due to the coaction of the slot 4! and roller 43 the return action is started slowly with rapid acceleration. With the cushioning of shock absorber 45 the return movement is terminated without shock. By lengthening the cam segments and reducing the number of dogs the following action may be prolonged for the application of heavier coatings to articles position-ed with greater spacings on the con eyor. The relative rapidit of the return movement is retained with an suh change n parts.

In the operation of the machine the chain conveyor is first set in motion. A variable speed transmission in the driving unit is desirable in order to obtain the most suitable conveyor speed.

Before the conveyor reaches table 6 an operator places the parts to be coated on the conveyor. The workholder i8 is ordinarily threaded or otherwise secured to the part prior to the positioning of the part upon a spindle l1.

As the conveyor engages the table 3 the belt i9 contacts the peripheral groove on the spindle l1 and rapidly rotates the spindle, with the workholder and article, on the supporting pin IS. The rotation of the articles continues through substantially the full semi-circle of engagement between the conveyor and the table. The conveyor and table turn in unison in a counterclockwise direction as viewed in Figure 2.

The dogs 33 are placed around the inner periphery of table 3 at circumferential. spacings conforming with the spacing between the spindles carrying articles. Consequently, the included angle between the radial lines from the center of the table through two adjacent dogs is the same as that between such radial lines through two adjacent spindles. With the arrangement illustrated having nine dogs the included angle is 46-360 divided by nine.

The starting positions of the spray guns 22 are shown in Figure 2. They are separately directed toward articles on adjacent spindles. The lower spray gun is set to coat the lower part of the article; the upper spray gun coats the upper portion of the article.

When the articles come in line radially with the spray guns a dog 33 riding on cam segment 34 engages arm 32 fastened to the shaft 23 and moves the spray guns thereon in synchronism with the movement of the articles for a distance equal to approximately two-thirds of the spacing between spindles. As shown in Figure 2 in solid lines a dog 33 is contacting arm 32 to begin the following movemen In the position of arm 32 in dash lines the following movement has terminated and the dog has dropped down out of engagement with the arm.

Controls for the spray guns function during the co-movement to discharge coating materials from the spray guns. Such controls are conventional and have not been illustrated. The duration of the synchronized travel is determined by the length of segment 34 since the dog 33 on reaching the end of the segment swings downwardly out of engagement with arm 32.

As the following movement is terminated a dog 33 riding upon cam segment 44 meets the end of return arm 31 and swings the arm on pivot stud 38. The lengths of the portions of arm 31 on either side of stud 38 are so selected that through the action of the roller 40 in slot 4| a reverse turning of shaft 29 results at an overall rate of speed at least twice that of the following speed. Consequently the guns return to their starting position in time to be in line with each successive spindle. The spray discharge from the guns is discontinued during their return movement.

In dash lines in Figure 2 is indicated the position of arm 31 as first contacted by a dog 33 to begin the return movement. As shown in solid lines, arm 31 has finished its pivoting movement returning the spray guns to their starting positions.

The shock absorb-er 45 not only provides a cushioning effect but also a positive stop of the return movement at the selected starting position.

- A hand unloading station is located on the out-. going portion of the conveyor.

sheeting, Wi

may be interposed the applied coating.

Spray station as used herein indicates a rather indefinite region in which the spray guns are located and the coating is deposited.

While table is the term applied to the rotating member 6, it should be interpreted sufiiciently broadly to include structures of a more open nature such as a spoked wheel having a center hub.

It is obvious that many changes in the details of construction and the proportion of parts may be made without departing from the spirit of the invention as set forth in the appended claims.

What is claimed is:

1. In a spray coating machine, a spray station, a travelling conveyor carrying a series of articles to be coated through the spray station, a spray gun within the spary station, a movable mounting for the spray gun at one side of the conveyor and in a starting position, a first arm rigidly connected at its inner end to the spray gun mounting and with its outer end extending toward the conveyor, means associated in movement with the conveyor engaging the outer end of the first arm and therethrough momentarily moving the spray gun mounting and the spray gun in following synchronism with articles on the conveyor, a second arm pivotally supported intermediate its ends at a point between the conveyor and the spray gun mounting, means associated in movement with the conveyor engaging the outer end of the second arm subsequent to the momentary fol lowing movement of the spray gun mounting by action of the first arm, such engagement of the outer end of the second arm turning the pivotally supported second arm and thereby moving the inner end of the second arm in a direction opposite to that of the conveyor travel, and a part on the spray gun mounting receiving the backward thrust of the inner end of the second arm, the inner end of the second arm and the part on the spray gun mounting being so constructed and designed that the thrust action of the inner end against the part moves the spray gun mounting back to its starting position.

2. In a spray coating machine, a spray station, a travelling conveyor carrying a series of articles to be coated through the spray station, a spray guri within the spray station, a rotatable shaft on which the spray gun is mounted, a first arm to increase the drying rate of extending radially from the shaft, means travelling in association with the conveyor, interengaging mechanism momentarily connecting said means with the first arm and therethrough rotating the shaft in following synchronism with the conveyor, a second arm pivotally supported intermediate its ends at a point between the rotatable shaft and the conveyor, momentary interengaging mechanism between the outer end of the second arm and said means travelling in association with the conveyor whereby the second arm is engaged subsequent to the action of the first arm and is pivotally turned with its outer end moved in the direction of the conveyor travel and its inner end moved in the opposite direction, and a projecting part of the shaft receiving the thrust of the inner end of the second arm whereby the shaft is rotated back to its original position.

3. A spray coating machine as set forth in claim 2 in which the projecting part has a slot, and a roller on the inner end of the second arm rides in said slot.

4. In a spray coating machine, a spray station, a travelling chain conveyor carrying a series of articles to be coated through the spray station, a spray gun within the spray station, a rotatable table having toothed engagement with the chain conveyor, a movable mounting for the spray gun in a starting position, means carried by the table engaging the movable mounting and momentarily moving it in synchronism with the conveyor travel, a lever arm pivotally supported intermediate its ends at a point between the conveyor and the movable mounting, separate means carried by the table momentarily engaging the outer end of the lever arm subsequent to the synchronous movement of the mounting, such engagement turning the lever arm with its outer end following the conveyor and its inner end thrust in the opposite direction, and a part on the movable mounting receiving the thrust of the inner end and causing the movable mounting to move in a reverse direction back to its starting position.

DONALD J. PEEPS.

Name Date Sykes et a1. Aug. 21, 1945 Number

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