US2209006A - Coating apparatus - Google Patents

Description

3 Sheets-Sheet l w. A, SMITH COATING APPARATUS Filed April 1s, 193e July 23, 1940.

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ATTORNEY July 23, 1940. w. A. SMITH 2,209,005

COATING APPARATUS Filed April 13, 1958 3 Sheet's-Sheet. 2

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' ATTORNEY July 23, 1940. w. A. SMITH COATING APPARATUS Filed April l5, 1938 3 Sheets-Sheet 3 am. QN Gm. Nm. mm.

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Patented July 23, 1940 UNITED" saras ooA'rING APPARATUS` William A. Smith, Akron, Ohio, assignor to The `Ohio Brass Company, Mansfield, poration of New Jersey Ohio, a cor-f l AppucatienApi-ii 13, 193s, serial No. 201,741

16 Claims.

This invention relates to the application of a coating to articles such as porcelain .insulators or other devices whichmay be rotated about an axis whiledipped in a coating bath; the particu- I lar embodiment of the invention shown and described having reference to the application of a coating of glazing material to porcelain insulators. v

One object of the invention is to provide an apparatus for applying coating' material to insulators or the like in which the operation is performed automatically by a coating machine.

A further object of the invention is to provide a coating apparatus in which the articles may b e coated quickly and economically and inwhich the coating material willbe uniformly applied to all of the articlestreated.

A further object of the `invention `is to provide a coating machine which shall be of improved construction and operation.

Other objects and advantages will appear from `the following description.

The invention is exemplified by the combination and arrangement of parts shown in the accompanying drawings and described in the following specification and by the steps of the process explained therein. The invention is more particularly pointed out in the appended claims.

In the drawings:

Fig. 1 is a part elevation and part section `of acoating machine showing one embodiment of thepresent invention, parts of the machine being omitted for convenience of illustration.

Fig. 2 is a fragmentary topV plan of the machine shovvn in Fig. 1.

Fig. 3 is a part elevation and part section of one of the work carrying arms shown on a larger scale than in Figs. 1 and 2.

Fig. 4 vis a fragmentary elevation of control mechanism for the work carrying arms.

Fig. 5 is a fragmentary plan of a portion of the mechanism shown inFig. 4.

Fig. 6 is a fragmentaryplan of another portion of the mechanism shown in Fig. 4. l

Fig. 7 is a fragmentary plan of a movable section of the track which controls the work carrying arms.

Fig. 8 is a fragmentary section of the track showing the roller mechanism for the work carrying arms which travel on the track.

In the manufacture of porcelain insulators and other ceramic products, it is customary to apply to the driedporcelain article, before it is fired, `a coating of glazing material, which, duringV the firing operation, is vitried and forms a glassy track I4 at their outer ends.

.- ends.

covering for the surface of the porcelain article, Many glaze compositions` are Well known in the art and usually comprise the proper glazing con-l stituents suspended in water,.forming a liquid bath into which the article may be dipped, the bath usually being of a consistency approximately that of cream. The application of theglazing material by hand is a Itedious and expensive operation, and of course, is subjectto variations due to the `human element entering into the operation. The glazing bath must be kept well stirred,

since the materialis heavier than the liquid in which it is suspended `and tends to settle toward the bottom. lThe present invention provides means formaintaining a uniform bath and for` Vsubjecting every article tothe bath in exactly the same way, so that all 'of the articles are coated alike.` i

In the embodiment of the invention shown in the drawings, the numeral I0 designates a supporting base to which `an upright shaft II is -rigidly fixed. Supported on the shaft I is a `stationary spider consisting of a hub I2 and radially extending arms I3 which carry a circular A second hub I5 is secured to the shaft Il and vis provided with l.braces I6, also connected to the track I4. Rotatably mounted upon the shaft Il and supported by bearings I1 and I8 is a rotatable reel comprising a hub I9, :arms 20, braces 2l and outer rim 22. Distributed around the rim22 and fixed thereon, is a pluralityof brackets 23 oneach of which is pivotally mounted a work carrying arm 2t. Each of the arms 24, asv shown more clearly in Fig. 3, comprises a sleeve 25 pivotally mounted on a pivot 26 carried by the bracket `23, the `sleeve 25 having a bearing tube 21 secured therein and provided with roller bearings 28 at its opposite A shaft29 is Ajournaled in the roller bearings 28 and its inner end is provided with a driving roller 30 fixed thereto and having a ring 3| of rubber or other suitable material on its periphery to provide a `driving tread for the roller 30. Freely rotatable on the inner end of the shaft 29 is a ring 32 mounted on a rollerbearingl 33 for a purpose to be more fully described later. A

iiexible extension 34 is secured tothe outer end of the shaft 29 and is encased infahousing tube 35 which is curved upwardly and carries a bearing sleeve36 at its outer end. Journaled on the sleeve 36 is a'work carrying head 31 and extending through the sleeve 36 is a driveshaft 38 which is xed at its outer end tothe end of the head 3'! and at its inner end to theexible shaft 3ft, so that rotation of the shaft 34 rotates the apparent.

head 31. A thimble 39 is removable, carried by the head 3'I and has xed to its outer surface a sleeve 39 of rubber or other yielding material which forms a cushion for supporting the work piece 4E). The thimble 39 is detachably held on the head 3'I by a spring ring 39 4having an inwardly bent end 39" which enters an opening in the ,head 3l. Porcelain insulators are usually provided with pin holes in which supporting pins are subsequently cemented and the sleeves 39' are made of sizes toiit snugly in the pin holes of the particular insulators for which they are intended The machine may be used for insulators having pin holes of different diameters by using sleeves 39.' of different thicknesses.v Y

It will bernoted from Fig. 3 that the right-V hand or outer end of the work supporting. arm is heavier than the inner endQSothat the tendency is for the outer end to'tilt downwardlyv bringing the driving roller 3| into contact with the cir- `cular track I 4,A as shown at theleft-hand side ofy Fig. l. As the supporting reel `for the arms 24 isrotat'ed, therollers 30 travel upon the track I4 and rotate the work supporting heads 39 and the work pieces 40 carried thereby, as will be readily The glazing bath is disposed at one side of the .rotating reel, as shown at the right-hand side of -Fig. 1, and comprises a tank 4| in which the glazing liquid 42 is maintained at a constant level. As the arm 24 carrying the piece 40 to be coated approaches the glazing bath, the driving roller 3D is caused to leave the track I4 and to engage a track 43 at a higher level than the track I4, Vso as to tilt the outer end'of the supporting arm 24 downwardly. The track 43 has an upwardly and outwardly offset portion 44 with inclined sections 45 and 46 at its ends. The section 44 is disposed opposite the-tank 4| so that after the work piece 4Ilxhas'p'assed the edge of` the tank and comes directly over the coating bath, the armk24l is still further tilted on itspivot 26 so that `*the lower portion of the work piece 40 dips into the coating bath. As the reel continues to rotate, the work supporting head'39 will be driven by the roller 3| traveling on the track section 44 of the surface 'coated depending upon the depth to. which the work is immersed in the coating material.

In most insulators it is desirable to coat the 4viiange and the lower portion of the outer periphery of the head, but not the top of the head or the inside of the pin hole. By holding the insulator with its axis slightly inclined to the hori- "zontal, as shown in Fig. l, `the desired portion of the insulator'will be coated. The angle of inclination ofthe axis is adjustable to suit the angle to insulators of different shapes or sizes or to produce different distributions of the glaze on the insulator as desired.` "In order to provide for this adjustment, the work supporting head is fixed to a pivot 4l which'is journaled in a split bearing 48 adjusted,'after which the cap screws are tightened to retain the head in its position.n Various gaging means may Ibe provided for. determining the ,Proper positionofthe' head for Vdifferent size in- `"sulators`. One'convenient means is to'provide a transverse opening through the pivot 41 in which a pin 50 may be inserted for engagement with a set of stop bars of various lengths to provide the desired settings for insulators of corresponding diameters. A stop 52 is fixed to the casing tube 35 to engage one end of the stop bars 5I. Various other means may, of course, be provided for indicating the proper settings of the work head.

The mechanism for directing the drive rollers 38 onto the raised track 43 will be understood more clearly from Figs. 2, 4, 5 and 6. Adjacent the operators position, the track I4 is provided with a switch blade 53 mounted on a pivot 54 and arranged to swing downwardly as shown in Fig. 4 to permit the approaching roller to ascend the inclined section 55 into engagement with the raised track section 43. It will be understood that the raised section 43 is tilted so as properly to engage the tread portion 3| when the work carrying arm 24 is tilted at an angle to the horizontal. Fixed to the movable track section 53 is anV operating arm 56 which is engaged by the drive roller 30 after it has continued onto the track section 43; thus, swinging the arm 56 downwardly and the track section 53 upwardly to close the gap in the track so that succeeding rollers will continue onto the track I4 until the switch section 53 is again lowered. Fixed to the switch section 53 is an operating arm 51, which is connected by means of a rod 5B, to an arm 59 pivotally mounted on a bracket 6i) secured to the track I4 at a point spaced around the track from tlie switch section 53. A trip arm 6I is fixed to the arm 59 in position to be engaged by a roller traveling along the track section 43. When the operating arm 56 has been moved downwardly by a roller passing onto the track 43 to close the switch section 53, the trip arm 6I will be moved to its dotted line position, shown in Fig. 4, so that it will be engaged by the roller on the track 43 when the roller has traveled along the track a sufficient distance to reach the trip mechanism. As the roller passes the trip mechanism, it will press the trip arm 6| downwardly to the full line -i position, shown in Fig- 4, thus opening the switch section 53 to admit the next roller which approaches the switch 53. l 1

As shown in Fig. 2, the bracket 60 is located at a position on the track I4 so that after one roller has moved into engagement with the track section 43, the switch 53 will remain closed until the next three rollers have passed the switch. The trip mechanism Ilzwill be operated by any roller traveling on the track 43 in time to direct= the fourth succeeding roller onto the raised track section 43. By this arrangement, the roller on every fourth arm will be directed onto the track section 43 and the three intermediate arms will continue in their horizontal position.

It will be noted from Figs. 4 and 8 that the track section 43 is provided with a downwardly projecting runway62 at its upper edge inposition to register with the freely rotating bearing ring 32 on the outer end of the shaft 29. The runwayV -62 is provided with a tapered or inclined end portion 63 for directingthe bearing roller 32 onto the runway shortly after the drive roller 3| has moved into engagement with the Vtrack section 43.

. As shown in Fig. 8, this will hold the tread member 3| out of Contact with theV track section I4 .so that the Work piece will not be rotated as it 'passes the operators position. rThis will permit the operator to remove the coated piece from the supporting head 39 and replace it with an uncoated piece. Theprojecting runway `62 extends only past the operators position, so that as the work piece leaves the operators position and approaches elevated section 4d, the drive roller again contacts with the track 43 so that the supporting head, which has now been supplied with a new work piece, is again rotated as it approaches and passes through the coating bath. v As the work piece leaves the bath, the inner end of the arm is directed downwardly by the inclined track section i6 and guided into a position beneath the track Ill. To permit the roller 3l to move downwardly beneath the track I4, the track is'provided with a pivoted section Ul, which is pressed downwardly by the roller as it moves from the inclined section #E to a position beneath the track I4, as will be apparent from Fig. 7.

'Ihe number of supporting arms which are permitted to pass the .switch 53 and continue on the track I4 before a second roller is directed onto the track section 3, may be varied. by changing the position of the bracket (i6 on the track it. It will be noted that a number of sets of bolt holes 65 are provided in the track iii so that the bracket Bil may be located in several different positions. Of course, when lthe bracket 5B is shifted, a diiferent operating rod 5B must be employed, of the proper length, for the new position of the bracket. The reel, as shown in the drawings, is provided with 23 work supporting arms. With the adjustment, shown in the drawings each work piece, after it has been submerged in the 'coating bath, will travel three times around the circuit, and on the fourth time around, it will again be directed onto the track 53. The reason for this plurality of times around the machine, after` it has been dipped, is to permit the coating to dry thoroughly before the piece is removed from the machine. It will be noted that during this drying operation, the axis of the work piece is inclined slightly to the vertical, as shown in Fig. 3, and that the work piece is continuously rotated. This permits `any excess material to drain from the lower side of the work piece, but does not permit 4a heavy coating toA collect at this lower side, since the piece is continuously rotated and no portion of the work is permitted to remain in the lower position.

By using a prime number of worksupporting arms, the bracket 60 may be set to pass any desired number of work carrying arms between the arms selected to enter the track section 33, and each piece, after it has been dipped, will make the same number of `circuits as the number of arms passed before it again enters the operators track section. Thispermits the drying time to be regulated to correspond with the various coating compositions and other 'conditions It has been found that a reel with 23 arms is particularly suitable for glazing porcelain insulators because it permits a wide range of adjustment of the number of arms passed before one is directed onto lthe operators track section, and on subsequent rotations successively directs the arms that have been passed onto the operators track section. It is evident that this operation would not be performed if the number of arms were an exact multiple of any of the number of arms `passed forthe various adjustments. Since the number 23 is a prime niunber, it is not a multiple of any number except I, so that each rotation of the reel will bring a different arm onto the operators` track section whatever the setting of the trip mechanism.

, Asupply .ofcoating fluid is contained in a 'ci-rcular tank 66, from which it is circulated by means of a pump 61 to the tank 4|. The liquid is drawn from the lower portion of the tank through a .pipe 68 to the pump 61 and is forced upwardly through a pipe BS to a T 1i), from which a part of the liquid passes through a pipe H to the tank 4I, the amount passing this way being controlled by valve l2. Within the tank the liquid is carried to various positions by branch pipes 'I3 and is discharged against the bottom of the tank through nozzles 'M to stir up the liquid in the bottom of the tank and prevent any settling. The surface level is maintained at a definite height by means `of an overflow pipe 15 through which the surplus liquid returns to the tank through a pipe 56. To provide ample overflow capacity and prevent `any variation in surface level due to restriction of the overflow outlet, the pipe is provided with an intake head or trough Ti which extends across the tank 4l. The head 'il is provided with a packing gland 'i8 which may be adjusted vertically A portion of the liquid from 'the pump may be directedthrough a pipe 19 and discharge into the tank 66 in a tangential direction, so as to keep the liquid rotating in the tank Sli and prevent settling. The amount of liquid passing through pipe 'FQ is controlled by valve 3B. When it is desired to drain the tank @l of the liquid, this may be done through 'a drain pipe 8l controlled by valve 82, the drain pipe leading into the tank G6. The reel for supporting the work arms is driven by motor 3 through reduction gearing contained in a gear case 8H.

When it is desired to permit the reel to rotate without permitting any of the work supporting arms to enter the operators track d3, the switch section 53 may be locked in a closed position by means of a pivoted catch 85. The rod F58 is bent laterally at its end, the bent portion entering a slot 36 in the upper end of the arm 57. The bent portion of the rod 5E is normally held at the righthand end of the slot d by the catch 35, but when it is desired tolock the switch in its closed position the catch is lifted and the arm 5l rotated in a clock-wise direction until the bent-end of the rod 58 is at the left-hand end of the slot 86. By swinging the catch S5 downwardly, the arm 57 is then locked in this position by the rod SQ which retains the switch in its closed position.

I claim:

l. In a coating machine, a rotatable work supporting head: a @Galline bath, means for supporting said head with one end thereof projecting from sald supporting means and with the axis of rotation thereof inclined` relative to the surface of said bath so that the projecting end oi said head is inclined upwardly, and means for rotating said head with a work piece thereon, while so supported, to bring various parts of said work piece into contact with said bath'while at least a portion of one end of said work piece is supported outside of said bath.

2. Iny a coating machine, means for applying coating material to a work piece, a supporting head for said work piece comprising a mandrel having a projecting end thereof inclined upwardly yto receive a work piece in position to be held by gravity thereon and supported thereby in an inclined position tov permit excess coating material to drain from the lower side of said work piece-and means for rotating said work .pieceabout' anl `inclined axis `while said work piece is so supported to prevent accumulation of a heavier coating at one side of said Work piece than at the other.

3. In a coating machine, a work supporting arm, means for pivotally supporting said arm between its ends, a work supporting head mounted on one end of said arm, a roller mounted on the other end of said arm, a drive shaft connecting said roller and work supporting head, a guide track for said roller, means for moving said roller on nsaid guide track to rotate said head, said guide track comprising two portions disposed in offset relation to each other to hold said head in different positions during diierent portions of the travel of said arm, said guide track being disposed at the side of said pivotally supporting means opposite said work supporting head to provide unobstructed space for work treating means and for movement of said arm at the work side Aof said supporting means,

4. In a coating machine, a Work supporting head, a roller connected With said head to drive said head, a pair of track sections for engaging said roller to rotate said roller and to guide said roller and head, said track sections providing alternative paths for said roller, and means for selectively directing said roller to either of said track sections.

5. In a coating machine, a work supporting arm having a work carrying head at one end thereof, a drive roller at the other end of said arm, a shaft connecting said roller and head, a pivotal support for said arm between the ends thereof, means for moving said support and arm in a direction transverse to said arm, a guide track for engaging said roller to rotate said head during the movement of said arm, a coating bath below and closely adjacent the path of movement of the pivotal support for said arm, said guide track having a portion thereof adjacent said coating bath arranged abo've the path of movement of the pivotal support for said arm for holding said arm in position to immerse a portion of a work piece on said head in said bath when said roller engages said track portion, and means for directing said roller onto said track portion.

6. In combination, a plurality of Work carrying members, means for moving said members successively in repeated cycles past an operating station, and means for selecting pre-determined ones of said work carrying members for special treatment at said station as said members pass said station, said selecting means being arranged to choose diiierent ones of said members at successive cycles of movement of said members past said station.

7. In combination, a plurality of work carrying devices, means for moving said devices successively past an operating station in repeated cycles, means for selecting one of each group of a given number of devices for special treatment as said devices past said station, the total number of said devices being a number that is not exactly divisible by the number of devices in each of said groups so that for each repeated cycle a diierent one of said devices will be selected from each group for said special treatment.

8. In a coating machine, a traveling carrier, a plurality of work supports mounted on said carrier and movable thereby successively, in recurrent cycles, past an operating station, means for selecting one of each group of a given number of said work supports for special operation as it passes said station, the total number of work supports on said carrier being a number that is not exactly divisible by the number of Work supports in each group, so that a different support will be selected from each group at successive cycles.

9, In a coating machine, a rotatable carrier, a plurality of work supports mounted on said carrier and rotatable thereby successively, in recurrent cycles, past an operating station, means for selecting one of each group of a given number of work supports for special operation as it passes said station, the total number of work supports on said carrier being a number that is not exactly divisible by the number of supports in each group so that a different support will be selected from each group for successive cycles, said selecting means being adjustable for changing the number in each group from Which selection is made, the total number of work supports on said carrier being a prime number so that a different one of said Work supports will be selected from each group at each successive cycle of operation no matter how many devices are included in each group.

l0. In a coating machine, a rotary carrier, a plurality of Work supporting devices mounted' on said carrier, a Work supporting head mounted n each of said devices, a drive roller operatively connected with each of said heads, a track for engaging said drive rollers to rotate said rollers and to guide said heads, a second track offset relative -to said rst named track, switch mechanism for directing said drive rollers from said first track to said second track, said w-ork supporting heads being directed through a different path of travel when said rollers engage said second track from the path of travel when said rollers are engaged by said first track, and means operated by the rollers engaging s-aid second track for operating said switch mechanism to direct the roller of one of each group of a pre-determined number of Work supports into engagement with said second track.

11. In combination, a rotatable member, a plurality of Work supporting arms pivotally mounted on said member, each of said arms having a rotatable head at one end and a drive roller at the other end for rotating said head, a track for engaging said drive rollers to rotate said heads and to guide said work supporting arms, a second track for holding said arms in a different position when said rollers engage said second track, a switch device for directing said rollers from said first to said second track, trigger mechanism operated by said rollers for operating said switch device to direct one of a group of a predetermined number of successive rollers from said first track to said second track, said trigger mechanism being adjustable relative to said track to vary the number of rollers in a group from which one is selected.

12. In a coating machine, a carrier, work supports mounted on said carrier, a coating bath adjacent the path of travel of said work supports, an operators station adjacent the path of travel of said work supports, said carrier being operable to move said work supports successively in recurrent -cycles past said coating bath and said operators station, means for rotating said work supports during movement of said carrier, means for manipulating said work support to subject work pieces thereon to said coating bath, means for diverting said Work supports from said rotating means during movement of said Work supports past said operators station, and means fo'. preventing operation, during one cycle of movement of said carrier, of saldi manipulating means and said diverting means on Work supports having Work thereon subjected to said bath during the next preceding cycle. y

13, In combination a bath and means for dipping a Work piece in said bath, said dipping means comprising a head having a projecting mandrel for receiving said' Work piece, and means for supporting said head with the projecting end thereof inclined upwardly and with the Work piece thereon immersed in said bath.

14. In combination a liquid bath and means for dipping a Awork piece in said bath, said dipping means comprising a pivotedi arm, a head on said arm having a projecting mandrel for receiving said Work piece, said arm having a bent portion to direct the projecting end of said mandrel in an upwardly inclined direction when the Work piece thereon is subjected tosaid bath.

15. A carrier having a plurality of Work supports thereon, means for operating said carrier to bring the supports thereon successively in repeatedl cycles past afn operating station, selecting mechanism for subjecting said supports to special treatment at said station, said selecting mechanism being operable to select one out of each group of a predetermined number of supports passing said station and at the next cycle to pass the one from each group selected at the preceding cycle.

16. A coating bath, a carrier, a plurality of Work supports on said carrier and moved thereby successively past said bath in repeated cycles and selecting mechanism constructed and arranged to operate one out of each group of a predeterj mined number of supports passing said bath to immerse a work piece thereon in said bath and to operate the other Work supports of said group to carry the Work thereon outside of said bath, the total number of Work supports on said carrier being a number that is not exactly divisible by the number of supports in each group so that at each successive cycle a diierent support in each group willA be operated to immerse the work piece thereon and each support will travel a plurality of cycles for each immersing operation thereof to permit time for drying of the Work piece thereon.

WILLIAM A. SMITH.

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