US2387273A - Coating apparatus - Google Patents

Description

Ot. 23, 1945. A. L KRONQUEST 2,387,273

CATING APPARATUS Filed oct. 11, 194s s snets-sheet 1 Oct. 23, 1945. A. L KRoNQUEsT 2,387,273

COATING APPARATUS Filed oct. 11,1943 s sheets-sheet 2 Oct. 23, 1945. A, KRONQUEST 2,387,273 COATING APPARATUS Filed Oct. l1, 1945 3 Sheets-Sheet 3 I by a restricted passage aiording constant com 1 Patented oci. 5194s COATING APPARATUS Alfred L. Kronquest, Syracuse, N. Y., assignor to Continental Can Company, Inc., New York, N. Y., a corporation of New York Application October 11, 1943, Serial No. 50535956 9 Claims.

This invention relates to coating apparatus and more particularly to apparatus for coating the interiors of containers with fiowable material by ooding lthe containers with such material and then permitting the surplus material to drain on, leaving an adherent coating on the container interior wall surfaces.

Apparatus ,embOdving the invention is adapted for use in coating articles, for example the interiorg of containers, withvarious owable subcessuchasol z mixtures a e invention is to provide improved apparatus of this kind which is of simple construction and is 'eillcient and rapidin operation.

Another object of the invention is to provide apparatus of the character stated in which delivery of ilowable material from a source of such for delivering the material to an article to be coated is controlled by a valve which is by-passed munication between the material source and the delivery device, the arrangement being such that there will be a constant but restricted now of material through. the delivery device even when the valve is closed, so as to prevent setting or congealing of the material in the delivery device.

Another object of the invention is to provide apparatus of this kind which is simple but reliableinoperation and in which the danger of congealing of the coating material in passages through which the material iiows is minimized.

Anotherobject of the invention Yis to provide apparatus of the character referred to in which a pump for placing the thermoplastic material under pressure, the pumpintak'e and discharge passages, a pressure chamber which receives the material discharged by the pump, and av valve for controlling 'the delivery of the coating material are all immersed in and therefore heated by a' supply of thermoplastic material constantly.

chamber out through the delivery tube,` even.

when the valve is closed. so that the material will not remain stationary in the tube and therefore will not be permitted to congeal in the tube.

material maintained under pressure to a device heating jacket C embracing va substantial por- Another object of the invention is ,to provide which is flowable at elevated temperatures but which congeals at ordinary or room" temperature.-

Other objects will become apparent from a'- reading of the following detailed description, the appended claims and the accompanying drawings. A' y I i N In the drawings: l j 1 Figure l isl a front elevation of apparatus embodying the invention, with parte broken away and others shown in section.

Figure 2 isa top plan view of the apparatus showninFigurel. v Figure 3 is a vertical section on the line I-J of Figure 1 drawn on an enlarged scale'. l.

Figurea is a fragmentary vertical sectional view of a container support, coating valve mechanism, and associated frame structuredrawn on an enlarged scale. y

Figure 5 is a plan view of an adapter ring. In the embodiment of the invention shown in the accompanying drawings, a framev Aserves to support a supply tank B adapted to contain the thermoplastic coating material F, and a tion of the `tank B and being 'adapted to contain a quantity .of heat transferring iluid i4 in contact with the walls'of the tank B. Coating units- Dcarried by the frame structure are mounted in alignment at the top of the apparatus and are adapted individually to receive inverted containers X-Y which are to be coated or treated. A pump generally designated E is immersed in the coating or treating fluid F. in the tank B and is arranged to be driven continuously by a motor G. The pump E delivers heated coating material to the u nits D which support the containers to be treated, but norm'lly the coating material is held -back by valve mechanism to be described later. In orderl to deliver the coating material to the inside of a container, the container is simplypushed downwardly so as to openthe associated valve and cause the interior of the container to be ilooded with the coating'material F.

Referring in more detail to the illustrative.

form of construction, equipment for maintaining the coating iluid hot and thus plastic and ilowable includes a gas pipe l extending underneath the Jacket C and having a vertical extension 2 secured to one end of the jacket C bya clamp I. B ranch pipes 4 extending `horizontally from a... aim the pipe I at spaced intervals are provided with vertical extensions 5 which lead respectively to .manually operable valves controlling the iiow formed with a. valve seat 42 adapted to be engaged by a'valve disc 43 formed on a. valve piston 44 mounted for vertical reciprocation in a bore '45 fonmedin the casing 40. A spring 48 inter- 5 d posed between each valve disc 43 and a ring 41 lrhe jacket tank c is substantially. sind with e suitable heatv transferringiiuid;i4,- such as oil. In order to maintain the jacketing. 'iluid Aat the desired temperature, 'a thermostatically controlled gas-valve unit AI5 having a heat responsive element I5 immersed in the fluid i4 is interposed between the gas pipe line i-2 and a fitting I1 which is adapted to' be connected to a -source `of gas-supply. Although the' flames at the burner heads 9 can be adjusted individually by the valves B when the apparaiuis is set up and operation is started, the thermostatic valve i5 will respond to slight changes in temperature of the heating fluid |4- for controlling the supply 0f gas to all of the burners simultaneously 'and -for thus` maintaining the heat transferring nuid at a substantiallylconstant temperature.

'I'he pump, E may be of any standar-d or suitable -construction and is immersed in the coating material F with itsintake passage I8 ar .ranged to receive uid directly from the tank B;

The pump discharge passage I9 is arranged to deliver coating uid under pressure into a pressure manifold orA chamber supported withinv the tank B, the fluid under pressure Within the chamber 20 being delivered into the containers under the control o f theoperator in a manner to be described later.

The pump E includes a shaft 2| coupled as at,l

22 to a shaft 23 journaled in a bearing 24 and equipped-at its upperV end with a bevel gear 25. 'Ihe gear 25 4meshes with a bevel pinion 25 secured'to one end of a shaft 21 Journaled in bearings 28 and equipped at its outer end with a pulley 2 9. A belt 30 vis trained around the pulley 29 and a pulley 3i on the motor G. 'I'he motor may be mounted for adjustment to vary the tension 'of the belt 30, and in the form shown the motor screwed as at. 48 into the bottom of the valve casing 40 yieldably urges the valve piston 44 upwardly, and yieldably holds the valve disc 43 on its cooperating seat 42. 'I'he ring 41 is formed with a plurality of openings 49 which aiiqrd communication of the manifold 20 with a chamber'5il inside of the valve casing 40.

The valve piston 44 is formed `with a circumferential recess 5| communicating through radial openings 52 with a bore 53 in the piston 44. A -counter-bore 54 in the piston 44 is threaded to receive the lower end of a vertically extending delivery tube 5,5. l

The valve piston 44 furthermore serves as a seat i'or a container support 56 having a vertically bored hub- 51 adapted to nt over the associated delivery tube 55.-4v The container support 56 includes a bottom 53 formed with drain openings se and provided with vertical webs et which extend from the hub 51 to a vertical flange 5l.

Figure 4 shows the parts of one container Y coating unit D in normal positions with a container X resting on the support 55 in readiness Afor being coated with the iiuid F.' In order to 30 cause delivery of the Afluid to coat the inside of the container, 'the operator presses downwardly on the container X which forces the support 56 downwardly and moves the valve piston 44 to ,disengage the valve disc 43 from the seat 42. With' the valve thus opened the heated treating fluid F flows upwardly through the openings 4! into the l chamber 50 and thence through the openings 52. the bore 53, and into the tube 55. The upper end of the tube is open and the uid is vdriven under pressure out of the tube so as to flood the interior opening se adapted to he closed by e lid a1.` A 1 drain pipe 36* communicates With the bottom of the tank'B and is controlled by a valve 36h.

As previously stated, coating iiuid is delivered into the containers only 'when the latter are depressed by the operator. inasmuch as the pump constantly delivers fluid under pressure to the manifold 20, it is desirable to provide a by-pass connection between the manifold and the tank B. Such a connection is indicated at 38 as comprising a conventional pressure relief or bypass device which preferably is adjustable to maintain a desired pressure within the manifold or chamber 20. I

The coating units D may all be of the same construction. Each unit D includes a valve genof the container X, thus assuring contactv of the iiuid withall portions of the container inner surface. The iiuid will be circulated through the container during the flooding operation and will pass out through the openings 59 in the support 56 and thus be returned to the tank B. In the practical use of the apparatus, containers to be coated are placed on each of the units D and only one container and associated support 56 are pressed downwardly at a time. I'he operator may start at either en'd and press the aligned containers downwardly in succession. allowing each depressed container to move back to normal position before the next container is depressed. In thisl way while a container is being held depressed, other and previously ooded containers will be standing in raised 'position and may be left there long enough to permit the excess coating nuid to drain completely from the supporting member 5B back into the tank B.

Inasmuch as the valves 35 oi' the umts D remain closed during substantial periods when containers erally designated 39 and comprising a xed casing 40 having threaded connection at 4| with the top of the manifold 20.- The casing 4011s are draining, there.`is a tendency for the coatingmaterial to'congeal within relatively cool delivery tubes 55. In order to prevent stoppage of the tubes 55due to congealing ofthe coating mate-I rial, each valve piston 44 is formed with a small opening 52 which communicates with the bore 53 directly under the tube 55. Itwill be apparent that when the valve 33 is held closed following the delivery-oil uuid through the-tube 55', heated thermoplastic material will flow slowly up through the opening 62, the bore 53, and the tube .55, thereby maintaining the treating uid in motion within the tube 5s end preventing the ina-"1 terial from cooling enough to cause it to congeal. 'I'he opening 62 is of such small iiow capacity that the material passed therethrough will flow slowly down the outside of the tube 55 `and out through the drain openings 59 without being elected substantially above the top of the' tube 55 and Without coming in contact with the container X.

The pump E, the pump intake and discharge passages I 8 and I9, the pressure chamber 20 and the valves 39 are all below the level of the heated thermoplastic material in the supply tank B, and consequently there can be no congealing of the material in these parts. Congealing oi material inside the tubes 55 when their associated valves I9 remain closed is prevented by the constant flow of heated thermoplastic material through the bypass passages 62 and the tubes 55.

Preferably the tank B is provided with a cover G3 formed with circularupstanding skirts 64 re- A spectlvely above and concentric with the supports 56 of the units D.

'I'he container supports 56 are loosely mounted on the valve pistons 44 and therefore may easily be adjusted so as to be adapted to receive containers of different sizes. vIn Figure 1 the supports 55 of the four units D nearest the right hand end ofthe drawings are adapted to receive containers X of a relatively large size, whereas the two other supports are shown as being adapted for receiving containers Y of relatively small size. The supports 56 of the two left hand units D are raised slightly by means of adapter or spacer bushings 55 to compensate for the lesser height of the containers Y. Adapter rings 56 formed with centering ilanges 81 are inserted inside the flanges Il.' It will be apparent that by using adapter bushings 85 and adapter rings 65 of different sizes, any size container within reasonable limits may be supported in the proper position relative to the delivery tubes 55.

Although the embodiment of the invention disclosed herein has features of construction rendering it especially suitable for coating articles with thermoplastic material, it willbeA apparent that apparatus constructed in accordance with the invention may be used for coating articles with other ilowable substances, e. g., cold water and glue mixtures, as previously mentioned.

The apparatus disclosed herein embodies the invention in the form now preferred, but it will be understood that changes may be made without departing from the invention as defined in the y claims.

Iclaim: l. In apparatus of the character described,

means for delivering ilowable material' to an article to be contacted by said material: means for maintaining the owable material under pressure necessary to effect delivery of the material: a .valve interposed between said two means for controlling the delivery of said material; and a restricted by-passpassage for aording communication between said two means independently of the condition .of said valve, said by-pass passage opening into the means in which the ilowable material is maintained under pressure vat a level at least as low as the level of the material therein.

2. In apparatus for coating the interiors of containers with nowabl'e material, a chamber for maintaining a SUPPLY of vtl'ie flowable material under pressure: a delivery tube extending upwardly and being adapted to project into an inverted container; a valve interposed between said chamber and said delivery tube for controlling the delivery of said material and when open having a flow capacity sufficient to pass said material rapidly enough to iiood the container; and a by-pass passage for affording constant communication between said chamber and said delivery tube irrespective of the condition of said valve, said by-Dass passage having sumcient flow capacity to enable the flowable material constantly to flow upwardly through said tube, out of the top of the tube, and thence downwardly outside of the tube without being ejected substantially above the top 0f the tube.

3. In apparatus for coating the interiors of containers with thermoplastic material, a chamber for maintaining a supply of the thermoplastic material under pressure; a delivery tube extending upwardly and being adapted to prolect into an inverted container; a valve interposed between said chamber and said delivery tube for controlling the delivery of said thermoplastic material and when open having a flow capacity suflicient to pass said material rapidly enough to flood the container; means for heating the thermoplastic material in said chamber and in contact with said valve to suchI a temperature that the heated material will not congeal in said chamber or in said valve; and means for preventing congeallng of the thermoplastic material in said delivery tube when said valve is closed comprising a by-pass passage for affording constant communicationy between said chamber and said delivery tube irrespective of the condition of said valve, said by-pass passage having suflicient ow capacity to enable the thermoplastic material constantly to ilow upwardly through said tube,'. out of the top of the tube, and thence downwardly outside of the tube without being ejected substantially above the top of the tube.

4. In apparatus for coating the interiors of containers with ilowable material, a chamber for maintaining a. supply of the flowable material under pressure; a delivery tube extending upwardly and being adapted to project into an inverted container; a valve interposed between said chamber and said delivery tube for controlling the delivery of said material and when Aopen having a iiow capacity suiiicient to pass said material rapidly enough to iiood the container; a container support mounted on said delivery tube and being connected to said valve whereby depressing of the container will move the support downwardly and said support being constructed to enable drainage of material from the ooded container; .and a by-pass passage for aifording constant communication between said chamber andsaid delivery tube irrespective of the condition of said valve,A said bypass passage having suilicient ow capacity to enable the' ilowablel material co'nstlamtl'yl to flow upwardly through said tube, out of the tot of the tube. and thence downwardly outside of the tube without being4 ejected substantially above the top of the tube.

5. In apparatus for coating objects with thermoplastic material. a Supply tank for the thermoplastic material; a pump mounted in said tank below the .level of thermoplastic material therein: a pressure chamber in said tank below the thermoplastic material level, said pump 'having an intake passage located in said tank below the thermoplastic material level. for 'receiving thermoplastic material from said tank and a discharge passage communicating with said pressure chamber and being located in said tank below the thermoplastic material level; a tube for delivering thermoplastic material from said pressure chamber for application to an article to be coated, the delivery end portion of said tube extending beyond said supply tank; a valve mounted in said tank below the thermoplastic material level for controlling the ilow of thersure; a plurality of spaced delivery units, each of said units comprising an upwardly extending delivery tube, a normally closed valve interposed ing the delivery end portion of said tube; a flange on said member adapted to embrace the side walls of a container oi one sized engaging said member; and a removable adapter ring adapted to be fitted within and'centered by said flange and having a Aconcentric ilange of smaller diameter for' embracing the side walls of a smaller size container.

8. InA apparatus of the character described, a pressure chamber; a delivery tube; a valve for controlling communication between said chamber and said tube and comprising a casing mounted on said chamber and a'reciprocable valve element in said casing, said tube being connected to said reciprocable element for movement therewith; a member mounted on said tube for adjustment longitudinally thereof and being engageable by the open end portion of a container extending between said tube and said pressure chamberJ` g5 means for supporting .a container in inverted position over said tube and being constructed to permit drainage of material from within the supi,

ported container. and means for opening the valve to effect flooding of the container; and meansior maintaining said pressure chamber,` said valve, and the thermoplastic material in said pressure chamber at plasticizing temperature, each oi said units being provided with a restricted bypass passage aiording constant communicatioxi'between said pressure tank and said delivery tube,

whereby when the valve of any oi said units is closed following ilooding of the associated container heated thermoplastic material will ow continuously and slowly through said delivery tube without being'ejected substantially above the top end o! said tube.

'1. In apparatus of the character described. a

y pressure chamber; a delivery tube; a valve interposed between said pressure chamber and said delivery tube; a member engageable by the open end of a container extending over and surroundover and surrounding the delivery end portion of said tube for maintaining the container withlits closed end spaced from the delivery endof said tube. said member being adapted normally to bear against said valve element; and means for maintaining'said member in adjusted position longitudinally of said tube and spaced from said valve element.

9. In apparatus of the character described, a pressure chamber; a delivery tube; a valve for controlling communication between said chamber and said tube and comprising acasingmounted on said chamber and a reciprocablevalve element in slaid' casing, said tube being connected to said reciprocable element for movement therewith; 4a member mounted on' said tube ior adjustment longitudinally thereof and being engageable by the open end portion of a container extending over and surrounding the delivery end portion of said tube for maintaining the container with its .closed end spaced from the delivery end of said tube, said member being adapted normally to bear against said valve element; and a spacer bushing adapted to betinterposed between said member and said valve element'ior maintaining said member relatively closer to the delivery end of saidtube than when said member engages said valve element.

ALFRED L. KRONQUEST.-

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