US2349444A - Apparatus for inside coating - Google Patents

Description

May 23, 1944. MCGOWAN APPARATUS FOR INSIDE (BOATING Filed June 29, 1940 INVENTOR AwWwL ATTORNEY Patented May 23, 1944 APPARATUS FOR INSIDE COATING Michael E. McGowan, Bloomfield, N. J., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application June 29, 1940, Serial No. 343,229

(c1. si -1s) 7: Claims.

considered, is to automatically coat the insidesurfaces of vitreous envelopes uniformly and in an economical and convenient manner.

Another object of my invention is the simultaneous application of an inside coating to a plurality of elongated vitreous envelopes or tubes.

A further object of my invention is the ro visionof apparatus for coating the inside surfaces of elongated vitreous envelopes, comprising upper and lower manifolds, or other coating devices, which grip the upper and lower end portions of said envelopes, and means for forcing coating material to said envelopes, including means for preventing the coating material from rising therein beyond a predetermined point, said apparatus also including means for removing the excess coating material therefrom, and releasing the envelopes from said manifolds.

Other objects and advantages of the invention, relating to the particular arrangement and construction of the various parts, will become apparent as the description proceeds.

In the drawing: g

Figure 1 is a plan of mechanism embodying my invention, with parts broken away.

Figure 2 is an elevational view, partly in vertical section on the line IIII of Figure 1, in the direction of the arrows. 7

Figure 3 is a vertical sectional view, on the line III-III of Figure 2, in the direction of the arrows.

Figure 4 is an enlarged sectional view of a portion of the top manifold and associated envelope.

Referring to the drawing in detail, like parts being designated by like reference characters, there i shown a coating machine comprising a conveyor i l having a plurality of clips l2 and I3 between which are held elongated vitreouse'n velopes or tubes M, such as those of the typeemploy-ed in the manufactur of fluorescent lamps. That is, they may be generally cylindrical hollow tubes, open top and bottom. The conveyor ll rotates and is adapted to periodically index or stop after it ha turned a distance equal to the circumferential distance between adjacent tubes it times the number of tubes handled at once.

Associated with the conveyor II is a table or bench 85 on which is mounted a standard or pedestal i6, carrying manifold guiding means or lugs I! and I8. Pivoted to said standard I6 is an upper movable device, such as a lever i9, carrying a manifold, reservoir, or other coating device 2| with arm 20 adapted to reciprocate in thelug I1, and a lower movable device, such as a lever 22, carrying a manifold, reservoir, or other coating device 23, with arm 38 adapted to reciprocate in the lug l8. In the present embodiment, the manifolds 2| and 23 are adapted to grip three envelopes or tubes M therebetween.

The upper manifold 2! has ports 2 25 and 26, through pipes 27, 28 and 29, each of which extends slightly below an associated resilient or rubber seal 3|, as shown most clearly in Figure l. The purpose of this construction is to prevent the coating material from extending quite to the upper end of the envelopes or tubes is.

The lower manifold 23, ha a corresponding number of ports 32, 33 and Ed in resilientor rubber nozzles 35, 3B and 31.

The, movable devices or levers i9 and 22 are operated through connecting rods 33 and 3d, the lower ends of which are pivoted to operating crank arms ll and 42, which may extend from a bell crank device 33, mounted on a shaft 36, pivoted in a bracket it! which is secured to the table 25. A lower arm M of the device 13 carries a roller engaged by an operating cam 46, mounted on a cam shaft 47 pivoted in a bracket 50 which is secured to table It. The operating arm 4! is controlled by a spring 48, so that said manifolds 2| and 23 tend to move together and grip the tubes M disposed therebetween until they are withdrawn from said tubes by action of the cam 46 on the roller-carrying arm M.

The lower manifold 23 carries a flexible tube 29, also connected to a pipe or tube 5i which extends into the bottom portion of a container or bottle 52 of coating fluid 53, the space between the tube 5| and the neck of the tube receiving aperture being closed by a cork or the like 544.

In order to cause the coating materia1 53 to rise in the tubes or lamp envelopes it when desired, I provide a connection 55 to a compressed air line 56, through a shut-off valve 57?, and an automatic control valve 58, which latter may be operated by cam 59 acting on roller 6i carried by the arm 62 of hell crank lever 63, pivoted to a bracket 64, which may be carried by the table i 5. Another arm 65 of the bell crank lever .63 is actuated by a spring 66, so that its roller 6! is caused to remain in engagement with the operating cam 59, whereby the valve 58 is opened and closed as desired.

In order to prevent the coating material from rising beyond the upper end portions of the tubes I4, I provide a special air relief valve 61, so adjusted that air is released therefrom when the coating fluid rises in the tubes l4 to the lower ends of, the tubes 21, 28 and 29.

As a safety precaution against inaccurate operation or failure of the valve 61, the upper manifold 2| is formed with sufficient capacity to function as an overflow reservoir and accommodate a considerable amount of coating fluid, for example, all in the bottle 52, before it overflows, so that said overfl'ow is returned to the reservoir 52; Said upper manifold is also desirably provided with a filling funnel 68 in order to allow for convenient replenishing of the supply of coating material.

The operation of the apparatus, previously described, is desirably as follows:

The conveyor II is caused to rotate at intervals, successively bringing, in the present embodiment, groups of three tubes l4 into position between the separated manifolds 2| and 23. When this indexing occurs, turning of the cam 46 with its shaft 41, as by drive shaft 69 through bevel gears H, allows the spring 48 to operate the bell crank 43 and thereby push the manifolds 2| and 23 toward one another into fluid-tight engagement with the tubes or envelopes l4. As

the cam 46 allows this engagement, the cam 59 also causes the valve 58 to open, admitting air' to the closed coating bottle 52, and forcing coating fluid therein, which may be fluorescent material, up through pipes 5|, 49, and the lower manifold 23 to a limit level on said tubes 14, defined by the lower ends of the pipes 21, 28 and 29. The air relief valve 61 then operates to prevent the fluid from rising above, or much above, this level.

Continued turning of the cam shaft 41 first takes the pressure off the coating fluid 53, as by closing the compressed air valve 58, and releases the air in the bottle 52, whereby the coating fluid in the lamp envelopes or tubes 14 drains back into said bottle, the cam 46 then operating to cause a withdrawal of the manifolds 2| and 23 from the tubes l4 gripped therebetween under the action of the spring 48.

The conveyor I l of the machine then moves on to index the next three tubes for repeating the coating operation. The tubes which have been coated may then be carried by the machine to baking or other means for fixing the coating thereto, after removing any excess from the bottom end portions thereof.

Although a preferred embodiment of my invention has been disclosed, it will be understood that I do not wish to be limited to the employment of my machine for coacting vitreous envelopes of the particular character disclosed, as other embodiments of my invention will be apparent to those skilled in the art and I, therefore, wish to be limited only by the spirit and scope of the appended claims,

I claim:

1. Apparatus for coating the inside of vitreous envelopes comprising a conveyor carrying said envelopes, means for causing said conveyor to index a plurality of said envelopes sequentially, a bracket mounted adjacent said conveyor and provided with lugs, levers pivoted on said bracket, upper and lower manifolds operatively connected to said levers, arms extending from said manifolds to and slidable in said lugs to cause said manifolds to reciprocate toward and away from one another upon movement of said levers so as to either grippingly connect with or release indexed envelopes, a shaft carrying a plurality of cams, a bell crank lever actuated by one of said cams and having one arm connected to one, and another connected to another of said manifold connected levers, means for turning said shaft so that said manifolds reciprocate toward and away from one another at predetermined intervals in synchronism with the indexing of said conveyor, a container holding a supply of coating fluid, means connecting said lower manifold to the fluid in said container, a source of compressed air, means connecting said source to said container over said fluid, another bell crank lever, a valve for controlling said compressed air, means connecting said other lever and valve, said other cam operating said other bell crank lever to open said controlling valve to admit air and force said coating fluid into said lower manifold and connected envelopes, after the latter have been gripped between said manifolds, for flushing said fluid over the inner surfaces of said envelopes, and then close said valve and allow said fluid to drain back into said container.

2. Apparatus for coating the inside of a vitreous tube comprising a bracket provided with lugs, levers pivoted on said bracket, upper and lower reservoirs operatively connected to said levers, arms extending from said reservoirs to and slidable in said lugs to cause said reservoirs to reciprocate toward and away from one another upon movement of said levers, means for moving said levers to cause said reservoirs to reciprocate toward and away from one another at predetermined intervals, so that they either grippingly engage and connect with the ends of said tube or release it, a supply of coating material,

- and means for forcing said coating material into said'lower reservoir and over the inner surface of said tube, and then allowing it to drain back into said supply.

3. Apparatus for coating the inside of a vitreous tube comprising a bracket provided with lugs, levers pivoted on said bracket, upper and lower reservoirs operatively connected to said levers, arms extending from said reservoirs to and slidable in apertures in said lugs to cause said reservoirs to reciprocate toward and away from one another upon corresponding movement of said levers, means for operating said levers to effect desired reservoir movement at predetermined intervals, whereby the latter are adapted to either grippingly engage and connect with the ends of said tube or release it, a bell crank lever having one arm connected to one and.

another connected to another of said reservoirconnected levers, means for operating said bell crank lever so that said reservoirs reciprocate toward and away from one another at predetermined intervals, a container for a supply of coating fluid, and means for forcing contained fluid: into said lower reservoir and over the inner surface of said tube, and then allowing it to drain backinto said reservoir.

4. Apparatus for coating the inside of a vitreous tube comprising a bracket provided with lugs, levers pivoted on said bracket, upper and lower reservoirs operatively connected to said levers, arms extending from said reservoirs to and slidable in said lugs to cause said reservoirs to reciprocate toward and away from one another upon corresponding movement of said levers, a shaft carrying a cam, means actuated by said cam and. having. one part connected to one and.

another part connected to another of said reservoir-connected levers, means for turning said shaft so that said reservoirs reciprocate toward and away from one another at predetermined intervals, a container for a, supply of coating material, and means for forcing contained material into said lower reservoir and over the inner surface of said tube, and then allowing it to drain back into said reservoir.

5. Apparatus for coating the inside of a vitreous tube comprising a bracket provided with lugs, levers pivoted on said bracket, upper and lower reservoirs operatively connected to said levers, arms extending from said reservoirs to and slidable in apertures in said lugs to cause said reservoirs to reciprocate toward and away from one another upon corresponding movement of said levers, means for operating said levers to eflect desired tube gripping or releasing movement of said reservoirs at predetermined intervals, a container for a supply of coating material, means connecting said lower reservoir to said container, a source of compressed air, means connecting said source to said container over said material, a bell crank lever, a valve for controlling said compressed air, means connecting said bell crank lever and valve, and means for operating said bell crank lever to open said valve to admit air and force said coating material into said lower reservoir and connected tube, after the latter has been gripped between said reservoirs, for flushing said material over the inner surface of said envelope, and then close said valve and allow said material to drain back into said container.

6. Apparatus for coating the inside of vitreous envelopes comprising a conveyor therefor, means for causing said conveyor to sequentially index a plurality of said envelopes, a standard mounted adjacent said conveyor and provided with guiding means, upper and lower coating-fluid containers slidably mounted with respect to said'guiding means, operating means movably carried by said standard and connected to said containers, means for driving said operating means to cause said containers to reciprocate toward and away from one another, so as to either grippingly connect with or release indexed envelopes, cam means, bell crank lever means actuated by said cam means and having arms connected respectively to said container operating means, means for turning said cam means so that said containers reciprocate toward and away from one another at predetermined intervals in synchronization with the indexing of said conveyor, a reservoir holding a, supply of coating fluid, means connecting said lower container to the fluid in said reservoir, a source of compressed air, means connecting said source to said reservoir over said fluid, another bell crank lever, a valve for controlling said compressed air, means connecting said other lever and valve, and said other cam being so shaped that it will operate said other lever and connected valve to cause air to force said coating fluid into said lower container, flush said fluid over the inner surfaces of said envelopes while the latter are gripped between said containers, and then remove the air pressure and allow said fluid to drain back into said reservoir.

7. Apparatus for coating the inside of a vitreous tube comprising a standard provided with guiding means, upper and lower coating-fluid containers slidably mounted with respect to said guiding means, operating means movably carried by said standard and connected to said containers, means for driving said operating means to cause said containers to reciprocate toward and away from one another at predetermined intervals, so that they either grippingly connect with the ends of said tube or release it, a supply of coating material, and means for forcing said coating material into said lower container and over the inner surface of said tube, while gripped between said containers, and then allowing it to drain back into said supply.

MICHAEL E. McGOWAN.

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