US3122320A

US3122320A - Method for filling electrically charged receptacle

Info

Publication number: US3122320A
Application number: US722712A
Authority: US
Inventors: Jerry G Beck; George E F Brewer; Gilbert L Burnside; John W Mistele; Smarsh Joseph
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1958-03-20
Filing date: 1958-03-20
Publication date: 1964-02-25
Anticipated expiration: 1981-02-25

Description

Feb. 25, 1964 J. G. BECK ETAL METHOD FOR FILLING ELECTRICALLY CHARGED RECEPTACLE 2 Sheets-Sheet 1 Filed March 20, 1958 J. G. BECK G. E. F. BREWER G. L. BURNSIDE J. W. MISTELE J. SMARSH FIG. 4

INVENTORS 6121b BY 6. FMMMM &

ATTORNEYS Feb. 25, 1964 J. G. BECK ETAL 3,122,320

METHOD FOR FILLING ELECTRICALLY CHARGED RECEPTACLE Filed March 20, 1958 2 Sheets-Sheet 2 FIG. 2B

J.G. BECK G.E.F. BREWER e.| BURNSIDE J.W. MISTELE J. SMARSH INVENTORS 5. 9. 22261) Ema ATTORNEYS United States Patent 3,122,320 METHGD FGR FELING ELECTRICALLY CHARGED RECEPTACLE Jerry G. Beck, Oak Park, George E. F. Brewer, Walled Lake, Gilbert L. Burnside, Oak Park, John W. Mistele, Detroit, and Joseph 'Smarsh, Livonia, Mich, assignors to Ford Motor Company, Dear-born, Mich, a corporation of Delaware Filed Mar. 20, 1958, Ser. No. 722,712 2 Claims. (Cl. 239-3) This invention relates to the handling of electrostatic spraying materials and more particularly to a method for replenishing water base paint consumed from an electrically charged paint pot.

In the usual installation for the electrostatic spraying of solvent type paints, the receptacle or paint pot which holds the paint reserve is grounded and a high potential is applied to, or adjacent to, a spraying head or atomizing nozzle. The spraying device is usually connected to receive paint from the receptacle by a dielectrical tube, such as rubber, and the column of paint therein being relatively non-conductive serves to isolate the electrically charged spray head from the grounded receptacle. However, the use of conductive water base paints requires that the paint pot be insulated from ground since the column of paint carries the hi h potential from the spray head to the paint pot.

Prior to this invention, in order to replenish the paint pot, it was necessary to shut down the apparatus and bleed or? any remaining charge in the paint receptacle prior to filling. The method which we hereby provide permits either the intermediate or continuous filling of the receptacle while it remains charged. Essentially, we move isolated unit quantities or particles of the water base paint from a grounded supply source through the air and deposit them into the charged container.

It is, therefore, an object of this invention to provide a method of replenishing an electrically charged water base paint receptacle.

This and other objects of our invention will become apparent from the following description in which:

1G. 1 illustrates a form of our invention as applied to an electrostatic spraying arrangement; and

FEGS. 2a, 2b, 3a, 3b, and 4 disclose alternate arrangements for the practice of our invention.

Referring to H6. 1, a paint pot is shown generally at 19 and contains a water base paint 21 which will be electrostatically applied. Flexible pipe 13 is connected to receive paint from pot 1t and convey it to a rotating cup atomizing head 14. A high potential from power supply 15 is applied to head 14 and causes the paint particles atomized by the spinning cup to be electrostatically charged and carried to an article upon which they will be deposited in a manner which is well known and understood in the art.

Receptacle 1'? is insulated from ground by dielectrical 11 which, in turn, is supported on grounded plate 12. For the purpose of filling the receptacle, in accordance with this invention, we provide a receiving funnel 26 with a neck extending through the top and into receptacle 1% A supply of water base paint is shown generally at 16 and a conduit 17 leads therefrom to a head 18 which may take the form of a sprinkler or shower head having perforations 22 formed therein. An intermediate receiving funnel 19, if desired, may be positioned between the head 18 and receiving funnel 20. Head 18 is grounded as shown. In the operation of this embodiment, replenishing paint from source 16 is sprayed or otherwise broken into discrete particles by perforated head 18. These particles fall freely through the air space between head 18 and funnel 19 and then pass through a second air space into receiving funnel 20. The purpose of intermediate funnel 19 is to collect any scattered droplets from head 18 that would not otherwise enter funnel 243. The first air space defined between head 18 and intermediate funnel 19 and the second air space between funnel 19 and receiving funnel 2i serve to isolate the grounded head 18 from the charged paint pot 1t). Funnel 19 may assume a potential intermediate that of the head 18 and the receiving funnel 2%.

FIG. 2 shows an arrangement for the transfer of larger quantities of water base paint from the source 16 into the paint pct 10 by means of an intermediate movable transfer vessel 36. Vessel 3b is insulated from ground and in the raised position shown by FIGURE 2(a) it may be filled through pipe 17 from source 16, then lowered and the contents discharged into pot 15) as shown in FIG. 2(b). We preferably provide two feet of air space between the bottom of the movable transfer vessel 3% and the top of pot 19 with the vessel in the raised position and two feet of space between pipe 17 and the top of the transfer vessel 3%; with the vessel in the lowered position.

FZGS. 3(a) and 3(2)) show another arrangement for replenishing the pot in accordance with the teaching of this invention wherein an intermediate isolated transfer vessel 31 is iixed in space between pipe 17 and pot 10 and is provided with a retractable fill ng pipe 32 by which the vessel may be filled from grounded source 16 through pipe 17. Filling pipe 32 is then lowered into vessel 31 upon the completion of the filling. Pot 1b is also provided with a retractable filling tube 33 which is lowered into the pot when not in use but which may be extended to receive paint from the transfer vessel. We preferably provide two feet of air space between the top of the intermediate vessel 31 and the filling pipe 17 and between the bottom of the vessel and the paint pot 16.

IN FIG. 4 we illustrate a further embodiment of our method. We provide a funnel 35 with a neck in communication with pot 1t and a substantially horizontal receiving throat. A pump 3'7 delivers paint under pressure from supply 16 to a nozzle 36 where the paint is broken into discrete particles and directed into the throat of the funnel. The inertia thus given the particles carries them through the air space and into the funnel 36 where they collect and drain into pot 10 thereby replenishing the paint supply.

It is, therefore, apparent that we have provided a method for the filling of a charged paint pot either continuously or intermediately from a grounded supply of water base paint without the necessity of removing the charge from the paint pot or otherwise interfering with the spraying operation.

We claim:

1. A method for transferring an electrically conductive paint from a source at a substantial ground potential to a receptacle at a substantial electrical potential with reference to the ground potential of the source, comprising the steps of spraying the paint from said source into paint particles, receiving said paint particles in a receiving funnel, conducting the paint from said receiving funnel into the receptacle, positioning an intermediate funnel between said source and said receiving funnel, maintaining said intermediate funnel at an electrical potential intermediate the ground potential of said source and the electrical potential of said receptacle, collecting a portion of said particles not received by said receiving funnel in said intermediate funnel, and directing said portion collected in said intermediate funnel to said receiving funnel to prevent the loss of paint in the transfer of the latter from said source to said receptacle.

2. A method for transferring an electrically conductive paint from a source at a substantial ground potential to a receptacle at a substantial electrical potential with reference to the ground potential of the source, said source being spaced from said receptacle, said method comprising the steps of spraying the paint from said source into paint particles, transferring said particles through air into a receiving funnel, said receiving funnel being carried by and assuming the potential of said receptacle, conducting the paint from said receiving funnel into said receptacle, positioning an intermediate funnel between said source and said receiving funnel, insulating said intermediate funnel from said source and from said receiving funnel, maintaining said intermediate funnel at an electrical potential intermediate the ground potential of said source and the electrical potential of said receptacle, collecting a portion of said particles not received by said receiving funnel in said intermediate funnel, and directing said portion collected in said intermediate funnel into said receiving funnel to prevent the loss of paint in the transfer of the latter from said source to said receptacle.

References Cited in the file of this patent UNITED STATES PATENTS 1,346,811 Diebold July 20, 1920 2,027,308 Schacht Jan. 7, 1936 2,358,227 Hiers Sept. 12, 1944 2,675,330 Schwartz et a1 Apr. 13, 1954 2,826,513 Blanchard Mar. 11, 1958 FOREIGN PATENTS 948,978 France Feb. 7, 1949 421,811 Great Britain Dec. 20, 1934 793,958 Great Britain Apr. 23, 1958