US3734407A

US3734407A - Dual spray and recirculation system

Info

Publication number: US3734407A
Application number: US00167699A
Authority: US
Inventors: Stefano A De
Original assignee: Crown Cork and Seal Co Inc
Current assignee: Crown Cork and Seal Co Inc
Priority date: 1971-07-30
Filing date: 1971-07-30
Publication date: 1973-05-22
Anticipated expiration: 1990-05-22
Also published as: ZA721931B; NL7209171A; GB1361887A; DE2236140A1

Abstract

An electrically operated solenoid actuated spray system for coating the insides of cans with lacquer or other coating substance. A nozzle extension adapted to extend into cans includes concentric chambers allowing hot lacquer to constantly recirculate by flowing through the nozzle extension to the nozzle tip and back again. Separate tubes are provided within the inner concentric chamber to transport the lacquer to dual nozzle spray outlets. Even though lacquer may remain in these tubes for periods of time when there are breaks in can production, the recirculating lacquer will keep the lacquer in the tubes hot and ready to be used thus preventing improper application when can coating resumes.

Description

ijited States Patent 1 De Stefano, Jr.

[ 51 May 22, 1973 54] DUAL SPRAY AND RECIRCULATION 1,523,855 1/1925 Barrows ..239/1321 SYSTEM Primary ExaminerRobert S. Ward, Jr. [75] Inventor. all??? :1 De Stefano, Jr., Phlladel y g E. Woodcock et a]. [73] Assignee: Crown Cork & Seal Company, [57] ABSTRACT Inc., Philadelphia, Pa.

An electrically operated solenoid actuated spray [22] ed J ly 0, 9 system for coating the insides of cans with lacquer or [21] Appl 167 699 other coating substance. A nozzle extension adapted to extend into cans includes concentric chambers a1- lowing hot lacquer to constantly recirculate by flowing 239/1311, through the nozzle extension to the nozzle tip and 239/139 back a ain. Se arate tubes are rovided within the g P P [51] Int. Cl ..B05b 1/24, 1305b 9/00 inner concentric chamber to transport the lacquer to [58] Field of Search ..239/128, 132.1,132.3, dual nozzle s ray outlets. Even thou h lacquer may P g 239/1325, 133, 134, 135, 137, 139, 13, 124 remain in these tubes for eriods of time when there P are breaks in can production, the recirculating lacquer [56] References Cited will keep the lacquer in the tubes hot and ready to be used thus preventing improper application when can UNITED STATES PATENTS coating resumes 1,642,418 9/1927 Kovanda et al ..239/l32.1 2,532,995 12 1950 Chausse.... ..239 133 x 14 Clams 4 Draw 1,288,879 12/1918 Harris "239/128 X Patented May 22, 1973 3,734,407

2 Sheets-Sheet 2 DUAL SPRAY AND RECIRCULATION SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to spraying mechanisms used in coating the interior surfaces of containers, particularly cans, as is required to protect the contents from contamination. In particular the invention relates to the type of spraying mechanism which utilizes an elongated nozzle extension which extends within the can to be sprayed so as to more readily achieve a uniform, thorough coating on the inside can surfaces. The use of various types of lacquers and enamels is contemplated.

2. Prior Art In the past, it has been difficult to achieve uniform, thorough spray coatings on the inside of both the bottom surface and the side surface of the can without the use of a nozzle extension. Even where nozzle extensions have been used, there has been a tendency for the lacquer to cool and solidify within the extension, while the nozzle is not in use and unpredictable and nonuniform spraying results. Of course, these periods of non-use result whenever the feeding of cans ceases due to breakdowns, stoppages and other uncontrollable lapses. In order to overcome these spraying difficulties after periods of non-use, it is necessary that the lacquer or other type of coating liquid within the nozzle extension remain fluid at all times.

As stated, can spray guns in the past have been of two general types. US. Pat. No. 3,062,177 issued to H6. Henrickson discloses the type which uses spray nozzles outside of the cans, in which it is difficult to achieve a satisfactory, uniform spray within the can. The other type is disclosed in US. Pat. No. 3,081,947, issued to CT. Walter, and employ elongated nozzles which are capable of spraying within the can, but in which the past have not employed a suitable nozzle recirculation system to keep the lacquer hot at all times.

Recirculating hose assemblies, such as the type disclosed in US. Pat. No. 3,529,626 issued to D.F. German have been used with spray systems, however, there has not been a recirculatory system which has effectively been used within a nozzle extension itself with its narrow elongated configuration. Nor are systems of the type disclosed in US. Pat. No. 3,529,626 designed to act as heating elements for adjacent conveying means to prevent the buildup of a residue.

BRIEF SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a spray system which employs a spray gun having an elongated nozzle with heating means to heat lacquer which may remain in the nozzle during short periods of non-use.

It is another object of the present invention to provide a recirculatory system for use in elongated-nozzlespray gun systems that are used in spraying the inside surfaces of cans.

It is a further object of the present invention to provide a spray system which has a bypass manifold that both returns the lacquer to the pump and heating means and recirculates it back through the nozzle assembly.

It is a still further object of the present invention to provide a spray system in which the lacquer residue which forms in the elongated tubes is kept hot by other recirculating lacquer to prevent it from solidifying.

It is yet another object of the present invention to provide a spray system which is actuated by electrically operated solenoids.

These and other objects are achieved by an embodiment of the invention which utilizes an elongated nozzle with dual spray means. Two flexible tubes extend through the nozzle to two spray outlets located in the tip of the nozzle. One of the spray outlets is used for spraying the bottom surface of the inside of the can while the other effectively sprays the side surfaces of the inside of the can. The flexible tubes are surrounded by a cylindrical member which forms an inner chamber through which hot lacquer is pumped to keep the ready-to-spray lacquer in the tubes hot.

The outer wall of the nozzle extension serves as a second concentric cylindrical member thus forming an outer chamber between cylindrical members. Lacquer which flows through the inner chamber formed by the inner-concentric member in the direction of the nozzle tip flows through a passage and back through the outer chamber egressing at the opposite end of the nozzle extension where it flows through a manifold which houses solenoid valves. Part of the lacquer flow as needed is forced into the tubes leading to the spray outlets while the remainder of the lacquer returns to heaters to be reheated and repumped.

Separate electric solenoid valves are used to actuate the can bottom and can side sprayers independently.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing the spray system and can transporting system and depicting a can in position to be sprayed,

FIG. 2 is a cross-sectional cutaway of the spray gun nozzle extension,

FIG. 3 is a cross-sectional view of a solenoid valve taken along line 33 of FIG. 2; and

FIG. 4 is a cross-sectional view of the nozzle block taken along line 44 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a manifold 10 has electrically operated solenoid valves 11 and 13 which are spray actuating means within the system. Piping 12 houses dual flow means which feeds from the manifold 10 to a portion of the valve housing unit 14. Adjacent the valve housing unit 14 is nozzle block 16 from which extends the nozzle extension 18 terminating in nozzle tip 20. A nozzle is shown extending into a can 22 which is being transported along rails 24. The can is spun by

spinner wheels

26 and 27 so that a uniform coating may be sprayed onto the inside walls of the can. Any suitable can transporting means may be used in lieu of the one just described and the system has utility for all type cans including those manufactured by a drawing process. As will be described in detail, lacquer is sprayed from the end spray outlet 44 onto the bottom surface 23 of the can 22 and from the side spray outlet 46 onto the side surface 25 of the can 22.

The nozzle can either be reciprocating or stationary as the spraying is taking place depending on the type of system employed.

Referring to FIG. 2,

tubes

28 and 30, carrying the spray for the end and for the body respectively, extend through nozzle extension 18. The end tube 28 is fluidly connected with end spray outlet 44 in the nozzle tip 20 and body tube 30 is fluidly connected with body spray outlet 46 in the side of the nozzle tip 20. The tubes 28- and 30 extend through the nozzle block 16 communi-.--

eating with lacquer passages 38 and 36' respectively which lead to the solenoid valves 11 and'13 in the by-' pass manifold 10.

Referring to FIG. 3, the lacquer passage 38 which connects with end spray tube 28 is shown leading to one of the solenoid valves 11 on the manifold block 10. A spring biased valve plunger 34 or other similar actuable means is used to close passageway 38 until the solenoid is actuated. Passageway 36 leads to an identical valve unit 13 and plunger (not shown) located in the manifold block 10 next to valve 11.

Referring to FIG. 2, an inner-cylindrical member 48 concentric within the outer extension wall 50 is placed within the nozzle extension 18 to form a channel or chamber 52 within the inner member 48 and a channel or chamber 54 between member 48 and the outer nozzle extension housing 50. The inner member may be welded in place as is shown by weld 55. Weld 57 is used to secure the outer wall 50 to the nozzle tip 20. The

tubes

28 and 30 are located within the inner-concentric member 48. Referring to FIGS. 1 and 3, lacquer infeed line 56 enters opening 58 of block 16 and communicates with inner chamber 52, thus allowing lacquer to flow toward the nozzle tip 20 through the extension 18 around

tubes

28 and 30. Lacquer flowing in this manner flows to outlet 53 where it passes into outer chamber 54 between the inner-concentric wall 48 and the outer wall 50. Lacquer thus flows back toward the nozzle block 16 through chamber 54. Communicating with chamber 54 in nozzle block 16 is opening 60 which leads into flow line 62 leading from the nozzle block 16.

Referring to FIG. 3 flow line 62 is shown communicating with passage 38 when the plunger 34 is in the actuated position. Also communicating with flow line 62 is flow line 70 which leads to cross passageway 72 which extends through the manifold block 10 as shown in FIG. 2 and leads to flow line 74. Flow line 74 intercepts out-flow line 64 in an identical symmetrical manner as flow line 70 does with flow line 62. Out-flow line 64 communicates with passageway 36 when the plunger (not shown) associated with valve 11 is in the open position. This structure is identical to that shown for valve 11, plunger 34, flow line 62 and passageway 38. Out-flow line 64 flows to the lacquer supply area (FIG. 1) which includes heating means and pumping means. Here the lacquer is reheated and then repumped through the system, entering the nozzle structure through line 56.

Thus, hot fluid normally is pumped from the supply area through line 56 to the nozzle structure. The lacquer is pumped through the system at high pressure, approximately 800 psi. The hot lacquer from the pumping station passes through opening 58 into inner chamber 52 where it flows around

tubes

28 and 30 heating them as it flows up the nozzle to opening 53 where it enters chamber 54 and flows back through the nozzle to outlet opening 60 which communicates with line 62. It is routed to the bypass manifold 10 through line' 62 where it enters valve assembly 11 and either passes through the valve 11 when actuated into passageway 38, or it flows down through flow-line 70 into the cross flow-line 72 and flow-line 74 into the opposite valve assembly 13. Here the lacquer will either flow into passageway 36 if valve 13 is actuated or it will flow out through line 64 to the lacquer supply area where it will be reheated and recirculated once again.

If either or both of the solenoids are actuated, the lacquer will flow into

passageways

36 and 38 leading to

tubes

30 and 28 which convey the lacquer to spray outlet 46 for spraying the side surfaces of the can or to spray outlet 44 for spraying the bottom surface of the can. The spray feeding means for the end spray and for the side spray are kept entirely separate with each of the solenoid valves 11 and 13 being independently actuated to control the spraying action in the separate sprayers independently.

Thus, it can be seen, that hot lacquer will be continually flowing through

channels

52 and 54 and serving to heat the lacquer already in

tubes

28 and 30 where itremains until it is sprayed. The effect of this is that even when the lacquer in

tubes

28 and 30 is not used for a period of time, it nevertheless is kept hot and suitable for spraying despite the period of non-use.

As shown in FIG. 3, solenoid valves are actuated to spray lacquer in the can. Springs (not shown) are used to return the valve to a closed position. This eliminates the problems associated with air-triggered pistons used in the past to pass lacquer to the extension and nozzle. While various embodiments of the invention have been shown and described, it will be understood that various modifications may be made. The appended claims are, therefore, intended to define the true scope of the invention.

What is claimed is:

l. A spraying system for spraying the interior of a container comprising:

a. feed means to supply fluid to be sprayed;

b. an elongated nozzle extension to convey the fluid to a point inside of a container before the fluid is sprayed, said nozzle extension including separate conveying means for the fluid to be sprayed on container side walls, and for the fluid to be sprayed on container bottom;

0. actuating means to spray the fluid from the nozzle extension onto the inner can surfaces; and

d. means to heat fluid while it is in the nozzle extension.

2. The spraying system of claim 1 wherein the actuating means includes separate actuating means for the separate conveying means.

3. A spraying system for spraying the interior of a 50 container comprising:

a. feed means including pumping means to supply fluid to be sprayed; b. a nozzle extension comprising:

i. an outer cylindrical wall;

ii. an inner concentric cylindrical wall positioned to form a first longitudinal chamber within said inner wall and a second longitudinal chamber between said inner and outer cylindrical wall, said first chamber communicating with said feed means,

iii. a nozzle tip at one end of said extension, said inner cylinder having an aperture near said nozzle tip to allow communication between said first and second chambers,

iv. at least one tube extending through the nozzle extension within said first chamber to said nozzle c. actuating means including a valve communicating with said tube;

d. fluid connecting means, between said second chamber and said tube; and

e. means to return fluid to be reheated and recirculated whereby during operation fluid is pumped through the first and second chambers, through the fluid connecting means where it either passes through the valve to said tube or is pumped back to said feed means.

4. A spraying system for spraying the interior of a container comprising:

a. feed means to supply fluid to be sprayed;

b. a nozzle extension comprising;

i. an outer cylindrical wall;

iv. dual tubes extending through the nozzle extension within said first chamber to said nozzle tip.

0. separate actuating means communicating with each of said dual tubes at the end of said extension opposite said tip nozzle to cause fluid to be sprayed;

d. fluid connecting means between said second chamber and said dual tubes; and

e. means to return fluid to be reheated and recirculated whereby fluid is fed from said feed means through said first chamber, toward said nozzle tip through the aperture into said second chamber away from said nozzle tip, through said fluid connecting means and into either said dual tubes to be conveyed to spraying position or through return means to be reheated and recirculated dependent on said actuating means.

5. The spraying system of claim 4 wherein said feed means comprises:

a lacquer source,

pumping means operable upon said lacquer source,

conveying means for transporting pumped lacquer to said first chamber.

6. The spraying system of claim 5 wherein the lacquer is pumped at approximately 800 psi.

7. The spraying system of claim 6 wherein the separate actuating means comprises electrically operated solenoid valves which may be independently actuated.

8. The spraying system of claim 4 including external heating means for said fluid.

9. A spraying system comprising:

an extended nozzle having an outer elongated cylin drical member, an inner concentric elongated cylindrical member secured within said outer member forming an outer chamber between said concentric members and an inner chamber within said 5 inner member, at least one tube disposed through the length of said inner chamber and terminating at a spray outlet, the interior of said tube being sealed from fluid communication with said inner and outer chambers, and fluid communication means between said inner and outer chambers;

feed and recirculation means to supply heated fluid to said tube to be sprayed and to supply and recirculate heated fluid to said chambers to continually heat fluid within said tube; and actuating means to cause fluid to be sprayed from the tube of said nozzle.

10. A spraying system for spraying inside wall and bottom surfaces of a container comprising:

a. a recirculation system in which circulating heated fluid heats non-circulating fluid not within the recirculation system preparatory to the spraying of the non-circulating fluid,

b. a nozzle extension housing a portion of said recirculation system in which the circulating heated fluid by its proximity to the non-circulating fluid heats the non-circulating fluid,

c. dual spray means including an independently actuating means for each of said dual spray means,

d. a manifold block housing said independent actuating means and having an internal passageway for fluid to flow between said independent actuating means.

11. The spraying system of claim 10 wherein said independent actuating means comprises dual solenoid valves, one for each of said spray means.

12. The spraying system of claim 11 wherein said recirculation system recirculates substantially all fluid except such fluid that may be pumped through said valves to said spray means when said valves have been actuated either independently or simultaneously.

13. The spraying system of claim 12 wherein said dual spray means comprises dual tubular members that convey fluid to be sprayed through said nozzle extension and are substantially surrounded by fluid flowing through said recirculation system.

14. A method of spraying comprising the steps of:

pumping heated fluid from a fluid supply source into an extended nozzle and related structure;

intermittently admitting part of the pumped fluid to at least one spray tube communicating with a spray outlet for intermittent spraying;

allowing the remainder of the pumped fluid to circulate around the spray tube to heat residual fluid in said tube and then to return to the fluid supply source for reheating and recirculation.

Claims

1. A spraying system for spraying the interior of a container comprising: a. feed means to supply fluid to be sprayed; b. an elongated nozzle extension to convey the fluid to a point inside of a container before the fluid is sprayed, said nozzle extension including separate conveying means for the fluid to be sprayed on container side walls, and for the fluid to be sprayed on container bottom; c. actuating means to spray the fluid from the nozzle extension onto the inner can surfaces; and d. means to heat fluid while it is in the nozzle extension.

3. A spraying system for spraying the interior of a container comprising: a. feed means including pumping means to supply fluid to be sprayed; b. a nozzle extension comprising: i. an outer cylindrical wall; ii. an inner concentric cylindrical wall positioned to form a first longitudinal chamber within said inner wall and a second longitudinal chamber between said inner and outer cylindrical wall, said first chamber communicating with said feed means, iii. a nozzle tip at one end of said extension, said inner cylinder having an aperture near said nozzle tip to allow communication between said first and second chambers, iv. at least one tube extending through the nozzle extension within said first chamber to said nozzle tip; c. actuating means including a valve communicating with said tube; d. fluid connecting means, between said second chamber and said tube; and e. means to return fluid to be reheated and recirculated whereby during operation fluid is pumped through the first and second chambers, through the fluid connecting means where it either passes through the valve to said tube or is pumped back to said feed means.

4. A spraying system for spraying the interior of a container comprising: a. feed means to supply fluid to be sprayed; b. a nozzle extension comprising; i. an outer cylindrical wall; ii. an inner concentric cylindrical wall positioned to form a first longitudinal chamber within said inner wall and a second longitudinal chamber between said inner and outer cylindrical wall, said first chamber communicating with said feed means, iii. a nozzle tip at one end of said extension, said inner cylinder having an aperture near said nozzle tip to allow communication between said first and second chambers, iv. dual tubes extending through the nozzle extension within said first chamber to said nozzle tip. c. separate actuating means communicating with each of said dual tubes at the end of said extension opposite said tip nozzle to cause fluid to be sprayed; d. fluid connecting means between said second chamber and said dual tubes; and e. means to return fluid to be reheated and recirculated whereby fluid is fed from said feed means through said first chamber, toward said nozzle tip through the aperture into said second chamber away from said nozzle tip, through said fluid connecting means and into either said dual tubes to be conveyed to spraying poSition or through return means to be reheated and recirculated dependent on said actuating means.

5. The spraying system of claim 4 wherein said feed means comprises: a lacquer source, pumping means operable upon said lacquer source, conveying means for transporting pumped lacquer to said first chamber.

9. A spraying system comprising: an extended nozzle having an outer elongated cylindrical member, an inner concentric elongated cylindrical member secured within said outer member forming an outer chamber between said concentric members and an inner chamber within said inner member, at least one tube disposed through the length of said inner chamber and terminating at a spray outlet, the interior of said tube being sealed from fluid communication with said inner and outer chambers, and fluid communication means between said inner and outer chambers; feed and recirculation means to supply heated fluid to said tube to be sprayed and to supply and recirculate heated fluid to said chambers to continually heat fluid within said tube; and actuating means to cause fluid to be sprayed from the tube of said nozzle.

10. A spraying system for spraying inside wall and bottom surfaces of a container comprising: a. a recirculation system in which circulating heated fluid heats non-circulating fluid not within the recirculation system preparatory to the spraying of the non-circulating fluid, b. a nozzle extension housing a portion of said recirculation system in which the circulating heated fluid by its proximity to the non-circulating fluid heats the non-circulating fluid, c. dual spray means including an independently actuating means for each of said dual spray means, d. a manifold block housing said independent actuating means and having an internal passageway for fluid to flow between said independent actuating means.

14. A method of spraying comprising the steps of: pumping heated fluid from a fluid supply source into an extended nozzle and related structure; intermittently admitting part of the pumped fluid to at least one spray tube communicating with a spray outlet for intermittent spraying; allowing the remainder of the pumped fluid to circulate around the spray tube to heat residual fluid in said tube and then to return to the fluid supply source for reheating and recirculation.