US3178114A - Rotary atomising heads for electrostatic spray guns - Google Patents

Rotary atomising heads for electrostatic spray guns Download PDF

Info

Publication number
US3178114A
US3178114A US147574A US14757461A US3178114A US 3178114 A US3178114 A US 3178114A US 147574 A US147574 A US 147574A US 14757461 A US14757461 A US 14757461A US 3178114 A US3178114 A US 3178114A
Authority
US
United States
Prior art keywords
sharp edge
high resistivity
insulating
head
source
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US147574A
Other languages
English (en)
Inventor
Point Marcel Auguste Roger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Machines Electrostatiques SA
Original Assignee
Sames Mach Electrostat
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sames Mach Electrostat filed Critical Sames Mach Electrostat
Application granted granted Critical
Publication of US3178114A publication Critical patent/US3178114A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B5/00—Electrostatic spraying apparatus; Spraying apparatus with means for charging the spray electrically; Apparatus for spraying liquids or other fluent materials by other electric means
    • B05B5/025—Discharge apparatus, e.g. electrostatic spray guns
    • B05B5/04—Discharge apparatus, e.g. electrostatic spray guns characterised by having rotary outlet or deflecting elements, i.e. spraying being also effected by centrifugal forces
    • B05B5/0403—Discharge apparatus, e.g. electrostatic spray guns characterised by having rotary outlet or deflecting elements, i.e. spraying being also effected by centrifugal forces characterised by the rotating member
    • B05B5/0407—Discharge apparatus, e.g. electrostatic spray guns characterised by having rotary outlet or deflecting elements, i.e. spraying being also effected by centrifugal forces characterised by the rotating member with a spraying edge, e.g. like a cup or a bell

Definitions

  • high resistivity materials otherwise known as semi-conducting materials, having a resistivity range between and 10 ohm cmF/cm.
  • high resistivity materials such as thermosetting resins of the ethoxyline (or epoxides) type, containing carbon black
  • thermosetting resins of the ethoxyline (or epoxides) type, containing carbon black it has been found that the sharp edge of these heads where the atomisation and projection of the paint particles takes place is very fragile.
  • Such sharp edges deteriorate rapidly and thus cause the electrostatic head to function badly.
  • the present invention therefore has as an object an improved construction of a rotary electrostatic head allowing the aforementioned drawbacks to be avoided.
  • the part of the rotary head comprising the sharp edge for centrifugal atomisation and at which the covering material, e.g. paint, arrives is made of an insulating material, that is to say a material whose resistivity exceeds 10 ohm cm. cm., and in that a portion made of a high resistivity material has a sharp edge which is located in the immediate neighbourhood of the edge of the insulating portion, this high resistivity portion being connected to a pole of a source of high direct voltage.
  • the centrifugal atomisation of the covering material and the creation of the electrostatic field operations are effected separately by an insulating portion and by a high resistivity portion respectively, both being rotatably driven at high speed, the two portions being provided with co-operating sharp edges.
  • This resistance may be measured by placing said portion between two electrodes connected to the terminals of a sourceof high direct voltage providing a constant current of 0.2 mm, for example.
  • the evaporated solvents may be prevented from inflaming it is necessary that, under the above conditions, therésage at the terminals be at least 2,000 v., which corresponds to a minimum resistivity of about 10 ohmcm. for said high resistivity material.
  • FIGURE 1 shows a section through an electrostatic head according to the invention mounted on the end of a gun, the end of the barrel of which has been diagrammatically shown, as has the axis of revolution and the paint feed pipe.
  • FIGURES 2 and 3 are similar views but relate to modifications which are also in accordance with the invention.
  • FIGURES 4 and 5 respectively show front and sectional views of a head according to the invention provided with fins.
  • FIGURE 6 diagrammatically shows the fixing of the fins, only two of which have been shown.
  • the outer insulating portion of the head which is substantially cylindrical, comprising the sharp edge 1' at which the paint arrives, delivered to the head through the pipe 5 located in the barrel 4 of the gun.
  • This feed pipe in no way interferes with the rotation of the head.
  • the revolving hub 2 of the head which is integral with the insulating revolving shaft but which is conductively connected at the end 6 to a source 9 of high direct voltage is also conductively connected through the spring 10 to a member 3 of high resistivity material having the general shape of a cone which narrows down and finally ends at 3' in an edge at a short distance from the edge 1' of the outer insulating portion 1. In this manner the paint, forced by centrifugal force against the inner wall of this insulating portion 1 does not normally come into contact with the high resistivity member 3.
  • the centrifugal atomising insulating member 1 which has a finely pointed conical shape is arranged inside the highly resistivity member 3 which has a generally cylindrical shape and the ionising sharp edge 3 of which, which creates the electric field, is located near the outside of the sharp edge 1'.
  • the insulating edge 1' projects slightly in
  • the paint arriving at passes through the openings 8, along the inner terminal surface of the insulating member 1 and, forced by centrifugal force, arrives at the edge 1. coming' into contact with the high resistivity member '3.
  • FIGURE 3 shows another embodiment according to the invention and in which the attachment of the centrifu'g'al at'orn'isingi insulating member 1 is differently made.
  • this member '1 is made in the shape of a sharp-edge ring mounted directly on an inner circular edge of the high resistivity member 3 the hub Z of whichmay be either of high resistivity or conducting material and is fixed to the electrically conducting end6 of the r'evolvirigsh'aft' of the gun.
  • This end is of course connected by an suitable means to one of theterm'inals of a source 9' of high direct voltage the other terminal of which is connected to the object to be covered, generally earthe'd.
  • the high resistivity member 3 of FIGURES 1, 2"and 3 could be 'made, if for any reason it" were desired, of a good electrically conducting material e'.g'. 'met'al, its role being to create the electric
  • Theheads according to the invention are also suitable for'the addition of fins whichhave the purpose of creating an axially-directed draught directed toward the object to be" covered; this draught increasesthe safety of the gun when in use due to the turbulence of the air causedinthe zone in the immediate vicinity of the ator'nisation' zorie. In fact the ratio of the quantity of air in relation to that of the fuel (evaporated solvent) increases so that the probability of combustion decreases.
  • the insulating member 1 made for example of nylon, is fixed by any suitable means on to a hollow metal socket screwed on the metal end 6' of the shaft providing the high-speed rotation of-the electrostatic head.
  • This insulating member [is provided on its outer surface with a number of fins 12 only three of which have been shown on FIGURE 4, but which are also angularly distributed over the entire perimeter ofthe head like those of a fan.
  • the high resistivity member 3 with the sharp edge 3 is secured concentrically inside the insulating member 1 so that the sharp edge 3 is located in the neighbourhood of the insulating sharp edgel.
  • this high resistivity member 3 is effected by means of a preferably insulating screw 13, of nylon for example, which is screwed into the hollow electrically conducting socket 1'1 and the head 14 of which ensures the gripping of the hub of this member 3'against the terminal surface of the socket 11.
  • a spraying head 'cornprising'a first rotatable member of insulating material' having a peripheral sharp edge, a second member of high resistivity material arranged coaxially around the said first member and having a peripheral sharp edge, the sharp edges of the 'said'first and second members being adjacent to one another, but spaced a short distance apart, means for supplying fluid coating material so as to form a film on at least that part of said "first rotatable member adjacent to its sharp edge, a source of high direct current voltage and means for connecting said source of high voltage to the said second member.
  • the second member has a substantially cylindrical form and said first member is partially the shape of a cone, a rotatable shaft, and means for attaching the first member to one end of the rotatable shaft.
  • a spraying head comprising a first substantially cylindrical rotatable member 'of insulating material having a peripheral sharp edge, a second member of generally conical form made of highly resistivity materialarranged coaXially within the said-"first member and having a peripheral sharp edge, the sharp edges of the said first and second members being adjacentto one another, but spaced a short distance apart, a rotatable shaft having at least its terminal part made of conducting material, a hub member I made of conducting materialfitted to said shaft, means conne'cting both sai'd first and secondmembers to said hub meinher, means for suppling fiuid coating material so as to form a film on at least that part of sa'idfirst rotatablelmember adjacent to its sharp edge, a source o f'hi gh direct- -currer1t voltage and means connecting the said source of high voltage to the said terminal part of said shaft
  • a spraying head comprising a first rotatable member of insulating material having a peripheral sharp edge, a second member of generally cylindrical form made of high resistivity material arranged coaxially around the said first member and having'a peripheral sharp edge, said first member being carried by saidsecond member and the sharp edges of the said first and second members being adjacent-to one another, but spaced at short distance apart, a rotatable shaft, means for mounting said second member on the rotatable shaft, means for suppling fluid coating material so as toform a film on at least that part of said first rotatable member adjacent to its sharp edge, a source of high direct current voltage and means for connecting said source of high voltage to the said second a member.

Landscapes

  • Electrostatic Spraying Apparatus (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
US147574A 1960-11-02 1961-10-25 Rotary atomising heads for electrostatic spray guns Expired - Lifetime US3178114A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR842739A FR1278677A (fr) 1960-11-02 1960-11-02 Perfectionnements aux têtes rotatives de pulvérisation pour pistolets électrostatiques, en vue du recouvrement d'objets, par exemple au moyen de peinture
FR845773A FR78780E (fr) 1960-11-02 1960-12-02 Perfectionnements aux têtes rotatives de pulvérisation pour pistolets électrostatiques, en vue du recouvrement d'objets, par exemple au moyen de peinture

Publications (1)

Publication Number Publication Date
US3178114A true US3178114A (en) 1965-04-13

Family

ID=26188009

Family Applications (1)

Application Number Title Priority Date Filing Date
US147574A Expired - Lifetime US3178114A (en) 1960-11-02 1961-10-25 Rotary atomising heads for electrostatic spray guns

Country Status (6)

Country Link
US (1) US3178114A (de)
CH (1) CH380603A (de)
DE (1) DE1221934B (de)
FR (2) FR1278677A (de)
GB (1) GB978763A (de)
NL (1) NL270215A (de)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3327948A (en) * 1964-07-07 1967-06-27 Cosmic Inc Method of electrostatic coating including velocity reduction
US3504851A (en) * 1967-06-15 1970-04-07 Villamos Automatika Intezet Electrostatic spray gun
US3536514A (en) * 1963-06-13 1970-10-27 Ransburg Electro Coating Corp Electrostatic coating method
US3895261A (en) * 1974-06-03 1975-07-15 Zalman Isaakovich Merkind Apparatus for application of powdered materials in electrostatic field
US4739935A (en) * 1986-03-12 1988-04-26 Nordson Corporation Flexible voltage cable for electrostatic spray gun
US4760965A (en) * 1986-05-16 1988-08-02 Behr-Industrieanlagen Gmbh & Co. Atomizer for electrostatically coating objects
US4798335A (en) * 1986-09-16 1989-01-17 Kabushiki Kaisha Toyota Chuo Kenkyusho Rotating spraying type coating apparatus
US4927081A (en) * 1988-09-23 1990-05-22 Graco Inc. Rotary atomizer
US6156392A (en) * 1999-07-13 2000-12-05 Nylok Fastener Corporation Process for triboelectric application of a fluoropolymer coating to a threaded fastener

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3411715A (en) * 1964-03-31 1968-11-19 Wallis Neil Rudolph Centrifugal electrostatic spraying head
ATE41610T1 (de) * 1982-10-13 1989-04-15 Ici Plc Elektrostatische spruehanlage.
GB2143153B (en) * 1983-07-12 1986-03-26 Ici Plc Spraying
DE3711128C3 (de) * 1987-04-02 1994-10-20 Lactec Gmbh Rotationszerstäuber

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2955565A (en) * 1956-03-19 1960-10-11 Electro Dispersion Corp Electrostatic coating apparatus
US2989241A (en) * 1956-07-16 1961-06-20 Ransburg Electro Coating Corp Apparatus for electrostatic spray coating
US2993468A (en) * 1957-07-22 1961-07-25 Vilbiss Co Apparatus for coating with atomized liquid
US3009441A (en) * 1959-06-18 1961-11-21 Ransburg Electro Coating Corp Apparatus for electrostatically spray coating
US3010428A (en) * 1957-09-10 1961-11-28 Interplanetary Res & Dev Corp Spraying devices
US3063642A (en) * 1959-03-31 1962-11-13 Sames Mach Electrostat Rotating heads for electrostatic atomizing and spraying apparatus
US3082956A (en) * 1958-11-26 1963-03-26 Sames Mach Electrostat Electrostatic spraying or atomising heads for liquids or pulverulent solids

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2955565A (en) * 1956-03-19 1960-10-11 Electro Dispersion Corp Electrostatic coating apparatus
US2989241A (en) * 1956-07-16 1961-06-20 Ransburg Electro Coating Corp Apparatus for electrostatic spray coating
US2993468A (en) * 1957-07-22 1961-07-25 Vilbiss Co Apparatus for coating with atomized liquid
US3010428A (en) * 1957-09-10 1961-11-28 Interplanetary Res & Dev Corp Spraying devices
US3082956A (en) * 1958-11-26 1963-03-26 Sames Mach Electrostat Electrostatic spraying or atomising heads for liquids or pulverulent solids
US3063642A (en) * 1959-03-31 1962-11-13 Sames Mach Electrostat Rotating heads for electrostatic atomizing and spraying apparatus
US3009441A (en) * 1959-06-18 1961-11-21 Ransburg Electro Coating Corp Apparatus for electrostatically spray coating

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3536514A (en) * 1963-06-13 1970-10-27 Ransburg Electro Coating Corp Electrostatic coating method
US4114564A (en) * 1963-06-13 1978-09-19 Ransburg Corporation Electrostatic coating apparatus
US3327948A (en) * 1964-07-07 1967-06-27 Cosmic Inc Method of electrostatic coating including velocity reduction
US3504851A (en) * 1967-06-15 1970-04-07 Villamos Automatika Intezet Electrostatic spray gun
US3895261A (en) * 1974-06-03 1975-07-15 Zalman Isaakovich Merkind Apparatus for application of powdered materials in electrostatic field
US4739935A (en) * 1986-03-12 1988-04-26 Nordson Corporation Flexible voltage cable for electrostatic spray gun
US4760965A (en) * 1986-05-16 1988-08-02 Behr-Industrieanlagen Gmbh & Co. Atomizer for electrostatically coating objects
US4798335A (en) * 1986-09-16 1989-01-17 Kabushiki Kaisha Toyota Chuo Kenkyusho Rotating spraying type coating apparatus
US4927081A (en) * 1988-09-23 1990-05-22 Graco Inc. Rotary atomizer
US6156392A (en) * 1999-07-13 2000-12-05 Nylok Fastener Corporation Process for triboelectric application of a fluoropolymer coating to a threaded fastener

Also Published As

Publication number Publication date
CH380603A (fr) 1964-07-31
NL270215A (de)
FR1278677A (fr) 1961-12-15
FR78780E (fr) 1962-09-07
DE1221934B (de) 1966-07-28
GB978763A (en) 1964-12-23

Similar Documents

Publication Publication Date Title
US3178114A (en) Rotary atomising heads for electrostatic spray guns
US4171100A (en) Electrostatic paint spraying apparatus
CA1082911A (en) Electrostatic spray coating apparatus
US4589597A (en) Rotary atomizer spray painting device
RU1806020C (ru) Устройство дл электростатического нанесени покрытий из электропроводных материалов
US3048498A (en) Electrostatic spray coating system
JP3291503B2 (ja) 静電噴霧装置
US3128045A (en) Electrostatic coating apparatus
US5358182A (en) Device with rotating atomizer head for electrostatically spraying liquid coating product
US4347984A (en) Electrostatic spray coating apparatus
JP3184455B2 (ja) 回転霧化頭型塗装装置
US5085373A (en) Apparatus for coating workpieces electrostatically
US6708908B2 (en) Paint atomizer bell with ionization ring
US9901941B2 (en) Electrostatic spray device for spraying a liquid coating product, and spray facility comprising such a spray device
US3540653A (en) Apparatus for dispersing and electrically charging substances in discrete particulate form
JPH0346093B2 (de)
US2894175A (en) Apparatus for spray painting
US6076751A (en) Method of charging using nonincendive rotary atomizer
US4157162A (en) Electrostatic spraying apparatus
CA2249905C (en) Safe charging
US6565021B2 (en) High speed rotary atomizer with directing air ring
US3075706A (en) Gun for atomization and electrostatic spraying of materials
US3498540A (en) Nozzle for powder spraying
US3219013A (en) Precharging device for electrostatic painting apparatus
KR860007968A (ko) 입자 분무기