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US2759764A - Liquid feeding apparatus - Google Patents

Liquid feeding apparatus Download PDF

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Publication number
US2759764A
US2759764A US431742A US43174254A US2759764A US 2759764 A US2759764 A US 2759764A US 431742 A US431742 A US 431742A US 43174254 A US43174254 A US 43174254A US 2759764 A US2759764 A US 2759764A
Authority
US
United States
Prior art keywords
shaft
feed tube
liquid
atomizer
wall
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
US431742A
Other languages
English (en)
Inventor
Robert C Juvinall
William L Smart
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.)
Ransburg Corp
Original Assignee
Ransburg Corp
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 Ransburg Corp filed Critical Ransburg Corp
Priority to US431742A priority Critical patent/US2759764A/en
Priority to DER16463A priority patent/DE1057921B/de
Application granted granted Critical
Publication of US2759764A publication Critical patent/US2759764A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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

Definitions

  • liquid coating materials generally contain solvents which readily attack the materials used in conventional liquid sealing devices. These qualities make the useful life of conventional sealing devices very short. Once the liquid coating material leaks past its seal, its abrasive and gummy qualities will quickly render the bearing structure and other moving parts to the rotating atomizi'ng device unserviceable. For this reason it is desirable in feeding liquid coating material so such a device that conventional mechanical seals and related packings be eliminated.
  • Our invention is directed to providing means for feeding liquid for downward flow through a hollow rotating shaft to the surface of an atomizing device or the like without using conventional packin-gs or liquid sealing devices.
  • liquid can be fed downwardly without dripping to a rotating hollow shaft by a downwardly presented stationary feed tube extending a substantial distance into the rotating hollow shaft with its lower portion smoothly curved toward the inner wall of the shaft and terminating in a sharp edge closely adjacent the inner wall.
  • the lower terminus of the stationary feed tube should lie closer to the inner wall of the shaft than any other portion of the feed tube and the end of the tube should be spaced less than .05 inch from the wall of the shaftand preferably not more than .015 inch especially at low liquid deliveries.
  • An object of our invention is to provide improvements in the protection of the bearing structure and other moving parts of a rotatable hollow shaft. Another object is to provide a more etfic'ient means for feeding liquid through a rotating hollow shaft.
  • Fig. 1 is a partially broken away el'evational view of an atomizing device for use in an electrostatic coating system embodying our invention
  • V Fig. 2 is a detailed view of the stationary feed tube shown in Fig. 1.
  • FIG. 1 there is shown an annularedg'ed atomizing device 10 which includes an atomizing disc 11 on the lower end of a rotatable hollow shaft 12.
  • the disc and shaft are rotated by an integral motor as sembly lying within housing 13 whose details are not shown as our invention is independent of the motor or other driving means for draft 12 and disc 11.
  • Shaft 12 e'it'tends axially through the major portion of housing 13. Lying above the upper end of rotatable shaft 12 is a stationary tube support 15 having an axial passageway concentric with shaft 12.
  • a stationary feed tube 16 having a lower terminus 16a is mounted concentrically within the passageway of stationary tube support 15 by means of a set screw 18 and sealed by an (i -ring 19.
  • one to the close tolerances involved terminus 16a should be securely emplaced in relation to the inner wall of shaft 12 and to this end set screw 18 is located to bear against the middleof the upper collar of tube 16 with a substantial area of the collar snugly fitted against tube support 15 both above and below the set screw.
  • a back plate 21) having an axial passageway communieating with stationary feed tube 16 is securely mounted on the upper end of stationary tube support 15. Liquid coating material is fed at a controlled rate by a line 21 from a reservoir 22 through the passageway in back plate 20 to the interior of feed tube 16.
  • Atomizing device 10 may be maintained at a high electrical potential by connection to a high voltage source 24 as shown or other means known to the art employed to efiect atician-depositing potential difference between the atomized coating material and the articles. This is generally accomplished by maintaining the articles and their supports at a diiference of potential from the atomizer, preferably by grounding the articles and maintaining the atomizer at high voltage as shown.
  • Fig. 2 is adetailed view of stationary feed tube 16 with its lower portion shown in cross section. At its upper end and along its major portion tube 16 is concentric with tube support 15 and rotating shaft 122. in order to bring the liquid coat ng material close to the inner wall of the rotating shaft for transfer from stationary feed tube 16 to notating shaft 12 in a smooth uniform flow and without the formation of liquid drops which might fall free from the end of tube 16 through the shaft, it was found desirable to bend the lower end of the feed tube to bring it within .05 inch of the inner wall of the shaft. To prevent undesirable turbulence in the liquid flow through tube 16 a gradual smooth curvature at the lower end of the feed tube was made. The curvature should be such that terminus 16a will constitute the lowermost portion a of the feed tube. Preferably a tangent to the outer surface of terminus 16a makes an angle of substantially less than 90 with the axis of shaft 12.
  • shaft 12 it should be noted that it is not necessary shaft 12 be exactly or even substantially vertical.
  • the axis of the shaft must only have some downward component. But if the shaft is inclined from the vertical, the terminus 16a of the feed tube should be positioned adjacent the lower side of the inner wall of the shaft so that terminus 16a is the lowermost portion of the feed tube.
  • One commonly used atomizing device which incorporates our invention employes a rotating hollow shaft having an inner diameter of approximately .75 inch.
  • Various coating operations carried on with such an atomizing device require liquid to be fed at deliveries of from 15 to 900 cubic centimeters per minute.
  • the device may be rotated at speeds of from several hundred to several thousand revolutions per minute.
  • a tube constructed in the form of stationary feed tube 16 was found to feed liquid coating material to the inner wall of the hollow shaft at deliveries and speeds within the above ranges and to effect onto the wall of the rotating shaft without dripping liquid transference smoothly or splashing.
  • the inner diameter of feed tube 16 When used with a hollow shaft having an inner diameter of .75 inch, the inner diameter of feed tube 16 was approximately .25 inch with its lower end uniformly curved with a radius of curvature of approximately 2.15 inches. The lower extremity of the feed tube had a sharp edge spaced less than .05 inch from the inner wall of the shaft.
  • the sharp edge of the tube was formed by grinding the open face of the tube substantially flat so that the open face of the tube which formed the sharp edge made an angle of approximately 15 to the axis of the hollow shaft and the lower end of the feed tube was closer to the inner wall of the shaft than was any other portion of the feed tube.
  • a liquid feeding device comprising a rotatable hollow shaft whose axis has a vertical component, an annular-edged atomizer mounted on the lower end of said shaft, said atomizer having an extended lower surface and a passageway concentric with the axis of said shaft leading from the inner wall of the said shaft to the lower surface of said atomizer, a downwardly presented stationary feed tube lying within said hollow shaft and having a sharp-edged lower terminus lying closer to the inner wall of said shaft than any other portion of the feed tube and spaced less than .05 inch from said inner wall, means for rotating said shaft and atomizer about their axis, and means for feeding liquid down said feed tube to its sharpedged terminus for flow onto the inner wall of said shaft and thence down said inner wall to the lower surface of said atomizer.
  • a liquid feeding device comprising an annular-edged atomizer having a rotatable hollow shaft whose axis has a vertical component, a stationary feed tube whose open lower end lies within the hollow shaft of said atomizer and terminates in a sharp-edged projection spaced less than .05 inch from the inner wall of said shaft, the open lower end of said feed tube making a substantial angle with the axis of said shaft, means for rotating said atomizer about its axis, and means for feeding liquid through said feed tube to be discharged from its lower end onto the rotating inner wall of said shaft for flow to the annular edge of said atomizer.
  • a liquid feeding device comprising an atomizer mounted for rotation about a generally vertical axis, said atomizer having an inner liquid-guiding surface concentric about said vertical axis, a downwardly presented stationary feed tube whose lower portion lies surrounded by the inner surface of said atomizer, the lower portion of said feed tube having a lowermost terminus closely adjacent the inner surface of the atomizer, and the lower portion of said feed tube being uniformly curved to make an angle of substantially less than between a tangent to the lower terminus of the feed tube and the axis of said atomizer, means for rotating said atomizer about its axis, and means for feeding liquid downwardly through said feed tube and over its lowermost terminus onto the rotating liquid-guiding surface of said atomizer.
  • a liquid feeding device comprising a downwardly disposed rotatable hollow shaft, said shaft having an inner diameter of approximately .75 inch; an annular-edged atomizer mounted on the lower end of said hollow shaft; a stationary feed tube having an inner diameter of approximately .25 inch which, except for its lower end, lies concentric with said hollow shaft, the lower end of said feed tube being uniformly curved with a radius of curvature of approximately 2.15 inches, the lower extremity of said feed tube having a sharp edge closely adjacent the inner wall of said shaft, and the open face of the tube making said edge being at an angle of approximately 15 to the axis of said hollow shaft; means for rotating said shaft and atomizer about their axis; and means for feeding liquid downwardly through said feed tube onto the rotating surface of said shaft.

Landscapes

  • Electrostatic Spraying Apparatus (AREA)
  • Nozzles (AREA)
US431742A 1954-05-24 1954-05-24 Liquid feeding apparatus Expired - Lifetime US2759764A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US431742A US2759764A (en) 1954-05-24 1954-05-24 Liquid feeding apparatus
DER16463A DE1057921B (de) 1954-05-24 1955-04-15 Rotierender Zerstaeuber fuer elektrostatische Spritzanlagen

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US431742A US2759764A (en) 1954-05-24 1954-05-24 Liquid feeding apparatus

Publications (1)

Publication Number Publication Date
US2759764A true US2759764A (en) 1956-08-21

Family

ID=23713225

Family Applications (1)

Application Number Title Priority Date Filing Date
US431742A Expired - Lifetime US2759764A (en) 1954-05-24 1954-05-24 Liquid feeding apparatus

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US (1) US2759764A (de)
DE (1) DE1057921B (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3478962A (en) * 1966-10-04 1969-11-18 Bosch Hausgeraete Gmbh Electrostatic painting apparatus
US20150053797A1 (en) * 2012-04-13 2015-02-26 Nordson Corporation Powder gun configurable for supply from venturi or dense phase pump

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1292545B (de) * 1961-10-28 1969-04-10 A Dipl Ing Elektrostatische Farbspritzpistole zum wahlweisen Spritzen mit und ohne Druckluft
DE1577637C3 (de) * 1964-08-26 1973-11-15 Robert Bosch Hausgeraete Gmbh, 7927 Giengen Vorrichtung zum Aufsprühen von flussigen Auftragsmitteln, insbesonde re von Lacken

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2218643A (en) * 1937-12-13 1940-10-22 Ray Oil Burner Co Fan for liquid fuel burners
US2483975A (en) * 1944-06-06 1949-10-04 Shell Dev Rotating atomizing cup burner and method of igniting and burning fuel therein

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH131307A (de) * 1927-03-15 1929-02-15 Siemens Ag Flüssigkeitszerstäuber.
BE487699A (de) * 1948-03-05

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2218643A (en) * 1937-12-13 1940-10-22 Ray Oil Burner Co Fan for liquid fuel burners
US2483975A (en) * 1944-06-06 1949-10-04 Shell Dev Rotating atomizing cup burner and method of igniting and burning fuel therein

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3478962A (en) * 1966-10-04 1969-11-18 Bosch Hausgeraete Gmbh Electrostatic painting apparatus
US20150053797A1 (en) * 2012-04-13 2015-02-26 Nordson Corporation Powder gun configurable for supply from venturi or dense phase pump
US10040081B2 (en) * 2012-04-13 2018-08-07 Nordson Corporation Powder gun configurable for supply from Venturi or dense phase pump
US11958067B2 (en) 2012-04-13 2024-04-16 Nordson Corporation Powder gun configurable for supply from venturi or dense phase pump

Also Published As

Publication number Publication date
DE1057921B (de) 1959-05-21

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