US3767115A — Electrostatic spray gun apparatus

Claim 1

Independent Claim 140 words

An electrostatic spray gun for setting up an electrostatic field between the gun and the object to be coated comprising: a material charging element connectable to a source of high potential; barrel means made of electrically insulated material; said barrel means having a front end and two passages terminating adjacent said front end; the first of said passages constituting a material coating conduit and the second of said passages constituting a conduit to contain said material charging element; said two passages being electrically insulated from each other in said barrel means such that said charging element and coating material do not contact each other; said charging element terminating at a charging electrode outside of said barrel adjacent said first passage whereby coating material emitted from said barrel is charged to an electrical potential outside of said barrel by said electrode.

Claim 2

Dependent Claim 140 words

An electrostatic spray gun for setting up an electrostatic field between the gun and the object to be coated comprising: a material charging element connectable to a source of high potential; barrel means made of electrically insulated material; said barrel means having a front end and two passages terminating adjacent said front end; the first of said passages constituting a material coating conduit and the second of said passages constituting a conduit to contain said material charging element; said two passages being electrically insulated from each other in said barrel means such that said charging element and coating material do not contact each other; said charging element terminating at a charging electrode outside of said barrel adjacent said first passage whereby coating material emitted from said barrel is charged to an electrical potential outside of said barrel by said electrode.

Claim 3

Dependent Claim 47 words

The gun of claim 1 including a nozzle cap at the front end of said barrel means with at least two holes therethrough spaced from each other and said charging element being removable from said nozzle cap for insertion through either of said at least two holes.

Claim 4

Dependent Claim 146 words

An electrostatic spray gun for setting up an electrostatic field between the gun and the object to be coated comprising: barrel means made of electrically insulated material; said barrel means having a front end and two passages terminating adjacent said front end, the first of said barrel passages constituting a material coating conduit; a material charging element connectable to a source of high potential in the second of said barrel passages and extending through the front end and electrically insulated in the barrel from said first passage; a rotatable coating material passing nozzle assembly mounted on the front end of said barrel with said charging element being mounted in said assembly and extending therethrough and terminating at an electrode; and means for maintaining the electrical contact with said charging element regardless of the angle of rotation of said nozzle assembly and electrode relative to said barrel.

Claim 5

Dependent Claim 146 words

An electrostatic spray gun for setting up an electrostatic field between the gun and the object to be coated comprising: barrel means made of electrically insulated material; said barrel means having a front end and two passages terminating adjacent said front end, the first of said barrel passages constituting a material coating conduit; a material charging element connectable to a source of high potential in the second of said barrel passages and extending through the front end and electrically insulated in the barrel from said first passage; a rotatable coating material passing nozzle assembly mounted on the front end of said barrel with said charging element being mounted in said assembly and extending therethrough and terminating at an electrode; and means for maintaining the electrical contact with said charging element regardless of the angle of rotation of said nozzle assembly and electrode relative to said barrel.

Claim 6

Dependent Claim 25 words

The gun of claim 3, wherein said means for maintaining electrical contact comprises a conductive ring mounted on the inner side of said nozzle assembly.

Claim 7

Dependent Claim 35 words

The gun of claim 3 wherein said charging electrode extends away from said nozzle assembly To a free tip with said electrode being angled outwardly toward the axial extended center line of the first passage.

Claim 8

Dependent Claim 153 words

An electrostatic spray gun for setting up an electrostatic field between the gun and the object to be coated comprising: a material charging element connectable to a source of high potential; barrel means made of electrically insulated material; said barrel means having a front end and two passages terminating adjacent said front end; the first of said passages constituting a material coating conduit; a high electrically resistive member having an electrical resistance and being connected to said charging element; the second of said passages containing said resistive member and charging element; said two passages being electrically insulated from each other in said barrel means such that said charging element and resistive member do not contact each other; said charging element terminating at a charging electrode outside of said barrel adjacent said first passage whereby coating material emitted from said barrel is charged to an electrical potential outside of said barrel by said electrode.

Claim 9

Dependent Claim 153 words

An electrostatic spray gun for setting up an electrostatic field between the gun and the object to be coated comprising: a material charging element connectable to a source of high potential; barrel means made of electrically insulated material; said barrel means having a front end and two passages terminating adjacent said front end; the first of said passages constituting a material coating conduit; a high electrically resistive member having an electrical resistance and being connected to said charging element; the second of said passages containing said resistive member and charging element; said two passages being electrically insulated from each other in said barrel means such that said charging element and resistive member do not contact each other; said charging element terminating at a charging electrode outside of said barrel adjacent said first passage whereby coating material emitted from said barrel is charged to an electrical potential outside of said barrel by said electrode.

Claim 10

Dependent Claim 53 words

The gun of claim 6 wherein valve means are provided in said first passage to control the flow of coating material to said front end; said valve means normally being in a closed position; and trigger means on said gun manually operable by an operator to move said valve from its closed position.

Claim 11

Dependent Claim 31 words

The gun of claim 7, wherein a rotatable nozzle assembly is provided on the front end of said barrel with said charging element extending therethrough until it terminates at its electrode.

Claim 12

Dependent Claim 21 words

The gun of claim 6 wherein the resistive member has an electrical resistance in the range of 50 to 1,000 megohms.

Claim 13

Dependent Claim 29 words

The gun of claim 6 including a nozzle mounted on the front end of said barrel with at least two holes therethrough to selectively position said charging electrode therein.

Claim 14

Dependent Claim 219 words

An airless electrostatic spray gun for setting up an electrostatic field between the gun and the object to be coated comprising: barrel means with two passages therethrough at least part of which is made of electrically insulated material; said barrel having a front end; a nozzle mounted on said front end and rotatable relative to said barrel and having a conductive ring on its inward side; the first of said two passages being a coating material conduit; valve means in said first passage to control the movement of coating material therethrough; trigger means on said gun manually operable to control the movement of said valve; and charging means comprising an outwardly extending electrode outside of said gun and attached to the front of said nozzle, a first charging element connected to said electrode and extending through said nozzle to said conductive ring, a second charging element in said barrel normally biased to contact said ring, a resistor in the range of 50 to 1,000 megohms in said second passage connected at one end to said second charging element and connectable at the other end to a source of high potential; whereby coating material emitted through said first passage is charged to an electrical potential after being emitted through said nozzle assembly by said electrode after it leaves the gun.

Claim 15

Dependent Claim 219 words

An airless electrostatic spray gun for setting up an electrostatic field between the gun and the object to be coated comprising: barrel means with two passages therethrough at least part of which is made of electrically insulated material; said barrel having a front end; a nozzle mounted on said front end and rotatable relative to said barrel and having a conductive ring on its inward side; the first of said two passages being a coating material conduit; valve means in said first passage to control the movement of coating material therethrough; trigger means on said gun manually operable to control the movement of said valve; and charging means comprising an outwardly extending electrode outside of said gun and attached to the front of said nozzle, a first charging element connected to said electrode and extending through said nozzle to said conductive ring, a second charging element in said barrel normally biased to contact said ring, a resistor in the range of 50 to 1,000 megohms in said second passage connected at one end to said second charging element and connectable at the other end to a source of high potential; whereby coating material emitted through said first passage is charged to an electrical potential after being emitted through said nozzle assembly by said electrode after it leaves the gun.

Claim 16

Dependent Claim 24 words

The gun of claim 11 with at least two holes through said nozzle to removably allow selective insertion of said first charging means therein.

Claim 17

Dependent Claim 120 words

A nozzle for an electrostatic spray gun comprising: an electrically non-conductive nozzle rotatably mountable on the front of an electrostatic spray gun; an electrical conductive element at least partially within said nozzle, said element having an external forward facing electrode and a conductive member on the nozzle side opposite said electrode for maintaining continuous electrical contact with a source of high potential regardless of the nozzle angle of rotation; and means for selectively positioning said conduCtive element at different locations comprising at least two holes through said nozzle extending from adjacent said conductive member to support and guide said external electrode, and to insure a proper charge on the coating material when the nozzle is rotated to a tightened position.

Claim 18

Dependent Claim 120 words

A nozzle for an electrostatic spray gun comprising: an electrically non-conductive nozzle rotatably mountable on the front of an electrostatic spray gun; an electrical conductive element at least partially within said nozzle, said element having an external forward facing electrode and a conductive member on the nozzle side opposite said electrode for maintaining continuous electrical contact with a source of high potential regardless of the nozzle angle of rotation; and means for selectively positioning said conduCtive element at different locations comprising at least two holes through said nozzle extending from adjacent said conductive member to support and guide said external electrode, and to insure a proper charge on the coating material when the nozzle is rotated to a tightened position.

Claim 19

Dependent Claim 31 words

The nozzle of claim 13 wherein the means for selectively positioning the conductive element comprises two holes through said nozzle extending from adjacent said conductive member to adjacent said external electrode.

Claim 20

Dependent Claim 14 words

The nozzle of claim 14 wherein said conductive member is an annular conductive ring.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1976-10-22	1977-04-23	1977-10-23	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1980-10-22	1981-04-23	1981-10-23	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1984-10-22	1985-04-23	1985-10-23	$7700.00	Window Closed / Lapsed

Electrostatic spray gun apparatus

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