COMPRESSED AIR THROTTLE DEVICE AND A POWDER SPRAY COATING DEVICE

• US 20090121051A1
• Filed: 02/16/2006
• Published: 05/14/2009
• Est. Priority Date: 02/17/2005
• Status: Active Grant

• Current Assignee: Gema Switzerland GmbH (Graco Incorporated)
• Original Assignee: ITW Gema GmbH (Illinois Tool Works Inc.)
• Inventors: Michael, Hanspeter
• Granted Patent: US 8,430,346 B2
• Time in Patent Office: Days
• US Class Current: 239/706
• CPC Class Codes: B05B 12/085 responsive to flow or pressure of liquid or other fluent material to be discharged B05B1/3006, B05B1/323, B05B7/1254 take precedence
• CPC Class Codes: B05B 5/0533 Electrodes specially adapted therefor; Arrangements of electrodes
• CPC Class Codes: B05B 7/1404 Arrangements for supplying particulate material
• CPC Class Codes: B05B 7/1472 Powder extracted from a powder container in a direction substantially opposite to gravity by a suction device dipped into the powder
• CPC Class Codes: Y10T 137/8242 Electrical
• CPC Class Codes: Y10T 137/8275 Indicator element rigidly carried by the movable element whose position is indicated
• CPC Class Codes: Y10T 137/86517 With subsequent closing of first port

Abstract

A compressed air throttle apparatus comprising at least one throttle valve adjusted by an electric motor, further an electric circuit fitted with contacting elements to alternatively interrupt and close the electric circuit in relation to the throttle valve settings. This throttle apparatus preferably is applicable to a compressed air path of powder spraycoating equipment.

Claims

1. A compressed air throttle apparatus in particular for powder spraycoating equipment, comprising at least one adjustable throttle valve,

characterized in that at least one electrical circuit is used which is fitted with electrically conductive contacting elements to alternately interrupt and close said path as a function of the setting of the minimum of one throttle valve.

2. Throttle apparatus as claimed in claim 1, characterized in that a stationary valve element and another valve element displaceable relative to the said former valve element and which is adjusted by it are used to change the aperture of a throttling duct of at least of one throttle valve, said throttling duct passing through a valve seat;

in that the minimum of one contacting element is mounted on the stationary valve element and at least one of the contacting elements is mounted on the displaceable valve element and can be displaced by latter relative to the stationary contacting element when the aperture of a throttling duct is being changed, the contacting elements contacting one another only in a predetermined position of the adjustable valve element and thereby close the electrical circuit, whereas in all other settings of the adjustable valve element the contacting elements are spaced from one another and thereby interrupt the electrical circuit.

3. Throttle apparatus as claimed in claim 2, characterized in that the displaceable valve element is displaceable along a straight center line and is mounted in irrotational manner about this center line, in that the displaceable valve element is fitted with a thread which engages another thread that may be rotated by a motor in order adjust the displaceable valve element along the center line relative to the throttle valve'"'"'s seat.

4. Throttle apparatus as claimed in claim 2, characterized in that one of the mutually contact-able elements, preferably the contacting element mounted on the displaceable valve element is a shunting element and in that at least two of the other contacting elements are mutually spaced apart and can be shunted by the shunting element to close electrical circuit respectively to interrupt said path by removing the shunting from them and thereby electrically separating them.

5. Throttle apparatus as claimed in claim 4, characterized in that the shunting contacting element is tippable to allow it to tip relative to other contacting elements with which to make contact even with all these other contacting elements and to shunt the latter when they are differentially spaced from the shunting, contacting element.

6. Throttle apparatus as claimed in claim 2, characterized in that a spring is prestressed into position between the displaceable valve part and the stationary valve part so as to be biased in the adjustment direction of the displaceable valve part, preferably in the opening direction of the minimum of one throttle valve.

7. Throttle apparatus as claimed in claim 4, characterized in that the spring is biased toward the shunting contact element.

8. Throttle apparatus as claimed in claim 3, characterized in that the displaceable valve part is constituted by at least two components, one of which is a valve element having a valve head adjacent to the valve seat to adjust the aperture of the throttling duct, another component being a guide element linked to the valve element to implement joint displacement along the center line but irrotationally supported with respect to said center line, and fitted with the thread.

9. Throttle apparatus as claimed in claim 1, characterized by a second throttle valve in addition to the throttle valve, and in that the two throttle valves are mechanically linked to each other in a manner that when one is displaced in the opening direction, the other shall be displaced in the closing direction and vice-versa when one is displaced into the closing direction the other undergoes a displace in the opening direction.

10. Throttle apparatus as claimed in claim 9, characterized in that the throttling ducts of the two throttle valves are configured mutually axially and are connected to each other by a connecting duct;

in that only one displaceable valve part is provided jointly for both throttle valves and runs through the throttling ducts of both throttle valves and through the connecting duct;

in that the connecting duct is fitted with a compressed air intake and in that each throttle valve is fitted at its valve side away from the connecting duct with a compressed air outlet.

11. Powder spraycoating equipment,

characterized by a throttle apparatus as claimed in claim 1 in at least one compressed air path to feed compressed air.

12. Powder spraycoating equipment as claimed in claim 11, characterized by a throttle apparatus as claimed in at least one of the above claims and configured in at least one of the following compressed air paths:

a conveyance air path for conveying compressed air to an injector for the purpose of pneumatically moving coating powder;

an additional air path for additional compressed air in a powder-air conveyance path within which coating powder is pneumatically moved by the conveyance air;

a shaping-air path for compressed shaping air to shape a sprayed powder cloud;

an electrode rinsing-air path for compressed rinsing air leading to a high voltage electrode used to electrostatically charge the coating powder; and

/or a fluidizing-air feed path for compressed fluidizing air to fluidize coating powder in a powder container.

13. Powder spraycoating equipment as claimed in claim 11, characterized by a throttle apparatus as claimed in either of claims 9 and 10, one of the two throttle valves being mounted in a conveyance air path conveying compressed conveyance air to an injector to pneumatically move coating powder, and the other of the two throttle valves being configured in an additional air path to feed compressed additional air to a powder-air conveyance path wherein the coating powder is pneumatically moved by the conveyance air.