Patent Application
20120080541
The invention relates to paint sprayers and, more particularly, to nozzle closure devices for paint sprayers.
Paint sprayers have the advantage of providing users with the ability to conveniently spray paint, glue, texture, or other liquids and partial liquids. A disadvantage of current paint sprayers is that after a user stops spraying, spray liquid can cure and harden in and around the spray nozzle. When the paint sprayer is used again, the nozzle can be blocked, partially blocked, or the cured spray liquid can be expelled from the nozzle onto the work piece, ruining the finish of the work piece. Another disadvantage of current paint sprayers is that the nozzles of the sprayers need to be cleaned to remove the buildup of cured spray liquid.
In one embodiment, the invention provides a nozzle assembly for use with a paint sprayer. The paint sprayer includes a reservoir configured to store a supply of liquid and a pump operable to draw liquid from the reservoir. The nozzle assembly includes a nozzle configured to receive liquid under pressure from the pump and operable to spray the liquid onto a surface, and a nozzle closure device that is movable between an open position, in which liquid is sprayed out of the nozzle generally unimpinged, and a closed position, in which the nozzle closure device covers the nozzle. The nozzle closure device is moved from the closed position to the open position by a force other than the liquid under pressure from the pump.
In another embodiment, the invention provides a paint sprayer including a body, a nozzle supported by the body for spraying liquid onto a surface, a reservoir configured to store a supply of liquid, a pump operable to draw liquid from the reservoir and direct the liquid under pressure to the nozzle, and a nozzle closure device coupled to the body adjacent the nozzle. The nozzle closure device is movable between an open position, in which liquid is sprayed out of the nozzle generally unimpinged, and a closed position, in which the nozzle closure device covers the nozzle. The nozzle closure device is moved from the closed position to the open position by a force other than the liquid under pressure from the pump.
Other aspects of the invention will become apparent by consideration of the description and accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
The pump 28 and the reservoir 32 are supported by the body 24 such that the illustrated paint sprayer 20 is a hand-held tool. The pump 28 is enclosed in the body 20 and is activated when a user actuates (e.g., pulls) the trigger 52. The reservoir 32 is configured to store a supply of liquid (e.g., paint). In the illustrated embodiment, the reservoir 32 is threadably coupled to the forward portion 56 of the body 24 to facilitate removing and refilling the reservoir 32 with liquid. In other embodiments, the pump 28 and/or the reservoir 32 may be separate from the body 24 of the paint sprayer 20. In such embodiments, the reservoir 32 may include a tube that connects the pump 28 to a remote reservoir or source of liquid.
In operation, the pump 28 draws liquid from the reservoir 32 and directs the liquid under pressure to the nozzle 44. The nozzle 44 receives the liquid from the pump 28 and sprays the liquid onto a work piece. In the illustrated embodiment, the paint sprayer 20 is a corded tool such that the pump 28 is powered by a wall outlet or generator. In other embodiments, the paint sprayer 20 may include a battery pack, such as a Li-ion or NiCad power tool battery pack, to power the pump 28.
As shown in
When in the open position (
Referring to
The illustrated linkage 80 includes a pivot arm 84, a connecting arm 88, a connecting hub 92, and two fingers 96. The pivot arm 84 is coupled to the trigger 52 and pinned to the body 24 of the paint sprayer 20 at a pivot point 100 (
When the trigger 52 is actuated, the trigger 52 pivots the pivot arm 84 about the pivot point 100, which pushes the connecting arm 88 toward the tip guard 36 of the paint sprayer 20 (i.e., in the direction of arrow B (
Actuating the trigger 52 also activates the pump 28 of the paint sprayer 20 to spray liquid from the nozzle 44. The trigger 52 thereby simultaneously actuates the duckbill valve 64 and the pump 28 to move the valve 64 toward the open position and to spray liquid from the nozzle 44. When the trigger 52 is released, the paint sprayer 20 ceases to spray liquid from the nozzle 44 and the linkage 80 allows the duckbill valve 64 to close to inhibit liquid from curing in and around the nozzle 44.
In some embodiments, the paint sprayer 20 may be designed to open the duckbill valve 64 a short time (e.g., less than about one second) before the pump 28 is activated and to close the duckbill valve 64 a short time (e.g., less than about one second) after the pump 28 is deactivated. For example, actuating the trigger 52 a small amount may actuate the linkage 80 to open the valve 64 before the pump 28 is activated. The pump 28 may then be activated when the trigger 52 is fully actuated. Likewise, when the trigger 52 is released a small amount, the pump 28 may be immediately deactivated. The linkage 80, however, may maintain the duckbill valve 64 in the open position until the trigger 52 is completely released. Such a configuration may help reduce interference of the duckbill valve 64 with liquid being sprayed from the nozzle 44. In other embodiments, the paint sprayer 20 may include separate triggers, or other user-engageable actuators, for the pump 28 and the actuator mechanism 76.
In other embodiments, the nozzle closure device 60 can be coupled to the tip guard 36 or another portion of the paint sprayer 20, rather than directly to the body 24 of the paint sprayer 20. Additionally or alternatively, the duckbill valve 64 may be actively closed by the linkage 80 instead of relying on the natural resilience of the elastomeric material of the valve 64. In still other embodiments, the duckbill valve 64 may be closed by a spring or another mechanism of the paint sprayer 20.
When in the open position, the pivot arm 112 is pivoted about the axis 132 until the sealing portion 116 and the intermediate portion 120 are sufficiently spaced apart from the nozzle 44 so that the arm 112 does not impinge on liquid being sprayed from the nozzle 44. When in the closed position, the pivot arm 112 is pivoted about the axis 132 until the sealing portion 116 is positioned over the nozzle 44 to cover the nozzle 44. In this position, the pivot arm 112 inhibits air from entering the nozzle 44 and curing liquid in and around the nozzle 44.
In the illustrated embodiment, the pivot arm 112 is manually pivoted between the open position and the closed position. During use, a user manually pivots the arm 112 to the open position and then operates the paint sprayer 20 by actuating the trigger 52. When finished, the user manually pivots the arm 112 to the closed position to cover the nozzle 44. In other embodiments, the pivot arm 112 may be pivoted between the open position and the closed position automatically. For example, in some embodiments, the trigger 52 may cause the pivot arm 112 to move between the positions. In such embodiments, the pivot arm 112 may be moved by mechanical, pneumatic, hydraulic (e.g., using the liquid being sprayed), or electromechanical devices that are actuated with the pump 28 or are actuated independent of the pump 28.
The disk 144 is coupled to the tip guard 36 adjacent the nozzle 44 and functions as an actuator mechanism. The illustrated disk 144 is rotatable about a nozzle axis 148 (see also
The rotatable disk 144 defines an elliptical opening 152 and two arcuate slots 156. The elliptical opening 152 has a greater dimension in one direction than in a perpendicular direction such that the opening 152 has a wide portion 160 and a narrow portion 164. The duckbill valve 140 extends through the opening 152. The arcuate slots 156 have constant and similar radii. Two pegs 168 are coupled to and extend outwardly from the tip guard 36. The pegs 168 extend through the slots 156 to limit the rotation of the disk 144 between the first and second rotational positions.
When in the first rotational position (
In the illustrated embodiment, the disk 144 is manually rotated between the first rotational position and the second rotational position. During use, a user manually rotates the disk 144 to the first rotational position to open the valve 140 and then operates the paint sprayer 20 by actuating the trigger 52. When finished, the user manually rotates the disk 144 to the second rotational position to cover the nozzle 44. In other embodiments, the disk 144 may be rotated between the first rotational position and the second rotational position automatically. For example, in some embodiments, the trigger 52 may cause the disk 144 to rotate between the positions. In such embodiments, the disk 144 may be moved by mechanical, pneumatic, hydraulic (e.g., using the liquid being sprayed), or electromechanical devices that are actuated with the pump 28 or are actuated independent of the pump 28.
In further embodiments, the duckbill valve 140 can be actively actuated to the closed position by a mechanism instead of relying on the natural resilience of the elastomeric material of the valve 140. In still further embodiments, rotation of the disk 144 can be constrained between the first and second rotational positions by a structure other than the illustrated slots 156 and pegs 168, or may be constrained by fewer or more slots and pegs. Additionally or alternatively, in some embodiments, the disk 144 can be biased toward one of the first and second positions. In such embodiments, the disk 144 can be maintained in the other of the first and second positions by a locking device (e.g., a latch, detents, etc.) when the paint sprayer 20 is in use (e.g., when the trigger 52 is actuated).
As shown in
The illustrated shape memory component 196 is, for example, a nickel-titanium FLEXINOL Shape Memory Alloy (SMA) wire manufactured by Dynalloy, Inc. The wire 196 has a first end 200 coupled to the cover 176 and a second end (not shown) coupled to a portion of the tip guard 36 or the body 24 of the paint sprayer 20. When heat is applied to the SMA wire 196, the wire 196 shrinks in length, pulling the cover 176 against the bias of the spring 192 from the closed position to the open position. In the illustrated embodiment, the SMA wire 196 is heated by applying an electrical current across the wire 196. The current used to heat the wire 196 may come from the paint sprayer 20 (e.g., from the power source used to power the pump 28) or from a separate power source.
When the trigger 52 of the paint sprayer 20 is actuated, an electrical current is applied to the SMA wire 196 to heat the wire 196, causing the wire 196 to shrink in length, overcome the bias of the spring 192, and slide the cover 176 to the open position. Actuating the trigger 52 also activates the pump 28 of the paint sprayer 20 to spray liquid from the nozzle 44. When the trigger 52 of the paint sprayer 20 is released, the paint sprayer 20 ceases to spray liquid from the nozzle 44 and removes the electrical current from the SMA wire 196. As the wire 196 cools, the wire 196 relaxes (i.e., expands in length), allowing the spring 192 to bias the cover 176 to the closed position to inhibit liquid from curing in and around the nozzle 44.
In other embodiments, the SMA wire 196 can be actuated by a device other than the trigger 52 such as, for example, a motion sensor. Additionally or alternatively, the cover 176 may be opened before the pump 28 is activated to spray liquid through the nozzle 44. For example, in some embodiments, actuating the trigger 52 a small amount can apply current to the SMA wire 196 before supplying power to the pump 28. The pump 28 may then be activated when the trigger 52 is completely actuated. In other embodiments, the cover 176 may be manually slid between the open and closed positions.
When in the open position, the pivot arm 208 is pivoted about the axis 228 until the sealing portion 212 and the intermediate portion 216 are spaced apart from the nozzle 44 so that the arm 208 does not impinge on liquid being sprayed from the nozzle 44. When in the closed position, the pivot arm 208 is pivoted about the axis 228 until the sealing portion 212 is positioned over the nozzle 44 to cover the nozzle 44. In this position, the pivot arm 208 inhibits air from entering the nozzle 44 and curing liquid in and around the nozzle 44.
As shown in
The illustrated shape memory component 236 is, for example, a nickel-titanium FLEXINOL Shape Memory Alloy (SMA) wire manufactured by Dynalloy, Inc. The wire 236 has a first end 240 coupled to the pivot arm 208 and a second end 244 coupled to a portion of the tip guard 36. When heat is applied to the SMA wire 236, the wire 236 shrinks in length, pulling the pivot arm 208 against the bias of the spring 232 from the closed position to the open position. In the illustrated embodiment, the SMA wire 236 is heated by applying an electrical current across the wire 236. The current used to heat the wire 236 may come from the paint sprayer 20 (e.g., from the power source used to power the pump 28) or from a separate power source.
When the trigger 52 of the paint sprayer 20 is actuated, an electrical current is applied to the SMA wire 236 to heat the wire 236, causing the wire 236 to shrink in length, overcome the bias of the spring 232, and pivot the arm 208 to the open position. Actuating the trigger 52 also activates the pump 28 of the paint sprayer 20 to spray liquid from the nozzle 44. When the trigger 52 of the paint sprayer 20 is released, the paint sprayer 20 ceases to spray liquid from the nozzle 44 and removes the electrical current from the SMA wire 236. As the wire 236 cools, the wire 236 relaxes (i.e., expands in length), allowing the spring 232 to bias the pivot arm 208 to the closed position to inhibit liquid from curing in and around the nozzle 44.
In other embodiments, the SMA wire 236 can be coupled to the body 24 of the paint sprayer 20, rather than the tip guard 36. In addition, the SMA wire 236 can be actuated by a device other than the trigger 52 such as, for example, a motion sensor. Additionally or alternatively, the arm 208 may be pivoted open before the pump 28 is activated to spray liquid through the nozzle 44. For example, in some embodiments, actuating the trigger 52 a small amount can apply current to the SMA wire 236 before supplying power to the pump 28. The pump 28 may then be activated when the trigger 52 is completely actuated.
Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described. Various features and advantages of the invention are set forth in the following claims.
This application claims priority to U.S. Provisional Patent Application No. 61/389,605, filed Oct. 4, 2010, the entire contents of which are incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 61389605 | Oct 2010 | US |
