CA1226431A - Color changer - Google Patents

Abstract

IMPROVED COLOR CHANGER
Abstract of the Disclosure An improved color changer for use with spray painting apparatus includes a housing having a plurality of passages connectable with air under pressure and with a plurality of supplies of fluids of different colors.
The passage for air connects directly with an air inlet to the apparatus and a selector knob is between an end of the housing whereat the passages for fluid terminate and a manifold which connects with a fluid inlet to the apparatus. The selector knob is movable to place the manifold into communication with one or more fluid passages to supply a selected one or more colors of fluid to the apparatus. The configuration of the housing, selector knob and manifold and of seals there between ensures reliable, leak-free operation of the color changer.

Description

- ~2Z6431 Background of the Invention The present invention relates to color changers in general and in particular to a color changer for use with an airbrush which is of improved structure for reliable and leakproof operation.
Airbrushes are commonly used by commercial artists and photographers to apply color and shading to drawings prints and photographs to accentuate highlights and to supply backgrounds to films as wolf as by hobbyists for painting models and projects. An airbrush is usually shaped like a pencil and as is well known utilizes air to atomize a fluid in a controlled pattern for deposit on an article.
In use of a typical airbrush a bottle containing fluid of a color to be applied is connected to the airbrush. The bottle has an outlet hole in its cap through which fluid is aspirated into a fluid inlet to the gun and a vent hole through which air is drawn US
the bottle empties so that a vacuum does not occur in the bottle and defeat further aspiration of fluid.
Compressed sir coupled to the airbrush passes through a small orifice adjacent the fluid inlet to the airbrush and draws the fluid out of the bottle due to the low pressure region developed across the bottle outlet as a result of venturi effect. The flow of sir then atomizes the fluid into droplets and applies it onto the surface being colored.
Prior airbrush and bottle assemblies have numerous drawbacks. For each different color or blend ox colors a different bottle has to be attached to the airbrush and in the case of a blend of colors different fluids must first be mixed together. The technique is time lZZ6431 consuming and tedious, and interrupts the flow of working with the airbrush. In addition, between color changes, a bottle of solvent has to be connected with the airbrush for flushing purposes. Moreover, the outlet holes from the bottles have a tendency to become plugged when relatively viscous fluids are used, as well as the vent holes due to the fluid being moved across the vents from the motion of the bottle during airbrushing.
To overcome the aforementioned disadvantages, color changers which selectively supply different colors of fluid or a solvent to an airbrush may be used, thereby obviating the particular problems encountered in using bottles. However, leakage problems have developed in using color changers, particularly when very low viscosity fluids such as inks are sprayed, which is not only messy, but the resulting drippings can mar the finish on articles being coated.
Object of the Invention The primary object of the present invention is to provide an improved color changer, which is very reliable in operation and of a structure to eliminate leakage of fluid during use.
Summary of the Invention In accordance with the present invention, there is provided an improved color changer for spray painting equipment, of a type including a housing having a plurality of conduits for connection with respective supplies of fluids, and outlets from said conduits; a manifold separate from said housing and having an Inlet and an outlet; and a selector member, having an inlet and an outlet, coupled with and rotatable about an axis Z2643~

between said housing and manifold, with said housing and manifold at opposite ends thereof and spaced apart one from the other, to move said selector member inlet into communication with a selected conduit outlet while maintaining said selector member outlet in communication with said manifold inlet, whereby fluid from a selected supply may be coupled with said manifold outlet. The improvement is characterized in that said selector member and housing, and said selector member and manifold, have overlapping cylindrical surfaces at opposite axial ends of said selector member and extending generally coaxial with said axis radially outwardly of said conduit outlets and said manifold inlet, and resilient annular seals are between said overlapping cylindrical surfaces and are slid able across at least one surface of each of said overlapping surfaces to permit rotation of said selector member between said housing and manifold while preventing leakage of fluid radially outwardly therefrom.
The foregoing and other objects, advantages and features of the invention will become apparent upon a consideration of the following detailed description, when taken in conjunction with the accompanying drawings.

Lo to Brief Description of the Drawings Fig. I is a side elevation view of a color changer in accordance with the invention, showing the same mounted on an airbrush;
Fig. 2 is an enlarged cross sectional side elevation view of the color changer Fig. 3 is taken substantially along the lines 3-3 of Fig. 2, and shows an arrangement of passages at an end of a barrel portion of the color changer;
Fig. 4 is taken substantially along the lines 4-4 of Fig. 2, end illustrates sun end of a rotatable selector for communicating with selected passages in the barrel, and Fig. is a front elevation view of the upper end of the color changer, showing its connection with the airbrush.
Detailed Description In Fig. 1 there is indicted generally et 20 an airbrush of a type with which the color changer of the invention ma be used. The airbrush is of conventional type, find includes an elongate or pencil-like body 22 having an inlet 24 for compressed air and an inlet 26 for fluid to be sprayed. A control knob 28 extends upwardly from the body, which when pushed down allows air to enter the airbrush and exit through a nozzle 30 and when pulled back opens the fluid inlet to the body, thereby allowing fluid to be aspirated or otherwise introduced into the body ion being emitted in an atomized spray entrained in air Strom the nozzle. A
thimble 32 on the body forwardly of the control knob is adjustable to permit the knob to be moved only a selected amount rearwr,rdly to control the flow rate of lZ2643~

Squid from the nozzle when the knob is pushed down and moved rearwardly.
The color changer itself is indicated generally at 34 and includes a housing or barrel 36 connected with and supported by the air inlet 24 to the airbrush by means of an air inlet conduit 3B and a connector 40. A
sleeve 42 is connected with the lower end of the barrel by a lock ring 44 and a flexible tubular conduit 46 carrying a plurality of fluid conveying tubes and a compressed air conveying tube extends into and is secured in the sleeve with the tubes in communication with associated passages through the barrel. A manifold 48 at an upper end of the color changer has a yoke 50 connected with and supported by the fluid inlet 26 to the airbrush and a color selector knob 52 is rotatable between the barrel and manifold to connect a selected one or more fluid passages in the barrel with the manifold for supplying one or more different colors of fluid to the airbrush for being erupted in a spray.
Reserving in particular to Figs 2-4 the barrel 36 is generally cylindrical and has a plurality of fluid passages aye at equally spaced angular increments extending longitudinally there through Strom a lower to an upper end of the barrel and an air passage 56 which extends from the lower end to an air outlet at an intermediate point alone the length of the barrel. The tubular conduit 46 contains a plurality of fluid conveying hoses or tubes 58 and an air conveying tube and is coupled to the lower end of the barrel with individual ones ox the fluid conveying tubes 58 in Communication with respective ones of the Squid passages aye and with the air conveying tube 60 in - lZ26431' communication with the air passage 56. To the end, the lower end of the sleeve 42 is attached to the end of the tubular conduit by means of complimentary ridges and recesses on the sleeve and conduit, end the two ore securely held together by Q retaining ring 62 extending around the sleeve. A circular pin locator 64 is mQintsined within an upper end of the sleeve by means of a flange on the sleeve being received within a recess in the pin locator, and has passages there through corresponding to and aligned with the passages in the barrel. An air pin 66 and bone fluid pins 68 sure received in respective passages through the pin locator, and lower ends of the pins are provided with barbs so that the sir pin may be securely connected with the air conveying tube MU and individual ones of the fluid pins with associated ones of the fluid conveying tubes 58. A
circular gasket 80 having passages there through aligned with those in the pin locator is positioned over the upper ends of the air and fluid pins, the air pin is extended into the barrel air passage 56 and the fluid pins into associated ones of the barrel fluid passages I and the lock rlng,~4 Is threaded onto the lower end of the barrel to connect the hose bundle to the barrel.
Although not shown, at an opposite end ox the tubular conduit 46 the air conveying tube 60 is connected with a supply of air under pressure and the fluid conveylnE tubes 58 with supplies Or fluids of different colors. Consequently, pressurized sir is coupled with the barrel air passage 56 while etch of the barrel fluid passages aye receives a different color of fluid ' .
.

1~26~31' To connect pressurized air to the airbrush 22, the air inlet conduit 38 is threaded into the outlet opening from the barrel air passage 56 and is coupled with an air connector 82 by means of threading the connector 40 onto the air inlet 24, and an wrung 84 provides fluid-tight connection between the air inlet conduit and the air connector Thus, upon depressing the control knob 28, air from the barrel passage 56 is admitted into the airbrush for aspirating fluids into the airbrush and atomizing the fluids into a spray To selectively connect one or more different colors of fluids in the barrel fluid passages aye with the fluid inlet 26 to the airbrush, the color selector knob 52 is rotatable mounted between and in sealed relationship with the upper end of the barrel 36 and the lower end of the manifold 48 for selectively coupling fluid in one or more of the barrel fluid passages with the manifold and thence with the airbrush fluid inlet.
The particular configuration of the barrel, selector knob and manifold, together with the arrangement and nature of seals there between, ensures that secure, fluid tight connections are established, so that there is no Leakage of fluid from the color changer To provide a leak proof rotfltable mounting of the color selector knob 52 between the barrel 36 and manifold 48, the upper end of the barrel has an inner annular recess 86 which is of e first diameter and lies radially inwardly of the fluid passages aye, and an annular recess 88 outwardly of the inner recess, which is of a second and forger diameter, extends radially outwardly of the fluid passages and defines a cylindrical rim 90 around the upper end of the barrel - - . _, _ lZZ643~

Similarly, the lower end of the mQnifo]d his on inner annular recess 92 of the first diameter, and an outer annular recess 94 of the second diameter which defines a cylindrical rim 96 Hound the lower end of the manifold.
The color selector knob 52 is received within the annular recesses in the barrel and manifold, and comprises a main cylindrical body portion 98 extending between and within the outer barrel recess 88 and the outer manifold recess 94 and having a diameter slightly smaller than the second diameter so that it is in spaced relationship from the cylindrical rims 90 and 96.
Sleeves 100 and 102 at opposite ends of the main body portion, of a diameter slightly less than the first diameter, are respectively received within the inner barrel recess 86 and the inner manifold recess 92 in spaced relationship with the annular walls of the recesses, and a circumferential rim 104 on the main body, knurled on its outer surface to facilitate manual gripping and rotation of the selector knob, extends outwardly from between the ends of the cylindrical rims.
To mount the color selector knob 52 and manifold 48 on the upper end of the barrel 36, shoulder screw 106, received within a central pQssflge 108 through the barrel, extends through coaxial passages in the barrel, color selector knob and manifold into threshed engagement with the manifold. A compression spring 110 between the head or the screw and à shoulder within the barrel passage yleldably urges the manifold, color selector knob and barrel together with a force which permits rotation of the selector knob, and a lock nut 112 is threaded onto an end of the screw which extends beyond the upper end of the manifold.

~2Z6431' To establish the secure, fluid tight connections between the barrel 36, color selector knob 52 and manifold 48, and to ensure that fluid cannot leak out of the color changer, annular seals 114 and 116, received within recesses in the surfaces of the selector knob sleeves 100 and 102, seal with the annular walls of the barrel and manifold recesses 86 and 92 to block any Leakage of fluid radially inwardly of the fluid passages aye To prevent any leakage radially outwardly, annular seals 118 and 120, received within recesses in the outer surface Or the selector knob main body 98 to opposite sides of the rim 104, seal with the annular wills of the barrel and manifold circumferential rims 90 and 96 To provide limited area high pressure points of sealing contact to enhance the sells sod minimize sliding resistance of the seals upon rotation of the color selector knob, each seal has a relatively small circumferential protuberance, such as the protuberance 122 on the seal 120, for slidingly and sealingly engaging the annular WAIT ureas of the manifold and barrel It is to be appreciflted that the psrticulsr configuration of the manifold, color selector knob and barrel, together with the arrangement of the snnulsr Silas results in the sealing action being completely independent of and uninfluenced by the force with which the screw 106 and spring 110 urge the components together Because the annular overlapping wall areas of the manifold, selector knob and barrel, between which the seals sure effected, extend cosxisl to the axis of rotation of the selector knob, while the snnulsr seals exert radially directed forces on the overlapping will ureas, the radial forces of the seals are not affected by the axially directed force exerted by the screw and spring, and the degree of sealing action obtained is determined solely by the dimensions of the components.
Color selection, upon rotation of the selector knob 52, is accomplished by providing 8 passage 124 in the sxia] direction through the knob and forming an elongate concave recess 126 in the lower surface of the knob to opposite sides of the opening to the passage. The passage and recess ore radially located to be rotatable across the outlets from the fluid passages aye through the barrel 36, and the arcuate extent of the recess is such that it may be positioned to overlie only a single one of the fluid passage outlets or to simultaneously overlie an adjacent pair of the outlets. Consequently, by rotating the fluid selector knob the passage 124 may replaced in communication with a selected one of the fluid passages to receive the color of fluid therein, or It may be simultaneously placed in communication with an adjacent pair of fluid passages to receive a blend of colors, with the ratios of the colors being determined by the extent to which the recess overlies each passage.
The manifold 48 receives the selected fluid or fluids from the selector knob 52, and in tint connection an annular channel 128 in the surface of the annular recess 94 is of a diameter to continuously overlie an outlet from the selector knob passage 124 as the knob is rotated. The manifold is connected to the airbrush by means of the Yoke 50, the arms of which extend to opposite sides of the airbrush, and a passage 130 in communication with the annular channel is formed through the manifold and one of the yoke arms. As best seen in lZ~:6431 Fig. 5, the sum having the passage 130 receives the fluid inlet 26 to the airbrush with the passage in communication with the inlet arm and a asp screw 134 closes an outer end of the inlet. A lock screw 136 extended through the other yoke arm to Q side of the airbrush may be tightened to mount the yoke on the airbrush.
Accordingly, upon rotation of the color selector knob 52 to place the recess 126 and passage 124 in communication with a selected one or more of the fluid passages aye through the barrel the selected color or colors of fluid flow through the selector knob passage 124 into the annular manifold channel 128, and thence through the manifold pflssage 130 to the fluid inlet to the airbrush for being emitted in an atomized spray. At the some time, because of the particular configurations of the barrel, manifold sod selector knob, and the arrangement of the seals 114, 116, 118 and 120, leakproof operation of the color changer is ensured, even under the circumstance where the fluids to be sprayed are supplied under pressure and not simply aspirated into the airbrush. Leakage of fluid radially outwardly of the color chsngér is prevented by the annular seals 118 and 116, while leakage radially inwardly is blocked by the seals 114 and 116. It is appreciated, of course, that instead of providing nine different colors of fluids through the fluid passages aye, in most circumstances it would be more advantageous if a solvent were supplied through one of the passages, so that the airbrush and color changer may readily be cleaned simply by selecting the solvent for spraying.

12264~1 While one embodiment of the invention has been described in detail, various modifications end other embodiments thereof may be devised by one skilled in the art without deporting from the spirit end scope of the invention, as defined In the appended claims.

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Claims (7)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An improved color changer for spray painting equipment, of a type including a housing having a plurality of conduits for connection with respective supplies of fluids, and outlets from said conduits; a manifold separate from said housing and having an inlet and an outlet; and a selector member, having an inlet and an outlet, coupled with and rotatable about an axis between said housing and manifold, with said housing and manifold at opposite ends thereof and spaced apart one from the other, to move said selector member inlet into communication with a selected conduit outlet while maintaining said selector member outlet in communication with said manifold inlet, whereby fluid from a selected supply may be coupled with said manifold outlet, wherein the improvement is characterized in that said selector member and housing, and said selector member and manifold, have overlapping cylindrical surfaces at opposite axial ends of said selector member and extending generally coaxial with said axis radially outwardly of said conduit outlets and said manifold inlet, and resilient annular seals are between said overlapping cylindrical surfaces and are slidable across at least one surface of each of said overlapping surfaces to permit rotation of said selector member between said housing and manifold while preventing leakage of fluid radially outwardly therefrom.

2. An improved color changer as in claim 1, wherein the improvement is further characterized in that said selector member and housing, and said selector member and manifold, also have overlapping cylindrical surfaces at opposite axial ends of said selector member and extending generally coaxially with said axis radially inwardly of said conduit outlets and said manifold inlet, and resilient annular seals are between said radially inwardly overlapping cylindrical surfaces and are slidable across at least one surface of each of said radially inwardly overlapping surfaces to permit rotation of said selector member between said housing and manifold while preventing leakage of fluid radially inwardly thereof.

3. An improved color changer as in claim 2, wherein the improvement is further characterized in that said housing has a generally planar surface in which said conduit outlets are disposed in an annular array, an annular recess is in said surface coaxial with said axis and radially inwardly of said conduit outlets and a cylindrical rim extends from a periphery of said surface coaxial with said axis and toward said manifold; said manifold has a generally planar surface in which said manifold inlet is disposed, an annular recess is in said manifold surface coaxial with said axis and radially inwardly of said manifold inlet and a cylindrical rim extends from a periphery of said manifold surface coaxial with said axis and toward said housing; and said selector member has a cylindrical main body portion of a smaller diameter than and received at opposite axial ends within said housing and manifold cylindrical rims coaxial with said axis to define said radially outwardly overlapping cylindrical surfaces between said main body portion and said housing and manifold cylindrical rims, and a pair of cylindrical extensions at said opposite ends of and coaxial with said main body portion and of a smaller diameter than and received within respective ones of said annular recesses to define said radially inwardly overlapping cylindrical surfaces between said cylindrical extensions and said annular recesses.

4. An improved color changer as in claim 3, wherein the improvement is further characterized in that ends of said cylindrical rims are spaced apart and said selector member main body portion has a circumferential rim extending between and radially outwardly of said cylindrical rim ends for being manually rotated to rotate said selector member.

5. An improved color changer as in claim 3, wherein the improvement is further characterized in that said manifold inlet comprises an annular channel in said manifold surface coaxial with said axis, said selector member main body portion has generally planar surfaces at its opposite axial ends and said selector member outlet comprises an outlet opening at an axial end of said main body portion and rotatable about said axis in constant communication with said annular channel.

6. An improved color changer as in claim 2, wherein the improvement is further characterized in that said housing, selector member and manifold are coupled together by a fastener which resiliently urges the same together in a direction along said axis.

7. An improved color changer as in claim 2, wherein the improvement is further characterized in that said annular seals have annular protuberances for slidingly engaging said at least one surface of said overlapping surfaces over limited areas to effect relatively high pressure seals with said at least one surface and reduce the sliding resistance of said annular seals there across.