GB2106794A

GB2106794A - Mixing and dispensing viscous liquids

Info

Publication number: GB2106794A
Application number: GB08225807A
Authority: GB
Inventors: Jeffery Cartwright
Original assignee: DIYCOLOR Ltd
Current assignee: DIYCOLOR Ltd
Priority date: 1981-10-03
Filing date: 1982-09-09
Publication date: 1983-04-20

Abstract

A device (1) for mixing and dispensing a viscous liquid (2), such as a paint colourant, which tends to separate into fractions and needs to be mixed thoroughly prior to use, includes a syringe (3) with a transparent barrel (5) in which a plunger (6) is slidable, the plunger (6) having an elastic head (7) which forms a sliding seal in the barrel (5). The syringe (3) further includes a rigid wire mixer (4) which passes sealingly through the plunger head (7) and is movable independently of the plunger (6) to agitate and mix the liquid (2). The barrel (5) has an external scale (12) for indicating the amount of liquid discharged and, for use with paint colourants, the device (1) may further include a shade card (13) with a colour- shaded scale (14) which can be matched with the scale (12) on the barrel (5). <IMAGE>

Description

SPECIFICATION Device for mixing and dispensing viscous liquids The present invention relates to devices for mixing and dispensing selectively predetermined amounts of viscous liquids which tend to separate into fractions.

The invention is concerned particularly, but not exclusively, with a device for mixing and adding precise amounts of liquid colourants to paints. Such devices can also be used, for example, to add accelerators to liquid resins.

As an alternative to stocking a large range of paints in different colours, some paint retailers use paint mixing machines so that the colour of paint required by a customer can be provided by adding appropriate amounts of colourant to a neutral or white paint. Such paint mixing machines are usually bulky and expensive, and are not intended to be used by the consumer. Cheap and simple mixing devices for use by the consumer have also been proposed but these usually contain a predetermined amount of colourant, all of which must be added to the paint to give a predetermined final colour.

There is a need for a device which allows the consumer to use only a portion, or all, of the colourant contained therein, so that the final colour of the tinted paint will depend more on the consumer's choice than on the manufacturer's predetermination of the amount of colourant in the device.

A problem arises in the provision of such a device, however, since most paint colourants are viscous liquid dispersions which tend to separate into fractions of different densities with time. Unless the colourant is thoroughly mixed before use, a greater proportion of one fraction relative to another fraction may be added to the paint, and this will result in an incorrect tint. Because of the viscosity of these colourants, they cannot merely be shaken prior to use, but must be actively mixed or stirred. Thus, the colourants must be supplied in a dispensing device which allows this prior mixing.

The object of the present invention is to solve this problem cheaply and simply.

Accordingly, the present invention provides a device for mixing and dispensing selectively predetermined amounts of a viscous liquid which tends to separate into fractions, comprising a syringe with a cylindrical barrel which allows the level of a liquid contained therein to be gauged, a plunger slidable in the barrel, and an outlet with a removable sealing closure through which the liquid may be discharged upon removal of the closure and sliding of the plunger, the syringe further including a mixer which is operable manuallyfrom outside the barrel and is movable independently of the plunger to agitate and mix the liquid prior to the removal of the closure and discharge of the liquid.

Preferably the syringe barrel is light-transmitting, that is, transparent or translucent. In some cases, however, the barrel may be opaque with a transparent axially-extending window for gauging the level of liquid.

Various arrangements for the mixer can be envisaged. In one case, for example, the mixer may comprise a rod which extends coaxially through the plunger and has a number of blades or vanes at its end within the barrel, so that rotation and axial movement of the rod causes the blades to pass through the liquid to effect thorough mixing thereof.

In another case, the mixer may comprise a rod or wire which extends through the barrel outlet to serve as its closure, and has a detachable vane or the like at its end within the barrel, so that, after stirring, the rod or wire can be pulled sharply to detach the vane and then removed from the outlet to permit discharge of the liquid. In yet another example, the mixer may be formed by a vaned rod, or a bent wire element, which extends through a sealed opening at the end of the barrel adjacent the outlet.

In view of the fact that the device according to the invention is intended to be discarded once its contents have been discharged, it is essential that the mixer arrangement be as simple as possible so that the device can be manufactured cheaply. With this in view, a preferred embodiment of the invention employs a readily-available type of syringe in which the plunger has a head of elastic material which forms a sliding seal with the wall of the barrel, and the mixer comprises a rigid wire element which extends parallel to the axis of the plunger and passes sealingly through the head in an eccentric position relative to the axis, the end of the wire element within the barrel being bent and/or coiled to lie in a plane substantially perpendicular to said axis.This arrangement can be assembled by simply pushing the wire through the plunger head, forming an efficient sliding seal around the wire which allows the latter to be moved axially in the barrel to mix the liquid without moving the plunger. This preferred embodiment has the advantage of being simpler than those arrangements discussed previously, as well as the advantages that the mixer does not significantly reduce the volume of the barrel and does not impede the discharge stroke of the plunger.

Although an experienced user may be able to judge the amount of liquid which has been discharged from the position of the plunger in a transparent or translucent barrel, it is preferable that the barrel has an external scale which can be compared with a part of the plunger head, usually a leading sealing flange thereof, to indicate the volume of liquid discharged from, or remaining in, the barrel. In the case of paint colourants, it is envisaged that the device may further include a display card, box, envelope or other packaging means for the syringe, having a graduated and/or colour-shaded scale for matching with the scale on the barrel, or that the scale on the barrel itself may be colour-shaded, in order to show the approximate depth of tinting produced by adding the indicated amount of colourant to a given amount of base paint.Some packaging means or syringe barrels may have a plurality of such scales, each applicable to a different amount of paint.

One embodiment of a device according to the present invention will now be more particularly described by way of example, with reference to the accompanying drawing which is a diagrammatic side view of the device.

Referring now to the drawing, there is shown a device 1 for mixing and dispensing a viscous liquid, in this case a paint colourant 2 which tends to separate into fractions of different densities if left undisturbed. The device 1 is constituted by a plastics syringe 3 of known type, which is provided with a mixer 4 for agitating and mixing the colourant 2 immediately prior to use.

The syringe 3 has a light-transmitting, in this case transparent, cylindrical barrel 5 for containing the colourant 2, a plunger 6 which has a rubber head 7 to effect a sliding seal in the barrel 5, and an outlet nozzle 8 through which the colourant 2 is discharged by sliding the plunger 6. The outlet nozzle 8 is sealed by a removable closure formed, in this example, by a pin 9, although a screw cap or the like may be used.

The mixer 4 is constituted by a piece of rigid wire which extends parallel to the plunger 6 and, passing through the rubber head 7 in an eccentric position, has an end portion 10 which is immersed in the colourant 2 and is bent and/or coiled to lie in a plane substantially perpendicular to the plungerS. The other end 11 of the mixer 4 is also bent to facilitate gripping by a user's thumb and finger.

The rubber head 7 of the plunger 6 forms an efficient sliding seal around the mixer 4, which allows the mixer 4 to be moved vigorously back-andforth along the barrel 5 to mix the colourant 2, without the risk of leakage or movement of the plunger 6. When the colourant 2 is thoroughly mixed, the pin 9 is removed from the nozzle 8 and the colourant discharged.

In order that the user can determine precisely the amount of colourant 2 to be discharged, the exterior of the barrel 5 is provided with an external scale 12 which is graduated, for example, in 2 ml increments towards the nozzle 8. To determine the quantity of colourant discharged, it is sufficient to line up the appropriate scale marking with the leading sealing flange 7A ofthe plunger head 7.

When the device 1 is to be used for tinting paints as in this case, it may include packaging means for the syringe, for example, a display card 13, having a graduated and colour-shaded scale 14 which matches the scale 12 on the syringe barrel 5, or the scale 12 on the barrel 5 itself may be colour-shaded, in order to show the depth of tinting produced by adding the indicated amount of colourant to a given amount of base paint, usually white paint. The card 13 may have two scales, one on each side of the device 1 mounted thereon, to indicate the shades produced when, for example, the colourant 2 is added to 1 litre of paint and 2.5 litres of paint respectively. The colour-shaded scale on the syringe barrel may be printed directly onto the barrel or it may comprise an adhesive strip, transfer, or the like applied to the barrel in such a way that the indicated depth of colour gradually increases towards the nozzle.

Claims

1. A device for mixing and dispensing selectively predetermined amounts of a viscous liquid which tends to separate into fractions, comprising a syringe with a cylindrical barrel which allows the level of a liquid contained therein to be gauged, a plunger slidable in the barrel, and an outlet with a removable sealing closure through which the liquid may be discharged upon removal of the closure and sliding of the plunger, the syringe further including a mixer which is operable manually from outside the barrel and is movable independently of the plunger to agitate and mix the liquid prior to the removal of the closure and discharge of the liquid.

2. A device as claimed in Claim 1, in which the plunger has a head of elastic material which forms a sliding seal with the wall of the barrel, and the mixer comprises a rigid wire element which extends parallel to the axis of the plunger and passes sealinglythrough the head in an eccentric position relative to the axis, the end of the wire element within the barrel being bent and/or coiled to lie in a plane substantially perpendicular to said axis.

3. A device as claimed in Claim 1 or Claim 2, in which the barrel is transparent or translucent.

4. A device as claimed in Claim 3, in which the barrel has an external scale which can be compared with a part of the plunger head to indicate the volume of liquid discharged from, or remaining in, the barrel.

5. A device as claimed in Claim 4, for mixing and dispensing paint colourants, in which the device further includes packaging means for the syringe, having at least one graduated and/or colour-shaded scale for matching with the scale on the barrel of the syringe.

6. A device as claimed in Claim 5, in which the packaging means comprise a display card with a colour-shaded scale, so that the syringe may be mounted on the card with the scales juxtaposed.

7. A device as claimed in Claim 4, for mixing and dispensing paint colourants, in which the external scale on the syringe barrel comprises a colourshaded scale which can be compared with said part of the plunger head to show the depth of tinting produced by the discharge of an indicated amount of colourant into a given amount a base paint.

8. A device for mixing and dispensing viscous liquids, substantially as herein described with reference to, and as shown in, the accompanying drawing.