Dip-tube Liquid Vaporizers

Abstract

A dip-tube vaporizer has a cylinder in which a piston member is slidable. The interior of the cylinder communicates through a slide-valve-controlled opening with a chamber formed between the piston and the cylinder wall. The chamber is filled by a previous stroke so that when a plunger rod is depressed a shoulder thereon engages the piston and the latter acts to pressurize the liquid in the chamber and thus to deliver it through a passage in the plunger rod to an atomizer nozzle. As the plunger rod rises it draws up liquid through the dip tube and delivers it to the chamber ready for the next dispensing stroke of the plunger.

Description

BACKGROUND OF THE INVENTION

1. Field of the invention

This invention relates to dip-tube liquid vaporizers.

2. Description of the prior art

Piston vaporizers have been proposed in which the dip-tube immersed in the container that holds the liquid to be vaporized is connected to an atomizer nozzle through a piston-and-cylinder unit fitted with valves so as to constitute a suction and delivery pump. At least one of these valves generally consists of a ball held to its seating by force of gravity. Consequently, such vaporizers operate only when vertical, with the nozzle higher than the container; for if, in particular, the container be turned upside down and the vaporizer be operated, it is possible for all the liquid contained in the dip-tube and cylinder to leak out through the nozzle.

The object of the present invention is a vaporizer improved so as to overcome this difficulty.

SUMMARY OF THE INVENTION

According to the present invention there is provided a vaporizer comprising a first cylinder containing a first sliding piston, a second cylinder containing a second hollow piston and forming an extension of the first cylinder while itself being extended by a dip-tube, an operating member bearing an atomizer nozzle and fixed to a delivery tube in communication with the nozzle and leading to the interior of the first piston, and a component such as a valve for closing the outlet from the said tube, together with a spring or the like for holding the valve in its closed position, the vaporizer being characterized by the fact that the second piston is extended into the first cylinder by a tubular liquid inlet, which is in communication with the second cylinder and forms one wall of an annular pump chamber within the first cylinder, that the first piston is linked by dead movement to the delivery tube, so that the latter can move axially in relation to the former, and that the vaporizer includes a distribution system, operated by the displacement of the delivery tube and tubular inlet in relation to the first piston, whereby the annular pump chamber is placed in communication either with the said tubular inlet or with the delivery tube.

When the operating member is actuated, the result is to isolate the annular chamber from the dip-tube, to connect that chamber to the atomizer nozzle and then to move the first piston so that the liquid contained in the annular chamber is supplied to the nozzle.

During the recovery movement of the operating member, communication is broken between the annular chamber and the atomizer nozzle and is reestablished between the said chamber and the dip-tube; then the annular piston returns to its initial position, thereby lowering the pressure in the chamber, so that the chamber is filled with liquid through the dip-tube.

BRIEF DESCRIPTION OF THE DRAWINGS

Three embodiments of vaporizers embodying the present invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:

FIG. 1 is a longitudinal section of a first embodiment of vaporizer;

FIGS. 2 to 4 are similar sections to that of FIG. 1 and show various stages of operation;

FIG. 5 is a section of a second embodiment;

FIG. 6 is a similar section to FIG. 5 and shows a different stage of operation; and

FIGS. 7 and 8 are longitudinal sections of the third embodiment of a vaporizer, showing two different stages of operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The vaporizer, as shown in the drawings, has a cylindrical body 1, which has a screw thread for screwing on to the top portion 2 of a bottle or other container holding liquid that is to be vaporized.

In the underside of the body 1 is a recess coaxial with the body, housing one flange 3a, fixed to a cylindrical sleeve 3, and another flange 4a, fixed to a cylinder 4, which is fitted over the sleeve 3 and has its bottom edge extended to form a cylinder 5 of smaller diameter. A dip-tube 6, is fitted into this cylinder 5.

A rod 7, which is fixed to an operating push-member 8, and has an axial bore 9, slides within the sleeve 3. At the top (as illustrated), the bore 9 is in communication with an atomizer nozzle 10, fitted into the push-member 8.

The rod 7 has a portion 7a, which is larger in cross section, its diameter being substantially the same as the inside diameter of the sleeve 3, the flange 3aon which, however, has an inside diameter smaller than the portion 7a of the rod 7, so that it restricts the upward movement of the rod.

The portion 7a of the rod 7 is followed (moving downwardly) by a portion of smaller cross section 7b, on which the top 11a of a piston 11, working in the cylinder 4, forms a sliding fit. The bore 9 terminates in a cavity 9a, in the bottom end face of the portion 7b.

The diameter of the upper part 11a, of the piston 11 is smaller than the inside diameter of the sleeve 3 and is joined to the piston 11 proper by a frustoconical portion, 11b. Upwards movement of the piston 11 is thus limited by the frustoconical portion 11b coming to bear against the end of the sleeve 3. The cylinder 4 is pierced by an opening 12, which lies opposite the frustoconical portion of the piston 11 when this is at the top of its stroke. A guide portion 13a, on a tubular member 13, can be engaged with a certain amount of play in the bottom end of the piston 11. This tubular member 13 forms an extension of a second hollow piston 13d, which moves in the cylinder 5; and since the diameter of the member 13 is smaller than that of the cylinder 4, there is an annular space within the cylinder, around the member 13.

The tubular member 13 contains a slide valve 15, the top end of which is extended to form a shank 15a, which forms a sliding fit in the guide portion 13a of the member 13 and is longer than the guide portion. The tubular member 13 contains a side opening 16, which lies below the valve 15 when this is in its raised position and which serves to place the annular chamber 14 in communication with the interior of the member 13 and hence with the cylinder 5.

A spring 17, is interposed between the slide valve 15 and the end of the cylinder 5. This spring biases the valve 15 to the remote end of the member 13, to bring the shoulder on the member 13 to bear on the piston 11, thereby cutting off the cavity within that piston, and to apply the portion 11b of the piston 11 against the bottom end of the sleeve 3; it also seeks, through the shank 15a of the valve 15, to thrust the rod 7 upwards, together with the push-member 8 secured thereto. The various members, when at rest, thus occupy the positions shown in FIG. 1.

As will be seen hereinafter, the purpose of the opening 12 is to allow air to enter the container to which the body 1 is screwed, to replace the volume of liquid vaporized; but this opening 12 is closed when the frustoconical portion 11b of the piston meets the bottom end of the sleeve 3. Again, when the vaporizer has been in use, the chamber 14 is filled with liquid for evaporation, but this chamber is cut off from the outside by virtue of the shoulder on the tubular member 13 bearing against the underside of the piston 11. It will thus be seen that the vaporizer is fully sealed when at rest and cannot leak.

When the push-member 8 is thrust towards the body as indicated by the arrow 18, the rod 7 moves within the piston 11 and exerts a thrust on the valve 15, which thus closes the opening 16, so that the chamber 14 is cut off from the cylinder 5 (FIG. 2).

Then the end of the rod 7 meets the guide portion 13a of the member 13 and drives it down until the wide-sectioned portion 7a of the rod meets the top 11a of the piston 11.

As the push-member 8 continues to move, the result is that the piston 11 is thrust downwards in the cylinder 4 (FIG. 3). The liquid contained in the chamber 14 flows through the clearance existing between the central opening in the piston 11 and the guide portion 13a and is driven through the bore 9 to the nozzle 10, where it is vaporized.

Moreover, air can enter the container through the clearance between the rod 7 and the sleeve 3 and through the opening 12.

When the push-member 8 is released, the spring 17 raises the slide valve 15, which moves clear of the opening 16 and comes to bear against the rear of the member 13. The shoulder on the latter then comes to bear against the underside of the piston 11, isolating the chamber 14 from the outside (FIG. 4).

From that moment, the various working parts, namely the push-member 8, the rod 7, the piston 11, the slide valve 15 and the tubular member 13, move as a single unit. The piston 11 rises within the cylinder 4, thereby lowering the pressure in the chamber 14, which causes liquid to rise from the container, up the dip-tube 6. From this dip-tube, the liquid passes into the cylinder 5 and flows through the opening 16 into the chamber 14, which becomes filled with liquid.

When the cycle is complete, the moving parts have resumed their positions shown in FIG. 1. The chamber 14 is full of liquid, which cannot pass down into the container again through the dip-tube 6, because the opening 16 is at the top of the chamber.

The vaporizer is thus ready for further action.

It will be noted that the vaporizer just described has no nonreturn valve. It can therefore work in any position, provided, of course, that the free end of the dip-tube 6 is immersed in the liquid to be vaporized.

In the embodiment illustrated in FIGS. 5 and 6, the valve 15 and the opening 16 have been dispensed with. The extension 13a of the tubular member 13 bears against the end of the rod 7 and contains an axial passage 13b, extending into a transverse passage 13c, which, when at rest, lies opposite a passage 11c, in the piston 11. Again, the axial bore 9 in the rod 7 does not extend to the end of the rod and is in communication with a transverse passage 9b, which lies opposite the passage 11c in the piston 11 when the shoulder 7a of the rod is in contact with that piston. The spring 17 is interposed between the bottom of the cylinder 5 and the member 13.

In FIG. 5, the vaporizer is at rest and the chamber 14 is full of liquid to be vaporized.

When pressure is applied to the push-member 8, the rod 7 moves within the piston 11 and exerts a thrust on the tubular member 13, so that communication is broken between the chamber 14 and the cylinder 5. Then the shoulder 7a comes into contact with the top 11a of the piston 11; the passage 9b then lies opposite the passage 11c.

As the push-member 8 continues moving, the piston 11 is thrust downwards in the cylinder 4 and the liquid contained in the chamber 14 is driven to the nozzle 10 by way of the passages 11c and 9b and the bore 9 (FIG. 6).

When the push-member 8 is released, the spring 17 raises the tubular member 13, which exerts a thrust on the rod 7, the shoulder on which abuts against the underside of the piston 11. The passage 11c is thus opposite the passage 13c once more and the chamber 14 is in communication with the cylinder 5. The piston 11, as it rises in the cylinder 4, lowers the pressure within the chamber 14, which thereupon fills with liquid.

The embodiment shown in FIGS. 7 and 8 again has its tubular member 13 with the collar 13d forming a piston sliding in the cylinder 5. When the vaporizer is at rest, however, the distance between the shoulder 7a on the rod 7 and the top 11a of the piston 11 is at most equal to the distance by which the shank 15a projects in relation to the guide portion 13a of the member 13.

That being so, when the push-member 8 is pressed, the rod 7 moves within the piston 11 and exerts a thrust on the valve 15, which covers the opening 16, thereby isolating the chamber 14 from the cylinder 5. The shoulder 7a on the rod 7 makes contact with the top 11a of the piston 11, however, before the end of the rod 7 has been able to exert a thrust on the guide portion 13a of the tubular piston extension 13 (FIG. 7).

When pressure on the push-member 8 is continued, the piston 11 is driven into the annular chamber 14 without this having been placed in communication with the atomizer nozzle 10; the effect of this is that the liquid contained in this chamber 14 is brought under pressure.

The pressure produced in the chamber 14 causes the piston 13d to be driven into the cylinder 5 and the shoulder 13b at the top of the member 13 comes away from the underside of the piston 11, thereby establishing communication between the annular chamber 14 and the nozzle 10 (FIG. 8); the liquid precompressed within the chamber thereupon escapes and passes to the nozzle, where it is vaporized. During this movement, the shank 15a of the slide valve 15 continues to bear against the end of the rod 7, so that the member 13 moves in relation to the valve, but the extent of this movement is insufficient to free the opening 16, so that the annular chamber 14 remains cut off from the cylinder 5.

Vaporization takes place for as long as the piston 11 descends. When the push-member 8 is released, the various moving parts rise and resume their initial positions, while liquid is being drawn into the cylinder 5 through the dip-tube 6.

The invention should naturally not be regarded as limited to the embodiment described and illustrated, but includes all modifications thereof. In particular, the rod 7 and the valve 15 could be made in one piece.

Claims

I claim:

1. A vaporizer comprising

a first cylinder,

a first piston slidable in the first cylinder,

a second cylinder,

a second, hollow, piston slidable in the second cylinder which cylinder forms an extension of the first cylinder,

a dip-tube forming an extension of the second cylinder,

an operating member carrying

means defining an atomizing nozzle,

a delivery tube communicating with the nozzle and with the interior of the first piston,

means for closing the outlet from the delivery tube, and

means for biasing the closure means to the closed position,

means defining a tubular liquid inlet extending from the second piston into the first cylinder, said inlet being in communication with the second cylinder,

an annular pump chamber within the first cylinder defined, in part, by said tubular liquid inlet,

means defining a lost motion connection between the first piston and the delivery tube, whereby the first piston can move axially relative to the delivery tube, and

means defining a distribution system operated by displacement of the delivery tube and the tubular inlet in relation to the first piston whereby the annular pump chamber is selectively placed in communication either with the tubular inlet or with the delivery tube.

2. A vaporizer as claimed in claim 1, in which the first cylinder is mounted so as to slide in relation to the delivery tube.

3. A vaporizer as claimed in claim 2, in which the delivery tube has an external shoulder arranged to abut with the annular piston once the rod has moved a certain distance.

4. A vaporizer as claimed in claim 2, in which the inlet passage has, in the vicinity of the end remote from the dip-tube, one or more openings by which the pump chamber can be placed in communication with the second cylinder and hence with the dip-tube and further comprising

a valve which bears against the delivery tube and is capable of closing the said openings, and is a sliding fit within the tubular inlet,

the end portion of that tubular inlet remote from the dip-tube being arranged to abut the underside of the first piston, thereby breaking communication between the annular chamber and the atomizer tube.

5. A vaporizer as claimed in claim 4, comprising a lost motion linkage between the tubular inlet and the delivery tube, the lost motion of that linkage being less than that of the said lost motion linkage between the delivery tube and the first piston. 6A vaporizer as claimed in claim 4, in which the lost motion of the lost motion linkage between the delivery tube and the first piston is at most equal to the distance existing, in a rest

position, between the end of the delivery tube and the tubular inlet. 7. A vaporizer as claimed in claim 4, in which the valve has

a shank abutting the delivery tube and is extendable upwards in relation to that end of the tubular inlet which is remote from the dip-tube when that

end is bearing against the underside of the first piston. 8. A vaporizer as claimed in claim 2, in which that end of the tubular inlet which is remote from the dip-tube abuts against the delivery tube and the first piston has a passage leading into the annular chamber and communicating selectively, according to the position of the piston, with a passage in

the tubular inlet or with a passage in the delivery tube. 9. A vaporizer as claimed in claim 1, comprising a sleeve fitted within the first cylinder, the first piston having a frustoconical portion arranged to abut

against the interior edge of the sleeve end. 10. A vaporizer as claimed in claim 1, in which the first cylinder has an opening by which the interior of the vaporizer can be placed in communication with atmosphere, and in

which the first piston, when at rest, closes that opening. 11. A vaporizer as claimed in claim 10, in which the opening is made substantially level with the said edge of the sleeve.