Dipper Tube Sprayer

Abstract

A sprayer wherein the dipper tube dipping into a liquid-carrying container is connected with a tube ending with a spraying nozzle through a sleeve-shaped piston controlled by the depression of last mentioned tube. The valve closing normally the passage through the piston is urged away by said depression of the tube against the action of a spring and its novelty resides in the provision of a thin peripheral lip provided in said valve and frictionally engaging the inner surface of the chamber so as to produce transiently a compression in said chamber when the valve is shifted by the sliding tube, after which the compressed liquid passes past the deformed lip towards the nozzle.

Description

Dipper tube sprayers are known, which include a pumping chamber connected with the dipper tube, a sleeve-shaped delivering piston slidingly fitted inside said chamber, a tube axially slidable inside the sleeve-shaped piston and opening into a spraying nozzle, a flap valve at the end of said tube opposed to the nozzle and adapted to engage a seat formed in the sleeve-shaped piston facing the chamber, means urging elastically the flap valve against said seat and consequently causing the sleeve-shaped piston to slide inside the pumping chamber towards the end of the latter facing away from the dipper tube and hand-operable means shifting the sliding tube in antagonism with said elastic means to shift with a lost motion the sleeve-shaped delivering piston.

When such a sprayer is to be used, the sliding tube is urged downwardly in antagonism with the elastic means; the flap valve moves first off its seat so as to connect the pumping chamber with the nozzle, following which the sleeve-shaped piston is carried along in its turn so that the liquid within the chamber is propelled towards the nozzle and is sprayed by the latter.

If the sliding tube is depressed slowly, the delivering pressure is very low at the start and the liquid is not correctly atomized and it may sometimes pass out of the nozzle as a solid non-atomized jet.

The present invention has for its object improvements in atomizers of the above referred to type with a view to cutting out its drawback.

According to said invention, the flap valve is provided with a thin peripheral lip engaging the wall of the pumping chamber after the manner of a piston.

Thus, when the sliding tube begins moving, no liquid can pass as yet immediately into the atomizing or pumping chamber and is first subjected to a preliminary compression by the flap valve and its thin peripheral lip. Subsequently, when the pressure has reached a predetermined value, the thin lip is deformed by said pressure and allows the liquid to pass beyond it and to reach the nozzle under a pressure which ensures its proper atomization.

There is described hereinafter by way of example and in a non-limited sense an embodiment of a dipper tube atomizer according to the present invention, reference being made to the single figure of the accompanying drawing showing said atomizer in axial cross-sectional view.

As illustrated, the atomizer includes a cylindrical body 1 adapted to be secured to a container 2 carrying the liquid to be atomized and to form a stopper for said container; to this end the body 1, made of plastics for instance, is tapped so as to be screwed over the neck of the container 2. An outer sleeve 3 is fitted with a force fit over the body 1.

Inside the body 1, there is provided a pumping chamber within an annular wall 4 the upper end of which carries an outer flange 4a held fast within a shoulder 1a closing partly the upper end of the body 1. The pumping chamber extends at its lower end so as to register with the dipper tube 5 which latter is closed at its upper end by a non-return ball valve 6.

Inside the pumping chamber 4, a sleeve-shaped piston 7 is slidingly fitted and, inside said piston 7, is again slidingly fitted a tube 8 the lower end of which abuts against the upper tail-end 9a of a flap valve 9. A spring 10 fitted between the flap valve and the lower end of the pumping chamber urges said flap valve against its annular seat 11 provided at the lower end of the sleeve-shaped piston 7; the tail end 9a of the flap valve engages then the bore in said sleeve-shaped piston. A clearance 12 is provided within the inner surface of the latter facing said tail end 9a and the lower end of the tube 8 which latter shows also a radial bore 13.

The upper end of this tube 8 is secured to a pusher member 14 and opens into an atomizing nozzle 15 extending through the side wall of said pusher member.

The sliding tube is provided at a point of its length with an annular shoulder 8a located, when the sprayer is inoperative, a short distance above the sleeve-shaped piston 7. The outer diameter of said annular shoulder is smaller than the inner diameter of a socket 16 fitted in the upper opening of the pumping chamber 4 and provided with an outer flange 16a clamped between the upper shoulder 1a of the body 1 and the outer flange 4a of the chamber wall.

The sleeve-shaped piston 7 is provided with an outer frustoconical surface 7a which engages, when the sprayer is inoperative, the lower edge of the socket 16.

According to the present invention, the flap valve 9 includes a thin peripheral lip 9b acting as a piston inside the pumping chamber 4 and the concavity of which faces the piston 7 in the case illustrated.

The drawing shows the sprayer in its inoperative condition for which the spring 10 holds the flap valve 9 on its seat 11 and also holds the frustoconical surface 7a of the sleeve 7 in contact with the edge of the socket 16 whereby the opening 17 connecting the chamber 4 through the upper end of the container 2 with the upper end of the chamber 4 through the wall of the latter is cut off. The pumping chamber 4 and the inside of the container are thus closed with reference to the external atmosphere above the piston 7 and no leak can be observed.

When the operator depresses the pusher member 14, the flap valve 9 moves off its seat but the sleeve-shaped piston 7 remains transiently in the position illustrated by reason of the friction between it and the wall of the chamber 4. These conditions prevail until the shoulder 8a on the tube 8 impinges against the piston. From this moment onwards and as the operator continues depressing the pusher member 14, the piston 7 moves in unison with the tube 8, so that the liquid carried inside the chamber 4 is urged into the spraying tube 8 through the clearance 12 and the radial bore 13, the liquid being finally atomized through the nozzle 15. Furthermore, the opening 17 which is now uncovered connects the upper end of the container 2 with the atmosphere alongside the tube 8, which prevents said container from being subjected to a reduced pressure.

When the flap valve 9 begins sinking inside the chamber 4, its peripheral lip 9b first compresses the liquid inside said chamber, after which it is deformed by the liquid under pressure, so that it allows then the liquid to flow past it in a compressed condition towards the nozzle 15.

When the operator releases the pusher member, the flap valve 10 rises and engages its seat 1 which cuts the chamber 4 off the bore in the tube 8 and the atmosphere. At the same time, the piston 7 rises and reduces the pressure in the chamber 4. This leads to a rise of the liquid out of the container 2 through the dipper tube 5. The frustoconical surface 7a of the sleeve 7 impinges then against the lower edge of the socket 16 and closes thus the opening 17 while the piston 7 and the tube 8 stop in the position then reached by them. The different parts of the sprayer have thus returned into their inoperative starting position as illustrated.

Claims

What I claim is:

1. In a sprayer including a compression chamber, a dipper tube forming an extension of said chamber, a sleeve-shaped piston slidingly fitted in said chamber and provided with an annular seat facing the chamber, a tube slidingly adapted to engage the end of the piston opposed to the seat to urge said piston towards the dipper tube, a spraying nozzle at the end of the tube opposed to the piston and hand-operable means adapted to urge the tube downwardly into engagement with the piston, the combination of a flap valve adapted to engage the seat on the piston to close the passage through the latter and to be urged away from said seat by the sliding tube before the latter engages the piston end, said valve being provided with a thin peripheral lip frictionally engaging the inner surface of the chamber and elastic means fitted inside the chamber and urging the flap valve against its seat thereby to shift the piston away from the dipper tube.