JPH0244864Y2 - - Google Patents

Description

[Detailed description of the invention] (Purpose of the invention) This invention relates to a push button with an injection port that is fitted into the movable valve stem of an aerosol injection device, and is effective even when the pressure of the injection gas contained in the injection container is low. The purpose is to provide a means by which a spray condition can be obtained.

Aerosol injection devices inject solutions using the pressure of injection gas stored in an injection container together with medical solutions and other ^solutions . The type and amount of propellant gas is adjusted. The injection gas is consumed by repeated injections of the solution, and the injection pressure gradually decreases, so even if a good aerosol state of the spray is obtained during the initial use after filling, the drop in the injection pressure will shorten the distance the spray reaches. In addition, there is a drawback that the particles of the fog become coarse.

By the way, when the injection liquid is injected from the injection port, negative pressure is generated near the rim of the injection port due to the ejector principle, but while the injection pressure is high, the gas released from inside is Since the pressure is sufficiently compensated, air outside the injection port is not sucked in, and there is no turbulence in the spray. However, when the injection pressure decreases to a certain degree, external air tries to enter the injection port with a force that is almost in the opposite direction to the injection direction, causing turbulence in the injection and often causing a liquid film to form at the injection port. The injection condition becomes extremely poor. Therefore, an important objective of this invention is to prevent the above-mentioned deterioration of the injection condition when the injection pressure is low.

(Structure of the invention) This invention will be explained below with reference to the illustrated embodiment. 1 is a movable valve stem of a well-known aerosol injection device, and the push button in this invention is this movable valve stem 1.
When the valve is opened, the liquid that rises through the movable valve stem 1 is discharged from the injection port 2 that is open at the front. Reference numeral 3 denotes a push button body into which a hollow ventilation pipe 4 is inserted, and this ventilation pipe 4 opens at the rear surface of the injection port 2 and the push button 3. 5
is an annular passage provided around the front part of the ventilation pipe 4 by fitting the ventilation pipe 4 as described above, and the passage 5 opens to the injection port 2 and is connected to the shaft hole 11 of the movable valve stem 1.

In the embodiment shown in FIGS. 1 and 3, several small protrusions 42 are provided on the circumferential surface of the conical part 41 at the front of the vent pipe 4, and the passage 5 for the injection port 2 is provided with several small protrusions 42.
Also, centering of the shaft hole 43 of the ventilation pipe is facilitated. Instead of the illustrated small projections 42, similar projections may be molded on the inner surface of the push button body 3, and the peripheral surface of the conical portion 41 of the vent pipe 4 may be molded into a smooth conical surface without projections. 4 and 5 show another embodiment of the vent pipe. This vent pipe and the vent pipe 4 shown in FIGS. 1 and 3 described above have substantially the same overall shape, except for the shape of the circumferential surface of the conical portion 41. Reference numeral 44 denotes a protrusion protruding from the conical surface in a threaded manner, and when the protrusion 44 engages with the inner surface of the push button body 3, the passage 5 and the shaft hole 43 can be easily centered with respect to the injection port 2. In addition, the solution passing through the annular passage 5 is twisted and discharged from the injection port 2 by the guide of the protrusion 44.

(Effect of the invention) This invention is made as described above, and by fitting the ventilation pipe 4 into the main body 3 of the push button, an annular passage 5 is provided around the front part of the ventilation pipe 4. Since it is connected to the axial hole 11 of the movable valve stem 1, when the injection device is opened, the injection liquid rising in the axial hole 11 passes through the passage 5 and is injected from the injection port 2 in an annular manner. During this injection, negative pressure is generated in the injection port 2 due to the ejector principle, but the vent pipe 4 is hollow as described above and opens at the rear surface of the injection port 2 and the push button body 3. Therefore, the negative pressure generated here is compensated by the air supply from the shaft hole 43 of the ventilation pipe. The direction of this air supply coincides with the injection direction, and there is no negative pressure compensation directional force that opposes the injection direction. Therefore, even when the injection pressure is low, there is no formation of a liquid film at the injection port.
A good aerosol spray can be obtained. Of course, when the injection pressure is high, the air compensation that coincides with the injection direction does not adversely affect the spray.

Thus, according to this invention, it is possible to provide an aerosol injection device that maintains a good spray state even when the injection pressure decreases due to consumption of the injection liquid, simply by shortening the spray reach distance. In addition, when using an aerosol injection device to apply skin agents, an excessively cold sensation is disliked, but with this invention, by designing the injection pressure to be low from the beginning, an excessively cold sensation can be avoided. Therefore, it is possible to provide an aerosol injection device particularly suitable for dispersing chemicals for application to the human body.

[Brief explanation of drawings]

Fig. 1 is a right side vertical sectional view of one embodiment of the low-pressure aerosol injection push button according to this invention, Fig. 2 is a front view of the same, Fig. 3 is a front view of the ventilation pipe, and Fig. 4 is another embodiment. The front view of the example ventilation pipe and FIG. 5 are also partially longitudinal side views. 1 is a movable valve stem, 11 is a shaft hole, 2 is an injection port, 3 is a push button body, 4 is a ventilation pipe, 41 is a conical part, 4
2 is a small projection, 43 is a shaft hole, 44 is a protrusion, and 5 is a passage.

Claims (1)

[Scope of utility model registration request] In a push button that fits into a movable valve stem 1 of an aerosol injection device and releases the injection liquid that rises through the movable valve stem 1 when the valve is opened from an injection port 2 that opens on the front side, the rear surface of the injection port 2 and the push button body 3 By fitting the hollow ventilation pipe 4 that opens into the push button body 3, an annular passage 5 connected to the shaft hole 11 of the movable valve stem 1 is provided around the front part of the ventilation pipe 4, and the passage 5 is injected. A low-pressure aerosol injection push button with an opening at mouth 2.