JPS582460Y2 - Piston device in small sprayers, etc. - Google Patents

Description

[Detailed explanation of the invention] This invention was devised to suppress water leakage as much as possible, which is impossible due to the nature of the material, when soft synthetic resin such as polyethylene is used as the material for the piston in small sprayers. It is something.

Soft synthetic resins such as polyethylene are inexpensive raw materials and have high chemical resistance, so they have been widely used as materials for pistons of small sprayers, etc. However, as a material, they have poor elasticity. Due to its low resilience, after a short period of use, a gap forms between the piston and cylinder, causing water leakage, which is not only functional, but also from a hygienic point of view when spraying chemical solutions, etc. I'm extremely unwell.

For this reason, some high-grade pistons that require chemical resistance have a fluoro rubber cap fitted to the piston head, but such pistons are cheaper than the polyethylene pistons. This is more than 20 times the average cost, which poses an economic problem.

This idea utilizes the elasticity of metal springs,
To provide a piston device that compensates for the above-mentioned material deficiencies of synthetic resins such as polyethylene, gives such materials elasticity and restorability similar to rubber, and allows the piston to be kept in close contact with the cylinder at all times, preventing water leakage. This is what I am trying to do.

Hereinafter, the present invention will be explained with reference to the embodiment drawings.

First, referring to FIG. 1, there is shown a small manual piston-type sprayer to which the present invention is implemented (the type of sprayer shown in the figure has been commonly used in the past).

), a cylinder 2 is arranged horizontally in the center of a sprayer main body 8 which is detachably attached to the mouth of a spray liquid container 9, and the upper end of a liquid riser pipe 3 is disposed below the cylinder 2. are connected to each other via an on-off valve (not shown), while the upper side of the cylinder 2 communicates with the spray hole of the nozzle end cap 7 via a liquid passage 4.

Although not shown, the passage pipe 4 is provided with an on-off valve at a position in front of the spray hole.

When the piston 1 is pushed into the cylinder 2 (to the right in the figure) against the restoring spring 5 by moving the operating lever 6 whose upper end is pivotally connected to the main body 8 as shown by the arrow A, the riser tube 3 is moved. The valve is closed, and the spray liquid in the cylinder 2 passes through the liquid passage pipe 4, opens the valve at its tip, and is sprayed in the form of a spray from the spray hole as shown by arrow C.

When you release your finger from the operating lever 6, the piston 1 returns to its original position due to the action of the restoring spring 5 (the operating lever 6 returns in the direction of the arrow opening). As shown in step 2, the liquid rises in the rising tube 3, opens the valve at the upper end of the tube, and the cylinder 2 is filled again.

(In this case, the valve at the tip of the liquid passageway 4 is closed.

) That is, by operating the operating lever 6, the spray liquid is sprayed using the principle of a push-up piston pump.

By the way, regarding the relationship between the cylinder 2 and the piston 1 in the case of the conventional example shown in FIG. outer diameter at the edge of the
is approximately 12 mm.

That is, the outer diameter of the portion of the piston 1 that makes sliding contact with the inner diameter of the cylinder 2 is approximately 1 mm larger than the inner diameter of the cylinder 2.

On the other hand, as mentioned earlier, soft synthetic resin materials such as polyethylene have poor elasticity and resilience, so as mentioned above, the edge of the piston, which has an outer diameter about 1 mm larger than the cylinder inner diameter, It is extremely rare that the entire circumference bends uniformly in the circumferential direction with respect to the inner circumference of the cylinder, and this part is in close contact with the inner circumference of the cylinder, and in almost all cases, as shown in Figure 4 of the attached drawings, The deflection of the end edge 10' of the piston is concentrated in one place, creating a large gap 16 between it and the inner periphery of the cylinder 2'. The piston will not return to its original shape, and water leakage will never stop.

The present invention was devised to eliminate the drawbacks of conventional products, and the structure of the piston part of the present invention is explained with reference to Fig. 2. The part 13 shown in black in the figure is a helical spring.
This helical spring 13 has its one end 12 expanded in spring diameter to a required diameter, and this expanded portion is biased so as to bulge outward. It is formed.

This helical spring 13 has its small diameter part inserted into the piston 1 , the end part bent in the diametrical direction of the spring diameter, and the small diameter end part applied to the spring receiving part 11 of the piston 1 , and the helical spring 1
The helical spring 13 is fixed to the piston 1 by being held down by the piston-side end of the restoring spring 5 passing inside the piston 3.

In this way, the annular spring portion 1 formed at one end of the helical spring 13
2 is fitted at a predetermined position on the inner surface of the thin end edge of the conical opening 10 of the piston 1, and the end edge is projected outward.

Furthermore, instead of using the helical spring as described above, it is also possible to use an annular spring 15 with a gap 14 as shown in FIG. An annular groove is provided at a required distance, and a gap 1 is provided in this annular groove.
Place the spring 15 in a state where the distance between the pistons 1 and 4 is narrowed, and
The end edge of the holder is made to bulge outward.

In addition, when the device of the present invention having the piston portion shown in FIG. 2 is implemented in the conventional type sprayer shown in FIG.
The inner diameter of the piston 1 is about 11 mm, while the maximum diameter of the piston 1 (the outer diameter at the edge of the conical opening 10) is about 12 mm.
The axial length of the conical opening 10 is approximately 5 mm, the wall thickness of the conical opening 10 is approximately 0.8 mm at the thicker portion on the small diameter side, and the thinner portion on the large diameter side. about 0.
It is 5 mm.

Further, it is preferable that the annular spring portion 12 or the annular spring 15 be disposed at a distance of about 71 mm inward from the thin end edge of the piston.

Note that the dimensions of each part described above are merely examples, and should be appropriately selected depending on the capacity of the sprayer, etc.

As described above, this invention is an extremely simple method in which an annular spring energized outward is fitted onto the inner peripheral surface of the thin end edge of the conical opening of the piston in the conventional piston. Through structural modification, the end edge of the piston is given elasticity and flexibility similar to those made of expensive rubber by utilizing the elasticity and flexibility possessed by the metal annular spring, This end edge elastically extends outward evenly over its entire circumference and is always in close contact with the inner circumference of the cylinder, allowing water to leak due to material defects that were unavoidable in conventional products. This makes it possible to completely prevent the occurrence of

The piston device according to this invention can be widely used as a piston device in atomizers other than those mentioned above, and also in devices other than atomizers.

[Brief explanation of the drawing]

The attached drawings are explanatory diagrams related to the present invention. Figure 1 is a partially cutaway front view of an example of a small manual piston-type sprayer implementing the present invention, and Figure 2 is a diagram showing the internal structure of the present invention. 3 is a front view showing another embodiment of the annular spring, and FIG. 4 is a conventional polyethylene piston showing the end edge of its conical opening and the inner periphery of the cylinder. This is an enlarged view of the gap formed between the two cylinders, cut along a plane perpendicular to the cylinder axis. In the figure, 1 is a piston, 2 and 2' are cylinders, 3 is a liquid riser pipe, 4 is a liquid passage pipe, 5 is a restoring spring, 6 is an operating lever, 7 is a nozzle end cover, 8 is a sprayer body, and 9 is a Spray liquid container, 10.
10' is a conical opening, 11 is a spring receiving part, 12 is an annular spring part, 13 is a helical spring, 14 is a gap, 15 is an annular spring, and 16 is a gap.

Claims (1)

[Scope of utility model registration request] An annular spring energized outward is fitted to the inner peripheral surface of the thin end edge of the conical opening of a piston made of soft plastic such as polyethylene, and the end edge of the piston is A piston device for a small sprayer, etc., characterized in that the piston device extends outward evenly over its entire circumference and is brought into close contact with the inner circumference of a cylinder.