BACKGROUND ART The manually operated pump for discharging small amount is the manually operated pump, in which the discharge rate by pumping is approximately 0.2 cc per one time, and which can be used when discharging the liquid or emulsion type contents filled in the vessel quantitatively by pumping. Such a pump is widely used secured in the cosmetic vessel and the like due to its convenience.

Fig. 1 shows a representative example of the conventional manually operated pump for discharging small amount. The conventional pump comprises: a cylindrical housing (20) forming the exterior surface of the pump; a shaft (30) having the liquid

passage therein; a cylindrical piston (40) reciprocating along the interior surface of the housing (20); a housing cap (25) securing the housing (20) and the cover (not shown) while guiding the reciprocating motion of the shaft (30); a conical pedestal (32) secured in the lower end of the shaft (30); a upper spring (52) positioned in the upper end of the piston (40); a lower spring (54) fitted in the conical pedestal (32); a ball (60) positioned in the lower part of the housing (20); and a tube (80) secured in the lower end of the housing and the like. Such a pump is secured to the vessel (not shown) filled with the contents by using the cover (not shown) with the screw groove formed therein.

The spring force of the upper spring (52) is greater than that of the lower spring (51) so that when the downward force is applied to the shaft (30), the lower spring (54) becomes compressed which is fitted to the conical pedestal (32), and the lower end of the interior surface (42) of the piston moves downwardly with the lower end of the surface (42) engaged with the upper end protrusion (33) of the conical pedestal (32), by the expansion force of the upper spring (52). When the lower end of the exterior surface (44) of the piston reaches the lower part of the housing (20) having small diameter, the piston (40) no longer moves downwardly and the shaft (30) continues to move downwardly while the upper spring (52) is compressed, so that the lower end of the interior surface (42) of the piston is spaced apart from the upper end protrusion (33) of the conical pedestal (32). At that time, the contents pressurized in the inner space (22) of the cylinder, are introduced to the gap formed between the low end of the inward surface (42) and the upper end protrusion (33) and then to the internal passage (38) through the inflow opening (36).

When the downward force is removed in the shaft (30), the shaft (30) moves upwardly and while the upper spring (52) expanded immediately, closes the gap formed between the lower end of the interior surface of piston (42) and the upper end protrusion

(33) of the conical pedestal (32). At this time, when the shaft (30) moves upwardly by the expansion force of the lower spring (54), the pressure of the interior surface (22) of the cylinder decrease, and in order to supplement this decrease of the pressure, the contents flows in through the tube (80) while the ball (60) of the lower part of the housing is lifted up.

Such a conventional pump requires two springs. Among them, the upper spring (52) provided in the upper part of the piston (40) renders the piston (40) to be engaged with the conical pedestal (32) when the shaft (30) moves up and down, so that the spring (52) makes the contents in the inner space (22) of the cylinder pressurized in the downward movement of the shaft (30) and also makes the decrease of the pressure occurred in the inner space (22) of the cylinder and in the upward movement of the shaft (30).

And said housing cap (25) renders the upper part of the housing closed off and the shaft (30) secured in the housing (20) while the housing cap (25) guiding the reciprocating motion of the shaft (30).

In this regard, the upper spring (52) and the housing cap (25) are the inevitable components in the conventional manually operated pump for discharging small amount.

However, in the small sized, manually operated pump, since the multiple parts are complicatedly installed and operated, there has been high possibility of the mechanical trouble and the disadvantage of the increasing of the manufacturing cost.

And in terms of the usage and the appearance, since it is preferable for the pump mounted in the upper part of the vessel to have as possible as small in volume occupied in the total vessel, the size of the parts constituting the pump has to be

smaller and the precise structure is required, there has been difficulty of the manufacturing process. And the more articles the customer requires, the more the number of parts constituting the pump tends to be increased. Therefore, the possibility of wrong operation during the use of pump becomes more and more due to the increase of the parts.

Therefore, an object of the invention is to solve the problems of such conventional technique. More particularly, the object of the invention is to perform the original function of the pump without upper spring by changing the structure of the shaft and the piston in the conventional, manually operated pump in which the discharge rate is approximately 0.2cc per one time.

And, further object of the present invention is to reduce the number of the total parts to simplify the manufacturing process and reduce the possibility of the wrong operation and further perform more improved function, by integrating the housing cap, cover etc, and changing the structure to have these parts simultaneously to perform further functions.

DISCLOSURE OF INVENTION In order to accomplish such objects, the manually operated pump for discharging small amount according to the present invention in which the discharge rate is approximately 0.2cc per one time by pumping, is characterized in that the pump comprising: a cylindrical housing forming the exterior surface of the pump; a shaft having the liquid passage therein and integrated with the conical pedestal in the lower end of the shaft ; a cylindrical piston reciprocating along the interior surface of the housing; a housing cap securing housing in the cover while guiding the reciprocating motion of

said shaft : a spring fitted in the lower end of said conical pedestal; a ball positioned in the lower end of the housing: a tube secured in the lower end of the housing; and the cover having the screw groove therein and secured in said housing cap and the like; wherein in the shaft, the length of the corresponding part of the shaft abutted in contact with the interior surface of the piston having relatively small diameter to slide with said interior surface, is longer than that of the interior surface of the piston; and wherein said piston has dual structure having the interior surface abutted on the piston and the exterior surface abutted on the interior surface of the housing, which the friction force between said exterior surface and the interior surface of the housing is greater than that of between said interior surface and the shaft.

The difference between the friction force between the exterior surface of the piston and the interior surface of the housing, and the friction force between the interior surface of the piston and the shaft is preferably resulted from the difference of the contact area. That is, the area in which the exterior surface of the piston abuts with the interior surface of the hosing is greater than that in which the interior surface of the piston abuts with the shaft. In case of the same quality of material and the same unevenness of the surface, the friction force proportionally increases due to the difference of the contact area.

Such manually operated pump according to the present invention is characterized in that the present pump performs the same function as the conventional manually operated pump for discharging small amount using two springs, by using just one spring positioned between the ball and the conical pedestal of the lower end of the shaft. It is because the structure of the shaft and the piston is absolutely different from that of the conventional shaft and the piston as mentioned above.

The invention is preferably characterized in the manually operated pump for discharging small amount in which the said hosing cap is integral with the cover.

More particularly, the invention does not require the individual housing cap because the inner cylindrical bending part having a circumferential part and a circumferential groove coaxially with said shaft was integrated with the upper end of said shaft. The inner cylindrical bending part guides the reciprocating motion of the shaft and closes off the inner space of the housing instead of the role of the housing cap and sealing liner.

The manually operated pump of the present invention may be applied to a pump having discharge rate, less than approximately 0.2 cc per one time, more preferably 0.05 to 0. 2 cc per one time. However, in some cases, the present invention may include the range having the definition of the pump for discharging some amount even though the discharge rate of the pump is somewhat deviated from said range. High viscous emulsion contents such as cosmetic lotion and low viscous liquid contents such as perfume are both available as the contents discharged.

Bulk state and spray state of fine liquid drop are both available as an ejection manner of the contents. The difference of such ejection manners depends on whether the ejection nozzle is secured to the discharge opening to which the contents are ejected outwardly from the pump. In case that the ejection nozzle is secured to the said discharge opening, the liquid type content is ejected in the mist state.

As shown below, the description refers to the drawing in order to describe the present invention more in detail, thereby, the scope of the invention is however not to be interpreted as a limitation of the invention.

Fig. 2 to Fig. 6 shows the manually operated pump for discharging small amount and its constituent parts according to various examples of the invention. The structure of the pump according to the present invention and the operating principle will be described with reference to the figures as follows.

With reference to Fig. 4, the upper end of the shaft (30) having internal passage (38) therein is secured to the actuator (10) and the spring (50) is fitted to the conical pedestal (32) in the lower end of the shaft (30). When the downward force is applied and removed to the actuator (10), the piston (40) having dual structure composed of interior surface (42) and exterior surface (44), slidably reciprocates along the interior surface of the housing (20).

The portions of the shaft (30) along which the interior surface (42) of the piston is slidably reciprocated, are portions between right step (34) and the upper end protrusion (33) of the conical pedestal (32). The diameter of those portions is shorter than that of other portions. The length of the interior surface (42) of the piston is relatively shorter than that of said portions. Among those portions, the sliding part (31) of the shaft is the portion abutted with the interior surface (42) of the piston when the downward force is applied to the actuator (10), so that it gives the friction force to the interior surface (42) of the piston in reciprocating motion.

According to one embodiment of the present invention, the friction force of the exterior surface (44) of the piston is greater than that of the interior surface (42) of the piston in reciprocating motion of the piston (40), since the area of the sliding part (31) in which the interior surface (42) of the piston abuts with the shaft, is smaller than the area in which the exterior surface (44) of the piston abuts with the interior surface of the

housing.

Thus, when the downward force is applied to the actuator (10) for pumping, the shaft (30) is moved down, and the sliding part (31) is firstly slid along the interior surface (42) of piston of which the friction force is relatively small. When the upper end of the interior surface (42) of the piston reaches the right step (34) of the shaft (30), the sliding motion is stopped, and during this procedure, the lower end of the interior surface (42) of the piston is spaced apart from the upper end protrusion (33) of the conical pedestal (32), and the contents of the inner space (22) of the cylinder is introduced through the inflow opening (36) into the internal passage (38) by way of the spaced gap.

Next, with the continuous downward movement of the shaft (30), the exterior surface (44) of the piston slides along the interior surface of the housing (20), and when the exterior surface (44) of the piston reaches the barrier step (24) of the housing (20), the sliding motion is stopped.

And, when the pumping is finished and the pressure applied to the shaft (30) is removed, the shaft (30) begins to move upwardly, at this time, the interior surface (42) of the piston, of which the friction force is also relatively small, firstly slides than the exterior surface (44) of the piston. Therefore, the inner space (22) of the cylinder is blocked against the internal passage (38) of the shaft (30) by the upper end protrusion (33) of the conical pedestal (32) of the shaft (30) engaged with the lower end of the interior surface (42) of the piston. Then, during the continuous upward movement of shaft (30), the exterior surface (44) of the piston slidably moves and the pressure of the inner space (22) of the closed cylinder continues to decrease. In order to supplement such a decrease of the pressure, the ball (60) is slightly lifted up, which blocks the lower

part of the housing by gravity, and the contents of the vessel is introduced through the tube (80) into the inner space (22) by way of such a gap.

Fig. 3 shows the vertical cross sectional view of the cover according to further embodiment of the present invention, wherein the inner cylindrical bending part (72) comprises: the first circumferential part (76) downwardly extended from the horizontal part (74) of the cover (70); the second circumferential part (78) spaced apart from the first circumferential part (76) in the central axis direction; and the connection (77) which interconnects the lower end of the first circumferential part (76) and the lower end of the second circumferential part (78) and forms the circular groove (79) in the top.

The connection (77) preferably have the structure to be stuck to the piston (40) and block the interior of the housing (20) against the exterior of the housing since the connection (77) is engaged with the piston (40) in state that the downward force is not applied to the actuator (10).

The upper end of the housing (20) is secured above the space composed of the vertical part (73) and the first circumferential part (76) among the interior structures of the cover (70), and the securing force is improved by the bending force due to the bending structure of the inner cylindrical bending part (72). More particularly, the second circumferential part (78) presses the whole of the inner cylindrical bending part (72) by abutting with the shaft (30), in which such a pressure is shown as reacting force by especially circular groove (79) etc, this spring reacting force reinforces the securing force between the upper part of the housing (20) and interior structure of the cover (70).

Fig. 4 to Fig. 6 shows the various examples of the pump having both two characteristics of the present invention.

Fig. 4 shows an example of the pump (200) according to the present invention, wherein the whole structure is identical to the pump (100) of Fig. 2 only except for the cover (200) integrated with the inner cylindrical bending part (72). As shown in comparison with Fig. 1, the inner cylindrical bending part (72) performs the role of the housing cap (25), instead of not having the housing cap (25). In the assembly process the assembly of the housing (20) and the cover (70) is completed by just fitting the cover (70) on top of the housing (20), so that the assembly process is very simple.

Fig. 5 shows an example of the pump (300) according to the present invention, wherein the configuration is identical to that of Fig. 4 except for the discharge nozzle (16) secured to the discharge opening (12) of the actuator (10).

Fig. 6 shows an example of the pump (400) according to the present invention, wherein the configuration is identical to that of Fig. 4 except for the ejection nozzle (14) secured in the discharge opening (12) of the actuator (10). Even though the whole structure of the pump (400) of Fig. 6 is identical to the pump (200,300) of the Fig. 4 and Fig. 5, it is possible for the pump (400) to spray the low viscous liquid contents with small water drop state by mounting the ejection nozzle (14) in the discharge opening (12).

The present invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention and all such modifications would be obvious to one skilled in the art.

BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is a vertical cross-sectional view of the representative conventional manually operated pump for discharging small amount; Fig. 2 is a vertical perspective view in cross-section of the manually operated pump (100) for discharging small amount according to an embodiment of the invention; Fig. 3 is a vertical cross-sectional view of the vessel cover with which the inner cylindrical bending part is integrated, according to an embodiment of the invention; Fig. 4 is a vertical cross-sectional view of the manually operated pump (200) for discharging small amount according to an embodiment of the invention; Fig. 5 is a vertical cross-sectional view of the manually operated pump (300) for discharging small amount, with the discharge nozzle secured in the discharge opening in Fig. 4; and Fig. 6 is a vertical cross-sectional view of the manually operated pump (400) for discharging small amount, with the ejection nozzle secured in the discharge opening.

Designation of the reference numerals 10 : actuator 12 : discharge opening 14 : ejection nozzle 16 : discharge nozzle 20 : housing 22 : inner space of the cylinder 24 : barrier step 30 : shaft 31 : sliding part 32 : conical pedestal

33 : upper end protrusion 38 : internal passage 40 : piston 42 : interior surface of the piston 44 : exterior surface of the piston 50 : spring 52 : upper spring 54 : lower spring 60 : ball 70 : vessel cover 72: inner cylindrical bending part 73 : vertical part 74 : horizontal part 76 : first circumferential part 77 : connection 78 : second circumferential part 79 : circular groove 80 : tube INDUSTRIAL APPLICABILITY The manually operated pump for discharging small amount of the invention is characterized in that the original function of the pump may be performed by means of just one spring by changing the structure of the shaft and the piston, the manufacturing process of the pump may be simplified by integrating the housing cap and vessel cover to reduce the number of parts, the assembly process of the parts is simple, and the pumping is easier. And, it is an advantageous to improve the securing force between the housing and the cover and the sealing of the interior of the housing. This manually operated pump for discharging small amount is available in pumping both of high viscous contents and low viscous contents. In some cases, in the configuration of the conventional pump, the vessel cover may be secured to use instead of the housing cover.