Pump dispenser

Abstract

[Problem] To provide a pump dispenser capable of preventing backflow of a content liquid and discharging a predetermined amount of the content liquid. [Solution] A piston body 11 of a pump dispenser 1A is formed, on an inner peripheral surface thereof, with an annular engagement part 69 that is formed so as to be elastically deformable. A rod-shaped valve body 17 is formed, on a shaft part 101 thereof, with an engagement projection part 111 that engages with the annular engagement part 69 of the piston body 11. When a nozzle 19 is pushed down, the annular engagement part 69 of the piston body 13 is engaged with the engagement projection part 111 of the rod-shaped valve body 17, the rod-shaped valve body 17 is also pushed down, a valve part 103 of the rod-shaped valve body 17 is seated on a valve seat part 45 of a cylinder body 11, and communication between a liquid chamber 51 and a liquid suction pipe 49 is blocked. Thus, since a discharge port 121 of the nozzle 19 and a liquid flow path 89 are blocked, and communication between the liquid chamber 51 and the liquid suction pipe 49 is blocked, backflow of the content liquid in the liquid chamber of the cylinder body 11 into a container 3 via the liquid suction pipe 49 can be suppressed.

Description

Pump dispenser

[0001] The present invention relates to a pump dispenser that is attached to the mouth of a container filled with a liquid content.

[0002] Generally, containers filled with a liquid content include those equipped with a pump dispenser for dispensing the liquid content in liquid form, and containers filled with a foaming liquid content such as hand soap, facial cleanser, shampoo, etc., equipped with a pump dispenser for mixing the liquid content with air and dispensing it in the form of foam. Such pump dispensers include a cylinder body, a piston body, etc., and are configured to dispense the liquid content sent from the cylinder body by the up and down movement of the piston body, or to mix the liquid content with air to generate and dispense foam.

[0003] For example, Patent Document 1 discloses a pump dispenser that includes a container containing a liquid content, a cylinder body having a liquid chamber communicating with the container, a piston body that moves up and down while sliding within the cylinder body, a nozzle having a discharge port provided at the upper end of the piston body, a cylindrical valve body that connects and disconnects the cylinder body and the discharge port of the nozzle, and a rod-shaped valve body that is slidably inserted within the cylindrical valve body and connects and disconnects the container and the liquid chamber of the cylinder body.

[0004] Patent No. 7493201

[0005] However, in the invention described in Patent Document 1, when the piston body is pushed down as a unit with the nozzle being pushed down, the cylindrical valve body and the rod-shaped valve body remain open until the rod-shaped valve body blocks the connection between the container and the liquid chamber of the cylinder body, i.e., the liquid flow path connecting the cylinder body and the nozzle outlet is connected, and the container and the liquid chamber of the cylinder body are connected, so there is a problem that the liquid contained in the cylinder body flows back from the liquid chamber of the cylinder body to the container, reducing the amount of liquid discharged to the outside. Furthermore, if the viscosity of the liquid contained is low or the descending speed of the piston body is slow, the liquid contained is more likely to flow back, further reducing the amount of liquid discharged.

[0006] The present invention has been made in view of the above-mentioned problems, and has an object to provide a pump dispenser that can prevent backflow of the content liquid and can discharge the content liquid at a predetermined amount.

[0007] As a means for solving the above problem, the invention described in claim 1 is a pump dispenser that is attached to the mouth of a container and discharges contents from a discharge outlet of a nozzle, comprising: a cylindrical cylinder body that communicates with the container; a cylindrical piston body that is slidably arranged within the cylinder body; a nozzle that is connected to the piston body and has a discharge flow path therein; a cylindrical valve body that is inserted from the upper end side of the cylindrical piston body and opens in the vertical direction, and has a valve portion for opening and closing a flow path from the piston body to a downstream side; a rod-shaped valve body that is slidably inserted at its upper end into the cylindrical valve body from below, and has a valve portion that is releasable from a valve seat portion at its lower end for opening and closing an inlet for contents that is arranged at the bottom of the cylinder body; and an elastic member that directly or indirectly biases the piston body upward against the rod-shaped valve body, wherein an engaging portion that is elastically deformable is formed on an inner peripheral surface of the piston body, and an engaging protrusion that engages with the engaging portion of the piston body is formed on the outer peripheral surface of a shaft portion of the rod-shaped valve body. In the pump dispenser according to this aspect, when the nozzle in an unpressurized state begins to be depressed, the piston body connected to the nozzle is also depressed, and the engaging portion formed on the piston body engages (contacts) with the engaging protrusion of the rod-shaped valve body, thereby also depressing the rod-shaped valve body. As a result, the valve portion of the rod-shaped valve body seats on the valve seat of the cylinder body, blocking the inlet for the content liquid, i.e., communication between the cylinder body and the container. This prevents the content (content liquid) from flowing back into the container via the inlet. This allows the content (content liquid or foam) to be discharged at a stable, predetermined amount to the outside. Furthermore, in the pump dispenser according to this aspect, when the piston body is released from being depressed, the elastic force of the elastic member pushes the piston body up, and accordingly, the cylindrical valve body and the rod-shaped valve body are also pushed up, and the valve portion of the cylindrical valve body closes the flow path from inside the piston body to the downstream side. Furthermore, as the rod-shaped valve body is pushed up, the valve portion of the rod-shaped valve body lifts off the valve seat of the cylinder body, opening the inlet for the content liquid. At this time, the volume of the cylinder body increases due to the rise of the piston body, creating a negative pressure state, so that the liquid content in the container can be sufficiently sucked into the cylinder body through the inlet.Furthermore, when the piston subsequently descends, the engaging portion is easily elastically deformed, so that it easily overcomes the engaging protrusion of the rod-shaped valve body, and the nozzle (piston body) can be pushed down smoothly.

[0008] The invention described in claim 2 is the invention described in claim 1, wherein the rod-shaped valve body is formed with a plurality of ribs provided at predetermined intervals in the circumferential direction of the shaft portion, and the plurality of ribs are formed with engaging protrusions on their upper portions that engage with the engaging portion of the piston body. According to the pump dispenser of this aspect, by providing a plurality of ribs on the rod-shaped valve body, it is possible to serve as a guide for the elastic member (spring) and a reinforcing role.

[0009] The invention described in claim 3 is the invention described in claim 1, wherein the cylinder body is a tubular liquid cylinder communicating with the container, and includes a large diameter portion, an annular flange portion connected to the upper end of the large diameter portion and extending radially outward, a bottom wall portion connected to the lower end of the large diameter portion and extending radially inward, and a small diameter portion extending upstream from the bottom wall portion; the piston body includes a small diameter cylindrical portion, a large diameter cylindrical portion formed integrally with the lower part of the small diameter cylindrical portion, and a seal portion provided on the outer peripheral surface of the large diameter cylindrical portion, and the engagement portion is formed on the inner peripheral surface of the connecting portion between the small diameter cylindrical portion and the large diameter cylindrical portion so as to hang down radially inward. According to the pump dispenser of this aspect, the engaging portion is formed on the inner circumferential surface of the connecting portion between the small-diameter cylindrical portion and the large-diameter cylindrical portion so as to hang down radially inward. Therefore, when the piston body is pushed down, the engaging portion engages (comes into contact with) the engaging protrusion on the rod-shaped valve body, thereby pushing down the rod-shaped valve body as well. This allows the valve portion of the rod-shaped valve body to seat on the valve seat of the cylinder body, blocking the inlet for the liquid content, thereby preventing the liquid content from flowing back into the container via the inlet. Furthermore, when the piston subsequently moves down, the engaging portion is more easily elastically deformed, allowing it to overcome the engaging protrusion on the rod-shaped valve body with the minimum necessary force, thereby allowing the nozzle (piston body) to be pushed down smoothly.

[0010] According to a fourth aspect of the present invention, in the first aspect, the cylinder body includes a cylindrical liquid cylinder communicating with the container and a cylindrical air cylinder integrally formed with the liquid cylinder, the piston body includes a cylindrical liquid piston slidably disposed within the liquid cylinder and a cylindrical air piston engaged with the upper outer periphery of the cylindrical liquid piston and slidably disposed within the air cylinder, and the engaging portion is formed to protrude radially inward from the inner circumferential surface of the cylindrical liquid piston. According to the pump dispenser of this aspect, the engaging portion is formed to protrude radially inward from the inner circumferential surface of the cylindrical liquid piston, so that when the piston body and the cylinder body are depressed, the engaging portion engages (comes into contact with) the engaging protrusion of the rod-shaped valve body, thereby depressing the rod-shaped valve body as well. As a result, the valve portion of the rod-shaped valve body seats on the valve seat of the cylinder body, blocking the inlet for the liquid content, and preventing the liquid content from flowing back into the container via the inlet.

[0011] According to the pump dispenser of the present invention, it is possible to provide a pump dispenser that prevents backflow of the content liquid and dispenses the content liquid at a predetermined amount.

[0012] 5A is a schematic cross-sectional view of a pump dispenser at an upper limit position according to one embodiment of the present invention. It is a partial enlarged view of portions A and B shown in FIG. 1, where (a) is a partial enlarged view of portion A shown in FIG. 1 and (b) is a partial enlarged view of portion B shown in FIG. 1. It is a schematic cross-sectional view of a pump dispenser at a lower limit position shown in FIG. 3. It is a partial enlarged view of portions C and D shown in FIG. 3, where (a) is a partial enlarged view of portion C shown in FIG. 3 and (b) is a partial enlarged view of portion D shown in FIG. 3. It is a view showing a state in which the pump dispenser shown in FIG. 1 is slightly pressed down, where (a) is a cross-sectional view of the pump dispenser and (b) is a partial enlarged view of portion E shown in FIG. 5A. It is a cross-sectional view showing a state in which the pump dispenser is pressed down from the position shown in FIG. 5. It is a partial enlarged view of portions F and G shown in FIG. 6, where (a) is a partial enlarged view of portion F shown in FIG. 6 and (b) is a partial enlarged view of portion G shown in FIG. It is a cross-sectional view showing a state in which the pump dispenser is further pressed down from the position shown in FIG. 6 and reaches the lower limit position. 12(a) and 12(b) are diagrams showing a state in which the pressure on the pump dispenser that has reached the lowest limit position shown in FIG. 8 has been released and the pump dispenser has been slightly raised, with (a) being a cross-sectional view of the pump dispenser and (b) being a partially enlarged view of part H shown in FIG. 9(a). 13 is a diagram showing a state in which the pump dispenser has been raised from the position shown in FIG. 9, with (a) being a cross-sectional view of the pump dispenser and (b) being a partially enlarged view of part I shown in FIG. 10(a). 14 is a diagram showing a state in which the pump dispenser has been raised from the position shown in FIG. 10, with (a) being a cross-sectional view of the pump dispenser and (b) being a partially enlarged view of part J shown in FIG. 11(a). 15 is a diagram showing a state in which the pump dispenser has been raised from the position shown in FIG. 11, with (a) being a cross-sectional view of the pump dispenser and (b) being a partially enlarged view of part K shown in FIG. 12(a). 16 is a schematic cross-sectional view of a pump dispenser at an upper limit position according to another embodiment of the present invention. 15A and 15B are partial enlarged views of portions L and M shown in Fig. 13, (a) being a partial enlarged view of portion L shown in Fig. 1, and (b) being a partial enlarged view of portion M shown in Fig. 1. 16A is a schematic cross-sectional view of the pump dispenser at the lowest position shown in Fig. 13. 16B are partial enlarged views of portions N and O shown in Fig. 15, (a) being a partial enlarged view of portion N shown in Fig. 15, and (b) being a partial enlarged view of portion O shown in Fig. 15.20(a) is a cross-sectional view of the pump dispenser, and (b) is a partially enlarged view of portion P shown in FIG. 17(a). 21 is a cross-sectional view of portion Q and portion R shown in FIG. 18, and (a) is a partially enlarged view of portion Q shown in FIG. 18, and (b) is a partially enlarged view of portion R shown in FIG. 18. 21 is a cross-sectional view of portion T and portion U shown in FIG. 21, and (a) is a partially enlarged view of portion T shown in FIG. 20(a). 21 is a cross-sectional view of portion U shown in FIG. 20(a). Fig. 24(a) is a diagram showing a state in which the pump dispenser is elevated from the position shown in Fig. 21, (a) is a cross-sectional view of the pump dispenser, and (b) is a partially enlarged view of part V shown in Fig. 23(a). Fig. 24(a) is a diagram showing a state in which the pump dispenser is elevated from the position shown in Fig. 23, (a) is a cross-sectional view of the pump dispenser, and (b) is a partially enlarged view of part W shown in Fig. 24(a). Fig. 24(a) is a partially enlarged view showing other forms of an inner convex portion of a piston body and an outer convex portion of a reinforcing rib of a rod-shaped valve body of a pump dispenser according to an embodiment of the present invention, (a) is a partially enlarged view of a first other form, and (b) is a partially enlarged view of a second other form.

[0013] The configuration of a pump dispenser according to one embodiment of the present invention will be described in detail below with reference to Figures 1 to 4. As shown in Figures 1 and 3, a pump dispenser 1A according to one embodiment of the present invention is attached to the mouth 5 of a container 3. The container 3 is filled with a liquid (content liquid, not shown) such as a cleanser, lotion, or emulsion. The pump dispenser 1A includes a cylinder body 11, a piston body 13, a cylindrical valve body 15, a rod-shaped valve body 17, a nozzle 19, and a base cap portion 21. These components are formed of a synthetic resin such as polypropylene or polyethylene.

[0014] The cylinder body 11 is a cylindrical liquid cylinder that communicates with the container 3 and includes: a large-diameter portion 31 having an outer diameter smaller than the inner diameter of the mouth 5 of the container 3; an annular flange portion 33 that is connected to the upper end of the large-diameter portion 31 and extends radially outward; a bottom wall portion 35 that is connected to the lower end of the large-diameter portion 31 and extends radially inward; and a small-diameter portion 37 that extends downward (upstream) from the bottom wall portion 35. The large-diameter portion 31 has at least one outside-air flow path hole 39 formed therein so as to penetrate its wall, for introducing outside air into the container 3. A sealing gasket 41 is attached to the underside of the annular flange portion 33 and is in contact with the upper end surface of the mouth 5. The small diameter portion 37 is provided with a plurality of ribs 43 (see FIGS. 1 and 3) provided at predetermined intervals in the circumferential direction for receiving an elastic member 117 (described later) when the piston body 13 descends, a valve seat portion 45 that serves as a valve seat for the rod-shaped valve body 17, and a cylindrical connecting portion 47 below the valve seat portion 45 for connecting a liquid suction tube 49 for guiding the content liquid (contents) from inside the container 3 into the small diameter portion 37. Here, the space partitioned by the cylinder body 11, the piston body 13, the rod-shaped valve body 17, and the cylindrical valve body 15 constitutes a liquid chamber 51.

[0015] The piston body 13 is provided in the cylinder body 11 so as to slide vertically along the inner circumferential surface of the large-diameter portion 31 of the cylinder body 11, and includes a small-diameter cylindrical portion 61 located at the upper part of the piston body 13, a large-diameter cylindrical portion 63 formed integrally with the lower part of the small-diameter cylindrical portion 61, and a seal portion 65 provided on the outer circumferential surface of the large-diameter cylindrical portion 63. The outer diameter dimension of the small-diameter cylindrical portion 61 is set to be approximately equal to the inner diameter dimension of the inner tube portion 125 (see below) of the nozzle 19, and a plurality of annular protrusions 67 (two in FIG. 2( a )) are formed on the outer circumferential surface of the upper part. At the connection portion between the small-diameter cylindrical portion 61 and the large-diameter cylindrical portion 63, annular engaging portions 69 (engaging portions) are formed that hang down radially inward on the inner circumferential surface and are elastically deformable and engage (contact) with each of the outer protrusions 111 (see below) of the plurality of ribs 107 of the rod-shaped valve body 17. As shown in FIG. 2B , the annular engagement portion 69 includes a first engagement wall 71 extending radially inward from the inner circumferential surface of the connecting portion, and a second engagement wall 73 extending downward from the tip of the first engagement wall 71. An inner protrusion 75 protruding radially inward is formed at the tip of the second engagement wall 73. A recess 77 is formed between the annular engagement portion 69 and the large-diameter cylindrical portion 63, and this recess 77 functions as a receiving portion for receiving the elastic member 117. The seal portion 65 is an annular band-shaped body with a shallow, tapered recess on its outer circumferential surface. The upper and lower ends of the outer edge of the seal portion 65 are integrally formed with the lower outer circumferential wall of the large-diameter cylindrical portion 63 so as to contact the inner circumferential surface of the large-diameter portion 31 of the cylinder body 11 while ensuring sufficient airtightness between the seal portion 65 and the inner circumferential surface of the large-diameter portion 31 and to slide vertically along the inner circumferential surface of the large-diameter portion 31.

[0016] The cylindrical valve element 15 is inserted into the upper side (downstream side) of the small-diameter cylindrical portion 61 of the piston body 13 and includes a cylindrical main body 81, a valve portion 85, and an annular engagement portion 87 formed inside the lower end. When the cylindrical valve element 15 is inserted into the small-diameter cylindrical portion 61 of the piston body 13, the space defined by the outer periphery of the cylindrical main body 81 and the inner periphery of the small-diameter cylindrical portion 61 forms a liquid flow path 89 for guiding the liquid contained in the liquid chamber 51 to the nozzle 19 (see FIG. 2( a)). The outer diameter of the cylindrical main body 81 is set smaller than the inner diameter of the small-diameter cylindrical portion 61. The valve portion 85 is provided on the outer periphery of the cylindrical main body 81 and includes an inclined wall 91 extending radially outward from the outer periphery of the cylindrical main body 81 toward the upper side, and an upright wall 93 extending upward from the tip of the inclined wall 91. The inclined wall 91 of the valve portion 85 functions as a valve portion by being centered and released from its lower surface on the upper end of the small-diameter cylindrical portion 61 of the piston body 13. The annular engaging portion 87 provided inside the lower end of the cylindrical main body 81 prevents the engaging portion 105 formed at the upper end of the rod-shaped valve element 17 inserted into the cylindrical main body 81 from coming off, as shown in FIG. 2A . The engaging portion 87 extends radially inward from the inner circumferential surface of the lower portion of the cylindrical main body 81 and has a tapered shape that faces inward. This facilitates insertion of the engaging portion 105 of the rod-shaped valve element 17 into the cylindrical main body 81 from below. When the inclined wall 91 of the valve portion 85 is released from the upper end of the small-diameter cylindrical portion 61 of the piston body 13, the discharge port 121 of the nozzle 19 communicates with the liquid flow path 89. When the inclined wall 91 is released from the upper end of the small-diameter cylindrical portion 61 of the piston body 13, the discharge port 121 of the nozzle 19 communicates with the liquid flow path 89. When the inclined wall 91 is seated on the valve portion 85, the discharge port 121 of the nozzle 19 communicates with the liquid flow path 89.

[0017] The cylindrical valve element 15 and the rod-shaped valve element 17 are arranged in a straight line within the piston element 13. The upper end of the rod-shaped valve element 17 is slidably inserted into the cylindrical valve element 15, and the rod-shaped valve element 17 includes a shaft portion 101 and a valve portion 103. The shaft portion 101 has a cylindrical upper end and an engagement portion 105 having an annular protrusion 105a extending radially outward from the outer periphery of the upper end and an engagement peripheral wall portion 105b extending upward (downstream) from the tip of the protrusion 105a. The shaft portion 101 also has a plurality of ribs 107 for reinforcing and for centering the elastic member 117, which are spaced apart circumferentially and extend from approximately the center toward the valve portion 103 (see FIGS. 1 and 3). The engagement peripheral wall portion 105b of the engagement portion 105 is configured as a flexible sealing portion around its periphery by providing a space 109 (see FIG. 2(a)). The rib 107 has a radially outward protrusion dimension (width dimension) from the upper portion to the central portion that is smaller than the radially outward protrusion dimension (width dimension) from the central portion to the lower portion. The rib 107 has outer protrusions 111 (engagement protrusions) that are provided at predetermined intervals (intermittently) in the circumferential direction and protrude radially outward. These outer protrusions 111 (engagement protrusions) are arranged at predetermined intervals (discontinuously) in the circumferential direction and engage with the inner protrusions 75 of the annular engagement portion 69 of the piston body 13. The large-diameter portion at the lower portion serves to center the elastic member 117. At the lower end of the rod-shaped valve element 17, the valve portion 103 has an annular portion 113 that is arranged opposite the valve seat portion 45 of the small-diameter portion 37 of the cylinder body 11 to open and close the inlet 53 provided at the lower portion of the small-diameter portion 37. The outer surface of the valve portion 103 has a plurality of receiving portions 115 that extend radially outward and are provided at predetermined intervals to receive the lower end of the elastic member 117. The annular portion 113 has a tapered shape such that the outer peripheral surface of its tip comes into surface contact with the sealing surface of the valve seat portion 45 of the small diameter portion 37. Here, the elastic member 117 is a compression spring, one end of which is housed in the recessed portion 77 of the piston body 13 and the other end of which abuts against the multiple receiving portions 115 of the valve portion 103, and the elastic force of the elastic member 117 constantly urges the piston body 13, the cylindrical valve body 15, and the nozzle 19 axially upward (upward in the plane of FIG. 1 ) relative to the rod-shaped valve body 17.

[0018] The nozzle 19 is connected to the piston body 13 and includes a discharge port 121 including a discharge passage 123 for discharging the content liquid, an inner cylindrical portion 125 communicating with the discharge port 121, and an outer cylindrical portion 127 positioned concentrically and radially outward of the inner cylindrical portion 125. The nozzle 19 also has a ceiling wall provided with ribs 129 hanging down from its underside. The ribs 129 are plate-shaped and are arranged in three locations within the discharge passage 123 and above the cylindrical valve body 15 at equal intervals in the circumferential direction, with their lower ends tapering radially outward. When the nozzle 19 is pressed down, the piston body 13 descends together with the nozzle 19, but the cylindrical valve element 15 does not descend due to the contact force with the rod-shaped valve element 17. Therefore, when the nozzle 19 is pressed down to a predetermined position, the rib 129 abuts against the upper edge of the cylindrical valve element 15, centering the cylindrical valve element 15 and then acting to press down the cylindrical valve element 15 as well. The inner circumferential surface of the inner cylindrical portion 125 is formed with annular engagement grooves 131 that engage with the multiple annular protrusions 67 of the small-diameter cylindrical portion 61 (see FIG. 2( a)). The outer cylindrical portion 127 is formed to be able to move up and down together with the inner cylindrical portion 125 of the nozzle 19 along the cylindrical guide portion 143 of the base cap portion 21.

[0019] The base cap portion 21 includes a top wall portion 141, a cylindrical guide portion 143 standing upright integrally from the center of the top wall portion 141, a cylindrical inner fitting wall portion 145 hanging down integrally from the center of the top wall portion 141, and a cylindrical outer fitting wall portion 147 hanging down integrally from the outer peripheral edge of the top wall portion 141. The annular flange portion 33 of the cylinder body 11 is fitted into the space defined by the cylindrical inner fitting wall portion 145 and the cylindrical outer fitting wall portion 147. The inner diameter of the cylindrical guide portion 143 is larger than the outer diameter of the inner tube portion 125 of the nozzle 19, and the outer diameter is smaller than the inner diameter of the outer tube portion 127. When the cylindrical guide portion 143 is inserted into the space formed between the inner cylinder portion 125 and the outer cylinder portion 127, the space defined by the cylindrical guide portion 143, the inner cylinder portion 125, and the outer cylinder portion 127 serves as an outside air flow passage 149 (see FIG. 1 ) for introducing outside air. The cylindrical outer fitting wall portion 147 has an internal thread portion 151 formed on its inner circumferential surface, which threads onto the external thread portion 7 formed on the opening 5 of the container 3.

[0020] Next, the operation of the pump dispenser 1A according to the first embodiment will be described with reference to FIGS. 1 to 12. First, as shown in FIGS. 1 and 2, when the nozzle 19 is positioned at the upper limit position in an unpressurized state, the piston body 13, the cylindrical valve body 15, and the nozzle 19 are pushed upward by a predetermined amount (toward the upper side of the paper in FIG. 1) away from the rod-shaped valve body 17 by the elastic force of the elastic member 117. At this time, the valve portion 85 (inclined wall 91) of the cylindrical valve body 15 is seated on the upper end of the piston body 13, blocking the discharge port 121 of the nozzle 19 from the liquid flow path 89 (valve-closed state). Furthermore, the valve portion 103 (annular portion 113) of the rod-shaped valve body 17 is separated from the valve seat 45 of the small-diameter portion 37, and the liquid chamber 51 is in communication with the inside of the container 3 via the suction tube 49 (valve-open state). Furthermore, the inner convex portion 75 of the annular engaging portion 69 of the piston body 13 is engaged (contacted) with the upper portion of the outer convex portion 111 of the rib 107 .

[0021] 5, when the nozzle 19 is slightly depressed, the piston body 13 is also depressed accordingly. At this time, the inner convex portion 75 of the annular engagement portion 69 of the piston body 13 engages with the upper portion of the outer convex portion 111 of the rib 107, thereby also pushing down the rod-shaped valve element 17. As a result, the valve portion 103 (annular portion 113) of the rod-shaped valve element 17 seats on the valve seat portion 45 of the small diameter portion 37 (see FIG. 5(b)), blocking communication between the liquid chamber 51 and the liquid suction tube 49 and closing the inlet port 53. Furthermore, as the rod-shaped valve element 17 is depressed, the cylindrical valve element 15 is also depressed together with the rod-shaped valve element 17 due to the engagement force between the engagement portion 105 of the rod-shaped valve element 17 and the engagement portion 87 of the cylindrical valve element 15 and the frictional resistance of the inner wall surface of the cylindrical main body portion 81. As a result, the valve portion 85 (inclined wall 91) of the cylindrical valve body 15 remains seated on the upper end of the piston body 13 (valve closed state).

[0022] 6 and 7 , when the nozzle 19 is further depressed, only the piston body 13 is depressed, and the plate-like rib 129 of the nozzle 19 abuts against the upper end of the cylindrical valve body 15. At this time, the valve portion 103 (annular portion 113) of the rod-shaped valve body 17 is seated on the valve seat portion 45 of the small-diameter portion 37, so the rod-shaped valve body 17 is not depressed, and the inner convex portion 75 of the annular engaging portion 69 of the piston body 13 rides over the arcuate surface of the outer convex portion 111 of the rod-shaped valve body 17 (see FIG. 7( b)). This releases the engagement (contact) between the engaging portion 69 and the outer convex portion 111. At this time, because the engaging portion 69 is formed to be elastically deformable, the resistance force when the inner convex portion 75 rides over the outer convex portion 111 is reduced, allowing the nozzle 19 to descend smoothly. Furthermore, after the inner convex portion 75 overcomes the outer convex portion 111, they are disengaged from each other, allowing the nozzle 19 (piston body 13) to be pressed down smoothly with less force. Furthermore, because the cylindrical valve element 15 is supported by the rod-shaped valve element 17, the position of the cylindrical valve element 15 does not change, and the pressing force of the nozzle 19 exceeds the frictional resistance of the inner wall surface of the cylindrical main body portion 81 of the cylindrical valve element 15, so that the upper end of the rod-shaped valve element 17 is inserted into the cylindrical main body portion 81 of the cylindrical valve element 15. As a result, the valve portion 85 (inclined wall 91) of the cylindrical valve element 15 is lifted off the upper end of the piston body 13 (open valve state), and the discharge port 121 of the nozzle 19 and the liquid flow path 89 are connected to each other. Here, as the nozzle 19 and the piston body 13 are pressed down further, the internal volume of the liquid chamber 51 decreases, and the pressure (internal pressure) of the liquid chamber 51 increases. As a result, the liquid in the liquid chamber 51 flows into the liquid flow path 89. The liquid then flows from the liquid flow path 89 through the discharge passage 123 of the nozzle 19 and is discharged from the discharge port 121 (see the arrow in FIG. 6).

[0023] 8 , when the piston body 13 is further pressed down together with the nozzle 19, the cylindrical valve body 15 is pressed down together with the nozzle 19 by abutting against the plate-like rib 129 of the nozzle 19. Furthermore, the upper end of the rod-shaped valve body 17 is inserted up to the top of the cylindrical main body 81 of the cylindrical valve body 15, the insertion amount of the rod-shaped valve body 17 into the cylindrical main body 81 of the cylindrical valve body 15 is maximized, the lower end of the piston body 13 abuts against the bottom wall 35 of the cylinder body 11, and the descent of the nozzle 19 and the piston body 13 stops (i.e., the nozzle 19 and the piston body 13 reach their lowest positions). Since the piston body 13 is positioned at the bottom of the cylinder body 11 (the lowest position of the piston body 13), the outside air flow passage hole 39 formed in the large diameter portion 31 of the cylinder body 11 and the outside air flow passage 149 are in communication. At this time, the volume of the upper space 55 partitioned by the inner circumferential surface of the large diameter portion 31 of the cylinder body 11, the large diameter cylindrical portion 63 of the piston body 13, the nozzle 19, and the base cap portion 21 increases, creating a negative pressure, and this negative pressure causes outside air to be drawn into the upper space 55 through the outside air flow passage 149. Note that the valve portion 85 (inclined wall 91) of the cylindrical valve body 15 remains unseated from the upper end of the piston body 13, and the valve portion 103 (annular portion 113) of the rod-shaped valve body 17 remains seated on the valve seat portion 45 of the small diameter portion 37.

[0024] 3, 4, and 9 to 12, a description will be given of the case where the nozzle 19 is released from its lowest position. As shown in Fig. 9, when the nozzle 19 is released from its lowest position (see Figs. 3 and 4), the elastic force of the elastic member 117 pushes up the nozzle 19 and the piston body 13. At this time, as the piston body 13 is pushed up, the valve portion 85 of the cylindrical valve body 15 is seated on the upper end of the piston body 13, blocking the discharge port 121 of the nozzle 19 and the liquid flow path 89. In addition, the annular portion 113 of the valve portion 103 of the rod-shaped valve body 17 remains seated on the valve seat portion 45 of the small diameter portion 37.

[0025] As shown in Figure 10, when the nozzle 19 and piston body 13 are further pushed up by the elastic force of the elastic member 117, the volume of the liquid chamber 51 increases, and the liquid chamber 51 enters a negative pressure state. Furthermore, since the valve portion 85 of the cylindrical valve element 15 abuts against the upper end of the piston body 13, it rises together with the piston body 13. Furthermore, as the piston body 13 rises, the rod-shaped valve element 17 rises due to frictional resistance of the engaging portion 105 of the rod-shaped valve element 17 against the inner wall surface of the cylindrical main body portion 81 of the cylindrical valve element 15, and the annular portion 113 of the valve portion 103 of the rod-shaped valve element 17 is released from the valve seat portion 45 of the small diameter portion 37 (see Figure 10(b)). As a result, the liquid chamber 51 and the container 3 are connected, and the liquid in the container 3 is sucked up into the liquid chamber 51 via the suction tube 49, filling the liquid chamber 51 with the liquid. Here, the liquid content in the container 3 is sucked up into the liquid chamber 51, creating a negative pressure state inside the container 3. However, because the outside air flow path hole 39 in the large diameter portion 31 of the cylinder body 11 is not closed by the seal portion 65 of the piston body 13, outside air in the upper space 55 flows into the container 3 through the outside air flow path hole 39, and the negative pressure state in the container 3 is resolved. Note that the multiple receiving portions 115 of the valve portion 103 of the rod-shaped valve body 17 abut against the lower end of the elastic member 117, restricting the lift of the rod-shaped valve body 17.

[0026] As shown in Figure 11 , when the nozzle 19 and piston body 13 are pushed up further from the position shown in Figure 10 by the elastic force of the elastic member 117, the inner convex portion 75 of the annular engaging portion 69 of the piston body 13 comes into contact with the lower part of the outer convex portion 111 of the rod-shaped valve body 17. Then, as shown in Figure 12 , when the nozzle 19 and piston body 13 are pushed up further from the position shown in Figure 11 by the elastic force of the elastic member 117, the inner convex portion 75 of the annular engaging portion 69 tries to ride over the arcuate surface of the outer convex portion 111 of the rod-shaped valve body 17 (see Figure 12(b)). Then, when the inner convex portion 75 of the annular engaging portion 69 completely rides over the outer convex portion 111 of the rod-shaped valve body 17, the inner convex portion 75 engages (comes into contact with) the upper part of the outer convex portion 111. As a result, the nozzle 19, piston body 13, and cylindrical valve body 15 reach their upper limit positions (see Figure 1) relative to the rod-shaped valve body 17. At this time, the insertion amount of the rod-shaped valve element 17 into the cylindrical valve element 15 is minimized, and the spatial volume of the cylindrical valve element 15 is maximized. As a result, negative pressure is generated in the internal space 95 (see FIGS. 11 and 12 ) of the cylindrical valve element 15, and the content liquid remaining in the discharge port 121 of the nozzle 19 and the discharge passage 123 downstream of the cylindrical valve element 15 is drawn in by the increased spatial volume (the so-called back suction function).

[0027] As described above, the pump dispenser 1A according to one embodiment of the present invention provides the following advantageous effects. With the pump dispenser 1A, when the nozzle 19 is at its upper limit, the inclined wall 91 of the valve portion 85 of the cylindrical valve element 15 rests on the upper end of the piston element 13, blocking the discharge port 121 of the nozzle 19 and the liquid flow path 89. When the nozzle 19 is pressed down, the inner convex portion 75 of the piston element 13 engages with the outer convex portion 111 of the rib 107 of the rod-shaped valve element 17, thereby pressing down the rod-shaped valve element 17 as well. The annular portion 113 of the valve portion 103 of the rod-shaped valve element 17 rests on the valve seat portion 45 of the small-diameter portion 37, blocking communication between the liquid chamber 51 and the liquid suction tube 49. As a result, the liquid contained in the liquid chamber 51 is prevented from flowing back into the container 3 via the liquid suction tube 49, and a predetermined amount of the liquid can be discharged stably to the outside.

[0028] Furthermore, according to the pump dispenser 1A, when the nozzle 19 is released from being pressed down, the piston body 13 is pushed up, increasing the volume of the liquid chamber 51 and placing the liquid chamber 51 in a negative pressure state. Furthermore, the annular portion 113 of the valve portion 103 of the rod-shaped valve body 17 is lifted off the valve seat portion 45 of the small diameter portion 37 of the cylinder body 11, and the liquid chamber 51 is connected to the container 3, allowing the liquid content within the container 3 to be sufficiently sucked up into the liquid chamber 51 via the suction tube 49. Furthermore, the inclined wall 91 of the valve portion 85 of the cylindrical valve body 15 is seated on the upper end of the piston body 13 up to the upper limit position of the nozzle 19, blocking the discharge port 121 of the nozzle 19 and the liquid flow path 89, thereby maintaining the sealing of the liquid chamber 51.

[0029] Furthermore, according to the pump dispenser 1A, the valve portion 103 of the rod-shaped valve body 17 is configured so that, after it is seated on the valve seat portion 45 of the cylinder body 13, the engagement (contact) between the outer convex portion 111 of the rod-shaped valve body 17 and the inner convex portion 75 of the piston body 13 is released as the piston body 13 descends, so that the nozzle 19 (piston body 13) can be subsequently pressed down smoothly with less force.

[0030] According to the pump dispenser 1A, when the nozzle 19 is released from being pressed down, the insertion amount of the rod-shaped valve element 17 into the cylindrical valve element 15 decreases, and the volume of the internal space 95 of the cylindrical valve element 15 increases, causing the internal space 95 to enter a negative pressure state, so that the content liquid remaining in the discharge port 121 of the nozzle 19 and the discharge passage 123 is drawn back into the internal space 95 (backsuction phenomenon). As a result, the amount of liquid remaining near the discharge port 121 of the nozzle 19 decreases, making it possible to prevent the liquid from dripping from the discharge port 121 of the nozzle 19.

[0031] According to the pump dispenser 1A, the cylindrical valve body 15 and the rod-shaped valve body 17 are arranged in a straight line in the internal space of the piston body 13, so there is no need to provide any unnecessary space downstream of the cylindrical valve body 15, which prevents the structure of the pump dispenser 1A from becoming complicated and reduces costs.

[0032] Next, a pump dispenser 1B (pump dispenser 1B according to another embodiment) for dispensing foamy contents obtained by mixing foamable content liquid filled in a container with air will be described with reference to Figures 13 to 23. In the following description, the same reference numerals are used for similar parts to those of the pump dispenser 1A described above, and their description will be omitted, and only different parts will be described.

[0033] As shown in Figures 13 to 16, the device includes a cylinder body 11, a piston body 13, a cylindrical valve body 15, a rod-shaped valve body 17, a nozzle 19, a mixing holder 23, a net holder 25, and a base cap portion 21. The cylinder body 11 is a cylindrical double cylinder composed of an air cylinder 161 and a liquid cylinder 163. The air cylinder 161 includes a large-diameter portion 31 having an outer diameter smaller than the inner diameter of the opening 5 of the container 3, an annular flange portion 33 connected to the upper end of the large-diameter portion 31 and extending radially outward, a bottom wall portion 165 connected to the lower end of the large-diameter portion 31 and extending radially inward, and an inclined wall portion 167 extending obliquely upward radially inward from the bottom wall portion 165. At least one outside air flow path hole 39 for introducing outside air into the container 3 is formed above the large-diameter portion 31, penetrating the wall portion. The space defined by the air cylinder 161, a liquid piston 175 of the piston body 13, the air piston 173, and an intake valve 177, which will be described later, serves as an air chamber 169.

[0034] The liquid cylinder 163 has an upper end connected to the upper end of a sloping wall portion 167 of the air cylinder 161, which is a large-diameter cylinder portion, and is equipped with a cylindrical main body portion 171 extending downward from this sloping wall portion 167, a plurality of ribs 43 provided at predetermined intervals in the circumferential direction for receiving an elastic member 117, which will be described later, when a piston body 13, which will be described later, descends, a valve seat portion 45 that serves as a valve seat for a rod-shaped valve element 17, which will be described later, and a cylindrical connecting portion 47 below the valve seat portion 45 for connecting a liquid suction tube 49 for guiding the content liquid from inside the container 3 into the liquid cylinder 163, which is a small-diameter cylinder portion. The space partitioned by the liquid cylinder 163, a liquid piston 175, and the rod-shaped valve element 17 and cylindrical valve element 15, which will be described later, forms a liquid chamber 51.

[0035] The piston body 13 is composed of an air piston 173, a liquid piston 175, and an intake valve 177 attached to the air piston 173. In this embodiment, the air piston 173 and the liquid piston 175 are connected to each other with the upper part of the liquid piston 175 inserted into the small diameter cylindrical part 61 of the air piston 173. The air piston 173 is provided in the air cylinder 161 so that its outer periphery slides up and down along the inner periphery of the large diameter part 31 of the air cylinder 161. The lower part of the liquid piston 175 is provided in the liquid cylinder 163 so that it slides along the inner periphery of the cylindrical main body part 171 of the liquid cylinder 163.

[0036] 13 and 15 , the air piston 173 includes a small-diameter cylindrical portion 61, a large-diameter cylindrical portion 63 concentric with the small-diameter cylindrical portion 61, a connecting portion 179 connecting the small-diameter cylindrical portion 61 and the large-diameter cylindrical portion 63, and a seal portion 65 provided on the outer peripheral wall at the lower end of the large-diameter cylindrical portion 63. The small-diameter cylindrical portion 61 has an outer diameter dimension set to be approximately equal to the inner diameter dimension of the intermediate cylindrical portion 126 of the nozzle 19, and includes an annular protrusion 181 extending radially inward from the inner peripheral surface, and a plurality of ribs 183 provided at predetermined intervals in the circumferential direction and extending downward from the underside of the annular protrusion 181. The annular protrusion 181 serves as a valve seat for a second valve 227 of a valve portion 85 of the cylindrical valve element 15, which will be described later. The connecting portion 179 is connected to the lower end of the small-diameter cylindrical portion 61, extends radially outward from the lower end of the small-diameter cylindrical portion 61, and connects to the upper end of the large-diameter cylindrical portion 63. The connecting portion 179 is formed with an annular recess 185 for fitting with an annular shaft portion 203 of the intake valve 177 (described later), and an intake hole 187 located radially outward of the annular recess 185 for introducing outside air into the air chamber 169. A plurality of intake holes 187 are formed at predetermined intervals in the circumferential direction. The seal portion 65 is an annular band-shaped body having a shallow, tapered recess on its outer circumferential surface. The upper and lower ends of the outer edge of the seal portion 65 are integrally formed with the lower outer peripheral wall of the large-diameter cylindrical portion 63 so as to contact the inner circumferential surface of the large-diameter portion 31 of the air cylinder 161 while ensuring sufficient airtightness between them and slide vertically along the inner circumferential surface of the large-diameter portion 31.

[0037] 13 and 15 , the liquid piston 175 is generally cylindrical and has a first step 189 (step, valve seat) at its upper part for receiving a first valve 225 of the valve portion 85 of the cylindrical valve element 15 (described later), an annular flange 191 extending radially outward from the outer circumferential surface at approximately the center, and an annular inward protrusion 193 (annular engaging portion) protruding radially inward from the inner circumferential surface at the lower part for receiving the elastic member 117. A tapered seal portion 195 that opens downward is provided at the lower part of the liquid piston 175. The seal portion 195 is configured to be able to slide up and down along the inner circumferential surface of the main body 171 of the liquid cylinder 163 while ensuring sufficient airtightness relative to the inner circumferential surface.

[0038] Here, the space partitioned by the cylindrical valve element 15, the mixing holder 23, and the small-diameter cylindrical portion 61 of the air piston 173 forms a mixing chamber 197 in which the content liquid and air are mixed. Also, as shown in Figures 14(a) and 16(a), when the air piston 173 is fitted into the liquid piston 175, the space partitioned by a plurality of ribs 183 facing in the longitudinal direction between the outer circumferential surface of the liquid piston 175 and the inner circumferential surface of the small-diameter cylindrical portion 61 of the air piston 173 forms a plurality of air flow paths 199 for introducing air from the air chamber 169 into the mixing chamber 197. As shown in Figures 13 and 15, the space partitioned by the air piston 173 and the base cap portion 21 forms an upper space 201.

[0039] The intake valve 177 includes an annular shaft portion 203, an annular outer valve portion 205 extending radially outward, and an annular inner valve portion 207 extending radially inward. The upper end of the annular shaft portion 203 is fitted into the annular recess 185 of the air piston 173. The annular outer valve portion 205 and the annular inner valve portion 207 are integrally formed on the lower end of the annular shaft portion 203 and are made of an elastic member. The radial dimension of the annular outer valve portion 205 is set so that it can cover the intake hole 187 and open when the internal pressure of the air chamber 169 is lower than the pressure outside the container 3. The radial dimension of the annular inner valve portion 207 is set so that it opens when the internal pressure of the air chamber 169 is higher than the pressure outside the container 3, and is seated and released on the annular flange portion 33 of the liquid piston 175, connecting the air chamber 169 to the multiple air flow paths 199.

[0040] 13 and 15, the mixing holder 23 mixes air with the content liquid to generate foam, and its outer periphery from the middle to the upstream side is fitted inside the small diameter cylindrical portion 61 of the air piston 173. The mixing holder 23 is a substantially cylindrical hollow member, and has an annular flange 209 at its upper end that extends radially outward, and is equipped with a plurality of reinforcing ribs 211 (two in the figure) that are provided at predetermined intervals in the circumferential direction and extend downward (upstream) from the underside of the annular flange 209. The mixing holder 23 also includes an annular protrusion 213 extending radially inward from the lower inner peripheral surface, plate-like lower ribs 215 (restriction and centering portions, located at three equally spaced locations in the circumferential direction) extending downward from the lower surface of the annular protrusion 213 and having inclined surfaces 215a toward the center of the lower surface, and at least one upper rib 217 extending upward from the upper surface of the annular protrusion 213. The annular protrusion 213 has a foam discharge hole 219 at its center that connects the discharge port 121 of the nozzle 19 with the mixing chamber 197. When the nozzle 19 is pushed down, the inclined surface 215a of the lower rib 215 causes the air piston 173 and the liquid piston 175 to descend together with the nozzle 19, but the cylindrical valve element 15 does not descend due to the contact force with the rod-shaped valve element 17, so when the nozzle 19 is pushed down to a predetermined position, the inclined surface 215a comes into contact with the upper edge of the cylindrical valve element 15. As a result, the cylindrical valve element 15 is pushed down together with the nozzle 19, the air piston 173, and the liquid piston 175, while coming to the center of the mixing holder 23.

[0041] As shown in FIGS. 13 and 15 , the net holder 25 is a cylindrical net that allows the foam generated in the mixing chamber 197 to pass through, thereby making the foam finer and more uniform (homogenizing) in size. It is fitted inside the downstream side of the mixing holder 23. A net 221a is provided at its upper end, and a net 221b is provided at its lower end. A foam passage 221c is formed in the net holder 25 to allow the foam to pass through. An annular protrusion 222 extending radially outward is formed on the outer periphery of the upper (downstream) part of the net holder 25. When the net holder 25 is fitted into the mixing holder 23, the annular protrusion 222 is sandwiched between the annular flange 209 of the mixing holder 23 and the inner cylindrical portion 125 of the nozzle 19. The mesh size of the nets 221a and 221b may be the same, or the mesh size of the downstream net 221a may be finer than the mesh size of the upstream net 221b. Also, it is not necessary to provide nets on both sides, and only one of the nets 221a and 221b may be used depending on the purpose.

[0042] The cylindrical valve element 15 is inserted into the upper side (downstream side) of the liquid piston 175 and includes a cylindrical main body 81, a valve portion 85, and an annular engaging portion 69 formed inside the lower end. When the cylindrical valve element 15 is inserted into the liquid piston 175, the space defined by the outer periphery of the cylindrical main body 81 and the inner periphery of the liquid piston 175 constitutes the liquid chamber 51 and also serves as a liquid flow path 89 for guiding the liquid content in the liquid chamber 51 to the mixing chamber 197. The outer diameter of the cylindrical main body 81 is set smaller than the inner diameter of the liquid piston 175. As shown in FIG. 14( a), the valve portion 85 is provided on the outer periphery of the cylindrical main body 81 and includes a first valve 225, a second valve 227, and a connecting portion 229 that connects the first valve 225 and the second valve 227. The first valve 225 is for connecting and disconnecting the mixing chamber 197 and the liquid flow paths 89, and is an annular valve extending radially outward and diagonally upward from the outer periphery of the cylindrical main body 81. The connecting portion 229 extends upward (downstream) from the tip of the first valve 225. The second valve 227 is for connecting and disconnecting the mixing chamber 197 and the multiple air flow paths 199, and is an annular valve extending outward from the tip of the connecting portion 229. Here, the first valve 225 is seated on the annular first step 189 of the liquid piston 175 to disconnect the mixing chamber 197 and the liquid flow paths 89, and is released from the first step 189 to connect and disconnect the mixing chamber 197 and the liquid flow paths 89. The second valve 227 seats on the annular protrusion 181 of the air piston 173, thereby blocking the mixing chamber 197 from connecting with the plurality of air flow paths 199, and when it lifts off the annular protrusion 181, the mixing chamber 197 connects with the plurality of air flow paths 199.

[0043] The rib 107 of the rod-shaped valve body 17 has an outer convex portion 111 formed on its upper portion, which protrudes radially outward and has an arc-shaped cross section, and which engages with the inward protruding portion 193 of the liquid piston 175 of the piston body 13.

[0044] The nozzle 19 comprises a discharge port 121 including a foam discharge passage 123 for discharging foam (contents), an inner cylinder 125 communicating with the discharge port 121, an intermediate cylinder 126 positioned concentrically and radially outward from the inner cylinder 125, and an outer cylinder 127 positioned concentrically and radially outward from the intermediate cylinder 126. The lower end of the inner cylinder 125 abuts against the upper end of the mixing holder 23, and the net holder 25 is fitted into the inner wall on the upstream side of the inner cylinder 125. The mixing holder 23 and the small-diameter cylindrical portion 61 of the air piston 173 are fitted into the inner wall of the intermediate cylinder 126.

[0045] The cylindrical guide portion 143 of the base cap portion 21 has an annular protrusion 231 formed on the inner periphery of its upper portion, extending radially inward. The cylindrical guide portion 143 has a plurality of ribs 233 (see FIGS. 13 and 14(a) ) formed at predetermined intervals in the circumferential direction, extending downward from the lower end of the annular protrusion 231. When the cylindrical guide portion 143 is inserted into the space formed between the intermediate cylinder portion 126 and the outer cylinder portion 127, the space defined by the cylindrical guide portion 143 and the intermediate cylinder portion 126 and outer cylinder portion 127 of the nozzle 19 forms an outside air flow passage 149 that introduces outside air into the air chamber 169 via the intake valve 177 (see FIG. 14(a) ).

[0046] Next, the operation of a pump dispenser 1B according to another embodiment will be described with reference to Figures 13 to 19. First, as shown in Figure 13, when the nozzle 19 is positioned at the upper limit position in an unpressurized state, the air piston 173, the liquid piston 175, and the cylindrical valve element 15 are pushed upward by a predetermined amount (toward the upper side of the paper in Figure 13) away from the rod-shaped valve element 17 by the elastic force of the elastic member 117. At this time, the air piston 173 is indirectly subjected to the elastic force of the elastic member 117 via the liquid piston 175. As a result, the first valve 225 of the cylindrical valve element 15 is seated on the annular first step 189 of the liquid piston 175, and the second valve 227 is seated on the annular protrusion 181 of the small-diameter cylindrical portion 61 of the air piston 173 (see Figure 14(a)). In this state, the mixing chamber 197 is blocked from the liquid flow path 89, and the mixing chamber 197 is also blocked from the multiple air flow paths 199. Furthermore, the valve portion 103 of the rod-shaped valve element 17 is unseated from the valve seat portion 45 of the liquid cylinder 163, and the liquid chamber 51 is in communication with the inside of the container 3 via the suction pipe 49. Furthermore, the annular outer valve portion 205 of the intake valve 177 blocks communication between the air chamber 169 and the intake hole 187 (valve closed state), and the annular inner valve portion 207 of the intake valve 177 blocks communication between the air chamber 169 and the multiple air flow paths 199 (valve closed state).

[0047] As shown in Figure 17, when the nozzle 19 is slightly depressed, the mixing holder 23, air piston 173, and liquid piston 175 are depressed together. At this time, the inward protrusion 193 of the liquid piston 175 is engaged (contacted) with the outer protrusion 111 of the rib 107, so that the rod-shaped valve element 17 is also depressed. As a result, the valve portion 103 (annular portion 113) of the rod-shaped valve element 17 is seated on the valve seat portion 45 of the liquid cylinder 163 (see Figure 17(b)), blocking communication between the liquid chamber 51 and the liquid suction tube 49. Furthermore, as the rod-shaped valve element 17 is depressed, the cylindrical valve element 15 is also depressed together with the rod-shaped valve element 17 due to the engagement force between the engagement portion 105 of the rod-shaped valve element 17 and the engagement portion 87 of the cylindrical valve element 15, and the frictional resistance of the inner wall surface of the cylindrical main body 81. Note that the first valve 225 remains seated on the annular first step 189 and the second valve 227 remains seated on the annular projection 181 .

[0048] 18 and 19, when the nozzle 19 is further depressed, the air piston 173 and the liquid piston 175 are depressed together. At this time, the valve portion 103 (annular portion 113) of the rod-shaped valve element 17 is seated on the valve seat portion 45 of the liquid cylinder 163, so the rod-shaped valve element 17 is not depressed, and the inward protrusion 193 of the piston element 13 attempts to ride over the arcuate surface of the outer convex portion 111 of the rod-shaped valve element 17 (see FIG. 19(b)). When the inward protrusion 193 rides over the outer convex portion 111, the engagement (contact) between the inward protrusion 193 and the outer convex portion 111 is released. This allows the nozzle 19 (piston element 13) to be subsequently depressed more smoothly with less force. Furthermore, the cylindrical valve element 15 abuts against the lower rib 215 of the mixing holder 23 and is depressed together with the nozzle 19. Furthermore, because the cylindrical valve element 15 is supported by the rod-shaped valve element 17, the position of the cylindrical valve element 15 does not change, and the downward force of the nozzle 19 exceeds the frictional resistance of the inner wall surface of the cylindrical main body 81 of the cylindrical valve element 15, so that the upper end of the rod-shaped valve element 17 is inserted into the cylindrical main body 81 of the cylindrical valve element 15. As a result, the first valve 225 of the cylindrical valve element 15 is lifted off the annular first step 189, and the second valve 227 is lifted off the annular protrusion 181, so that the mixing chamber 197 and the liquid flow path 89 communicate with each other, and the mixing chamber 197 and the air flow path 199 communicate with each other (see FIG. 19( a)). Here, as the air piston 173 and the liquid piston 175 are further pressed down, the internal volumes of the air chamber 169 and the liquid chamber 51 decrease, and the pressures (internal pressures) of the air chamber 169 and the liquid chamber 51 increase. As a result, the annular inner valve portion 207 of the intake valve 177 is lifted off the annular flange portion 33 of the liquid piston 175 (open valve state), the air chamber 169 and the air flow path 199 are connected, and the air in the air chamber 169 flows into the air flow path 199 (see the arrow in FIG. 19A). Meanwhile, the annular outer valve portion 205 of the intake valve 177 remains closed. As the liquid piston 175 is pushed down, the volume of the liquid chamber 51 decreases and the pressure increases, causing the liquid in the liquid chamber 51 to flow into the liquid flow path 89 (see the arrow in FIG. 19A). As a result, the air flowing through the air flow path 199 and the liquid flowing through the liquid flow path 89 flow into the mixing chamber 197, where they are mixed to generate foam.

[0049] The foam generated in the mixing chamber 197 is first homogenized to a certain extent by passing through the foam discharge holes 219 of the mixing holder 23. The foam then passes through the nets 221b, 221a and foam passage 221c of the net holder 25, and is discharged from the discharge port 121 of the nozzle 19. Here, the foam is made finer and homogenized by passing through the nets 221a, 221b of the net holder 25.

[0050] Then, by further pushing down the nozzle 19, the lower surface of the flange portion 191 of the liquid piston 175 comes into contact with the upper end of the liquid cylinder 163, and the descent of the nozzle 19 stops (see FIGS. 15 and 16 ). At this time, outside air is sucked into the upper space 201, which has been negatively pressurized due to the increased volume, via the outside air flow passage 149. Because the air piston 173 is positioned below the air cylinder 161 (the lowest position of the air piston 173), the outside air flow passage 149 is connected to the outside air flow passage 39 formed in the large diameter portion 31 of the air cylinder 161. Furthermore, the upper end of the rod-shaped valve element 17 is inserted up to the top of the cylindrical main body 81 of the cylindrical valve element 15, and the insertion amount of the rod-shaped valve element 17 into the cylindrical main body 81 of the cylindrical valve element 15 is at its maximum.

[0051] Next, with reference to Figures 20 to 24, the operation of the pump dispenser 1B when the nozzle 19 is released from its lowest position will be described. As shown in Figure 20, when the nozzle 19 is released from its lowest position, the liquid piston 175, the air piston 173, the mixing holder 23, and the nozzle 19 are pushed up by the elastic force of the elastic member 117. At this time, as the air piston 173 and the liquid piston 175 are pushed up, the first valve 225 of the cylindrical valve element 15 is seated on the annular first step 189, and the second valve 227 is seated on the annular protrusion 181 (see Figure 20(b)). This blocks the mixing chamber 197 from the liquid flow path 89, and also blocks the mixing chamber 197 from the air flow path 199, preventing bubbles remaining downstream from flowing back into the liquid flow path 89 and the air flow path 199. The annular portion 113 of the valve portion 85 of the rod-shaped valve element 17 remains seated on the valve seat portion 45 of the liquid cylinder 163. Furthermore, the annular outer valve portion 205 and the annular inner valve portion 207 of the intake valve 177 are in a closed state.

[0052] 21 and 22, when the elastic force of the elastic member 117 further pushes the liquid piston 175, the air piston 173, the mixing holder 23, and the nozzle 19 up relative to the cylinder body 11, the volumes of the liquid chamber 51 and the air chamber 169 increase, and the liquid chamber 51 and the air chamber 169 become negative pressure. Furthermore, the cylindrical valve element 15 rises together with the liquid piston 175 and the air piston 173, because the first valve 225 is seated on the annular first step 189 and the second valve 227 is seated on the annular protrusion 181. Furthermore, as the piston body 13 rises, the rod-shaped valve element 17 rises due to the frictional resistance of the engaging portion 87 of the rod-shaped valve element 17 against the inner wall surface of the cylindrical main body 81 of the cylindrical valve element 15, causing the annular portion 113 of the valve portion 103 of the rod-shaped valve element 17 to be unseated from the valve seat 45 of the liquid cylinder 163 (see FIG. 22(b)), and the multiple receiving portions 115 of the valve portion 103 of the rod-shaped valve element 17 to abut against the lower end of the elastic member 117, thereby restricting the rise of the rod-shaped valve element 17. As a result, the liquid chamber 51 and the container 3 are communicated, and the liquid content in the container 3 is sucked up into the liquid chamber 51 via the suction tube 49, filling the liquid chamber 51 with the liquid content. Furthermore, the negative pressure state in the air chamber 169 opens the annular outer valve portion 205 of the intake valve 177 (see FIG. 22( a)), and the air chamber 169 and the outside air flow passage 149 are connected via the intake hole 187. This allows outside air in the upper space 201 to flow into the air chamber 169. Here, the liquid content in the container 3 is sucked up into the liquid chamber 51, creating a negative pressure state inside the container 3. However, in this state, the outside air flow passage hole 39 in the large diameter portion 31 of the air cylinder 161 is not closed by the seal portion 65 of the air piston 173, so outside air in the upper space 201 flows into the container 3 via the outside air flow passage hole 39, and the negative pressure state in the container 3 is resolved.

[0053] 23, when the liquid piston 175, the air piston 173, the nozzle 19, and the mixing holder 23 are pushed up further from the position shown in Fig. 21 by the elastic force of the elastic member 117, the cylindrical valve element 15 slides upward along the axial direction of the rod-shaped valve element 17. At this time, the inward protruding portion 193 of the piston element 13 comes into contact with the lower part of the outer convex portion 111 of the rod-shaped valve element 17 (see Fig. 23(b)).

[0054] 24, when the liquid piston 175, the air piston 173, the nozzle 19, and the mixing holder 23 are pushed up further from the position shown in FIG. 23 by the elastic force of the elastic member 117, the inward protrusion 193 of the piston body 13 tries to ride over the arcuate surface of the outer convex portion 111 of the rod-shaped valve element 17 (see FIG. 24(b)). Then, when the inward protrusion 193 completely rides over the outer convex portion 111, the annular engaging portion 69 of the cylindrical valve element 15 engages (contacts) with the upper part of the engaging portion 87 of the rod-shaped valve element 17. As a result, the nozzle 19, the mixing holder 23, the air piston 173, the liquid piston 175, and the cylindrical valve element 15 reach their upper limit positions relative to the rod-shaped valve element 17 (see FIG. 13). At this time, the insertion amount of the rod-shaped valve element 17 into the cylindrical main body 81 of the cylindrical valve element 15 is minimized, and the internal space volume of the cylindrical main body 81 is maximized. As a result, the foam remaining in the outlet 121, including the outlet passage 123 of the nozzle 19 downstream of the cylindrical valve body 15, and the foam passage 221c of the net holder 25 is drawn toward the cylindrical main body 81 by the amount of the increased spatial volume (the so-called back suction function).

[0055] In the pump dispenser 1B according to another embodiment of the present invention, when the nozzle 19 is at the upper limit, the first valve 225 of the cylindrical valve element 15 is seated on the annular first step 189 of the liquid piston 175, blocking the discharge port 121 of the nozzle 19 and the liquid flow path 89. When the nozzle 19 is pressed down, the inward protrusion 193 of the liquid piston 175 is engaged (contacted) with the outer protrusion 111 of the rib 107, so that the rod-shaped valve element 17 is also pressed down, and the valve portion 103 of the rod-shaped valve element 17 is seated on the valve seat 45 of the liquid cylinder 163, blocking communication between the liquid chamber 51 and the liquid suction tube 49. As a result, the liquid contained in the liquid chamber 51 is prevented from flowing back into the container 3 via the liquid suction tube 49, and the discharge amount of the liquid contained can be stabilized and a predetermined amount can be discharged to the outside.

[0056] Furthermore, according to the pump dispenser 1B, when the nozzle 19 is released from being pressed down, the liquid piston 175 is pushed up, increasing the volume of the liquid chamber 51 and placing the liquid chamber 51 in a negative pressure state. Furthermore, the rod-shaped valve element 17 is also pushed up together with the cylindrical valve element 15, causing the valve portion 103 of the rod-shaped valve element 17 to be unseated from the valve seat portion 45 of the liquid cylinder 163. As a result, the liquid chamber 51 and the container 3 are connected to each other, and the liquid content within the container 3 can be sufficiently sucked up into the liquid chamber 51 via the suction tube 49. Furthermore, since the first valve 225 of the cylindrical valve element 15 remains seated on the annular first step portion 189 and the second valve 227 remains seated on the annular protrusion 181 until the nozzle 19 reaches its upper limit position, the liquid chamber 51 can be kept sealed.

[0057] Furthermore, according to the pump dispenser 1B, the valve portion 103 of the rod-shaped valve body 17 is configured so that after it seats on the valve seat portion 45 of the liquid cylinder 163, the engagement (contact) between the inward protrusion 193 of the liquid piston 175 and the outer convex portion 111 of the rod-shaped valve body 17 is released as the piston body 13 descends, so that the nozzle 19 (piston body 13) can be subsequently pressed down smoothly with less force.

[0058] According to the pump dispenser 1B, when the nozzle 19 is pushed up from the lower limit position to the upper limit position, the insertion amount of the rod-shaped valve element 17 into the cylindrical valve element 15 decreases, increasing the volume of the space in the cylindrical main body 81 of the cylindrical valve element 15 and generating a negative pressure in the internal space 95, whereby foam remaining in the discharge port 121 including the discharge passage 123 of the nozzle 19 is pulled back into the internal space 95 of the cylindrical valve element 15 via the net holder 25 (backsuction phenomenon). Furthermore, even if the foam remaining near the discharge port 121 of the nozzle 19 turns into liquid over time, the amount is small, so dripping of liquid from the discharge port 121 can be prevented.

[0059] According to the pump dispenser 1B, the cylindrical valve body 15 and the rod-shaped valve body 17 are arranged in a straight line in the internal space of the liquid piston 175, so that the installation area of ​​the mixing chamber 197 and the net holder 25 arranged downstream of the cylindrical valve body 15 is not encroached upon, and therefore the structure of the pump dispenser 1B is prevented from becoming complicated and costs can be reduced.

[0060] In the pump dispenser 1A according to one embodiment of the present invention and the pump dispenser 1B according to another embodiment, the inner convex portion 75 of the piston body 13 and the inward protruding portion 193 of the liquid piston 175 are configured to ride over the arcuate surfaces of the outer convex portions 111 of the ribs 107 of the rod-shaped valve body 17 during the ascending and descending movements of the piston body 13. However, for example, as shown in FIG. 25( a), the inner convex portion 75 of the piston body 13 may come into contact with the surface of the outer convex portions 111 of the ribs 107 of the rod-shaped valve body 17 and slide without resistance. Alternatively, as shown in FIG. 25( b), the inner convex portion 75 of the piston body 13 may be configured to be provided with irregularities 233 on the surface of the outer convex portions 111 of the ribs 107.

[0061] In pump dispenser 1A and pump dispenser 1B, ribs 107 are provided on rod-shaped valve body 17, but ribs 107 are not necessarily required to be provided and may be omitted to the extent that there is no problem with the strength of shaft portion 101 and the centering of elastic member 117. In this case, outer convex portion 111 is formed so as to protrude radially outward from shaft portion 101 of rod-shaped valve body 17.

[0062] In the pump dispenser 1A and the pump dispenser 1B, the piston body 11 is formed with an annular engaging portion 69, but the engaging portion 69 may be formed at predetermined intervals (intermittently) in the circumferential direction. Furthermore, the rod-shaped valve body 17 is provided with outer convex portions 111 formed at predetermined intervals (intermittently) in the circumferential direction, but the outer convex portions 111 may be annular. In this case, the engaging portion 69 and the outer convex portion 111 may be configured to be annular, or the outer convex portion 111 may be configured to be annular, and the engaging portion 69 may be formed at predetermined intervals in the circumferential direction.

[0063] 1A, 1B... Pump dispenser, 3... Container, 5... Mouth portion, 11... Cylinder body, 13... Piston body, 15... Cylindrical valve body, 17... Rod-shaped valve body, 19... Nozzle, 69... Annular engaging portion (engaging portion), 85... Valve portion (valve portion of cylindrical valve body), 101... Shaft portion, 103... Valve portion (valve portion of rod-shaped valve body), 107... Rib, 111... Outer convex portion (engaging convex portion), 117... Elastic member

Claims

1. A pump dispenser that is attached to the mouth of a container and discharges contents from a nozzle outlet, comprising: a cylindrical cylinder body that communicates with the container; a cylindrical piston body that is slidably arranged within the cylinder body; a nozzle that is connected to the piston body and has a discharge flow path therein; a cylindrical valve body that is inserted from the upper end side of the cylindrical piston body and is open in the vertical direction and has a valve portion for opening and closing a flow path from within the piston body to the downstream side; a rod-shaped valve body that has its upper end slidably inserted from below into the cylindrical valve body and has at its lower end a valve portion that is capable of seating on and releasable from a valve seat portion that opens and closes an inlet for contents that is arranged at the bottom of the cylinder body; and an elastic member that directly or indirectly urges the piston body upward against the rod-shaped valve body, wherein the piston body has an engaging portion that is elastically deformable formed on its inner peripheral surface, and the rod-shaped valve body has an engaging protrusion that engages with the engaging portion of the piston body formed on the outer periphery of its shaft.

2. A pump dispenser as described in claim 1, characterized in that the rod-shaped valve body has a plurality of ribs formed at predetermined intervals in the circumferential direction of the shaft portion, and the plurality of ribs have engaging protrusions formed on their upper portions that engage with the engaging portion of the piston body.

3. The pump dispenser described in claim 1, characterized in that the cylinder body is a cylindrical liquid cylinder communicating with the container, and includes a large diameter portion, an annular flange portion connected to the upper end of the large diameter portion and extending radially outward, a bottom wall portion connected to the lower end of the large diameter portion and extending radially inward, and a small diameter portion extending upstream from the bottom wall portion, the piston body includes a small diameter cylindrical portion, a large diameter cylindrical portion formed integrally with the lower part of the small diameter cylindrical portion, and a seal portion provided on the outer peripheral surface of the large diameter cylindrical portion, and the engagement portion is formed on the inner peripheral surface of the connecting portion between the small diameter cylindrical portion and the large diameter cylindrical portion so as to hang down radially inward.

4. The pump dispenser according to claim 1, characterized in that the cylinder body includes a cylindrical liquid cylinder communicating with the container and a cylindrical air cylinder formed integrally with the liquid cylinder, the piston body includes a cylindrical liquid piston arranged to be slidable within the liquid cylinder, and a cylindrical air piston engaged with the upper outer periphery of the cylindrical liquid piston and arranged to be slidable within the air cylinder, and the engaging portion is formed to protrude radially inward from the inner periphery of the cylindrical liquid piston.

Images