JP7709863B2 - Pump-type discharge device - Google Patents

Description

This invention relates to a discharge device that is attached to a container and discharges its contents, and more specifically, to a pump-type discharge device that is configured to suck the contents from the container and pressurize and discharge the contents by the up and down movement of a piston linked to a nozzle part.

This type of device can improve the convenience of the container or the product contained in the container, by allowing the contents to be dispensed without opening, lifting, or tilting the container, and by allowing the dispenser to dispense a fixed amount for normal use. This type of device is sometimes used for containers containing detergents, which are viscous or foamy fluids such as shampoo, hand soap, and body soap, and one example is described in Patent Document 1.

To give an overview of the configuration, the device described in Patent Document 1 has an air cylinder attached to the mouth of the bottle, and a liquid cylinder is integrally formed on the radially inner side of the air cylinder and on a concentric circle. The air piston, which slides against the inner surface of the air cylinder, and the liquid piston, which slides against the inner surface of the liquid cylinder, are arranged on a concentric circle and are integrated. A flow path is formed through the liquid piston on the central side, and the flow path is connected to the liquid chamber and the nozzle, which are partitioned by the liquid cylinder and the liquid piston. In addition, an opening/closing valve is provided in the flow path, which opens when the liquid piston moves toward the bottle to connect the nozzle and the liquid chamber, and closes when the liquid piston moves to the opposite side to block communication between the nozzle and the liquid chamber. The opening/closing valve has a shaft-shaped member extending in the axial direction, and the shaft-shaped member is disposed in the above-mentioned flow path. A valve body portion is formed at one end (upper end) of the shaft-shaped member opposite the bottle, and the outer diameter of the valve body gradually increases toward the opposite side (upper side) of the bottle. In contrast, a funnel-shaped valve seat that fits tightly to the valve body is formed at one end (upper end) of the liquid cylinder opposite the bottle. In addition, a spring is provided to push up the liquid piston and return it to its original position.

Therefore, when the liquid piston is released from being pressed down via the nozzle, the spring pushes up the liquid piston, causing the valve seat and valve body to come into close contact with each other, closing the on-off valve and holding the liquid piston at its upper limit position. In this way, the shaft-shaped member functions to bring the valve seat of the liquid piston, pushed up by the spring, into close contact with the valve body to close the on-off valve and to restrict the rise of the liquid piston, so it need only be configured not to move upward. In contrast, after the liquid piston is pushed down, the shaft-shaped member needs to move down in the process of the liquid piston being pressed down to approximately the lower limit position, because its valve part needs to come into contact with the hole and close the hole as it rises.

Patent No. 5435794

When no downward force is applied to the nozzle portion, the liquid piston is constantly under upward pressure from the spring, so the valve seat portion of the liquid piston and the valve body portion at the upper end of the shaft-shaped member are in close contact with each other. These liquid pistons, shaft-shaped members, or the valve seat portion and the valve body portion are usually made of synthetic resins such as thermoplastic resins for ease of manufacture, and therefore, if the valve seat portion and the valve body portion are in contact with each other for a certain period of time while under load, they will become stuck together. In particular, when the valve seat portion and the valve body portion are in an unused state and no contents such as cleaning agent have yet adhered to their contact surface, and the valve seat portion and the valve body portion are prone to softening due to the high temperature of the storage location, the valve seat portion and the valve body portion are prone to becoming stuck together, combined with the tapered shape of the valve seat portion and the valve body portion.

When the nozzle part is pressed down in this so-called stuck state, not only is the liquid piston pressed down, but the shaft-shaped member also descends with the liquid piston. That is, as mentioned above, the shaft-shaped member is restricted from moving upwards, but is able to move downwards, and when it is used for the first time (pressed down) without having been used before, there is no content such as a cleaning agent inside the liquid piston, only compressible air. Therefore, even if the internal volume of the liquid cylinder decreases and the internal pressure rises due to the descent of the liquid piston, this pressure is not high enough to prevent the descent of the shaft-shaped member and to peel the valve body part from the valve seat, so the shaft-shaped member remains stuck to the liquid piston and descends with the liquid piston.

When the nozzle part is pressed down in this way and then the downward force is released, the liquid piston is pushed up by the elastic force of the spring. As a result, the internal volume of the liquid cylinder into which the liquid piston is inserted increases. In this case, although the compressed air expands as the liquid piston descends, the internal pressure of the liquid cylinder does not become negative, so the contents cannot be sucked into the liquid cylinder.

As such, when starting to use the device, even if the nozzle is pressed down once or several times, it may result in a situation where the contents cannot be dispensed due to a so-called blank shot. However, in the past, the basic structure described above was maintained due to requirements from the standpoint of manufacturability, cost, etc., and there was room for the development of an effective means to eliminate the above-mentioned inconveniences when starting to use the device.

This invention was made with a focus on the above technical problems, and aims to provide a highly convenient pump-type discharge device that can immediately discharge the contents when used for the first time after being stored at high temperature in an unused state, thereby preventing so-called "empty discharge."

In order to achieve the above object, the present invention provides a pump-type discharge device that includes a cap attached to the upper opening of a container body that contains the contents, a nozzle portion that is held by the cap so as to be movable up and down and has a discharge port for discharging the contents, a piston that moves up and down together with the nozzle portion, a cylinder into which the piston fits closely, and in which the internal volume increases as the piston rises relatively to suck in the contents and the internal volume decreases as the piston moves relatively down to push out the contents, an axial valve body that is inserted into a hole that penetrates the piston in the vertical direction and is prevented from falling out in the upward direction, and a valve portion that is provided at the upper end of the axial valve body, fits closely into the hole to close the hole and determine the upper limit position of the piston, and opens the hole as the piston moves relatively down. The pump-type discharge device is characterized by having a descent prevention portion that engages with the axial valve body when the axial valve body descends together with the piston before the piston reaches a predetermined lower limit position to prevent the descent of the axial valve body.

In this invention, the descent prevention portion may be an abutment portion provided inside the cylinder against which the lower end portion of the axial valve body abuts.

In addition, in this invention, a suction port is formed at the lower end of the cylinder to absorb the contents by increasing the internal volume of the cylinder, and a ball-shaped valve body that closes the suction port from inside the cylinder is provided inside the cylinder so as to be movable up and down, and the abutment portion may be constituted by the ball-shaped valve body.

In this invention, a holder member is provided inside the cylinder, into which the lower portion of the axial valve body is inserted and which engages the axial valve body in the upward direction to prevent it from coming off in the upward direction, and the descent prevention portion may be formed by a radial protrusion provided on the axial valve body so as to abut against the upper end of the holder member from above.

In this invention, when the nozzle part is pushed down with the cap attached to the container body, the piston descends inside the cylinder together with the nozzle part, and the internal volume of the cylinder decreases. As a result, the internal pressure of the cylinder increases, and a force acts on the axial valve body in a direction that restricts the movement toward the inside of the cylinder, i.e., the descent, causing the piston to descend relative to the axial valve body. If an intake port is provided at the lower end of the cylinder and a ball-shaped valve body is placed on the intake port, the ball-shaped valve body is pressed against the intake port to close the intake port.

When the nozzle part is released from being pressed down and the piston rises together with the nozzle part, the internal volume of the cylinder increases and the internal pressure decreases, causing a suction action into the cylinder. If the above-mentioned ball-shaped valve body is provided, the ball-shaped valve body opens and the suction port opens, and the contents are sucked into the cylinder from inside the container body. When the nozzle part is then pressed down again, as described above, the piston descends relative to the axial valve body, and the valve part formed at the upper end of the axial valve body moves away from the hole part formed at the upper end of the piston, opening the hole part, and as a result, the contents sucked into the cylinder are pushed out through the hole part into the nozzle part and discharged from the discharge port.

On the other hand, for example, when the nozzle part is pressed down for the first time in an unused state, if the valve part is fixed to the hole part, the axial valve body may fall together with the piston's descent caused by pressing down the nozzle part. In that case, when the axial valve body descends a certain dimension determined by design, it engages with the descent prevention part and its descent is restricted. When the piston further descends, the valve part and the hole part are released from the fixation, and the hole part opens. Therefore, the pressure inside the cylinder becomes the same as the pressure of the environment. Then, since the valve part comes into contact with the hole part and closes the hole part in the process of the piston rising, a suction action occurs inside the cylinder due to the decrease in the internal pressure of the cylinder caused by the piston rising. In a configuration with a ball-shaped valve body, as described above, the suction port opens and the contents are sucked into the inside of the cylinder, and then the nozzle part is pressed down to discharge the contents from the nozzle part. In this way, after the nozzle part is pressed down once, the contents can be reliably discharged, and the convenience of the discharge device or the discharge container to which it is attached can be improved by suppressing so-called blank shots.

1 is a cross-sectional view showing an example of a pump-type discharge device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the state in which the axial valve body is descending together with the liquid piston. 11 is a cross-sectional view showing a state in which the axial valve body is prevented from descending by a descending prevention portion and is pushed up relative to the liquid piston. FIG. 11 is a cross-sectional view showing a state in which the liquid piston has descended to a lower limit position without accompanying the axial valve body and discharged the contents. FIG. 13 is a partial cross-sectional view showing a schematic example of a downward movement prevention portion formed by a locking body and a protrusion provided on an axial valve body. FIG.

Figure 1 shows a cross-sectional view of a pump-type discharge device according to one embodiment of the present invention. The pump-type discharge device shown here is a so-called pump former 1, which is configured to mix the liquid contents filled inside a bottle 2, which corresponds to the container body in this invention, with air to form foam and discharge the foam. The pump former 1 has a cap 4 that is removably attached to the mouth 3 of the bottle 2, and is attached to the bottle 2 by the cap 4. Specifically, the mouth 3 is a cylindrical opening formed on the upper end side of the body of the bottle 2, and a male thread is formed on its outer periphery. In addition, a female thread that fits into the male thread is formed on the inner periphery of the cap 4. In other words, the pump former 1 is attached to the bottle 2 by screwing the mouth 3 into the cap 4.

As shown in FIG. 1, the cap 4 has an outer cylindrical portion 5 that covers the outside of the mouth portion 3 and has the above-mentioned female thread formed on its inner circumference, and an inner cylindrical portion 6 with a short axial length that is inserted into the inside of the mouth portion 3. Therefore, the outer cylindrical portion 5 is tubular and larger than the outer diameter of the mouth portion 3, and the outer cylindrical portion 5 and the inner cylindrical portion 6 are formed integrally by extending downward from the upper surface portion 7 of the cap 4 so as to be positioned on a concentric circle. Furthermore, the center of the upper surface portion 7 is open, and a guide stem portion 8 is provided to surround the opening. The guide stem portion 8 is a cylindrical portion that extends upward from the upper surface portion 7 and is an integral portion of the upper surface portion 7. The nozzle portion 9 is held so that it can move up and down by this guide stem portion 8.

The nozzle portion 9 is a portion for performing a pressing operation to eject the contents of the bottle 2, and has a top surface portion 10 to which a pressing force is applied as a so-called nozzle head, a nozzle opening 11 corresponding to an ejection port for ejecting foam, a cylindrical inner tube portion 12 in which a flow path P communicating with the nozzle opening 11 is formed, and a cylindrical outer tube portion 13 which is larger in diameter than the inner tube portion 12 and is formed concentrically with the inner tube portion 12. The nozzle opening 11 can be shaped appropriately according to design requirements, and in the example shown in FIG. 1, it is shaped to extend radially outward from the above-mentioned flow path P.

Each of the cylinders 12 and 13 extends downward in the axial direction from the top surface 10 of the nozzle 9 in FIG. 1, and the axial length of the inner cylinder 12 is set longer than that of the outer cylinder 13. The outer diameter of the inner cylinder 12 is set slightly smaller than the inner diameter of the guide stem 8, so that it can be inserted into the guide stem 8. The inner diameter of the outer cylinder 13 is set slightly larger than the outer diameter of the guide stem 8, so that the guide stem 8 can be inserted inside it. In other words, by inserting the guide stem 8 between the inner cylinder 12 and the outer cylinder 13 in the radial direction, the nozzle 9 is guided by the guide stem 8 and each of the cylinders 12 and 13 to move in the axial direction. Small gaps are formed between the outer peripheral surface of the inner cylinder 12 and the inner peripheral surface of the guide stem 8, and between the outer peripheral surface of the guide stem 8 and the inner peripheral surface of the outer cylinder 13, and these gaps serve as air passages. Air is introduced into the air cylinder, which will be described later, through these air flow paths.

In the example shown in FIG. 1, a net holder 14 that forms a homogeneous foam is disposed on the inner peripheral surface of the inner tube 12. This net holder 14 is a cylindrical member, and a net (not shown) is attached to each of both ends in the axial direction. The inner diameter of the inner tube 12 into which the net holder 14 is inserted is narrower above the position where the net holder 14 is disposed, and the net holder 14 is held in a state where it abuts against the step where the inner diameter changes from large to small. Then, as described below, the contents that have been whipped by mixing with air pass through the net holder 14, forming a fine, homogeneous foam.

A cylinder member 15 is held inside the cap 4. As shown in FIG. 1, the cylinder member 15 is tightly fitted to the outer periphery of the inner cylindrical portion 6 and is integrated with the cap 4, and the lower part of the cylinder member 15 has a slightly smaller diameter than the fitting part that fits into the inner cylindrical portion 6. In addition, a flange 16 that extends outward in the radial direction is formed at the upper end of the cylinder member 15. The outer diameter of the flange 16 is approximately the outer diameter of the tip of the mouth portion 3 (the outer diameter of the opening of the mouth portion 3) or slightly larger. A sealant 17 is sandwiched between the tip of the mouth portion 3 (opening end) and the lower surface of the flange 16 (the lower surface of the flange 16 in FIG. 1) to ensure airtightness and liquid tightness. The flange 16 and the sealant 17 are sandwiched between the upper surface portion 7 of the cap 4 and the tip of the mouth portion 3 by attaching the cap 4 to the mouth portion 3 with a screw, and seal the mouth portion 3.

To further explain the configuration of the cylinder member 15, the cylinder member 15 shown here is integrally formed with an air cylinder 18, which is part of the air pump that pushes air to the nozzle portion 9, and a liquid cylinder 19, which is part of the liquid pump that pushes the contents to the nozzle portion 9. The air cylinder 18 is a large-diameter portion of the cylinder member 15 that is formed below the above-mentioned fitting portion in the axial direction, and a first air intake hole 20 for taking air into the inside of the bottle 2 is formed in a part of the upper end side of the peripheral wall portion that constitutes the air cylinder 18, penetrating the air cylinder 18 in the plate thickness direction.

On the other hand, the liquid cylinder 19 is a cylindrical part with a smaller diameter than the air cylinder 18, and is formed concentrically with the air cylinder 18. In the example shown in FIG. 1, the liquid cylinder 19 is a cylindrical shape in which the bottom of the air cylinder 18 is folded upward and the central part is further folded downward. In other words, the liquid cylinder 19 and the air cylinder 18 are formed concentrically and slightly offset in the axial direction, and at least a part of them overlap each other in the radial direction. In the example shown here, the liquid cylinder 19 is formed continuously with the air cylinder 18. As shown in FIG. 1, the boundary part between the cylinders 18, 19 is a convex curved part formed by curving the bottom of the air cylinder 18 so that it protrudes upward in FIG. 1, and the flange of the liquid piston described later comes into contact with the boundary part, thereby preventing further movement (pushing) of the nozzle part 9 and each piston. This position is the stroke end, i.e., the lower limit position, of the nozzle part 9 and each piston when each piston is pushed toward the bottle 2. The example shown in Figure 1 shows the nozzle unit 9 in the upper limit position.

An air piston 21 is fitted inside the air cylinder 18, sliding in the axial direction (up and down direction in FIG. 1) while maintaining an airtight state on its inner circumferential surface. The air cylinder 18 and the air piston 21 constitute an air pump. The air piston 21 has a piston head 22 that divides the inside of the air cylinder 18 into upper and lower parts in FIG. 1, and a sliding part 23 that is integrated with the piston head 22 and contacts the inner circumferential surface of the air cylinder 18. Of the two interiors divided by the piston head 22, the interior below the piston head 22 in FIG. 1 is the air chamber 24. In the example shown in FIG. 1, the sliding part 23 is formed in a cylindrical shape, and is in slidable contact with the inner circumferential surface of the air cylinder 18 at two points, the upper and lower parts, while maintaining airtightness. The sliding part 23 reciprocates in the axial direction to open and close the first air intake hole 20 mentioned above.

At a predetermined radial position in the piston head 22, a second intake hole 25 for introducing air into the air chamber 24 is formed penetrating the piston head 22 in the plate thickness direction. In addition, a check valve 26 is provided at a portion of the piston head 22 radially inward of the second intake hole 25, which connects the air chamber 24 to the outside of the bottle 2 according to the internal pressure of the air chamber 24, and also connects the air chamber 24 to a mixing chamber, which will be described later.

The check valve 26 is a component that has a membrane-like (diaphragm-like) valve body that protrudes inward and outward in the radial direction at the lower end of a cylindrical portion that is formed on the piston head 22 and extends upward in FIG. 1. The portion that extends outward in the radial direction is the outer valve portion, and the portion that extends inward in the radial direction is the inner valve portion.

The outer valve portion covers the second air intake hole 25 from the inside of the air chamber 24 so that it closes the second air intake hole 25 when the internal pressure of the air chamber 24 becomes greater than the pressure outside the bottle 2, and opens the second air intake hole 25 when the internal pressure of the air chamber 24 becomes less than the pressure outside the bottle 2. In other words, the outer valve portion constitutes an air intake valve 27 that introduces and blocks outside air into the air chamber 24.

The inner valve portion is configured to communicate between the air chamber 24 and the mixing chamber when the internal pressure of the air chamber 24 is higher than the pressure outside the bottle 2, and to block communication between the air chamber 24 and the mixing chamber when the internal pressure of the air chamber 24 is lower than the pressure outside the bottle 2. That is, the inner valve portion is in contact with the flange of the liquid piston, which will be described later, and is configured to open and close depending on the pressure difference between the air chamber 24 and the mixing chamber. In this way, the inner valve portion constitutes an air exhaust valve 28 that supplies and pushes out air from the air chamber 24 to the mixing chamber.

In addition, a cylindrical portion 29 extending upward in FIG. 1 is integrally formed in the center of the piston head 22 in the radial direction. The upper end portion of the cylindrical portion 29 in FIG. 1 is tightly fitted inside the lower portion of the inner cylinder portion 12 formed in the nozzle portion 9 described above, and is integrated with the nozzle portion 9. The lower end portion of the net holder 14 described above is inserted inside the upper end portion of the cylindrical portion 29. In the example shown in FIG. 1, a convex rib portion is formed on the outer peripheral surface of one end of the cylindrical portion 29, and a concave groove portion that fits into the convex rib portion is formed on the inner peripheral surface of the inner cylinder portion 12. The cylindrical portion 29 and the inner cylinder portion 12 are firmly connected by the fit between the convex rib portion and the concave groove portion. The cylindrical portion 29 and the inner cylinder portion 12 may be connected by means of a screw fit or a snug fit.

The inner diameter of the upper end of the cylindrical portion 29 is slightly larger than the outer diameter of the lower end of the net holder 14. In addition, one or more protrusions 30 protruding inward in the radial direction are formed on the inner peripheral surface of the lower side of the part of the larger inner diameter of one end of the cylindrical portion 29. The protrusions 30 abut the lower end of the net holder 14 to hold the net holder 14, and when the nozzle portion 9 is pressed down, they contact one end of the axial valve body described later to push and move the axial valve body. Furthermore, the inner diameter of the protrusions 30 is set to about the inner diameter of the net holder 14 so as not to particularly hinder the flow of the contents in the flow path P. Then, as shown in FIG. 1, when the nozzle portion 9 is in the upper limit position, a clearance C is set between the upper end of the valve body portion of the axial valve body described later and the side of the protrusions 30 that contact the upper end. The lower end of the net holder 14 is adapted to fit into a fitting portion formed by the part with the larger inner diameter and the protrusion 30 at one end of the cylindrical portion 29 described above. In this way, the air piston 21 and the nozzle portion 9 are integrated, and the net holder 14 is held in the flow path P between them. Therefore, when the top surface portion 10 of the nozzle portion 9 is pressed toward the bottle 2 to push down the nozzle portion 9, the air piston 21 moves (descends) together with the nozzle portion 9 toward the bottle 2, and the internal volume of the air chamber 24 partitioned by the air cylinder 18 and the air piston 21 decreases. Then, the inside of the air chamber 24 is pressurized, and the air inside the air chamber 24 is pushed out of the air chamber 24. In addition, when the air piston 21 is pushed down toward the bottle 2 by the above-mentioned clearance C, the protrusion 30 comes into contact with the upper end of the valve portion of the axial valve body and pushes the axial valve body down toward the bottle 2.

The liquid piston 31 of the liquid pump is fitted to the lower end of the cylindrical portion 29 in FIG. 1. As shown in FIG. 1, the liquid piston 31 is formed in a cylindrical shape extending in the axial direction, and one end (the upper end in FIG. 1) of the liquid piston 31 is fitted to the other end of the cylindrical portion 29. Specifically, a recess is formed in the other end of the cylindrical portion 29, recessed in the axial direction into which one end of the liquid piston 31 fits. The inner diameter of the recess is set to an inner diameter such that one end of the liquid piston 31 fits. In addition, an air flow path (not shown) is formed between the recess and one end of the liquid piston 31. The space between the fitting portion between the other end of the cylindrical portion 29 in the axial direction and the liquid piston 31 and the net holder 14 fitted inside the cylindrical portion 29 is the mixing chamber 32 in which the air and the liquid contents are mixed. One end of the air flow path described above is connected to the flow path P in the cylindrical portion 29 described above, and the other end is connected to the space partitioned by the liquid piston 31 and the air piston 21.

A flange 33 that protrudes outward in the radial direction is formed on the outer peripheral surface of the liquid piston 31. As described above, the flange 33 is a portion that defines the lower limit positions of the air piston 21 and the liquid piston 31. Also, as shown in FIG. 1, when the nozzle portion 9 is at the upper limit position, the air exhaust valve 28 is in contact with the upper surface of the flange 33. The other end of the liquid piston 31 is fitted into the inner peripheral surface of the liquid cylinder 19 so as to slide in the axial direction (up and down direction in FIG. 1) while maintaining a liquid-tight state. Therefore, the liquid pump described above is constituted by the liquid cylinder 19 and the liquid piston 31, and the cylindrical space formed by the liquid cylinder 19 and the liquid piston 31 is the liquid chamber 34. As described above, when the top surface portion 10 of the nozzle portion 9 is pressed toward the bottle 2 side to press down the nozzle portion 9, the liquid piston 31 moves toward the bottle 2 together with the air piston 21, and the internal volume of the liquid chamber 34 described above decreases. Then, the inside of the liquid chamber 34 is pressurized, and the liquid inside the liquid chamber 34 is pushed out of the liquid chamber 34.

Inside the liquid chamber 34, there is a return mechanism that returns the nozzle portion 9 and each piston to their original position when the force pushing the nozzle portion 9 and each piston toward the bottle 2 side is released, and a valve mechanism that connects the liquid chamber 34 to the inside of the bottle 2 in response to pumping of the nozzle portion 9 and also connects the liquid chamber 34 to the mixing chamber 32 and the flow path P. First, the return mechanism is described. In the embodiment shown here, the return mechanism is configured to return the nozzle portion 9 and each piston 21, 31 by the elastic force of a coil spring (hereinafter simply referred to as a spring) 35. A spring receiving portion is formed on the other end of the liquid piston 31 described above, into which one end of the spring 35 is fitted. The spring 35 is arranged in a compressed state below the spring receiving portion. Therefore, an elastic force that pushes the liquid piston 31 upward toward the opposite side to the bottle 2 side (upper side in FIG. 1) is constantly acting on the liquid piston 31.

The valve mechanism is an on-off valve that opens when the contents are pushed out of the liquid chamber 34 and closes when the contents are sucked up from inside the bottle 2 into the liquid chamber 34, and is provided at the upper end of the liquid piston 31. More specifically, an axial valve body 36 is disposed along the central axis of the liquid cylinder 19 and the liquid piston 31 that fits into it. The axial valve body 36 is an axial member whose upper end is the valve body portion 37 and whose lower end is formed with a retaining portion that prevents the valve body 36 from coming off in the upward direction, and whose upper end protrudes above the liquid piston 31 through a hole formed in the center of the upper end of the liquid piston 31.

As shown in FIG. 1, the valve body 37 is tapered so that the outer diameter gradually increases toward the upper side. In contrast, the hole is a tapered hole of the same shape (or a similar shape) as the tapered shape of the valve body 37, and the tapered inner peripheral surface serves as the valve seat 38. In other words, the valve mechanism is configured so that the hole is closed when the valve body 37 comes into contact with the valve seat 38, and the hole is opened when the valve body 37 moves away from the valve seat 38.

Regarding the structure for preventing the axial valve body 36 from coming off upward, the lower end of the axial valve body 36 in FIG. 1 is in the shape of a downward arrowhead or a triangular cross section, as shown in FIG. 1. The lower end is inserted into the inside of a cylindrical locking body 40 provided at the bottom of the liquid cylinder 19, contacts the inner circumferential surface of the locking body 40, and slides on the inner circumferential surface of the locking body 40 in that state. That is, the axial valve body 36 and the locking body 40 are in frictional contact, and the frictional force generated between them restricts the relative movement of the two in the axial direction. Furthermore, the upper end of the locking body 40 protrudes slightly toward the inner circumferential side and is so-called hook-shaped, and the lower end of the above-mentioned axial valve body 36 with a triangular cross section is caught on this part, and as a result, the locking body 40 restricts the upward movement of the axial valve body 36, that is, prevents it from coming off. Therefore, the lower end of the shaft-shaped valve body 36 becomes the engagement portion 41 for the locking body 40, and the upper end of the locking body 40 protruding toward the inner circumference becomes the hook portion 42. This locking body 40 corresponds to the holder member in this invention.

The locking body 40 is not completely cylindrical over its entire axial length, but has multiple slits 43 formed in the peripheral wall at the lower end along the axial direction. This is to allow the contents sucked up into the locking body 40 to flow into the liquid cylinder 19. In addition, a flange that protrudes radially outward is formed at the lower end of the locking body 40, and the lower end of the spring 35 that constitutes the return mechanism described above abuts against this flange. In other words, a reaction force that pushes up the liquid piston 31 acts on the locking body 40, and this reaction force fixes the locking body 40 to the lower end side of the liquid cylinder 19.

At the bottom of the liquid cylinder 19, a check valve is provided that opens when the contents are sucked up from the inside of the bottle 2 into the inside of the liquid chamber 34 and closes when the contents are pushed out from the liquid chamber 34. In the example shown in FIG. 1, the check valve is configured by a ball valve 44. That is, at the bottom of the liquid cylinder 19, a funnel-shaped valve seat portion 45 whose inner diameter gradually decreases downward is formed. The opening on the center side of this valve seat portion 45 corresponds to the suction port in this invention, and a ball 46 is arranged so as to contact the tapered surface of the valve seat portion 45 from above. Furthermore, a tube 47 for introducing the contents filled inside the bottle 2 into the inside of the liquid chamber 34 is connected to the bottom of the liquid cylinder 19. The tip of the tube 47 extends to the vicinity of the bottom of the bottle 2 (not shown).

In the example shown in Figure 1, the ball 46 corresponds to the abutment portion and ball-shaped valve body in this invention, and in addition to the function of opening and closing the suction port, it has the function of pushing the aforementioned axial valve body 36 up relative to the liquid piston 31, that is, the function of a descent prevention portion that abuts the lower end of the axial valve body 36 to prevent its descent. It is necessary to prevent the descent of the axial valve body 36 when the axial valve body 36 descends together with the descent of the liquid piston 31. The liquid piston 31 abuts against the upper end of the liquid cylinder 19, i.e., the upper end of the part where the bottom of the air cylinder 18 is folded back upward, and the lower limit position is regulated, and this is the stroke end. If the distance by which the liquid piston 31 descends from the upper limit position shown in Figure 1 to this lower limit position, i.e., the stroke amount, is S31, in order to push up the axial valve body 36, which descends together with the liquid piston 31, relative to the liquid piston 31, it is necessary to abut the axial valve body 36 against the ball 46 before the liquid piston 31 reaches the lower limit position to prevent its descent. Therefore, in the example shown in Figure 1, if the distance (stroke amount) from the upper limit position where the engagement portion 41 of the axial valve body 36 engages with the hook portion 42 of the locking body 40 to the lower limit position (descent prevention position) where it abuts against the ball 46 is S36, the stroke amount S36 of the axial valve body 36 is smaller than the stroke amount S31 of the liquid piston 31 (S36>S31).

In addition, in the normal state where the axial valve body 36 can move up and down independently of the liquid piston 31, when the nozzle portion 9 is pushed down, the upper end of the axial valve body 36 engages with the protrusion 30 provided inside the cylindrical portion 29 and descends together with the nozzle portion 9. If the lower end of the axial valve body 36 descending in this manner abuts against the ball 46, the nozzle portion 9 is prevented from being pressed down, and therefore the descent of the liquid piston 31 is prevented before it reaches its lower limit position. To avoid such a situation, the above-mentioned stroke amounts S31 and S36 are set as follows:
S31-C≦S36
Here, C is the above-mentioned clearance, which is the distance by which the nozzle portion 9 and the liquid piston 31 move downward until the protrusion 30 provided inside the cylindrical portion 29 abuts against the upper end of the shaft-shaped valve body 36.

In the pump former 1 according to the present invention described above, the upward force of the spring 35 is constantly acting on the liquid piston 31. On the other hand, the axial valve body 36 arranged inside the liquid piston 31 is restricted from moving upward by the engagement portion 41 at its lower end being caught by the hook portion 42 of the locking body 40. The valve seat portion 38 formed at the upper end of the liquid piston 31 is pressed against the valve body portion 37 provided at the upper end of the axial valve body 36, so that the liquid piston 31 is ultimately restricted from moving upward by the axial valve body 36 and held at the upper limit position. In this state, the valve body portion 37 and the valve seat portion 38 are tightly attached by the elastic force of the spring 35. In the bottle 2 to which the pump former 1 is attached, i.e., in the storage or preservation state before the start of use of the product, the valve body portion 37 and the valve seat portion 38 are kept in close contact for a long period of time, so that, for example, when the environmental temperature is high, the valve body portion 37 may become stuck to the valve seat portion 38.

The behavior when the valve body portion 37 and the valve seat portion 38 (the axial valve body 36 and the liquid piston 31) are stuck at the start of the pump former 1 will be explained. When the nozzle portion 9 is pushed down, the air piston 21 and the liquid piston 31, which are integrated with the nozzle portion 9 by fitting the cylindrical portion 29 into the inner cylinder portion 12 of the nozzle portion 9, descend. The axial valve body 36, which is stuck to the liquid piston 31, also descends together with the liquid piston 31. Figure 2 shows the state in the middle of the descent, and the opening and closing valve is closed because the valve body portion 37 is stuck to the valve seat portion 38. In addition, the engagement portion 41 at the lower end of the axial valve body 36 is disengaged downward from the hook portion 42 of the locking body 40. Furthermore, the ball 46 remains on the valve seat portion 45 of the suction port, and the suction port is closed. Therefore, when the liquid piston 31 is pushed down, the air in the liquid chamber 34 is compressed and the internal pressure increases. If the adhesive force that secures the valve body 37 to the valve seat 38 is greater than the force that pushes up the shaft-shaped valve body 36 based on this internal pressure, the shaft-shaped valve body 36 will continue to descend while remaining attached to the liquid piston 31.

The stroke amount S31 of the liquid piston 31 to the lower limit position and the stroke amount S36 of the axial valve body 36 until it abuts against the ball 46 are set in the relationship described above, so that the lower end of the axial valve body 36 abuts against the ball 46 (i.e., the descent prevention portion) before the liquid piston 31 descends to the lower limit position. Therefore, when the liquid piston 31 is pushed down to the lower limit position, the axial valve body 36 installed inside it is pushed up relative to the liquid piston 31 because the descent is prevented by the ball 46. This state is shown in Figure 3. As a result, the valve body portion 37 is pulled away from the valve seat portion 38, the on-off valve opens, and air escapes from the liquid cylinder 19.

After that, when the nozzle part 9 is released from the depressed state, the liquid piston 31 and the air piston 21 integrated with it are pushed up by the spring 35. As a result, the internal volume of the liquid piston 31 increases and the internal pressure decreases, so the ball valve 44 opens and the contents are sucked from inside the bottle 2 into the liquid cylinder 19.

In this way, when the nozzle part 9 is pushed down again after moving it up and down once at the start of use, the adhesion between the axial valve body 36 and the liquid piston 31 has already been released, so the liquid piston 31 and the air piston 21 move down, and the axial valve body 36 remains at the upper limit position. That is, the valve mechanism (opening and closing valve) consisting of the valve body part 37 and the valve seat part 38 opens, and the contents are pushed out from the inside of the liquid cylinder 19 into the mixing chamber 32. In addition, the air inside the air chamber 24 is pressurized and supplied to the mixing chamber 32. As a result, the contents and the pressurized air are mixed to form bubbles, which are further refined by passing through the net held by the net holder 14, and then discharged from the nozzle opening 11. The state in which the nozzle part 9 is pushed down to the lower limit in this way is shown in Figure 4.

Therefore, according to the pump former 1, which is the discharge device according to the present invention shown in FIG. 1, when the nozzle part 9 is pressed down at the beginning of use, the contents may not be discharged the first time, but the adhesion between the axial valve body 36 and the liquid piston 31 can be reliably eliminated by one press down, and the contents in the bottle 2 can be reliably sucked into the liquid chamber 34. As a result, the contents can be discharged from the nozzle opening 11 by subsequent press down operations, and the convenience of the product or commodity to which the discharge device or pump former 1 is attached can be improved or improved by avoiding or suppressing the so-called blank shot, which is a useless press down that does not discharge the contents. Note that the operation of the pump former 1 under normal circumstances after the start of use of the pump former 1 is the same as that described in the above-mentioned Patent No. 5435794, and therefore a detailed description thereof will be omitted.

This invention is not limited to the above-mentioned embodiment, and the downward prevention part in this invention is only required to engage with the axial valve body 36 to prevent its downward movement before the liquid piston 31 reaches the lowest position when the axial valve body 36 descends together with the liquid piston 31, and to push the axial valve body 36 up relative to the liquid piston 31. Therefore, the downward prevention part in this invention is not limited to the ball 46 or ball valve 44 described above. As another example of the downward prevention part, FIG. 5 shows an example in which the protrusion 36A formed on the axial valve body 36 so as to abut against the locking body 40 and its upper end is used as the downward prevention part. To be more specific, a protrusion 36A protruding outward in the radial direction is formed at a predetermined position in the vertical direction of the axial valve body 36. The protrusion 36A may be the lower end of the portion where the axial valve body 36 is enlarged in diameter, or may be the lower end of a rib (not shown) formed along the outer circumferential surface of the axial valve body 36 in the axial direction. The radius of this protrusion 36A measured from the center of the axial valve body 36 is greater than the inner diameter of the upper end opening of the cylindrical locking body 40. In other words, the protrusion 36A is shaped to abut against the upper end of the locking body 40 from above. Therefore, in the example shown in Figure 5, the protrusion 36A abutting against the upper end of the locking body 40 corresponds to the abutment portion in this invention.

In the configuration shown in FIG. 5, the distance (dimension) from the protrusion 36A of the axial valve body 36 at the upper limit position to the upper end of the locking body 40 is the stroke amount S36 of the axial valve body 36 described above, so the position of the protrusion 36A is determined so that the relationship between the stroke amount S36, the stroke amount S31 of the liquid piston 31, and the clearance C satisfies the above-mentioned condition. Therefore, even in the case of the configuration shown in FIG. 5, when the axial valve body 36 descends together with the liquid piston 31, the protrusion 36A abuts against the upper end of the locking body 40 before the liquid piston 31 descends to the lower limit position, preventing the descent. As a result, the axial valve body 36 is pushed up relative to the liquid piston 31, and the fixation of the axial valve body 36 to the liquid piston 31 can be released.

Furthermore, this invention is not limited to pump formers, but may be a device that ejects liquids or highly viscous fluids.

REFERENCE SIGNS LIST 1 pump former 2 bottle 4 cap 9 nozzle portion 11 nozzle mouth 15 cylinder member 18 air cylinder 19 liquid cylinder 21 air piston 31 liquid piston 32 mixing chamber 34 liquid chamber 35 spring 36 shaft-shaped valve body 36A projection 37 valve body portion 38 valve seat portion 40 locking body 41 engagement portion 42 hook portion 44 ball valve 45 valve seat portion 46 ball C clearance S31, S36 stroke amount

Claims (4)

a piston that moves up and down together with the nozzle portion; a cylinder into which the piston fits closely, the internal volume of which increases as the piston rises relative to the cylinder and which sucks in the contents and the internal volume of which decreases as the piston moves relatively downward to push out the contents; an axial valve body that is inserted into a hole that penetrates the piston in the vertical direction and is prevented from coming out in the upward direction; and a valve portion that is provided at the upper end of the axial valve body, fits closely into the hole to close the hole and define an upper limit position of the piston, and opens the hole when the piston moves relatively downward.
4. A pump-type discharge device comprising: a descending prevention portion which, when the axial valve body descends together with the piston, engages with the axial valve body before the piston reaches a predetermined lower limit position to prevent the descent of the axial valve body. 2. The pump type discharge device according to claim 1,
The pump-type discharge device according to claim 1, wherein the downward prevention portion is an abutment portion provided inside the cylinder against which the lower end portion of the shaft-shaped valve body abuts. 3. The pump type discharge device according to claim 2,
A suction port is formed at the lower end of the cylinder to absorb the contents by increasing the internal volume of the cylinder;
a ball-shaped valve body that closes the suction port from inside the cylinder is provided inside the cylinder so as to be movable up and down;
The pump-type discharge device according to claim 1, wherein the abutment portion is constituted by the ball-shaped valve body. 2. The pump type discharge device according to claim 1,
a holder member for inserting a lower portion of the axial valve body therein and engaging the axial valve body in an upward direction to prevent it from coming off in an upward direction is provided inside the cylinder;
A pump-type discharge device according to claim 1, wherein the descent prevention portion is constituted by a radial protrusion provided on the shaft-shaped valve body so as to abut against an upper end of the holder member from above.