Pump-type dispenser

Abstract

A pump-type dispenser capable of dispensing liquid contents in the same manner as a conventional dispenser and that additionally has excellent recyclability is proposed.　A pump-type dispenser (100) comprises a pump that is driven by a stem (7a) moving forward and backward, and a head (12) that has a discharge port (12d) and is connected to the stem (7a). One of the head (12) and a cap (10) includes an extension part (12e) that extends toward the other of the head (12) and the cap (10), and the other of the head (12) and the cap (10) includes an elastic piece (10e) that is bent by the extension part (12e) when the head (12) is advanced toward the cap (10). The elastic piece (10e) comprises an elastic piece body (10f) and a reinforcement rib (10g). The reinforcement rib (10g) has a rib root part (10j) and a rib gradual transition part (10k).

Description

Pump-type dispenser

[0001] The present invention relates to a pump-type dispenser.

[0002] A known pump-type dispenser includes a cap that is attached to the mouth of a container, a pump that is held at the mouth by the cap and is driven by the back and forth movement of a stem, and a head that is connected to the stem; the liquid contents in the container are dispensed from the discharge port of the head by moving the head toward the cap (see, for example, Patent Document 1).

[0003] As shown in Patent Document 1, a coil spring is provided inside such a pump-type dispenser to return the head, which has been moved toward the cap, to its initial position.

[0004] JP 2011-31950 A

[0005] However, while most of the components of such pump-type dispensers are made of synthetic resin, the coil spring is made of metal. Therefore, when discarded after use, the pump-type dispenser cannot be recycled as a resin product in its current state. Furthermore, in general, in this type of pump-type dispenser, the components are firmly fixed to each other, for example, by fitting, to prevent them from coming apart during normal use. Therefore, it takes time and effort to disassemble the pump-type dispenser and separate the coil spring from the other components.

[0006] The present invention aims to solve these problems and to propose a pump-type dispenser that can dispense the liquid content in the same way as conventional dispensers and that is also highly recyclable.

[0007] The present invention is a pump-type dispenser comprising: a cap to be attached to the mouth of a container that contains liquid contents; a pump that is held at the mouth by the cap and is driven by the back and forth movement of a stem; and a head that has a discharge port that discharges the liquid contents to the outside and is connected to the stem, and the liquid contents in the container are discharged from the discharge port by moving the head toward the cap, wherein either the head or the cap is provided with an extension portion that extends toward the other of the head or the cap; and the other of the head or the cap is provided with an elastic piece that is deflected by the extension portion when the head is advanced toward the cap, the elastic piece comprising an elastic piece main body and a reinforcing rib that is narrower than the elastic piece main body, and the reinforcing rib has a rib root portion located on the root side of the reinforcing rib, and a rib gradual change portion whose thickness gradually decreases from the rib root portion toward the tip side of the reinforcing rib. In this specification, the gradually changing rib portion where the thickness gradually decreases is not limited to a portion where the thickness changes along a single straight line or curve, but also includes a portion where the thickness changes in stages (step-like).

[0008] When the head is moved to its forward limit, it is preferable that the tip end of the rib base portion be located at the same position in the front-to-back direction as the contact portion with the elastic piece in the extension portion, or on the base side of the reinforcing rib.

[0009] When the length in the front-rear direction from the base end of the reinforcing rib to the tip end of the extension portion when the head is moved to the retreat limit is defined as L, and the length in the front-rear direction from the base end of the reinforcing rib to the tip end of the rib base portion when the elastic piece and the extension portion are not in contact with each other before the head and the cap are combined is defined as L1, it is preferable that the following formula (1) be satisfied: 0.3×L≦L1≦0.6×L (1)

[0010] It is preferable that the extension portion has an arc-shaped inner peripheral portion that contacts the elastic piece and deflects the elastic piece, the elastic piece has an arc-shaped outer peripheral portion that contacts the arc-shaped inner peripheral portion, and the radius of curvature of the arc-shaped outer peripheral portion is smaller than the radius of curvature of the arc-shaped inner peripheral portion.

[0011] According to the pump-type dispenser of the present invention, when the head is moved toward the cap, the extension bends the elastic piece, allowing the head to return to its initial position as the bent elastic piece returns to its original position. However, if a flexible elastic piece is constantly bent with a relatively large force, it may become worn and lose its restoring ability. In contrast, the elastic piece of the present invention includes an elastic piece main body and a reinforcing rib. The reinforcing rib has a rib base portion located on the base side and a rib gradually changing portion whose thickness gradually decreases from the rib base portion toward the tip side of the reinforcing rib. That is, the base side of the elastic piece is thicker due to the rib base portion, while the tip side of the elastic piece is thinner than the base side. Therefore, before the head is operated (when the head is moved to the retraction limit and the extension portion is in contact with the tip side of the elastic piece), the tip side of the elastic piece is more likely to bend, while the base side of the elastic piece is less likely to bend. Therefore, by adjusting the thickness of the base of the elastic piece so that the elastic force required to return the head to its original position after dispensing the contents is primarily exerted at the base of the elastic piece, a pump-type dispenser that is less susceptible to settling can be realized. Furthermore, when the head is fully retracted and the extension is in contact with the tip of the elastic piece, no pressing force is acting on the head, so the force acting on the tip of the elastic piece is also small. Therefore, the tip of the elastic piece, which remains bent in the state before the head is operated, can also be mitigated from the effects of settling. Furthermore, because the reinforcing rib has a gradually changing rib portion, the resistance does not change suddenly when applying pressing force to the head, resulting in excellent operability.

[0012] Furthermore, the pump-type dispenser of the present invention uses the above-mentioned elastic piece instead of a metal coil spring, so there is no need to separate the metal parts when disposing of it as in conventional pump-type dispensers, and it can be reused as a resin product, making it highly recyclable.

[0013] Fig. 5 is a cross-sectional side view showing a state before an elastic piece in one embodiment of a pump-type dispenser according to the present invention is bent. Fig. 6 is a perspective view of the periphery of the elastic piece shown in Fig. 1. Fig. 7 is a plan view of the elastic piece shown in Fig. 1. Fig. 8 is a cross-sectional side view of the pump-type dispenser shown in Fig. 1 in a state where the head is pressed. Fig. 9 is a partially enlarged view of the periphery of the elastic piece shown in Fig. 5.

[0014] Hereinafter, a pump-type dispenser 100, one embodiment of a pump-type dispenser according to the present invention, will be described with reference to the drawings. In this specification, the vertical direction refers to the direction along the illustrated central axis O (the central axis of the stem 7a, described later), with the side where the pipe 4 is located being referred to as "down" and the side where the head 12 is located being referred to as "up." Note that in this specification, the downward movement of the head 12 when pressed is referred to as the head 12 advancing, and the upward return movement of the pressed head 12 is referred to as the head 12 retreating. Therefore, in the following description, the vertical direction may also be referred to as the front-rear direction. Furthermore, the radial direction refers to a direction perpendicular to the central axis O within a plane perpendicular to the central axis O, and the circumferential direction refers to a direction circumferentially around the central axis O within this plane.

[0015] The pump dispenser 100 of this embodiment is used by being attached to the mouth of a bottle-shaped container (not shown). The liquid content to be dispensed by the pump dispenser 100 may be, for example, a cosmetic product (such as a milky lotion or a lotion), shampoo, body soap, hand soap, or facial cleanser.

[0016] The pump-type dispenser 100 is composed of a cylinder 1, a valve member 2, a pipe 4, an internal member 5, a piston 6, a tubular member 7, a holder 8, a packing 9, a cap 10, a cover 11, and a head 12. The cylinder 1, the valve member 2, the internal member 5, the piston 6, the tubular member 7, and the holder 8 are components that constitute the "pump" in this specification. Of the above components, the valve member 2, the piston 6, and the packing 9 are made of a soft, elastic synthetic resin (e.g., polyethylene (LDPE), HDPE, foamed PE)), while the other components are made of a hard synthetic resin (e.g., polypropylene (PP), polybutylene terephthalate (PBT), polyacetal (POM), polyketone (POK) resin, etc.). Each component of the pump-type dispenser 100 is essentially shaped around a central axis O.

[0017] The cylinder 1 includes a disk-shaped bottom wall 1a with an upwardly protruding central portion, a cylindrical tube wall 1b rising from the outer edge of the bottom wall 1a, and a flange wall 1c extending radially outward from the top of the tube wall 1b. A through-hole (suction port 1d) is provided in the protruding central portion of the bottom wall 1a. A cylindrical holding tube 1e is provided on the underside of the bottom wall 1a, surrounding the suction port 1d and extending downward to hold the pipe 4. A through-hole (vent hole 1f) is provided in the tube wall 1b.

[0018] The valve member 2 includes a base 2a, a valve body 2b that covers the suction port 1d inside the base 2a and seats on the upper surface of the bottom wall 1a, and an elastically deformable connecting piece 2c that connects the base 2a and the valve body 2b. The valve member 2 functions as a check valve, and when the pressure inside the cylinder 1 is reduced, the valve body 2b that has been closing the suction port 1d moves away from the bottom wall 1a, opening the suction port 1d.

[0019] In this embodiment, the base 2a is cylindrical with a lid, and the central portion of the top surface protrudes upward, and has an opening (not shown) through which the liquid content passes after passing through the suction port 1d. The base 2a is fitted and held on the inner circumferential surface of the cylindrical wall portion 1b, thereby holding the valve member 2 within the cylinder 1.

[0020] The pipe 4 is hollow, and its upper end is inserted into the holding cylinder 1e and is fitted and held therein.

[0021] The internal member 5 is disposed inside the cylinder 1 and moves up and down relative to the cylinder 1. The internal member 5 includes a cylindrical connecting tube 5a and a bottom portion 5b that closes the lower end of the connecting tube 5a and extends radially outward. The connecting tube 5a is provided with a hole (communication port 5c) that passes through it, and the top surface of the bottom portion 5b is provided with an annular portion 5d that is located radially outward of the connecting portion with the connecting tube 5a.

[0022] The piston 6 is inserted into the connecting tube 5a and disposed inside the cylinder 1. The piston 6 in this embodiment has an annular base 6a. An outer sliding piece 6b extending upward and downward from the base 6a is provided on the outer edge of the base 6a. The outer sliding piece 6b slidably and liquid-tightly contacts the inner circumferential surface of the tube wall portion 1b. An inner sliding piece 6c extending upward and downward from the base 6a is provided on the inner edge of the base 6a. A lower portion of the inner sliding piece 6c liquid-tightly contacts the lower portion of the connecting tube 5a that protrudes radially outward, and an upper portion of the inner sliding piece 6c slidably and liquid-tightly contacts the inner circumferential surface of an expanded diameter portion 7b (described later) of the tubular member 7.

[0023] The tubular member 7 is a member having an overall tubular shape. The tubular member 7 includes a cylindrical stem 7a and an expanded diameter portion 7b that is connected to the lower end of the stem 7a and has a larger diameter than the stem 7a. When the connecting tube 5a is inserted into the stem 7a, the two are fitted together, so that the internal member 5 and the tubular member 7 move together relative to the cylinder 1.

[0024] The holder 8 has a portion located radially outward of the stem 7a and a portion located radially outward of the expanded diameter portion 7b, and is equipped with a holder base 8a that is fitted and held on the inner circumferential surface of the cylindrical wall portion 1b. A flange 8b extending radially outward is provided at the upper end of the holder base 8a. The holder 8 prevents the internal member 5, piston 6, and cylindrical member 7 from slipping out of the cylinder 1.

[0025] The packing 9 is in the shape of an annular plate, and is inserted into and fitted into the cylindrical wall 1b of the cylinder 1. When the pump-type dispenser 100 is attached to a container (not shown), the packing 9 is sandwiched between the opening of the container and the flange wall 1c. This prevents problems such as the content liquid spilling out of the opening when the container is turned over, for example.

[0026] The cap 10 has a disk-shaped top wall 10a with a central through-hole. A cylindrical peripheral wall 10b extends downward from the outer edge of the top wall 10a. The upper portion of the inner peripheral surface of the peripheral wall 10b bulges radially inward to fit and hold the flange wall 1c, thereby holding the cylinder 1 in the cap 10. The inner peripheral surface of the cap 10 is provided with a female threaded portion 10c that screws into a male threaded portion provided on the mouth of a container. The cap 10 can be attached to a container by threading the male threaded portion and the female threaded portion 10c. Furthermore, the outer peripheral surface of the peripheral wall 10b is provided with anti-rotation recesses 10d extending vertically, as shown in the partially enlarged view of FIG. 1 . Multiple anti-rotation recesses 10d are provided at intervals circumferentially.

[0027] The cap 10 also includes an elastic piece 10e extending upward from the upper surface of the top wall 10a and capable of elastically deforming radially inward (see FIGS. 2, 3, and 4). The elastic piece 10e indicated by solid lines in FIGS. 3 and 4 illustrates the elastic piece 10e in a state before it is deflected (i.e., the elastic piece 10e is not in contact with the extension portion 12e, described below, before the cap 10 and the head 12 are assembled). In this embodiment, a total of six elastic pieces 10e are provided at equal intervals around the circumference. As described below, the elastic piece 10e is elastically deformed by the head 12 pressed against it when the contents are dispensed, and its restoring force returns the head 12 to its original position when the pressing force on the head 12 is released.

[0028] The elastic piece 10e includes a plate-shaped elastic piece main body 10f and a reinforcing rib 10g that is narrower than the elastic piece main body 10f (having a shorter circumferential length than the elastic piece main body 10f). The reinforcing rib 10g is provided at each of the circumferential ends of the elastic piece main body 10f. The elastic piece main body 10f of this embodiment has an arc-shaped outer peripheral portion 10h that is arc-shaped (with a curvature radius Ra) as shown in FIG.

[0029] As shown in Fig. 4, the reinforcing rib 10g includes a rib root portion 10j located at the root side of the reinforcing rib 10g, a rib gradually changing portion 10k whose thickness gradually decreases from the rib root portion 10j toward the tip side of the reinforcing rib 10g, and a rib tip portion 10m extending from the rib gradually changing portion 10k toward the tip side of the reinforcing rib 10g. As shown in the figure, the thickness (radial length) of the rib root portion 10j is substantially constant from the root side end 10n of the reinforcing rib 10g to the tip side end 10p of the rib root portion 10j and is substantially the same as the thickness of the elastic piece main body 10f. As shown in Fig. 4, the rib gradually changing portion 10k extends while being slightly curved so that its thickness gradually decreases from the tip side end 10p of the rib root portion 10j to the tip side end 10q of the rib gradually changing portion 10k. The rib tip 10m extends from the tip end 10q of the rib gradually changing portion 10k to the tip end 10r of the rib tip 10m so that the thickness is substantially constant. The tip end 10r of the rib tip 10m is located closer to the base than the tip end 10s of the reinforcing rib 10g.

[0030] However, if a flexible elastic piece is constantly bent with a relatively large force, it may become sagged and its recovery performance may decrease. To address this issue, in this embodiment, the base side of the elastic piece 10e is thickened by the rib base portion 10j, while the tip side is thinner than the base side. Therefore, the tip side of the elastic piece 10e is easily bent and the base side of the elastic piece 10e is less likely to bend, thereby suppressing sagging of the base side of the elastic piece 10e. In this embodiment, the elastic force required to return the head 12 is adjusted to be exerted mainly at the base side of the elastic piece 10e, including the thickness of the rib base portion 10j.

[0031] The cover 11 includes a cylindrical peripheral cover wall 11a. The peripheral cover wall 11a surrounds the peripheral wall 10b and the elastic piece 10e. A retaining projection 11b protruding radially inward is provided at the lower end of the peripheral cover wall 11a and engaging with the lower end of the peripheral wall 10b. A vertically extending rib 11c is provided on the inner peripheral surface of the peripheral cover wall 11a. The lower portion of the rib 11c engages with the anti-rotation recess 10d, thereby preventing the cover 11 from rotating and being held in place by the cap 10. The upper portion of the rib 11c protrudes radially inward more than the lower portion. The lower end surface of the upper portion contacts the upper surface of the top wall 10a, and the retaining projection 11b engages with the lower end of the peripheral wall 10b as described above, thereby preventing the cover 11 from slipping out of the cap 10. An inward flange 11d extending radially inward is provided at the upper end of the peripheral cover wall 11a.

[0032] The head 12 is cylindrical and includes a tubular portion 12a into which the stem 7a is inserted and fitted. The upper portion of the tubular portion 12a is provided with a top portion 12b whose upper surface is recessed downward and which has a passageway inside that leads to the tubular portion 12a. The top portion 12b is provided with a cylindrical nozzle 12c that extends radially outward and leads to a passageway inside the top portion 12b. The tip of the nozzle 12c is provided with a discharge port 12d through which the content liquid is discharged by the pump-type dispenser 100.

[0033] The head 12 also includes an extension portion 12e extending downward from the top portion 12b and the nozzle 12c. In this embodiment, the extension portion 12e is cylindrical and centered on the central axis O. As shown in FIG. 1 , the lower portion of the extension portion 12e is inclined so as to widen radially outward as it extends generally downward, and the inner edge of this inclined portion contacts the outer circumferential surface of the elastic piece 10e (elastic piece main body 10f). Here, the portion of the extension portion 12e that contacts the elastic piece 10e is referred to as the contact portion 12f. As shown in FIG. 3 , the inner circumferential surface of the extension portion 12e where the contact portion 12f is provided is referred to as the arc-shaped inner circumferential portion 12g, and the radius of curvature of the arc-shaped inner circumferential portion 12g is referred to as Rb. In this embodiment, the radius of curvature Ra of the arc-shaped outer circumferential portion 10h of the elastic piece 10e is set to be smaller than the radius of curvature Rb of the arc-shaped inner circumferential portion 12g.

[0034] In the pump-type dispenser 100 constructed using such components, as shown in FIG. 1, before the head 12 is pressed, the contact portion 12f of the extension portion 12e contacts the elastic piece 10e, and the head 12 is in the uppermost (retracted) position. The elastic piece 10e of this embodiment is thicker at the base due to the rib base portion 10j of the reinforcing rib 10g, but thinner at the tip end than the base end. Therefore, before the head 12 is pressed, the tip end of the elastic piece 10e bends, while the base end of the elastic piece 10e is less likely to bend, as shown in FIG. 1. As described above, in the elastic piece 10e of this embodiment, the elastic force for returning the head 12 is adjusted to be exerted mainly at the base end of the elastic piece 10e, including the thickness of the rib base portion 10j. This allows the effect of sagging to be suppressed while maintaining the function of returning the head 12. Furthermore, when the head 12 has moved to the upper limit, the force acting on the tip of the elastic piece 10e is small before the head 12 is pressed, so the effects of settling on the tip of the elastic piece 10e, which remains bent as shown in Figure 1, can be mitigated.

[0035] When the head 12 is pressed from above to lower it (advance the head 12 toward the cap 10), the stem 7a is pushed down along with the head 12 (the stem 7a advances toward the cap 10 along the central axis O). As the stem 7a is pushed down, the bottom 5b also descends via the connecting tube 5a, releasing the liquid-tight contact between the annular portion 5d and the lower portion of the inner sliding piece 6c. When the head 12 is further pushed down, the piston 6 also descends along with the tubular member 7 and internal member 5, pressurizing the interior of the cylinder 1. As a result, the liquid in the cylinder 1 passes through the communication port 5c, passes through the connecting tube 5a, the stem 7a, the tubular portion 12a, the passages provided inside the top portion 12b, and the inside of the nozzle 12c, and is then discharged to the outside world from the discharge port 12d. When the head 12 is pressed and the piston 6 descends below the vent hole 1f, the container (not shown) communicates with the outside world through the vent hole 1f. This prevents the pressure inside the container from becoming negative even if the liquid contained in the container decreases, preventing the container from being deformed or crushed.

[0036] Furthermore, when the head 12 is pressed down, the contact portion 12f of the extension portion 12e that contacts the elastic piece 10e applies a pressing force to the elastic piece 10e, causing the elastic piece 10e to bend radially inward as shown in Fig. 5. The reinforcing rib 10g of this embodiment has a rib gradually changing portion 10k (see Fig. 6), and the thickness of the reinforcing rib 10g gradually changes toward the rib base portion 10j. This prevents a sudden change in resistance when a pressing force is applied to the head 12, resulting in excellent operability.

[0037] 2, the radius of curvature Ra of the arc-shaped outer peripheral portion 10h of the elastic piece 10e is set to be smaller than the radius of curvature Rb of the arc-shaped inner peripheral portion 12g. In other words, compared to when the radii of curvature Ra and Rb are equal, the contact area between the contact portion 12f and the elastic piece 10e is reduced, and the sliding resistance when the head 12 is pressed down is reduced, so that excessive force is not required when pressing the head 12.

[0038] Thereafter, when the pressure on head 12 is released, the elastic force of elastic piece 10e, which has been elastically deformed, acts on head 12, causing head 12 to begin to rise. As a result, the radially outwardly protruding lower part of connecting tube 5a and the lower part of inner sliding piece 6c come into liquid-tight contact again, and piston 6 rises together with internal member 5, reducing the pressure inside cylinder 1. As a result, valve body 2b moves away from bottom wall 1a, opening suction port 1d, and allowing the liquid content in the container to be sucked into cylinder 1 through pipe 4.

[0039] As described above, the pump-type dispenser 100 of this embodiment can return the head 12 to its original position after discharging the liquid contents without using a metal coil spring, and can be used in the same way as conventional pump-type dispensers.

[0040] The inventors have conducted extensive research into the wear of the elastic piece 10e and have found that the effects of wear can be suppressed by appropriately designing the elastic piece 10e and the extension portion 12e. This point will be described in detail with reference to FIGS.

[0041] In Figure 4, the imaginary line indicates the extension portion 12e when the head 12 has moved to its upper limit (retraction limit). Here, L denotes the vertical (front-to-back) length from the base end of the reinforcing rib 10g (the connection between the reinforcing rib 10g and the top wall 10a) to the tip end 12h of the extension portion 12e. Also, L1 denotes the front-to-back length from the base end of the reinforcing rib 10g (the connection between the reinforcing rib 10g and the top wall 10a) to the tip end 10p of the rib base 10j when the elastic piece 10e and the extension portion 12e are not in contact before the cap 10 and the head 12 are assembled. It has been found that setting the elastic piece 10e and the extension portion 12e according to the following formula (1) is effective in suppressing the effects of sag. 0.3×L≦L1≦0.6×L (1) In this embodiment, L1 is set to 0.4×L, and it has been found that this setting is particularly effective in suppressing settling.

[0042] As shown in Figure 6, when the head 12 has moved to its lowermost position (forwardmost position), it has been found that it is effective in suppressing the effects of sagging if the tip end 10p of the rib base 10j is in the same position in the front-to-back direction as the contact portion 12f with the elastic piece 10e in the extension portion 12e, or is located on the base side of the reinforcing rib 10g (below the contact portion 12f) relative to the contact portion 12f.

[0043] Although one embodiment of the present invention has been described above, the present invention is not limited to this specific embodiment, and unless otherwise specifically limited in the above description, various modifications and variations are possible within the spirit and scope of the present invention as defined in the claims. For example, the configurations of the above-described embodiment can be added or deleted as appropriate, and the configurations of one embodiment can be incorporated into other embodiments. Furthermore, the effects of the above-described embodiment are merely examples of the effects resulting from the present invention, and do not mean that the effects of the present invention are limited to the above-described effects.

[0044] For example, the pump described above is merely an example, and other types of pumps are also included in the present invention. Furthermore, the number and locations of the elastic pieces 10e are not limited to those described in the above embodiment and can be modified as appropriate. Furthermore, the number and locations of the reinforcing ribs 10g are not limited to those described in the above embodiment and can be modified as appropriate. Furthermore, the reinforcing ribs 10g may not have rib tip portions 10m, and the tip end portions 10p of the rib base portions 10j may be connected to the inner circumferential surface of the elastic piece main body 10f. The outer circumferential surface of the elastic piece main body 10f is not limited to being arc-shaped in plan view as in this embodiment, but may be linear in plan view, for example. Furthermore, the extension portion 12e is not limited to being cylindrical, but may be, for example, rectangular.

[0045] Furthermore, although the elastic piece 10e in this embodiment bends toward the central axis O, it may also be bendable in a direction away from the central axis O. In this embodiment, the elastic piece 10e is provided on the cap 10 and the extension portion 12e is provided on the head 12, but the extension portion 12e may be provided on the cap 10 and the elastic piece 10e may be provided on the head 12.

[0046] 1: Cylinder 1a: Bottom wall portion 1b: Cylinder wall portion 1c: Flange wall 1d: Suction port 1e: Retaining cylinder 1f: Vent port 2: Valve member 2a: Base portion 2b: Valve body portion 2c: Connecting piece 4: Pipe 5: Internal member 5a: Connecting cylinder 5b: Bottom portion 5c: Communication port 5d: Annular portion 6: Piston 6a: Base portion 6b: Outer sliding piece 6c: Inner sliding piece 7: Cylindrical member 7a: Stem 7b: Expanded diameter portion 8: Holder 8a: Holder base portion 8b: Flange 9: Packing 10: Cap 10a: Top wall 10b: Peripheral wall 10c: Female thread portion 10d: Anti-rotation recess 10e: Elastic piece 10f: Elastic piece main body 10g: Reinforcing rib 10h: Arc-shaped outer periphery 10j: Rib base portion 10k: gradually changing rib portion 10m: rib tip portion 10n: root side end portion of reinforcing rib 10p: tip side end portion of rib root portion 10q: tip side end portion of gradually changing rib portion 10r: tip side end portion of rib tip portion 10s: tip side end portion of reinforcing rib 11: cover 11a: cover peripheral wall 11b: retaining protrusion 11c: rib 11d: inward flange 12: head 12a: cylindrical portion 12b: top portion 12c: nozzle 12d: discharge port 12e: extension portion 12f: contact portion 12g: arc-shaped inner peripheral portion 12h: tip side end portion 100: pump-type discharger O: central axis

Claims

1. A pump-type dispenser comprising: a cap to be attached to the mouth of a container which holds liquid contents; a pump which is held at the mouth by the cap and which is driven by the back and forth movement of a stem; and a head which has a discharge port for discharging the liquid contents to the outside and which is connected to the stem, and which discharges the liquid contents from the container from the discharge port by moving the head towards the cap, wherein one of the head and the cap is provided with an extension portion which extends towards the other of the head and the cap, and the other of the head and the cap is provided with an elastic piece which is deflected by the extension portion when the head is advanced towards the cap, the elastic piece comprising an elastic piece main body and a reinforcing rib which is narrower than the elastic piece main body, and the reinforcing rib has a rib root portion which is located on the root side of the reinforcing rib, and a rib gradual change portion which gradually becomes thinner from the rib root portion towards the tip side of the reinforcing rib.

2. A pump-type dispenser as described in claim 1, wherein when the head is moved to its forward limit, the tip end of the base portion of the rib is located at the same position in the fore-and-aft direction as the contact portion with the elastic piece in the extension portion or on the base side of the reinforcing rib.

3. The pump-type dispenser according to claim 1, which satisfies the following formula (1), where L is the length in the front-rear direction from the base end of the reinforcing rib to the tip end of the extension when the head is moved to the most retracted position, and L1 is the length in the front-rear direction from the base end of the reinforcing rib to the tip end of the rib base when the elastic piece and the extension are not in contact with each other before the head and the cap are combined. 0.3×L≦L1≦0.6×L...(1) 4. A pump-type dispenser as described in claim 1, wherein the extension portion has an arc-shaped inner peripheral portion that contacts the elastic piece to deflect the elastic piece, the elastic piece has an arc-shaped outer peripheral portion that contacts the arc-shaped inner peripheral portion, and the radius of curvature of the arc-shaped outer peripheral portion is smaller than the radius of curvature of the arc-shaped inner peripheral portion.

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