JPH10249251A - Pump dispenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a return spring which converts the swinging motion of a trigger to the ascending/descending motion of a piston and at the same time, returns the trigger into a direction in which it is initially positioned by molding the return spring of a plastic material in a laterally almost arc fashion so that the return spring is elastically deformable in a stretchable direction. SOLUTION: The pulling of a trigger 12 enables the rotation of a pinion 48 following the rotation of a sector gear 46 and consequently, the descending of a piston 16 through a rack 44. In turn, a liquid contained in a cylinder 14 is pressurized and the pressurized liquid is jetted from the orifice 24 of a nozzle 22 through a secondary valve 38. In this case, the base piece 50a of a return spring 50 molded of a plastic material in a laterally almost L form is pulled downward resulting in the elastic deformation of the return spring 50. Thus a restoring force to return the return spring 50 to its original shape is generated on the spring 50 by the elastic deformation. Further, the piston 16 is caused to ascend by the restoring force when the traction force of the trigger 12 is relieved, and the liquid contained in a container 18 is sucked into the cylinder 14 through a primary valve 36.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump dispenser which draws up a liquid in a container into a cylinder, pressurizes and discharges the liquid in a container by reciprocation of a piston in conjunction with swing of a trigger.

[0002]

2. Description of the Related Art A pump dispenser which is attached to the mouth of a container and allows liquid in the container to flow out manually has been widely provided.

As disclosed in Japanese Patent Application Laid-Open No. 08-224509, this type of pump dispenser is formed, for example, with a trigger that can be pulled (swinged) freely against the biasing force of a return spring, and has a cylinder. A piston slidable therein is operatively connected to the trigger. Then, the liquid in the container is sucked into the cylinder and pressurized by the reciprocation of the piston in the cylinder accompanying the swing of the trigger, and the pressurized liquid is caused to flow out of the orifice (outlet) at the nozzle tip. , This pump dispenser is configured.

[0004] This type of pump dispenser is formed by covering the above-mentioned components with a cover, and most of the components including the cover are generally molded from plastic. In view of the recent problem of refuse disposal and recycling, the return spring has been made of plastic.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
As disclosed in Japanese Patent Application Laid-Open Publication No. H11-163, a known plastic return spring is formed into, for example, a substantially meandering shape or a substantially arcuate shape on the side, and biases a repulsive force (spring force) caused by compression in a reducing direction. Available as

However, in order to obtain a biasing force equivalent to that of a metal spring, such a known return spring as a compression spring requires a large volume and a large amount of deflection.
Therefore, it is necessary to secure a large peripheral space. Therefore, when a plastic return spring is used, the overall size of the pump dispenser is likely to be increased.

[0007] In the compression type return spring, the thickness is proportional to the spring force (biasing force).
Ensuring a large spring force for this compression type return spring tends to involve an increase in the size of the return spring itself. That is, also from this point, it is inevitable that the pump dispenser becomes large.

When a return spring having a substantially meandering side surface or a substantially arcuate side surface is compressed, the return spring is usually reduced by bending at a specific location, and the bending is repeated by repeated swinging of the trigger. Is repeated. In other words, in a known return spring that generates a biasing force by restoring from a compressed state, the deterioration of a specific portion and the restoring force (biasing force) caused by the deterioration.
May be reduced.

Further, in the case of a plastic return spring, there is a possibility that the shape of the return spring will vary during molding. Such a variation in the shape causes a shift in the mounting position of the return spring, and therefore, the workability at the time of mounting tends to be reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pump dispenser capable of reducing the size of a plastic return spring and reducing the space around the plastic return spring, and suppressing a decrease in a biasing force caused by deterioration of the return spring.

[0011]

In order to achieve this object, according to the present invention, a piston slidable along an axis in a cylinder arranged substantially on a vertical axis extends in a horizontal direction. It is provided at the lower end of a vertical portion of a substantially shaft-shaped piston shaft having a nozzle integrally at the upper end. Then, a rack integrally provided on the vertical portion side end of the piston shaft, a sector gear integrally provided on the rear surface of the trigger, and a pinion rotatably supported and meshable with both the rack and the sector gear. The swinging motion of the trigger can be converted into a linear motion in the vertical direction of the piston via a conversion mechanism having a combination.

A return spring for returning the towed trigger to the initial position under the biasing force is molded from a plastic material into a substantially arcuate side surface capable of elastic deformation in the extension direction. Each end of the return spring is locked to a corresponding member so as to be elastically deformable in the extension direction with the pulling of the trigger.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

As shown in FIG. 1, in a pump dispenser 10 according to the present invention, a trigger 12 supported swingably in a front-rear direction (left-right direction in the drawing) and a cylinder 14 are provided.
A piston 16 slidably disposed inside the cylinder is operably connected via a conversion mechanism 17 that converts the swinging motion of the trigger into a linear motion of the piston in the cylinder.

The pump dispenser 10
Liquid is detachably attached to the container 18 by screwing the bottle cap 20 to the mouth 18a, and reciprocates the piston 16 inside the cylinder 14 due to the swinging motion of the trigger 12 to suck up and add liquid from the container. The nozzle 22 is configured to be pressurized so that the pressurized liquid flows out of the orifice 24 at the tip of the nozzle 22.

As shown in FIGS. 1 and 2, according to the present invention, a cylinder 14 having a substantially straight pipe shape is provided, for example, as a lower half of a housing 26 on a vertical axis which is a liquid suction direction. Stipulated. And the cylinder
A piston 16 having a pair of upper and lower skirt-shaped seal pieces 16a and 16b, which can be slidably contacted with the inner peripheral surface of the piston 14 under elasticity, is integrally connected to the lower end of the piston shaft 28, for example, integrally. , Has been fixed.

In this embodiment, the piston shaft 28 is formed, for example, as a substantially 側面 -shaped tubular body having the nozzle 22 extending in the horizontal direction integrally at the upper end of a vertical portion 28a serving as its main body. A vertical flow path 29 and a horizontal flow path 30 are continuously defined inside the vertical portion and the nozzle. Then, the internal outflow path 32 is communicated with the vertical flow path 29 of the piston shaft, and the piston 16 is
It is located at the lower end of 28a.

That is, the pump dispenser of the present invention
In 10, the piston 16 and the nozzle 22 are
14, and thus can be moved up and down integrally with the housing 26 (see FIG. 3).

Here, the piston shaft 28 is embodied as a substantially 側面 -shaped side surface having the nozzle 22 integrally at the upper end of the vertical portion 28a. However, the present invention is not limited to this. A piston shaft may be used, and a separate nozzle may be integrally connected to and fixed to the upper end.

As shown in FIG. 1, a suction tube 34 is disposed so as to communicate with the inflow passage 33 at the lower end of the cylinder 14, and a primary valve 36 for controlling the flow of liquid in the inflow passage. However, the opening of the inflow path is provided so as to be freely opened and closed.

A secondary valve 38 for controlling the outflow of the liquid from the inside of the cylinder 14 is provided, for example, in the horizontal flow path of the nozzle.
The opening on the side of the vertical flow path 30 is freely openable and closable in this horizontal flow path, and a spinner (vortex member) 40
These are arranged at the distal end portion of the horizontal flow path, and are fitted undetachably to the distal end of the nozzle 22 by fitting the nozzle cap 41 with the orifice 24 therein.

In this embodiment, the secondary valve
38, the spinner 40 is integrally formed, for example, via a connecting member 42 having a substantially meandering side surface, and the secondary valve can be elastically closed under a biasing force from this connecting member. .

As can be seen from FIG. 2 in addition to FIG. 1, the upper half of the housing 26 is formed in a substantially box shape having an open upper surface, and a pair of left and right opposed side walls 26
The trigger 12 is swingably supported by the loose fit of the side projection 12a on the trigger a. Then, the swinging movement of the trigger 12 having the side projection 12a as a fulcrum is performed via the conversion mechanism 17,
It can be converted into a linear motion (elevation motion) of the piston 16 in the elevating direction.

The conversion mechanism 17 is a vertical part of the piston shaft.
A rack 44 integrally provided on the side end of the 28a, a sector gear 46 integrally provided on the back of the trigger, a rack,
It is provided with a combination with a pinion 48, which is installed between the side walls 26a of the upper half of the housing so as to mesh with both of the sector gears and is supported by the shaft.

As can be seen from FIG. 2, in this embodiment, the rack 44 includes a vertical portion of the piston shaft.
28a are formed symmetrically at the left and right side ends, respectively, and correspondingly, sector gears 46 and pinions 48 are similarly provided at right and left distances from each other. In addition, the rack 44, the sector gear 46 and the pinion 48 respectively arranged on the left and right
It goes without saying that each of them exhibits an integrated operation.

In such a configuration, the rear (right side in FIG. 1)
The sector gear 46 rotates about the side projection 12a by the swinging movement of the trigger 12 caused by the pulling of the trigger 12, and accordingly, the pinion 48 rotates in the corresponding direction about the support shaft 48a. The linear movement of the rack 44 in the elevating direction accompanying the rotation of the pinion 48 causes the piston shaft 2
8, that is, the piston 16 is moved up and down with respect to the cylinder 14 (see FIG. 3).

A return spring 50 for biasing and holding the trigger 12 in the initial position direction before towing is provided so that a biasing force in the corresponding direction can be applied to the trigger. As shown in FIGS. 1 and 2, according to the present invention, the return spring 50 has a substantially arcuate side surface that can be elastically deformed in the direction of extension, for example, the extension piece 50b extends forward from the upper end of a vertically extending base piece 50a. The left side of the return spring is molded from a plastic material into a substantially rectangular shape extending to the left (in the left side of the figure), and is elastically deformable in the direction of extension along with the pulling of the trigger 12. The pieces are respectively locked to the corresponding members.

The extension piece 50b of this return spring is
For example, it is formed in a left / right separated shape that can be arranged with the nozzle 22 interposed therebetween. The distal end of the extension piece 50b of the return spring is inserted and locked in a constituent member other than the piston shaft 28, for example, a concave portion 52 having an open upper surface provided at the upper end of the side surface 26a of the housing.

As can be clearly seen from FIG. 4 in addition to FIG. 1, for example, the vertical portion 28a of the piston shaft
Are formed integrally with side end pieces 53 extending to the left and right sides.On the rear surface of these side end pieces, for example, holding pieces 54 capable of holding a base piece 50a of a return spring are formed, respectively. ing. As can be clearly seen from FIG. 4, in this embodiment, the base piece 50a of the return spring is formed into a left and right separated shape that can be arranged with the vertical portion 28a of the piston shaft interposed therebetween.

As shown in FIGS. 1 and 4, the holding piece 54 has, for example, a substantially box shape penetrating the base piece 50a of the return spring in the vertical direction so as to be able to be inserted therein. Is formed. Then, the holding piece 54
A hook 56 engageable with the lower edge is provided on the base piece 50a of the return spring, and a slit 58 for ensuring elastic deformation of the hook in the contraction direction is provided at the end of the base piece.

With such a configuration, the base piece 50a can be held by the holding piece 54 under insertion from above. The engagement of the hook 56 with the peripheral edge of the lower holding piece after the insertion into the holding piece 54 prevents the detachment of the base piece 50a from the holding piece.

As shown in FIGS. 1 and 2, for example, a flange 60 is integrally provided on the outer peripheral surface of the upper end portion of the cylinder portion of the housing 26. The bottle cap 20 is disposed rotatably with respect to the housing 26 by the holding of the inner flange 20a at the upper end between the flange 60 and the lower end of the cover 62 disposed above. , Are supported.

As shown in FIG. 1, for example, a gasket 63 is wound around the cylinder portion along the lower surface of the housing flange 60, and the upper end of the container opening 18a is brought into close contact with this gasket. Liquid tightness of the container 18 can be ensured.

The cover 62 is formed, for example, in a hollow shape having a substantially inverted U-shaped cross section, which can open at least the upper half portion of the housing 26 from above. The fitting of the locking projection 66 to the housing 64a allows the housing to be attached to the housing. The cover 62 is, for example, a nozzle cover which can be opened and closed by bending a hinge 68 at an upper end which is a thin portion.
70 is formed integrally with the front surface thereof.

In the closed position (see the solid line in FIG. 1), the nozzle cover 70 engages with the tip of the nozzle 22, for example, below the nozzle cap 41 to lower the nozzle, and hence the piston.
Nozzle receiver 72 to prevent descent of 16 and orifice 24
A sealing body 74 that can be brought into close contact with the front surface of each is integrally formed on the inner surface thereof.

In such a configuration, the lowering of the nozzle 22 is prevented under the engagement with the nozzle receiver 72 due to the closing of the nozzle cover 70, so that the outflow of the liquid due to the unexpected pulling of the trigger 12 Is prevented. Then, when the nozzle cover 70 is closed, the orifice 24 at the tip of the nozzle is liquid-tightly sealed by the sealing body 74, so that leakage of liquid due to tipping over or the like is reliably prevented.

In the pump dispenser 10 having such a cover 62, the nozzle cover 70 is moved to the open position shown by the dashed line in FIG.
If it is removed from the front surface of the nozzle 24, the nozzle 22 can be moved up and down with the swing of the trigger 12, that is, the piston 16 can be moved up and down.
The nozzle cover 70 can normally be held at its open position by holding means (not shown).

With the nozzle cover 70 open, the trigger 12
Is pulled from the initial position shown in FIG. 1, the sector gear 46 in the counterclockwise direction in the figure around the side projection 12a of the trigger.
, The pinion 48 rotates in the corresponding direction, that is, clockwise. Then, due to the downward movement of the rack 44 accompanying the rotation of the pinion 48 in the clockwise direction in the figure, the piston shaft 28, that is, the piston 16 is lowered inside the cylinder 14 in conjunction with the swing of the trigger 12.

When the piston 16 descends inside the cylinder 14 from the upper position shown in FIG. 1 to the lower position shown in FIG. 3, the liquid in the cylinder is pressurized. Channel 32, vertical flow path of piston shaft
It flows from 29 through the secondary valve 38 to the horizontal flow path 30 of the nozzle, and flows out of the orifice 24 at the nozzle tip through the spinner 40, for example, as a spray flow (see FIG. 1).

Here, as shown in FIG. 3, when the piston shaft 28 is lowered with the pulling of the trigger 12, the base piece 50a of the return spring is connected to the tip of the extension piece 50b locked in the recess 52 of the housing. , The return spring 50 is elastically deformed in its extending direction. Then, due to this elastic deformation, a restoring force to the initial shape is generated in the return spring 50, and this restoring force is
The force is applied to the piston shaft 28 as a force for raising the base piece 50a with respect to the housing 26 at the tip of the extension piece 50a.

That is, in the present invention, the trigger 12
The restoring force generated under the elastic deformation in the extension direction accompanying the traction of the spring is used as the biasing force of the return spring 50.

When the traction force is released at the traction position of the trigger 12 shown in FIG.
Under a restoring force of 50, i.e., a biasing force, the piston shaft 28 and, consequently, the piston 16 rise with respect to the cylinder 14, and the negative pressure in the cylinder accompanying the rise of the piston causes the liquid inside the container 18 to rise. Is sucked into the cylinder via the suction tube 29, the inflow passage 33, and the primary valve 36. Then, the liquid sucked into the cylinder 14 waits in the cylinder until it is pressurized by the lowering of the piston 16 due to the next swing of the trigger 12.

A negative pressure prevention hole 76 for preventing a negative pressure in the container from flowing (sucking up) from the container 18 to the cylinder 14 is formed as a lateral hole in the side wall of the cylinder. The negative pressure prevention hole 76 is closed by the piston skirt-shaped sealing pieces 16a and 16b at the piston 16 rising position shown in FIG. 1 and is opened by the lowering of the piston from this rising position. In the open state, air can flow into the container 18 (see FIG. 3).

As described above, in the pump dispenser 10 of the present invention, the return spring 50 is made of plastic having a substantially arcuate side surface, and the return spring is arranged so as to be elastically deformable in the direction of extension under the traction of the trigger 12. Have been. When the return spring 50 having the substantially arcuate side surface is extended, the deformation is not concentrated at one place, and almost the entire area except the holding portion of the base piece 50a and the tip of the extension piece 50b is deformed. Therefore, even if the return spring 50 made of plastic is repeatedly used, the deterioration of the specific portion hardly occurs, and the reduction of the biasing force due to the deterioration of the specific portion is sufficiently suppressed.

Further, in such an extension type return spring 50, since a biasing force is obtained by restoring from its overall elastic deformation, a large biasing force can be obtained without increasing the wall thickness. Therefore, the size of the return spring 50 can be sufficiently reduced without reducing the biasing force.

Since the return spring 50 is elastically deformed in the direction of extension, it is not necessary to provide a space around the return spring for allowance for bending. In other words, in addition to reducing the size of the return spring 50, the peripheral space for the bending allowance can be eliminated.
The overall size of the pump dispenser 10 can be sufficiently reduced.

Here, in the embodiment of the present invention, the return spring 50 has a base piece 50a extending in the vertical direction.
The extension piece 50b is formed to have a substantially 側面 shape in which the extension piece 50b is extended forward from the upper end of the side surface. In the shape of a substantially 、 shape, a substantially 側面 shape on the side, and a roughly Π shape on the side,
A return spring may be formed.

The base piece 50a of the return spring is
The piston shaft is kept
Although it is connected to 28, the present invention is not limited to this. For example, the return spring base piece may be rotatably connected to the piston shaft by partial locking. However, if the base piece 50a is immovably held by the holding piece 54 as in this embodiment, the position of the terminal of the extension piece 50b of the return spring is automatically determined, and the mounting process of the return spring 50 becomes complicated. It can be done easily without doing.

In particular, as in this embodiment, the base piece 50a
Can be inserted from above into the holding piece 54 of the piston shaft, and the tip of the extension piece 50b can be inserted and locked into the concave portion 52 at the upper end of the housing 26. The mounting of the return spring 50 becomes possible. Therefore, it is possible to easily cope with assembly by an automatic machine.

In this embodiment, the extension piece
50b is locked at the upper end of the housing 26,
If the component does not descend together with the piston shaft 28, the return spring 50 can be elastically deformed in the extension direction in accordance with the downward movement of the piston shaft, so that the return spring 50 is not limited to the housing. The extension piece of the spring may be locked.

The extension piece 50b of the return spring
However, it is formed into a left-right separated shape that can be arranged with the nozzle 22 interposed, but it is sufficient if a biasing force in the corresponding direction can be applied to the trigger 12 via the piston shaft 28 and the conversion mechanism 17, The present invention is not limited to this. For example, the extension piece may be provided only on one of the left and right sides of the nozzle. However, if the extension pieces 50b are arranged on the left and right sides of the nozzle 22, the biasing force generated by the elastic deformation can be obtained substantially equally in the left and right directions, so that the inclination of the piston shaft 28 due to the biasing bias can be reliably prevented. The smooth lifting and lowering of the piston shaft, that is, the piston 16, can be easily ensured.

Here, in such a configuration, as shown in FIGS. 1 and 4, the connecting piece 78 is connected between the left and right extending pieces 50b.
It is preferable that they are integrally connected. In this way, if the left and right extension pieces 50b are connected to each other, it is possible to reliably prevent the extension pieces from shaking in the left and right directions during molding, so that the position of the tip of the extension piece with respect to the base piece 50b is stabilized. Also in this respect, workability in mounting the return spring 50 is improved.

Further, in this embodiment, the holding pieces 54 of the piston shaft are provided at two vertically separated positions. However, the present invention is not limited to this, and the base piece 50a of the return spring may be held on the piston shaft 28 by any one of the holding pieces 54.

However, if the holding pieces 54 are provided at the upper and lower two places, the base piece 50a can be stably held easily, and the work of inserting the base piece into the holding piece does not become complicated.

In this embodiment, the base piece 50a of the return spring is formed so as to be separated left and right. However, the present invention is not limited to this. For example, the side end piece 53 of the piston shaft is connected to the vertical portion 28a. If the rear surface has a continuous shape, the left and right integrated base pieces can be held on the piston shaft 28.

The embodiments of the present invention described above are intended to explain the present invention, and do not limit the present invention in any way. Modifications or alterations within the technical scope of the present invention may also be made. It goes without saying that all are included in the present invention.

[0057]

As described above, according to the pump dispenser of the present invention, since the plastic return spring is formed into a substantially arcuate side surface which can be elastically deformed in the direction of extension under the traction of the trigger. In addition, deterioration at a specific location due to the elastic deformation hardly occurs. Therefore, a decrease in the biasing force of the return spring due to the deterioration of the specific portion is sufficiently suppressed.

Since the return spring is elastically deformed in the extension direction, the thickness of the return spring can be sufficiently suppressed, and it is not necessary to provide a space for the allowance of the return spring in the vicinity thereof. Therefore, the overall size of the pump dispenser can be sufficiently reduced by reducing the size of the return spring and eliminating the peripheral space for the bending allowance.

Further, a return spring is formed into a shape in which the extension piece extends from the upper end of the vertically extending base piece, and the return spring is engaged with the piston shaft by holding the base piece by the holding piece. If it can be stopped, the position of the terminal of the extension piece of the return spring is determined by itself, so that the mounting process of the return spring can be easily performed without complication.

In particular, if the base piece can be inserted from above into the holding piece of the piston shaft, and the tip of the extension piece can be inserted and locked into a predetermined recess, the insertion from one upward direction is also possible. Since the return spring can be attached to the above, it is possible to easily cope with assembly by an automatic machine.

Further, if the extension piece of the return spring is formed into a left-right separated shape that can be arranged with the nozzle interposed therebetween, the biasing force generated by the elastic deformation can be obtained almost equally in the left and right directions, resulting from the biasing biasing force. The inclination and the like of the piston shaft can be reliably prevented, and the smooth lifting and lowering of the piston shaft, that is, the piston can be easily ensured.

If the left and right extending pieces of the return spring are integrally connected, the extension piece can be reliably prevented from shaking in the left and right directions during molding. Stabilization of the position also improves workability in mounting the return spring in this regard.

[Brief description of the drawings]

FIG. 1 is a schematic side view, partially broken, of a pump dispenser according to the present invention in an initial state.

FIG. 2 is a schematic exploded perspective view of a pump dispenser.

FIG. 3 is a schematic side view of a partially broken pump dispenser in a retracted state of a trigger.

FIG. 4 is a schematic perspective view of a piston shaft and a return spring as viewed from the rear.

[Explanation of symbols]

 10 Pump dispenser 12 Trigger 14 Cylinder 16 Piston 17 Conversion mechanism 18 Container 20 Bottle cap 22 Nozzle 24 Orifice 26 Housing 28 Piston shaft 44 Rack 46 Sector gear 48 Pinion 50 Return spring 50a Base 50b Extension piece 52 Recess 54 Holding piece 56 Hook

Claims (6)

[Claims] A piston slidable inside a cylinder is provided so as to be interlocked with a trigger, and a liquid in a container is reciprocated by reciprocation of the piston in the cylinder due to traction of the trigger against a biasing force of a return spring. In a pump dispenser that draws the pressurized liquid into a cylinder and pressurizes the same, and allows the pressurized liquid to flow out of an orifice at the tip of the nozzle, the piston slidable along the axis in the cylinder, which is arranged on a substantially vertical axis, is horizontal. A rack provided at a lower end of a vertical portion of a substantially Γ-shaped piston shaft having the above-mentioned nozzle integrally extended at an upper end, and provided integrally with a vertical portion side end of the piston shaft; a back surface of the trigger; Combination of a sector gear integrally provided with a pinion and a pinion rotatably supported and able to mesh with both the rack and the sector gear. The above-mentioned return, in which the swinging motion of the trigger is converted into a linear motion in the elevating direction of the piston via the conversion mechanism having a bias, and the pulled trigger is returned to the initial position under the biasing force. The spring is molded from a plastic material into a substantially arcuate side that can be elastically deformed in the direction of extension, and each end of the return spring is locked to the corresponding member so that it can be elastically deformed in the direction of extension as the trigger is pulled. A pump dispenser characterized by being performed. A piston slidable inside the cylinder is provided so as to be interlocked with the trigger, and the liquid in the container is reciprocated by the reciprocation of the piston in the cylinder accompanying the pulling of the trigger against the biasing force of the return spring. In a pump dispenser that draws the pressurized liquid into a cylinder and pressurizes the same, and allows the pressurized liquid to flow out of an orifice at the tip of the nozzle, the piston slidable along the axis in the cylinder, which is arranged on a substantially vertical axis, is horizontal. A rack provided at a lower end of a vertical portion of a substantially Γ-shaped piston shaft having the above-mentioned nozzle integrally extended at an upper end, and provided integrally with a vertical portion side end of the piston shaft; a back surface of the trigger; Combination of a sector gear integrally provided with a pinion and a pinion rotatably supported and able to mesh with both the rack and the sector gear. The above-mentioned return, in which the swinging motion of the trigger is converted into a linear motion in the elevating direction of the piston via the conversion mechanism having a bias, and the pulled trigger is returned to the initial position under the biasing force. The return spring is formed from a plastic material in a substantially arcuate shape in which the extension piece extends forward from the upper end of the vertically extending base piece, and is elastically deformable in the extension direction as the trigger is pulled. A predetermined range of the base piece is integrally held by the piston shaft, and the extension piece is locked by at least a component other than the piston shaft. 3. The pump dispenser according to claim 2, wherein at least the extension piece of the return spring is formed into a left-right separated shape that can be arranged with the nozzle interposed therebetween. 4. The pump dispenser according to claim 3, wherein the left and right extending pieces of the return spring are partially integrally connected. 5. The pump dispenser according to claim 2, wherein the extension piece of the return spring is formed in a curved shape curved downward. 6. The vertical portion of the piston shaft is formed with a holding piece that allows the base piece of the return spring to be inserted from above, and the vertical portion of the piston shaft is inserted into the holding piece peripheral edge when the base piece is inserted into the holding piece. With the engagement of the hook, the base piece of the return spring can be held on the piston shaft, and a concave part with an open upper surface is formed on one of the upper end of the trigger and the upper end of the housing serving as a fixing member,
The pump dispenser according to any one of claims 2 to 5, wherein the extension piece of the return spring can be locked by inserting the tip into the recess.