Trigger-type liquid dispenser

Abstract

The present invention provides a trigger-type liquid dispenser that ensures good sealing between the piston and the inner circumferential surface of the cylinder in the initial position while also ensuring sufficient piston stroke. [Solution] The trigger-type liquid dispenser 1 comprises a dispenser body 4, a trigger 5, a cylinder 6, and a piston 7. The dispenser body 4 has a fitting recess 4a that opens forward, the cylinder 6 is fitted into the fitting recess 4a, and the piston 7 is fitted inside the cylinder 6. The outer circumferential surface of the cylinder 6 has a pressure contact projection 6a, which protrudes radially outward and extends continuously in the circumferential direction to be pressed against the fitting recess 4a. The piston 7 has a front sliding portion 7a1, which slides against the inner circumferential surface of the cylinder 6 and is positioned in front of the pressure contact projection 6a in its initial position.

Description

[[Technical Field]]

[0001] The present invention relates to a trigger-type liquid ejector. [[Background Art]]

[0002] A trigger-type liquid ejector is known which comprises an ejector body, a trigger, a cylinder and a piston, wherein the ejector body is attached to a mouth portion of a container, the trigger is biased forward and is retractably supported by the ejector body, the ejector body has a fitting recess opening forward, the cylinder is fitted into the fitting recess, the piston is fitted into the cylinder, the ejector body, the cylinder and the piston define a pump chamber, when a pulling operation is performed on the trigger, the piston retracts together with the trigger from an initial position to reduce the volume of the pump chamber, thereby feeding the liquid in the pump chamber to an ejection outlet of the ejector body for ejection, and when the pulling operation is released, the piston returns to the initial position together with the trigger to expand the volume of the pump chamber, thereby feeding the liquid in the container into the pump chamber (see, for example, Patent Document 1). [[Prior Art Documents]] [[Patent Documents]]

[0003] [[Patent Document 1]] Japanese Unexamined Patent Publication No. 2019-177898 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] In the conventional trigger-type liquid ejector as described above, an outer peripheral surface of the cylinder has a pressure contact portion, the pressure contact portion is expanded in diameter and is pressure-contacted with the fitting recess, the piston has a sliding cylindrical portion, the sliding cylindrical portion has a cylindrical shape with a constricted intermediate portion in the front-rear direction, the sliding cylindrical portion has a front sliding portion and a rear sliding portion, the front sliding portion slides relative to an inner peripheral surface of the cylinder, the rear sliding portion slides relative to the inner peripheral surface of the cylinder, and the front sliding portion is located rearward of the pressure contact portion in the initial position.

[0005] Setting the piston position further forward in the initial position increases the piston stroke and thus the amount of liquid that can be discharged in a single pulling operation. However, because the cylinder becomes thicker at the position of the expanding pressure contact area, depressions due to shrinkage of the resin material are likely to occur on the inner surface at this position during injection molding. Therefore, simply setting the piston position further forward in the initial position does not guarantee good sealing between the front sliding part and the inner surface of the cylinder in the initial position.

[0006] Therefore, the object of the present invention is to provide a trigger-type liquid dispenser that can ensure good sealing between the piston and the inner circumferential surface of the cylinder in the initial position while ensuring the stroke of the piston. [Means for solving the problem]

[0007] One embodiment of the present invention is as follows:

[0008] [Section 1] It comprises a sprayer body, trigger, cylinder and piston, The aforementioned sprayer body is attached to the mouth of the container, The trigger is supported by the ejector body so as to be retractable while biased forward. The ejector body has a fitting recess that opens forward, The cylinder is fitted into the fitting recess, The piston is fitted into the cylinder, The ejector body, the cylinder, and the piston partition the pump chamber. The piston, when pulled towards the trigger, retracts from its initial position together with the trigger, thereby reducing the size of the pump chamber and sending the liquid inside the pump chamber to the nozzle of the dispenser body for ejection; when the pulling operation is released, it returns to its initial position together with the trigger, thereby expanding the pump chamber and sending the liquid inside the container into the pump chamber. The outer surface of the cylinder has a pressure-contacting protrusion. The aforementioned pressure-contacting protrusion protrudes radially outward and extends continuously in the circumferential direction, and is pressed against the fitting recess. The piston has a front sliding portion, The front sliding portion slides against the inner circumferential surface of the cylinder and is located in front of the pressure contact protrusion in the initial position, in a trigger-type liquid dispenser.

[0009] [Section 2] The piston has a sliding cylinder portion, The sliding cylinder portion has a cylindrical shape with a constricted middle section in the front-rear direction. The sliding cylinder portion has the front sliding portion and the rear sliding portion, The trigger-type liquid dispenser according to item 1, wherein the rear sliding portion slides against the inner circumferential surface of the cylinder and is located behind the pressure contact protrusion in the initial position.

[0010] [Section 3] The cylinder has an outside air inlet and a recessed portion, The recessed portion is recessed on the inner circumferential surface of the cylinder in front of the outside air inlet. The aforementioned front sliding portion is located in front of the recessed portion in the initial position. The rear sliding portion is located behind the outside air inlet in the initial position. The trigger-type liquid dispenser according to item 2, wherein the outside air inlet draws outside air radially outward and directs it into the container as the piston returns to its initial position upon release of the pulling operation.

[0011] [Section 4] The cylinder has a cylindrical wall portion and a front wall portion, The cylindrical wall portion has the pressure-contacting protrusion, The front sliding portion and the rear sliding portion slide against the inner circumferential surface of the cylindrical wall portion. The front wall portion extends radially inward from the front end of the cylindrical wall portion and extends continuously in the circumferential direction. The sliding cylinder portion has an annular protrusion, The trigger-type liquid ejector according to Item 2 or 3, wherein the annular convex portion protrudes forward from the front sliding portion, continuously extends in the circumferential direction, and abuts against a rear surface of the front wall portion in the initial position.

[0012] [Item 5] The ejector body has a rear wall and a guide cylinder, the rear wall defines a rear portion of the pump chamber, the guide cylinder is formed in a cylindrical shape extending forward from the rear wall, the piston has an inner sliding portion, The trigger-type liquid ejector according to any one of Items 1 to 4, wherein the inner sliding portion slides against an outer peripheral surface of the guide cylinder.

Effects of the Invention

[0013] According to the present invention, there can be provided a trigger-type liquid ejector capable of securing the stroke of the piston while ensuring good sealing performance between the piston and the inner peripheral surface of the cylinder at the initial position.

Brief Description of Drawings

[0014] [Figure 1] It is a partial cross-sectional side view showing a trigger-type liquid ejection container according to an embodiment of the present invention. [Figure 2] It is an enlarged view of part A in FIG. 1.

Mode for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be illustratively described with reference to the drawings.

[0016] As shown in Figure 1, in one embodiment of the present invention, the trigger-type liquid dispenser container 1 has a trigger-type liquid dispenser 2 and a container 3. The container 3 has a mouth portion 3a, a body portion (not shown), and a bottom portion (not shown) connected in this order, and contains liquid inside. The mouth portion 3a is cylindrical with a central axis O. The liquid is not particularly limited and can be, for example, a mold remover, detergent, deodorant, pesticide, hair styling product, or other chemical. In this embodiment, the direction from the bottom to the mouth portion 3a along the central axis O of the mouth portion 3a is referred to as upward, and the opposite direction is referred to as downward.

[0017] The trigger-type liquid dispenser 2 comprises a dispenser body 4, a trigger 5, a cylinder 6, and a piston 7. The dispenser body 4 is mounted on the mouth 3a of the container 3, and the trigger 5 is supported by the dispenser body 4 so as to be retractable while being biased forward by a spring 8. The dispenser body 4 has a fitting recess 4a that opens forward, the cylinder 6 is fitted into the fitting recess 4a, and the piston 7 is fitted inside the cylinder 6. The dispenser body 4, cylinder 6, and piston 7 partition the pump chamber 9. In this embodiment, the front-rear direction is perpendicular to the up-down direction. The direction from the central axis O toward the trigger 5 is forward, and the opposite direction is backward.

[0018] The ejector body 4 has an internal flow path C. The internal flow path C has a vertical flow path C1 extending in the vertical direction and a horizontal flow path C2 extending forward from the upper end of the vertical flow path C1, with a nozzle at the front end of the horizontal flow path C2. The pump chamber 9 communicates with the internal flow path C. The ejector body 4 has an upstream backflow suppression section 4b and a downstream backflow suppression section (not shown). The upstream backflow suppression section 4b is provided in the vertical flow path C1 upstream of the pump chamber 9 and suppresses the backflow of liquid. The upstream backflow suppression section 4b is composed of a ball valve, but is not limited to this. The downstream backflow suppression section is provided in the horizontal flow path C2 downstream of the pump chamber 9 and suppresses the backflow of liquid. The ejector body 4 has a nozzle member 4c that forms the front end of the horizontal flow path C2, and the nozzle member 4c has a nozzle and a downstream backflow suppression section.

[0019] When the piston 7 is pulled by the trigger 5, it retracts from its initial position (the position shown in Figure 1) together with the trigger 5, thereby reducing the size of the pump chamber 9 and sending the liquid inside the pump chamber 9 through the downstream backflow suppression unit to the nozzle of the ejector body 4 for ejection. At this time, the upstream backflow suppression unit 4b prevents the liquid from being sent from the pump chamber 9 into the container 3.

[0020] When the pulling operation is released, the piston 7 returns to its initial position together with the trigger 5 due to the biasing force of the spring 8, thereby expanding the pump chamber 9 and sending the liquid in the container 3 into the pump chamber 9 through the upstream backflow suppression section 4b. At this time, the downstream backflow suppression section prevents outside air and liquid from being sent into the pump chamber 9.

[0021] The outer circumferential surface of the cylinder 6 has a pressure contact projection 6a, which protrudes radially outward and extends continuously in the circumferential direction to be pressed against the fitting recess 4a. The piston 7 has a front sliding portion 7a1. The front sliding portion 7a1 slides against the inner circumferential surface of the cylinder 6 and is positioned in front of the pressure contact projection 6a in the initial position. With the above configuration, even if a depression due to shrinkage occurs on the inner circumferential surface of the cylinder 6 at the position of the pressure contact projection 6a where the cylinder wall is thicker, good sealing performance between the piston 7 and the inner circumferential surface of the cylinder 6 can be ensured in the initial position by contact between the front sliding portion 7a1 and the inner circumferential surface of the cylinder 6.

[0022] The piston 7 has a sliding cylinder portion 7a. The sliding cylinder portion 7a is cylindrical with a constricted middle section in the front-rear direction. The sliding cylinder portion 7a has a front sliding portion 7a1 and a rear sliding portion 7a2. The rear sliding portion 7a2 slides against the inner circumferential surface of the cylinder 6 and is located behind the pressure contact protrusion 6a in the initial position. With the above configuration, even if a depression due to shrinkage occurs on the inner circumferential surface of the cylinder 6 at the position of the pressure contact protrusion 6a where the cylinder 6 has increased wall thickness, the contact between the rear sliding portion 7a2 and the inner circumferential surface of the cylinder 6 ensures even better sealing performance between the piston 7 and the inner circumferential surface of the cylinder 6 in the initial position.

[0023] The cylinder 6 has an outside air inlet 6c and a recessed portion 6b. The recessed portion 6b is recessed on the inner circumferential surface of the cylinder 6 in front of the outside air inlet 6c. The front sliding portion 7a1 is located in front of the recessed portion 6b in its initial position, and the rear sliding portion 7a2 is located behind the outside air inlet 6c in its initial position. The outside air inlet 6c draws outside air radially outward as the piston 7 returns to its initial position due to the release of the pulling operation, directing it into the container 3. With the above configuration, when the piston 7 returns to its initial position, even after the front sliding portion 7a1 has passed in front of the outside air inlet 6c, it can still draw outside air into the outside air inlet 6c via the recessed portion 6b when it passes through it. Therefore, it is possible to easily introduce outside air into the container 3 to replace the liquid discharged from inside the container 3. Furthermore, the recessed portion 6b can reduce the sliding resistance when starting the piston 7 by the towing operation, thereby improving operability.

[0024] The cylinder 6 has a cylindrical wall portion 6d and a front wall portion 6e. The cylindrical wall portion 6d is cylindrical with an axis P extending along the front-rear direction and has a pressure contact projection portion 6a, and the front sliding portion 7a1 and the rear sliding portion 7a2 slide against the inner circumferential surface of the cylindrical wall portion 6d. The front wall portion 6e extends radially inward from the front end of the cylindrical wall portion 6d and extends continuously in the circumferential direction. The sliding cylindrical portion 7a has an annular projection portion 7a3, which protrudes forward from the front sliding portion 7a1 and extends continuously in the circumferential direction, and in the initial position abuts against the rear surface of the front wall portion 6e. With the above configuration, the rigidity of the front end of the cylindrical wall portion 6d can be increased by the front wall portion 6e, thereby improving the sealing performance between the front sliding portion 7a1 and the inner circumferential surface of the cylinder 6 in the initial position. Furthermore, when the piston 7 returns to its initial position, the annular projection 7a3 abuts against the rear surface of the front wall portion 6e, stopping the piston 7. This prevents the front sliding portion 7a1 from abutting against the rear surface of the front wall portion 6e and causing damage.

[0025] The ejector body 4 has a rear wall 4d and a guide tube 4e. The rear wall 4d partitions the rear of the pump chamber 9, and the guide tube 4e is cylindrical and extends forward from the rear wall 4d. The piston 7 has an inner sliding part 7b, which slides against the outer circumferential surface of the guide tube 4e. With the above configuration, the stability of the operation of the piston 7 can be improved by the guide tube 4e.

[0026] The fitting recess 4a has a circumferential wall surface 4a1 and an end wall surface 4a2. The end wall surface 4a2 is connected to the rear end of the circumferential wall surface 4a1 and is the front surface of the rear wall 4d. The outer peripheral edge of the end wall surface 4a2 has an annular recess 4a3. The annular recess 4a3 opens forward and extends continuously in the circumferential direction. The cylindrical wall portion 6d of the cylinder 6 is arranged along the circumferential wall surface 4a1, and the front end of the cylindrical wall portion 6d is fitted into the annular recess 4a3. The outer peripheral surface of the front end of the cylindrical wall portion 6d has a locking projection 6d1, and the circumferential wall surface 4a1 has a locking projection 4a4. The locking projection 6d1 protrudes radially outward, and the locking projection 4a4 protrudes radially inward. The locking projection prevents the cylinder 6 from coming out of the fitting recess 4a by contacting the locking projection 6d1. The peripheral wall surface 4a1 has a vent 4a5, which communicates with the inside of the container 3. The rear wall 4d has a communication port 4d1, which connects the pump chamber 9 to the internal flow path C. With the above configuration, it is not necessary to align the cylinder 6 in the circumferential direction when fitting the cylinder 6 into the fitting recess 4a.

[0027] The cylinder 6 has a folded wall portion 6f. The folded wall portion 6f is cylindrical, extending radially inward from the sliding cylinder portion 7a and rearward from the inner peripheral edge of the front wall portion 6e. The piston 7 has a connecting portion 7c, an inner cylinder portion 7d, and a flange portion 7e. The connecting portion 7c is connected to the trigger 5 so as to be able to move forward and backward with the trigger 5. The inner cylinder portion 7d is cylindrical, smaller in diameter than the folded wall portion 6f and extending in the front-rear direction, and the front end of the inner cylinder portion 7d is closed by the connecting portion 7c. The front end of the inner cylinder portion 7d has an inner sliding portion 7b. The flange portion 7e extends radially outward from the inner cylinder portion 7d and connects to the middle of the sliding cylinder portion 7a in the front-rear direction, and extends continuously in the circumferential direction. The guide cylinder 4e has a hollow portion 4e1 that communicates with the inside of the container 3. With the above configuration, the rigidity of the front end of the cylindrical wall portion 6d is further increased by the folded wall portion 6f, thereby further improving the sealing performance between the front sliding portion 7a1 and the inner circumferential surface of the cylinder 6 in the initial position. In addition, since the guide cylinder 4e has a hollow portion 4e1 that communicates with the inside of the container 3, the operating force required for towing operations can be reduced, further improving operability.

[0028] The piston 7 has a contact cylinder portion 7f, which is cylindrical in shape and extends rearward from the flange portion 7e. The rear end of the contact cylinder portion 7f comes into contact with the end wall surface 4a2 when the piston 7 retracts from its initial position to the rear end position of the stroke due to the pulling operation, thereby stopping the piston 7. With the above configuration, when the piston 7 retracts to the rear end position of the stroke, the contact cylinder portion 7f comes into contact with the end wall surface 4a2 and stops the piston 7, so that the rear sliding portion 7a2 or the inner sliding portion 7b does not come into contact with the end wall surface 4a2 and get damaged.

[0029] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and the embodiments described above can be modified in various ways without departing from the spirit of the present invention. [Explanation of symbols]

[0030] 1. Trigger-type liquid dispensing container 2. Trigger-type liquid dispenser 3 containers 3a Mouth 4 Squirt body 4a Fitting recess 4a1 Peripheral wall surface 4a2 End wall surface 4a3 Annular recess 4a4 Locking projection 4a5 Ventilation opening 4b Upstream backflow suppression section 4c Nozzle component 4d Rear wall 4d1 Communication port 4e Guide tube 4e1 Hollow part 5 Trigger 6 cylinders 6a Press-fitted protrusion 6b Recess 6c Outside air intake 6d Cylinder wall 6d1 Locked protrusion 6e Front wall section 6th floor, folded wall section 7 pistons 7a Sliding tube part 7a1 Front sliding part 7a2 Rear sliding part 7a3 Annular protrusion 7b Inner sliding part 7c Connecting part 7d Inner cylinder part 7e Flange section 7f Contact cylinder part 8 springs 9 Pump Room C Internal flow path C1 Vertical channel C2 cross flow path O center axis P axis center

Claims

1. It comprises a sprayer body, trigger, cylinder and piston, The aforementioned sprayer body is attached to the mouth of the container, The trigger is supported by the ejector body so as to be retractable while biased forward. The ejector body has a fitting recess that opens forward, The cylinder is fitted into the fitting recess, The piston is fitted into the cylinder, The ejector body, the cylinder, and the piston partition the pump chamber. The piston, when pulled towards the trigger, retracts from its initial position together with the trigger, thereby reducing the size of the pump chamber and sending the liquid inside the pump chamber to the nozzle of the dispenser body for ejection; when the pulling operation is released, it returns to its initial position together with the trigger, thereby expanding the pump chamber and sending the liquid inside the container into the pump chamber. The outer surface of the cylinder has a pressure-contacting protrusion. The aforementioned pressure-contacting protrusion protrudes radially outward and extends continuously in the circumferential direction, and is pressed against the fitting recess. The piston has a front sliding portion, The front sliding portion slides against the inner circumferential surface of the cylinder and is located in front of the pressure contact protrusion in the initial position, in a trigger-type liquid dispenser.

2. The piston has a sliding cylinder portion, The sliding cylinder portion has a cylindrical shape with a constricted middle section in the front-rear direction. The sliding cylinder portion has the front sliding portion and the rear sliding portion, The trigger-type liquid dispenser according to claim 1, wherein the rear sliding portion slides against the inner circumferential surface of the cylinder and is located behind the pressure contact protrusion in the initial position.

3. The cylinder has an outside air inlet and a recessed portion, The recessed portion is recessed on the inner circumferential surface of the cylinder in front of the outside air inlet. The aforementioned front sliding portion is located in front of the recessed portion in the initial position. The rear sliding portion is located behind the outside air inlet in the initial position. The trigger-type liquid dispenser according to claim 2, wherein the outside air inlet draws outside air radially outward and directs it into the container as the piston returns to its initial position upon release of the pulling operation.

4. The cylinder has a cylindrical wall portion and a front wall portion, The cylindrical wall portion has the pressure-contacting protrusion, The front sliding portion and the rear sliding portion slide against the inner circumferential surface of the cylindrical wall portion. The front wall portion extends radially inward from the front end of the cylindrical wall portion and extends continuously in the circumferential direction. The sliding cylinder portion has an annular protrusion, The trigger-type liquid dispenser according to claim 2, wherein the annular projection protrudes forward from the front sliding portion and extends continuously in the circumferential direction, and abuts against the rear surface of the front wall portion in the initial position.

5. The ejector body has a rear wall and a guide tube, The rear wall partitions the rear of the pump room, The guide tube has a cylindrical shape extending forward from the rear wall, The piston has an inner sliding portion, The trigger-type liquid dispenser according to claim 1, wherein the inner sliding portion slides against the outer circumferential surface of the guide cylinder.

Images