JPH08105197A - Piston for coking gun - Google Patents

Abstract

PURPOSE: To prevent the occurrence of complexity of a washing work for a conventional piston for a coking gun and to facilitate mounting and demounting of a piston and simplify washing thereof. CONSTITUTION: A piston body 1 consisting of a hand drum-form drum part 6 and a trapezoidal expansion part 7 protruding from the front of the drum part 6 is formed of synthetic resin. Slide contact parts 8 and 9 inclining toward the inner peripheral surface of a cylinder 2 and brought into close contact with the inner peripheral surface of a cylinder 3 and radially resiliently bendable are arranged at the front and rear edges of the outer periphery of the drum part 6, and a cavity part 12 the slide contact side on the rear side of which is released is arranged in the central part of the drum part 6. In the cavity part 12, the tip part of a piston rod is removably engaged with the piston body 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a caulking gun for filling a paste caulking material into gaps in a building such as a glass peripheral edge of a glass window, an aluminum sash joint, a wall surface and a floor surface, and more particularly, an improvement. The present invention relates to a caulking gun having a piston that is set.

[0002]

2. Description of the Related Art A caulking gun has been widely used in the past as a tool for filling a paste-like caulking material into a gap in a building. The structure of a typical caulking gun is, as shown in a simplified manner in FIG. 8, a cylinder (2) in which a nozzle (5) is attached to the tip and a handle (30) is fixed to the base. A piston rod (3) equipped with a piston (31) is fitted, and the piston rod (3) is intermittently moved forward by operating a lever (32) of a handle (30). The caulking material contained in the cylinder (2) is pushed out from the nozzle (5) by operating the lever, and the pushed caulking material fills the gap of the glass frame, for example.

The piston of the above-mentioned conventional caulking gun
The (31) is made of thick leather so that the caulking material inside the cylinder does not leak to the back side of the piston (31) when the piston moves, and the elasticity of the leather makes the outer circumference of the piston inside the cylinder (2). It has a structure in which it is elastically attached to the circumference.

[0004]

The piston formed of leather as described above has a proper elasticity so that it has good adhesion to the inner surface of the cylinder, and since it is flexible, abrasion of the inner surface of the piston does not occur. It has the advantage of being few. However, when the caulking work with the caulking gun is completed, it is necessary to take out the residual caulking material in the cylinder and clean the caulking gun including the inside of the cylinder. A large amount of caulking material adheres to the piston formed in 1., and since it is leather, it is difficult to clean it, and the wiping and cleaning work thereof is extremely complicated and requires a lot of labor and time. Furthermore, if the caulking material remains on a part of the circumferential surface of the piston, it solidifies and makes it difficult to smoothly push out the piston.At the same time, this causes the caulking material to enter the cylinder and solidify, making it difficult to clean. I was expecting it.

Moreover, the leather is deteriorated and hardened over time, making it difficult to retain the initial elasticity, and not only must the leather be replaced with new leather, but the piston made of leather must have a nut as shown in FIG. (33) The replacement work is never easy because it is firmly screwed with.

In order to remedy this inconvenience, a piston for a caulking gun has been proposed in which a cylindrical metal material is processed to form a disk-shaped piston body, and an elastic O-ring is fitted on the outer peripheral surface of the piston body. There is. (Actual Kaihei 3-115256
(See issue)

However, the disk-shaped metal piston as in the above invention has the advantages that the durability is improved and deformation does not occur as compared with the leather piston.
Since the airtightness with the cylinder depends on the rubber piston ring fitted on the outer circumference of the piston, part of the viscous caulking material penetrates into the gap between the piston and the cylinder, making the piston lighter. Not only hindering such sliding, but also causing an excessive load on the piston ring, causing the piston ring to be worn and damaged early, and must be replaced in a short period of time. In addition, since the cylinder is disk-shaped, even if the piston is moved to the end, the caulking material in the front cap of the funnel-shaped cylinder cannot be pushed out, and the caulking material is wasted.

The present invention is a departure from the conventional idea that the piston in the caulking gun must be made of leather, the drawbacks of the leather piston described above are eliminated, and the caulking material in the front cap is also removed at the final stroke position of the piston. A synthetic resin piston for a caulking gun having a structure capable of being extruded.

Still another object of the present invention is to provide a piston in which the work of attaching and detaching the piston and the piston rod is easy.

[0010]

According to the present invention, a piston body is formed of a synthetic resin, a bulge portion is provided at a tip end portion of the piston body, and front and rear end peripheral edges of the piston body portion are brought into close sliding contact with an inner surface of a cylinder. The above problem was solved by forming a structure.

That is, in the piston of the caulking gun of the present invention, the piston body is formed of synthetic resin, and the piston body is composed of a drum-shaped body and a trapezoidal bulge protruding from the front surface of the body. The body has slidable contact portions on the front and rear edges of its outer periphery that are inclined toward the inner peripheral surface of the cylinder and are in close contact with the inner peripheral surface of the cylinder. An annular groove is provided on the slide contact part so that it can be flexibly elastically deformed in the diametrical direction, and the rear slide contact part also has a fin shape that can be slightly elastically deformed in the diametrical direction. A hollow portion whose rear sliding contact side is opened is provided in the portion, and an engaging means for engaging with the piston rod tip portion is provided in the hollow portion or at the center position of the trapezoidal bulging portion. It is a feature.

A means for facilitating the attachment / detachment of the piston and the piston rod is such that the piston rod, which is eccentric to the piston washer and is located at the center of the cylinder, is located at the intermediate position of the hollow portion of the piston body. Two retainer rings each provided with a circular opening sized to wrap along are supported rotatably by a stepped portion in the cavity and rotatably and permanently inserted into the retainer ring by the two retainer rings and the piston washer. It is characterized in that an engaging means with the tip end portion of the piston rod is configured.

As the synthetic resin forming the piston, various resins such as polyethylene, polypropylene, nylon and polyester can be applied, but polyethylene or polypropylene is preferable from the viewpoint of durability of the caulking material against solvent and economical efficiency. . The piston is preferably mass-produced by molding, or the molding material may be ground by a processing machine such as a lathe to finish the structure described above.

The body of the piston body is preferably an hourglass shape with a hollow rather than a disk shape. The sliding contact portion may be formed so that the front edge and the rear edge of the drum-shaped body portion elastically adhere to the inner surface of the cylinder. An annular end face with a narrow vertical surface is formed on the front sliding contact part, and the rear sliding contact part has an almost knife-edge-shaped cross section, and the rear sliding contact part is somewhat softer. It may be configured to elastically deform. By providing the sliding contact portions in front of and behind the body portion in this way, the piston can reliably maintain its normal posture and move lightly. The shape of the bulging portion of the piston body is preferably trapezoidal in cross section so as to substantially match the funnel-shaped space shape of the front cap of the cylinder.

[0015]

The bulging portion and the sliding contact portion on the front side accurately perform the pushing action of the caulking material filled in the cylinder when the piston moves forward, and the sliding contact portion on the rear side slides along the inner surface of the cylinder. Prevents the piston from tilting and ensures normal movement. The trapezoidal bulging portion is located in the front cap when the piston is in the most advanced position, and also pushes the caulking material in the front cap toward the nozzle so that the caulking material does not remain in the front cap. The synthetic resin forming the piston body enhances the accuracy and durability of the piston and facilitates the cleaning of the piston after the caulking work.

[0016]

EXAMPLE An explanation will be given below with reference to the drawings showing an example of the present invention. In FIG. 1, (1) is the piston body,
(2) is a cylinder, (3) is a piston rod, (4) is a front cap, and (5) is a nozzle.

The piston body (1) according to the present invention is made of polyethylene resin and, as shown in FIGS. 1 and 2, has a drum-shaped body (6) and a body (6) protruding from the front surface thereof. And a trapezoidal bulge (7). The body (6) is inclined toward the inner peripheral surface of the cylinder (2) at the front and rear edges of its outer periphery, and the outermost periphery is the cylinder.
Sliding contact parts (8) and (9) that are in close contact with the inner peripheral surface of (2) are provided, and an annular groove (10) is formed on the inner surface side of the front sliding contact part (8) and a narrow width is formed on the front surface side. An annular end surface (11) is provided so that the sliding contact portion (8) can elastically bend slightly in the diameter direction. The rear sliding contact portion (9) is formed to be thinner than the front sliding contact portion (8) and has a fin shape that is extremely elastically deformable in the diameter direction.

Further, the rear sliding contact portion is provided at the center of the body portion (6).
A cavity (12) with an open side (9) is provided.
An engaging means for engaging with the piston rod tip is provided inside the (12) or at the center position of the trapezoidal bulge (7). In the figure, (13) is an annular groove provided for smoothing the flexure of the sliding contact part (8) on the front side. The annular groove (13) and the groove (10)
Reduce the thickness of the base of the sliding contact (8)
It facilitates elastic bending of (8). However, this annular groove (13) does not necessarily have to be provided in the piston of the present invention.

One embodiment of the means for engaging the piston body (1) and the piston rod (3) has circular openings (14) and (15) at eccentric positions, as shown in FIGS. It is composed of two retainer rings (16) and (17). That is,
At the middle of the inner circumference of the cavity (12) of the piston body (1), the step (1
8) is formed, and two retainer rings are formed on this step (18).
(16) and (17) are rotatably supported and set in a non-pulled state by a C-shaped clip (19). These two retainer rings (16) (17) are circular enough to pass the piston washer (20) and wrap around the piston rod (3) located in the center of the cylinder (2) along the inner circumference. Opening (14)
(15) is provided in an eccentric position, and at the center of the bulging part (7), the snap ring (21) that fastens the tip of the piston rod (3) and the piston washer (20) can be fitted. A concave portion (22) is provided, and the two retainer rings (16) (17) and the concave portion (22) constitute an engaging means with the tip of the piston rod.

As shown in FIG. 3, two retainer rings (16)
In the state where the circular openings (14) and (15) of (17) are matched,
Since the piston washer (20) part of the piston rod (3) can pass through the circular openings (14) (15), when the piston body (1) and piston rod (3) are engaged, Insert the piston washer at the tip of the rod (3) through the circular openings (14) and (15) and move it to the center, and then the outer retainer ring (16), for example, two pieces protruding from the surface. Use the protrusions (23) (23) to rotate 180 degrees (1
(2 times), the piston rod (3) is moved by the part of the periphery of the openings (14) (15) of the front and back retainer rings (16) (17) as shown in FIG. Position it at the center of (1) and place the tip of the piston rod (3) in Figure 3.
As described above, the piston body (1) and the piston rod (3) can be engaged with each other in a non-pulled state by being fitted into the recess (22). In this engaged state, the tip end of the piston rod including the piston washer (20) fluctuates slightly in the front-rear direction within the cavity (12), but this does not have any effect on the caulking material filling operation. Rather, such a rough engagement between the piston body (1) and the piston rod (3) absorbs variations in the supporting accuracy of the piston rod of the caulking gun, and the sliding contact part (before and after the piston (1) ( 8) Good sliding contact between (9) and the inner wall of cylinder (2). Further, it is convenient to operate the piston rod lightly without giving force.

Further, the piston body (1) and the piston rod
As another engagement means with (3), as shown in FIG. 7, one retainer ring (24) is fixed to an intermediate position of the hollow portion of the piston body (1), and this retainer ring (24) is fixed. ring
A guide groove (25) for the piston rod (3) is formed at the center of (24), and a window opening (communicating with this guide groove (25) through which the tip of the pistol rod including the piston washer (20) can enter and exit ( 26), the piston rod (3) is moved to the center after the tip of the pistol rod (3) is inserted into the cavity through the window opening (26). The piston rod (3) can be engaged with (1) in a non-pulled state.

If a free engagement is desired, the tip of the piston rod (3) is made into a male screw (27) and the inner center of the bulge (7) is fitted, as shown in FIG. The nut material (28) is embedded in the piston body (1) and the piston rod.
(3) and may be configured to be screwed together. Also in this mode, the piston body (1) or the piston rod (3)
Both can be easily attached and detached by turning.

[0023]

As described above, in the piston for the caulking gun according to the present invention, the piston body (1) is formed of synthetic resin, and the piston body (1) has a drum-shaped body (6).
And a trapezoidal bulge protruding from the front of this body (6)
The body (6) is slidably attached to the body (6) at the front and rear edges of the outer periphery of the body (6) inclining toward the inner peripheral surface of the cylinder (2) and closely contacting the inner peripheral surface of the cylinder (3). Part (8) (9) is provided,
The sliding contact part (8) on the front side is provided with an annular groove (10) on its inner surface side so that the sliding contact part (8) is elastically bendable in the diametrical direction.
The rear sliding contact part (9) is thinner than the front sliding contact part (8) and has a fin shape that is elastically deformable in the diametrical direction.
Cavity (12) with the rear sliding contact side open to the center of (6)
Is provided in the hollow portion (12), or at the center position of the trapezoidal bulge portion (12) is provided with an engaging means with the piston rod tip portion, the piston body is made of synthetic resin. Therefore, the cleaning of the piston after the completion of the caulking operation becomes significantly easier than in the conventional case, and the deterioration of the caulking material due to the solvent does not occur.

The body portion (6) of the piston body (1) has an hourglass shape, and the sliding contact portions (8) and (9) that are in close contact with the inner surface of the cylinder (2) are provided at the front and rear edges of the body. The piston body (1) pushed by the rod (3) can always move smoothly in a normal posture without tilting, and the caulking work can be performed smoothly.

The trapezoidal bulge (7) is the piston body.
Since (1) is located in the front cap (4) in the most advanced state, the caulking material in the front cap (4) can also be pushed out toward the nozzle (5).
The caulking material can be used without waste.

Then, for example, as shown in FIGS. 3 to 5, at the intermediate position of the hollow portion (12) of the piston body (1),
Piston washer (20) can pass and cylinder
Two retainer rings (16) (17) with circular openings (14) (15) eccentrically positioned to wrap the piston rod (3) located in the center of (2) along the inner circumference. ) The cavity
The piston rod (3) can be inserted into the central part of the bulging part (7) of the piston body (1) so that the piston rod (3) can be rotated inside the (12) and cannot be pulled out. In the structure in which the concave portion (22) is provided and the two retainer rings (16) (17) and the concave portion (22) are configured so that the piston rod tip portion and the piston main body (1) can be engaged, Piston body
The (1) and piston rod (3) can be easily attached and detached, and the caulking gun can be cleaned more easily after work.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a main part of the present invention.

FIG. 2 is a side view of a piston body.

FIG. 3 is a cross-sectional view showing an embodiment of an engaging means between a piston body and a piston rod.

FIG. 4 is a rear view of the piston body of FIG.

FIG. 5 is a rear view showing a state where a piston rod is engaged with the piston body.

FIG. 6 is a cross-sectional view showing another embodiment of the engaging means between the piston body and the piston rod.

FIG. 7 is a cross-sectional view showing still another embodiment of the engagement means between the piston body and the piston rod.

FIG. 8 is a partial sectional side view showing a main part of a conventional caulking gun.

[Explanation of symbols]

1. Piston body 2. Cylinder 3. Piston rod 4. Front cap 5. Nozzle 6. Torso
7. Bulging part 8. Front sliding contact 9. Rear sliding contact 10. groove
11. End face 12. Cavity part 14. Circular opening 15. Circular opening 16. Retainer ring 17． Retainer ring

Claims (3)

[Claims] 1. A piston body is formed of synthetic resin, and the piston body comprises a drum-shaped body and a trapezoidal bulge projecting from the front surface of the body, and the body has an outer periphery. The front and rear edges are provided with sliding contact portions that are inclined toward the inner peripheral surface of the cylinder and are in close contact with the inner peripheral surface of the cylinder, and the front sliding contact portion is provided with an annular groove on the inner surface side thereof. The sliding contact part is configured to be able to flex very little in the diameter direction,
The rear sliding contact portion also has a fin shape that can be slightly elastically deformed in the diametrical direction, and a hollow portion with the rear sliding contact portion side open is provided at the center of the body portion, and the inside of this hollow portion or the above-mentioned stand A piston in a caulking gun, characterized in that engaging means for engaging with a tip end portion of the piston rod is provided at a center position of the bulging portion of the shape. 2. The piston for a caulking gun according to claim 1, wherein the piston body is formed of a polyolefin resin such as polyethylene or polypropylene. 3. A circular opening having a size capable of passing a piston washer and enclosing a piston rod positioned at the center of the cylinder along the inner circumference is provided at an eccentric position at an intermediate position of the hollow portion of the piston body. A pair of retainer rings is supported by a step portion in the hollow portion and is rotatably and fitted in a non-pullable state. The two retainer rings and the piston washer constitute an engaging means with a tip end portion of a piston rod. Claim 1 characterized in that
Piston in the caulking gun described.