KR100261341B1 - Caulking gun and cartridge with afterflow prevention - Google Patents

Abstract

A caulking gun and cartridge combination is provided with afterflow prevention. The cartridge has a tubular body (8), a forward dispensing opening (9) at a forward end of the tubular body, and a backwall (11, 12) movably disposed within the tubular body (8). The caulking gun has a trough (1) for receiving the cartridge, and a piston (4) movable parallel to the trough (1). A trigger handle (23) is used for pushing the backwall (11) forward within the tubular body and causing a reduction of volume within the chamber (13) in the cartridge. The backwall slides substantially in a contact-less manner within the tubular body, preferebly by way of a reduced diameter (OD) of the backwall (11) relative the inner diameter (ID) of the tubular body (8), so that it is pushed backwardly when the body retracts radially after actuation. Alternatively, the cartridge body may be prevented from expanding or may even be actively squeezed so that afterflow caused by the volume reduction of the relaxing tube body is safely prevented.

Description

Caulking cartridge prevents backflow

Caulking guns of this type have had undesirable backflow (i.e., the interior of the cartridge is still subjected to excessive pressure, resulting in the added amount of compound being pushed out of the cartridge).

The main reasons for the flow phenomenon are already known. First, the cartridge wall, which is generally thin-walled, expands during plunger operation, and the cartridge wall loosens after plunger operation, according to the natural law that the system always tries to return to a loose state. Conventional cartridge backwalls have been invented to maintain the foremost position, and due to the fact that the plunger of the caulking gun is typically immovable with respect to the return movement, the cartridge's degradation will leak out, i.e. from the dispensing tip. do. Secondly, most caulking composites are highly viscous, and at least at the edges are compressible, causing substantial pressure build-up, which causes the plunger to bleed out of the dispensing tip even after it is no longer pushed forward.

The problem of post flow described above is often solved by quickly disengaging the gun plunger and moving it back as soon as a sufficient amount of the compound is administered in the environment of the prior art structure.

U.S. Gallex patent 5,236,105 describes a novel device for preventing over emissions. In that device, conventional caulking guns have retrofitted the old device with several members: a female element, a male element, a return spring and a stop. The spring is used as a practical pressing element, actively pulling the back wall out of the cartridge and introducing a relative vacuum inside the cartridge.

U.S. Keller Patent No. 4,834,266 describes a plunger device in which an elastic sealing ring is pressed toward the inner wall surface of the cartridge by a radial component that pushes the plunger forward in dispensing mode. When the plunger is no longer in operation, the sealing ring is released slightly so that the plunger releases the cartridge pressure inside.

One of the above methods of preventing postflow is certainly unsatisfactory. The devices mentioned in the two above patents are very complicated and somewhat expensive.

The present invention relates to a caulking gun and a dispensing cartridge. More particularly, the cartridge is located in the gun structure and the piston presses the plunger forward to reduce the volume occupied by the composition inside the cartridge, thereby reducing the composition in front of the cartridge. A synthetic dispenser of the type pushed out of an open tip.

1 is a perspective view of a conventional caulking gun;

2 is a cross-sectional view of a conventional caulking gun;

Figure 3 is a similar cross sectional view of a caulking cartridge according to the first embodiment of the present invention;

4 is a rear view of the back wall of the caulking cartridge of the second embodiment;

FIG. 5 is a cross sectional view taken along the line V-V of FIG. 4;

6 is a front view of a piston corresponding to the embodiment of FIGS. 4-5;

7 is a cross sectional view of a rigid sleeve according to a third embodiment of the present invention;

8 is a schematic front cross-sectional view of the trough of the caulking gun; And

9 is a side view of a caulking gun with a squeeze device.

It is therefore an object of the present invention to provide a caulking gun and cartridge which prevents postflow, which overcomes the disadvantages of these general types of conventional devices and methods. The primary objective is to provide a simple and inexpensive device that is applicable to a wide array of cartridges and caulking guns and safely prevents spills or overemissions.

According to the present invention for this and other purposes, the tubular body has a substantially tubular body, a front dispensing opening at the front end of the tubular body, and a rear wall movably disposed within the tubular body, the tubular body An improved caulking cartridge of that type is provided, having a wall having an inner wall surface defining an inner diameter of the tubular body, and defining a room bounded therein by the inner wall surface and the front and back walls. The back wall has a smaller diameter than the inner diameter of the tubular body and is improved because a substantially contactless space distance is defined between the inner wall surface and the outer periphery of the back wall.

According to an added feature of the invention, the distance is at least 0.2 mm, which may go up to 1.0 mm or more.

According to another feature of the invention, there is provided a spacer ridge formed at the periphery of the back wall that abuts the inner wall surface of the tubular body and defines the clearance.

For this and other purposes, according to the invention, a synthetic caulking gun and cartridge are also provided. The cartridge has a substantially tubular body, a front dispensing nozzle at the front end of the tubular body, and a back wall movably disposed within the tubular body, the tubular body being positioned between the front end and the back wall therein. Define. Thereby, the caulking gun comprises a body defining a trough for receiving the cartridge and a horizontally movable piston in the trough for pushing the back wall forward in the tubular body and reducing the amount in the room of the cartridge. The tubular body has a wall with an inner wall defining the diameter of the tubular body, and the back wall has a smaller diameter than the inner diameter of the tubular body and defines a substantially contactless space distance between the inner wall and the back wall.

According to another feature of the invention, there is provided a means operatively associated with the tubular body of the cartridge, while the piston pushes the rear wall forward while preventing the radial expansion of the tubular body. Such prevention means may be in the form of a rigid tubular sleeve, which is tightly fitted to the tubular body, for example by sliding the cartridge into the sleeve.

According to another feature of the invention, the tubular sleeve is formed of a rigid material selected from PVC, fiber reinforced plastics and metal.

According to another feature of the invention, the preventing means is a clamp device arranged in the trough of the caulking gun for selective squeezing of the tubular body of the cartridge.

According to another feature of the invention, the caulking gun has a trigger handle that pushes the piston forward to administer the caulking compound, and the clamping device is caulked such that the tubular body can be squeezed simultaneously with the piston pressing forward of the back wall. Is connected to the gun's trigger handle.

Other features contemplated as features of the invention are set out in the appended claims.

Although the present invention has been illustrated and described as implemented in caulking guns and cartridges that prevent postflow, nevertheless, various modifications and structural features are within the scope of equivalents of the claims and without departing from the spirit of the invention. As changes may be made, the details are not intended to be limited as illustrated.

However, the structure of the present invention, together with its additional objects and advantages, will be best understood from the following description of the specific embodiment in connection with the accompanying drawings.

In the drawings, in particular with reference to FIG. 1, a conventional caulking gun is shown. The front body 1 is formed of a trough 2 which receives a caulking cartridge. The piston stem 3 pushes the plunger head 4 forward toward the front wall 5 of the trough 2. The locking dog 6 prevents the stem 3 from moving forward, and the spring 7 presses the dog 6 to the locked position. The stem 3 is released and moved backward by swinging the dog 6 forward to a substantially vertical release position.

2, a typical conventional caulking tube has a tubular body 8. In general, the body is formed from a cylindrical tube 8 formed of paper laminate, fiber plastic, wound metal sheet or the like. The cylindrical tube 8 is relatively soft and its inner chamber pressure increases, expanding radially. The nozzle tip 9 is formed in the front closure wall 10. The tube 8 is hermetically closed at the rear with the rear wall 11. The outer circular flange 12 of the rear wall 11 has an outer radius that matches the inner radius of the tube 8. The flange 12 forms a sliding seal between the inner wall surface of the tube 8 and the rear wall 11. The reinforcing ring 14 together with the circular seal flange 15 is tightened at the rear edge of the tube 8. During storage, the back wall 11 is disposed directly adjacent the ring 14 such that the flange 12 is tightened under the seal flange 15. After the front wall 10 is drilled and the nozzle tip 9 is cut to form a dispenser opening, the back wall 11 is pushed forward to administer the caulking compound 13.

When the rear wall 11 is pushed forward and the flange 12 slides along the inner wall surface of the tube 8, the caulking compound 13 is pressed from the dispensing tip because of the increased pressure in the tube chamber. In addition to pushing the composite out of the dispensing tip, the increased pressure also causes the tube body to expand radially. In fact, it can be seen that the radial pressure of the cylindrical tube wall is exactly twice the pressure acting axially towards the dispensing opening. This radial "flow" of the tube 8 causes post flow when the piston 4 no longer operates and the tube 8 elastically releases its increased diameter to the released position.

In connection with Fig. 3 showing the first embodiment of the present invention, the outer diameter 0D of the circular flange 12 is smaller than the inner diameter ID of the tube 8 by the interval ΔD. The spacing DELTA D is selected in the dependent state in the caulking compound 13, ie in viscosity and its reaction rate with air. In other words, the higher the viscosity of the composite, the larger the interval DELTA D. Moreover, the more composites that are relatively inactive in the atmosphere, the larger the interval DELTA D. In general, tubes of typical silicone, glycerol esters, resins and rosin acids, etc. are provided with a spacing (ΔD) of 1 mm.

Tubes of composite with high viscosity may be provided with ΔD ≦ 0.2 mm. Appropriate spacing may be selected by those skilled in the art.

The inner wall surface of the flange 12 and the tube 8 forms a contact-less seal by a small amount of caulking compound that can penetrate between them. Since the dispensing opening is substantially larger than the limited range by (approximately) the interval DELTA D, only a negligible amount of caulking compound will exit through the zone. As soon as the pressure of the piston is released and the piston moves back, the rear wall 11 fits with it as the tube wall achieves its released position. If the caulking composite in the gap between the flange 12 and the tube still maintains its viscosity (when its viscosity is at its highest point), the back wall 11 slides easily. Immediately after the back wall reaches its terminated position (ie, the position where the tube body is terminated), the remaining caulking composite exposed to air cures to form the appropriate seal. The composite remaining in the cartridge chamber is sealed to the atmosphere.

After manufacture, ie during storage prior to initial use, the back wall 11 is sealed similar to a conventional conventional device.

A caulking tube device with a spacing D, which is less than 0.0 mm, hardens when the composite contained in such a tube is in contact with air, and it may seem unreasonable at first because such an opening is somewhat contrary to common sense. However, after operation, the inventor was able to confirm that the sealing ring of the dried composite was formed between the flange 12 and the inner wall surface of the tube 8. When the piston 4 pushes the rear wall 11 forward during the next dispensing operation, such a temporary seal is broken and the slide seal between the flange 12 and the inner wall surface of the tube 8 is made of a soft composite. When the pressure of the piston 4 is released by the piston stem 3 immediately upon dispensing, the retracting tube 8 can push the rear wall 11 back without causing undesirable post flow.

With reference to FIG. 4, a second embodiment is defined which has an actively pulling back feature that can be combined with the first embodiment. The flange 12 is provided with two opposing latches 16. When the piston 4 is pushed towards the opening defined by the flange 12, it engages under the latch 16. Thus, when the rear wall 11 is engaged, it is possible to actively retract the rear wall 11 by pulling back from the stem 3. In a preferred embodiment (FIG. 6), the piston plunger 4 is provided with cutouts 17 which allow selective engagement of the piston 4 with the latches 16.

4 again, the spacing between the inner tube wall and the flange 12 can be defined by the circumference of the rear wall 11, ie ridges 19 formed as a whole in the flange 12. have.

In the third embodiment, radial expansion of the tube 8 is prevented together since the inelastic sleeve 18 slides in the tube 8. Sleeve 18 may be formed from rigid PVC, fiber reinforced plastic, metal or similar material. The inner diameter of the sleeve 18 is selected to correspond to the outer diameter of the tube 8. Moreover, the sleeve 18 is made as thin as possible so that it still fits into the trough 2 of the caulking gun.

In connection with Fig. 8, the rigid sleeve can be replaced with a top cover 20 which is articulated at the corner of the trough 1 of the caulking gun body. The lid 20 is selected and latched to the latch hook 21, the rigid sleeve being formed from a caulking tube.

And in the fourth embodiment, the tube 8 is squeezed in addition to dispensing by advancing the rear wall 11. When dispensing is no longer desired, the squeeze in the tube 8 is released. Thus, in a preferred structural embodiment of the present invention, the caulking gun is provided with a clamp device for transmitting the back wall 11 and squeezing the tube at the same time. As shown in Figures 8-9, the lid 20 is reinforced with two strips 22 connected between the latch 21 and the trough body 1, at opposite ends thereof. When the trigger handle 23 is pulled to advance the piston 4, the wedge 24 is pulled down the strip 22. This causes the strip 22 to squeeze the lid 20 and thus to actively compress the caulking tube 8. The lid 20 is preferably formed with a diameter slightly larger than the trough. This leads to a slightly elliptical cross section of the space occupied by the caulking cartridge.

We have referred to herein as "caulking gun" and "caulking compound", but the term is commonly used in the related art, that is, to reduce the amount of piston actuation in tubular vessels and to be of a type that is prone to the above-described flow problems It should be contemplated that any dispenser with a composite will be understood.

Claims (4)

A caulking cartridge of the type having a substantially tubular body, an opening dispensing forward at the front end of the tubular body, and a back wall movably disposed within the tubular body, The tubular body has a wall having an inner wall surface defining the inner diameter of the tubular body, and defines a chamber bounded by the inner wall surface and the shear and back wall, The back wall has a diameter smaller than the inner diameter of the tubular body and defines a substantially contactless space between the inner wall surface and the outer periphery of the back wall. Caulking cartridge. The caulking cartridge according to claim 1, wherein said clearance is at least 0.2 mm. A caulking cartridge according to claim 1, wherein said clearance is at least 1.0 mm. The caulking cartridge according to claim 1, further comprising a spacer ridge formed on the circumference of the rear wall and in contact with the inner wall surface of the tubular body and defining the space distance.

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