CA2145611A1 - Tool for injecting sealant into cracks - Google Patents
Tool for injecting sealant into cracksInfo
- Publication number
- CA2145611A1 CA2145611A1 CA002145611A CA2145611A CA2145611A1 CA 2145611 A1 CA2145611 A1 CA 2145611A1 CA 002145611 A CA002145611 A CA 002145611A CA 2145611 A CA2145611 A CA 2145611A CA 2145611 A1 CA2145611 A1 CA 2145611A1
- Authority
- CA
- Canada
- Prior art keywords
- block
- foam
- crack
- sealant
- backing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G23/00—Working measures on existing buildings
- E04G23/02—Repairing, e.g. filling cracks; Restoring; Altering; Enlarging
- E04G23/0203—Arrangements for filling cracks or cavities in building constructions
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G23/00—Working measures on existing buildings
- E04G23/02—Repairing, e.g. filling cracks; Restoring; Altering; Enlarging
- E04G23/0203—Arrangements for filling cracks or cavities in building constructions
- E04G23/0211—Arrangements for filling cracks or cavities in building constructions using injection
Abstract
The tool comprises a foam block bonded to a rigid backing block. The tool is pressed against the wall, whereupon the foam conforms to, and forms a seal to, the wall surface. A conical recess is provided in the backing block for receiving the nozzle of a caulking gun, and a through-hole conveys sealant, injected under pressure, through the tool and into the crack. A rigid spigot may be provided for positioning the apparatus correctly relative to prepared recesses along the length of the crack.
Description
21~5B~ l Title: TOOL FOR INJECTING SEALANT INTO CRACKS
This invention relates to the injection of sealant or filler into cracks (including voids and such like recesses) in walls, floors, etc, made of concrete, masonry, plaster, and the like, and wood.
BACKGROUND TO THE INVENTION
The conventional techniques for filling small cracks tend to fall into two categories. The light techniques produce what amounts to just a surface coating of the sealant, with very little penetration of the crack. The heavy techniques use injection ports at spaced intervals along the crack; the outside of the crack is covered with a sealing compound, or an elaborate mechanical means is provided for sealing the port to the wall; and then pressurized equipment injects the compound into the crack. The light techniques, though inexpensive enough, provide little more than cosmetic treatment; the heavy techniques can work well enough, even to restore structural integrity in some cases, but are limited by their high cost.
The invention is aimed at providing a tool which enables sealant to be injected deep into the crack, and which is inexpensive enough that the tool can be used on a one-time-use basis, and preferably which is so inexpensive to produce that it can be favourably priced when on the same counter shelf as, for example, tubes of caulking.
The invention is aimed at providing a tool which is particularly suitable for use with conventional tubes o~
caulking, sealants, adhesives, grouts, and fillers. The tool is intended for use with conventional caulking injection-guns;
or, the injection can be done by manual compression of a soft container.
GENERAL FEATURES OF THE INVENTION
The invention makes use of a property of some synthetic polymers -- notably compressible and elastomeric materials, and especially soft foam materials -- namely, the ability of a flat block of the material to conform intimately to a nominally flat wall surface when pressed lightly against the surface. A block of the elastically compressible, or elastomeric, material is loaded against the wall surface by means of a solid backing block, which enables the force pushing the block against the wall to be spread evenly throughout the elastomeric block.
The invention is herein described as it relates to sealing cracks in walls, but it will be understood that the repair sites may be in floors, or in other structures or articles in which the sealing of cracks is required.
Sealant (or other injectable repair material) is injected through a through-hole through the blocks, and out through an exit-mouth in the elastomeric block, and into the crack. The elastomeric material serves to seal the wall surface area around the mouth of the through-hole, allowing pressure to be built up, which produces good penetration of the crack, without the sealant leaking or extruding between the block and the wall surface.
The compressible elastomeric material preferably is expanded, cross-linked, polyvinyl chloride foam material, that is formed with an integral skin. Also, low density neoprene foam, and some solid silicone and polyurethane-based elastomers may be used.
The contact face of the elastomeric block may be flat, concave, convex, or angled, as required for specific repair sites. The degree of compressibility and elasticity of the 21~6~
material is selected with reference to the extent and size of the crack, the viscosity of the sealant, the injection pressure available, and the force available for holding the block against the wall. Also, the dimensions of the block of elastomeric material are important, as will be explained.
THE INVENTION IN RELATION TO THE PRIOR ART
Prior art from the field of filling cracks, which may be considered relevant to the invention, includes the following patent publications: US-2,815,895 (1957, Reed) US-4,509,884 (1985, Trout); US-4,884,922 (1989 Haq); US-5302,205 (1994, Priddy). These references show more or less elaborate means for forming a seal onto the wall surface around the crack, and a means for injecting the sealant into the cracks. The references do not show the use of a block of softly compressible elastomeric material to provide the seal to the wall surface, nor the use of a rigid or solid backing block to enable the elastomeric block to be pressed firmly and evenly against the wall.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
By way of further explanation of the invention, exemplary embodiments of the invention will now be described with reference to the accompanying drawings, in which:
Fig 1 is a pictorial view of a tool for aiding the operation of injecting sealant into a crack in a wall surface, which embodies the invention;
Fig 2 is a cross-section of the tool of Fig 1;
Fig 3 is a pictorial view of another version of the tool;
Figs 4a,4b,4c,4d are views of a component of a further version of the tool;
2i4~
Fig 5 is a cross-section illustrating another version of the tool.
The apparatuses shown in the accompanying drawings and described below are examples which embody the invention. It should be noted that the scope of the invention is defined by the accompanying claims, and not necessarily by specific features of exemplary embodiments.
As shown in Fig 1, the tool 20 comprises a backing-block 23, made of rigid nylon, and a foam-block 25, made of soft, elastically compressible, foam material. The two blocks are of the same length and width dimensions, and are glued together, face to face.
The foam-block 25 includes a contact face 27, which is adapted for being placed in direct touching contact with the surface of a wall. The contact face 27 is rectangular, and the general manner of use of the tool 20 is that the tool is placed in contact with the wall, over a crack 29 to be filled, with the long dimension of the rectangle disposed along the length of the crack (see Fig 2).
A through-hole 30 is located centrally of the blocks, and extends right through both blocks. The through-hole 30 terminates at an exit mouth 32, which opens into the face 27.
At its other end, the through-hole 30 includes a tapered socket 34. This is suitable for receiving the nozzle 36 of a sealant injector 38. The sealant injector 38 may be, for example, a caulking gun.
In operation, the person takes the tool in one hand, and applies it to the wall, over the crack. The person places the nozzle of the injector into the socket 34. The person holds the injector in one or both hands, and presses the nozzle 21~S6~ 1 firmly into the socket, with a force whereby the tool is held firmly against the wall surface. The force with which the tool is held against the wall may be derived entirely from the force with which the nozzle is pressed into the socket, or the person may apply a separate force directly to the tool (e.g with his other hand).
With the tool held firmly against the wall, the person may now apply pressure to the injector, causing sealant to be injected therefrom. The sealant passes through the through-hole 30, and emerges from the mouth 32. It might be considered that the sealant might, at this point, extrude between the wall surface and the contact face 27 of the foam block -- and in fact the sealant would do so if there were nowhere else for the sealant to go, and if the sealant were injected at a high enough pressure. However, the crack offers a path of smaller resistance to the flow of sealant.
It will be understood that, for effective operation of the tool, it is necessary to press the contact face of the foam block so firmly against the wall surface that the sealant can more easily enter the crack than it can extrude between the foam block and the wall.
The designer must ensure that, when the sealant is injected, the sealant goes into the crack, rather than between the foam block and the wall.
The factors which determine where the sealant will go are:
- the magnitude of the force, as applied by the person, with which the contact face of the foam block is pressed against the wall surface;
- the conformability of the foam block to the wall surface, and the ability of the foam block to form a seal with respect to the wall surface;
21~5~11 - the dimensions of the area of contact between the foam block and the wall, both as to the dimension measured along the length of the crack, and the dimension laterally across the crack.
As to the force, the available force is that force which can be applied by the person, using the hands and fingers. In fact, the designer should see to it that the needed force is on the light side, because sometimes the cracks may be in hard-to-reach places, where it would be awkward for a person to apply a large force.
As to the conformability of the foam material, the foam material as noted herein is highly conformable to wall surfaces, and to the (slight) irregularities normally found in wall surfaces. The foam material is of such a consistency that if an object such as a finger is pressed lightly into the foam, the foam deflects, and, in effect, the foam "flows"
around the end of the object, accommodating the object into the surface of the material. When the object is withdrawn from the surface of the material, the surface regains, or rebounds to, its original flatness. However, often this rebound is not immediate -- that is to say, the impression of the object may remain in the surface for a time after the object is withdrawn. Whilst a reasonable rebound time may be tolerated, the elastomeric material should be selected on the basis that a rapid rebound is one of the required properties.
For the purpose of the invention, the foam material is the more suitable the more the material has this combination of conformability with a rapid rebound characteristic. It is recognised that with the soft foam material as described, the light force required to make the foam conform to the wall surface, to the extent required for the sealant to enter the crack, and not extrude between the foam and the wall, is the kind of force that can be applied with the fingers.
214~61 i As to the dimensions of the contact face of the foam-block, the foam-block as shown is a rectangle 60-70 mm long and 30-40 mm wide. Thus, the length of the leakpath through which leaking sealant would have to travel is about 15 mm width-wise, and about 25 mm length-wise.
It is recognized that these force-, conformability-, rebound-and dimensional-properties, as desired, can be met in and by the structures as described herein.
The designer should also be concerned that the nozzle 36 of the in~ector should form an adequate seal within the socket 34. It would hamper the operation of filling the cracks if the sealant were to leak out around the nozzle due to the nozzle being a poor fit in the socket. Of course, a little leakage of sealant at this point is tolerable.
The designer must see to it that sealant will not leak around the nozzle when the nozzle is pressed into the socket with the same magnitude or level of force as is being used to press the block against the wall. Then, the tool can be held against the wall by pressing the nozzle into the socket.
The designer should also bear in mind that nozzles vary as to size and shape. It has been found that satisfactory results were achieved when the socket was a tapered or conical, from 10 mm in diameter, down to 6 mm.
When the nozzle is pressed into the socket with the kind of fairly light pressure needed to hold the tool against the wall, it is found -- the nozzle being conical, as mentioned --that that same light pressure is enough to ensure that very little sealant leaks past the nozzle.
214S6ii In use, the person lays the tool against the wall, and squeezes the sealant out. The sealant being generally very viscous, it takes several moments for the sealant to flow into the crack. With the dimensions of the blocks as described, an easy-to apply hand pressure will result in sealant travelling along the crack, and emerging from the ends of the foam block, and from the crack. When the person sees beads of sealant starting to appear in the crack, past the ends of the tool, he stops squeezing the sealant out, and allows any back-pressure to dissipate; and then he repositions the tool over the next portion of the crack. Again, he squeezes the sealant out until a bead of sealant again appears in the crack, beyond the end of the tool. This continues until the whole length of the crack is filled.
Fig 3 shows an alternative form of tool, in which the tool is especially adapted for filling cracks in the corners of rooms etc. The contact face in this case is of a right-angle-V-shape, as shown. Again, the important dimensions are that the leak-path distances from the mouth of the through-hole is 25 mm lengthwise and 15 mm widthwise.
The tool as described is very inexpensive to produce. The tool may be offered for sale at the same sales-counter as the tubes of sealant, caulking guns, etc. The person will then pick up one of the tools when he buys the sealant. The tool is inexpensive enough that the person can purchase it on a one-time-use basis. For this reason, ease of clean-up of the tool is not very important -- although clean-up presents little difficulty, since there are no intricate passageways or the like in the tool that might harbour solidified sealant.
The tool is manufactured by glueing or bonding together the two blocks. Alternatively, the tool may be manufactured in one piece using a polymeric material, cast or moulded with the density increasing from the bottom to the top of the mould.
214~6 11 The resulting composite block would be compressible and deformable at one face, and relatively solid and rigid behind that.
It is important that the sealing effect between the elastically compressible foam block and the wall surface extend right around the through-hole, i.e that there be no channels or the like in the foam block which would allow sealant to extrude out and escape, rather than penetrate the crack. In fact, in an alternative embodiment, the backing-block is provided with one or more ridges which encircle the mouth of the through-hole, and which serve to concentrate the compression, and hence sealing, action of the foam block onto the wall surface.
As mentioned, an adequate seal between the nozzle of the injector and the socket can generally be assured if the socket is correctly designed. However, the seal at this point can be enhanced by the use of, for example, a screw thread connection between the nozzle and the socket, or by the use of a shape of socket other than conical. Sometimes, the nozzle of the injector is provided with an annular ridge, near the tip, which can be useful for ensuring a good seal.
The consistency of the elastomeric foam material is an important characteristic as regards the performance of the tool. The material should not be too hard nor too soft. Good results have been obtained when the foam has the density of the close-packed, closed-cell foam. Such foam is not too soft: if such foam is pressed against the wall, the foam material "flows" into irregularities in the surface, such as cracks. When the foam is taken away, an impression of the shape of the crack is retained. The nature of such foam is such that, after a few moments, the impression disappears.
21~6~1 As mentioned, for the foam material to have the most advantageous balance of conformability and rapid-rebound, the foam material should be of the small-cell, closed-cell type.
It is contemplated in the broad scope of the invention that the elastically deformable (compressible) material required in the invention might be a solid, i.e non-cellular, elastomeric material. Certainly, a very soft rubber (or plastic) might have the required degree of conformability, and would have almost instant rebound. However, most non-celled materials, if soft enough to be conformable to the wall surface, would have insufficient structural strength or toughness, and would tend to crumble.
The use of celled foam has another advantage, which goes to the manner of deflection of elastomeric materials. If a block of the non-celled material were compressed locally, the material would be subject to internal pressures which extend more or less throughout the bulk of the material. As a result, even a localized stress produces a non-localized or general bulk deflection. On the other hand, when the material is celled, the material substantially cannot transmit deflections or stresses throughout its bulk. The material can deflect locally, without that deflection being felt in the bulk of the material. This property means that a block of celled foam material is generally much more conformable to the irregularities of a wall surface than a block of soft, but solid, rubber.
The block of elastomeric foam material preferably should be skinned. That is to say, the material should be manufactured in such a manner that the cells at the surface are all closed off, leaving the surface smooth and unbroken. The benefit of the foam material being skinned is that the surface is thereby rendered more durable and tear resistant. Also, the surface is thereby rendered largely impervious to the encroachment of 21456~:1 the sealant material into the cells.
The thickness of the elastomeric foam block is important. If the foam block were too thick, the tool as a whole might be unstable, in that a person might rock or tip the tool by (carelessly) pressing a little off-line. When the foam block is not too thick, the tool sits firmly against the wall when under pressure, and really cannot be tipped or rocked. Of course, the foam block must be thick enough that it is not possible to push through the foam with the backing block, thereby bottoming the backing block. A thickness of foam of less than 6 mm, and preferably around 3 mm, has been found satisfactory, when the block has the length and width dimensions as mentioned above.
The foam material should have the correct combination of properties. Thus it is not enough for the material simply to be conformable: putty is conformable, but is not elastic, as required in the invention. Also, celled foam can be made rigid, but only the elastic type is suitable in the invention.
Also, a soft sponge material, like a bath sponge, being of the open-cell type, would tend to absorb the sealant material, and quickly become unusable.
The American Standard Test Method specification for determining the Indentation Load Deflection of an elastomeric cellular material, is ASTM D 1667. In that specification, under procedure B (which is titled Compression Set), the material is compressed to 50% of its thickness, and held for 72 hours. The compressive force is then removed, and the thickness is measured after 30 minutes of recovery time.
Scoring is from 50 to 0, with a higher number indicating a slower rebound.
Also, procedure D of ASTM D 1667 is titled Compression Deflection. In this test, a block of the material is 6 l ~
compressed to a standard percentage of its thickness and the force required to achieve this compression is expressed as a pressure on the material, measured in pounds per square inch.
Standard compressions of 25% and 50% are used.
For the purposes of the tool as described herein, the material should be such that, in the Compression Set procedure B, the material recovers to 35 or lower. That is to say, the material remains no more than 35% compressed thirty minutes after the compressive force is removed.
Preferably also, the material should be such that, in the Compression Deflection procedure D, the 25% compression is achieved at a loading of between 3 and 7 psi, good results having been obtained at 4 psi.
In the invention, the best results may be expected when the compressibility (i.e compression deflection) is high, and the recovery (compression set) is low. Generally, however, with closed cell elastomeric materials, materials with the higher compressibilities tend to have the slower recovery rates.
The density of the material also is important in determining performance. A density of 10 lbs per cubic foot (0.16 gm/cm3) has been found to give good results.
Figs 4a,4b,4c,4d show a variation on the design of the backing block 39, in which adequate rigidity is achieved by forming the block in the particular shape.
Fig 5 shows the use of a rigid spigot or plug. The spigot 40 is bonded into the backing block 43, and engages a recess 45 in the wall. The complementary recesses 45 are prepared in the wall beforehand, being spaced at suitable intervals along the length of the crack. The recesses may be surface-levelled later, if required, with suitable filler.
21~56 1 ~
A device of the type as described in relation to Figs 1 and 2 has been used to inject acrylic latex caulking to a depth of 2 cm in a crack with a width of 0.5 mm, using only finger and hand operation of the tool, as described.
As described, the tool may be used to aid in the injection of e.g silicon sealants, rubberised sealants, adhesives, fillers, caulking, grouts, and anything else of a liquid or pasty nature that is used for filling cracks.
This invention relates to the injection of sealant or filler into cracks (including voids and such like recesses) in walls, floors, etc, made of concrete, masonry, plaster, and the like, and wood.
BACKGROUND TO THE INVENTION
The conventional techniques for filling small cracks tend to fall into two categories. The light techniques produce what amounts to just a surface coating of the sealant, with very little penetration of the crack. The heavy techniques use injection ports at spaced intervals along the crack; the outside of the crack is covered with a sealing compound, or an elaborate mechanical means is provided for sealing the port to the wall; and then pressurized equipment injects the compound into the crack. The light techniques, though inexpensive enough, provide little more than cosmetic treatment; the heavy techniques can work well enough, even to restore structural integrity in some cases, but are limited by their high cost.
The invention is aimed at providing a tool which enables sealant to be injected deep into the crack, and which is inexpensive enough that the tool can be used on a one-time-use basis, and preferably which is so inexpensive to produce that it can be favourably priced when on the same counter shelf as, for example, tubes of caulking.
The invention is aimed at providing a tool which is particularly suitable for use with conventional tubes o~
caulking, sealants, adhesives, grouts, and fillers. The tool is intended for use with conventional caulking injection-guns;
or, the injection can be done by manual compression of a soft container.
GENERAL FEATURES OF THE INVENTION
The invention makes use of a property of some synthetic polymers -- notably compressible and elastomeric materials, and especially soft foam materials -- namely, the ability of a flat block of the material to conform intimately to a nominally flat wall surface when pressed lightly against the surface. A block of the elastically compressible, or elastomeric, material is loaded against the wall surface by means of a solid backing block, which enables the force pushing the block against the wall to be spread evenly throughout the elastomeric block.
The invention is herein described as it relates to sealing cracks in walls, but it will be understood that the repair sites may be in floors, or in other structures or articles in which the sealing of cracks is required.
Sealant (or other injectable repair material) is injected through a through-hole through the blocks, and out through an exit-mouth in the elastomeric block, and into the crack. The elastomeric material serves to seal the wall surface area around the mouth of the through-hole, allowing pressure to be built up, which produces good penetration of the crack, without the sealant leaking or extruding between the block and the wall surface.
The compressible elastomeric material preferably is expanded, cross-linked, polyvinyl chloride foam material, that is formed with an integral skin. Also, low density neoprene foam, and some solid silicone and polyurethane-based elastomers may be used.
The contact face of the elastomeric block may be flat, concave, convex, or angled, as required for specific repair sites. The degree of compressibility and elasticity of the 21~6~
material is selected with reference to the extent and size of the crack, the viscosity of the sealant, the injection pressure available, and the force available for holding the block against the wall. Also, the dimensions of the block of elastomeric material are important, as will be explained.
THE INVENTION IN RELATION TO THE PRIOR ART
Prior art from the field of filling cracks, which may be considered relevant to the invention, includes the following patent publications: US-2,815,895 (1957, Reed) US-4,509,884 (1985, Trout); US-4,884,922 (1989 Haq); US-5302,205 (1994, Priddy). These references show more or less elaborate means for forming a seal onto the wall surface around the crack, and a means for injecting the sealant into the cracks. The references do not show the use of a block of softly compressible elastomeric material to provide the seal to the wall surface, nor the use of a rigid or solid backing block to enable the elastomeric block to be pressed firmly and evenly against the wall.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
By way of further explanation of the invention, exemplary embodiments of the invention will now be described with reference to the accompanying drawings, in which:
Fig 1 is a pictorial view of a tool for aiding the operation of injecting sealant into a crack in a wall surface, which embodies the invention;
Fig 2 is a cross-section of the tool of Fig 1;
Fig 3 is a pictorial view of another version of the tool;
Figs 4a,4b,4c,4d are views of a component of a further version of the tool;
2i4~
Fig 5 is a cross-section illustrating another version of the tool.
The apparatuses shown in the accompanying drawings and described below are examples which embody the invention. It should be noted that the scope of the invention is defined by the accompanying claims, and not necessarily by specific features of exemplary embodiments.
As shown in Fig 1, the tool 20 comprises a backing-block 23, made of rigid nylon, and a foam-block 25, made of soft, elastically compressible, foam material. The two blocks are of the same length and width dimensions, and are glued together, face to face.
The foam-block 25 includes a contact face 27, which is adapted for being placed in direct touching contact with the surface of a wall. The contact face 27 is rectangular, and the general manner of use of the tool 20 is that the tool is placed in contact with the wall, over a crack 29 to be filled, with the long dimension of the rectangle disposed along the length of the crack (see Fig 2).
A through-hole 30 is located centrally of the blocks, and extends right through both blocks. The through-hole 30 terminates at an exit mouth 32, which opens into the face 27.
At its other end, the through-hole 30 includes a tapered socket 34. This is suitable for receiving the nozzle 36 of a sealant injector 38. The sealant injector 38 may be, for example, a caulking gun.
In operation, the person takes the tool in one hand, and applies it to the wall, over the crack. The person places the nozzle of the injector into the socket 34. The person holds the injector in one or both hands, and presses the nozzle 21~S6~ 1 firmly into the socket, with a force whereby the tool is held firmly against the wall surface. The force with which the tool is held against the wall may be derived entirely from the force with which the nozzle is pressed into the socket, or the person may apply a separate force directly to the tool (e.g with his other hand).
With the tool held firmly against the wall, the person may now apply pressure to the injector, causing sealant to be injected therefrom. The sealant passes through the through-hole 30, and emerges from the mouth 32. It might be considered that the sealant might, at this point, extrude between the wall surface and the contact face 27 of the foam block -- and in fact the sealant would do so if there were nowhere else for the sealant to go, and if the sealant were injected at a high enough pressure. However, the crack offers a path of smaller resistance to the flow of sealant.
It will be understood that, for effective operation of the tool, it is necessary to press the contact face of the foam block so firmly against the wall surface that the sealant can more easily enter the crack than it can extrude between the foam block and the wall.
The designer must ensure that, when the sealant is injected, the sealant goes into the crack, rather than between the foam block and the wall.
The factors which determine where the sealant will go are:
- the magnitude of the force, as applied by the person, with which the contact face of the foam block is pressed against the wall surface;
- the conformability of the foam block to the wall surface, and the ability of the foam block to form a seal with respect to the wall surface;
21~5~11 - the dimensions of the area of contact between the foam block and the wall, both as to the dimension measured along the length of the crack, and the dimension laterally across the crack.
As to the force, the available force is that force which can be applied by the person, using the hands and fingers. In fact, the designer should see to it that the needed force is on the light side, because sometimes the cracks may be in hard-to-reach places, where it would be awkward for a person to apply a large force.
As to the conformability of the foam material, the foam material as noted herein is highly conformable to wall surfaces, and to the (slight) irregularities normally found in wall surfaces. The foam material is of such a consistency that if an object such as a finger is pressed lightly into the foam, the foam deflects, and, in effect, the foam "flows"
around the end of the object, accommodating the object into the surface of the material. When the object is withdrawn from the surface of the material, the surface regains, or rebounds to, its original flatness. However, often this rebound is not immediate -- that is to say, the impression of the object may remain in the surface for a time after the object is withdrawn. Whilst a reasonable rebound time may be tolerated, the elastomeric material should be selected on the basis that a rapid rebound is one of the required properties.
For the purpose of the invention, the foam material is the more suitable the more the material has this combination of conformability with a rapid rebound characteristic. It is recognised that with the soft foam material as described, the light force required to make the foam conform to the wall surface, to the extent required for the sealant to enter the crack, and not extrude between the foam and the wall, is the kind of force that can be applied with the fingers.
214~61 i As to the dimensions of the contact face of the foam-block, the foam-block as shown is a rectangle 60-70 mm long and 30-40 mm wide. Thus, the length of the leakpath through which leaking sealant would have to travel is about 15 mm width-wise, and about 25 mm length-wise.
It is recognized that these force-, conformability-, rebound-and dimensional-properties, as desired, can be met in and by the structures as described herein.
The designer should also be concerned that the nozzle 36 of the in~ector should form an adequate seal within the socket 34. It would hamper the operation of filling the cracks if the sealant were to leak out around the nozzle due to the nozzle being a poor fit in the socket. Of course, a little leakage of sealant at this point is tolerable.
The designer must see to it that sealant will not leak around the nozzle when the nozzle is pressed into the socket with the same magnitude or level of force as is being used to press the block against the wall. Then, the tool can be held against the wall by pressing the nozzle into the socket.
The designer should also bear in mind that nozzles vary as to size and shape. It has been found that satisfactory results were achieved when the socket was a tapered or conical, from 10 mm in diameter, down to 6 mm.
When the nozzle is pressed into the socket with the kind of fairly light pressure needed to hold the tool against the wall, it is found -- the nozzle being conical, as mentioned --that that same light pressure is enough to ensure that very little sealant leaks past the nozzle.
214S6ii In use, the person lays the tool against the wall, and squeezes the sealant out. The sealant being generally very viscous, it takes several moments for the sealant to flow into the crack. With the dimensions of the blocks as described, an easy-to apply hand pressure will result in sealant travelling along the crack, and emerging from the ends of the foam block, and from the crack. When the person sees beads of sealant starting to appear in the crack, past the ends of the tool, he stops squeezing the sealant out, and allows any back-pressure to dissipate; and then he repositions the tool over the next portion of the crack. Again, he squeezes the sealant out until a bead of sealant again appears in the crack, beyond the end of the tool. This continues until the whole length of the crack is filled.
Fig 3 shows an alternative form of tool, in which the tool is especially adapted for filling cracks in the corners of rooms etc. The contact face in this case is of a right-angle-V-shape, as shown. Again, the important dimensions are that the leak-path distances from the mouth of the through-hole is 25 mm lengthwise and 15 mm widthwise.
The tool as described is very inexpensive to produce. The tool may be offered for sale at the same sales-counter as the tubes of sealant, caulking guns, etc. The person will then pick up one of the tools when he buys the sealant. The tool is inexpensive enough that the person can purchase it on a one-time-use basis. For this reason, ease of clean-up of the tool is not very important -- although clean-up presents little difficulty, since there are no intricate passageways or the like in the tool that might harbour solidified sealant.
The tool is manufactured by glueing or bonding together the two blocks. Alternatively, the tool may be manufactured in one piece using a polymeric material, cast or moulded with the density increasing from the bottom to the top of the mould.
214~6 11 The resulting composite block would be compressible and deformable at one face, and relatively solid and rigid behind that.
It is important that the sealing effect between the elastically compressible foam block and the wall surface extend right around the through-hole, i.e that there be no channels or the like in the foam block which would allow sealant to extrude out and escape, rather than penetrate the crack. In fact, in an alternative embodiment, the backing-block is provided with one or more ridges which encircle the mouth of the through-hole, and which serve to concentrate the compression, and hence sealing, action of the foam block onto the wall surface.
As mentioned, an adequate seal between the nozzle of the injector and the socket can generally be assured if the socket is correctly designed. However, the seal at this point can be enhanced by the use of, for example, a screw thread connection between the nozzle and the socket, or by the use of a shape of socket other than conical. Sometimes, the nozzle of the injector is provided with an annular ridge, near the tip, which can be useful for ensuring a good seal.
The consistency of the elastomeric foam material is an important characteristic as regards the performance of the tool. The material should not be too hard nor too soft. Good results have been obtained when the foam has the density of the close-packed, closed-cell foam. Such foam is not too soft: if such foam is pressed against the wall, the foam material "flows" into irregularities in the surface, such as cracks. When the foam is taken away, an impression of the shape of the crack is retained. The nature of such foam is such that, after a few moments, the impression disappears.
21~6~1 As mentioned, for the foam material to have the most advantageous balance of conformability and rapid-rebound, the foam material should be of the small-cell, closed-cell type.
It is contemplated in the broad scope of the invention that the elastically deformable (compressible) material required in the invention might be a solid, i.e non-cellular, elastomeric material. Certainly, a very soft rubber (or plastic) might have the required degree of conformability, and would have almost instant rebound. However, most non-celled materials, if soft enough to be conformable to the wall surface, would have insufficient structural strength or toughness, and would tend to crumble.
The use of celled foam has another advantage, which goes to the manner of deflection of elastomeric materials. If a block of the non-celled material were compressed locally, the material would be subject to internal pressures which extend more or less throughout the bulk of the material. As a result, even a localized stress produces a non-localized or general bulk deflection. On the other hand, when the material is celled, the material substantially cannot transmit deflections or stresses throughout its bulk. The material can deflect locally, without that deflection being felt in the bulk of the material. This property means that a block of celled foam material is generally much more conformable to the irregularities of a wall surface than a block of soft, but solid, rubber.
The block of elastomeric foam material preferably should be skinned. That is to say, the material should be manufactured in such a manner that the cells at the surface are all closed off, leaving the surface smooth and unbroken. The benefit of the foam material being skinned is that the surface is thereby rendered more durable and tear resistant. Also, the surface is thereby rendered largely impervious to the encroachment of 21456~:1 the sealant material into the cells.
The thickness of the elastomeric foam block is important. If the foam block were too thick, the tool as a whole might be unstable, in that a person might rock or tip the tool by (carelessly) pressing a little off-line. When the foam block is not too thick, the tool sits firmly against the wall when under pressure, and really cannot be tipped or rocked. Of course, the foam block must be thick enough that it is not possible to push through the foam with the backing block, thereby bottoming the backing block. A thickness of foam of less than 6 mm, and preferably around 3 mm, has been found satisfactory, when the block has the length and width dimensions as mentioned above.
The foam material should have the correct combination of properties. Thus it is not enough for the material simply to be conformable: putty is conformable, but is not elastic, as required in the invention. Also, celled foam can be made rigid, but only the elastic type is suitable in the invention.
Also, a soft sponge material, like a bath sponge, being of the open-cell type, would tend to absorb the sealant material, and quickly become unusable.
The American Standard Test Method specification for determining the Indentation Load Deflection of an elastomeric cellular material, is ASTM D 1667. In that specification, under procedure B (which is titled Compression Set), the material is compressed to 50% of its thickness, and held for 72 hours. The compressive force is then removed, and the thickness is measured after 30 minutes of recovery time.
Scoring is from 50 to 0, with a higher number indicating a slower rebound.
Also, procedure D of ASTM D 1667 is titled Compression Deflection. In this test, a block of the material is 6 l ~
compressed to a standard percentage of its thickness and the force required to achieve this compression is expressed as a pressure on the material, measured in pounds per square inch.
Standard compressions of 25% and 50% are used.
For the purposes of the tool as described herein, the material should be such that, in the Compression Set procedure B, the material recovers to 35 or lower. That is to say, the material remains no more than 35% compressed thirty minutes after the compressive force is removed.
Preferably also, the material should be such that, in the Compression Deflection procedure D, the 25% compression is achieved at a loading of between 3 and 7 psi, good results having been obtained at 4 psi.
In the invention, the best results may be expected when the compressibility (i.e compression deflection) is high, and the recovery (compression set) is low. Generally, however, with closed cell elastomeric materials, materials with the higher compressibilities tend to have the slower recovery rates.
The density of the material also is important in determining performance. A density of 10 lbs per cubic foot (0.16 gm/cm3) has been found to give good results.
Figs 4a,4b,4c,4d show a variation on the design of the backing block 39, in which adequate rigidity is achieved by forming the block in the particular shape.
Fig 5 shows the use of a rigid spigot or plug. The spigot 40 is bonded into the backing block 43, and engages a recess 45 in the wall. The complementary recesses 45 are prepared in the wall beforehand, being spaced at suitable intervals along the length of the crack. The recesses may be surface-levelled later, if required, with suitable filler.
21~56 1 ~
A device of the type as described in relation to Figs 1 and 2 has been used to inject acrylic latex caulking to a depth of 2 cm in a crack with a width of 0.5 mm, using only finger and hand operation of the tool, as described.
As described, the tool may be used to aid in the injection of e.g silicon sealants, rubberised sealants, adhesives, fillers, caulking, grouts, and anything else of a liquid or pasty nature that is used for filling cracks.
Claims (26)
- CLAIM 1. Apparatus for aiding the operation of injecting crack-sealing material into a crack, wherein:
the apparatus includes a compression block and a backing block, and a through-hole through the two blocks;
the material of the compression block is an elastically compressible elastomeric material;
the compression block has a contact surface which is adapted for contact with a wall or other surface in which the crack is located;
the through-hole terminates at an exit mouth in the contact surface;
the material of the backing block is bulky, solid, and rigid, and the backing block is suitable for providing mechanical backing support to the foam block;
in the apparatus, the compression block and the backing block are unitary to the extent that, upon the apparatus being placed with the contact surface in contact with the wall surface, a force applied to the backing block will be transmitted substantially evenly throughout the compression block;
the compression block and the backing block are formed with a through-hole through the two blocks;
the through-hole is formed with a means for receiving sealant under pressure, and for conveying the pressurized sealant through the through-hole to the wall surface, and into the crack. - CLAIM 2. Apparatus of claim 1, wherein the compression block is substantially without inherent mechanical rigidity.
- CLAIM 3. Apparatus of claim 1, wherein the material of the compression block is of such a consistency that the material is capable of conforming to a shape imposed on the material by a light pressure.
- CLAIM 4. Apparatus of claim 1, wherein the backing block and the foam block were formed as separate components, and were bonded together.
- CLAIM 5. Apparatus of claim 4, where a surface of the backing block, being the surface of the backing block to which the foam-block is bonded, was formed with a convex ridge thereon, the ridge being disposed circumferentially around the through-hole.
- CLAIM 6. Apparatus of claim 1, where the device was formed in one block from foam or foam material having, at a base of the block, a low density whereby the material permits compression or deformation, and having, at a top of the block, a higher density, whereby the material is substantially rigid.
- CLAIM 7. Apparatus of claim 1, wherein the material of the foam block comprises an expanded cross-linked polyvinyl chloride of low density.
- CLAIM 8. Apparatus of claim 1, wherein the material of the foam block comprises neoprene foam.
- CLAIM 9. Apparatus of claim 1, wherein the material of the foam block comprises elastomeric silicon or polyurethane.
- CLAIM 10. Apparatus of claim 1, wherein the material of the compression block is an elastomeric foam.
- CLAIM 11. Apparatus of claim 10, wherein the foam material is of the kind which, after the material is deflected by an object, whereby the object leaves an impression in a surface thereof, the material rebounds rapidly after the object is withdrawn.
- CLAIM 12. Apparatus of claim 10, wherein the foam material is of the closed-cell kind.
- CLAIM 13. Apparatus of claim 10, wherein the foam material is of the type that was formed with an integral surface skin.
- CLAIM 14. Apparatus of claim 1, wherein the contact face of the foam block is flat and planar.
- CLAIM 15. Apparatus of claim 14, wherein the contact face is a rectangle, 30 mm by 60 mm.
- CLAIM 16. Apparatus of claim 15, wherein the foam block is around 3 mm thick.
- CLAIM 17. Apparatus of claim 1, wherein the contact face is right-angle-V-shaped, whereby the contact face fits into a corner between two walls.
- CLAIM 18. Apparatus of claim 1, wherein the dimensional extent of the contact face is such that, when the backing-block is pressed against the wall, the contact face extends to at least 25 mm from the exit mouth in the direction along the length of the crack, and extends to at least 15 mm from the exit mouth in the lateral direction with respect to the crack.
- CLAIM 19. Apparatus of claim 1, where the means for receiving sealant under pressure comprises a female socket formed in the backing block, the socket being a component of the through-hole.
- CLAIM 20. Apparatus of claim 19, wherein the socket is conical.
- CLAIM 21. Apparatus of claim 1, wherein the material of the foam block has a compression set, as defined in ASTM D 1667 procedure B, of 35% or lower
- CLAIM 22. Apparatus of claim 1, wherein the material of the foam block has a compression deflection, as defined in ASTM
D 1667 procedure D, of between 3 and 7 psi. - CLAIM 23. Apparatus of claim 1, wherein the material of the foam block has a density of about 10 lbs/cu ft (0.16 gm/cm3).
- CLAIM 24. Procedure for injecting sealant into cracks in a wall surface, wherein the procedure includes the steps of:
providing an apparatus of the structure as claimed in claim 1;
providing an operable injector, having a nozzle, which is effective, when operated, to inject sealant under pressure out of the nozzle;
(a) placing the apparatus with the contact face of the apparatus in direct touching contact with the wall surface, and over a crack in the wall surface;
(b) inserting the nozzle into the socket in the backing-block, and pressing the nozzle into the socket, thereby pressing the apparatus against the wall surface;
(c) operating the injector, to inject sealant through the through-hole and into the crack;
(d) applying and maintaining enough force pressing the apparatus against the wall that the sealant is prevented from extruding out between the contact face and the wall surface;
(e) injecting enough sealant that sealant emerges from the crack, beyond the contact surface;
(f) stepping the apparatus along the length of the crack, and repeating steps (a) to (e) until the length of the crack is filled. - CLAIM 25. Apparatus of claim 1, wherein the apparatus is formed with a rigid spigot, which protrudes from the contact face, and which is suitable for insertion into a complementary recess formed in the wall surface.
- CLAIM 26. Procedure of claim 24, wherein the procedure includes the steps of:
providing an apparatus of the structure as claimed in claim 25;
making complementary recesses in the wall surface at spaced intervals along the length of the crack;
positioning and engaging the apparatus with the spigot in the respective recesses in sequence, each in turn, and injecting sealant at each engagement.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002145611A CA2145611A1 (en) | 1995-03-27 | 1995-03-27 | Tool for injecting sealant into cracks |
| GB9605552A GB2299365A (en) | 1995-03-27 | 1996-03-15 | Tool for injecting sealant into cracks |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002145611A CA2145611A1 (en) | 1995-03-27 | 1995-03-27 | Tool for injecting sealant into cracks |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2145611A1 true CA2145611A1 (en) | 1996-09-28 |
Family
ID=4155512
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002145611A Abandoned CA2145611A1 (en) | 1995-03-27 | 1995-03-27 | Tool for injecting sealant into cracks |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2145611A1 (en) |
| GB (1) | GB2299365A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9289922B2 (en) | 2006-11-14 | 2016-03-22 | Atomic Energy Of Canada Limited/Energie | Device and method for surface replication |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB644132A (en) * | 1946-03-01 | 1950-10-04 | Karl Pauli Billner | Methods and apparatus for molding plastic material |
| GB821535A (en) * | 1956-06-27 | 1959-10-07 | Hugh Phillips | Improvements in and relating to the filling of cracks in plaster and other surfaces |
| EP0469717B1 (en) * | 1990-06-30 | 1995-08-09 | Hayashi Kensetsu Kogyo Kabushiki Kaisha | A method and device for injecting a repairing agent into concrete |
-
1995
- 1995-03-27 CA CA002145611A patent/CA2145611A1/en not_active Abandoned
-
1996
- 1996-03-15 GB GB9605552A patent/GB2299365A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9289922B2 (en) | 2006-11-14 | 2016-03-22 | Atomic Energy Of Canada Limited/Energie | Device and method for surface replication |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2299365A (en) | 1996-10-02 |
| GB9605552D0 (en) | 1996-05-15 |
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