CA1249796A

CA1249796A - Destructible container for a multi-component settable means

Info

Publication number: CA1249796A
Application number: CA000480462A
Authority: CA
Inventors: Gusztav Lang; Peter Mauthe
Original assignee: Hilti AG
Current assignee: Hilti AG
Priority date: 1984-04-30
Filing date: 1985-04-30
Publication date: 1989-02-07
Also published as: JPH0542472B2; AU586158B2; EP0163019A1; ATE32623T1; JPS60252675A; DE3561670D1; ES286400Y; ES286400U; AU3984985A; US4651875A; DE3416094A1; EP0163019B1

Abstract

ABSTRACT OF THE DISCLOSURE
A destructible container is arranged to maintain the components of a multi-component settable mass in separate regions until they are ready to be mixed for anchoring a fastener member in a borehole. The container is made up of an elongated outer cartridge and an inner cartridge positioned within the outer cartridge so that a space for one of the components is formed between the inner cartridge and the outer cartridge. The multi-component mass includes a resin component filled into the outer cartridge and a hardenable component filled into the inner cartridge. The space within the outer cartridge is divided into two separate regions, preferably one follow-ing the other in the elongated direction of the outer cartridge. The resin component is present in each region, however, a thixotropic agent is included in one region but not the other so that the viscosity of the resin component is greatly increased within the one region. Preferably, the increased viscosity component is present in the region of the outer cartridge forming the trailing end of the container when it is inserted into a borehole so that flow out of the borehole is, for practical purposes, prevented.
Accordingly, a resin component which is highly fluid prior to the mixing operation, such as methylmethacrylate (MMA) can be used.

Description

The invention is directed to a destructible container for a set-table multi-component mass used for anchoring a fastening member in a borehole. The container is formed of an outer cartridge and an inner car-tridge positioned within the outer cartridge with one of the cartridges filled wi-th a resin component and filler materials of -the mass and the o-ther cartridge wi-th a hardenable component and possibly wi-th additional Eiller materials.
The chemical anchoring oE fastening members using a settable mass or material has definite advantages as compared to a mechanical anchoring, such as where a dowel is secured by an expansion procedure in a receiving material. These advantages include the lack of an ex-pansion pressure developed in the receiving material and anchoring the fastening member where only minor edge distances in the receiving material are involved.
In previously known chemical anchoring procedures relatively highly viscous materials, such as polyester resin, an epoxy resin or a polyurethane resin have been used as the settable material enclosed within a container.
Where there has been insufficient cleaning of -the bore-hole prior to the insertion of -the settable material or where the receiving ma-terial is poxous or has fine micro-fissures hardly discernable by the naked eye, the adhesion of such highly viscous resins with the receiving material is limited. Apar-t Erom the reduc-tion in anchoring values, which can be determined immediately, unfavorably long time behaviour can occur particularly where the fastening member undergoes al-ternating s-tresses. To overcome such disadvan-tages, the use of low viscosity, that is highly fluid resins, has been attempted, however, when used in boreholes directed vertically upwardly or horizontally, such ma-terial tends to leak or run ou-t of the borehole prior to becoming set. To avoid -the loss of -the material it has been known to utilize a mul-tichamber container and -to fill it at the opening into the borehole with components of a particularly rapidly settable, foamable resin mixture.
Such Eoamable masses, however, have a considerably lower strength so that it is necessary -to use longer fas-tenlng members and the boreholes must be correspondingly deeper, which results in increased assembly time and material costs.
Further, water is required for the foaming process and it is not always available in -the different receiving materials in which the fastening member is -to be secured.
Other options for sealing the opening to the borehole, such as plugs or -the like, have proved -to be unsuitable in actual practice, because they become damaged or des-troyed when the fas-tening member is driven in which is usually effected by a rotational action.
ThereEore, the primary object of -the present invention is to arrange a settable mul-ti-component mass or ma-terial in a container for use in anchoring fastening members so that high anchoring values are attained and a simple and low cost installation is afEorded.
In accordance with the present invention, the container is divided into regions one holding a low viscosi-ty resin component and another with the resin component including thixotropic agents for increasing the viscosity of -the component. Preferably, the low viscosity 3_~r~

resin component is located in the leading region of the con-tainer as it is inserted into a borehole with the increased viscosity component being located at the -trailing end of the container.
As a resul-t, the resin componen-t in the container is separa-ted into two different regions wi-th the component in each region having a differen-t viscosi-ty. After the insertion oE the container into a borehole, -the portion of the resin component located in the inner part of the bore-hole is more highly fluid than the portion of -the component located at the opening in-to the borehole. The portion of the resin component enriched with known thixotropic agents, siuch as pyrogenous silicic acids, kaolin, asbestos, montmorrilonite or the like, forms a thick or heavy paste which can adapt to the borehole wall and to the fastening member to be anchored for preventing any flow out of the borehole of the highly fluid portion of the resin componen-t. ThereEore, a low viscosity resin, such as methylmethacrylate (MMA) can be used as the resin com-ponent. Such a highly fluid resin component is capable of forming an adequa-te bond to any dust remaining on the borehole wall and can provide an effective connection wi-th the receiving material. If the receivi.ng material has hairline cracks in the region of the borehole, then such cracks can be filled by the highly fluid resin component and the strength of the receiving ma-terial is improved.
For the simple fabrication of -the container, in a preferred embodiment the con-tainer is made up of an outer car-tridge and an inner cartridge. The inner car-t-ridge holds the hardenable componen-t while the space within the outer cartridge around the inner cartridge holds the resin component. The trailing portion of the outer cartridge as it is inserted into the borehole contains the thixotropic agents along wi-th the resin component.
Such an arrangement is favourable because the resin componen-t involves a volume which is much grea-ter than that of -the hardenable component. Bo-th the outer cartridge and the inner cartridge are formed of easily destructible plastics or glass. When broken up or fragmented, the material forming the cartridges affords additional filler materials.
To prevent any flow of the highly fluid portion of the resin component out of the borehole, the layer -thickness of the viscous portion containing the thixo-tropic agents must be sufficiently greatA On the other hand, the thickness o~ the viscous portion cannot be -too great, since the viscous portion does not adhere to the borehole wall as well as the highly fluid portion of the resin component so -that there would be a resultant reduc-tion :in the strength of the anchor formed. For a favorable relationship be-tween the two portions, it is advantageous for the leng-th of the trailing portion of the resin component containing the thixotropic agents to be in the range of 0.2 to 0.4 of the length of the leading end portion oE the resin component. Such a length ratio affords op-timum conditions for anchoring a fastening member. The portions of the resin componen-t having different viscosities can be achieved using the same or different resins. Accordingly, the leading end portion filling the base of the borehole may consist of methyl-methacrylate while the resin portion at the en-trance into the borehole can be a polyester or epoxicle resin.
A-t the transi-tion between the leading end por-tion and -the trailing end portion of the resin component, it is possible for the two portions to mix. To prevent such mixing a separation layer can be provided be-tween the leading end portion and -the trailing end portion. Such a separation layer must be easily destruc-tible while the fastening member is being inserted. Accordingly, the separation layer may be formed of a foil, glass, or a partially set resin layer. Furthermore, i-t is also possible to use a layer of wax or the like between the two different regions. If the container is not completely filled by the sealed glass cartridges, any remaining open space within the container can be separated from the components forming the mass using a separation layer by filling the open space with a fibrous material. For the proper use of the container embodying -the presen-t invention it is important that i-t is inser-ted into -the borehole in the proper manner, tha-t is, that the leading end of the container is inser-ted firs-t into -the borehole. If the trailing end of the container is inserted first into the borehole, the vi.scous por-tion of the resin component is located at the base of the borehole and there is nothing to prevent the highly fluid portion from running out of the borehole. To facili-tate the proper insertion of -the container, it is possible to provide it with markings.
To ensure -the proper introduction of -the con-tainer in-to the borehole, it is advantageous to provide a cover on the -trailing end of the container, tha-t is, the trailing end of the outer cartridge. The outside dimensions of the cover are preferably greater than -the diameter of the bore-hole in which the container is to be inserted. The cover can be placed on a sealed container or it can be connec-ted -to -the con-tainer by inter-engaging locking members or by a threaded connection or i-t can form the seal for the trailing end of the container. To avoid any interference with the placement of the fastening element into the container, the cover must be formed of an easily des-tructible material, for instance, a plas-tics material or the like.
The various features of novelty which charac-terize -the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure.
For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descrip-tive material in which there are illustrated and described preferred embodiments of the invention.
IN T~IE ~RAWINGS
Figure 1 is a cross-sectional view of a con-tainer embodying the present invention along the longitudinal axis of the container;
Figure 2 is a partial view of another container embodying -the presen-t invention with a cover at the container end;
Figure 3 is a further embodiment of -the con-tainer, similar to Figure 2, wi-th a locking member engaying the end of the container, and, Figure ~ is yet another embodiment of the inven-tion with the cover threaded onto -the end of the container.

7~

The invention is illustrated as a destructible container 10 shown in Figure 1. I-t is made up oE an elongated outer cartridge 11 and an elonga-ted inner cartridge 12. Cartridge 12 is located wi-th:in the outer cartridge with the inner car-tridge spaced inwardly from the outer cartridge so that a space or volume is provided in -the outer cartridge around -the inner cartridge. The con-tainer is inser-ted into a borehole having a similar diameter for securing a fas-tening member driven in-to the container when it is positioned wi-thin the borehole.
The driving in action breaks up -the material forming the inner and outer cartridges.
The ou-ter cartridge in this example preferably contains a resin component 13. The volume within the outer cartridge around the inner cartridge is divided into a leading end region 1~ and a trailing end region 15.
The portion of the resin component 13 located within -the -trailing end region 15 is enriched wi-th a -thixo-tropic agent and, as a resul-t, has a very high viscosity.
~o The portion of the resin component located in the leading end region 14 of the outer cartridge 11 has a low viscosity and is formed of methylmethacrylate (MMA). The highly fluid portion of -the resin component 13 in the leading end region 14 contains a relatively high amount of filler material, such as hollow glass spheres, quar-t~ powder, glass -tubelets or the like. The outer cartridge 11 and -the inner cartridge 12 are formed of an easily destructible material, that is, a material -that breaks or fractures easily, such as glass or a brittle plastics material.
A hardenable component 16 is located, in th:is example, ~2~

within the inner cartridge 12. Component 16 consists, for instance, of dibenzoyl peroxide, polymethylmethacrylate-particles and filler ma-terial, such as quartz powder.
Mixing of the resin component 13 in the leading end region 14 with the component in the trailing end region 15 during storing and handling of -the container 10 is prevented by using a separation layer 17 which ex-tends -transversely of the longitudinal axis of the container and separates the -two regions 14, 15. The separation layer may be formed of foil, glass or the like.
When an outer cartridge 11 formed of glass is being sealed by melting the glass, it is practically unavoidable to form an air space 18 in the trailing end of the outer cartridge 11. To prevent air within the space 18 from causing a chemical change in the resin component 13 in the trailing end region 15, and also to prevent any displacement of the components within the outer cart-ridge, an end cover lg is inserted into the outer cartridge 11 before the sealing operat:ion so that the cover separa-tes the resin component from any air in space 18. Further, the cover 1~ bears against the -trailing end of the inner car-tridge 12 preventing it from becoming displaced.
The leng-th Ll of the trailing end region 15 con-taining -the resin component 13 is approximately one-third of the leng-th L2 of the leading end region 14 (note Figure 1).
The following is an example of the size and make-up of a container embodying the present invention for use with 12mm anchor rods:

Length of -the outer car~ridge : 110 mm Diameter of the outer cartridge : 11.7 mm Length of -the inner cartridge : 90 mm Diarneter of the inner cartridge : 6.3 mm Length L2 of the leading end region of outer cartridge : 65 mm Content of the leading end region of ou-ter cartridge : 7.1 g Quartz (granule size 1.2 -to l.g mm)

2.5 g Methylmethacrylate (MMA) Length Ll of the trailing end region : 25 mm Con-tent of the trailing end region of outer cartridge : 1.15 g Methylmethacrylate (MMA) 2.~ g Quar-tz powder (particle size 10 to 60 um) 0.09 g pyrogenous silicic acid The inner cartridge contains:
0.6 g dibenzoyl peroxide 0.2 g polymethylmethacrylate (PMMAA: particle size 0.1 mm) 1.7 g quartz powder (particle size 10 - 60 um) In Figure 2 the trailing end of a container 20 is shown formed of an outer cartridge 21 and an inner cartridge 22. The outer cartridge 21 con-tains -the resin component 23. The space between the trailing end of the f~

resin component 23 and the -trailing end of the outer cartridge 21 is filled wi-th a fibrous material 24. The fibrous material prevents any displacement of the inner cartridge 22 or of the resin component 23 in -the space within the outer cartridge about the inner cartridge.
For identifica-tion purposes and also -to preven-t the in-ver-ted insertion of -the container 20 into a borehole, a cover 25 is secured over the trailing end oE the outer cartridge 21. The cover 25 is formed oE an easily broken plastics material and has an outside diameter preferably larger than the diameter of the borehole in the receiving material intended to receive the con-tainer 20. A harden-able component 26 is filled into the inner cartridge 22.
In Figure 3 container 30 is made up of an outer cartridge 31 and an inner cartridge 32. Outer cartridge 31 in the space around the inner cartridge, contains a resin component 33. As distinguished from the embodiments illustrated in Figures 1 and 2, outer cartridge 21 is not sealed in a melting operation, rather it is closed by a sealing disc 34 and a cover 35 in locking engagemen-t with the trailing end of -the outer car-tridge 31. Due -to this arrangement, the outer cartridge 31 can be filled with -the resin component 33 and the inner cartridge 32 so that practically no air is present within the outer cartridge.
The hardenable component 36 is Eilled into the inner cartridge 32.
In Figure ~ another container 40 is displayed made up of an ou-ter cartridge 41 and an inner cartridge 42. The resin cornponent 43 is filled into the outer cartridge. The trailing end of the outer cartridge 41 has a thread 44 on which a cover 45 is screwed closing -the open trailing end of the outer cartridge. A hardenable com-ponent 46 is contained within the inner cartridge 42. The inner cartridge 42 and the resin component 43 wi-thin -the outer cartridge and around the inner cartridge are main--tained in the posi-tion shown by a membrane 47 contacting -the trailing end of -the inner car-tridge 42 and the trailing end of the resin component 43. The membrane 47 is spaced inwardly from -the open trailing end of the outer cart-ridge 41 and a spring element 48 extends between the membrane 47 and the cover 45. The cover 45 along with -the membrane 47 and the spring element 48 are formed of materials which are easily broken or destroyed. If re-quired, however, the cover 45 and the spring element 48 can be removed before the container 40 is inserted into a borehole.
In opera-tion the car-tridge is inserted in the borehole wi-th the leading end entering first. The anchor device (no-t shown) is then driven in, breaking -the con-tainer. The components then mix, fill the voids around the anchor device, enter the crevices and cracks (iE
any) in -the receiving material, and harden. The anchor rod is -thus bonded in place.
Having described wha-t is believed to be the best mode by which the invention may be performed, it wlll be seen -that the lnven-tion may be particularly defined as follows:
A destructible container including a se-ttable multi-component ma-terial for anchoring a fas-tening member in a borehole, said con-tainer comprising an ou-ter car-t-~ k~

rldge, and an inner cartridge located within said outer cartridge so that a volume is present within said outer cartridge exterior of said inner cartridge, said multi-component rnaterial. comprising a resin component filled into one of said ou-ter cartridge and inner cartridge and a hardenable component filled into the o-ther one of said outer cartridge and inner cartridge and being separated from said resin component, wherein the improvement com-prises that the one of said outer cartridge and inner cartridge containing said resin component has a first region and a second region separated from the other one of said outer cartridge and inner cartridge, said f:irst and second regions each containing said resin component, means separating said first and second regions, and a thixo-tropic agen-t in only one of said first and second regions for increasing the viscosity of said resin component therein so that upon destruc-tion of said cartridges and displacemen-t of said means separating said first and second region said resin componen-t and sai.d hardenable component intermix within the borehole into which said container is i.nser-ted.
While specific embodiments of the inventi.on have been shown and described in deta:il to illustrate the application of the inventive principles, it will be under-stood that the invention may be embodied otherwise without departing from such principles.

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A destructible container including a settable multi-component material for anchoring a fastening member in a borehole, said container comprising an outer cartridge, and an inner cartridge located within said outer cartridge so that a volume is present within said outer cartridge exterior of said inner cartridge, said multi-component material comprising a resin component filled into one of said outer cartridge and inner cartridge and a hardenable component filled into the other one of said outer cartridge and inner cartridge and being separated from said resin component, wherein the improvement comprises that said outer cartridge is elongated in the insertion direction in which said container is inserted into the borehole and has a leading end forming the first end inserted into the borehole and an opposite trailing end, said inner cartridge is elongated in the insertion direction of said container and has a leading end and a trailing end, and the one of said outer cartridge and inner cartridge filled with the resin component is divided intermediate the leading end and the trailing end into a leading end region extending from the leading end and a trailing and region extending from the trailing end, and said leading end region forms said first region and said trailing end region forms said second region and a thixotropic agent being located only in said trailing end region, for increasing the viscosity of said resin component therein so that upon destruction of said cartridges and displacement of said means separating said first and second region said resin component and said hardenable component intermix within the borehole into which said container is inserted.

2. A destructible container, as set forth in Claim 1, wherein a filler material is included in said resin component.

3. A destructible container, as set forth in Claim 1. wherein a filler material is included within said resin component and said hardenable component.

4. A destructible container, as set forth in Claim 1, wherein said resin component and filler material is located within the volume in said outer cartridge enclosing said inner cartridge, and said hardenable component is located within said inner cartridge.

5. A destructible container, as set forth in Claim 4, wherein the length in the elongated direction of said trailing end region containing the thixotropic agent is in the range of 0.2 to 0.4 times the length in the elongated direction of the leading end region containing the resin component.

6. A destructible container, as set forth in Claim 5, wherein a separation layer extending transversely of the elongated direction separates the leading end region and the trailing end region so that the resin components therein do not intermix.

7. A destructible container, as set forth in Claim 5, including a cover secured to the trailing end of said outer cartridge and said cover having a larger diameter than the largest diameter of said outer cartridge.

8. A destructible container, as set forth in Claim 5, wherein the trailing end of the resin component containing the thixotropic agent within the trailing end region within said outer container is spaced from the trailing end of said outer cartridge, a separation layer within said outer cartridge extending transversely of the elongated direction and in contact with the trailing end of the resin component within said trailing end region and with the trailing end of said inner cartridge so that an air space is formed between said separation layer and the inside surface of the trailing end of said outer cartridge.

9. A destructible container, as set forth in Claim 5, wherein said outer cartridge and inner cartridge are formed of an easily breakable material.

10. A destructible container, as set forth in Claim 9, wherein said outer cartridge and inner cartridge are formed of one of glass and a brittle plastics material.