Abstract:
A connection insert includes a central adhesive supply channel and outlets which are perpendicular to the channel. The connection insert consists of a plurality of parts, and comprises an inner part provided with the adhesive supply channel and an outer sleeve that can be at least partially inserted into a borehole of a component.

Description:
This is a Divisional Application of Non-Provisional patent application Ser. No. 11/910,763, filed on Apr. 29, 2008, which claims priority to and benefit of Provisional Application No. 60/562,081, filed Apr. 14, 2004, the disclosures of both applications being incorporated by reference herein. Application Ser. No. 11/910,763 is a §371 of PCT/EP2006/61394, filed on Apr. 6, 2006, which claims benefit of German Application Number 20 2005 005 579.4 filed on Apr. 7, 2005. 
    
    
     The invention relates to a connection insert and more specifically to a connection insert with adhesive supply channel. 
     This connection insert is used for the fastening of components to boards, these boards generally having a soft inner core and hard cover boards. These boards are generally called lightweight boards. The connection insert is provided with a central adhesive supply channel and with outlets for the adhesive which are perpendicular to the channel. In a construction, the above-mentioned board-shaped components are used, among other uses, for the production of furniture. The connection inserts are used for guiding the adhesive such that it reaches the connection inserts and the latter form a fixed connection with the fixed regions of the boards. However, it is also conceivable that the end regions of the connection inserts are inserted into boreholes or recesses of the board-shaped components so that they support the adhesive connection. 
     It is a disadvantage of the previously known connection inserts that the guiding of the adhesive is not precisely defined, so that it frequently happens that the adhesive does not arrive at the point where the actual adhesive connection is to take place. However, a precise guidance is required because adhesives are considered to be semi-fluidic; that is, their viscosity is relatively high. 
     It is an object of the disclosure to design a connection insert of the initially described type such that a precise guidance of the injected adhesive is ensured, so that the adhesive connections take place at the defined locations. 
     This object is achieved in that the connection insert consists of a plurality of parts and comprises an inner part having the adhesive supply channel and an outer sleeve enveloping the inner part. 
     The adhesive is placed in the connection insert by means of a suitable device from a front side. The outside surface of the inner part and the inside surface of the outer sleeve may be designed such that a targeted adhesive guidance is feasible. In particular, depending on the usage of the connection insert, the outer sleeve can be designed such that targeted adhesive connections are achieved. Since it causes the distribution of the adhesive, it could also be called a distributor sleeve or an adhesive guiding sleeve. 
     In the simplest construction, the connection insert consists exclusively of the inner part and the outer sleeve. An annular gap is arranged between the inside surface of the outer sleeve and the outside surface of the inner part. 
     For reinforcing the adhesive connection between the connection insert and the adjacent component, for example, to a board, the inner part has a head at least at one end, which head can at least partially form-lockingly and/or force-lockingly be inserted in a borehole or in a recess of the component. The connection of the head of the inner part with the component can take place in a particularly simple manner. The circumferential surface of the head is profiled such that the raised parts mold themselves into the material bounding the borehole or the recess. This becomes possible because the concerned components consist of wood or a wood-like material. The profiling of the circumferential surface can be formed by harpoon-type webs, so that the inner part can be pressed in one direction into the borehole or into the recess, but that a pulling-out in the opposite direction is possible only by destroying the material parts bounding the borehole or the recess. The mutually spaced harpoon-type webs may be shaped in a surrounding manner to the head of the inner part; they may also extend over certain partial regions of the circumference; or the may extend in the direction of the longitudinal center axis of the inner part, so that an antitwist protection is correspondingly provided in the last embodiment. 
     For gluing the head of the inner part to the surfaces bounding the borehole or the recess, the head of the inner part is equipped with at least one, for example two diametrically opposite adhesive outlet opening(s). The adhesive outlet opening or openings is/are expediently designed in a slot shape as well as extending in the direction of the longitudinal axis of the inner part. 
     In order to also permit the gluing-together over the entire length of the shaft of the inner part, the inner part has several mutually spaced circumferential grooves on the circumferential surface. So that adhesive can also penetrate into these circumferential grooves, the inner part outside the head has at least one adhesive outlet opening, preferably with two mutually diametrically opposite adhesive outlet openings. Through each adhesive outlet opening, the adhesive can then arrive in the annular gap between the outside surface of the inner part and the inside surface of the outer sleeve. So that the adhesive can also arrive in the end regions of the shaft of the inner part, each adhesive outlet opening is arranged in the central region of the shaft. 
     The adhesive can be pressed into the adhesive supply channel of the inner part only from a front side. So that the quantity of the adhesive remaining in this channel is limited, the adhesive supply channel is divided into two sections, and that only one section extends into the region of the adhesive outlet openings. For securing the outer sleeve, the inner part is equipped with a locking ring on the side facing away from the head. The locking ring is designed such that such a deformation takes place as a result of the effect of a compression force. Thus, the outer sleeve can be placed upside down onto the inner part. In addition, a lateral distribution of the adhesive takes place. So that the adhesive can be distributed over the entire length or height of the shaft of the inner part and also over the inside surface of the outer part, the inside surface of the outer sleeve is constructed as a profiling which is formed of indentations and elevations extending in the longitudinal direction. In other words, the elevations and indentations extend transversely to the circumferential grooves of the shaft of the inner part. 
     In addition, in the end region facing the head of the inner part, the outer sleeve is provided with several slots in order to facilitate the joining or the snapping-together of the inner part with the outer sleeve. Furthermore, when adhesive is supplied, the latter emerges from the slots, which has a positive influence on the adhesive connection. 
     The adhesive supply normally takes place under pressure. Particularly the outer sleeve could be called an adhesive guiding element so that the adhesive is pressed into the end regions in a targeted manner. After a reduction of the supply pressure, the adhesive could flow back into the central region of the outer sleeve. In order to prevent this, the outer sleeve is equipped with flexible retaining elements for the adhesive on the outside surface at least in the end regions. These retaining elements are designed such that they form a corresponding abutment. The retaining elements may be arranged in different fashions. Thus, they extend radially or tangentially with respect to the outside surface of the outer sleeve in the end regions facing the outside surface of the outer sleeve. Although it is sufficient for the retaining elements to be arranged in the end regions, in another embodiment, they are arranged radially with respect to the longitudinal center axis of the outer sleeve and extend over the entire length or almost the entire length of the outer sleeve. In this case, the lengths of the retaining elements increase from the center region to the end regions of the outer sleeve, for example in a continuous manner. As a result, analogously an outer contour is created relative to the longitudinal section, which can be considered to be concave. The retaining elements are expediently constructed as bristles, strips or the like. 
     It is also provided that the adhesive supply channel has a sieve or a perforated plate in the end region. This proportions the adhesive quantity and prevents that impurities penetrate into the adhesive supply channel. Depending on the usage, it may also be expedient to provide the outer sleeve with several openings, which are circular or have a configuration deviating from the circular shape. 
     The range of applications of the connection insert is diverse. Thus, the outer and the inner part each have a cup-shaped construction, and the connection insert can be fixed to a furniture component or a furniture leaf by a generally known eccentric fitting. 
     The connection insert may be called a dowel in order to fasten fittings or the like, for example, by a screw. 
     The connection insert will be explained in greater detail by means of the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded as well as perspective view of the inner part and the outer sleeve of a connection insert of the present disclosure as a detail; 
         FIG. 2  is a front view of the inner part; 
         FIG. 3  is a sectional view of the inner part; 
         FIG. 4  is a view of a first embodiment of a connection insert arranged between two cover layers; 
         FIG. 5  is a view of a second embodiment of a connection insert arranged between two cover layers; 
         FIG. 6  is a cut-away view of the connection insert arranged between two spaced cover layers of the boards; 
         FIG. 7  is a view of the connection insert according to the present disclosure in combination with an eccentric fitting; 
         FIGS. 8 to 10  are views of three different embodiments of the connection insert equipped with retaining elements; and 
         FIG. 11  is a sectional view of a connection insert according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The connection insert illustrated in  FIGS. 1 to 7  consists of an inner part  10 , which will be explained in detail, and of an outer sleeve  12 , which can be fitted onto a shaft  11  of the inner part  10  and will also be explained in detail. At one end, the inner part  10  is also equipped with a head  13  whose circumferential surface is profiled. This profiling consists of several harpoon-type webs  14 , as illustrated particularly in  FIGS. 2 and 3 . The inner part  10  is provided with an adhesive supply channel  15  consisting of two sections  15   a  and  15   b . As illustrated particularly in  FIG. 3 , the two sections  15   a ,  15   b  of the adhesive supply channel  15  are mutually separated by a wall. In addition, the tube-shaped inner part  10  is provided with two mutually diametrically opposite adhesive outlet openings  16 ,  17 . These are designed as oblong holes and are arranged such that only adhesive can penetrate from section  15   a  to the outside. 
     As shown in  FIGS. 1 to 3 , the shaft  11  of the inner part  10  also has several circumferential grooves  18  on the exterior side and are spaced with respect to one another. The figures also illustrate that the inner part  10  is equipped with a locking ring  19  on the side situated opposite the head  13 . When the outer sleeve  12  fitted onto the shaft  11 , the locking ring extends beyond the outer sleeve and prevents separation of the inner part  10  and the outer sleeve  12 . This outer sleeve  12  can be deformed because of the form-elastic and material-elastic characteristics of plastic materials, so that the outer sleeve  12  can be placed upside down onto the inner part  10 . 
     As illustrated by  FIGS. 1 and 2 , in the region of the head  13 , the inner part  10  is also provided with two mutually diametrically opposite, slot-type openings  20  through which adhesive emerges for the gluing of the head  13  to the elements it is inserted into. 
       FIGS. 4 to 6  show the arrangements of a lightweight board with the cover layers  21 ,  22  and a connection insert arranged in-between. For this purpose, the outer sleeve  12  is pushed onto the shaft  11  of the inner part  10 . The adhesive can then be pressed into the section  15   a  of the adhesive supply channel  15 , penetrates the radial adhesive outlet openings  16 ,  17  and is then distributed into the annular gap  25  between the inside surface of the outer sleeve  12  and the outside surface of the shaft  11 . Slots arranged in an end region of the outer sleeve  12  ensure the exiting of the adhesive which thereby comes in contact with the cover layers of the lightweight boards in a targeted manner. For locking the outer sleeve  12  with the shaft  11 , the outer sleeve  12  is provided with slots  23  extending in the longitudinal direction on the side assigned to the head  13  of the inner part  10 . 
     In the embodiment according  FIG. 4 , the locking ring  19  is supported on the assigned surface of the cover layer  22 , while, in the embodiment according to  FIG. 5 , the cover layer  22  is provided with a recess  24  in which the locking ring  19  engages.  FIGS. 4 and 5  illustrate that the harpoon webs  14  of the head  13  pit or dig into the material of the cover layer  21  bounding the borehole. In addition, the securing also takes place by gluing. 
       FIG. 6  shows the arrangements according to  FIGS. 4 and 5  in the cut-away condition. This figure illustrates that an annular gap  25  is formed between the outside surface of the shaft  11  and the inside surface of the outer sleeve  12 , the adhesive running in this annular gap  25  and being deposited on the interior sides of the cover layers  21 ,  22 . 
       FIG. 7  shows a variant for fixing a corner connection fitting in a lightweight board. The inner part  10  and the outer sleeve  12  each have a cup-shaped construction. The adhesive guidance is analogous to the descriptions of  FIGS. 1 to 6  and is not shown in detail. In addition, the bracing takes place by an eccentric fitting  26 , which is generally known. Also, a dowel  27  is inserted in a borehole of a board  28  which, in turn, is fixed in another component  30 . 
       FIGS. 8 to 10  show embodiments, in which retaining elements  29  in the form of bristles, strips or the like are placed on the outside surface of the outer sleeve  12 . The figures show that the adhesive is pressed by pressure into the end regions of the outer sleeve  12 . After the reduction of this pressure, the adhesive could flow back, although only partially and only by a relatively small amount. In order to prevent this, essentially radially extending retaining elements  29  are placed in the end regions of the outer sleeve  12  in the embodiment according to  FIG. 8 . Also in the embodiment according to  FIG. 9 , the retaining elements  29  are fixed in the end regions. In this embodiment, at least the end regions facing the outside surface of the outer sleeve  12  extend tangentially or approximately tangentially. 
     In the embodiment according to  FIG. 10 , the retaining elements  29  are essentially distributed over the entire length and also over the entire circumference of the outer sleeve  12 . They are again disposed radially with respect to the longitudinal center axis of the outer sleeve  12 . However, in a longitudinal sectional view, a concave shape of the outer contour is obtained because the lengths of the retaining elements  29  increase continuously from the center region to the end regions. The retaining elements  29  may be bristles consisting, for example, of a plastic material. 
       FIG. 11  shows an embodiment in which, in contrast to the previously described constructions, the effective length of the connection insert can be changed. 
     This is achieved by an extension sleeve  31  which is telescopically displaceably fitted over the outer sleeve  12 . The remaining construction of the connection insert according to  FIG. 11  basically corresponds to the previously described variants; that is, the above-mentioned outer sleeve  12  is placed on the shaft  11  of an inner part  10  having an adhesive supply channel  15 . 
     As mentioned above, the telescopically displaceable extension sleeve  31  is pushed into this outer sleeve  12 . The extension sleeve  31  can be displaced relative to the outer sleeve  12  in the axial direction of the entire arrangement, whereby the overall length of the connection insert can be changed in a simple manner and can be adapted to different thicknesses of lightweight boards. 
     At its free front-side end  32 , the extension sleeve  31  is provided with axially extending slots  33  through which adhesive can penetrate toward the outside. 
     Deviating therefrom, the extension sleeve  31  may be provided with adhesive outlet boreholes in the front-side region. It is also conceivable to construct the face of the extension sleeve  31  in a wavy shape or to provide it with radial serrations in order to permit an exiting of adhesive. 
     The connection insert is not limited to the illustrated embodiments. It is essential that the connection insert is constructed of several parts, preferably two parts, and is formed of the inner part  10  and the outer sleeve  12 . Furthermore, it is important that the guiding of the adhesive is precisely defined by the adhesive supply channel  15 , by the adhesive outlet openings  16 ,  17 , by the radial grooves  18  and by the annular gap  25 . 
     Although the present disclosure has been described and illustrated in detail, it is to be clearly understood that this is done by way of illustration and example only and is not to be taken by way of limitation. The scope of the present disclosure is to be limited only by the terms of the appended claims.