US20100146904A1

US20100146904A1 - Cast-in channel

Info

Publication number: US20100146904A1
Application number: US12/653,620
Authority: US
Inventors: Markus Heudorfer; Holger Basche; Juergen Gebhard; Ulrich Birnbaum
Original assignee: Hilti AG
Current assignee: Hilti AG
Priority date: 2008-12-17
Filing date: 2009-12-16
Publication date: 2010-06-17
Also published as: CN101748802A; CA2688782A1; EP2199475B1; EP2199475A2; EP2199475A3; DE102008054799A1

Abstract

The present invention relates to a cast-in channel having a channel body which forms a receiving space for receiving a connecting element used to fixedly attach a fastening element to the cast-in channel, the channel body further being provided with rim holes and with anchoring members which can be fixedly attached to the channel body by mounting them in the rim holes. The free ends of the rim holes point toward the receiving space.

Description

This claims the benefit of German Patent Application DE 10 2008 054 799.9, filed on Dec. 17, 2008 and hereby incorporated by reference herein.
The present invention relates to a cast-in channel.

BACKGROUND

Cast-in channels of this type are used to provide flexible fixing points on a cast component, such as one of concrete. To this end, such cast-in channels are placed in the formwork prior to casting the component and incorporated therein during the casting process. Fastening elements can be fixedly attached to the cast-in channels using channel nuts, rear- engagement elements or T-head bolts as connecting elements, which are received in the receiving space within the channel body. The loads are transferred into the cured component via the channel geometry and the anchoring members.
Cast-in channels whose anchoring members are permanently attached to the body of the channel, for example by welding, must be completely manufactured at the factory. Therefore, they take up a large volume during shipping, which results in high shipping costs. In addition, different cast-in channels must be provided for different loads, which requires a considerable logistical effort.
German Patent DE 34 07 801 C1 describes a cast-in channel having a channel body which forms a receiving space which is accessible from the outside via a mounting opening and serves to receive a connecting element used to fixedly attach a fastening element to the cast-in channel, the channel body further being provided with rim holes and with anchoring members which can be fixedly attached to the channel body by mounting them in the rim holes. The anchoring members each include a shank which is threaded over its entire length and has a conical head member at one end. The rim holes each have an internally threaded portion, the free ends of the anchoring members being passed through the receiving space and screwed into said internally threaded portion to fixedly attach the anchoring members to the channel body.

SUMMARY OF THE INVENTION

The drawback of the known approach is that the anchoring members have to be inserted through the mounting opening and screwed in over their entire length. The outwardly projecting rim holes increase the volume occupied during shipping even when the anchoring members are not yet mounted. In addition, to be able to install the anchoring members, the receiving space must be freely accessible.
It is an object of the present invention to provide a cast-in channel which will overcome the aforementioned disadvantages.
The present invention provides a cast-in channel having a channel body which forms a receiving space for receiving a connecting element used to fixedly attach a fastening element to the cast-in channel, the channel body further being provided with rim holes and with anchoring members which can be fixedly attached to the channel body by mounting them in the rim holes. In accordance with the present invention, the free ends of the rim holes point toward the receiving space.
The anchoring members are attached externally to the body of the channel with respect to the receiving space. Because of this, the anchoring members can also be attached to a channel body that has previously been provided with an infill. Advantageously, the rim hole pointing toward the interior of the receiving space has an internal thread adapted to threadedly receive an externally threaded anchoring member to fixedly attach the same to the channel body. It is not necessary for the shank to be externally threaded over its entire length. Advantageously, only the free end is provided with an externally threaded portion, which makes the entire cast-in channel easier and less expensive to manufacture. In addition, different types of anchoring members can be attached to the same type of channel body, which also allows the cast-in channel to be adapted to different load requirements at the construction site, if necessary. Even a previously assembled cast-in channel can be easily adapted to a different type of load, also directly at the construction site, for example. Yet, until the anchoring members are attached to the channel body, the cast-in channel occupies a minimum volume during shipping. In spite of the attachment point provided on the channel body, adjacent channel bodies will not be damaged by the attachment point during shipping.
If, prior to making the rim holes, the channel body is provided with an anti-corrosion coating to protect the base material from external influences, this anti-corrosion coating may be damaged during the formation of the rim holes, so that this portion of the channel body would no longer be protected from corrosion. In particular, if the rim hole is provided with an internal thread as an attachment means, corrosion protection is typically no longer provided in this region. By mounting the anchoring members in the rim holes, they are fixedly attached to the channel body, while at the same time the rim hole is almost completely sealed off from the exterior. Thus, although rim holes are provided, adequate corrosion protection is ensured even for a previously corrosion-protected channel body.
Preferably, at least one depression which faces outwardly with respect to the receiving space is provided in the channel body, at least one of the rim holes being located in the depression. This depression, which may be cup-shaped, creates additional space, permitting the rim hole to be larger, without reducing the mounting space for the connecting element within the receiving space. If the rim hole has an internal thread for attachment of an anchoring member, it is thereby possible to provide a relatively greater number of thread turns. The greater grip length at the rim hole allows greater loads to be transferred to the base material, whereby the load-carrying capacity of the cast-in channel can be ensured while reducing the amount of material required to manufacture the same. In addition, by providing the depression, this portion of the channel body is work-hardened, so that the material of the channel body has a higher strength in this highly stressed region.
Preferably, the at least one depression has a bottom portion, and at least one of the rim holes is located in the bottom portion of the depression, which allows for simple manufacture of the channel body, and enables the loads to be transferred to the base material in an advantageous manner. Advantageously, the rim hole located in the bottom portion is oriented perpendicular to the bottom portion.
Preferably, the bottom portion of the at least one depression is non-concentric in cross section with respect to the rim hole located therein. This allows the depression to be adapted according to the loading of the cast-in channel, for example. The bottom portion may be of elliptical or polygonal, such as rectangular configuration. The bottom portion does not have to be minor-symmetrical with respect to the rim hole located therein. Further, the bottom portion may be circular in cross section, and its center may be offset from the center of the rim hole.
Preferably, the depth of the at least one depression is less than or equal to the material thickness of the channel body, whereby the channel body is advantageously strengthened in the region of the depression formed therein.
Preferably, the rim height of the at least one rim hole is no greater than the depth of the at least one depression, so that the free end of the rim hole will not reduce the mounting space for the connecting element within the receiving space.
Preferably, at least the bottom portion of the at least one depression is provided with reinforcing indentations, thereby advantageously strengthening this region of the depression and imparting advantageous load-carrying characteristics to the cast-in channel.
Preferably, the anchoring members are inseparably mounted in the rim holes. In this manner, the anchoring members are prevented from unintentional loosening once they are attached to the channel body. For example, an adhesive may be provided to captively secure the anchoring members to the channel body once they are attached, for example screwed thereto. In an alternative embodiment, the free end of the rim hole is rolled over and the anchoring members are screwed in at a predetermined maximum torque.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is explained in more detail below with reference to exemplary embodiments. In the drawing,

FIG. 1 is a side view of a cast-in channel;

FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1;

FIG. 3 is a top view of the channel body along the line III-III of FIG. 2; and

FIG. 4 is a cross-sectional view similar to FIG. 2, showing a second exemplary embodiment of a cast-in channel.

DETAILED DESCRIPTION

In all of the figures, like parts have been given like reference numerals.
The cast-in channel 11 illustrated in FIGS. 1 through 3 has a channel body 12 and anchoring members 26 fixedly attached thereto. Channel body 12 forms a receiving space 13 for receiving a connecting element 7 used to fixedly attach a fastening element 6 to cast-in channel 11, receiving space 13 being accessible from the outside via a mounting opening 14 extending along the length dimension of channel body 12.
Channel body 12 is provided with two depressions 21 which face outwardly with respect to the receiving space 13 and which each have a bottom portion 22. Each bottom portion 22 is provided with a rim hole 15 having an internal thread 17 to allow attachment of anchoring members 26, the free end 16 of said rim hole pointing toward receiving space 13. Bottom portion 22 of depression 21 is non-concentric in cross section with respect to the rim hole 15 located therein. In addition, bottom portion 22 of depression 21 is provided with reinforcing indentations 23.
Anchoring members 26 are provided at their free ends with an externally threaded portion 27, allowing anchoring members 26 to be screwed into internal thread 17 of rim hole 15 so as to be fixedly attached to channel body 12. Anchoring members 26 are inseparably mounted in rim holes 15 by an adhesive (not shown) provided between external thread 27 of anchoring member 26 and internal thread 17 of rim hole 15.
Depth T of depression 21 is no greater than material thickness D in the region of channel body 12 adjacent to depression 21. Rim height K of rim hole 15 is no greater than depth T of depression 21.
In the case of cast-in channel 31 shown in FIG. 4, rim hole 35 used for attachment of an anchoring member 46 is formed directly on a rear wall 38, the free end 36 of the rim hole pointing toward receiving space 33. Apart from that, cast-in channel 31 has the same features as the cast-in channel 11 described above.

Claims

1. A cast-in channel comprising:

a channel body forming a receiving space for receiving a connecting element used to fixedly attach a fastening element to the cast-in channel, the channel body further being provided with rim holes and with anchoring members capable of being fixedly attached to the channel body by mounting the anchoring members in the rim holes, the free ends of the rim holes pointing toward the receiving space.

2. The cast-in channel as recited in claim 1 wherein the channel body has at least one depression which faces outwardly with respect to the receiving space, at least one of the rim holes being located in the depression.

3. The cast-in channel as recited in claim 2 wherein the at least one depression has a bottom portion, and at least one of the rim holes is located in the bottom portion of the depression.

4. The cast-in channel as recited in claim 3 wherein the bottom portion of the at least one depression is non-concentric in cross section with respect to the rim hole located therein.

5. The cast-in channel as recited in claim 2 wherein the depth of the at least one depression is less than or equal to the material thickness of the channel body.

6. The cast-in channel as recited in claim 2 wherein the rim height of the at least one rim hole is no greater than the depth of the at least one depression.

7. The cast-in channel as recited in claim 2 wherein the bottom portion of the at least one depression is provided with reinforcing indentations.

8. The cast-in channel as recited in claim 1 wherein the anchoring members are inseparably mounted in the rim holes.