U.S. patent application number 09/808250 was filed with the patent office on 2001-11-08 for attachment element for an anchor rod.
Invention is credited to Wieser, Jurgen.
Application Number | 20010038780 09/808250 |
Document ID | / |
Family ID | 7634835 |
Filed Date | 2001-11-08 |
United States Patent
Application |
20010038780 |
Kind Code |
A1 |
Wieser, Jurgen |
November 8, 2001 |
Attachment element for an anchor rod
Abstract
An attachment element for an anchor rod (14) including a
substantially cylindrical expansion member (1) having an axial bore
(8), and one-piece expandable member (2) extending, at least
partially, into the axial bore (8) of the expansion member (1)
without a possibility of disengagement from the expansion member
(1) and having, at least along a portion of its longitudinal
extent, a conical section tapering in a direction opposite to a
setting direction (S) of the anchor rod (14), an axial bore (4),
and at least two elongate slots (11).
Inventors: |
Wieser, Jurgen; (Kaufering,
DE) |
Correspondence
Address: |
BROWN & WOOD LLP
One World Trade Center
New York
NY
10048-0557
US
|
Family ID: |
7634835 |
Appl. No.: |
09/808250 |
Filed: |
March 14, 2001 |
Current U.S.
Class: |
411/265 |
Current CPC
Class: |
F16B 13/124
20130101 |
Class at
Publication: |
411/265 |
International
Class: |
F16B 039/36 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 15, 2000 |
DE |
100 12 645.6 |
Claims
What is claimed is:
1. An attachment element for an anchor rod (14), comprising a
substantially cylindrical expansion member (1) having an axial bore
(8); and one-piece expandable member (2) extending, at least
partially, into the axial bore (8) of the expansion member (1)
without a possibility of disengagement from the expansion member
(1) and having, at least along a portion of a longitudinal extent
thereof, a conical section tapering in a direction opposite to a
setting direction (S) of the anchor rod (14), an axial bore (4),
and at least two elongate slots (11).
2. An attachment element according to claim 1, wherein the bore (4)
of the expandable member (2) tapers in the setting direction
(S).
3. An attachment element according to claim 1, wherein the
expandable member (2) has, at an end thereof facing in a direction
opposite to the setting direction (S), an opening (15) a diameter
of which at least correspond to an inner diameter of the axial bore
(8) of the expansion member (1).
4. An attachment element according to claim 1, wherein the
expandable member (2) has, on an outer circumference thereof, a
shoulder (6) facing in the setting direction (S) and cooperating
with a mating shoulder (13) provided on the expansion member (1),
whereby disengagement of the expandable member (2) from the
expansion member (1) is prevented.
5. An attachment element according to claim 1, wherein the bore (4)
of the expandable member (2) has, at least along a portion of a
length thereof, a shaped profile (5).
6. An attachment element according to claim 1, wherein the
expandable (2) has, in an end region of the elongate slots (2)
facing in a direction opposite the setting direction (S), at least
one hinge (9).
7. An attachment element according to claim 6, wherein the hinge is
formed by weakening of material.
8. An attachment element according to claim 7, wherein the hinge is
formed by an inner groove (9) provided in the wall of the bore (4)
of the expandable member (2).
9. An attachment element according to claim 1, wherein both the
expansion and expandable member (1, 2) are formed of a plastic
material.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a attachment element for an
anchor rod including a substantially cylindrical expansion member
having an axial bore, and a one-piece expandable member extending,
at least partially, into the axial bore of the expansion member
without a possibility of disengagement from the expansion member
and having at least along a portion of a longitudinal extent
thereof, a conical section tapering in a direction opposite to a
setting direction of the anchor rod.
[0003] 2. Description of the Prior Art
[0004] The attachment elements of the above-described type become
anchored by the expandable member being pulled into the expansion
member, with the expansion member being supported either directly
or via a spacing sleeve on a thrust bearing support of a bolt
element. The expandable member can be connected with the bolt
element by a threaded connection.
[0005] German Publication DE 197 40 823A1 discloses an attachment
element having a substantially cylindrical expansion member
provided with an axial bore, and an expandable member having, at
least along a portion of its longitudinal extent, a conical section
tapering in a direction opposite to the setting direction. The
expandable member is formed of a plurality of clamp segments which
are held together, with a possibility of radial elastic expansion,
by an O-ring and which extend into the axial bore of the expansion
member. Upon insertion of an anchor rod, which is provided with an
appropriate outer profile, the segments expand radially outwardly,
with the O-ring elastically pressing the segments against the outer
surface of the outer profile of the anchor rod. Upon application of
a tensile load to the anchor rod, the expandable element, which is
formed of separate segments, is pulled further into the expansion
member. Due to the conicity of the expandable member, which is
defined by a cone tapering in direction opposite the setting
direction, the expansion member expands radially, upon the
expandable member being pulled thereinto.
[0006] The drawback of the attachment element which is disclosed in
DE 197 40 823A1, consists in that the anchor rod need be precisely
centered with respect to the expandable member to insure the
radially outward movement of all of separate segments. Otherwise,
tilting of the expandable member can occur which makes the
insertion of the anchor rod practically impossible which, in turn,
make impossible the expansion of the attachment element. In
addition, the diameters of the anchor rod and the expandable member
should be precisely matched because if the segments are located to
close to the center of the expandable member, insertion of the
anchor rod can be effected only with much difficulties.
[0007] Another drawback of the known attachment element consists in
that the anchor rod need be provided with an appropriate outer
profile to provide a connection of the anchor rod with the
expandable member which is capable to withstand large loads.
[0008] An object of the present invention is to provide an
attachment element for an anchor rod which would not hinder the
insertion of the anchor rod and would insure self-centering of the
anchor rod upon insertion.
[0009] Another object of the present invention is to provide an
attachment element which would not require that the anchor rod be
provided with an outer profile for establishing a connection
capable of withstanding high loads.
[0010] A further object of the present invention is to provide an
attachment element which can be simply and economically
produced.
SUMMARY OF THE INVENTION
[0011] This and other objects of the present invention, which will
become apparent hereinafter, are achieved by providing an
attachment element of the type described above in which the
expandable member has a central bore and at least two slots
extending along at least the front portion of the expandable
member.
[0012] The expandable member is formed as a one-piece member and,
because of this, is centered in the expansion member even before
the attachment member is set in a bore of a constructional
component. This insures insertion of the anchor rod without any
problem. The slots, which are provided in the front section of the
expandable member, divide the expandable member in that section in
a plurality of elastically radially expandable segments, which are
expanded radially outwardly upon the insertion of the anchor rod.
When a load, which acts in a direction opposite to the setting
direction, is applied to the anchor rod, and the anchor rod is
pulled out of the bore, the elastically expandable segments are
pressed against the outer surface of the anchor rod, whereby
frictional forces, which act between the segments and anchor rod,
increase. Upon application to the anchor rod of a force acting in a
direction opposite the setting direction, the frictional forces
acting between the elastically expandable segments and the anchor
rod cause pulling of the expandable member into the axial bore of
the expansion member, with the conical section of the expandable
member expanding the expansion member radially outwardly. Forming
the expandable member as a one-piece member simplifies its
manufacture and facilitate the assembly of the attachment
element.
[0013] The bore of the expandable member advantageously tapers in
the setting direction. As a result, the radial pressure applied by
the elastic segments to the anchor rod increases upon further
insertion of the anchor rod as the segments need to perform a
longer pivot movement.
[0014] Advantageously, the expandable member has at its end facing
in a direction opposite to the setting direction, an opening a
diameter of which at least correspond to an inner diameter of the
axial bore of the expansion member. This insures centering of the
anchor rod, upon its insertion, in the axial bore of the expandable
member. Preferably, the diameter of the anchor rod is smaller than
the diameter of the axial bore of the expandable member, whereby
the insertion of the anchor rod can be effected without any
hindrance.
[0015] Advantageously, the expandable member has, on its outer
circumference a shoulder facing in the setting direction and
cooperating with a mating shoulder provided on the expansion member
which prevents disengagement of the expandable member from the
expansion member. The provision of the stop shoulder on the outer
circumference of the expandable member also prevents sliding of the
expandable member out of the expansion member upon the insertion of
the anchor rod. Providing cooperating shoulders on the expansion
and expandable members also facilitates the assembly of the
attachment member. The region of the axial bore of the expandable
member, which adjoins the stop shoulder, can be made conical. This
provides for additional expansion of the expansion member in a bore
of a constructional component.
[0016] The axial bore of the expandable member has, at least along
a portion of its length, a shaped profile engagable with a
corresponding profile of the anchor rod. This provides, in addition
to a forcelocking connection of the expandable member with the
anchor rod, a formlocking connection therebetween, such a
combination the connection can withstand much higher loads.
[0017] Preferably, the expandable member has, in the region of the
elongate slots, at least one hinge. This improves swinging
characteristic of the expandable segments. In addition, the
provision of the hinge permits to obtain a better relationship
between the diameter of the axial bore of the expandable member and
the length of the elongate slots. The hinge, preferably, is
produced by weakening of the material.
[0018] Advantageously, the weakening of material is effected by
forming an inner groove in the wall of the bore of the expandable
member. This insures economical manufacturing of the expandable
member. The weakening of material can also be achieved by using a
material with a high elasticity.
[0019] Preferably, the expansion and expandable member are formed
of a plastic material, in particular, by injection molding. This,
on one hand, insures an economical manufacturing of the attachment
element and, on the other hand, permits to form the hinge by using
elastic material.
[0020] The novel features of the present invention, which are
considered as characteristic for the invention, are set forth in
the appended claims. The invention itself, however, both as to its
construction and its mode of operation, together with additional
advantages and objects thereof, will be best understood from the
following detailed description of preferred embodiments, when read
with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS:
[0021] The drawings show:
[0022] FIG. 1 a cross-sectional view of an attachment element
according to the present invention inserted in a bore in a
constructional component with an anchor rod being introduced into
the bore of the expansion member of the attachment element;
[0023] FIG. 1a a cross-sectional view similar to that of FIG. 1 but
with the anchor rod in its end position; and
[0024] FIG. 2 a side view of the inventive attachment element shown
in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] An attachment element for an anchor rod 14 according to the
present invention, which is shown in FIGS. 1, 1a and 2, has a
cylindrical expansion member 1 with an axial bore 8 and a partially
extending into the bore 8 expandable member 2.
[0026] The expandable member 2 has a conical and region extending
in the setting direction S and tapering in a direction opposite to
the setting direction S. A substantially cylindrical section
extending in the direction opposite the setting direction S,
adjoins the conical end section. The expandable member 2 has a
central bore 4 having, in its end region facing in, the setting
direction, an inner profile 5. A stop shoulder 6, which faces in
the setting direction S, is provided in the end region of the
expandable member 2 remote from the front, facing in the setting
direction S, end of the expandable member 2.
[0027] The expansion member 1 has, in its region remote from the
expandable member 2, a flange 7 which defines the setting depth of
the expansion member 1. As shown in FIG. 1, the flange 7 lies on a
surface of a constructional component 10 in the bore 3 of which the
attachment element is set. At its end opposite the flange 7, the
expansion member 1 has a shoulder 13 cooperating with the stop
shoulder 6 of the expandable member 2. The shoulder 13 limits the
displacement of the expandable member 2 in the setting direction.
At its end opposite the flange 7, the expansion member 1 surrounds
the substantially cylindrical section of the expandable member
2.
[0028] The expandable member 2 has, in its region coinciding with
the end of the expansion member 1 facing in the setting direction
S, a circumferential groove 9 which serves as a hinge between the
cylindrical section of the expandable member 2 and the expandable
section of the expandable member 2 which is formed of a plurality
of segments 12 separated by longitudinal slots 11. At its end
facing in the direction opposite to the setting direction, the
expandable member 2 has an opening 15 the diameter of which is
larger than the inner diameter of the bore 8 of the expansion
member 1. This provides for an automatic centering of the anchor
rod 14 with respect to the opening 15 when it is introduced into
the expansion member 1 and the expandable member 2.
[0029] The diameter of the bore 4 of the expandable member 2 in the
region of the expandable member 2 facing in the setting direction S
is smaller than the outer diameter of the anchor rod 14. Upon being
inserted into the expandable member 2, the anchor rod 14 displaces
the segments 12 radially outwardly about a pivot axis defined by
the inner groove 9. When a force, which acts in a direction
opposite to the setting direction S, it applied to the anchor rod
14, the segments 12 apply pressure to the outer surface of the
anchor rod 14, forming a forcelocking connection between the
expandable member 2 and the anchor rod 14. Thus, when the anchor
rod 14 is pulled out, the expandable member 2 is likewise pulled
out, in the direction opposite the setting direction, into the bore
8 of the expansion member 1. The conical region of the expandable
member 2, which tapers in the direction opposite to the setting
direction S, expands the expansion member 1. This further enhance
anchoring of the dowel in the bore 3 of the constructional
component 10 (FIG. 1a).
[0030] Though the present invention was shown and described with
references to the preferred embodiments, such are merely
illustrative of the present invention and are not to be construed
as a limitation thereof, and various modifications of the present
invention will be apparent to those skilled in the art. It is,
therefore, not intended that the present invention be limited to
the disclosed embodiments or details thereof, and the present
invention includes all variations and/or alternative embodiments
within the spirit and scope of the present invention as defined by
the appended claims.
* * * * *