U.S. patent application number 14/809978 was filed with the patent office on 2015-12-03 for cage nut.
The applicant listed for this patent is RUIA GLOBAL FASTENERS AG. Invention is credited to Thorsten SCHRAER.
Application Number | 20150345536 14/809978 |
Document ID | / |
Family ID | 43299514 |
Filed Date | 2015-12-03 |
United States Patent
Application |
20150345536 |
Kind Code |
A1 |
SCHRAER; Thorsten |
December 3, 2015 |
CAGE NUT
Abstract
Cage nut for installation in an elongate, preferably rectangular
opening which is only accessible from one side, comprising a nut
body with a cylindrical internal thread carrier having an internal
thread and an abutment part attached thereto, and a cage
encompassing the nut body, wherein the abutment part is adapted to
the shape of the opening and has a slightly smaller width and a
slightly shorter length than the opening, although the length of
the abutment part is significantly greater than the width of the
opening; the cage is configured resiliently and is adapted to the
shape of the opening such that it can be clipped into the opening
and the cage supports stop elements which only allow a rotation of
the abutment part with respect to the cage in the screwing-in
direction of the internal thread from an installation position
parallel to the longitudinal direction of the cage into a retaining
position approximately perpendicular thereto.
Inventors: |
SCHRAER; Thorsten;
(Gerolsbach, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
RUIA GLOBAL FASTENERS AG |
Neuss |
|
DE |
|
|
Family ID: |
43299514 |
Appl. No.: |
14/809978 |
Filed: |
July 27, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13819177 |
Feb 26, 2013 |
9121431 |
|
|
PCT/DE2011/050028 |
Aug 31, 2011 |
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14809978 |
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Current U.S.
Class: |
411/111 |
Current CPC
Class: |
F16B 37/044 20130101;
F16B 31/04 20130101; F16B 39/32 20130101; F16B 37/042 20130101 |
International
Class: |
F16B 37/04 20060101
F16B037/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2010 |
DE |
202010012019.5 |
Claims
1. Cage nut for installation in an elongate, preferably rectangular
opening which is only accessible from one side, comprising a nut
body with a cylindrical internal thread carrier having an internal
thread and an abutment part attached thereto, and a cage
encompassing the nut body, characterized in that the abutment part
is adapted to the shape of the opening and has a slightly smaller
width and a slightly shorter length than the opening, although the
length of the abutment part is significantly greater than the width
of the opening; in that the cage is configured resiliently and is
adapted to the shape of the opening such that it can be clipped
into the opening and in that the cage supports stop elements which
only allow a rotation of the abutment part with respect to the cage
in the screwing-in direction of the internal thread from an
installation position parallel to the longitudinal direction of the
cage into a retaining position approximately perpendicular
thereto.
2. Cage nut according to claim 1, wherein the stop elements are
formed such that, in the installation position, they hold the nut
body in a floating manner in the cage.
3. Cage nut according to claim 1, wherein the internal thread is
provided with a thread securing means (clamping means) in the
region remote from the screwing-in side.
4. Cage nut according to claim 1, wherein the cage is configured
such that it exerts a spring force on the nut body towards the
opening.
5. Cage nut according to claim 4, wherein an annular abutment
surface for spring elements of the cage is arranged on the nut
body, and this abutment surface is provided with cams or with an
undulating profile such that the cams or the elevated portions of
the undulating profile engage with the resilient elements of the
cage precisely when the nut body leaves its floating installation
position in the cage.
6. Cage nut according to claim 1, wherein the stop elements rest on
an annular abutment which is arranged in the nut body coaxially to
the internal thread on the side facing the opening, and this
abutment has recesses for receiving the stop elements, which
recesses are arranged such that the stop elements are accommodated
therein in the retaining position.
7. Cage nut according to claim 6, wherein the transition from the
abutment into the recesses in the direction of rotation is
configured as a bevel.
8. Cage nut according to claim 6, wherein the transition from the
recesses into the abutment is configured as a stop surface which
extends parallel to the axis of rotation of the internal
thread.
9.-11. (canceled)
Description
TECHNICAL FIELD
[0001] The present invention relates to a cage nut for installation
in an elongate, preferably rectangular opening which is only
accessible from one side, comprising a nut body with a cylindrical
internal thread carrier having an internal thread and an abutment
part attached thereto and a cage which encompasses the nut
body.
PRIOR ART
[0002] For so-called "blind applications", i.e. for applications in
which the installation point can only be accessed from one side,
such as large metal sheets, special section tubes, bodywork parts
or similar sheet metal parts, so-called "blind rivet nuts" have
hitherto been used to introduce a nut thread into parts of this
type. These blind rivet nuts (also denoted by BRN) are seated using
a specific processing tool, in that by squeezing the blind rivet
nuts, a so-called "closing head" is produced which fixes the nut.
Since the corresponding blind rivet nuts per se and particularly
also the closing head which has formed are relatively weak, in the
past it has only been possible to use blind rivet nuts to attach
light or ancillary components. The "high-strength blind rivet nut"
developed by the company Avdel was the first blind rivet nut to
also allow structural connections having relatively high
pre-tensioning forces, due to the relatively high thread strength
of said nut.
[0003] Even in the case of these high-strength blind rivet nuts,
the problem arose relatively quickly that bolts with a strength of
10.9 or above, which are to be screwed as far as the yield point,
generate such high pre-tensioning forces that the closing head
starts to sink or starts to deform during the bolt installation. In
the worst case, this would result in the closing head shearing off,
i.e. the blind rivet nut would be destroyed and would then have to
be replaced. In any case, the subsequent sinking/deformation would
result in a significantly lower pre-tensioning force, compared to
the presets given by the defined torque and angle of rotation
bolting procedure. The additional angle of rotation caused a
sinking/deformation of the BRN instead of the desired increase in
pre-tensioning force. Due to this sinking or deformation, the
industry routinely experiences problems in achieving the defined
bolting curves even with high-strength blind rivet nuts and thus in
monitoring the correct assembly of tie bars on vehicles, for
example.
[0004] Another possibility known from the prior art of providing
sheet metal parts with internal threads is the use of so-called
cage nuts. However, to install cage nuts, in the prior art it was
necessary for either the rear side of the part to also be
accessible or additional auxiliary holes were required to introduce
the cage nut from the side, as is necessary for so-called "C-clips"
of the prior art. A cage nut of this type, configured as a clip, is
disclosed, for example in EP 703 021 B1 which would appear to be
the closest prior art in respect of the present invention.
PRESENTATION OF THE INVENTION
[0005] It is therefore the object of the present invention to make
it possible to introduce an internal thread into an opening, which
is accessible from only one side, in a sheet metal component,
without requiring additional auxiliary openings (as is the case for
C-clips), and without the pre-tensioning force restrictions of the
prior art blind rivet nuts.
[0006] The object of the present invention is achieved by a cage
nut which is capable of being installed in an elongate opening
which is only accessible from one side, in that this cage nut has
an abutment part which is adapted to the shape of the opening and
has a slightly smaller width and a shorter length than the opening,
although the length of the abutment part is significantly greater
than the width of the opening, the cage being of a resilient
configuration and being adapted to the shape of the opening such
that it can be clipped into the opening, and the cage supports stop
elements which only allow a rotation of the abutment part with
respect to the cage in the screwing-in direction of the internal
thread from an installation position parallel to the longitudinal
direction of the cage into a retaining position approximately
perpendicular thereto.
[0007] In this respect, the stop elements are preferably configured
such that they hold the nut body in a floating manner in the cage
in the installation position. This measure ensures that the nut
body is retained securely in the installation position even during
transportation and during processing and also during the
clipping-in procedure.
[0008] It is also preferred to provide the internal thread with a
thread securing means (clamping means) in the region remote from
the screwing-in side. This ensures that the nut body is rotated in
any case in good time out of the installation position into the
retaining position before the end of the screwing-in procedure,
since the clamping means forces an adequate transfer of torque
between the bolt and the nut body which causes the rotation of the
nut body by 90.degree..
[0009] It is further preferred that the cage is configured such
that it exerts a spring force on the nut body towards the opening.
In this way, the nut body is held even more securely in the
installation position, thereby ruling out an accidental premature
rotation during transportation or during the clipping in
procedure.
[0010] A particularly preferred configuration is provided when an
annular abutment surface for spring elements of the cage is
arranged on the nut body, and when this abutment surface is
provided with cams or with an undulating profile such that the cams
or the elevated portions of the undulating profile engage with the
spring elements of the cage precisely when the nut body leaves its
floating installation position in the cage. This can ensure that
the nut body locks securely into the retaining position from the
installation position.
[0011] A further particularly preferred construction is provided
when the stop elements rest on an annular abutment which is
arranged in the nut body coaxially to the internal thread on the
side facing the opening, and when this abutment has recesses for
receiving the stop elements, which recesses are arranged such that,
in the retaining position, the stop elements are accommodated
therein. This measure prevents the nut body from being able to be
rotated again into a new installation position beyond the retaining
position during installation.
[0012] In this respect, it is particularly preferred when the
transition from the abutment into the recesses in the direction of
rotation is configured as a bevel. This measure ensures a smooth
transition into the retaining position and allows different sheet
thicknesses to be compensated.
[0013] It is further preferred that the transition from the
recesses into the abutment is configured as a stop surface which
extends parallel to the axis of rotation of the internal thread.
This measure can reliably rule out an "over rotation" of the nut
body again into an installation position.
[0014] A further embodiment of the present invention which is
particularly simple to produce is provided when positioned on the
blind side of the cage, onto the cylindrical internal thread
carrier, is a plastics material part which has a central opening
and also has resilient arms which extend beyond a blind-side
surface of the cage level with the abutment part and hold said
abutment part in a floating manner in the installation
position.
[0015] In this respect, it is particularly preferred when the
plastics material part is provided with a collar which extends in
the direction of the blind side and concentrically encloses the
cylindrical internal thread carrier.
[0016] Finally, it is particularly preferred when the dimensions of
the blind-side surface of the cage and of the plastics material
part are similar to those of the abutment part and when the arms
are respectively arranged diagonally in the vicinity of the corners
of the plastics material part in the screwing-in direction of the
internal thread, while the stop elements are in each case arranged
opposite the arms.
[0017] In the following, the present invention will be described in
more detail on the basis of the embodiments illustrated in the
drawings.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0018] FIG. 1 shows a cage nut according to the invention
introduced into an opening in a metal sheet and already being in
the retaining position;
[0019] FIG. 2 is a sectional view of the cage nut, according to the
invention, of FIG. 1, in the installation position cut parallel to
the axis of rotation of the internal thread;
[0020] FIG. 3 shows the cage nut, according to the invention, of
FIG. 1 in the installation position;
[0021] FIG. 4 shows different modified embodiments of the cage nut
according to the invention;
[0022] FIG. 5 is a three-dimensional view of an embodiment of a
cage nut according to the invention;
[0023] FIG. 6 is a sectional view through the axis of rotation of
the internal thread and parallel to the long edges of the nut body
of FIG. 5;
[0024] FIG. 7 shows the embodiment of FIG. 5 from above;
[0025] FIG. 8 is a sectional view of the embodiment of FIG. 5, cut
through the axis of rotation of the internal thread and parallel to
the short edges of the nut body;
[0026] FIG. 9 is a three-dimensional view of the cage belonging to
the nut body shown in FIG. 5;
[0027] FIG. 10 is a sectional view through the cage of FIG. 9,
viewed from the long side;
[0028] FIG. 11 shows the cage of FIG. 9, viewed from the short
side;
[0029] FIG. 12 shows the cage of FIG. 9 from above;
[0030] FIG. 13 is a three-dimensional view obliquely from above in
the installation position of the cage nut assembled from the parts
according to FIGS. 9 and 5;
[0031] FIG. 14 shows the assembled cage nut of FIG. 13, viewed from
the long side;
[0032] FIG. 15 shows the assembled cage nut of FIG. 13, viewed from
above;
[0033] FIG. 16 shows the assembled cage nut of FIG. 13, viewed from
the short side;
[0034] FIG. 17 is a spatial view of a further particularly
preferred embodiment of the cage nut according to the invention in
the installation position;
[0035] FIG. 18 is a spatial exploded view of the cage nut of FIG.
17 from below;
[0036] FIG. 19 is a spatial exploded view of the cage nut of FIG.
17 obliquely from above;
[0037] FIG. 20 shows the cage nut of FIG. 17 in the installation
position from below;
[0038] FIG. 21 shows the cage nut of FIG. 17 in the installation
position from the side, cut partially along the axis of rotation of
the internal thread;
[0039] FIG. 22 shows the cage nut of FIG. 17 in the installation
position from above;
[0040] FIG. 23 shows the cage nut of FIG. 17 from the side, fitted
into a suitable opening; and
[0041] FIG. 24 shows the cage nut of FIG. 17 fitted into a suitable
opening, in the installed position, viewed from the blind side.
WAY(S) OF IMPLEMENTING THE INVENTION
[0042] FIG. 1 shows a cage nut 10 according to the invention which,
in this case, has already been inserted into an opening 12 in a
metal sheet 14, and is already in the retaining position. For
reasons of clarity, the corresponding bolt which is screwed into
the nut is not shown.
[0043] The illustrated cage nut 10 according to the invention
comprises a nut body 16 which is surrounded by a cage 18. The nut
body 16 comprises a cylindrical internal thread carrier 20 with an
internal thread 22 and an abutment part 24 which is in the form of
an elongate rectangle bevelled at the corners and which develops
out of the sheet-side end of the internal thread carrier 20. The
cage 18 consists of a thin sheet of spring steel and has an
elongate rectangular base plate 26, the shape of the base plate 26
approximately corresponding to the shape of the abutment part 24
and the dimensions of the opening 12 being selected to be slightly
greater than the dimensions of the abutment part 24 or of the base
plate 26.
[0044] Two bent-up resilient arms 28 adjoin in each case in the
centre of the two short sides of the base plate 26. In this
respect, the arms 28 are initially bent obliquely outwards away
from the sheet 14 and are then bent slightly obliquely inwards away
from the sheet 14. The arms 28 partly engage over the internal
thread carrier 20 level with the end, remote from the sheet 14, of
the internal thread carrier 20.
[0045] At its end remote from the sheet 14, the internal thread
carrier 20 has an annular abutment surface 30 which is respectively
provided, in the areas in which it comes closest to a side of the
abutment part 24, with cams 32 which arch upwards. In this respect,
the arms 28 of the cage 18 are provided with corresponding bulges
34 so that they can lock with the cams 32. The cams 32 are thus
arranged in a spacing of 90.degree. in each case. Therefore, two
opposite cams 32 are covered in each case by the arms 28 both in
the installation position and in the retaining position.
[0046] FIG. 2 is a sectional view of the cage nut 10, according to
the invention, of FIG. 1 in the installation position and along the
axis of rotation of the internal thread 22, viewed from the side of
the sheet. This figure clearly shows the opening 36 for the passage
of a fitting bolt, which opening is arranged in the base plate 26
of the cage 18. Formed opposite the points of origin of the arms
28, on the edge of the opening 36 are stop elements 38 which are
bent vertically upwards away from the sheet side, starting from the
base plate 26 of the cage 18. In the installation position shown
here, i.e. if the longitudinal directions of the base plate 26 of
the cage 18 and of the abutment element 24 of the nut body 16
correspond, the stop elements 38 run on an annular guide path 40
which extends coaxially around the internal thread 22 at the
sheet-side end of the internal thread 22. Relative to the
sheet-side surface 42 of the abutment part 24, this guide path is
arranged offset away from the plane of the sheet 14. The guide path
40 is provided with two recesses 44 which receive the stop elements
38 when the cage nut 10 is in the retaining position. Here, only
one recess 44 is shown because of the sectional illustration. The
further recess which is not shown is formed point-symmetrically to
the axis of rotation of the internal thread 22.
[0047] The transition from the guide path 40 into the recess 44 is
configured as a bevel 46, thereby allowing a sliding transition
from the installation position into the retaining position of the
nut 10. The transition from the recess 44 back into the guide path
40 is configured as a stop surface 48 which runs parallel to the
axis of rotation of the internal thread 22. This reliably prevents
an "over rotation" of the nut body 16 out of the retaining position
back into the installation position. Furthermore, the stop surface
48 can be configured such that it interrupts the entire guide path
and extends as far as the sheet-side surface 42 of the abutment
part 24. This measure can prevent the cage nut 10 according to the
invention from being turned against the screwing-in direction into
the retaining position from the installation position during
transportation or installation before it has even been
installed.
[0048] FIG. 3 shows the cage nut 10 according to the invention,
again from the viewing direction of FIG. 1, but in the installation
position. Therefore, a comparison of FIGS. 1 and 3 allows a
detailed description of the installation and bolting
procedures.
[0049] The cage nut 10 is delivered in the installed state shown in
FIG. 3. In this state, the longitudinal sides of abutment part 24
and of base plate 26 of the cage 18 are arranged parallel to one
another. As a result, the nut body is held in a floating manner
above the base plate 26 by the stop elements 38. The small cams 32
shown in FIG. 1 on the annular abutment surface 30 are located
under the corresponding recesses 34 in the resilient arms 28. As a
result, the nut body 16 is held to some extent in an anti-rotation
manner in this position, so that accidental turning of the nut body
16 relative to the cage 18 during transportation or installation is
substantially avoided.
[0050] FIG. 2 clearly shows how, in this position, the nut body 16
is held in a floating manner against the spring force of the
resilient arms 28 of the cage 18 by the stop elements 38 which are
supported on the guide path 40, i.e. there is a defined distance
between the base plate 26 of the cage 18 and the sheet-side surface
42 of the abutment part 24 of the nut body 16.
[0051] In this state, the cage nut 10 according to the invention is
clipped into a suitable opening 12, for example in a metal sheet
14. The spring force of the cage 18 holds the cage nut 10 in the
opening 12.
[0052] A bolt can then be screwed into the internal thread 22. To
ensure a reliable change-over from the installation position into
the retaining position of the nut, the internal thread 22 is
provided with a thread securing means (clamping means) in the
region remote from the screwing-in side.
[0053] To ensure that the nut body 16 is also secured in the
retaining position, the enlarged retaining cams 32' which can be
clearly seen in FIG. 3 are also provided. These retaining cams 32'
are configured such that they also ensure adequate spring
pre-tension by the resilient arms 28 of the cage 18 on the nut body
16 when the nut body has been moved towards the sheet 14 after the
stop elements 38 have sunk into the recesses 44. These enlarged
cams 32' also ensure that the nut body 16 cannot be rotated again
beyond the retaining position into a new installation position,
because the tracking of the spring pre-tension ensures that the
stop elements 38 rest securely against the stop surface 48.
[0054] FIG. 4 shows further possibilities of configurations
according to the invention of the resilient arms 28 of the cage 18.
As already shown in FIG. 1-3, these arms 28 can either engage on
the end, remote from the sheet 14, of the internal thread carrier
20, in which case the respective engagement surfaces 30b, 30c can
either be smooth or can be configured with an undercut 50 to secure
the resilient arms 28.
[0055] An alternative construction provides the support of the
spring arms 28 on the retaining part 24 of the nut body 16. In this
case as well, an undercut 52 can be provided to secure the
resilient arms 28 more effectively.
[0056] The following FIGS. 5 to 16 show an embodiment of a cage nut
according to the invention in detailed workshop drawings.
[0057] In this respect, identical reference numerals relate to
identical elements, as stated above.
[0058] FIG. 5 is a three-dimensional spatial view of the
corresponding nut body 16, and here the crosswise arrangement of
the cams 32 and 32' and the different sizes thereof can be seen
very clearly.
[0059] FIG. 6 is a sectional view of the nut body of FIG. 5, cut
parallel to the long side of the nut body 16 through the axis of
rotation of the internal thread 22.
[0060] Here, the recess 44 for locking the stop elements 38 in the
retaining position can be seen particularly clearly.
[0061] FIG. 7 shows the nut body 16 of FIG. 5 from above. This
figure also very clearly shows the crosswise arrangement and the
different sizes of the cams 32 and 32'.
[0062] FIG. 8 is a sectional view of the nut body 16 of FIG. 5, cut
parallel to the short side of the nut body 16 through the axis of
rotation of the internal thread 22.
[0063] FIG. 9 is a three-dimensional view of a cage 18 which
matches the embodiment of the nut body according to FIG. 5. This
figure particularly clearly shows the configuration of the
resilient arms 28 with the recesses 34 for locking the retaining
cams 32, 32' and the formation of the stop elements 38.
[0064] FIG. 10 shows the cage of FIG. 9, viewed from the long
side.
[0065] FIG. 11 shows the cage 18 of FIG. 5, viewed from the short
side.
[0066] FIG. 12 shows the cage 18 of FIG. 9 from above.
[0067] FIG. 13 is a three-dimensional view, obliquely from above
and in the installation position, of the assembly of the nut body
16 with the cage 18 to produce the cage nut 10 according to the
invention, i.e. in the form in which the cage nut 10 according to
the invention is delivered and is inserted into a corresponding
recess in a metal sheet.
[0068] FIG. 14 shows the cage nut 10 according to the invention,
assembled and in the installation position, viewed from the long
side, and this figure shows particularly clearly how the nut body
16 is held in a "floating" manner between the stop elements 38 and
the relatively small cams 32 which are locked into the recesses 34
in the resilient arms 28. The substantially larger configuration of
the enlarged cam 32' can also be seen here very clearly.
[0069] FIG. 15 shows the cage nut 10 according to the invention in
the assembled state and in the installation position, viewed from
above. This figure also clearly shows the configuration and
arrangement of the cams 32, 32'.
[0070] FIG. 16 shows the assembled cage nut 10 according to the
invention, viewed from the short side, also in the installation
position.
[0071] The present invention provides for the first time a cage nut
specifically for unilateral access. Unlike cage nuts of the prior
art, the cage nut according to the invention can be directly
inserted into a rectangular hole in a metal sheet or in a tubular
profile. No auxiliary holes are required for inserting the cage at
the side, as is necessary in the case of so-called C-clips of the
prior art. According to the invention, for the first time, the cage
18 is itself clipped directly into the hole and is fixed
automatically by an undercut in the cage. The nut body 16 rests on
two stop elements 38 which develop out of the base plate 26 of the
cage 18. The two resilient arms 28 have two functions: firstly, to
generate a spring effect/pretension to allow the cage 18 to be
clipped into the rectangular hole 12 in the metal sheet 14 and
secondly, to hold down/press down the nut body 16 with a spring
force, so that the nut body 16 rests on the stop elements 38, even
when an appropriate counter force is generated by the
inserting/impressing of a bolt for the bolting down procedure.
[0072] The internal thread 22 of the nut body 16 is advantageously
provided with a thread securing means (clamping means) in the
region remote from the metal sheet, up to which securing means the
bolt can be screwed in from the lower side without relatively great
resistance. As soon as the bolt runs against the clamping means,
the nut body 16 rotates relative to the cage 18 and to the metal
sheet 14. Since the nut body 16 only sits on the two stop elements
38, configured as sheet metal lugs, of the cage 18, the nut body
can be easily rotated. After a rotation by 90.degree., the two stop
elements 38 lock into the rectangular recess 44 under the internal
thread 22. As soon as the stop elements 38 lock into the recess 44,
the spring force of the resilient arms 28 presses the nut body 16
down onto the sheet 14. At the same time, further rotation of the
nut body 16 is stopped, because the stop elements 38 in the recess
44 run against the edge 48 and become locked there or further
rotation is blocked by this edge 48. To ensure that even when the
nut body 16 sinks, sufficient spring force from the resilient arms
28 of the cage 18 still acts on the nut body 16, said nut body 16
can have in the upper region a type of cam 32' which compensates
the height difference during the sinking onto the sheet. After the
nut body 16 has been blocked on the stop elements 38, the bolt can
then be screwed in against the clamping/securing means until the
set tightening moment is reached. Since the abutment part 24 has a
contact surface which is great enough such that the maximum surface
pressure of the sheet 14, which can be made of aluminium, for
example, is not exceeded, the cage nut according to the invention
functions as a standard nut-bolt connection, but with the advantage
of a simple clip-in installation, also with only unilateral
access.
[0073] FIGS. 17 to 24 show an embodiment of the cage nut 110
according to the invention which can be produced in a particularly
economical manner.
[0074] FIG. 17 shows this cage nut 110 obliquely from above, in
other words, viewed from the blind side. This embodiment of the
cage nut also has a nut body 116 which is enclosed by a cage 118.
In this case as well, the nut body 116 comprises a cylindrical
internal thread carrier 120 with an internal thread 122 and an
abutment part 124 which is in the form of an elongate rectangle
rounded off at the corners, and which develops out of the
workpiece-side end of the internal thread carrier 120. The cage 118
consists of a thin sheet of spring steel and has an elongate
rectangular base plate 126, the shape of the base plate 126
approximately corresponding to the shape of the abutment part 124.
Adjoining the two narrow sides of the rectangular base plate 126
are curved resilient elements 127 which extend in a direction away
from the blind side, have a slight offset 129 and an end stop 131,
using which elements 127 the cage 118 can be clipped into a
suitable opening of a corresponding size in a workpiece.
[0075] Furthermore, attached to the longitudinal sides of the base
plate 126 is a respective stop element 138 which also extends away
from the blind side. In this respect, the two stop elements 138 are
attached diagonally opposite one another and against the diagonal
in which the nut body 116 would move when a bolt is screwed into
the internal thread 122. In the present case, the embodiment is
illustrated for a right-handed thread as the internal thread 122,
and the embodiment would be mirror-inverted for a left-handed
thread.
[0076] The function of the stop elements 138 is to prevent the nut
body 116 from being able to rotate in the wrong direction, for
example when a bolt is to be unscrewed again, and to serve as stop
elements in the screwing-in direction, and thus the nut body 116
abuts against these stop elements 138 at approximately 90.degree.
with respect to the installation position when a bolt is screwed in
and thus remains in position.
[0077] In this embodiment as well, the design engineer faces the
problem that the nut body must be held in a "floating" manner above
the plane of the workpiece in the installation position. In this
embodiment, this is achieved by a plastics material part 160 which
is also rectangular and approximately has the dimensions of the
abutment part 124 or of the base plate 126 of the cage 118,
although it can be shorter in the longitudinal direction. This
plastics material part 160 is positioned directly onto the
blind-side surface of the base plate 126. To make this possible, it
has a passage opening, through which the internal thread carrier
120 passes. To improve the mounting of the plastics material part
160 on the internal thread carrier 120, it is possible for a collar
164, arranged coaxially to the internal thread carrier 120, on the
plastics material part 160 to extend in the direction of the blind
side, as shown here. The plastics material part 160 can be attached
to the internal thread carrier 120 either by an interference fit
(provided by the resilience of the plastics material of the
plastics material part 160) of the internal thread on the passage
opening 162 or additionally on the collar 164.
[0078] Shown here is a reinforced attachment by pressing, and it is
possible to see the corresponding deformations 166 on the internal
thread carrier 120, which rule out the possibility of the plastics
material part 160 sliding off the internal thread carrier 120. To
be able to hold the nut body 116, the plastics material part 160 is
provided with arms 168 which are resilient and completely encompass
the base plate 126 and partly encompass the abutment part 124. To
improve the elastic deformability of the arms 168, said arms can be
partly separated from the plastics material part 160 by means of a
wedge-shaped notch 170. Furthermore, a recess 172 for each of the
arms 168 can be provided in the base plate 126.
[0079] As shown here, the resilient elements 127 on each of the
longitudinal sides of the base plate 126 can merely be formed in
the vicinity of the corners of the base plate 126 and can be
separated by a recess 133, depending on the size of the
corresponding cage nut and on the desired spring force for the
clipping-in procedure, although a continuous metal sheet can also
be used which extends over the entire narrow side without a
recess.
[0080] The configuration of the individual constituents of plastics
material part 160, cage 118 and nut body 116 becomes even clearer
in the exploded drawings of FIGS. 18 and 19. FIG. 18 shows the
exploded drawing obliquely from below, i.e. viewed from the
screwing-in side. Viewed upwards from the bottommost drawing, the
nut body 116 with the internal thread 122 and the internal thread
carrier 120 can be clearly seen. From the side shown here, after
installation, an appropriate bolt can be screwed into the internal
thread 122. In the embodiment illustrated here, this figure shows
very clearly how not only the edges of the base plate 124 are
rounded off but also, to achieve an improved utilisation of space
in the cage 118, how the narrow sides of the rectangular abutment
part 124 are rounded off in the form of a circular arc. The next
illustration upwards is of the cage 118 and in this figure, the
recesses 172 for the arms 168 and the passage opening 174 through
the base plate 126 of the cage 118 are very clearly visible. In an
installed state, the internal thread carrier 120 extends with a
corresponding clearance through the circular opening 174.
[0081] Shown further up is the plastics material part 160, the
opening 162 for receiving the internal thread carrier 120 and the
arms 168 with the wedge-shaped recesses 170, arranged next to them,
being particularly clearly visible here.
[0082] FIG. 19 shows the same exploded view, but here it is
obliquely from above, in other words, viewed obliquely from the
blind side. This figure also shows upwards from below: nut body
116, cage 118 and plastics material part 160. The opening 174 in
the base plate 126 of the cage 118 for the passage of the internal
thread carrier 120 and also the recess 172 for the arms 168 of the
plastics material part 160 can also be seen particularly clearly
here. In the illustration of the plastics material part 160, only
one of the arms 168 with the wedge-shaped recess 170 and the collar
164 can be seen. The rounding, in the shape of a circular arc, of
the narrow sides of the abutment part 124 of the nut body 116 can
also be clearly seen here.
[0083] FIG. 20 shows the preferred embodiment of the cage nut 110,
viewed from the screwing-in side. This figure also clearly shows
the rounding, in the shape of a circular arc, of the narrow sides
of the abutment part 124 of the nut body 116.
[0084] FIG. 21 shows the further embodiment of the cage nut 110
according to the invention from the side and partially cut along
the axis of rotation of the internal thread 122. This figure shows
particularly clearly how the base plate 126 of the cage 118 is
received between the plastics material part 160 and the abutment
part 124 of the nut body 116, while the collar 164 of the plastics
material part 160 forms an interference fit with the internal
thread carrier 120.
[0085] FIG. 22 shows the further embodiment of the cage nut 110
according to the invention from the blind side. This figure shows
particularly clearly the arms 168 and the recesses thereof 170.
[0086] Finally, FIG. 23 shows how the further embodiment of the
cage nut 110 is inserted into a corresponding opening 112 in a
workpiece 114. This figure shows particularly clearly how the stop
ends 131 of the clips 127 come into contact with the workpiece,
while the undercut 129 of the clips 127 hold the cage nut 110 in a
defined position. The figure also clearly shows here how the
abutment part 124 is held by the arms 168 and the stops 138 such
that it floats above the plane of the workpiece 114.
[0087] FIG. 24 shows the illustration of FIG. 23 from the blind
side. This figure particularly clearly shows the opening 112, to be
provided for the installation of the cage nut 110, in the workpiece
114.
[0088] Starting from the installed state shown in FIGS. 23 and 24,
the following takes place when a bolt is screwed into the internal
thread 122:
[0089] As a result of the bolting procedure, on the one hand the
nut body 116 is drawn onto the plane of the workpiece 114 and on
the other, is subjected to a torque. As a result, the arms 168 draw
aside, the nut body rotates by 90.degree. in the screwing-in
direction until it contacts with its longitudinal side the narrow
edge of the stop elements 138. The nut body 116 is then located in
the retaining position in which it rests with a large part of its
base area on the workpiece 114 outside the opening 112, and thus
forms a reliable abutment for the bolting procedure, with which
abutment an excessively high load by the workpiece 114 is avoided,
since an adequate surface is available to divert the forces.
[0090] A release of the bolting is again easily possible, because
then, as soon as the bolting forces cease, the nut body is rotated
back into the installation position until it comes into contact
again with the broadsides of the stop elements 138, as a result of
which the cage nut is again located in the installation position.
The arms 168 can snap in again and the nut could even be removed
from the opening again by compressing the clip 127.
[0091] Therefore, the present invention affords the following
advantages:
[0092] The cage nut 10;110 according to the invention can be
clipped directly into a punched, rectangular hole. No tools or aids
are required for this installation and the cage nut can also be
easily installed using only one hand. Unlike a "C-clip" nut when
introduced through the auxiliary hole, the cage nut according to
the invention cannot fall on the blind side and thus
"disappear".
[0093] The cage nut 10;110 according to the invention can be used
for different sheet metal thicknesses by an appropriate
configuration of the cage 18;118. Furthermore, there is a smooth
contact surface for the component to be installed, and not a curved
surface, as in the case of the "C-clip" nut. This produces a
reduced sinking of the connection.
[0094] The cage nut 10;110 according to the invention is
advantageously bolted automatically by the insertion and screwing
in of the bolt.
[0095] Finally, in the present invention, the contact surface of
the abutment part 24;124 can be configured to be large enough so
that sheets of light metal (for example aluminium) also withstand
the surface pressure when a bolt is installed beyond the elastic
limit.
* * * * *