U.S. patent application number 09/785725 was filed with the patent office on 2001-10-04 for device for the detachable fastening of a steering wheel on a steering shaft.
This patent application is currently assigned to TRW Automotive Safety Systems GmbH & Co.KG. Invention is credited to Kreuzer, Martin.
Application Number | 20010026730 09/785725 |
Document ID | / |
Family ID | 7939571 |
Filed Date | 2001-10-04 |
United States Patent
Application |
20010026730 |
Kind Code |
A1 |
Kreuzer, Martin |
October 4, 2001 |
Device for the detachable fastening of a steering wheel on a
steering shaft
Abstract
The invention relates to a device for the detachable fastening
of a steering wheel on a steering shaft having an axis. The
steering wheel has a hub provided with a through-bore arranged
perpendicularly to the axis of the steering shaft and the
through-bore intersects a groove arranged in the steering shaft.
The device comprises a fastening means arranged in the
through-bore. The fastening means has a bolt with a head and a
shaft provided at least partially with an external thread and has a
nut able to be screwed onto the shaft of the bolt. The nut is able
to engage into the groove and the through-bore has two oppositely
directed radial support surfaces arranged between the bolt head and
the nut. One support surface is arranged on the bolt head side and
the other support surface is arranged on the nut side. A spring
element is provided which engages one of the bolt and the nut and
exerts a force onto one of the bolt and the nut. The force aims for
an increase of a distance between the bolt head and the nut.
Inventors: |
Kreuzer, Martin;
(Kleinwallstadt, DE) |
Correspondence
Address: |
TAROLLI, SUNDHEIM, COVELL, TUMMINO & SZABO L.L.P.
1111 LEADER BLDG., 526 SUPERIOR AVENUE
CLEVELAND
OH
44114-1400
US
|
Assignee: |
TRW Automotive Safety Systems GmbH
& Co.KG
|
Family ID: |
7939571 |
Appl. No.: |
09/785725 |
Filed: |
February 16, 2001 |
Current U.S.
Class: |
403/355 |
Current CPC
Class: |
B62D 1/10 20130101; Y10T
403/7084 20150115; Y10T 403/18 20150115; Y10T 74/20834 20150115;
Y10T 403/7018 20150115; Y10T 403/7067 20150115 |
Class at
Publication: |
403/355 |
International
Class: |
B25G 003/28 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 30, 2000 |
DE |
200 05 884.3 |
Claims
1. A device for the detachable fastening of a steering wheel on a
steering shaft having an axis, said steering wheel having a hub
provided with a through-bore arranged perpendicularly to said axis
of said steering shaft, and said through-bore intersecting a groove
arranged in said steering shaft, said device comprising a fastening
means arranged in said through-bore, said fastening means having a
bolt with a head and a shaft provided at least partially with an
external thread and having a nut able to be screwed onto said shaft
of said bolt, said nut being able to engage into said groove, said
through-bore having two oppositely directed radial support surfaces
arranged between said bolt head and said nut, one support surface
being arranged on the bolt head side and said other support surface
being arranged on the nut side, and a spring element being provided
which engages one of said bolt and said nut and exerts a force onto
one of said bolt and said nut, said force aiming for an increase of
a distance between said bolt head and said nut.
2. The device according to claim 1, wherein said spring element is
arranged between said support surface on said nut side and said nut
and exerts a force onto said nut in a direction of said bolt head
toward said nut.
3. The device according to claim 1, wherein said spring element is
arranged between said support surface on said bolt head side and
said bolt head.
4. The device according to claim 1, wherein said nut is secured
against rotation in said through-bore.
5. The device according to claim 1, wherein said end of said
through-bore on said nut side is secured against said nut falling
out.
6. The device according to claim 1, wherein said nut has a conical
chamfer with which it engages into said groove.
Description
TECHNICAL FIELD
[0001] The invention relates to a device for the detachable
fastening of a steering wheel on a steering shaft.
BACKGROUND OF THE INVENTION
[0002] The use of steering wheels provided with gas bags in
automobiles requires new techniques for the installation of the
steering wheel on the steering shaft, because the interior of the
steering wheel is no longer accessible from above.
[0003] It is known for example from the DE 41 06 096, to provide
the steering shaft with a groove and to provide the hub with a
through-bore which intersects this groove, and in this through-bore
to arrange a fastening means consisting of a bolt and a nut screwed
onto this bolt, a part of the bolt and/or of the nut engaging into
the groove of the steering shaft on tightening of the nut and bolt
connection and in this way locking the hub and the steering shaft
with each other. As also in the use of nuts screwed from above onto
the steering shaft, the torques occurring during traveling are
transferred via force-fitting serrations in the steering shaft and
the hub.
BRIEF SUMMARY OF THE INVENTION
[0004] In order to be able to separate the steering wheel from the
steering shaft without difficulty, for example for changing the
steering wheel or the gas bag module, it is necessary that the nut
and bolt connection can be detached simply and reliably.
[0005] This is achieved in a device for the detachable fastening of
a steering wheel on a steering shaft having an axis. The steering
wheel has a hub provided with a through-bore arranged
perpendicularly to the axis of the steering shaft and the
through-bore intersects a groove arranged in the steering shaft.
The device comprises a fastening means arranged in the
through-bore. The fastening means has a bolt with a head and a
shaft provided at least partially with an external thread and has a
nut able to be screwed onto the shaft of the bolt. The nut is able
to engage into the groove and the through-bore has two oppositely
directed radial support surfaces arranged between the bolt head and
the nut. One support surface is arranged on the bolt head side and
the other support surface is arranged on the nut side. A spring
element is provided which engages one of the bolt and the nut and
exerts a force onto one of the bolt and the nut. The force tries to
increase, i.e. aims for an increase of a distance between the bolt
head and the nut. The fastening means consisting of bolt and nut
forms a nut and bolt connection. On tightening of the nut and bolt
connection, the spring element is compressed and pre-stressed. On
detaching of the nut and bolt connection, the energy stored in the
spring provides for the bolt head and nut to be pressed apart and
for the nut to leave the engagement with the groove, so that the
steering wheel can be simply removed from the steering shaft.
[0006] In a preferred embodiment of the invention, the spring
element is arranged between the support surface on the nut side and
the nut. In this way, it is ensured that on detachment of the nut
and bolt connection the nut moves outwards to the end of the
through-bore on the nut side and no longer engages into the groove
of the steering shaft.
[0007] In a further preferred embodiment of the invention, the
spring element is arranged between the support surface on the bolt
head side and the bolt head. In this way, the bolt can be easily
removed after the detachment of the nut and bolt connection.
[0008] It is necessary to secure the nut against rotation in the
through-bore, in order to avoid a co-rotation of the nut with the
bolt during the tightening movement or during the detachment of the
connection.
[0009] Advantageously the end of the through-bore on the nut side
is secured against the nut falling out, e.g. by caulking.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The single FIGURE shows a device according to the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] The device shown is used for the detachable fastening of a
steering wheel on a steering shaft 10, the steering wheel having a
hub 30 which is provided with a through-bore 20. This through-bore
20 intersects a groove 40 formed in the steering shaft. In the
through-bore 20 a constriction is constructed, which forms two
radial support faces 110 and 120.
[0012] An essential component of the device is a fastening means
50. This fastening means 50 has a bolt 60 with a bolt head 70 and
also a shaft 90, which is provided at least partially with an
external thread 80, and has a nut 100 which is able to be screwed
onto the shaft 90 and is arranged in the through-bore 20 such that
the bolt head 70 and the nut 100 are separated from each other by
the radial support surfaces 110 and 120. The support surface 110
here faces the bolt head 70 and the support surface 120 faces the
nut 100. The nut 100 is provided with an internal thread and has at
its end facing the support surface 120 on the nut side a preferably
conical chamfer 102 which is constructed such that it can engage
into the groove 40 of the steering shaft 10.
[0013] In the through-bore 20 a guide is provided for the nut 100
in order to secure it against rotation in the through-bore 20 and
to prevent a co-rotation of the nut with the bolt movement during a
screwing procedure.
[0014] Between the nut 100 and the support surface 120 on the nut
side a spring element 130 is arranged, preferably a spiral spring.
Between the support surface 110 on the bolt head side and the bolt
head 70, a washer can be provided.
[0015] In order to prevent the nut 100 from falling out from the
through-bore 20 with a detached nut and bolt connection 50, the end
of the through-bore 20 on the nut side is secured by suitable
means, e.g. by caulking 140.
[0016] To connect the steering wheel with the steering shaft, with
a detached nut and bolt connection 50, the steering wheel is placed
onto the steering shaft. Serrations (not illustrated) in hub and
steering shaft provide for a torque transmission between the
steering wheel and the steering shaft. The nut 100 is only screwed
onto the shaft 90 so far that the spring element 130 holds the nut
100 by elastic force in a position close to the opening 150 of the
through-bore 20 on the nut side, so that the nut 100 does not
prevent the placing of the steering wheel 30 onto the steering
shaft 10.
[0017] After placing the steering wheel onto the steering shaft,
therefore firstly the conical chamfer 102 of the nut 100 does not
engage into the groove 40 of the steering shaft 10. By a tightening
of the nut and bolt connection by rotation of the bolt head 70, the
nut 100 is moved along its guide toward the support surface 120 and
in so doing arrives in engagement with the groove 40 and via the
conical chamfer 102 locks the hub 30 of the steering wheel with the
steering shaft 10. The support surfaces 110 and 120 provide for the
nut to assume a defined position with respect to the groove 40.
After the tightening of the nut and bolt connection 50, the
steering wheel is secured on the steering shaft.
[0018] The spring element 130 is compressed and prestressed by the
movement of the nut 100 in the direction of the support surface
120.
[0019] To detach the connection between the hub 30 of the steering
wheel and the steering shaft 10, the nut and bolt connection 50 is
detached, in turn by rotating of the bolt head 70. The spring
element 130 gradually relaxes and moves the nut 100 from the
support surface 120 away toward the opening 150 on the nut side
with the bolt head 70 as before lying against the support surface
110. In this way, the engagement of the nut 100 with the groove 70
is reliably released and the steering wheel can be lifted from the
steering shaft.
* * * * *