Spring mechanism for the hinge of a motor-vehicle sun visor

A motor vehicle sun visor (P) has a substantially tubular spring mechanism (R) fitted in its hinge-rod housing for gripping the rod to retain the visor in a desired angular position on the rod in use. The spring mechanism is formed from a single piece of sheet spring metal and is of substantially tubular form with a longitudinal curved wall (1) connected at opposite longitudinal edges to two parallel flat walls (2, 2') which grip the hinge rod in use. The other edges of the flat walls are joined to two curved wall portions whose free edges (6, 6') define an aperture. The curved wall and wall portions are a close fit in the tubular housing (8) with a longitudinal projection (7) thereof fitted in the aperture to prevent relative rotation of the spring mechanism and the housing, and the spring mechanism has outwardly-projecting tabs (5, 5', 5") which snap engage in a recess (10) in the housing wall to restrain the spring mechanism against axial movement in the housing.

BACKGROUND OF THE INVENTION 
The present invention relates to spring mechanisms for the hinges of 
motor-vehicle sun visors and to sun visors incorporating such spring 
mechanisms. 
SUMMARY OF THE INVENTION 
The object of the invention is to provide a new spring mechanism for 
retaining a motor-vehicle sun visor in a desired position of use which has 
greater functional efficiency and is easier to assemble than known spring 
mechanisms designed for the same purpose. 
In keeping with this object, and others that will become apparent later on, 
one aspect of the invention resides in a spring mechanism for a hinge of a 
sun visor of a motor-vehicle that includes a resilient sheet element 
having a longitudinally curved wall portion with two opposite longitudinal 
edges, two flat parallel wall portions that are parallel to each other, 
and two curved wall portions having free edges facing each other so as to 
define an aperture. The two flat parallel wall portions extend between the 
two opposite longitudinal edges and the two curved wall portions. The 
resilient sheet element has a single piece construction. At least one 
retaining tab extending outward from said resilient sheet element is 
provided to retain the resilient sheet material. 
It is a further object to fit the resilient sheet material with the tab 
into a hinge-rod housing of a sun visor so that the flat wall portions 
grip a rod which extends axially through the tubular mechanism and the 
housing. In this position the aperture between the free ends of the two 
curved portions cooperates with a projection provided on the inner wall of 
the housing to prevent relative rotation of the resilient sheet material 
and the housing while the retaining tab engages a recess in the housing 
wall to oppose relative axial movement. The retaining tab is formed as a 
spring. 
It is an additional object to form the resilient sheet element symmetrical 
about a longitudinal plane of symmetry which passes through the 
longitudinal curved wall portion and which bisects the aperture. The two 
flat parallel faces are arranged parallel to this longitudinal plane of 
symmetry. 
It is still another object that three retaining tabs project respectively 
from the longitudinal curved wall portion and the two flat wall portions. 
The retaining tabs each diverge outward from the resilient sheet element 
in the same direction symmetrically at an acute angle with respect to a 
longitudinal axis of the resilient sheet material. The resilient sheet 
element and the tabs form a single piece structure. 
It is yet another object that the resilient sheet element be composed of 
spring metal and be substantially tubular in form. 
It is an additional object to provide a tubular housing with an inner wall. 
All of the curved wall portions are fitted against the inner wall. The two 
flat parallel wall portions thereby are arranged so that a space forms 
between the two flat wall portions and the inner wall. The two flat 
parallel wall portions are formed to resiliently expand into this space to 
accommodate gripping the hinge rod between the two flat parallel wall 
portions to thereby retain a sun visor on the hinge rod in a desired 
angular position of use. A relative rotation of the resilient sheet 
element and the housing is prevented by a projection formed in the housing 
and fitted between the free edges of the two curved wall portions in the 
aperture. The housing has a recess in which is engaged the retaining tab 
so as to restrain the resilient sheet element against axially moving in 
the housing. 
It is yet another object to provide the housing with an open end. The 
resilient sheet element has a receiving area into which one tab is 
depressible so that the tab extends outwardly no further than an outer 
surface of the resilient sheet element. The resilient sheet element is 
formed so as to be slidable into the housing through the open end while 
the one tab is depressed into the receiving area. The one tab is formed to 
engage the recess in the housing upon reaching the recess by snapping into 
engagement so as to prevent a withdrawal of the resilient sheet element 
from the housing. 
It still another object to provide the housing with a wall against which a 
longitudinal end of said resilient sheet element abuts as the one tab 
reaches the recess. 
The novel features which are considered as characteristic for the invention 
are set forth in particular in the appended claims. The invention itself, 
however, both as to its construction and its method of operation, together 
with additional objects and advantages thereof, will be best understood 
from the following description of specific embodiments when read in 
connection with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Turning now to the drawings, FIGS. 1 and 2 depict a spring mechanism R 
having a single piece structure composed of a resilient sheet material, 
preferably metal such as spring steel. The spring mechanism R is 
substantially tubular in shape with a longitudinal plane of symmetry and 
with a longitudinal aperture bisected by this plane. 
The spring mechanism R has a curved wall 1 with longitudinal edges 
connected to two flat walls 2, 2'. The flat walls 2, 2' are parallel to 
the plane of symmetry and therefore parallel to each other. The flat walls 
2, 2' are also each connected to a respective curved wall portion 3, 3' 
whose free edges 6, 6' are separated by a predetermined distance that 
defines the longitudinal aperture. The curved wall 1 and the two flat 
walls 2, 2' have respective longitudinally-elongated apertures or 
receiving areas near one end 4 of the mechanism R with respective tabs 5, 
5', 5". The tabs are composed of the spring metal and project outward from 
edges of the apertures adjacent the end 4. Each tab 5, 5', 5" extends 
across its respective aperture and also diverges outward slightly at an 
acute angle with respect to the longitudinal axis of the spring mechanism 
R. The tabs 5, 5', 5" are provided to retain the spring mechanism R in the 
hinge housing of a sun visor. 
The end portion of a motor-vehicle sun visor P is shown in FIGS. 3 and 4 
and incorporates a housing 8 for the hinge rod (not shown) of the visor 
and also for the spring mechanism R. The housing 8 has a 
generally-cylindrical portion in which the curved wall 1 and wall portions 
3, 3' of the spring R are a close fit. A longitudinal projection 7 is 
close fit between the opposing edges 6, 6' of the wall portions 3, 3' so 
as to prevent the spring R from rotating within the housing 8. The wall of 
the housing 8 also has a recess 10 which accommodates the tabs 5, 5', 5" 
of the spring R. 
The spring mechanism R is slid axially into the housing 8 from the right 
hand end of the housing shown in FIG. 4. During this axial sliding, the 
tabs 5, 5', 5" are resiliently depressed into their respective apertures 
or receiving areas in the walls 1, 2, 2'. When the spring R is fully 
inserted, its end 4 abuts an end shoulder 9 of the housing 8 and the tabs 
5, 5', 5" spring out into the recess 10 in the housing wall to prevent 
withdrawal of the spring mechanism R from the housing 8. 
A hinge rod of a sun visor is inserted through the through-hole of the 
spring mechanism R and is gripped resiliently between the two 
generally-flat walls 2, 2', which can flex apart into the adjacent space 
in the housing 8 to accommodate the rod as required. When the motor 
vehicle is traveling over normal road surfaces, the sizing of the hinge 
rod and the spring R and the resiliency of the spring R are such that a 
hinge rod with a cylindrical shape is held firmly in any selected angle of 
inclination of the sun visor. When the motor-vehicle will travel over 
uneven ground resulting in a great deal of vibration, a hinge-rod may be 
used which, instead of being completely cylindrical, has longitudinal 
flats on its circumferential surface, that is, parallel to generatrices of 
the cylinder. In this case, the two flat walls 2, 2' of the spring 
mechanism R engage the longitudinal flats on the hinge rod to establish 
specific angular positions of the visor P which are particularly stable. 
Indeed, it will be appreciated, that, to pivot the visor on such a rod, 
the two flat walls, 2, 2' will have to be forced apart to pass over the 
larger-diameter portions of the rod between the flats. 
It will be understood that each of the elements described above, or two or 
more together, may also find a useful application in other types of 
constructions differing from the types described above. 
While the invention has been illustrated and described as embodied in a 
spring mechanism for the hinge of a motor-vehicle sun visor, it is not 
intended to be limited to the details shown, since various modifications 
and structural changes may be made without departing in any way from the 
spirit of the present invention. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications without omitting features that, 
from the standpoint of prior art, fairly constitute essential 
characteristics of the generic or specific aspects of this invention. 
What is claimed as new and desired to be protected by Letters Patent is set 
forth in the appended claims.