Apparatus for articulation of movable panels

An improved apparatus for the articulation of automobile trunk lids. The apparatus consists of a first link attached to the lid having a gooseneck shape and an elongate slot, a second link pivotable between one end of the first link and the trunk body, a pin connected to the trunk body and slidable within the elongate slot, a latch pivotable at one end to the first and second links and having a head which latches upon the pin when the lid is opened, and a torsion bar slidable along a cam surface of the latch, which biases the latch and links towards the lid open position. Since the latch holds the lid in place when it is fully open, the torsion bar may be weaker and thereby have a more optimum torque curve.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention is an improvement of the apparatus shown in French 
patent application No. 75/24807 filed Aug. 8, 1975 and relates to an 
apparatus for articulation of movable panels about a horizontal axis, the 
arrangement mounted entirely inside an automobile trunk. 
2. Description of the Prior Art 
In the aforementioned patent, the articulation apparatus is characterized 
by the fact that it consists of an element in the form of a gooseneck 
articulated, at one of its ends, with a link mounted so as to pivot about 
an axis integral with a fixed part of the trunk. The gooseneck has an 
elongated slot, acting as a cam, cooperating with a guide pin integral 
with the fixed part of the trunk, thus permitting suitable guiding of the 
gooseneck during manipulation of the trunk lid. 
In the example illustrated, the equilibrating or compensating arrangement 
for the lid is realized on each side by a torsion bar resting on, and 
guided directly by, a roller integral with the articulation between the 
link and the gooseneck. 
Therefore, the action of the torsion bar is applied at a well-defined 
point, integral with the articulation, which determines simultaneously the 
curve of equilibration in the course of lid motion and its maintenance in 
the open position. 
However, this solution does not offer the desired equilibration curve and, 
besides, reliable holding of the lid in the open position is conditoned on 
the overestimation of the capacity of the torsion bars, which entails the 
provision of an adjustment for modifying their initial tension. 
SUMMARY OF THE INVENTION 
An object of the present invention is to avoid the above drawbacks, and 
particularly to seek a better adapted equilibration curve. Another object 
is to hold the lid in the full-open position by a positive and complete 
latching in order to eliminate the need for overequilibration. 
To this end, the improvement consists of replacing the supporting and 
guiding roller for the torsion bar by a catch mounted so as to pivot on 
the axis of articulation of the link with the gooseneck. The upper edge of 
the catch has a recess in which the torsion bar is engaged so that it may 
follow the special cam-like profile of this recess during manipulation of 
the lid. 
There results an equilibrating torque transmitted to the lid by the 
ensemble of articulations of the arrangement and a torque tending 
constantly to pivot the head of the catch towards the gooseneck so as to 
latch the head on a fixed pin integral with the trunk which also serves to 
guide the elongated slot of the gooseneck. 
This action of the catch permits a relatively reduced effort on the part of 
the torsion bar, thus permitting a decrease in the torsion formerly 
necessary for holding the lid open. Consequently, the manipulation becomes 
smoother and, moreover, permits holding the lid in a more open position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Adopting the same reference numbers as those used in the aforementioned 
patent to designate identical elements, the articulating arrangement 
according to the present FIG. 1 consists of gooseneck-shaped element 4, 
integral with the lid to be manipulated (not shown), the displacement of 
which is guided with respect to a fixed support 7 fastened to the trunk 3 
by means of the bolts 14. 
For this purpose the gooseneck 4 has an elongate slot 5 in the form of a 
cam traversed by a guide pin 8 integral with the support 7. 
In the course of manipulating the lid, the gooseneck pivots with respect to 
the support 7 by the intermediary of a link 6 articulated on the one hand 
about an axis 9 integral with the trunk and on the other about an axis 11 
integral with one end of the gooseneck 4. 
The articulating ensemble, constituted by the arrangement described above, 
is associated with an equilibrating or compensating arrangement for the 
lid represented here by a set of torsion bars 10. 
In conformance with the essential characteristic of the improvement, the 
end of the torsion bar presses on a flat piece in the form of a catch 15 
mounted so as to pivot, essentially at its middle, on the common axis 11 
of articulation of the link 6 with the gooseneck 4. This piece 15 will 
preferably be made of molded plastic. 
The catch 15 is composed of these parts: 
a head 16 intended to latch onto the guide pin 8 of the support (FIG. 3), 
to assure positive holding of the lid in the full-open position (shown 
dashed, FIG. 1). 
a recess 17 in the form of a cam made in the upper edge of the catch, 
serving to support and guide the torsion bar 10, the profile of which is 
suited to the desired equilibration curve (FIG. 2). 
a deeper cavity 18 within the catch 15 which is an extension to the rear of 
the preceding recess 17, serving to accommodate and shield the end of the 
torsion bar 10 when the lid is open (FIG. 2). 
The catch is provided, moreover, with a projection 19 situated between its 
axis 11 and its head 16 engaging a concentric slot 20 in the gooseneck 4 
in order to limit the swing of the hook about its axis. 
The apparatus works as follows: 
In the solid-line position in FIG. 1 (lid closed), the torsion bar 10 
exerts a force F.sub.1 on the recess of the catch which creates an 
equilibrating torque transmitted by the ensemble of different 
articulations of the arrangement and which causes the catch 15 to pivot 
about the axis 11 and holds it at the end of its travel as determined by 
the projection 19 engaging the slot 20. 
During opening of the lid, the catch 15 stays in this position until its 
head 16 comes into contact, via its engagement ramp 21, with the guide pin 
8. 
In opening the lid further, the head of the catch finally hooks onto the 
pin 8, being pulled back against the latter by the torque created by the 
force F.sub.2 of restraint of the torsion bars. 
In this regard it must be pointed out that the catch 15 always tends to 
pivot in the same direction, since in the course of opening the lid the 
forces exerted by restraint of the torsion bar always intersect the line 
22 between the axes of the link 6 from the same side. 
The hooking of the catch is enabled by a small amount of play between the 
projection 19 and the end of the slot 20, which permits maintaining the 
head 16 of the catch pressed against the guide pin 8 by the action of the 
force F.sub.2. 
The resultant hooking assures full opening of the lid and holding it there 
in a reliable manner. 
The presence of the holding catch permits a significant decrease in the 
torsion torques necessary for equilibrating the lid, because of the fact 
that its being held in the completely open position is no longer assured 
only by the torsion bars, the solution of the aforementioned prior patent. 
The opening of the lid consequently takes less effort and is smoother. 
Also, the precise and reliable latching of the open lid eliminates the sag 
of the torsion bar so as to gain 3 to 5 degrees in the angle of the open 
lid. 
In order to limit the play between the head 16 of the catch, the guide pin 
8 and the slot 5 in the gooseneck, the latter exhibits a slight taper 23 
at its end to assure firm contact with the pin 8 at the end of travel. 
To close the lid, it is merely pushed downward. The force transmitted by 
the gooseneck 4 to the catch 15 frees the latter in making it pivot in the 
reverse direction, for unlatching, due to the reaction of the pin 8. 
Obviously, many modifications and variations of the present invention are 
possible in light of the above teachings. It is therefore to be understood 
that within the scope of the appended claims, the invention may be 
practiced otherwise than as specifically described herein.