Polyvalent suspension balance for assembly lines for manufactured goods, especially motor vehicles

A polyvalent suspension balance for the assembly lines of manufactured goods, especially motor vehicles, involving at least one overhead device for coupling to an aerial conveyer drive is disclosed. The suspension balance consists of two vertical curved arms, shaped roughly like a wide-open C, each of which separately connects an overhead coupling piece to at least one lower and separate anchoring member for the substructure of the product to be assembled. The said curved arms are articulated about a more or less vertical axis which has great freedom of movement, thereby making it possible to gain easy access to all of the products during all stages of their assembly. Application is to assembly lines for relatively bulky and complex manufactured goods, especially to the production lines of motor vehicles.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention concerns a polyvalent suspension balance for assembly lines 
for manufactured goods, especially assembly lines for the production of 
motor vehicles. 
2. Description of the Prior Art 
Experience has shown that a wide range of translation devices and systems 
are used in the production of certain relatively bulky and complex 
manufactured goods, in particular the production of motor vehicles from 
the initial assembly of the empty body until the vehicles emerge at the 
end of the finish assembly line. Accordingly, there is successive and/or 
alternate use of suspended conveyer belts and monorail circuits with 
tackle, suspension balances and swing trees, and of ground-level assembly 
lines or lines with tables, running wheels and guide tracks, both 
controlled or free wheeling, which may or may not involve the use of 
sleds, sledges, pushed or pulled wagons, etc. This results in the use of 
an extremely wide variety of materials, the moving portions of which must 
frequently be returned empty to the starting point of each assembly phase, 
giving rise to a large amount of mechanized or manual handling or 
maneuvering between the various segments of the assembly line and 
seriously impacting on the costs associated with design, construction, 
operation and maintenance of such production lines. 
SUMMARY OF THE INVENTION 
The object of this invention is to eliminate the aforementioned drawbacks 
by using one standard translation device for the entire assembly line, a 
device which is capable, however, of providing optimum freedom of access 
to the entire product throughout all its different assembly phases, access 
not only for the working personnel but for the mechanisms providing parts 
and tooling. 
An aerial conveyer with suspension balances is the most appropriate 
translation system for meeting these criteria as it provides greater 
positioning flexibility in space, depending on needs, for the products to 
be assembled, thereby making all the manual operations to be carried out 
on these products ergonomically feasible at a normal human height, this 
without recourse to substantial civil engineering efforts in the course of 
constructing the production line. In addition, given the smaller 
investments and lesser degree of technical competence associated with such 
an installation, it is particularly well suited for the construction of 
assembly plants in the developing countries. 
A polyvalent suspension balance for the assembly lines of manufactured 
goods, especially motor vehicles, involving at least one overhead device 
for coupling to an aerial conveyer drive in accordance with the object of 
this invention, consists in two vertical curved arms, shaped roughly like 
a wide open C, each of which separately connects an overhead coupling 
piece to at least one lower and separate anchoring member for the 
substructure of the product to be assembled, said C-shaped arms being 
articulated independently about a more or less vertical axis which 
provides great freedom of movement thereby making it possible to gain easy 
access to all of said products during all stages of their assembly. 
According to a preferred assembly mode for the invention, each of the 
C-shaped arms, situated respectively at the front and rear of the 
suspension balance, is mounted so as to pivot directly to the overhead 
coupling piece and is articulated at its lower end to the center of a 
separate pair of anchoring members, with the connecting piece between said 
pairs of anchoring members during use consisting solely of the 
substructure of the product to be assembled, thereby ensuring great 
accessibility to the underneath portions of said assembled structure. 
For safety purposes, each anchoring member is provided with a means for 
locking the substructure of the products to be assembled to the 
aforementioned suspension balance. 
Preferably, each locking device consists of a rotary lock featuring a head 
with a known shape, roughly that of a parallelpiped so as to interlock in 
the appropriate housings in the substructure of the products to be 
assembled, which is caused to rotate by the interaction of an 
uninterrupted series of four saw-toothed control notches in the lateral 
surface of the cylindrical pivoting surface of the lock with at least one 
radial pin made unitary with a sliding ring mounted vertically around the 
body of the lock, so that each rising movement in said sliding ring 
induces one fourth of a turn of the head of the lock. 
As a result, the lifting of the sliding ring which induces rotation in the 
head of the lock may be ensured automatically by the presence of abutments 
or stops placed judiciously at the appropriate locations along the 
assembly line, thereby bringing about the locking and unlocking of the 
products to be assembled. 
When the products to be assembled are motor vehicles, the housings in the 
substructure of the vehicles for the anchoring and locking members may 
advantageously consist of the jack positioning and placement housings in 
the chassis frame. 
Finally, according to a preferred variant of manufacture, the overhead 
coupling part includes a transverse horizontal bar with freely rotating 
rollers at each of its ends, which form a horizontal stabilizer by working 
in a known manner in conjunction with the lateral guide rails made unitary 
with the support structure of the aerial conveyer so as to prevent any 
rocking of the unit during work on the products during assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As shown in FIG. 1 in particular, the suspension balance consists of an 
overhead coupling piece 1 attached with the help of appropriate brackets 2 
to any type of aerial conveyer drive device. Two vertical arms 3, shaped 
roughly like a wide-open C, are situated at the front and rear 
respectively, of the suspension balance, each of which separately links 
the overhead coupling piece 1 to a separate pair of anchoring members 4 
for the substructure of the product to be assembled, which in the case of 
FIGS. 2a to 2f consists of the chassis frame 5 of a motor vehicle. Each of 
the C-shaped arms 3 is mounted so as to respectively pivot on the overhead 
coupling piece 1 via a first joint 6. At the lower end of each arm 3 is a 
second joint 7 which is at the center of a linking tube 8 raised at its 
end so as to define each separate pair of anchoring members 4. 
The C-shaped arms 3 are thus independently articulated around vertical axes 
with large angular freedom of movement, on the order of 180 degrees, 
thereby allowing, as clearly shown in FIGS. 2a to 2f, easy access to the 
entire product being assembled, in this case motor vehicles, during the 
entire assembly process. In addition, the single connecting and stiffening 
element between the separate pairs of anchoring members 4 consists 
uniquely, during use, of the substructure 5 of the product to be 
assembled, likewise ensuring a high degree of access to the lower parts of 
said structure while eliminating weight from the suspension balances on 
their return circuit when empty. 
Generally speaking, in their normal position the C-shaped arms 3 are in 
plane symmetrical with the suspension balance and work may be carried out 
with no difficulty on about 95 percent of the total surface area of the 
products to be assembled. Further, a slight movement of the arms 3, 
imparted manually by an operator or by an appropriate arrangement 
installed at the desired location along the assembly line, is sufficient 
to provide access to the remaining 5 percent. Nevertheless, the large 
freedom of movement of the C-shaped arms 3 proves to be very useful for 
entirely freeing the front or rear portion of the products to be 
assembled, especially when large-sized parts are added or in order to 
facilitate separation of the completed products at the end of the assembly 
line. 
For safety purposes, each anchoring member 4 is provided with a locking 
device 9 for attaching the substructure 5 of the products to be assembled 
to the suspension balance. In addition, the overhead coupling piece 1 
includes a transverse horizontal bar 10 provided with freely rotating 
rollers 11 at each end, forming a horizontal stabilizer by a known method 
of interaction between the said rollers 11 and the lateral guide rails 
(not shown) formed unitarily with the structure supporting the aerial 
conveyer so as to prevent any rocking of the entire unit during the manual 
or automated operations carried out on the products during assembly. 
For installations which are small in size, the locking device 9 may be a 
manually activated rotary lock of the type shown in FIGS. 3 and 4, which 
includes a head 12, of a known more or less parallelpiped shape designed 
to interlock in an appropriate housing of the substructure 5 of the 
product to be assembled, and provided with a knurled lower collar 13 such 
that it can be rotated 90 degrees in alternate directions. The heads are 
extended by a cylindrical pin 14, which may turn in each upper end of the 
connecting tubes 8 making up the pairs of anchoring members 4. The heads 
are limited in translation and rotation by the interaction of stops 15, 
which are screwed radially into the cylindrical pin 14, and corresponding 
horizontal openings 16, each of which extends about a fourth of the way 
around the tubes 8 close to the ends thereof, so as to allow only a one 
quarter turn in rotation of the lock heads 12. 
According to a preferred mode of manufacture of the locking device 9, shown 
in FIGS. 5 and 6, the locking device also consists of a rotary lock made 
up of a head 17 whose shape is similar to that of the preceding lock, 
extended by a cylindrical pin 18, mounted in free rotation inside a 
tubular lock body 19 screwed into the ends of the tubes 8 of the anchoring 
points 4 and axially immobilized in the said lock body 19 by the 
simultaneous action of an upper support ring 20 and a lower stop washer 
axially screwed at 22 into the cylindrical pin 18. The lock head 17 is 
caused to rotate by the interaction of an uninterrupted series of four 
sawtoothed control steps 23, made in the lateral surface of the pin 18, 
with two diametrically opposed pins 24, which slide within the 
corresponding vertical openings 25 made in the lock body 19 and which move 
unitarily with a vertically sliding ring 26 mounted around the lock body 
19 so that each lifting of the said ring 26 induces a one quarter turn 
rotation of the lock head 17. 
Each pin 24 also involves an extension 27 which protrudes beyond the 
sliding ring 26, forming a control organ for the locking device. The 
lifting of the sliding ring which includes the rotation of the lock head 
17 may thus, thanks to this control organ, be provided either manually or 
automatically by the interaction of the extensions 27 with retractable 
stops or notches which are arranged at appropriate points along the 
assembly line. 
When the products to be assembled are motor vehicles, as shown in FIGS. 2a 
to 2f, the housings in their substructure for the anchoring members 4 and 
locking units 9 may advantageously be the receptor and positioning 
housings for jacks on the underside of the chassis frame. 
The polyvalent suspension balance which is the subject of this invention 
thus provides, by simple, reliable and inexpensive means, optimal 
accessibility to all parts of the products to be assembled, throughout the 
different phases of their manufacture, whether such access is for 
operators or for the devices providing parts and tooling. It thus lends 
itself both to use on relatively rudimentary assembly lines involving 
mostly manual operations and to highly automated assembly lines which 
require, for example, great freedom of access and movement for the arms of 
programmable automated equipment, in that each suspension balance may 
easily be effectively immobilized and stabilized by appropriate means, 
associated with the horizontal stabilizer described above or with some 
other feature, during the time of operation of the automated equipment. 
The range of application of the present invention is not limited to the 
assembly lines for motor vehicles, but, as previously noted, may extend to 
all production lines for manufactured goods, especially those which are 
relatively bulky and complex. Likewise, various modifications may be made 
to the mode of manufacture described without thereby departing from the 
framework of the invention. Accordingly, for example, the locking devices 
9 may be provided with seals which ensure they are protected when the 
suspension balances pass through installations for treating the surface of 
the products to be assembled. 
Obviously, numerous 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.