Method for supplying parts to an automatic assembling machine

A carrier for supplying to an automatic assembling machine at least one chassis and several parts to be assembled on each chassis includes a first portion for receiving each chassis and a second portion associated with the first portion for storing the parts to be assembled on the chassis. According to the method, the chassis are loaded on the first portions of the carrier and sets of corresponding parts are loaded on the second portions in a predetermined relationship, whereupon, corresponding parts of the sets are simultaneously transferred to the respective chassis.

CROSS REFERENCES TO RELATED APPLICATIONS 
Reference is made to copending U.S. application Ser. No. 380,997 filed May 
21, 1982, Ser. No. 390,061 filed June 18, 1982, and Ser. No. 391,472 filed 
June 23, 1982, assigned to the assignee of the present application, and 
containing related subject matter. 
BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention generally relates to a method and apparatus for supplying 
parts to be automatically assembled on a chassis by an automatic 
assembling machine, and more particularly, to a carrier member with 
pallets for receiving the parts and the chassis for assembly and a method 
of using the same. 
2. Description of the Prior Art 
An automatic assembling machine conventionally assembles parts onto a 
chassis supported by a carrier. Generally, one unit supplies the parts and 
another unit, distinct from the parts supplier, supplies the chassis to a 
carrier. The automatic assembling machine sequentially picks up the parts 
from the parts supplier and assembles them on the chassis transported by 
the carrier. 
However, a complex apparatus is required to assemble many kinds of parts on 
a chassis with a single automatic assembling machine since each of the 
different parts requires a respective parts supplying unit and assembly 
jig. Furthermore, conventional automatic assembling machines are generally 
constructed to assemble only one type of equipment, that is, only one 
arrangement of parts on a particular chassis. Accordingly, such automatic 
assembling machines are special purpose machines which require 
significant, costly changes when the equipment to be assembled is 
modified. 
OBJECTS AND SUMMARY OF THE INVENTION 
Accordingly, it is an object of this invention to avoid the above-described 
difficulties encountered with the prior art in the automatic assembly of 
parts on chassis. 
More particularly, it is an object of the present invention to provide a 
device and method by which a chassis and parts to be assembled thereon are 
supplied to an automatic assembling machine so as to permit the latter to 
be of simple structure. 
It is another object of this invention to provide a device and method by 
which chassis and parts to be assembled thereon are supplied or carried to 
an automatic assembling machine so as to permit the latter to have great 
flexibility to accommodate changes in the design of the products to be 
assembled. 
It is a further object of this invention to provide a device and method, as 
aforesaid, which causes an automatic assembling machine to produce 
assemblies with high precision and efficiency. 
In accordance with an aspect of the present invention, a device for 
supplying an automatic assembling machine with at least one chassis and a 
plurality of parts to be assembled on each chassis includes a carrier 
member with at least one first portion for receiving each chassis and a 
second portion associated with each first portion for storing the 
plurality of parts to be assembled on the chassis. 
According to the method of the present invention, when sets of 
corresponding parts are to be assembled on several respective chassis, 
such chassis are loaded on respective first portions of a carrier member, 
and the sets of corresponding parts are loaded on second portions of the 
carrier member which are respectively associated with the first portions. 
The various parts of each set are loaded in a predetermined relationship 
to each other. The corresponding parts of the sets are simultaneously 
transferred from the second portions to the predetermined locations on the 
chassis located on the respective first portions. 
The above, and other objects, features and advantages of the invention will 
be apparent from the following detailed description of an illustrative 
embodiment thereof which is to be read in connection with the accompanying 
drawings.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
Referring to the drawings in detail, and initially to FIG. 1 thereof, a 
carrier 1 according to an embodiment of this invention for use in an 
automatic assembling apparatus is shown to include a base plate 2 with 
four pallets 3 arranged thereon and fixed in alignment with each other. 
Suspension handles or keepers 4 are respectively mounted adjacent the four 
corners of the base plate 2. 
Each of the pallets 3 of the carrier 1 has positioned thereon before the 
assembling operation a chassis 5 and main parts 6 which may be various 
types of gears, levers, bearings and the like required for assembly on the 
chassis 5. When the carrier 1 is loaded with the chassis 5 and the main 
parts 6, it is transferred to an assembly center to be described where an 
automatic assembling machine sequentially picks-up, feeds, and assembles 
the main parts 6 onto the chassis 5. At the assembly center, common parts 
and some other parts, such as reel shafts, screws, and the like are 
separately fed and assembled onto the chassis 5. In addition to the 
feeding and assembly of the parts on the chassis 5, other operations such 
as tightening of the screws, lubrication of parts, magnetization of 
magnetic members, and other associated operations can be automatically 
performed at the assembly center. The feeding, processing and assembling 
of the parts on the chassis 5 are simultaneously performed for the four 
pallets 3 of the carrier. 
FIGS. 2A, 2B and 3 illustrate in detail the structure of the pallets 3 of 
the carrier 1. The pallets 3 are molded of a plastic material having high 
precision such as bulk molding compound (BMC). A chassis positioning 
loader 9 for positioning and loading the chassis 5 thereon is formed 
integrally at one end portion 3a of the pallet 3. A parts positioning 
loader 10 for positioning and loading the parts 6 is integrally formed 
with the other end portion 3b of the pallet 3. The parts positioning 
loader 10 includes several parts receiving members 11, 12 and 13 which 
receive and position respective parts 6a, 6b and 6c. 
The chassis positioning loader 9 includes an outer circumference guide 
portion 14 integrally formed with the pallet 3 and defining a recess which 
engages part or all of an outer circumference 5a of the chassis 5. The 
outer circumference guide portion 14 engages and horizontally positions 
the chassis 5 in the carrier 1. Alternate means for receiving the chassis 
5 in the chassis positioning loader 9 will be suggested to those of skill 
in the art. For example, an engaging part such as a guide pin or a guide 
hole can be formed integrally with the pallet 3 to engage another engaging 
part on the chassis 5 such as a hole or a shaft. 
The parts 6 stored in the parts positioning loader 10 can be classified 
into three types. One type, such as parts indicated at 6a, includes 
various types of gears, bearings and washers which are generally 
disc-shaped, do not have a predetermined orientation for operation, and 
can be stacked. A second type of part indicated at 6b includes various 
types of levers or other members which have a non-circular shape, can be 
stacked, and have a predetermined orientation for assembly on chassis 5. A 
third type of part indicated at 6c is in the form of a sub-assembly of 
several parts which cannot be stacked and also has a predetermined 
orientation for assembly on chassis 5. 
The parts 6a are stacked in the parts receiving members 11, the parts of 
sub-assembly 6c are positioned or oriented in the parts receiving member 
12, and the parts 6b are stacked in the predetermined orientation in the 
parts receiving member 13. 
A cylindrical recess 15 is formed in a raised portion of the pallet 3 to 
define each of the members 11 which receives a plurality of parts 6a of 
the same kind. The recess 15 extends vertically in the pallet 3. A slit 16 
extends vertically at a side surface of the recess 15. As will be 
explained more fully hereinbelow, the slit 16 supplies air to the recess 
15 to prevent inversion of the parts 6a remaining in recess 15 when the 
uppermost part 6a is withdrawn. When the parts 6a have holes at the 
center, guide pins (not shown) can be integrally formed with the pallet 3 
for positioning the parts 6a in each recess 15. 
The parts 6b with holes 20 formed therein are stacked by inserting a guide 
pin 19 formed integrally with the pallet 3 through the holes 20. At the 
same time, portions of the outer circumference of the parts 6b engage 
outer guide portions 21 comprising recesses formed integrally with the 
pallet 3 so that the parts 6b are stacked in a predetermined orientation. 
Thus, in the illustrated embodiment, guide pin 19 and guide portions 21 
cooperate to define the parts receiving member 13 for parts 6b. 
Alternatively, two or more guide pins 19 can be used to engage the outer 
circumferences of the parts 6b to maintain the parts 6b in the 
predetermined orientation. In yet another embodiment, pockets or recesses 
can be formed in the pallet 3 which have the same general configuration as 
the parts 6b to stack the parts 6b in the predetermined orientation. 
The parts of sub-assembly 6c are properly oriented by a plurality of guide 
pins 17 formed integrally with the pallet 3 to define the parts receiving 
member 12 and which are inserted in respective holes 18 formed in at least 
one of the parts 6c. Alternatively, when the parts 6c have ribs at their 
outer circumferences, three or more guide pins 17 can be formed integrally 
with the pallet 3 to engage the ribs and defining the parts receiving 
member 12 for orienting the parts 6c. As explained above in respect to 
member 13, recesses or pockets can be formed in the pallet 3 to engage the 
outer circumferences of the parts 6c and thereby define the parts 
receiving member 12 for properly orienting the parts or sub-assembly 6c. 
An arrangement of conveyers for transporting carriers 1 embodying this 
invention to and from a number of assembly stations in an automatic 
assembling apparatus making use of this invention will now be described. 
In particular, a pair of parallel and adjacent conveyers 23 and 24 are 
provided to transfer the carriers 1 in the direction of the arrow adjacent 
to conveyer 23 in FIG. 4. A plurality of assembly centers or stations, for 
example, three assembly stations 25, 26 and 27 in FIG. 4, are arranged 
outside of the conveying system adjacent conveyer 24 for performing the 
feeding, processing and assembling operations with respect to the carriers 
1 which are transported by conveyers 23 and 24 to and from the various 
assembly stations 25, 26 and 27. 
In addition, another conveyer 28 is spaced from and parallel to conveyer 
23, and a pair of conveyers 29, 30 are provided for connecting the 
respective ends of the conveyer 28 to the corresponding ends of conveyers 
29, 30. In this regard, conveyers 23, 24, 28, 29 and 30 define an endless 
conveyer line, with carriers 1 being transferred by the endless conveyer 
line in the direction indicated by the arrows in FIG. 4. The conveyers may 
be formed by any suitable conveyer system, for example, the conveyers may 
be comprised of roller conveyers, that is, each conveyer being comprised 
of a plurality of rotatable rollers over which carriers 1 travel. In this 
regard, carriers 1 can be stopped at any position along the conveyers by 
means of appropriate stopping members interposed in their path and can 
immediately resume their travel upon release of the stopping members. 
Conveyers 23, 24 and 28 are each divided into a plurality of short 
conveying sections, 23a, 24a and 28a, respectively, each conveying section 
corresponding to a respective one of the assembly stations. In this 
manner, independent feeding and discharging of carriers 1 with respect to 
assembly stations 25, 26 and 27 can be easily accomplished. 
A distributor 31 is arranged at the front end of the conveyer 29, that is, 
the end adjacent conveyers 23 and 24, for selectively feeding carriers 1 
to either conveyer 23 or conveyer 24, as will be apparent hereinafter. In 
addition, loading stations 32, 33 are arranged at, for example, two 
downstream positions of conveyer 28 for supplying carriers 1 to the 
conveying system, and an unloading station 34 is arranged at the upstream 
position of conveyer 28 for removing from the conveying system those 
carriers on which the chassis 5 and respective parts 6 have been assembled 
together. In this manner, four chassis 5 and associated parts 6 to be 
assembled thereon are placed on each carrier 1, and the latter are then 
supplied to the respective loading stations 32, 33 where they are 
transferred to the conveyer 28. The conveyer 28 then moves the carrier 1 
to the conveyer 29, where the distributor 31 selectively feeds the 
carriers 1 to either the conveyer 23 or the conveyer 24 according to a 
preset distribution arrangement. The carriers 1 can then be transferred or 
fed to a first assembly station 25 by the respective conveyer 23 or 24. In 
particular, the carriers 1 from the conveyer 23 and the conveyer 24 are 
transferred to the assembly station 25 by a carrier loader thereat, which 
will be described in more detail hereinafter, and placed on a movable 
table of assembly station 25, where feeding, processing and assembling 
operations of the parts 6 on the chassis 5 are automatically performed. 
Upon completion of the above operations, the carriers 1 are discharged 
onto one of the conveyers 23, 24 by the carrier loader to be transferred 
to the next assembly station 26. It is to be appreciated that the carrier 
loader is movable between a first position in opposing relation to the 
movable table of assembly station 25 and a second position in opposing 
relation to the conveyers 23, 24. Feeding and discharge of the carriers 1 
with respect to the assembly stations 26, 27 at downstream positions of 
conveyers 23, 24 are performed in a similar manner. Upon completion of the 
above operations with respect to the assembly station 27, the carriers are 
transferred to unloading station 34 by the conveyers 30 and 28 and there 
unloaded from the conveyer 28, for example, by an operator. The various 
steps of the operation may be easily varied by switching the feeding and 
discharge lines of the carriers 1 at the assembly stations 25, 26 and 27 
by means of the conveyers 23 and 24. 
Referring now to FIGS. 5, 6 and 7, the construction of the assembly station 
25 will now be described. It is to be appreciated, however, that the 
assembly stations 26 and 27 may also be of the same construction. In 
particular, the assembly station 25 includes a horizontal, substantially 
U-shaped mounting beam 38 supported by vertical members above a horizontal 
base 37 and parallel to the latter. The inner side surfaces 38a, 38b of 
the connecting segment, and a leg, respectively, of U-shaped mounting beam 
38 have mounting plates 39, and 40, respectively, secured thereto, 
mounting plates 39 and 40 therefore being perpendicular to each other. A 
plurality of keys 41 are vertically mounted on the mounting plate 39 and 
are spaced from each other at predetermined intervals in the direction of 
the X-axis, that is, the horizontal direction along surface 38a. In a like 
manner, a plurality of keys 42 are vertically mounted on the mounting 
plate 40 and are spaced from each other at predetermined intervals in a 
Y-axis horizontal direction. Working units 43 and 44 are mounted on 
selected ones of the keys 41 and 42, respectively, and can be easily 
removed from one key and mounted on another key. The working units include 
working heads mounted on the lower ends of the working units 43 and 44 
which are vertically reciprocable. 
A movable table 45 is mounted on base 37 and is adapted to be driven in the 
X-axis and Y-axis directions in the horizontal plane of the base 37, as 
shown in FIG. 6, and a shift table 46 is also horizontally reciprocable 
within a limited range in the X-axis direction on the movable table 45. It 
is to be appreciated that the feeding, processing and assembling 
operations with respect to the carrier 1 and the four chassis 5 thereon 
occur on the shift table 46. It is to be further appreciated, however, 
that the shift table 46 is provided to minimize the movements of the table 
45 and thereby provide a compact machine, but may be eliminated if 
desired. In that case, all movements of a carrier 1 would be affected by 
the movements of table 45. 
A loader guide 47 is horizontally suspended from the other leg of mounting 
beam 38 amd extends in the X-axis direction, and a carrier loader 48 is 
slidably mounted to the underside of the loader guide 47 for horizontal 
reciprocable movement in the X-axis direction between a first position in 
opposing relation to the upper surface of the movable table 45 of the 
assembly station 25 and a second position in opposing relation to the 
upper surfaces of the conveyers 23 and 24. The carrier loader 48 includes 
first and second chucking stations 49 and 50 (FIG. 7), which will be 
discussed in greater detail hereinafter, and which are in opposing 
relation to the conveyers 23 and 24, respectively, when the carrier loader 
48 is moved to its second position. The chucking stations 49 and 50 are 
used for transferring the carriers 1 between the conveyers 23 and 24 and 
the shift table 46, and accordingly, the chucking stations 49 and 50 
include four suspension pawls 51 and 52, respectively, for engaging with 
the four suspension keepers or handles 4 of each carrier 1 to lift the 
carriers 1 from the conveyers 23 and 24 or the shift table 46. 
The conveyer 23 transfers each carrier 1, prior to the assembly operation, 
to a position opposite assembly center 25, and at which carrier loader 48 
is positioned as indicated by the solid lines in FIG. 7. The suspension 
pawls 51 of one chucking station 49 of the carrier loader 48 engage the 
keepers 4 on the carrier 1 to lift the carrier 1 from the conveyer 23. The 
carrier loader 48 then moves to the position shown in broken lines on FIG. 
7 so as to move carrier 1 from a position over the conveyer 23 to a 
position over the moving table 45 in the assembly center 25. When shift 
table 46 is moved to the position shown in broken lines, that is, below 
chucking station 49, carrier 1 is released by the latter and lowered onto 
shift table 46. The moving table 45 is next moved in the X-axis direction 
and the Y-axis direction according to a predetermined control program or 
procedure while working heads of the working units 43 and 44 are 
vertically moved in synchronism with the movements of moving table 45 to 
perform the feeding, processing and assembly of the main parts 6 on each 
chassis 5 and any other associated operations. During these assembling and 
related operations, the carrier loader 48 is positioned above the 
conveyers 23 and 24, as indicated by the solid lines of FIG. 7, so as to 
avoid interference with movements of working units 43 and 44. After the 
assembly operations have been performed to assemble the parts 6 on each 
chassis 5, shift table 46 is moved to the position shown in full lines on 
FIG. 7, and carrier loader 48 is moved to the position shown in broken 
lines for disposing chucking station 50 above shift table 46 supporting 
the carrier 1 on which assembly operations have been performed, while a 
new carrier 1, on which assembly operations are to be performed, is 
suspended from pawls 51 of chucking station 49. The chucking station 50 
then lifts the carrier on which assembly operations have been performed, 
and the empty shift table 46 is returned to the position shown in broken 
lines under chucking station 49 to receive from the latter the new carrier 
1 on which assembly operations are to be performed. 
Upon the return of carrier loader 48 to the position shown in full lines on 
FIG. 7, chucking station 50 is disposed above conveyer 24 and its pawls 52 
are released to lower onto conveyer 24 the carrier 1 which assembly 
operations have been performed at assembly center or station 25. At the 
same time, another carrier 1 on which assembly operations are to be 
performed is engaged by pawls 51 of chucking station 49 and lifted from 
conveyer 23 in preparation for the next operating cycle at station 25. 
It will be appreciated that the successive carriers 1 on which assembly 
operations are to be performed are brought to station 25 on conveyer 23, 
and, after performance of such assembly operations, each carrier 1 is 
transported away from station 25 on conveyer 24 to the next assembly 
center or station 26 where a similar cycle of operations is performed. 
However, at such station 26, the carriers 1 on which assembly operations 
are to be performed are drawn from conveyer 24 and thereafter returned to 
conveyer 23 for further transport to the last assembly center or station 
27. 
Reference will now be made to FIGS. 8A and 8B in explaining the nature of 
the work units 43, 44 that are provided at each of the assembly centers or 
stations 25, 26 and 27 for assembling parts 6 on each related chassis 5 
and performing other associated operations. As shown in respect to work 
unit 43, a lift base 55 is vertically reciprocable relative to a mounting 
member 55a which is secured on a respective key 41 on plate 39. 
A working head 56, which may be of various types, is mounted on a front 
surface of the lift base 55 so that the working head 56 may be 
interchanged. In the illustrative embodiment, head 56 includes a head 
holder 57 which has four chucking heads 58 extending downwardly therefrom. 
The four chucking heads 58 are positioned with a predetermined distance 
therebetween corresponding to the distances between corresponding 
locations on the four pallets 3 of the carrier 1. In an exemplary 
embodiment, the chucking heads 58 are connected to a vacuum pump (not 
shown) and can lift the main parts 6 by the suction of air through 
openings 58b formed in their lower end portions 58a. The chucking heads 58 
are elastically urged downwardly relative to holder 57 by compression 
springs 59 mounted in surrounding relationship to chucking heads 58. 
At each of the assembly centers 25, 26 and 27, when a carrier 1 is placed 
on the shift table 46 mounted on the respective movable table 45, such 
carrier 1 is movable in the X-axis and Y-axis directions shown on FIGS. 8A 
and 8B relative to heads 58, by movement of the movable table 45 in the 
X-axis and Y-axis directions. Accordingly, the four chassis 5 and the 
corresponding parts 6 on the four pallets 3 of the carrier 1 are 
simultaneously positioned with respect to the four chucking heads 58 of 
the working head 56. 
For example, by movement of carrier 1 in the direction indicated by the 
arrow on FIG. 9A, each chucking head 58 is respectively positioned over a 
corresponding part 6 on the respective pallet 3 of the carrier 1, as shown 
on FIG. 9B. As illustrated in FIGS. 8A and 9C, downward movement of lift 
base 55 of working unit 43 then lowers the working head 56 so that the 
lower ends 58a of the chucking heads 58 are elastically urged by springs 
59 against the respective parts 6a. The suction draws the uppermost parts 
6a in the stacks thereof to the lower ends 58a. As shown in FIG. 9D, each 
chucking head 58 of working head 56 subsequently lifts the respective part 
6a in response to upward movement of the lift base 55. 
As illustrated in FIG. 10, the guide recesses 15 contain stacks of the 
parts 6a which have a relatively small diameter and which are relatively 
light in weight, such as washers. During the lifting of each uppermost 
part 6a by a chucking head 58, the interior of the recess 15 under the 
lifted part 6a is placed under a low pressure by the piston phenomenon 
resulting from the close fit of the lifted part in recess 15. In the 
absence of the slits 16 opening laterally into recesses 15, such low 
pressure under the uppermost part 6a would cause the next lower part 6a to 
be lifted upwardly and possibly toppled. The slits 16 prevent such 
toppling or inversion of the parts 6a by supplying air to the recesses 15 
under the lifted uppermost part. The slits 16 also prevent a change in the 
orientation or tilt of the next part 6a which would block the suction 
action in the next operation of the chucking head 58. 
The positions of the chucking heads 58 in the X-axis and Y-axis directions 
with respect to the chassis 5 placed on the four pallets 3 of the carrier 
1 are determined by further suitable movements of the movable table 45. 
Consequently, the chucking heads 58 are positioned at the assembled 
positions of the previously lifted parts 6a on the respective chassis 5, 
as shown in FIG. 9E. 
As shown in FIGS. 8B and 9F, the lift base 55 is moved downwardly and 
lowers the working head 56 whereby the parts 6a adhered by suction to the 
lower ends 58a of the chucking heads 58 are elastically urged to their 
assembled positions on the respective chassis 5 to be assembled thereon. 
Then, the suction applied to the chucking heads 58 is released so that the 
parts 6a are detached from the lower ends 58a of the chucking heads 58 and 
remain in this assembled position on chassis 5, as illustrated in FIG. 9G, 
when the lift base 55 lifts the working head 56 to its initial position 
where it is ready for the next assembly operation cycle. 
A suitably programmed computer or microprocessor can be utilized to 
conventionally control pneumatically or otherwise powered movements of the 
movable table 45 in the X-axis and Y-axis directions, vertical movements 
of working head 56, and the movements of carrier loader 48 during the 
assembly of the parts 6 on each chassis 5. In such case, changes in the 
design or type of articles to be assembled are easily accommodated by 
rewriting and storing a control program in the computer. In the event of 
such changes, the parts feeding units, the assembly jigs and the like at 
the assembly stations or centers 25, 26 and 27 need not be modified. An 
automatic assembling machine is thus made very flexible and can serve for 
many different assembling operations if the parts to be assembled are 
carried thereto in accordance with the present invention. 
In addition to the working unit 43 described hereinbefore, other working 
units can be incorporated at the respective assembly centers 25, 26 and 27 
for performing, for example, the tightening of screws, the mounting of 
polygrips and polywashers, the lubrication of parts, the magnetization of 
magnetic members, and the assembly and processing of other commonly used 
parts, and the like. These operations can be performed in association with 
control of the movement of the movable table 45 in the X-axis and Y-axis 
directions as hereinbefore described. 
The number of feeding units and assembly jigs for the parts 6 at the 
assembly centers 25, 26 and 27 can be significantly reduced since each 
chassis 5 and the parts 6 to be assembled thereon are fed onto a carrier 1 
and then transferred to the assembly centers 25, 26 and 27 where the 
predetermined assembly operations are performed. 
Since each chassis 5 and the respective parts 6 are positioned on the 
carrier 1, the movable table 45 at each of the assembly centers 25, 26 and 
27 need only control the horizontal movement of the carrier 1 in the 
X-axis and Y-axis directions. Many kinds of parts 6 can be efficiently 
mounted on the chassis 5 since only simple vertical movements of the 
working heads 56 of the working units 43 and 44 are required, and the 
vertical movements of the working heads 56 can be easily controlled by a 
suitably programmed computer or microprocessor. 
Since some of the parts 6 which are stacked on each pallet 3 of a carrier 1 
at the loading stations 32 and 33 are the same, the number of parts loaded 
onto a pallet of carrier 1 can exceed the number of parts required for one 
chassis. The number of loading operations for the parts 6 can thus be 
significantly reduced. The parts 6a and 6b which are to be retained in 
stacks by receiving members 11 and 13 can be supplied thereto in the form 
of stacks on, for example, a string, a rod, or in a magazine. Accordingly, 
the time for stacking and loading the parts 6a, 6b and 6c on the carrier 1 
can be significantly reduced. 
The parts 6b and 6c which must be assembled in a predetermined orientation 
on a chassis 5 can be supplied to the assembly centers or stations 25, 26 
and 27 in that predetermined orientation by being suitably positioned 
relative to carrier 1 before the latter is transferred or conveyed to the 
assembly centers 25, 26 and 27. The assembling operation is thus much 
easier than in the prior art since the working heads 56 of the working 
units 43 and 44 only lift and lower parts which are supplied in the proper 
predetermined orientation and, therefore, do not require turning. 
Having described a specific preferred embodiment of the invention, it is to 
be understood that the present invention is not limited to that precise 
embodiment, and that various changes and modifications may be made therein 
by one skilled in the art without departing from the spirit or scope of 
the invention as defined in the appended claims.