U.S. patent application number 12/127956 was filed with the patent office on 2008-12-04 for vehicle framing system for plurality of vehicle body styles.
This patent application is currently assigned to COMAU, INC.. Invention is credited to Velibor Kilibarda, Leonard A. Zanger.
Application Number | 20080295335 12/127956 |
Document ID | / |
Family ID | 28454869 |
Filed Date | 2008-12-04 |
United States Patent
Application |
20080295335 |
Kind Code |
A1 |
Kilibarda; Velibor ; et
al. |
December 4, 2008 |
VEHICLE FRAMING SYSTEM FOR PLURALITY OF VEHICLE BODY STYLES
Abstract
A method for randomly interchanging up to four pairs of side
framing gates at a framing station of a vehicle for randomly
interchanging up to four pairs of side framing gates at a framing
station of a vehicle assembly line while maintaining a
predetermined build cycle time interval of the assembly line. The
method includes positioning first and second carousels on opposite
sides of the assembly line upstream of the framing station and
third and fourth carousels on opposite sides of the production line
downstream of the framing station. The method further includes
providing a first linear track structure extending from the first
carousel to a first side of the framing station, a second linear
track structure extending from the second carousel to a second,
opposite side of the framing station, a third linear track
structure extending from the third carousel to the first side of
the framing station, a third linear track structure extending from
the third carousel to the first side of the framing station, and a
fourth linear track structure extending from the fourth carousel to
the second side of the framing station. The carousel are provided
with at least two sides, possibly three sides, four sides or more,
each side capable of receiving a framing gate. The method includes
randomly interchanging framing gates positioned at the framing
station by a combination of rotary movements of the carousels and
linear movements of framing gates along the linear track
structures.
Inventors: |
Kilibarda; Velibor;
(Birmingham, MI) ; Zanger; Leonard A.; (Bloomfield
Hills, MI) |
Correspondence
Address: |
YOUNG & BASILE, P.C.
3001 WEST BIG BEAVER ROAD, SUITE 624
TROY
MI
48084
US
|
Assignee: |
COMAU, INC.
Southfield
MI
|
Family ID: |
28454869 |
Appl. No.: |
12/127956 |
Filed: |
May 28, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11165475 |
Jun 23, 2005 |
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12127956 |
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|
10401471 |
Mar 28, 2003 |
6932263 |
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11165475 |
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60370891 |
Apr 8, 2002 |
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Current U.S.
Class: |
29/897.2 |
Current CPC
Class: |
B23K 2101/006 20180801;
Y10T 29/49622 20150115; B23Q 7/02 20130101; B62D 65/02 20130101;
B23K 37/047 20130101 |
Class at
Publication: |
29/897.2 |
International
Class: |
B21D 53/88 20060101
B21D053/88 |
Claims
1. A method of body framing on a vehicle assembly line in which
loosely pre-assembled vehicle bodies are moved incrementally along
a single assembly line from station to station, successive loosely
pre-assembled vehicle bodies arrive at a framing station along the
assembly line at predetermined build cycle time intervals, and each
loosely pre-assembled vehicle body arriving at the framing station
is welded to form a rigid vehicle body, the method for body framing
comprising the steps of: positioning a plurality of more than three
pairs of opposed side framing gates at opposite sides of the
framing station for use in welding a respective plurality of more
than three vehicle body styles allowing random production of the
plurality of more than three vehicle body styles on the single
assembly line; and randomly exchanging with a transfer apparatus
assembly any of the plurality of pairs of side framing gates
positioned at the framing station with any other of the plurality
of pairs of side framing gates within the predetermined build cycle
time interval to allow the random production interchange of the
more than three vehicle body styles on the single assembly line
while maintaining the predetermined build cycle time interval.
2. The method of claim 1, wherein the randomly exchanging step with
the transfer apparatus assembly includes the step of coacting a
rotary transfer apparatus with a linear transfer apparatus.
3. The method of claim 2, further comprising the step of:
delivering framing gates with the rotary transfer apparatus to the
linear transfer apparatus for delivery to the framing station.
4. The method of claim 3, further comprising the steps of:
positioning first and second carousels on the rotary transfer
apparatus of on opposite sides of the assembly line upstream of the
framing station; and positioning third and fourth carousels on the
rotary transfer apparatus on opposite sides of the assembly line
downstream of the framing station.
5. The method of claim 4, further comprising the steps of:
providing a first linear track system of the linear transfer
apparatus extending from the first carousel to a first side of the
framing station; providing a second linear track structure of the
linear transfer apparatus extending from the second carousel to a
second, opposite side of the framing station; providing a third
linear track structure of the linear transfer apparatus extending
from the third carousel to the first side of the framing station;
and providing a fourth linear track structure of the linear
transfer apparatus extending from the fourth carousel to the second
side of the framing station.
6. The method of claim 5, further comprising the step of:
selectively receiving a framing gate on at least one side of at
least one of the first, second, third, and fourth carousels, each
carousel having a polygonal configuration including at least two
sides, each side capable of receiving a framing gate.
7. The method of claim 6, further comprising the steps of:
providing the plurality of more than three pairs of opposed side
framing gates to include four pairs of framing gates; providing
each carousel with three sides; positioning a first pair of the
four pairs of framing gates on opposite sides of the framing
station; positioning a second pair of the four pairs of framing
gates on respective first sides of the first and second carousels;
positioning a third pair of the four pairs of framing gates on
respective second sides of the first and second carousels;
positioning a fourth pair of the four pairs of framing gates on
respective first sides of the third and fourth carousels; and
randomly interchanging all of the pairs of framing gates by at
least one of linear gate movements along the linear track
structures and a combination of rotary movements of the carousels
and linear gate movements along the linear track structures.
8. The method of claim 5, further comprising the steps of:
providing a base structure; providing a first pair of spaced
pillars mounted on the base structure on the first side of the
framing station; and providing a second pair of spaced pillars
mounted on the base structure on the second side of the framing
station; moving the first and second pairs of pillars on the base
structure between outboard positions spaced outwardly from the
assembly line and inboard positions proximate the assembly line,
the first pair of pillars in its outboard position linearly aligned
with the first and third linear track structures, and the second
pair of pillars in its outboard position linearly aligned with the
second and fourth linear track structures; delivering the framing
gates to the respective pillar pairs along the respective linear
track structures with the pillar pairs in the outboard positions;
and thereafter moving the pillar pairs to the inboard positions to
position the framing gates proximate the assembly line for
clampingly engaging loosely preassembled vehicle bodies preparatory
to welding operations.
9. A method for use in delivering framing gates to a framing
station on a vehicle body assembly line, the carousel comprising
the steps of: providing a base structure positioned proximate the
assembly line and including a support surface and a central pivot
shaft upstanding from the support surface; providing a carousel
body supported on the support surface, mounted on the pivot shaft
for rotary movement about the axis of the shaft, and defining a
plurality of sides, each side adapted to receive a framing gate;
generating an air cushion between the support surface and an
underface of the carousel body to lift the carousel body off of the
support surface; and applying a turning force to the carousel body
to rotate the body about the central axis to bring successive sides
of the body into a position proximate the assembly line.
10. The method of claim 9, wherein the air cushion generating step
further comprises the step of providing a plurality of air bags
positioned on the underface of the carousel body and each air bag
including a plurality of apertures in confronting relation to the
support surface allowing pressurized air delivered to the air bags
to inflate the bags to raise the carousel body off of the support
surface and air escaping from the air bags through the apertures to
generate an air cushion between the air bags and the support
surface.
11. The method of claim 10, wherein the air cushion generating step
further comprises the step of providing air bags positioned in
circumferentially spaced relation about the central axis of the
pivot shaft.
12. The method of claim 10 intended for use with a linear track
structure having one end positioned proximate the framing station
and a free end, and further comprising the step of: supporting a
respective framing gate on a carousel track structure located on
each side of the carousel body and configured to be aligned with
the free end of the linear track structure as the respective side
of the carousel body is moved into a position proximate the
assembly line allowing the framing gate to be slid off the carousel
track structure and onto the linear track structure for delivery to
the framing station.
13. A method for use in delivering framing gates to a framing
station on a vehicle body assembly line, the method comprising the
steps of: providing a linear track structure having one end
positioned proximate the framing station and a free end; providing
a carousel positioned proximate the assembly line, defining a
plurality of sides each adapted to receive a framing gate, and
mounted for rotation about a central axis to bring successive sides
of the carousel into a position proximate the free end of the track
structure and in linear alignment with the track structure; and
moving a framing gate positioned on a side of the carousel in
alignment with the track structure from the carousel side, onto the
track structure, and along the track structure to the framing
station with a transfer device.
14. The method of claim 13 further comprising the step of: engaging
a framing gate with a trolley operative to move the framing gate
along the track structure to the framing station.
15. The method of claim 14 further comprising the step of:
supporting a framing gate positioned on the respective side of the
carousel, wherein each side of the carousel includes a carousel
track structure configured to be aligned with the free end of the
linear track structure as the respective side of the carousel is
moved into a position proximate the free end of the linear track
structure.
16. The method of claim 15, further comprising the steps of:
latching a framing gate to a respective side of the carousel with a
first latch device; supporting the carousel with a base structure;
latching the carousel to the base structure with a second latch
device; and actuating the second latch device with a latch control
device operative in response to arrival of a carousel side at a
position proximate the free end of the linear track structure to
latch the carousel to the base structure and releasing the first
latch device to release the framing gate from the carousel and
allow the trolley to move the released framing gate along the
linear track structure to the framing station.
17. The method of claim 16, further comprising the step of:
operating a third latch device to latch the trolley to a framing
gate, the third latch device actuated prior to release of the first
latch device and following engagement of the second latch device,
and wherein the first latch device is released following engagement
of the third latch device to allow the trolley to move the released
framing gate to the framing station.
18. The method of claim 17 further comprising the steps of:
defining a support surface with the base structure; generating an
air cushion between the support surface and an underface of the
carousel to lift the carousel off of the support surface; and
applying a turning force to the lifted carousel to rotate the
carousel about the central axis to bring successive sides of the
carousel into position proximate the free end of the track
structure and in linear alignment with the track structure.
19. The method of claim 18 further comprising the step of releasing
the second latch, wherein the second latch device is released
following the air cushion generating step, thereafter the applying
turning force step is actuated to bring a respective side of the
carousel carrying a respective framing gate into alignment with the
linear track structure, thereafter the second linear latch device
actuating step is actuated to latch the carousel to the base
structure, thereafter the third latch device operating step is
actuated to latch the trolley to the respective framing gate,
thereafter the framing gate latching step is actuated so that the
first latch device is released to release the respective framing
gate from the carousel, and thereafter actuating the trolley to
move the respective framing gate to the framing station.
20. The method of claim 19, further comprising the step of
deactivating the air cushion generating step to lower the carousel
back down to the support surface prior to actuation of the trolley
to move the respective framing gate to the framing station.
21. A method for use in delivering framing gates to a framing
station on a vehicle body assembly line, the transfer apparatus
comprising the steps of: positioning a linear track structure
having one end proximate the framing station and a free end; moving
a carousel positioned proximate the assembly line, defining a
plurality of sides each adapted to receive a framing gate, to bring
the carousel into a position proximate the free end of the track
structure and in linear alignment with the track structure; and
operating a transfer device operative to move a framing gate
positioned on a side of the carousel in alignment with the track
structure from the carousel side, onto the track structure, and
along the track structure to the framing station.
22. The method of claim 21 further comprising the step of operating
a trolley operative to engage a framing gate and move the gate
along the track structure to the framing station.
23. The method of claim 22, further comprising the step of
supporting a framing gate, wherein each side of the carousel
includes a carousel track structure for supporting a framing gate
positioned on the respective side of the carousel and configured to
be aligned with the free end of the linear track structure as the
respective side of the carousel is moved into a position proximate
the free end of the linear track structure.
24. The method of claim 23 further comprising the step of: latching
a framing gate to a respective side of the carousel with a first
latch device; supporting the carousel with a base structure;
latching the carousel to the base structure with a second latch
device; and actuating the second latch device with a latch control
device operative in response to arrival of a carousel side at a
position proximate the free end of the linear track structure to
latch the carousel to the base structure and release the first
latch device to release the framing gate from the carousel and
allow the trolley to move the released framing gate along the
linear track structure to the framing station.
25. The method of claim 24 further comprising the step of,
actuating a third latch device to latch the trolley to a framing
gate, the third latch device actuated prior to release of the first
latch device and following engagement of the second latch device,
and wherein the first latch device is released following engagement
of the third latch device to allow the trolley to move the released
framing gate to the framing station.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application and claims
benefit of pending U.S. application Ser. No. 11/165,475 filed Jun.
23, 2005, which is a divisional application and claims benefit of
U.S. application Ser. No. 10/401,471, filed Mar. 28, 2003, now U.S.
Pat. No. 6,932,263, which claims the benefit of U.S. provisional
application Ser. No. 60/370,891 filed on Apr. 8, 2002, each of
which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to an assembly line framing
system for clamping and thereafter welding a loosely assembled
motor vehicle body, a framing system that accurately positions and
locates predetermined areas of a loosely assembled motor vehicle
body for accurately clamping and welding the vehicle body together
with a high degree of repeatability between consecutive vehicle
bodies on the assembly line, and more particularly a framing system
especially adapted to weld a plurality of different predetermined
vehicle body styles without interrupting the predetermined build
cycle time interval of the assembly line.
BACKGROUND OF THE INVENTION
[0003] The construction of a unitized vehicle body commences with
the formation of individual major body panels by stamping the
panels from sheet metal blanks. Typically, these major panels
include a floor panel, right and left body side panels, a fire wall
and either a roof panel or transversely extending inner members to
which a roof panel is subsequently mounted. After the individual
panels are stamped, some preliminary assembly operations can then
be performed on the individual panels such as for example adding
door hinge and latch hardware to body side panels at appropriate
locations proximate the door opening, adding seat mounting brackets
and reinforcements to the floor panels, etc.
[0004] Next a set of panels that together constitute a sub-assembly
of the finished vehicle body is loosely assembled together. This
initial loose assembly of panels frequently is accomplished by a
"toy tab" arrangement in which one or more panels is formed with a
tab which projects from an edge and which is received in a slot in
an adjacent panel. This technique interlocks the panels and frame
members to each other to form a preliminary loosely assembled
vehicle body wherein the panels and frame members will not separate
from each other but the panels and frame members can tilt or move
relative to one another. This initial loosely assembled
sub-assembly is then moved along the assembly line to a framing
station where the various panels and frames are welded to each
other to form a rigid permanently assembled vehicle body.
[0005] The welding operation step at the framing station is one of
the most important steps in the assembly of the vehicle body
because it establishes the final welded alignment of the various
panels and headers relative to each other which is essential to
subsequent assembly operations performed on the subassembly. During
the welding operation it is critical that the various panels and
headers be precisely and accurately located and aligned relative to
one another and be held fixedly in the desired position. The
positioning of the various panels and header members during the
welding operation typically is accomplished by a pair of side
framing gates which are positioned on opposite sides of the
assembly line and which carry a plurality of individual clamps
arranged thereon to clamp the various body components in desired
positions.
[0006] It is desirable to perform as many welding operations as
possible at the initial framing station since the relative
positioning of the various panels and headers is critical to the
ability to precisely relocate and reclamp the vehicle body at
subsequent stations along the assembly line. Due to variations
between assembly stations and variation in movement of the various
panels and headers it is impossible to subsequently relocate and
reclamp the vehicle body without inadvertently stacking up
tolerances or creating variances between the relative positioning
of various panels and headers. Therefore it is desirable to frame
as much of the vehicle body as possible at the same framing station
so that a maximum number of welding operations can be performed on
the vehicle body without having to subsequently reclamp and
relocate the vehicle body since reclamping and relocating can
increase the tolerances between the relative positions of the
various panels and headers of the vehicle body and decrease the
repeatability between consecutive vehicle bodies in the production
line.
[0007] It is common practice in the present automotive industry for
one particular car model to be offered in several different body
styles. Accommodating each body style requires clamping and welding
different body locations as well as gaining access to different
body areas so that the clamping and welding apparatus can be
properly positioned while extending through the framing gates. To
avoid having to provide separate assembly lines and framing
stations for the different body styles of a particular car model,
it is desirable to provide a single framing station that can be
adapted to accommodate a plurality of different body styles in a
quick and efficient manner while insuring the accuracy and
repeatability that are required of the welding operation.
SUMMARY OF THE INVENTION
[0008] The present invention provides a method of body framing that
accurately and efficiently clamps and welds a loosely assembled
vehicle body with a high degree of repeatability between
consecutive vehicle bodies in a production line while also being
able to adapt to a plurality of different loosely assembled body
components, corresponding to different vehicle body styles, in a
quick and efficient manner. Specifically, the present invention
provides a method of body framing wherein a plurality of vehicle
body styles can be interchangeably accommodated at a single framing
station without interrupting the predetermined build cycle time
interval of the assembly line. More specifically, the present
invention provides a method of body framing wherein four different
body styles can be interchangeably accommodated at a single framing
station without interrupting the predetermined build cycle time
interval of the assembly line.
[0009] The body framing system of the invention is intended for use
with a vehicle assembly line in which loosely preassembled vehicle
bodies are moved incrementally along a single assembly line from
station to station, successive loosely preassembled vehicle bodies
arrive at a framing station along the production line at
predetermined build cycle time intervals, and each loosely
preassembled vehicle body arriving at the framing station is welded
to form a rigid vehicle body.
[0010] According to an example of the present invention, the method
of body framing includes positioning a plurality of more than three
pairs of opposed side framing gates at opposite sides of the
framing station for use in welding a respective plurality of more
than three vehicle body styles allowing random production of the
plurality of more than three vehicle body styles on the single
assembly line. The method also includes randomly exchanging with a
transfer apparatus assembly any of the plurality of pairs of side
framing gates positioned at the framing station with any other of
the plurality of pairs of side framing gates within the
predetermined build cycle time interval to allow the random
production interchange of the more than three vehicle body styles
on the single assembly line while maintaining the predetermined
build cycle time interval.
[0011] According to another example of the present invention, a
method for use in delivering framing gates to a framing station on
a vehicle body assembly line includes providing a base structure
positioned proximate the assembly line and including a support
surface and a central pivot shaft upstanding from the support
surface, and providing a carousel body supported on the support
surface, mounted on the pivot shaft for rotary movement about the
axis of the shaft, and defining a plurality of sides, each side
adapted to receive a framing gate. The method also includes
generating an air cushion between the support surface and an
underface of the carousel body to lift the carousel body off of the
support surface, and applying a turning force to the carousel body
to rotate the body about the central axis to bring successive sides
of the body into a position proximate the assembly line.
[0012] According to another example of the present invention, a
method for use in delivering framing gates to a framing station on
a vehicle body assembly line includes providing a linear track
structure having one end positioned proximate the framing station
and a free end, and providing a carousel positioned proximate the
assembly line, defining a plurality of sides each adapted to
receive a framing gate, and mounted for rotation about a central
axis to bring successive sides of the carousel into a position
proximate the free end of the track structure and in linear
alignment with the track structure. The method also includes moving
a framing gate positioned on a side of the carousel in alignment
with the track structure from the carousel side, onto the track
structure, and along the track structure to the framing station
with a transfer device.
[0013] According to another example the present invention, a method
for use in delivering framing gates to a framing station on a
vehicle body assembly line includes positioning a linear track
structure having one end proximate the framing station and a free
end, and moving a carousel positioned proximate the assembly line,
defining a plurality of sides each adapted to receive a framing
gate, to bring the carousel into a position proximate the free end
of the track structure and in linear alignment with the track
structure. The method also includes operating a transfer device
operative to move a framing gate positioned on a side of the
carousel in alignment with the track structure from the carousel
side, onto the track structure, and along the track structure to
the framing station.
[0014] Other objects, advantages and applications of the present
invention will become apparent to those skilled in the art when the
following description of the best mode contemplated for practicing
the invention is read in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The description herein makes reference to the accompanying
drawings wherein like reference numerals refer to like parts
throughout the several views, and wherein:
[0016] FIG. 1 is a perspective view of a body framing system
according to the present invention;
[0017] FIG. 2 is a schematic plan view of the body framing
system;
[0018] FIG. 3 is a perspective view of a portion of the framing
system;
[0019] FIG. 4 is a plan view of a carousel used in the framing
system;
[0020] FIG. 5 is a schematic plan view of the carousel of FIG.
4;
[0021] FIG. 6 is a plan view of a carousel base and linear track
structure used in the framing system according to the present
invention;
[0022] FIG. 7 is a perspective view of the linear track
structure;
[0023] FIG. 8 is a schematic cross sectional view of the track
structure;
[0024] FIG. 9 is a perspective view of the carousel base
structure;
[0025] FIG. 10 is a perspective view of a carousel section;
[0026] FIG. 11 is a schematic view of a cushion system to
facilitate turning of the carousel;
[0027] FIGS. 12 and 13 are detailed views of the cushion
system;
[0028] FIGS. 14 and 15 are end and perspective views respectively
of a latch release mechanism used in the framing system according
to the present invention;
[0029] FIGS. 16, 17 and 18 are further detailed views of the latch
release mechanism;
[0030] FIGS. 19 and 20 are elevational and perspective views
respectively of a trolley assembly used in the framing system
according to the present invention;
[0031] FIG. 21 is a perspective view of a lift mechanism forming a
part of the trolley assembly;
[0032] FIGS. 22 and 23 are perspective views of a trolley forming a
part of the trolley assembly;
[0033] FIGS. 24, 25 and 26 are elevational, cross-sectional and
perspective views, respectively, of a caterpillar bearing used in
the framing system according to the present invention;
[0034] FIG. 27 is a schematic view of a carousel assembly;
[0035] FIG. 28 is a schematic view illustrating the manner in which
the framing system according to the present invention operates to
interchange pairs of training gates at the framing station;
[0036] FIG. 29 is a simplified schematic view of a carousel
according to the present invention having two sides; and
[0037] FIG. 30 is a simplified schematic view of a carousel
according to the present invention having four sides.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] As seen in FIG. 1, the framing system of the present
invention is intended for use with a vehicle assembly line 10 in
which loosely preassembled vehicle bodies 12 are moved
incrementally along the assembly line from station to station,
successively loosely preassembled vehicle bodies arrive at a
framing station 14 along the assembly line at predetermined build
cycle time intervals, and each loosely preassembled vehicle body
arriving at the framing station is welded to form a rigid vehicle
body. The framing system, broadly considered, (FIGS. 1, 2 and 5)
includes framing station 14, a plurality of carousel assemblies 18,
20, 22 and 24; a plurality of linear track structures 26, 28, 30
and 32; a plurality of trolley assemblies 34, 36, 38 and 40; and a
plurality of framing gate pairs 42/43, 44/45, 46/47, and 48/49.
[0039] Framing station 14 includes a first framing station assembly
50 positioned on one side of the assembly line 10 and a second
framing station assembly 52 positioned on the opposite side of the
assembly line 10 and constituting a mirror image of framing station
assembly 50. With reference to FIG. 3, framing station assembly 50
includes a base structure 54 and a pair of axially spaced pillars
56, 58 mounted on tracks 60 and moved by a motor mechanism 62, in
unison, between a retracted outboard position to facilitate loading
of the framing gates and an inboard position, seen in FIG. 3,
proximate the assembly line 10 where framing gates carried by the
pillars can clampingly engage a loosely preassembled body 12 prior
to the welding operation.
[0040] Framing station assembly 50 further includes a track
structure 64 positioned between the pillars 56 and 58 and defining
a top rail 66, and a plurality of welding guns 68 (FIG. 1)
positioned on or proximate the base 54 and arranged to extend in
known manner through suitable openings in the framing gates to
access the loosely preassembled vehicle bodies 12 clampingly
engaged by the framing gates to perform the desired welding
operations on the clamped vehicle bodies. Further details of a
framing station suitable for use as a part of the invention framing
system are described in U.S. Pat. No. 6,173,881 assigned to the
assignee of the present invention.
[0041] The structure and operation of the framing system will now
be described with specific reference to carousel assembly 18,
linear track structure 26, and trolley assembly 34. In overview it
will be understood that carousel assembly 18, linear track
structure 26, and trolley assembly 34 coact to move framing gates
upstream along assembly line 10 to framing station assembly 50 from
a location on one side of the assembly line; carousel assembly 20,
linear track structure 28 and trolley assembly 36 coact to move
framing gates upstream to framing station assembly 52 from a
location on the opposite side of assembly line 10; carousel
assembly 22, linear track structure 30, and trolley assembly 38
coact to move framing gates downstream to framing station assembly
50 from a location on the one side of assembly line 10; and
carousel assembly 24, linear track structure 32 and trolley
assembly 40 coact to move framing gates downstream to framing
station assembly 52 from a location on the opposite side of
assembly line.
[0042] With reference to FIGS. 2, 3, 4, 10 and 11, carousel
assembly 18 includes a carousel body 70 having a triangular
configuration constituted by at least two sides or, as illustrated,
three identical carousel sections 72 which are configured to be
clustered and bolted together to form a three sided or triangulated
carousel body. It should be recognized that two sided
configurations, similar to that shown schematically in FIG. 29, or
four sided configurations, similar to that shown schematically in
FIG. 30, or more sides can be provided as desired for the
particular assembly without departing from the present invention.
Journals 76 positioned at the inner juncture of the clustered and
bolted carousel sections 72 are received on an upstanding pivot
post or shaft 78 carried by a carousel base structure 80 to mount
the carousel body for rotation about the central axis of pivot
shaft 78.
[0043] Carousel assembly 18 further includes an annular turn table
82 underlying the carousel body, a servo motor 84 including a
pinion gear or tire 86 driving the turntable, and a fixed annular
support plate 88 positioned on base 80 in underlying relation to
turntable 82 and defining an upper annular support surface 88a.
Carousel assembly 18 further includes a plurality of
circumferentially spaced air bag assemblies 90 (FIGS. 11, 12 and
13) positioned in downwardly opening cavities 82a in the under face
of turntable 82 in overlying relation to support surface 88a of
support plate 88. There can be two air bags assemblies underlying
each carousel section 72 for a total of 6 circumferentially spaced
air bag assemblies underlying the carousel body. It will be seen
that when pressurized air is delivered to the air bag assemblies 90
via conduits 92 connected to a suitable source of pressurized air,
pressurized air will inflate the diaphragm 90a of each air bag and
the pressurized air will flow through apertures 90b in the lower
wall of the diaphragm and flow radially outwardly, as seen by the
arrows in FIG. 12 to create an air film or cushion beneath the
diaphragm 90a. This inflating action of the air bags has the effect
of raising the carousel body 70 on the post 78 off of support
surface 88a with the upward movement of the carousel body permitted
and defined by sliding movement of annular bearings 76 on post 78,
and has the further effect of creating an air film between the
carousel body and the support surface 88a so that the motor 84 via
the pinion gear or tire 86 and turntable 82 can readily turn the
carousel body to bring successive sides of the carousel body into
proximity and alignment with assembly line 10. Each carousel frame
section 72 has a generally lattice configuration (FIG. 10)
including a vertical rectangular main body portion 72a, an upper
track structure 72b, a lower track structure 72c, and a connector
structure 72d. Main body 72a can be formed for example of a series
of spaced vertical post members 72e; upper track structure 72b can
be formed of a series of spaced horizontal post members 72f
supporting a pair of laterally spaced longitudinally extending
angle irons 72g; and lower track structure 72c can include a
plurality of spaced horizontal post members 72h supporting an apron
track 72i which in turn supports a round bar guide rod 72j. A
plurality of spaced saddle gussets 72k interconnect the main body
72a and lower track structure 72c. Connector structure 72d is
configured to meet with the connector structure 72d of the
remaining carousel sections in jigsaw puzzle fashion to form the
triangular configuration of the carousel clustered about central
post 78, Carousel assemblies 20, 22 and 24 are identical to the
described carousel assembly 18.
[0044] Referring now to FIGS. 29 and 30, the illustrated carousel
assemblies 18a, 18b respectively are identical in operation and
function to the previously described carousel assembly 18 with the
exception of having two sides or carousel sections 72a, and four
sides or carousel sections 72b respectively for receiving and
delivering framing gates to the framing station assembly 50. It
should be recognized that the carousel assembly can have at least
two sides according to the present invention, and can include three
sides, or four sides, or more four sides, depending on the
particular framing station assembly to be supplied with framing
gates, as well as other considerations, such as available floor
space and flexible changeover requirements for the assembly
line.
[0045] Linear track structure 26 is arranged for coaction with
carousel assembly 18 and specifically is arranged to deliver
framing gates from carousel assembly 18 to framing station assembly
50. Track structure 26 (FIGS. 3, 6, 7 and 8) includes a belt
shuttle frame 91, a vertical guide track 93, a horizontal guide
track 94, and a round bar rail 96. Belt shuttle frame structure 91
has a generally tubular steel frame construction and defines an
overall cage configuration. Vertical guide track 93 is supported on
belt shuttle frame structure 91 in overlying relation to the belt
shuttle frame structure and runs the full length of the track
structure. Horizontal guide track 94 is supported on the belt
shuttle frame structure 91 in a position above and laterally of
vertical guide rail 93 and extends from a first end 96a at a
location intermediate the track structure to a second end 96b
proximate the framing station assembly 50. Round bar rail 96 is
fixedly secured to the upper face of track 96 and is coextensive
with the track, extending from a location 96a intermediate the
track structure to a location 96b proximate framing station
assembly 50. Track structure 32 is identical to track structure 26;
track structure 28 is a mirror image of track structure 26; and
track structure 30 is identical to track structure 28.
[0046] Trolley assembly 34 (FIGS. 7, 19, 20, 22 and 23) includes a
trolley 98, a lift mechanism 100, and a shuttle belt assembly 102.
Trolley 98 is intended to move slidably along the track structure
26 while conveying a framing gate from the carousel to the framing
station. Trolley 98 includes a lower base member 104 and an upper
dump member 106. Base member 104 includes lower clamping plates 108
and further defines a plurality of rollers 110 configured to
rollably engage opposite side faces of vertical track 92 as the
trolley moves along the track structure. Base 104 further includes
rollers 112 adapted to rollably engage the lower edge of guide rail
92 as the trolley moves along the track structure. Dump member 106
defines an arcuate semicircular cut out 106a for coaction with
round bar rail 96 and further includes rollers 114 for coaction
with lifter mechanism 102, and cam follower rollers 116 for
rollable engagement with the upper face of horizontal guide track
94. Dump member 106 is pivotally mounted on base member 104 by a
pivot shaft 118 and includes a receiver section 106b including a
cut out 106c and carrying spaced pilot plates 120 defining a notch
or a slot 122 therebetween for receipt of a gate dog member carried
by a framing gate.
[0047] Lift mechanism 100 is intended to pivotally move dump member
106 about the axis of pivot 118 between a raised position in which
the notch 122 can engage the gate dog on a framing gate and a
lowered position in which the gate dog is released and the gate is
free to move relative to the trolley. Lift mechanism 100 (FIGS. 19,
20 and 21) includes a frame structure 124 (including a horizontal
base plate portion 124a, a vertical plate portion 124b and spaced
vertical plate portions 124c); a vertical slide plate 126 mounted
for vertical sliding movement on vertical plate portion 124b by
linear bearings 128 and including at its upper end a U-shaped
receiver portion 126a receiving the rollers 114 of the dump member
106 of the trolley; a toggle mechanism including a first upper
toggle link 130 pivotally connected at its upper end to slide plate
126 and a second lower toggle link 132 pivotally connected at its
lower end to vertical plate portions 124c, and an air cylinder 134
including a cylinder 134a pivotally mounted between plate portions
124c and a piston rod 134b pivotally mounted at its free end to the
pivotal connection at 136 between the lower end of the upper toggle
link 130 and the upper end of lower toggle link 132. It will be
seen that actuation of air cylinder 134 has the effect of opening
and closing the toggle movement and thereby sliding vertical slide
bracket 126, including the upper receiver portion 126a, up and down
to thereby (by virtue of the capture of rollers 114 in receiver
portion 126a) pivot the dump member 106 of the trolley about the
axis of pivot shaft 118 and move the pilot plates 122 into and out
of engagement with the framing gate dog.
[0048] Shuttle belt assembly 102 (FIGS. 3, 6, 7 and 19) includes a
powered pulley 140 mounted between spaced plates 91a proximate the
downstream end of belt shuttle frame structure 91; an idler pulley
142 mounted between spaced plates 91b proximate the upstream end of
belt shuttle frame structure 91; a pair of toothed endless belts
144 arranged in endless fashion around pulleys 140 and 142; and a
servo motor 146 drivingly connected to powered pulley 140 and
operative to drive the pulley and thereby drive the toothed endless
belts 144. Belts 144 are fixedly secured to the underface of
trolley base member 104 using clamping plates 108 whereby actuation
of servo motor 146 has the effect of moving trolley 98 along track
structure 26 from the downstream end of the structure to the
upstream end of the structure. As the trolley moves along the track
structure, rollers 110 engage opposite side faces of vertical guide
rail 92 and rollers 112 engage the lower edge of guide rail 92 to
guide the movement of the trolley along the track structure.
Trolley assembly 40 is identical to trolley assembly 34; trolley
assembly 36 is a mirror image of trolley assembly 34; and trolley
assembly 38 is a mirror image of trolley assembly 40.
[0049] Framing gate 42 will now be described in detail. It will be
understood that the remaining framing gates have a similar
construction but will differ from each other with respect to
tooling, clamps, etc. carried by the gate since the clamps and
tooling will be peculiar to the particular motor vehicle body style
for which the gate is designed. Framing gate 42 (FIGS. 3, 11 and
14) has a generally rectangular lattice configuration and a
generally tubular steel frame construction. The upper edge of the
gate includes a plurality of guide rollers 150 for rollably guiding
in the angle irons 72g of a respective upper track of a respective
carousel; a pair of axially spaced bearing structures 152 on the
lower edge of the gate rollably guiding on the round bar guide rail
72j of a respective lower track of a respective carousel; and a
gate dog 154 along the lower edge of the gate for coaction with the
notch 122 of the dump member of the respective trolley 98. Bearings
152 can be of the "caterpillar" type capable of crawling along the
round bar guide rail 72j and capable of jumping the gap between the
round bar guide rail 72j and the round bar guide rail 96 of the
associated linear track structure as the gate is moved along the
track structure by the trolley. Bearings 152 can, for example, be
of the type shown in FIGS. 24, 25 and 26, available from Thompson
Industries, Inc., as part number RW-1WA. Gate 42 further includes
finger members 156 projecting downwardly at the rear face of the
gate in rearwardly spaced relation to the main body structure 42a
of the gate. Fingers 156 facilitate the engagement of the gate with
the pillars 56, 58 after arrival of the gate at the framing station
in a manner more fully described in U.S. Pat. No. 6,173,881 B1
assigned to the assignee of the present application. Specifically,
the fingers 156 coact with the pillars 56 and 58 in the manner
shown and described with reference to FIG. 13 of U.S. Pat. No.
6,173,881 or in the manner shown and described with reference to
FIG. 20 of that patent. Gate 42 will be seen to define a plurality
of mounting plates 158 positioned on the main body 42a of the gate
in selected positions and in various configurations with respect to
the gate. It will be understood that these mounting plates are for
use in mounting tooling and clamping components on the gate for use
in clamping the loosely preassembled body at the framing station
prior to the welding operation. It will be further understood that
a pair of gates (42, 43, for example) would be used in clamping the
loosely preassembled vehicle body at the framing station from
opposite sides of the assembly line and that each pair of framing
gates (42, 43; 44, 45; 46, 47; and 48, 49) would include mounting
plates and tooling and clamping components peculiar to the body
style corresponding to the respective pair of framing gates.
[0050] The invention framing system further includes a latching
device for latching and unlatching a gate to the carousel and a
latching device for latching and unlatching the carousel to the
base structure. For reasons of compactness and servicing, these two
latching functions are combined in a single combined latch assembly
160, seen in FIGS. 14-18. Combined latch assembly 160 includes a
base structure 162 that is adapted to be fixedly secured to a
carousel base structure 80 at a location proximate a corner of the
carousel base structure; a further base structure 164 adapted to be
fixedly secured to the carousel base structure proximate base
structure 162; a jib slide structure 166 adapted to be fixedly
secured to the carousel body proximate each corner of the carousel
body; a T-bar slide 168 slidably mounted in each jib slide and
including spaced rollers 170 at the upper end of the slide; a plate
slide 172 mounted for vertical sliding movement on the base plate
162 and including spaced rollers 174 proximate an upper edge of the
slide plate; an air cylinder 176 including a cylinder 178 mounted
on a piggy back plate 180 with the free end of piston rod 182
pivotally mounted to a lower edge of base plate 162; an air
cylinder 184 including a cylinder 186 mounted on piggy back plate
180 and with the free end of piston rod 188 pivotally secured to
the slide plate 172; an L-shaped lift bar or arm 190 fixedly
secured at one end to slide plate 172 and terminating in a vertical
tip portion 190a; a finger 192 pivotally mounted on lift bar 190
proximate tip portion 190a and including a hook shaped upper
portion 192a; and a pair of cam rollers 194 mounted on base member
164 and slidably and cammingly engaging opposite edge surfaces of
finger 192. Latch assembly 160 is intended for selective coaction
with a precision dog 196 provided on the rear face on each framing
gate and a locator block 198 provided at each corner of the
carousel body. In overview, rollers 174 are sized to coact with
block 198 to lock the carousel body to the carousel base structure
and rollers 170 are sized to coact with precision dog 196 to lock a
framing gate to a respective side of the carousel body.
Specifically, as the carousel body is turned to bring one side of
the carousel body into alignment with the assembly line, cylinder
176 is fired to move plate slide 172 upwardly on base plate 162
(carrying the cylinder 186 with it in piggyback fashion) to move
rollers 174 into straddling relation with the locator block 198
proximate the respective side of the carousel. This upward sliding
movement of plate 172 has the effect of bringing the top edge 190b
of arm 190 into engagement with the lower end 168a of T-bar slide
168 without upwardly displacing the slide thereafter the cylinder
186 is fired to move slide 172 further upwardly, while retaining
locking engagement between rollers 174 and precision block 198, to
raise the T-bar slide 168 and disengage rollers 170 from precision
dog 196 to unlatch the framing gate from the carousel body. As
T-bar slide 168 is moved upwardly by arm 190, cams 194 operate to
move the hooked portion 192a of finger 192 into overlying relation
with a peg 168b on the lower end of slide 168. When cylinder 184 is
thereafter fired to re-engage rollers 170 with precision dog 196 to
re-establish a latched connection between the respective framing
gate and the carousel body, rollers 170 are moved downwardly in a
positive manner by the positive pulling action of hook portion 192a
on peg 168b, rather than relying on gravity to accomplish the
latching movement of the slide 168. Following firing of cylinder
184 to positively move the rollers 170 into latching engagement
with the precision dog on the respective framing gate, the cylinder
176 can be fired to further lower slide 172 to disengage rollers
174 from locator 198 to unlatch the carousel body from the carousel
base structure to allow turning movement of the carousel body to
bring a new framing gate into alignment with the assembly line. As
plate slide 172 moves downwardly to disengage rollers 174 from
locator block 198, cams 194 selectively engage the opposite edges
of finger 192 to allow the finger to rotate outwardly and move
downwardly to the disengaged position seen in FIG. 16 preparatory
to a new unlatching operation of a respective framing gate.
OPERATION
[0051] In the overall operation of the framing system of the
invention, the four carousel assemblies 18, 20, 22 and 24 and the
four linear track structures 26, 28, 30 and 32 coact to bring
selected pairs of framing gates to the framing station for use in
clamping the opposite sides of a loosely preassembled vehicle body
preparatory to the welding operation. With particular reference to
carousel assembly 18 and linear track structure 26, the carousel
body can be selectively rotated to bring each of the three sides of
the carousel body into alignment with the assembly line to deliver
a framing gate to the track structure 26 for delivery to the
framing station 14 following each turning movement of the carousel.
To facilitate the rotation of the carousel body, pressurized air is
delivered to air bags 90 to inflate the air bags and lift the
carousel body off of support surface 88a while pressurized air
flows through the diaphragm apertures 90b to form a film of air
between the diaphragms of the air bags and the support surface 88a,
thereafter motor 84 can be actuated to rotate the carousel body
through 120' to bring successive sides of the carousel body into
alignment with the assembly line. Note that (FIGS. 6 and 10) the
downstream end 94a of track 94 is chamfered and that the ends 72l
of carousel lower track 72c are complementarily chamfered so that
as each side of the carousel body moves into alignment with the
assembly line the respective chamfered end of the carousel lower
track structure moves into a nesting, parallel disposition with
respect to chamfered track end 94c.
[0052] During the rotation of the carousel body between successive
positions, latch assembly 160 has been actuated in a manner such
that the carousel body is free to turn relative to the carousel
base and each gate carried by the carousel body is fixed with
respect to the respective side of the carousel body by engagement
of rollers 170 with precision dog 196. As a respective side of the
carousel body carrying a desired framing gate arrives at a position
in alignment with the assembly line, cylinder 176 is fired to latch
the carousel body to the carousel base structure, thereafter air
cylinder 134 is actuated to raise slide plate 126 and pivot dump
member 106 upwardly about the axis of pivot shaft 118 to move the
dog 154 on the framing gate into groove 122 on the receiver 106b of
the dump member, thereafter cylinder 184 is fired to disengage
rollers 170 from precision dog 196 to unlatch the framing gate from
the carousel body, thereafter the delivery of pressurized air to
the air bags 96 is discontinued to allow the carousel to settle
back down onto the support surface 88a, thereafter servo motor 146
is actuated to drive powered pulley 140 and power endless belts 144
and the endless belts in turn move trolley 98 along the track
structure 26 to move the framing gate along the track structure to
the framing station. Specifically, as the trolley and the captured
framing gate move along the track structure toward the framing
station, the caterpillar bearings 152 on the lower edge of the
framing gate crawl along the round bar 70c, jump the gap between
the round bar 70c and the round bar 96, and continue crawling along
the round bar 96 until the framing gate arrives in the proximity of
the framing station.
[0053] Meanwhile, the trolley pushes the framing gate along the
track structure, and is guided on the vertical rail 92 by virtue of
the rollers 110 and the rollers 112, guided on the round bar 72j of
the carousel lower track structure by virtue of the sliding
engagement of the arcuate groove 106a with the round bar 72j,
followed by sliding engagement of the arcuate groove 106a on the
round bar 96; and guided on the lower track structure of the
carousel body by virtue of the rolling engagement of the rollers
116 on the track apron 72i proximate the round bar followed by
rolling engagement of the rollers 116 on the horizontal guide plate
194 proximate the round bar 196. The sliding movement of the
framing gate along the track structure is further facilitated by
the rolling engagement of the rollers 150 in the overhead angle
irons 72g of the carousel followed by rolling engagement of the
rollers 150 in overhead angle iron tracks 200 forming a
continuation of the angle irons 72g and extending to a location
overlying the framing station 14. As the gate approaches the
framing station the pillars 56 an 58 are in the retracted or
outboard positions to allow passage of the gate in front of the
pillars to position the gate on the pillars. As the leading edge of
the gate reaches and traverses the first pillar 58, the front
caterpillar bearing 152 loses contact with rail 96 but the gate
continues to be firmly guided during this brief transition time by
the continued engagement of the trailing caterpillar bearing 152 on
the round bar 96, by the firm guidance of the overhead rollers 150
in the overhead tracks 200, and by the firm guidance of the lower
edge of the trolley with the guide rail 92, the round bar 96, and
the horizontal rail 94 proximate the round bar 96. Once the leading
edge of the gate has traversed the pillar 58, the leading
caterpillar bearing 152 engages the round bar 164 and the movement
of the framing gate continues until the leading edge of the framing
gate encounters the second pillar 56 and moves past the second
pillar 56 to position the gate against both pillars 56 and 58, at
which time the framing gate is secured to the pillars in the matter
described in U.S. Pat. No. 6,173,881, thereafter the pillars
carrying the captured framing gate are moved from the outboard
positions to the inboard positions to coact with the pillars and
the matching framing gate 43 on the opposite side of the assembly
line to firmly clamp a loosely preassembled vehicle body
therebetween preparatory to the welding operation. As the pillars
move forwardly to the inboard positions, the framing gate is able
to move with the pillars by virtue of the passage of the overhead
guide rollers 150 through suitable gaps 200a provided in the
overhead guide rails 200.
[0054] The framing gate 42 will remain mounted on the pillars 56,
58 for coaction with the framing gate 43 carried by the pillars at
the framing station on the opposite side of the assembly line for
as long as it is desired to continue to build the same body style
vehicle. Specifically, the pillars will be moved to an inboard
position each time a vehicle body arrives, thereafter the vehicle
body will be clamped, thereafter the vehicle body will be welded,
thereafter the pillars will be moved outwardly to the outboard
positions until the arrival of the next successive loosely
preassembled vehicle body at the framing station, thereafter the
pillars will again be moved to the inboard positions and the
clamping and welding cycle repeated. This pattern will continue for
as long as it is desired to continue to build the same body style.
However, and in accordance with an important feature of the
invention, the pair of framing gates 42, 43 required to build the
specific body styles can be randomly and readily interchanged for
any of the other sets of framing gate pairs (44, 45; 46, 47; 48,
49) without interrupting the build cycle time of the assembly
line.
[0055] That is, the combined rotary carousel and linear track
arrangement of the invention allows the interchange of framing
gates corresponding to four different body styles at the framing
station without interrupting the build cycle time of the assembly
line so that any mix of the four body styles can be provided at any
time and during any time period without any penalty in the number
of vehicles produced by the assembly line during that time period.
For example, and with reference to FIG. 28, with framing gate pair
42 and 43 positioned on opposite sides of the framing station 14;
framing gate pair 44 and 45 positioned respectively on first sides
of the carousels 30 and 32 proximate the assembly line; framing
gate pair 46 and 47 positioned respectively on second sides of
carousels 30 and 32 removed from the assembly line; and framing
gate pair 48 and 49 positioned respectively on first sides of
carousels 26 and 28 removed from the assembly line, framing gates
42 and 43 can be randomly interchanged with any of the other pairs
of framing gates within the build cycle time of the assembly line.
Assuming a build cycle time for the assembly line of 45 seconds,
the described arrangement, with the gates positioned as described,
allows any of the gate pairs to be interchanged with the gate pair
42, 43 in less than 45 seconds. Specifically, it will be seen that
an exchange can be accomplished by simple linear movements of gate
pairs along the linear track structures or by a combination of
linear movements of gate pairs along the linear track structures
and rotary movement of selected carousels.
[0056] In the scenario where only linear movement of the involved
gate pairs is required (as for example replacing gate pair 42, 43
with gate pair 44, 45 simply by moving gate pair 42, 43 linearly
downstream from the framing station to the vacant side of carousels
26, 28 and moving gate pair 44, 45 downstream to the framing
station) the exchange time consists of only approximately 3 seconds
to perform the various latching and unlatching operations, and 5
seconds of linear sliding time for a total of approximately 8
seconds, well within the 45 second build cycle time target.
[0057] In the more complicated scenario where it is desired to
exchange gate pairs 42 and 43 with gate pairs 46 and 47, carousels
30 and 32 are rotated counterclockwise through 120.degree. to bring
gates 46 and 47 into proximity with the assembly line while gate
pair 42 and 43 is slid downstream to the vacant sides of carousels
26 and 28, thereafter gates 46 and 47 are slid downstream to
opposite sides of the framing station. The total time for this
operation being approximately 16 seconds to rotate the carousels, 5
seconds to perform the sliding operations, and approximately 3
seconds to perform the various latching operations for a total time
of 26 seconds, again well within the 45 second build cycle time
target.
[0058] To exchange gates 48 and 49 for gates 42 and 43, carousels
30/32 are rotated 120.degree. clockwise to bring the vacant side of
these carousels into alignment with the assembly line while
carousels 26 and 28 are rotated 120.degree. counterclockwise to
bring gates 48 and 49 into proximity to the assembly line,
thereafter gates 42/43 are slid upstream to occupy the vacant side
of carousels 30/32 while gates 48/49 are slid upstream to move
gates 48 and 49 to the opposite sides of the framing station. The
total time for this exchange again being approximately 26 seconds,
including 16 seconds to rotate the carousels, 5 seconds to perform
the sliding operations, and approximately 3 seconds to perform the
various latching operations, again well within the 45 second build
cycle time target.
[0059] Similar analysis of the various frame interchange scenarios
will establish that the combination of rotary and sliding movement
allows the random interchange of four pairs of framing gates to
allow the random production of any mix of four body styles on the
assembly line without interrupting the build cycle time of the
assembly line so that the assembly line can turn out the same
number of vehicles irrespective of the mix amongst the four body
styles. It will also be apparent that the arrangement allows the
production of five body styles on the same assembly line, but, in
this case, there are certain interchange scenarios where it would
not be possible to interchange the pair of gates positioned at the
framing station with another pair of gates positioned on one of the
carousels within the build cycle time, even though certain
interchanges would be possible within the build cycle time.
[0060] The invention apparatus and method will be seen to provide
the random interchange of more than three pairs of side framing
gates at a framing station while maintaining a predetermined build
cycle time interval of the assembly line to allow any random mix
of, for example, four body styles on a single assembly line without
compromising the ability of the assembly line, to maintain
operation at the predetermined build cycle time interval. Further,
the apparatus and method according to the present invention, by
virtue of its compact packaging, allows the random interchange to
be performed in the context of the physical floor plan constraints
of a typical motor vehicle assembly plant building and specifically
allows the system to be installed within the typically 50' wide
bays dictated by the structural columns of the building.
[0061] While the invention has been described in connection with
what is presently considered to be the most practical and preferred
embodiment, it is to be understood that the invention is not to be
limited to the disclosed embodiments but, on the contrary, is
intended to cover various modifications and equivalent arrangements
included within the spirit and scope of the appended claims, which
scope is to be accorded the broadest interpretation so as to
encompass all such modifications and equivalent structures as is
permitted under the law.
* * * * *