Note: Descriptions are shown in the official language in which they were submitted.
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CAR BODY ASSEMBLY AND WELDING STATION WITH RECIPROCAL
GATE-SIIPPORTING SYSTEM
FIELD OF THE INVENTION
The present invention relates to a production
line framing apparatus for clamping and thereafter
welding a loosely-assembled vehicle body, and more
particularly, a framing apparatus that accurately
positions and locates predetermined areas of a loosely-
assembled vehicle body for accurately clamping and
welding the vehicle body together with a high degree of
repeatability between consecutive vehicle bodies on the
production line. The framing apparatus can also be
adapted to handle a plurality of different predetermined
vehicle body configurations.
BACKGROUND OF THE INVENTION
The construction of a "unitized vehicle body"
commences with the formation of individual major body
panels by stamping the panels from a sheet metal blank.
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 header members on
which a roof panel is subsequently mounted. After the
individual panels are stamped, some preliminary assembly
operations may 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 panel, et cetera.
Next, a set of panels that together constitute
a sub-assembly of the finished vehicle body is then
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 of an adjacent panel. This technique interlocks
the panels and frame members to each other to thereby
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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 may
tilt or move relative to one another. This initial
loosely-assembled sub-assembly is then brought to a
welding station where the various panels and frames are
welded to each other in a rigid, permanently assembled
relationship.
This initial welding operation step 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 sub-assembly. During the welding
operation, it is desirable 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 is
accomplished by clamping frames which carry a plurality
of individual clamps arranged thereon to clamp various
body components in the desired position.
It is desirable to perform as many welding
operations as possible within the same welding 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 production line. Due to variations between assembly
stations and variation and 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 the various panels and headers.
Therefore, it is desirable to frame as much of the
vehicle body as possible within the same welding station
so that a maximum number of welding operations can be
performed on the vehicle body without having to
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subsequently reclamp and relocate the vehicle body since
reclamping and relocating may 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.
To accomplish multiple welds, programmable
robotic welders have been used to perform several welds
at different locations on a vehicle body at a single
welding station. The programmable robotic welders are
typically located at a welding station and on opposite
sides of the conveyor line passing through the welding
station. When the vehicle body sub-assembly is conveyed
to and positioned at the welding station, the head of one
welder may, for example, be extended to pass through the
vehicle door opening to apply several tack welds along
the seam between the vehicle body side panel and the
vehicle body floor panel. In situations where the
clamping frames are positioned at opposite sides of the
vehicle body, clearance problems can arise and may
restrict the range of motion of the welding head that
must first pass through the clamping frame before the
welding head can gain access to the vehicle body.
welding head access problems can require that the
portions of the vehicle body that cannot be accessed by
the welding head at the first welding station must
instead be accessed at a subsequent, second welding
station. This is an undesirable situation, since the
vehicle body must be relocated and reclamped at a
subsequent, second welding station, thereby increasing
the likelihood of tolerance buildup between the relative
positions of the various panels and headers of the
vehicle body and also decreasing the repeatability
between consecutive vehicle bodies in the production
line.
Another problem arises when separate clamping
frames are employed at opposite sides of the vehicle
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body, since the two clamping frames must be independently
located in a predetermined relationship relative to each
other and to the position occupied by the vehicle body
that the frames are to clamp in place. Since the two
separate clamping frames are not directly connected to
one another, the frames must use a common positional
reference that is either defined by a spatial orientation
or by a fixture or linkage assembly. These types of two-
frame systems exhibit problems with repeatability, since
two-frame referencing techniques inherently create
tolerance build-ups within the systems due to repeated
movements, thermal expansion and contraction, mechanical
wear, et cetera. Also, when separate clamping frames are
changed to accommodate different vehicle body styles or
configurations, the problems with repeatability can be
further magnified, which is undesirable.
In the automotive industry today, it is common
for one particular car model to have 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 clamping frame. To avoid the
situation of having to supply separate production lines
and welding stations for the different body styles of a
particular car model, it is desirable to provide a single
welding station that can be adapted to accommodate a
plurality of different body styles in a quick and
efficient manner while ensuring the accuracy and
repeatability that are required of the welding operation.
SUMMARY OF THE INVENTION
The present invention provides a framing
apparatus 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 predetermined, different loosely-assembled
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vehicle body configurations and styles in a quick and
efficient manner. A vehicle body welding station
according to the present invention includes a work
station for welding components of a loosely, pre-
5 assembled body with respect to one another. The body is
movable along a fixed path of travel through the work
station in a production line. A base frame extends
transversely with respect to the fixed path of travel of
the vehicle underbody at the work station to allow an
underbody of the vehicle to be accurately positioned with
respect to the base frame at the work station. At least
one pillar is located at each side of the fixed path of
travel at the work station and is mounted on the base
frame for reciprocal movement transversely with respect
to the fixed path of travel. Each pillar is movable
between a first position, which allows entry and accurate
positioning of the underbody with respect to the base
frame and which also allows entry of other components
into the work station, and a second position for
accurately locating and clamping the other components
with respect to the underbody. At least one welder is
located at each side of the fixed path of travel for
fixedly connecting the other components to the underbody
at the work station while the pillars are in the second
position.
At least one rail is located on each side of
the fixed path of travel for guiding movement of the
pillar between the first and second positions along the
rail. At least one drive is located on each side of the =
fixed path of travel for reciprocally moving the pillar
between the first and second positions along the rail.
At least one gate is located on each side of the fixed
path of travel and is supportable on the pillar for
movement between the first and second positions. If it
is desirable to provide interchangeable gate assemblies,
means can be provided on each side of the fixed path of
travel for moving the gate from a seated position
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supported by the pillar to an unseated position
disengaged from the pillar. In addition, if it is
desirable to automate changing of the gate assemblies, at
least one indexer can be provided on each side of the
fixed path of travel for moving the gate from the
unseated position to a changeover position. To
accommodate accurate positioning of the removable gate
assemblies with respect to the pillar, at least one
locator can be disposed on each gate for accurately
positioning the gate with respect to the pillar.
The present invention also includes a second
embodiment which provides an alternative gate transfer
apparatus and/or mechanism and an alternative gate
locating apparatus and/or mechanism. The gate is
operative to receive various fixtures and welding
equipment operative to weld a vehicle body. The gate
transfer apparatus is adapted to move a gate into and out
of engagement with a pillar. The pillar may then move
toward or away from the vehicle body. The gate transfer
apparatus includes a lower rail and an upper rail
operative to engage and support the gate, the gate being
movable on the upper and lower rails, and a drive
mechanism including a releasable hitch and complementary
socket or link which is operative to engage the gate.
The drive mechanism pushes or pulls the gate along the
upper and lower rails into and out of engagement with the
pillar.
The gate transfer apparatus may be driven from
above the gate or at ground level. The lower rail may be
configured to support the weight of the gate. In one
preferred embodiment, the drive mechanism may be a
conveyor belt. The gate transfer apparatus allows the
gate to disengage from the transfer apparatus when the
gate engages the pillar. In one preferred embodiment,
the gate, once on the pillar, disengages from the gate
transfer apparatus by slipping out of gaps in the upper
rail, while the lower rail includes removable rail
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segments positioned on the pillar which may be located
collinear with the lower rail during gate movement along
the rails.
Furthermore, the present invention may also
include a gate positioning mechanism to position the gate
on the pillar. The gate positioning mechanism includes
at least two gate locators positioned on the pillar and
at least two engaging members positioned on the gate.
The engaging members are adapted to mate with the
locators on the pillar to fix the position of the gate
thereon.
In one preferred embodiment, the gate includes
locating segments having engaging surfaces while the
pillar includes roller pockets which are configured to
trap the engaging surfaces of the locating segments. The
pillars may also include lower roller pockets uniquely
adapted to lift the gate off of the lower rail to provide
an accurate vertical position for the gate. The gate
positioning mechanism may also include a fore/aft locking
mechanism preferably including a locking pin positioned
on the gate and an extending roller pocket positioned on
the pillar.
According to one aspect of the invention, there
is provided in an apparatus for supporting a frame for
movement relative to a workpiece to be processed at a
work station, the improvement comprising:
at least two moveable pillars on each side of a
fixed path of travel through the work station for
synchronized reciprocation between first and second end
limits of travel toward and away from the fixed path of
travel of the workpiece;
at least one gate connectible in a repeatable
located position with respect to the moveable pillars on
each side of the fixed path for synchronized
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reciprocation between first and second positions toward
and away from the fixed path of travel of the workpiece;
gate drive means engageable with a registered
gate located in the repeatable located position on the at
least two pillars for moving the registered gate along
the fixed path of travel of the workpiece to remove the
registered gate from the at least two pillars, and
engageable with a replacement gate for moving the
replacement gate into registry with the at least two
pillars in the repeatable located position as the
previously registered gate is removed; and
locating means engageable between each pillar
and the corresponding gate for locating the gate with
respect to the moveable pillar in at least two
dimensions, wherein the locating means includes at least
two vertically spaced locators on each pillar for
defining a vertical position and a horizontal position
along an axis normal to the fixed path, and the
vertically spaced locators on one pillar are offset with
respect to the vertically spaced locators on the other
pillar, such that the gate engages with the vertically
spaced locators on each pillar only when immediately
adjacent the repeatable located position.
According to another aspect of the invention
there is provided in an apparatus for supporting a frame
for movement relative to a workpiece to be processed at a
work station, the improvement comprising:
a base frame extending transversely with
respect to a fixed path of travel at the work station,
the workpiece accurately positionable with respect to the
base frame at the work station;
at least one pillar on each side of the fixed
path of travel at the work station and mounted on the
base frame for reciprocal movement transversely with
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respect to the fixed path of travel, each pillar moveable
between a first position allowing entry and accurate
positioning of the workpiece with respect to the base
frame and allowing entry of other components into the
work station, and a second position for accurately
locating and clamping the other components with respect
to the workpiece;
at least one gate connectible in a repeatable
located position with respect to the moveable pillar on
each side of a fixed path of travel of the workpiece for
synchronized reciprocation between first and second
positions toward and away from the fixed path of travel
of the workpiece;
gate drive means engageable with a registered
gate located in the repeatable located position on the at
least one pillar for moving the registered gate along the
fixed path of travel of the workpiece to remove the
registered gate from the at least one pillar, and
engageable with a replacement gate for moving the
replacement gate into registry with the at least one
pillar in the repeatable located position while the
previously registered gate is removed; and
at least one welder on each side of the fixed
path of travel for fixedly connecting the other
components to the workpiece at the work station while the
pillars are in the second position.
According to a further aspect of the invention,
there is provided in an apparatus for supporting a frame
for movement relative to a workpiece to be processed at a
work station, the improvement comprising:
at least two moveable pillars on each side of a
fixed path of travel through the work station for
synchronized reciprocation between first and second end
limits of travel toward and away from the fixed path of
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travel of the workpiece;
at least one gate connectible in a repeatable
located position with respect to the moveable pillars on
each side of the fixed path for synchronized
reciprocation between first and second positions toward
and away from the fixed path of travel of the workpiece;
gate drive means engageable with a registered
gate located in the repeatable located position on the at
least two pillars for moving the registered gate along
the fixed path of travel of the workpiece to remove the
registered gate from the at least two pillars, and
engageable with a replacement gate for moving the
replacement gate into registry with the at least two
pillars in the repeatable located position simultaneously
as the previously registered gate is removed; and
locating means engageable between each pillar
and the corresponding gate for locating the gate with
respect to the moveable pillar in at least two
dimensions, the locating means including at least two
vertically spaced locators on each pillar for defining a
vertical position and a horizontal position along an axis
normal to the fixed path, and a moveable locator for
locating the gate in a predetermined position along an
axis parallel with respect to the fixed path of travel of
the body when the moveable locator is in a first position
and for allowing movement of the gate with respect to the
pillars when the moveable locator is in a second
position.
According to another aspect of the invention,
there is provided an apparatus for supporting a frame for
movement relative to a workpiece to be processed at a
workstation comprising:
at least one pillar at the workstation for
reciprocal movement between a first position allowing
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entry and accurate positioning of at least one workpiece
into the workstation, and a second position for
accurately locating and clamping of the workpiece into
the workstation;
at least one gate connectible in a repeatable
located position with respect to the moveable pillar on
each side of a fixed path of travel of the workpiece for
synchronized reciprocation between first and second
positions toward and away from the fixed path of travel
of the workpiece;
gate drive means engageable with a registered
gate located in a repeatable located position on the at
least one pillar for moving the registered gate along the
fixed path of travel of the workpiece to remove the
registered gate from the at least one pillar, and
engageable with a replacement gate for moving the
replacement gate into registry with the at least one
pillar in the repeatable located position simultaneously
as the previously registered gate is removed; and
a pillar drive connected to the pillar at the
workstation for driving the pillar harmonically between
the first and second positions, wherein the pillar drive
includes a reversible motor, a crank arm connected to the
motor for rotation through a predetermined rotational
arc, and a link connected between the crank arm and the
pillar for translating rotational motion of the motor
into harmonic motion of the pillar between the first and
second positions.
According to a further aspect of the invention,
there is provided in a vehicle body welding system
including a workstation for welding components of a
preassembled body with respect to one another, the body
moveable along a fixed path of travel through the
workstation, the improvement comprising:
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at least one pillar at the workstation for
reciprocal movement between a first position allowing
entry and accurate positioning of components into the
workstation, and a second position for accurately
locating and clamping of the component;
at least one gate connectible in a repeatable
located position with respect to the moveable pillar on
each side of the fixed path for synchronized
reciprocation between first and second positions toward
and away from the fixed path of travel of the body;
locating means engageable at two spaced
locations between each pillar and the corresponding gate
for locating the gate with respect to the moveable pillar
in at least two dimensions, wherein the locating means
includes a moveable locator for locating the gate in a
predetermined position along an axis parallel with
respect to the fixed path of travel of the workpiece when
the moveable locator is in a first position and for
allowing movement of the gate with respect to the pillars
when the moveable locator is in a second position; and
a pillar drive connected to the pillar at the
workstation for driving the pillar harmonically between
the first and second positions.
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
The description herein makes reference to the
accompanying drawings wherein like reference numerals
refer to like parts throughout the several views, and
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wherein:
Figure 1 is a perspective view of a pair of
simultaneously reciprocal pillars taken from a side
facing a fixed path of travel at a work station and with
both pillars in a second position according to the
present invention;
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Figure 2 is a perspective view of the pair of
simultaneously reciprocal pillars illustrated in Figure 1
from an opposite orientation illustrating the rear view
of the pillars with respect to the fixed path of travel
at the work station;
Figure 3 is an exploded perspective view of one
of the pillars and rail assembly including a drive unit
according to the present invention;
Figure 4 is an exploded perspective view of the
other pillar of the pair previously illustrated in
Figures 1 and 2 including a rail assembly and drive shaft
having universal joints for connection to the drive unit
of Figure 3;
Figure 5 is a plan view of the pair of
simultaneously reciprocating pillars, illustrated in
Figures 1 through 4 according to the present invention,
at a predetermined location with respect to a body
moveable along the fixed path of travel through the work
station;
Figure 6 is a side elevational view showing the
pair of simultaneously reciprocal pillars, according to
the present invention, with respect to the vehicle body
moveable along the fixed path of travel through the work
station, according to the present invention;
Figure 7 is a plan view showing a work station
having a pair of simultaneously operable pillars on each
side of the fixed path of travel through the work
station, wherein each pair of pillars is simultaneously
moveable from a first position spaced transversely from
the fixed path of travel to a second position disposed
inwardly with respect to the fixed path of travel for
accurately locating and clamping body components with
respect to the underbody at the work station;
Figure 8 is a side elevational view of the work
station shown in the plan view of Figure 7 illustrating
the relative movement of the pillars between the first
and second positions;
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Figure 9 is an exploded perspective view of a
reciprocal crank arm and link assembly for moving each
pillar between the first and second positions;
Figure 10 is an exploded perspective view of a
sliding pillar unit;
Figure 11 is an exploded perspective view of a
lift system for moving a gate from a seated position
supported by the pillar to an unseated position
disengaged from the pillar according to the present
invention and including a geneva drive configuration for
vertically moving the gate between the seated and
unseated positions;
Figure 12 is a detailed cross-sectional view of
a geneva drive according to the present invention having
a roller cartridge removable radially with respect to a
rotational axis of a drive shaft according to the present
invention;
Figure 13 is a side elevational view of a gate
having a plurality of locators disposed thereon for
accurately positioning the gate with respect to the
pillar according to the present invention;
Figure 14 is an exploded perspective view of a
reciprocal drive unit for moving the pillars between the
first and second positions;
Figure 15 is a detailed elevational view of a
balcony-mounted transfer system for exchanging gates
mounted on the pillars by moving the gates from the
unseated position to a changeover position;
Figure 16 is an elevational view showing the
balcony-mounted transfer system with respect to the
moveable pillar and the fixed path of travel through the
work station;
Figure 17 is a perspective view of the work
station illustrating the pair of moveable pillars on one
side of the fixed path of travel and the balcony mounted
transfer system for moving a gate assembly into and out
of contact with the supporting pillars;
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Figure 18 is a side elevational view of the
work station illustrating the balcony-mounted transfer
system, the interchangeable gates, the moveable pillars,
and lifter unit for transferring the gate assembly from
5 the seated position supported by the pillars to the
elevated position engageable with the balcony-mounted
transfer unit;
Figure 19 is a perspective view of an
alternative embodiment including a gate transfer
10 apparatus and a gate locating apparatus;
Figure 20 is an elevational view of a pillar
and the gate locating apparatus according to the
alternative embodiment;
Figure 21 is an elevational view of a vehicle
body at a work station that includes a pillar having a
gate locating apparatus, according to the alternative
embodiment, coupled with a gate transfer apparatus
according to the first embodiment;
Figure 22 is a side view of a releasable
locking hitch or pin and complementary socket or link
used to transfer gates according to the alternative
embodiment;
Figure 23 is a top view of an upper rail
associated with the gate transfer apparatus of the
alternative embodiment;
Figure 23A is a cross-sectional view of the
upper rail of the gate transfer apparatus according to
the alternative embodiment;
Figure 23B is a view taken along the lines D-D
illustrated in Figure 23A;
Figure 24 is an elevational view of a vehicle
body with the gate transfer apparatus according to the
alternative embodiment as well as the gate locating
apparatus according to the alternative embodiment;
Figure 25 is a detailed, exploded view of a top
roller pocket and a locating segment of the gate locating
apparatus, according to the alternative embodiment;
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Figure 26 is a detailed, perspective view of a
lower roller pocket and a locating segment of the gate
locating apparatus, according to the alternative
embodiment;
Figure 27 is a detailed, elevational view of
the top roller pocket and a locating segment of the gate
locating apparatus, according to the alternative
embodiment;
Figure 28 is a detailed, elevational view of
the lower roller pocket and the lower locating segment of
the gate locating apparatus, according to the alternative
embodiment;
Figure 29 is a detailed, perspective view of a
fore/aft lock in the gate locating apparatus, according
to the alternative embodiment;
Figure 29A is a side elevational view of Figure
29;
Figure 29B is an elevational view of Figure 29;
Figure 30 is an elevational view of the gate
locating apparatus, according to the alternative
embodiment;
Figure 31 is a perspective view of a preferred
embodiment of gate locating means according to the
present invention; and
Figure 32 is a perspective view of a preferred
embodiment of gate indexing means according to the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In Figure 7, a work station 10 is illustrated
in a vehicle body welding system for welding components
of a pre-assembled vehicle body in precise alignment with
respect to one another. The vehicle body 12 is moveable
along a fixed path 14 of travel through the work station
10. A base frame 16 extends transversely with respect to
the fixed path 14 of travel at the work station 10
allowing the underbody portion of the body 12 to be
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accurately positionable with respect to the base frame 16
at the work station 10.
In Figures 1 through 10, at least one pillar 18
is located on each side of the fixed path 14 of travel at
the work station 10 and is mounted on the base frame 16
for reciprocal movement transversely with respect to the
fixed path 14 of travel. Each pillar 18 is moveable
between a first position, shown in phantom in Figure 8,
which allows entry and accurate positioning of the
underbody portion of the body 12 with respect to the base
frame 16 and which allows entry of other body components
of the body 12 into the work station 10, and a second
position, illustrated in Figures 1, 2, 5, 7, and.8, for
accurately locating and clamping the other body
components with respect to the underbody portions of the
body 12. At least one welder 20, best illustrated in
phantom in Figure 8, is located on each side of the fixed
path 14 of travel for fixedly connecting the other body
components to the underbody portion of the body 12 at the
work station 10 while the pillar 18 is in the second
position.
In Figure 7, at least one rail 22 is located on
each side of the fixed path 14 of travel for guiding each
pillar 18 in movement between its first and second
positions. Preferably, at least two rails 22 are
provided for each pillar 18. At least one drive motor 24
is located on each side of the fixed path 14 of travel
for reciprocally moving the pillar 18 between its first
and second positions. Preferably, a pair of pillars 18
are located on each side of the fixed path 14 of travel
and are simultaneously moveable in reciprocal motion
between the first and second positions in response to
actuation of the drive motor 24.
As best illustrated in Figures 1 through 4 and
9, the drive motor 24 rotates a shaft 26 back and forth
through 180 of movement. A lever arm 28 is connected to
the shaft 26 for rotation with the shaft 26. A link 30
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is pivotally connected to the outer end of the lever arm
28 at one end and is pivotally connected to the pillar 18
at an opposite end of the link 30. More particularly,
the opposite end of the link 30 is connected to the
pillar 18 through a pivot pin connection 32. This lever
arm 28 and link 30 assembly provides harmonic motion to
the pillar 18, as the pillar 18 moves between its first
and second positions, such that maximum acceleration is
reached midway between the first and second positions and
the pillar 18 decelerates as the pillar 18 approaches its
first and second positions. Preferably, a lever arm 28
and link 30 are both provided for each pillar 18 to be
moved simultaneously in response to actuation of the
drive motor 24. It is also preferable to save space and
protect the lever arm 28 and link 30 assembly from damage
by housing the lever arm 28 and link 30 within a hollow
portion of each pillar 18. A drive shaft extension 34
can be positioned between the pair of pillars 18 and
preferably includes universal joints 36 at each end of
the drive shaft extension 34. Alternatively, the drive
motor 24 can be positioned between two pillars 18. The
large base dimension in the transverse direction of the
pillar 18 and the plurality of slide connections to the
rail 22, as best illustrated in Figure 3, provide
sufficient stability to repeatably reciprocate the
slidable pillars 18 between the first and second
positions when supporting a fully configured gate
assembly as will be described in greater detail below.
Each pillar 18 includes a gate support surface 38 and
first and second gate locator support surfaces 40 and 42
respectively.
As best illustrated in Figures 5 through 8, at
least one gate 44 is located on each side of the fixed
path 14 of travel and is supportable on at least one
pillar 18 for movement between the first and second
positions. As best illustrated in Figure 8, each gate 44
typically includes a plurality of clamping fixtures and
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may also include welding machines as is known in the art.
Typically, a gate 44 is specifically configured for a
particular vehicle body style to be assembled at a work
station as the appropriate components and underbody
portions of the body 12 travel along the fixed path 14
through the work station 10. If alternate body styles
are to be accommodated and handled at a single work
station 10, it is desirable to adapt the gate 44 for
attachment to the pillar 18 in a manner to allow
interchangeable gates 44 to be substituted for different
vehicle body styles as desired. In Figures 8 and 13, the
gate 44 can include a pillar engaging surface 46
complementary in size and shape to accommodate engagement
with the gate support surface 38 of the pillar 18. At
one end of gate 44, as best illustrated in Figure 13, at
least one locator 48 is provided for accurately
positioning the gate 44 with respect to the pillar 18.
Preferably, first and second locators 48 are provided as
illustrated in Figure 13. At one end of the gate 44, the
locator 48 positions the gate 44 accurately in the
transverse and the longitudinal direction with respect to
the fixed path 14 of travel through the work station 10.
At an opposite end of the gate 44, locators 48 accurately
position the gate 44 in the transverse position while
permitting limited longitudinal movement to allow for
variances between different gates 44 and operating
conditions of the system, such as, for example, thermal
expansion and contraction, or the like. Each locator 48
includes a male portion 50 and a female portion 52. As
illustrated in Figure 13, two male portions 50 are
connected to the gate 44, with one located at an upper
portion of each pillar 18 and another located at a lower
portion of each pillar 18. The corresponding female
portion 52 is connected to the pillar 18 at the first and
second gate locator support surfaces 40 and 42. Such a
configuration permits the gate 44 to be moved in a
vertical direction to disengage the gate 44 from a seated
CA 02309982 2000-05-11
position, supported by the pillar 18, to an unseated
position, disengaged from the pillar 18, where the
locators 48 have the male portions 50 disengaged from the
female portion 52. When in the seated position and
5 supported by the pillar 18, the gate 44 is accurately
located in the transverse direction, longitudinal
direction, and vertical direction with respect to the
work station 10.
As illustrated in Figure 11, at least one lift
10 54 is provided on each side of the path 14 of travel for
moving the gate 44 from the seated position, supported by
the pillar 18, to an unseated position, disengaged from
the pillar 18. The lift 54 is engageable with the gate
44 when the pillar 18 is in the first position, spaced
15 transversely from the fixed path 14 through the work
station 10. The lift 54 includes a moveable platform 56
for reciprocal motion between an upper end limit of
travel and a lower end limit of travel. The moveable
platform 56 is slidably supported for vertical movement
along vertically extending rails 58 at each longitudinal
end of the platform 56 (only one being shown in Figure 11
and the other being a mirror image thereof). The
platform 56 preferably includes a longitudinally
extending, gate-supporting rail 60 for engaging rollers
62 connected to the bottom of the gate 44, as best
illustrated in Figures 16 through 18.
In Figure 11, the lift 54 includes a reversible
drive motor 64 for moving the platform 56 between the
upper and lower end limits of travel while carrying a
gate 44. In a preferred configuration, the reversible
drive motor 64 actuates a geneva drive 66 for moving the
platform 56 between two end limits of travel. Details of
the geneva drive 66 are best illustrated in Figures 11
and 12. The geneva drive 66 advantageously includes a
roller cartridge 68 that can be removed radially with
respect to the rotational axis of a drive shaft 70
CA 02309982 2000-05-11
16
without having to disassemble and remove the entire
reversible drive motor 64.
In Figure 12, a vertically extending portion 72
of the moveable platform 56 supports a plurality of
generally rectangular blocks 74 having first and second
roller-engaging cam surfaces 76 and 78 respectively
formed on opposite sides of each block 74. The radially
removable roller cartridge 68 supports first and second
rollers 80 and 82 respectively for movement about a
rotational axis of the roller cartridge 68. The roller
cartridge 68 includes at least one radially and
longitudinally extending slot 84 formed in a peripheral
surface for receiving a longitudinally extending bar key
86. The bar key 86 also extends longitudinally into
another radially and longitudinally extending slot 88
formed in a sleeve 90 having an outwardly extending
flange 92. The sleeve 90 is engaged over the end of the
drive shaft 70 driven by the reversible drive motor 64.
A key 96 is engaged within a keyway slot 98 formed in the
shaft 70 and extends radially outward into a second
keyway slot 100 formed on the inner surface of the sleeve
90. The key 96 connects the sleeve 90 to the drive shaft
70 for common rotation about a rotational axis. An
anchor cap 102 is fixedly connected to an outer end 104
of the drive shaft 70 and engages with a shoulder 106
formed on an inner surface of the sleeve 90 to maintain
the sleeve 90 and flange 92 in a predetermined
longitudinal position with respect to the rotational axis
of the drive shaft 70. A longitudinally moveable collar
108 slidably engages along the external surface of the
sleeve 90 and is moveable to a position to sheath the
flange 92 and at least a portion of the roller cartridge
68. A plurality of bolts threadingly engage the flange
92 to fix the collar 108 with respect to the flange 92,
for supporting the outer periphery of the roller
cartridge 68 and the outer circumference of the flange 92
with the inner surface of the collar 108. The one or
CA 02309982 2000-05-11
17
more bar keys 86 connect the roller cartridge 68 to the
sleeve 90 and flange 92 in order to transmit the rotary
motion from the drive shaft 70 to the roller cartridge
68. Rotation of the roller cartridge 68 moves the first
and second rollers 80 and 82 respectively along the first
and second cam surfaces 76 and 78 of the blocks 74 to
drive the platform 56 in motion between the end limits of
travel. Such a configuration allows the collar 108 to be
unbolted from the flange 92 and allows the bar key 86 to
be unbolted from the roller cartridge 68 and the sleeve
90 in order to permit the roller cartridge 68 to be moved
radially with respect to the drive shaft 70. By removing
the roller cartridge 68 radially without disturbing the
surrounding equipment, maintenance of the roller
cartridge 68 is simplified, and any down time for repair
of the roller cartridge 68 for the lift 54 is thereby
reduced.
In Figures 15 through 18, a balcony-mounted
transfer system or indexer 110 is illustrated for moving
a gate 44 from the unseated position, illustrated in the
upper phantom outline of Figures 15 and 16 after being
raised by the lift 54, to a changeover position best
illustrated in Figures 17 and 18. The indexer 110 is
positioned above the reciprocal pillars 18 when the
pillars 18 are in their first position, spaced
transversely from the fixed path 14 of travel through the
work station 10. Along the upper portion of each gate
44, locators 112 are provided in longitudinally spaced
positions as best illustrated in Figures 17 and 18. At
least one of the locators 112 on each gate 44 serves to
position the gate 44 in the transverse and longitudinal
directions. The other locator 112 serves to position the
gate in the transverse position while allowing some
longitudinal variation to accommodate thermal expansion
and retraction or the like. As illustrated in Figures 16
through 18, each gate 44 includes a plurality of rollers
62 engageable with the rail 60 formed on the upper
CA 02309982 2000-05-11
18
surface of the moveable platform 56 of lift 54. As the
platform 56 moves from the lower end limit of travel to
the upper end limit of travel, the gate 44 is moved from
the seated position to the unseated position. Prior to
the complete removal of the male portion 50 from the
female portion 52 of the locators 48 which attach the
gate 44 to the pillars 18, the upper locators 112 become
partially engaged with the male portions 114 partially
engaged within the female portions 116. Therefore, as
the gate 44 is moved between the seated and unseated
positions by movement of the lift 54, the gate 44 passes
through the transition of having locators 48 fully
engaged, followed by having the locators 48 and locators
112 both being partially engaged, and finally having the
locators 112 being fully engaged and the locators 48
being fully disengaged when the gate 44 reaches the upper
end limit of travel of the lift 54. As illustrated in
Figures 15 through 18, the male portion 114 of the
locator 112 is located on the upper portion of the gate
44, and the female portion 116 of the locator 112 is
located on the balcony-mounted transfer system 110. The
balcony-mounted transfer system 110 includes an elongate
carriage 118 supporting the female portion 116 for
reciprocal movement longitudinally and parallel to the
fixed path 14. As illustrated in Figures 17 and 18, the
transfer system or indexer 110 can extend longitudinally
on either or both sides of the work station 10, thereby
defining a changeover or idle position for one of the
gates 44 when the idle gate 44 is not supported by the
pillars 18. The gate 44 is moveable by the indexer 110
along the supporting rail 60 of the platform 56 and
further along adjacent portions of rail extending
longitudinally parallel to the fixed path 14 (not shown).
As illustrated in Figures 16 through 18, the carriage 118
is driven in movement longitudinally along a path
parallel to the fixed path 14 by a drive motor 128. The
drive motor 128 rotates a shaft 120 connected through a
CA 02309982 2000-05-11
19
universal joint 122 to a drive gear 124. The drive gear
124 can be driven in either rotational direction and
operably engages a rack 126 connected to the carriage
118. Preferably, the balcony-mounted transfer system 110
is disposed on each side of the fixed path 14 of travel
at the work station 10 to provide automated indexing or
changing of gates 44 as required to accommodate different
vehicle body styles.
In operation, the cyclical operation of the
framing apparatus according to the present invention can
be described as follows. The drive motor 128 of the
balcony-mounted transfer system 110 is activated to carry
a supported gate 44 to an unseated position directly
above the pillars 18, when the pillars 18 are located in
the first position while the lift 54 is located in the
upper end limit position. The carriage 118 then stops at
the appropriate position with respect to the work station
10, and the lift 54 is actuated to drive the geneva drive
66 to move the lift 54 from the upper position to the
lower position to lower the gate 44 onto the pillars 18.
As the gate 44 is lowered by the lift 54, the gate 44 is
supported on the rail 60 by rollers 62 and the male
portions 50 of the locators 48 incrementally engage with
the female portions 52 located on the pillars 18, while
the male portions 114 of the locators 112 simultaneously
incrementally disengage from the female portions 116
connected to the carriage 118. When the lift 54 reaches
the lower end limit of travel, the gate 44 is accurately
and securely positioned with respect to pillar 18 and is
freed from the carriage 118. The pillar 18 is then
driven in reciprocal movement from the first position to
the second position by the drive motor 24 via shaft 26,
lever arm 28, and link 30. This cycle between first and
second positions of the simultaneously reciprocal pillars
18 continues as necessary until a new vehicle body style
is to be accommodated and a different gate is needed. At
that point in time, the pillar 18 is positioned at its
CA 02309982 2000-05-11
first position and the reversible drive motor 64 is
actuated to drive the geneva drive 66 to raise the lift
54 from the lower position to the upper position. As the
lift 54 moves between the lower position and the upper
5 position, the gate 44 is engaged by the rail 60 via the
rollers 62 which are connected to the gate 44. As the
gate 44 moves from the seated position to the unseated
position, the male portions 50 of the locators 48
incrementally disengage from the female portions 52
10 while, simultaneously, the male portions 114 of locators
112 incrementally engage with the female portions 116
connected to the carriage 118. When the lift 54 reaches
the upper end limit of travel, the male portions 114 of
locators 112 are fully engaged within the female portions
15 116 connected to the carriage 118, and the gate 44 is
completely disengaged from the pillars 18, and the male
portions 50 of the locators 48 are completely disengaged
from the female portions 52 connected to the pillars 18.
When in this position, the drive motor 128 for the
20 indexer 110 can be actuated to move the gate 44 in either
longitudinal direction to thereby place the gate 44 in an
idle or changeover position, while simultaneously moving
a new gate 44 into the appropriate position for lowering
on the lift 54 and ultimate engagement on the pillars 18.
Of course, it should be recognized that the framing
apparatus according to the present invention can be
practiced without a balcony-mounted transfer system if
there is no need or desire to provide for indexing gates
with respect to the supporting pillars 18.
According to the present invention, an
alternative gate transfer apparatus is illustrated in
Figures 19 through 30. Figures 19 through 30 also
generally illustrate a work station 10 adapted to receive
a vehicle body 12 which travels along a fixed path 14
through work station 10. As previously explained
hereinabove, a pair of pillars 18 may be positioned on
either side of the body 12. The pillars 18 are adapted
CA 02309982 2000-05-11
21
to receive one or more gates 44 which include at least
one welder 20 and other fixtures necessary to perform
operations on the body 12.
The alternative gate transfer apparatus is
generally positioned at ground level. As illustrated in
Figure 19, the alternative gate transfer apparatus
preferably includes a lower rail 160 and an upper rail
180. Upper and lower rails 160 and 180 serve to guide
the gate 44 into and out of engagement with the pillars
18. As illustrated in Figures 19, 20, and 24, lower rail
160 includes an angled upper surface forming an inverted
V-shaped, cross-sectional configuration. Lower rail 160
is stationary and is supported from the ground by a
suitable frame structure. Gate 44 includes a pair of V-
rollers 162 positioned on the bottom of the gate 44. V-
rollers 162 are adapted to engage lower rail 160 to
support the weight of the gate 44 and to guide the gate
44 either toward or away from the pillars 18. V-rollers
162 may be attached to the bottom of the gate 44 in a
variety of different ways. One way is to provide a
housing 163 in which the rollers 162 are mounted. V-
rollers 162 are preferably made of steel, although one of
ordinary skill in the art would recognize that other
materials, including alloys, may be suitable as well. It
is to be understood that the profile of lower rail 160
and the corresponding rollers 162 placed on gate 44 are
not limited to a V-shaped configuration. Other
configurations would be apparent to those of skill in the
art as well. This embodiment supports the weight of the
gate 44 primarily on the lower rail 160.
As illustrated in Figures 19, 23, 23A, 23B, and
24, the upper rail 180 is preferably a U-shaped channel
adapted to receive a plurality of rollers 182. Rollers
182 are positioned on the top surface of gate 44 and are
preferably supported by a pin 45. Rollers 182 have an
axis of rotation which is generally perpendicular to the
ground. Upper rail 180 is stationary and preferably
CA 02309982 2000-05-11
22
supported from the ceiling with a suitable support
structure. Because the weight of gate 44 is supported by
the lower rail 160, the necessary support structure
holding upper rail 180 in place is reduced.
As shown in Figures 19 and 22, gate 44 is moved
along lower rail 160 and upper rail 180 with the
assistance of a drive 150. In this embodiment, drive 150
includes a conveyor belt 151 positioned adjacent lower
rail 160. Such a conveyor belt 151, for example, may be
a commercially available MARK C conveyor belt. The
conveyor belt 151 provides a significant advantage in
that it may be precisely controlled. As illustrated in
Figure 22, conveyor belt 151 runs generally parallel with
the ground. It is to be understood, however, that
conveyor belt 151 may be positioned at any angle with
respect to the ground. In addition, a conveyor link 174
is mounted on conveyor belt 151 and operates to drive the
gate 44 in either direction into engagement or out of
engagement with pillars 18. It is to be understood by
those skilled in the art that other types of drive
mechanisms may be used to move the gate 44 into and out
of engagement with pillars 18.
As illustrated in Figure 22, conveyor link 174
includes an outwardly projecting arm 176 and a roller
pocket 177 attached thereto. Roller pocket 177 includes
a pair of rollers 179 and further includes gaps 177A.
Gate 44, in turn, includes at least one locking member or
pin 172 operative to releasibly engage within the roller
pocket 177. Locking pin 172 engages roller pocket 177 by
passing into and out of gaps 177A when pillars 18 move
from their second position to their first position.
Conveyor link 174 and locking pin 172 together act as a
trailer hitch and ball to pull or push the gate 44. In
this way, when locking pin 172 is engaged with respect to
conveyor link 174, conveyor belt 151 operates to pull or
push the gate 44 into or out of the gate locating
apparatus of pillars 18.
CA 02309982 2000-05-11
23
The alternative embodiment also provides
structure to permit the gate 44 to disengage from the
gate transfer apparatus when the gate 44 has engaged
pillars 18 so that pillars 18 can move from the first
position to the second position. As illustrated in
Figures 19 and 24, pillars 18 can include an attached
pair of rail segments 166 which are collinear with the
stationary lower rail 160 when pillars 18 are in the
first position. Rail segments 166 are separated from the
stationary rail 160 by splits 164. In this way, when
gate 44 is positioned on rail segments 166, pillars 18
can move forward with the gate 44 into the second
position.
As illustrated in Figures 19 and 23, upper rail
180 includes gaps 184 to allow rollers 182 to exit the
channel defined by the upper rail 180. Gaps 184 are
slightly larger than the diameter of rollers 182 and are
positioned in a staggered pattern to align with the
rollers only when the gate 44 is in the engaged position
on the pillars 18. In a preferred embodiment, gate 44 is
configured with three offset rollers 182. This
arrangement allows at least two rollers 182 to be engaged
within upper rail 180 at one time when gate 44 is not
captured by pillars 18. Thus, it is only when gate 44 is
captured by pillars 44 that rollers 182 are aligned to be
disengaged through the gaps 184 from the upper rail 180.
For example, when the trailing roller of rollers 182
passes across one of the gaps 184 during the process of
removing gate 44 from pillars 18, the two leading rollers
of rollers 182 will remain engaged within the upper rail
180.
The present invention can include a second gate
locator. The second gate locator locates and/or
positions the gate in a vertical position indicated by
arrows A in Figure 19, a fore and aft position indicated
by arrows B in Figure 19, and fixes the angle at which
the gate 44 rests with respect to the ground as indicated
CA 02309982 2000-05-11
24
by arrow C in Figure 19. The second gate locator is
illustrated in Figure 19, and Figures 24 through 30. In
general, gate 44 is located vertically and the angle of
the gate with respect to the ground is fixed when a
plurality of locating segments 200, positioned on the
gate 44, engage a plurality of corresponding roller
pockets 220 positioned on pillars 18. Gate 44 is
configured to include a plurality of locating segments
200 positioned at the top fore position of gate 44, at
the bottom fore position of gate 44, at the top aft
position of gate 44, and at the bottom aft position of
gate 44 respectively.
Each locating segment 200 is adapted to engage
the corresponding complementary roller pocket 220
positioned on one of the pillars 18 to locate the gate 44
vertically and/or fore and aft with respect to the
pillar. As shown in Figure 25, upper locating segments
200U each include an extension 200A extending away from
the gate 44 and further include a downwardly projecting
member 200B which slides into one of the upper
corresponding complementary roller pockets 220.
Preferably, the downwardly projecting member 200B
includes a pair of engaging surfaces 210UB, 21OUF which
contact upper back and front rollers 223UB, 223UF in
upper roller pockets 220U. Engaging surfaces 21OUB,
210UF each preferably include ramps 211 which facilitate
the reception of engaging surfaces 21OUB, 21OUF into the
upper roller pockets 220U. Rollers 223UB, 223UF
positioned in roller pockets 220U, and locating segments
200U are both preferably constructed with steel. Thus,
it is to be understood that the dimensions of the
locating segments 200U and, in particular, the engaging
surfaces 210UB, 21OUF must be accurately dimensioned to
engage between rollers 223UB, 223UF to precisely locate
the gate 44 with respect to the pillars 18 in a
repeatable manner. Such an arrangement provides solid,
repeatable placement of the gate 44 on the pillars 18.
CA 02309982 2000-05-11
As illustrated in Figures 24 through 26, top or
upper roller pockets 220U include a pair of rollers
223UB, 223UF, while lower or bottom roller pockets 220B
include three rollers 225BB, 225BF and 225A, each of
5 which is mounted within a roller housing 221. As
illustrated in Figures 24 and 26, the bottom fore and aft
locating segments 200B also preferably include engaging
surfaces 21OBB, 210BF and 210A adjacent the bottom of
gate 44. Engaging surfaces 210BB, 210BF and 210A
10 function in combination with bottom rollers 225BB, 210BF
and 225A to precisely locate the front and back position
and the vertical position of the gate 44. Bottom
engaging surfaces 21OBB, 210BF and 210A also include
ramps 211 which operate to engage lower rollers 225BB,
15 225BF and 225A to lift gate 44 off of rail segments 166.
Preferably, ramps 211 operate to lift gate 44 only a few
millimeters, such as, for example, 2 millimeters, off of
rail segments 166 to accurately set the vertical position
of gate 44.
20 As illustrated in Figures 24, 27, and 28, the
fore and aft rollers 223UB, 223UF and 225BB, 225BF
corresponding to the upper and bottom of gate 44 are
offset with respect to one another so that the engaging
surfaces 210UB, 21OUF of the aft locating member 200B are
25 offset or not aligned with the engaging surfaces 210UB,
21OUF of the fore locating member 200B. Similarly, top
fore and top aft, as well as, bottom fore and bottom aft
engaging surfaces 210UB, 21OUF, 21OBB, 210BF are offset.
Offsetting the fore and aft engaging surfaces 210 and
fore and aft rollers 223 and 225 allows the fore engaging
surfaces 210 to freely pass by the aft rollers 223 and
225 during loading and unloading of the gate 44 with
respect to the pillar 18. This is illustrated in Figure
28 where the fore and aft engaging surfaces are labeled
210FS and 210AS respectively, and fore rollers are
labeled 225FRA and 225FRB and the aft rollers are labeled
225ARA and 225ARB. This offset configuration
CA 02309982 2000-05-11
26
provides an efficient way to engage and disengage gate 44
from pillars 18 since the engaging surfaces 210 do not
encounter resistance until they engage their
corresponding roller pockets 220. This also reduces wear
on the locating surfaces.
According to the present invention, the
alternative embodiment also includes a fore/aft locking
member. In particular, as illustrated in Figures 29 and
30, gate 44 includes a fore/aft locking pin 230. Locking
pin 230 engages movable roller pocket 234 to engage the
fore/aft locating surfaces 231F, 231A. Movable roller
pocket 234 includes a pair of rollers 238F, 238A mounted
within a body 236. A cylinder 240 is operative in moving
roller pocket 234 outward to engage the fore/aft locating
surfaces 231F, 231A of locking pin 230. The fore/aft
locating surfaces 231F, 231A of locking pin 230
preferably includes beveled edges 232 to facilitate
capturing the pin 230 within the moveable pocket 234.
The locking pin 230, when engaged, prevents gate 44 from
moving in a fore or in an aft direction and locating
surfaces 231F, 231A precisely locate the gate 44 in the
fore and aft direction with respect to the pillars 18.
It is to be understood by one of ordinary skill in the
art that the fore/aft locating and locking mechanism can
be implemented in any of a number of different
configurations. For example, a locking pin with locating
surfaces could be supported from the pillars 18 and could
engage a roller pocket positioned on the gate 44.
During operation of the alternative embodiment,
conveyor belt 151 and connected drive link 174 operably
engage with the drive pin 172 positioned on gate 44 when
the pillars are in the retracted position, to push gate
44 along lower and upper rails 160 and 180 toward pillars
18 while pillars 18 are in the retracted or first
position. When pillars 18 are in the first position,
rail segments 166 are collinear with the stationary lower
rail 160. As gate 44 travels toward pillars 18, the fore
CA 02309982 2000-05-11
27
engaging surfaces 21OUB, 21OUF of the fore locating
segments 200U, 200B pass the aft roller pockets 220U,
220B as a result of being offset from the aft rollers
223UB, 223UF and 225UB, 225BF. Top and bottom fore
engaging surfaces 21OUB, 21OUF, 210BB, 210BR of locating
segments 200U, 200B then engage top and bottom fore
roller pockets 220U, 220B. Simultaneously, aft engaging
surfaces 21OUB, 21OUF, 210BB, 210BR of aft locating
segments 200U, 200B engage aft roller pockets 220U, 220B.
The bottom engaging surfaces 210A ramp onto the bottom
rollers 225A of bottom roller pockets 220B to vertically
position the gate 44.
In Figures 23 through 26, 29, and 30, movable
roller pocket 234 moves forward to engage the fore/aft
locating surfaces 231F, 231A of locking pin 230
positioned on gate 44. After gate 44 is located on
pillars 18, pillars 18 move forward from the first
position into the second position. Necessary welding
and/or other operations can be performed on the vehicle
body 12 when the pillars 18 are in the second position.
When pillars 18 move forward, upper rollers 182 pass
through the gaps 184 in the upper rail 180 and are
thereby disengaged from the upper rail 180. It is to be
understood that each engaging surfaces 210 is
sufficiently long in length so that when upper rollers
182 approach gaps 184, the engaging surfaces 210 are
captured in the respective roller pockets 220, such that
gate 44 is always captured within either the gate
transfer apparatus or by pillars 18. The rail segments
166 separate from the stationery lower rail 160 as the
gate 44 moves forward to its second position. In the
second position, the appropriate welding or other
operations can be performed on the vehicle body 12 by the
devices positioned on gate 44 or by robotic devices
located at the work station.
Gate 44 is removed from pillars 18 and taken
away in the opposite manner as described hereinabove.
CA 02309982 2000-05-11
28
More particularly, the pillars 18 retract back to the
first position and upper rollers 182 pass back through
gaps 184 into upper rail 180 and are re-engaged with
upper rail 180 as the gate 44 is moved away from the
pillar 18. Rail segments 166 also then become collinear
with the lower rail 160, and locking pin 172 of the gate
44 is engaged with drive link 174. Gate 44 can include
locking pins 172 at both the fore and aft locations. In
this way, when one gate 44 is being pushed by conveyor
belt 151 toward pillars 18 from one direction, another
gate 44 can simultaneously be pulled by another conveyor
belt out of engagement with pillars 18 from the opposite
direction. Lower and upper rails 160 and 180 may include
switches to allow different gates to enter and exit
engagement with pillars 18.
The present invention includes many significant
advantages, not the least of which is that the great
majority of the superstructure typically positioned about
pillars 18 is now removed and is no longer necessary.
This will allow robots or others devices additional
clearance to access the vehicle body 12 from the sides
and/or from a gantry above the work station. It is to be
also understood that drive link 174 can be moved into and
out of position when pillars 18 are in the first position
to provide even greater clearance for robots to=access
the body 12.
Referring now to Figure 31, the preferred
embodiment of the gate locating means is shown in
perspective view with all other structure removed for
purposes of clarity. The gate locating means 300
includes a plurality of roller pockets 302, 304, 306,
308. Each of the roller pockets 302, 304, 306, 308
includes opposing locating rollers 310, 312 disposed
adjacent a central portion of the corresponding pocket
302, 304, 306, 308. In addition, opposing alignment
rollers 314, 316 are positioned on at least one side of
the locating rollers 310, 312, and preferably on both
CA 02309982 2000-05-11
29
sides of the opposing locating rollers 310, 312 in order
to align locating surfaces of the gate prior to
engagement with the locating rollers 310, 312.
Positioning the opposing alignment rollers 314, 316 on
both sides of the locating rollers 310, 312 reduces wear
on the locating rollers 310, 312 by aligning the gate
with the locating rollers 310, 312 prior to contact with
the locating surfaces of the gate (not shown in Figure
31). This configuration will provide alignment of the
gate prior to engagement with the locating rollers 310,.
312 when-the gate is being loaded onto the pillars from
either side or direction.
Each of the lower roller pockets 304, 308
includes a positioning roller 318 for lifting the gate
vertically into a predetermined position. Preferably,
the positioning roller 318 is located adjacent to the
center portion of each of the lower roller pockets 304,
308. Preferably each of the lower roller pockets 304,
308 also includes at least one guarding roller, and most
preferably two guarding rollers 320, 322, with one
guarding roller disposed on each side of the positioning
roller 318 to act as an upstream guarding roller and a
downstream guarding roller to reduce the wear on the
positioning roller 318 disposed therebetween. As the
locating surface of the gate approaches one of the lower
pockets 304, 308, the lower locating surface of the gate
engages first with one of the guarding rollers 320, or
322, prior to being positioned in the predetermined
vertical position lifted slightly from the guide rail by
the positioning roller 318. Simultaneously, the
vertically extending locating surfaces of the gate engage
first with the opposing alignment rollers 314, 316 prior
to being finally located in the desired predetermined
location on the pillars by the locating rollers 310, 312
in each of the roller pockets 302, 304, 306, 308. This
configuration accurately positions the gate in two
dimensions with respect to the pillar support structure.
CA 02309982 2000-05-11
The gate is also positioned with respect to a
third axis by engagement with the movable roller pocket
324. The movable roller pocket 324 preferably includes
opposing position-capturing rollers 326, 328 for operably
5 engaging locating surfaces formed on the gate extending
in a direction preferably normal to both the locating
surfaces on the gate operably engagable with the locating
rollers 310, 312 and the locating surface engagable with
the positioning roller 318. As the movable roller pocket
10 324 is reciprocated into engagement with the locating
surfaces on the gate, the gate is captured along the
third axis to accurately position the gate in three
dimensions with respect to the pillar. Further alignment
of the gate with respect to the work station is not
15 required. This reduces the amount of wear on the
alignment rollers, since multiple vehicle bodies are
processed at the work station prior to changing the gate
for another body style configuration. Prior known
devices require alignment of the gate when closing or
20 approaching with respect to the vehicle body at the work
station, and therefore wear occurs on the alignment
mechanisms for every single vehicle body welded. In the
present invention, wear occurs on the aligning, locating
and capturing rollers only when the gate is changed on
25 the pillars. Since the position of the pillars in the
closed orientation is known, further locating of the gate
with respect to the automotive body is not required for
each vehicle body to be welded. This increases the
dimensional accuracy and repeatability of the present
30 invention over that possible with the prior known
devices. The present invention is capable of reaching
tolerances, even with repetitive gate changeovers over
extended periods of time beyond, that capable of the
prior known devices.
Referring now to Figure 32, the preferred
embodiment of the gate transfer means 330 is shown in
exploded perspective view with other portions of the
CA 02309982 2000-05-11
31
present invention removed for clarity. In the
illustration of Figure 32, the gate is schematically
shown as 44 and would be positioned on the pillars (not
shown in Figure 32) waiting for reciprocation of the
pillar toward the vehicle body to be welded. Movement
toward the vehicle body would be toward the lower left as
illustrated in Figure 32. A frame 332 supports the rail
334 carrying the gate 44. The gate 44 is movably
supported on the rail 334 by roller bearings 336. A
drive engaging member 338 is connected to the gate 44 for
slidable engagement with a slot 340 connected to a
carriage 342 for driving the gate 44 in reciprocal
movement along the rail 334. The drive engaging member
338 is in operable engagement with the slot 340 when the
pillar is in the retracted position spaced away from the
fixed path of travel of the vehicle body. When in this
retracted position, the drive engaging member 338 is
disposed operably within the slot 340 allowing the
carriage 342 to move the gate 44 off from the pillars
(not shown) and on to the rail 334 into a standby
location toward the upper left as illustrated in Figure
32. When this gate 44 is required again, the carriage
342 drives the gate 44 from the standby position on rail
334 on to the pillar and into a ready location. The
drive engaging member and slot allow the pillars to
reciprocate the gate toward the fixed path of.the vehicle
body for clamping the vehicle body to perform welding
operations at the work station. Reciprocation of the
gate 44 slides the drive-engaging member out of the slot
until the gate 44 is returned to the retracted position
by the pillars. It should be recognized that the drive
engaging member 338 could be connected to the carriage,
while the slot 340 could be formed on the gate without
departing from the spirit and scope of the present
invention.
The gate 44 can also include a slot 344 for
receiving a lock member (not shown). The lock member can
CA 02309982 2000-05-11
32
prevent the gate from moving along the rail or moving
with respect to the pillars beyond a limited range of
movement required for positioning of the gate as the gate
is engaged by the movable roller pocket 324, as
previously described. The lock member can be reciprocal
into and out of engagement with the slot 344 formed on
the gate 44 in order to prevent the gate from being
dislodged from the pillars when not engaged and driven by
the carriage 342.
While the present 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
claims of the present invention, 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.
