Apparatus and methods for engaging a workpiece

Inbound and outbound parallel conveyors carry parts supported on a screen tray engaged by the conveyors. The parts are conveyed to a station on the inbound conveyor line where a substance is applied to a first portion of the parts. The parts are then conveyed to an inverting apparatus which inverts the parts onto another tray screen so that the relative locations of the parts on the tray screen are maintained to prevent masking each other when the substance is applied to a second portion of the parts. The parts are then conveyed to another location where the upwardly disposed second portions of the parts receive a coating of the substance. The inverting operation is accomplished by the inverting apparatus, slideably engaged to a lateral mobile assembly, which engages the parts tray from the conveyor within a lower tray receptacle. The parts are clamped between the lower tray and an upper screen tray removably engaged in an upper tray receptacle. In order to fix the locations of differently sized parts on the tray during rotation and movement of the carrier frame, during the clamping operation, a compliant material such as vertical bristles, disposed above and below the tray screens, is displaced through the screen holes to engage the parts thereabout.

TECHNICAL FIELD 
The present invention relates to apparatus and methods for engaging a 
workpiece, and more particularly to apparatus and methods for engaging and 
spatially reorienting a workpiece to accomplish an operation thereon such 
as applying a substance, such as paint, to the surface of the workpiece. 
BACKGROUND OF THE INVENTION 
The painting of mechanical parts may be accomplished by manually placing 
the parts on an underlying platform, applying paint to the exposed 
surfaces of the parts, allowing the parts to dry and then individually 
turning the parts over onto the platform and applying paint to the 
remaining unpainted portions. When painting a large number of parts, this 
procedure is very time consuming. In addition, the procedure is expensive 
because typically the parts are inverted by hand. 
Conventional apparatus and methods have been disclosed for engaging and 
supporting a workpiece. In U.S. Pat. No. 3,681,835--Evans, et al, there is 
disclosed a wire mesh jig board for preparing electronic assemblies 
including a pair of spaced apart parallel screens which are adapted to 
receive pin pairs therethrough for engaging an electronic cable to the 
board. 
In U.S. Pat. No. 4,121,817--Pavlovsky, there is disclosed an apparatus for 
engaging an irregularly shaped workpiece including a lower support plate 
having holes therein arranged to receive vertical support members of 
various heights to support a workpiece for retention thereof in a fixed 
relationship with a support plate by an upper opposing clamp. 
In U.S. Pat. No. 3,463,478--Hennessey, there is disclosed an apparatus for 
supporting a workpiece in a selected position including a base having 
openings for receiving pins therein which support the workpiece at a 
desired orientation relative to the base. 
In U.S. Pat. No. 4,098,046--Papa, there is disclosed a guide frame for the 
retention of slideable articles wherein the guide frame includes top and 
bottom members each having opposing cantilevered ribs terminating in 
opposing parallel spaced apart bars which form top and bottom channels for 
receiving and engaging the article therein. 
In U.S. Pat. No. 2,621,807--Rendich, there is disclosed an apparatus for 
positioning and retaining display devices including a base member having 
spaced apart openings therein for receiving support members at 
predetermined locations to engage and accurately position a display device 
on the base. 
In U.S. Pat. No. 3,559,980--Terai, et al, there is disclosed a system for 
adjusting the position of a plurality of jigs for supporting several 
workpieces in proximate relationship prior to welding the workpieces 
together wherein the controller moves the jigs vertically to form a 
support conforming to the shape of the workpiece for receiving the 
workpiece thereon. 
In U.S. Pat. No. 3,175,820--Schiler, there is disclosed a rotary table for 
rotatably supporting workpieces thereon wherein threaded support elements 
are vertically adjusted relative to the table to receive and support the 
workpiece thereon. 
In U.S. Pat. No. 3,178,168--Abernathy, there is disclosed an apparatus for 
positioning and supporting a container including a base having receptacles 
therein for receiving and supporting upright dowels to receive an inverted 
box thereon in order to perform operations on the box. 
In U.S. Pat. No. 3,181,858--Daniels, there is disclosed a support for a 
workpiece including a plurality of yielding members which are resiliently 
biased to a vertical position, but which yield to a portion of the 
workpiece extending below the plane thereof when the workpiece slides 
across the top of the support, and then which return to an erect position. 
In U.S. Pat. No. 3,442,251--Perkel, there is disclosed an apparatus for 
coating articles including a container having a rotary shaft supporting 
opposing adjustable arm members forming a grid structure for engaging the 
articles therebetween, and a sprayer assembly for applying a solution to 
the article as it is rotated in the container. 
SUMMARY OF THE INVENTION 
In order to avoid performing each step of the painting process manually, 
automated equipment may be used to increase the speed of the painting 
operation and reduce the concurrent expense. It is proposed herein to 
place the parts individually on a first conveyor which supports the parts 
and carries them to a first painting location where paint is applied to 
the exposed surfaces. The parts are dried and then automatically inverted 
onto a second conveyor which carries the parts back to the first location, 
or to a second painting location where paint is applied to the unpainted 
surfaces. It is desirable, therefore, to automatically remove the 
partially painted parts from the first conveyor, invert the parts, and 
then place the parts onto the second conveyor so that the painting can be 
completed. It is also desirable that during the inversion process, each 
part retain its location relative to the other parts so that the parts are 
not covering each other when being painted. However, the designated parts 
to be painted may be of different sizes and shapes wherein some extend 
upwardly to different vertical heights. It is desirable, therefore, that 
these parts of varying sizes and shapes be automatically removed from a 
conveyor assembly, engaged and inverted in such a manner so that they 
retain their relative locations. 
The present invention, therefore, comprises apparatus for engaging a 
workpiece having first and second surfaces. The apparatus includes first 
and second workpiece engaging means disposed in a spaced apart 
relationship. The first engaging means has a first surface, a second 
surface, and at least one through opening extending between the first and 
second surfaces. The apparatus also includes means for positioning the 
first and second engaging means to engage the first and second surfaces, 
respectively, of the workpiece between the second surface of the first 
engaging means and the second engaging means. Also included are means to 
move compliant means through the opening at the first surface of the first 
engaging means in a first direction such that the compliant means extends 
through the opening and beyond the first surface of the second engaging 
means to engage the workpiece. The first engaging means includes resilient 
means disposed between a noncompliant portion of the compliant means and 
the first surface of the first engaging means so that the movement of the 
compliant means in the first direction engages the resilient means between 
the compliant means and the first engaging means to cause corresponding 
movement of the first engaging means in the first direction to engage the 
workpiece between the first engaging means and the second engaging means 
thereby restricting further movement of the first engaging means in the 
first direction. The movement of the compliant means continues in the 
first direction to cause (i) compression of the resilient means between 
the noncompliant portion and the first surface, and (ii) penetration of 
the compliant means through the opening extending between the first and 
second surfaces. 
The invention also comprises apparatus for engaging and rotating a 
workpiece, having first and second surfaces, so that a surface operation 
can be perforated on the first and second surfaces. The apparatus 
comprises first and second workpiece engaging means disposed in a spaced 
apart relationship. The first engaging means includes a first surface, a 
second surface, and at least one through opening extending between the 
first and second surfaces. Also included are means for positioning the 
first and second engaging means, after a surface operation has been 
performed on the first surface of the workpiece, to engage the first and 
second surfaces, respectively, of the workpiece between the second surface 
of the first engaging means and the second engaging means. Means are 
included for moving a compliant means operatively connected to the first 
engaging means, in a first direction through the opening at the first 
surface of the first engaging means in a manner that the compliant means 
extends through the opening and beyond the surface to engage the workpiece 
and to hold the workpiece securely relative to the first and second 
engaging means. The apparatus also includes means for rotating the first 
and second engaging means and the compliant means in engagement with the 
workpiece, to invert the workpiece; and means for moving the compliant 
means away from the workpiece so that the compliant means is disengaged 
from the workpiece. Also included are means for positioning the first and 
second engaging means to disengage the workpiece from between the second 
surface of the first engaging means and the second engaging means in 
preparation for performance of a surface operation on the second surface. 
In an exemplary embodiment, the present invention comprises apparatus for 
engaging and rotating a workpiece having first and second surfaces so that 
a surface operation can be performed on the first and second surfaces. The 
workpiece is removably supported on a first surface of a platform also 
having a second surface, and at least one through opening extending 
between the first and second surfaces thereof. The apparatus includes 
first platform engaging means for removably engaging the platform after a 
surface operation has been performed on the first surface of the 
workpiece. Workpiece engaging means are disposed in a spaced apart 
relationship from the platform engaging means. The apparatus also includes 
means for positioning the platform engaging means and the workpiece 
engaging means to engage the first and second surfaces of the workpiece; 
as well as means for moving compliant means, operatively connected to the 
platform engaging means, in a first direction through the opening at the 
first surface of the platform in a manner that the compliant means extends 
through the opening and beyond the second surface of the platform to 
engage the workpiece and to hold the workpiece securely relative to the 
platform and the workpiece engaging means. Also included are means for 
rotating the platform engaging means, the workpiece engaging means and the 
compliant means to invert the workpiece. Means are included for moving the 
compliant means away from the workpiece so that the compliant means is 
disengaged from the workpiece, as well as means for positioning the first 
and second engaging means to disengage the workpiece from between the 
platform and the workpiece engaging means to permit the platform to be 
disengaged from the platform engaging means in preparation for performance 
of a surface operation on the second surface of the workpiece. 
The compliant means and the first and second engaging means may be slidably 
engaged to a support member of a frame means. The workpiece engaging means 
includes a second platform engaging means for removably engaging a second 
platform having first and second surfaces and at least one through opening 
extending between the first and second surfaces of the second platform. 
Rotation of the frame member and inversion of the workpiece causes the 
workpiece to be supported on the second platform in preparation for 
disengaging the second platform from the second platform engaging means in 
preparation for performance of said surface operation on said second 
surface of said workpiece. 
The present invention also includes a method for engaging a workpiece 
comprising the steps of placing first and second workpiece engaging means 
in a spaced apart relationship from the workpiece, the first workpiece 
engaging means having a first surface, a second surface and at least one 
through opening extending between the first surface and the second 
surface. The first and second engaging means are positioned to engage the 
first and second surfaces, respectively, of the workpiece between the 
second surface of the first engaging means and the second engaging means. 
Compliant means are moved in a first direction through the opening at the 
first surface of the first engaging means in a manner that the compliant 
means extends through the opening and beyond the second surface to engage 
the workpiece and to hold the workpiece securely to the first and second 
engaging means. 
The present invention also comprises a method for applying a substance to a 
workpiece. The method comprises the steps of locating the workpiece on a 
first support member at a first selected orientation of the workpiece 
wherein a first portion of the workpiece is oriented toward the first 
support member, and a second portion of the workpiece is oriented away 
from the first support member. The workpiece is automatically conveyed to 
a first location for applying the substance to the second portion of the 
workpiece. The method also includes the steps of automatically receiving 
the first support member and engaging the workpiece between the first 
support member and a second support member so that the second portion of 
the workpiece is oriented against the second support member. The first 
support member, the second support member and the workpiece are 
automatically inverted to a second selected orientation wherein the second 
portion of the workpiece is supported on the second support member, and 
the first portion is oriented away from the second support member. The 
workpiece is automatically disengaged from between the first support 
member and the second support member, and the second support member 
automatically removed and the workpiece is conveyed to the first location 
for applying the substance to the first portion of the workpiece. 
It is therefore an object of the present invention to provide apparatus and 
methods for engaging a workpiece.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIGS. 1 through 3 there is shown an exemplary embodiment of 
the present invention comprising a conveyor assembly for carrying trays 
supporting small parts to be painted. The conveyor assembly includes an 
inbound conveyor 20 having spaced apart parallel conveyor chains 22 
adapted to receive a plurality of trays 24 thereon. Each tray 24 (FIG. 2) 
includes a rectangular tray frame 26 having opposing parallel longitudinal 
members 28, and opposing parallel lateral members 30, which engage a 
screen mesh 32 therebetween; screen mesh 32 having a first surface 36 and 
an opposing surface 38 (FIG. 3). Tray 24 receives parts 42, mechanically, 
or manually as shown pictorially in FIG. 1, onto first surface 36, and 
tray 24 is then placed onto conveyor 20 to convey parts 42 for painting 
downline thereof. Each part 42 (FIG. 2) includes a first upper portion 44 
which is exposed for painting, a second lower portion 45 (FIG. 3) which is 
disposed against screen upper surface 36, and sides 46 between first 
portion 44 and second portion 45. Trays 24, including part 42 and a larger 
part 42' (FIG. 4), are transferred onto inbound conveyor 20 at a station A 
shown in FIG. 1, and engaged therewith to be conveyed through a first 
painting compartment 48 as shown in FIG. 4A where the upwardly directed 
exposed portions 44, 44' and sides 46, 46' of parts 42, 42' are painted. 
Tray frame 26 includes slotted receptacles 49 at opposing surfaces 50, 51 
thereof which are adapted for engaging conveyor chain 22 in a manner to be 
described later in order to secure tray 24 to conveyor chains 22. After 
the exposed portions of parts 42, 42' have been painted, tray 24 is then 
conveyed into an oven compartment 54 where the painted surfaces of parts 
42, 42' are dried. After parts 42, 42' have been dried, tray 24 is 
conveyed downline to an inverter assembly 56 which is slideably engaged to 
a lateral mobile assembly 107. Tray 24 moves horizontally movement, when 
viewing FIG. 1, along an axial centerline 109 of conveyor line 20 from 
left to right. Inverter assembly 56 then moves in a leftward direction, 
when viewing FIG. 1, along centerline 109 toward conveyor line 20 to an 
"engaged" position at a station B proximate to an end of conveyor line 20 
as shown in FIGS. 1 and 4B to feet and receive tray 24 therewithin. 
After engaging tray 24, inverter assembly 56 moves in a rightward direction 
along centerline 109, when viewing FIG. 1, away from conveyor line 20 to a 
station C shown in FIGS. 1 and 4C. At station C, inverter assembly 56 is 
rotated about axis 109 through 180.degree. of travel in order to invert 
parts 42 so that parts 42, 42' are supported on a tray 24' which prior to 
inversion was located above tray 24. In this manner and second portions 
45, 45' of parts 42, 42' are oriented in an upward direction. Lateral 
mobile assemb1y 107, which is slideably engaged to a fixed main support 
assembly 110 along an axis 113 perpendicular to axis 109, is then moved in 
a downward direction, when viewing FIG. 1, along axis 113 to a station D 
shown in FIGS. 1 and 4D. At station D inverter assembly 56 is aligned with 
an axial centerline 114 of a second outbound conveyor 116 which is spaced 
apart from and parallel to first conveyor line 20 and which is movable in 
both a right to left direction and left to right direction. Inverter 
assembly 56 then moves in a leftward direction along axis 114 toward 
conveyor line 116 to a station E proximate to an end of conveyor 116 and 
shown in FIG. 4E, where tray 24' supporting parts 42, 42' is engaged by 
conveyor 116. Inverter assembly 56 then returns to station D as shown in 
FIG. 4F, and tray 24' is carried in a right to left direction by conveyor 
line 116 through a second painting compartment 120. The upwardly oriented, 
unpainted portions 45, 45' of parts 42, 42' are painted in painting 
compartment 120 and then conveyed further downline on tray 24' by conveyor 
116 to oven 54 where parts 42, 42' are dried. After drying, the parts 42, 
42' are carried downline on tray 24' by conveyor 116 to station F where 
tray 24' and parts 42, 42' are unloaded from conveyor line 116. All 
operations described herein are automatically performed, except for 
loading parts 42, 42' onto tray 24, and loading tray 24 onto conveyor line 
20 at station A, and removing tray 24' from conveyor line 116 at station 
F. If desired, these operations may also be accomplished automatically by 
machinery which is not part of the present invention. lateral mobile 
assembly 107 and inverter assembly 56 then return to station C in 
preparation for receiving the next tray 24 carrying parts thereon. 
Referring to FIGS. 5 and 6, a brief introduction to inverter assembly 56 is 
provided in order to understand the inversion operation at station C more 
clearly. FIGS. 5 and 6 show a simplified embodiment of inverter assembly 
56 which will be described in more detail later. It should be appreciated 
that in describing the components of the present invention, their relative 
positions defined as "upper" and "lower", when viewing FIGS. 2 through 6, 
will be used to provide a clearer description, with the understanding, 
however, that after inversion of these components, the descriptive labels 
"upper" and "lower" will no longer be descriptive of their relative 
positions. When at station B, inverter assembly 56 receives tray 24 from 
conveyor 20 for engagement in a first lower tray receptacle 60. The second 
upper screen tray 24' is removably slideably engaged in a second tray 
receptacle 86 of inverter assembly 56. A clamping action is provided by 
upward vertical movement of tray 24 and downward vertical movement of tray 
24' to hold parts 42, 42' therebetween. Clamping movement of trays 24, 24' 
is halted, as shown in FIG. 6, by engagement with part 42'. In order to 
prevent differently sized parts 42, 42' from moving during movement of 
inverter assembly 56, a first compliant material 372 and a second 
compliant material 372', such as vertical bristles, are displaced through 
holes in screens 32, 32', as shown in FIG. 6B, to engage parts 42, 42' 
therebetween. Clamping movement of trays 24, 24' results from vertical 
movement of tray receptacles 60, 86. Compliant materials 372', 372 are 
supported from upper, lower support bases 246, 315, respectively. Upper 
support base 246, including compliant material 372', is disposed above 
tray 24' and is attached to an upper platen 220 thereabove. Lower support 
base 315, including compliant material 372, is disposed below tray 24 and 
attached to a lower platen 300 therebelow. Movement of upper, lower 
platens 220, 300 in the "clamped" direction is initiated by a rack and 
pinion (not shown in FIGS. 5 and 6A through 6D). Vertical clamping forces 
are imparted to tray receptacles 86, 60 by vertical movement of upper, 
1ower platens 220, 300. When screens 32', 32 engage part 42' having the 
greatest vertical height, movement of screen trays 24', 24 and tray 
receptacles 86, 60 is halted. However, further clamping movement of 
platens 220, 300 and support bases 246, 315 including compliant material 
372', 372 therewith, is permitted to allow penetration of compliant 
material 372', 372 through the holes in screens 32', 32 and about parts 
42, 42' in a "clamped" position. 
When in the "clamped" position, inverter assembly 56 is then rotated 
180.degree. to an inverted position as shown in FIG. 6C. The compliant 
material 372', 372 engages parts 42, 42' to prevent their movement during 
rotation of inverter assembly 56. After inversion, platens 220, 300 are 
moved by the rack and pinion assembly vertically away from each other, 
causing screen trays 24', 24 and compliant materials 372', 372 to separate 
to locations shown in FIG. 6D. In the newly inverted position, screen tray 
24' supports parts 42, 42'. Screen 24' is then engaged by conveyor 116 and 
slideably removed from tray receptacle 86 for conveyance downline by 
second conveyor line 116. Therefore, when inverter assembly 56 returns to 
station B (FIG. 1) to receive another tray from first conveyor line 20, 
tray receptacle 86 now occupying the lower position is empty in 
preparation to receive the next tray from conveyor line 20. In addition, 
screen tray 24, engaged by tray receptacle 60, is located above the newly 
received tray to provide a clamping means for the newly received parts. 
In an exemplary embodiment, compliant material 372, 372' comprises 
bristles, made out of nylon or the like, which extend vertically through 
the holes in screens 32, 32', respectively, from support bases 315, 246, 
respectively, in the "clamped" position. The bristles extend in a vertical 
direction adjacent to sides 46, 46' of part 42, 42', respectively, and 
engage upper, lower surfaces 44, 45 and upper, lower surfaces 44', 45' . 
As discussed previously, the part 42' having the greatest vertical height 
is held in position between screens 32, 32' with additional lateral 
support provided by the penetration of compliant material 372, 372'. The 
smaller part 42 is engaged at lower surface 45 and upper surface 44 by 
compliant material 372, 372', respectively, which in addition engages part 
42 at sides 46 thereof. It can be appreciated that the type of compliant 
material 372, 372' will depend upon the length of penetration required to 
engage the smaller parts 42. When the parts 42, 42' are generally of the 
same vertical height, a compliant material such as rubber may provide 
sufficient penetration to reach upper surface 44, lower surface 45 ahd 
sides 46. However, when parts 42, 42' are of different vertical heights, a 
bristle-type compliant material may be more suitable to provide the depth 
of penetration to engage upper surface 44, lower surface 45 and sides 46. 
A1though parts 42, 42' have been described herein and shown in the 
drawings, the present invention contemplates that numerous parts of 
varying sizes, shapes and vertical heights will be supported on screens 
32, 32' for operations described in the present invention. 
In order to describe the present invention in more detail, reference is 
made to FIG. 7 where inverter assembly 56 includes first lower tray 
receptacle 60 having opposing horizontally disposed parallel lower support 
ledges 62, 64 which have respective inner, outer surfaces 66, 68 and 70, 
72. Guide rails 74, 76 are disposed longitudinally along inner surfaces 
66, 70, respectively, for engaging a slotted channel 80 disposed about the 
perimeter of tray 24 along sides 82 thereof. Inverter assembly 56 includes 
second upper tray receptacle 86 disposed above first tray receptacle 60 
and comprising parallel horizontally disposed upper support ledges 90, 92; 
support ledge 90 having an inner surface 96 and an outer surface (not 
shown); support ledge 92 having an inner surface 100 and an outer surface 
102. Upper support ledge 90 is disposed in a parallel relationship above 
lower support ledge 62; likewise upper support ledge 92 is disposed in a 
parallel relationship with lower support ledge 64. Guide rails 104, 106 
are disposed longitudinally along respective inner surfaces 96, 100 for 
engaging slotted channel 80' disposed about the perimeter of tray 24' 
along sides 82' thereof. Tray 24' includes a tray frame 26' for supporting 
a screen mesh 32' having a first upper surface 36' and a second lower 
surface (not shown). Upon receipt of tray 24 within first tray receptacle 
60, first tray receptacle 60 is caused to move in an upward vertical 
direction while second tray receptacle 86 is caused to move in a downward 
vertical direction to engage part 42 rigidly therebetween in a "clamped" 
position. 
Inverter assembly 56 includes a carrier frame 150 having rear upper and 
lower horizontal support members 152, 154 which are joined at opposite 
ends thereof by rear vertical supports 156, 158 to form a rear frame 160. 
Perpendicularly disposed to rear frame 160 at opposite upper ends 161, 162 
thereof are upper forwardly extending sidearms 164, 166, respectively. 
Frame 150 also includes lower forwardly extending sidearms 167, 168 which 
are perpendicularly disposed to rear frame 160 below upper sidearms 164, 
166, respectively, at opposite lower ends 169, 170 (FIG. 10), 
respectively, of frame 160. Upper, lower sidearms 164, 167 (FIG. 7) and 
upper, lower sidearms 166, 168, respectively, are joined at the respective 
distal ends thereof by vertical support members 176, 178. 
In order to guide and support tray receptacles 60, 86 in their vertical 
travel between the "clamped" and "unclamped" positions, carrier frame 150 
includes a rearward vertical guide shaft 186 (FIG. 9) and a forward 
vertical guide shaft 188 (FIG. 7) engaged vertically between upper, lower 
carrier sidearms 164, 167; and a rearward vertical guide shaft 190 and a 
forward vertical guide shaft 192 engaged between upper, lower carrier 
sidearms 166, 168. Upper support ledge 90 at rear portion 193 thereof 
includes a passageway 195. Passageway 195 and the rear portion passageway 
of lower support ledge 62 are axially aligned to receive rear guide shaft 
186 therethrough for vertical slideable engagement therewith. Forward 
portions 197, 198 of upper, lower support ledges 90,62, respectively, 
include passageways 199, 200, respectively, which are axially aligned to 
receive guide shaft 188 therethrough for vertical slideable engagement 
therewith. Likewise, upper, lower support ledges 92, 64 at rear portions 
201, 202, respectively, include passageways 204, 206, respectively, which 
are axially aligned to receive rear guide shaft 190 therein for vertical 
slideable engagement therewith; and upper, lower support ledges 92, 64 at 
forward portions 207, 208, respectively, (FIG. 7) include passageways 209, 
210 which are axially aligned to receive forward guide shaft 192 for 
vertical slideable engagement therewith. 
Referring to FIG. 7, in order to impart a clamping force to upper, lower 
tray receptacles 86, 60, inverter assembly 56 includes upper platen 220 
having a rear support member 222 disposed in lower parallel relationship 
to upper horizontal support 152 of rear frame 160 and extending 
transversely between and proximate to upper sidearms 164, 166. Extending 
forwardly from rear support member 222 at opposite ends 224, 226 thereof, 
are platen upper support arms 230, 232, respectively, disposed parallel to 
and inboard of carrier upper sidearms 164, 66, respectively, and extending 
longitudinally approximately the length thereof. Disposed inboard of 
platen support arms 230, 232 and extending forwardly from platen rear 
support member 222 are support members 236; each longitudinal platen 
support member 236 having an upper surface 238 and a lower surface 240. 
Attached to lower surface 240 of platen support members 236 is an upper 
planar base member 246 Planar base member 246 extends longitudinally 
proximate to ends 248, 250 of upper sidearms 164, 166, respectively, and 
extends laterally substantially the distance between support arms 230, 
232, terminating at planar base member ends 254, 256, respectively. Base 
member end 254 (FIG. 9) is spaced inward from an imaginary plane extending 
vertically downward from an inner surface 257 of carrier sidearm 164 to 
define a channel 260; likewise planar base member end 256 is spaced inward 
from an imaginary plane extending vertically downward from an inner 
surface 262 of carrier sidearm 166 to define a channel 264. Channels 260, 
264 are sized to receive conveyor chains 22 and conveyor drive sprockets 
265 (FIG. 8), disposed in rotatable engagement therewith, when inverter 
assembly 56 is in the "clamped" position. 
In order to slideably engage upper platen 220 (FIG. 7) to guide shafts 186, 
188, 190, 192 between upper carrier sidearms 164, 166 and tray upper 
support ledges 90, 92, respectively, platen upper support arm 230, at 
rear, forward ends 270, 248, respectively thereof, includes guide blocks 
274 (FIG. 9), 276 (FIG. 7), respectively, which are attached to an outer 
surface 278 of platen support arm 230. Guide blocks 274, 276 include 
passageways (not shown) vertically therethrough for engaging guide shafts 
186, 188, respectively, for vertical slideable movement thereon. Likewise, 
platen upper support arm 232 (FIG. 7), at rear, forward ends 284, 286 
(FIG. 8), respectively thereof, include guide blocks 288, 290, attached to 
outer surface 292 thereof. Guide blocks 288, 290 include passageways (not 
shown) vertically therethrough for engaging guide shafts 190, 192, 
respectively, for vertical slideable movement thereon. 
In addition, an upward opposing clamping force is provided by a lower 
platen 300 (FIG. 7) having a rear lower support member 302 horizontally 
disposed parallel to rear upper support member 152 extending laterally 
proximate to carrier lower sidearms 167, 168. Extending forwardly from 
rear support member 302 at opposite ends 304, 306 (FIG. 11) thereof are 
platen lower support arms 310, 311 disposed parallel to and inboard of 
carrier lower sidearms 167, 168 and extending longitudinally approximately 
the length thereof. Disposed inboard of platen lower support arms 310, 311 
and extending forwardly from rear lower support member 302 are platen 
lower longitudinal support members 312, each having an upper surface 313 
and a lower surface 314. Attached to upper surface 313 is a lower planar 
base member 315. Planar base member 315 extends longitudinally beyond an 
end 320 of platen lower support arm 311, and extends laterally 
substantially the distance between platen support arms 310, 311. Lower 
base member 315 includes opposite end surfaces 322, 324. End surface 322 
is spaced inward from an imaginary plane extending vertically upward from 
an inner surface 323 of platen lower support arm 310 to define a channel 
330 therebetween; likewise end surface 324 is spaced inward from an 
imaginary plane extending vertically downward from an inner surface 332 of 
a support arm 311 to define a channel 334. Channels 330, 334 are sized to 
receive conveyor chains 22 and conveyor drive sprockets 265 for rotatable 
movement therein. 
In order to slideably engage lower platen 300 to guide shafts 186, 188, 
190, 192 between carrier lower sidearms 167, 168 and tray lower support 
ledges 62, 64 (FIG. 7), respectively, platen lower support arm 310 (FIG. 
11) at rear, forward ends 340, 318, respectively thereof, include rear 
guide block 344, forward guide block 346 attached to an outer surface 348 
of platen support arm 310. Rear guide block 344 and forward guide block 
346 include passageways (not shown) vertically therethrough for engaging 
guide shafts 186, 188, respectively, (FIGS. 7 and 11) for vertical 
slideable movement thereon. Likewise, platen lower support arm 311 at 
rear, forward ends 351, 320, respectively thereof, includes guide blocks 
354, 356 attached to an outer surface 358 of support arm 311. Guide blocks 
354, 356 include passageways (not shown) vertically therethrough for 
engaging guide shafts 190, 192 for vertical slideable movement thereon. 
Referring to FIGS. 8 and 10, conveyor 20 includes a plurality of sprocket 
assemblies 265 engaged to conveyor chains 22 for supporting conveyor 20 
and causing longitudinal movement thereof. Sprocket assemblies 265 are 
rotatably mounted to vertical support members 364 which are anchored to 
the ground. Conveyor chains 22 include a horizontal support floor member 
366 disposed below an upper segment 368 of conveyor 20 to prevent sagging 
thereof due to the weight of conveyor chains 22. Floor member 366 is 
supported by vertical support members 369 anchored to the ground. Conveyor 
upper segments 368 (FIG. 8) are disposed above lower platen 300 in 
alignment with carrier lower support ledges 62, 64 in order to introduce 
tray slotted channels 80 into receptacle guide rails 74, 76. Trays 24 are 
bevelled at corners 370 of tray frame 26 in order to assist in guiding 
trays 24 onto guide rails 74, 76. 
As discussed previously, it is desirable that during the inversion of parts 
42, 42', that their relative positions remain fixed so that there is no 
bunching or masking of parts 42, 42' when passing through painting 
compartment 120 on outbound conveyor line 116 (FIG. 1). When parts 42 are 
of the same size and shape, the clamping of upper, lower screens 32, 32' 
may be sufficient to fix the positions of parts 42 during inversion. 
However, when parts 42 are of different sizes and shapes, such as for 
example parts 42, 42' shown in FIG. 7, screens 32, 32' will be prevented 
from further travel in the "clamping" direction of travel by part 42' 
which has the greater vertical height, thereby leaving part 42 free to 
move when inverter assembly 56 is rotated to an "inverted" position. In 
order to retain the relative positions of different sized and shaped parts 
42, 42' during rotation of inverter assembly 56, upper base member 246 
includes a lower surface 371 for attaching compliant material 372' 
thereto. Likewise, lower base member 315 includes an upper surface 373 for 
engaging thereto compliant material 372. 
Referring to FIGS. 7 and 10, upper base member 246 and upper tray 
receptable 86 are maintained in a spaced apart relationship by resilient 
spacer elements 378 engaged between upper guide blocks 274, 276, 288, 290 
and tray upper support ledges 90, 92, respectively. Likewise, lower base 
member 315 is maintained in a spaced apart relationship from lower tray 
receptacle 60 by resilient spacer elements 380 engaged between lower guide 
blocks 344, 346, 354, 356 and lower support ledges 62, 64, respectively. 
Therefore, as a clamping force is applied to platen upper support arms 
230, 232 and platen lower support arms 310, 311 causing them to move 
vertically toward each other, upper support ledges 90, 92 and lower 
support ledges 62, 64 engaged therewith by resilient members 378, 380, 
respectively, are caused to move in a like direction until engaging part 
42'. As the downward vertical movement of support ledges 90, 92 and the 
upward vertical movement of lower support ledges 62, 64 are halted by 
engagement of part 42' between upper screen 32' and lower screen 32, the 
upward movement of lower base member 315 and the downward movement of 
upper base member 246 continues causing resilient members 378, 380 to 
compress. The clamping movement of upper base members 246 and lower base 
member 315 continues until the opposing vertical forces caused by 
compression of resilient members 378, 380 and engagement of parts 42 
between compliant material 372, 372' is sufficient to prevent further 
clamping movement of base members 246, 315. As the clamping movement of 
upper, lower base members 246, 315 continues after the clamping movement 
of screens 32', 32 is halted, compliant material 372', 372 is displaced 
through the holes in screens 32', 32, respectively, to fixedly engage the 
smaller size parts 42 therebetween. It is desirable therefore that 
compliant material 372, 372' be sufficiently pliable to penetrate through 
screens 36, 36' to locations adjacent to and in contact with parts 42, 
42', yet be sufficiently rigid to engage parts 42, 42' and to prevent 
vertical or horizontal movement thereof so that the relative positions of 
parts 42, 42' are maintained during rotation of inverter assembly 56. When 
parts 42, 42' are of relatively uneven sizes and shapes, it is preferable 
to employ nylon bristles or the like, illustrated in FIG. 7, as a 
compliant material 372', 372 wherein bristles 384 are vertically mounted 
to upper, lower base members 246, 315 for vertical penetration through 
screens 36', 36. The lengths of bristles 384 are dependent upon the depth 
of penetration required through screens 36', 36 to fixedly engage parts 
42, 42'. On the other hand, if the parts 42 are of more uniform size and 
shape, a foam rubber material or the like may be employed as a compliant 
material 372, 372' due to the fact that the depth of penetration through 
screens 36, 36' is not as critical. 
An additional advantage of the apparatus and methods of the present 
invention is the engagement of compliant material 372, 372' about parts 
42, 42' instead of a rigid material, e.g., metal, to avoid scratching or 
marring the freshly painted surfaces of parts 42. In addition, the 
clamping pressure of screens 36, 36' against the largest part 42' may be 
reduced because the compliant material 372, 372' also engages part 42' to 
assist in holding it in position. 
In an exemplary embodiment illustrated in FIG. 8, each resilient member 378 
includes a helical spring 388, having an upper end 390 and a lower end 
392, axially disposed about a bolt 394 disposed in a vertical passageway 
396 in each upper guide block 274, 276, 288 and 290. Each bolt 394 
includes a threaded end 398 engaged to upper support ledges 90, 92, and a 
head portion 400 engaged within a counterbored passageway 402 in 
communication with passageway 396 through upper surfaces 404 of upper 
platen guide blocks 274, 276, 288 and 290. Likewise, each resilient member 
380 includes a helical spring 406, having an upper end 408 and a lower end 
410, axially disposed about a bolt 412 which is disposed in a vertical 
passageway 414 in each lower platen guide blocks 344, 346, 354 and 356. 
Each bolt 412 includes a threaded end 416 engaged to lower support ledges 
90, 92 and a head portion 418 engaged within a counterbored passageway 420 
in communication with passage 414 through lower surfaces 422 of lower 
guide blocks 344, 346, 354 and 356. Therefore, as base members 246, 315 
travel toward each other in a clamping vertical direction, screens 36, 36' 
move therewith until the clamping movement of screens 36, 36' is halted 
wherein base members 246, 315 continue in a clamping direction compressing 
springs 388, 406 and displacing bolts 394, 412 vertically through 
counterbored passageways 402, 420. 
In order to move base members 246, 315 and screens 36', 36 between the 
"clamped" and "unclamped" positions, upper platen 220 includes a rack 426 
(FIG. 7) depending downwardly from upper rear horizontal support bar 222 
and having teeth 430 along an inner edge 432 thereof. Lower platen 300 
includes a rack 434 depending upwardly from rear horizontal support 302 
having teeth 436 along an inner edge 438 thereof. Teeth 430, 436 of rack 
members 426, 434, respectively, engage a pinion gear 442 therebetween 
which is rotated by a shaft 444 (FIG. 8) engaged thereto and disposed in 
parallel relationship with sidearms 164, 166 of carrier frame 150 so that 
rotation of pinion gear 442 in a counterclockwise direction, when viewing 
FIG. 10, causes upward vertical movement of lower platen 300 and downward 
vertical movement of upper platen 220 to impart to base members 246, 315 
and screens 36', 36 movement in the "clamping" direction. Rotation of 
pinion gear 442 in the clockwise direction causes base members 246, 314 
and screens 36, 36' to move vertically to the "unclamped" position. 
Rotation of pinion gear 442 is effected by a rotary actuator motor 446 via 
drive shaft 444 fixed to pinion gear 442. 
In order to rotate inverter assembly 56 to the "inverted" position, a 
spider 462 (FIG. 8) is attached to rear frame 160 at rear upper support 
152 and rear lower support 154. Spider 462 includes a receptacle 464 
through the axial center thereof for engaging a shaft 466 in a fixed 
relationship therewith. Rotation of shaft 466 is effected by a rotary 
actuator motor 468 having a drive shaft 469 extending horizontally 
therefrom, which has a pinion 470 fixed at the distal end thereof. Pinion 
470 is rotatably engaged to a gear wheel 474 attached to proximal end 476 
of shaft 466. Shaft 466 is supported on an inverter assembly base 478 at 
an upper surface portion 480. Upper surface portion 480 includes a forward 
shaft support 482 and a rear shaft support 484 including journal bearings 
486 therein to allow rotation of shaft 466 about an axis 490 thereof. 
Locking collars 492, disposed circumferentially about shaft 466 inboard of 
shaft supports 482, 484, prevent axial displacement of shaft 466 and 
inverter assembly 56. Inverter assembly base 478 includes an upper frame 
portion 496 having a rear support wall 497 and sidewalls 498, 499 (FIG. 9) 
depending vertically downward from upper surface 480, and a forward 
support wall 500 (FIG. 8) depending downwardly from upper surface 480 to a 
location below carrier frame 150, and then depending downwardly and 
forwardly therefrom to define a lower frame 502 which includes a 
horizontal bottom support 504 having laterally extending edges 505 and is 
integrally joined to rear wall 497, sidewalls 498, 499 and forward support 
wall 500. Rotary actuator motor 468 is secured to a mounting platform 506 
which is attached to rear wall 497 of inverter assembly base 478 proximate 
to upper surface portion 480. 
Referring to FIGS. 8 and 10, lower frame 502 is slideably engaged to guide 
frame 108 of lateral mobile assembly 107. Guide frame 108 includes 
vertical side portions 512, 513 which define a guide channel 514 having an 
axis which is disposed parallel to conveyor centerline 109 (FIG. 1). Side 
portions 512, 513 at the respective inner surfaces thereof, include a 
plurality of upper and lower rollers 515 for rotatably engaging 
horizontally extending edges 505 of bottom support flange 504 
therebetween. Rollers 515 support inverter assembly base 478 and inverter 
assembly 56 within guide channel 514 for longitudinal movement between the 
"engaged" position, illustrated in FIG. 8, wherein the majority of the 
length of lower tray receptacle 60 is disposed above conveyor chains 22 to 
receive tray 24 therein, and the "disengaged" position wherein inverter 
assembly 56 is displaced in a rightward direction, when viewing FIG. 1, 
away from conveyor chains 22. Displacement of inverter assembly between 
the "engaged" and "disengaged" positions may be accomplished in a manner 
know to those of ordinary skill in the art. Preferably however, there is 
incorporated a rodless linear drive cylinder assembly indicated at 521 
which is manufactured by Festo Pneumatic Company, New York. Linear drive 
assembly 521 includes a cylindrical sleeve portion 522 mounted to main 
support assembly 110 in a direction parallel to axis 109 (FIG. 1). Sleeve 
portion 522 is mounted to a forward end of main support assembly 110 by a 
support arm 524 depending downwardly from sleeve portion 522, and at a 
rear end (not shown) of main support assembly 110 in a like manner. A 
cylindrical yoke 526 is slidably engaged to sleeve portion 522 for axial 
movement thereon. Yoke 526 is engaged to flange 504 of inverter assembly 
base 478 by bolts 527. Sleeve portion 522 axially encloses a double acting 
piston therein (not shown) which includes a magnetic portion which is 
magnetically coupled to yoke 526 so that axial movement of the double 
acting piston within the sleeve portion 522 by a liquid or gas acting 
against the piston, causes axial movement of yoke 526 and inverter 
assembly base 478/inverter assembly 56 therewith 
Lateral mobile assembly 107 (FIG. 10) includes a pair of downwardly 
depending parallel support flanges 529 (only one of which is shown) which 
define a guide channel having an axis perpendicular to the axis of guide 
channel 514. Lateral mobile assembIy 107 is slideably engaged within and 
supported by main support assembly 110 along guide frame 112 thereof. 
Guide frame 112 includes a pair of parallel support sidewalls 540 (only 
one of which is shown) having a plurality of upper and lower rollers 542 
for rotatably engaging support flanges 529 at respective upper and lower 
surfaces thereof Rollers 542 support lateral mobile assembly 107 for 
longitudinal slideable movement therealong between station C, aligned with 
conveyor line 20, and station D, aligned with conveyor line 116 (FIG. 1). 
Displacement of lateral mobile assembly 107 between station C and station 
D is accomplished in a manner known to those of ordinary skill in the art; 
however preferably a linear drive cylinder assembly is utilized which is 
similar to drive cylinder assembly 521 described previously with reference 
to displacement of inverter assembly 56 between the "engaged" and 
"disengaged" positions. 
Other embodiments not disclosed herein, but which are encompassed within 
the spirit and scope of the present invention as disclosed herein are also 
included as part of the present application.