U.S. patent application number 16/357604 was filed with the patent office on 2019-09-12 for automated door assembly and methods, press used therewith, and adhesive therefor.
The applicant listed for this patent is Masonite Corporation. Invention is credited to George CUCCHI, Bei-Hong LIANG, Michael MACDONALD.
Application Number | 20190275780 16/357604 |
Document ID | / |
Family ID | 50513508 |
Filed Date | 2019-09-12 |
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United States Patent
Application |
20190275780 |
Kind Code |
A1 |
CUCCHI; George ; et
al. |
September 12, 2019 |
AUTOMATED DOOR ASSEMBLY AND METHODS, PRESS USED THEREWITH, AND
ADHESIVE THEREFOR
Abstract
A door pressing system for pressing interior passage doors,
exterior entry doors, bi-fold doors, and/or closet doors features a
multi-door pressing station including first and second presses, a
loading device, and a discharging device. The pressing station is
configured to alternatively move the first and second presses into
operative alignment with the loading and discharging devices. The
press in operative alignment delivers a pressed assembled door to
the discharging device and receives an assembled door layup to be
pressed from the loading device. The other press that is out of
operatively alignment presses an assembled door received therein.
Additional methods and systems are also provided.
Inventors: |
CUCCHI; George; (Odessa,
FL) ; LIANG; Bei-Hong; (Naperville, IL) ;
MACDONALD; Michael; (Batavia, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Masonite Corporation |
Tampa |
FL |
US |
|
|
Family ID: |
50513508 |
Appl. No.: |
16/357604 |
Filed: |
March 19, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15445040 |
Feb 28, 2017 |
10232599 |
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16357604 |
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14215693 |
Mar 17, 2014 |
9579818 |
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15445040 |
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61793524 |
Mar 15, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B32B 37/18 20130101;
E06B 3/822 20130101; E06B 3/7017 20130101; E06B 3/72 20130101; B27D
3/02 20130101; B27M 3/18 20130101; B27D 5/003 20130101; B30B 7/023
20130101 |
International
Class: |
B32B 37/18 20060101
B32B037/18; B27M 3/18 20060101 B27M003/18; B27D 5/00 20060101
B27D005/00; B30B 7/02 20060101 B30B007/02; B27D 3/02 20060101
B27D003/02; E06B 3/72 20060101 E06B003/72 |
Claims
1. A system for making doors comprising: a first pressing station
comprising a first press including a first set of platens, and a
second press including a second set of platens, each set of platens
respectively having at least one platen movable relative to the
other platen of the set of platens between an open state and a
closed state; the first pressing station configured to
alternatingly move the first and second presses between (i) a
loading/unloading position, in which one of the first and second
presses is in the open state to receive at least a first assembled
door in a layup state to discharge at least a second of assembled
door that has been pressed, and (ii) a pressing position, in which
the other of the first and second presses is in the closed state
for pressing a third of assembled door a first accumulator
configured to hold the assembled doors that have been pressed in
the first pressing station while an applied adhesive develops bond
strength; a second pressing station comprising a third press
including a third set of platens, and a fourth press including a
fourth set of platens, each set of platens respectively having at
least one platen movable relative to the other platen of the set of
platens between an open state and a closed state, the second
pressing station configured to alternatingly move the third and
fourth presses between (i) a loading/unloading position, in which
one of the third and fourth presses is in the open state to receive
at least a fourth of assembled door and to discharge at least a
fifth of assembled door that has been pressed, and (ii) a pressing
position, in which the other of the third and fourth presses is in
the closed state for pressing a sixth of assembled door; a second
accumulator configured to hold the assembled doors that have been
pressed in the second pressing station while the applied adhesive
develops bond strength; and a conveyor configured to carry doors
away from the first and second accumulators.
2. The system of claim 1, wherein the first and second presses are
movable vertically between the loading/unloading position and the
pressing position, and the third and fourth presses are movable
vertically between the loading/unloading position and the pressing
position.
3. The system of claim 1, further comprising hydraulics for moving
the first, second, third, and fourth presses vertically between the
loading/unloading position and the pressing position.
4. The system of claim 1, wherein the first pressing station is
configured to alternatively move the first and second presses after
each individual assembled door is delivered thereto, and wherein
the second pressing station is configured to alternatively move the
third and fourth presses after each individual assembled door is
delivered thereto.
5. The system of claim 1, wherein a conveyor configured to deliver
the first, second, third, or fourth press by the conveyor.
6. (canceled)
7. The system of claim 1, wherein each of the first and second
accumulators comprises a star conveyor.
8. The system of claim 1, further comprising: a first frame
assembly station configured to apply adhesive to door frame
components and to frame the door frame components and applied
adhesive into door frames; a first door assembly station configured
to secure door skins on opposites surfaces of the door frames
assembled in the first frame assembly station to provide assembled
doors to be delivered to the first or second press; a second frame
assembly station configured to apply adhesive to door frame
components and to frame the door frame components and applied
adhesive into door frames; and a second door assembly station
configured to secure door skins on opposites surfaces of the door
frames assembled in the second frame assembly station to provide
assembled doors to be delivered to the third or fourth press.
9. The system of claim 8, wherein the first and second presses are
movable vertically between the loading/unloading position and the
pressing position, and the third and fourth presses are movable
vertically between the loading/unloading position and the pressing
position.
10. The system of claim 8, further comprising hydraulics for moving
the first and second presses vertically between the
loading/unloading position and the pressing position, and for
moving the third and fourth presses vertically between the
loading/unloading position and the pressing position.
11. The system of claim 8, wherein the first pressing station is
configured to alternatively move the first and second presses after
each individual assembled door is delivered thereto, and wherein
the second pressing station is configured to alternatively move the
third and fourth presses after each individual assembled door is
delivered thereto.
12. The system of claim 8, wherein the first and second frame
assembly stations, and the first and second door assembly station
comprise conveyors.
13. (canceled)
14. (canceled)
15. (canceled)
16. The method of claim 21, further comprising: applying adhesive
to door frame components and framing the door frame components and
applied adhesive into door frames; securing first and second door
skins on opposites surfaces of the door frames to provide the
assembled doors in the layup state.
17. A system for making door frames, comprising: a core attachment
station for connecting an expandable core to a top rail and a
bottom rail; a robotic system comprising first and second grippers
configured to grip the top rail and the bottom rail, respectively,
and to draw the top and bottom rails apart from one another so as
to expand the connected expandable core; and a framing station
configured to connect first and second stiles to the top and bottom
rails and thereby form a door frame.
18. The system of claim 17, wherein the robotic system is
configured to connect the first and second stiles to the top and
bottom rails to form the door frame.
19. The system of claim 17, wherein the door frame has four
corners, and wherein the framing station comprises a jig system
configured to support and hold the door frame at the four
corners.
20. The system of claim 19, wherein the jig system comprises clamps
each comprising at least one respective nozzle for applying
adhesive to associated edges of the stiles and rails where the
stiles and rails abut one another.
21. A method of making doors, comprising: providing the system for
making doors of claim 1; successively delivering assembled doors in
a layup state to the first and second pressing stations;
discharging the pressed first assembled door from the first press
of the first pressing station and loading the second assembled door
in the layup state into the first press of the first pressing
station, and simultaneously pressing the third assembled door in
the second press of the second pressing station; moving the second
press into the loading/unloading position and the first press into
the pressing position; discharging the pressed fourth assembled
door from the third press of the second pressing station and
loading a fifth assembled door in the layup state into the third
press of the second pressing station, and simultaneously pressing a
sixth assembled door in the fourth press of the second pressing
station; and moving the fourth press the loading/unloading position
and the third press into the pressing position.
22. The method of claim 21, further comprising the step of holding
the pressed fourth assembled door in the second accumulator and
holding the pressed first assembled door in the first
accumulator.
23. The method of claim 22, further comprising the step of
transporting the assembled doors away from the first and second
accumulators via a conveyor.
24. The system of claim 8, wherein the first frame assembly station
comprises a first core attachment station for connecting a first
expandable core to a first top rail and a first bottom rail; a
first robotic system comprising first and second grippers
configured to grip the first top rail and the first bottom rail,
respectively, and to draw the first top and bottom rails apart from
one another so as to expand the connected first expandable core;
and a first framing station configured to connect first and second
stiles to the top and bottom rails and thereby form a first door
frame.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY
[0001] This application claims the benefit of priority to U.S.
provisional application No. 61/793,524, filed Mar. 15, 2013, the
complete disclosure of which is incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention is directed to systems and methods,
particularly automated systems and methods, for manufacturing doors
having first and second door facings and internal door frames,
multi-door pressing stations for use therewith, and adhesives and
doors processed and manufactured in the course of using the systems
and practicing the methods.
BACKGROUND
[0003] A door such as a hollow core door typically includes two
molded or flush door skins (sometimes called "door facings")
attached to opposite sides of an interior door frame, which is
typically made of wood but sometimes metal or composites. The door
facings are often molded from a composite of wood fiber and resin
compound, although fiberglass-reinforced polymeric door facings and
steel door facings are also known. The door frame typically
includes stiles and rails positioned around the perimeter of the
door that together form the frame. The interior of the door may
optionally include a core.
[0004] Manual assembly of doors is relatively labor intensive,
expensive, and subject to quality variations. During manual
assembly, a door facing is placed on a production table with its
intended exterior surface face down. Adhesive is applied, typically
via a roll coater, to the opposite sides of the stiles and rails.
The core and/or lock block(s), if any, are likewise coated. The
adhesively coated frame parts (stiles and rails) are then placed by
hand on the door facing on the table. Typically, the rails are
placed at the top and bottom of the door facing, and the stiles are
placed on opposite sides of the door facing. With the adhesive
applied to a second upward-facing side of the stiles and rails, a
second door facing is placed with its interior surface on the
second side of the frame. Another door facing is then placed with
its exterior surface face down on the previously assembled door and
the process repeated until a stack of doors has been assembled. In
this manual assembly process, the assembled doors should be handled
carefully, given that the components of the door are in a loose
"layup" state and can easily shift during transportation.
[0005] In the above-described manner, each successive door assembly
is stacked on top of the previous door assembly until a
predetermined quantity of door assemblies has been stacked. The
stack of door assemblies is then transported to and loaded in a
press. The press applies pressure to the entire stack for a period
of time sufficient to allow the adhesive to bond the door facings
to their respective frames. Conventional adhesives, such as
polyvinyl acetate, may take approximately thirty minutes or more to
cure or harden in the press before the door reaches "green"
strength. The door achieves "green" strength when the adhesive has
reached sufficient bonding strength to hold the door components
together for further handling.
[0006] Once green strength is achieved, the doors may be removed
from the press and moved to an in-process inventory until the
adhesive reaches adequate cure strength. Depending upon the
adhesive used and ambient conditions, the doors may need to remain
in inventory for a relatively long period of time, for example two
hours or more, or even as long as twenty-four hours, before the
adhesive reaches adequate bonding strength for final
processing.
[0007] After reaching adequate cure strength the doors are then
moved to a final processing station. Final processing includes edge
trimming the doors to customer specification and optional coating
and/or painting of door skins and exposed edges of the stiles and
rails around each door perimeter. Using this process, manufacturing
time for a door may be twenty-four hours or more, from the time
production is initiated to the resulting finished door is complete
and ready for delivery to a customer or user.
SUMMARY
[0008] According to an embodiment of the invention described in
greater detail below, a door pressing system is provided for
pressing doors, such as interior passage doors, exterior entry
doors, bi-fold doors, and/or closet doors. In accordance with this
embodiment, the system includes a multi-door pressing station
featuring a first press including a first set of platens, and a
second press including a second set of platens, each set of platens
respectively having at least one platen movable relative to the
other platen of the set of platens between an open state and a
closed state. The system further includes a loading material
handling and movement device configured to deliver assembled doors
in a layup state to the multi-door pressing station, and a
discharging material handling and movement device configured to
receive assembled doors that have been pressed by the multi-door
pressing station. The multi-door pressing station is configured to
alternatingly move the first and second presses between a
loading/unloading position and a pressing position. In the
loading/unloading position, one (e.g., the first) of the first and
second presses is in the open state and operative alignment with
the loading and discharging material handling and movement devices
to receive at least a first of the assembled doors in the layup
state delivered by the loading material handling and movement
device and to discharge at least a second of the assembled doors
that has been pressed to the discharging material handling and
movement device. In the pressing position, the other (e.g., the
second) of the first and second presses is in the closed state for
pressing a third of the assembled doors and is out of operative
alignment with the loading and discharging material handling and
movement devices. In one variation of this embodiment, the
multi-door pressing station is movable vertically between the
loading/unloading position and the pressing position. In another
variation of this embodiment, the first and second presses move
alternatingly between the loading/unloading position and the
pressing position.
[0009] In accordance with another embodiment, a system for making
any of passage doors, interior passage doors, exterior entry doors,
bi-fold doors and/or closet doors includes at least one framing
station, at least one adhesive coating station, at least one
assembly station, and at least one pressing station. The framing
station is configured to receive framing components such as rails
and stiles, and optionally lock blocks and/or cores, from delivery
component lines, especially automated delivery component lines, to
assemble door frames. The assembled door frames are sent to an
adhesive coating station which applies adhesive to the door frames.
The assembly station optionally orients the door skins and joins
first and second door skins to opposite surfaces of the frames to
form assembled doors. The pressing station includes a first press
and a second press for alternatingly pressing the assembled doors
and receiving/discharging the assembled doors prior to/after
pressing. After the assembled doors are discharged from the
pressing station, the pressed assembled doors may be received by a
non-linear accumulator.
[0010] In accordance with a further embodiment, a system is
provided for making door frames for at least one of interior
passage doors, exterior entry doors, passage doors, closet doors,
and/or bi-fold doors. The system includes a core attachment station
for connecting an expandable core to a top rail and a bottom rail,
and a robotic system, including a pair of grippers, for
respectively gripping top and bottom rails. The grippers draw the
top and bottom rails apart to expand the attached expandable core,
and the robotic system delivers the spaced apart top and bottom
rails and the expanded core to a framing station where the top and
bottom rails are attached to a pair of stiles to form a door frame.
The framing station may include a jig system for supporting and
holding the rails and stiles at the four corners of the door frame
where the rails and stiles abut during the attachment process. The
stiles and rails may be attached via quick-setting adhesive, a
mechanical fastener or a combination thereof to allow the frame to
be self-supporting.
[0011] In accordance with a further embodiment, a system is
provided for making door frames for at least one of interior
passage doors, exterior entry doors, passage doors, closet doors,
and/or bi-fold doors. The system includes a framing station
including a jig system for supporting and holding the rails and
stiles in the arrangement of a door frame. One or more lock blocks
may be secured to the door frame components, typically a stile,
prior to the attachment process at the jig station. Adhesive is
applied and/or mechanical fasteners are employed to join the rails,
stiles, and another other frame components so as to allow the frame
to be self-supporting. In accordance with this embodiment, a lock
block selected from a set of lock blocks may be adhered to a
respective stile prior to being delivered to the framing station.
Likewise, an expandable core selected from a set of expandable
cores may have its opposite ends adhered to respective pairs of
rails prior to being delivered to the framing station.
[0012] In accordance with a variation of the above and other
embodiments, the jig system includes four clamping members, one at
each of the four corners where the rails and stiles abut.
[0013] According to another variation of the above and other
embodiments, each of the clamping members further includes at least
one adhesive nozzle for applying adhesive to associated edges of
the stiles and/or rails where the rails and stiles abut.
[0014] In accordance with a further embodiment, a door pressing
system for making doors, in particular at least one of interior
passage doors, exterior entry doors, bi-fold doors, and/or closet
doors is provided. The system includes a multi-door pressing
station, which in turn includes at least a first press and a second
press, each having a pair/set of movable platens, for receiving
assembled doors. The pressing station is adapted so that one of the
presses performs a pressing operation on at least one assembled
door layup while the other press receives and/or discharges a
pressed second assembled door. A loading system is provided for
successively delivering door layups to the pressing station, and a
discharging system is downstream of the pressing station for
carrying off pressed assembled doors. The pressing station is
operable to selectively and alternatingly move the first and second
presses between a first (loading/unloading) position wherein one of
the presses is oriented to receive at least a first assembled door
layup from the loading system and discharge at least a pressed
second assembled door to the discharge system, and a second
(pressing) position in which the other of the presses is oriented
to press at least a third assembled door.
[0015] In accordance with a variation of the above and other
embodiments disclosed herein, presses of the multi-door pressing
station are movable in tandem with one another between the first
and second positions. Movement may be accomplished using suitable
hydraulic equipment, for example. The movement may be vertical
movement between upper and lower positions with correspond to the
first and second pressing positions, or vice versa.
[0016] In accordance with a further embodiment, a door assembly
system is provided for pressing and curing a plurality of assembled
doors including door skins adhered to a frame assembly. The door
assembly station features a multi-door pressing station including
at least first and second presses, each press having a pair of
movable platens, for moving the platens between and open state for
receiving door assemblies and a closed state for pressing door
assemblies. The pressing station applies pressure to each assembled
door in the first press to perform a pressing operation on the
assembled door(s) in the first press while receiving and/or
discharging one or more assembled doors into/from the second press.
A non-linear accumulator is downstream of the pressing station for
holding at least first and second pressed assembled doors during an
adhesive curing process.
[0017] In accordance with a further embodiment, the multi-door
pressing station delivers pressed assembled doors to an accumulator
in the form of a star conveyor that rotates a plurality of pressed
assembled doors through a circular path. The accumulator holds the
pressed assembled doors during a curing process.
[0018] In accordance with still a further embodiment, a system is
provided for making door frames for at least one of interior
passage doors, exterior entry doors, passage doors, bi-fold doors,
and/or closet doors. The system includes a core attachment station
for attaching an expandable core to a top rail and a bottom rail
with a first adhesive. A lock block attachment station connects at
least one lock block to a stile with a second adhesive, which may
be the same as or different than the first adhesive. A robotic
system delivers the top and bottom rails and the adhesively
attached core to a framing station where the top and bottom rails
are adhesively attached to a pair of stiles to form a door
frame.
[0019] Still another embodiment disclosed herein features a method
of assembling a door, which features: successively delivering
assembled doors in a layup state via a loading material handling
and movement device to a multi-door pressing station including
first and second presses; discharging at least a first of the
assembled doors having been pressed from the first press of the
multi-door pressing station to a discharging material handling and
movement device, and loading at least a second of the assembled
doors in the layup state into the first press of the multi-door
pressing station while the first press is in operative alignment
with the loading and discharging material handling and movement
devices, and simultaneously pressing at least a third of the
assembled doors in the second press of the multi-door pressing
station; moving the second press into operative alignment with the
loading and discharging material handling and movement devices; and
discharging the at least third of the assembled doors having been
pressed from the second press and loading at least a fourth of the
assembled doors in the layup state into the second press while the
second press is in operative alignment with the loading and
discharging material handling and movement devices, and
simultaneously pressing the at least second of the assembled doors
in the first press. The embodiment may further include applying
adhesive to door frame components and frame the door frame
components and applied adhesive into door frames; and securing
first and second door skins on opposite surfaces of the door frames
to provide the assembled doors in the layup state.
[0020] Still another embodiment of the present invention features
an assembled door or pre-assembled door, which may include one or
more of the following features: a door frame with abutting ends and
edges of the stiles and rails adhesively attached to one another;
an expandable or expanded core adhesively and/or mechanically
attached to rails; lock blocks adhered and/or fastened to a stile
prior to the stile being laid-up as a door frame or door assembly,
and other structures described herein.
[0021] Other embodiments, including apparatus, systems, stations,
methods, doors, door skins, and the like which constitute part of
the invention, will become more apparent upon reading the following
detailed description of the exemplary embodiments and viewing the
drawings. It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and therefore not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The accompanying drawings are incorporated in and constitute
a part of the specification. The drawings, together with the
general description given above and the detailed description of the
exemplary embodiments and methods given below, serve to explain the
principles of the invention. In such drawings:
[0023] FIGS. 1A, 1B, and 1C are partial schematic views
collectively illustrating an exemplary automated door production
line, wherein FIG. 1C illustrates finishing components downstream
of the pressing station;
[0024] FIG. 2 is a schematic view of a frame assembly station of
the door production line according to the present invention.
[0025] FIG. 2A is an enlarged partial view of the frame assembly
station of FIG. 2, depicting the rails and core after being
assembled at the core attachment station where the core is adhered
to a pair of rails;
[0026] FIG. 2B is an enlarged partial view of the frame assembly
station of FIG. 2, depicting the rail grippers moving apart the
rails to thereby expand the attached core as the distance between
the rails is made to match a length of an associated stile;
[0027] FIG. 2C is an enlarged partial view of the frame assembly
station of FIG. 2, depicting the rail grippers delivering the rails
and core to a frame assembly jig;
[0028] FIG. 2D is an enlarged partial view of the frame assembly
station of FIG. 2, depicting a stile, which includes an associated
lock block affixed thereto, being delivered by arms to the frame
assembly section;
[0029] FIG. 2E is an enlarged partial view of the frame assembly
station of FIG. 2, depicting the frame assembly jig from an angle
different than the angle shown in FIGS. 2C and 2D wherein an
assembled frame is shown with another rail/core assembly being
suspended above the already assembled frame;
[0030] FIG. 2F is an enlarged partial view of the frame assembly
station of FIG. 2, depicting the frame assembly jig assembling a
frame while an already assembled frame is transported by conveyor
from the jig toward the adhesive coating station;
[0031] FIG. 3 is a schematic of the frame assembly jig according to
the present invention with an assembled frame being suspended by
four clamps while rail grippers expand a rail/core assembly above
the frame conveyor;
[0032] FIGS. 4A-4C are partial views depicting the frame handling
arms which retrieve the door frame from the adhesion station and
place the door frame onto the bottom door skin at the bottom skin
layup station;
[0033] FIG. 4D is a schematic showing the frame handling arm used
in conjunction with an alignment mechanism for squaring the door
frame during the layup process;
[0034] FIGS. 5A-5C are partial views depicting a top skin layup
station and a pick-and-place mechanism that utilizes suction cups
to lift and place a top skin onto an assembled frame at a top skin
layup station;
[0035] FIGS. 6A-6E are partial views respectively depicting the
vertically movable two-press pressing station at various stages of
operation;
[0036] FIGS. 6F and 6G are schematic illustrations depicting the
two presses in their respective loading positions;
[0037] FIG. 7 depicts a pair of non-linear accumulators in the form
of star conveyors; and
[0038] FIG. 8 depicts an exemplary motor-driven star conveyor.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S) AND EXEMPLARY
METHOD(S)
[0039] Reference will now be made in detail to exemplary
embodiments and methods as illustrated in the accompanying
drawings, in which like reference characters designate like or
corresponding parts throughout the drawings. It should be noted,
however, that the invention in its broader aspects is not limited
to the specific details, representative devices and methods, and
illustrative examples shown and described in connection with the
exemplary embodiments and methods.
[0040] FIGS. 1A-1C collectively depict an automated door production
line according to an embodiment of the present invention.
[0041] In an exemplary embodiment, the door production line is a
synchronous system designed to operate at a specific rate of door
build, for example one door produced per unit of time. In order to
avoid bottlenecks and maximize throughput, each step in the
process, including transportation, occurs at a preset rate intended
to assure that the door build rate is achieved and optionally
optimized. Therefore, it is important to provide suitable press
time and proper adhesives and adhesive application to sufficiently
bond the components of the door together. Improper bonding can lead
to quality issues, or failure of the frame which would thus
necessitate suspension of line operation.
[0042] The production line may be divided for purposes of
discussion into five (5) different sections or stages of the
production process. First, referring to FIGS. 1A and 2, at least
one frame assembly station 100 is provided whereby rails 110,
stiles 120, lock blocks 130 and cores 140 are delivered to a
central framing jig 101. At the central framing jig 101, the frame
components are assembled into a door frame 150. In FIG. 1A, a
second frame assembly station 100' is also shown. Thereafter, as
best shown in FIG. 1B, at least one adhesive coating and layup
station 200 receives assembled frames 150 and the assembled frames
150 are coated with adhesive at coater 210, after which door skins
220, 230 are applied to the assembled door frame 150. The door
skins 220, 230 are delivered from a door skin delivery station 300.
As further shown in FIG. 1B, the assembled doors or door layups are
then passed to a pressing station 400 and thereafter to an
accumulator station 500. The assembled and pressed doors are
thereafter passed to a single conveyor 600 where the doors are
delivered to finishing stations where the assemble doors may be
trimmed, painted, inspected, and stacked.
[0043] With reference to FIGS. 1A and 2, the frame assembly station
100 receives rails 110, stiles 120, lock blocks 130, and cores 140,
which are delivered to the central framing jig 101 by material
handling devices, which preferably are moving conveyors, such as
conveyors having continuous moving belts for delivery of the frame
components. The rails 110, stiles 120, lock blocks 130, and cores
140 preferably are delivered in sets of predetermined numbers and
arranged in a form that facilitates maintenance of the door build
rate. Various material handling and movement devices and methods
may be used to transport components of each door assembly, and are
simply designated by the arrows in the individual stations and
between stations. Material handling and movement devices may
include, for example, conveyors, gantries, manipulators, grippers,
automated guided vehicles, pick and place systems and automated
storage/retrieval systems. The components and stations of the
production line may be operated by an operator's control,
automatically by utilizing various sensors including optical,
magnetic, and radio sensors, or any combination of manual and
automatic operation. Though specific examples of material handling
and movement are provided in the exemplary description of certain
stations, these may be modified as would be understood by one of
ordinary skill in the art upon viewing this disclosure.
[0044] Core attachment station 142, best shown in FIG. 2, includes
an automated rail delivery system whereby rails 110 are introduced
by an automated rail picking and placing device, such as a
mechanical arm, which removes the rails 110 from the delivery
device, such as fork truck 10. The automated rail picking and
placing device places a predetermined number of rails 110 onto a
moving conveyor belt that delivers the rails 110 to a rail indexing
device 112 that selects a pair of rails 110a, 110b from the rail
delivery system. In an exemplary embodiment the rail delivery
system includes a top rail conveyor and a bottom rail conveyor,
although a single rail conveyor or more than two rail conveyors may
be used as discussed in connection with the first and second stile
conveyors. As also shown in FIG. 2, a single top rail 110a may be
selected from the top rail conveyor and a single bottom rail 110b
is selected from the bottom rail conveyor. In various exemplary
embodiments, a door having more than one top rail 110a, such as a
double top rail (not shown), more than one bottom rail 110b, such
as a double bottom rail (not shown), or both a double bottom rail
and double top rail, and/or one or more intermediate rails (not
shown) may be desired. Therefore, the rail indexing device 112 is
capable of variably selecting a single rail 110a, 110b or multiple
rails from the top rail conveyors, the bottom rail conveyors, and
optionally intermediate rail conveyors (not shown). If more than a
single top and/or bottom rail 110a, 110b is selected, the two or
more top rails 110a are attached, for example, by fasteners or an
adhesive such as a hot melt adhesive to form a multi (e.g. double)
top rail. Two or more bottom rails 110b may be processed in similar
manner to form a multi (e.g., double) bottom rail.
[0045] After being selected, the rails 110a, 110b are moved to a
core attachment station 142. At the core attachment station 142, a
core 140 is connected to the top rail 110a and to the bottom rail
110b, for example, by a hot melt adhesive. Additionally or as an
alternative, fasteners may be used to establish or strength the
connection. The core 140 is preferably placed onto a material
delivery mechanism by an operator O1 and then is brought to the
core attachment station 142 by a conveyor or indexing device 144.
The core 140 may be an expandable core, such as made from
expandable cardboard, honeycomb, or any suitable substance
depending on the door that is to be assembled. In an exemplary
embodiment, the core 140 is an expandable corrugated cardboard core
or honeycomb paper core. The production line is set up and operated
so that the core 140 is variable and optionally different cores 140
may be selectively attached to the rails or omitted from the
assembled frame. Optionally, the core may be formed in situ.
[0046] A thermoplastic hot melt adhesive attaches the core to the
rails 110a, 110b. The thermoplastic hot melt adhesive may be
preheated and applied in a liquid, softened, or molten state. For
example, the liquid adhesive may be extruded from nozzles under
pressure. The adhesive bonds nearly instantaneously so that the
rails may be moved apart in order to allow the core to be expanded
quickly after contacting the rails and adhering the core and rails
to one another. The bond strength is sufficient to allow the core
to remain attached to the rails as the rails are moved apart from
one another and also to remain attached and fixed as the rails are
assembled into a frame and the assembled frame is connected to door
skins.
[0047] As best shown in FIG. 2, a stile assembly station includes
an automated stile delivery system through which stiles 120 are
introduced by an automated stile picking and placing device, such
as a mechanical arm, which removes the stiles 120 from the delivery
device, which is illustrated as a fork truck 20. The automatic
stile picking and placing device places a predetermined number of
stiles 120 onto two conveyor belts 122, 124 that deliver the stiles
120 to respective stile indexing devices 126, 128. Stile indexing
devices 126, 128 deliver one set of stiles 120 to the left side of
the frame assembly jig 101 and another set of stiles 120 to the
right side of the frame assembly jig 101. In the preferred
embodiment, the stiles 120 delivered from the conveyor 122 are
passed to the stile indexing device 126 for delivery to the right
side of the frame assembly jig 101, and the stiles 120 delivered
from the conveyor 124 pass below the frame assembly jig 101 to the
stile indexing device 128 on the left side of the frame assembly
jig 101.
[0048] The stile assembly station includes an automated lock block
delivery system whereby lock blocks 130 are introduced by an
automated lock block picking and placing device, such as a
mechanical arm, which retrieves the lock blocks 130 from a carrier
device, which is illustrated as another fork lift 30 in FIG. 2. The
automated lock block picking and placing device selectively places
lock blocks 130 for delivery to two conveyor belts 132, 134 that
deliver the lock blocks 130 to respective lock block indexing
devices 136, 138 in the form of rollers which deliver the lock
blocks 130 one-by-one to the left side of the frame assembly jig
101 and one-by-one to the right side of the frame assembly jig
101.
[0049] Both the stiles 120 and the lock blocks 130 are moved to
lock block attachment stations 139a, 139b. At the lock block
attachment stations 139a, 139b, the lock blocks 130 receive
adhesive from a pressurized nozzle and are positioned in front of a
respective stile 120 in order to be affixed to the associated stile
120. Each stile 120 moves in the direction of the arrows depicted
at the stile indexing devices 126, 128. In the preferred
embodiment, the lock blocks 130 are attached to the stiles 120 via
adhesive, for example a hot melt adhesive, but the lock blocks may
be attached by a mechanical fastener, or a combination of adhesive
and mechanical fastener. While FIG. 2 depicts a single lock block
130 being attached to each stile 120 on the right and left sides of
the frame assembly jig 101 at the lock block attachment stations
139a, 139b, optionally only a single lock block 130 may be attached
at one of the lock block attachment stations 139a, 139b.
Optionally, multiple lock blocks may be attached to the stiles 120
at the stations 139a, 139b. The movement and handling of all the
components in frame assembly station 100 may be handled manually or
automatically by robotic systems such as pick and place robotic
arms, robotic indexers, and the like. In the illustrated
embodiment, the rails 110, the stiles 120, and the lock blocks 130
are handled automatically.
[0050] Each lock block 130 is secured to its associated stile 120
preferably through use of a thermoplastic hot melt adhesive,
fastener, or combination thereof. The adhesive is preferably a
viscous, fast setting adhesive that is applied to either the lock
block 130 and/or the stile 120 at a point in the production line
that allows the lock block 130 to be brought into engagement with
the stile 120 before the adhesive has set. The bond strength is
such that the lock block remains secured to the stile 120 during
the frame assembly process. The assembled frame is thereafter
transferred onto the associated door skin and thereafter the
assembled door layup is transported to the press 420, as described
in greater detail below.
[0051] As discussed in more detail below, the central framing
section includes a frame assembly jig 101 for supporting and
holding the rails 110 and stiles 120 by raised arms until four
clamps 180a, 180b, 180c and 180d grasp the frame at the
corresponding four corners where the rails 110 and stiles 120 abut
during the attachment process to allow the frame 150 to be
self-supporting. Thereafter, the assembled frame 150 is passed to a
conveyor for delivery to the adhesive coating station while another
door frame 150 is assembled on the frame assembly jig 101.
[0052] FIGS. 2A-2F collectively illustrate a frame assembly process
performed at the frame assembly jig 101. FIG. 2B illustrates the
rails 110a, 110b and the core 140 after being assembled at the core
attachment station 142 where the core 140 is adhesively adhered
between and to a pair of rails 110a, 110b. A pair of rail grippers
162, 164 grasps the rails 110a, 110b and deliver the rail/core
assembly to the frame assembly jig 101. As best shown in FIG. 2B,
the rail grippers 162, 164 are configured to increase the distance
between rails 110a, 110b to thereby expand the core 140 as the
distance between the rails 110a, 110b is made to match a length of
an associated stile 120.
[0053] FIG. 2C depicts the rail grippers 162, 164 delivering the
rails 110a, 110b and the core 140 to the frame assembly jig 101. As
best shown in FIG. 2D, an assembled frame 150 is shown on the lower
conveyor 155. FIGS. 2C and 2D are additional views illustrating the
assembled frame 150 on the lower conveyor 155 while the rail
grippers 162, 164 reach the frame assembly jig 101. FIG. 2D also
illustrates a stile 120a, which includes an associated lock block
130a affixed thereto, being delivered by arms 101a to frame
assembly section.
[0054] FIG. 2E depicts the frame assembly jig from a different
angle than the angle shown in FIGS. 2C and 2D. In FIG. 2E, an
assembled frame 150a is shown with another rail/core assembly 143
suspended above the previously assembled frame 150a. The assembled
frame 150a is held in place by four clamps 180a, 180b, 180c and
180d (FIG. 2) positioned at the four corners of frame 150a while
the rail grippers 162, 164 (FIG. 2C) deliver the next rail/core
assembly 143 to the frame assembly jig 101. Also shown in FIG. 2E
is another pair of stiles 120 with associated lock blocks 130 on
opposite sides of the rail/core assembly 143. The additional stiles
120 are delivered by arms 101a to the frame assembly jig 101 for
adhesion to the rail/core assembly 143 while the four clamps 180a,
180b, 180c and 180d release the assembled frame 150a onto the
conveyor 155.
[0055] In the preferred embodiment, there are three arms 101a on
each side of the frame assembly jig 101 and each arm 101a is
provided with conveyor belts 101b that are driven by motorized
rollers 101c mounted at the end of each arm 101a. The conveyor
belts 101b convey the stiles 120 to the frame assembly jig 101.
Once the four clamps 180a-180d grasp the assembled frame 150, the
arms 101a retract to permit the assembled frame 150 to interact
with and be transported by the conveyor 155 disposed below the jig
101.
[0056] As best seen in FIG. 2E, the core 140 dangles or bows
downwardly due to its weight because it is held in place only by
way of its adhesion to the rails 110 that are suspended by the rail
grippers 162, 164. The core 140 is expanded cardboard or like
paper-like material and thus has little structural strength when so
suspended.
[0057] FIG. 2F depicts the frame assembly jig 101 assembling a
frame while the immediately previously assembled frame 150 is
transported by the conveyor 155 from the jig 101 to the adhesive
coating station described below.
[0058] As described above, the assembly of the attached lock block
130 and the stile 120 and the assembly of the attached rails 110a,
110b and core 140 are transferred to the frame assembly area and
supported by frame assembly jig 101. Robotic handling devices such
as a clamp and gantry system may be used to deliver the frame
components to the frame assembly jig 101. After the expandable core
140 is adhered to the rails, the rails 110a, 110b are drawn apart
to expand the core 140. The rails 110a, 110b and stiles 120 are
then secured together to form the assembled frame 150. The rails
110a, 110b and stiles 120 may be attached to one another using
mechanical fasteners, adhesive, for example, a hot melt adhesive,
or any combination of fasteners and adhesive. In various exemplary
embodiments, different combinations of the lock blocks, the stiles,
the rails, and the core may be delivered to the production line. It
should be noted that the term frame 150 used throughout the rest of
this description includes the assembled stiles 120, rails 110,
optional lock block(s) 130, and optional core(s) 140.
[0059] FIG. 3 is a schematic of the frame assembly jig 101
according to the present invention with an assembled frame 150
suspended by four clamps 180a, 180b, 180c and 180d while rail
grippers 162, 164 expand a rail/core assembly above the frame
conveyor 155. As best shown in FIG. 3, the arms 101a of the frame
assembly jig 101 deliver stiles 120 from opposite sides of the jig
101. The arms 101a include conveyor belts 101b driven by motorized
rollers 101c at the terminal ends of each arm 101a. Each arm 101a
reciprocates in the direction of arrow `A` in order to deliver a
stile 120 to the assembly area where it is clamped to the rails
110a, 110b by the clamps 180a, 180b, 180c and 180d. In order to
facilitate transfer of the assembled frame 150 from the clamps
180a-180d to the conveyor 155, the conveyor 155 moves in the
vertical direction, designated by arrow `B`, toward the assembled
frame 150 suspended above the conveyor 155 so that the assembled
frame 150 comes to rest on the conveyor 155 when released by the
clamps 180a-180d without unwanted force of being dropped from the
clamps 180a-180d onto the conveyor 155. Alternatively, the
assembled frame 150 may be moved vertically downward to come to
rest on the conveyor 155.
[0060] In operation, the clamps 180a-180d release the assembled
frame 150 onto the conveyor 155 after a clamping period sufficient
to permit the adhesive to cure sufficiently to maintain the
connection between the rails 110 and the stiles 120. The adhesive
that secures the rails 110 and the stiles 120 may be a
thermoplastic hot melt that achieves a nearly instantaneous bond.
The adhesive is relatively viscous in order to allow it to remain
affixed to the rails 110 and the stiles 120 without dripping.
Unlike the adhesives securing the lock blocks 130 to the stiles 120
and the core 140 to the rails 110, the adhesive securing the rails
110 to the stiles 120 is relatively flexible and tacky, allowing
the resulting frame 150 to be squared up as elsewhere explained.
The adhesive is applied to the rails 110 by being extruded under
pressure through nozzles. Then, the clamps are moved to a position
adjacent the opposite ends of the rails 110a, 110b being delivered
to the jig 101 in preparation for assembling the next door
frame.
[0061] It is noted that each clamp 180a, 180b, 180c and 180d shown
in FIG. 3 is provided with an adhesive extrusion system, including
a reservoir, associated tubing connected to an extrusion nozzle,
and a pump for transporting the adhesive from the reservoir to the
nozzle through the tubing, which includes one or more nozzles. When
the clamps 180a-180d are positioned adjacent the opposite ends of
the rails 110a, 110b, the clamps 180a-180d extrude an appropriate
amount of adhesive onto the ends of the rails 110a, 110b. The
pressurized adhesive extrudate, for example, is sent in the
direction of arrows `C` with respect to the rail 110a shown in FIG.
3 and in the similar direction with respect to the rail 110b. The
adhesive is thus applied to exposed ends of the rails 110, which
are joined to edges at the ends of the stiles 120. While it is
preferred to use extruded adhesive for fastening the corners of the
stiles 120 and the rails 110 together, mechanical fasteners may
alternatively be used either separately or in conjunction with
adhesive, such as applied through use of nail guns, corrugated
fasteners and the like. Yet alternatively, the stiles 120 and the
rails 110 may be connected through use of appropriately dimensioned
and configured tongue and groove joints or other profiled joints
sufficient to hold the resulting frame together for placement on a
door skin, with the door skin having an appropriately located
adhesive to secure the door frame to the door skins.
[0062] After the adhesive is applied to the ends of the rails 110a,
110b, the respective stiles 120 are delivered from the arms 101a to
the assembly area where the stiles 120 are positioned adjacent the
ends of the rails 110a, 110b and clamped by the clamps 180a, 180b,
180c and 180d. It will be understood by those of skill in the art
that the clamps 180a-180d are designed for movement within the
space defined by the jig 101 between the clamping position shown in
FIG. 3 to an extrusion position adjacent the rails 110a, 110b.
Additionally, the clamps 180a-180d are provided with suitable
extrusion mechanisms to accomplish the foregoing extrusion
operation.
[0063] With reference to FIGS. 1A and 1B, it is noted that the
frame assembly jig 101 supplies assembled frames 150 to the
conveyor 155 for further processing by the door production line. In
the preferred embodiment, a second frame assembly station 100' is
provided that has the same features and structures as the frame
assembly station 100 described above. Like the frame assembly
station 100, the second frame assembly station 100' uses automated
technology to manufacture assembled door frames 150' which are the
same as door frames 150 and these door frames 150' are delivered
downstream via conveyor 155' for further processing as described
below. As best shown in FIG. 1A, the second frame assembly station
100' includes all of the same structure as the first frame assembly
station 100. Like parts are labeled with like reference numerals,
except that the reference numerals of the second frame assembly
station are indicated with a prime '.
[0064] After each frame 150, 150' is assembled, either through the
assembly system and process described above or preassembly, the
frame 150, 150' is moved to an adhesive coating station 210, 210'
and adhesive coating and layup station 200. In the interest of
brevity, only the first frame 150 and first adhesive coating
station 210 are discussed below. The adhesive coating station 210
is capable of applying an adhesive to both sides of the frame 150.
Adhesive application may be accomplished by passing the frame 150
through a double roll coater of the frame adhesive station 210. In
an exemplary embodiment, the roll coater applies adhesive to the
frame 150 in an amount between about 6 and about 25 g/sft (grams
per square foot) as measured on the surface of the stiles 120 and
the rails 110. In various exemplary embodiments, the amount of
adhesive is between about 15 and about 20 g/sft. This amount of
adhesive is believed to assist quality issues, such as by
preventing pillowing or peeling of the door skin from the frame
150. After the adhesive is applied, the frame 150 is transferred to
door skin assembly stage of the adhesive coating and layup station
200. The adhesive is preferably a reactive hot melt adhesive or a
polyurethane reactive (PUR) hot melt adhesive. The adhesive has an
open time of about 90 seconds, sufficient to allow the door to be
assembled, transported to the pressing station 400 and thereafter
pressed. The adhesive has an extended open time and high tack. Full
cure of the adhesive typically takes 24 hours or more. If a PUR is
used, the moisture needed for the reaction is available from the 6%
to 8% moisture content of the door skins and the 6% to about 10%
moisture content of the stiles/rails.
[0065] Referring to FIG. 1B, it will be understood that the frame
assembly stations 100, 100' deliver assembled frames 150, 150' via
conveyors 155, 155' which run parallel to each other. The frame
adhesive coating station 210 will now be described and it will be
understood by those of skill in the art that a similar frame
adhesive coating station 210' receives door frames 150' in the same
manner as described below with respect to the frame 150. It should
further be understood that third, fourth, fifth, and other
production lines with corresponding stations may be provided.
[0066] The frame 150 is delivered to the frame adhesive coating
station 210 via conveyor 155. As the frame 150 passes through the
frame adhesive coating station 210, adhesive is applied to both
opposite sides of the frame 150, while a first door skin 220 is
delivered from the door skin delivery station 300 via conveyor 310
(See FIG. 1B). The door skin 220 is delivered automatically to a
bottom skin layup area 205 and located by positioning members
within a bottom skin layup area 205 downstream of frame adhesive
coating station 210. At the bottom skin layup area 205, the door
skin 220 is located downstream of the frame adhesive coating
station 210 and the frame 150 exiting the adhesive coating station
210 is retrieved by robotic handling device 212 described below.
The robotic handling device 212 (see FIG. 1B and FIGS. 4A-4C) is
configured to retrieve the assembled frame 150 after application of
adhesive, and thereafter place the assembled frame 150 onto the
door skin 220 which has been located in the bottom skin layup area
205. After the assembled frame 150 has been placed onto the door
skin 220, the frame/skin assembly is conveyed to a top skin layup
area 215.
[0067] As shown in FIG. 1B and FIGS. 4A-4C robotic handling devices
212, 212' are utilized at bottom skin layup areas 205, 205' to
retrieve the door frame 150, 150' exiting the frame adhesive
coating station 210, 210'. In the preferred embodiment, the robotic
handling device 212 includes three synchronized handling arms 213a,
213b, 213c which retrieve the assembled frame 150 via gripping
rollers as it exits the frame adhesive coating station 210 and
locate the frame 150 onto the respective bottom door skin 220. The
three handling arms 213a-213c are synchronized such that two of the
three arms 213a-213c (213a and 213c in FIG. 4A) place an assembled
door frame 150 onto a bottom door skin 220 while the third handling
arm (213b in FIG. 4A) begins to retrieve the next door frame 150
from the adhesion station 210. FIG. 4C also shows an alignment
plate 215 for aligning with and squaring the door frame 150 prior
to the door frame 150 being placed onto the bottom door skin 220,
as will be described in more detail below.
[0068] With reference to FIG. 4D, the handling arms 213b, 213c are
schematically shown gripping the door frame 150. Each handling arm
213b, 213c comprises gripping rollers 214b, 214c that grip opposite
vertical surfaces of each stile 120 of the door frame 150. The
gripping rollers 214b, 214c are rotatably mounted on the handling
arms 213b, 213c and reciprocate toward and away from the stiles 120
to perform the gripping action. During operation, two of the
handling arms 213b, 213c selectively grip a door frame 150 exiting
the adhesive coating station 210 with the gripping rollers 214b,
214c and deliver the frame 150 toward the bottom skin layup areas
205. Prior to placing the door frame 150 onto the bottom skin 220,
the handling arms 213b, 213c drive the forward rail 110 against the
alignment plate 215 in order to square-up the door frame 150 which
may have shifted or become misaligned during transport along the
conveyor 155 and through the adhesive coating station 210. More
specifically, the door frame 150 is pushed against the alignment
plate 215 and, if the door frame is not square (see dotted lines in
FIG. 4D), the rail 110 will be pushed until it is flush against the
alignment plate 215 to square the door frame 150. The gripping
rollers 214b, 214c are adapted to rotate during the alignment
process. In the preferred embodiment, the alignment plate 215 may
be moved horizontally into and out of the bottom skin layup areas
205 to contact the door frame 150 and then move out of the layup
area 205 during placement of the door frame 150 onto the bottom
door skin 220. The second production line (designated with primes
') operates in the same manner.
[0069] With reference to FIG. 1B, the door skin delivery station
300 provides a system for delivering door skins 220 to the door
assembly stage of the adhesive coating and layup station 200. More
specifically, the door skin delivery station 300 includes an
operator O2 who places by hand a series of door skins 220 onto
conveyor 305 and a second operator O3 who places by hand a series
of door skins 230 onto conveyor 315. The door skins 220 are
conveyed to a flipper, preferably in the form of a star conveyor
308, where the door skins 220 are flipped over so that their
intended outer surfaces rest on the conveyor and thereby expose the
intended inner surfaces of the door skins 220. An exemplary star
conveyor 308 is shown in FIG. 8. The flipped door skins 220 are
conveyed by conveyor 310 to the bottom layup area 205 or 205'. The
door skins 230 are conveyed by conveyor 315 to conveyor 320 without
being flipped (so that their interior surfaces rest on the conveyor
320), and the door skins 230 are then conveyed by the conveyor 320
to the top skin layup area 215 or 215'.
[0070] As evident from FIG. 1B, the door skin assembly station 300
includes a first skin feeder and a second skin feeder. The skin
feeders may include a door skin pallet or multiple pallets of the
door skins 220 and 230. In the exemplary embodiment, the first skin
conveyor 310 provides bottom door skins 220 and the second skin
feeder 320 provides top door skins 230. The top and bottom door
skins 220, 230 may be any variety of door skins including wood
composite door skins, solid wood door skins, polymer door skins,
sheet molding compound door skins, fiberglass-reinforced skins,
molded door skins, steel door skins, and flush door skins. Although
two skin conveyors 310, 320 are shown, a single skin conveyor may
be utilized which provides both the top and bottom door skins 220,
230. Alternatively, additional conveyors may be provided.
[0071] Door skins 220, 230 may be unloaded from the pallets P and
placed onto the conveyors 305, 315 either manually or through a
robotic handling device such as a vacuum gantry. If the door skins
220, 230 are removed from the pallets P manually, the operators O2,
O3 moving the door skins 220, 230 may also perform a visual quality
inspection. If a door skin 220, 230 is found to be unsatisfactory,
the operator may place it on a disposal conveyor (not shown). If
the door skin 220, 230 is found to be acceptable, the operator(s)
O2, O3 places it on a production conveyor. Alternatively, the door
skin 220, 230 may be removed from the pallets P with an automated
device and a camera or set of cameras may be oriented and directed
so that a remote operator can perform visual inspection. The
operator O2, O3 is then able to determine if the door skins 220,
230 are acceptable and signal the robotic handling system to place
the door skins 220, 230 on either the production conveyor or the
disposal conveyor. In various exemplary embodiments, the inspection
may be performed automatically by tactile inspection devices, such
as touch probes, and/or non-tactile inspection devices, such as
laser or optical sensors. For example, a camera may optically
capture the image of a door skin 220, 230. The image may then be
processed and measured by a controller or microprocessor. If the
door skin 220, 230 is acceptable, the controller/microprocessor can
signal the robotic handling device to place the door skin 220, 230
on the production conveyor 305, 315. If the door skin 220, 230 is
not accepted, the controller/microprocessor signals the robotic
handling device to place the door skin 220, 230 on the disposal
conveyor.
[0072] Turning now to the top skin layup station, the top door skin
230 is moved to the top door skin layup station 215 or 215'. At the
top door skin layup station 215 or 215', the top door skin 230 is
placed onto the frame 150 or 150' opposite the bottom door skin 220
so that the interior surface of the top door skin 230 faces
downwardly towards the frame 150 or 150'. In the preferred
embodiment, the top door skin 230 is lifted from conveyor 320 by a
vacuum cup lifting structure, for example, as best shown in FIGS.
5A-5C. As best depicted in FIG. 5A, the top door skin is lifted
from the conveyor 320 by an array of pneumatically-actuated vacuum
cups 330 mounted to a movable support structure 340. As best shown
in FIG. 5B, the door skin 230 is positioned above a respective door
frame 150, 150' placed on a bottom skin at layup station 205, 205'.
As best shown in FIG. 5C, the top door skin 230 is then placed onto
the frame 150, 150'. Various stops, limits, tactile sensors, and
non-tactile sensors may be used to align and position the door skin
230 and the frame 150, 150' so that the door frame is squared prior
to receiving the door skins 220, 230 at the layup stations 205,
205', 215, 215'.
[0073] Referring now only to the first assembly line in the
interest of brevity, after the top door skin 230 is placed onto
frame 150, the assembled door layup is transferred to a pressing
station 400 where the door is pressed to more fixedly bond the door
skins 220, 230 to the frame 150 having the core 140. As discussed
above, because the production line is automated, each step is
performed at the set rate of movement to avoid bottlenecks. For
example, the amount of time for the lock block attachment
station(s) 139a, 139b to attach the lock blocks 130 to the stiles
120 is equal to rate of movement, the time for the frame 150 to be
transferred to the adhesive coating and layup station 200 equals
the rate of movement, and the time in between completed doors
coming off the production line is equal to the rate of movement. In
various exemplary embodiments, the rate of movement of the
presently described system is about 7 seconds to about 15 seconds,
for example about every 8 seconds, though the time may vary
depending on several factors such as the adhesive selected, as
would be understood by one of ordinary skill in the art upon
viewing this disclosure. The rate of movement may not be long
enough, however, for sufficient bond strength to form between the
door skins 220, 230 and the frame 150.
[0074] As best shown in FIGS. 1B and 6A-6E, the double press 420
allows for a pressing time that at least achieves the required
throughput of pressing station 400, 400'. Again in the interest of
brevity, only pressing station 400 is discussed below, with the
understanding that pressing station 400' operates in a like manner.
Although the pressing station 400 is depicted with a double press
420, it should be understood that the pressing station 400 may
include three, four, or more presses. Each of the presses has a
pair of spaced, movable platens operated by a hydraulic system. The
double press 420 includes a lower press 420a and an upper press
420b. FIG. 6A depicts an assembled door layup (with frame 150 and
door skin 230) entering the first press 420a aligned with the
conveyor 155. The assembled door layup is passed to a conveyor
located in the first press 420a. In accordance with the preferred
embodiment, the press thereafter is indexed down to align the
second press 420b with the conveyor 155. The press 420 reciprocates
vertically in response to its supporting hydraulic actuators in
order to move the presses 420a, 420b vertically in tandem with one
another. The presses are alternatingly moved between a
loading/unloading position and a pressing position. When either one
of the presses 420a, 420b is in its loading/unloading position,
that press 420a or 420b is in operative alignment with the loading
and discharging material handling and movement devices, e.g.,
conveyor 155, to receive at least a first assembled door layup
delivered by the loading material handling and movement device and
to discharge at least a second assembled door that has been pressed
to the discharging material handling and movement device. The
platens of the press 420a or 420b in the loading/unloading position
are in an open state or mode to receive at least the first
assembled door layup and to discharge at least the pressed second
assembled door. At the same time, the other press 420a or 420b in
the pressing position has its respective platens closed for
pressing at least a third assembled door layup. The press 420a or
420b in the pressing position is out of operative alignment with
the loading and discharging material handling and movement devices,
e.g., conveyor 155. As shown in the drawings, in the "closed"
state, the platens of the press 420a or 420b do not necessary
contact one another as they apply pressure to the assembled door
layup.
[0075] The alternating cycle of the press 420 assures that one
press 420a, 420b is pressing an already assembled door layup while
the other press 420a, 420b is either receiving an assembled door
layup and/or discharging an assembled door after having been
pressed. FIG. 6C depicts the pressing station 400 wherein an
assembled door layup is being received into the top second press
420b as shown in FIG. 6B. In FIG. 6D, the second (top) press 420b
is being closed to press the assembled door layup and the pressing
station 400 is thereafter indexed to align the (lower) first press
420a with the conveyor 155 as shown in FIG. 6A. Using the double
press 420, the pressing of assembled door layups is alternated
between the lower and upper presses 420a, 420b, with the result
that an assembled and fixed door exits each press 420a, 420b after
having been pressed for a period sufficient to bond the skins 220,
230 to the frame 150. An assembled door layup can therefore undergo
a pressing operation, which may include opening and closing the
platens of the lower and upper presses 420a, 420b, for
approximately twice as long as the rate of movement. The extra
press time allows a greater bond to be created between the door
skins 220, 230, and the frame 150 and the core 140.
[0076] In various exemplary embodiments, the press imparts
approximately 100 psi to the door skins 220, 230 adjacent the stile
and rail sections. The principal bonding of the skins 220, 230
occurs along the stiles 120 and the rails 110, the areas where the
maximum pressure is applied. The pressure along the remaining areas
of the door skins 220, 230 covering the core 140 varies.
[0077] The double press 420 is capable of rapid closure. For
example, an upper platen and a lower platen in each of the lower
and upper presses 420a, 420b of the double press 420 are capable of
transitioning from an open position to a closed state of contacting
the door skins 220, 230 and reaching a final pressure in fewer than
10 seconds. In various exemplary embodiments, the double press 420
is capable of reaching final pressure in approximately one second
or less. A fast closing double press 420 allows for a faster acting
adhesive to be used and therefore quicker set and cure times.
[0078] In various exemplary embodiments, one of the upper and lower
platens or both platens may be moved towards or away from the
assembled door layup. As best shown in FIGS. 6C and 6D, actuators,
such as hydraulic or pneumatic cylinders, may be connected to the
upper platen. FIG. 6E depicts an assembled and pressed door (frame
150 and top skin 230) leaving the lower first press 420a and
passing onto the discharge conveyor. FIGS. 6B and 6C depicts the
upper press 420b in an open position and the lower press 420a in a
closed position. Each of the upper and lower press 420a, 420b may
also include a conveyor 465, for example a belt conveyor or powered
rollers as shown in FIG. 6A, to assist in loading and discharging
the assembled and pressed door into and from the respective presses
420a, 420b. In FIGS. 6A, 6B, and 6E, the lower platens are hidden
by the conveyors 465. The conveyors 465 remain within the
respective presses 420a, 420b during pressing operation. The
conveyors 465 are preferably made from a flexible material that is
durable enough to withstand the pressure applied by the platens. In
various exemplary embodiments, the conveyor 465 may include a first
side and a second side with an open center section (not shown). The
first and second sides may include belts or rollers and be
positioned along the edges of the resulting door to contact the
door skins 220, 230 adjacent the frame 150. The first and second
side conveyors and open center section allow the lower platen to
contact the central region of the bottom door skin 220 directly.
Various other devices and methods allow for positioning the
assembled door layups into the lower and upper presses 420a, 420b,
for example a push rod, may also be used. The double press 420 may
also include various stops, limits, tactile sensors, and
non-tactile sensors may be used to align and position the door to
square the frame 150 before pressing.
[0079] FIGS. 6F and 6G illustrate a schematic representation of the
double press 420 in an upper position where the assembled door
layup is delivered into the upper press 420b (FIG. 6F) and in a
lower position where the assembled door layup is delivered into the
lower press 420a (FIG. 6G). Movement of the entire press 420
between the upper position (FIG. 6F) and the lower position (FIG.
6G) is accomplished by hydraulic cylinder and piston assemblies
430. The lower press 420a includes an upper/top platen 421a and a
lower/bottom platen 422a, and the upper press 420b includes an
upper/top platen 421b and a lower/bottom platen 422b. Movement of
the platens 421a, 422a of the first lower press 420a is
accomplished by hydraulic cylinder and piston assemblies 440
interconnecting the lower platen 422a and the upper platen 421a.
Movement of the platens 421b, 422b of the second upper press 420b
is accomplished by hydraulic cylinder and piston assemblies 450
interconnecting the lower platen 422b and the upper platen 421b. As
will be understood by one of skill in the art, the various
hydraulic cylinder and piston assemblies may be driven by the
hydraulic lines illustrated in FIGS. 6F and 6G.
[0080] As best shown in FIG. 1B, after leaving the pressing station
400, 400' (FIG. 1B), the assembled and pressed doors are then
passed to an accumulator station 500, 500' preferably in the form
of a non-linear accumulator 520, 520' that holds the assembled and
pressed doors during a cooling and curing period. The accumulator
520, 520' thus reduces the footprint of the production line while
the doors are curing before being sent for finishing as described
below. FIG. 7 depicts a pair of non-linear accumulators 520, 520'
in the form of star conveyors which receive the assembled and
pressed doors from conveyors 155, 155', respectively, and rotate
the assembled and pressed doors about an axis until the doors are
discharged onto the single finishing conveyor 600 (FIGS. 1B and
1C). As best shown in FIG. 1B, these side-by-side accumulators 520,
520' transfer the doors assembled on parallel lines 155, 155' and
pass through parallel presses 400, 400' onto a single conveyor 600.
FIG. 8 depicts an exemplary motor driven, rotating star conveyor
that has aligned and spaced cooperating arms that hold pressed
doors of the type used as accumulators 520, 520'.
[0081] Although the exemplary embodiments discussed above are with
respect to a double press 420, it should be understood that the
pressing apparatus may alternatively have three, four, five, or
more presses. As the number of presses increases, the pressing time
per press can likewise increase without slowing the overall
movement time. Moreover, the presses 420a, 420b may be placed
side-by-side on the same level or otherwise oriented as opposed to
the stacked relationship shown in FIGS. 6C and 6D. Various material
handling devices, such as a switching conveyor, may provide the
assembled door layups to the presses 420a, 420b, etc. in an
alternating or successive fashion.
[0082] As best shown in FIG. 1C, after transiting the pressing
stations 400, 400' and the accumulators 500, 500', the pressed
assembled doors are moved along conveyor 600 to a number of
optional finishing stations as needed. For example, a door may be
passed through a stile trimming station 620 and a rail trimming
station 640 to remove excess frame material. If the blades of the
trimming stations 620, 640 are not parallel the door may need to be
rotated between the stile trimming station 620 and the rail
trimming station 640. After the edges have been trimmed, the door
may be placed through an edge coating station 660 that applies a
protective preferably colored coating to the exposed edges of the
stiles. Because the stiles extend vertically in the assembled door,
their edges are viewable to the user so the coating masks the edges
and also provides a protective barrier. Here the edges of the door,
such as the exposed rails 110a, 110b and stiles 120 may be coated,
painted, laminated, or otherwise finished. Other painting or
coating may be accomplished at this station or separately.
[0083] When a door has completed assembly and pressing, it passes
to an inspection station 670 and is inspected by an inspector I who
checks the door for quality. In various exemplary embodiments the
quality inspection may be performed automatically as discussed
above with respect to the door skin delivery station 300. Any
unacceptable door is either discarded or reworked, and all doors
passing inspection are sent to a star conveyor 680 and then to
palletizer 690 for stacking.
[0084] A number of commonly used and commercially available
adhesives have been discussed above such as PUR and EVA hot melt
adhesives. However, aspects of the present invention are also
directed to the novel use of adhesive compositions. In an exemplary
embodiment, a PUR adhesive comprising polyurethane and isocyanurate
is used in the above-disclosed system. These chemicals increase the
initial green or set strength of the adhesives, securing the bond
between the door skin and the frame, eliminating delamination
caused by the stresses of bowed or warped skins.
[0085] The foregoing detailed description of the certain exemplary
embodiments has been provided for the purpose of explaining the
principles of the invention and its practical application, thereby
enabling others skilled in the art to understand the invention for
various embodiments and with various modifications as are suited to
the particular use contemplated. This description is not
necessarily intended to be exhaustive or to limit the invention to
the precise embodiments disclosed. Additional embodiments are
possible and are intended to be encompassed within this
specification and the scope of the appended claims. The
specification describes specific examples to accomplish a more
general goal that may be accomplished in another way.
* * * * *