Apparatus for assembling planar work pieces

A machine for edge-to-edge joining of planar sheets or strips of material into a board or ribbon of material includes an upper fixed press platen, a lower vertically movable platen, a plurality of rails between the two platens for curing glue used in the joining process, and a delivery table which is movable to and from a position between the platens. The delivery table is provided with grooves holding spacer members to maintain the strips in evenly spaced relationship. Glue is applied to the strips and they are placed on the table, and the table is then moved between the platens. The rails press the strips upwardly against the upper platen, and the lower platen is then moved upwardly to compress the strips, and is shiftable longitudinally to move them into abutting relationship. The initial spacing and subsequent abutment during the assembling and pressing prevent overlapping of the pieces during the joining process.

This invention relates to an apparatus for assembling and gluing together 
substantially planar work pieces made of wood, particularly wood veneer, 
to form boards thereof. 
BACKGROUND OF THE INVENTION 
Assembling machines for joining pieces of veneer are known, one example of 
such a machine being found in Swiss Pat. No. 425,182. In that patent, 
pieces of veneer are fed into a machine, the pieces extending transversly 
to the direction of transportation. The pieces are assembled and glued 
together in the machine one after the other into a continuous ribbon of 
veneer. With such machines, it is not possible to produce plywood boards 
which are visibly assembled prior to gluing together. In other words, it 
is not possible to observe the pieces of veneer as they are initially 
placed into the relationship which they will occupy in the final product, 
and it is therefore not possible to form a board or ribbon of material 
which has a surface corresponding to a desired decoration. 
A manually operated arrangement is shown in German Pat. No. 948,916, 
wherein it is possible to observe the pieces of material as they are 
placed into position for a subsequent gluing together, but the manual 
operation disclosed therein is not suitable or profitable for an 
industrial manufacturing process. 
In U.S. Pat. No. 2,526,342, there is shown an apparatus by which wooden 
strips or boards can be visually assembled into a desired relationship and 
assembled mechanically by pressing together the lateral edges which have 
been previously wetted with glue to form boards. With this arrangement, 
however, it is not possible to assemble thin work pieces or pieces or 
veneer into boards by gluing them under pressure. In that patent, the 
sides of the wooden strips which are to glued together must be disposed 
longitudinally with respect to the direction of passage and it is 
therefore not possible to also and simultaneously put several boards 
together into an elongated ribbon of material. 
BRIEF DESCRIPTION OF THE INVENTION 
Accordingly, it is an object of the present invention to provide an 
arrangement of apparatus by which thin planar work pieces such as, for 
example, veneers, can be visually assembled into a desired pattern and can 
then be glued together mechanically and simultaneously into a board or 
ribbon of material. 
Briefly described, the invention includes an apparatus for the assembly and 
adhering together of a plurality of substantially planar sheets of 
material, such as wood veneer, to form a unitary board therewith, 
comprising an upper fixed press platen, a lower press platen, said lower 
platen being vertically movable toward and away from the upper platen and 
being shiftable in a direction substantially parallel with the upper 
platen, a delivery table for receiving planar sheets of material with 
adhesive applied thereto, the table being movable to a position below the 
upper platen and fixation means for promoting curing of the adhesive 
between said upper and lower platens, the fixation means being vertically 
movable toward and away from the upper platen.

As seen in FIG. 1, the apparatus includes a feed arrangement indicated 
generally at 1, a press arrangement indicated generally at 2, a stacking 
arrangement indicated generally at 3, and a control apparatus 13. The feed 
arrangement 1 includes a delivery table 5 which is longitudinally movable 
in the direction of arrow 4, table 5 being guided by rollers 6 which ride 
in side channels or rails 7. The rails 7, which are on opposite sides of 
the table, are shaped as inwardly facing U-shaped members and are attached 
by means of supports 8 to a frame 9. Frame 9 is fixedly attached to 
pressing apparatus 2. 
The rails 7 extend into and substantially through the pressing arrangement 
2 so that the delivery table 5 is longitudinally movable from the position 
illustrated in FIG. 1 into the pressing arrangement. This movement is 
accomplished as a result of a conventional drive which can be, for 
example, an hydraulic or pneumatic thrust piston drive, as schematically 
indicated at 30 (FIG. 2) an electromechanical spindle drive, or any other 
convenient drive means. 
In the embodiment shown, the delivery table 5 is provided with means 
defining longitudinal grooves 10 which extend parallel to the direction of 
movement 4 of the table 5. A plurality of individually and independently 
movable spacer members 11 are disposed in each of the grooves 10. The 
spacers 11 can be individually shifted by hand or can be moved by means of 
a piece of veneer 12, or other work piece, which is to be put on the table 
in such a way that, in each groove 10, a spacer 11 is arranged to lie 
between that piece of veneer and the next. Thus, the various pieces of 
veneer which are placed on the table are separated uniformly by at least 
two spacer members, resulting in a uniform spacing being established 
between the applied pieces of veneer 12. As will be apparent from FIGS. 8 
and 9, the longitudinal grooves 10 are constructed as inverted T-grooves. 
In the embodiment shown, there are three longitudinal grooves 10 in the 
table, at least two such grooves being required for reliable functioning. 
It will be observed that the grooves terminate inwardly of the ends of 
table 5, the ends of the grooves thereby constituting a limit at the ends 
for the shiftable spacers 11 and, thus, also a stop for the first piece of 
veneer placed on the table (see also FIG. 2). 
The press apparatus 2 comprises a frame 14, an upper fixed press platen 15 
having a downwardly facing working surface, a lower movable press platen 
16 having an upwardly facing working surface, and a fixing means 17 
disposed therebetween. The fixing arrangement is vertically movable, i.e., 
liftable and lowerable, by means such as hydraulic or pneumatic cylinders 
schematically indicated at 31 (FIG. 2), the fixing means including a 
plurality of heatable rails 18 which extend in parallel relationship with 
each other and also in parallel to the direction of movement 4. At 
opposite ends the rails are interconnected with each other by cross-strips 
19, as shown in FIGS. 2 and 7. The rails 18 can be heated by means of a 
resistance heating system or a liquid heating system. In order for the 
delivery table 5 to be insertable between two press platens 15 and 16 and 
for the fixing means 17 to be liftable against the upper press platen 16, 
the delivery table 5 is provided with a plurality of recesses 20 disposed 
in the vicinity of rails 18, the width of each of the recesses being 
greater than the width of rails 18 to provide clearance. 
The lower press platen 16 may be pressed by means of any pressing drive 
arrangement such as a piston arrangement schematically shown at 32 (FIG. 
2) against the upper press platen 15 and is also arranged to be shiftable 
by a shifting arrangement 33, in the direction of movement of arrow 4 in a 
direction substantially parallel to the upper press platen 15 so that the 
return shifting into the starting position may take place during or after 
the lowering process. 
The pressing arrangement as well as the shifting arrangement can consist 
of, for example, pneumatically or hydraulically driven cylinder and piston 
assemblies. The lower press platen 16 is likewise equipped with recesses 
21 extending in the direction of movement 4 so that, when they are lifted 
against the upper press platen 15, the rails 18 of the fixing means 17 can 
lie in the recesses 21. 
A stop strip 22 is attached to the upper press platen 15 at its output end 
so that the first piece of veneer 12 placed on the table and inserted into 
the press apparatus can abut against the stop strip during the joining and 
pressing process. This is best seen in FIGS. 2-6. 
The stacking arrangement 3 comprises a stacking table 23 provided with 
stops 24 and serves for the depositing of the assembled and glued-together 
plywood boards 25. A transfer arrangement can also be included in the 
stacking arrangement 3 so that individual or several stacked plywood 
boards 25 can be conveyed to a transporting and packaging apparatus. 
The manner in which the above-described apparatus operates will be apparent 
from FIGS. 2-11 and is hereinafter described. 
Individual pieces of veneer, or other material to be joined, are placed on 
the delivery table 5 by hand, the longitudinal sides 26 being previously 
provided with a coating of glue, the pieces being arranged to lie 
transversely with respect to the direction of movement 4. It will be 
observed that the pieces of veneer, as seen in FIG. 1, can be selected in 
correspondence with a desired decorative arrangement and can be assembled 
substantially as they will appear in the completed board. Between the 
individual pieces of veneer 12 the spacers 11, guided in longitudinal 
grooves 10 are pushed longitudinally along the grooves so that there is 
always a uniform gap between adjacent ones of the veneer pieces. The 
primary purpose of the spacing is to guarantee that during the assembly 
and motion of the pieces and during the fixation step the pieces of veneer 
cannot be pressed against each other in such a way that one piece tends to 
ride up over an adjacent piece, the pieces being prevented from abutting 
directly against each other until the appropriate time in the process when 
pressure is applied by the upper and lower platen members. 
As soon as the pieces of veneer 12 required for a plywood board 25 have 
been placed on the delivery table 5, the table is shifted automatically 
into the pressing apparatus 2 by triggering a starting signal and it will 
be observed at this stage that the fixation means 17 and the lower press 
platen 16 are in their lower positions as shown in FIGS. 3 and 8. If a 
previously assembled plywood board 25 still exists in the pressing 
apparatus, the completed board is pushed by the delivery table 5 onto the 
stacking table 23 when the table with the newly placed strips is inserted 
into the pressing apparatus. As soon as the delivery table 5 reaches its 
terminal position, as illustrated in FIG. 3, the fixation means 17 is 
lifted automatically as shown by arrows 27 (FIG. 4) so that the rails 18 
located in the recesses 20 of the delivery table 5 lift the individual 
pieces of veneer 12 and press them against the lower working surface of 
the fixed upper press platen 15 (see FIGS. 4 and 9). The first placed 
piece of veneer lies, at that stage, a short distance short of the stop 
strip 22 attached to the upper platen 15 while the remaining pieces lie 
firmly, uniformly spaced from one another, against the working surface of 
upper platen 15. The delivery table 5 is then returned to its starting 
position (see FIG. 5) whereupon the lower press platen 16 is pressed 
vertically upwardly by means of a pressure drive arrangement in the 
direction of arrow 28 against the pieces of veneer 12, being pressed 
against the upper press platen 15. During this step the rails 18 lie in 
the recesses 21 provided in platen 16. While the pressure is applied, the 
lower press platen 16 is then moved in the direction of arrow 4 which 
causes the individual pieces of veneer to be shifted in the direction of 
arrow 4 in such a way that the first one is pressed firmly against stop 
strip 22 and subsequent ones are firmly pressed against each other so that 
all of the adjacent edges of the various pieces are brought into firm 
abutting relationship. It will be observed that the coefficients of 
friction of the components must be selected such that the coefficient of 
friction between the working surface of upper platen 15 and of the 
fixation means 17 are to be lower than the coefficient of friction between 
the veneer pieces and lower platen 16 so that the shifting of the lower 
platen guarantees driving of the pieces of veneer into the above-described 
abutting relationship. 
Pressure in the direction of arrows 4 and 28 is then maintained until a 
firm glued connection of the assembled pieces of veneer is established. 
During this time, the delivery table 5 is supplied with new pieces of 
veneer 12 for the production of the next plywood board 25. After the 
adhesive has been cured or dried, depending upon the nature of the 
adhesive used, the lower press platen is returned downwardly to its 
starting position and fixation means 17 is also lowered, the finished 
plywood board lying on the fixation means (see FIGS. 2 and 7), and a new 
operating cycle can be commenced with the insertion of the delivery table 
into the press apparatus 2 and simultaneous ejection of the finished 
plywood board 25 onto the stacking table 23. The entire sequence can 
readily be made automatic by incorporating suitable switches and control 
elements in the control arrangement 13. 
As a result of the fact that the veneer pieces are adhered together in 
directions transverse to the direction of motion, it is also possible to 
assemble the finished plywood board directly into a ribbon by pressing the 
first of the newly inserted veneers against the last of the veneer pieces 
assembled into a board immediately before, instead of using the stop strip 
22. For this purpose, stacking table 23 can be replaced by an apparatus to 
hold the previously completed board in the position of stop strip 22. 
The arrangement according to the invention will guarantee a faultless, 
simultaneous assembly and gluing together of several pieces, particularly 
thin planar pieces such as veneers, into a board so that the individual 
pieces of veneer are first arranged visually to correspond to a desired 
decor. Since this apparatus permits the production of boards as well as 
ribbons, the machine is universally usable for both small scale operations 
and mass production. 
While certain advantageous embodiments have been chosen to illustrate the 
invention it will be understood by those skilled in the art that various 
changes and modifications can be made therein without departing from the 
scope of the invention as defined in the appended claims.