U.S. patent number 3,894,908 [Application Number 05/353,242] was granted by the patent office on 1975-07-15 for i-beam type truss joist forming apparatus with automated web infeed.
This patent grant is currently assigned to Truss Joist Corporation. Invention is credited to Alan W. Johnson, John R. Russell, Arthur L. Troutner, Stanley J. Wilmorth.
United States Patent |
3,894,908 |
Troutner , et al. |
July 15, 1975 |
I-beam type truss joist forming apparatus with automated web
infeed
Abstract
In I-beam type truss joist forming apparatus comprising means
for successively cutting continuous longitudinal grooves in the
opposed side faces of a pair of laterally spaced wooden chords,
applying glue to the grooves, compressing the side margins of a
plurality of wooden web members to form beveled margins and
inserting the web margins into the chord grooves there is provided
means for rendering the apparatus adjustable to accommodate chords
of different thickness and webs of different widths; means for
guiding the chords in longitudinal operating paths; automated
apparatus for feeding the webs one at a time between the chords;
improved means for compressing the longitudinal margins to the
precise bevel required for a precision fit in the grooves of the
chords; and means for locating the webs with their compressed side
margins registering with the grooves in the chords and for
maintaining them in this operative relationship pending and during
the I-beam assembly operation.
Inventors: |
Troutner; Arthur L. (Boise,
ID), Russell; John R. (Boise, ID), Wilmorth; Stanley
J. (Eagle, ID), Johnson; Alan W. (Boise, ID) |
Assignee: |
Truss Joist Corporation (Boise,
ID)
|
Family
ID: |
23388303 |
Appl.
No.: |
05/353,242 |
Filed: |
April 23, 1973 |
Current U.S.
Class: |
156/560; 106/2;
156/257; 156/535; 271/157; 414/797.6; 144/255; 156/258; 271/24;
271/158; 144/3.1; 144/136.1 |
Current CPC
Class: |
B27M
3/0026 (20130101); B27G 11/00 (20130101); B27M
1/02 (20130101); Y10T 156/1066 (20150115); Y10T
156/1064 (20150115); Y10T 156/1754 (20150115); Y10T
156/14 (20150115) |
Current International
Class: |
B27M
1/00 (20060101); B27G 11/00 (20060101); B27M
3/00 (20060101); B27M 1/02 (20060101); B27d
001/10 (); B32b 001/10 () |
Field of
Search: |
;156/257,258,266,289,304,313,390,516,517,529,535,556-560,563-566,570-575,578,236
;144/3,136,255,315,320 ;29/2J,238 ;52/729 ;106/2 ;117/6,149
;118/227,228,259 ;214/8.5A,8.5G ;271/3.1,24,157-159 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Cosby; Clifton B.
Assistant Examiner: Kittle; John E.
Attorney, Agent or Firm: Farley; Eugene D.
Claims
Having thus described my invention in preferred embodiments, I
claim:
1. In I-beam type truss joist forming apparatus comprising chord
feed means arranged to drive longitudinally in laterally spaced
relation a pair of chords having longitudinal grooves in their
opposed side faces, web member feed means positioned for placing
between the chords a plurality of web members arranged end-to-end,
web member drive means for driving said web members longitudinally
between said chords, and guide means disposed to guide the chords
and web members into assembled relation to each other with the side
margins of the web members engaged in the grooves of the chords,
the improvement wherein said web member feed means comprises:
a. support means positioned to support a first stack of
flatwise-oriented web members between and above the chords,
b. conveyor means mounted longitudinally between the chords beneath
the stack for engaging at timed intervals the lowermost web member
of the first stack and conveying it between the chords to said web
member drive means, and
c. stack feed means positioned adjacent the support means and
operable to feed a second stack of web members onto the top of a
partially depleted first stack supported on the stack support means
and including skid plate means supporting a second stack to be fed
and stack pusher means positioned for pushing said second stack to
be fed onto the stack support means, the stack pusher means
comprising:
1. reciprocating carriage means provided with at least one pushing
arm and
2. drive means connected to the pushing arm for moving it angularly
between an advanced angular position wherein it engages and pushes
the stack to be fed along the skid plate means on the advancing
pass of the carriage, and a retracted angular position wherein it
is separated from the stack to be fed on the retracting pass of the
carriage.
2. In I-beam type truss joist forming apparatus comprising chord
feed means arranged to drive longitudinally in laterally spaced
relation a pair of chords having longitudinal grooves in their
opposed side faces, web member feed means positioned for placing
between the chords a plurality of web members arranged end-to-end,
web member drive means for driving said web members longitudinally
between said chords, and guide means disposed to guide the chords
and web members into assembled relation to each other with the side
margins of the web members engaged in the grooves of the chords,
the improvement wherein said web member feed means comprises:
a. first support means positioned to support a first stack of
flatwise-oriented web members between and above the chords,
b. conveyor means mounted longitudinally between the chords beneath
the first stack for engaging at timed intervals the lowermost web
member of the first stack and conveying it between the chords to
said web member drive means,
c. stack feed means positioned adjacent the first support means for
feeding a stack of web members onto the top of a partially depleted
first stack supported on the first support means,
d. second support means positioned adjacent the stack feed means
for supporting a plurality of web member stacks aligned in the
stack feed direction, and
e. reciprocating stack-advancing means positioned for advancing the
stacks along the second support means and transferring them to the
stack feed means, one stack at a time.
3. The apparatus of claim 2 wherein the second support means
comprises pallet means.
4. The apparatus of claim 3 including pallet positioning means for
positioning the pallet with the stacks in operative alignment with
the stack feed means.
5. The apparatus of claim 3 wherein the stack-advancing means
comprises a reciprocating carriage and a ram mounted thereon.
6. The apparatus of claim 2 including conveyer means
interconnecting the second support means and the stack feed
means.
7. The apparatus of claim 6 wherein the conveyer means comprises
gravity roller conveyer means.
8. I-beam type truss joist forming apparatus comprising chord feed
means arranged to move longitudinally in laterally spaced relation
a pair of chords having longitudinal grooves in their opposed side
faces, web member feed means for feeding web members from a supply
one at a time between the chords in end-to-end aligned relation to
each other, web member drive means and guide means disposed to
guide the chords and web members into assembled relation to each
other with the side margins of the web members engaged in the
grooves of the chords, and a laterally adjustable frame supporting
the chord feed means so as to process I-beam type truss joists of
variable width, the frame comprising:
a. a pair of laterally spaced, longitudinally extending frame
members supporting the chord feed means,
b. a plurality of cross frame members interconnecting the
longitudinal frame members,
c. a plurality of V-ways mounted one on each cross frame member
d. one longitudinal frame member being fixed
e. roller means mounted on the underside of the other longitudinal
frame member and bearing against the associated V-way, and
f. adjustment means engaging the said other longitudinal frame
member for shifting it laterally to the predetermined position of
lateral adjustment.
9. The apparatus of claim 8 wherein the adjustment means comprises
screw means.
10. The apparatus of claim 8 including indexing means positioned
for determining the lateral position of the said other longitudinal
frame member.
11. I-beam type truss joist forming apparatus comprising chord feed
means arranged to move longitudinally in laterally spaced relation
a pair of chords having longitudinal grooves in their opposed side
faces, web member feed means for feeding web members from a supply
one at a time between the chords in end-to-end aligned relation to
each other, web member drive means and guide means disposed to
guide the chords and web members into assembled relation to each
other with the side margins of the web members engaged in the
grooves of the chords, the chord feed means comprising:
a. pairs of rollers positioned for engagement with opposite
surfaces of the chords,
b. one of the pairs comprising powered rollers for driving the
chords in the feed direction,
c. the other pair being idler rollers applying resilient pressure
to the chords,
d. resilient mounting means mounting said other pair of rollers and
comprising a walking beam, journal means journaling the rollers to
the walking beam ends and resilient pressure-applying means
connected to the central portion of the walking beam.
12. The apparatus of claim 11 including adjustable stop means for
positioning the said other pair of rollers and comprising a pair of
outwardly extending threaded studs, a fixed limit block, each stud
having one end fixed to the walking beam adjacent an end thereof
and the other end penetrating the limit block, and lock nut means
threaded on the studs and bearing on the limit block.
13. I-beam type truss joist forming apparatus comprising chord feed
means arranged to move longitudinally in laterally spaced relation
a pair of chords having longitudinal grooves in their opposed side
faces, web feed means for feeding webs from a supply one at a time
between the chords in end-to-end aligned relation to each other,
web drive means and guide means disposed to guide the chords and
webs into assembled relation to each other with the side margins of
the webs engaged in the grooves of the chords, the web drive means
comprising:
a. pairs of rotatably mounted upper and lower crimp wheels
positioned for engaging the upper and lower surfaces of the
webs,
b. the peripheral surfaces of each pair of wheels being divergently
beveled at an angle predetermined to impress tongues in the web
side margins,
c. the wheels of each pair being provided with coplanar integral
flanges positioned to contact each other and act as stops, limiting
the degree of compression of the web margins, and
d. drive means connected to the crimp wheels for driving them at
the predetermined rotational speed.
14. I-beam type truss joist forming apparatus comprising chord feed
means arranged to move longitudinally in laterally spaced relation
a pair of chords having longitudinal grooves in their opposed side
faces, web feed means for feeding webs from a supply one at a time
between the chords in end-to-end aligned relation to each other,
web drive means and guide means disposed to guide the chords and
webs into assembled relation to each other with the side margins of
the webs engaged in the grooves of the chords, and web hold-down
means for preventing the bowing of the webs and comprising:
a. an upper and a lower guide bar assembly, one positioned above
and the other below the web in contact therewith in mutually
opposed cooperating relation,
b. each assembly including at least three parallel longitudinally
arranged guide bars,
c. each guide bar comprising a contact shoe bearing against the web
and
d. mounting means mounting each guide bar to a frame member.
15. The apparatus of claim 14 wherein the mounting means for the
guide bars of one guide bar assembly comprises resilient mounting
means applying resilient pressure to the component guide bars of
the assembly.
16. The apparatus of claim 14 including laterally adjustable
mounting means for mounting the central guide bar of each guide bar
assembly for lateral adjustment.
17. The apparatus of claim 16 wherein the central guide bar
mounting means comprises a support arm, a sleeve fixed to the
support arm, a horizontal indexing bar receiving the sleeve, and
clamp means arranged for clamping the sleeve to the indexing bar at
a selected location thereon.
18. I-beam type truss joist forming apparatus comprising chord feed
means arranged to move longitudinally in laterally spaced relation
a pair of chords having longitudinal grooves in their opposed side
faces, automated web feed means for feeding web members one at a
time between the chords in end-to-end aligned relation to each
other, web member drive means and guide means disposed to guide the
chords, web members into assembled relation to each other with the
side margins of the web members engaged in the grooves of the
chords, and adhesive-repellent applicator means for applying an
adhesive repellent to the edges of the chords, said applicator
means comprising:
a. upper and lower rollers positioned for engaging the upper and
lower edges of the chords and
b. roller moistening means associated with each roller and
positioned for moistening the surfaces of the rollers with an
adhesive repellent liquid.
19. The apparatus of claim 18 including a reservoir containing
adhesive repellent liquid and receiving the lower portion of the
lower roller for moistening the same, a plurality of
liquid-applying nozzles mounted in operative relation to the upper
roller for moistening the same, and conduit means including pump
means communicating with a source of liquid and positioned for
applying liquid to the upper roller.
20. The apparatus of claim 19 including adjustable, fluid operated
cylinder mounting means for mounting the nozzles in predetermined
positions of vertical adjustment.
21. The apparatus of claim 19 including slide and guide nozzle
mounting means for mounting the nozzles in predetermined positions
of lateral adjustment.
Description
BACKGROUND OF THE INVENTION
This invention relates to the manufacture of I-beam type truss
justs comprising a pair of chords or flanges and an interconnecting
web. It pertains particularly to I-beam type truss joists having
wooden components.
Troutner U.S. Pat. No. 3,616,091 describes apparatus for
manufacturing I-beam truss joists of the foregoing class. The
apparatus basically comprises chord feed means arranged to move a
pair of chords longitudinally in laterally spaced relation with two
sides thereof facing each other. Cutters are mounted adjacent the
infeed end of the apparatus for cutting longitudinal grooves in the
opposed side faces of the chords.
Web feed means downstream from the cutter means receives flat web
members between the grooved chords. Shaping wheels are positioned
for engaging the side margins of the webs for compressing them to a
beveled contour matching the tapered groove contour in the chords.
A glue applicator is positioned for applying glue to the beveled
web margins.
Associated chord guiding and positioning means guides the chords
against the webs, wedging the beveled margins of the latter into
the grooves of the former. Holding means is arranged for holding
the webs and chords in their assembled relation pending spring-back
of the compressed margins of the webs with resultant application of
bonding pressure to the joint.
The foregoing apparatus is particularly applicable to the forming
of I-beam type truss joists from webs comprising pieces of plywood
and chords comprising 2.times.4's or other dimension lumber. The
chords also advantageously may comprise lengths sawn from billets
comprising the laminated products resulting from the gluing
together of sheets of wood veneer in accordance with the procedure
set forth in Troutner U.S. Pat. No. 3,723,230.
While the foregoing apparatus and the procedure using it have met
with substantial commercial success, nevertheless there remain
areas of operation wherein certain difficulties have been
encountered.
It accordingly is the general object of the present invention to
provide apparatus for forming I-beam type truss joists from wooden
chords and webs which is adaptable to the large scale manufacture
of such products at competitive prices, and which is characterized
by the inclusion of the following improved features:
1. A frame of sophisticated design enabling adjustment to
accommodate webs and chords of varying dimension thereby making
possible the production in a single machine of joists of assorted
sizes.
2. An automated unit for feeding the webs to the production
line.
3. Improved side and top guides for the chords.
4. Improved crimping means for compressing and beveling the side
edges of the webs.
5. Means for applying constant and adjustable pressure on all the
elements of the work during the entire processing operation.
6. Inclusion of applicator means for applying a glue repellent to
the finished I-beam product, thus preventing sticking together of
adjacent I-beams in a finished stack thereof.
SUMMARY OF THE INVENTION
The foregoing and other objects of the invention are accomplished
by the provision of apparatus for forming wooden chords and webs
into I-beam type truss joists which comprises in combination chord
feed means for moving a pair of chords initially in spaced relation
greater than the overall width of a web, cutter means positioned
for making grooves in the opposed faces of the chords, glue
applying means arranged for applying glue to the grooves, automated
web feeding means for feeding a web into the area between the two
chords in the plane of the grooves, and chord guide means for
guiding the chords against the margins of the web thereby, engaging
the edges of the chord in the grooves.
Improved forming means press the web margins into a beveled
contour. Adjustable frame means mount the processing units for
adjustment as required to accommodate chords and webs of varying
dimension. Guiding and positioning elements guide the joist
components into proper assembling relation to each other.
Pressure applying means applies a constant and adjustable pressure
to the work, thereby maintaining them in proper relation to each
other during all processing operations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is a side elevation of the presently described I-beam type
truss joist forming apparatus, partly in section and with parts
broken away for convenience of illustration, taken along line 1a,
1a of FIG. 2a.
FIG. 1b is a continuation of FIG. 1a taken along line 1b, 1b of
FIG. 2b.
FIG. 2a is a plan view of the infeed end of the apparatus with
parts broken away for convenience of illustration.
FIG. 2b is a continuation of FIG. 2a.
FIGS. 3, 4 and 5 are fragmentary sectional views taken along lines
3--3, 4--4 and 5--5, respectively, of FIG. 2a.
FIG. 6 is a fragmentary, plan, sectional view taken along line 6--6
of FIG. 5.
FIG. 7 is an enlarged, foreshortened, sectional view taken along
line 7--7 of FIG. 2b, parts being broken away better to show
interior construction.
FIG. 8 is a fragmentary elevation taken along line 8--8 of FIG.
2b.
FIGS. 9, 10 and 11 are enlarged, fragmentary, sectional views taken
along lines 9--9, 10--10 and 11--11, respectively, of FIG. 2b.
FIG. 12 is a fragmentary, foreshortened sectional view taken along
line 12--12 of FIG. 16, parts being broken away for convenience of
illustration.
FIG. 13 is an enlarged, foreshortened, fragmentary, sectional view
taken along line 13--13 of FIG. 2a.
FIG. 14 is an enlarged sectional view taken along line 14--14 of
FIG. 13.
FIG. 15 is an enlarged, fragmentary, foreshortened view taken along
line 15--15 of FIG. 2a.
FIG. 16 is a fragmentary, foreshortened plan view taken along line
16--16 of FIG. 12.
FIG. 17 is a fragmentary, foreshortened, elevation taken along line
17--17 of FIG. 16.
FIG. 18 is an enlarged, fragmentary section taken along line 18--18
of FIG. 2b.
FIG. 19 is a diagrammatic, fragmentary plan view of the outfeed
portion of the apparatus.
FIG. 20 is a fragmentary enlarged elevation taken along line 20--20
of FIG. 19.
FIG. 21 is a foreshortened plan view taken in the direction of the
arrows of line 21--21 of FIG. 20 with parts broken away for
convenience of illustration.
FIG. 22 is a fragmentary section taken along line 22--22 of FIG. 21
and
FIG. 23 is an end view of an I-beam type truss joist which is the
product of the operation of the present apparatus.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
The end product of the operation of the hereindescribed I-beam type
truss joist forming apparatus is illustrated in FIG. 23. Indicated
generally at 9, it comprises a pair of elongated chords or flanges
10 and an interconnecting web 12. Chords 10 have tapered grooves 14
in their opposed faces and web 12 has tapered side edge portions 16
engaged in the grooves. A glue connection is provided between the
grooves and web side edge portions 16. The web 12 is provided in
segments either in glued abutment or in spaced relation to each
other to suit the needs of a particular purpose.
As noted above, chords 10 may comprise lengths of dimension lumber
or lengths of laminated lumber manufactured by gluing together
sheets of wood veneer to the desired thickness and then sawing the
resulting billet to the desired width and length. Web 12 may
comprise pieces of plywood of the desired dimensions glued end to
end and having side margins crimped or compressed to the desired
tapered tongue configuration.
The present apparatus incorporates means for manufacturing the
joists shown in FIG. 23. With reference to FIGS. 1 and 2, the
apparatus basically comprises, listed in downstream relationship to
each other:
A frame having a lateral adjustment subassembly indicated generally
at A;
A chord infeed drive indicated generally at B;
A groove cutting subassembly for the chords, indicated generally at
C;
A vertical press roll assembly for the chords indicated generally
at D;
A glue applying subassembly for the web margins, indicated
generally at E;
A first stage web infeed subassembly indicated generally at F;
A second stage web infeed subassembly indicated generally at G;
A web-conveying subassembly indicated generally at H;
A crimp wheel subassembly for compressing the web margins and
shaping them into tongues, indicated generally at I;
A chord and web uniting subassembly, indicated generally at J;
and
A subassembly for applying glue repellent to the finished joists,
indicated generally at K.
Considering these various component subassemblies in greater detail
and in the order named:
THE SUPPORTING FRAME
Referring to FIGS. 1, 2 and 13, the frame which supports the
apparatus of the invention includes a plurality of vertical legs 18
which support two pairs of longitudinally extending, laterally
spaced, parallel main frame members 20. Each of the latter
comprises a pair of vertically spaced, oppositely directed channel
members 21 interconnected and braced by means of diagonal webs 23.
Cross frame members 22 interconnect and brace legs 18 at spaced
intervals along the length of the apparatus.
One of the longitudinal main frame members 20, i.e. the left hand
frame member as viewed in FIG. 13, is welded or otherwise fixed to
legs 18. However, the companion main frame member 20 is mounted for
lateral adjustment in order to make the apparatus adjustable
laterally as required to produce I-beam products of assorted
heights. The means by which this is accomplished is illustrated
particularly at A in FIGS. 1a and 12.
As is apparent from a consideration of those figures, cross frame
members 22 support integral V-ways 24. Integral support blocks 26
are bottom mounted on frame member 20. The blocks in turn mount two
pairs of rotatably mounted support rollers 28. These bear against
V-ways 24.
One end of a threaded shaft 30 is supported rotatably in a bearing
32 and passes through a threaded bore 34 formed within each support
block 26. The upper or right hand end of shaft 30 is rotatably
mounted and laterally secured in bearing 36.
A sprocket 38 meshing with a chain 40 is fixed to shaft 30. Chain
40 interconnects shaft 30 with one or more downstream shafts 30 so
that all may be driven from a common power source. At least one of
shafts 30 has a squared end 42 to which a suitably dimensioned
wrench can be applied. This causes the shafts to rotate in unison,
causing the right hand frame 20 to move laterally in a maintained
parallel relationship with respect to left-hand frame member
20.
Means are provided for measuring the lateral adjustment thus
accomplished and for locking the two frame members in a selected
position of lateral adjustment. The means employed for this purpose
is illustrated in FIGS. 1a and 13.
One of the ends of a pair of indexing cross bars 44 is integrated
with the left hand frame member 20. The other of the ends of each
cross bar is received and supported by an indexing block 46 mounted
on the bottom surface of right hand frame member 20. The cross bar
terminates integrally with one of legs 18 on the right hand side of
the apparatus.
The cross bar has a series of spaced bores 48. An indexing bolt 50
is threaded through indexing block 46. The bolt is dimensioned to
register with a selected one of bores 48 through the indexing cross
bar.
Accordingly, with bolts 50 removed, right hand frame member 20 may
be indexed in selected increments by the rotation of shafts 30. The
indexing operation is carried on until indexing cross bars 44
register with selected bores 48. The bolts then are reinserted,
thus locking the left and right handed frame members 20 in the
desired lateral spacing.
THE CHORD INFEED DRIVE
The drive which feeds the chords into the machine is generally
similar to that disclosed in U.S. Pat. No. 3,616,091, aforesaid. It
is indicated generally at B and illustrated particularly in FIGS.
1a, 2a and 3 of the drawings.
The chord infeed drive includes four pairs of cooperating flanged
rollers 52 and 54. There are two roller pairs on each side of the
apparatus, disposed inwardly of side frames 20.
The two pairs of bottom rollers 54, one pair on each side, are
drive rollers. The two pairs of top rollers 52, one pair on each
side, are idler pressure rollers. Drive rollers 54 are keyed to the
ends of short cross shafts 56, one pair on each side, which have
journaled supports 58 on structural side plates 59 provided for the
purpose.
Sprocket pairs 60, one pair on each side, are keyed centrally to
shafts 56 and are rotatably linked together by means of chains 62,
so that they may be driven in unison. The drive comprises a motor
64 having its shaft 66 connected to a drive sprocket 68. The latter
in turn drives chain 70, the lower end of which is trained around a
sprocket 72. Sprocket 72 is fixed on the end of a splined cross
shaft or drive shaft 74 supported in bearings 76. The drive shaft
mounts adjacent each of its ends, and within the structural
framework of side frame members 20, a sprocket 78. Each of these
sprockets engages and drives a chain 80 which in turn engages a
sprocket 82 keyed to the adjacent shaft 56, thereby driving the
lower rollers 54.
Since drive shaft 74 extends across the width of the apparatus, it
is necessary that it be adjustable in length to accommodate
relative lateral changes in position of side frames 20, as
described above. When making this adjustment, right hand shafts 56
and their associated sprockets are supported by and move with the
right hand one of frame members 20. Accordingly, they require no
adjustment when the latter is moved to a new lateral position.
However, a set screw 86 is threaded into the hub of right hand
sprocket 78. Upon loosening the set screw, sprocket 78 may be moved
along the drive shaft to its new position, after which set screw 86
again may be secured. This will position sprocket 78 properly in
alignment with the companion elements of the chain and sprocket
drive train.
To provide proper timing, provision is made for driving the chords
at a controlled and uniform rate.
To this end, flanged drive rollers 54 have serrated peripheral
surfaces 88 for gripping the chords as they move into the machine.
Also, resilient pressure applying means is associated with flanged
idler rollers 52 so that the latter are under a continuous
resilient pressure exerted in the downward direction.
Idler rollers 52 are supported by a pair of horizontally inclined,
inwardly disposed stub shafts 90. The stub shafts are integral with
a walking beam 92 which in turn pivotally is supported at its
center line by a clevis 94 formed on the lower end of a shaft
96.
Shaft 96 comprises the piston rod of an air cylinder 98 mounted on
the top of frame member 20 by means of a bracket 100. The cylinder
is of the cushion type which, when actuated, urges the rollers
resiliently downwardly against the upper surfaces of the
chords.
Stop means is provided for limiting the downward travel of rollers
52 in order to facilitate the introduction of chords into the
apparatus.
The stop means comprises a pair of threaded studs 102 welded to the
upper surface of walking beam 92, one on each side of clevis 94.
The studs extend upwardly through openings in a pair of limit
blocks 104 welded to the outside face of plate 59. A pair of lock
nuts 106 is threaded onto the ends of each of studs 102. Hence by
adjusting the position of the lock nuts the extreme lower limit of
travle of rollers 52 when the apparatus is empty may be determined.
This in turn facilitates feeding the chords into the apparatus.
THE GROOVE-CUTTING SUBASSEMBLY
The groove-cutting subassembly, indicated at C of FIGS. 2a and 3,
is positioned a short distance inwardly of the infeed end of the
apparatus, just downstream from the chord feeding subassembly B. It
has for its function cutting the tapered grooves 14 on the inwardly
facing or opposed surfaces of the two chords 10. There are two such
subassemblies, one positioned on each side of the apparatus and
working on the adjacent chord.
Each of the groove cutting subasemblies comprises a rotary cutter
108 disposed in a horizontal plane and direct-driven by an upright
motor 110. The motor is supported adjustably on a bracket 112
mounted on the inner face of frame member 20. The bracket 112 is
designed in known manner, not illustrated, to allow for the
vertical and lateral adjustment of the cutter. This in turn permits
proper location and depth of the groove 14 cut in chord 10.
THE CHORD VERTICAL PRESS ROLLER SUBASSEMBLY
Stationed at intervals along the length of the apparatus are
vertical press roller subassemblies for the chords, indicated
generally at D and illustrated in FIGS. 1, 2, 3 and 13.
These have for their function exerting a downward rolling pressure
on chords 10, thus guiding the chords through the apparatus and
aligning them accurately, particularly in close proximity to cutter
heads 108 as the latter cut grooves 14 in chords 10. This in turn
enables the cutter heads to locate the grooves with the accuracy
required for efficient assembly of the joists in the latter stages
of operation of the machine.
The press roller subassemblies comprise vertically aligned pairs of
rollers 114 and 116. Two of such pairs are located on each side of
the machine, inwardly of side frames 20.
The supporting structure for the rollers is illustrated
particularly in FIGS. 1a and 13.
Two pairs of opposed longitudinal bars 118 are mounted on two pairs
of vertical frame plates 119. The latter are integrated with the
inner faces of frame members 20.
Bars 118 are relatively adjustable vertically in order to
accommodate the passage of chords of varying width. They
accordingly are mounted on frame plates 119 by means of bolts 120
which pass through a selected one of a series of angularly aligned
bores 121 through frame plates 119. The bolts are also received in
horizontal slots 122 formed within bars 118.
The desired degree of lateral adjustment of the press rollers thus
may be obtained by inserting the bolts in the appropriate ones of
bores 122. This allows for passage through the machine of chords 10
having different incremental vertical dimensions so that the
horizontal center lines of the chords 10 will always be maintained
substantially aligned with the horizontal center lines of frame
members 20.
The lower roller 116 of each roller pair is rotatably mounted on
bar 118 in fixed position by means of a shaft 123. The structure of
the roller is such as to provide for automatic lateral adjustment
to allow for thickness variations in the chords. Accordingly, the
rollers include laterally shiftable side flanges 124. These are
secured by spring-loaded, laterally projecting screws 125.
The upper pressure roller 114 of each pair is resiliently
displaceable in a vertical plane to accommodate irregularities in
the width of the chords. It is rotatably mounted on a stub shaft
126. The latter is integral with and supported by a bracket 128
which is pivotally mounted on the upper longitudinal bar 118 by
means of a pivot bolt 130, FIG. 3.
Pivotally mounted to the upper end of bracket 128 by means of pin
132 is a threaded stud 134. This stud passes through a fixed arm
136 which in turn is integral with frame 118. It also mounts a
compression spring 138 retained by an adjusting nut 140. Upper
rollers 114 thus are continuously biased in the downward direction,
while permitting vertical displacement as required to accommodate
deviations in thickness of the chords.
THE GLUE APPLYING SUBASSEMBLY
The glue applying subassembly, indicated generally at E, has for
its function the application of glue along the surfaces of grooves
14 in the chords, preparatory to inserting web members 12 in the
grooves.
It comprises two units placed slightly downstream from cutters 108,
one associated with each chord.
Each unit consists of two principal components: an air jet to clean
out of the grooves the sawdust and shavings generated by the
operation of cutters 108 and a glue applicator head designed to
apply the glue to the surfaces of the cleaned grooves. These are
illustrated particularly in FIGS. 2a, 4, 5 and 6.
Each glue applying unit comprises a head 150 supported on a pair of
upright, elongated screws 152. The latter are threaded into
horizontally aligned, horizontally adjustable mounting blocks
154.
The length of screws 152 is somewhat greater than the vertical
dimension of head 150. The outwardly extending segments of the
screws above and below head 150 accordingly are used as supports
for compression springs 156 and 158. The latter provide a vertical
floating adjustment of the heads as required to compensate for any
minor irregularities in the placement of chord grooves 14.
Each head 150 has an outwardly projecting tongue 160. This is
shaped to project into tapered groove 14 in the chord. As shown in
FIG. 6, this tongue serves the dual functions of providing an air
jet and a glue applicator head.
To this end tongue 160 has an angled leading portion 162 on the
edge which is disposed toward the infeed end of the machine. An air
jet outlet 164 projects through this angled leading portion. Outlet
164 communicates with a passageway 166 to which air under pressure
is supplied from a suitable source through conduit 168. The air
source operates continuously so that as chord 10 progresses through
the machine, the air jet cleans sawdust shavings and any other
foreign material from chord grooves 14.
The glue applicator head includes a glue passageway 170 fed by
conduit 172, FIG. 6. Conduit 172 communicates with a glue reservoir
containing a quantity of suitable glue. The latter preferably
comprises a water based glue which, upon application to the wooden
chords and webs, will swell the fiber structure of the wood. This
produces an internal clamping action which holds the chords and
webs in assembled relation pending setting of the glue, as will
appear hereinafter.
Glue passageway 170 communicates with a vertically disposed
passageway 174 which in turn leads to recesses 176 provided in the
upper and lower surfaces of the tongue. Upon the introduction of
glue into passageway 170, it is transmitted continuously into
passageway 174 and recesses 176 and accordingly is applied
continuously to both side walls of groove 14 as the chord
progresses past the head.
Provision is made for lateral adjustment of block 154, and hence of
head 150, to accommodate variations in groove depth.
As shown particularly in FIG. 5, block 154 is supported by a pair
of horizontally disposed threaded studs 178. These pass through
bores formed within block 154. The studs have a substantially
greater length than the horizontal width of the block.
The desired lateral adjustment thus is made possible by clamping
the block between two nuts 182 threaded onto the studs. The outer
ends of studs 178 are formed onto a right angle bracket 184 which
in turn is integral with a plate 185 welded to channel frame member
21.
Since the passage of the chords through the machine is
intermittent, it is desirable to provide means for discontinuing
the glue feed whenever tongue 160 is not in engagement with the
walls of a groove 14.
A limit switch 183 is mounted on one side of the machine just ahead
of one of glue heads 150. The switch has a moveable arm projecting
into the path of chord 10. It controls the source which supplies
glue to the glue head. It functions in a manner such that glue is
supplied to head 150 upon engagement of the switch by a chord.
However, when the chord moves beyond the switch, the supply of glue
is cut off.
FIRST STAGE WEB INFEED SUBASSEMBLY
The apparatus heretofore described serves the function of feeding
the chords in parallel, relatively widely spaced relation to each
other, cutting two longitudinal grooves in the opposed faces of the
chords, cleaning the grooves and applying glue to them. There next
is described apparatus for introducing into the machine, at a
station downstream from the glue-applying subassembly, web members
which are fed to a location between the spaced apart chords where
they may be integrated into the I-beam structure.
The web members 12 introduced in this manner normally comprise
plywood sheets cut to size and supplied in a selected one of
several commercial thicknesses. In the alternative, however, they
may comprise sheets of lumber, wood particle board, or other
suitable structural material, preferably characterized by
compressibility and spring back following the application and
release of pressure.
Whereas the webs were fed to the apparatus manually in Troutner
U.S. Pat. No. 3,616,091, referred to above, it is a primary feature
of the presently described apparatus that the web members are fed
automatically at an accelerated rate. This is accomplished in two
stages. In the first stage, indicated generally at F, the webs in
large number are stockpiled in a plurality of stacks, their end
surfaces coated with liquid glue, and advanced into working
position for feeding into the machine.
In the second stage, indicated generally at G, the stacks are moved
individually into feeding position and the component webs fed one
at a time between the spaced, moving chords.
The frame which supports the first and second stage web infeed
subassemblies includes legs 19 which support the right hand ends of
a pair of longitudinally spaced frame members 186, FIGS. 12, 16 and
17. These frame members extend substantially at right angles to the
line of travel of the chords. Their left hand ends are supported by
legs 18.
Frame members 186 are positioned and arranged to mount a pallet
188. The pallet is located in precise working position by means of
a transverse stop 190 and a pair of angled longitudinal side guides
192 formed in the top of frame members 186, FIG. 17.
Pallet 188 supports a plurality of web stacks 194, arranged side by
side in longitudinal progression. For convenience of operation, the
web stacks and pallet are assembled in another location and
deposited on frame members 186 by means of a lift truck. Once
deposited, a coating of glue is applied to the end faces of the
stacks. The glue employed comprises a liquid glue having an
assembly time sufficient to permit at a later time the webs to be
assembled between the chords in edge-abutting lineal relationship,
whereupon the glue applied to the web edges sets and thus joins the
webs end to end.
The first stage infeed drive comprises a carriage indicated
generally at 198 which mounts a ram positioned for pushing the
stacks of web members in the feed direction along the surface of
pallet 188, FIGS. 2a, 12, 16 and 17.
The ram includes a pair of spaced vertical pusher bars 200 integral
with longitudinal frame members 202. The latter are supported by
and bridge a pair of side plates 204.
The carriage thus comprised moves on two pairs of guide rollers 206
rotatably mounted on stub shafts 208. The latter in turn are
mounted on the inner faces of the lower margins of side plates 204.
The rollers are spaced vertically in pairs to register with and
track on the top and bottom surfaces of a horizontally disposed
pair of tracks 210 supported on the upper surfaces of frame members
186.
Pairs of horizontally arranged stabilizing rollers 212 are
rotatably mounted on laterally extending ears 214 by means of
shafts 216. Ears 214 are formed integrally upon both lower side
edges of end plates 204 and are located in such a manner as to
position rollers 212 to register with and track on the outer faces
of tracks 210, thereby stabilizing the carriage assembly.
The ram-mounting carriage 198 is driven by an assembly including
anchor blocks 218 located on the bottom of carriage end plates 204,
one on each side. Blocks 218 provide anchors for drive cables 220
which are trained around pairs of longitudinally spaced idler
pulleys 222. The latter are rotatably mounted on support brackets
224 by means of pins 226. Brackets 224 are mounted on leg
structures 18, 19 and are bridged by power air cylinders 228, one
on each side.
Each cylinder is of the class having a floating reciprocating
piston to owhich the ends of one of cables 220 are attached. It
accordingly provides a reciprocating drive for the cable which, in
turn, is transmitted through anchor blocks 218 to the carriage. The
limits of carriage travel are determined by a pair of stops 230,
one on leg 18 and the other on leg 19, positioned in the path of
travel of the carriage anchor block 218.
Also associated with the first stage web infeed subassembly is a
gravity conveyor having for its function the transmission of web
stacks 194, one at a time, from the first stage to the second stage
web infeed subassemblies. The gravity conveyor is indicated
generally at 284 and is illustrated in FIGS. 2a, 2b, 13, 14 and
16.
To accommodate the lateral expansion of the machine as required to
process I-beams of various dimensions, the gravity conveyor is of
such a construction as to be longitudinally expandable. It consists
of a pair of laterally extending, longitudinally-spaced, slidable
bars 286 and 288. The bars are formed in two segments. The infeed
segments of bars 286 are pivotally secured to a pair of brackets
290 by means of pins 292, FIG. 13. Brackets 290 in turn are fixed
to the tops of a longitudinal sub frame 294 integral with leg
structure 18.
The outfeed segments of bars 288 are pivoted to a pair of brackets
296 by means of pins 298. Brackets 296 in their turn are fixed to
channel 21 of laterally moveable frame 20.
Both pairs of bars 286 and 288 have formed on their bottom portions
cooperating longitudinal slots 300, 302. The outfeed segments of
bars 286 have integral outwardly disposed stub shafts 304 which
pass through slots 302 and are retained by clips 306, FIG. 14. The
infeed end segments of bars 288 have integral, inwardly disposed
horizontal stub shafts 308 which pass through slots 300 and are
retained by clips 310.
An integral shoulder 311 is formed along the bottom margin of each
bar 288. The shoulder bears against and supports the bottom edge of
the companion bar 286.
The above structure provides a central truss support while at the
same time allowing for the adjustment of right hand longitudinal
frame member 20 as heretofore described. Bars 286, 288 mount along
their entire lengths a series of closely spaced rollers 307. The
rollers are mounted rotatably by means of stub shafts 309 and are
dimensioned and arranged in such a manner that their upper
peripheral surfaces extend slightly above the planes of bars 286,
288.
Gravity conveyer 284 discharges onto an aligned skid plate 374
supported by laterally adjustable, right hand longitudinal frame
member 20. The infeed side of conveyer 284 is elevated slightly
higher than at the outfeed side. Consequently, when a stack 194 of
webs is pushed by ram carriage 198 onto the conveyer, the stack
will be propelled by gravity along the entire length of the
conveyer, coming to rest eventually on skid plate 374.
THE SECOND STAGE WEB INFEED SUBASSEMBLY
The second stage web infeed subassembly has for its function
transferring the individual stacks 194 of web members from their
ready position on skid plate 374 to a bin located in working
position between the grooved chords 10. The web members then are
dispensed from the bin one at a time and assembled with the chords
in a manner to be described.
The second stage web infeed subassembly, indicated generally at G
in the drawings, is illustrated in FIGS. 2a, 2b, 12, 13 and 15.
Basically considered, the second stage web infeed subassembly
comprises a web stack advancing carriage which sweeps a web stack
194 along the upper surface of skid plate 374, and a dispensing bin
positioned to receive the stack and dispense its component webs
individually from the bottom of the stack.
As shown particularly in FIGS. 12 and 15, the web stack advancing
carriage, indicated generally at 231, includes cross frame members
232 bridging a pair of rectangular end frames 234. The frame thus
comprised is supported on blocks 236 which provide slides for
reciprocating the carriage between advanced and retracted
stations.
To this end blocks 236 have formed within them longitudinal bores
238 with connecting slots 240 which communicate with the
exterior.
Blocks 236 are guided by a pair of laterally spaced, horizontal
rails 242 having integral supporting webs 244. The webs are
supported on the tops of frame members 246 which in turn are
integrated with the leg frame structure 18. Rails 242 are received
slidably in bores 238 of support blocks 236 while webs 244 are
received in slots 240 of the blocks, thereby permitting the sliding
reciprocation of the carriage on the rails.
Stop means are provided for stopping and properly locating the
carriage at its advanced and retracted stations. The stop means
employed comprises stop blocks 248 integrated with structural frame
members 246 and positioned for abutment with the carriage frame at
the end positions of carriage travel.
The reciprocating drive for web stack advancing carriage 231
comprises a pair of drive cables 250 secured to brackets 251 which
are supported on carriage frames 234. Cables 250 are trained around
idler pulleys 252 supported on frame members 254. The latter in
turn are supported by and integral with leg frame structure 18.
The drive for the carriage comprises a pair of double acting air
cylinders 258. These are mounted on and bridge frame members 254,
one on each side of the unit. Like cylinders 228 they are
conventional in construction, being of the class having a free
floating, air driven piston to which the ends of cables 250 are
connected.
Carriage 231 supports pushing or sweeping means which, during the
advancing motion of the carriage, engages the ready stack 194 of
webs waiting on skid plate 374 and slides it along the plate until
it is discharged into the web dispensing bin. The construction of
this unit also is illustrated particularly in FIGS. 12 and 15.
A pair of cooperating, retractable, web stack pusher plates 260 are
supported in a vertical operating position on pairs of vertically
spaced ears 262. The latter are integral with the inner portions of
carriage end frames 234.
Pusher plates 260 are mounted for angular movement in the
horizontal plane by providing in ears 262 bores through which pass
the ends of pivot posts 266. The pivot posts mount sleeves 268 to
which pusher plates 260 are welded. Cross pins 270 at both ends of
the posts retain the plates.
To drive pusher plates 260 between their advanced and retracted
angular positions, sleeves 268 mount horizontally extending tabs
272. Pivot pins 274 pivotally connect to tabs 272 the extendable
operating members 276 of pneumatic cylinders 278. The bases of the
cylinders are pivotally connected by means of pins 280 to the frame
of the carriage, specifically to a plate carried by cable anchor
block 251, FIG. 12.
As noted above, carriage 231 operates to discharge a stack of webs
into a web dispensing bin from which the webs are fed between the
traveling grooved chords. The bin is indicated generally at 312 and
illustrated particularly in FIGS. 1, 2 and 13.
Bin 312 is located along the longitudinal center line between main
frame members 20. It consists of spaced, longitudinal, web bottom
supports 314. These support four corner posts 316. The left hand
posts 316 extend into upper portions 318.
The bin frame thus constituted is supported rigidly by four
integral support arms 320. These extend laterally outwardly from,
and are welded to, vertical support plates 119.
The upper frame portions 318 have integral outwardly extending webs
322 to provide additional guiding means for the incoming web stack
194.
The webs contained in the bin are dispensed individually from the
bin bottom through slots 321 provided by notches in corner posts
316. The slots have a vertical dimension slightly greater than the
thickness of one of webs 12. This permits passage of the web
through the slot while retaining the balance of web stack 194 in
the bin.
THE WEB CONVEYING SUBASSEMBLY
The web conveying apparatus is located directly below bin 312 along
the longitudinal center line of the machine. It serves the
functions of dispensing the webs from the bin by scraping them off
the bottom of stack 194, one at a time, and conveying them in
timed, positioned sequence to the downstream processing units of
the machine.
Indicated generally at H, the web conveying subassembly is
illustrated particularly in FIGS. 1, 2 and 13. It consists of an
endless chain 326 having attached thereto evenly spaced,
web-engaging lugs 328.
The top run of chain 326 is supported by two idler sprockets 330.
These in turn are supported by pairs of bearings 332 on cross
shafts 334.
The mounting of the chain assembly is such that it may be adjusted
laterally, as may the other units of the machine, to accommodate
webs of varying width in the construction of I-beams of assorted
sizes.
To this end bearings 332 are bolted to brackets 338 by means of
bolts 336. Brackets 338 are integral with longitudinal frame
elements 340. These in turn support a pair of sleeves 342 secured
to the underside of both ends of frame elements 30.
Cross bars 44 pass through and adjustably support sleeves 342. A
threaded indexing clamp 344 releasably locks sleeves 342 to the
cross bars. Indexing lines 346 on the surface of bars 44 facilitate
the proper lateral positioning of chain 326.
The infeed end of the bottom run of chain 326 is guided by an idler
sprocket 348 rotatably supported by bearings 350 into which cross
shaft 352 mounting the sprocket is journaled. Bearings 350 are
adjustably mounted to a U-shaped bracket 354 by means of bolts 356.
The bolts are received in slots 358 formed within bracket 354, FIG.
1a.
The legs of bracket 354 extend upwardly and are welded to the
underside of longitudinal frame 340.
The outfeed end of chain 326 is guided by drive sprocket 360 fixed
to the shaft 364 of a gear motor 362. The motor is detachably
mounted on frame 340. The chain is additionally supported by a
longitudinal bar 366 on which tracks the upper run of the chain,
FIGS. 1a and 13.
The chain drive is controlled by means of a travel limit switch
(not illustrated) which energizes drive motor 362 as required to
move lugs 328 in stepped sequence. During each step, one of lugs
328 engages the lowermost web in bin 312, drives it out of the bin,
and to the next processing stage. The chain drive then stops with
the next lug 328 in operative position with respect to the next web
12, awaiting the signal which will initiate the next step of the
chain drive.
As the sequence progresses and the web stack in bin 312 diminishes
to the broken line position 368 of FIG. 13, a sensing switch 372
signals for the introduction of a new stack 194 of webs to be
introduced into the bin.
THE CRIMP WHEEL SUBASSEMBLY
The crimp wheel subassembly, indicated generally at I, serves dual
functions.
It receives the webs urged forwardly one at a time by conveyer 324
and continues to drive them at a controlled rate predetermined to
abut their end edges and crowd them together. This facilitates
setting of the glue applied to the end edges while the webs were
stacked on the first stage web infeed subassembly F.
The crimp wheel subassembly also serves the function of compressing
the side margins of each web to form beveled marginal tongues 16
which subsequently are inserted into the glue-moistened grooves 14
of the chords to unite the three components of the I-beam
assembly.
The construction and manner of operation of the crimp wheel
subassembly is illustrated particularly in FIGS. 2b, 7, 8 and 18.
The crimp wheels are indicated at 376 and 378. They are arranged in
vertically aligned pairs and have a vertical spacing such as to
grip the side margins of web 12, as best seen in FIG. 18. They not
only drive the web toward the outfeed apparatus, but also shape its
side margins.
To this end the peripheral edges 380 of crimp wheels 376 and 378
are beveled in the desired contour for shaping the web margins.
They thus compress the wood to provide tapered margins or tongues
16.
To limit the converging pressures acting on the web margins, crimp
wheels 376 and 378 are provided with coplanar integral flanges 382,
383, respectively. In the operation of the crimp wheels, they
contact each other and act as stops, limiting the degree of
compression of the wood.
The drive for the crimp wheels is illustrated particularly in FIGS.
7 and 8.
Upper crimp wheels 376 are supported on shafts 384 having journal
support in bearings 386. The latter are adjustably secured to frame
plates 119, 387.
Lower crimp wheels 378 are supported on shafts 388 having journal
support in bearings 390. These are detachably mounted to frame
plates 119, 387.
Shafts 384 and 388 mount pairs of meshing gears 392, 394,
respectively. The outer ends of shafts 388 mount drive sprockets
396. These in turn engage a pair of drive chains 398 which mesh
with a pair of sprockets 400.
Sprockets 400 are carried by internally splined sleeves 402
rotatably supported by two pairs of bearings 404.
As with the other elements of the apparatus, provision is made for
lateral extension of the crimp wheel subassembly drive as required
to accommodate webs of various widths.
Accordingly, there is provided a splined drive shaft 403 which is
received by and drives internally splined sleeves 402. Shaft 403 is
integral with the right hand sleeve 402 but is free to move
longitudinally within the left hand sleeve 402, making possible the
desired lateral adjustment.
The right hand end of the right hand sleeve 402 mounts a second
sprocket 406 which is fixed to sprocket 400. Sprocket 406 meshes
with a chain 408 driven by a sprocket 410. The latter in turn is
driven by the shaft of a gear motor 412 mounted on the undersurface
of main frame member 20.
THE CHORD AND WEB UNITING SUBASSEMBLY
Up to this point in the progression of the chord and web components
through the various processing units of the apparatus, the
components have been maintained laterally spaced from each other.
As the components pass through the crimp wheel station, FIG. 7, the
horizontal spacing still is maintained. However, the crimp wheels
position the web with its marginal tongues 16 in precise horizontal
alignment with grooves 14 of the chords.
In the next processing stage, the web movement is continued
linearly in the machine direction. However, the chords are guided
inwardly toward the web until the tongues of the web enter the
glue-moistened grooves of the chords.
Since the chords and webs comprise structural members of great
strength and stiffness, a substantial effort is required to achieve
this result. This effort is resisted by the chords and webs with
the result that, in the absence of properly applied restraining
forces, the chords tend to back away from the web in the horizontal
plane and the web tends to bow in the vertical plane. These adverse
tendencies, if permitted freedom, would cause the tongues of the
web to pop out of the grooves of the chords at intervals along the
length of the assembly, resulting in the formation of discontinuous
joints.
It accordingly is the function of the chord and web uniting
subassembly to guide the chords into assembling relation with the
web, to maintain the web and chords in precise relation to each
other as they are assembled, and to maintain the web and chords in
their assembled condition until a semi-permanent union has been
created.
This union is created partly by the wedging action of the mating
beveled surfaces of the web tongues and the chord grooves; partly
by the spring back forces exerted by the crushed wood of the web
marginal tongues; and partly by incipient bonding of the glue
applied previously to the chord grooves by glue-applying
subassembly E.
The chord and web uniting subassembly comprises a group of
cooperating roller and guide bar assemblies indicated at J in the
drawings and illustrated in detail in FIGS. 1b, 2b, 7, 9 and
11.
The roller assemblies locate the chords in both vertical and
horizontal planes; the guide bar assemblies prevent bowing of the
web.
Positioned upstream and downstream from crimp rollers 376 and 378,
and immediately adjacent thereto, are vertically arranged pairs of
guide rollers 375, 416. These stabilize and guide the joists as
they pass through the crimp rollstation. Rollers 375 bear against
the outside faces of the chords while rollers 416 bear against the
inside faces thereof. The latter rollers thus serve as fulcrums
about which the chords bend as they converge toward the webs, FIG.
2b.
Rollers 375 are supported on brackets 377 and are rotatably mounted
on vertical stub shafts 379, FIG. 7.
Rollers 416 are supported on brackets 418 and are rotatably mounted
on vertical stub shafts 420. The brackets are secured to the inner
faces of frames 20.
Positioned downstream from rollers 416, toward the outfeed section
of the apparatus, are a group of rollers 422. These are illustrated
in FIGS. 1b, 2b, 11 and 19. They bear against the outer side faces
of the chords and guide the chords into wedging engagement with the
side margins of the webs, thereby causing the tongues of the webs
to enter the grooves of the chords.
Rollers 422 are supported on brackets 424 and are rotatably mounted
on vertical stub shafts 426. The brackets are integral with and
mounted on the inner faces of frames 20. They include pairs of
horizontal support members 428 to which stub shafts 426 are secured
by means of bolts 430 penetrating flat terminal segments of the
shafts, FIG. 11.
Cooperating at the chord and web joining station with horizontally
acting roller pairs 422 which bear against the side faces of the
chords, are a plurality of vertically acting roller pairs 434 which
bear against the edge surfaces of the chords.
Rollers 434 are supported on two pairs of longitudinally disposed
mounting bars 432. These are similar in design and manner of
attachment to mounting bars 118 previously described, FIG. 1b.
These rollers are rotatably mounted and supported on bars 432 in
the same manner as rollers 114 are mounted on bars 118, previously
described.
The guide bar assemblies prevent bowing of the webs and position
their beveled side margins accurately with respect to the grooves
of the chords. They are indicated generally at 436 and illustrated
particularly in FIGS. 2b, 9 and 10.
One guide bar assembly is positioned above and the other below the
web in mutually opposed cooperating relationship.
Each assembly includes three guide bars, the left hand one being
fixed to the stationary frame member 20, FIG. 9; the right hand one
being fixed to laterally shiftable frame member 20; and the
intermediate one being adjustable laterally so that it may be
located along the longitudinal center line of webs of varying
width.
The outermost guide bars 438 are supported by outwardly extending
arms 440 which are welded to plates 119 carried by the respective
frame members 20.
The intermediate or center line guide bars 442 are supported by a
pair of longitudinally spaced, vertically extending support arms
444. These are rendered laterally adjustable by integrating them
with horizontal sleeves 446 slidably mounted on horizontal indexing
bars 448. They are relatively elongated in the infeed direction so
that they closely approach the crimp rolls. This insures adequate
web stabilization in an area where it is most needed.
The left ends of bars 448, FIG. 9, are integral with stationary
frame 20. The right hand ends are received by guide sleeves 450
which are integral with laterally adjustable frame 20. Indexing
lines 452 are marked on both bars 448. Clamping screws 454 make
possible releasably clamping sleeves 446 to the bars at the
selected index marks.
Guide bars 438, 442 support contact shoes which slidably engage the
moving web. The upper contact shoes are resiliently mounted to
accommodate the work; the lower shoes are fixed.
As shown particularly in FIGS. 9 and 10, upper guide bars 438, 442
slidably support a series of vertically disposed screws 456. The
leading ends of the screws mount compression springs 460, pass
through bores formed within longitudinal channels 464 and are
threaded into aligned bores formed within longitudinal frictional
guide shoes 468.
Guide shoes 468 bear against the work and are formed of a material
such as "Teflon" or other plastic which is tough, wear resistant,
and has a low coefficient of friction. The guide shoes are pressed
resiliently against the surface of the work by compression springs
460 and are backed up by the longitudinal channel members 464.
The mounting of the lower group of guide bars 438, 442 is similar
to that described above, with the exception that they are not
resiliently mounted, spacers 469 being substituted in the
assemblies for compression springs 460.
ADHESIVE-REPELLENT APPLICATOR SUBASSEMBLY
The chords and web leave the chord and web uniting subassembly K as
an integrated I-beam type truss joist precursor which is
sufficiently self sustaining to be passed to downstream processing
units. Pending final curing of the glue which forms the bond
between chords and web, and as part of subsequent processing
procedures it may be expedient to stack or nest the joists in
direct contact with each other.
This poses a problem, since occasionally excess glue may have been
deposited on the top or bottom surfaces of the chords by operation
of the glue applying subassembly E. More significantly, where the
chords comprise sawn lengths of glue-lam timbers composited from
glued together sheets of wood veneer, the glue applied in grooves
14 of the chords may ooze or seep through any voids which may be
present in the veneer components of the chords and find its way to
the chord surfaces. Accordingly, when the embryonic joists leaving
the present apparatus subsequently are nested or stacked, their
surfaces may become permanently and irrevocably glued to one
another.
To avoid this possibility, the joists leaving the machine are
passed through an adhesive-repellent applicator. This has for its
function applying to side edge surfaces of the joist chords a
quantity of an adhesive repellent which prevents the contacting
surfaces of adjacent joists from sticking to each other. A variety
of solutions may be used for this purpose. One class of such
solution which is satisfactory is that comprising an aqueous
emulsion or solution of mineral or vegetable wax.
The construction and mode of operation of the adhesive-repellent
applicator subassembly K is illustrated in FIGS. 19, 20, 21 and
22.
As illustrated, this subassembly is contained in a frame located
just downstream of the chord-and-web joining subassembly and
comprises base plate 538; a pair of vertical side plates 484 on
each end, horizontally spaced to form a central guideway; and a top
plate 494 connecting the tops of the side plates.
This frame houses a pair of cooperating top idler and bottom
powered rolls 472, 474, respectively. These comprise
liquid-applicator rolls, continuous across the width of the
apparatus, and positioned to contact the top and bottom edge
surfaces of chords 10 as required to apply liquid adhesive
repellent to them.
To enable accommodating chords of varying width, top idler roll 472
is mounted rotatably for vertical adjustment.
To this end, both ends of roll 472 are rotatably supported by a
pair of bearings 476 journaling stud shafts 478 which extend
outwardly from the ends of the roll, coaxially therewith.
The bearings are provided with marginal vertical slots 482 which
receive and are guided by the inner margins of end plates 484.
A pair of threaded studs 486 are vertically aligned along the
center line of stub shafts 478. The lower ends of the studs are
secured to the tops of the bearings 476. Their central portions
pass through and support both ends of a crossframe 488 which is
adjustably secured in a selected vertical position by means of
pairs of clamping nuts 490.
Cross frame 488 is formed with T-shaped cross heads 492. The side
margins of the cross heads are slotted and, like the side margins
of bearings 476, receive the inner side margins of spaced side
plates 484 in slide-and-guide relationship.
The upper ends of stud bolts 486 pass through openings in the ends
of top frame member 494. A pair of lock nuts 496 are threaded to
the upper portions of the stud bolts and limit the vertical
position of roll 472, thereby imparting the desired vertical
adjustability to the assembly.
Raising and lowering of roll 472 are accomplished by means of a
centrally located air cylinder 498.
The connection of the cylinder to the roll, FIG. 22, is via piston
rod 503 of the cylinder, a clevis 504 mounted as a head on the end
of a piston rod, a vertical longitudinal web 500 extending upwardly
from the upper surface of cross frame 488 and having a plurality of
horizontally spaced perforations, and a bolt 502 received in a
selected one of the perforations. Thus, raising and lowering the
piston rod raises and lowers correspondingly roll 502, which
thereafter is maintained gravitationally in precisely the selected
position of adjustment by means of lock nuts 496.
It will be recalled that the right hand longitudinal frame member
20, as viewed in FIG. 2a, is adjustable laterally with respect to
the companion left hand frame member 20, which is fixed. This is
necessary in order to accommodate webs of varying width in the
production of I-beam joists of assorted sizes. This requires that
the adhesive repellent applicator subassembly K be correspondingly
adjustable.
Accordingly, just as connecting clevis 504 mounted on piston rod
503 of the cylinder is positionable laterally, so is cylinder 498
shiftable to a corresponding position of lateral adjustment.
This is made possible by providing in top plate 494 a pair of
marginal slots 508 and an intermediate slot 510, all arranged
longitudinally of the plate and in substantial parallelism to each
other.
The base of cylinder 498 is provided with a flange 505. This is
adjustably secured to top plate 494 by means of bolts 506 passing
through the flanges and slots 508. The piston rod 503 of the
cylinder extends through central slot 510.
The desired lateral adjustment of the assembly then may be secured
by removing pin 502 from clevis 504, FIG. 22, loosening bolts 506,
sliding cylinder 498 and the attached assembly to its new location,
reinserting pin 502 and tightening down on bolts 506.
Roll-moistening means is associated with upper roll 472 as required
to maintain its peripheral surface moistened with adhesive
repellent solution.
The roll-moistening means employed comprises a pair of liquid
applying nozzles 512 mounted on cross frame 488, FIG. 22, by means
of a bracket 518. Each nozzle is connected to a valve 514 which in
turn communicates with a reservoir 542 by means of a conduit 516
with included pump. One such nozzle is positioned directly over the
working areas of roll 472, above the upper surfaces of chords
10.
The left hand nozzle 512 as viewed looking in the machine
direction, i.e. that illustrated in FIG. 22, is fixed. The right
hand nozzle is mounted for lateral adjustment on cross frame member
488, in a manner not illustrated.
Thus to adjust the unit to accommodate joists of different widths,
the fixed left hand nozzle 512 is located over the left hand chord
10. The shiftable right hand nozzle is moved until it registers
with the right hand chord 10 after which it is secured.
Then to insure the application of uniform downward pressure on both
ends of roll 472, bolt 502 is removed from clevis 504 and bolts 506
are removed from cylinder base 505. The cylinder with its attached
piston rod 503 is shifted to the desired new location. Bolt 502 is
reinserted through clevis 504 in the appropriate opening in web 500
of cross frame member 488. This secures the piston rod connection.
The cylinder then is secured by tightening down on bolts 506 in the
new location of the cylinder.
Like upper applicator roll 472, lower applicator roll 474 spans the
entire width of the joist. Unlike the upper roll, however, its
peripheral surface is moistened by direct immersion in reservoir
542, which serves as a source of supply for nozzles 512. Also, the
lower roll serves as a drive roll which drives the joist through
the outfeed portion of the apparatus at substantially the same
speed as chords 10 are fed into the apparatus.
To accomplish these dual functions, both ends of roll 474 mount
outwardly extending stub shafts 522. These are journaled in end
bearings 520. The bearings are detachably mounted on end frame
members 484 by means of bolts 524.
A sprocket 526 is fixed to the end of one of shafts 522 just inside
frame 484 as shown in FIG. 20. Sprocket 526 engages drive chain 528
which at its lower end engages and is driven by a sprocket 530
fixed to drive shaft 532 of motor 534. The motor in turn is
detachably mounted by means of bolts 536 to frame bottom plate
538.
The lower portion of the complete length of roll 474 is immersed in
the adhesive-repellent solution 450, previously described,
contained in the reservoir 542. The reservoir is mounted on
supports 544 integral with frame bottom plate 538.
By this arrangement the bottom surfaces of chords 10 are
continuously coated with glue repellent liquid by transfer of the
liquid from the upper peripheral surface of roll 474 to the
undersurfaces of the chords. Contemporaneously, the upper surfaces
of the chords are coated with the liquid by transfer from the
peripheral surface of upper roll 472, which is continuously
replenished with liquid in the area of the chords by spray nozzles
512.
The joists accordingly leave the apparatus in a self-sustaining
condition with the side edges of the chords coated with an adhesive
repellent. They then are conveyed to further processing.
Since the apparatus is adaptable to the production of continuous
joists of great length, i.e. 80 feet or more in length, it may be
desirable to subdivide them into shorter lengths, or to trim them
to uniform length. If so, the chords may be passed through a
conventional flying cut-off saw 548, FIG. 19. They then may be
conveyed by a conveyor 550 to downstream stations where they are
stacked, oven heated for completing the cure of the adhesive,
nested, and packaged for storing and shipment.
OPERATION
In the operation of the apparatus, chords 10 are fed continuously
into the chord infeed sub-assembly B. Feed rollers 54 drive the
chords forwardly at the machine speed. Hold down rollers 52 press
the chords against the feed rollers to insure a uniform drive.
The chords maintained in laterally spaced apart relationship pass
first through a groove cutting subassembly C, wherein cutters 108
machine beveled longitudinal grooves in the opposed side faces of
the chords. The vertical chords press roller subassembly D holds
the chords precisely in position to insure accurate cutting of the
grooves.
The chords next pass through a glue applying subassembly E where
glue applying heads 150 first direct a jet of air into the grooves
to clean them out and then apply a liquid glue to the cleaned
groove surfaces.
The chords next pass a station in which web members 12 are
introduced into the space between the chords.
The webs are supplied to the apparatus in stacks 194, FIGS. 12 and
13. In the first stage web infeed subassembly F the stacks
supported on a pallet 188 are precisely located on a horizontal
support and their end faces manually coated with glue. A ram
indicated generally at 198 pushes the stacks one at a time onto a
skid plate 374 which is a component of the second stage web infeed
subassembly G.
The latter subassembly comprises a carriage 231 provided with
cylinder driven pusher arms 260 adjustable between open and closed
positions. The stack is pushed by ram 198 between the frame
components of carriage 231 with pusher arms 260 in the open
position of FIG. 15. The arms then are closed, carriage 231
advanced, and the stack skidded forwardly on skid plate 374 into a
bin 312. The bin is positioned between the traveling chords. There
it is deposited on top of a partly diminished working stack.
Individual webs are scraped off the bottom of the stack in bin 312
by means of a web conveying subassembly H, FIGS. 2a and 13. The
conveyer comprises a longitudinally disposed chain 326 mounting
spaced lugs 328 which engage the lowermost web of the stack and
advance it to the next processing stage.
The webs are fed by the assembly including drive chain 326 into a
crimp wheel subassembly I having for its function compressing the
longitudinal side margins of the webs into beveled tongues
dimensioned for reception in the grooves of the chords. The
compression is achieved by application of vertically arranged
cooperating pairs of crimp rolls 380, FIGS. 2b and 7. The crimp
rolls serve the supplemental function of picking up the drive of
the web members from drive chain 326 and driving them into
end-to-end crowded relationship with each other, thereby bringing
together the glue-moistened end surfaces of the webs to integrate
them into a continuous web.
Next the continuously traveling chords and web are brought together
in joist-forming relationship to each other. This is accomplished
in the chord and web uniting subassembly J, FIGS. 1b, 2b, and
10.
In this subassembly there are positioned rollers 375 which engage
the outer faces of the chords in a relatively upstream position,
downstream rollers 416 which engage the inner faces of the chords
and serve as fulcrums about which the chords are bent toward in the
direction of the webs, longitudinally arranged guide bars 436 which
bear against the top and bottom surfaces of the web to prevent it
from bowing, horizontal guide rolls 422 which engage the side faces
of the chords and guide the chords in the direction of the web, and
vertical guide rolls 434 which engage the top surface of the chords
and position them vertically.
The net result is to align the tongues of the webs precisely with
the glue moistened grooves of the chords, to maintain the chords
and webs in their position of precise alignment, and to wedge the
tongues into the grooves. This forms a joist assembly which is
rendered self-sustaining by the frictional engagement of the
tongues of the grooves and in particular by the springback force
exerted by the fibers of the compressed wood tongues.
The joists thus formed then pass through an adhesive-repellent
applicator subassembly K, FIGS. 19, 20, 21 and 22 where a liquid
wax or other glue repellent is applied by means of rolls 472, 474
to the edges of the chord components of the joists to prevent them
from sticking together as the joists are stacked and nested in
subsequent handling. The joists next are cut to length, if
necessary, by means of a flying cutoff saw 548, FIG. 19, and
conveyed away on a conveyer 550 to such further processing as
stacking, oven heating to set the glue, nesting, and bundling for
transportation and storage.
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