U.S. patent number 3,913,904 [Application Number 05/479,548] was granted by the patent office on 1975-10-21 for stacking machine for rubber or the like sheet material.
This patent grant is currently assigned to Mayer Refrigerating Engineers, Inc.. Invention is credited to Louis Occhetti.
United States Patent |
3,913,904 |
Occhetti |
October 21, 1975 |
Stacking machine for rubber or the like sheet material
Abstract
The invention contemplates mechanism for automatically so
converting a continuous delivery of pliant sheet material into a
horizontally reciprocating motion that a uniformly wide vertical
stack of sheet product is developed, as a pallet load of horizontal
layers, for shipment, storage or further processing. In the form
described, the reciprocating mechanism includes a cut-off device so
that discrete sheets are developed to precise length, once for each
half of the reciprocation cycle, and so that all cut sheets or
layers are stacked in vertical register, regardless of the
developed height of the stack.
Inventors: |
Occhetti; Louis (Bloomfield,
NJ) |
Assignee: |
Mayer Refrigerating Engineers,
Inc. (Paramus, NJ)
|
Family
ID: |
23904471 |
Appl.
No.: |
05/479,548 |
Filed: |
June 14, 1974 |
Current U.S.
Class: |
270/30.04;
270/30.1 |
Current CPC
Class: |
B65H
45/103 (20130101); B65H 29/46 (20130101) |
Current International
Class: |
B65H
29/38 (20060101); B65H 29/46 (20060101); B65H
45/00 (20060101); B65H 45/103 (20060101); B65H
029/46 () |
Field of
Search: |
;270/30,31,41,79,39
;271/173,273 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Michell; Robert W.
Assistant Examiner: Millin; Vincent
Attorney, Agent or Firm: Hopgood, Calimafde, Kalil,
Blaustein & Lieberman
Claims
What is claimed is:
1. Apparatus for cutting and stacking sheets of pliant elastomeric
material severed from a continuously supplied web of the material,
comprising a frame including horizontal guide ways and horizontally
spaced upstanding means for supporting the same, a carriage guided
by said ways and first drive means for reciprocating displacement
of said carriage along said ways and over the space between said
upstanding means, web-supply means fixedly positioned above said
carriage for gravitationally downwardly delivering continuous web
to said apparatus generally in the central vertical plane on either
side of which said carriage is reciprocable, first and second
vertically spaced web-hugger means carried by said carriage and on
a common vertical web-supporting alignment which passes through
coincidence with said plane on each reciprocating displacement
stroke of said carriage, web-cutting means on said carriage between
said hugger means and synchronized with carriage displacement to
sever the web into like successive sheets, second drive means for
said hugger means and synchronized with said first drive means to
provide substantially the same speed of web-advance as for carriage
displacement, a pair of web-pinch rolls and pendulous support means
therefore about a horizontal axis through said plane, said pinch
rolls being positioned vertically between said web-supply means and
said web-hugger means, means connected to and reacting between said
carriage and a part of said frame for angularly displacing said
rolls about the axis of pendulous support as a function and in the
direction of the position of said upper web-hugger means along the
path of carriage reciprocation, said pinch rolls and at least the
upper portion of said hugger means being separable for admission of
a leading edge of supplied web material, and means responsive to a
run-out of web material for actuating said separable rolls and
hugger means to separated relation and for terminating
reciprocation of said carriage, with return to said plane of the
web-supporting alignment of said web-hugger means, whereby upon
run-out of supplied web material, said apparatus automatically
conditions itself for clean reception of the leading edge of a
subsequent supply of web material.
2. The apparatus of claim 1, and including an elevator having a
horizontal platform and vertically movable in the space beneath and
traversed by carriage, and means synchronized with the displacement
cycle of said carriage for depressing the platform elevation as a
function of web thickness.
3. The apparatus of claim 2, in which said synchronizing means
includes coacting trip elements on said carriage and at a given
position between the ends of carriage traverse along said ways, and
means for effecting a predetermined incremental elevator drop in
response to each operation of said trip elements.
4. The apparatus of claim 1, in which said web-cutting means
includes a first horizontal shear element fixedly mounted to said
carriage and a second horizontal shear element movable for coacting
with said first shear element and having a path of movement
adjacent to and below said first shear element.
5. Apparatus according to claim 1, in which said last-defined means
includes means responsive to entry of the leading edge of a new
supply of web material for automatically returning said pinch rolls
and hugger means to web-engaging position and for rendering said
first drive means operative to resume reciprocation of said
carriage.
6. Apparatus for stacking horizontal layers of pliant elastomeric
sheet material from a continuously supplied web of the material,
comprising a frame including horizontal guide ways and horizontally
spaced upstanding means for supporting the same, a carriage guided
by said ways and first drive means for reciprocating displacement
of said carriage along said ways and over the space between said
upstanding means, web-supply means fixedly positioned above said
carriage for gravitationally downwardly delivering continuous web
to said apparatus generally in the central vertical plane on either
side of which said carriage is reciprocable, elevator means within
said frame and including means for controlling the elevation of a
stack-receiving platform beneath the path of reciprocating
displacement of said carriage, web-hugger means carried by said
carriage and on a common vertical web-supporting alignment which
passes through coincidence with said plane on each reciprocating
displacement stroke of said carriage, second drive means for said
hugger means and synchronized with said first drive means to
provide substantially the same speed of web-advance as for carriage
displacement, said first drive means including means coacting with
adjustably preselected opposite limits of carriage travel along
said ways for reversing the direction of carriage displacement, a
pair of web-pinch rolls and pendulous support means therefore about
a horizontal axis through said plane, said pinch rolls being
positioned vertically between said web-supply means and said
web-hugger means, means connected to and reacting between said
carriage and a part of said frame for angularly displacing said
rolls about the axis of pendulous support as a function and in the
direction of the position of said upper web-hugger means along the
path of carriage reciprocation, said pinch rolls and at least the
upper portion of said hugger means being separable for admission of
a leading edge of supplied web material, and means responsive to a
run-out of web material for actuating said separable rolls and
hugger means to separated relation and for terminating
reciprocation of said carriage, with return to said plane of the
web-supporting alignment of said web-hugger means, whereby upon
run-out of supplied web material, said apparatus automatically
conditions itself for clean reception of the leading edge of a
subsequent supply of web material.
7. Apparatus according to claim 6, in which said means for
controlling elevation includes a synchronizing connection
responsive to carriage reciprocation, the elevation-change rate
being proportional to the number of carriage reciprocation strokes
and to the thickness of supplied web material.
8. Apparatus according to claim 7, in which said means for
controlling elevation includes means for selectively adjusting the
elevation-change rate to assure maintenance of essentially the same
plane of horizontal support offered by the topmost ply of a stack
of sheet material being loaded onto the platform.
9. Apparatus according to claim 6, in which said first drive means
includes means determining a first and longer amplitude of the
reciprocation cycle of said carriage as well as means determining a
second and shorter amplitude of the carriage-reciprocation cycle,
cycles of longer and shorter amplitude being interlaced.
10. Apparatus according to claim 9, in which the longer and shorter
amplitude cycles are symmetrically disposed about a midpoint common
to said longer and shorter amplitude cycles, whereby folded
material is automatically stacked without cumulative build-up of
elevation localized at the ends of the stack.
11. Apparatus according to claim 6, in which said last-defined
means includes means responsive to entry of the leading edge of a
new supply of web material for automatically returning said pinch
rolls and hugger means to web-engaging position and for rendering
said first drive means operative to resume reciprocation of said
carriage.
Description
This invention relates to a machine for automatically stacking, in
successive horizontal layers, pliant sheet material that is
delivered continuously to the machine.
It is an object of the invention to provide an improved stacking
machine of the character indicated.
Another object is to provide such a machine which will continuously
accommodate a continuous feed of incoming sheet material, without
subjecting the material to interrupted or intermittent motion in
the longitudinal direction of material motion.
A further object is to provide cut-off mechanism in such a machine
whereby severed sheets are uniformly stacked, in vertical
register.
It is also an object to achieve the above objects regardless of the
developed vertical height of the stack, within the vertical
stacking capacity of the machine.
Another specific object is to provide such a machine with automatic
capability of reconditioning itself to accept a new supply of input
material, upon exhaustion of a continuous preceding run of input
material.
A still further specific object is to achieve the above objects
without subjecting the input material to stretching or other undue
forces.
It is a general object to achieve the above objects in a machine
which is basically simple and foolproof, which has inherently high
capacity to handle relatively high speeds of continuous
input-material supply, and which is relatively simple to adjust for
various desired elemental lengths of stacked material and for
various different thicknesses of input material.
Other objects and various further features of novelty and invention
will be pointed out or will occur to those skilled in the art from
a reading of the following specification in conjunction with the
accompanying drawings. In said drawings, which show, for
illustrative purposes only, a preferred form of the invention:
FIG. 1 is a simplified view in elevation of a machine of the
invention, shown connected to a horizontal conveyor for continuous
supply of pliant sheet material;
FIG. 2 is an enlarged fragmentary view of material-handing means at
the upper or input end of the machine;
FIG. 3 is a further enlarged view to show detail of one part of the
handling mechanism of FIGS. 1 and 2;
FIG. 4 is a plan view of horizontally reciprocated meshanism in the
machine of FIG. 1;
FIG. 5 is an enlarged view in elevation of the mechanism of FIG. 4,
parts being shown in section taken substantially at the plane 5--5
of FIG. 4;
FIG. 6 is a diagram schematically representative of coacting parts
of the machine and arranged in vertical elevation; and
FIGS. 7 and 8 are simplified diagrams applicable to an alternative
employment of structure already shown, FIG. 7 being a simplified
view in elevation to show a folded stack of uncut material, and
FIG. 8 being an electrical control schematic therefor.
Referring first to FIG. 1, the invention is shown in application to
a machine contained within and supported by upstanding floor-based
structure in the form of four legs 10, spaced at the corners of an
elevator platform 11 and united at its upper end by connecting
upper and lower beams 12-13 and by braces 14. Motor means 15 has
sprocket-drive connection to endless lift chains 16 in each of the
legs 10, relying upon synchronized interconnection as suggested at
16', for positive control of the elevation of platform 11; as
shown, a pallet 17 to be loaded stands upon the base or floor and
straddles the elevator 11 with sufficient vertical clearance D to
enable insertion of the lift fork of a conventional fork-lift
truck, for pallet placement and replacement. An upper frame
including laterally spaced horizontal girders 18 is rigidly spaced
by columns 19 on and above beams 12; girders 18 are rigidly spaced
by end members 18' and establish a horizontal track for a
reciprocating carriage 20, extending laterally between girders 18
and shown in FIG. 1 only by schematic phantom outline. Girders 18
extend in horizontally offset relation beyond the horizontal extent
of the supporting frame means 12, so that carriage operations may
serve the entire platform capacity of elevator 11, and it will be
understood that except for carriage 20 and elevator 11 the entire
area between girders 18 (and between the below beams 12) is open,
for accommodation of stacking operations.
A continuous web of pliant sheet material, such as soft uncured
rubber, is continuously supplied by endless conveyor means 21 to
the indicated machine. Conveyor means 21 is shown suspended by
means 22 from overhead or ceiling beams and extends horizontally
for right-to-left discharge to a first hugger mechanism 23 of the
stacking machine. A portion of the incoming sheet material is
visible at 24, as it enters the hugger means 23, where continuous
horizontal motion is converted to continuous vertically downward
motion. The inlet hugger means 23 is also suspended from above, and
the suspension frame includes a rigid frame means 25
interconnecting the overhead frame and the track frame 18--18', to
assure synchronized and fully registered operation. Further
material-handling means 26 has pendulous pivoted connection to the
overhead frame and automatically guides incoming sheet material to
the carriage 20, in accordance with carriage position, as will be
described in connection with FIGS. 2 and 3.
In FIG. 2, the inlet hugger mechanism 23 is seen to comprise a
vertically oriented first endless belt 28 spanning vertically
spaced rolls 29-30; suspension-link means 31 is pivoted on the same
fixed axis as the drive shaft to roll 29 and carries the lower roll
30 at its swingable lower end. A second endless belt 32 courses
upper rolls 33-34 to establish a down-ramp for the material 24
discharged from conveyor 21; this down slope brings the material 24
to the vertically downward running course of belt 28. A lower roll
35, beneath roll 33 and at the elevation of roll 30, establishes a
vertically downwardly running course of belt 32 matched to the
speed and direction of the adjacent course of belt 28, as suggested
by synchronized connection 36 of the respective belt drives to the
drive for conveyor 21. As shown, the rolls 33-34-35 and a further
idler roll 37 are all fixedly mounted with respect to frame means
25, and the swingable mounting of belt 28 enables adaptation to
thickness of incoming sheet material. Adjustable means 38 enables
selection of the force with which the adjacent courses of belts
28-32 will hug the incoming material 24. It will be understood that
means (not shown) are provided for selective retraction of
suspension 31 from the material-hugging position shown, as for
initial set-up purposes.
The pendulous material-handling means 26 accommodates vertically
downwardly discharged material 24 issuing continuously from the
inlet hugger 23. Means 26 comprises adjacent pinch rolls 40-41
lightly squeezed by resilient means 42 in their application to both
sides of the full width of material 24. As shown, the pinch-roll
suspension is carried by end-frame plates 43 keyed at 44 to a
mounting shaft 45, the ends of which project for support in
bearings (not shown) in frame 25; one end of shaft 45 carries a
sprocket wheel 46 (FIG. 2) by which it derives rotary reciprocating
drive from a chain connection 47 to a drive-sprocket wheel 48, and
the latter is secured to its frame-mounted pivot shaft 49. A
telescoping link 50 has pivoted connection at its lower end to part
of the horizontally reciprocating carriage 20, and at its upper end
link 50 has keyed connection to shaft 49; thus, movement of
carriage 20 to the right or left of its centered position (FIG. 2)
will cause shaft 49 to partially rotate as it tracks the
instantaneous orientation of the telescoping link 50, and this
partial rotation correspondingly alters the pendulous orientation
of the pinch-roll suspension frame 43 about its pivot axis 45, as
suggested by phantom outlines 26a and 26b for the extreme outer
oriented positions of means 26 in FIG. 2.
Corresponding ends of the pinch rolls 40-41 have pivoted support at
the lower end of one of two bell cranks 51-52, and the latter are
pivotally mounted at 53-54 to the adjacent end-frame plate 43.
Remaining arms of bell cranks 51-52 are horizontally slotted and
overlap, for pinned connection at 55 to single-acting
roll-retraction actuating means 56; actuation by means 56 involves
downward thrust of pin 55 and thus a separating displacement of
rolls 40-41, against the tension of resilient means 42. As
indicated in FIG. 2, automatic control means 57 responds to
detected run-out of material 24 to actuate means 56 and to thus
retract rolls 40-41 from their material-squeezing position. To
complete the description of the pinch-roll assembly, funnel-shaped
elongate guide plates 58-59 span the distance between endframe
plates 43; they define a wide-open convergent mouth for initial
guidance of the leading edge of new material supplied from conveyor
21, via hugger 23. It will later be clear that under such
initial-feed conditions, the pinch rolls 40-41 are separated and
carriage 20 (as well as assembly 26) is in its centered position,
with the mouth of guide means 58-59 directly beneath the vertical
discharge alignment of hugger 23.
The carriage 20 will be described in connection with the generally
plan and side-elevation aspects of FIGS. 4 and 5, respectively.
Basically, the carriage frame is open-rectangular, being defined by
opposed pairs of channels 61-62, 63-64 and having plural sets of
flanged wheels 65 to ride wear plates on lower flanges of the track
girders 18. An upper hugger 66 establishes precise vertical
alignment of material 24, received from the pinch rolls 40-41 and
delivered to horizontally acting cut-off means 67, and a lower
hugger 68 establishes precise vertical alignment of successively
severed sheets for stacking, as well as delivery of said sheets in
such synchronism with the traverse of carriage 20 as to assure
registry of the stacked sheets. Operations to be synchronized with
carriage position are picked off by track-mounted limit switches,
to be described later in connection with FIG. 6, as these switches
become actuated by a carriage trip lug 69.
As shown, the cut-off mechanism comprises a fixed or anvil shear
element 70 which is removably mounted to an anvil plate 71, forming
part of the rigid frame structure of carriage 20. The movable shear
element or blade 72 is horizontally reciprocated between positions
shown in FIG. 5 by solid outline (72) and by dashed outline (72').
Blade 72 is mounted on a slight angular bias to the transverse
dimension of carriage 20, so that, for any given cut-off, shear
action develops progressively across the sheet material 24, as will
be understood. Blade 72 is shown mounted at the forward end of
slide plate structure 73 which mounts spaced sets of blocks 74-75,
clamped to guide spaced parallel rods 76-77. In turn, rods 76-77
are slidable in corresponding sets of guide bushings, such as ball
bushings 78--78' for rod 76, and 79--79' for rod 77, these bushings
being mounted by means 80--80' to parts 81--81', respectively, of
the carriage frame. Parellel to and between the rods 76-77,
double-acting fluid-pressure means 82 is mounted to the carriage
frame and includes an actuating-rod connection 82 to a bracket
forming part of the slide structure 73. It will later be explained
how the fast "out-in" reciprocating cycle of means 82-83 is
initiated, to produce a cut-off stroke, twice per reciprocating
cycle of carriage motion.
The upper hugger 66 comprises counter-rotating first and second
endless belts 85-86 which have adjacent vertically downwardly
driven courses for engagement of material 24. Belt 85 runs over a
large upper roll 87 and a small lower roll 88, both suitably
shaft-mounted and journaled in the carriage frame. The upper roll
87 receives its drive via sprocket connection 89 to an upper shaft
90, and this drive is synchronized with that of conveyor 21, as
suggested by legend in FIG. 5; shaft 90 is shown mounted by
pillow-block means 91 on the respective carriage-frame members
61-62.
The other belt 86 of hugger 66 has a floating suspension, being
hung from spaced plates 92. Thus, the large upper roll 93 is
shaft-mounted to correspond in size and elevation with the adjacent
roll 87, but the shaft 94 for roll 93 is journaled in plate 92;
springs 95, preloaded by adjustment at 96, resiliently load the
upper parts of hugger 66 to the material 24. The lower roll 97 for
belt 86 is also floating, being mounted by shaft 98 to the lower
ends of plates 99, the latter having pivotal connection to plates
92, via shaft 94; and further springs 100, preloaded by adjustment
at 101, resiliently load the lower parts of hugger 66 to material
24. Tensioning means for belt 86 is indicated at an adjustable
bell-crank suspension 102 for a tension roll 103, and similar means
for tensioning roll 85 is merely suggested at roll 103'. Drive to
belt 86 is via meshing 1:1 gears 104-105 on shafts 90-94.
The lower hugger 68 may be as described for hugger 66, being
mounted to carriage-frame structure 106 and comprising
counter-rotating endless belts 107-108 on a material (24) engaging
vertical orientation aligned with that of hugger 66. As shown, belt
108 runs on upper and lower rolls 109-110 on carriage-fixed rotary
axes, whereas the suspension belt 107 is semi-floating. The shaft
111' of the upper roll 111 for belt 107 is journaled in plate means
112 that is pivotally suspended from pillow-block means 113, and
the lower roll 114 is journaled on a floating axis, at shaft 114',
the same being journaled in link-plate means 115 pivotally
suspended from shaft 111'. Shaft 114' has synchronized drive
connection to the upper hugger, as suggested at 116, and a 1:1
reversed-direction connection 117 of adjacent lower roll shafts
establishes full synchronization for the remaining hugger belt 108.
Tension-spring means 118 is connected at one end to the carriage
frame and at its other end to the suspension plate means 115, to
assure desired loading of the floating part of the lower hugger,
and a limit switch 119 monitors the position of plate means 115 for
correct material thickness, as will be understood.
Operation of the machine will best be understood in reference to
FIG. 6 wherein many of the described parts will be recognized. But
it will help to first identify certain additional parts having to
do with automating features. Thus, a frame-mounted light source 120
and aligned photcell 121 establish a beam across the path of
material 24 as it issues from the lower hugger 68; detected
presence of the beam will mean run-out of the supplied material 24,
the photocell output being used appropriately to provide a visual
display of the run-out condition, or drive shut down, as desired.
If material 24 is not being supplied at high speed, detected
presence of the beam will also mean that the trailing end of a
cut-out piece 24' of material has been released from hugger 68; and
such information may be used to incrementally and downwardly
reposition the elevator 11 in accordance with the known
sheet-material thickness.
In the preferred embodiment, however, I employ a central
frame-mounted switch or trip means A, coacting with passage of lug
means 69 to generate an elevator-reposition impulse, for each
stroke of carriage 20. The output of switch A is amplified and
supplied to suitable signal-processing means 122 for control of
motor 15, which in turn has a reduction-gear connection 15' to the
elevator sprocket drives 16--16'. Also in the preferred embodiment,
limit switch 119 is used as the detector of run-out of material 24,
being specifically used to automatically reposition carriage 20 to
its centered position; as shown, such carriage-centering control
means 123 is operative upon the carriage drive motor 124.
In the start-up of the machine, for any new supply of sheet
material 24 from conveyor 21, carriage 20 will have been
"centered," with the vertical alignments of huggers 66-68 directly
beneath the pinch-roll assembly 26, and with the latter vertically
positioned; the carriage-centered location will have been
determined by contact of trip lug 69 with a carriage-center limit
switch A along track 18. At the same time, in view of the detected
run-out of the prior supply of material 24, the pinch-roll jaws
51-52 will have been opened by control from the output of means
119, as indicated by legends in FIGS. 2 and 6. Also, the elevator
11, loaded with an empty pallet 17, will have been positioned at
the top of its travel, awaiting application of the first sheet 24'
to be cut from the new supply of material 24.
As the new supply of material enters the machine and feeds
vertically through hugger 23, through the open jaws of the
pinch-roll assembly 26, through hugger 66, through open cut-off
elements at 67, and through hugger 68, the lower hugger switch 119
detects full loading of the mechanism and will be understood to
initiate carriage drive in one direction, as for example, in the
right-to-left direction, the requisite control connection to
drive-control means 127 for motor 124 being suggested at 128. On
its way to the left end of the carriage traverse, trip lug 69 (FIG.
4) intercepts and actuates a "left" cut-off limit switch B along
track 18, and operation of switch B will be understood to initiate
the rapid in-out reciprocation cycle of the cut-off actuator 82. At
this point, the cut-off first piece (which is too short) continues
to be held and fed by hugger 68 as the leading edge of the next
length of material 24 continues its motion and enters hugger 68;
the left-ward traverse motion of of carriage 20 also continues,
until trip lug 69 intercepts and actuates a third limit switch C,
for reversing-control operation upon the drive means 124.
It has been previously indicated that carriage-drive speed
substantially matches material-feed speed, e.g., on conveyor 21 and
by huggers 23-66-68. For assurance of this condition, motor-drive
control 127 is shown governed by synchronizing means 129 having
separate inputs 130-131 for respectively sensing speed of the
material-feeding mechanism and for sensing the driven speed of the
carriage, it being understood that control means 127 is responsive
to means 129 in the sense and magnitude necessary to have
carriage-traverse speed match the material-feed speed. But since
the direction of carriage traverse must reverse twice per
reciprocation cycle, the synchronizing means 129 is shown with an
appropriate gating function, triggered to determine a synchronizing
interval, once per traverse. Thus, actuation of reversing switch C
will be understood to operate a reverse-drive and gate-initiating
function via input 132 to synchronizing means 129, causing
commencement of the left-to-right carriage traverse and the
performance of synchronizing functions to assure correct speed of
such traverse; and the corresponding reversing switch D at the
other end of track 18 (operative upon a further input 133 to means
129) will be understood to perform similar functions, to assure
right-to-left traverse at the correct speed.
Returning to the operation of the machine upon material 24, it will
be recalled that the short-cut initial piece was immediately
succeeded by new material 24 entering hugger 68. Prior to lug
actuation of the reversing switch C, and while carriage 20 is still
in its right-to-left traverse, the short-cut piece is dropped onto
pallet 17, and the operator may simply grasp and remove it if he
wants to assure that all loaded pieces are of uniform size. Pallet
17 may therefore be "clean" at the time of actuation of reversing
swich C, after which time the cut leading edge of the new material
may be just contacting pallet 17. Now, since carriage-traverse
speed and material-feed speed are closely matched, the new piece
will neatly lie down upon the upper surface of pallet 17, without
any drag force whatsoever, in the course of continued left-to-right
traverse. During this left-to-right traverse, lug 69 intercepts and
actuates a "right" cut-off limit switch E calling for another
cut-off cycle by means 82 (67). Thereafter, and prior to the end of
the left-to-right traverse, the freshly cut end of the piece 24' is
released from hugger 68, allowing the same to drop to what will
become the right-hand limit of a developed stack 135 of cut sheets
24' . It will be understood that the right-hand reversing switch D
is so positioned in relation to the described events that
carriage-traverse reversal may occur when the vertical plane of
newly fed stock 24 is at a location slightly offset beyond the
horizontal end of the severed and dropped piece 24' and that the
new right-to-left traverse is so coordinated that the leading edge
of the new sheet 24' necessarily registers with the right-hand edge
of stack 135; since carriage speed is synchronized with
material-feed speed, the right-to-left traverse accomplishes
application of the new piece 24' in correct, non-dragging, register
with the stacked previous piece or pieces. Again, cut-off
determined by switch B on right-to-left traverse is operative to
provide precisely the correct length, matching that of the piece
24' produced on left-to-right traverse, and with the released cut
trailing end falling down into correct registry prior to initiation
of the next traverse reversal.
It will also be recalled that each time the trailing end of a cut
piece 24' is released from hugger 68, the switch or trip A
developes a momentary "piece count" response, so that the elevator
position becomes indexed downwardly to the extent of one sheet
thickness. This being the case, the horizontal plane for
pallet-loading each newly cut sheet 24' is always at the same
elevation, so that the described cycle of reversing traverse,
cut-off and release can repeat to assure correct registration of
all pieces in stack 135; in FIG. 1, I show adjustable means at 15'
whereby a machine operator may correct the elevator-reposition
increment so as to assure a correct and substantially constant
elevation for the top sheet of the stack at all times. When the
desired number of pallet-loaded sheets has been counted, or the
conveyor-delivered material 24 has become exhausted, the operation
may be terminated, and elevator 11 lowered to permit pallet removal
and replacement.
In the course of the described traverse reciprocation of carriage
20, it will be appreciated that the pinch-roll assembly 26
oscillates pendulously about the axis of its rocking shaft 45. In
so doing, this assembly controls the uniform delivery of material
24 to the upper carriage hugger 66, appropriate to the
instantaneous location of carriage 20 with respect to the
"centered" location. Such control enables the machine to handle
high speeds of continuous material feed without development of
jamming or folds of material at any part of the machine.
The described machine will be seen to have achieved all stated
objects with basically simple and foolproof structure. Large stacks
135 are quickly and uniformly generated, without development of any
dragging forces on the material; this is most important in the
handling of fresh uncured material 24, such as rubber.
While the invention has been described in detail for the preferred
form shown, it will be understood that modifications may be made
without departure from the scope of the invention. For example, in
the event that the pallet-loaded material is merely to be developed
as a stack of continuous, alternately folded material, the
described cut-off functions may be eliminated merely by appropriate
disabling or removal of the limit switches B and E. The uniformity
of traverse reversals and synchronizing of carriage-traverse speed
with material-feed speed, coupled with downward indexing of
elevator position, will assure perfect alignment and registry of
all folds of the developed stack.
Preferably, I so devise the carriage-traverse control that long and
short folded lengths are stacked in interlaced relation. For
example, in FIG. 7, a first left-to-right traverse is terminated by
switch D controlled reversal ("D-Fold"), and a second traverse
right-to-left is terminated by switch C controlled reversal
("C-Fold"), thus determining first and second extremeouter folds of
the material 24. On the third and fourth traverses, switches E and
B determine the right and left folds ("E-Fold," "B-Fold") of
lesser-spaced folds of the same material, the latter folds being
symmetrically offset inwardly of the outer folds determined by
switches D and C. Successive traverses thereafter sequence in the
same cyclic pattern of reliance on switches D and C for outer
folds, and on switches E and B for inner folds, in stacked
interlaced relation. The net result is a neat self-retaining stack
of folded uncut material wherein adjacent folds do not cumulatively
build the ends of the stack any more than the flat spans between
folded ends.
A circuit for establishing the interlaced stack of FIG. 7 is
schematically presented in FIG. 8, wherein motor 124 is driven for
traverse directions in accordance with the "F" (forward) or "R"
(reverse) state of a flip-flop 140, the "C" and "D" outer trips
being shown connected to change flip-flop state upon each actuation
by lug 69. Trip "A" is connected to a divide-by-two counter 141,
which is so connected to relay means 142 as to change the state of
its contacts once every two traversals of the switch A position.
Thus, on the first two traverses, the contacts of relay 142 may be
open, allowing trips "C" and "D" to determine the first two
traverse reversals. After counting two traverses at 141, relay 142
is actuated to place the inner-fold trips "B" and "D" in
controlling relation with flip-flop 140, thereby setting the stage
for shorter "forward" and "reverse" traverses, before recycling
with two longer "forward" and "reverse" traverses. It will be
understood that, although not shown in FIG. 8, switch A is also
used for the elevator-repositioning function described in
connection with FIG. 6, thus assuring uniformity of respective
developed long and short lengths throughout the stack of FIG. 7
.
* * * * *