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Патент USA US3033572

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May 8, 1962
c. H. KRETZ, JR
3,033,562
VACUUM-BLAST PICKUPS FOR SHEET MATERIAL
Filed Feb. 5, 1960
2 Sheets-Sheet 1
F/G_/
INVENTOR.
CHARLES H. KRETZ, JR.
A T TORNEY
May 8, 1962
3,033,562
c. H. KRETZ, JR
VACUUM-BLAST PICKUPS FOR SHEET MATERIAL
2 Sheets-Sheet 2
Filed Feb. 5, 1960
INVENTOR.
CHARLES H. KRETZ; JR
BY
A 7'TORNEV
3,033,562
Unite Sates Patent 0
2
1
FIG. 5 is a cross section elevation view taken along the
line 5+5 of FIG. 2.
3,033,562
VACUUM-BLAST PICKUPS FoR SHEET MATERIAL’
Y
'
_
The method of this invention ‘is particularly applicable
to the handling, of ?exible sheet material. By ?exible
San Mateo, (Ialif.
Filed Feb. 5, 1960, Ser. No. 7,068
7 Claims.
'
“I The Method of the Invention I
Charles H. Kretz, Jr., 313 ‘Rolling Hills Drive, .
> :
Patented May 8, 1962.
sheet material, in this sense, is meant a sheet ofmaterial
(Cl. 271-46) »
(Granted under Title 35, ‘US. Code (1952), see. 266)
whose dimensions and weight and stiffness are so pro~
portioned that when a sheet of the material is supported
The invention described herein may be manufactured
at'two substantially spaced points de?ning a line, lying
and used by and for the Government of the United States 10 in the surface of the material when the sheet is plane, rela
of America for governmental purposes without the pay
tively close to one boundary of the sheet and the sheet isv
ment of any royalties thereon or therefor.
’
held at these points in ‘such amanner that the straight line
This invention relates to pickups for sheet material and
lying in the surface of theimaterial and passing‘through, Y "
more particularly to pickups using a combination of vac
the two points remains as a straight line oriented generally
uum and blast.
The invention also relates to a method 15
handling sheet material in stacks. The apparatus of the
invention is especially useful in collating machines'of the
type shown in my pending application, Serial No. 626,553,
and hang down from the line of support. ' Ordinary paper
such as used in‘writing, printing, and mimeographing falls
?led December 5, 1956, and is an improvement on the
pickup assembly described in that patent application,
reference to which may be made for the background set
ting of this invention. The collating machine of the afore
mentioned patent application is a machine in which stacks
horizontally, the sheet will droop because of its weight‘
20
into .thispcategory of ?exible sheet material as may also
plastics, ?ber products, metal foil, and materials of other
compositions.
The method of the invention is directed to removing the
top sheet from a stack of sheet material and holding it in
such a clon?iguration'that it doesnotdroop, and retaining
of sheet material, such as paper, to be collated move as a,
it in this con?guration until it is.released,__ for example,.
unit relative to a collector station while pickup means, 25 intoa collector. The methodaccomplishes?the' functions
moving with the unitary motion, gradually pick up
a sheet
from each stack and deposit it at the collector station as
that stack passes adjacent the collector station.
of separating at least a part of the topsheet from contact
with the next sheet so that two sheets ~are not removed
together from the stack and of making the‘v top sheet rigidi
Priorart pickups of the type shown in the aforemen
so that the stack and, it can be bodily separated from each
30
tioned application for the handling of sheet material in,
other while it remains rigid and does not droop.
.
stacks‘comprise. a movable assembly including vacuum
The method comprises bending the top sheet of a stack
cups, suckers, or the like adapted to engage the top sheet
in such' a way that the sheet becomes rigid by'virtue of
of material in a stack adjacent its leading edge and a
being bent or having a crimp put in it so ‘that it will,v so
blast such as an air blast directed against the leading edge
to speak, support its own weight through its stilfness
35
of the top sheet in the stack and other adjacent sheets so
without drooping when held at as few as two points sub
as to separate the upper sheet from those next to it. ' With
stantially spaced apart. The method further comprises.
the removal, bodily, of the top sheet from the stack which
other than those just described, the top sheet of a stack’
can be (accomplished either by leaving the stack in its
is picked upnear its leading edge, but its trailing edge is
original position and moving the top‘ sheet away from it
40
allowed the droop downward. When such a sheet with
or by holding the top sheet still and removing the stack
such pickup assemblies having essentially no elements
its drooping trailing edge is moved relative to a collector
into which collector the sheet is to be deposited, thedroop
ing portion of the sheet may strike an edge of the collector
which sometimes causes the sheet to be knocked off the
pickups and lost to the collating operation.
from it or by a combination of these two procedures
wherein the top sheet and the stack are each ‘moved in
opposite directions away from their original positions.
The method of the invention is applicable to‘ sheets of
Also, such 45 material of practically any shape: round, rectangular, ir
prior art pickups sometimes pick up two sheets together,
which is undesirable. An object of the present invention
is to provide a method for handling sheet material in
stacks which will certainly separate the top sheet from.
regular, etc. The sheets may be oriented in any of several
directions: horizontally, vertically, orat an angle to the
vertical. In carrying out the method of the invention, the
top sheet of a stack is bent in such a manner as to render
the stack and will bend it and grasp it in such a manner. 50, the sheet relatively rigid. The sheet is grasped at at least
that it is crimped and thus the sheet remains relatively
rigid, rather than having its trailing edge drooping, so
two spaced points to retain the sheet in the rigid con
?guration. The grasping of the sheet mayoccur prior to
that it can be readily deposited in a collector or otherwise‘.
the bending or subsequent thereto. After being grasped
disposed of without danger of being knocked off or falling
55 and bent, the sheet is retained 'in its. rigid con?guration
off the pickup assembly. '
while the sheet and the stack are’ separated from each,
Another object of the invention is to provide pickup.
otherf The sheet is held in this rigid position until it is
apparatus of a type suitable to carry out the method of.
the invention.
_
.
Other objects and many of the attendant advantages of
this invention will be readily appreciated as the same be
comes better understood by reference to the following
detailed description when considered in connection with
the accompanying drawings wherein:
released from the grasps.
'
By way of example only, several applications of the
method are described herein with reference to a common
sized sheet of paper considered to be 8 x 11 inches in
size, designating the 11-inch edges as the sides and the
8-inch edges as the top and bottom.
One application of the method of the invention would
FIG. 1 is a front elevation partially in cross section of 65 be grasping the top sheet of a stack of such paper at two
points located on a midline running from top to bottom
a preferred embodiment of the apparatus of the invention,
with the paper-retaining lip omitted for clarity;
FIG. 2 is a top view of the embodiment of FIG. 1;
FIG. 3 is an elevation view taken along the line 3—3‘in
FIG. 2;
FIG. 4 is an elevation view partially in cross section,
taken along the line 4-4 in FIG. 2; and
of the sheet and, for convenience, relatively close to the
top and bottom, say one inch from each such edge. j These
two points, when the sheet is plane, de?ne a straight line,v
the ‘aforementioned midline passing from top to bottom.
If now the paper is bent so that these two points approach
' each other in space, the two points moving away from the
3,033,562
3
4 s
stack in the process so that the top sheet becomes convex
towards the stack, then the sheet becomes stiff or rigid
in the direction parallel to the sides so that when it is
separated from the stack, either by moving the grasped
points away’ from the stack or moving the stack away
from the top sheet, or by a combination of such motions,
the paper remains rigid without drooping, being perhaps
inthe form of a catenarian cylinder or the like. In con
.
combination of such motions can be used with either. the
stack- remaining stationary and the top sheet moving, or
vice versa, or motion of both elements taking place.
In using the method. of the invention, although various . '
amounts of bending or crimping can be used in various
situations, it is preferable in a typical situation to bend
or crimp the sheet only deep enough to produce the de
sired rigid con?guration and so that no partof the sheet
trast, if the sheet were held at the same places, not in
extends appreciably out of a plane. In the'jcase of the
accordance with the invention, but in such a manner that 10 common 8 by 11 inch, themost distant portions may not
the midline passing through the points was retained as a
straight line, as it is when the sheet is plane, the two long
sides would hang down with the sheet bending about the
midline and taking a shape somewhat resembling the same general type cylinder but concave downward toward the 15
stack.
‘
If the sheet is now to be moved bodily in the direction
be as much as 1A1 inch from each other out of a plane.
The method of the invention can be carried out either
by hand or by various types of apparatus and the se
quence of steps can be varied.
For performing the func
tion of bending the paper, various items of equipment can
be used. For example, an air blast directed against the
edges of the sheets in a stack close to the top of a stack
ofv its short dimension (i.e., in‘ the direction parallel to
can be used to assist in separating the top sheet from con
the top and the bottom) for the purpose of depositing it in
tact with the next sheet and to assist in bending the top
the‘collector, for example, then it can be seen that the 20 sheet. Also, suction devices at properly spaced points
sheet will move readily past any upstanding side of the
can bend the sheet While a restraining element holds in
collector when it is held according to the method of the
its original position a point intermediate the areas sub
invention in a rigid con?guration whereas, if his held in
jected to the greatest displacement in the bending proc
drooping fashion, not according to the invention, the
ess. Friction grasping devices such as rubber ?ngers,
drooping portions of the sheet may very well brush against 25 rubber rollers and the like can also be used to accom
an upstanding side of the collector and produce undesir
plish the bending and the gripping functions. Additional
" able results such'as ‘folding the sheet as it enters the col
bends can be produced about points other than the one
lector or causing a jam if sheets are deposited in rapid
aforementioned point of restraint to assist in separating
sequence in the collector or being knocked from the grasp
the top sheet from ‘contact with the next sheet and in
at the two points of suspension and hencerbeing lost vfrom
generating a rigid con?guration. Conveniently such
the collection process.
‘
"
7. Another application of the method of the invention
envisions grasping the rectangular sheet at two substan
tially spaced points lying on a line which, when the
other bends can be made to occur about points as ful
crums located intermediate the'aforementioned point of
restraint and each of the grasp points. One preferred
embodiment of an apparatus well suited to carry out the
7
sheet is plane, is generally parallel to say a long side of 35 method of the invention is the following:
the sheet and is located relatively closer to one such long
edge rather than lying in the middle of the paper Con
Apparatus of The Invention
sider the rectangle formed by dropping normals to the
long edge from these two points. A point lyingwithin
this rectangle, and conveniently generally equidistant from
' By way of a simpli?ed explanation of the construction
and operation of the illustrated preferred embodiment,
40 the invention may be considered for the moment as 'be
the short sides of this rectangle and relatively close to
ing applied to a collating machine of the type described
the said long edge of the sheet is retained in contact with
in
my aforementioned pending patent application. That
the next sheet, as by pressing the top sheet against the
machine comprises an assembly of supports for sheet ma
stack, and the top sheet is bent so that the two points
terialmounted to move as a unit relative to a base so
to be grasped are moved away from the next sheet. The 45 that each sheet material support in turn passes adjacent
two points to be grasped are then grasped and with the
a collector station. The assembly of supports for sheet
third point still held in its aforedescribed position, the
material may move as a unit relative to the base in any
sheet, assumes a rigidity by virtueof the crimps placed
of numerous ways such as, for example, having the sup
in it, there being a tendency to bend about an axis
ports mounted in the manner of a Ferris Wheel, or mount~
parallel to the top and bottom edges of the sheet for
ed like a train traveling on a closed loop of track,
the reason that the said third point is located interme
mounted on an endless belt, mounted for reciprocation on
diate the short sides of the aforementioned rectangle
and also a tendency to bend about an axis parallel to
tracks or other guides, or mounted for rotation about an
axis through the base. The machine further comprises
and relatively close to the said long edge of the sheet for
pickup means for picking up a sheet of material from
the reason that the said third point is located intermediate 55 each support, which pickup means is mounted to move
the long sides of the aforementioned rectangle;
with the assembly of supports relative to the base and
Although the method described made reference to the
also to undergo additional motion toward and away from
sheet material being rectangular in shape and the grasp
a stack of paper in its respective support so that as the
points being on a line parallel and close to one edge,
assembly of supports moves relative to the base, the pick
and made reference to the sheet material as being plane,
up means gJadually picks up a sheet of paper from its
none of these conditions is necessary for the accomplish
support and deposits it at the collector station as it passes
ment of the method of the invention so long as the
adjacent the collector station. For illustration purposes,
general relative locations of the several points are main
the embodiment of the invention shown in the drawing
tained. Shapes of materials other than rectangles can
may be regarded as applied to an assembly of supports
be used. The grasp points need not lie on a line parallel 65 mounted for rotary motion relative to a base. These
to an edge of the material, but can be diagonal or more
supports, of which onedis indicated generally by the nu
or less haphazardly located. ’ The sheets of material need
meral 1, are generally located circumjacent the axis of
not necessarily be plane and, in fact, when stacks of
rotation and can be held in position in any convenient
paper are used in the method, they are often initially
manner such as being mounted on separate arms like
warped. The stack of material need not necessarily be 70 the spokes of a wheel, but preferably they .are located
horizontal and the paths of the top sheet and the stack
on a rotatable disc 2 mounted for rotation about an axis
in separating from one another need not be necessarily
passing transversely to the plane of a disc and through a
in the direction of the thickness of the stack of material.
base not shown. The axis can be thought of as lying
For example, the top sheet can be slid o?? relative to the
in a plane perpendicular to the plane of a paper and off to
stack instead of being lifted off from the stack or any 75 the left beyond the boundaries of FIG. 1. The support
3,033,562
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5
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6
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crimping of the sheet 16 and allows an air passage in the
region of the block 12 lying between the shoulder 17 and
the sucker 10, which controls the vacuum in the sucker
in this case is constituted by a tray having sides 4, a
back end 6, and a sheet retaining member 8 forming "a
partial front, end. The member 8 is omitted from FIG.
1 for clarity. The support may be made ‘of sheet metal
10 as anpadditional safeguard‘ against picking up two
sheets. It also further discourages the second sheet from
adhering to the?rst' sheet since the second sheet would
be compelled to bend on a different radius. The bend
ing of the paper occasioned by restraining its forward
region with pin 36 and raising portions of it to engage
or any other suitable material and serves simply to hold
the sheet material in position.
Theass'embly of supports'is regarded as rotating in
such a manner that it is moving toward the observer as
,viewed in FIG. 1.
10 the suckers 10 causes the sheet 16 to assume arigid con- 7
The pickup assembly comprises a pair of vacuum pick
?guration displacingrthe main portion of the sheet away
ups or suckers or the like generally indicated at 10‘, con
from the stack of material as shown in FIGS. 1, 3 and 4.
veniently provided in identical blocks 12 and 14 and
The ‘drive rod 44 then rises through the bearing 52 rais
adapted to engage the ‘top sheet 16 of ' a stack16' of
ing the pickup assembly so that the assembly carrying _
sheet material in a support 1 near the leading edge of
the sheet. Each of the blocks also is provided with a
with it the top sheet 16 is bodily separated from the stack
of material. However, before the pickup, assembly starts
step or shoulder 17 toencourage bending of the top 7
to rise, the air blast is preferably cut o?, to'preclude any
sheet of material to facilitate its separation from the next
tendency of the second sheet to ?oat up‘ with the ?rst
sheet. Rotation of the disc ,2 carries the sheet 16 over
Each vacuum: pickup is shown as including .a suction
cup 18 inserted in, a counterbore in its respective block. 20 a collector into which the sheet 16 is dropped by releas-1
ing the vacuum applied to the suckers 10, the sheet hav
The vacuum is supplied through a bore 20 in the block
' ing been retained in its rigid con?guration until released
to which it is transmitted from a pipe 22 connected by a
from the suckers.
?exible tube or the like 24 to a vacuum pump or mania
It will be apparent from the foregoing that inv the op
fold. The vacuum supply pipe 22 as well as a com
pressed air supply pipe 26 serves as support for blocks 25 eration of the apparatus, the abutment or stop pin 36
comes to rest against the top sheet of material in the stack
12 and 14 which-are held to them, by set screws 28 or
at a point relatively close'to the leading edge of the sheet
sheet.
'
-
thalike.
‘
"
.
15
'
.
j'
"
.
’
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and. located intermediate the substantially spaced suckers,
as‘measured in the direction of the said leading’ edge.
V
’_The.‘compressed air pipe 26, supplied through tube
30 with air from a pump or‘manifold not shown, trans
mits compressed air through abore 32 in each of blocks 30 The suckers are seen to be located along a line parallel
to the leading edge of the sheet and placed further away
12 and 14 to a blast opening or nozzle 34. Although,’
from this edge than the pin 36', the suckers being located
as is evident in FIG. 5, the port 34 for the air blast is
in a plane displaced outward from the top sheet of the
shown as ‘located entirely some distance below the hori
stack measured in the direction of the thickness of the
zontal surface of the block 40 forming the step 17, it is
stack. The shoulders 17 lie intermediate the tip of the
sometimesfdesirable to increase the size of the port so 35
pin
36 and their respective suckers. That is, they are
that the openingextends upward in FIG. 5 until it is
‘further back from the-leading edge thanis the pin 36 but
. ?ush with said‘ surface. This arrangement is particu
i not as far back as the suckers and they are displaced
larly useful when sheet material having a strong tendency
from the top‘ ‘of ‘the stack not quite as far as the suckers
to pronounced curling at the edges is used. " In such a
10. For simplicity, the stack has been illustrated as show
40
case, the horizontal surface forming the step 17 serves
ing the sheets of material all lying ?at, or plane and with
as a footto limit'the curling of the paper and‘the blast
the tips of the suckers 10 lying in the same plane and
nozzle 34 is, then in‘ a position to blow‘air between the
their center lines lying on a line parallel to the front edge
top sheets instead of completely under them. I
The pickup assembly further includes an abutment pin.
36, preferablyladjustably mounted as by threads and
’ of the sheet. _Similarly, the shoulders 17 have been
45
locknut 38 in block 40 carried by pipes 22 and 26 to ' 7
which it is ?xed by set screws 42.
i
The pickup assembly is shown as supported by drive
rod 44 to which the rest of the pickup assembly is
fastened by virtue of block 46 which is ?xed to pipes 50
22 and 26 by set screws 48 and to which is ?xed drive
rod 44 by set screw 59. Drive rod 44 is mounted for
reciprocation, by cam or other means not shown, in bear
shown as lying in a plane parallel tolthe planes of the
sheets and on a line parallel to the leading edges of the
sheets.
The pin 36 has been shown as lying midway be
tween planes passing through the center line of the
suckers, respectively, and perpendicular to the leading
edge of the top sheet. However, none of these speci?c
arrangements is necessary for the successful operation of
the invention. The suckers need not lie in exactly the
same plane nor need they be located at the same distance
back from the leading edge of the. stack. The pin need
ing 52 of disc 2.
not be exactly centrally located relative to the suckers
55
and the shoulders 17 need not be symmetrically located.
As long as the pin 36 is generally close to the leading
The operation of the illustrated embodiment is as fol
lows: The drive rod 44 descends through'bearing 52 in
edge and is at least as close to the leading edge of the
FIG. 1 until the pin 36 rests on top of the stack‘ of ma
sheet as is the line joining the suckers and is located
‘
.
Operation
,
V
terial in the stack support 1 as shown in FIG. 1 prefera 60 generally intermediate the planes passing, respectively,
through the suckers perpendicular to the leading edge of
bly generally close to one edge thereof.‘ Air under pres
sure is thereafter admitted to pipe 26 whileya vacuum
the sheet, then the pin 36 will perform its function. Simi
is applied to pipe 22. The air blast directed through port
larly, the shoulders 17 may be located within a range of
positions so long as they remain generally intermediate
34 blows against theedges ‘of the ‘sheet material in the
stack which tends to separate the upper sheet from con 65 the tip of the pin and the tips of the suckers as regards
distance back from the leading edge of the stack and
tact with the next sheet. Assisting the separation opera-p
distance away from the top sheet of the stack.
tion are the suckers 10 and the steps or ledges '17. The:
As previously pointed out, the member 2 is regarded
suckers 10 attract and grasp the top sheet 16, thus bend
for simplicity as a rotating disc moving out ‘from the
ing the sheet initially about the bottom of pin 36 as. a
fulcrum and also subsequently, in general,‘ about the 70 paper in FIG. 1 toward the observer. The invention
comprehends situations, as also previously pointed out,
shoulders or steps 17. The ‘shoulders 17 limit the mo
wherein the separation of the top sheet 16 from the stack
tion of the portions of the sheet 16 which engage the.
and its release from the pickup into a collector can be
shoulders 17 to a distance away from the top ofthe stack
accomplished
either by moving the element 2 away from
which is less than the distance of the suckers 10 from the
top of the stack. This causes an additional bending or 75 the rod 44 while the rod 44 is held stationary or moving
8,083,562
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the rod 44 and the element 2 simultaneously in opposite
directions,- the motions including, if desired, components
the scope of the appended claims the invention may be
practiced otherwise than as speci?cally described.
transverse to the direction of the thickness of the stack
as well as components in the direction of the thickness
of the stack. The deposit of the sheet into the collector
can be accomplished by moving the sheet over the collec
What is claimed is :v
'
‘
1. The method of handling, in a stack, sheet material
GI
tor or moving thelcollector under the sheet. The term
“leading edge” has been used for convenience only as a
of a character subject to drooping which comprises re
taining at its original location inthe original con?gura
tion of the stack a point on the top sheet located, rela
tively close to one edge thereof; bending said top sheet '
means of identifying a convenient reference line, and is
about said point so as largely to separate said top sheet
significant when the motion of the element 2 is assumed‘ 10 from contact with the next sheet and to crimp said top
a to be out of the paper towards the observer in FIG. 1.
sheet into a relatively rigid con?guration; grasping said
As previously indicated, thevcon?guration of the sheet
material in the stack need not be rectangular nor plane.
sheet at two substantially-separated points thereof located
Although for simplicity and convenience in description,
being maintained free of contact with any object press
ing it at said two separated ‘points against said next sheet
at least as far from said edge as said ?rst point and on
The contour of the sheets may be any desired shape and
either side of a .plane containing said ?rst ‘point and
the position in the stack may be in the form of curved 15 normal to said edge; while said sheet is grasped and held
surfaces, as often happens with the warping tendencies
7 in the rigid con?guration so produced, bodily separating
of some paper,.rather than a plurality of planes.
said sheet and said stack from each other; said top, sheet
reference has been made to the points of contact of pin
36, shoulders 17, and suckers 10 with the sheet material,
it is to be understood that the contacts can be, and usu
ally are, over a measurable region rather than merely at a
geometrical point. The shape of the areas of contact is
>
in said stack during the interval of time spanned by- the
aforedescribed steps of said method; and'retaining said
sheet in said rigid con?guration until released from said
grasps.
relatively unimportant. For example, in some embodi
2..An' apparatus of the character described compris
ments of the invention, small pins and adjustable screws 25 ing a support for a stack of sheet material, a vacuum
have been used to provide the limiting abutments in place
pickup assembly for picking up a single sheet of ma
of shoulders 17. .
terial from the top of. said stack, said vvacuum pickup
The position of the tip of'the pin 36 is varied by screw!
assembly comprising a‘ framework mounted for-‘motion
ingit in or out of the block ‘ill to adjust it to the ideal
relative to the stack support and including an"v abut
position for whatever sheet material is being used. If 30 ment adapted to engage the top surface of the stack of
the sheet material is relatively heavy and/or sti?er than
'sheet material in said stack support and thus stop the
ordinary paper, the tip of the pin must not be so far away
motion of said pickup assembly relative to said stack
from the level of the suckers since the suckers would
and retain, while it remains so engaged, the portion of
perhaps be unable to attract and grasp this type of ma
the top sheet of material in the stack at substantially its
terial from too great a distance. If the apparatus is to 35 original location; said abutment being located’so as to
be used with material which is not truly ?exible within
be adapted to engage said top sheet relatively close to‘
the meaning of that term, as previously set forth, then
one edge thereof; a pair of sucker tips substantially spaced
the tip of the pin 35, the abutments 1'7, and the suckers " from each other, one on each side of said abutment and‘
10 may all be adjusted to the same level since. in this case
spaced at least as. far back from the said edge of the top
separation of the top sheet of material from the stack 40 sheet of material as is said abutment and so mounted
and drooping do not appear as problems. An example
on said framework as to remain out of contact With said
of such a case would be sheet material constituted by
top sheet of material while said top sheet is ?ush against
pasteboard. To adjust 'all three categories of abutment , the second sheet in said stack, whereby to prevent said
to the same level, the pin 36 is screwed into the block sucker tips from pressing said top sheet against said sec
40 until it is level with the shoulders 17 and sucker tips 45 ond sheet in said stack; said elements being so arranged
18' are replaced by slightly longer tips which project out
that when said vacuum is applied to'said sucker tips,
from their counterbores to the level of shoulders 17.
Other types of restraints than pin 36 and the like can i be used for fulcrums for bending. For example, a jet
or blast of air directed normal to the top sheet would 50
serve as well. Various gripping devices other than
suckers can also be used for grasping the sheet'material.
Rubber ?ngers, rollers and the like have been previously
mentioned for this purpose.
Although the term “sucker” or “sucker tip” is used in
this speci?cation and generally may be thought to imply
a rubber tip such as illustrated for example in U.S. Patent
No. 2,163,274, it is intended to include a mere hole in a
block such as block 12, a rubber washer or the like in a
counterbore, a suction pipe such as shown in US. Patent 60
No. 326,124 or any similar element.
said top sheet is bent‘ largely out of contact with the
next sheet into a relatively rigid con?guration so that it
can be carried away from said stack without drooping.
3. The apparatus of claim 2 further including means
for directing an air blast against the edges of said sheetv
material in said stack to assist separating the top sheet
from contact with the second sheet and to bend the said
top sheet into position so that it can readily be grasped
by said sucker tips.
4. The apparatus of claim 3 further including a pair
of abutrnents each located respectively intermediate said
?rst abutment and one of said sucker tips as regards dis
tance from said edge and ‘distance from said stack sup
port.
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5. The apparatus of claim 2 further including means
for adjusting with reference to said framework the‘ rela
Although the pickup assembly is shown as preferably
tive distances of said ?rst abutment on theone hand and
generally close to one edge of the stack of sheet material,
said suckers on the other hand from said stack support.
its position can be varied, if desired. If it were placed
6. An apparatus of the character described for handling
so that the suckers spanned the midline of the top sheet, 65
in a stack sheet material of a character subject to droop-.
then the pin 36 would be relocated in line with the suckers
ing comprising means for retaining a point on the top
and shoulders 17 could be eliminated or relocated in line
sheet relatively close to one edge thereof in the location
with the suckers intermediate the pin 36 and the suckers,
in contact with ‘the next sheet that it ?nds itself in the
and the blast nozzles would preferably be relocated to
original configuration of the stack; means for bending
direct ‘the blast against the edges of the stack general 70 the top sheet of said stack away from said point so that
ly normal to the leading edge.
said sheet is largely separated from-the next sheet and
Obviously many other modi?cations and variations of
is rendered into a substantially rigid con?guration; meansv
the present invention are possible in the light of the above
for grasping said top sheet at two substantially spaced
teachings. It is therefore to be understood that within 75 points located at least as far from said edge as said ?rst
8,033,562
point and on either side of a plane passing thrOugh said
?rst point normal to said edge to retain said top sheet
in said rigid con?guration; means limiting the action of
said grasping means relative to said top sheet ‘to prevent
said grasping means from pressing said top sheet against
the second sheet in said stack; and means for bodily
separating said top sheet and said stack from each other
while said sheet is held in said rigid con?guration and
for retaining said sheet in said rigid con?guration until
10
top sheet, during said bending step, about two points
each located respectively intermediate the said ?rst point
and each of the said second mentioned points respectively
as regards distance back from said edge and the distance
away from the top of said stack; while said sheet is
grasped and held in the rigid con?guration so produced,
bodily separating said sheet and said stack from each
other; said top sheet being maintained free of contact with
any object pressing it at said two separated points against
10 said next sheet in said stack during the interval of time
it is released from said grasps.
> spanned by the aforedescribed steps of said method; and
7. The method of handling, in a stack, sheet material
retaining said sheet in said rigid con?guration until re
of a character subject to drooping which comprises re
taining at its original location in the original con?gura
leased from said grasps.
tion of the staok a point on the top sheet located relatively
close to one edge thereof; bending said top sheet about 15
References Cited in the ?le of this patent
said point so as largely to separate said top sheet from
UNITED STATES PATENTS
contact with the next sheet and to crimp said top sheet
into a relatively rigid con?guration; grasping said sheet
at two substantially separated points thereof located at
least as far from said edge as said ?rst point and on 20
either side of a plane containing said ?rst point and
normal to said edge; producing additional bends in said
853,910
1,501,582
1,911,884
2,594,373
Tyden ______________ __ May 14,
Cheshire ____________ _._ July 15,
Darbaker _____________ __ May 30,
Watson _____________ __ Apr. 29,
1907
1924
1933
1952
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