U.S. patent number 3,882,744 [Application Number 05/391,176] was granted by the patent office on 1975-05-13 for electrostatographic web feeding apparatus.
This patent grant is currently assigned to Xerox Corporation. Invention is credited to Alan F. McCarroll.
United States Patent |
3,882,744 |
McCarroll |
May 13, 1975 |
Electrostatographic web feeding apparatus
Abstract
Electrostatographic web feeding apparatus disclosing details of
a paper brake operating in conjunction with the paper sheet cutter
for a paper roll or other web feed machine. The disclosed brake is
actuated by a single electrical solenoid, and provides a positive
paper stop at two spaced points on the paper substantially
simultaneously and evenly, thereby preventing paper path skew. Two
individual linear brake rods are pivotally connected to opposite
ends of a teeter arm transverse the paper path. The solenoid is
pivotally connected to the center to the teeter arm. The two brake
rods are commonly driven but pivotable with respect to one another
to automatically prevent one from applying any pressure to the
paper until the other has also made contact, and then to
automatically provide even and self adjusting brake pressure. Each
has an independent return spring and is normally maintained
slightly away from the web. This brake is disclosed operating in
combination with feed means and a fixed curved perforated paper
bubble forming member for smooth registered feeding into
electrostatographic imaging means.
Inventors: |
McCarroll; Alan F. (Rochester,
NY) |
Assignee: |
Xerox Corporation (Stamford,
CT)
|
Family
ID: |
23545564 |
Appl.
No.: |
05/391,176 |
Filed: |
August 24, 1973 |
Current U.S.
Class: |
83/262;
83/402 |
Current CPC
Class: |
G03G
15/6523 (20130101); Y10T 83/4594 (20150401); B65H
2301/51212 (20130101); Y10T 83/6472 (20150401) |
Current International
Class: |
G03G
15/00 (20060101); B26d 005/42 () |
Field of
Search: |
;83/262,402 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schran; Donald R.
Claims
What is claimed is:
1. In electrostatographic web feeding apparatus for feeding
downstream a web of image supporting material from a web supply to
an imaging means for transfer of an image from said imaging means
to said web in registration, including registered web cutter means
for cutting said web into individual sheets, the improvement
comprising:
first web feed means for feeding said web from said web supply into
said cutter means;
said cutter means being located downstream from said first web feed
means;
web brake means for rapidly and evenly stopping said web at said
cutter means and preventing skewing of said web relative to said
cutter means,
said web brake means providing, upon actuation, substantially
simultaneous and automatically even pressure stopping engagement
with said web at at least two spaced points transversely of said
web,
said web brake means being actuated in conjunction with said cutter
means;
bubble means associated with said brake means for formation of an
expandable bubble of said web to prevent interruption of web
feeding while said web is stopped by said web brake means; and
second web feed means for feeding said web downstream from said
brake means and said cutter means; wherein said brake means
comprises:
brake drive means;
an elongated teeter arm connected to said drive means and extending
transverse the direction of movement of said web;
pivotal connecting means providing connection for movement by said
drive means of said teeter arm toward said web, but free
intermediately pivotable movement of said teeter arm relative to
said web;
and at least two independent web engaging means, each including
frictional web brake surfaces, respectively connected to said
teeter arm on opposite sides of said pivotal connecting means for
relative pivotal movement on said teeter arm relative to said web
in response to uneven pressures on said web brake surfaces;
said web engaging means both being connected to said teeter arm for
movement therewith toward said web by said brake drive means.
2. The apparatus of claim 1, wherein said brake drive means is a
single linear drive means pivotably connected to said teeter arm
intermediately thereof.
3. The apparatus of claim 1, wherein there are only two web
engaging means, spaced substantially apart transverse said web, and
wherein fixed guide means are provided for restricting the movement
of said web engaging means to linear movement normal said web.
4. The apparatus of claim 1, further including return spring means
urging and normally maintaining said web engaging means out of
contact with said web.
5. The apparatus of claim 2, wherein said brake drive means is a
single linear short stroke, electrical solenoid directly pivotally
connected centrally to said teeter arm, and having a linear output
movement normal said web.
6. The apparatus of claim 4, further including independently
adjustable mechanical spacing means for setting the maximum spacing
of said web engaging means a small distance away from said web.
7. The apparatus of claim 1, wherein said first and second web feed
means both operate continuously and at substantially the same web
feeding speed.
8. The apparatus of claim 1, wherein said bubble means is a
substantially continuous smooth surfaced fixed hump member
extending into the path of said web to continuously preform and
maintain a small bubble in said web over said surface of said hump
member, and
wherein said hump member is a thin, slightly curved, plate which is
highly multiply perforated to offer insubstantial air flow
resistance.
Description
The present invention relates to electrostatographic web feeding
apparatus providing accurate sheet-feeding with web stopping and
cutting, including an improved web cutter brake which operates very
rapidly and evenly and prevents web skewing.
Previously published art relevant to the present invention includes
particularly the "bubble chopper" disclosed in U.S. Pat. No.
3,639,053, issued Feb. 1, 1972, to Merton R. Spear, Jr. Reference
may be had to that patent for a discussion of background and other
relevant teachings, including an exemplary electrostatographic
system. Other relevant published references include, for example
U.S. Pat. No. 3,673,905, issued July 4, 1972, to Tateomi Kono, U.S.
Reissue Pat. No. 27,720, issued Aug. 7, 1973, to R. C. Hanson, et
al. (originally U.S. Pat. No. 3,416,861), and the references cited
in these patents.
An exemplary embodiment of the present invention is shown and
described hereinbelow as a part of an otherwise conventional
exemplary xerographic apparatus and process. Accordingly, said
xerographic apparatus and system need not be described in detail
herein.
All of these references are hereby specifically incorporated by
reference in this specification.
Further features and advantages of the present invention pertain to
the particular apparatus and functions whereby the above-mentioned
aspects of the invention are attained. Accordingly, the invention
will be better understood by reference to the following description
and to the drawings forming a part thereof, which are generally to
scale, wherein:
FIG. 1 is a side view of an exemplary web feeding apparatus
embodiment of the present invention, partially schematicised for
clarity;
FIG. 2 is basically the same as FIG. 1, but showing the web brake
and cutter actuated;
FIG. 3 is a top view of the embodiment of FIGS. 1 and 2,
illustrating the perforated web bubble forming platen; and
FIG. 4 is a front view, transversely across the web path, of the
embodiment of FIGS. 1-3, illustrating details of the web brake
structure.
Referring now to the drawings, FIGS. 1 - 4, there is shown therein
an exemplary web feeding apparatus 10 in accordance with the
present invention. This apparatus 10 includes a paper brake 12
operating in conjunction with a paper cutter 14 for cutting a web
of paper 16 from a paper roll 18 into individual image receiving
sheets. The apparatus 10 also provides accurate sheet feeding of
the paper 16 into an imaging means 20 in registration with an image
thereon. The imaging means 20 shown here schematically is a portion
of a conventional xerographic drum and associated transfer corotron
for the transfer of a xerographic toner image to the paper 16 in a
conventional manner. As noted above, many of the components of the
apparatus 10 and the associated electrostatographic system are
conventional, and, therefore, need not be described herein. Those
components which are conventional are illustrated schematically for
clarity.
Referring to FIG. 1 in particular, the path of the paper 16 will
now be described in relation to the sequence or relative location
of the disclosed apparatus 10 components acting on it as it moves
downstream from the supply roll 18. It may be seen that the
continuous web of paper 16 is continuously pulled from the supply
roll 18 by a first web feed means 22, here comprising a
continuously rotating conventional set of paper feeding friction
drive wheels. This first feed means 22 is shown here directly
adjacent the upstream end of a hump member 24 which extends into
and deforms the path of the uncut web to form a web or hump. After
passing over the hump member 24, the web feeds through the paper
brake 12 located at the downstream end of a hump member 24. The web
then passes through the closely adjacent (immediately downstream)
conventional paper cutter 14, which is adapted to rapidly sever the
entire web transverse the web direction of travel so as to cut the
web into desired lengths of individual sheets of paper. The cutter
14 is followed downstream by a second conventional paper feeding
means 26 for further feeding the paper on into the imaging means
20. The second web feed means 26 may comprise continuously
operating conventional feed rollers operating at substantially the
same web feeding speed as the first feed means 22, e.g.,
approximately 10 percent faster.
FIG. 2 illustrates both the paper cutter 14 and paper brake 12
being actuated to stop and then evenly cut the web 16. It will be
appreciated that the operation of these two members is coordinated
and synchronized with the position of the image on the imaging
means 20, as described in the cited references. During this stop
and cut operation the web is completely stopped by the paper brake
12, as will be discussed further herein, so that the web will not
be moving as the paper cutter 14 is operating. This insures a
smooth and even cut and prevents jamming or skewing of the web
during the paper cutting operation. Here, the imaging means 20 is
upstream.
To avoid interruption of the feeding, (with possible damage to the
web in high speed feeding) there is provided here a novel means for
forming a bulge or bubble of a controlled position and direction of
bulging in the web of paper 16. This bubble is caused to expand
smoothly in a direction normal the web path while the downstream
edge of the web is stopped by the paper brake 12, so as to absorb
and confine the additional length of paper being continuously fed
downstream towards the paper brake 12 by the first feed means 22
during paper braking.
It has been found that uncontrolled formation of this bubble or
buckle in the paper can result in multiple ripples and paper jams
or wrinkling, particularly in high speed operations. The disclosed
hump member 24 prevents this by providing positive pre-forming of
the bubble and control over both the position and direction of the
web bubble during both its expansion and contraction, for
significantly improved reliability. It may be seen that the hump
member 24 provides a continuous bubble or loop in the otherwise
substantially planar path of the web 16 at all times, including the
time periods in which the paper brake 12 is not engaging the web at
all. Thus, when the paper brake 12 is actuated, the paper bubble is
already pre-formed, i.e., initially partially buckled in the
desired position and direction of buckling or bubbling. The web
bubble will then continue to expand in the same shape and
direction, as illustrated by the differences between FIGS. 1 and 2.
It may be seen that the hump member 24 is a substantially
continuous and smooth surfaced fixed platen extending slightly into
the path of the web, having a curvature, as shown, of much less
than 90.degree.. Thus, it does not present any significant
obstruction or significant frictional resistance to the feeding of
the web over its surface.
An important feature of the hump member 24 is that it is multiply
apertured to prevent a vacuum from forming between it and the web
16. This allows the web 16 to very rapidly rise away from the hump
member 24 into an expanded web bubble when the paper brake 12 is
actuated. The rapid expansion of the web bubble requires the large
area of the web over the hump member 24 to rapidly move away from
its normal directly overlying position. By making the hump member
as a thin, slightly curved, metal plate which is highly multiply
perforated (to offer an insubstantial air flow resistance) this can
be achieved. The hump member 24 does not offer any significant
resistance to the rapid increase or expansion of the web bubble
away from its supporting surface. Yet the web 16 is initially fully
and continuously supported by the surface of the hump member
24.
These same advantages also apply to the desired rapid decrease in
the bubble size when the web brake is released. The perforations
prevent any air pressure trapping under the bubble as it is dropped
downwardly.
During the expansion of the web bubble, means are preferably
provided to limit its longitudinal extent at the upstream and
downstream ends of the hump member 24. In the apparatus 10 this is
provided at the upstream end of the feed means 22 and at the
downstream end by a curved paper guide or deflector 28 directly
adjacent the entrance to the paper brake 12.
If desired, conventional blower or fan means may be additionally
provided for blowing a positive air pressure flow from underneath
up through the perforated hump member 24 against the bottom of the
web 16. This provides further insurance of the smooth, rapid,
outward expansion of the web bubble away from the surface of the
hump member 24 during paper braking.
It may be seen that with the above-described web bubble forming
arrangement that no moving parts are required and the paper is
fully supported in the normal (unbraked) paper path on a smooth
surface. Further, the space above the hump member 24 is
unrestricted so that the paper bubble can rise as far as necessary
above the surface of the hump member 24 without restriction. With
this arrangement the first feed means 22 and its feeding of the web
smoothly from the supply roll 18 can be substantially unaffected by
the stopping of the web downstream of the hump member 24 by the
paper brake 12. Only the second feed means 26, which is located
here downstream of the paper brake 12, and paper cutter 14, will be
affected by the stopping of the web. This can be taken care of
simply by allowing the wheels of the second feed means 26 to slip
slightly during the brief time period between the time the paper
brake 12 stops the web and the time the paper is severed by the
cutter 14. As soon as the paper is cut it is free to continue its
downstream movement by the second feed means 26. Continuous
operation of the second feed means 26 is desirable even though some
slipping occurs, in order to maintain tension on the web as it is
being severed, which is desirable.
Considering now in particular the paper brake 12, the operation
thereof is illustrated in the side view of FIG. 2 and the details
thereof are more fully disclosed in the front or transverse web
view of FIG. 4. The web brake 12 provides, upon actuation, a very
rapid stopping of the web without skewing, tearing or buckling of
the web. These have been problems with many prior paper brakes when
used for rapidly stopping for cutting a segment of a rapidly moving
web. The paper brake 12 automatically provides substantially
simultaneous and even pressure stopping engagement with the web at
two points spaced apart transversely on the web, thereby positively
preventing web skewing from either the braking itself or from the
operation of the paper cutter 14.
The paper brake 12, of course, is actuated in conjunction with the
paper cutter 14, but its braking operation should be completed
prior to the beginning of the cutting operation of the paper cutter
14. That is, the web is preferably fully stopped in the paper
cutter 14 before the paper cutter begins to cut the paper. Also,
the paper brake 12 is preferably closely adjacent the paper cutter.
It is desirable that the web brake 12 engage the web only
intermittently and as briefly as possible only during the operation
of the paper cutter 14, so as to interfere as little as possible
with the normal web feeding, and to require as small as possible a
web bubble expansion over the hump member 24. The brake 12 is
particularly suited for such rapid braking and release of the
web.
The paper brake 12 is preferably driven by a single short stroke
linearly operating commercially available electrical solenoid 30.
The solenoid 30 is shown mounted to a fixed frame 32 with its
operating rod or plunger stroke normal the plane of the web 16. The
operating plunger of the solenoid 30 is pivotally connected to the
center of a teeter arm 34, so that actuation of the solenoid 30
draws the teeter arm 34 upwardly towards the frame 32 and the web
16. However, the teeter arm 34 is free to rotate or teeter
intermediately relative to the solenoid 30 about the pivotal
inter-connection provided by pivotal connecting means 36, which may
be a conventional pin connection.
The teeter arm 34 is an elongated bar extending transversely across
a major portion of the web, and generally parallel thereto. It is
preferably a thin plate set edgewise (perpendicular) to the web so
as to form a strong, but light weight beam for transmitting the
force of the solenoid 30 to its outer ends. It may be seen that
these outer ends of the teeter arm 34 are each connected to the
bottom ends of elongated vertically extending brake rods 38 and 40
respectively. These connections are also conventional pivotal pin
connections. Both of the brake rods 38 and 40 are preferably thin
cylindrical steel rods extending upwardly from the ends of the
teeter arm 34 perpendicularly toward the web 16. They are
preferably restrained or guided for purely linear reciprocal
movement in this direction by a pair of fixed cylindrical slide
guides 42, shown in the partially broken away section around the
brake rod 40.
The brake rods 38 and 40 each have frictional brake pads 44 and 46,
respectively, at their upper ends adapted to engage the bottom of
the web 16 and also to force the web 16 upwardly against directly
overlying fixed brake pads 48 and 50. Thus, upon actuation of the
solenoid 30, one area of the web is rapidly caught and stopped
between the brake pad 44 on the brake rod 38 and its mating fixed
brake pad 48, and another quite separate area of the web is
simultaneously caught and stopped between the brake pad 46 on the
brake rod 40 and the mating fixed brake pad 50.
It may be seen by the above-described connection that the two brake
rods 38 and 40, and the respective brake pads 44 and 46 thereon,
are commonly or simultaneously driven by the connection to the
teeter arm 34 by the solenoid 30 toward the web when the solenoid
is actuated. However, the two brake rods are individually freely
pivotable with respect to one another. Thus, if one moving brake
pad 44 or 46 contacts the the paper before the other, the teeter
arm rapidly pivots to bring the other brake pad into engagement
with the paper. Thus, the paper brake 12 cannot stop the paper at
one braking point prior to its being stopped at the other braking
point. Further, the described pivotal mounting also insures that
the braking force remains even between the two braking areas at all
times, during both actuation and removal of the braking forces. The
solenoid 30 cannot apply an uneven force between the two brake
rods. Also, the two separate braking actions provided by the two
brake rods are also automatically self-adjusting regardless of the
initial spacing or adjustment of the brake pads relative to the
web. Further, the described pivotal connections prevent any
tortional or lateral forces from acting on the brake rods.
Therefore, they can be reciprocally slidably mounted in the simple
cylindrical bushings provided by the rod guides 42 without any
danger of binding during operation.
The pivotal connection of each brake rod equidistantly on opposite
sides of the pivotal connecting means 36 allows pivotal movement of
the teeter arm relative to the web in direct response to uneven
pressures between the brake pads 44 and 46. Thus, the teeter arm 34
cross-transmits and evenly balances these pressures while at the
same time rapidly applying braking pressure to both brake pads
through the common central upward movement of the same pivotal
connecting means 36 by the solenoid 30.
Each brake rod 38 and 40 has a separate return spring 52 and 54,
respectively, to normally urge and retain it away from the web 16
except when the solenoid 30 is actuated (energized). These are
preferably sufficiently strong coil springs under pre-compression
to rapidly inactivate the paper brake as soon as the electrical
energization is removed from the solenoid 30. Mechanical spacing
stops 56 and 58, which are independently screw adjustable, are
provided as brake adjustments to limit the maximum extent of
movement of the ends of the teeter arm 34 away from the web 16.
This thereby determines the maximum spacing of the brake pads 44
and 46 out of contact with the web. By adjusting the stops 56 and
58, the brake rods 38 and 40 can be independently maintained only a
short distance from the web. This means that only a very short
stroke of the solenoid 30 is required to bring the brake pads into
paper contact, for faster braking action upon actuation of the
solenoid 30.
In conclusion, it may be seen that the above-described structure
provides a very simple and rapid acting, yet effective web feeding
system in which the paper may be stopped and cut without skewing,
and with minimum interference to the continuous web feeding
operation. It will be appreciated, in accordance with the teachings
of the above and other references, that various of the components
of the feeding apparatus 10 could be relocated up or downstream
with respect to one another along the paper path and still achieve
the same basic advantages and objectives. Various other
modifications or improvements will be apparent to those skilled in
the art. Although the exemplary embodiments described herein are
presently considered to be preferred, the following claims are
intended to cover all variations and modifications as fall within
the true spirit and scope of the invention.
* * * * *