U.S. patent number 3,754,754 [Application Number 05/204,634] was granted by the patent office on 1973-08-28 for document separator for accidental bunching.
This patent grant is currently assigned to Honeywell Information Systems Inc.. Invention is credited to John Allan Peterson.
United States Patent |
3,754,754 |
Peterson |
August 28, 1973 |
DOCUMENT SEPARATOR FOR ACCIDENTAL BUNCHING
Abstract
A document handling device is provided with a feed arrangement
having a pair of rollers arranged to cooperate in feeding documents
of varying size and thickness singly and sequentially from a stack,
without adjustment of the device.
Inventors: |
Peterson; John Allan (New
Brighton, MN) |
Assignee: |
Honeywell Information Systems
Inc. (Waltham, MA)
|
Family
ID: |
22758757 |
Appl.
No.: |
05/204,634 |
Filed: |
December 3, 1971 |
Current U.S.
Class: |
271/122;
271/125 |
Current CPC
Class: |
B65H
3/0669 (20130101); B65H 3/0661 (20130101) |
Current International
Class: |
B65H
3/06 (20060101); B65h 003/06 (); B65h 003/52 () |
Field of
Search: |
;271/36,37,38,39,41,34,51,40 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Aegerter; Richard E.
Assistant Examiner: Stoner, Jr.; Bruce H.
Claims
What is claimed
1. In a device for feeding documents singly and sequentially from a
stack, feed means comprising a first roller and second roller each
having surfaces juxtaposed one with the other for imparting motion
to a document placed there between,
a first gear interconnected to said first roller and a second gear
interconnected to said second roller,
a drive shaft having one drive gear engaging said first gear and
another drive gear engaging said second gear,
said second roller and said second gear being mounted in a housing
and said housing being pivotably mounted for rotation about the
axis of said drive shaft to bring said juxtaposed surfaces into
mating engagement whereby said second gear and said other drive
gear are maintained in driving engagement and a fixed distance
apart on centerlines during rotation of said housing.
2. The device of claim 1 which further includes torque limiting
means connecting said second roller to said second gear.
3. The device of claim 2 which further includes biasing means
attached to said housing for urging first and second rollers into
mating engagement.
4. The device of claim 3 wherein said torque limiting means is a
magnetic particle clutch.
5. The device of claim 1 which further includes means for rotating
said drive shaft, and
clutch means interconnecting said drive shaft with said means for
rotating said shaft.
Description
BACKGROUND OF THE INVENTION
The present invention relates to sheet feeding devices, and more
particularly to apparatus for feeding sheets of varying widths and
thicknesses singly from a stack of sheets without adjustment to the
feed mechanism and with a minimum wear of the contact surfaces of
the feeding device.
In prior art devices employed for feeding sheet material singly
from a stack, various combinations of rollers, belts and throating
arrangements have been used to insure that double feeding (the
feeding of two or more cards) does not occur during operation of a
device. In card or sheet feeders which are to be employed in data
processing equipment, it is necessary to attain relatively high
speeds in the document feeding devices to satisfy the requirements
of electronic or optical card readers which operate at speeds
compatible with computer operation. It should be evident that a
minimum of operator time spent in making adjustments to the feeder
would be of major concern when providing a device which is to be
acceptable to the industry. Thus, operation of the feeding device
at a relatively high document output and the reliability required
in the data processing area, serve to impose strict requirements on
the design of such a device.
In the past, friction rollers have been combined with oppositely
rotating rollers and stationary plates to perform single sheet
feeding from a stack. However, in most of these designs, there is a
high rate of wear on the moving parts due to continuous frictional
contact between one roller and another, or between a feed roller
and a stationary member. Many of these prior art arrangements may
also prove to be detrimental to the document being fed in that
roller slippage and other friction surfaces contracting the
document are capable of smearing or erasing information located on
the document surface.
Additionally, many of those devices of the prior art, which are
intended to feed sheets singly from a stack, employ auxiliary
belts, rollers, and fluid pressure means which tend to increase the
physical size of the device and increase the cost of the equipment,
while decreasing the reliability and efficiency of operation.
The present invention, therefore, has as an object to provide a
device for feeding sheets singly and sequentially from a stack
which is effective over a wide range of sizes and thicknesses of
sheets without requiring external adjustment of the device.
It is a further object of the invention to provide a sheet feeding
device of the type described wherein the contact surfaces of the
feeding device are subject to a minimum of wear.
Another object of the invention is to provide a device of the type
described wherein smearing, erasing or transferring of ink located
on the printed surface of the sheets is minimized.
And yet another object of the invention is to provide a sheet
feeding device which is less expensive, simpler in operation and
more reliable than those of the prior art.
SUMMARY OF THE INVENTION
The aforementioned objects are achieved in the present invention by
providing a device for feeding documents singly and sequentially
from a stack which has in combination with means for supporting a
stack of documents to be sequentially fed from the top of the
stack, document feed means adjacent the stack, and means for
guiding the top-most document and each successive document
sequentially into the feed means. The feed means comprises a first
roller means and a second roller means, each having surfaces
juxtaposed one with the other, between which a document is guided
and by which a document is subsequently fed. Means are provided for
driving the first roller such that the juxtaposed surface rotates
in a direction to move the document away from the stack when the
document is disposed between the rollers and means are provided for
driving the second roller to rotate its mating surface in the
opposite direction from the first roller. Torque limiting means are
connected between the second roller and the second roller driving
means. The torque limiting means is adjusted such that the second
roller driving means is not effective to rotate the roller when in
contact with the first roller means either directly, or with a
single document therebetween. The torque limiting means however is
effective to rotate the second roller means when two documents are
disposed between the surface of the rollers producing a low
friction "slip" surface between the documents. A double feed
therefore is prevented by the second document being moved back into
the stack through rotation of the second roller means by operation
of the second roller drive means.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the invention, reference
should be made to the accompanying drawing wherein:
FIG. 1 is an elevational view showing a document feeding device
having the present invention employed therein;
FIG. 2 is a perspective view, partially in section, showing a
fragmentary portion of FIG. 1, in which details of the structure of
the document feeder are taken on an enlarged scale for clarity;
and
FIG. 3 is a fragmentary elevational view similar to FIG. 1 but
taken on the opposite side of the document feeder, showing further
details of the device and also taken on an enlarged scale for
clarity.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown a device for feeding
documents singly and sequentially from a stack which comprises a
hopper 10 in combination with a feed device 12 and take-away
transport 14. The hopper 10, feed device 12 and transport 14 taken
together cooperate to remove the top card from a stack and present
it to a station (not shown) downstream on the transport, at which
work is performed on the document.
The hopper 10 which is shown in the present embodiment, is of a
type which is the subject matter of copending U. S. Patent
Application Ser. No. 209,808 filed Dec. 20, 1971 by J.A. Peterson
which is assigned to the assignee of the present invention. The
construction of the hopper 10, as shown, is therefore explained in
greater detail in the aforementioned patent application. However,
for the purposes of the present invention it should be understood
that any arrangement which will feed a stack of documents such that
the top-most documents are moved into the feed device 12 could be
employed with the present invention, as the invention is not
limited to the details of the construction of the hopper
itself.
For purposes of the present description, the hopper 10 is shown to
include a follower plate 16 inclined at approximately 45.degree.
and supported for movement on a belt 17. The plate when driven by
belt movement in the direction of the arrows is effective to move a
plurality of documents supported thereon toward the feed device 12.
Movement of the feed belt 17 is controlled by a switch or sensor 18
to properly position the first document with respect to the feed
device 12.
At the opposite side of the feed device 12, the transport 14 is
seen to comprise a pair of rollers 19 and 21 into which a document
is fed after passing through the feed device. The roller 21, also
serves to support a transport belt 22 which is effective to move
the document downstream of the arrangement described to a
subsequent work station. The transport 14, as shown, is exemplary
in nature and is intended to merely indicate one suitable
receptacle for single documents which have been fed by the feed
device 12. Other such devices for feeding, stacking or arranging
the single documents flowing from the feed device 12 may be
substituted, without departing from the spirit of the present
invention.
Referring now to FIGS. 2 and 3, in these views there are depicted
details of the feed device 12, shown in FIG. 1. The feed device 12
is shown to be driven by a motor 23 which may be mounted on
suitable structure adjacent the rollers 19 and 21 of the transport
14. The motor 23 drives the feed device 12 by means of a continuous
belt 24, and may also be connected to the rollers 19 and 21 to
effect operation of the transport 14. In the device shown, the
motor 23 is continuously in operation while the document feeder is
activated.
It will be noted from FIG. 2 that the major portion of the feed
device 12 is mounted in a housing 26 which is pivotable about a pin
27 when the belt 24 is disengaged from the motor 23 to facilitate
access to the components of the feed device 12.
The belt 24 is drivingly engaged to a pulley mounted on a shaft 29
which is supported for rotation in suitable bearings in the housing
26. The shaft 29 is connected to a second shaft 31 through a
permanent magnet clutch 32.
The shaft 31 is mounted in suitable bearings in the housing 26 and
has mounted thereon a pulley 34 in driving engagement with a second
drive belt 36. The belt 36 is further engaged with a pulley 37
mounted on a shaft 38, also supported in the housing 26.
A pair of gears A' and B' are mounted on the shaft 38 for rotation
thereby, and in meshing engagement with a pair of gears A and B
which are mounted for rotation on shafts 39 and 40, respectively.
The shaft 39 is rigidly supported by bearings in the housing 26 for
rotation, and has a feed roller 41, attached at one end
thereof.
It will be noted that the shaft 40 is not supported rigidly in the
housing 26 but is mounted for rotation in a pivotable support 42.
The shaft 40 has mounted on it a magnetic particle clutch 43 with
the gear B mounted on the input hub of the clutch and a separator
roller 44 mounted on that portion of the shaft at the opposite side
of the magnetic particle clutch. Thus, the rotation of the
separator roller 44 and the portion of the shaft 40 on which it is
mounted takes place by torque transmitted through the magnetic
particle clutch 43, when the gear B is driven.
The support 42 is mounted for pivotable rotation, having one flange
provided with an opening for receiving the shaft 38 and the
opposite flange being supported by a shaft 46 which is fixed to the
housing 26. The shaft 46 is located on the same center line as the
shaft 38, and therefore it should be evident that the support 42 is
so supported as to pivot about the center line of the shaft 38.
Referring now to FIG. 3, it will be seen that the pivotable support
42 is provided with an angle member forming an arm 47 extending
outwardly from the support. A helical spring 48 is disposed with
one end attached to the lower portion of the arm 47 and the
opposite end attached to a threaded member 49 which is movable in a
slot 50 in the housing 26 to adjust the spring tension.
Intermediate of the spring 48 and the support 42, a shock absorber
51 having its piston rod 52 attached to the arm 47 is provided. The
shock absorber 51 may be of any type known in the art, either
adjustable or chosen to produce a stiffness in the range to provide
a dampening effect on the system when a document is released and
the spring 48 biases the roller 44 into engagement with the roller
41.
For a detailed description of a typical sequence of operation,
reference should be had to FIGS. 1, 2 and 3 taken in sequence. As
shown in FIG. 1, the hopper 10 is loaded with a plurality of
documents which rest at substantially a 45.degree. angle on the
follower plate 16 and a portion of the structure (not shown)
adjacent the belt 17. With the motor 23 in operation and the clutch
32 disengaged, both the feed roller 41 and the separator roller 44
are inactive. The sensor which is downstream of the feed device 12
is substantially set up to control the spacing between documents
and as such, operates to initiate engagement of the clutch 32 and
thereby feed a document from the hopper 10.
When the clutch 32 is engaged, the motor 23 is effective through
the belts 24 and 36 to rotate the pair of gears A-A' and the feed
roller in the direction shown in FIG. 2. Simultaneously, the gear
set B-B' is rotated such that the separator roller 44 is rotated in
the same direction as the feed roller 41 with the magnetic particle
clutch 43 engaged, provided that the rollers 41 and 44
separated.
It should here be noted, that by pivoting the support 42 about the
center line of the shaft 38, the roll 44 is movable relative to the
roll 41 without disengagement from the drive gears B-B', as the
shafts 40 and 38 which retain the drive gears are maintained a
fixed distance apart on centers.
It will further be noted that the separator roller 44 is not
directly driven by the shaft 40 but is driven through the magnetic
particle clutch 43. The magnetic particle clutch 43 is shown as
illustrative of an adjustable torque limiting device which
restricts the torque at the separator roller 44 to a value less
than the torque which is put into the system at the gears B-B'. The
device used is a model 97015-012 Fast Step Clutch and Brake Unit,
manufactured by Lear Siegler Incorporated and has a rated torque of
15 pound-inch. As is known to one familiar with this type of
magnetic power clutch, the application of a voltage to the device
causes engagement of the clutch and torque to be applied from the
input shaft to the output shaft. When the torque set up by the
particular voltage is overcome by the rotated portion of the shaft,
the clutch will slip, acting as a drag-type clutch or torque
limiting device. As indicated above therefore, with the roller 44
out of contact with the roller 41 (either through slippage between
a pair of documents therebetween or by being manually held apart),
and the clutch 43 energized, the roller 44 is rotated in the same
direction as the roller 41.
Referring to FIG. 3, the rollers 41 and 44 are seen to be forced
into engagement by virtue of the spring 48 and its adjustment
relative to the arm 47. Thus, the feed roll 41 and the separator
roller 44 impart to one another a normal force which is readily
adjustable through movement of the fixed end of the spring 48 along
the slot 50 of the housing 26. Each of the juxtaposed rollers 41
and 44 is provided with a surface of high friction material to
provide a high tangential resistance between the rollers when in
contact. The normal force between the rollers 41 and 44 is adjusted
such that the torque at the roller 44 provided through the clutch
43 is overcome by rotation of the roller 44 when in contact with
the separator roller, or in contact with the separator roller with
a single document therebetween. During normal feeding operations,
when a single document is introduced between the feed roller 41 and
the separator roller 44 (roller 44 being rotated by roller 41 and
the clutch 43 slipping) the document is transferred downstream in
normal fashion.
However, when a double feed occurs, and two documents enter between
the rollers 41 and 44, slippage occurs between the two documents,
and the roller 44 no longer has the proper torque applied to it by
the roller 41 to overcome the torque produced at the clutch 43.
Thus, the shaft 40 takes over, and rotates the roller 44 in an
opposite direction to its feeding direction and sends the document
back into the hopper 10 from which it is fed on the next feed
cycle.
Both the feed roll 41 and the separator roller 44 have high
friction materials bonded to their circumferential surfaces.
Therefore, when the separator roll 44 is spring loaded against the
feed roll 41, the amount of torque transferred to the separator
roll in the counter-clockwise direction (as viewed in FIG. 2) is
adjusted by varying the spring force such that it is greater than
the torque applied in the clockwise direction by the magnetic
particle clutch 43. The separator roll 44 now rotates in a
counter-clockwise direction, driven by the feed roll 41 due to the
friction between the two rolls, creating no relative motion between
the two rolls which could cause wear.
From the foregoing, therefore, it should be evident that the
present invention provides a device which overcomes objectionable
features of prior art feed devices and which operates in a simple
manner to provide sequential feeding from a stack of documents.
This normal feed condition exists when the juxtaposed rolls are in
contact and there is no document between them and also when there
is a single document being driven through. If only a single
document is present, the torque may still be transferred through
the document due to the fact that the friction between the single
document and the rolls is also great enough to overcome the torque
applied in the clockwise direction by means of the magnetic
particle clutch. However, when two or more documents enter between
the rolls, the separator roll immediately reverses in the clockwise
direction and feeds the excess document back into the stack until
there is only a single document between the rolls which is the
proper, or next document. The separator roll then is again driven
in the counter-clockwise direction by the mating surface of the
feed roll. Thus, there is no relative movement between the rolls or
auxiliary rolls, etc., as the above takes place completely and
passively due to the lesser amount of friction between two or more
sheets of paper or other material of which the documents comprise.
As paper to paper or document to document friction is not enough to
overcome the torque applied by the magnetic particle clutch, the
separator roll rotates clockwise until a multi-sheet feed has been
cleared.
No adjustment is necessary to accommodate narrow document
thicknesses due to the self-adjusting gap between the rollers, and
the spring tension applying the normal force between the rolls need
seldom be made after the device is in operation.
* * * * *