[0001] This invention relates to apparatus for manipulating sheet material and, more particularly,
to an apparatus for providing equal access to dual face surfaces of a sheet/mailpiece
for printing/scanning on each side thereof.
[0002] Material handling systems frequently require that sheet material, such as the internal
mailpiece contents or mailpiece envelopes, be turned over to match a specific downstream
requirement. For example, mailpiece fabrication equipment typically requires that
mailpiece content material be oriented face-up or face down depending upon the orientation
of a receiving envelope This requirement has come under increasing demand as new and
old equipment have, over the course of time, been merged. That is, some mailpiece
fabrication systems require a face-up orientation while others employ a face-down
presentation. Effective utilization and coordination of all systems/machines becomes
inefficient when specific mailpiece fabrication jobs can only be processed on specific
machines.
[0003] Furthermore, various inversion modules have been developed to reorient the envelope
or mailpiece content material for printing or scanning purposes. That is, a requirement
often exists for a mailpiece envelope to have information printed on both face surfaces
such as a destination address on one side thereof and a return address on the other
side (typically on the rear face of the envelope flap). At other times, a sheet may
have content material printed on one side while a destination address is printed on
the opposite side such that, when folded, the destination address may be aligned with
and seen through a transparent window of an envelope.
[0004] One apparatus for inverting the orientation of a mailpiece envelope, or its content
material, includes a twist module wherein the sheet material is directed linearly
along a spiral path, typically affected by a series of twisted belts or chords. While
such twist modules retain the respective leading and trailing edge position of the
sheet material, such modules require a lengthy axial path to change the face-up/ face-down
orientation of the sheet material. Furthermore, twist modules are not reconfigurable
to handle straight runs wherein sheet material inversion is not required. Consequently,
a substitute module or entirely separate mechanism must be introduced to reconfigure
the sheet material handling equipment.
[0005] A need, therefore, exists for an apparatus to manipulate sheet material for providing
access to the dual face surfaces of the sheet material and for performing additional
processing operations such as printing and/or scanning information on each side of
the sheet material.
[0006] The accompanying drawings illustrate presently preferred embodiments of the invention
and, together with the detailed description given below, serve to explain the principles
of the invention. As shown throughout the drawings, like reference numerals designate
like or corresponding parts.
[0007] Figure 1 is a perspective view of a sheet handling apparatus according to the present
invention including first and second conveyor modules each having a conveyor surface
which lies face-to-face along at least a portion thereof such that sheet material
may be conveyed and transferred from one module to the other.
[0008] Figure 2 is a top view of the first and second conveyor modules wherein a pneumatic
pressure source develops a negative, positive or neutral pressure differential across
the respective conveyor surfaces to accept, hold and release sheet material along
the conveyor surface.
[0009] Figure 3 depicts an enlarged top view of the conveyor modules wherein a processor
controls the pneumatic pressure source such that a negative pressure differential,
or vacuum, is developed to secure sheet material to the conveyor surfaces during transport.
[0010] Figure 4 depicts the top view of Figure 3 wherein the processor controls the pneumatic
pressure source to neutralize the pressure differential across the first conveyor
surface (i.e., along the face-to-face interface) while a negative pressure differential
is developed across the second conveyor surface to transfer the released sheet material
from first conveyor module to the opposing second conveyor module.
[0011] Figure 5 depicts the top view of Figure 3 wherein the processor controls the pneumatic
pressure source to develop a positive pressure differential across the first conveyor
surface (i.e., along the face-to-face interface) while a negative pressure differential
is developed across the second conveyor surface to transfer the released sheet material
from first conveyor module to the opposing second conveyor module.
[0012] The invention will be fully understood when reference is made to the following detailed
description taken in conjunction with the accompanying drawings.
[0013] A sheet handling apparatus is provided for conveying sheet material/mailpieces along
a feed path which facilitates access to the dual face surfaces thereof for the purpose
of printing, and/or scanning information contained, thereon. The sheet handling apparatus
includes first and second conveyor modules each having a conveyor surface, a portion
of which is disposed in opposing, face-to-face relation with a portion of the other
conveyor surface. Furthermore, the conveyor surfaces cooperate with a means for developing
a pressure differential across the conveyor surfaces to hold the sheet material on
the conveyor surfaces and transfer the sheet material across the modules during transport.
A processor controls the pressure differential means such that the sheet material
is held against the conveyor surfaces by a negative pressure differential developed
across the conveyor surface and transferred from one conveyor surface to the other
by controlling the pressure differential of both modules when the sheet material is
interposed between the face-to-face interface. Furthermore, the remaining end portions
of each conveyor surface are oppositely disposed and openly accessible to perform
other sheet material processes. For example, the sheet material may be scanned along
and/or printed on each face surface.
[0014] An apparatus is described for handling sheet material which enables access to both
sides thereof for performing additional operations. Though, in the broadest sense
of the invention, the apparatus enhances the ability to manipulate and/or handle sheet
material along a continuous feed path while facilitating other sheet material processing
operations such as printing, scanning, collation, cutting, folding, insertion, etc.
In the context used herein, "sheet material" means any page, document, or media wherein
the dimensions and stiffness properties in a third dimension are but a small fraction,
e.g., 1/100th of the dimensions and stiffness characteristics in the other two dimensions.
As such, the sheet material is substantially "flat" and flexible about axes parallel
to the plane of the sheet. Hence, in addition to individual sheets of paper, plastic
or fabric, objects such as envelopes and folders may also be considered "sheet material"
within the meaning herein. The embodiments disclosed herein, therefore, are merely
illustrative of the inventive teachings and should not be construed as limiting the
invention to a particular type or construction of sheet material, but interpreted
broadly in context of the specification and appended claims.
[0015] The invention employs two principle features including the ability to share/transport
documents along a common, coplanar feed path, and a system configuration which enables
access to both sides of a document for performing additional operations such as printing
and/or scanning. Figure 1 shows an isolated perspective view of the sheet handling
apparatus 10 according to the present invention. The sheet handling apparatus 10 includes
first and second conveyor modules 12, 14 each having roller-driven conveyor surfaces
12C, 14C, a means 16 for developing a pressure differential across the conveyor surfaces
12C, 14C of the conveyor modules 12, 14, and a processor 20 for independently controlling
the pressure differential means 16.
[0016] More specifically, the conveyor modules 12, 14 are arranged such that an end portion
of one conveyor surface 14C opposes the other conveyor surface 12C along a face-to-face
interface FF. Furthermore, while the remaining portions 12EP, 14EP of the conveyor
modules 12, 14 are diametrically opposite, i.e., 180° out-of-phase, the end portions
12EP, 14EP are openly accessible for other sheet material processes. The import of
this arrangement/feature will be discussed in greater detail in subsequent paragraphs
when discussing the operation for controlling the sheet handling apparatus.
[0017] To facilitate the description, only one of the conveyor modules, e.g., the first
conveyor module 12 will be described inasmuch as the structural configuration of each
module is essentially identical. Furthermore, when structural elements are common
to both modules 12, 14, a similar/common reference numeral or character will be employed
for identification purposes. In Figures 1 and 2, the conveyor surface 12C is composed
of a flexible material which is porous or includes a plurality of openings/apertures
12CO to permit the passage of air therethrough. The conveyor surface 12C is furthermore,
disposed about a pair of rollers 22, 24 to produce linear surface segments 26 between
the rollers 22, 24. Moreover, the rollers 22, 24 are driven in the direction of arrows
D, though the motor(s) for driving the rollers 22, 24 is not shown.
[0018] The means 16 for developing a pressure differential across the conveyor surface 12C
includes, inter alia, one or more pneumatic pumps S
1, S
2 and a plenum 30 disposed in fluid communication with the pneumatic pumps S
1, S
2,. The plenum 30 is disposed between the linear segments 26 of the conveyor surface
12C and the rollers 22, 24 at each end of the conveyor module 12. The plenum 30 includes
a plurality of apertures 30A disposed through a sidewall structure 30W of the plenum
30. Furthermore, the sidewall structure 30W is disposed adjacent the conveyor surface
12C and, in addition to tensile loads which may be imposed by the rollers 22, 24 on
the conveyor surface 12C, the sidewall structure 30W provides a degree of lateral
and/or vertical support for the conveyor surface 12C. Moreover, the apertures 30A
are sufficiently close to the conveyor surface 12C such that air/fluid will flow substantially
normal to the conveyor surface 12C (i.e., through the openings 12CO) rather than in
a direction parallel to and/or between the sidewall structure 30W and the interior
conveyor surface 12C.
[0019] Finally, the plenum 30 comprises at least one chamber 34-1, but may include additional
chambers 34-2 to facilitate the transfer of sheet material from an upstream conveyor
module 12 to a downstream conveyor module 14. The significance and use of a multi-chambered
plenum 30 will become apparent when discussing the operation of the sheet handling
apparatus 10
[0020] The pneumatic pumps S
1, S
2 are capable of generating a positive, negative and/or neutral pressure differential,
P, V, N, respectively, across the conveyor surface 12C. For example, to develop a
negative pressure differential V, a command or signal is issued by the processor 20
to the pneumatic pumps S
1, S
2 to generate a vacuum V (see Fig. 2) or low pressure within one or both of the chambers
34-1, 34-2. The higher atmospheric pressure, externally of the chambers 34-1, 34-2,
effects fluid flow through the openings 12CO of the conveyor surface 12C and the apertures
30A of the plenum 30.
[0021] In Figures 3 and 4, the operation for controlling the sheet handling apparatus 10
is depicted. While sheet material 40 may be adequately conveyed and handled by conveyor
modules having a single-chambered plenum, the figures emphasize the advantages of
a multi-chambered plenum 30 to enhance the control/transfer of sheet material from
one conveyor module 12 to another module 14. In Figure 3, sheet material 40 is introduced
and is held against the conveyor surface 12C of the first conveyor module 12 by a
vacuum V created in the chambers 34-1 and 34-2 of the plenum 30. The pressure differential
is maintained across the conveyor surface 12C by the fluid communication established
between the apertures 30A of the sidewall structure 30W and the openings 12CO of the
conveyor surface 12C, i.e., even as the conveyor surface 13C slides across the sidewall
surface 30W. Even as the conveyor surface 12C transitions from one chamber 34-1 to
the next 34-2, the sheet material 40 continues to be urged against the conveyor surface
12C inasmuch as the pneumatic pump S
2 continues to draw a vacuum in the second chamber 34-2.
[0022] In Figure 4, when the sheet material 40 is conveyed to the interface FF, i.e., the
area where the conveyor surfaces 12C and 14C are face-to-face, the pneumatic pump
S
2 is de-activated so as to neutralize the pressure, denoted by the encircled N within
the chamber 34-2. At the same time or simultaneously, a vacuum V is created or has
been maintained in the first chamber 34-1 of the second conveyor module 14. Consequently,
the sheet material 40 is transferred from the first conveyor module 12 to the second
conveyor module 14. And, subsequently, a vacuum V maintained in the second conveyor
module continues the transport of the sheet material 40 along the feed path FP.
[0023] Alternatively, and referring to Fig. 5, a positive pressure differential P may be
established in the second chamber 34-2 of the first conveyor module 12. More specifically,
a negative pressure differential may be maintained in both first and second chambers
34-1, 34-2, via the first and second pneumatic pumps S
1, S
2 until a sheet of material 40 has fully entered the interface region, between the
first and second conveyors 12, 14. Various sensing apparatus may be employed, e.g.,
leading edge photo-optic sensors (not shown), to detect the position of the sheet
material 40 along the feed path FP. When it is determined that the sheet material
40 is correctly positioned, the pneumatic pump S
2 converts to pressurize the chamber 34-2 and produce a positive pressure differential
across the conveyor surface 12C. As such, the sheet material 40 is urged from the
conveyor surface 12C to the opposing conveyor surface 14C. Inasmuch as the conveyor
surface 14C is drawing a vacuum, the negative pressure differential maintains the
sheet material 40 in position as it continues along the feed path, i.e., provided
by the conveyor surface 14C of the second module 14.
[0024] In addition to providing a means for conveying sheet material, various processing
devices may be disposed adjacent each of the accessible end portions 12EP, 14EP of
the conveyor surfaces 12C, 14C. For example, if the conveyor modules are processing
mailpieces, various mailpiece processing operations may be performed on the exposed
face surfaces of the mailpieces. For example, a first printer 50a (see Figs. 1 and
2) disposed adjacent the first exposed end portion 12EP of the first conveyor surface
12C may print a destination address on one side of a mailpiece envelope 54 traveling
along the first conveyor surface 12C, and a second printer 50b disposed adjacent the
second exposed end portion 14EP of the second conveyor surface 14C may print a return
address on the opposite side of the envelope 54 as it travels along the second conveyor
surface 14C. Alternatively, or additionally, a first scanner 60a (located adjacent
to or substituting for the printer 50a) may scan or read information contained on
one side of the mailpiece envelope 54 while a second scanner 60b may scan or read
information contained on the opposite side of the envelope 54.
[0025] In summary, the present invention provides an apparatus for transferring sheet material
from one conveyor surface to another. Complexity is minimized and reliability optimized
by reducing the number of moving parts. That is, aside from a common conveyor system,
the apparatus employs a pneumatic system to hold, transfer and convey the sheet material.
Moreover, the apparatus provides access to dual face surfaces of the sheet material,
e.g., a mailpiece envelope, to perform various other processing operations such as
printing and/or scanning.
[0026] Although the invention has been described with respect to a preferred embodiment
thereof, it will be understood by those skilled in the art that the foregoing and
various other changes, omissions and deviations in the form and detail thereof may
be made without departing from the scope of this invention. For example, while the
apparatus 10 shows only two conveyor modules 12, 14 disposed in linear, coplanar relationship,
multiple conveyor modules, e.g., three modules, may be joined in overlapping relation
to return the sheet material 40 to its original orientation, i.e., face up or face
down. Furthermore, while the invention shows a substantially linear feed path, it
should be understood that the upstream and downstream modules 12, 14 need not be linear
or aligned, but may be staggered or misaligned, i.e., forming an angle relative to
each other.
[0027] Moreover, the invention has been described in the context of a device wherein processing
operations, whether in connection with a mailpiece 40 or other sheet of material,
may be performed along an open or accessible portion of one of the conveyor surfaces
12C, 14C or conveyor modules 12, 14. It should also be appreciated that the sheet
handling apparatus 10 is a device capable of transporting sheet material 40 along
a co-planar feed path which prepares or presents the sheet material 40 in a suitable
orientation for use by a downstream processing device. That is, the sheet handling
apparatus 10 may be used to convey, transfer and deliver sheet material so as to present
one face surface or another to a subsequent processing station including, but not
limited to a printing and/or scanning station.
1. A sheet handling apparatus (10) for conveying sheet material along a feed path (FP),
comprising,
first and second conveyor modules (12, 14) having first and second conveyor surfaces
(12C, 14C), respectively, for driving the sheet material along the feed path, the
conveyor modules (12, 14) being arranged such that at least a portion of the first
conveyor surface (12C) opposes at least a portion of the second conveyor surface (14C)
along a face-to-face interface (FF);
a means (16) for developing a pressure differential across the first and second conveyor
surfaces (12C, 14C) to hold the sheet material on one of the conveyor surfaces and
transfer the sheet material from the first to the second conveyor surfaces during
transport; and
a processor (20) operative to independently control the pressure differential means
such that sheet material may be transferred from one conveyor module (12) to the other
conveyor module (14) by controlling the pressure differential developed across each
of the first and second conveyor surfaces (12C, 14C) when the sheet material is interposed
between the face-to-face interface (FF).
2. The sheet handling apparatus according to Claim 1, wherein a negative pressure differential
is developed across at least one of the conveyor surfaces (12C, 14C) to convey the
sheet material along the feed path (FP).
3. The sheet handling apparatus according to Claim 2, wherein the pressure differential
across the first conveyor surface is neutralized while a negative pressure differential
is developed across the second conveyor surface to transfer the sheet material from
the first to the second conveyor module.
4. The sheet handling apparatus according to Claim 3, wherein the pressure differential
across the first conveyor surface (12C) is neutralized while a negative pressure differential
is developed across the second conveyor surface (14C) to transfer the sheet material
from the first to the second conveyor module along the face-to-face interface (FF).
5. The sheet handling apparatus according to any preceding claim, wherein the first and
second conveyor surfaces define a substantially linear, coplanar feed path (FP) for
transporting the sheet material.
6. The sheet handling apparatus according to any preceding claim, wherein the first and
second conveyor surfaces (12C, 14C) each include a plurality of openings (12CO) therein,
and wherein the pressure differential means associated with each of the first and
second conveyor modules includes at least one pneumatic pump (S1, S2) and a plenum
(30) defining a chamber disposed in fluid communication with the pneumatic pump (S1,
S2), the chamber, furthermore, defining a sidewall structure having a plurality of
apertures therein disposed adjacent the respective conveyor surface (12C, 14C) such
that air may pass through the orifices thereof and through the apertures of the plenum
(30) to produce a pressure differential across the conveyor surface.
7. The sheet handling apparatus according to Claim 6, wherein the pressure differential
means associated with each of the first and second conveyor modules further includes
first and second pneumatic pumps (S1, S2), the first pneumatic pump (S1) being disposed
in fluid communication with the first chamber (34-1) and the second pneumatic pump
(S2) being disposed in fluid communication with the second chamber (34-2), and wherein
the second pneumatic pump (S2) is independently controlled by the processor (20) to
produce a neutral or positive pressure differential a portion of the conveyor surface
corresponding to the face-to-face interface to transfer sheet material from one conveyor
module (12) to the other conveyor module (14).