Sheet feeding or delivering – Feeding – Separators
Reexamination Certificate
2001-09-25
2004-03-02
Walsh, Donald P (Department: 3653)
Sheet feeding or delivering
Feeding
Separators
C271S099000, C271S023000, C271S035000, C271S165000
Reexamination Certificate
active
06698748
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to feed mechanisms and methods for feeding sheets and envelopes from a stack into a utilization device.
2. Background Information
Current estimates place the number of envelopes used annually in the United States at over 100 billion. A significant percentage of these envelopes are used in connection with bulk mailings, and are accordingly filled, addressed and processed by a variety of automated machines. A lynchpin of all automated processes is the automatic envelope inserter. Automatic inserters are large, complex machines that are loaded with contents to be inserted (e.g., individual letter sheets and/or fillers) and envelopes in which these contents are to be inserted. Other machines such as binders, that bind inserts together (into a books, catalogs, newspapers or magazines), presses that apply logos and decoration, addressing machines, collating and a variety of other machines are also used selectively to process individual sheet-like materials in bulk mailing and other processes. These various devices can be termed generally “utilization devices” as they utilize sheet-like materials that are typically dispensed in stacks.
FIG. 1
shows a high-volume envelope inserter in current use by industry. The exemplary inserter
100
is a large, modular unit that combines various contents stored in hoppers (not shown) in the rear
102
of the machine and that directs (arrows
104
and
106
) contents
105
onto a raceway
108
downstream (arrow
110
) toward a stack of envelopes
112
. At each point along the raceway, additional insert sheets are added to the contents. These contents may be folded, or otherwise compacted, to fit within the selected envelope by mechanism within the inserter. Envelopes are drawn from the stack
112
, and directed downstream (arrow
114
) to a inserting station
116
at which the closed-but-unsealed envelope flaps
118
are opened so that the final contents
120
can be inserted thereinto. The filled envelopes
122
are then transferred further downstream (arrow
124
) to a stacking position or further-processing module (not shown).
Industrial inserters, referred to generically as swing-arm inserters, are available from a variety of well-known companies including Bell & Howell (Phillipsburg), as well as by Mailcrafter (Inserco model), Pitney Bowes (AMOS model), EMC Document System (Conquest Lsi model) and H M Surchin (Cornish model). A rotary variation is made by Buhrs (BB300 and BB 500) series. One more-specific example is the Bell & Howell Imperial™.
Most inserters cycle at least 10,000 per hour without any material. However, once the various hopper materials are inserted into the envelopes, the net production is significantly slower. Due to paper handling problems, swing-arm inserters often net less than one third of their capabilities. A typical swing-arm machine in production may net less than 3000 completed envelopes per hour. After careful study, it is now recognized that the primary cause is the unreliable feeding of materials from the hoppers onto the collating raceway. The hopper is subject to jams, double feeds and no feeds. The design of these hoppers has not changed significantly in 30 years. And for that matter, they have changed little since their invention 60 years ago, as exemplified by U.S. Pat. No. 2,325,455.
With reference to
FIG. 1
, the envelope stack
112
, the stacking location or “feed station”
130
consists of a series of upright guide rails
132
,
134
that, respectively, contain the four opposing sides of each envelope in the stack.
As also shown in
FIG. 1
, the contents
105
entering the raceway originate from separate feed hoppers
150
,
152
, and
154
. The hoppers include separate stacks of folded or unfolded sheet material
158
. Each stack
158
represents a piece of the total inserted package
120
to be provided to the downstream envelope
118
. The number of hoppers used varies based upon the number of content sheets to be inserted. For the purposes of illustration, further reference will be made to the hopper
154
, which is the first hopper along the raceway
108
. The hopper includes a rear backing guide
160
and a pair of front corner guides
162
. The guides
160
and
162
essentially contain the stack of materials
158
so that bottom sheets can be stripped and directed (arrow
104
) one at a time into the raceway
108
.
With further reference to
FIGS. 2-6
, a content feed hopper and associated feeding and singulating assembly is shown in further detail, according to a prior art implementation. The stack of sheet-like materials (envelope inserts)
158
is confronted by a front stop
170
that retains the stack against forward movement into the raceway area. The stack is suspended at its rear (adjacent to the rear guide
160
) by a partial floor
172
. An opening
174
is defined between the front edge of the floor
172
and the front stop
170
. This opening defines the region through which bottom sheets
176
are allowed to pass out of the stack and into the raceway, as will be described. At the bottom of the front stop
170
is located an adjustable pin
180
that is implemented as a threaded thumb screw with a projecting conical point
182
. As shown in the plan view of
FIG. 6
, there are two pins
180
located at a horizontal spacing along the front stop
170
. These pins are used to retain the front end of the stack of materials
158
from entering the opening
174
. The pins are adjusted fairly finely because the points, if overly retracted, will not support the stack, while if overly projecting, will tear or prevent the bottom sheet
176
from passing over the pin
182
and into the opening when needed.
More particularly,
FIGS. 3-5
show the general sequence by which a conventional vacuum sucker assembly
190
is used to draw bottom sheets
176
from the stack of materials
158
. The sucker assembly
190
consists of a moving bracket arm
192
mounted on a common rotating shaft
194
. In the illustrated example, the shaft moves an associated sucker assembly on each feed hopper simultaneously. The operative element of the sucker assembly
190
is a vacuum lead tube
196
that is adjustable upwardly and downwardly (double arrow
198
in
FIG. 2
) and rotationally (double curved arrow
200
in
FIG. 2
) using associated turn screws
202
and
204
, respectively. These adjustments bring a suction cup
210
at the end of the feed tube
196
into a desired alignment with respect to the bottom of the stack. As will be described, these adjustments are problematic, and must be attended to regularly.
Referring to the feed operation in
FIG. 3
, the suction cup
210
engages the bottom sheet
176
and then draws it downwardly in a rotational motion as shown beneath the bottom edge of the front stop
170
, having overcome the holding force of the pin point
182
—in a generally downward-peeling motion away from the overlying stack. A moving hold-down finger
212
retracts to allow the rotational downward movement of the sheet
176
, and then returns to the position shown in
FIG. 3
, in which it interferes with any return upward movement of the sheet
176
. In accordance with
FIG. 4
, once the finger
212
is brought back into interfering contact with the sheet
176
, the suction cup drops its vacuum and continues on its rotational path away from interference with the sheet
176
. Just prior to the disengagement, a jawed gripper or “plucker” assembly
220
moves into engagement with the forward edge of the sheet
176
. The forward edge has been restrained by the finger
212
to enable an accurate grip upon the sheet
176
. Once grip is achieved, the mechanism causes the upper jaw
222
to close against the lower jaw
224
, and thereby firmly grasp the sheet. The gripper assembly
220
then rotates as shown in
FIG. 5
(double arrow
226
). When the gripper assembly
220
has swung sufficiently, the upper jaw and lower jaw,
222
and
224
, pass between a set of stripper guides
230
that, in this example are a pair of upright
Bower Kenneth W
Cesari and McKenna LLP
Crowley H. W.
Loginov William A.
Walsh Donald P
LandOfFree
System and method for singulating a stack of sheet-like... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System and method for singulating a stack of sheet-like..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System and method for singulating a stack of sheet-like... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3291448