Information
-
Patent Grant
-
6398204
-
Patent Number
6,398,204
-
Date Filed
Friday, April 28, 200024 years ago
-
Date Issued
Tuesday, June 4, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Ellis; Christopher P.
- Deuble; Mark A.
Agents
- Caesar, Rivise, Bernstein, Cohen & Pokotilow, Ltd.
-
CPC
-
US Classifications
Field of Search
US
- 414 7982
- 414 757
- 271 2
- 271 177
- 271 178
- 271 215
- 198 405
- 198 411
-
International Classifications
-
Abstract
A stacking apparatus for stacking flat articles on edge is provided where each article has a front perimeter edge and two faces and the stacking apparatus receives each flat article as it enters the stacking apparatus moving in a direction generally parallel to the face of each article. The stacking apparatus includes a discharge magazine for sequentially receiving and stacking the flat articles face-to-face in an on-edge stack. The discharge magazine includes an article inlet, a register wall wherein the front perimeter edge of each envelope contacts the register wall to align each front perimeter edge of each article as the articles enter said stack. The discharge magazine further includes an article face support member, wherein a face of one of the flat articles abuts the article face support member, and a segmented roller for receiving and aligning the flat articles for insertion into the on-edge stack. The segmented roller includes a rotatable segmented cylinder having a longitudinal central axis. The segmented cylinder is located adjacent the article inlet and has a planar surface thereon substantially parallel to the longitudinal central axis of the segmented cylinder. The planar surface in the segmented cylinder opens a gap between a prior article and the segmented roller, receives a single article and incrementally rotates to drive the article against a register wall, with the segmented roller continuing to rotate until the planar surface is rotated into position to open an additional gap between the stack and the segmented roller ready to receive the next article entering the article inlet.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to mass mail handling equipment. More particularly, this invention relates to an improved apparatus for taking a series of flat articles such as envelopes, orienting them, and then stacking the articles in groupings.
In the high volume mail industry, in both U. S. First Class and Third Class mail, envelopes are filled with various letter pieces using automated mail inserters. For example, U.S. Pat. No. 5,029,832 and U.S. Pat. No. 5,211,384 disclose an in-line inserter device having envelope and feeding assemblies, an envelope inserting station, a sealing and stacking assembly, and various diverter stations.
Mass-mailing equipment has become very diverse in its functions. For instance, inserting equipment transport envelopes along an inserting track while various types of inserts are automatically inserted into the envelopes. The envelopes are normally transported to another piece of equipment that automatically seals the envelopes, weighs them and affixes postage. Still additional equipment automatically reads the zip codes or zip code indica on the envelopes and indicates zip code breaks in the envelope groups for zip code pre sorting. This allows the user to take advantage of lower postage rates. Other mass-mailing equipment may include remittance processing equipment and zip code sorting equipment.
Customers utilizing mass-mailing equipment may have differing needs and requirements. Therefore, mass-mailing equipment is generally designed for one specific function. Each piece can then be connected by conveyor or other transport means to additional mail processing equipment so that a customized system can be assembled. One problem with this approach is that adjacent mail processing equipment may require the envelopes to be oriented in a position which is different from the discharge device of the preceding equipment. This necessitates transition conveyors or re-orientation devices.
For example, most mail processing inserting equipment in use today move the envelopes along a track with their faces (the addresses) face down and the flaps extended with the back of the flaps up during the insertion mode. The envelopes, as they leave the inserting machine, may have the flaps moistened and sealed before exiting the inserting machine. If the envelope is then going to have postage applied, it must be turned over 180 degrees so that the postage can be affixed to the face of the envelope. Other operations may require the envelope to be turned 90 degrees.
One such stacking apparatus is disclosed in U.S. Pat. No. 4,705,157. Here, a device is disclosed for turning envelopes 90 degrees as the envelopes are moved forward through the device from an entrance location to an exit location using two endless belts adjacent to one another. The envelopes are ultimately stacked once they leave the exit location.
Currently, many inserters simply eject the filled envelope onto a short flat conveyor, allowing the envelopes to free float on the conveyor. This causes the possibility that the zip order of the envelopes will get mixed up, the possibility of envelopes becoming disorderly and difficult to quickly pick up, and the possibility of envelope flaps popping opened prior to proper glue drying. Additionally, this method is an inefficient use of conveyor space, allowing only a short amount of time before the conveyor becomes full. This requires the increased attention from an operator. Often, an operator is forced to shut down the entire machine so that he or she can catch up with the emptying of the conveyor. Obviously, this drastically reduces the overall throughput of envelopes.
These mail inserters may run at speeds, for example, from several hundred filled envelopes per hour to approximately 18,000 envelopes per hour. These speeds have created a need on the end of the inserters to collect the filled envelopes in such a way as to allow the operator to load them into mail trays or other forms of storage quickly and efficiently. In addition, since these envelopes are often prearranged in special zip code order, this order must be maintained by the operator and then separated into different trays depending on these zip code groupings.
This area has proven to be the “bottleneck” of the mail insertion process. Many times, the operator has a difficult time keeping up with the inserter. Additionally, the envelopes are not presented in such a way that the zip code breaks can be read easily. The operator may develop fatigue, possibly even carnal tunnel syndrome, because of excess handling of envelopes. One means to assist here is the inclusion of an envelope stacking apparatus at the end of the system to secure the sorted mail pieces in a stacked position to facilitate the orderly removal of the processed mail pieces from the system.
One area of difficulty with envelope stacking apparatus is the high likelihood of jamming and high complexity of various apparatus presently available. For example, one method used to handle envelopes after inserting, as provided in U.S. Pat. No. 4,903,955, is a conveyor that turns the envelopes on edge and horizontally stacks them using a wire auger, in the form of an enlarged corkscrew. Shortcomings of this method include the requirement for a complex algorithm to keep an open part of the auger exposed to the incoming envelope in addition to a possible short life of a spring clutch used to turn the auger.
U.S. Pat. No. 4,705,157 provides an article turning apparatus for turning envelopes to an on-edge position and discharging those envelopes for stacking on a conveyor. Two belts receive an envelope in a horizontal position and turn it ninety degrees to an on-edge position. This patent also discloses a segmented roller that assists in stacking the envelopes vertically. However, here, the segmented roller turns continuously and the segmented roller is adapted to strike the surface of the last discharged envelope to create a pulsing force. This system does not prevent the jamming of an incoming envelope.
U.S. Pat. Nos. 5,485,989 and 5,201504 do handle higher speed inserters and offset the stack at a zip break. However, the conveyors disclosed in these patents are complex and costly and require that the zip break signal be given to it via electronic communication from the inserter.
PCT Serial No. PACT/93/02731 discloses an apparatus for stacking sheet like articles having a discharge magazine that includes conveyor belts and a document stop element for receiving articles on edge. A sensing means indexes the conveyor belts to allow envelopes to be stacked on a magazine.
OBJECTS OF THE INVENTION
Accordingly, it is a general object of the present invention to provide an improved on edge stacking apparatus for stacking a plurality of flat articles on edge which overcomes the disadvantages of the prior art.
It is a further object of the present invention to provide an improved on-edge stacking apparatus for stacking a plurality of flat articles such as envelopes on edge that operates at high speed.
It is a still further object of the present invention to provide an improved on-edge stacking apparatus for stacking a plurality of flat articles such as envelopes on edge that operates without jamming.
It is yet another object of the present invention to provide an improved on-edge stacking apparatus for stacking a plurality of flat articles such as envelopes on edge that provides a means to separate different groups of the articles.
It is still another object of the present invention to provide an improved on-edge stacking apparatus for stacking a plurality of flat articles such as envelopes on edge that re-orients from a flat position to an upright, on-edge position.
It is a further object of this invention to provide an improved on-edge stacking apparatus for stacking a plurality of flat articles such as envelopes on edge that does not require an operator to shut down the apparatus on a regular basis so that the operator can catch up with the emptying of the stacked articles.
It is a further object of this invention to provide an improved on-edge stacking apparatus for stacking a plurality of flat articles such as envelopes on edge that does not require a complex algorithm to operate causing potential jamming and failure of the apparatus.
It is a further object of this invention to provide an improved on-edge stacking apparatus for stacking a plurality of flat articles such as envelopes on edge that provides a means to offset a horizontal envelope stack to mark zip code changes.
It is a further object of this invention to provide an improved on-edge stacking apparatus for stacking a plurality of flat articles such as envelopes on edge that maintains pressure on the envelopes in the stack to allow time for the flap glue to dry.
It is a further object of this invention to provide an improved on-edge stacking apparatus for stacking a plurality of flat articles such as envelopes on edge where the articles are moved from a flat position to a horizontal position, either clockwise or counterclockwise using a single belt.
Other objects and many attendant features of this invention will become readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.
SUMMARY OF THE INVENTION
These and other objects of this invention are achieved by providing an on-edge stacking apparatus for stacking flat articles on edge, each article having a front perimeter edge and two faces. The stacking apparatus receives each flat article as each article enters the stacking apparatus moving in a direction generally parallel to the faces of each the article. The stacking apparatus includes a discharge magazine for sequentially receiving and stacking the flat articles face-to-face in an on-edge stack, and includes an article inlet, an article edge receiving means where each front perimeter edge contacts the article edge receiving means to align each front perimeter edge of each article as the articles enter the stack, and an article face receiving means wherein a face of one of the flat articles abuts the article face receiving means. The stacking apparatus further includes a segmented roller for receiving and aligning the flat articles for insertion into the on-edge stack, which includes a rotatable segmented cylindrical having a longitudinal central axis. The segmented cylinder is located adjacent the article inlet and has a planar surface substantially parallel to its longitudinal central axis. The planar surface on the segmented cylinder opens a gap between a prior article and the segmented roller, receives a single article and incrementally rotates to drive the article against the article edge receiving means. The segmented roller continues to rotate until the planar surface is rotated into position to open an additional gap between the stack and the segmented roller, where the next envelope is received.
DESCRIPTION OF THE DRAWINGS
Other objects and many attendant features of this invention will become readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1
is an isometric view of an on-edge stacking apparatus in accordance with one preferred embodiment of the present invention;
FIG. 2
is a top view of a belt turn-up mechanism as used in the on-edge stacking apparatus of
FIG. 1
;
FIG. 3
is a partial top view of the on-edge stacking apparatus of
FIG. 1
depicted without an envelope stack;
FIG. 4
is a partial top view of the on-edge stacking apparatus of FIG.
1
. Depicted with an envelope stack and a single envelope entering the envelope stack with a segmented roller in its home position and an envelope engaging the segmented roller;
FIG. 5
is a partial top view of the on-edge stacking apparatus of FIG.
1
. Depicted with an envelope stack and a single envelope entering the envelope stack showing the segmented roller during rotation;
FIG. 6
is a partial top view of the on-edge stacking apparatus of FIG.
1
. Depicted with an envelope stack with the segmented roller in its home position awaiting an envelope;
FIG. 7
is a partial top view of the on-edge stacking apparatus of
FIG. 1
depicted with an envelope stack and showing an envelope offset device in an extended position such that the envelope stack is offset to indicate a zip code break; and
FIG. 8
is a partial top view of the on-edge stacking apparatus of
FIG. 1
depicted with an envelope stack and showing an envelope offset device in a retracted position, subsequent to the offset device being in an extended position, such that an additional zip code break is shown
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the various figures of the drawing wherein like reference numbers refer to like parts throughout the several views, there is shown in
FIG. 1
an on-edge stacking apparatus
10
, for stacking articles such as envelopes, in accordance with one preferred embodiment of the present invention. The on-edge stacking apparatus comprises several major components: a belt turn-up mechanism
20
, a discharge magazine
40
, an article stack offsetting means
60
, and an article stack conveyor
80
. Each of these components may operate individually, or in combination with the other components of the system. Each is discussed in detail below.
As can be seen in
FIGS. 1 and 2
, the on-edge stacking apparatus
10
of the present invention uses a belt turn-up mechanism
20
to turn a generally flat article such as an envelope
12
from flat to on-edge. The unique design of the belt turn-up apparatus allows use of a single belt
22
. This belt turn-up mechanism
20
can be set up to either turn the envelope
12
clockwise or counterclockwise simply by re-threading the belt over existing pulleys
24
in the system. The entrance
26
to the belt turn-up apparatus
20
offers an area to mount an electronic reading device that can detect a zip code break mark on the incoming envelope.
As can best be seen in
FIGS. 3-8
, once the envelope
12
is on edge, the envelope is transferred through the discharge magazine
40
onto a conveyor
80
, usually about 6 to 8 feet long, and inserted into the rear of an envelope stack
100
. The discharge magazine
40
takes a series of on-edge envelopes
12
and aligns them to be stacked. The discharge magazine
40
utilizes a novel segmented roller
42
in which a segment is removed such that the generally cylindrical segmented roller
42
has a fiat, planar surface
44
that is perpendicular to the longitudinal axis of the segmented roller
42
. As can be seen in
FIG. 3
where a first envelope
12
A is entering the discharge magazine
40
, as the envelope
12
A enters the article inlet
46
of the discharge magazine
40
, the segmented roller
42
, stationary in its home position, maintains a gap
48
for the first envelope
12
A to enter. The flat, planar surface
44
of the segmented roller
42
acts as a guide to the incoming envelope
12
A. If the flat, planar surface
44
of the segmented roller
42
was not there, the incoming envelope
12
would crash into the roller. As soon as the first incoming envelope
12
A (and each succeeding incoming envelope
12
), approaches the segmented roller
42
and enters the gap
48
, the segmented roller
42
indexes 360 degrees and then stops to assist in driving the first envelope
12
A to start the horizontal stack
100
and then stacks each succeeding envelope
12
behind the first envelope
12
A into the stack
100
. As can be seen in
FIG. 4
, the stack
100
is formed and the gap
48
formed by the flat, planar surface
44
of the segmented roller
42
on each rotation continues to be maintained for each successive envelope
12
.
FIG. 5
depicts an envelope
12
in the process of being moved by the segmented roller
42
against a register wall
52
, as described below. Here, the segmented roller
42
has rotated approximately 135 degrees.
FIG. 6
shows the segmented roller
42
back in its home position awaiting the next envelope to enter.
Preferably, as depicted in
FIG. 1
, the segmented roller
42
is formed in three sections. This decreases the mass of the roller to allow for easier incremental driving of the roller
42
.
In addition to the segmented roller, there is optionally a second continuously rotating roller
50
which is an assist drive roller that runs continuously and assures that the incoming envelope is driven to an article edge receiving means, preferably in the form of a register wall
52
, where the front perimeter edges
14
of envelopes
12
are aligned for stacking.
As indicated above, after rotating the 360 degrees, the segmented roller
42
stops and holds in its home position, awaiting the next envelope
12
. As can be seen particularly clearly in
FIG. 1
, a face
16
of the first envelope
12
A entering to form the stack
100
mates with an article face receiving means
54
in the form of a movable upright support member provided to hold the first envelope
12
A and the succeeding envelopes
12
upright in an on-edge position. As each successive envelope
12
enters the stack
100
and the stack
100
increases in size, the article face receiving means
54
may be incrementally moved along a conveyor
80
, either manually or as described below, to allow additional room for a large stack
100
or envelopes
12
.
Optionally, mounted on the discharge magazine
40
is a conveyor sensor, preferably a pressure sensitive stack switch
82
which is used to sense the pressure of the horizontal envelope stack
100
against the article face receiving means
54
. When pressure due to a large number of envelopes in the stack
100
causes the switch to trip, a horizontal conveyor belt on the conveyor
80
indexes to relieve this pressure, thereby making room for the next envelope or series of envelopes
12
to enter.
As best can be seen in
FIGS. 7 and 8
, another optional feature of the on-edge stacking conveyor is the ability to offset the registered edge of the horizontal envelope stack
100
so as to easily identify the zip code change or count to the off loading operator. This is accomplished by a printing (zip code, bar code, optical mark, etc.) Being read onto the envelope
12
by an electronic reading device as the envelope
12
enters the on-edge stacking apparatus. This data is then used to index an article stack offset means
60
such as a cylinder having an electronically controlled shaft that moves in a longitudinal direction, to cause the front perimeter edge
14
of the envelope stack
100
to create an offset
62
from the envelopes
100
previously received in the stack. When a new zip code break is read, the offset means
60
retracts, causing new envelopes to move to the original article edge receiving means
52
. The result is an indexed stack with zip code breaks easily identified, thereby saving significant time unloading the envelopes
12
into mail trays.
Without further elaboration, the foregoing will so fully illustrate our invention that others may, by applying current or future knowledge, readily adopt the same for use under various conditions of service.
Claims
- 1. A stacking apparatus for stacking a plurality of flat articles on edge, each article having a front perimeter edge and two faces, said stacking apparatus adapted to receive each of said plurality of flat articles as each article enters said stacking apparatus moving a direction generally parallel to said faces of each article, said stacking apparatus comprising:(a) a discharge magazine for sequentially receiving and stacking said flat articles face-to-face in an on-edge stack, comprising: i) an article inlet, ii) an article edge receiving means, wherein each front perimeter edge contacts said article edge receiving means to align each front perimeter edge of each article as said articles enter said stack, iii) an article face receiving means wherein a face of one of said flat articles abuts said article face receiving means; (b) a segmented roller for receiving and aligning said flat articles for insertion into said on-edge stack, comprising a rotatable segmented cylinder having a longitudinal central axis, said segmented cylinder disposed adjacent said article inlet and having at least one planar surface thereon substantially parallel to the longitudinal central axis of said segmented cylinder, said planar surface in said segmented cylinder being adapted to open a gap between a prior article and said segmented roller, said planar surface receiving a single article and so that said segmented roller may be incrementally rotated to drive said article against said article edge receiving means, said segmented roller continuing to rotate until one of said at least one planar surfaces is rotated into position to open an additional gap between said stack and said segmented roller adapted to receive the next article entering the article inlet; and c) an article stack offset means to periodically move said article edge receiving means to provide a mark for a change in an article parameter such as a zip code.
- 2. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 1, wherein said segmented roller includes a single planar surface and said segmented roller is adapted to rotate 360 degrees for each article received.
- 3. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 1, wherein said segmented roller is adapted to be stationary during the receiving of each article and subsequently rotates to drive that article against the article receiving means.
- 4. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 1, wherein said segmented roller includes a single planar surface, said segmented roller adapted to be stationary during the receiving of each article while said planar surface forms said gap, said segmented roller then adapted to rotate 360 degrees for each article received.
- 5. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 1, wherein the segmented roller is adapted to rotate at a continuous rate.
- 6. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 1, wherein the segmented roller is adapted to be substantially stationary during insertion of an article to provide a gap for the article to enter and then indexes to drive the article toward the article edge receiving means.
- 7. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 1, wherein said article face receiving means is movable along a conveyor to provide additional space, as required, for articles while providing a compressive force to the stack of articles.
- 8. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 7, including a sensor to index said conveyor to provide said additional space.
- 9. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 1, including a continuously rotating additional roller adjacent said segmented roller to assist in driving each article to said article edge receiving means.
- 10. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 1, including a belt turn-up mechanism that reorients each article ninety degrees prior to entry into said discharge magazine.
- 11. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 10, including a belt turn-up mechanism that reorients each article ninety degrees prior to entry into said discharge magazine, wherein said belt turn-up mechanism uses a single belt.
- 12. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 10, including a belt turn-up mechanism that reorients each article ninety degrees prior to entry into said discharge magazine, wherein said belt turn-up mechanism uses a single belt; said belt turn-up mechanism adapted to turn said articles either clockwise or counterclockwise.
- 13. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 1, including an article stack offset means to periodically move said article edge receiving means to provide a mark for a change in an article parameter such as a zip code, said article stack offset means being a retractable stop.
- 14. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 1, including an article stack offset means to periodically move said article edge receiving means to provide a mark for a change in an article parameter such as a zip code, said article stack offset means adapted to offset said articles at specific article counts.
- 15. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 1, including an article stack offset means to periodically move said article edge receiving means to provide a mark for a change in an article parameter such as a zip code, said article stack offset means adapted to offset said articles when an electronic signal is received.
- 16. A stacking apparatus for stacking a plurality of flat articles on edge, each article having a front perimeter edge and two faces, said stacking apparatus adapted to receive each of said plurality of flat articles as each article enters said stacking apparatus moving in a direction generally parallel to said faces of each article, said stacking apparatus comprising:(a) a discharge magazine for sequentially receiving and stacking said flat aisles face-to-face in an on-edge stack, comprising: i) an article inlet, ii) an article edge receiving means, wherein each front perimeter edge contacts said article edge receiving means to align each front perimeter edge of each article as said articles enter said stack, iii) an article face receiving means wherein a face of one of said flat articles abuts said article face receiving means; (b) a segmented roller for receiving and aligning said flat articles for insertion into said on-edge stack, comprising a rotatable segmented cylinder having a longitudinal central axis, said segmented cylinder disposed adjacent said article inlet and having a single planar surface thereon substantially parallel to the longitudinal central axis and is adapted to rotate 360 degrees for each article received, said planar surface in said segmented cylinder being adapted to open a gap between a prior article and said segmented roller, said planar surface receiving a single article and so that the segmented roller may be incrementally rotated to drive said article against said article edge receiving means, said segmented roller continuing to rotate until one of said at least one planar surfaces is rotated into position to open an additional gap between said stack and said segmented roller adapted to receive the next article entering the article inlet, said segmented roller adapted to be stationary during the receiving of each article and subsequently rotates 360 degrees to drive that article against the article receiving means; and c) an article stack offset means to periodically move said article edge receiving means to provide a mark for a change in an article parameter such as a zip code.
- 17. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 16, wherein said article face receiving means is movable along a conveyor to provide additional space, as required, for articles while providing a compressive force to the stack of articles.
- 18. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 17, including a sensor to index said conveyor to provide said additional space.
- 19. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 16, including a continuously rotating additional roller adjacent said segmented roller to assist in driving each article to said article edge receiving means.
- 20. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 16, including a belt turn-up mechanism that reorients each article ninety degrees prior to entry into said discharge magazine.
- 21. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 20, including a belt turn-up mechanism that reorients each article ninety degrees prior to entry into said discharge magazine, wherein said belt turn-up mechanism uses a single belt.
- 22. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 20, including a belt turn-up mechanism that reorients each article ninety degrees prior to entry into said discharge magazine, wherein said belt turn-up mechanism uses a single belt; said belt turnip mechanism adapted to turn said articles either clockwise or counterclockwise.
- 23. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 16, including an article stack offset means to periodically move said article edge receiving means to provide a mark for a change in an article parameter such as a zip code, said article stack offset means being a retractable stop.
- 24. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 16, including an article stack offset means to periodically move said article edge receiving means to provide a mark for a change in an article parameter such as a zip code, said article stack offset means adapted to offset said articles at specific article counts.
- 25. A stacking apparatus for stacking a plurality of flat articles on edge according to claim 16, including an article stack offset means to periodically move said article edge receiving means to provide a mark for a change in an article parameter such as a zip code, said article stack offset means adapted to offset said articles when an electronic signal is received.
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Foreign Referenced Citations (4)
Number |
Date |
Country |
519942 |
Nov 1953 |
BE |
1 289 491 |
Feb 1969 |
DE |
406127784 |
Apr 1994 |
JP |
PCTUS9302731 |
Mar 1993 |
WO |