U.S. patent number 3,682,473 [Application Number 05/117,520] was granted by the patent office on 1972-08-08 for first-in first-out storing device for postal documents.
This patent grant is currently assigned to DeStaat der Nederlanden Ten Deze Vertegenwoordigd Door De. Invention is credited to Cornelis Kuyt.
United States Patent |
3,682,473 |
Kuyt |
August 8, 1972 |
FIRST-IN FIRST-OUT STORING DEVICE FOR POSTAL DOCUMENTS
Abstract
A movable carriage adjacent the input end of a stack of postal
documents having a pivoted spring-urged stacking head in contact
with the stack, which head both feels and feeds the documents in
the stack and operates a pair of micro switches on the carriage to
move the carriage toward or away from the stack to maintain
substantially the same pressure by the head on the stack regardless
of the number of documents fed to or removed from the stack.
Inventors: |
Kuyt; Cornelis (Katwijk Aan
Zee, NL) |
Assignee: |
DeStaat der Nederlanden Ten Deze
Vertegenwoordigd Door De (The Hague, NL)
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Family
ID: |
19803751 |
Appl.
No.: |
05/117,520 |
Filed: |
February 22, 1971 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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826922 |
May 22, 1969 |
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Foreign Application Priority Data
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May 27, 1968 [NL] |
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6807471 |
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Current U.S.
Class: |
271/199; 271/179;
414/788.8; 414/797.6; 271/3.05; 271/3.13; 271/149; 271/201;
414/794.4; 414/907 |
Current CPC
Class: |
B07C
1/025 (20130101); B65H 31/06 (20130101); B65H
83/02 (20130101); B65H 29/50 (20130101); B65H
2220/11 (20130101); B65H 2220/01 (20130101); B65H
2220/02 (20130101); B65H 2701/1916 (20130101); B65H
2301/321 (20130101); B65H 2513/40 (20130101); B65H
2301/4214 (20130101); B65H 2515/34 (20130101); B65H
2515/34 (20130101); Y10S 414/12 (20130101); B65H
2513/40 (20130101) |
Current International
Class: |
B65H
29/50 (20060101); B07C 1/02 (20060101); B65H
29/00 (20060101); B07C 1/00 (20060101); B65h
029/14 () |
Field of
Search: |
;271/68,87,DIG.7,62B
;214/7 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Aegerter; Richard E.
Assistant Examiner: Stoner, Jr.; Bruce H.
Parent Case Text
This application is a continuation-in-part of U.S. application Ser.
No. 826,922, filed May 22, 1969, and now abandoned.
Claims
I claim:
1. A first-in first-out stacking device for postal type documents
comprising:
a. means (H) for holding a stack of the documents,
b. a carriage means (Stw) adjacent the input end of the stack,
c. means (TD) for moving said carriage means toward and away from
said input end of the stack,
d. stacking means (Stk) pivotally mounted on said carriage means
for movement relative to said carriage means and for successively
feeding documents onto the input end of the stack,
e. means (B 1, B 2) on said carriage means for successively feeding
documents to said stacking means,
f. means (RM) fixed at the output end of said holding means and the
stack for successively removing documents from the stack,
g. spring means (VV) between said carriage means and said stacking
means for urging said stacking means against the input end document
in the stack, and
h. a pair of spaced limit switch means (S I, S II) mounted on said
carriage and controlled by the position of said stacking means with
respect to said carriage means to operate said means for moving
said carriage to maintain said carriage means within the spacing of
said limit switch means at a predetermined distance from the input
end of the stack.
2. A device according to claim 1 wherein said stacking means
includes a stop plate (T) at the input end of the stack.
3. A device according to claim 1 wherein said means for moving said
carriage means includes a reversible motor means.
4. A device according to claim 1 wherein said stacking means
comprises a friction belt for moving the documents, and rollers
around which said belt rotates.
5. A device according to claim 1 wherein said stacking means also
includes worm means for feeding the trailing portion of a document
toward the stack to be out of the way of the next succeeding
document fed to said stacking means.
6. A device according to claim 1 wherein said feeding means on said
carriage means comprises a pair of pinching belts between which the
documents are fed and a plurality of rollers for backing up said
belts.
7. A device according to claim 6 wherein said stacking means
includes a pivot coaxial with one of said rollers.
8. A device according to claim 1 wherein said pair of limit switch
means include a cam means mounted on said stacking means.
Description
BACKGROUND OF THE INVENTION
This invention relates to a stacking-device for temporarily storing
postal documents, such as letters and the like in an intermediate
stack, with a view to further automatic treatment. Conventional
intermediate stacking-devices of this type possess a carriage
allowing the introduction of the letters and their formation into a
stack.
These stacking carriages must be movable in order to make room for
the stack to be formed. The movement is controlled by means of a
lever which records the place of the last letter introduced. This
recording is electrically converted into a movement from or to the
stack. The lever, however, must also have a normal position
intermediate between the two switching positions, in order to avoid
oscillating of the carriage. The resulting hysteresis is increased
further by the mass of the carriage, which causes too slow a
reaction in comparison with the rapid movements of the incoming
letters. The slow reaction of the carriage leads to much variation
in the stack pressure, which results in difficulties in the
stacking and taking-off actions. If the pressure in the stack is
too high the leading edges of limp letters will be creased; and if
the pressure is too low cards will rebound after having reached the
stop-plate, thus causing trouble at the removing end.
Because the stacking-devices have smooth bottom and side surfaces,
the letters must be supported to prevent them from falling over. At
the supplying end, the carriage must keep the letters upright;
while at the removing end this is done by the removing device. If
the length of the stack does not exceed about 20 centimeters a
minimal pressure will suffice to support the stack, but if the
stack has a length of more than 30 centimeters the stack pressure
required to prevent the stack from falling becomes inconveniently
large necessitating a different adjustment of the pressure of the
feeler against the incoming letters. In such a case the feeler not
only determines the place of the letter, but also the stack
pressure, and this larger stack pressure impedes the correct
introduction and removal of the letters.
SUMMARY OF THE INVENTION
In order to distribute the stack pressure as favorably and as
evenly as possible, the stacking-device according to this invention
has a stacking-head pivotally mounted on a movable carriage, which
head is kept in contact with the rear of the stack by a spring. In
the normal state, of no supply and no removal, the stacking-head is
kept in a state of equilibrium by the spring and its carriage
stands still. However when documents are introduced into the stack,
the stacking-head pivots backwardly out of its state of equilibrium
until it closes a first contact, which starts a transport device to
move the carriage backward until the stacking-head is returned to
its state of equilibrium and the contact is opened to stop the
carriage. When documents are being removed at the front or other
end of the stack, the stacking-head pivots forwardly out of its
state of equilibrium until it closes a second contact, which starts
the transport device to move the carriage forward until the
stacking-head is returned to its state of equilibrium, and the
second contact is opened to again stop the carriage. These
operations take place in such a way that the stacking-head only
swivels through a small angle, and the pressure in the stack is
kept practically constant.
Accordingly, the carriage supports a very lightly hinged
stacking-head instead of a feeling lever, which head always pushes
with the same adjusted force against the stack, because it mainly
reacts to differences of pressure arising during the stacking
operations. The position of the stacking-head determines whether
the carriage must move, but the front of the stacking-head does not
move with the carriage, it remains stationary while the spindle or
pivot for the stacking head moves with the carriage, so that during
movements of the carriage the pressure on the stack remains
unchanged. Thus, since the pressure of the incoming letters against
the stacking-head is practically constant, They are not creased and
they are all conveyed up to their stop-plate.
BRIEF DESCRIPTION OF THE VIEW
The above mentioned and other features, objects and advantages and
the manner of attaining them are described more specifically below
by reference to an embodiment of this invention shown in the
accompanying drawing, wherein:
The FIGURE is a schematic plan view of a first-in first-out
stacking device according to a preferred embodiment of this
invention, with parts of its supporting table broken away.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
The device is shown herein mounted on a top of a table TA along
which a carriage Stw may be moved by a chain CH driven by a gear
and reversible motor mechanism or transfer device TD. The letters L
which enter the carriage Stw are pinched between two belts B 1 and
B 2 and first move past five rollers I through V on the carriage
before they reach the roller A on the pivotal axis of the mounting
for the pivoted stacking-head Stk, at which roller A they approach
the end of their pinching between the two belts B 1 and B 2. The
belt B 1 may be directly driven by a motor M mounted on the
carriage Stw, and it may drive the belt B 2 by frictional contact
therewith and the letters L fed between these two belts. These
letters L thus completely emerge from the pinching belts B 1 and B
2 only when their trailing edges have left the roller V.
When the leading edge of each letter L will have arrived
approximately at the roller C on the pivoted stacking-head Stk, it
is pulled by friction with the stacking belt S over the input end
of the stack as far as the stop-plate T mounted on the
stacking-head Stk, which plate T is adjacent the stack holding
means H which may include a rotating worm like WT described below.
The stacking belt S may be driven by a belt SS between the stacking
head pivot roller A and roller B to insure that belts B 1, B 2 and
S all travel at the same speed, and also to avoid the weight of
having a separate drive motor on the stacking head for the belt
S.
In the meantime, owing to the propulsive action of the rotating
worm W, the trailing edge of each letter L is pushed toward the
stack, in order to make room as rapidly as possible between the
letter that has just arrived and the next letter, particularly if
there is only a very small interval between these two successive
letters. Similar parallel worms WT may be provided along the top of
the table TA under the stack to insure movement of the stack
against the letter removing device RM.
The small increase of the pressure between the stacking-head Stk
and the letter L that has just arrived, which increase is due to
the thickness of this letter, causes the stacking-head Stk to move
away from the stack. This is possible because the stacking-head Stk
swivels around the spindle of the roller A under the influence of a
spring VV between the head Stk and the carriage Stw until an
equilibrium is reached. A cam SN which is fixed to the
stacking-head Stk, moves the lever of the microswitch SI fixed on
the carriage Stw until this switch closes. This then causes the
carriage Stw to be moved backwardly, such as on its wheels Wh which
roll on the top of the table TA, by means of the chain CH coupled
to the gear and reversible motor mechanism of the transport device
TD. During this movement the stacking-head Stk, which carries the
cam SN, remains in its place resting on the stack, whereas the
microswitches SI and SII move along with the carriage Stw. This
movement of the carriage Stw continues until the microswitch SI
opens again to stop further movement of the carriage Stw.
When the stack starts moving under the action of the worms WT and a
removing device RM for the letters L at the removing end, the
stacking-head Stk is moved along with the withdrawing stack by the
spring VV. Again the carriage Stw remains stationary until the cam
SN actuates or closes the microswitch S II, which now causes the
carriage Stw to move along with the stack until the microswitch S
II is opened which is when the stacking-head Stk reaches the state
of equilibrium again, and the carriage Stw is stopped.
While there is described above the principles of this invention in
connection with specific apparatus, it is to be clearly understood
that this description is made only by way of example and not as a
limitation to the scope of this invention, such as other types of
driving means may be used for the carriage, removing device, belts,
etc.
* * * * *