Stacker apparatus

An improved banknote stacker is described which provides a high level of flexibility and a high degree of stacking efficiency with a reduced level of jams and crumpled banknotes. In one embodiment the improved banknote stacker includes upper and lower housings having molded fingers and slots for interconnection with a banknote validator, banknote transport apparatus including a self adjusting belt-pulley arrangement, a prestorage compartment, a banknote pusher having a home sensing arrangement which allows it to be controlled using a simple open-loop control, and a banknote magazine for storing stacked banknotes and providing ready access to the stacked banknotes.

FIELD OF THE INVENTION 
The present invention relates to an improved banknote stacker apparatus for 
stacking paper currency. It also relates to an improved validator-stacker 
unit for validating and then stacking acceptable banknotes, in which a 
stacker may be readily attached to and detached from a validator which may 
be used alone or in conjunction with the stacker. In particular, the 
improved stacker apparatus according to the present invention operates in 
conjunction with a banknote validator which receives a banknote from a 
customer, verifies that the banknote is acceptable and provides an 
electrical signal indicating that the banknote is acceptable. The improved 
stacker apparatus takes banknotes which are accepted by the banknote 
validator and compactly and neatly stores them. 
BACKGROUND OF THE INVENTION 
In some applications, a banknote validator feeds accepted banknotes to a 
bin or storage container where they are loosely stored. For example, some 
vending machines include a banknote validator so that paper currency can 
be accepted for the purchase of expensive items for which it is onerous 
for a customer to pay in coins. Currency which is accepted is fed from the 
outlet of the currency validator to a cashbox where it is loosely stored 
until collected by the vending machine's owner. In other vending machines, 
space may be at a greater premium or for other reasons it may be highly 
desirable to compactly and neatly stack accepted currency rather than 
loosely storing it. 
As a result, various stacker arrangements have been previously developed. 
See, for example, U.S. Pat. No. 4,050,562 assigned to the assignee of the 
present application, and U.S. Pat. Nos. 4,011,931, 4,000,892, 3,977,669, 
3,917,260, 3,851,744, 3,788,333, 3,765,523, 3,655,186 and 3,222,057. Two 
commercially used stacker arrangements are briefly described below. In the 
first, a banknote which has been accepted by a validator is allowed to 
fall under the influence of gravity into a first compartment of a stacker, 
a pusher unit then pushes the fallen banknote into a stack in a storage 
compartment of the stacker. This arrangement does not maintain positive 
control over a banknote. As a result, jams and poorly stacked banknotes 
are likely to occur more frequently than is desirable. Such less than 
optimal operation is more frequently observed where worn, old banknotes 
are being stacked. 
In a second commercial arrangement, a stacker is included as part of an 
integral validator-stacker unit. In this unit, a common drive belt 
provides for positive control of a banknote's movement from insertion 
until it is stacked. This integral arrangement is mechanically complex and 
lacks the flexibility to make it readily adaptable to meet a wide range of 
different applications. This second arrangement limits stacking to a 
single direction, and does not allow the operation of its validator 
without its stacker. 
SUMMARY OF THE INVENTION 
The apparatus of the present invention provides flexibility and 
adaptability while achieving a reduced level of jamming and improper 
stacking. These improvements, as well as positive banknote control, are 
achieved while using fewer electronic and mechanical components than found 
in currently available validator-stacker units which maintain positive 
control of banknotes during handling. As a result, both the stacker and 
the combined validator-stacker unit according to the present invention are 
relatively compact. The stacker of the present invention is readily 
attached to a validator and, in normal service, requires no adjustments to 
maintain proper belt tension, bill path alignment or belt speed control. 
It is an object of this invention to provide a validator-stacker 
combination that maintains positive control of a banknote from its 
insertion into the validator until it is stacked. 
It is a further object of this invention to provide a stacker that requires 
no mechanical or electrical adjustments to compensate for normal 
manufacturing tolerances, the wear and tear of parts during normal 
operation, or typical changes in environmental conditions during 
operation. 
It is also an object of this invention to provide a mechanical interface 
system to a validator which allows the stacker to be readily designed so 
as to stack banknotes in an upward, downward or horizontal direction. 
It is also an object of this invention to provide a simple mounting scheme 
to allow a person to mount the stacker to a validator on-site without the 
need for undue alterations or adjustments which would make it necessary to 
make the installation off-site. 
It is an additional object of this invention to provide an easily 
replaceable banknote magazine to allow flexibility in the number of 
banknotes stacked by simply changing magazines to obtain different 
capacities. 
A further objective of this invention is to provide a stacker with a 
reduced number of components that insures proper banknote positioning 
thereby eliminating the need for multiple sensors commonly used to detect 
banknote position, and requiring only a single sensor to detect both the 
home position of the pusher and the stacker full condition. 
Another object of this invention is to provide a system which makes 
efficient use of the space available to stack the maximum number of 
banknotes in a given stacker volume and to insure that the stack is 
without crumpled banknotes. 
A further object of this invention is to provide a cam and scissor design 
for a banknote pusher which allows simple open-loop motor control while 
insuring accurate home position detection. 
Another object of this invention is to provide a banknote magazine which is 
simply and positively fastened closed and has multiple methods for 
removing banknotes to account for variations in mounting requirements. 
It is also an object of this invention to provide a system for maintaining 
a relatively constant speed of banknote transport through a validator 
whether the validator is used to drive a stacker or not, while maintaining 
a low cost open-loop speed control system for controlling the validator's 
banknote transport system. 
Another object of this invention is to provide a stacker that is low in 
cost and simple to assemble. 
Another objective of this invention is to have the banknote magazine be 
separable from the stacker at a non-critical area such that important 
alignments are not affected by the removal or opening of the banknote 
magazine. 
A further object is to provide a banknote magazine which includes no 
electronic components so that one banknote magazine can be replaced by 
another without affecting the stacker's electronic system in any way, and 
without having to make or break any electrical connections. 
These and other objects will be apparent from the following detailed 
description. It will also be apparent that an embodiment of the invention 
need not achieve all of the above objects to come within the scope of the 
present invention as defined by the claims. 
Throughout this specification and the claims, where reference is made to a 
"banknote" or "banknotes", the reference is intended to include all types 
of paper currency and the like. Similarly, where reference is made to the 
"face" of a banknote or banknotes, the reference is intended to include 
either major surface.

DETAILED DESCRIPTION 
One embodiment of the present invention is shown in FIGS. 1-13. FIG. 1 
shows an overall view of a banknote validator 100 connected to a stacker 
200 to form a validator-stacker unit. The stacker 200 incorporates several 
major component groups: banknote transport means 300 which is best 
illustrated in FIGS. 4 and 5, pre-storage compartment 400 which is best 
illustrated in FIG. 6, pusher means 500 which is best illustrated in FIGS. 
7 and 8, and banknote magazine 600 which is best shown in FIG. 7. 
The details of validator 100 pertaining to banknote validation are not part 
of this invention. As a result, those aspects of the validator are not 
discussed further below. Various aspects of the electrical and mechanical 
connection of the validator 100 and the stacker 200 do form a part of this 
invention and are further described below. 
The validator 100 employed in the embodiment illustrated in FIGS. 1-13 and 
described herein is a commercially available unit sold by Mars 
Electronics, Folcroft, Pa. That validator is generally as described in 
U.S. patent application Ser. No. 659,411 filed Oct. 10, 1984 and assigned 
to the assignee of the present application. 
The validator 100 determines whether inserted banknotes are acceptable. 
Banknotes are inserted one at a time into validator 100 at a banknote 
entrance 102 which is defined by an upper housing 104 and a lower housing 
106. From entrance 102, a banknote is transported lengthwise through the 
validator to the validator's banknote output by a series of pairs of 
pulleys or rollers 108, 110, 112 and 114, and a pair of belts 118, which 
are driven by a drive means 116 including a motor and drive train. FIG. 13 
illustrates the preferred arrangement of the upper pairs of rollers 110 and 
114 and the belts 118. As shown in FIG. 13, the rollers 114 are mounted on 
a shaft 115 whose ends extend beyond casing 150 of validator 100. For the 
sake of clarity, throughout the remaining discussion, only a single set of 
belts and pulleys will be discussed; however, it should be realized that in 
the preferred embodiment there are two sets of components and that the edge 
portions of a banknote are controlled by these components while the central 
portion of the banknote passes between them. 
While a banknote is transported edgewise through the validator 100, it is 
tested by a group of sensors to ascertain its validity and denomination. 
Output signals from the sensors are processed by logic circuits in 
validator 100 to determine whether the banknote is acceptable. A banknote 
which is found unacceptable is ejected back through entrance 102 by 
reversing the drive means 116. 
An acceptable banknote is driven by the belt 118 and the rollers 112 and 
114 into an interconnection region 120 in which the validator 100 and the 
stacker 200 make their connection together. As further discussed below, in 
connection with FIGS. 2A, 2B, 3A and 3B, interconnection means in the 
interconnection region 120 establish a smooth uninterrupted path for a 
banknote to follow in leaving validator 100 and entering stacker 200. 
As shown in FIG. 1, and in greater detail in FIGS. 4 and 5, stacker 200 
includes transport means 300 having a series of pulleys 306, 308 and 310, 
a belt 312, and a roller 304. The transport means 300 is driven by the 
roller 114 as will be discussed in greater detail below. 
Transport means 300 transports the accepted banknote from the stacker's 
entrance into a pre-storage compartment 400. Compartment 400 frames the 
banknote and holds it stiff. The dimensions of compartment 400 are chosen 
so that crumpling and jamming of accepted banknotes are prevented. 
After a predetermined amount of time sufficient to allow the accepted 
banknote to be fully driven into compartment 400 so that its leading edge 
has reached stop 402, a pusher means 500 is operated. Pusher means 500 
forces the accepted banknote from prestorage compartment 400 into a stack 
in banknote magazine 600 where it is stored until removed. As will be 
discussed below, the magazine 600 is designed to be readily removed or 
opened so that stacked banknotes can be removed. Now that the overall 
operation from bill insertion to stacking and removal has been briefly 
discussed, the details of this embodiment of apparatus according to the 
present invention will be described in greater detail. 
Interconnection of Validator and Stacker 
When the leading edge of a banknote reaches the region 120 shown in FIG. 1, 
it begins to leave the validator 100. Both the upper housing 104 and the 
lower housing 106 of the validator have interconnection means comprising 
integrally formed fingers 124 and slots 126 in the region 120 as shown in 
detail in FIGS. 2A and 2B (upper housing detail) and 3A and 3B (lower 
housing detail). 
When validator 100 is used without stacker 200, the fingers 124 of the 
upper housing 104 mesh with slots in an end cap which is not shown. The 
slots for the end cap are the same as slots 206 shown in FIG. 2B. In 
conjunction with the surface of the lower housing 106, the end cap defines 
an exit way which directs accepted bills downwardly out of bill validator 
100 at an angle of roughly 30.degree. from the horizontal. 
When stacker 200 is used with validator 100, fingers 204 and slots 206 of 
the stacker's upper housing 202 mesh with the slots 126 and fingers 124 of 
upper housing 104 of validator 100. Fingers 210 and slots 212 of lower 
housing 208 mesh with slots 126 and fingers 124 of lower housing 106 of 
validator 100. The meshing of these fingers and slots with their 
corresponding slots and fingers in the validator's upper and lower 
housings results in a smooth and uninterrupted banknote path from 
validator 100 into stacker 200. This type of path avoids malfunctions due 
to jamming which might otherwise occur as the banknote makes the 
transition from validator to stacker. 
Additionally, in the preferred embodiment, proper alignment of the 
validator 100 and stacker 200 is further ensured by shaft 115 fitting into 
slot 222 in casing 220 of the stacker 200 (FIG. 7). Such an arrangement 
comprises interconnection means for aligning the stacker and validator. 
Surfaces of stacker upper and lower housings 202 and 208 define a banknote 
receiving means comprising passageway walls which establish an initial 
portion of the banknote passageway in the stacker. These passageway walls 
guide a banknote around a corner and vertically upwards into the banknote 
transport means 300. In a preferred embodiment the banknote passageway 
walls are molded to include at least one finger and slot. It should be 
apparent that consistent with the present invention a banknote could be 
directed horizontally, or vertically downwards with only minor 
modifications. While the banknote receiving means of the preferred 
embodiment is shown and described, other less sophisticated banknote 
receiving means might be used in other embodiments. For example, an open 
space defined by sidewalls might suffice to receive a gravity fed banknote 
in position relative to a pusher. 
Banknote Transport Means 
As the leading edge of the banknote reaches region 220 (shown in FIG. 1) of 
the stacker 200, it begins to enter the stacker's banknote transport means 
300. Transport means 300 is shown in detail in FIGS. 4 and 5. Transport 
means 300 includes a belt-pulley arrangement 302 which is driven by the 
validator roller 114 (which will also be referred to as the stacker 
driving roller) to transport banknotes edgewise. As shown, transport means 
300 is frictionally driven, but it will be apparent other drive 
arrangements could be used, and that transport means 300 could be 
otherwise engaged with the drive means of validator 100. Transport means 
300 also includes a roller 304 which is biased against belt 312 and pulley 
306 by a leaf spring 305. 
The belt-pulley arrangement 302 includes locating pulley 306, belt tension 
pulley 308, floating pulley 310, and belt 312 which are arranged as 
described below, and shown in FIGS. 4 and 5. As illustrated in FIG. 6, and 
as discussed above in connection with FIG. 12 and the validator's banknote 
pulleys and belts, two sets of components are used in transport means 300 
with one set on each edge of the banknote path; however, only a single set 
is discussed. 
Locating pulley 306 is mounted on and free to rotate about a pulley pin 307 
which is secured to a wall of prestorage compartment 400 in a fixed 
position relative to the banknote path. The roller 304 is located in 
stacker housing 202 and opposite locating pulley 306. Once the lagging 
edge of the banknote is clear of stacker driving roller 114 and floating 
pulley 310, the locating pulley 306 and the roller 304 provide the force 
to drive the banknote up to stop 402 and fully into compartment 400. The 
leaf spring 305 provides sufficient force to prevent the banknote from 
slipping once stacker driving roller 114 stops turning; however, this 
force is insufficient to crumple or jam a bill and it is small enough so 
that belt 312 slips against the banknote once the banknote's leading edge 
reaches stop 402 until drive roller 114 is stopped. This controlled 
slippage is important; in the preferred embodiment driver roller 114 is 
operated for a predetermined time which is slightly longer than that 
required to drive the leading edge of a banknote to the stop 402, and then 
it is turned off. Without slippage, a sensor would have to be used to sense 
when a banknote was fully in or nearly fully in prestorage compartment 400 
so that drive means 116 could be turned off. Otherwise jamming or 
crumpling of the banknote would result. Such a sensor and associated 
control circuitry may be readily added, but such an addition adds overall 
cost and complexity to the system. 
Returning to the belt pulley arrangement 302, the belt tension pulley 308 
of that arrangement is mounted on and free to rotate about a shaft 309. 
The ends of shaft 309 are located in an opening 314 in housing 208. Shaft 
309 is biased into the opening 314 by the force of spring 316. The opening 
314 is a slot having its lower boundary defined by a horizontal wall 317 
and its upper boundary defined by a wall 318 which is at an angle of 
.gamma..degree. to wall 317 and the banknote path between the rollers 108 
and 112, and 110 and 114. The preferred value for angle .gamma. for this 
embodiment is approximately 6.degree.. 
Finally, floating pulley 310, the third pulley of belt-pulley arrangement 
302, is positioned between locating pulley 306 and belt tension pulley 
308. Floating pulley 310 is mounted on and free to rotate about shaft 311. 
Shaft 311 is located in a slot 320 in the housing 208. The slot 320 is 
parallel to the banknote path between the rollers of validator 100. 
When stacker 200 is not mounted to the validator 100, the belt-pulley 
arrangement 302 arranges itself as shown in FIG. 4. The belt pulley 
arrangement 302 provides a relatively constant tension in belt 312 
independent of minor variances in the manufacturing tolerances of the 
components included in that arrangement. As an example of such 
manufacturing tolerances, belt 312 may vary in length by up to 1/16 of an 
inch. A vector analysis of the relative forces on the components of the 
belt-pulley arrangement 302 will illustrate mathematically how the 
arrangement is self-adjusting. 
FIG. 5, however, visually illustrates the self-adjusting nature of 
belt-pulley arrangement 302. When validator 100 is attached to stacker 
200, pulleys 308 and 310 move as shown in FIG. 5. Pulley 310 moves 
horizontally to the right and pulley 308 moves rightwards and upwards 
following the wall 318 of opening 314. When the validator 100 is 
connected, the stacker driving roller 114 applies a force against the belt 
312 in the area of floating pulley 310 displacing it along slot 320. As a 
result, belt tension pulley 308 moves against the force of spring 316 
along the wall 318 of opening 314. This movement of both pulley 308 and 
pulley 310 maintains the tension on belt 312 and the normal force against 
stacker driving pulley 114 at relatively constant values regardless of 
tolerances of components and ordinary wear and tear of parts. 
This arrangement also results in the belt 312 being in contact with the 
surface of the stacker driving pulley 114 over a fairly wide angle 
.omega..degree. thereby preventing slippage of belt 312. Angle .omega. for 
this embodiment is approximately 25.degree.. The portion of belt 312 
labeled 322 in FIG. 5 also provides a diverting surface which helps to 
direct banknotes into the stacker's banknote transport means 300 and 
around the corner at a point where the banknote is changing its direction 
of travel from horizontal to vertical. 
While the transport means 300 is shown in conjunction with prestorage 
compartment 400, pusher 500, and banknote magazine 600, it could be used 
to deliver banknotes to any desired banknote storage compartment. 
Speed Control 
Before turning to additional discussion of the banknote path and prestorage 
compartment 400 where a banknote is temporarily stored before being 
stacked, it is important to note one further aspect of the functioning of 
the banknote transport means 300. Since transport means 300 is 
frictionally driven by the stacker drive. roller 114 which is a part of 
the validator 100 the transfort means 300 is seen as a load by the motor 
of the drive means 116 of validator 100. One aspect of the banknote 
transport system of the validator of U.S. application Ser. No. 659,411 is 
that it avoids the use of complicated speed control circuitry to hold 
transport speed constant with variations in line voltage or in the load to 
be transported. The validation circuitry in this validator compensates for 
banknote speed variations up to 20% from normal speed without making any 
speed adjustments, and if this limit is exceeded by a banknote it is 
returned. 
In the absence of some form of speed adjustment, the additional load 
presented by the stacker's transport means 300 may result in a slowing of 
the banknote speed in the validator 100 by an amount greater than 20%. The 
validator 100 and stacker 200 share a common power supply circuit 140 which 
is located in the validator. Circuit 140 is illustrated in FIG. 11. 
Briefly, a source of 15 volts (V) for both validator 100 and the pusher 
500 is derived as shown at the top of FIG. 11. An AC input voltage is full 
wave rectified using a bridge rectifier 141. The rectified signal is then 
fed as an input to a capacitor 142 and a voltage regulator 143. Capacitor 
142 is either small or may be omitted entirely. As a result, the input 
voltage of regulator 143 is unregulated or only slightly regulated and it 
falls below the required input voltage of regulator 143 causing the 
average output voltage of regulator 143 to be less than 15 V. Also 
connected to the voltage regulator 143 is a diode 144 which has one of its 
leads connected to the input of regulator 143 and its other lead connected 
to the regulator's output. Voltage regulator 143 produces at its output a 
regulated supply of 15 V only so long as the voltage at its input equals 
or exceeds approximately 171/2 V. The stacker's electronic circuitry 550 
is also illustrated in FIG. 11. As will be described below, the electronic 
circuitry 550, in conjunction with control signals from validator 100, 
controls the operation of pusher means 500. By including a capacitor 555 
in the power input circuit of the circuitry 550 as shown in FIG. 11, the 
load presented by stacker transport means 300 is compensated for and 
banknotes travel through validator 100 or the combined validator 
(100)-stacker (200) unit at a substantially constant speed. 
Banknote Path and Prestorage Compartment 
The initial portion of the banknote path through the stacker 200 has been 
previously described. Throughout the banknote path, the edges of a 
banknote traveling along the path are held in channels 241 and 242. The 
banknote passageway defined by these channels has a predetermined width in 
a direction perpendicular to the face of a banknote in the passageway. 
Preferably, this width is approximately ten times the thickness of a 
typical banknote. These channels are best illustrated in FIG. 12. The 
channel size is determined by the design and fabrication of the stacker's 
upper housing 202 and lower housing 208 which together define the 
prestorage compartment 400. The stability of these stacker parts with 
respect to environmental changes such as changes in temperature, humidity 
and pressure, and with respect to wear under normal operating conditions 
is important in order to insure that the sizes of the channels 241 and 242 
are maintained substantially constant. Molded polycarbonate is one suitable 
material for the housings 202 and 208. The controlled size of the banknote 
path allows a banknote to freely travel along that path, but it does not 
allow room for the banknote to fold or buckle. Thus, jams are prevented 
and do not occur even when the leading edge of the banknote reaches the 
stop 402, and the banknote transport means 300 continues to operate. 
The prestorage compartment 400 is shown in detail in FIG. 6. The inner 
surfaces 405 and 407 of outer sidewalls 404 and 406 of prestorage 
compartment 400 are spaced apart by a distance slightly greater than the 
width of the widest banknote which is to be accepted. Inner sidewalls 410 
and 412 define the width of the channels in which the edges of the 
banknote travel. The central portion of prestorage compartment 400 is an 
open window 420 which is larger than a pusher plate 540 which is used to 
push the banknote from compartment 400 into banknote magazine 600. 
Pusher 
Pusher 500 is shown in detail in FIGS. 7-9. Pusher 500 includes a pusher 
actuating mechanism consisting of a chassis 504, motor 506, right angle 
gear train 508, two cams 520 mounted on the gear train output shaft, a 
pair of scissors 530, a pusher plate 540 and extension springs 546. 
Additionally, a position sensor switch 560, and a sensing switch 
activating fork 562 together with fork spring 564 are part of the pusher 
500. Each scissor 530 is supported at one end by a clevis pin 531 to the 
pusher plate 540 and at the other end by a second clevis pin 532 to the 
chassis 504 through an elongated slot 534. Additionally, each scissor 530 
is held against one of the cams 520 by means of the force exerted by the 
springs 546. 
The cams 520 are eccentric and have two cam surfaces. On one side is the 
cam surface 521 (FIG. 7) upon which the scissors rest. On the other side 
is the cam surface 525 (FIG. 9) upon which the sensing switch activating 
fork 562 rests. The cams 520 are mounted on shaft 509 of gear train 508, 
and they rotate when motor 506 causes gear train 508 to turn the gear 
train shaft 509. Home position of the pusher plate 540 and scissors 530 is 
defined when the pusher plate and scissors are in their closest proximity 
to shaft 509 as shown in FIG. 7. The home position is maintained over a 
large range of cam position by providing two flat cam sides 522 as part of 
cam surface 521 as shown in FIG. 7. FIG. 7 shows an angle of x.degree. 
between one of the cam sides 522 and scissor 530. The greater this angle x 
becomes, the greater the range of cam home position with respect to 
scissors 530 and pusher plate 540. That is, as the cam rotates about its 
axis 509 through the region determined by the flat sides 522 of cam 
surface 521 and measured by angle x, no motion is imparted by cam 520 to 
scissors 530 and pusher plate 540. Once cam 520 has rotated further than 
x.degree. from its home position, the round portion of cam surface 521 
begins to move the scissors 530 and actuator plate 540 through the window 
420 in the prestorage compartment 400. As pusher plate 540 is forced 
through window 420, a banknote in prestorage compartment 400 is moved into 
banknote magazine 600 as illustrated in FIG. 8. As the cam 520 continues to 
rotate, the scissors 530 finally are fully extended. Then as the cam 520 
returns to its home position, the force of springs 546 retract the 
scissors 530 and pusher plate 540. The above description briefly explains 
how pusher means 500 operates without considering how it fits into the 
operation of the overall validator-stacker unit. 
For pusher means 500 to function properly, it is necessary to control the 
time at which motor 506 is turned on thereby causing the pusher means 500 
to operate. Quite simply, the motor should be turned on shortly after a 
banknote has fully entered prestorage compartment 400. It should not be 
turned on when there is no bill in compartment 400 or when a bill is part 
way in compartment 400. 
In the present embodiment, the electronic circuitry for controlling motor 
506 is located on a printed circuit board mounted in stacker 200. The 
preferred embodiment of this circuitry is shown in FIG. 11 as circuit 550. 
Circuit 550 includes connector P1 connector P2, connector P3, motor control 
chip U1, sensor switch 560, motor 506, as well as, discrete resistors and 
capacitors connected as shown therein. It should be noted that switch 560 
and motor 506 while connected to circuit 550 are not on the printed 
circuit board. Connector P3 makes several connections to the logic 
circuitry of validator 100. One connection is for a signal from validator 
100 which establishes whether pusher motor 506 should be turned on or off. 
A second connection is for a signal from validator 100 which establishes 
which direction motor 506 should turn. A third connection provides a 
signal to validator 100 that the stacker 200 is attached to validator 100. 
Finally, a fourth connection provides a signal to validator 100 indicating 
whether the cams 520 are at home position or not. Connector P1 connects 
sensor switch 560 to the printed circuit board and a sensor signal through 
connector P3 to validator 100. Connector P2 connects pusher motor 506 to 
motor control chip U1 which controls the power delivered to motor 506. In 
response to "motor on" and "motor direction" signals from connector P1, 
chip U1 determines the sense with which 15 V is applied to motor 506. 
Since the control signals to cause circuit 550 to turn the motor 506 on 
and off, and to control its direction of rotation are produced by logic 
circuits in validator 100 such as a microprocessor control circuit, this 
arrangement allows the use of a single microprocessor in the 
validator-stacker unit rather than having one in validator 100 and one in 
stacker 200. 
In the present embodiment a control signal to turn motor 506 on so that cam 
520 rotates clockwise is produced after a sufficient time has passed for an 
accepted banknote to fully enter the prestorage compartment 400. 
Alternatively, a banknote position sensor might be used to sense that a 
banknote is in the proper position for stacking, and a start control 
signal is then produced in response to a signal from that banknote 
position sensor. Following a motor on signal, cams 520 begin to rotate. 
Once cams 520 have rotated more than x.degree. (FIG. 7) in the clockwise 
direction, the scissors 530 are extended thereby pushing the pusher plate 
540. In the process of extending the pusher plate 540 the banknote is 
pushed through opening 420 and into the banknote magazine 600 as shown in 
FIG. 8. The banknotes already in magazine 600 are clamped between the 
pusher plate 540 and pressure plate 606 which in turn is exerting a force 
against pressure spring 610. During this process, the edges of the bill 
previously in the channels 241 and 242 of the banknote path are folded 
inward by the side walls of opening 420 and spring back to an essentially 
flat position upon clearing the bill retention tabs 604. The bill is now 
held in the stack by the force of the pressure plate 606 and bill 
retention tabs 604, and the pusher plate 540 returns to its home position 
as shown in FIG. 7. In the preferred embodiment, the pushing sequence is 
repeated with the cam 520 rotating a full cycle in the counterclockwise 
direction to insure that banknotes are properly stacked in magazine 600. 
The validator is now ready to accept another bill. 
In order to reverse motor rotation and to stop motor 506 at the appropriate 
time, sensing means are provided to sense when the cams 520 have completed 
a first rotation and returned to their home position for the first time, 
and also to sense when a second rotation has been completed. Also in the 
preferred embodiment, a maximum time is allowed for a complete push to be 
completed. If this time is exceeded, the motor 506 is de-energized and the 
magazine 600 is either full, or a jam or other malfunction has occurred. 
A suitable sensor switch arrangement is shown in FIG. 9. This arrangement 
makes use of the cam surface 525 on the opposite side of cam 520. It 
consists of a position sensing switch 560 mounted to chassis 504 and a 
switch activating fork 562. Fork 562 is supported and pivoted around pin 
563. The fork 562 has a stop point 565 near its end closest the switch 560 
to insure it is located in a predetermined location so that it is 
interrupting switch 560 when cam 520 is in its home position. This 
position of fork 562 is its stop position. The other end of the fork 562 
is positioned relative to the cam surface 525 of cam 520. The fork 562 is 
biased to its stop position by the tension of a spring 564. The stop 
position is also known as the home position of fork 562 and corresponds to 
the home position of cam 520. The cam surface 525 of cam 520 is designed so 
that when it is in its home position the fork 562 is then closest in 
proximity to shaft 509. The cam surface 525 is in its home position during 
the time that cam surface 521 is in its home position. 
The breadth of the home position for the fork 562 is determined by virtue 
of the cam shape on cam surface 525 just as discussed for cam surface 521. 
This cam shape may include two flat sides 523 at an angle of y.degree. from 
the line drawn through points 526 and 527 of FIG. 9. 
When cam 520 rotates, cam surface 525 rotates and cause fork 562 to pivot. 
This causes the end of the switch activating fork 562 to move from 
position 528 to position 529 as illustrated in dashed lines in FIG. 9. 
This movement causes the switch 560 to change electrical state thereby 
indicating a non-home condition. The determination of the sensed home vs. 
non-home condition of fork 562 is related to the combination of distances 
"f", "d" and "e" of FIG. 9 and angle y between the cam surface 525 and the 
actuating fork 562. 
The design of the sensor switch activating arrangement is such that the 
sensed return to home position occurs at a time after the pusher plate 540 
is actually in its home position and indicates non-home before the pusher 
plate 540 actually leaves its actual home position. This is illustrated by 
FIG. 10. 
The relationship of the angles x and y of the flat sides 522 on cam surface 
521 and the flat sides 523 on cam surface 525, as well as the distances 
"f", "d", and "e" of FIG. 9, provides an actual home position of the 
pusher plate 540 of about 25% of the revolution of the cams 520 while 
providing a sensed home of about 13% of the revolution of the cams 520 as 
illustrated in FIG. 10. Thus tolerance is provided which allows an open 
loop motor control system and which allows coasting or reversing with a 
fixed brake (reverse motor direction) time. Without such an arrangement, a 
more expensive and sophisticated motor control system may be required. 
While the pusher 500 is shown as used with transport means 300, prestorage 
compartment 400, and banknote magazine 600, in other embodiments, it might 
be used with any suitable banknote positioning means for receiving 
banknotes from a validator and positioning them properly relative to the 
pusher plate 540, and any suitable banknote storage compartment for 
facially stacking banknotes. 
Banknote Magazine 
The banknote magazine 600 is a separable unit used to store the collected 
and stacked banknotes. The number of banknotes stacked and stored can be 
varied by changing the magazine's depth 601 to any arbitrary size. The 
magazine 600 can be readily attached to or detached from the remainder of 
stacker 200 in the factory or in the field. The magazine 600 is fastened 
to the remainder of stacker 200 by a pivoting clevis pin 620 which allows 
the magazine to rotate open and close for easy banknote removal. A spring 
clip 622 located at the top of stacker 200 is used to hold the magazine 
600 in its closed position. 
The magazine 600 consists of the magazine enclosure 602, bill retention 
tabs 604, pressure plate 606, and a pressure spring 610 which is retained 
in place by clevis pin 611 as shown in FIGS. 7 and 12. Additionally, the 
magazine 600 has a top access door 612 with hinge pin 613 and spring 614. 
Side doors 615 for side access are provided with side door pins (not 
shown) and springs (not shown). 
Banknotes may be removed from the magazine 600 by lifting the spring clip 
622 to allow the magazine to be tilted open and the top door 612 to be 
opened giving access to the stacked bills. For applications where the top 
door 612 is no accessible or there is no room to tilt open the magazine 
600, side doors 615 can be opened and the banknotes removed from the side. 
The pressure plate 606 is located inside the magazine enclosure 602 and is 
guided by means of a slot 616 in the base of enclosure 602, and by a 
guiding tab 617 on the pressure plate 606. The pressure plate 606 is 
biased against the banknote retention tabs 604 by the force of pressure 
spring 610. The pressure spring 610 is supported in place by the clevis 
pin 611. The pressure spring 610 is preferably a double torsion spring so 
that it takes up a minimum of space in magazine 600, thus allowing the 
largest possible space for stacking banknotes. The design of the pressure 
spring 610 is such that its range of angular rotation during operation of 
the stacker 200 is small relative to the number of coils in the spring. 
Consequently, the operating force of the pressure spring 610 against 
pressure plate 606 is relatively constant. Further, the same spring 
arrangement can be used with stackers of different capacities with the 
total range of angular rotation during operation still being relatively 
small so that a relatively constant force against pressure plate 606 is 
always maintained regardless of the size of magazine 600. This allows the 
use of the same stacker drive unit without modification for various 
capacity magazines 600 as all magazines will present a common load. 
Preferably this common load is relatively low so that a small economical 
motor 506 can be used to drive pusher 500.