U.S. patent number 3,761,079 [Application Number 05/121,411] was granted by the patent office on 1973-09-25 for document feeding mechanism.
This patent grant is currently assigned to Automata Corporation. Invention is credited to Leo L. Azure, Jr..
United States Patent |
3,761,079 |
Azure, Jr. |
September 25, 1973 |
DOCUMENT FEEDING MECHANISM
Abstract
A feeding mechanism receives a stack of documents, such as
data-bearing cards, in a hopper, the hopper defining a feed throat
through which the cards are fed individually and in succession. A
feed roller is positioned for engaging the lowermost one of the
stacks of cards, generally centrally of the planar surface thereof,
the cards tending to bow about the feed roller and toward the
support surface. The initial feeding effect of the feed roller in
each cycle is to buckle or spring the card engaged thereby away
from the stack and toward the support surface, thereby breaking
frictional contact between that card and the adjacent card of the
stack, greatly facilitating the feed operation. Drive rollers
receive each card as it is fed through the throat from the hopper
and transport the card from the hopper. In one embodiment, the feed
roller is driven through a lost motion clutch from a drive shaft,
in turn driven at a constant rotational speed. By virtue of the
lost motion clutch, and the relative surface tangential velocities
of the drive rollers and the feed rollers, the cards of the stack
are fed individually and in succession, with uniform spacing
between the trailing and leading edges of successive cards
regardless of the lengths of the cards. Means are provided in the
support surface of the hopper for separating the stack from the
feed roller, thereby to interrupt the feed cycle. In a second
embodiment of the invention, the feed roller is driven at a
constant speed without the use of a lost motion clutch, and control
means are provided for automatically effecting the separation of
the stacks of cards from the feed roller. The automatic control
means includes suitable detection means for enabling the feed means
to feed successive cards of the stack, and thus provide the
individual and successive feeding of the cards with the uniform
spacing therebetween as aforenoted. In a typical application, the
drive rollers drive the card through a sensing station, such as for
optical sensing of indicia presented on the cards, and provide a
stabilizing control on the card in the region of the sensing
station for improving the accuracy of the sensing operation.
Inventors: |
Azure, Jr.; Leo L. (Richland,
WA) |
Assignee: |
Automata Corporation (Richland,
WA)
|
Family
ID: |
22396545 |
Appl.
No.: |
05/121,411 |
Filed: |
March 5, 1971 |
Current U.S.
Class: |
271/116; 271/23;
271/10.03 |
Current CPC
Class: |
G06K
13/103 (20130101); G06K 13/10 (20130101) |
Current International
Class: |
G06K
13/103 (20060101); G06K 13/10 (20060101); G06K
13/02 (20060101); B65h 003/06 () |
Field of
Search: |
;271/41,23,29,52,36,56,57,DIG.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Blunk; Evon C.
Assistant Examiner: Stoner, Jr.; Bruce H.
Claims
What is claimed is:
1. A card feeding apparatus comprising:
means for receiving a stack of cards, and having associated
therewith a support surface,
means defining a throat of a height to pass a single card and
communicating with said support surface,
feed means positioned to protrude from said support surface to
engage the stack of cards generally centrally of the surface of the
card next adjacent thereto, said cards, when engaged with said feed
means, being supported on said feed means and thereby displaced by
said feed means in said central portion thereof from the plane of
said support surface and said cards tending to bow toward the plane
of said support surface at the opposite ends thereof and the ends
immediately adjacent said throat being received on and supported by
said support surface, and
means for selectively enabling said feed means to frictionally
engage and feed the said next ajdacent card of the stack, initially
to buckle the card in the portion thereof intermediate the feed
means and the throat toward said support surface to break contact
thereof with the successive card of the stack and thereby to
facilitate feeding of the cards, individually and in succession,
from the stack and through the throat.
2. Apparatus as recieved in claim 1 wherein said feed means
comprises a roller mounted on a drive shaft to be driven in
rotation thereby.
3. Apparatus as recited in claim 2 wherein the surface of said feed
roller includes a high friction material.
4. Apparatus as recited in claim 3 wherein said high friction
material comprises polyurethane.
5. Apparatus as recited in claim 1 further comprising drive means
for receiving and engaging each successive card fed through said
throat by said feed means from said hopper and completing transport
of said card from said stack and through said throat.
6. Apparatus as recited in claim 5, further comprising:
means defining a lateral reference position for one longitudinal
edge of said cards as engaged and driven by said drive means,
and
said drive means includes a positively driven drive roller and an
idler roller engaged therewith, said drive and idler rollers
receiving and engaging a card therebetween when fed through said
throat by said feed means, and said idler roller being skewed with
respect to the direction of transport of said cards by said drive
means to urge each said card as engaged and driven thereby toward
said reference position.
7. Apparatus as recited in claim 6 wherein said cards include
indicia receiving areas thereon arranged in columns and positioned
in relation to a selected lateral edge of each said card, and
wherein said skewed idler roller urges the said selected edge of
each said card to said reference position.
8. Apparatus as recited in claim 5 further comprising means for
determining the engagement by said drive means of each card fed
through said throat for actuating said selective enabling means to
displace said stack of cards from said feed means as each card is
engaged by said drive means, and for determining when passage of
each such engaged card through said throat has been completed,
thereupon to actuate said selective enabling means for engaging
said stack of cards with said feed means for feeding a successive
card through said throat.
9. Apparatus as recited in claim 8 wherein said determining means
comprises switching means and a sensing element, said sensing
element being positioned to be contacted by a card when engaged and
driven by said drive means and thereby to actuate said switching
means.
10. Apparatus as recited in claim 8 wherein said determining means
comprises photoelectric sensor means for detecting when each card
has been engaged by said drive means and producing an output signal
to effect actuation of said selective enabling means to displace
said stack of cards from said feed means until passage of a card
through said throat has been completed.
11. Apparatus as recited in claim 8 wherein each said card includes
a predetermined number of timing marks disposed longitudinally
thereof in accordance with the direction of transport of the card
and there is further provided:
means for sensing the timing marks from each said card during
transport thereof by said drive means and producing an output
timing pulse in response to sensing of each mark,
means responsive to sensing of a first timing mark from each card
by said sensing means to actuate said selective enabling means to
displace said stack of cards from said feed means,
counter means preset to produce an output signal upon accumulation
of a count corresponding to the predetermined number of timing
marks on each said card and responsive to said sensing means for
counting the output timing pulses therefrom, and
said selective enabling means being responsive to the output signal
from said counter to release said stack of cards for engagement
with said feed means.
12. Apparatus as recited in claim 5 wherein said feed means
comprises:
a shaft and means for rotating said shaft at a constant rotational
velocity,
a feed roller rotatably mounted on said shaft and positioned
thereby to protrude from said support surface,
means coupling said feed roller to said shaft for rotation of said
feed roller by said shaft, and providing relative rotation
therebetween through a predetermined slack angle,
said drive means transporting each said card at a greater speed
than said feed roller, and
said feed roller being rotated by each said card when engaged by
said drive means at a greater rotational velocity than that of said
drive shaft to advance through said slack angle and said feed
roller terminating rotation upon engagement thereof with the
successive card of the stack as said drive means withdraws each
said card from said stack and through said throat, and said shaft,
at said constant rotational velocity thereof, closing the slack
angle of said coupler to thereupon again produce rotation of said
feed roller by said shaft.
13. Apparatus as recited in claim 12 wherein said coupling means
comprises:
a hub fixed to said feed roller and having a pair of shoulders
angularly displaced with respect to the axis of said drive shaft
and defining therebetween the maximum lost motion angle of said
coupler, and
said drive shaft includes a pin positioned thereon for rotation
therewith, said pin engaging one of said shoulders of said hub for
effecting rotation of said feed roller and said feed roller, when
rotated relative to said drive shaft in advancing through the lost
motion angle, causing the other of said hubs of said coupling means
to engage said pin, whereby said other hub limits the advance of
said feed roller relative to the drive shaft to the maximum slack
angle.
14. Apparatus as recited in claim 5 wherein said drive means
comprises a first drive roller and associated idler roller for
receiving and engaging each successive card fed through said throat
by said feed means,
a second drive roller and associated idler roller for receiving and
engaging each card following engagement thereof by said first drive
roller,
said second drive roller having a higher surface tangential
transport speed than said first drive roller thereby to assure that
each card in the portion thereof intermediate said first and second
drive rollers and the respectively associated idler rollers is
maintained taut during the transport thereof.
15. Apparatus as recited in claim 14 further comprising:
means defining a lateral reference position for one longitudinal
edge of said cards as engaged and driven by said drive means,
and
said idler roller associated with said first drive roller is skewed
with respect to the direction of transport of said cards by said
drive means to urge each said card as engaged and driven thereby
toward said reference position.
16. Apparatus as recited in claim 15 wherein said cards include
indicia receiving areas thereon arranged in columns and positioned
in relation to a selected lateral edge of each said card, and said
cards are driven by said drive means such that said skewed idler
urges said selected lateral edge of each said card to each said
reference position.
17. Apparatus as recited in claim 16 further comprising scanning
means disposed to scan the indicia receiving areas of said cards in
the region intermediate said first and second drive rollers and the
respectively associated idler rollers and including a plurality of
scanning elements positioned in relation to said reference position
for scanning respectively associated ones of said columns of
indicia receiving areas of said cards.
18. A card feeding apparatus comprising:
a hopper for receiving a stack of cards and including a support
surface and a throat communicating with said support surface, said
throat being of a height to pass a single card therethrough,
feed means positioned to protrude inwardly of said hopper relative
to said support surface to engage a stack of cards received in said
hopper generally centrally of the surface of the card next adjacent
said feed means, said cards, when engaged with said feed means,
being supported on said feed means and thereby displaced by said
feed means in said central portion thereof from the plane of said
support surface and said cards tending to bow toward the plane of
said support surface at the opposite ends thereof and the ends
immediately adjacent said throat being received on and supported by
said support surface,
said feed means being cyclically operable to frictionally engage
and feed the said next adjacent card of the stack, individually and
in succession for the plurality thereof, said feed means in each
cycle of operation thereof initially buckling the portion of the
card intermediate said feed means and throat toward said support
surface to break contact thereof with the successive card of the
stack and thereby to facilitate feeding of said cards through the
throat, and
drive means for receiving each card fed through the throat by said
feed means for completing transport of the card from the hopper and
through the throat to thereby define the timing of each successive
cycle of operation of said feed means.
19. Apparatus as recited in claim 18 wherein said feed means
comprises:
a feed roller,
a shaft for said feed roller adapted to be driven at a constant
rotational velocity,
means coupling said feed roller to said shaft for rotating said
feed roller in response to the rotation of said shaft, and
affording a slack angle through which said feed roller is rotatable
relative to said shaft, and
said drive means transports each said card at a rotational velocity
in excess of that of said shaft, such that each card, when engaged
and driven by said drive means, rotates said feed roller to advance
the same through said slack angle of said coupling means until said
feed roller engages the next successive card of the stack and
thereupon terminates rotation substantially immediately, and said
shaft closes said slack angle of said coupling means while rotation
of said feed roller has terminated, to reinitiate rotation of said
feed roller for feeding a successive card of the stack.
20. Apparatus as recited in claim 18 wherein there is further
provided:
separating means selectively operable to separate said stack of
cards from said feed means to interrupt feeding of the stack of
cards.
21. Apparatus as recited in claim 20 wherein said separating means
comprises:
a plate mounted adjacent said feed roller, and
an actuator for moving said plate to displace the stack from said
feed roller to interrupt further feeding of cards therefrom.
22. A card feeding apparatus comprising:
a hopper for receiving a stack of cards and having associated
therewith a support surface and a throat communicating with said
support surface, said throat being of a height to pass an
individual card therethrough from said stack,
a feed roller positioned to protrude inwardly of said hopper
relative to said support surface to engage a stack of cards
received in said hopper, generally centrally of the surface of the
card next adjacent thereto, said stack of cards when engaged by
said feed roller, tending to bow toward said support surface,
said feed roller frictionally engaging and feeding the said next
adjacent card of the stack through said throat individually and in
succession for the plurality of cards of the stack, and, for each
card, initially buckling the card in the portion thereof
intermediate the feed means and the throat toward said support
surface to break contact of the card with the successive card of
the stack and thereby to facilitate feeding of the successive
cards, and
means for selectively displacing the stack of cards from said feed
roller to interrupt the feed operation thereof, said selective
separating means including means for detecting engagement of each
successive card with said drive roller to separate the stack of
cards from the said feed roller and to determine completion of
passage of each said card through said throat to deactivate said
separating means and enable engagement of the next successive card
of the stack with the feed roller for initiating a successive feed
cycle.
23. Apparatus for automatically and selectively feeding cards
individually and in succession from a stack of cards, and providing
precise spacing between the trailing and leading edges of the
successively fed cards, comprising:
means for receiving a stack of cards to be fed, said receiving
means including defining a throat of a height to pass a single card
fed from the stack,
said throat defining means comprising a stop against which the
leading edges of the cards are positioned and a support surface
adjacent said stop, said stop being spaced from said support
surface to define said throat, and
said support surface receiving thereon and supporting said stack of
cards, and positioning the card immediately supported thereon in
alignment with said throat for being fed therethrough,
a shaft and means for rotating said shaft at a constant rotational
velocity,
a feed roller rotatably mounted on said shaft and positioned
thereby in fixed axial relation to said receiving means to support
a stack of cards received in said receiving means, by engaging said
stack at a position displaced from the leading edges of the cards
of said stack,
means coupling said feed roller to said shaft for rotation of said
feed roller thereby, for feeding a card of the stack engaged by
said feed roller through said throat, said coupling means providing
relative rotation between said feed roller and said shaft through a
predetermined slack angle,
drive means for receiving and engaging each card as fed through
said throat for completing transport of said card from said stack
and through said throat, said drive means transporting each said
card at a greater speed than the feed speed of said feed roller
when coupled to said shaft for rotation at the constant rotational
velocity thereof, said feed roller, while engaged with a card being
transported by said drive means, being rotated at a greater
rotational velocity than that of said drive shaft to advance
through said slack angle of said coupling means, and terminating
rotation upon engagement thereof with the successive card of the
stack as the trailing edge of the card being transported by said
drive means is withdrawn from engagement with said feed roller,
said constantly rotating shaft thereupon closing said slack angle
of said coupling means while rotation of said feed roller has
terminated, to reinitiate rotation of said feed roller for feeding
a successive card of the stack, and
said slack angle of said coupling means being selected in
accordance with the rotational velocity of said shaft, the radius
of said feed roller, the displacement of the feed roller from said
throat, and the card transport speed of said drive means so as to
effect the reinitiation of rotation of said feed roller to feed
each successive card of the stack with a fixed spacing between the
trailing and leading edges of successively fed cards.
24. Apparatus as recited in claim 23 wherein said stack of cards is
urged against said feed roller and said support surface and wherein
said feed roller is positioned relative to said support surface
such that the said stack of cards tends to bow about the feed
roller.
25. Apparatus as recited in claim 23 wherein:
said support surface extends in a generally common plane toward
said feed roller for at least a portion of the distance between
said feed roller and said throat, and
said feed roller, when rotation thereof is reinitiated, initially
causes the card with which it is engaged to buckle in the portion
thereof intermediate the feed roller and the throat and toward said
support surface to break contact of that card with the next
successive card of the stack, thereby to reduce frictional
engagement therewith and facilitate feeding of the card from the
stack.
26. Apparatus as recited in claim 25 wherein said feed roller is
positioned to protrude from the plane of said support surface,
thereby to space said cards in the portion thereof engaged by said
feed roller from the plane of said support surface.
27. Apparatus for automatically and selectively feeding cards
individually and in succession from a stack of cards, and providing
precise spacing between the trailing and leading edges of the
successively fed cards, comprising:
means for receiving a stack of cards to be fed and defining a
throat of a height to pass a single card fed from the stack,
said receiving means including a surface defining said throat and
supporting the stack of cards received in said receiving means
adjacent the leading edge of the card of the stack which first
passes through said throat during feeding of said cards, in
succession, from said stack,
a feed roller positioned in fixed axial relation to said receiving
means and displaced from said throat to support a stack of cards
received in said receiving means, said feed roller being positioned
relative to said support surface to cause said cards, when engaged
therewith, to bow toward said support surface from the location of
the engagement thereof with said feed roller, and
drive means for receiving and engaging each successive card fed
through said throat by said feed roller and completing transport of
each said card from said stack and through said throat, and
means for selectively enabling said feed roller to feed the next
acjacent card of the stack in timed relationship to the passage of
the trailing edge of the next previously fed card through said
throat.
28. Apparatus for automatically and selectively feeding cards
individually and in succession from a stack of cards, and providing
precise spacing between the trailing and leading edges of the
successively fed cards, comprising:
means for receiving a stack of cards to be fed and defining a
throat of a height to pass a single card fed from the stack,
said receiving means including a surface defining said throat and
supporting the stack of cards received in said receiving means
adjacent the leading edge of the card of the stack which first
passes through said throat during feeding of said cards, in
succession, from said stack,
a feed roller positioned in fixed axial relation to said receiving
means and displaced from said throat to support a stack of cards
received in said receiving means,
drive means for receiving and engaging each successive card fed
through said throat by said feed roller and completing transport of
each said card from said stack and through said throat,
means for selectively enabling said feed roller to feed the next
adjacent card of the stack in timed relationship to the passage of
the trailing edge of the next previously fed card through said
throat, said feed roller exerting a longitudinal force on the card
of the stack with which it is engaged to effect feeding of said
card to said throat and exerting a transverse force on said card
tending to buckle said card away from said stack, and
restraining means intermediate said throat and said feed roller for
limiting the extent of buckling produced by said transverse force,
thereby to direct the engaged card to move through said throat in
response to said longitudinal force.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a document feeding mechanism and, more
particularly, to such a mechanism for feeding documents, such as
cards, from a stack thereof in succession and with precise and
predetermined spacing between the trailing and leading edges of
successive documents.
2. State of the Prior Art
Various types of document feeding apparatus have been proposed
heretofore in the prior art. Numerous applications of such
apparatus are found in data processing systems, particularly as
terminal units for deriving source data from source documents for
supply to subsequent electronic processing systems. The documents
may comprise cards of the data processing type, bearing data
encoded indicia. Typically, the cards are combined in superposed
relationship in a stack from which they are to be fed individually
and in succession, or serially. The cards then pass through a
sensing station for reading of the data indicia, such as by optical
detection equipment. The data processing systems which receive the
data process the data electronically, and thus at high speeds. For
optimum efficiency therefore, the documents must be fed as rapidly
as possible, while affording precise and uniform spacing between
the leading and trailing edges of successively fed cards to assure
accurate interpretation of the data. Prior art feed mechanisms,
however, have not been completely satisfactory, however, both with
regard to the feed rates which they provide and to the reliability
and uniformity of the feed operation.
For example, the cards are typically received in a hopper with
biasing means, such as a static weight, imposed thereon to urge the
stack of cards into position for engagement with the feed
mechanism. Relatively high frictional forces thus exist between the
lowermost card of the stack and the next adjacent card which tend
to prevent the separation of these adjacent cards. As a result, a
relatively high driving force is required to separate the cards and
thereby permit individual feeding of successive cards. The
necessity of using high driving forces impedes the effectiveness
and particularly the speed of the feeding mechanism.
Many of the previous mechanisms designed for feeding cards employ a
picker finger which engages the trailing edge of the lowermost card
in a stack to force it out of the stack. In such a mechanism, the
requisite driving force of the picker finger may result in damage
of the trailing edge of the card which is to be fed. A potentially
more serious defect is that if the trailing edge which is to be
engaged by the picker finger is warped or mutilated, the lowermost
card may not be fed, or the feed mechanism may attempt to feed both
the lowermost and the next adjacent card of the stack
simultaneously. In either case, the failure may result in loss of
data and typically requires operator attendance to correct the
defect.
Even ignoring the situations in which a picker finger mechanism
fails to feed the cards properly, such mechanisms are inherently
slow in operation, due to the necessity of limiting the force with
which a picker finger contacts the trailing edge of the cards.
Numerous other types of feeding mechanisms have also been proposed
in the prior art. For example, the prior art discloses the use of
feed rollers for feeding various sheet-like materials including
data-bearing cards as well as industrial sheet-like materials for
use in various material-handling applications. Such prior art
mechanisms, however, have been undesirably complex in construction
or have imposed requirements as to the configuration of the
mechanism and the relationship of the operating, moving parts
thereof as to render them both inconvenient in use and of excessive
cost and complexity.
One feed roller system known in the art requires the reciprocation
of the entire supporting and drive structure for the feed roller to
effect intermittent engagement of the feed roller and the
successive cards of the stack. Such mechanisms are of undue
complexity due to the requirement of the reciprocating movement of
the feed roller and its associated driving mechanism. Another type
of document feeding apparatus of the prior art requires the use of
a plurality of belts cooperating with a pneumatic system
communicating through apertures in the rotating belts to effect
engagement of a card of a stack with the belt for feeding. Such
mechanisms are objectionable due to the complexity thereof and the
noise attendant to the operation, in addition to their presenting
severe maintenance problems in view of the tendancy of the
pneumatic system to become clogged by loose particulate material
carried by the cards. Furthermore, these various other types of
prior art apparatus are not capable of reliably feeding the cards
at high rates of speed and at uniform velocities with precise and
fixed spacing between the trailing and leading edges of successive
cards as required for high speed data processing systems.
Furthermore, when a feed mechanism is employed for supplying
documents to a sensing station for reading, such as by optical
detection equipment, it is important that the mechanism afford a
stable condition of the document in the region thereof within the
sensing station, thereby to assure accurate reading or sensing of
data from the document. The mechanisms of the prior art,
particularly when operated at a high speed, fail to afford these
stable characteristics of the document to enable accurate reading
of data therefrom.
A further defect of such prior art mechanisms, including the picker
finger type, is that the feed apparatus operates in a precise
repeating interval such that a given mechanism is operable for
feeding cards of only a single length. Even as to pior art
mechanisms capable of feeding documents of varying lengths, such
mechanisms do not afford a precise, uniform spacing between the
trailing and leading edges of successive documents.
SUMMARY OF THE INVENTION
The document feeding mechanism of the invention is of greatly
simplified construction relative to prior art mechanisms, and yet
affords greater versatility and reliability, with higher feed rates
than heretofore attainable with such document feeding mechanisms.
Generally, the mechanism of the invention provides for feeding
individual cards from a stack thereof, in succession, and with
precise spacing between the trailing and leading edges of
successive cards regardless of the length of the cards of the
stack, even when cards of different lengths are intermixed in a
stack. In addition to the precise control of the relative
longitudinal positions of the cards being fed, the system also
affords precise positioning of the cards in a transverse direction
with respect to a fixed reference location. In addition, and of
particular importance when the mechanism of the invention is
employed in a system for sensing information from the cards being
fed, the mechanism affords a region in the transport path of each
card wherein the card is stabilized in its physical configuration,
albeit being transported at high speed, to assure accurate and
reliable sensing of data from the card. Stabilizing of the card as
it passes through such a sensing region is of particular importance
for optical sensing of data indicia from the card.
In one embodiment of the mechanism of the invention, and as
specifically disclosed herein, the documents comprise data-bearing
cards which are received in a stack in a hopper, the successive
cards of the stack lying horizontally in superposed relationship in
a vertical stack. As later specified, however, the particular
orientation of the stack, be it horizontal, vertical, or otherwise,
is immaterial and accordingly the referenced relative relationship
and position of the stack within a hopper is merely for purposes of
illustration.
The stack of cards is received in a hopper and brought to a forward
position with the leading edges of the cards, with respect to the
direction of feed thereof, engaging a front, or forward, wall of
the hopper comprising a stop structure. Egress of the cards from
the hopper, as fed, is afforded by a throat defined by the stop and
the support surface and providing an opening slightly greater than
the thickness of a single card.
A feed roller protrudes from the support surface of the hopper,
engaging the lowermost card of the stack in a generally central
portion thereof. The stack is urged into engagement with the feed
roller, the stack of cards thereby tending to bow about the feed
roller and toward the support surface.
Means are provided for intermittently enabling the feed roller to
feed the cards of the stack, and particularly the lowermost card of
the stack, i.e., the card engaged by the feed roller. The initial
effect of the feed roller in each feed cycle is to cause the card
engaged thereby to buckle downwardly, or away from the stack, in
the portion thereof between the feed roller and the throat, and
thus toward the support surface, thereby breaking frictional
contact between the two lowermost cards of the stack and greatly
facilitating the feeding operation. The support surface limits the
extent of buckling of the lowermost card and thus the card, having
been subjected to the buckling effect, is fed through the
throat.
Drive rollers positioned opposite the throat from the hopper
receive and engage each card as fed through the throat to transport
the card from the hopper. In a preferred embodiment of the
invention, two pairs of drive rollers are provided, displaced
longitudinally in the direction of the card transport. Typically,
sensing means for sensing data from the cards is positioned to scan
the cards in the region intermediate the two sets of drive
rollers.
The first set of drive rollers includes one roller positively
driven and a second, idler roller, the latter being skewed with
respect to the longitudinal feed direction of the cards, so as to
urge the card engaged by that first set of drive rollers toward a
predetermined reference position. The cards preferably are printed
so as to define data indicia receiving positions relative to a
given edge thereof and the sensing apparatus is correspondingly
positioned relative to the noted reference position. Accordingly,
precise positioning of the sensing elements relative to the
location of data indicia on each card is assured.
The second set of drive rollers affords a slightly greater surface
tangential velocity than the first, aforementioned set, whereby
each card in the region between the two sets of drive rollers is
subjected to a tensioning force, tending to flatten and stabilize
each card during transport through the sensing region. The enhanced
stability of the card in this sensing region thereby affords
greater reliability of the data sensing operations.
In one embodiment of the invention, the feed roller is connected to
a drive shaft by a lost motion coupler which permits relative
rotation of the roller and the shaft through a predetermined slack
angle defined by the coupler. In this embodiment, particularly, the
drive rollers afford a greater surface tangential velocity than
that of the feed roller, whereby each card, upon being engaged by
the drive roller, is transported at a greater speed than afforded
by the feed roller. As a result, the feed roller is rotated by the
card at an angular velocity greater than that of its drive shaft,
causing the coupler to advance through the slack angle. Typically,
the coupler is advanced through the maximum slack angle and the
card being driven slides, or slips, across the feed roller. As the
card being driven breaks contact with the feed roller, the latter
stops substantially instantaneously upon contacting the next card
of the stack. The continuous rotation of the drive shaft, however,
closes the slack angle of the coupler. During this interval, the
card currently being driven by the drive rollers is completely
removed from beneath the stack and the next superposed card of the
stack comes into position to be fed. The size of the slack angle
defined by the coupling is selected, in general, in relation to the
basic geometry of the system and specifically such that the drive
shaft closes the slack angle of the coupler to thereby effect drive
of the feed roller at a predetermined time after the trailing edge
of the preceding card passes through the throat. The optimum speed
of card transport, of course, occurs when the feed of the next
successive card is initiated substantially immediately following
the passage of the trailing edge of the preceding card through the
throat. In any event, since the distance from the feed roller to
the throat is fixed, the spacing between the trailing and leading
edges of successively fed cards is maintained constant, regardless
of the length of the cards.
Separating means are provided for displacing the stack of cards
from the feed roller to thereby interrupt the feed cycle. It will
be appreciated that any card already engaged by the drive roller
will be removed from the hopper, thereby avoiding jamming of a card
at an intermediate position in the feed operation. Furthermore,
once feed is reinitiated, the precise spacing between successive
cards is once more established.
In a second embodiment of the invention, the feed roller is
directly connected to the constantly rotating drive shaft and the
lost motion coupler is eliminated. Detecting means are provided for
automatically controlling the separating means in each feed cycle.
The detecting means determines, in effect, that a card has been
engaged by the drive roller, thereby to separate the stack from the
feed roller and furthermore to detect when the trailing edge of a
card being driven has passed through the throat, thereby to release
the separating means and effect engagement of the feed roller with
the next successive card of the stack. The electronic timing
afforded by this technique again assures the precise and uniform
spacing of the trailing and leading edges of successively fed
cards, regardless of the length thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a card feeding mechanism in
accordance with the invention;
FIG. 2 is a top view of the card feeding mechanism of FIG. 1 with
the top cover removed to reveal the operating elements;
FIG. 3 is a side elevational view of the card feeding mechanism of
the invention, taken along line 3--3 in FIG. 2;
FIG. 4 is a front elevational view of the card feeding mechanism of
the invention taken along line 4--4 of FIG. 3;
FIG. 5 is a schematic view of the card feeding mechanism, taken
along line 5--5 of FIG. 2, and illustrating a first step in
dispensing a card from the hopper;
FIG. 6 is a view similar to FIG. 5 illustrating a second step in
dispensing a card from the hopper;
FIG. 7 is a view similar to FIG. 5 illustrating a third step in
dispensing a card from the hopper;
FIG. 8 is a view similar to FIG. 5 illustrating a fourth step in
dispensing a card from the hopper;
FIG. 9 is a schematic view of a portion of the card feeding
mechanism of the invention illustrating an alternative timing
system for controlling the card feed cycles;
FIG. 10 is an illustration of a typical data card to be fed by the
mechanism of the invention; and
FIG. 11 is a schematic block diagram of an electronic timing
circuit for controlling the card feed cycle.
DETAILED DESCRIPTION OF THE INVENTION
The card feeding mechanism of the invention is shown in perspective
view in FIG. 1, as generally identified at 12, and includes a card
feed hopper 14 defined by a forward wall 16, side walls 18 and 20,
and a horizontal support surface, more readily seen in later
figures. A plurality of cards 22 are stacked in superposed
relationship and received in the hopper 14. As later discussed, the
cards may be received in the stack shown, for feeding from the top
or the bottom of the stack, as desired, or may be held on edge,
i.e., a horizontal stack, by suitable modifications of the
mechanism. The vertical stack hopper, as shown, is thus only
representative of one possible configuration of the feeding
mechanism of the invention. A discard or receiving hopper 24 is
provided for receiving the cards after they have been fed from the
card hopper 14 and through a scanning station 26 which may include,
for example, an optical scanning head. A weight 28 is positioned on
the cards in the feed hopper 14 providing a static biasing of the
stack toward the feed mechanism, also as later detailed. A feed
interrupt button 30 is provided to interrupt the feeding of the
cards, as desired, as well as a main power on-off switch 31.
With concurrent reference to FIGS. 2 through 5, the horizontal
support surface in the hopper is formed by a rear plate 32 and a
front plate 34. Front plate 34 includes a rear slot 36 and openings
38 and 40 in the forward portion. A feed control plate 42 is
pivotally mounted on a rod 44, intermediate the rear plate 32 and
the front plate 34. A slot 43 opening into slot 36 is formed in a
forward central portion of the control plate 42. The rod 44 is
journaled in the side walls of the hopper. A crank arm 46 is fixed
at one end to the control plate 42 and at the other end is pinned
to the plunger, or actuated rod, 48 of a solenoid 50. Solenoid 50
is energized by depressing button 30, through a suitable electrical
circuit (not shown), to withdraw the rod 48, i.e., move the rod
upwardly in the view of FIG. 3, and thereby rotate the plate
counterclockwise, about the axis of rod 44. The front wall 16 is
secured to the side walls such that the bottom thereof is spaced
upwardly from the plate 34. A stop 17 is vertically supported on
front wall 16 by bolts 17b which extend through slots 17a in the
stop 17 to threadably engage the front wall 16. The stop 17 and
plate 34 define a dispensing throat 102 aligned with the bottom
card in the stack and just slightly greater in height than the
thickness of a single card, and which permits passage therethrough
of a single card at a time. The slots 17a permit vertical
adjustment of the stop 17 with respect to the front wall 16 and the
front plate 34, to adjust the height of the throat 102.
A feed roller 52 is rotatably supported on a drive shaft 60 in
openings 36 and 43. The top of the feed roller extends above the
plane of plates 32 and 34; the cards, as received thereon, thereby
tend to bow slightly about the roller 52 and toward the support
surface. The outer circumference of the feed roller is covered with
a high friction material. The roller 52 thus serves as a frictional
pick, as driven by shaft 60, to feed each card of the stack,
individually and in succession, through the throat 102.
In accordance with a first embodiment of the invention, the feed
roller is driven through a lost motion coupler from the shaft 60 to
afford a periodic or cyclic, automatically controlled intermittent
feed operation. Particularly, an abutment 54 is fixed to the feed
roller 52 and forms angularly spaced shoulders 56 and 58. The
angular separation between the shoulders 56 and 58 defines an angle
of lost motion, or override, between the clutch and the drive shaft
60, as explained more fully hereinafter. A pin 62 is fixed to the
drive shaft 60 for engagement with shoulders 56 and 58. The roller
52 is driven in a forward direction by shaft 60 when pin 62 engages
shoulder 56, and is free to rotate relative to the shaft 60 until
shoulder 58 engages pin 62.
A motor 66 is mounted beneath the back plate 52 and has an output
shaft 68 connected to a pulley 70. Electrical current to motor 66
is controlled by on-off switch 31. This output shaft 68 drives belt
72 through pulley 70 which is affixed thereto. The belt 72 engages
a pulley 74 which is fixed on the drive shaft 60.
Drive rollers 76 and 78 are provided at the forward end of the
front wall 16 and cooperate with idler rollers 80 and 82,
respectively, to pull the cards from the hopper as each is fed into
engagement therewith by the feed roller. A bracket (not shown)
resiliently urges the idler rollers 80 and 82 against the drive
rollers 76 and 78 for rotation therewith. The rollers 76 and 78 are
secured to shafts 86 and 88, respectively, which are journaled in
suitable supports (not shown) in the machine. A large pulley 90
fixed to the drive shaft 60 drives pulley 92 affixed to shaft 86,
through a belt 94. A pulley 96 secured to shaft 86 drives belt 100,
to, in turn, drive pulley 98 affixed to shaft 88.
The first idler roller 80, with its associated shaft, is skewed
with respect to the direction of transport of the cards, so as to
impart a transverse force to each card, urging the card toward the
side wall 18. An angle of skew of from 5.degree. to 10.degree. is
normally adequate, although the necessary angle may vary for
different apparatus and materials being transported. Whereas the
drive rollers 76 and 78 have a high friction surface material,
preferably the idlers 80 and 82 both have a low friction surface
material, such as nylon. Thus, the skewed idler 80 will impart the
desired transverse force to the cards without tending to smudge
indicia, such as pencil marks, on the cards. Note also that the
associated high friction drive roller 76 is in parallel axial
alignment with the rollers 52 and 78, simplifying the assembly and
alignment of the components of the system. This dynamic transverse
positioning control of the skewed idler assures that each card is
accurately positioned in the lateral direction when passing through
the scanning station, and particularly with respect to a fixed
reference position, as defined by the wall 18. This further permits
of a slight enlargement of the transverse dimension of the hopper,
facilitating insertion and stacking of cards therein, as well as
movement of the cards in the hopper during feed operations. The
latter result is of particular significance with respect to a
second feature of the invention, to be described.
Preferably, each card, an example of one of which is shown at 22'
in FIG. 10, is printed with a pattern of indicia receiving areas
and various preprinted indicia such as timing marks, referenced in
position to the longitudinal edge of the card which engages the
reference wall 18 of the hopper and transport mechanism.
Correspondingly, the sensing means of the system are positioned
with respect to the wall 18 for scanning the respectively
associated columns of indicia receiving areas and preprinted
indicia of the card. The dynamic card positioning control, in
association with the pre-established dimensional relationships,
thereby assures that accurate sensing of data from the cards will
obtain.
The pulley sizes are such that the tangential surface velocity of
drive roller 76 is faster than that of feed roller 54; thus, the
card is driven by roller 76 at a greater speed than that at which
it is fed by roller 54. Further, the tangential velocity of drive
roller 78 is slightly greater than that of drive roller 76. This
differential velocity of the drive rollers positively ensures that
the cards are maintained taut, and do not become creased or jammed
in the intervening space between the drive rollers, and even tends
to straighten out or flatten any bent or creased cards. Desirably,
the optical scanning head 26 has optical probes 26a extending
toward the plate 34 and in the intervening space between the idler
rollers 80 and 82 for scanning the surface of the cards as they
pass therebeneath.
The operation of the card feeding mechanism in accordance with the
first embodiment of the invention will now be described with
reference to FIGS. 5 through 8. As noted, the cards 22 tend to bow
slightly about the feed roller 52. In FIG. 5, the roller 52 is
assumed to be at rest, the pin 62 of drive shaft 60 having rotated
to a position just prior to engaging the shoulder 56. The drive
shaft 60, which rotates at a constant speed, then drives the feed
roller 52 when the pin 62 comes into contact with shoulder 56 of
abutment 54. The feed roller 52 then begins rotational movement in
a counterclockwise direction as seen in FIG. 5, the surface of the
roller, having a high coefficient friction, engaging and advancing
the lowermost card 22a in the stack, causing it initially to buckle
downwardly in the region intermediate the feed roller 52 and the
front wall 16 and stop 17, and toward the support surface 34. This
buckling of the card 22a reduces the frictional engagement between
the bottom two cards 22a and 22b in the stack, greatly facilitating
the feed operation.
As the rotation of the feed roller 52 continues, the bottom card
22a advances through the throat 102 as a result of the frictional
driving force of the rotating feed roller 52. As seen in FIG. 6,
the forward or leading edge of the card 22a having passed through
the throat 102, is engaged by the drive roller 76 and idler roller
80. Since the tangential surface speed of the drive roller 76 is
greater than that of feed roller 52, the card 22a, when driven, or
pulled, by the drive roller 76, moves faster and by so doing
increases the surface tangential speed, and thus the rotational
velocity, of the feed roller 52. The drive shaft 60, however,
maintains its constant rotational velocity. Accordingly, shoulder
62 disengages from pin 62 and feed roller 52 continues in more
rapid counterclockwise rotation with respect to shaft 60 until
shoulder 58 of abutment 54 engages the pin 62. This relationship is
maintained, even though shaft 60 continues rotation, due to the
greater speed of the card as driven by drive roller 76; the card
effectively drags across feed roller 52 despite the high frictional
contact therewith due to the positive engagement of the card by the
drive roller 76 and idler 80.
In the transport of the card and during the foregoing, the leading
edge of the card is subsequently engaged by the second drive roller
78 and its associated idler 82, the latter having a slightly
greater surface tangential velocity than the roller 76 and its
associate idler 80. This is conveniently achieved by making roller
76 of slightly greater circumference, in proportion to the increase
in driving speed desired, and providing the same speed of angular
rotation. As a result, the card is made taut in the intervening
space, as aforedescribed.
When the trailing end of the card 22a has reached the position
illustrated in FIG. 7, at the point of tangential contact with the
feed roller 52, the pin 62 normally is in contact with shoulder 58
of abutment 54. At the next instant, and thus when contact between
card 22a and the feed roller 52 is broken, the next card 22b in the
stack comes into contact with the feed roller 52 and cause the
roller 52 to stop, substantially instantaneously. At the same time,
as illustrated in FIG. 8, the drive roller 60 continues to rotate,
advancing the pin 62 through the angle of lost motion from shoulder
58 to shoulder 56. During this movement of pin 62, the card 28 is
withdrawn from the hopper through throat 102 by the drive rollers
76 and 78. The card 22a thus is completely withdrawn from the
hopper by the time pin 62 reaches shoulder 56. A new dispensing
cycle then commences.
By this mechanism, the spacing between the trailing edge of one
card and the leading edge of the next, successive card is precisely
determined and maintained constant, in accordance with the relative
rotational speeds of the drive shaft 60 for the feed roller 52, and
of drive roller 76, as selected for the geometry of the device and
particularly the distance from the tangential point of each card
with the feed roller 52 and the throat 102. It will be appreciated
that this distance is constant, regardless of the overall length of
a card. Thus, when dispensing cards of different lengths by this
mechanism, the trailing edge of one card will always be a fixed
distance from the leading edge of the successive card, so long as
the cards are long enough to cause rotation of pin 62 between
shoulders 56 and 58. This will be true regardless of whether cards
of different size are interspersed within the stack.
When it is desired to interrupt the feeding of the cards, such as
when a partial stack remains in the feed hopper 14, the interrupt
button 30 is pushed to energize solenoid 50, which in turn raises
the control plate 42. By this action, the stack of cards is lifted
upwardly so that the lowermost card in the stack is not in contact
with the feed roller 52. However, the feed roller 52 and the drive
rollers 76 and 78 continue to rotate and complete the feeding
process for any card whose feeding cycle has commenced. When the
solenoid is de-energized, the interrupt plate is lowered so that
the bottom card in the stack contacts the feed roller 52 and
feeding of the cards continues.
A further embodiment of the invention is shown in FIG. 9, in which
elements identical to elements previously identified and described
herein are identified by identical numerals. As contrasted to the
previously described embodiment, in FIG. 9, the cyclic or
intermittent feed operation for successive cards of the stack 22 is
afforded by automatic actuation of the control plate 42 in timed
relationship to the feeding of each card through the throat 102. In
this instance, the feed roller 52' is affixed to and continuously
driven by the continuously rotating drive shaft 60. Again, the feed
roller 52' has a high friction surface to operate as a frictional
pick for feeding each card presented in engagement therewith.
Automatic control of the plate 42 is afforded by an
electro-mechanical sensor identified as a micro-switch 110
including a feeler 112. The feeler 112 normally extends through an
aperture 114 in the support surface intermediate the drive rollers
76 and 78, and preferably directly adjacent the roller 76.
Normally, the feeler 112 projects above the surface and is
deflected or pushed downwardly as a card proceeds thereover,
substantially as illustrated in FIG. 9. Solenoid driver circuit 116
receives a signal from micro-switch 110 when the feeler 112 is
depressed to energize the solenoid 50 and thereby raise the control
plate 42. The stack of cards 22 is in turn lifted from engagement
with the feed roller 52' and the feed cycle thereupon is
discontinued. Subsequently, when the card 22a being fed is
transported by the drive rollers to the position that the trailing
edge passes over the feeler 112, the latter is released and
projects upwardly. The circuitry including micro-switch 110 and
driver 116 thereby de-energizes solenoid 50, releasing plate 42 and
thereby enabling engagement of the stack of cards 22 with the feed
roller 52'. The feed cycle is thereupon reinitiated.
The feed control technique of FIG. 9 thus affords precise spacing
between the trailing and leading edges of successive cards, that
spacing substantially being equal to the distance between the
throat 102 and the feeler 112 of the micro-switch 110. It will be
apparent that other locations of one or more position sensing
switches may be selected to effect this same operation.
Particularly, it is necessary to sense that a card has been engaged
by the first drive roller 76 prior to actuation of control plate 42
to separate the stack 22 from the feed roller 52', and to determine
that the trailing edge of that card has passed through throat 102
prior to initiating feeding of the next card of the stack through
that same throat 102 upon engaging the stack 22 again with the feed
roller 52'.
If desired, the solenoid driver circuit 116 may be activated by a
control button actuated by the operator to override the signals
provided by micro-switch 110 and thereby to actuate control plate
42 to the raised position when it is desired to manually interrupt
the feeding of cards. Again, however, it is desirable that the
engagement of the card by the drive roller 76 be assured, prior to
actuation of the control plate 42 from the external control button
actuation, to assure that any card, once in the process of being
fed, is fed completely through the sensing station. A suitable
signal for this purpose may be derived from the micro-switch 110
and the requisite control circuitry provided in the solenoid driver
circuit 116, as will be apparent to those skilled in the art.
A generalized representation of a card of the type which may be fed
by the mechanism of the invention is shown in FIG. 10, sufficient
for explaining a further embodiment of the invention shown in block
diagram form in FIG. 11. This latter embodiment comprises an
optical detecting system for affording energization of the solenoid
50 with resultant actuation of control plate 42 in an automatic
manner to effect timing of the feed cycles.
Referring to FIG. 10, the card 22a includes a column 120 of timing
marks, as are typically provided in such data cards. Each timing
mark 120 is aligned with a row of indicia receiving areas aligned
in columns A, B, C, and D. In the disclosed example of the data
card 22a, there are provided 50 such timing marks corresponding to
the 50 rows of indicia receiving areas.
In FIG. 11 is shown a block diagram of the control circuitry for
automatic actuation of the control plate 42. A timing mark channel
sensor 130 is provided in the sensor 26 for sensing the column of
timing marks 120, as is typical, in addition to the sensors for the
columns of data indicia receiving areas A through D. The sensor 130
produces an output signal, upon detection of each of the timing
marks, to a timing mark counter 132. Counter 132 produces an output
pulse upon the accumulation thereby of a count equal to the number
of timing marks on each of the cards being fed.
A flip-flop and solenoid driver circuit 134 receives the output of
sensor 130 at the set terminal S thereof and the output of counter
132 at the reset terminal R thereto. The circuit 134 thereby
supplies an energizing signal to the solenoid, when set upon
receipt of a first timing mark signal from sensor 130, and remains
set until detection of the last such timing mark in accordance with
the output of counter 132, whereupon the solenoid energizing signal
from flip-flop 134 and its associated driver circuit is terminated,
as the flip-flop 134 is reset.
In relation to the discussion of FIG. 9, it will be appreciated
that the circuit of FIG. 11 provides for energization of solenoid
50 and thus actuation of control plate 42 and separation of the
stack 22 of cards from feed roller 52' when the card has been
transported into the sensing region and the first timing mark
thereof sensed by sensor 26. Furthermore, this assures engagement
of the card by the first drive roller 76 at that time. The solenoid
remains actuated, therefore, until the card has been transported
through the sensing station and the last timing mark thereof
detected. By appropriate selection of the geometry of the
structure, suitable dimensions of the preprinted timing mark with
respect to the trailing edge of each card, and of the mechanism,
may be selected to assure that the trailing edge has passed through
the throat 102 at the time the last timing mark of each card is
detected. Thereupon, the solenoid is de-energized and the stack
engages the feed roller 52' to reinitiate the feed cycle.
Whereas the system of FIG. 11 implies knowledge of the number of
timing marks on each card to be fed, variable length cards may
nevertheless be fed provided the same number of timing marks
appears on each. Conversely, means may be provided to change the
preset count of counter 132 in accordance with a different number
of timing marks on each group of cards to be fed.
As a further alternative, optical detection means may be utilized
to detect the entry of a card into and exit from a given position
in the drive roller region of the transport mechanism, similar to
the mechanical-electrical sensing scheme of FIG. 9. As a further
alternative, a special control track may be afforded on each card
22a adaptable for optical or other detection for automatically
recognizing the entry into or exit of a card relative to the drive
roller region of the mechanism for correspondingly energizing and
de-energizing the solenoid to actuate the control plate.
In any of these various embodiments, there is provided the
intermittent, or cyclical, feeding effect of the feed roller with
respect to the stack of cards, either mechanically through the
provision of the lost motion clutch or by electro-mechanical means
including the various types of detecting means for identifying the
condition of transport of a card through the drive roller region
affording automatic actuation of the control plate, and thus timed
control of the engagement of the stack of cards with the feed
roller. With respect to each of these alternative feed control
functions, the stack of cards is urged into engagement with the
feed roller, tending to bow thereabout in the direction of a
support surface through which the feed roller protrudes. It will be
appreciated that the noted support surface is adequate so long as
it restricts the degree of buckling of the cards upon initial
feeding thereof; in the disclosed embodiments, that support surface
is also utilized as, or is integral with, the surface which, with
the stop 17, defines the throat 102 through which the cards are
individually fed.
It will also be appreciated, as previously noted, that the stack 22
of cards may be oriented in any position, as desired, such as for
side feed or inverted feed. In the side feed, the cards are stacked
on edge and the feed and drive rollers are positioned in the same
relationship with respect to the stack as hereinabove specifically
disclosed. In the inverted arrangement, the cards are received on a
support plate which is then raised to engage the top-most card of
the stack into engagement with the feed roller, now positioned
above the stack. Resilient biasing means, such as negator springs,
then are utilized in conjunction with a support plate for the stack
to urge the stack into engagement with the feed roller. In any of
these embodiments, and even where the stack is urged in sideward or
upsidedown fashion into engagement with the feed roller, the same
driving functions as hereinabove described obtain. Thus, reference
to the lowermost card of a stack implies that card which engages or
is in position to engage, the feed roller in the successive cyclic
feed operations, for any such orientation of the stack.
In summary, there has been described a simple and efficient card
feeding mechanism with means for automatically maintaining a
precise and predetermined spacing between the trailing and leading
edges of successively fed cards, regardless of the length of the
cards. Further, the card feeding mechanism provides for
interrupting the feed without requiring shut-down of the mechanism,
and which assure completion of feed of any card in the process of
being transported. Precise timing of reinitiation of feed is also
assured. In addition, the relative transport speeds of the drive
rollers assure that the card is maintained taut and flat in the
region therebetween to permit accurate reading of data therefrom.
In addition, the dynamic alignment technique afforded by the skewed
idler of the first drive roller provides precise lateral
positioning of each card in the sensing region, with respect to a
fixed lateral or transverse reference position, assuring accurate
positional relationships of the columns of data indicia positions
of the cards as transported through the sensing region with respect
to the data sensing means of the sensing station.
The card feed mechanism can be operated at high speeds with a high
degree of reliability. Speeds as high as 1,700 cards per minute
have been easily attained by this mechanism. The moving elements
operate continuously in rotation and avoid the problems presented
by reciprocatory feeding mechanisms. The only element in the feed
mechanism of the invention which is subject to any intermittent
motion is the drive roller, and this has extremely low inertia.
Thus, the total inertia involved in starting and stopping each card
in each successive feed cycle is essentially that of the single
card being fed. In any of the embodiments, to increase the rate of
feeding of the cards, substantially all that is required is to
increase the speed of the drive motor, thereby proportionally
increasing the speed of each of the drive rollers and the feed
roller.
The circumferential, card-engaging surfaces of the drive and feed
rollers are made of material which has a high coefficient of
friction. Preferably a layer of polyurethane is molded onto the
outer surface of each of these rollers. Alternatively, the rolls
can be covered with rubber or other such high friction materials. A
suitable polyurethane material can be purchased from Industrial
Science of Portland, Ore., as Shore B 60-70 durometer.
It will be apparent to those skilled in the art that numerous
modifications and adaptations of the system of the invention may be
made, and thus it is intended by the appended claims to cover all
such modifications and adaptations as fall within the true spirit
and scope of the invention.
* * * * *