U.S. patent number 3,564,169 [Application Number 04/653,892] was granted by the patent office on 1971-02-16 for static punch card reader.
This patent grant is currently assigned to AMP Incorporated. Invention is credited to Bruce Richard McFadden, Gilbert Carl Sitz.
United States Patent |
3,564,169 |
Sitz , et al. |
February 16, 1971 |
STATIC PUNCH CARD READER
Abstract
A static punchcard reader assembly is disclosed having an array
of contact spring members, one for each possible bit position and
hole in a data card. An interposed plate is provided to receive the
ends of the spring members and to prevent fouling thereof on a
card. The assembly includes a mechanism for effecting relative
movement between contact spring members and conductive pads
disposed in planar array on the interposed plate or, alternatively,
on a sheet engaged by portions of the contact members made to
project through card holes. Embodiments are disclosed featuring an
assembly effecting contact closure with constant spring deflection
in a manner insensitive to card dimensions and particularly card
thickness, and an adjustment is provided in one embodiment for
causing the contact members to engage fresh surfaces on conductive
pads to extend the life of the assembly relative to contact wear.
An embodiment is disclosed which features a wiping action under low
force loads also to increase wipe.
Inventors: |
Sitz; Gilbert Carl (Harrisburg,
PA), McFadden; Bruce Richard (Harrisburg, PA) |
Assignee: |
AMP Incorporated (Harrisburg,
PA)
|
Family
ID: |
24622686 |
Appl.
No.: |
04/653,892 |
Filed: |
July 17, 1967 |
Current U.S.
Class: |
200/46;
235/447 |
Current CPC
Class: |
G06K
7/06 (20130101) |
Current International
Class: |
G06K
7/06 (20060101); G06k 007/04 () |
Field of
Search: |
;200/46,164
;235/61.111--113 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Smith, Jr.; David
Claims
We claim:
1. In a device for switching a plurality of electrical circuits, an
array of contact members each comprising a cantilevered leaf spring
having a mounting portion, an end-projecting portion carrying a
contact surface thereon, and a thin flat spring portion supporting
said end portion to provide substantial deflection and spring
action therefore; an insulating block fixedly mounting said contact
members with their spring portions extending at an appreciable
angle outwardly from said block to permit movement of the end
portions of said contact members toward and away from said block
under a spring force developed by said spring portions; first means
comprised of a thin plate of insulating material having a plurality
of holes therein, including an individual hole for each contact
member aligned therewith to receive the corresponding contact
member; an array of conductive members disposed upon and carried by
said thin plate, said array of conductive members having portions
complementary to the array of contact members; drive means for
moving the array of contact members and the array of conductive
members disposed on said plate relatively together to effect a
switching action therebetween; guide means to guide and position a
data card having holes therein into a predetermined reading
location in which the holes in said card permit an engagement
between certain of said contact members and certain of said
conductive members and portions of said card apart from said holes
preclude switching action between the remainder of said contact
members and said conductive members; and second means for mounting
said plate for movement by said drive means to a position in which
each hole in said plate surrounds the said end portion of the
corresponding one of said contact members to receive said end
portion and to preclude damage to said contact members by said
card.
2. The device of claim 1 including means to limit the position of
said first means relative to said block to limit deflection of said
contact member spring portions and prevent overstress of said
contact members in use.
3. The device of claim 1 wherein there is included a further means
operable to effect a wiping action between said certain of said
contact members and certain of said conductive members during a
first portion of relative movement therebetween to provide a wiping
under reduced contact pressure.
4. The device of claim 3 wherein there is included means to
position said block and said array of contact members in a position
relatively fixed to cause a deflection of said contact members
resulting in a second wiping action causing the contact surfaces
carried on the end portions of said contact members to reside in a
prewipe zone of contact with said conductive members responsive to
a final portion of relative movement.
5. The device of claim 1 wherein there is included a further plate
positioned between said drive means and said card, said further
plate including an array of recesses complementary to the end
portions of said contact members and positioned to receive said end
portions to facilitate the use of said device with cards of
different thicknesses.
6. The device of claim 1 wherein there is included a trigger means
operated by engagement with said card to actuate said drive means
and effect an automatic operation of said device responsive to the
full insertion of a card therewithin.
7. The device of claim 1 wherein said conductive members are
disposed on said plate adjacent the holes therein and the end
portions of said contact members have the said contact surfaces
positioned to engage said conductive members with a further portion
positioned to extend through the said plate.
8. In a switch assembly having an array of individual contact
members each including a contact surface and an array of conductive
members each including a second and larger contact surface, means
to effect an engagement between contact members and conductive
members in a first zone of contact engagement therebetween to
effect a switching action and adjustment means coupled to one of
said arrays for positioning said array of conductive members
relative to said array of contact members wherein said engagement
occurs in a fresh zone of contact between said members to increase
the life of said device.
9. In a device for switching a plurality of electrical circuits, an
array of contact members each including a mounting portion, a
spring portion and an end portion carrying a contact surface
thereon, an insulating block fixedly mounting said contact members
with the spring portions extending at an appreciable angle
outwardly from said block to permit movement of the end portions of
said contact members toward and away from said block under a spring
force developed by said spring portions, an array of conductive
members having portions complementary to the array of contact
members, drive means operable to move the array of contact members
and the array of conductive members relatively together to effect a
switching action therebetween, means to guide and position a data
card having holes therein between said array of contact members and
said array of conductive members, the holes therein permitting an
engagement between certain of said contact members and certain of
said conductive members and portions of said card apart from said
holes precluding switching action between the remainder of said
contact members and said conductive members, further means
comprised of a thin plate of insulating material having holes
therein in an array complementary to the arrays of contact members
and conductive members, said plate being driven by said drive means
so that the holes thereof surround the said end portions of said
contact members to receive said end portions and to preclude damage
to said contact members by said card, and including an adjustment
means coupled to said array of conductive members for positioning
said conductive members relative to said contact members so that
the engagement between each contact member and a conductive member
occurs in a different zone on said conductive member to provide a
fresh area of contact therebetween and extend the life of the
device.
10. In an assembly for reading data cards having data defined
therein by the position of holes therein or the lack thereof, an
array of contact spring members, one for each possible bit position
in said card, and each including a contact surface and a projecting
portion, a plate member carrying a series of conductive pads, one
for each contact member in alignment therewith, a driving plate and
means to drive said driving plate, means positioning said driving
plate relative to said plate member carrying said conductive pads
so as to receive and position a data card therebetween with the bit
positions thereof aligned with said contact members, the contact
pad carrying plate member further having a series of holes therein
in alignment with said bit positions on a card inserted in said
assembly with portions of said contact members extending outwardly
to pass through said holes upon operation of said driving plate to
drive said card against the rear of said contact pad carrying plate
member and drive said contact pad carrying plate member toward said
contact members whereby the projecting portions of the contact
members extend through holes in said card causing the contact
surfaces of said contact members associated therewith to engage the
conductive pads to effect switch action, said projecting portions
of said contact members being of a configuration relative to the
holes in said card and to the holes in said conductive pad carrying
plate member to facilitate a slight transverse movement of said
plate member to provide a wiping action between said contact
members and said contact surfaces, means to effect said slight
movement during operation of said driving means, and including an
adjustment means coupled to said conductive pad carrying plate
member to adjust the position thereof so as to cause an engagement
between said contact surfaces and said conductive pads in a fresh
zone of contact to increase the life of said assembly.
11. In an assembly for reading data cards having data defined
therein by the position of holes therein or the lack thereof, an
array of cantilevered leaf spring contact members, one for each
possible bit position in said card, and each including a mounting
portion, an end projecting portion having a contact surface
thereon, and a thin flat spring portion supporting said end portion
to provide spring action therefor; a movable plate member carrying
a series of conductive pads, one for each contact member in
alignment therewith; means comprising a driving plate for imparting
a transverse motion to said movable plate member with respect to
said contact members; means positioning said driving plate relative
to said movable plate member so as to receive and position a data
card therebetween with the bit positions thereof aligned with said
contact members; the movable plate member further having a series
of holes therein in alignment with said bit positions on a card
inserted in said assembly; and means to drive said driving plate to
in turn drive said card against said movable plate member and
displace said movable plate member transversely toward said contact
members into a predetermined reading position in which the
end-projecting portions of the contact members extend through holes
in said card, causing the contact surfaces of said contact members
associated therewith to engage the conductive pads to effect switch
action.
12. The assembly of claim 11 wherein the shape of said end
projecting portions of said contact members relative to the holes
in said card and to the holes in said movable plate member permits
a slight transverse movement of said plate member to provide a
wiping action between said contact members and said contact
surfaces; and means are provided to effect said slight movement
during operation of said drive means.
13. In a switch assembly an array of individual contact spring
members each including a contact surface, a complementary array of
conductive members each including a second and larger contact
surface, means to effect an engagement between contact members and
conductive members in a first zone of contact engagement
therebetween to effect a switching action which establishes a
selected pattern of interconnections between members, means to
cause a wiping engagement between the selected pattern of
interconnections which occurs during engagement under light wiping
pressure followed by a second wiping action due to deflection of
said contact spring members, and adjustment means coupled to one of
said arrays for positioning said array of conductive members
relative to said array of contact spring members wherein said
engagement occurs in a fresh zone of contact between said members
to increase the life of said assembly.
Description
BACKGROUND OF THE INVENTION
Static punched card readers differ from dynamic readers by
providing one contact spring member for each possible bit position
in a data card rather than a single row of contact members made to
scan rows of bit positions by relative movement of a card with
respect to such members. The problems of obtaining a low
resistance, stable contact interface through many cycles of use are
much greater with readers which must read a card in a fixed
position that with dynamic readers, The wipe between contact
surfaces which is necessary to clear such surfaces of foreign
objects such as card fibers or bits of card material which tend to
accumulate in a reader after use with many hundreds of thousands of
cards is inherent in a scanning or dynamic-type reader, but is not
inherent in a static-type reader. Thus, in many of the prior art
static reader devices, a considerable design effort has been made
to achieve wiping action. Many of the devices resulting from this
effort have resulted in a wiping action under increasing pressure.
Unfortunately, contact wear is directly proportional to contact
pressure and reduced contact life is a direct incident thereof.
As another problem, particularly affecting static card readers, the
use of a number of contact spring members equal to the number of
possible bit positions means that the reader assembly must contain
a relatively large number of individually mounted and supported
members having spring characteristics and thus including at least a
portion free for spring movement. For example, the data card having
the greatest usage includes 960 bit positions requiring that the
reader therefore have at least 960 individual spring contact
members. The failure of any one of these contact members to make
adequate contact results in failure of the assembly. Also worth
pointing out is the fact that all punched data cards, even those of
less bit capacity, have bit positions on relatively close
center-to-center spacing requiring a complementary spacing of
contact spring members in a reader assembly and ultimately
requiring that the individual contact members include at least
portions which are quite small. Those skilled in a related art will
immediately appreciate the problems inherent in production of
devices of this type and, further, of the problems of maintenance
during use. As a specific problem with devices of these
characteristics, based upon experience, the requirement that the
contact spring members engage the card or, alternatively, extend
through a hole therein makes it possible for an individual spring
to be fouled on a card by being caught up a card hole on the edge
thereof. If this happens the contact spring member may become
broken or damaged. As previously mentioned, disablement of a single
contact spring effectively disables the whole reader unit and
necessitates a replacement of the major physical part thereof.
U.S. Pat. No. 2,830,759 to E. Hudes et al., grated April 15, 1958,
and U.S. Pat. No. 3,042,299 to A. Sherman, granted Jul. 3, 1962,
represent static card readers having a multiplicity of individual
contact spring members made to extend for a considerable length for
spring deflection and engagement with or insertion through data
cards. U.S. Application S.N. 296,812 by Glen R. Ekers, filed Jul.
22, 1963, now U.S. Pat. No. 3,352,981 issued on Nov. 14, 1967,
evidences a static card reader construction utilizing a substantial
contact pressure to reduce open circuits caused by foreign objects
including card fibers lodged in the assembly or extending from a
data card.
Some of the prior art static card reader assemblies attempt to
solve the problem of spring damage by the use of a surrounding
insulating shroud or projections of an insulating block housing the
contact members. One such prior art assembly is shown in U.S. Pat.
No. 2,941,054 to G. N. Willis, granted Jun. 14, 1960. Readers
having the type of construction shown in the new Willis patent
usually are limited to use with cards of certain and carefully
controlled dimensions and a particular card thickness.
SUMMARY OF THE INVENTION
The present invention relates to a card reader assembly utilized to
read a card having punched holes therein defining data and,
particularly, to a reader device having improved features of ease
of initial assembly and maintenance free operation during use. It
is an object to prevent damage of reader contact members by cards
and a further object to provide a reader of extended life by
providing constant deflection of contact spring members and a
reduction in contact pressure through a novel wiping action. It is
another object to extend reader life by providing an adjustment to
provide fresh contact areas for contact engagement without
replacement of device components.
The problems previously outlined are eliminated and the foregoing
objectives are achieved through a card reader device which may be
manually operated or motorized to respond to the insertion of a
data card to drive such card in a planar engagement with a planar
array of contact spring members; the members in alignment with card
holes being caused in different embodiments to either make or break
contact with a conductive path, such as a printed circuit pad
secured on a flat sheet member. Each of the contact members is made
to extend from a contact block in a manner causing a controlled
deflection of the contact members with an end of each contact
member projecting to engage the card surface or extend through a
card hole to sense the presence or absence of such hole. A plate
member having a hole for each contact member in alignment with the
possible bit positions and holes in the data card is provided with
the projecting portion of contact member being made to extend
therethrough so that the entire array of contact spring members is
maintained to avoid fouling of any of the members on the card or
holes therein in a manner to cause contact member damage or damage
to such card. In one embodiment the contacting surface of each
contact member is located away from the card surface so as to
engage a conductive pad on a side of an insulating member opposite
to that engaged by the card and provision is made in the
card-driving mechanism to facilitate use with cards of different
dimensions and, in particular, cards of different thickness. In one
embodiment the plate contains the conductive paths positioned to
mate with the contact members and effect the contact-switching
action of the device. In an alternative embodiment the conductive
paths are disposed on a further member and contact switching occurs
in a read-through arrangement with signal current caused to flow
through a hole in the card. The driving mechanism of the device for
one embodiment includes structure to effect an initial wiping of
contact member and conductive pads while engagement pressure is
relatively low. The wiping action provided is of a substantial path
length to ease assembly and maintenance tolerances of the various
elements of the device. Low wiping pressure achieved through the
greatest part of the wipe operates to extend contact life while
still providing the contact surface cleaning action required in use
with punched data cards, particularly, cards of a paper base stock.
As a separate embodiment of the invention, an adjustment is
provided which operates to move the member carrying the conductive
pads a slight amount. This feature, in conjunction with the shape
of the contact members, permits all contact and wiping engagement
to thereafter occur on a fresh contact surface of the conductive
pads on such sheet.
In the drawings:
FIG. 1a is a perspective showing a card position for insertion in a
slot which represents the entry of the reader assembly of the
invention;
FIG. 1b is an exploded and perspective view of the reader assembly
of the invention;
FIG. 1c is a perspective of the contact spring of the assembly of
the invention;
FIG. 2 is a side elevational view in section of the assembly of the
invention in an open position prior to receiving a card;
FIG. 3 is a view of the assembly of FIG. 2, but in a closed and
reading position;
FIG. 4 is an elevational and sectional view from the rear of the
assembly as shown in FIG. 2;
FIG. 5a is an enlarged, partially sectional view showing contact
member disposition relative to a card and conductive path, in an
open position;
FIG. 5b is a view of the elements of FIG. 5a, but in a closed and
reading position;
FIG. 6 is a view of the structure of FIG. 5, but in use with a card
of different thickness;
FIGS. 7a--7e depict contact engagement and wiping action effected
by the assembly of the invention in one embodiment;
FIGS. 8a--8d depict contact engagement and wiping action following
a different setting of the driving linkage of the assembly of the
invention to provide fresh contact surfaces;
FIGS. 9a and 9b are enlarged, partially sectional views showing an
alternative embodiment for read-through operation, depicting
respectively opened and closed contact positions; and
FIGS. 10a--10d depict contact engagement and wiping action effected
by the assembly of the invention in the alternative embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
Referring now to FIGS. 1a and 1b, a general description of the
invention will first be given. The invention device 10 is shown in
FIG. 1a mounted vertically in the top or surface of equipment
served thereby, such as in the desk portion of a computer console.
The device 10 includes an operating lever L projecting above the
mounting surface for manual operation by one using the reader. A
card C having data thereon or therein defined by the position of
holes H punched therein is positioned above 10 preparatory to
insertion in a slot S which extends within 10. FIG. 1b shows
certain of these elements in detail. The card C is of a design to
accommodate 168 possible bit positions arranged in 12 rows formed
into 14 columns. In general, cards of this type have an identifying
number encoded thereon by the pattern of holes placed in certain of
the bit positions. The exemplary showing should not be taken to
mean that the invention is limited in its application to cards
having a particular number of bit positions. It is contemplated
that data cards of various types, including plastic cards for
credit or security usage having relatively few holes therein may be
accommodated by the invention, as well as standard tabulating cards
having 960 bit positions and formed of paper base material which
may be accommodated by merely using more of the elements shown in
the same general relationship. It is also to be understood that a
horizontal mounting of the assembly 10 is contemplated and that the
manually operated lever to be described in the exemplary embodiment
could readily be replaced by a motorized drive means, such as a
solenoid connected in a simple push-pull manner.
Card reading is effected by the insertion of the card C into the
slot S which, in accordance with the invention concept, is made to
engage a trigger 106, shown in FIG. 1b, disposed in the path of
insertion of the card. In accordance with the arrangement of the
invention the actuation of the trigger effects an automatic closure
of a driving mechanism displacing the card in a sense transverse to
its major surface, driven by a backup pressure plate 40 into
engagement with an array of individual cantilever supported contact
spring members 164. Switching action results by reason of portions
of the contact members extending through holes in the card to sense
the presence of such holes and thus to close an electrical circuit
between portions of the contact members 164 and portions of
conductive pads 132 which are, in such embodiment, separated from
any engagement with the card or surfaces thereof. In an alternative
embodiment the conductive pads are disposed in a sheet driven by
the backup plate. In both embodiments, a member 124 of insulating
sheet material having holes therein of the configuration of the
holes 130 in the card positioned in the array of bit positions for
the card is utilized to receive the ends of the contact members
during reader operation. The sheet member or plate 124 is also used
during initial assembly of the device in a manner to be described
and is of a construction made by a technique providing an inherent
control of tolerances both of the hole itself and of hole-to-hole
spacing. This feature is particularly advantageous when used in
applications for tabulating cards or cards having a relatively
large number of data bit positions.
The reader device 10 includes a main frame 12 with the pressure
plate 40 driven by a driving linkage to effect card displacement
and contact closure for switch action. The device includes a fixed
block 160 containing the contact members 164 extending therefrom
and positioned free for deflection and spring action. The sheet
member 124 which serves to receive the card is, in one embodiment,
carried by a slide frame 140 loaded under spring pressure relative
to the fixed contact member block 160. In the one embodiment the
conductive pads 132 engaged by the contact spring members are
disposed on member 124. In an alternative embodiment the conductive
pads are disposed on a sheet 42 of insulating material affixed to
the main driving plate 40 of the device. In the one embodiment a
camming mechanism including a slide cam 90 is arranged to jog the
member carrying the conductive pads to effect a wiping action prior
to any substantial deflection of the contact members 164 but after
initial engagement of such contact members with the conductive pads
so as to effect a wiping under reduced force loads to increase
contact life. In this same embodiment an adjustment for the cam
slide is provided in the driving linkage for displacing the
member-carrying conductive pads 132 a slight amount to establish
contact between all contact spring members and the conductive pads
in a different zone to provide fresh contact areas for all
operations of the device thereafter.
The device 10 operates to effect a mechanical reading of a punched
data card by causing individual spring members 164 carrying contact
portions to be deflected or not deflected to sense the presence or
absence of a card hole with such sensing resulting in a switch
action defined by a related closure of certain contacts. This
mechanical reading of the card is then converted into an electrical
reading of the card by an appropriate application of signals to one
or the other of the mating contact elements, contact spring members
or conductive pads, the other member being either interconnected or
connected to a lead in a manner to develop an associated flow of
current as an output signal. With the reader device of the
invention, output signals may be developed simultaneously from all
of the switch closures caused by the mechanical reading or may be
developed on a row-by-row or column-by-column basis through the use
of external scanning equipment such as a stepping switch or solid
state equivalent thereof.
DETAILED COMPONENT DESCRIPTION
Turning now to a detailed description of assembly 10, FIG. 1b shows
to the right a main frame assembly 12 which carries the driving
mechanism and linkage of the device along with structure to
position and drive the remaining elements and to mount the device
in a panel for use. The assembly 12 includes a main frame 14, which
in a preferred embodiment is stamped out of metal stock and formed
into a generally boxlike configuration; housing, to the right the
card-driving mechanism, and at the bottom, a linkage and structure
to effect contact wipe at reduced loads, as well as the trigger
106. Extending to the left of 14 are pairs of projecting flanges
identified as 16 at the top between which is fitted a mounting
plate 17, apertured as at 19, and anchored to 16 by a series of pin
members as shown. The assembly 10 is mounted on the panel of use by
bolts or suitable other fastenings passed through holes 19 of plate
17. Frame 14 further includes a pair of flanges 18 extending from
the lower portion thereof to the left which are spaced from flanges
16 to define a recessed area generally shown as 20, terminated in a
vertical and flat surface 22 which operates as a stop or bearing
surface limiting displacement to the right of the other movable
portions of the assembly.
At the bottom of flanges 18, disposed in a horizontal sense, are
slots 24 which serve to support, for limited horizontal movement,
the cam slide 90 disposed between the lower flanges. Frame 14
includes a pair of further projecting flanges 26 extending
oppositely from the flanges 16 and 18 in a position to contain
portions of the main pressure plate 40, which portions extend on
either side of such plate as at 50, adjacent to the flanges 26.
Movement of the pressure plate to the right is restricted by
projections 32 located at the top and near the bottom of the main
frame. These projections can be better seen in FIG. 4. The sides of
the main frame, including the various flanges 16, 18 and 26, are
held together by integral straps which extend across the back of
the frame in the manner depicted in FIGS. 3 and 4, by the numeral
34. The main pressure plate is comprised of a base plate 40 having
permanently affixed to the surface thereof an insulating sheet 42
which, in one embodiment, contain a series of rectangular holes 44
disposed in an array and positioned to accommodate portions of the
contact spring members 164 of the assembly which each project
therewithin through a card hole during reading. In another
embodiment, sheet 42 is made to contain conductive pads in lieu of
the holes 44, the pads being in turn connected to conductive paths
which extend outwardly of the assembly to be terminated to input
and output leads in a manner to be described hereinafter. The upper
end of plate 40 and sheet 42 is beveled as at 48 to serve as a
guide for card insertion. The center of such end is relieved as at
49 to facilitate grasping the end edge of a card during card
withdrawal. As a preferred construction, base plate 40 is stamped
and formed of sheet metal stock and the sheet 42 is formed of a
plastic board punched out to define the holes 44 and then bonded to
the base plate 40 by a suitable adhesive.
Plate 40 includes a pair of flanges 50 which have the configuration
and position indicated in FIGS. 1b--4. Each flange 50 includes an
eccentric surface 52. Extending through the surface 52 of each
flange 50 is a cam including an enlarged portion 31 of a dimension
to bear against the surfaces of the two eccentrics 52. The cam is
anchored for rotary movement by an off-centered portion extending
from 31 and shown as a pin 30, which is made to project through a
bearing support 28 in each of the flanges 26 and 50 in the manner
depicted in FIG. 1b. As the cam is rotated in limited movement
about 30, the main pressure plate is driven along a horizontal axis
extending from left to right of the assembly.
As can be discerned from FIG. 4, a spring 39 extends around 31 with
one end thereof anchored in 31 and the other end thereof tied to
the main frame through a pin 41. The spring 39 operates to drive 31
in a counterclockwise direction to effect closure of the device and
card reading. The spring is loaded when the pressure plate is
positioned fully to the right in the main frame, as indicated in
FIG. 2 so as to effect the displacement indicated in FIG. 3.
Referring to FIGS. 2--4, the operating lever L is made to extend
from a lever portion 54 upwardly to an operating knob 56 and
downwardly to a sleeve portion 55 which surrounds 31. The sleeve
portion 55 includes in the upper surface a slot 57 extending
partially around the periphery thereof. A pin member 33 affixed to
31 is fitted within slot 57 to be engaged by the end thereof and
driven by 55 during operating of the lever L. The lever L may be
seen to pivot about 31 as biased by a tension spring 62 tied by a
pin to the portion 54 of the lever and by a further pin 66 to the
near projecting flange 16 of the main frame 14, as shown in FIG.
1b. The spring 62 tends to pull L in a counterclockwise sense
relative to FIGS. 2 and 3. As previously mentioned, the lever L
could be replaced by a motorized drive attached below the surface
of the mounting panel, the upper part of 54 being eliminated.
The pins 30 of the cam are made to extend outboard of flanges 26,
as shown in FIG. 4, and a pair of links 68 are provided positioned
on pins 30 for relative rotary movement. Links 68 depend from the
pins 30 and are tied together by an actuating rod 74 extending
between the links on each side of the assembly. An actuating arm
35, secured against movement relative to 31 by a pin 37, extends
downwardly from 31 to engage the actuating rod 74 and drive such
rod and thereby drive links 68 from the position shown in FIG. 2 to
the position shown in FIG. 3. Links 68 are biased in a clockwise
sense relative to FIGS. 1b--3 by tension springs 76, anchored by a
pin 78 in each link and by a pin 80 in the flange portion 18 of the
main frame 14. The bottom ends of links 68 carry a rod 82 extending
between the two links. In the center of the rod, as shown in FIGS.
2--4, is an adjustment mechanism comprised of a bolt member headed
as at 84 in a position of access for adjustment and threaded as at
86 to mate in complementary threading in the cam slide 90. Movement
of the links 68 results in a movement of the cam slide.
Cam slide 90 is comprised of a block of hard material recessed at
the right-hand end, as shown in FIG. 1b, by the numeral 92 to
contain a rod 94, which is made to receive the threaded bolt member
86. At each side of 90 a pair of projecting pins 98 are positioned
to engage the guide slots 24 of the projecting flanges 18 to align,
limit and guide the cam slide for horizontal movement under drive
of links 68. Toward the center of the top of 90 is a groove 100
which extends thereacross to define camming surfaces including a
first surface 102 of a depth greater than a second surface 104
adjacent thereto. FIGS. 1b, 2 and 3 reflect the operation of these
surfaces relative to driving a slide frame to effect a particular
contact wiping engagement associated with one embodiment of the
invention, and heretofore mentioned.
Secured to the lower strap 34 of the main frame is trigger 106
formed in a preferred embodiment of flat metal stock into the
configuration best shown in FIG. 1b. The trigger includes a
latching arm 108 which has a depending and angularly disposed
camming surface 110, supported by a portion 112 in a position to be
engaged by the end of 35 during operation of the driving mechanism.
FIG. 2 shows the trigger in a set position holding 35 to the left
against rotation in a counterclockwise sense. FIG. 3 shows the
trigger-following release of 35, which release permits an automatic
closure of the assembly under drive of the elements heretofore
mentioned. As the assembly is reset by operation of lever L, the
end of 35 engages the camming surface 110 to depress 106 and slide
up and over 110 to be latched by 112. The portion 114 formed out
from the center of 106, as shown in FIG. 1b, carries a tab 116
positioned to extend up into the card-receiving slot S to be
operated by a card insertion. The trigger is pivotally mounted and
biased in a clockwise sense with respect to a showing in FIG. 4 by
a spring member 120 secured about an anchoring pin 122, seated
within the strap 34, as shown in FIGS. 2 and 3. One end of the
spring 120 bears against the trigger and the other end is bent to
fit within an anchoring hole in the strap 34. This end is
identified as 123 in FIG. 1b. A spring 118 is disposed between the
strap 34 and the trigger to accommodate trigger movement transverse
to the strap as the main pressure plate is operated. FIGS. 2 and 3
reflect this movement.
Referring again to FIG. 1b, a sheet or plate 124 is provided which
serves the function heretofore mentioned of receiving the contact
spring members 164 during operation of the assembly. The plate 124
includes at the top edge a slight bevel 126 which cooperates with
the bevel on slide frame 140 to accommodate card insertion within
the assembly. The center of the top edge of plate 124 is relieved
as at 128 to facilitate card removal. The plate is preferably
formed out of plastic board material such as phenolic sheet,
punched out to define an array of holes 130. In the embodiment
herein disclosed the holes are rectangular and in a pattern
corresponding to the pattern of possible bit positions in a card to
be read and also corresponding to the positions of contact members
164.
As an important aspect of the invention, to be described in more
detail hereinafter, the plate 124 serves in both preferred
embodiments of the invention as a means to receive the ends of the
contact members during operation of the reader device. The plate
124 also serves as a sort of jig fixture during initial assembly of
the device, the holes therein permitting a final check of the
position of the contact springs 164 for a proper alignment with any
slight individual adjustment of a contact spring being made
relative to a given hole in the sheet 124. With the contact block
160 containing the contact springs positioned on a flat surface the
plate 124 may be positioned thereon with the slide frame 140 which
carries the plate disposed between the contact block and the plate
and having a preapplied adhesive so that the plate may be aligned
with each contact spring member made to extend through a related
hole therein and with the slide frame thereby properly positioned
relative to this alignment and permanently secured to the plate
124. Operation of the plate during use to prevent fouling of the
card by the contact members will be described hereinafter.
In one embodiment of the invention the plate 124 is provided with a
conductive pad disposed along at least one side of each hole to be
contacted by a contact member. FIG. 1b shows that this structure
may be provided by portions of conductive strips 132 extending
along each row of holes to electrically common the paths for each
hole of a given row. In this embodiment the strips 132 are extended
out to the edge of the plate 124, as indicated by the numeral 134
for termination to input and output leads through some suitable
connector means, such as a standard printed circuit edge connector.
The opposite side of the portion of the plate carrying the
extensions 134 and the projecting portion shown as 136 of the plate
engage the surfaces 22 on either side of the main frame to limit
rightforward displacement of the plate 124.
Plate 124 is, as previously mentioned, secured to a slide frame
140, which includes side members 142 and top and bottom members 150
rigidly fastened together or, if desired, made integral as by
casting. Within each side member 142, at the top and bottom thereof
are apertures in which are seated springs 146 which are made to
engage the contact block shown as 160. In the embodiment shown in
FIG. 1b these springs are in loose engagement with the contact
block and the slide frame and are compression springs which tend to
push the slide frame 140 and plate 124 away from block 160. As an
alternative, it is also contemplated that in a standard fashion the
ends of the slide springs may be fastened to the block 160 and to
the slide frame and made to operate in tension to tend to pull the
frame and plate 124 toward the block 160. This latter feature will,
as to be described hereinafter, permit a normally closed switch
operation of the device. In the embodiment actually depicted in
FIG. 1b, normally open switch operation is contemplated. The bottom
crossmember 150 of the frame includes a projecting flange 151 which
is made to extend beneath the contact block 160 in all positions of
the device operation. A pair of compression springs 153 are seated
in recesses in the flange 151 to bear against the bottom of contact
block 160 and spring load the slide frame 140 downwardly relative
thereto. FIGS. 2 and 3 show this arrangement. On the bottom of
flange 151 is a projection which forms a camming surface 155 also
as shown in FIGS. 2 and 3. This camming surface engages the
surfaces 102 and 104 and also the top surface of the cam slide 90
to control movement of the slide frame during device closure. A
projection 152 from the top crossmember 150 limits downward
movement of the slide frame 140. As can be discerned, movement of
the slide frame effects a corresponding movement of the plate 124,
which is rigidly secured thereto. The thickness of the slide frame
permits the plate 124 to be held in a position limiting deflection
of the contact spring members during operation.
The contact block 160 is comprised of a series of blocks of
insulating material, shown as 162, which are fitted together to
entrap a series of contact members in an array corresponding to the
array of holes in plate 124 and in sheet 42 of the main pressure
plate. Each of the blocks 162 is relieved at the rear, as at 163,
as shown in FIG. 1b to provide a slot extending across the block to
accommodate termination to or between the individual contact
members. Each of the contact members 164 include a terminating
portion at the rear end, such as the barrel 180 into which may be
inserted a contact pin member terminated to an electrical lead. The
contact members may be interconnected in a variety of ways,
including individual connections to each contact member or busing
together of all of the contact members of a column or a given row,
depending upon the application of use and the type of electrical
readout preferred. It may be necessary to alter the disposition of
conductive strips 132 to a column disposition, rather than the row
disposition indicated. This could be accomplished by having the
conductive strips 132 extend downwardly between the column of holes
with a portion thereof extending outwardly beneath each hole to
form a conductive pad for such hole. The immediately foregoing
description applies equally well to the alternative embodiment
wherein the conductive pads are placed on the sheet 42 of the main
pressure plate.
A pair of stiffeners shown as 182 are provided on each side of the
contact block 160 and the contact block is secured to the main
frame 14 by a suitable attachment to the projecting flanges 16 and
18, as fitted within the recess portion 20 therebetween. The
projecting portions of the stiffeners shown in FIG. 1b are of a
size to facilitate this.
FIG. 1c shows the contact members 164 in greater detail relative to
other components of the assembly. Each contact member includes a
rounded end portion 166 of reduced width, which is made to engage a
card C or extend through a hole in such card in a manner depicted
in FIG. 5b. The reduced width of the end of the contact member
permits a reading with wide variations in card hole tolerance or
positioned in the reader device. The end of the contact member may
be turned up as at 168 to operate in conjunction with the plate 124
to prevent the contact member from accidentally catching on any
portion of the card. In one embodiment the contact member end 166
serves as merely a sensing means and in an alternative embodiment
the portion 166 is made to have a contact-bearing surface to effect
a read-through contact engagement in the manner to be hereinafter
described. The contact member is rounded upwardly, as at 170 as
shown in FIG. 1c and downwardly as at 172 to define a line contact
surface which in one embodiment may be positively controlled to be
either in engagement or out of engagement with a mating conductive
pad on strip 132. The rounded portion 170 serves in both
embodiments to orient the sensing or contact portion 166 in a sense
which is substantially transverse to the holes of a card and to the
disposition of conductive pads. Each contact member includes a
cantilever arm shown as 174 in FIG. 1c extended from a support
portion 178 which is trapped within the block 162 and which extends
to the rear of the block assembly for suitable termination to leads
or busing members, as previously mentioned. The contact members are
thus made and mounted to permit a substantial but controlled spring
action on deflection to either make or not make contact, depending
upon the presence or absence of a hole in a card C. Overstress is
precluded by the position of plate 124 as held by slide frame 140.
The spring action provided by contact members of the configuration
shown permits repeated deflection in use without taking a set which
could result in either a failure of contact closure or at least
cause a high resistance circuit path resulting in poor electrical
performance.
In an actual assembly the contact members 164 were made of phosphor
bronze material approximately 0.012 inch thick with the portion 172
approximately 0.380 inch in length and approximately 0.050 inch in
width. The end portion defining 166, 168 and 170 was about 0.018
inch in width. In a test involving appreciable deflection of an
array of some 960 contact springs of a configuration shown the
greatest permanent deflection in any of the contact spring members
after 50,000 cycles was only about 0.001 inch, an amount not
incompatible with excellent operating characteristics.
DETAILED ASSEMBLY OPERATION
Referring now to FIG. 2 and to the operation of one embodiment of
the device of the invention, the assembly 10 is shown in an open
position preparatory to receiving a card C inserted therein. As can
be discerned, portion 116 of trigger 106 is disposed within the
card slot projecting upwardly from the end thereof and biased by a
spring 120 into this position. The driving mechanism is disposed to
the right with the pressure plate 40 fully to the right. In the
embodiment shown in detail in FIG. 1b the plate 124, as carried by
slide frame 140, is positioned to the right, as driven by the
compression springs 146. At this time the individual contact
members are in the relative position shown in FIG. 5a. The arm 35
and cam 31 are biased for counterclockwise rotation by a spring 39.
At this time pin 33 is disposed toward the center of the slot 57
with the operating lever L biased in the position shown in FIG. 2
by a spring 62. Also, at this time, links 68 are disposed generally
vertically, biased in a clockwise sense by a spring 76 to in turn
hold the cam slide 90 to the left with the right-handed pin 98 in
engagement at the end of the guide slot 24. The cam surface 155 is
thus made to rest on top of the cam slide out of the cam groove
containing camming surfaces 102 and 104. The slide frame 140 is
thus disposed upwardly to compress springs 153, which in turn tend
to drive the slide frame downwardly.
FIG. 3 shows the assembly of the invention following insertion of a
card C which engages portion 116 of the trigger, driving the
trigger 106 downwardly to release 35 and thereby release 31. As 31
is released it is driven in a counterclockwise sense relative to
FIG. 3 by a spring 39 to rotate to a position with pin 33 in
engagement with the left-hand end of slot 57. As 31 rotates within
eccentric 52 it drives the main pressure plate to the left which
carries the card C the plate 124, and the slide frame 140 to the
left. Also, as 35 moves counterclockwise after release from the
trigger, it engages rod 74, driving such rod to the right which in
turn drives links 68 in a counterclockwise rotary movement against
the spring force provided by 76. This movement of links 68 draws
the cam slide 90 to the right, causing the surface 155 on the
bottom of slide Frame 140 to enter groove 102. dropping the slide
frame downwardly. FIG. 7a shows the relative position of a contact
member 164 to a conductive pad just prior to operation with the
contacts in an open circuit condition. FIG. 7b shows first
engagement between a contact member and a conductive pad. The
driving linkage of the device is adjusted so that an engagement as
depicted in FIG. 7b is made prior to any vertical movement of the
slide frame caused by 155 entering into the camming groove. FIG. 7c
shows the resulting wiping action caused by the slide frame being
dropped vertically as 155 moves into engagement with camming
surface 102. FIG. 5b shows the contact member 164 in closure and it
should be apparent that the ends of the contacts are held from
being caught on the card. In accordance with the setting shown in
FIGS. 2 and 3, the cam slide continues to move to the right until
155 rides up onto surface 104. This results in the wiping action
shown in FIG. 7d, which is approximately equal to but in a reverse
sense, from the wipe occurring in FIG. 7c. Further movement of the
slide frame under drive of the pressure plate to the left causes a
deflection of the contact members as indicated in FIG. 7e to place
the contact members in contact with a prewiped contact zone on the
conductive pads.
In accordance with a further aspect of the invention the adjustment
mechanism can be operated by a few turns of the threaded portion 86
to displace the cam slide to the right from the position shown in
FIG. 2, so that 155 rests in a normal position in the center
surface 104. Operation of the unit will then cause the slide frame
carrying the conductive pads to move to the left effecting a
displacement of contact surfaces between the open circuit position
shown in FIG. 8a and the point of initial contact shown in FIG. 8b.
As the cam slide 90 is then drawn to the right, surface 155 will
engage the left-hand end of surface 104 to be driven upwardly onto
the top of the cam slide effecting the wiping action shown in FIG.
8c. This wiping action may be compared to that depicted in FIGS.
7b--7d, to indicate that wiping is occurring on a fresh zone of
contact on the conductive pad. Final closure of the contacts
operates to deflect the contact members effecting a further wipe,
as indicated in FIG. 8d, which leaves the interface between contact
members and conductive pads in a prewiped zone. The configuration
of the contact members permits this adjustment to provide fresh
contact surfaces. This feature is of considerable practical
advantage in that the life of the contact members can be more
easily increased than can the life of the conductive pads
considering the various factors of tolerance and the amount of
contact material required.
In use with a card having holes with a maximum dimension of
approximately 0.125 inch, the spacing between contact surfaces 172
and conductive strips 132 when the assembly is in an open position
may be approximately 0.032 inch. The first wiping movement
resulting from drive of the slide frame downwardly can be made
approximately 0.010 to 0.020 inch with the second or final movement
being approximately half that.
FIG. 6 depicts the switching elements of the assembly in use with a
card of substantially greater thickness than that evidenced in
FIGS. 5a and 5b. As can be seen, the closure motion of the device
of the invention, in conjunction with the configuration of the
contact members facilitates a use with cards of varying thickness.
It is also to be noted that variations in other card dimensions,
including the length or width of card holes or the position of card
holes relative to the invention assembly can be accommodated by the
invention.
Following the operation just described to effect card reading, the
card may not be withdrawn from the assembly until operation of the
lever L, which must be displaced to the right relative to the
showing in FIGS. 2 and 3. This displacement results in an
engagement of the left-hand end of slot 57 with pin 33 to rotate
cam 31 in a clockwise sense. This in turn results in a driving
engagement of 31 with eccentric 52 in flange 50 to draw the
pressure plate to the right permitting the slide frame to move to
the right under drive of the compression springs 146, breaking all
contact and freeing the card from engagement with contact members.
Simultaneously, arm 35 is rotated clockwise until the end thereof
engages portion 110 of the trigger to depress the trigger 106 until
the end of 35 slides over 108 to engage and be latched by 112 in
the position shown in FIG. 2. The trigger is in an upward position
loaded by spring 120 and ready for operation with the next card to
be inserted. Movement of the operating lever L again loads spring
39 and the lever is maintained in the position shown in FIG. 2 by
spring 62. Also, simultaneously, links 68 are pulled to the left by
the spring 76, following the movement of 35 and its engagement with
rod 74. As this occurs the cam slide is drawn back to the position
of FIG. 2, driving the slide frame upwardly a slight amount. The
assembly is now ready for use with another card.
In the foregoing description contact closure has been described for
normally open operation; i.e., where all of the contacts are
normally or initially out of contacting engagement and contact
closure and switching action results from device operation. It
should be apparent that normally closed operation can be obtained
by an arrangement of the springs 146 to operate in tension to
maintain the slide frame 140 and plate 124 to the left, with the
driving plate then operating to force a card to drive the contact
members out of engagement with conductive pads on plate 124.
It is also contemplated that the feature of the invention relating
to the use of a plate such as Plate 124 described above for
receiving the contact members may be used to advantage in an
assembly wherein contact is made through a card hole. In this
embodiment conductive pads are placed in the sheet 42 mounted on
the pressure plate 40. These conductive pads are formed in the
positions of holes 44. FIGS. 9a and 9b depict this arrangement. As
can be discerned, contact is made through the portion 166 of each
contact member and the conductive pads shown as 190 in the sheet
42. The conductive pads 190 may be interconnected by strips
extended in a suitable fashion outwardly of the zone of contact
engagements for termination by a suitable technique. It is
contemplated that the sheet 42 may be extended at the bottom
thereof to accommodate a printed circuit edge connector or the like
device for such termination. FIGS. 10a--10d depict contact
engagement between the portion 166 of each contact member and the
conductive pad 190. The wipe shown is similar to that evidenced in
FIGS. 8a--8d and results in a final contact engagement in a prewipe
zone, in the manner previously described. In this latter embodiment
the plate and the slide frame structure can be fixed to the
pressure plate, if desired, to fix the card-receiving slot
dimension.
It is also contemplated that alternative switching paths can be
provided utilizing conductive pads on plate 124 and on sheet 42.
Auxiliary circuits for control or other purposes can be handled in
this manner with the contact member configuration shown. If the
alternative structure is used, however, the feature of
accommodating cards of different thicknesses by permitting a
portion of the contact member to extend through the card and into
the hole of 42 cannot be carried out. In certain applications
control of card thickness can be expected because of a single
source of cards and the read-through arrangement may be
preferred.
In summary, the invention has been described in several
embodiments, one effecting a contact closure and engagement which
develops reading signals which do not pass through a card hole and
the other effecting a reading with signals passing through a card
hole. Both embodiments utilize a plate member which has holes
therein to surround spring contact members when such are in a
reading position to preclude fouling thereof on any portion of a
card to be read. Additional features are included to provide a
wiping engagement under reduced contact pressure and an adjustment
which introduces fresh areas of contact for increasing contact
life. It is contemplated that these features may be selectively
used as application requirements dictate. In a general sense the
device of the invention is a multiple switch structure capable of
achieving a plurality of switching engagements and having a
particular use as a card reader for reading functions wherein
contact engagements are in a pattern related to holes in a
card-defining data.
Having now disclosed the invention in terms intended to enable a
preferred mode of practice thereof, claims are appended which
define the subject matter asserted as inventive.
* * * * *