U.S. patent number 3,573,558 [Application Number 04/831,672] was granted by the patent office on 1971-04-06 for printed circuit card holder with control and display units.
This patent grant is currently assigned to Radiation Incorporated. Invention is credited to Frank Draper Babcock.
United States Patent |
3,573,558 |
Babcock |
April 6, 1971 |
PRINTED CIRCUIT CARD HOLDER WITH CONTROL AND DISPLAY UNITS
Abstract
A handle for a printed circuit card is provided with a slot for
accepting the card, with keyed contacts at the edge of the card
projecting into the slot. The card is permanently fastened to the
handle by rivets. A plurality of spaced, substantially parallel
holes extend through the handle from its front surface to a point
of intersection with the slot to expose the contacts on the card.
Separate indicator units and control units are slidably received in
respective ones of the holes and are frictionally retained therein
with spring-loaded terminals of the units electrically contacting
the keyed contacts on the printed circuit card. A further array of
keyed contacts at the opposite edge of the card is adapted to mate
with a female connector when the card is inserted into position in
a card shelf, the handle being exposed with legends and indicator
units visible thereon and with control units accessible for
selective exercise of control on the operation of the circuit
carried by the card.
Inventors: |
Babcock; Frank Draper (Eau
Gallie, FL) |
Assignee: |
Radiation Incorporated
(Melbourne, FL)
|
Family
ID: |
25259583 |
Appl.
No.: |
04/831,672 |
Filed: |
June 9, 1969 |
Current U.S.
Class: |
361/679.08;
439/61; 439/483; 439/490; 361/796; 361/752; 361/773; D14/240;
361/679.21 |
Current CPC
Class: |
H05K
7/1461 (20130101) |
Current International
Class: |
H05K
7/14 (20060101); H02b 001/62 () |
Field of
Search: |
;317/101,101 (DH)/
;317/101 (CB)/ ;174/68.5 ;340/178,178.1 ;211/41 ;200/16,167,172
;16/(Inquired) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Smith, Jr.; David
Claims
I claim:
1. A printed circuit card holder for retaining a card having keyed
terminals associated with the printed circuit carried by said card
adjacent at least two edges of said card, said holder
comprising:
an electrically insulative body member having four sides, opposite
pairs of which are substantially parallel to one another, and
having two ends;
a pair of electrically insulative ribs projecting in spaced
parallel relation from and substantially perpendicular to one of
said sides of said body and defining a slot therebetween of width
sufficient to accept the thickness of said printed circuit card and
the thickness of the printed circuit carried by said card, said
slot extending partly into said body member at said side from which
said ribs project;
a plurality of spaced substantially parallel holes extending
through said body member from the side opposite said side from
which said ribs project and intersecting the portion of the slot
extending into said body;
a printed circuit card in said slot and fastened to said ribs with
the keyed terminals at one edge of said card exposed in at least
some of said holes intersecting said slot; and
control and display means mating with respective ones of said some
of said holes and having electrical connectors electrically
contacting keyed terminals at said one edge of said card for
electrical interaction with the circuit carried by said fastened
card.
2. The card holder according to claim 1 further including a surface
contour at each of said ends to facilitate gripping of the holder
for transfer of the associated card from one position to
another.
3. The card holder according to claim 1 wherein said control and
display means are slidably insertable into and slidably removable
from said holes.
4. A printed circuit card holder for retaining a card having keyed
terminals associated with the printed circuit carried by said card
adjacent at least two edges of said card, said holder
comprising:
an electrically nonconductive handle having a front edge and a rear
edge;
a slot in said rear edge of said handle sufficiently wide to accept
a printed circuit card;
a plurality of spaced-apart holes extending in a substantially
parallel array through said handle from said front edge to said
rear edge and intersecting said slot;
a printed circuit card fastened in said slot with the keyed
terminals along one edge of said card projecting toward said front
edge of said handle and exposed in at least some of said holes
intersecting said slot; and
a plurality of control and display means slidably engaged in
respective ones of said some of said holes, via said front edge of
said handle for selective withdrawal from said front edge, and
having electrical connectors electrically contacting the keyed
terminals at said one edge of said card exposed in said holes for
electrical interaction with the circuit carried by the fastened
card, said control and display means being fixedly mounted relative
to said card for electrical operation therewith and said electrical
connectors continuously contacting the respective keyed terminals
at said one edge of said card.
5. The combination according to claim 4 wherein said control means
comprises switch means for selectively electrically connecting and
disconnecting portions of the circuit carried by said card via the
respective keyed terminals with which the electrical connectors of
the respective control means make contact.
6. The combination according to claim 4 wherein said display means
comprises indicator means for detecting and displaying the
operating state of a portion of the circuit coupled to the
respective keyed terminals with which the electrical connectors of
the respective display means make contact.
7. The combination according to claim 4 wherein said control means
comprises means for selectively modifying the operation of the
circuit coupled to the respective keyed terminals with which the
electrical connectors of the respective control means make contact.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to printed circuit boards
or cards, and more particularly to devices to permit ease of
handling of printed circuit boards for insertion in and removal
from card racks, and to accommodate replaceable indication units
and control units for direct electrical and mechanical connection
to the printed circuit board associated with the device.
It has been typical practice to provide indicators and controls
associated with the circuit on a particular printed circuit card at
a location or locations remote from the card itself. For example,
lamps for indicating the nature of the circuit operation or the
present operational state (e.g., "on" or "off") of a particular
portion of the network on a printed circuit card, and manual
pushbutton switches for instituting a change of operational state
of that portion of the network, might be located in banks or racks
containing a multiplicity of similar indicating and control units
associated with other cards for implementing and detecting an
overall system operation. Electrical connection between these units
and the respective cards is accomplished by soldering wires or
leads of appropriate length between terminals with which the units
and cards are in electrical contact.
The printed circuit card contains a plurality of spaced printed
contacts adjacent one edge of the card and keyed to make electrical
connection with the respective contacts of a mating female
connector. This makes for ease of replacement of cards in large
banks, since a defective card or a card whose function is to be
updated need merely be withdrawn from the respective connector and
a new card, of appropriate function, inserted in its place.
Usually, the cards are located in a spaced parallel array in racks
or shelves, the distance between cards being sufficient to permit
accommodation of components such as transistors or diodes on
adjacent cards without interference or obstruction. Each card may
be provided with a handle to simplify handling and replacement of
cards without touching the actual circuitry or components mounted
on the card.
The indication units and control units may be of the plug-in type
for insertion into sockets wired to the electrical connectors for
the respective printed circuit cards, but quite often these units
are permanently wired in their banks.
In these prior art arrangements, then, it has been necessary to
provide separate panels for cards and for display and control
purposes, leading to some delay in matching card with indication
and/or control unit when failures occur in one or both. Moreover,
the number of potential sources of failure increases in proportion
to the number of wiring connections, solder joints, and so forth.
Such problems, of course, are in addition to perhaps the most
significant disadvantage of the prior art multicard arrangements,
namely, that of time-consuming and costly initial installation and
subsequent replacement.
SUMMARY OF THE INVENTION
According to my invention, a card handle or card holder is provided
with a rear slot for receiving and retaining a printed circuit
card, and with several holes running from front to rear and
intersecting the slot. The holes are of appropriate size and shape
to accept individual respective display units and control units
therein, and the front of each of these units is exposed in the
respective handle to permit an identifying designation or symbol
with respect to the function or circuit relationship of the unit to
be imprinted thereon.
Active units retained in a card handle are provided with slots that
register with the slot in the handle, and that expose spring-loaded
electrical contacts or connectors adapted to mate with printed
contacts on the card when the card is fully inserted into the
handle. Normally, the handle is fastened to the card after the card
has been inserted fully into the slot at the rear of the handle.
Each card is provided with what may be termed front edge and rear
edge printed contacts, the latter being standard for electrical
connection with a mating female connector when the card is
installed for use in a printed circuit card rack or shelf. The
provision of front edge contacts on each card is essential to my
invention to permit the aforementioned indication or control units
to be pushed into the appropriate hole in the handle whereupon the
spring-loaded contacts on the respective unit accept the matching
contacts on the card.
This provides an electrical connection between the circuit printed
on the card and the electrical elements in the unit. Mechanical
retention of each unit is also assured in part by the clamping
action of the spring contacts on the card contacts, and further by
the provision of a tight or frictional fit between the sides of the
unit and the walls of the hole into which it is to be inserted.
Removal of an active unit from the handle is effected by
withdrawing the handle and card assembly from its operational
position in the card rack or shelf and pushing the unit out from
the rear toward the front of the handle.
Passive units are provided in the form of blanks carrying
appropriate legends identifying the function of the unit or its
relationship to an associated piece of apparatus.
In addition to those advantages noted above, it will be observed
that no tools are required for removal or replacement of a unit; no
soldering or other auxiliary fastening procedure is required to
establish electrical contact between printed circuit card and
control or display unit; and the units are disposed immediately
adjacent and in direct contact with the associated card.
A feature of my invention is that the printed circuit cards to
which respective handles are attached are conveniently mounted in
operational position in the shelf or rack in a clean, uncluttered
panoramic assembly. The handles are juxtaposed along the shelf and
are provided with gripping surfaces to permit ease of removal of
the associated card without disturbing adjacent cards or elements
mounted thereon. Moreover, each of the units retained in the handle
is clearly visible and accessible to operating and maintenance
personnel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a complete printed circuit card
handle assembly;
FIG. 2 is a fragmentary side view, partly in section, of the
assembly of FIG. 1;
FIG. 3 is a fragmentary top view of the assembly of FIGS. 1 and
2;
FIG. 4 is a sectional view of the handle taken through its
longitudinal plane of symmetry and showing a fragmentary portion of
the printed circuit card to be inserted therein;
FIG. 5 is a fragmentary, exploded rear view of the handle card
assembly;
FIG. 6 is a perspective view of a control unit for insertion into
the handle of FIGS. 1--5;
FIG. 7 is a rear view of the control unit of FIG. 6;
FIGS. 8 and 9 are side and rear views of a switch constituting a
part of the control unit of FIGS. 6 and 7;
FIG. 10 is a perspective view of an indicator unit for insertion
into the handles of FIGS. 1--5;
FIG. 11 is a perspective view of a shelf assembly of printed
circuit cards with handles; and
FIG. 12 is a section view taken through a shelf of FIG. 11.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 through 5, inclusive, an exemplary printed
circuit card handle 10 has a substantially rectangular blocklike
central portion 11 with contoured extensions 12 at either end. A
pair of spaced parallel flanges or ribs 13 project perpendicularly
from the rear surface 14 of handle 10, as is perhaps best viewed in
FIGS. 3 and 5, and the flanges are provided with a pair of aligned
holes 15, 16 at either end for a purpose which will be discussed
presently. The central region 11 of handle 10 is provided with a
plurality of holes 17, 18, 19, 20 (FIGS. 4 and 5) extending
entirely through the block from front surface 21 to rear surface
14, the holes being of generally rectangular shape. As will
subsequently become clear, more or fewer holes may be provided
according to the specific printed circuit card with which the
handle is to be associated.
A gap or slot 22 (FIGS. 3 and 5) formed by the space between
flanges 13 is carried into the hole area at the rear surface 14 of
the handle as slots 23, 24, 25 (FIG. 4) to accommodate a section 26
of a printed circuit card 30 to be fastened to the handle.
Preferably, handle 10 is composed of heat resistant or fire
retardant opaque plastic material and is provided with a fine grain
surface finish. In practice, the handle is of one-piece
construction, formed in its basic shape by any well-known molding
process and subsequently machined as may be required to provide
specific hole and slot tolerances and to remove any burrs or sharp
edges. Flanges 13 need not be continuous as shown, but may appear
at the ends only, and may be tapered at either end, as at 31, to
permit some sidewise adjustment of the printed circuit card 30
during insertion into and assembly with the handle, as will be
discussed. The concave contours 33 at either end of central portion
11 and running smoothly into extensions 12 afford a gripping
surface, as between thumb and forefinger, during installation and
removal of the handle card assembly.
A typical handle produced in accordance with my invention had the
following approximate dimensions, presented by way of example only:
width (between side surfaces 35 and 36) of 1 inch; depth (between
front surface 21 and rear surface 14) of 1.0 inch, flange depth of
0.5 inch; body length (from end to end) of 4.3 inches; length of
central block region (11) of 3 inches; hole width of 0.75 inch;
hole length of 0.550, except hole 17 whose length is 0.750 inch;
0.06 radius at corners of each hole; material thickness of 0.08
inch between adjacent holes; slot width (between flanges 13) of
0.062 inch; slot depth (into hole area of body) of 0.25 inch. The
mating printed circuit card 30 for handle 10 is of completely
conventional design, being provided with conductive circuit paths
and conductive thru-holes and component mounting holes and with a
region of keyed contacts 38 adjacent edge 39, except that card 30
is also provided with a further array of keyed contacts 40 at
section or region 26 which is to be the handle end of the card.
This region 26 is designed to mate and to be inserted into the slot
extending into the body of handle 10 via slot 22 between flanges
13. When the card is so inserted, keyed contacts 40 are registered
with those of holes 17--20 into which active control and display
units are to be inserted, and holes 41 in the card are aligned with
respective hole pairs 15 and 16 in flanges 13. The width of slot 22
is sufficient to accept the thickness of the insulative portion of
board 30 and of the conductive regions overlying and adhering to
the board surfaces. Typically, the printed circuit card is
approximately 0.054 inch thick. After insertion of card 30 into
handle 10 the two are permanently fastened together by rivets 43
and 44 (FIGS. 2 and 3) passing through holes 15 and 16 of flanges
13 and the aligned holes in the card.
As previously observed, a printed circuit card handle according to
the present invention not only serves as a holder by which to
conveniently grip the card for ease of insertion into and removal
from a shelf comprising a bank of mating female connectors for
keyed contacts 38 on a plurality of cards, without directly
touching the card itself or the circuit paths or components
thereon, but the handle also serves as an escutcheon and as a means
for retaining functional control and display units in direct
operative relationship with the network on the respective printed
circuit card.
A typical control unit 50 is shown in FIGS. 6 through 9 inclusive.
Required control may be exercised, for example, by a normally open,
momentary pushbutton switch 51 of the single-pole, single throw
type. Switch 51 has a finger- or thumb-operated pushbutton 52,
which, when actuated, causes a closed circuit path to be completed
between one or more pairs of spring contacts, e.g. 53, 54 disposed
at the rear of the switch. Preferably, these contacts are composed
of beryllium copper with a finish of gold plate over nickel, and
are so separated (typically, by 0.4 inch) on the switch body that
they will mate with respective ones of the keyed contacts 40 on the
printed circuit card when the overall control unit is pushed into
its appropriate hole in handle 10. Contacts 53 and 54 may be
similar to those available from Transitron Electronics Corp.,
Wakefield, Mass., designated as printed circuit contacts series
25003. The two contacts constituting a single contact pair (either
53 or 54) are approximately 0.04 inch wide, project about 0.3 inch
beyond the rear surface 55 of the body of switch 51, and are spaced
by a distance and possess a spring constant that a minimum
withdrawal force of approximately two ounces is required to
separate each contact pair from the mating contacts of a 0.054 inch
thick printed circuit card.
The switch 51 is housed within a control unit casing 57 with
pushbutton 52 projecting through a hole in front wall 58 and
contacts 53 and 54 exposed at a slot 59 (typically 0.062 inch wide)
in the rear of the housing, or projecting therefrom. Housing 57 is
preferably composed of heat resistant or fire retardant opaque
plastic material, and once the switch is placed inside and the
cover plate (front wall) 58 is replaced the entire assembly may be
maintained separable or inseparable, as desired. Slot 59 in housing
57 aligns with and matches the width of slot 22 in handle 10 when
the overall control unit 50 is pushed into an appropriate hole,
e.g., hole 20, of the handle. The control unit is dimensioned to
encounter a tight (frictional) fit upon insertion into its
respective hole, and this, in conjunction with the spreading open
of the switch contact sets by the keyed contacts of board 30 as the
unit is pushed into the hole to effect electrical connection
between switch and printed circuit, ensures retention of the unit
in the handle. Each active unit, such as control unit 50, is
sufficiently long that its complete insertion into the hole results
in a secure electrical connection with the mating contacts of the
printed circuit board (FIGS. 1 and 2). Fasteners may also be used
to retain a unit.
The front wall 58 of the unit may have an overhanging flange or lip
relative to the sides of the unit to "bottom" against front surface
21 of the handle, or may simply "bottom" on (seat against) the
printed circuit card. In either event, this assures that undue
force will not be exercised to push the unit into place despite
appropriate electrical connection occurring between switch and
board contacts. Moreover, while removal of any individual unit from
handle 10 may be accomplished by simply withdrawing the handle and
printed circuit card assembly from the shelf in which the circuit
card is normally operating, and then turning the assembly over and
pushing the appropriate unit from the rear toward the front of the
handle; a slot 60 (FIGS. 6 and 7) may be provided in the underside
of the lip, if used, of front wall 58 to permit the unit to be
pried loose from the handle without withdrawing the card handle
assembly.
A typical display or indicating unit 62 is shown in FIG. 10. The
housing 57 of display unit 62 is substantially the same as housing
57 of control unit 50, except that the interior is modified to
accept and mount a miniature lamp 63. The pins or leads of lamp 53
are connected to spring contacts 64, 65 of the same type as those
described above with reference to control unit 50. These contacts
or terminals may be fixedly positioned relative to housing 57 and
gap 59 by provision of slots (not shown) in which contacts 64, 65
are locked without interfering with the capability of the contacts
to undergo spreading and retraction when pushed on and removed from
the board. The housing of indicator unit 62 is composed of
transparent or translucent plastic and either the lamp or the
plastic may have an identifying color (e.g., red or green) to
indicate the state of the circuit on the associated printed circuit
card. For example, in the overall assembly shown in FIGS. 1 and 2,
indicator units 68 and 69, displaying the legends "ON" and "OFF"
respectively, might be provided with green and red lamps,
respectively. As in the case of the previously described insertion
and removal of control unit 50, each indicator unit is simply
pushed into the proper hole of handle 10, whereupon its contacts
engage the proper contacts of board 30, and may be withdrawn by a
reversal of that operation. The holes in the handle position the
units and guide them into the contact area of the associated
printed circuit card.
In the case of a switching unit as a control unit 50 for a
particular circuit, actuation of the switch (i.e., turning it "on")
completes a connection between otherwise isolated terminals
(contacts) on the printed circuit board, and thereby establishes a
circuit connection. For example, this may set a logic storage
element to provide a signal to control operation of a particular
segment of the circuit, and completion of a sequence of operating
steps may provide an indicator signal back to an indicator unit 62
to light the respective lamp, as an indication of a particular
operational state of the circuit.
The handle 10 may also accept a passive unit or a "blank" 70 (FIGS.
1 and 2), which may merely be a faceplate bearing any desired
legend to be exposed to view when the blank is inserted into the
desired hole, and having sufficient material projecting beyond the
underside of the faceplate to ensure retention of the blank in the
respective hole (e.g., 17) in handle 10.
An overall assembly of a plurality of printed circuit cards with
attached handles in an operational shelf or rack is shown in FIG.
11, and a section through the shelf is shown in FIG. 12. Shelves 75
and 76 are merely two of several such shelves arranged in a
vertical bay, for example, to mount a large number of printed
circuit cards in electrical connection with a similar number of
mating female connectors (not shown) mounted at the rear of each
shelf. The cards are inserted into respective guides 77 at top and
bottom of each shelf as may be observed by reference to shelf 75
from which the cover has been removed to show some of the detail of
the frame. Each card is inserted and withdrawn by its respective
handle, the handles 10 being in juxtaposed relationship along each
shelf and providing sufficient spacing between cards to prevent
interference between circuit components mounted on adjacent cards.
A cover 78 is shown as retained on the frame of shelf 76, the cover
having an opening of sufficient extent to expose every handle on
that shelf, and thereby to visually display the legends on the
units and the indicator units associated with each handle and to
provide access to the control units.
* * * * *