Note: Descriptions are shown in the official language in which they were submitted.
PLUG-IN POWER SUPPLY ADAPTER
BhCKGROUND OF THE INVENTION
This invention relates generally ~o an improved
s AC adapter of the type used to provide a DC voltage to
an associated electronic instrument from an AC supply
voltage. More particularly, this invention relates to
a compact and low profile power supply adapter for
plug-in connection to a standard electrical socket,
~u without obstructing or interfering with adjacent
electrical sockets of a standard duplex or guad wall
outlet or the like. The invention is particularly
designed for use with electronic instruments in a
medical environment, and further includes means for
15 removably mounting the power supply adapter onto or in
close association with the instrument when not in use.
Modern medical treatment facilities utilize a
variety of sophisticated electronic instruments in the
course of patient diagnosis and treatment. As one
20 common example, electronically operated medication
infusion pumps are commonly used for administering one
or more selected medical fluids to a patient at a
- prescribed flow rate and time schedule. Such fluid
medication infusion pumps and other electronic
25 equipment require a source o~ electrical power to
maintain the instrument in a desired operational
state.
In this regard, many electronic instruments
designed for medical as well as nonmedical uses are
constructed to operate on a DC power supply which can
be obtained in the alternativ2 from batteries or by
use of an appropriate transformer and rectifier
~ connected to a standard AC power source. In this
- latter case, the AC adapter frequently comprises a
power supply adapter designed for direct plug~in
~ connection to an AC power supply outlet, with an
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elongated cord extending between the plug-in adapter
and the associated electronic instrument used to
supply DC to the instrument.
In he past, plug-in power supply adapters have
s included a relatively compact housing or case having
the components of an AC adapter mounted therein.
Conductive prongs associated with the transformer
components have protr~lded outwardly from the adapter
case for plug-in connection in the manner of a
o standard electrical plug with an associated AC power
supply receptacle, such as one socket of a standard
duplex or quad wall outlet, or a multisocket strip, or
the liXe.
Accordingly, the adapter case essentially
comprises the body of an electrical plug for manual
grasping in the course of plug-in and unplugging
movements. However, the physical size and shape of
the adapter case has typically ~xceeded the width and
height of a conventional electrical plug, such that
the adapter case partially overlies and therefore
obstructs access to adjacent electrical sockets. For
example~ in a conventional duplex or quad wall outlet,
plug-in connection of a single AC/D~ power supply
; adapter to one of the electrical ~ockets normally
25 obscures and thus precludes access to all of the
remaining electrical sockets in the wall outlet.
Additional electrical devices which may be desirad or
necessary, especially in a medical treatment facility
must therefore be plugged into a different wall
30 outlet~
Moreover, in a medical treatment environment, it
is often necessary to transport electronic medical
instruments from one place to another. For example,
: fluid infusion pumps are often transported with
3s patients throughout different areas of a hospital or
the like, or from one patient room to another for use
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with different patients as the need arises. While
such instruments may be battery powered for short term
operation in a mobile environment, it is important
that the electrical power cor~ and associated power
s supply adapter remain with the instrument so that
normal operation can be resumed quickly and easily by
mere plug-in connection of the adapter to a power
supply outlet.
However, transport of the power supply adapter
and associated cord with the instrument poses
particular problems in that the adapter is relatively
heavy and thus difficult to transport with the
instrument in a secure and stable manner and/or can
become easily separated from the instrument and is
15 thus rPlatively easily misplaced.
There exists, therefore, a significant need for
an improved power ~upply adapter of the plug-in type
wherein the adapter can be plugged into a standard
electrical socket without interfering with access to
adjacent sockets, and furlher wherein the adapter
includes means for convenient and stable mounting in a
; stored position in association with an electronic
instrument for transport purposes. The present
invention fulfills these needs and provides further
2s related advantages.
SUMMARY OF THE INVENTION
In accordance with the invention, an improved
power supply adapter is provided for plug-in
30 connection to a standard AC power supply receptacle
and to provide a DC voltage to an associated
~-~ electronic instrument, particularly such as a medical
instrument. The power supply adapter is designed with
an AC adapter assembly mounted within a compact
35 adapter case having an end face with conductive plug
prongs protruding therefrom. The components of the
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transformer assembly are arranged generally in-line
between the conductive prongs and a power cord, such
that the case can be constructed with a narrow width
and low profile height to avoid obstructing adjacent
s electrical sockets of a standard duplex or quad wall
outlet or the like.
The case of the power supply adapter further
includes means for relatively simple removable
mounting in a stored position on or in close
o association with the electronic instrument when the
power supply adapter is not in use. In a preferred
form, the mounting means comprises a mou~ting clip
formed integrally with the adapter case ~or secure yet
removable mounting onto a bracket arm or other support
5 structure associated with the electronic instrument.
Other features and advantages of the present
; invention will become more apparent from the following
detailed description, taken in conjunction with the
accompanying drawings which illustrate, by way of
example, the principles of the invention.
DESCRIPTION OF THE DRAWINGS
These and other advantages of the present
invention are best understood with reference to the
2s drawings, in which:
Fig. 1 is a front perspective view illustrating
an alectronic medical instrument with an associated
power cord and a plug-in power supply adapter
embodying the novel features of the invention;
Fig. 2 is an enlarged rear perspective view of
the power supply adapter;
Fig. 3 is an enlarged top plan view of the power
supply adapter, with a portion of the adapter case
removed to illustrate the arrangement of components of
s an AC adapter assembly;
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Fig. 4 is an exploded perspective view o~ the
power supply adapter;
Fig. 5 is a fragmented perspective view
illustrating mounting of the power supply adapter in a
s stored position in association with the electronic
instrument of Fig. 1; and
Fig. 5 is a sectional view depicting an
alternative preferred form of the power supply
adapter.
DETAILED DESCRIPTION OF_THE PREFERRED EMBODIMENT
As shown in the exemplary drawings, an improved
AC adapt~r re~erred to generally in Fig. 1 by the
reference numeral lO is provided for use with an
.: Is electronic instrument 12, such as a fluid medication
. infusion pump. The power supply adapter lO is
designed for quick and easy plug-in connection to ~
standard AC power supply rec:eptacle 14, and to provide
a DC voltage via a power cord 16 to the electronic
instrument 12. The AC adapter 10 is particularly
constructed with an ~longated geometry having a
`: relatively narrow width and low profile height, such
: that the AC adapter lO does not obstruct or otherwise
,`i; inter~ere with access to adjacent electrical sockets
17 of a multisocket receptacle 14.
Although the power supply adapter lO of the
present invention may be used with a wide range of
electrical and/or electronic instruments, the
illustrative drawings show the adapter lO in a
preferred environment of use, namely, in association
with an electronic instrument 12 in a medical
: environment. Fig. 1 illustrates the instrument 12 in
the form of a fl~id medication infusion pump
corresponding with the MiniMed III fluid infusion pump
35 marketed by MiniMed Technologies of Sylmar,
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California, which infuslon pump shall also be referred
to by the reference numeral 12.
The illustrative in~usion pump 12 comprises a
relatively compact instrument adapted for mounting
onto a conventional portable medical equipment pole 18
by means of an appropriate clamp fixture 20, such as
an adjustable clamp fixture of the type described in
U.S. Patent 4,832,29~, which is incorporated by
reference herein. The infusion pump 12 is shown to
o include multiple parallel pumping systems for
independent programming and control to regulate
administration of multiple medical fluids from
appropriate reservoirs 22 to the patient (not shown)
via suitable tubing 24.
~s The electronic control components and associated
electrcnically powered pumping devices are integrated
into the housing of the infusion pump 12. The
infusion pump 12 is designed for normal operation by
connection to an appropriate 120 volt AC power supply
; 20 receptacle 14 by means of the AC adapter 10 and the
power cord 16, with the AC adapter 10 comprising an
adapter for supplying a se:lected DC voltage to the
infusion pump 12.
As shown best in Figs. 2-4, the AC adapter lO
includes a relatively compact housing or case defined
by a lower base 28 and an upper cap 30O These case
components, in the preferred form, are ~onstructed
from a relatively lightweight and high impact molded
: plastic, such as glass-filled nylon. The base 28 and
the cap 30 have a generally shell-shaped configuration
which cooperatively define a hollow case interior for
receiving and supporting the components of an AC
adapter electrical assembly 32.
More ~pecifically, the AC adapter electrical
assembly 32 comprises a tranisformer 34 securely seated
; within the base 28 in a nested or cradled relation
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with respect to a plurality of short locator tabs 36.
The transformer 34 is positioned in close proximity
with a forward end wall 38 from which a plurality of
conductive prongs 40 pro~rude in a conventional three
s prong array for plug-in connection to the AC power
supply receptacle 14. In the preferred form, these
conductive prongs 40 are securely mounted near their
rear ends within the end wall 38 as by means of insert
molding or the like.
10rrhe remaining components of the AC adapter
electrical assembly 32 are mounted within the adapter
case in a generally in-line configuration with respect
to the transformer 34 and the conductive prongs 40.
Figs. 3 and 4 show these remaining components in the
s orm of a filter capacitor 42 and a rectifier 44. All
o~ these transformer components are appropriately
coupled electrically by means o~ suitable conductive
wires 46.
; A selected trio of the wires 46 are assembled
within a protective outer sheath 48 to define the
power cord 16 connected to the associated electronic
instrument 12. In this regard, these conductive wires
46 are suitably collected for passage through a notch
50 formed in a rear end wall 52 of the base 28. A
~: 2;strain relief fitting 54 is mounted at the rear end
wall 52 and defines a flexible structu~al member
connected between the base 28 and the power cord 16 to
anchor the power cord 16 securely to the adapter 10.
In other words, the strain relief fitting 54 has
a mounting head plate 56 at one end thereof for seated
reception against an inboard side 9f the rear end wall
52 on the base 28, with a narrow neck 58 adjacent the
head plate 56 and sized for close-fit reception
through the open notch 50. From the neck 58, the
3s strain relief fitting 54 includes an alternating
.~sequence of plate and nec~ segments 60 and 62 which
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define a flexible structure to securely retain the
associated end of the power cord 16 therein.
Importantly, the strain relie~ itting 54 is
designed to permit flexure (Fig. 2) substantially at
s the adapter case as may be required for adapter use in
close clearance locations. Moreover, the fitting 54
is desi~ned to prevent or resist cord ~reakage at the
adapter as may otherwise occur, for example, when the
adapter is unplugged by pulling on the power cord 16.
o With the AC adapter electrical assembly 32
installed within the lower base 28 and the strain
relief fitting 54 mounted thereto, the adapter case is
closed by mounting the cap 30 onto the base 28. Such
mounting may occur by use of snap-fit connections,
ultrasonic weldingr and/or adhesive, with a
permanently closed adapter ase construction being
desired.
The resultant AC adapter 10 includes the
components of the AC adapter electrical assembly 32 in
~o a substantially in-line arrangement between the
conductive prongs 40 and the power cord 16. The
adapter 10 thus has an elongated shape which can be
easily grasped and/or manipulated manually for plug-in
connection to and unplugging from a power supply
receptacle.
The elongated AC adapter electrical assembly 32
further presents a relatively narrow width and low
profile height conforming generally with the
dimensions of a standard ele~trical power plug, such
that plug-in connection of the AC adapter 10 to an
~ electrical socket 17 ~Fig. 13 does not interfere with
:~ or otherwise obstruct access to adjacent electrical
- sockets 17 of a typical duplex, quad, or strip outlet
17. As a result, t~e adjacent sockets 17 remain
s available for easy access and plug-in connection with
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other electronic instruments as may be necessary or
desirable.
- Although the specific size and shape of the AC
adapter 10 of the present invention may vary according
5 to a range of design criteria, it is noted that the
width and height of the adapter case are predominantly
a function of the size and shape of the transformer
34. In this regard, through the use of a compact
transformer such as that available from ISL Products
o International, Ltd., of Syosset, N~w York, under model
desi~nation EI 41, it has been possible to ~onstruct
an AC adapter lO with a low profile height of about
1.5 to 1~6 inch and a narrow width of about 1.7 to 1.8
inch~
In accordance with further aspects of the
improved AC adapter 10 of the present inYention ~ the
assem~led adapter case defines a rearwardly projecting
mounting clip 64 for convenient removable mounting of
the AC adapter 10 in a stored position with respect to
zo the associated eiectronic instrument 12. The clip 64
is shown in the form of a rearwardly projecting clip
leg 66 formed integrally with the basa 28 and/or cap
30 at one side of the cas~. Conveniently, to prevent
undesired increase in the case width or height, the
s clip leg 66 is formed as a continuation of a wider
frontal portion of the case within which the
~; transformer core 34 is mounted, but in spaced relation
with a narrow rear case portion having the filter
: capacitor 42 therein.
~o In the preferred form, the clip leg 66 cooperates
with the narrow rear portion of the case to define a
rearwardly open slot 68 sized for reception of a
bracket arm 70 of the clamp fixture 20, as viewed in
Fig. 5. That is, the clip 64 permits the adapter 10
~ ~ to he removably mounted quickly and easily onto the
.~ bracket arm 70 in close stored association with the
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medical instrument 12. A lock tooth 72 at the inboard
fres end of the clip leg 66 includes tapered leading
and trailing edges for facilitating secure clip-on
mounting and subsequent removal of the adapter 10 from
3 the bracket arm 70.
~ support strap 74 having Velcro-type fasteners
may also be mounted onto th~ bracket arm 70 for
releasably supporting the power cord 16 in a coiled or
oth2r suitably compact configuration.
o One alternative preferred form of the improved
power supply adapter is shown in Fig. 6, with
components corresponding generally with those shown
and described in FIGS. 1-5 being identified by common
primed re~erence numerals. As shown, a modified
adapter 10' includes a tran~former 34' mounted within
a compact case in in-line relation with a plurality of
: conductive plug prongs 40'. The remaining components
of The AC adapter lO' include one or more filter
capacitors 42' and a rectifier 44', which are insert
molded within a separate case portion 78 spaced
rearwardly from the transfor~er 34 r .
A strain relief fi~ting 54' is interposed between
th~ transformer 34' and the capacitors 42' and the
rectifier 44', with all of the components again
positioned in a generally in-line configuration
between the prongs 40' and a power cord 16'.
Although an exemplary embodiment of the present
invention has been sho~n and described, it will be
appaxent to those having ordinary skill in the art
that a number of changes, modifications, or
alterations to the invention as described herein may
be madel none o~ which depart from the spirit of the
: present invention. All such changes, modifications,
and alterations should therefore be ~een as within the
3~ scope of the present invention.
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