U.S. patent number 3,711,806 [Application Number 05/215,023] was granted by the patent office on 1973-01-16 for power pack.
This patent grant is currently assigned to Dormeyer Industries, Inc.. Invention is credited to Robert W. Flentge.
United States Patent |
3,711,806 |
Flentge |
January 16, 1973 |
POWER PACK
Abstract
A power pack unit for reducing line voltage and changing
frequency including a transformer having a molded bobbin of
insulating material and an enclosure casing where the bobbin
includes insulating flanges integrally formed to insulate the
transformer core from the winding terminals and channels for
receiving primary and secondary terminals that can be located in
place and as a subassembly mounted into a casing made of two parts
which are suitably fastened together.
Inventors: |
Flentge; Robert W. (Roselle,
IL) |
Assignee: |
Dormeyer Industries, Inc.
(Chicago, IL)
|
Family
ID: |
22801321 |
Appl.
No.: |
05/215,023 |
Filed: |
January 3, 1972 |
Current U.S.
Class: |
336/92; D13/110;
336/107; 336/192; 336/198 |
Current CPC
Class: |
H01F
27/266 (20130101) |
Current International
Class: |
H01F
27/26 (20060101); H01f 027/02 () |
Field of
Search: |
;336/92,105,107,192,198
;321/8 ;320/2 ;307/150 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kozma; Thomas J.
Claims
The invention is hereby claimed as follows:
1. A power pack for use with a small electrical appliance to reduce
line voltage and provide a low operating voltage, said power pack
comprising a transformer subassembly enclosed within a case and
cover assembly from which project primary terminals for plugging
into a wall outlet and a secondary line cord or terminals for
connection to the appliance, said transformer subassembly including
a bobbin molded of electrical insulating material, primary and
secondary windings on the bobbin, secondary soldering lugs anchored
to the bobbin and connected to the secondary winding and the
secondary line cord, primary terminals carried in channels formed
in the bobbin connected to the primary winding, a laminated iron
core fastened to the bobbin and surrounding the windings,
insulating flanges integrally formed on the bobbin for insulating
the laminated core from the primary terminals and the secondary
lugs, locating holes in said laminated core, said case and cover
assembly including transformer locating pins for engaging in said
laminated core locating holes to orient the transformer subassembly
within the case and cover assembly, said cover including openings
for the primary terminals to project therethrough, and means on the
cover coacting with the bobbin to lock the terminals in the
channels and inhibit movement thereof.
2. The combination as defined in claim 1, wherein support means
within the case and on the cover coact with the locating pins to
prevent movement of the transformer subassembly relative the
casing.
3. The combination as defined in claim 2, wherein said primary
terminals include prongs that engage the wall outlet and anchor
portions extending at right angles to the prongs for anchoring the
terminals in the channels.
4. The combination as defined in claim 1, wherein said cover means
includes primary terminal locking pins engaging the bobbin at the
primary terminals to squeeze the channels in which the primary
terminals are located.
5. The combination as defined in claim 1, wherein said cover means
includes primary terminal locking pins engaging the bobbin and the
terminals to lock the terminals to the bobbin.
6. The combination as defined in claim 1, wherein said channels are
defined by opposed walls, and said terminal locking means including
primary terminal locking pins such that when the cover is in closed
position relative the case said locking pins engage one of the
channel walls to move it toward the other channel wall and
frictionally grip the terminals therein.
7. The combination as defined in claim 1, wherein the cover is
sonically welded to the case.
8. The combination as defined in claim 1, wherein the cover is
glued to the case.
9. The combination as defined in claim 3, wherein the cover is
sonically welded to the case.
10. The combination as defined in claim 3, wherein said channels
are defined by opposed front and back walls, said front wall and
said terminal anchor portion having aligned holes, and said
terminal locking means including primary terminal locking pins such
that when the cover is in closed position relative the case said
locking pins enter the holes of said channel walls and anchor
portions to lock the terminals in place on the bobbin.
11. A power pack for use with a small electrical appliance to
reduce line voltage and provide a low operating voltage, said power
pack comprising a transformer subassembly enclosed within a case
and cover assembly from which project primary terminals for
plugging into a wall outlet and a secondary line cord or terminals
for connection to the appliance, said transformer subassembly
including a bobbin molded of electrical insulating material,
primary and secondary windings on the bobbin, secondary soldering
lugs anchored to the bobbin and connected to the secondary winding
and the secondary line cord, primary terminals carried in channels
formed in the bobbin connected to the primary winding, a laminated
iron core fastened to the bobbin and surrounding the windings,
insulating flanges integrally formed on the bobbin for insulating
the laminated core from the primary terminals and the secondary
lugs, locating holes in said laminated core, said case and cover
assembly including means coacting with said laminated core locating
holes to orient the subassembly within the case and cover assembly,
said cover including openings for the primary terminals to project
therethrough, and means on the cover coacting with the bobbin to
lock the terminals in the channels and inhibit movement
thereof.
12. The combination as defined in claim 11, wherein said
subassembly orienting means includes locating pins extending from
the case and cover.
13. The combination as defined in claim 11, wherein said
subassembly orienting means includes rivets extending through said
case and cover and which also locks the cover and case
together.
14. The combination as defined in claim 11, wherein said
subassembly orienting means includes rivet holes in the case and
cover, and rivets extending through the holes and the laminated
core locating holes to orient the subassembly and lock the cover
and case together.
Description
This invention relates in general to a power pack for reducing line
voltage and for providing alternating current, direct current or
battery charger operation, and more particularly to a power pack
that is uniquely constructed to enable it to be inexpensively
manufactured while at the same time meeting the stringent
requirements of Underwirters' Laboratories approval.
The use of power packs is becoming more popular for small
appliances where it is desired to operate the appliance at a
voltage substantially lower than line voltage or by battery. For
example, power packs for small appliances are presently being
marketed where the 110 volt AC line voltage is reduced to 12 volts
and rectified to provide DC voltage. Another example of power pack
usage is where nickel cadmium batteries are employed for powering
small appliances and a need to recharge the batteries from time to
time requires the use of a line voltage operated battery charger
power pack. The reduction of voltage to a lower level by use of a
power pack is significant to assist in obtaining Underwriters'
Laboratories approval on appliances.
While domestically made power packs are presently available, their
cost is too high to compete with foreign-made units. The main
reasons of high cost reside in labor costs caused by taping,
staking, gluing and potting operations necessitated to provide a
power pack unit that will meet Underwriters' Laboratories
approval.
The power pack of the present invention is unique in that it
eliminates the above-mentioned costly operations, and provides an
assembly that can be quickly and easily put together and which will
ultimately pass Underwriters' Laboratories tests. While the power
pack of the invention merely includes the well known transformer in
a casing, it is unique in the construction of the bobbin and the
casing to facilitate ease of assembly and to eliminate certain
procedures which are costly, while at the same time satisfying the
rigorous standards of Underwriters' Laboratories. In this respect
the bobbin is initially formed to eliminate certain heretofore
necessary taping operations. Further, the terminals are mounted and
associated with the bobbin in such a way as to eliminate staking or
gluing operations. Finally, the transformer assembly is enclosed
with a housing to eliminate potting and gluing operations, and the
housing is constructed to permit assembly by use of sonic welding,
gluing or riveting. The power pack circuitry may be such as to
reduce line voltage, charge batteries, or change input frequency
from 60 Hz. to DC or pulsating DC.
It is therefore an object of the present invention to provide a new
and improved power pack for alternating current, direct current, or
battery charger applications which is simple in construction and
inexpensive to assemble, while at the same time satisfying
Underwriters' Laboratories requirements.
Another object of this invention is in the provision of a power
pack that can be easily and inexpensively assembled in a case
without the need for taping, staking, gluing or potting
operations.
Other objects, features and advantages of the invention will be
apparent from the following detailed disclosure, taken in
conjunction with the accompanying sheet of drawings, wherein like
reference numerals refer to like parts, in which:
FIG. 1 is a perspective view of the power pack according to the
invention and illustrating in phantom a hair clipper that may be
connected to and operated by the power pack as one example of
usage;
FIG. 2 is a side elevational view of the transformer subassembly
for the power pack and illustrating particularly the transformer
bobbin;
FIG. 3 is a bottom plan view of the transformer subassembly of FIG.
2 with the primary terminals omitted for purposes of clarity;
FIG. 4 is an end elevational view of the transformer subassembly of
FIG. 3 and looking in the direction of the arrows 4--4 of FIG.
3;
FIG. 5 is an end elevational view of the transformer subassembly
and looking in the direction of the arrows 5--5 of FIG. 3;
FIG. 6 is a top plan view of the power pack case into which the
transformer subassembly is placed;
FIG. 7 is a vertical sectional view taken substantially along line
7--7 of FIG. 6;
FIG. 8 is an end elevational view of the power pack case looking
generally along line 8--8 of FIG. 6;
FIG. 9 is an enlarged detail elevational view of a transformer
locating pin in the power pack case and looking generally along
line 9--9 of FIG. 6;
FIG. 10 is a top plan view of the cover for the power pack
case;
FIG. 11 is a bottom plan view of the cover;
FIG. 12 is a side elevational view of the cover looking in the
direction of the arrows 12--12 of FIG. 11;
FIG. 13 is an end elevational view of the cover and looking in the
direction of the arrows of line 13--13 of FIG. 11;
FIG. 14 is a somewhat diagrammatic view of the trans-former
subassembly which is to be mounted in the power pack case;
FIG. 15 is an enlarged detail view taken along line 15--15 of FIG.
14;
FIG. 16 is a vertical sectional view taken through the power pack
case and illustrating the transformer subassembly in place within
the case but omitting the line cord;
FIG. 17 is a view similar to FIG. 4 but illustrating a modified
form of locking pins for locking the terminals in place on the
bobbin; and
FIG. 18 is a longitudinal sectional view of a modification where
the cover is riveted to the case.
Referring now to the drawings and particularly to FIG. 1, the power
pack of the invention, generally designated by the numeral 20, is
illustrated as having primary terminals 21 adapted to be insertable
in a standard electrical wall outlet, and a secondary cord 22
having a plug 23 adapted to engage terminals of a small electrical
appliance such as a hair clipper 24 which is shown in phantom. The
power pack, when used for an electrical appliance functions to
reduce the wall outlet voltage to a lower voltage which eliminates
the possibility of incurring dangerous electrical shock from the
appliance. For example, where the wall outlet voltage would be 110
volts AC, the voltage preferably is reduced to about 12 volts.
Additionally, the voltage may remain as alternating current voltage
or be rectified to provide direct current voltage. It should
further be appreciated that the power pack may be constructed to
charge a battery, such as a rechargeable nickel cadmium
battery.
The invention relates to the power pack construction where a molded
electrical insulating plastic case and cover encloses a transformer
subassembly. The case, generally indicated by the numeral 30, FIGS.
6-8, after having the transformer subassembly 31, FIGS. 2-5 and 14,
inserted therein, is closed by the cover 32 which is welded, glued,
riveted, or otherwise secured to the case. Because of the structure
of the transformer bobbin and the cover, taping, staking, gluing
and encapsulating are eliminated, thereby greatly reducing the
overall cost of the power pack.
The transformer subassembly includes a bobbin 35 molded of a
suitable electrical insulating plastic, such as nylon, Delrin or
the like. The bobbin supports the transformer windings, the
transformer core, secondary terminals and primary terminals.
As seen particularly in FIGS. 2-5, the bobbin includes a hollow
rectangular in cross section body 36 having winding flanges 37, 38
and 39. The primary winding 40 is wound between flanges 38 and 39
and terminates in primary leads 41, while the secondary winding 42
is wound between the flanges 37 and 38 and terminates in secondary
leads 43. A laminated frame or core 44, shown in phantom in FIGS.
2-5, surrounds the bobbin and the windings and also extends through
the center of the bobbin body 36 to magnetically couple the
windings, and is provided with pin locating holes 45 to facilitate
the mounting of the transformer in the case and cover and thereby
inhibit movement therein.
Insulating flanges 50 and 51 are integrally formed on the bobbin
and extend from opposite ends parallel to the iron core 44 and
extend along one side of the iron core ends to insulate the iron
core from the lugs and terminals, thereby eliminating the need to
apply insulating taping or other insulating material to the
subassembly. Holes 52 and 53 are formed in the flanges 50 and 51,
respectively, to align with the pin locating holes 45 of the
laminations so that locating pins can extend into the pin locating
holes of the core from the flange side of the laminations.
The winding flange 37 is of increased thickness at the lower side
and also includes lug sockets for receiving anchoring ends 55 of
secondary lugs 56. The lugs are provided with lead connecting tabs
57, to which the secondary winding leads 43 and the secondary cord
leads are attached, such as by soldering prior to insertion of the
transformer subassembly into the case 30. Accordingly, the lugs 56
are of a suitable electrical conducting metal and serve to couple
the secondary winding leads to the secondary cord leads.
The primary terminals 21 include prongs 60 which engage in a wall
outlet, anchoring portions 61 extending at right angles to the
prongs, and soldering tabs 62 extending at right angles from the
prongs and onto which the primary leads of the primary winding may
be soldered. Channels 63 are formed in the bobbin 35 for receiving
the anchoring portions and a part of the prongs of the primary
terminals when the primary terminals are mounted on the bobbin.
Each channel 63 includes a section 63a into which the anchoring
portion 61 of the terminals is inserted, and a section 63b
extending at right angles to the section 63a and into and through
which the prongs 60 are inserted. The channel section 63a is
defined by a rear wall 64 and a front wall 65. The rear wall 64 is
a part of the insulating flange 51 which insulates the terminals
from the laminations 44. Openings 66 are defined in the bobbin for
receiving the soldering tabs 62 and providing room so that the
primary leads of the primary winding may be wound around the tabs
and soldered thereto. As will be more clearly explained hereafter,
when the transformer subassembly is assembled with the case and
cover, the front wall 65 is forced toward the back wall 64 so as to
frictionally grip the terminal anchor portions 61 and hold the
terminals against undesirable movement when they are being inserted
into and withdrawn from a wall plug. It is not necessary to stake
the terminals in any fashion when mounting and securing them in
place on the bobbin and within the case and cover.
The transformer subassembly illustrated in FIG. 14 which is
essentially ready to be mounted into a case and cover subassembly
includes a plurality of diodes 69 connected between the secondary
lugs 56 and the secondary leads 22a and 22b of the secondary cord
22 to provide four-way rectification of the AC output from the
secondary winding of the transformer. It should be appreciated that
if it was desired only to step down the AC voltage, the rectifying
diodes 69 would not be needed. Likewise, the transformer circuitry
may be otherwise revised as required.
The case 30 includes a bottom wall 71, opposite upstanding side
walls 72, and front and back walls 73 and 74. In order to
facilitate molding procedures, all of the walls have some taper
outwardly toward the upper open end. A partition wall 75 extends
between the opposite side walls and adjacent the front wall 73 to
define a transformer chamber 76 and a diode chamber 77. Within the
diode chamber 77 upstanding walls 78, 79 and 80 coact with the
front wall 73 to provide a cord strain relief section. At the upper
end of the front wall 73 a short extension 81 is provided and which
defines a cord groove 82 through which extends the secondary
cord.
Within the transformer chamber 76 a rectangular upstanding
supporting ridge 83 forms the bottom of the laminations which
support the bobbin and windings within the case as shown in FIG.
16. Locating pins 84 are formed on the ridge 83 and adapted to
receive the locating holes 45 of the laminations so as to properly
locate the transformer subassembly within the case 30 as
illustrated in FIG. 16. Following the mounting of the transformer
subassembly within the case 30, the cover 32 may then be mounted in
place. To facilitate mounting the cover on the case, a peripheral
notch 85 is formed along the upper outer periphery of the
upstanding walls.
The cover 32 is essentially flat and provided with a peripheral
skirt 90 which coacts with the peripheral notch 85 of the case
during assembly of the cover onto the case. Primary terminal prong
openings 91 are provided in the cover and through which the primary
terminal prongs 60 extend. Transformer locating pins 92 are
provided on the cover for engaging in the locating holes 45 of the
transformer laminations. Shoulders 93 are defined with the pins 92
for bottoming on the laminations and for maintaining the
transformer subassembly in tightly arranged relationship within the
case and cover when the cover has been secured onto the case. A
strain relief lug 94 extends from the cover to coact with the walls
78, 79 and 80 and fully define the cord strain relief.
A pair of terminal locking pins or pressure pins 96 extend from the
cover 32 for abutting the walls 65, FIG. 4, to drive the walls 65
toward the walls 64 and lock the primary terminal anchoring
portions firmly in place and also enable the terminals to sustain a
sufficient amount of pull so that the power pack can pass
Underwriters' Laboratories approval. A short extension 97 extends
from one end of the cover and includes a cord groove 98 to coact
with the cord groove 82 on the case and define a cord hole for the
secondary cord. The cover is preferably secured to the case by
sonic welding. However, it may be secured in place by gluing, or by
riveting as hereinafter described.
An alternate form of locking the primary terminals in place on the
bobbin is shown in FIG. 17, wherein the pressure or locking pins
100 extending from the cover are slightly longer than the pins 96
and are formed to pass through holes 65a formed in the walls 65 and
holes 61a formed in the terminal locating pins 61. The pins 100
seat against the wall 64 which coacts with wall 65 to form the
channel 63a.
The embodiment of FIG. 18 differs from the other embodiments in
that it illustrates how the cover member may be riveted to the
case. The case is generally identified by the numeral 110, while
the cover is generally identified by the numeral 111. The case 110
differs in construction from the case 30 in that the locking pins
84 of case 30 are omitted and rivet holes 112 are formed in the
upstanding supporting ridge 83a to align with the locating holes 45
of the transformer core 44 when the transformer subassembly is
positioned within the case. Similarly, the locating pins 92 on the
cover member 32 are omitted and the cover 111 is provided with
rivet holes 113 in the pin bases 92a which align with the locating
holes 45 of the transformer frame 44 when the cover is in place on
the case. Rivets 114 then extend through the rivet holes and
transformer core locating holes. The rivets are provided with heads
on one end and then rolled over at the other end to lock the cover
on the case. Recesses are provided in both the cover and case so
that the rivet heads and rivet rollover portions are recessed below
the cover and case surfaces.
It will be understood that modifications and variations may be
effected without departing from the scope of the novel concepts of
the present invention, but it is understood that this application
is to be limited only by the scope of the appended claims.
* * * * *