Note: Descriptions are shown in the official language in which they were submitted.
2080085
sackaround of the Invention
This invention relates to heater assemblies for use in
clothes dryers and, more particularly, to an improved heater
assembly in which is easier to fabricate and simpler to install.
In the manufacture of clothes dryers for household or
commercial use, a heater assembly is usually fabricated by a
supplier at his manufacturing site. Completed assemblies are
then shipped to the appliance manufacturer where they are
installed in the dryer as part of the assembly process. During
this installation, the heater assembly is first installed in a
mounting fixture and the fixture then installed in the dryer.
Heater assemblies comprise coils of open heating wire mounted on
insulators which, in turn, are supported on wire rods. A set of
electrical terminals are attached to the ends of the wire for
insertion in an appropriate receptacle or socket. While a heater
assembly is not flimsy, neither is it particularly rugged. As a
practical matter therefore, the more a heater assembly is
handled, the greater the risk it may become damaged and unusable.
In addition to the above, it is also disadvantageous to
have so many parts required for the installation of the heater
assembly. Besides the cost of the parts, the more parts there
are, the more assembly time is probably required to manufacture
an assembly. Added cost factors include enhanced inventories,
etc. It thus would be beneficial to eliminate as many parts as
possible, particularly if in doin~ so a way could be found to
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also make a heater assembly less vulnerable to damage, for
example, during shipment and installation.
Summary of the Invention
Among the several.objects of the present invention may
be noted the provision of a heater assembly for use in an
appliance such as a clothes dryer; the provision of such an
assembly which becomes part of a heating unit installed in the
appliance rather than simply another part thereof; the provision
of such an assembly which is readily interfaced with the heating
unit to produce a unit which is readily installable in the
appliance: the provision of such a heater assembly to facilitate
a heating unit requiring fewer parts than prior units installable
in the same type appliance; the provision of such a heater
assembly which simplifies assembly of the heating unit prior to
installation; the provision of such a heater assembly to use
conventional insulator assemblies, or new integral insulator
assemblies; the provision of such a heater assembly in which the
potential of damage to a heater coil is reduced because handling
of the assembly is greatly reduced; and, the provision of such a
eater assembly which is designed to conform to a support
structure within the appliance to provide an improved fit of the
unit within the appliance and reduce potential damage which might
occur when the appliance is moved.
In accordance with the invention, generally stated, a
heating unit installable in a clothes dryer has first and second
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sections which fit together to form the unit. A heater assembl~
for the heating unit comprises an open coil heating element, and
a plurality of insulators to each o4 which two or three
convolutions of the coil are attachable. A support is provided
on which the insulators are mounted in a spaced relation from
each other. The insulators and support together form an
insulator assembly installable in the unit. The support includes
a flat plate section on which the insulators are mounted and side
pieces which attach the insulator assembly to a sidewall of one
of the sections thereby to mount the heater assembly in the
unit. Other objects and features will be in part apparent and in
part pointed out hereinafter.
Brief Description of the Drawings
Fig. 1 is a schematic representation of the present
invention in use in a clothes dryer;
Fig. 2 is a perspective view of an assembled heating
unit ready for installation in the clothes dryer;
Fig. 3 is a perspective view of the heating unit of Fig.
2 with a heating assembly of the present invention being
installed therewith;
Fig. 4 is an end view of the heater assembly;
Fig. 5 is a plan view of the heater assembly;
Fig. 6 is a side elevational view of the heater assembly;
Fig. 7A and Fig. 7B are elevational views of respective
insulators used in the heating assembly;
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Fig. 8 is a plan view of support on which insulators are
mounted:
Fig. 9 is a perspective view of an alternate embodiment of
the heater assembly;
Figs. 10 and 11 are respective plan and elevational views
of a shallow pan heating unit section with a heater assembly
installed;
Fig. 12 on the same sheet as Fig. 1 is a perspective view
of another insulator support structure installable in the
section of Figs. 10 and 11; and,
Fig. 13 on the same sheet as Fig. 9 is a plan view of
another support structure installable in the section of Figs. 10
and 11.
Corresponding reference characters indicate corresponding
parts throughout the drawings.
Description of Preferred Embodiments
Referring to the drawings, an appliance such as a clothes
dryer is indicated generally D. The dryer has a tub U in
which articles A of clothing, towels, or other articles to
be dried are placed. A heating unit H is ins~alled in the
appliance on one side of the tub, and a blower assembly B on
the other side thereof. The heating unit includes a heater
assembly 10 which is described in more detail hereinafter.
Blower B includes a blower motor M by which air is drawn
into an air inlet I of the heating unit. This air is
heated by heater 10 as it flows through the heater
assembly. Tha air exits the heating unit at its upper end
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through holes or perforations P formed in the outer shell S of
the unit. The heated air is then drawn through the tub and over
the articles to dry them, the heated air entering and exiting the
tub through openings O formed in an outer wall W of the tub. The
air is then discharged from the appliance after passing through
the blower. As shown in Fig. 1, the heating unit is a vertically
oriented unit in which the heater assembly is fitted into the
lower end of the unit. The unit is designed to fit between inner
and outer supports X and Y raspectively. The unit has a flange F
(see Figs. 2 and 3) which abuts against support X and are
attachable to it by bolts. The outer support has a series of
indentations Z vertically spaced from one another. The outer
shell of the heating unit (including heater assembly 10) is
contoured to matingly fit in these indentations and insure a snug
fit of the heating unit in the appliance.
Heating unit H is shown in more detail in Figs. 2 and
3. In Fig. 2, the unit is shown with the heater assembly 10 in
place, and in Fig. 3 with the heater assembly positioned for
installation prior to installation of the unit in the dryer. The
unit has a first shell section Sl and a second shell section S2.
When connected together, the upper end of the unit (as viewed in
Fig. 1) is a closed end and the other (lower) end is an open
end. Section Sl extends the entire length of the unit; while
section S2 terminates at a point intermediate the length of the
unit. When attached to each other, the sections define a hollow
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enclosure through which air is drawn. The enclosure is generally
rectangular in cross-section with rounded corners corresponding
to the curvature of the shell sections. As noted, perforations
(not shown) are formed in the upper end of section Sl for heated
air to escape the unit into the tub. Section S2 has rounded
protruberances P shaped to conform to the indentations X to fit
the unit in place in the dryer. The sections also have mating
flanges F1 and F2 respectively for joining the sections together.
As noted, heater assembly 10 is connected to the heating
unit at the lower end of section S2. Previously, the heating
unit required a separate installation of a heater assembly within
the unit. This not only complicated the design of the heating
unit but also that of the heater assembly. Assembly of the
heating unit took longer than is now require with the heater
assembly of the present invention, thus increasing the cost of
the appliance.
Referring to Figs. 4-6, heater assembly 10 is shown in
more detail. The assembly first includes an least one open coil
heating element 12. The coil is arranged to extend
longitudinally of the assembly. An insulator assembly 14
includes a plurality of insulators 16 mounted, in a spaced
relationship, on a support member 18. Two insulator assemblies
14A, 14B are shown in the drawings, although it will be
understood that more or fewer insulator assemblies could be
used. Various types of insulators can be used with the insulator
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assembly. Shown in Figs. 7A and 7B are respective insulators 16A
and 16B. Shown in Fig. 8 is a support 20 on which the insulators
are mounted. Support 20 includes a flat, metal plate 22 in which
spaced openings 24A-24C are formed. Further, plate 22 may have
stiffener beads 2S extending lengthwise of the support. If
present, both of these beads, which are formed in a punching
operation can extend in the direction (up or down) or one in each
direction. Each insulator has opposed, centrally located slots
26A, 26B respectively. To install an insulator in the support,
the insulator is inserted through the opening and the respective
slots fitted into the edge of the support adjacent the opening.
This is effected by positioning the insulator parallel to the
longitudinal axis of the support. Once positioned, the
insulators are twisted in the openings until they are orthogonal
to the longitudinal axis. This is the position of the insulators
shown in Figs. 4 and 5. The insulators have respective notches
28A, 28B formed on each side of their upper and lower ends. A
separate convolution of coil 12 is received in each notch for the
insulators to support the upper and lower reaches of the coil as
it is installed in the assembly. Again, it will be understood
that while coil 12 is shown to have three upper and three lower
reaches in the Figs., the heater assembly could have a different
configuration in which the coil has more or fewer reaches. In
addition to the insulator assembly described above, heater
assembly 10 can also employ an insulator assembly in which the
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insulators and support are formed of a compatible, ~usible
material which allows the insulators and support to be fused
into an integral assembly. Such an insulator assembly is
disclosed in co-pending United States patent application 774,715
which is assigned to the same assignee as the present
application.
The insulator assembly is installable in a pan 30. The
pan has sidewalls 32A, 32B, and a base 34. The sidewalls have
spaced, horizontal slots 36 in which tabs 38 formed at each end
of the supports 22 are received. One end of the support has a
95- bent tab inserted into a slot at an angle, then brought back
parallel with the bottom of the pan locking the bent tab and
enabling the other differently designed tab to be inserted into
the opposite slot. After insertion, this tab is twisted or bent
to lock the insulator assembly in place. As seen in Figs. 4 and
6, coil 12 extends beyond the upper end of the sidewalls. As
shown in Figs. 4 and 5, a terminal block 40 i8 mounted in
sidewall 32B. The block extends vertically of the sidewall and
has two terminals 42A, 42B for electrically connecting the
heater assembly into a heating circuit of the appliance. The
respective ends 44A, 44B of coil 12 are connected to the
terminal block to connect coil 12 in the heating circuit.
Pan 30 iB generally U-shaped in cross-section. The ends
of pan 30 are open, and the heater assembly, when installed,
helps define the open end portion of the heating unit. The
upper end of each sidewall is outwardly turned to form respective
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flanges 46A, 46s. These flanges interface with flange Fl of the
heating unit when the heater assembly is installed. Each flange
has a screwhole 48 which registers with a corresponding screwhole
in flange Fl. Screws 50, insertable through the screwholes, help
connect the heater assembly to the heating unit once the heater
assembly is installed. It will be noted that the length of the
flanges 46A, 46B are less than the length of the pan. The
section of the pan along which these flanges do not extend forms
a lip 52 which is insertable beneath the back edge 54 of heating
unit section S2. To install the heater assembly 10 with the
heating unit, heater assembly is positioned as shown in Fig. 3 to
the rear of section S2. The heater assembly is held at an angle
with respect to the heating unit so lip 52 is beneath the back
edge of section S2. Heater assembly 10 is then pushed forward so
the lip extends along the inside of the section until the flange
portion of the pan sidewalls abut against back edge 54. The
screwholes 48 on the flanges should then align with the
screwholes in flange Fl and the screws 50 are then inserted to
attach the heater assembly to the unit.
It is a feature of the heater assembly that pan 30 be
contoured so to facilitate installation of the heating unit in
the appliance. For this purpose, pan 30 has three, parallel,
hump shaped protruberances 56A, 56C extend orthogonally to the
longitudinal axis of the pan. This humps are spaced along the
length of the pan with hump 56A being at the end of the pan
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adjacent section S2, hump 56B slightly rearward thereof, and hump
56C adjacent the opposite end of the heater assembly. Each hump
begins at one sidewall of the pan, extends along the base of the
pan, and terminates at the other sidewall. In addition, a
protruberance 58 extends from hump 56A rearwardly of the pan to a
point just short of hump 56C. This protruberance also extends
from one sidewall of the pan to the other across the base of the
pan. It subsumes the portion of hump 56B which extends across
the base of the pan. As previously mentioned, and as shown in
Fig. 1, the purpose of the humps is to provide a snug fit of the
heating unit into the appliance, wherein the support Y has a
corresponding contoured surface into which the humps fit. This
makes it difficult to dislodge the installed heating unit either
during movement of the appliance from one place to anather, or by
~ibrations which occur during normal use.
What has been disclosed is a heater assembly which
becomes an integral part of an installed heating unit. In prior
appliance applications, a heater assembly was installed within a
heating unit, not as part of it. This construction required more
components, took longer to make, and was not as reliable as the
heater assembly of the present invention. The disclosed heater
assembly further can take advantage of advances in insulator
assembly construction to further increase its reliability.
Referring now to Figs. 9-13, alternate embodiments of
the heater assembly are shown. With respect to Fig. 9, section
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S1' of a heating unit H' has a deeper pan than the other section
of the heater (not shown). A heater assembly 60 is directly
installable into section S1' adjacent the open end of this
section.
Assembly 60 first includes an least one open coil
heating element 62. The coil extends longitudinally of the
heating unit when the heater assembly is installed in section
S1'. An insulator assembly 64 (three of which are shown in Fig.
9) includes a plurality of insulators 66 mounted, in a spaced
relationship, on a support member 68. It will be understood that
more or fewer insulator assemblies could be used. Again, various
types of insulators, such as those shown in Figs. 7A and 7B,
could be used with the insulator assemblies. The support 68
shown in Fig. 9 includes a flat, metal plate 70 in which spaced
openings 72 are formed. The openings are identical to the
openings 24A-24C described with respect to support 22 of the
previous embodiment. The insulators are installed on the support
in the manner previously described, and separate convolutions of
coil 62 are fitted in the respective notches formed in the
insulators. With three insulators mounted on the respective
plates 70, the heater assembly will have three courses extending
both above and below the plates. Again, more or fewer insulators
could be mounted on each plate, and the number of courses would
change accordingly. It will be understood that an integral
insulator assembly such as disclosed in co-pending
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application 774,7l5 could be used in this embodiment.
In Fig. 9, the plates 70 are shown to have a flat,
central section 74 in which the openings 72 are formed, and
downwardly turned side pieces 76A, 76B which are narrower in
width than section 74. The side pieces taper in width from their
end joining section 74 to their distal end. Each side piece also
has an opening 78 in their distal end for attaching the insulator
assembly to a sidewall 80 of section Sl'. The overall width of
the insulator assemblies correspond to the inner width of section
Sl', for the insulator assemblies to fit within the section.
Attachment of the insulator assemblies to the sidewall can be
performed in any convenient manner. For example, the sidewall
can have openings 82 corresponding to the openings 78 in the side
pieces. A screw 84, bolt, or other fastener can then be used to
attach the insulator assembly to the sidewall. Or, the side
pieces can be welded to the inner face of the sidewalls.
As an alternative to the embodiment of Fig. 9, Figs. 10
and 11 illustrate a shallow pan section S2' of the heating unit
H'. Section S2' has a circumferential flange F2'. A heater
assembly 67' is for installation in this heating unit section.
Because of the shallowness of the pan, the heater assembly will
substantially extend above the sides of the section. This is
unlike heater assembly 60 in which generally covered by the
sidewalls of section Sl'.
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Referring to Fig. 12, the heater assembly 67 is shown to
have a support member 68' (three of which are shown in Figs. 10
and 11). Each member includes a plate 70' having a flat, central
section 74' in which openings 72A'-72C' are formed. The plate
also has side pieces 76A', 76B' which of narrower in width than
section 74'. At the lower end of each side piece is an outwardly
turned tab section 84A, 84B respectively. The tab sections each
have an inner portion 86A, 86B of the same width as the side
pieces, and an outer, narrower width section forming respective
tabs 88A, 88B. Openings corresponding to the width and thickness
of the tabs are formed in the sidewall of section Sl' and the
tabs fit into these openings to install the insulator assemblies
in place.
Regardless of which support member is used, the heater
assembly is installed in section Sl' of the heating unit prior to
mating of the other section of the heating unit with section
Sl'. Because the heater assembly is directly installable to
section S1', rather than on come other element which is then
installed in the heating unit, heater assembly 60 requires fewer
parts than previous heater assemblies required, and the heating
unit takes less time to assemble than previously.
In view of the foregoing, it will be seen that the
several objects of the invention are achieved and other
advantageous results are obtained.
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As various cnanges could be made in the above
constructions without departing from the scope of the invention,
it is intended that all matter contained in the above description
or shown in the accompanying drawings shall be interpreted as
illustrative and not in a limiting sense.
0196E/4369
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