The present invention relates to an electric heater assembly for supporting an electrical heating element and in particular it relates to a clothes dryer having such a heater assembly.
Electric clothes dryers typically provide for warmed air flow through a rotating drum to remove moisture from clothing articles tumbling in the drum. The air is warmed by passing over energized electrical heating elements supported within a heater housing. In one construction of electrical clothes dryers, the rotating drum is closed at one end by a rear end head. This rear end head is provided with a pattern of apertures through which air passes into the rotating drum. In one embodiment, the rear end head rotates with the drum and in another embodiment the rear end head remains stationary while the cylindrical outer wall of the drum rotates.
A heater assembly is typically mounted within the dryer adjacent the rear end head of the drum. In the embodiment where the rear end head rotates with the drum, the heater assembly has been known to comprise a circular stationary rear support wall mounted to the rear wall of the dryer. This circular stationary wall typically has a peripheral flange that extends towards the rear end head of the drum and that is spaced from the rear end head to provide an air gap. A housing is formed between the rear end head, the rear support wall and the peripheral flange. In the past, an electrical heating element in the form of a helical coil has been mounted to the rear support wall of the clothes dryer assembly. This mounting has been accomplished by the use of metal brackets with insulators attached to the rear support wall, or more recently, by ceramic brackets attached to the rear wall of the housing. The brackets have typically been placed in two arcuate patterns whereby the coils are stretched from bracket to bracket forming a generally arcuate shape. While this heater arrangement has been quite effective, the assembly of the brackets onto the rear wall and then subsequent stretching of the heater coils onto the brackets about the heater rear wall is a relatively labour intensive operation. Further, in certain instances the number of coil rotations between brackets may not be consistent due to human operator error. This has been known to result in an uneven heat distribution.
In other heater assembly embodiments, it is known to mount coils to mica support insulating plates. Further, it is known to support a zigzag configured electrical heating element also known as meander-shaped windings. Such a heater configuration is disclosed in U.S. Pat. No. 4,845,345 issued Jul. 4, 1989. In this configuration, zigzag heating elements extend outwardly between apertures in a first mica plate. The first mica plate is secured to a second mica plate and portions of the heating element are held in place between the first and second mica plates. While this configuration results in a highly stable heating element which is simple to manufacture, this heating element configuration does not lend itself readily to use in electric clothes dryers.
The present invention relates to an electric heater assembly for supporting an electrical heating element. Preferably, this heater assembly is adapted for use in a laundry clothes dryer. In a preferred clothes dryer embodiment, the heater assembly has at least one arcuate shaped support plate made of an insulation material that supports the electrical heating element. The support plate has a series of inner and outer notches cut into its inner and outer side edge portions. The support plate is adapted to be mounted to a housing support wall also forming a part of the electric heater assembly. The housing support wall has a first inner and second outer series of tab members that extend along respective arcs. Each of the tab members has a flap portion that is spaced from the housing support wall. The flap portions or members align with the inner and outer notches of the support plate allowing the support plate to be positioned against the housing support wall. The support plate may then be rotated relative to the housing support wall so that the flap members engage and hold the support plate relative to the housing support wall. The assembly of the heater element with respect to the support plate and the subsequent in shop assembly of the support plate relative to the housing support wall is relatively simple and efficient when compared to the use of prior art insulating brackets.
The insulation material for the arc-shaped support plate may comprise any suitable insulation material which can be formed into a plate. The preferred insulation material of the present invention is mica. It should be understood that other ceramic materials may be satisfactory.
The housing support wall in one embodiment may be mounted vertically in a clothes dryer such that the electrical heating assembly is mounted in the dryer adjacent a rear end head that closes off an end portion of the rotating drum in the dryer.
In accordance with an embodiment of the invention there is provided an electric heater assembly for supporting an electrical heating element in a clothes dryer having a rear panel. The electric heater assembly comprises at least one support plate and a housing support wall. The at least one support plate comprises an electrical insulation material for supporting the electrical heating element. The support plate comprises side edge portions respectively including notches spaced along the side edge portions. The housing support wall is mounted to the rear panel of the clothes dryer and comprises tab members extending therefrom. The tab members each comprise flap members spaced from the housing support wall. The flap members are positioned to respectively align with the notches of the support plate to permit the support plate to be positioned relative to the housing support wall and to slide relative to the housing support wall so that each of the flap members overlappingly engages in and holds the at least one support plate relative to the housing support wall.
In accordance one embodiment of the invention there is provided an electric heater assembly for supporting an electrical heating element. The heater assembly comprises at least one arcuate shaped support plate and a housing support wall. The support plate comprises an electrical insulation material for supporting the electrical heating element. The support plate comprises inner and outer concentrically curved side edge portions respectively including inner and outer notches spaced along the respective inner and outer concentric curved side edge portions. The housing support wall comprises a first series of spaced apart inner tab members extending therefrom and positioned along a first arc, and a second series of spaced apart outer tab members extending from the housing support wall and positioned along a second arc concentric with and radially outward of the first arc. Each of the first and second tab members has a flap member spaced from the housing support wall. The flap members of the inner and outer tab members are positioned to respectively align with the inner and outer notches of the support plate to permit the support plate to be positioned relative to the housing support wall and to be rotated relative to the housing support wall so that each of the flap members overlappingly engages at least one of the support plates so as to hold the support plate relative to the housing support wall.
For a better understanding of the nature and objects of the present invention reference may be had by way of example to the accompanying diagrammatic drawings in which:
The present invention relates to an electric heater assembly for supporting an electrical heating element and in particular it relates to a clothes dryer having such a heater assembly. Referring to
Motor 28 draws or rotates fan 30 to draw the air 20 through the drum 12. The motor 28 through pulley 35 and belt 33 also causes the rotation of the dryer drum 12. In an alternative embodiment, separate motors may be used to rotate the fan 30 and the drum 12.
A heater assembly 32 is mounted by suitable bolts 34 to the rear panel 16 of the dryer 10. The heater assembly 32 is positioned adjacent the end head 22 to define a heater housing 25. The heater assembly 32 has a housing supporting wall 36 that is spaced from the rear end head 22.
The heater assembly 32 has an upstanding outer peripheral wall or flange portion 44 that extends around the periphery of the housing support wall 36. The flange portion 44 is angled approximately at 90° to the housing support wall 36. The flange portion 44 further extend towards the rear end head 22. An air gap 46 extends between the flange portion 44 and the rear end head 22 of the dryer drum.
Zig-zag configured heating elements 48 are mounted via support plate assembly 50 to the housing support wall 36 of the heater assembly 32 in a manner described in more detail hereinafter. The heating elements 48 are connected to a source of electrical supply through terminals. When electrical energy is fed via the terminals to the heating elements 48, the elements dissipate heat and warm air passing over and around the elements 48. The warmed air subsequently enters the drum 12 through openings 23 in the rear end head 22 to dry articles and clothing contained in the drum 12.
A spacer 38 is mounted to heater housing 34 inwardly adjacent the support plate assembly 50. The spacer 38 keeps rear end head 22 from contacting heating elements 48 in the event the drum 12 shifts within the cabinet of the clothes dryer 10 due to mishandling during shipment.
Referring to
The housing support wall 36 has a first series of spaced apart inner tab members 54. The inner tab members 54 are cut and pushed out from the main wall portion 40. It should be understood that in an alternative embodiment, the tab members 54 may be separate parts secured by suitable means such as, for example, bolts or screws to the main wall portion. The inner tab members 54 are positioned along a first arc represented by dashed line 56. The housing support wall 36 has a second series of spaced apart outer tab members 58. The outer tab members 58 extend inwardly from the outer peripheral flange portion 44. The outer tab members are cut and pushed in from the peripheral flange portion 44. In an alternative embodiment the outer tab members 58 may comprise separate pieces that are fixed to the outer peripheral portion 44 by suitable means such as, for example, screws. In still yet another alternative embodiment the outer tab members 58 may extend from the main wall portion 40 of the housing support wall 36 in a manner similar to that shown for the inner tab members 54. The outer tab members 58 are positioned along a second arc 59 following the circumference of the flange portion 44. This second arc is not a true arc in view of the fact that the outer peripheral flange portion 44 is not in a true circle shown in
The housing support wall 36 further includes at least one first limiting tab member 62 having a corresponding flap member 64 that is spaced from the housing support wall 36 and, as shown, form the main wall portion 40. The housing support wall 36 further comprises a second limiting tab member 66. The purpose of the limiting tab members 62 and 66 will be described in more detail hereinafter.
The housing support wall 36 further includes raised bosses 70 shown spaced about the main wall portion 40 between the first and second arcs 56, 59. Alternatively, the raised bosses 70 may only have upper surface portions that are positioned between the first and second arcs 56, 59.
Referring now to
The construction of the supporting plates may comprise any suitable insulating ceramic material and preferably, is a mica material. The mica material provides for good electrical insulating properties however, the mica is subject to expansion and contraction as it is heated and cooled with the energization and deenergization of the heating elements 48.
As shown in the drawings the first and second, or upper and lower, support plates 74, 76 each comprise inner and outer concentrically curved side edge portions 90 and 92 respectively. These side edge portions 90, 92 each include a plurality of inner and outer notches 94, 96 spaced along respective inner and outer concentric curved side edge portions 90, 92. The notches are shown to have angled edges.
In
Referring to
It should be understood that some radial play exists, as well as axial play, between the support plates 74, 76 and all the tab members 54, 56, 62 and 66. This limited play permits the expansion and contraction of the support plates 74, 76 as they are heated and cooled with the energization and deenergization of the heating element 48. Hence the overlapping engagement referred to herein is a loose engagement.
Further, the flaps 60 hold the support plates 74, 76 against the raised boss portions 70 (see
As shown in
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the present invention as disclosed herein.
Number | Date | Country | Kind |
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2,594,248 | Jul 2007 | CA | national |