Electric heating unit for clothes dryers

Claim 2

A heater box assembly for a laundry appliance such as an electrically heated clothes dryer, comprising: a first member having means for forming an air inlet for the laundry appliance; a second member attached to said first member to provide a box means having an enclosed heating chamber, said second member having means for forming an air inlet to the chamber; a heating means including a pair of insulators and a wire heating element wound about the insulators with adjacent turns being spaced from each other; and means for mounting said heating means in the heating chamber with a pair of insulators in spaced relationship and with the ends of each insulator protruding therefrom including biasing means for urging the pair of insulators away from each other thereby applying a tension on the wire to compensate for the thermal expansion of the wire; said mounting means including aligned cutout portions in each of said first and second members coacting together as the members are assembled to provide an aligned pair of apertures to receive the protruding ends of each of said pair of insulators with one of the pair of apertures maintaining one of the pair of insulators substantially rigid in said chamber and the other pair of apertures being shaped to enable relative movement of said other insulators away from the one insulator under the urging of said biasing means to maintain the wire heating element under tension.

Claim 3

A heater box assembly in accordance with clAim 1, wherein the wire heating element is of a material of an iron base.

Claim 4

A heater box assembly according to claim 1, wherein said biasing means comprises a pair of springs disposed on the outside of the heating chamber, each of said springs being anchored to the box means formed by said first and second members and attached to a protruding end of said other insulator so that said springs are removed from the heat generated by the wire heating element to prevent the deleterious effect of the heat thereon.

Claim 5

A heater box assembly according to claim 1, wherein said bias means comprises a resilient spring anchored to said box means and attached to the other of said pair of insulators.

Claim 6

A heater box assembly for a laundry appliance such as an electrically heated clothes dryer comprising: a first member having means for forming an air inlet for the laundry appliance; a second member attached to said first member to provide a box means having an enclosed heating chamber, said second member having means for forming an air inlet to the chamber; a heating means including a pair of insulators and a wire heating element wound about the insulators with adjacent turns being spaced from each other; and means for mounting said heating means in the heating chamber with a pair of insulators in spaced relationship including biasing means comprising a resilient spring anchored to said box means and attached to one of said pair of insulators for urging the pair of insulators away from each other thereby applying a tension on the wire to compensate for the thermal expansion of the wire, said means for mounting said pair of insulators comprising brackets attached to one of said first and second members, each of said brackets having a slot for receiving an end of said insulators, said brackets being arranged in pairs with the slots of one pair opening in a direction opposite to the slots of the other pair so that the resilient spring holds the other of said pair of insulators against the base of the slots of the one pair of brackets while the one insulator is urged away from the base of its slots of the other pair of brackets.

Claim 7

A heater box assembly for a laundry appliance such as an electrically heated clothes dryer comprising: a first member having means for forming an air inlet for the laundry appliance; a second member attached to said first member to provide a box means having an enclosed heating chamber, said second member having means for forming an air inlet to the chamber; a heating means including a pair of insulators and a wire heating element wound about the insulators with adjacent turns being spaced from each other; and means for mounting said heating means in the heating chamber with a pair of insulators in spaced relationship including biasing means comprising a resilient spring anchored to said box means and attached to one of said pair of insulators for urging the pair of insulators away from each other thereby applying a tension on the wire to compensate for the thermal expansion of the wire, said means for mounting said pair of insulators comprising brackets attached to one of said first and second members, each of said brackets having a slot for receiving an end of said insulators, said brackets being arranged in pairs with the slots of one pair opening in a direction opposite to the slots of the other pair so that the resilient spring holds the other of said pair of insulators against the base of the slots of the one pair of brackets while the one insulator is urged away from the base of its slots of the other pair of brackets.

Claim 8

A heater box assembly according to claim 1, wherein each of the insulators of said pair are cylindrical members provided with axially spaced fins to maintain separation between adjacent turns of the wire heating element thereon.

Claim 9

A heater box assembly according to claim 6, wherein each of said insulators has passageways extending between each of the axially spaced fins to enable the passage of air therethrough for cooling of said insulator.

Claim 10

A heater box assembly according to claim 1, wherein the means forming the inlet in the first member has a shape complementary to an opening in a wall of the laundry device and is adapted to snugly fit therein; and further including means for mounting the heater assembly in said opening comprising a tab disposed on said first member coacting with a slot adjacent the opening in the wall, and a fastening means disposed on said box a substantial distance from the coacting tab and slot whereby the heater box assembly is mounted in the opening by engaging the tab in the slot and then securing the fastening member to the wall of the laundry device.

Claim 11

A heater box assembly for a laundry appliance such an electrical heated clothes dryer, comprising: a first member having means for forming an air inlet for the laundry appliance; a second member attached to the said first member to provide a box means having an enclosed heating chamber, said second member having means for forming an inlet to the chamber; a heating means including a pair of insulators and a wire heating element wound about the insulator with adjacent turns being spaced from each other; and means for mounting said heating means in the heating chamber with the pair of insulators in spaced relationship, said means for mounting including biasing means for urging both of the insulators of said paiR in a direction away from each other thereby applying a tension on the wire to compensate for the thermal expansion of the wire.

Claim 12

A heater box assembly for a laundry appliance such an electrical heated clothes dryer, comprising: a first member having means for forming an air inlet for the laundry appliance; a second member attached to the said first member to provide a box means having an enclosed heating chamber, said second member having means for forming an inlet to the chamber; a heating means including a pair of insulators and a wire heating element wound about the insulator with adjacent turns being spaced from each other; and means for mounting said heating means in the heating chamber with the pair of insulators in spaced relationship, said means for mounting including biasing means for urging both of the insulators of said paiR in a direction away from each other thereby applying a tension on the wire to compensate for the thermal expansion of the wire.

Claim 13

A heater box assembly in accordance with claim 9, wherein said mounting means comprises resilient spring means attached to one of said first and second members and resiliently mounting each of said pair of insulators in the heating chamber.

Claim 14

A heater box assembly according to claim 1, wherein said mounting means disposes said heating means in the heating chamber with the flow of air substantially perpendicular to the direction of the wire heating element thereby eliminating hot spots on the heating element.

Claim 15

A heater box assembly for a laundry appliance such as an electrically heated clothes dryer, comprising: a first member having means for forming an air inlet for the laundry appliance; a second member attached to said first member to provide a box means having a heating chamber, said second member having means for forming an air inlet to the chamber; a heating means including a pair of insulators and a wire heating element of an iron base material wound about the insulators with adjacent turns being spaced from each other; each of said pair of insulators being a cylindrical member having axially spaced fins to maintain separation between adjacent turns of the wire heating element and each insulator having passageways extending between each of the spaced fins to enable passage of air therethrough for cooling the insulator; and means for mounting said heating means in the heating chamber with the pair of insulators in spaced relationship including biasing means for urging the pair of insulators away from each other thereby applying a tension on the wire to compensate for the thermal expansion of the wire; said mounting means comprising means defining cutout portions in both of said first and second members, said cutout portions being arranged in aligned pairs so that the attachment of said first and second member forms pairs of aligned apertures to assemble said pair of insulators in the desired position in the heating chamber, one pair of said pairs of apertures receiving the ends of one of said pair of insulators and maintaining said one insulator in a substantially fixed position relative to said heating chamber, the other of said pair of apertures each having an elongated configuration to receive the ends of the other insulator of said pair of insulators and enabling relative movement of the other insulator away from the one insulator and relative to said heating chamber; and said biasing means comprising a pair of springs disposed on the outside of the heating chamber, each of said springs being anchored to the box means formed by said first and second members and attached to a protruding end of said other insulator so that said springs are removed from the heat generated by the wire heating element to prevent the deleterious effect of the heat thereon.

Claim 16

A heater box assembly for a laundry appliance such as an electrically heated clothes dryer, comprising: a first member having means for forming an air inlet for the laundry appliance; a second member attached to said first member to provide a box means having a heating chamber, said second member having means for forming an air inlet to the chamber; a heating means including a pair of insulators and a wire heating element of an iron base material wound about the insulators with adjacent turns being spaced from each other; each of said pair of insulators being a cylindrical member having axially spaced fins to maintain separation between adjacent turns of the wire heating element and each insulator having passageways extending between each of the spaced fins to enable passage of air therethrough for cooling the insulator; and means for mounting said heating means in the heating chamber with the pair of insulators in spaced relationship including biasing means for urging the pair of insulators away from each other thereby applying a tension on the wire to compensate for the thermal expansion of the wire; said mounting means comprising means defining cutout portions in both of said first and second members, said cutout portions being arranged in aligned pairs so that the attachment of said first and second member forms pairs of aligned apertures to assemble said pair of insulators in the desired position in the heating chamber, one pair of said pairs of apertures receiving the ends of one of said pair of insulators and maintaining said one insulator in a substantially fixed position relative to said heating chamber, the other of said pair of apertures each having an elongated configuration to receive the ends of the other insulator of said pair of insulators and enabling relative movement of the other insulator away from the one insulator and relative to said heating chamber; and said biasing means comprising a pair of springs disposed on the outside of the heating chamber, each of said springs being anchored to the box means formed by said first and second members and attached to a protruding end of said other insulator so that said springs are removed from the heat generated by the wire heating element to prevent the deleterious effect of the heat thereon.