Electric heating elements

• US 4,214,150 A
• Filed: 05/10/1978
• Issued: 07/22/1980
• Est. Priority Date: 05/10/1978
• Status: Expired due to Term

• Current Assignee: Emerson Electric Company
• Original Assignee: Emerson Electric Company
• Inventors: Cunningham, Donald M.
• Primary Examiner(s): Reynolds, B. A.
• Assistant Examiner(s): Roskoski, Bernard
• Application Number:
  US05/904,556
• Time in Patent Office: 804 Days
• Field of Search: 219/518, 219/452, 219/467, 200/85 R, 200/85 A
• US Class Current: 219/447.1
• CPC Class Codes: H05B 3/76 Plates with spirally-wound heating tubes

Abstract

An electric heating element for the top panel of a cooking stove, having terminals adapted to be plugged into a terminal block carried by the stove panel, and embodying means for automatically interrupting current flow to the heating element when a cooking utensil is removed therefrom. The means for automatically interrupting the current flow comprises a weight responsive switch with at least one contact in the terminal block.

Claims

1. An electric heating element of the type comprising a sheathed unit having a flat, spiralled active heating portion with a pair of terminal portions extending downwardly from and laterally of said heating portion, each terminal portion having a rigid terminal pin extending outwardly of the sheated end, said flat heating portion being adapted to directly support a cooking vessel to heat the latter and its contents, the improvement comprising support means, said sheathed with being removable mounted on said support means:

a pair of contact members carried by said support means and, each adapted for connection to an electric power conductor, said contact members being adapted for electric contact with respective terminal pins to provide electrical current to said active heating portion to heat the same,

vertically movable means normally disposed in an upper position above the plane of said flat heating portion when no cooking vessel is supported on said active heating portion, but movable downwardly to a lower position at least within said plane by the weight of a cooking vessel placed on said active heating portion, and

means providing for movement of at least one of said contact members out of electrical contact with its respective terminal pin in response to movement of said vertically movable means to its upper position.

2. The construction according to claim 1 wherein said contact members are disposed within the cavity of a dielectric terminal block, and wherein said sheathed unit is of the plug-in type with said terminal pins inserted into said terminal block cavity in associated relation with said contact members when said heating element is in a normal operating position to support a cooking vessel.

3. The construction according to claim 1 wherein each of said contact members is a spring blade normally biased out of electrical contact with the related terminal pins when said vertically movable means is in its upper position.

4. An electric heating element of the type comprising a sheathed unit having a flat, spiralled active heating portion with a pair of terminal portions extending downwardly from and laterally of said heating portion, each terminal portion having a rigid terminal pin extending outwardly of its end, the winding of said spiralled active heating portion providing a central opening in the same, and said flat heating portion being adapted for support within an opening of a stove panel and adapted to directly support a cooking vessel, the improvement comprising:

a dielectric terminal block supported by said stove panel and extending downwardly from an undersurface of the latter, said terminal block having a cavity and said terminal pins being disposed within said cavity in spaced side-by-side relation,

a pair of spaced spring blade contact members fixed within said cavity in adjoining relation with respect to respective terminal pins but spring biased out of electrical contact with the same, each contact member being adapted for for electrical connection to a power conductor,

vertically movable means including a head portion movable through the central opening in said spiralled active heating portion, said head portion being normally disposed in an upper position above the plane of said flat heating portion when no cooking vessel is supported on the latter, but movable downwardly to a lower position at least within said plane by the weight of a cooking vessel, and

means transmitting movement of said vertically movable means to said contact members whereby when said head portion is in its upper position, said contact members are spring biased out of electrical contact with respective terminal pins, and when said head portion is in its lower position said contacts are moved against the force of said spring bias and into electrical contact with said terminal pins.

5. The construction according to claim 4 wherein said vertically movable means includes a stem portion depending from said head portion,

a lever pivoted intermediate its ends, one end being operatively associated with said stem portion and the other lever end supporting a block of insulating material which is adapted to press against said contact members and move them into electrical contact with respective terminal pins.

6. The construction according to claim 4 wherein said sheathed unit is of the plug-in type with said terminal pins inserted into said terminal block cavity in associated relation with said contact members when said heating element is in a normal operating position to support a cooking vessel.