US2136708A - Hot plate - Google Patents

Description

Nov. 15, 1938. HFHV PATRICK H 0T PLATE Filed Jan. 10, 1936 INVENTOR.

ATTORNEYS Patented Nov. 15, 1938 UNITED STATES PATENT OFFICE;

2,136,708 f HOT PLATE Harry H. Patrick, Los Angeles, Calif. Application January 10, 1936, Serial No. 58,542

1 Claim.

This invention relates to a device known as a hot plate. The function of a hot plate is to supporta cooking utensil over a flame while preventing the utensil from being overheated. Heretofore hot plates have been constructed embodying an upper sheet and a lower sheet forming an air chamber therebetween, to prevent overheating of the upper plate. In such hot plates, the upper sheet or cover is heated by conduction from the flame sheet or flame plate, and the presence of air in the air chamber causes an insulating effect that delays the heating of the cover plate.

The general object of this invention is to produce a hot plate having a construction that will provide a gas chamber for the gases of combustion between the upper and lower plates, but from which the flame is excluded. In this Way the gases of combustion at a very high temperature but unignited, are caused to contact directly with the cover plate or sheet to impart their temperaure, giving the same a high temperature immediately without undue delay, but without bringing the flame directly into contact with the cover plate.

Further objects of the invention will appear hereinafter.

The invention consists in the novel parts and combination of parts to be described hereinafter, all of which contribute to produce an efficient hot plate.

A preferred embodiment of the invention is described in the following specification, while the broad scope of the invention is pointed out in the appended claim.

In the drawing:

Fig. 1 is a plan of a hot plate embodying my invention, and in which my improvement is incorporated with a griddle, certain parts being broken away.

Fig. 2 is a Vertical section on theline 2-2 of Fig. 1.

Fig. 3 is a plan of a simpler embodiment of the invention in which the griddle plate is omitted.

Fig. 4 is a section on the line 4;4 of Fig. 3; and Fig. 5 is a fragmentary developed section on the line 5-5 of Fig. 3, further illustrating details of the construction.

In practicing my invention, I form the hotplate body with a flame sheet I (see Fig. 4) and a .cover sheet 2, preferably with offset flanges 3 secured together, for example, by spot welding.

By reason of the offset flanges a gas chamber 4 is formed between the two sheets. These two sheets are foraminous or perforate; and in the present instance the flame sheet is formed of a plate with a multiplicity of minute perforations 5 throughout the area, that are small enough to prevent passage of the flame from an ordinary gas burner. The cover sheet 2 is also formed of a plate with small perforations 6, that are preferably out of line with those in the flame sheet.

In order to stiffen the hot-plate and diffuse the heat toward the outer area of the hot-plate, I provide the sheets with ribs 1, preferably produced by offsetting the metal to form substantially radial grooves. As shown, the metal is offset inwardly into the gas chamber, but should not be in contact with the other sheet, to prevent conduction of heat between the plates except at their contacting flanges.

The radial grooves l of one sheet are also preferably staggered between those of the other sheet.

In the simple form of the invention shown in Figs. 3 and 4, a wire handle 8 is provided secured between the flanges 3, and this handle preferably projects in the plane of the flanges, enabling the plate to be used with either sheet uppermost.

In the embodiment illustrated in Fig. 1, the construction is the same as that described, but an imperforate griddle plate is secured over the cover sheet and in contact with the same. This griddle plate is preferably provided with a marginal flange ID, the lower edge of which is formed with a crimp l I under the edge of the superposed flanges 3', and the griddle plate may be slightly dished downwardly by forming it with a slight upwardly offset bead l2 at the edge. A handle l3 should be provided, secured to the griddle plate.

When the hot-plate is in use, the flame from the burner is arrested at the flame sheet I or I, but the hot gases of combustion from the flame pass up through the perforations 5 or 5' into the gas chamber, such as the gas chamber 4 between the sheets. In the case of the construction shown in Fig. 4, these hot but unignited gases impinge directly onto a substantial part of the area of the bottom of the cooking utensil through the perforations 6 imparting their heat directly to the same by convection; in the other construction, these hot gases impinge upon the under-side of the griddle plate through the perforations of the cover-sheet 2' beneath it, imparting their heat to the same by convection. The griddle plate 9 also receives a considerable amount of heat by conduction from the upper sheet 2' as it is in contact with the same throughout substantially its entire area.

The radial grooves l and l assist in diffusing the heat to the outer areas of the plates.

The heat imparted to the cover plate is carried off so rapidly to the edges of the hot plate that the unlgnited gases of combustion that pass into the gas chamber will not reignite after passing up through the flame sheet.

It is understood that the embodiment of the in- :vention described herein is only one of the many 'embodlments this invention may take, and I do not wish to be limited in the practice of the invention, nor in the claim, to the particular embodiment set forth.

What I claim is: V e

A hot plate for heating a cooking utensil over a gas flame, consisting of an upper perforated plate having an unobstructed upper face so that the utensil may rest upon'the same, a lower perforated plate, and an imperforate plate above, and in contact with, the upper perforated plate, said plates being attached together at their edges, said perforated plates having a multiplicity of minute closely placed unobstructed perforations therethrough extending throughout substantially the entire area of the perforated plates, the lower perforations operating to permit passage of a substantial portion of the gases of combustion from the flame into the space between said perforated plates so that said space operates as a gas chamber filled with the hot gases of combustion, the perforations in the upper plate operating to expose a considerable portion of the area of the imperforate plate to direct contact with the hot gases in the said gas chamber, so that the said imperforate plate acquires a considerable portion of its heat from its direct contact with the said gases.

HARRY H. PATRICK.

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