US3756218A

US3756218A - Grate

Info

Publication number: US3756218A
Application number: US00234801A
Authority: US
Inventors: L Simpson
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-03-15
Filing date: 1972-03-15
Publication date: 1973-09-04
Anticipated expiration: 1990-09-04

Abstract

A grate for supporting combustible material during burning having a cross member; legs mounted on the cross member adapted to support the member in elevated, horizontal position; and a plurality of air conduits mounted on the cross member and extended outwardly and downwardly therefrom so as to define a platform for the support of the material which is inclined toward the cross member; each conduit having an entrance remote from the member and an exit adjacent to the member so as to permit air heated by combustion to be drawn upwardly in convection currents through the conduits for discharge against the cross member to cool the grate and to improve combustion by establishing a flow of air about the material.

Description

Unite States Patent 11 1 Simpson |4s| Sept. 4, 1973 GRATE [76] lnventor: Lee S. Simpson, 440 N. Cornelia,

{52] US. Cl. 126/121, 126/165 [51] Int. Cl. F2311 3/02 [58] Field of Search 126/121, 165

[56] References Cited UNITED STATES PATENTS 3,240,206 3/1966 Schutt 126/121 1,640,771 8/1927 Hannum 126/121 2,453,954 11/1948 Wright 126/121 X 3,001,521 9/1961 Reilly 126/165 X 3,635,211 1/1972 Englert 126/121 Primary Examiner-William F. ODea Assistant Examiner-Peter D. Ferguson Attorney-Herbert A. Huebner, Richard M. Worrel et a1.

[57] ABSTRACT A grate for supporting combustible material during burning having a cross member; legs mounted on the cross member adapted to support the member in elevated, horizontal position; and a plurality of air conduits mounted on the cross member and extended outwardly and downwardly therefrom so as to define a platform for the support of the material which is inclined toward the cross member; each conduit having an entrance remote from the member and an exit adjacent to the member so as to permit air heated by combustion to be drawn upwardly in convection currents through the conduits for discharge against the cross member to cool the grate and to improve combustion by establishing a flow of air about the material.

1 Claim, 3 Drawing Figures GRATE BACKGROUND OF THE INVENTION The present invention relates to an improved grate and more particularly to such a grate which is intended for use in a conventional fireplace for improved combustion and radiant heating and for increased operational life of the grate.

Conventional grates used in fireplaces, incinerators, and the like to support materials to be burned suffer from common deficiencies. Such grates are used in an intensely heated environment while supporting relatively heavy loads. In order to withstand the heat, the grates are normally constructed of solid metal bars which tend to deform under such heat and load conditions. Similarly, continued heating and cooling of the grate causes the metal to become increasingly brittle. Consequently, after a relatively short period of time, the weight of the combustible material deposited on the grate causes it to deform beyond a useful shape and often to fracture so as to be useless.

Another problem frequently encountered with conventional grates is that of an insufficient supply of oxygen during combustion. Depending upon the design of the grate, the design of the fireplace or incinerator, and the buildup of ashes, the circulated air is frequently insufficient to maintain optimum combustion. This necessitates frequent rearranging of the combustible material, repositioning of the grate ancl removal of the ashes under the grate in order to achieve proper burning. Further, conventional grates frequently are not sufficiently well designed to preclude the combustible material from falling forward off the grate. Thus, in the case of a fireplace, there is a significant danger that the fire be transmitted to adjacent areas. Similarly, in the case of a fireplace, conventional grates make no provision for enhancing the production of heat by radiation and convection. Consequently, an excessive amount of the heat produced from the fire is lost by upward movement through the chimney.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an improved grate which is resistant to intense heat and heavy loads.

Another object is to provide such a grate which is self-cooling.

Another object is to provide such a grate which utilizes the natural properties of heated air so as to initiate circulation of air about the grate for improved combustion of the material supported thereon.

Another object is to provide such a grate which has an inclined platform for the support of combustible material in braced relation against the inner wall of the fireplace in which it is used so as to minimize the likelihood of the material falling out of the fireplace.

Another object is to provide such a grate which has a cross member adapted to emit radiant heat so as to improve the heating characteristics of the fireplace.

A further object is to provide such a grate which motivates air heated by combustion in convectional currents upwardly and outwardly from the fireplace so as to improve the heating characteristics of the fireplace.

A still further object is to provide such a grate which is of simple, utilitarian construction so as not to detract from the over-all appearance of the fireplace.

Further objects and advantages are to provide improved elements and arrangements thereof in a device for the purposes described which is dependable, economical, durable and fully effective in accomplishing its intended purposes.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a transverse vertical section of a conventional fireplace showing the grate of the present invention positioned for use therein.

FIG. 2 is a somewhat enlarged perspective of the grate.

FIG. 3 is a somewhat further enlarged side elevation of the grate with portions thereof broken away to show the movement of heated air there'through.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawing, FIG. 1 shows the grate of the present invention, generally indicated by the numeral 10. The grate is preferably constructed of a metal such as low carbon steel. The grate is shown in FIG. 1 in position in such a conventional fireplace 11 having a floor 12, an inner wall 13, and a mouth 14. Combustible material 15 such as logs are shown positioned on the grate in FIG. 1.

The grate 10 has a tubular cross member 20 having opposite ends 21 and a peripheral surface 22. A pair of legs 23 are mounted, as by welding, on the periphery surface of the member adjacent to the opposite ends thereof. The legs extend downwardly, normal to the member, so as to support the member in elevated, horizontal relation when the grate is positioned on the floor 12 of the fireplace 11.

A plurality of tubular air conduits 30 each having an entrance end 31 and an exit end 32 are mounted, as by welding, on the surface 22 of the member 20 in spaced, parallel relation between the opposite ends 21 of the member. The conduits extend righ't-angularly from the member so as to define an angle of some-what less than with respect to the legs 23. Each conduit is mounted on the member so as not to be flush with the peripheral surface thereof thereby defining a passage 33 between the exit end and the peripheral surface. Each of the passages opens downwardly, as best shown in FIG. 3. The conduits extend from the member in a common plane so as to define a platform 34.

OPERATION by conventional practice in order to start a fire. The

material is then ignited.

Upon combustion, the grate 10 operates automatically without adjustment to perform its unique functions. The grate operates on the well-recognized principle that air, when heated, expands and rises with respect to relatively cooler air in the same vicinity. Thus, air within the conduits 30 is heated by conduction from the tire on the platform 34 and consequently expands and moves in convectional currents upwardly through the inclined conduits. As can perhaps best be seen in FIG. 1, the air in the vicinity of the inner wall 13 of the fireplace 11 is drawn in a vacuum effect into the entrance ends 31 of the conduits to replace the air moving upwardly in the conduits. The intense heat of combustion occurring on the platform 34 causes the conduits themselves to become intensely heated. Consequently, the already heated air passing through the conduits becomes even more heated by conduction during such passage and thereby expands to increase its velocity as travel continues through the conduits. This heating of the air passing through the conduits correspondingly cools the conduits themselves by transporting the heat with the moving air. Since this transmission of heat by conduction is continued as long as combustion continues, the conduits are continually being cooled during such combustion. The result is that the conduits are maintained at a temperature below that which would otherwise be possible thereby greatly extending the operational life of the grate. Conventional grates are normally constructed of solid metal bars which, because of a lack of provision for internal cooling, readily deform during continued use under the conditions of intense heat and heavy loads supported thereon. The grate of the present invention therefore remains structurally rigid for a significantly longer period than conventional grates.

Upon reaching the exit end 32 of the conduits 30, the now intensely heated air is caused to be discharged from the conduits through the passages 33. Because the passages face downwardly, the heated air is discharged downwardly. Consequently, the air, because of its tendency to rise, travels in both directions about the peripheral surface 22 of the cross member and eventually upwardly and outwardly in convection currents through the mouth 14 of the fireplace for improved heating as best shown in FIGS. 1 and 3.

The heating is further improved by passage of the intensely heated air about the peripheral surface 22 of the cross member 20. Such passage, as well as the proximity of the cross member to the point at which combustion is occurring, causes the cross member itself to become intensely heated. The positioning of the cross member adjacent to the mouth 14 of the fireplace 11 thus further improves heating since the cross member itself emits radiant heat from its surface upwardly and outwardly through the mouth of the fireplace.

The increase in the velocity of the air as it passes through the conduits 30 continues to draw more air through the entrance ends 31 of the conduits so as to create a continuous movement of air therethrough as long as combustion continues on the platform. Correspondingly, relatively cooler air is drawn in a vacuum effect from the mouth 14 of the fireplace 11 under the grate and through the spaces between the conduits so as to replace the heated air which is drawn through the conduits. Such cooler air contains a significantly higher percentage of oxygen than the air removed during combustion and movement through the grate thereby making possible improved combustion of the material 15 on the platform.

Finally, the inclination of the platform 34 defined by the conduits 30 serves securely to retain the combustible material 15 thereon and to preclude its falling off the grate l0. Ordinarily, the combustible material is supported on the platform, as shown in FIG. 1, in braced relation against the inner wall 13 of the fireplace 11. It should also be noted that the simple, utilitarian construction of the grate insures that it does not detract from the individually aesthetic qualities of the fireplace in which it is used.

The present invention therefore provides a grate having an extremely long operational life, improved characteristics of combustion, improved characteristics of heating by radiation and convection, and improved characteristics of safety.

Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the illustrative details disclosed.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A grate for use in the burning of logs in an open fireplace, comprising:

A. a cross member of -a cylindrical configuration formed of a heat-conducting material;

B. means including a plurality of similarly configured, vertically oriented legs fixed to said cross member adapted to support said cross member above the plane of a floor of a selected open fireplace, within the opening thereof and at the interface of a heated body of atmosphere and a body of atmosphere to be heated;

C. a plurality of elongated tubular members for supporting logs in a burning state arranged in coplanar relation, each said tubular member being suspended at one end thereof from said cross member, and disposed at a downward inclination with respect to said cross member;

D. means defining within the uppermost end of each of said elongated members a discharge opening disposed in juxtaposition with the external surface of said cross member for discharging heated air at said interface; and

E. means defining within the lowermost end of each of said elongated members an intake opening for receiving air from said heated body of atmosphere, whereby the elongated members are cooled as air is drawn through the intake openings of said elongated tubular members, further heated within the tubular members, as heat is transferred thereto, and finally discharged from the uppermost ends of said tubular members at said interface bodies of atmosphere.

a: a: a a a:

Claims

1. A grate for use in the burning of logs in an open fireplace, comprising: A. a cross member of a cylindrical configuration formed of a heat-conducting material; B. means including a plurality of similarly configured, vertically oriented legs fixed to said cross member adapted to support said cross member above the plane of a floor of a selected open fireplace, within the opening thereof and at the interface of a heated body of atmosphere and a body of atmosphere to be heated; C. a plurality of elongated tubular members for supporting logs in a burning state arranged in coplanar relation, each said tubular member being suspended at one end thereof from said cross member, and disposed at a downward inclination with respect to said cross member; D. means defining within the uppermost end of each of said elongated members a discharge opening disposed in juxtaposition with the external surface of said cross member for discharging heated air at said interface; and E. means defining within the lowermost end of each of said elongated members an intake opening for receiving air from said heated body of atmosphere, whereby the elongated members are cooled as air is drawn through the intake openings of said elongated tubular members, further heated within the tubular members, as heat is transferred thereto, and finally discharged from the uppermost ends of said tubular members at said interface bodies of atmosphere.