US2808824A - Fireplace structure - Google Patents

Description

Oct. 8, 1957 D. L. CAGE 2,808,824

FIREPLAGE: STRUCTURE Filed March 21. 1955 3 sheets-'sheet 2 afg?. 44.

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'l`m l 5iL lfm DARCV L. CAGE) IN VEN TOR.

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- A TTORNEYS.

United States Patent FIREPLACE STRUCTURE Darcy L. Cage, Los Angeles, Calif., assignor to Superior Fireplace Company, Los Angeles, Calif., a corporation of California Application March 21, 1955, Serial No. 495,566

3 Claims. (Cl. 126-120) This invention relates to improved draft control means for building into a fireplace.

Modern fireplaces are designed with the aim of increasing ones View of the fire. To this end, the walls defining the firebox are made vertical so that a plurality of fireplace openings may be formed. A modern fireplace may be constructed in a wall between two adjacent rooms, with a fireplace opening being provided on each side of the wall. Also, where a wall or partition extends only part way across a room, a pair of corner openings may be formed, one in a side of the partition and the other adjacent thereto and in the end face of the partition. Likewise three openings may be provided, using corner posts of tubular metal or of masonry construction. Then, too, a modern fireplace may be built as in the middle of a room, with fireplace openings on al1 four sides of the fireplace.

In fireplace constructions of the above mentioned character it is necessary that the chimney flue extend straight up from above the firebox, rather than from the rear of the firebox or off to one side thereof as in fireplaces of old style. This requirement presents problems in constructing the throat portion of a fireplace for controlling the draft as desired and for preventing downdraft currents from being swept into the firebox from the chimney flue.

It is -an object of this invention to provide a draft control form which is especially well suited for forming the throat portion of a fireplace of modern design.

A further object of the invention is to provide a draft control form for a modern fireplace having a plurality of fireplace openings, and which draft control form conducts air into the chimney fiue from each of such openings and prevents downdrafts from being swept into the fireplace chamber or firebox of the fireplace.

The invention is furthermore directed to providing a draft control form which may be fitted easily into a fireplace structure even by those who are not experts in the masonry art, for as will be made clear hereinafter, the draft control form of the present invention makes it possible to build a replace structure without the need for constructing arcuate masonry walls as are usually required in the building of old style replaces.

The draft control form of the present invention is designed for construction from metal places, e. g. press rolled structural steel. Thus it is necessary that the form be so constructed and arranged as to allow for expansion and contraction thereof as a result of heat changes, so that the structure will not cause cracking of the masonry walls of the fireplace. The fireplace throat structure of the present invention is so constructed and adapted to be arranged in a fireplace structure that it may expand and contract freely without cracking or otherwise weakening the masonry walls of the fireplace.

The draft control form of the present invention includes a damper which is manually swingable between a throat-open position and a throat-closed position, and it'V is an object of the present invention to provide an irnice proved structure of the above mentioned character which will provide an opening of maximum size through the throat structure when the damper is moved to its throatopen position. Y

The fireplace throat structure of the present invention is adapted to be mounted adjacent the lower front portion of the fireplace fiue and to be Yso positioned with relation to the fireplace flue that when the damper is moved to its open position, the damper will define a front wall of a pocket in the lower end portion of the flue, whereby downdrafts from the fiue will be prevented by the damper from blowing into the fireplace chamber and, instead, will be neutralized in the flue pocket.

It is a general object of the present invention to provide an improved draft control form of the above mentioned character for mounting in the throat section of a fireplace, which is relatively simple in construction and adapted to be manufactured efficiently and in accordance with mass production procedures, with the view to supplying improved forms for fireplaces to the public at a low cost. y

Further objects and advantages of the present invention will appear during the course of the following part of this specification in which the details of construction and mode of operation of a preferred embodiment thereof are described with reference to the accompanying drawings, in which:

Fig. 1 is a vertical section of the left hand portion of a fireplace structure having a throat form of the present invention mounted therein, the section being taken in a plane passing through the side walls and parallel to the front and rear walls of the fireplace structure;

Fig. 2 is a vertical section of the fireplace structure taken on line 2-2 of Fig. l;

Fig. 2a is a sectional detail taken on line 2a-2a of Fig. 2;

Fig. 3 is a bottom plan view of the fireplace throat structure as the same appears when looking upwardly from within the fireplace chamber;

Fig. 4 is a perspective view of the fireplace throat form showing the front thereof;

Fig. 5 is a perspective view of the throat form looking toward the back thereof;

Fig. 6 is a fragmentary view in elevation of a lower corner portion of the damper and its adjacent parts of the throat form shown on an enlarged scale;

Fig. 7 is a section taken on line 7-7 of Fig. 6;

Fig. 8 is a representation similar to that of Fig. 6, but showing a modified form of construction for pivotally mounting the damper in the throat form;

Fig. 9 is a section taken substantially along line 9-9 of Fig. 8;

Fig. 10 is a bottom view of the throat structure of this invention mounted in a fireplace having side and front replace openings;

Fig. ll is a view similar to that of Fig. l0, but showing the structure of the present invention as the same may be installed in a fireplace structure having four fireplace openings therein; and

' Fig. 12 is a detailed section taken on line 12-12 of Fig. 10.

Referring to the drawings in detail and with the use of reference numerals, a fireplace structure, designated generally by reference numeral 15, is illustrated in Figs. 1 to 3, as being formed of masonry walls providing a hearth 16, fireplace chamber 17, throat portion 18, and a ue 19. The walls of the fireplace Structure 15 are herein illustrated as being formed from brick and they comprise a front wall 20, side Walls 21 and 22, and a back Wall 23. The fireplace structure 15 is of the type in which the chamber 17 is accessible from the front and back thereof, and Vaccordingly the front and back walls have openings 24 and 25 respectively formed therein. Lintel bars 26 and 27 span the openings 24 and 25 respectively, and serve to support the front and back walls of the fireplace structure.

The back wall of the flue is defined by a central vertical region or portion of the inside face of the back wall 23, while the front wall of the flue is defined by a vertical portion of an inside face of an upper portion 29 of the front wall 20, such upper wall portion 29 being spaced nearer the back wall 23 than is the lower portion of front wall 29, whereby the axis of the ue is nearer to the baci(` wall 23 than to the lower portion of the front wall 20. Reference numeral 30 designates a horizontally arranged angle iron which supports the lowermost course of brick in the upper front wall portion 29.

As mentioned above, the present invention is directed to providing a sheet metal structure mountable in the throat portion 18 of the fireplace structure. A draft control or throat form embodying the invention is shown in Figs. 4 and 5 as the same appears before mounting in the fireplace structure. Such draft control form is designated generally by reference numeral 32 and it comprises a front wall 33 and two side walls 34 and 35. The form is open in the back thereof.

For convenience in description, the top edge of the front wall is designated by reference numeral 36, while the bottom edge is designated by reference numeral 37. These edges extend in respective horizontal planes when the draft control structure is positioned as shown in the fireplace structure. The front wall 33 is constituted of a lower panel 38 and an upper panel 39, which panels are integral along their top and bottom edges respectively. The lower panel 38 is substantially rectangular in shape and is inclined rearwardly from a vertical plane passing through the bottom edge 37 of the form to an angle with said vertical plane of about to 20. The upper panel 39 is likewise inclined rearwardly, and in this case from the plane of the lower panel 38 by about 15 to 20 so that the top edge 36 of the front wall is disposed in a plane common to the rear edges of the side walls 34 and 35.

Since the cross sectional area of the flue is substantially less than the cross sectional area of the lower portion of the throat 18, the upper portion of the throat structure is made smaller in cross sectional area than the lower portion thereof. To this end the upper panel of the front wall is shaped as a frustum portion of an isosceles triangle, whereby the top edge of the upper panel is shorter than the bottom edge thereof. The side walls 34 and 35 are inclined inwardly toward each other in the upper portions thereof and the rearward edges 40 of the side walls are disposed in a vertical plane passing through the top edge 36 of the form. These rear edges define with the top edge 36 a full opening in the back of the form. The

bottom edges of the side walls are designated by reference f numerals 41 and 42 and these bottom edges lie in a vertical plane common to the bottom edge 37 of the front wall.

The sheet metal from which the side walls are formed are bent along their respective bottom edges 41 and 42 to provide outwardly extending side flanges 43, which are made to be anchored in respective side walls 21 and 22 of the fireplace structure, thereby to support the draft control form in the throat section of the fireplace structure.

At its top edge 36 and its bottom edge 37 the sheet metal of the front wall is bent forwardly to provide narrow flanges 45 and 46 respectively, which serves to strengthen the metal form and to hold opposite edges of a blanket 47 of heat insulating material, e. g. rockwool, as a cover on the outside surfaces of the front and side walls.

Reference numeral 49 designates an angle iron bar which is secured at its ends to the side surfaces of respective side walls 34 and 35. This angle iron bar comprises two'strip portions 50 and 51 and the angle bar is positioned in the draft control form so that strip Slis inclined downwardly and rearwardly from the front edge of the strip 50. The ends of the angle iron bar are positioned in the lower rear corners of the respective side walls of the form.

An improved feature of the present invention is the provision of a metal downdraft support plate 53, which extends downwardly and rearwardly from the angle iron bar 49. This support plate serves to define the rear portion of the top wall of the fireplace chamber 17. It is bent along its lowermost edge to provide a lip 54, which in the embodiment illustrated inthe drawing, becomes inserted between the upwardly projecting leg of the lintel bar 27 and the inside face of back wall 23 for anchoring the support plate to the masonry walls of the fireplace structure. The support plate rests along its upper edge on the top surface of the inclined strip 51 of angle iron bar 49 and is free to slide toward the apex of the angle iron bar thereby to accommodate expansion and contraction of the support plate resulting from changes in heat inherent in fireplace structures. In this connection it is to be noted, too, that the metal plates forming the front and side walls of the draft control form are also free to expand and contract, since these walls are separated from adjacent masonry walls of the fireplace structure by the rockwool blanket 47. Thus the draft control form and its downdraft support plate are free to expand and contract without cracking or otherwise fracturing the masonry walls of the fireplace structure.

In constructing the fireplace, it is preferred that the void resulting from the downward slant of the downdraft support plate be covered with masonry material as shown at S5 for leveling oi the bottom wall of the lower portion of the flue. This lower portion of the flue is herein referred to as the downdraft pocket portion thereof.

The draft control form has a damper plate 57 pivotally mounted therein for swinging between throat-closed position of the dotted line structure in Fig. 2, and throat-open position of the full line representation of Fig. 2. This damper plate is substantially rectangular in shape and spans the inside of the hollow draft control structure. At its lower longitudinal edge 58 the damper plate is bent forwardly to provide a lower end ange 59, while the top longitudinal edge of the damper plate is bent backwardly to provide a narrow longitudinally extending ange 60. Short pivot rods or pins 61 are seated in the arcuate bend which forms the narrow flange 59. The damper plate has a pair of spaced apart slots 62 formed therein, extending substantially at right angles from the lower longitudinal edge 58. These slots 62 accommodate upright lugs 63 which are mounted on the top surface of the angle iron bar 49. The lugs have holes 64 formed therein for rotatively receiving respective pins 61. By this structure it is clear that the damper plate is hinged on the top surface of the angle iron bar whereby it is selectively moveable between its throat-open and throatclosed positions.

When moved to its throat-closed position, the damper plate engages the inside face of the front lower panel 38 along the upper longitudinal edge of the damper plate. Also when in its throat-closed position, the free edge of the lower narrow flange S9 of the damper plate becomes positioned closely adjacent or preferably in contact with the top surface of the angle iron bar, thereby to effectively close the throat.

In Figs. 8 and 9 an alternative structure for pivotally mounting the damper plate 57 in the draft control form is shown. in this embodiment the damper plate has outwardly extending pins 66 which are mounted in respective -end portions of the lower end portion of the damper plate.

These pins are rotatable in respective holes 67 formed in the side walls of the draft control structure, whereby the damper plate is pivotally mounted between the side walls.

For manual operation of the damper, a lug 70 is mounted on the forwardly disposed face of the damper plate and preferably at the midpoint thereof. `A short link 71 has one of its ends pivoted to said lug and its opposite end is pivoted to one end of an operating lever or handle 72. The lower portion of the operating lever 72 is accessible through the openings 24 and 25 of the f fireplace. Intermediate its ends, the operating lever is pivotally mounted to the ends of arms 73 and 74, which in turn are welded or otherwise 'suitably secured to the front wall 33 and the angle iron bar 49 respectively. As best shown in Fig. 2a, the pivotal mounting of the handle 72 to the mounting arms 73 and 74 is effected by means of washers 7S, one on each side of the handle, and a bolt 76 which passes through the pivot assembly, whereby the joint of the handle and mounting arms are such as will oder sufcient frictional resistance to their movement to insure that the damper plate will be prevented from accidental displacement from its adjusted position.

Referring again to Fig. 2 of the drawing, the upper edge of the damper plate is disposed substantially in the vertical plane of the rear edges of the side walls and top edge of the front wall when the damper plate is moved to its full throat-open position. Also, when in such throat-open position, the damper plate extends upwardly from the angle iron bar to a line below the lines along which the side walls of the form are bent to converge toward each other, and the damper plate is substantially parallel to the lower panel of the front wall, thus defining a rear wall of a passageway through the draft control form of maximum cross sectional area for the flow of smoke up into the ue. Thus the damper plate forms a front wall of a pocket 78 in the lower end portion of the liuc, whereby any downdraft currents from the flue are neutralized by such pocket and prevented by the damper plate from blowing downwardly into the fireplace chamber.

In order to insure that the damper plate may not be swung rearwardly into the pocket 78, the lug 70 and the mounting arms 73 and 74 are of such length that the operating lever 72 will strike against the free edge of the lower ange 59 of the damper plate, thereby limiting rearward movement of the damper plate when swinging from its throat-closed to its throat-open position.

In Fig. 10 of the drawing, the invention is shown as the same may be embodied in a fireplace structure having a front fireplace opening 80 and a side opening 81. In constructing a fireplace of this type, an upright post 83 may be used as a support means between adjacent fireplace openings and also an L-shaped lintel bar 84 is used to span these openings. Since in the construction shown in Fig. 10 there is no lintel bar in the back wall of the fireplace structure for supporting the lip on the lower end of the downdraft support plate 53, the support plate is anchored to the back wall of the fireplace by having its lip 54 secured between adjacent layers of brick in the back wall of the fireplace.

Referring to Figs. 3 and 10 together, it will be apparent that a fireplace embodying my invention may be formed in the end of a partition to provide three openings to the fireplace chamber. In Fig. l1 the invention is illustrated as the same may be adapted to a fireplace structure having four-way openings therein. In this structure a rectangular lintel bar S5 is used to span the tops of the four openings, and four corner posts 86 are used to support the masonry walls of the fireplace structure above the hearth.

While I have herein shown and described my invention in what I have conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of my invention, which is not to be limited to the details disclosed herein, but is to be accorded the full scope of the claims so as to embrace any and all equivalent structures.

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

1. A fireplace structure having walls dening a fireplace chamber, a vertical fine above the chamber, and a throat section between the chamber and the flue for passage-of smoke from the chamber to the fiue, a metal hollow draft control form positioned in the throat section and anchored in the walls of the fireplace structure, said form being open in the bottom thereof to the chamber and being open in the rear thereof to the flue, a damper plate pivotally mounted in the form for movement between throat closed and throat-open positions, and a downdraft support plate extending downwardly and rearwardly from the form and anchored at its lower end in the fireplace structure, the upper end of the support plate being slideably 'supported on the form to accommodate expansion and contraction thereof, the support plate defining at least a portion of a top wall for the chamber.

2. A metal form adapted to be mounted in the throat section of a masonry fireplace structure to serve as a damper controlled conduit for flow of smoke from the chamber of tlie fireplace structure to the liue thereof, said form comprising a front wall and two side walls, the front wall being defined by two side edges and substantially horizontal top and bottom edges, said lside walls having respective front, bottom and rear edges, the bottom edges of the side walls and the bottom edge of the front wall being disposed substantially in a common horizontal plane, the side walls being integral at their front edges with respective side edges of the front wall, the rear edges of the side walls and the top edge of the front wall lying in common substantially vertical plane, the front wall being constituted of a rearwardly inclined lower panel and a rearwardly inclined upper panel, the lower panel being substantially rectangular in shape, the bottom edge of the lower panel constituting the bottom edge of the front wall, the top edge of the upper panel constituting the top edge of the front panel, the degree of rearward inclination of the upper panel being greater than that of the lower panel, each of the side walls having a flange extending outwardly from the bottom edge thereof for anchoring in the masonry walls of the firev place structure whereby to support the said form in the fireplace structure, an angle iron comprising two plate strips extending between and supported at its ends to the side walls adjacent the rearward bottom corners of the side walls, one of the angle iron strips being disposed in a substantially horizontal plane,.the other of the angle iron strips being inclined downwardly and rearwardly from the forward edge of said one angle iron strip, the angle iron being spaced from the inside face of the front wall, a rectangular damper plate of a length sufiicient to substantially span the form inside the form between the side walls, said damper plate being mounted in the form to pivot on an axis extending along one longitudinal edge of the damper plate and positioned above and parallel to the horizontal strip of the angle iron, the damper plate being of a width sufficient that when the damper plate is in throat-closed position it will engage the inside face of the lower panel along the longitudinal edge of the damper plate opposite said one longitudinal edge thereby closing the throat, a downdraft support plate extending downwardly and rearwardly from the angle iron and having one edge portion thereof slideably resting on said other angle iron 'strip to accommodate expansion and contraction of the Support plate, and lever means operatively associated with the damper plate for selectively swinging the damper plate on its said pivot axis between throatopen and throat-closed positions.

3. A form for forming a throat portion in a fireplace structure, the fireplace structure having a fireplace chamber and a ue, the form being adapted to conduct smoke upwardly from the chamber to the flue and comprising a front wall and two side walls, the form being open in the bottomV thereof for communication with the chamber and open in the rear thereof for communication with the iiue, a damper plate pivotally mounted in and extending between said side walls for movement between throatclosed and throat-open positions, and a downdraft support plate extending downwardly and rearwardly from the form, means on the lower end of the support plate for anchoring the lower end of the plate to the fireplace structure, the upper end of the support plate being slideably supported on the form to accommodate expansion and contraction of the plate.

References Cited in the le of this patent UNITED STATES PATENTS Wayland Nov. 30, Richardson Dec. 4, Cage Nov. 30, Klann Oct. 3, Bruander June 25,

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