US3362394A - Stove - Google Patents

Description

Jan. 9, 1968 N. R. QQLE ET A1. 3,362,394

` STQVE Filed sept. 23, 1965 2 sheets-sheet 1 -b O v ATTORNEYS Jan. 9, 1968 N, R COLE ET'AL STOVE 2 sheets-Sme; 2

Filed Sept. 23, 1965 TORS NORMAN R. COLE PHILIP A. DURYEE ATTORNEYS United States Patent O ABSCT F THE DISCLSURE The heater is made of sheet metal and comprises a ire box or combustion chamber and an ash receiving drawer positioned below a grate at the base of the re box. A damper is provided adjacent the ash drawer to Control the circulation of air in the fire box and to serve as a cover for the ash drawer when the damper is inverted.

The present invention relates to a prefabri-cated combination heater and fireplace unit particularly designed for use in boats, but also suitable Ifor trailers, cabins and other small structures.

Representative objects of the invention are to provide such a unit which is safe -for boat use, compact and light weight, simple to install, requires little wall clearance, is quick and easy to start and adjust, has provision for dustless ash removal without disturbing the fire, is durable and eiiicient, and relatively inexpensive to produce.

Other obje-cts and advantages of the invention will appear and be understood in the following description and claims, the invention consisting in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawings:

FIG. 1 is a perspective view of a stove embodying the present invention and with front slide damper partly open;

FIG. 2 is a vertical sectional view taken along the line 2 2 of FG. 1;

FIG. 3 is a transverse sectional view taken as indicated by line 3-3 in FIG. 2;

FIG. 4 is a fragmentary horizontal sectional view taken as shown by line 4--4 of FIG. 2, but with the lower damper in open position;

FIG. 5 is a detail vertical sectional view through the hinge of the door illustrating the door in open position; and

FIG. 6 is a perspective view showing the ash drawer removed from the stove and fitted with the lower damper unit as a lcover preparatory to dumping.

Referring to the drawings, it is seen that the stove of the present invention has a sheet metal heat exchanger 10 which may be a rectangular prism in shape with square top and bottom walls 1a-10b, and integral rectangular back and side walls 10c and 10d-10d, respectively. The heat exchanger is divided into an upper tire box and a lower ash collection chamber by a removable expanded mesh grate 11 which is supported on an inturned flange 12.

At the front of the fire box the sheet metal forming the side walls 10d continues at 16e-19e to define the vertical edges of a rectangular opening 13 which is fitted with a removable door 14. Sheet metal cross-pieces 10j-10g define the top and bottom of the front opening 13 and at their ends these, join the side portions 10e at butt joints, there being a pair of backing pieces 15 at the top joints and a backing strip 16 at the bottom joints to which the respective parts are spot welded. At the lower edge of the front opening 12 the cross-piece 10g is rolled at 10g inwardly over the backing strip 16 while at the sides and top of the front opening the portions 10e and 10f have fianges 10e and 10j', respectively, which turn inwardly at acute dihedral angles.

The front quarter of the grate support flange 12 is provided by the lower portion of the backing strip 16, and the other three quarters are formed by angle strips spot welded to the back and side walls of the heat exchanger. Along their edges the top and bottom walls 10a10b are formed with down-turned marginal lips 10d-10b. The upper lips 10a define an outer skirt which is welded over the top of the vertical walls, whereas the lower lips 10b tit inside the bottom of the vertical walls.

Continuing to the construction of the door 14, it is seen that there is provided a solid transversely-corrugated upper panel 20 surmounting a grill panel 21. The latter is selectively covered by a slide shutter 22 having an upper thumb screw 23 threaded therethrough to bear against the panel 20, Side tracks 24 of I-section slidably receive the shutter 22 and are welded to the side edge portions of the panels 20-21. At their back the tracks 24 are formed with stiffening flanges 24a. When the screw 23 is tightened it -forces the shutter 22 outwardly against the front flange of the tracks 24 and thereby locks the shutter at the desired opening.

To hinge the door 14 at the bottom and support it in open position the ydoor is provided with inner and outer out-turned downwardly sloped bottom lips 25-26 arranged to straddle the bottom edge ofthe opening 13. The inner lip 25 functions to retain the lower end of the door relative to the heat exchanger, whereas the outer lip 26 serves as a stop when the door is swung open to a nearly horizontal position as shown in FIG. 5. In this position the outer edge of the lip 26 bears against the front face of the crosspiece 10g.

At its upper end the door panel 20 is centrally dished outwardly and is perforated to receive a bolt 27 on which is pivoted a latch 28. This latch comprises a length of sheet metal strap bent to form an open loop 29a serving as a catch and to form a flattened substantially closed loop 28b serving as a handle. It will be noted that the ends of the -catch 28a are spread by a spacer 30 sleeved on the bolt 27 while the head of the bolt is covered by the outer half of the handle loop.

When the door 14 is locked, the -catch 28a is wedged between the front of the cross-piece 10e and the back face of a front cross-brace 32 which bridges a three-sided shield 31 open to the front of the heat exchanger. Spa-ced from the sides 10d and back 10c of the latter the shield presents perforate Walls 33 and a solid wall 34, respec tively.

The walls 33 may comprise grills of cold rolled expanded steel mesh each bordered at the front by a leg 35, at the top and bottom by U-rails 36-37, and at the back by a respective forward flange extension 34a of the back wall 34. Sets of Z-brackets 38 and 39-39a are welded to the top and bottom corners of the side walls 10d and are bolted at 40 to the legs 35 and fianges 34a. The bolts in the ilanges 34a also connect iianges 41a of a mounting panel 41 which is spaced by an air gap behind the back wall 34 of the shield and extends above and below the top and bottom levels of the shield. Mounting holes 42 are located in the extensions of the panel 41 to receive screws for securing the unit to a bulkhead.

Directing attention to the portion of the heat exchanger beneath the fire grate 11, housed therein is a removable ash box 43 and a combination under-fire draft control and ash box cover 44. The ash box 43 takes the form of a sheet metal drawer which slides through the opening .13a between the cross-piece 10g andthe bottom wall 10b to directly underlie the grate 11. However, the front wall 43a of the ash drawer is purposely shorter than this opening 13a so that there will be an under-fire draft gap between the top of the front wall 43a and the bottom edge of the cross-piece 10g. Air fiow through this gap is controlled by the front wall 44a of the combination unit 44 which is of a size to -completely cover the opening 13a. The remainder orf unit 44 comprises a slide tray 44h open at the rear and having a pair of up-turned shallow side flanges idc-44C which t part way over the sides 13b of the ash drawer 43.

T he ront draft control wall 44a has a lower handle ddh of loop configuration above which there is a rectangular cutout 44d to receive a matching handle 43h on the front of the ash drawer. To keep the ash drawer 43 and combination unit 44 in position and prevent rattling, the side Walls i315 and the side flanges 44C are provided with respective leaf springs 13s-44s, one above the other, which are secured at one end and free at the other, and belly outwardly in the center to yieldingly engage the lower portion of the side walls 10c of the heat exchanger as illustrated in FG. 4.

A stub exhaust stack 5t! is provided in a center opening in the top `wall a of the heat exchanger for` receiving a vent pipe equipped with a standard damper disc (not shown). The outside opening of the vent pipe should be covered with a suitable draft cap to keep out water and give a constant negative draft.

The stove of the present invention may be very compact; for example, the heat exchanger 10 may be 6 X 6 x 13 with a 3" stack, in which case the shield 31 may be spaced about an inch `from the heat exchanger, and the mounting panel 41 about 3A behind the shield. For this example, a minimum clearance of 4 below the stove and of 12" on the sides of the stove are recommended. If this side clearance is not possible for a particular installation, additional shielding in the form of side plates duplicating the mounting plate 41 may be provided.

It is preferred that the heat exchanger and related parts be made of a non-corrosive high heat-resistant material such as stainless steel. However, the exterior of the heat exchanger should be painted dark for maximum heat radiation and the front face of the mounting plate 41 and of the adjacent back wall 34 should be light for maximum heat reflection.

To start the stove, a sheet of newspaper is crumpled and placed on the grate 11 together with a handful of charcoal briquets or other fuel. The paper is ignited after opening the vent pipe damper and opening the lower draft cover 44a by pulling the lower handle 44h out about an inch. The door 14 is then closed and the slide damper 22 placed in lowered closed position. After the fire is well started the vent damper in the stack is adjusted toward closed position to contain the stove heat and conserve fuel. The lower draft control 44a may be closed or left open as necessary to maintain the desired iire.

After the lire is well started the stove can be used as a fireplace by opening the slide damper 22 in the door, or when not on a boat underway, by removing the door completely by lifting it free when partly open. The top surface of the heat exchanger may be used for warming or cooking.

During operation of the stove, air circulates upwardly around the heat exchanger and also in the space between the back wall 34 and the mounting plate 41. This not only aids heat circulation but helps to keep the surrounding structure from overheating. The exterior side `grills not only protect from direct contact with the hot heat exchanger, but also serve to increase convection heating. At the same time the open area of the grill allows the direct passage of radiant heat from the sides of the stove.

The removable drawer 43 below the fire bed collects the ashes and permits ash removal without disturbing the re. Preparatory to removing the drawer 43, the unit 44 is withdrawn by gripping the handle 44h, and is then inverted to locate the tray 44!) uppermost with the handle 43h back in the cutout 44C for application as a cover on the ash drawer 43 when it is removed as illustrated in FIG. 6. With the unit 44 over the drawer 43 the ashes can be dumped `without diiculty even in a stiff breeze by gradually opening the cover with the assembly upside down.

It is believed that the invention will have been clearly understood from the foregoing detailed description of our illustrated now preferred embodiment. Minor changes in the details of construction will suggest themselves and may be resorted to without departing from the spirit of the invention. We accordingly intend that no limitations be implied and that the hereto annexed claims be given a scope fully commensurate with the broadest interpretation to fwhich the employed language fairly admits.

What is claimed is:

1. A stove comprising a sheet metal heat exchanger having a fire box exhausted at the top and having a bottom ash collection chamber with respective front openings, a grate between said fire box and chamber, a door on the front opening of the lire box, a removable ash collection drawer in said chamber and leaving a gap in the upper part of the front opening of the ash collection chamber, a removable and invertable bottom `damper covering said gap and overlying the front of said drawer, said bottom damper being slidably mounted relative to said drawer for selectively controlling air circulation through said gap and grate and said bottom damper serving as a tray normally underlying the bottom of said drawer and adapted to serve as a cover for the drawer when the bottom damper is inverted, shield means surrounding the sides and back of said heat exchanger is in spaced relation thereto, and means `for mounting said shield means on the heat exchanger.

2. A stove according to claim 1 in which said bottom damper has a front handle and a cutout, and said drawer has a front handle extending forwardly through said cutout, said cutout being located such that said drawer handle will project through the cutout when said tray is beneath the `drawer and also when the tray is serving as a cover for the drawer.

3. A stove according to claim 1 in which said door has a bottom grill portion selectively covered by a vertically sliding shutter and means for selectively locking said shutter relative to the door.

4. A stove according to claim 1 in which said shield means has a front brace, and said door is hinged at its bottom end, and has an upper latch swingably mounted thereon to move from a locked position between said brace and heat exchanger to an unlocked position beneath the level of said brace.

5. A stove according to claim 4 in which said door is detachably hinged at its lower end for lift-out from said heat exchanger when the door is open, said latch by engagement with said brace resisting upward movement of the door relative to the heat exchanger when the latch is in locked position.

6. A stove according to claim 1 in which an additional shield is spaced behind the back of said shield means and is secured to the shield means, said additional shield also serving as a mounting -bracket for the stove.

7. A stove according to claim 1 in which said shield means has respective open grills opposing the sides of the heat exchanger and is closed opposite the back of the heat exchanger, and an additional shield spaced behind the back of said shield means and projecting above and below the top and bottom of said shield means, said additional shield being connected to said shield means by forwardly extending closed extensions of the additional shield and having openings in its upper and lower projecting portions to receive fasteners for mounting the stove.

8. A stove according to claim 1, in which said shield means has respective open grills opposing the sides of the heat exchanger and is closed opposite the back of the heat exchanger, an additional shield spaced behind the back of said shield means and connected thereto by forwardly extending closed extensions of the additional shield to form a vertical tunnel open top and bottom.

5 6 9. A stove according to claim y8 in which said shield References Cited means and .additional shield both extend below the lev el UNITED STATES PATENTS of the bottom of said heat exchanger, and 1n whlch sa1d tunnel is exposed at its lower end to the space beneath 635566 10/,1899 Mllbum 1%65 X said heat exchangen 5 2,716,405 8/ 1955 Nelson 126-67 X 10. A stove according to claim 1 in which said door has a pair of side rails presenting opposed channels, a FOREIGN PTENTS solid corrugated upper panel and ya lower grill panel 222,188 6/*1959 Allstralla. mounted in the back of said channels, a slide shutter ex- 156,873 1/21921 Great Britain.

tending between said channels for selectively covering said 10 587,182 4/ 1947 Great Britain. grill, and a lock screw at'the top of the shutter to selectively bear Iagainst the upper panel. CHARLES J. MYHRE, Przmary Examiner.

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