US 1973171 A
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Patented Sept. 11, 1934 UNITED STATES PATENT OFFICE FURNACE rani sIGHT William H. iacobi, Keokuk, Iowa, assignor to Springfield Boiler Co., Springfield, Ill., a cer--` poration of Illinois The general object of the present inventon is the improvement of means provided to permit visual inspection of the interier of a furnace chamber, such as the combustion cha'mber of a boiler urnace, in which high temperatures are maintained. More specific objects of the invention are to provide simple and effective means for opening and closing a peep hole in a urnace wall, and for protecting an operator inspecting the interior of the furnace through' said peep hole, against injury from furna'ce heat or glare and for preventing an objectionable i'nflux 'oi air or outflow of furnace gases through the peep hole while the interior of the furnace is being inspected.
'A preferred embodinent of the present invention comprises a peep hole door adjustable to place either a transparent portion or a less fran gible opaque portion of the door in register with the peep hole proper, and preferably adjustable also to move the door entirely out of register with 'the peep hole so that a slice'bar, steam lance or like instrumentality may be inserted in the peep hole. The door and its supporting means are characterized by their mechanical Simplicity and effectiveness, and 'by the easy and effective man ner in'which they may be mounted on a fire door, masonry or other portion of a furnace wall. The invention is further characterized by the provisions made for protecting the glass forming the transparent portion of the door against njury from the high temperature to which it is sub- I jected when in register with the peep hole.
The various features of novelty which characterize my invention are pointed out withparticularity in the claims annexed to and forining a part of this specification. For a better understanding of the invention, however, and the advantages possessed by it, reference should be had to the accompanying drawing and desoriptive matter in which I have illustrated and described a preferred embodiment of the invention.
Of the drawing:-`
Fig. 1 is a sectional elevation of a portion of a furnace wall provided With a peep ho le;
Fig. 2 is an elevation of the peep hole door and doorway; i
Figs. 3 and 4 are views taken similarly to Fig. 2 with the movable door shownin dierent positions; and
Fig. 5 is a partial section on the line 5--5 of Fig. 2. i i
In the drawing, A represents the wall of a furl nace chamber, such as the combustion chamber of the boiler furnace, in which high temperatures of the` opening A'.
are maintained, and A' represents a peep hole opening formed in the wall proper. When the peep hole is formed in a masonry portion of the furnace wall, the peep hole is advantageously conical in form with its outer end smaller than its inner end. In'such case also, the peep hole is advantageously provided with a lining A formed of suitably shaped tiles or refractory cement.
- Attached to the furnace wall at its outer side, as by means of bolts -B' imbedded in the lining A is a metallic peep hole door frame B. The 'latter is advantageously formed, as shown, with a plate-like body portion B having a. hollow boss or tubular extension 13 at its outer: side, the axis of the passage in which is in line with the axis The outer end of the hollow boss B forms a seat 13 for a door member C shown as hinged by a pivot pin'c' to a lug B formed on the tubular portion 13 of the member 315 B. The doormember C comprises a portion C of suitable thickness to insure durability, which normally engages the seat 13 and closes the peep hole `as shown in Figs. 1 and 2. The door mem- .ber C is formed with a Window opening C which is brought into register with the peep hole when the member C is in the position shown in Fig. 3. The parts Band C may advantageously be formed of cast iron or steel, or oi a more refractory metal alloy in some cases. r i
The door member C supports a transparent body or window pane D which extends across the openingC The window pane D is preferably in the form of a disc made of highly refractory glass, and the gla'ss is advantageously colored to cut down the transmission of heat and light rays while: leaving the glass sufiiciently transparent. As shown, the glass D is held between annular clamping members E and E' Secured to the body portion of the door C, as by screws E `'I'o reduce the risk of overheating the glass D, I advantageously nterpose a'wire screen F between the glass D and the interior of the furnace. This screen F may be formed of Monel metal or other metal wellsadapted to withstand high temperatures. As shown, the' screen F is clamped between the body of the, door C -at the margin of the opening C and the clamping ring E', so that the screen is in good heat conducting relation with the door and clamping rings. quence it Will be maintained at a relatively low temperature, and partly by intercepting heat rays and partly by absorbing heat by radiation from the inner face of the glass D, the screen F is thus effective to prevent the glass D from attaining In consean objectionably high temperature during the period:: in which the glass is exposed to the heat of the urnace through the peep hole. As a further protection against injury of the glass when the latter is heated and cooled I advantageously form a small aperture in the glass at or about its center. Thisapertu'e serves, as I have found, to substantially'reduce the risk of glass fracture as a result of its thermal eXpansion and contraction.
In the preferred Construction illustrated the adjustment of the door C is facilitated by providing it with a handle G mounted on a:pivot pin G earried by cars 0 formed for the purpose on the door. The handle G is advantageously provided with a tongue Gr adapted to enter the space between a pair of lugs B formed on the boss B when the door is in its normalor closed position of the apparatus as shown in Figs. 1 and 2. As shown, the tongue G is formed with oppositely projecting portions (3 constituting lock bar parts which in'the position of the parts shown in Figs; l and 2, are behind the lugs B so that the door is then snugly held'in its closed position. g
Advantageousiy and as shown, the door C is provided with a stop C which engages the boss `B when the parts are turned into the position .shown in Fig. 3. 'It is contemplated that the door will be manually held in the position shown in `E'ig. 3 by the operator inspecting the furnace, during 'the inspection periods, and the stop 0 assists the operator in holding the door in proper position for inspection ipurposes. `As appears sfromrFig. 4, the stop C may also seri/ethe further purpose of holding the cloormemberC in the position in which no 'portion of the door memberC extendsacross the `peep hole opening. When the door is in the ;position shown in Fig. 4, 'the action of 'gravity tends to maintain it 'in that position.
Except when in the "position shown in Fig.- 4, gravity tends to hold the door 'in its normally :closedposition shown in Figs. 1 and.2.
In the position of the door shown in Fig. 4,'a
slice bar, steam lance or'analogous :instrumen- 'FandcglassD are :brought'into position above "the boss'B fto permit :theremoval of furnace dust eaccumulating on the door parts and impairing `thetransparency of the glass D. While the present invention may be used in connection with peepholes 'of varioussizes, 'ithas been found convenient and desirable 'inlthe use of the present inventionto make the minimum diameter of the :peep hole iapproximately five inches, as a hole `nisur-;h size :is convenient and suitable not only foriinspection purposes, but also for the insertion and manipulation of a slice bar, steam lance or liker instrumentality.
'As those skilled in theart will readily understand, the construction illustrated is simple, dur- 'able and efiective, and' is relatively inexpensive tomanufacture .and install. It can bereadily attached to aurnace fire or :inspection door as well as 'to brick work, and may be mounted on the brick work of `the furnace without requiring 'obi 'jectionabl'e modfication'of *suchbrick work. The
provision of a suitable inspection opening or `-'openings facilitated by the use of the present invention, contributes to efiiciency in furnace op- :in the art that changes may be made in the form of the apparatus disclosed without departing from the spiritof my invention as set forth in the appended claims and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.
Having now described my invention, what I ;claim as new and desire to secure by Letters Patent is:-
l. A furnace peep hole door Construction com- :prising a door frame memberadapted to be attached to a substantially vertical wall of 'the fur-hace and formed with an outwardly projecting bosshaving apeep hole passage therethrough, a
door member pivotally connected to said frame member to ireely turn with respect thereto in 'a Vertical plane about an axs at one side of said passage into cne `or another of three positions and comprising a transparent portion in register with said passage in one .of said positions and an opaque portion in register with said passage in another of said positions, :said door member being out of 'line with said passage in the third position, a projection carried by said door member and engaging said boss .when the door member is in said third position, said members being so relatively arranged that when the door member isin saidthirdpositiongravity tends .to maintain the door member in said ,position and when in said first position gravity `tends to move the door member into said second position.
2. A furnace peep hole door Construction comprising adoorrame member .adapted to be attached to the wall of `the lfurnace .and formed with an'outwardly p'ojecting boss having a .peep hole passage therethrough, a doormem'ber pivotally connected `to said framelmember to turn with respect thereto in -a vertical plane about an axis at one side of said passage into one or another of three positions and .comprising a 'transparent portion in register with said passage in one of said positions and an opaque portion in register with said passage inanother of said positions, said door .member being out of line with said passage in the third position, said members having cooperating positioning.partspositively' indicating when said door member is in any one of said three positions.
3. The combination with a substan'tially .vertical wall of `a furnace chamber having a peep hole extending through said wall, of a structure at the outer end of said peep hole comprising a 'for'the passage of cooling air to the furnace side thereof. i
4. The combination with a substantially Vertical wall of a furnace chamber having a peep hole extending through said wall, of a structure at the outer end of said peep hole comprising a frame formed with an opening substantially registering with said peep hole, and a door arranged to be swung in a vertical plane parallel to the plane of said. opening to a plurality of operating positions, a transparent member mounted in said door and arranged to register with said opening in one position of said. door, a small central aperture in said member for the passage of cooling air to the fu'naoe side thereof, and. a Wire screen mounted in said door at the furnaoe side of said member and in good heatconducting re lation with said door.
5. A furnace peep hole door structure including a transparent member of colored glass having one side exposed to the interier of a furnace and its other side to atmosphere and mounted in a movable part of said door structure, said member being formed with a small central aperture for the passage of cooling air to the furnace side of said member.
6. A furnace peep hole door construction comprising a door frame member adapted to be attached to a substantially vertical wall of the furnace and formed. with an outwardly projecting boss having a peep hole passage therethrough, a door member pivotally connected to said frame member to turn with respect thereto in a vertical plane about an axis at one side of said. passage into one or another of three positions and comprising a transparent portion registering with said passage in one of said positions and an opaque portion register-ing with said. passage in another of said positions, said door member being out of register with said. passage in the third position, a projection carried by said door member and engaging said boss when the door member is in said first and third mentioned positions, said members being so relatively arranged that when the door member is in said third position gravity tends to maintain the door member in said position and when in said first position gravity tends to move the door member into said second mentioned position, and means for looking said door member in said second position.
WILLIAM H. JACOBI.