US1643766A - Heat-resisting plate - Google Patents

Description

Sept. 27, 1927.

A. FAHRENWALD HEAT RESISTING PLATE Filed April 21. 1926 Patented Sept. 1927.

UNITED STATES A 1,643,766 PATENT OFFICE.

FRANK A. FAHRENWALD, OFCHICAGO HEIGHTS, ILLINOIS.

.nnl'r-nnsrs'rmo PLATE.

Application filed April 21, 1926. Serial No. 103,655.

This invention relates to plates used for providing heat-resisting metallic surfaces, such, for instance, as furnace hearths, dampers, and the like, and has for its object to provide a plate which will not crack or warp when subjected to unequal temperatures at different points in its area, or fluctuating temperatures as encountered in the average high temperature, operations. 1 Attempts heretofore made to use plates in the situations referred to have generally involved the use of solid one-piece plates, either of cast or rolled material, but the maintenanceof'fiat or unchanging metal surfaces, particularly when carrying loads at high temperatures or when used for heat checking purposes, have involved the most trying difficulties because of the short life of such members due to excessive warping and cracking. In practically all flat metal surfaces exposed to high temperatures, the heating of the member providing the surface is unevenly distributed throughout the exposed area. Moreover, the temperature fluctuates from time to time, both in location and degree, and the expansion and contraction attending these temperature fluctuations eventually cause the metal to crack or to buckle or Warp in accommodating itself thereto; and this occurs even in plates made of heat resisting alloys. For these reasons, it is not economically practicable to pro: vide heat resisting surfaces of large areas by a single piece plate.

In my Letters Patent No. 1,629,689, issued May 24; 1927, for heat resisting dampers and the like, disclosing by way of illustration a movable heat resisting barrier but including a construction applicable to heatresisting walls in general I have disclosed means by which to overcome the abovestated difficulty, and this is accomplished by making heat-resisting plates, whether for use in providing hearth surfaces where they are mounted horizontally, or approximately horizontally, or for dampers, or the like, where they are either mounted horizontally or suspended or otherwise supported in substantially vertical position, of an assembly of relatively small plates or members, so arranged with respect one to another and to the whole area that the stresses caused by thermal expansion and contraction do not exceed a predetermined maximum at which the surfaces of the members will retain their original form indefinitely; these members being provided with means for maintaining them in their predetermined relative positions in which they collectively make up the whole surface required, without material interruption of the surface at the places where the members meet.

Since one of the principal difficulties encountered in making a heat-resisting plate of a plurality of separately formed members assembled edge to edge, is in providing proper interengagement of the members to interlock them and hold their edges in proper registry without interrupting or obstructing the working surface, the invention of my said Letters Patent further consists in the provision of oppositely extending interspaced projections or lugs which lie all on one and the same side of the plane of the wall, and preferably the side opposite to the working surface, and at the meeting marglnal portions of said members, so that each member carries one or more such lugs or projections which cross the meeting edges and lap upon the adjacent member, thereby avoiding displacement of each member in either direction perpendicular to the working surface.

Inasmuch as some uses of sectional plates embodying the present invention will render desirable the provision of means for interlocking the separately formed members against relative displacement in the plane of the working surface, the present invention supplements the invention of the said Letters Patent by constructing some of the interlocking parts for interengagement in the last-named direction in addition to the interlock which they effect in the direction perpendicular to the Working surface, this being accomplished, for instance, by providing slots in a suitable number of the lappmg lugs or projections, and providing studs or dowel-like projections in registry with these slots on the members which the slotted lugs overlap.

In order that the invention may be fully understood, the preferred embodiment thereof is illustrated in the accompanying drawing, in which- Figure 1 is an outer face elevation of a multiple section plate, the members of which are provided with means for interlocking them when assembled edge to edge.

Figure 2 is an inner face elevation of the same, showing the working surface provided thereby.

- one of the constituent sections or members of theil plate separated from the other members; an

Figures 7 and 8 are, respectively, a detail elev'ational view and a transverse section on the line 8 8 of Figure 7 showing the means for interlocking the members against displacement in the plane of the working surface.

1 represents end members and 2 intermediate members, of which latter there may be any desired number assembled to produce a plate suitable for forming the working surface of a heat resisting plate, for instance, a furnace hearth. These plat-es have on one side substantially smooth and unobstructed surfaces which collectively provide the area of working surface required, and upon their faces opposite to this working surface, each is provided with one or more lapping lugs or projections 4 integral with the marginal portion, through which the member meets an adjacent member. There are lapping lugs 4 on each member at each point 5, so that neither member can move relatively to the other in a direction perpendicular to the working surface. In addition to the lapping lugs 4, a membermay carry on its marginal portion, other integral lapping lugs 6 formed with slots 7, and the meeting marginal portion of an adjacent member may be formed with integral studs or dowels 8 in position to enter the slots 7 and thereby hold the members against separation in the direction of the plane of the working surface, see particularly Figures 6, 7, and 8.

Preferably, the members are beveled or chamfered at their meeting edges 5, as shown more clearly in Figure 8. For convenience in assembling the members or plate sections,

the studs or dowels 8 may have such tolerance I of the plate section or member as tofacilitate assembly, the lug being thereafter pressed into parallelism with the plate.

Preferably, the plate sections-will be produced from heat-resisting alloy.

I claim:

1. A sectional heat resisting plate, comprising a plurality of plate sections assembled in a plane edge to edge, the meeting marginal portion of each plate section at the line of meeting being provided with a. lug or lugs projecting therefrom in the direction of the plane of the plate and lapping'upon the plate section which meets it, the lugs on the two sections at each line of meeting being on the same side of the plane of the plate, and means being provided for interlocking the plate members against separation in the direction of the plane of the plate.

2. A sectional heat resisting plate, com-' prising a plurality of plate sections assembled in a plane edge to edge, the meeting marginal portion of each plate section at the line of meeting being provided with a lug or lugs projecting therefrom in the direction of the plane of the plate and lap ping upon the plate section which meets it,

the lugs on the two sections at each line of meeting being on the same side of the plane of the plate, and means being provided for interlocking the plate members against separation in the direction ofthe plane of the plate, consisting of openings constructed in some of the lapping lugs and projections on marginal portions of adjacent sections which enter said openings.

Signed at Chicago, Illinois, this 14th day of April, 1926.

FRANK A. FAHRENWALD.

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