US3025045A

US3025045A - Furnace trays

Info

Publication number: US3025045A
Application number: US760267A
Authority: US
Inventors: Martin N Ornitz
Original assignee: Blaw Knox Co
Current assignee: Blaw Knox Co
Priority date: 1958-09-10
Filing date: 1958-09-10
Publication date: 1962-03-13
Anticipated expiration: 1979-03-13

Description

M. N. ORNITZ FURNACE TRAYS March 13, 1962 2 Sheets-Sheet 1 Filed Sept. 10, 1958 F ig.l.

Fig.2.

F ig.3.

INVENTOR. Martin N. Omiiz BY zQ Z M A ATTORNEYS March 13, 1962 M. N. ORNITZ 3,025,045

FURNACE TRAYS Filed Sept. 10, 1958 2 Sheets-Sheet 2.

INVENTOR. Martin N. Ornitz ATTORNEYS.

Unite I States Patent Ofilice 3,025,045 Patented Mar. 13, 1962 aware Filed Sept. 10, 1958, Ser. No. 760,267 5 Claims. (Cl. 263-47) This invention relates to furnace trays and particularly to trays for carrying articles to be annealed or heat treated through annealing or heat treating furnaces, as, for example, continuous furnaces having doors at each end and rails or rollers therein to support and carry the trays bearing the articles to be treated for passage through the furnace. The trays may be moved through the furnace in series, the doors being opened to admit a new tray and to remove the finally heated tray. Generally, the trays leaving the furnace pass through a water or an air quench. The trays are thus subject to severe thermal shock and are likely to fracture due to the high thermal stresses which occur in the several parts of the tray. My construction is also useful for immovable work supporting trays in other types of heat treating furnaces.

Annealing and heat treating trays have heretofore been used. Such trays are generally made in the form of a grill or a grating integrally cast of a heat resisting steel. Such trays are very susceptible to failure due to the aforementioned thermal shock. Modifications of such integrally cast structure have been proposed in which intersecting members may move differentially in an effort to overcome the problem of failure from thermal shock. For example, Menough Patent 2,710,746 provides a construction in which the intersecting members are not rigidly secured together.

The present invention provides a structure differing from the prior art structures and having a unique articulated construction of simple, effective, inexpensive form relatively free at the joints between the members. In the present invention, the members are free to independently undergo such thermal deflection as may be imposed on them in service, yet the structure is strong, durable, simple and easy to assemble, so that the cost is low.

I provide a plurality of spaced substantially parallel primary elements, each having openings therethrough, a plurality of spaced substantially parallel cross elements disposed transversely to the primary elements and extending through the openings in the primary elements, the cross elements being notched at spaced intervals along their lengths whereby the notches engage portions of the primary elements adjacent the openings therein, and keeper means secured in some of said openings whereby the cross elements are restrained from substantial vertical movement and hence are held in fixed relationship with the primary elements.

Preferably, the keeper means are secured in at least two of the openings for each cross element whereby the elements are substantially restrained from vertical movement. The slots are preferably wider at a portion thereof whereby the cross tie elements may enter initially through such wider portion and then fit within the narrower portion with the notches in the cross tie elements embracing a portion of the sides adjacent the slots of the narrower portions in loose interlocking engagements, and the keeper means is secured in at least two of the wider portions of the slots.

In the foregoing general description, I have set out certain objects, advantages and purposes of the present invention. Other objects, advantages and purposes will be apparent from a consideration of the following description and the accompanying drawings illustrating a preferred embodiment in which- FIGURE 1 is a top plan View of a furnace tray according to my invention;

FIGURE 2 is a side FIGURE 1;

FIGURE 3 is an FIGURE 1;

7 FIGURE 4 is an isometric view of a segment of the tray of FIGURE 1; and

FIGURE 5 is a segmental section on the line VV of FIGURE 1.

Referring to the drawings, I have illustrated a furnace tray having a plurality of spaced substantially parallel primary or load bearing elements 10, each having spaced slots or openings 11 therein. Each slot 11 is provided with a wider main portion 11a and a narrower adjacent offset portion 1112 so as to form an L-shape. A plurality of spaced substantially parallel cross elements 12 are inserted in the slots 11. The cross elements 12 are inserted through the widermain portion 11a of slot 11 until notches 13 in cross elements 12 overlie the narrower otfset portion 11b of slot 11. The cross elements 12 then drop downwardly so that the notch 13 is in engagement with the step forming the narrower offset portion 11b of the slot. A short bar 14 is inserted in the wider main portion 11a of the slot 11 and is welded in place to act as a keeper for the cross elements 12. The cross elements 12 are thus held in interlocking relation in the load bearing elements but are free for movement within the smaller portion offset 11b of the slot 11.

In the embodiment shown in the drawings the load bearing elements 10 are generally symmetrical in section with the slots 11 spaced substantially along their neutral axes, so that the trays are bodily reversible and either side may be the load supporting side. In service they are reversed from time to time as deflections and sags develop due to creep of the alloy material of which they are made, and in such reversed position the trays are self-straightening with respect to deflections formed while in their original position. This feature is preferred in most cases but my articulated tray construction is not limited to use with symmetrical elements or reversible trays.

It will be understood that, while I have illustrated and described a presently preferred embodiment of my invention, the invention may be otherwise embodied within the scope of the following claims.

I claim:

1. A furnace tray comprising a plurality of spaced substantially parallel primary elements, each having openings therethrough each of said openings having a main portion and an offset portion on one side thereof, a plurality of spaced substantially parallel cross elements disposed transversely to the primary elements and extending through the openings in the primary elements, the cross elements being notched at spaced intervals along their lengths, said cross elements being so disposed that the notched portions of the cross element lie in the offset portions of the openings and the notches engage portions of the primary elements adjacent the openings therein, and keeper means whose length is short of and out of contact with the next adjacent primary elements and which are free of the cross elements secured in some of said openings to retain the notches in engagement with the primary elements, whereby the cross elements are restrained from removal from the openings and are simultaneously free to move in loosely fitting fixed relationship with the primary elements.

2. A furnace tray comprising a plurality of spaced substantially parallel primary elements, each having slots therein at spaced intervals, said slots each having a main elevation of the tray of end elevation of the tray of portion and an offset portion on one side thereof, a plurality of spaced substantially parallel cross elements disposed at substantially right angles to the primary elements and extending through the slots therein, the cross elements having notches disposed at spaced intervals along their lengths, said cross elements being so disposed that the notched portions lie in the offset portion of the slots and the notches interlock with the portions of the primary elements adjacent the slots, and keeper means whose length is short of and out of contact with the next adjacent primary elements and which are free of the cross elements secured in at least two of the slots for each cross element retaining the notches in engagement with the primary elements whereby the cross elements are substantially restrained from removal from the slots and are simultaneously free to move in loose fitting fixed relationship with the primary elements.

3. A furnace tray comprising a plurality of spaced substantially parallel load bearing elements, each having therethrough a plurality of slots at spaced intervals along their lengths, said slots each having a main portion and an offset portion on one side thereof a plurality of spaced substantially parallel cross tie elements disposed at substantially right angles to the load bearing elements and extending through the slots therein, the cross tie elements being notched at spaced intervals along their lengths, said cross tie elements being so disposed that the notched portions lie in the offset portion of the slots and the notches embrace the load bearing elements adjacent the slots therein in an interlocking engagement, and keeper means whose length is short of and out of contact with the next adjacent primary elements and which are free of the cross elements secured in at least two of the slots for each cross element retaining the notches in engagement with the primary elements whereby the cross elements are substantially restrained from removal from the slots and are simultaneously free to move in loose fitting fixed relationship with the load bearing elements.

4. A reversible furnace tray comprising a plurality of spaced substantially parallel load bearing elements, each with a plurality of spaced slots along its length, a plurality of spaced substantially parallel cross tie elements with notches spaced along their lengths, said cross tie elements being disposed at substantially right angles to the load bearing elements and extending through the slots therein, said slots being wider at a portion thereof to form a wider main portion and generally rectangular narrower offset portion whereby the cross tie elements may enter initially through the wider main portion and then drop into the narrower offset portion as the notches embrace a portion of the load bearing element adjacent the slots in the narrower offset portion of the slots in a loose interlocking engagement, and keeper means whose length is short of and out of contact with the next adjacent pri mary elements and which are free of the cross elements secured in the wider main portion of at least two of the slots for each cross tie element whereby the cross tie elements are substantially restrained from removal from the slots and are simultaneously free to move in loosely interlocking engagement with the load bearing elements. 5. A reversible furnace tray comprising a plurality of spaced substantially parallel load bearing I-beams, each with a plurality of spaced slots disposed along the web thereof, a plurality of notched spaced substantially parallel tie bars disposed at substantially right angles to said beams and extending through the slots therein, said slots being of generally L-shaped configuration and wider than the tie bars in an upper portion thereof and narrower than the tie bars in a lower portion thereof, the notches in. the tie bars being spaced along the lengths thereof at intervals substantially coincident with the slots in the beams whereby the notches in the notched portions of the tie bars will rest in the narrower portions of the slots and the tie bar will embrace a portion of the I-beam adjacent the slots in the narrower portion of the slots with the tie bars into a loose fitting interlocking engagement with the beams in the narrower section of the slots, and keeper means whose length is short of and out of contact with the next adjacent load bearing I-beams secured in the wider portion of the slots free of the tie bars in at least two of said slots for each tie bar whereby the tie bars are substantially restrained from vertical movement and hence are held in a loosely interlocking engagement with the beams whereby said beams and tie bars may expand and contract independently of each other,

References Cited in the file of this patent UNITED STATES PATENTS 1,140,657 Benjamins May 25, 1915 1,426,736 Hess Aug. 22, 1922 2,710,746 Menough June 14, 1955 2,834,267 Beebe May 13, 1958 l l l 1