US2421743A - Metal screen - Google Patents

Description

I June 10, 1947. w. G. CARTTER EII'AL 3 METAL SCREEN Filed June so, 1944 VV/ZL/AM 6: CAETTEE, JEQEOLD A. DUFF)? ATTORNEY.

INVENTORS.

Patented June 10, 1947 UNITED STATES PATENT OFFICE METAL SCREEN William G. Cartter and Harold A. Duffy, Monrovia, Calif.

Application June 30, 1944, Serial No. 542,866

Claims.

This invention relates to an improved metal screen construction and method of fabricating, such screens being of a character suitable for radiant mantles in gas heaters, plates on gas stoves, air filters, and various other types of plates or partitions where a Wall structure of a foraminous nature is desired or required.

A series of adjacently arranged wire coils provides an efiicient screen element for uses where air or other gases are intended to pass through in a broken or tortuous path. In the case of such a screen employed as a radiant mantle wherein a gas burner is located adjacent or in proximity to such screens the wire coils may be heated to incandescence at the same time permitting products of combustion to rise through or otherwise pass through the interstices between the coils. In the case of air filters air may be forced through such coils which if coated with oil or some other viscous or tacky substance will cause foreign particles to collect thereon while permitting the cleaned air to travel through.

Screens of this type as heretofore manufactured have required welded connections of the wire coil to some form of supporting medium or enclosure, and in the case of intermediate ribbons or partitions between adjacent coils such ribbons or partitions have also been required to be welded to a frame or supporting enclosure. Considerable limitation has been thus imposed in the manufacture and adaptation of such metal screens, in that (1) highly skilled labor must be employed to assemble them; (2) their size and shape and consequently adaptations of the same have been limited by the structure; (3) provision for expansion and contraction of the wire coils and supporting elements or dividing elements has not been adequate for some purposes; and (4) in the event of damage or destruction of the wire coil or coils or one or more of the supporting partitions or ribbons the entire unit is. thereby rendered faulty and must be discarded or repaired by replacement of the entire coil or ribbon element.

It is an object of our invention to provide a metal screen of the character described which involves an exceptionally simplified process of manufacture, the assembly being feasible by the use of unskilled labor. The wire coils and dividing ribbons are not fixedly anchored but are suitably confined within a channeled frame, adequate provision is made for expansion and contraction of the wire coils and the dividing ribbons, the screen by reason of its inherent character is adaptable for manufacture in various sizes and shapes, and if any one or more of the wire coil elements or dividing ribbon elements are damaged or destroyed only such deficient elements need be replaced and the entire unit can bereadily and simply repaired by opening up the confining channel frame and inserting replacement elements therein We thus overcome all of the objections to former structures noted above and achieve other objects and advantages which will become more apparent from a consideration of the detailed description which follows taken in conjunction with the drawings.

In the drawings:

Figure 1 is a top plan view of a screen embodying our invention. The same view might be considered an elevation of the screen if the same is regarded as having a vertical installation.

Figure 2 is an enlarged fragmentary section of the screen.

Figure 3 is a fragmentary cross section of the screen taken on the line 33 of Figure 2.

Figure 4 is a cross sectional View of one of the dividing ribbons'or partitions.

Figure 5 is a plan view or an elevational View illustrating the assembly of the screen.

Figure 6 is a fragmentary elevational view of the upper right hand corner of the screen looking from the right hand side.. V

Our screen It! comprises a channel frame ll supporting and confining a plurality of wire coils l2 arranged in parallel relationship and the coils being separated by a plurality of preferably fluted ribbons or partitions l3.

The frame I0 is U shaped in cross section as will appear in Figure 3, providing a channel M of sufficient width to freely accommodate the wire coils l2, the width of the channel being slightly greater than the outside .diameter of the coils whereby such coils may be easily inserted or withdrawn but at the same time being retained by the channel of the frame in substantially parallel relationship in the same plane. The depth of the channel is preferably of about the proportion illustrated which is approximately equal to the outside diameter of the wire coils. It is sufiicient,' however, if the channel is deep enough to extend to approximately the tangent of the coil which rests therein, being in such case equal to approximately one-half the. outside diameter of the coil.

This channel frame may be made by a continuous process well known to the metal art wherein a flat strip of sheet metal is formed into the chan nel. The strip of formed metal is suitably cut into lengths representing the perimeter of the finished frame. Spaced notches 15 are cut in the sides I6 of the channel at points representing the corners of the finished frame. In the form illustrated, these notches iii are formed with an angle of approximately 90 so that when the outside wall ll of the frame is bent to produce the desired rectangular configuration clearance is provided whereby the edges of the notch approximately meet as shown.

At one end of the frame section the side walls I6 are cut away leaving an extending tongue or cleat 20, the latter being a continuation of the wall I I. At the other end of the frame the wall I! is cut away approximately half the width of such ,wall leaving a pair of extending tongues o cleats 2i and 22, these latter being continuations of the side walls [6 of the frame.

Assuming that the frame channel has been formed with the spaced notches and end cleats described, such frame is bent into the form illustrated in Figure which represents the letter U with one of the vertical arms longer than the other. Such form provides an open guide comprising side legs 23 and 24, a bottom end leg 25, and an extending leg 26 which will be bent over to form the top end leg of the frame when finished.

This arrangement provides parallel opposing guide channels defined by the legs 23 and 24 into which sections of wire coil l2 and intermediate fluted ribbons l3 can be slid by an operator.

The wire coils can be of any suitable metal with the helical turns having such spacing as meets the requirements of the purposes for which the screen is intended. The coil sections are preferably slightly shorter than the inside space between the walls I! of the opposite legs 23 and. 24 to facilitate ready insertion of the coil sections and also provide for expansion of the coils when heated. Ease of assembly is the most important function in this respect, as the coils will accommodate themselves to normal expansion of the metal. Ifintended for use as. a radiant mantle, chrome steel would be a suitable metal for the coils, but other metals are also suitable for the purpose, and a. wide variety of metals can be employed for the various uses to which the screen may be put. It is not necessary that the coils be made of spring wire although for some purposes such might be preferable.

The separating ribbons or partitions [3 may be made from thin, flat strips of metal preferably fluted in the manner illustrated to provide alternate oppositely disposed arcuate segments 30 adapted to engage a contiguous segmental area of adjacent wire coils. Such a form of ribbon may have a zig-zag edge 3| such as illustrated, characterized by alternately disposed peaks 32 and 33. The fiuting of the ribbons in the manner described not only provides for supporting the wire coils intermediate of the frame against deformation by sagging or bowing or under the influence of pressure or weight but inherently strengthens the ribbons themselves, thus increasing their efficiency for the purpose used.

The ribbons may be formed with short turned ends 34 adapted to lie parallel and adjacent to the outside wall I! of the frame legs 23 and 24, with the edges 35 of these ends closely adjacent to the side Walls l6 of the frame legs 23 and 24 to confine the ribbons against any tendency to twist or be displaced. These turned ends 34 are not essential, however, as the ribbons may terminate adjacent the frame elements, being in such case merely cut off in suitable lengths. Whether the turned ends 34 are employed or whether the ribbons are merely cut into the required lengths, it is desirable that the end portions of the ribbons be slightly free of the ends, that is to say that the overall length of the ribbons be slightly less than the distance between the inside surfaces of the frame walls not only to facilitate assembly of the ribbons but to provide space for expansion. These ribbons may be made of chrome steel, as an example, or any other suitable metal, having in mind whatever purpose is intended.

After the last wire coil I2 is inserted, the top end leg 26 of the frame is bent over into the position shown in broken lines in Figure 5. Whereupon, the cleat o tongue 20 may be bent down against the outside of the leg 23 and the opposite cleats 2| and 22 may be folded over upon the top (or outside wall) of the leg 26, thus securing the frame, wire coils and fluted ribbons as a complete unit. Any other equivalent or otherwise suitable means for fastening the free corners of the frame may be employed in lieu of the cleat arrangement shown and described.

It is important to note that no welding or mechanical fastenings are necessary between wire coils and fluted ribbons or between either of the latter and the channel frames, the structural shape of the three primary elements being such that the correct relationship is maintained by mutual interaction without supplemental securing means. Moreover, the rigidity of the fluted ribbons in the direction of their width is such that even though very thin metallic ribbons are employed they will prevent distortion of the wire coils either from influence of their own weight or sagging tendency or from any ordinary pressure imposed thereupon. We have thus produced a fiat, substantially firm and rigid perforate or foraminous screen of the character defined in the objects and preamble of this specification, of a durable nature and suitable for numerous purposes.

Although we have herein shown and described our invention in what we have conceived to be the most practical and preferred embodiment,.it is recognized that departures may be made therefrom within the scope of our 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 devices and methods.

Having. described our invention, What we claim as new and desire to secure by Letters Patent is:

1. A foraminous screen comprising: a channel frame having straight side legs, a series of wire coil sections arranged parallel and in substantially the same plane across said frame with their end portions confined in the channels of said frame side legs, and partitioning ribbons having channel-like portions disposed between said Wire coil sections and partially confining said sections between adjacent ribbons.

2. A foraminous screen comprising: a channel frame having straight sides, a series of wire coil sections arranged parallel and in substantially the same plane across said frame with their end portions confined in the channels of said frame side legs, and partitioning ribbons between said wire coil sections, said ribbons being fluted to form alternately disposed substantially arcuate faces engaging segmental surface portions of said wire coils, said wire coil sections and said supporting ribbons being maintained in said frame by mutual interaction of said three elements without any supplemental securing means.

3. A metal screen comprising a channel frame of rectangular form, wire coils and metallic ribbons alternately arranged across said frame with their ends confined in and supported by opposite side channels of said frame, and the end channels of said frame sustaining the outermost coils along their exterior longitudinal surface, said ribbons having oppositely disposed flutes engaging circumferential portions of adjacent coils.

4. A metal screen comprising a channel frame of rectangular form, wire coils and fluted metallic ribbons alternately arranged across said frame with their ends confined in and supported by opposite side channels of said frame, said ribbons being fluted alternately in the opposite direction whereby concave surfaces are formed which engage segmental surface areas of oppositely disposed wire coils contiguous to each of said ribbons, and the end channels of said frame sustaining the outermost coils along their exterior longitudinal surface.

5. A metal screen comprising a channel frame of rectangular form, wire coils and fluted metal- 110 ribbons alternately arranged across said frame with their ends confined in and supported by opposite side channels of said frame, said ribbons being fluted alternately in the opposite direction whereby concave surfaces are formed which engage segmental surface areas of oppositely, disposed wire coils contiguous to each of said ribbons, and the end channels of said frame sustaining the outermost coils along their exterior longitudinal surface, said frame, wire coils, and fluted ribbons being completely detached one from the other except by the mutual confining and supporting engagement effected by the assembled relationship described.

WILLIAM G. CARTTER.

HAROLD A. DUFFY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 662,736 Prahar Nov. 27, 1900 1,674,764 Dauphinee June 26, 1928 2,286,479 Farr June 16, 1942 1,099,786 Brown et a1 June 9, 1914

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