US3383822A - Grating - Google Patents

Description

May 21, 1968 A. VIEHMANN ETAL 3,383,822

GRATING Filed Dec. 1'?, 1965 Z 427 I 45 442744 zg f* l INVENToRs: Z y? GEoRGEAA/IEHMANN DENNIS A. ASEDGLEY WAYNE RowNlNG THEIR ATTORNEYS United States Patent O" 3,383,822 GRATING George A. Viehmann, New Providence, NJ., and Dennis A. A. Sedgley, Etobicoke, Ontario, and Wayne Browning, Toronto, Ontario, Canada, assignors to Construction Specialties, Inc., Cranford, NJ., a corporation of New Jersey Filed Bec. 17, 1965, Ser. No. 514,4S 3 Claims. (Cl. 52-667) ABSTRACT 0F THE DISCLGSURE As described herein, a grating includes a plurality of elongated support bars, each bar having a base ilange, a top flange and a connecting web having a bi-concavical shape, and key members for connecting the support bars together in substantially parallel, spaced-apart relation. The grating further includes a plurality of wear strips which are removably attached to the support bars by longitudinally extending grooves formed in the top anges of the bars.

This invention relates to gratings and, more particularly, to a novel and improved grating for installation in openings in sidewalks, streets, floors or buildings and the like.

Conventional gratings often comprise either a metal casting which has a plurality of openings or which has interconnected crossed series of spaced-apart plates or strips. Among the many disadvantages with the gratings of the metal casting type are that they are expensive to produce inasmuch as molds are required for each sizecast grating. Gratings made up of spaced-apart metal bars are also costly, the means for connecting the bars being complicated and time-consuming to assemble, requiring, for example, riveting, bolting or welding of a large number of elements to connect them. Furthermore, it has been almost impossible to achieve uniform spacing and parallelism of the grating bars where separately formed spacers are used in the assembling of the grating bars. The spacers cannot be cut to uniform length and with ends perpendicular to their axes so that the gratings assembled with spacers have visible irregularities in the relation of the grating bars.

Another disadvantage of the presently known gratings, particularly when they are located in heavily traveled places, such as the entrances to buildings, is that the upper surfaces of the grating bars which are walked across quickly wear smooth and are thereby rendered slippery and dangerous and the grating must therefore be replaced or the surface repaired. In order to overcome the expense and inelciency of replacing the grating or repairing the surface, gratings have been devised which have grooves cut out in the top surfaces of the support bars for receiving replaceable rubber wear strips. While this has resulted in considerable improvement in design, some dissatisfaction arises from the fact that the only method for installing or removing the wear strips from the grating bars is by sliding the strips into or out of the grooves located in the top surfaces of the bars. It can readily be seen that due to the exible characteristic of the rubber, the replacement and installation becomes exceedingly difficult with increased sizes of gratings.

The foregoing and other disadvantages of presently devised gratings of the above-described types are overcome in accordance with the present invention by a novel and improved iloor grating comprising a plurality of elongated support elements or bars of generally I or T-shaped cross-section having a base flange, a top ilange and a connecting web, and key members for connecting the support elements together in substantially parallel, spacedapart relation. Advantageously, the key members com- 3,333,822, Patented May 21, 1968 prise elongated metal strips or bars of generally rectangular cross-section which are inserted through the aligned openings in the webs of the grating bars and then are twisted to engage the Webs of the bars in locking relationship and maintain the support elements in substantially parallel spaced-apart relation.

The grating further comprises a plurality of wear strips which cover and are removably attached to the grating bars by longitudinally extending grooves formed in the top ilanges of the bars. Each groove is generally an inverted keystone-shape in cross-section deiined by a longitudinally extending base, side walls which diverge obliquely from the base toward the top of the groove and longitudinally extending ilanges which extend inwardly beyond the side walls of the groove. The wear strips have ribs which are received in the grooves of the support elements and are generally complementary to the grooves and cover portions which are substantially coextensive with the top anges of the grating bars. The construction of the wear strip is such -that the wear strip can be rolled or pressed into the grooves and when so inserted the connecting web of the wear strip is pulled downwardly and the cover portion is held flat against the surface of the top tlange of the grating bar.

The grating bars of the grating are best formed by extrusion of a suitable material, such as bronze or aluminum. The extrusions are then sheared at suitable intervals to provide bars of the desired length.

The key members which interconnect the support elements are also best formed by extrusion, and the spacing slots of the key members which engage the webs of the grating bars may be stamped, cut or otherwise formed at appropriate and accurate spacings, depending upon the type of grating desired.

The wear strips which are preferably made of a desirable plastic, such as a vinyl plastic, by molding or extrusion, and then installed by rolling or pressing their lower ribs into the grooves of the support members and the grating is thus completed.

The yfabrication of the parts and the assembly of the complete grating, as described above, are highly efiicient and simple `for the reason that the key members are of one part structure and a locking relationship and alignment and spacing of the support elements are effected merely Eby inserting and twisting the key members. By suitably 4forming the key members, a l'Wide variety of bar spacings can be provided so that the purchaser of such a grating is not limited in his choice to a particular standard grating as he would lbe if he chose to buy cast or similar gratings.

Another important advantage of the grating is that the wear strips, because they can be pressed or rolled into the grooves of the support elements, can `be replaced easily -when they become w-orn.

lFor a better understanding of the invention, reference may be had to the following description of an exemplary embodiment, taken in conjunction with the figures of the accompanying drawings, in which:

FIGURE l is a View in cross section of the grating, not in locking relationship, and with the wear strips removed from the support elements;

flange y12, a top flange 14 and a connecting web 16, and key members `18. The key members 18 comprise elongated metal strips inserted through aligned key bed openings `22 in the connecting webs 16 of the support elements and then twisted to receive the connecting webs 16 0f the support elements -10 in locking relationship and maintain the support elements 1i) in substantially parallel spaced-apart relation as shown in `-FiGURES 3 and 4.

More particularly, the key members 18 are spacing bars which comprise a rod-like center member 28, substantially rectangular side members and 32, and substantially rectangular notches or cutouts 34 of about the same or slightly less width than the web 16 for aligning the key members 18 Iwith the bars 1li. Upon initial installation, the key members 18 are pushed through the key bed openings '22 in the webs 16 of a plurality of the bars 10, the openings 22 being generally complementary in shape to the key members 13. The cutouts 34 are aligned 'with the openings 22 in the connecting webs d5 (FlG- URES 1 and 2). Thereupon, the key members 18 are gripped between the .bars `1G and rot-ated or twisted about 90 until a locking relationship is attained between the key members 18 and the connecting webs 16. In the preferred embodiment of the invention, the connecting webs 16 have concavities or shallow concave grooves 31S and 36 in their opposite sides. Inasmuch as the spacing slots G4 are preferably of rectangular cross section and wider than the portion of the web between .the grooves `35 and 36 in the -web dd, the key members can be rotated relatively freely until the key member is turned tirough an angle of about Thereafter the key member 18 engages the web 16 above and below the grooves 3S and 36. `Due to the tight lit of the web 15s in the notches 34, sculling of the web occurs which results in -a tight interlock between the key members and the grating bars.

T he grating further comprises wear strips 24, removably attached to the bars 10 by longitudinally extending grooves 26 formed in the top flanges `14 of the -bars di?. Each of the grooves 26 of bars 10 comprises a longitudinally extending base 37, obliquely diverging side walls 38 and 40 and inwardly extending flanges 42 and 44 having diverging curved surfaces 45 and 46 merging with upper surface of the top flange The wear strips 24 have outwardly extending generally triangular ribs 47 which are received in the grooves 25, Connecting webs 48 on the strips 24 extend between the flanges 42 and 44 and are united with the cover strips 50 which cover the top lilange 14. The wear strips '24 are preferably made by molding or extrusion of a moderately resilient elastomer or polymer. Vinyls are preferred inasmuch as they are highly durable and provide .for a long, useful service. In addition, in order to minimize slippage and `facilitate the drainage of water, cover strips 50 may have circular upper surfaces, rectangular upper surfaces, or may be provided twith longitudinal grooves in their upper surfaces.

Due to the sh-ape of the ribs 47 and webs 4S of wear strips 24, the curved surfaces 45 and 45 on the flanges 42 and 44 and the resilient characteristic of the wear strips 24, the installation of the strips 24 can be accomplished merely by rolling or pressing the strips 214 into the grooves 26 so that the ribs 47 snap beneath the flanges 4 2 and 44 thereby locking the cover strips to the bars. Replacement is accomplished by prying one end of the strip from a groove and then peeling the wear strip 24 out of the grooves 26. Because of this, the replacement of worn out wear strips and installation of new strips is greatly facilitated even where gratings having extended lengths are concerned. In addition, when the wear strips 24 are installed in the grooves 26 of the support elements 10, a firm ifrictional engagement is provided between ribs 47 of the wear strips 24 and the bases 37 and side walls 38 and 4t) of the grooves 26 and between cover strips S0 of the wear strips 24 and the top flanges 14 ofthe support elements 10 `whenever slight pressure is placed on the 4 wear strips 24, yand thus the wear strips 24 are prevented from slipping longitudinally along the support elements. d0.

The above-described structure of the support elements 10 and the wear strips 24- of the grating accordingly provides for a firm, but at the same time, readily removable attachment of the wear strips 24 to the support elements 1t! and worn-out wear strips are easily removed and replaced by new ones which can be rolled or pressed into the support elements 1t). The foregoing features of the easy replacement and attachment of the wear strips and the assembly of the grating bars with key members of one-piece part structure which can be accurately machined to close tolerances preventing unequal spacing or out-of-'parallelism of the grating bars are important advantages of the "rating of this invention.

The above-described embodiment of the invention is merely exemplary and those skilled in the art will be able to make any modifications and variations of it without departing from the spirit and scope of the invention. All such modifications and variations are intended t0 be included within the scope of this invention as defined in the appended claims.

We claim:

1. A grating for openings in floors, streets, sidewalks and the like comprising a plurality of support bars, each of said bars having a top flange and a connecting web, each connecting web having concavities formed in the opposite sides thereof and extending along the length of said web, said web having thickened portions above and below the concavities and a centrally located thinned portion between the concavities and with key bed openings extending along the length of the concavities, and a plurality of key members extending transversely through the key bed openings in said connecting webs, each key member having a center member and side members containing notches dividing said side members into a plurality of spacing elements spaced from each other by a distance greater than the web thickness at said thinned portion and less than the thickness of the thickened portions of the connecting webs for frictionally engaging the thickened portions of the connecting webs in locking relation ship when said key member is rotated from the position it is received in said openings.

2. A grating according to claim 1 further comprising a plurality of unitary wear strips, each strip covering and removably attached to the top flange of each support bar.

3. A grating according to claim 2 wherein each of the said support bars comprises a longitudinally extending groove formed in said top Iflange, said groove having a longitudinally extending base, upwardly diverging side walls, and longitudinally extending flanges which extend inwardly beyond the side walls of said groove and wherein each of said wear strips comprises a rib formed along the lower surface of said groove, a web positioned between the top flanges of said support bars and a cover member flaring laterally out from said web and substantially coextensive with said top flanges of said bars.

References Cited UNITED STATES PATENTS 1,946,035 2/1934 Reuter 52-667 2,082,197 6/1937 Bates 52-667 2,181,812 11/1939 Kammerer 52--181 2,275,105 3/1942 Greulich 52-667 2,404,570 7/1946 Elliott 52-667 FOREIGN PATENTS 37l,l47 4/1932 Great Britain. 909,988 1l/l962 Great Britain.

BOBBY R. GAY, Primary Examiner.

DAV] D l. WTLDIAMOWSKY, Examiner.

R. D. KRAUS, Assis/arzt Examiner.

Images