US3420015A

US3420015A - Metal grating

Info

Publication number: US3420015A
Application number: US630416A
Authority: US
Inventors: Nicholas Joseph Costanzo Jr
Original assignee: ALUMINUM PLASTIC PRODUCTS CORP
Current assignee: ALUMINUM PLASTIC PRODUCTS CORP
Priority date: 1967-04-12
Filing date: 1967-04-12
Publication date: 1969-01-07
Anticipated expiration: 1986-01-07

Description

Jan. 7, 1969 nlllLuuwul.mLuul'JuuLu 5f T5 Illlll'" i I l N.' J. COSTANZO, JR

METAL GRATING Filed April l2, 1967 24 25 22 J/111,10* 460.911.910', 26\l 23 l v l 27 2' FIGA.

- INVENTOR N. Joseph Costanzo ,Jr.

BY 27/ l ATTORNEY N. J. COSTANZO, JR

METAL GRATING Filed April 12, 1967 INVENTOR 2| N. Joseph Costonzo,Jr.

ATTORNEY United States Patent O Claims ABSTRACT OF THE DISCLOSURE Disclosed is a grating including a number of slats extending in a iirst direction and a number of tread carrying T sections extending in a second direction, at right angles to the direction of the slats. The T sections are connected frictionally with the slats by grooves in the slats and in legs of the T. Forces imparted to the arms of the T section are transmitted to the slats by ears at the ends of the T arms and through the T legs. The T arms are crowned to provide water run-off and are grooved to prevent slippage of a person or object placed thereon. The slats have resilient rubber feet mounted on the bottoms thereof at spaced locations.

The present invention relates generally to metal gratings and more particularly to a metal grating having a load-bearing surface comprising the arms of a T.

Briefly described, the present invention is a metal grating comprising a plurality of first elongated bars and a second plurality of bars, each having a T cross-section, wherein the second bars intersect the iirst bar-s and upper arms of the T are substantially coplanar to define a load bearing surface. The rst and second bars are interconnected solely by a frictional iit between slots formed in the T legs and in the first bars. Strength, for structural purposes, is added to the construction by providing downwardly depending ears at the ends of the T arms, which ears intersect the T arms at a substantial angle. The ears extend to the upper edge of the first bars so that the load exerted on the T arms is transmitted to the tirst bars.

One of the primary, although not the exclusive, functions of the grating of the present invention, is as a false flooring, frequently referred to in the art as a duck board. Duck boards are extensively utilized in commercial retail establishments where personnel stand for prolonged time periods. In particular, duck boards are extensively utilized in bars, at supermarket checkout counters and behind meat market cases.

In the past, duck boards have generally been fabricated as wooden gratings or as rubber mats. While wood and rubber provide the resiliency required for comfort to the feet of a person standing for long time intervals, each suffers from several different disadvantages. In particular, rubber mats are relatively expensive if a large area is to be covered, such as behind a bar or behind a rneat market case. Also, rubber mats are not practical in areas where appreciable liquid drops to the oor because of the absorbing properties of the rubber material. While wooden duck boards are inexpensive, they also absorb a great deal of liquid.

Liquids absorbed by the prior art duck boards and rubber mats cause the duck boards to become odoriferously offensive. A wooden duck board can be cleaned by spraying water thereon, with only moderate success, but a rubber mat can never have the odor from a meat counter or tavern bar removed therefrom. To remove odors from a wooden duck board, the duck board must be moved physically from the location where it is usually located to an outdoor area where it can be sprayed readily. Wooden duck boards, however, are very heavy and require two 3,420,015 Patented Jan. 7, 1969 relatively strong men to move them from the area of utilization to the area of cleaning, whereby periodic, daily cleaning of a duck board, as required for cleanliness, is expensive, troublesome and perhaps injurious to health.

Being fabricated from extruded aluminum, the grating of the present invention is not heavy, nor does it become odoriferously offensive after prolonged time periods of liquid exposure. In addition, the T arms of the present invention have sufficient resiliency to be deiiected under the weight of a human so that a person standing on the grating for prolonged time periods does not suffer from fatigue any more than a person standing on a rubber mat or wooden duck board.

As an added feature to the present invention, the T arms are crowned slightly to enable water to run off of them and the arms are grooved to prevent a person from slipping as he walks across the grating.

Another feature of the present invention relates to means for preventing possible slippage of the metal duck board, while reducing the noise level introduced thereby virtually to zero. These two features are accomplished by placing slotted, pliable rubber feet at spaced portions on the bottom of the rst or lower bars.

Another feature of the grating of the present invention, which is also true of wooden duck boards but not of rubber mats, is that liquids can pass through the grid arrangement of the first and second bars to the iioor and be easily drained across the iioor without impeding liquid flow.

While one of the primary purposes of the grating of the present invention is as a substitute for Wooden duck boards or rubber mats in retail establishments, it is to be understood that the grating can be utilized for other purposes. For instance, the grating of the present invention is ideally suited as a false ooring at installations where -complex electronic equipment is located. At such installations, wires from the equipment run beneath the false flooring from one console to another. With the light weight grating sections of the present invention, the wires can pass between adjacent ones of said first bars, and, in the event of cable malfunction, a oor section is easily removed.

It is, accordingly, an object of the present invention to provide a new and improved metal grating.

Another object of the present invention is to provide a new and improved light Weight metal grating, particularly adapted for use as liooring.

A further object of the present invention is to provide a new and improved false flooring that is relatively light and easy to move, is not porous, whereby it does not become offensively odoriferous and has sufiicient resiliency to enable a person to stand on it for prolonged time periods without undue fatigue.

Still another object of the present invention is to provide a new and improved metal grating, particularly adapted for use as a false flooring, but which is not subject to slip or high noise level.

The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of one specic embodiment thereof, especially when taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a top view of a preferred embodiment of the grating of the present invention;

FIGURE 2 is a side view of the grating illustrated by FIGURE 1;

FIGURE 3 is an end view of the grating illustrated by FIGURE l;

FIGURE 4 is an enlarged cross-sectional view of a portion of the grating, taken through the lines 4-4 of FIGURE 2;

FIGURE 5 is a cross-sectional view taken through the lines 5 5, FIGURE 4;

FIGURE 6 is an exploded perspective View illustrating the manner by which a pair of slats mate;

FIGURE 7 is a perspective view illustrating a plurality of the gratings of FIGURE 1 and illustrating one preferred use for the gratings;

FIGURE 8 is an enlarged view of the grating illustrated by FIGURE 7, specically showing the manner in which the grating is deflected in response to a load;

FIGURE 9 is an enlarged detail view illustrating the connection of a foot to the bottom of one of the slats;

FIGURE 1() is a further view illustrating a foot attached to one of the slats, which view is at right angles to the view illustrated by FIGURE 9; and

FIGURE 1l is a perspective view of a preferred ernbodiment of one of the feet specifically illustrated on the slats of FIGURES 9 and 10.

Reference is now made to FIGURES 1-4 of the drawings, wherein there is illustrated a first plurality of extruded aluminum longitudinally extending slats or bars 21, each having its longitudinal axis parallel to the remaining slats. Extending at right angles to bars 21 is a second plurality of extruded aluminum slats or bars 22, each having substantially parallel longitudinal axes. Each of

bars

21 and 22 is interconnected with each other, with the lower ends of bars 22 being connected to the upper edges of each of bars 21 to form thereby a grid or grating.

As indicated by FIGURES 3, 4 and 6, each of bars 22 has a T cross-section taken transversely to the bar longitudinal axis. Each T includes a downwardly depending leg 23 having arms 24 and 25 extending outwardly at substantially right angles to the leg of the T. Downwardly depending

ears

26 and 27 are respectively provided at the ends of arms 24 and 25, whereby the arms and ears intersect each o.her at a substantial angle, as shown on the drawing. Leg 23 of each bar 22 is connected frictionally to each of bars 21, while

ears

26 and 27 extend downwardly from arms 24 and 25 to engage the upper edges of bars 21.

Frictional engagement between leg 23 of each of bars 22 and each of slats 21 is accomplished by providing

slots

28 and 29 in

bars

21 and 22, respectively. Each of

slots

28 and 29 is approximately the same length, in a preferred embodiment 0.281 inch, wi.h slot 28 extending downwardly from the upper edge of slat 21 while slot 29 extends upwardly from the lower edge of leg 23. The width of slot 29 is slightly less than the thickness of slat 21, while the width of slot 28 is slightly less than the thickness of leg 23. In a particular embodiment of the invention, the thickness of bar 21 is 175 mils, while slot 29 has a width of 172 mils. Leg 23 has a thickness of 55 mils and slot 23 a width of 52 mils, whereby each of the

slots

28 and 29 has a width of 3 mils less than its mating bar thickness. As illustrated by FIGURES 4 and 5, leg 23 is wedged into bar 21 so that the roots of

slots

28 and 29 engage each other. By providing equal length slots in bar 21 and leg 23 and mating the two slot roots in contact with each other, there is in excess of a half-inch contact area between bars 21 and legs 23.

It has been found that by providing

equal length slots

28 and 29, rather than a single long slot in only one of the extruded aluminum bars 21 or 22, a problem of bar arcing as the slots are punched is obviated. Arcing of a bar while punching a full slot having a length in excess of a half-inch is very likely to occur with extruded aluminum. If either of

bars

21 or 22 arcs during the punching operation to form

slots

28 or 29, alignment problems are likely and the bottom edges of

ears

26 and 27 will not contact the upper edges of bars 21. It is important for the bottom edges of

ears

26 and 27 to engage the upper edges of bars 21 to transmit forces applied to the upper surfaces of T ar ms 24 and 25 to bars 21 by a member other than the leg 23.

Connecting bars 21 arid 22 together by .means of the frictional engagement between

slots

28 and 29 and the bars provides a construction that is economical from a fabricating standpoint. In addition, the press t between T leg 23 and bar 21 enables bar 22 to be readily replaced in the event of fracture. Replacement is accomplished in a facile manner by applying pliers to leg 23 in proximity to slot 29 and pulling the leg upwardly so that it clears the upper edge of bar 21.

In one preferred embodiment, bars 21 are spaced from each other by approximately 12 inches, with the extreme left and right bars 21 being spaced from the extremities of bars 22 by one inch. Slots 28 are punched in bars 21 at spacings of approximately 21A inches from each other, and each of bars 21 has a width between

ears

26 and 27 of approximately 1% inches, leaving a separation between adjacent ones of bars 22 of approximately 1/2 inch. It has been found that with a grating having these dimensions, bars 22 are sufficiently elastic to deilect approximately 1/s inch at the points midway between bars 21 for a compressive load of approximately 2 pounds per square inch applied against the upper surface of T arms 24 and 25, i.e., along the longitudinal axis of T leg 23. The grating has sufficient strength to withstand, without fracture, a heavy load of 5 pounds per square inch, yet has sufficient give to be comfortable to a human standing on it for prolonged time periods.

One of the contemplated uses of the grating of the present invention is as a duck board, structures on which personnel serving the public stand for prolonged time periods. In particular, duck boards are frequently employed as false ooring in taverns, behind meat counters and the like, where a considerable amount of fluid is constantly descending to a permanent door.

To enable uid dropped on the grating of the present invention to be drained to the door and prevent the uid from collecting on the upper surface of bars 22, each of arms 24 and 25 is arched to form a crown having its highest point aligned with T leg 23. The upper surfaces of arms 24 and 25 have elongated grooves 31 formed therein in alignment with the longitudinal axes of bars 22. Grooves 31 prevent personnel walking on the grating from slipping but are sufliciently shallow, however, to prevent accumulation of liquid therein, being approximately 2t) mils deep.

Reference is now made to FIGURE 7 of the drawings wherein a plurality of gratings of the type illustrated in FIGURE 1 are arranged in modular form with the bottoms of bars 21 placed on a permanent iloor. The longitudinal axes of bars 22 are aligned to form a single composite elongated duck board to enable a human to stand behind a bar or the like. From FIGURE 7, it is seen that the foot of a person standing on the grating spans a plurality of bars 22, whereby the load of the person is distributed over a number of the bars and is transmitted to the floor through a number of transversely extending slats 21 via arms 24, 25,

ears

26, 27 and legs 23.

Reference is now made to FIGURE 8 of the drawings, wherein the manner in which one of bars 22 is denected in response to a human load of approximately 2 pounds per square inch is illustrated. In FIGURE 8, the unloaded position of bar 22 is indicated by dotted line 32, while the position of the bar upon being deected is shown in full lines. It is noted that bar 22 is deflected between adjacent slats 21 in an arc closely resembling a catenary. Deflection of bar 22 from the dotted to the full-line position indicated by FIGURE 8 provides sufficient give in response to the force exerted by a pound man to enable the man to stand comfortably for prolonged time periods.

It is also noted that if the grating of the present invention is placed on an uneven oor or surface, i.e., one which is not exactly at, the extruded aluminum bars 21 have adequate flexibility to seat into the floor, whereby the load is transmitted to the iloor throughout the length of bars 21 and not through only a few portions thereof.

It has been found in typical uses of the grating of the present invention that the one inch spacing between the ends of slats 21 and the extreme left and right bars 22 is usually required to pre-vent tipping in response to a human load as the person moves to the extreme end of the grating.

A further feature of the invention relates to securing feet 33 to bars 21 so that they extend from the lower edges of those bars. Feet 33 prevent the grating from slipping relative to the floor on which it is located while reducing the noise introduced by the grating virtually to zero. Further, in certain instances, feet 33 maintain the bottom edges of slats 21 above the oor on which the grating is mounted, wherebyliquid flowing off of bars 22 onto the floor can be drained.

Each of feet 33 is fabricated from a flexible, relatively soft material, such as polyvinyl. Each foot 33 is approximately 2 inches in length and includes a base 36 from which

fingers

34 and 35 extend upwardly. Fingers 34 and 3S are separated from each other by slot 37, having a width slightly less than the thickness of slat 21, whereby the fingers frictionally engage the sides of the bars 21. Bars 21 seat at the root of slot 37, forcing the bottom surface of base 36 into engagement with the floor on which the grating is placed. The bottom surface of base 36 includes a plurality of grooves 38, extending longitudinally of foot 33. Grooves 37 provide a secure grip between foot 33 and floor on which the grating is placed, whereby slippage of the grating on the oor is precluded.

While I have described and illustrated one specific embodiment of my invention, it will be clear that variations of the details of construction which are specifically illustrated and described may be made without departing from the true spirit and scope of the invention as dened in the appended claims.

I claim:

1. A grating comprising a first plurality of elongated metal bars having substantially parallel longitudinal axes, a second plurality of elongated metal bars having substantially parallel longitudinal axes approximately at right angles to said axes of the first plurality, each bar of said first plurality intersecting each bar of said second plurality, each bar of said second plurality having a substantially T shaped cross section including a leg and first and second arms extending substantially at right angles from the top of the leg, each of said arms having a substantial extent away from the leg in a plane substantially at right angles to both said axes, the T leg of each bar of said second plurality being secured to each bar of said first plurality so that the T arms of all the bars in the second plurality are substantially co-planar, ear means on each of said bars in the second plurality, said ear means downwardly depending from each end of the T arm and intersecting said arms at a substantial angle, said ear means extending to and contacting the upper edge of each bar of said first plurality for transmitting loads imparted to the T arms to the bars of said first plurality, the separation between the ears of adjacent ones of said bars of said second plurality being less than the width of both ears of said bars of said second plurality.

2. The grating of claim 1 wherein the bars of said first and second plurality are spaced from each other and the bars of said second plurality are sufficiently elastic in response to compressive forces applied along the longitudinal axis of the T leg to be deflected approximately 0.125 inch when loaded with a pressure of 2 pounds per square inch.

3. The grating of claim 1 wherein said T arms together are crowned from one end to the other, the highest point of the crown being aligned with the T leg.

4. The grating of claim 1 wherein said first and second bars include slots transverse t'o their longitundial axes, the slots in the first plurality of bars extending downwardly only from the upper edges of the bars, the slots in the second plurality of bars extending upwardly only from the lower edges of the T legs, said slots being mated so that slots in the first and second plurality of bars engage, the slots on one of said plurality of bars being narrower than the thickness of each of the other plurality of bars for securing said bars to each other only by friction.

5. The grating of claim 1 wherein said T arms together are crowned from one end to the other, the highest point of the crown being aligned with the T leg.

6. The grating of claim 5 wherein the upper surface of each T arm is grooved along the longitudinal axis of the second bar.

7. The grating of claim 1 wherein the upper surface 0f each T arm is grooved along the longitudinal axis of the second bar.

8. The grating of claim 1 wherein said first and second bars include slots transverse to their longitudinal axes, the slots in the first plurality of bars extending downwardly only from the upper edges of the bars, the slots in the second plurality of bars extending upwardly only from the lower edges of the T legs, said slots being mated so that slots in the first and second plurality of bars engage, the slots on one of said plurality of vbars being narrower than the thickness of each of the other plurality of bars for securing said bars to each other only by friction.

9. The grating of claim 1 Ifurther including a plurality of spaced plastic feet secured to the lirst plurality of bars, so they extend from the bottoms of the bars of the first plurality.

10. The grating of claim 9 wherein the bottoms of said feet include longitudinally extending grooves.

References Cited UNITED STATES PATENTS 1,419,446 6/ 1922 Bogert.

2,319,468 5/1943 Nagin 52--669 X 2,469,070 5/ 1949 Greulich 52-180 2,645,985 7/1953 Beebe 52-669 X FOREIGN PATENTS 1,035,343 1953 France.

1,377,320 1964 France.

JOHN E. MURTAGH, Primary Examiner.

U.S. CI. X.R.