Rubber coated plywood for road material

May 7, 1940. c. u. gramelspacher 2,199,700

RUBBER COATED PLYWOOD FOR ROAD MATERIAL Filed Aug. 16, 1938

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Patented May 7,1940

2,199,700

UNITED STATES PATENT OFFICE

2,199,700

RUBBER COATED PLYWOOD FOR ROAD MATERIAL

Clarence U. Gramelspacher, Jasper, Ind.

Application August 16, 1938, Serial No. 225,131

Claims.

My invention relates to covers for highways.

It is the object of my invention to provide a plywood covering for highways' coated with vulcanized rubber to prevent skidding of automobiles. 5 I have found that wet rubber, such as a wet rubber tire, engaging a wet rubber surface will not skid. There is a high frictional resistance between the two rubber surfaces, even though they are wet. This is not true of a wet concrete, 10 brick or asphalt surface engaged by a rubber tire.

It is therefore the object of my invention to provide a strong resilient base, preferably in sections, of plywood, which can be firmly anchored . to the underlying road base of concrete and the ¹⁰ like, and to provide this laminated veneer body with a coating of protecting rubber, preferably corrugated, on its surface.

It is a further object to provide vulcanized strips of sponge rubber on the edges so as to 20 permit of the necessary expansion and contraction.

I have found that laminated wood is tough, resilient and has a long life. It is particularly desirable to arrange' the sections of laminated 25 wood with the grain transverse to the direction of travel of vehicles on the road.

It is also desirable to have the corrugations of the rubber running parallel with the grain so that these corrugations are either transverse or 30 diagonal to the line .of travel on the road.

It is my object to provide such road coverings particularly at road intersections, highway crossings and at such points where traffic must stop, because of the high coefficient of friction 35 that this road covering provides for the stopping of automotive vehicles.

Referring to the drawing:

Figure 1 is a vertical section taken transversely through adjacent strips.

Figure 2 is a section on the line 2—2 looking in the direction of the arrows on Figure 1.

Figure 3 is a diagrammatic view of a highway partly covered, on curves and intersections, with the road covering of this invention.

Referring to the drawing in detail, I is the earth surface upon which a concrete or other road supporting layer is placed. This layer is designated 2. Mounted upon and anchored within the concrete layer 2 are the sections of rubber 5<> covered plywood generally designated 3. These sections are composed of a plurality of layers of wood veneer 4, joined together by adhesive 5.

After they are so assembled with the grain of the wood preferably running lengthwise of the 55 oblong sections, the body of wood is wrapped (CL 94—15) with a rubber covering 6. The top of this rubber covering 7 is corrugated.- The side walls are provided with layers of rubber 8 of such composition that it will sponge when vulcanized.

There has already been assembled in the wood © veneer layers attaching bodies 9 having enlarged heads I® extending beyond the body of the assembly. The complete section is then placed in a vulcanizing press and vulcanized. It is now ready for assembling. W

Holes ί I are formed in the concrete base 2. The enlarged heads 10 are inserted in the holes, which holes are preferably filled with a plastic material such as concrete or molten lead 12, so that when the material 92 hardens, the section will be firmly attached to the base 2.

The bodies 9 are provided with nuts 9α so that in the event the upper rubber surface 7 wears away, then the nuts 9α may be removed and the sections of wood in the remaining rubber lifted 2® from the bodies 9. The wood sections can then be recovered with rubber, revulcanized and replaced.

Any holes left in the rubber for receiving the nuts 9α, when the sections are so replaced, can 23 be filled with rubber and vulcanized in position. ® It will be understand that the plywood sections are capable of withstanding a high temperature in a vulcanizing press to have the rubber vulcanized thereto. The rubber protects the wood 3® veneer from water, freezing and dirt.

It will be further understood that the method of attaching is optional. I comprehend within my invention making the edges of these sections interlocking, either with or without the sponge 35 rubber fillers on the margins thereof.

As will be observed in Figure 3, I arrange at maximum dimension each of the blocks 3 transversely of the road. This places the corrugations , 7 transversely of the road. 40

A great variety of different ways of attaching these blocks may be employed, depending upon the nature of the underlying base 2, whether it is desired to recover the wood sections, et cetera.

It will be understood that I desire to com- 45 prehend within my invention such modifications as may be necessary to adapt it to varying conditions and uses.