US3416727A

US3416727A - Synthetic plastic railroad tie

Info

Publication number: US3416727A
Application number: US552365A
Authority: US
Inventors: Benjamin P Collins
Original assignee: Benjamin P. Collins
Current assignee: BENJAMIN P COLLINS
Priority date: 1966-04-27
Filing date: 1966-04-27
Publication date: 1968-12-17
Anticipated expiration: 1985-12-17

Description

Dec. 17, 1968 Filed April 27, 1966 B. P. COLLINS SYNTHETIC PLASTIC RAILROAD TIE 5 Sheets-Sheet l 1^ MAQ Tfn. U0 pl) 2L M ATTORNEYS Dec. 17, 1968 7 B. P. coLLlNs 3,416,727

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ATTORNEYS United States Patent O 3,416,727 SYNTHETIC PLASTIC RAILROAD TIE Benjamin P. Collins, 340 Merwins Lane, Fairfield, Corm. 06430 Filed Apr. 27, 1966, ser. No. 552,365 2 Claims. (Cl. 23S-84) ABSTRACT OF THE DISCLOSURE A synthetic railroad tie primarily constructed in laminations of molded shredded hardwood ller and a synthetic resin of phenol formaldehyde.

This invention relates to railroad ties and particularly to railroad ties made from a synthetic resin and filler.

In the prior art, wooden railroad ties have been used for many years, the ties being embedded in rock ballast roadbeds and having the rails placed on top thereof. The rails are fastened to the ties in various manners such as by spikes or the like. These ties have been subject to relatively rapid decay and rotting, a tie in some instances lasting only about fifteen years even if the tie has been properly impregnated with creosote or the like. If the creosoting operation is not complete, then the life of the tie may be much shorter.

The ties for a standard railroad gauge, for example, are 6 x 8 X 86 and 7" x 9 X 8'6", so that as a result, the wood must be obtained from trees of relatively large size in order to obtain good ties without splits and defects. Lumber of this size is becoming quite scarce at the present time.

When it is necessary to replace the ties, a rather dif- I'icult problem exists because either the track must be taken up in parts or the ballast bed dug out to permit removal of ties and placing of new ones therein, and such interferes with railroad traic.

Other types of material for ties also have been suggested such as concrete, metal and the like. None of these has been satisfactory. In the case of a concrete tie, the concrete may crack in cold weather and any water therein will accentuate the cracks as it freezes. Also concrete is quite heavy, it being about ten times as heavy as a conventional wooden tie. The resiliency of a concrete tie also has not been `completely satisfactory even though pads may be used therebetween. The same thing is true of steel ties which are extremely heavy and quite expensive.

In the case of wood ties, after the tree has been cut, the tie must be cut into a rectangular form and permitted to season for a long period of time before it can be subjected to the pressure-creosoting operation. This has resulted in a tremendous backlog in the demand for ties. Approximately 40 million are used annually in the United States. An an example, arstandard mile of railroad track will have 3,200 ties therein.

One of the objects of the present invention is to provide a railroad tie which is relatively inexpensive, is readily made, and which will satisfactorily perform its service as a tie.

Another of the objects of the invention is to provide a tie which will not fail under normal railroad service in extreme conditions of use.

Another of the objects of the invention is to provide a tie which is relatively light-weight and which can be made in places close to the point of use.

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Still another of the objects of the invention is to provide a tie which is waterproof and lire-resistant as compared with the standard wooden tie.

In one aspect of the invention, the railroad tie of the present invention may be formed in a mold and may be of one piece or may be laminated. Also, it could be made in a standard plastic extruding machine.

In the preferred form, the tie is made with shredded wood liber as the filler and a phenol formaldehyde resin binder mixed with a resin derived from Southern pine- Wood and sold under the trademark Vinsol of Hercules Powder Company. The shredded wood and phenol formaldehyde with pinewood resin is mixed and put into molds following which it is subjected to heat and preferably pressure in order to cure the resin. It is possible to control the density and characteristics of the tie by differing the amount of pressure exerted on the mold as well as by proportion of materials. Similarly, if the tie is to be extruded, the conditions under which the extrusion takes place can be controlled.

These and other objects, advantages and features of the invention will become apparent from the following description and drawings which are merely exemplary.

In the drawings:

FIG. 1 schematically shows a tie made in accordance with the prior art and one in accordance with the present invention; and

FIGS. 2a and 2b show an infrared spectrum curve of the synthetic resin used in the present invention.

Refrering to FIG. 1, the prior art is illustrated in the upper portion thereof wherein steel rails 10 are placed on ordinary wooden ties 11 which may be of the creosoteimpregnated hard-wood type. The ties are carried on a ballast bed 12 of rock, as is known in the art.

The lower portion of FIG. 1 shows rails 10 supported `on a tie 13 made in accordance with the present invention. In the particular form shown, there is a cut-out portion 14 extending between the rails, said cut-out portion 14 resulting in a web 15 of reduced section relative to the

end pieces

16, 16 of the tie. The rails are held in place on the ties by spikes or other holding devices.

In the case of the tie of the present invention, the apertures -for receiving the holding spikes can be pre-bored or placed in the tie at the time of molding. This is for the reason that the synthetic resin is relatively hard and might be diicult to work in the field.

The cut-out portion 14 has an advantage in that it will permit the ballast to enter the area and hold the tie from side motion caused by a train passing thereover. Such side motion will result in the track becoming misaligned. Also, it is possible to make the tie without the cut-out portion.

In the form illustrated in FIG. 1, the tie is solid but it also could be made of laminated pieces. By use of the plastic, it is possible to make the tie with the cut-out porj tion with a minimum of loss inasmuch as the mold can be formed as compared with cutting such a tie from a wooden block:

In a preferred example, the tie is made using a shredded wood fiber as the filler and preferably hard-wood as the filler material. One constituent of the synthetic resin is phenol formaldehyde, the phenol formaldehyde being mixed with the shredded wood fiber and placed in the mold.

In a preferred form, `the phenol formaldehyde resin is mixed with a resin derived from Southern pinewood composed of a complex mixture of various chemical components. The constituents are believed to include acidic materials derived from rosin acids and oxidized rosin acids, neutral high-molecular-weight compounds, and acidic phenolic materials in the form of substituted phenolic ethers, poly phenols and other high-molecular-weight phenols. As an example, one such resin is that sold under the trademark Vinsol by Hercules Powder Company. A typical analytical value for such a Vinsol is as follows:

Softening point C 120 ASTM ring and ball softening point C 112 Acid No. percent 94 Saponication No. do 165 Unsaponifiable matter do 7.7 Gasoline soluble do 17 Acetone insoluble do 0.05 Toluene insoluble do Gasoline insoluble do 83 Petroleum ether insoluble do 98 Coefficient of cubicle expansion per 1 C. (S0- 170 C.) 0.00056 Density at C. 1.218 Specific heat, 20 (20-245 C.) 0.50 Bulking density (approximately):

Flake lbs./cu. ft 42 Pulverized lbs./cu. ft

The mold into which the materials are placed can be subjected to heat and pressure in a conventional molding machine. It is also possible to provide probes or rods extending into the ends of the mold so as to leave apertures in the ends of the ties or appropriate places so as to accelerate curing of the resin. It is desirable to mix sufficient quantities of the wood fiber with the phenol formaldehyde so as to obtain, under the pressure and heat used, a tie which is of substantially the same density, or greater, as the standard hard-wood tie such as oak.

Merely as an example, a tie can be made between and percent by weight wood fiber, and the remainder is phenol formaldehyde resin modified by VinsoL As an example, 5% by weight of Vinsol can be mixed with 5% by weight of phenol formaldehyde resin and then 90% by weight shredded wood fiber mixed therewith and a tie formed therefrom. As mentioned, the resin mixture can be classified as a Vinsolmoditied phenol formaldehyde resin.

Infrared spectra made of one resin are shown in FIGS.

2a and 2b wherein curve A is an acetone extract, curve B is a benzene extract, and curve C is a chloroform extract. These various extracts were subjected to an infrared analysis in a conventional infrared spectrometer.

It should be apparent that the ties can be made in various lengths and that they can be produced at various points inasmuch as the materials in their unreacted form can be readily transported thereto.

It should be evident from the foregoing that variations may be made in the details of the invention without departing from the spirit thereof except as defined in the appended claims.

What is claimed is:

1. A tie for supporting railroad track rails on a ballast roadbed comprising a main body portion composed of continuous molded laminations of shredded hardwood filler and a synthetic resin of pinewood resin modified phenol formaldehyde, said body portion having enlarged laminated end portions, said laminated body portion having a substantially flat recessed portion on the under side thereof extending between said end portions, said body portion having a substantially flat uninterrupted top surface for receiving and supporting said rails thereon, and said recessed portion flatly engaging the ballast whereby said rails are firmly and uniformly supported on said roadbed against side motion.

2. A railroad tie according to claim 1 wherein the pinewood modified resin phenol formaldehyde resin has an infrared spectrometer characteristic as depicted in FIGS. 2a and 2b of the drawings.

References Cited UNITED STATES PATENTS 3,289,940 12/1966 Groff 238-29 2,611,545 9/1952 Bartlett 238-84 2,324,758 7/1943 Bowden 260-25 1,320,873 11/1919 Langford 23S-84 1,110,684 9/1914 Handman 23S-84 1,566,550 12/1925 McWilliam 238-84 958,226 5/1910 Cleary 238-84 1,431,631 10/ 1922 Chamberlain 238-89 5 ARTHUR L. LA POINT, Primary Examiner.

U.S. Cl. X.R.