Paving block

Application

Claims.

This invention relates to a paving block and ^particularly to ,a block -adapted for the construction .of railway crossings.

Various forms of railway crossings have been .proposed heretofore but all of them with which I .am familiar are characterized by serious dejects. Timber floored crossings, for example, lack the .desired durability, while other forms of construction which have longer life are undesirable .-for .one reason or another. I have invented a ,10 novel form of paving block particularly suited Jor the construction of railroad crossings which -entirely overcomes the objections to the crossing .floors -or paving which have -been used heretofore.

In the preferred .embodiment, the invention .comprises :a block having a tread portion of wear2,294,582

PAVING BLOCK

Francis C. Sullivan, McKeesport, Pa.

November 14, 1939, Serial No. 304,356

-resisting -material such as .cast iron and a body portion of non-metallic material -such as concrete. The tread and -body portions of the -block are .secured together by .anchor members embedded therein. The blocks are of such dimensions that they may be .easily laid side by side .between the rails -and on the outside of the latter to form a level pavement presenting -a surface which is highly resistant to abrasion. Numerous other novel features and .advantages of the -invention will be pointed -out -during the course of the following-detailed description which refers to the .accompanying drawings illustrating the preferred embodiment.

In the drawings—

Fig. 1 is a view partly in plan and partly in section on a plane parallel to the tread-surface;

Fig.'2 is a longitudinal section through a block, -taken -along the line II—II of Fig. 1 showing the -block .as installed at a crossing; line I—I of .Fig. 2 illustrates the plane of the section shown in Fig. 1;

Fig. 3 is a transverse section through a railroad track having the blocks of my invention laid thereon to form a crossing;

Fig. 4 is a transverse section through a block -taken along the line IV—IV of Fig. 2;

Fig. 5 is a -similar section taken along the line V—V of Fig..2;

Fig. 6 is a partial bottom -plan view of the tread portion;

.Fig. 7 is a .partial section taken along the line VII—VII of Fig. 6;

Fig. 8 is a partial section through the tread portion -before the formation of the body portion, .showing an anchor .member in .an intermediate -stage; and in a sand mold.

(Cl. 94—12)

Fig. 9 is a section showing a portion of Fig. 4 to enlarged scale.

Referring now in detail to the drawings, a paving block indicated .generally at iO com„5 prises a tread portion I t and a body portion 12. The tread portion is preferably of abrasionresisting material such as cast iron and has its exposed surface roughened as by the formation of “diamonds” to provide good traction. The under-surface of the tread portion 11 is not flat but is grooved longitudinally and transversely as at 13 or otherwise shaped to provide preferred lines of fracture, for a purpose which will appear later. A peripheral skirt or apron 14 extends 15 downwardly from the edge of the tread portion. This skirt or apron tapers inwardly toward the exposed surface of the tread portion. The tread has a longitudinal, .depending rib 14α.

The tread portion 11 may conveniently be cast Anchor members or struts 15 preferably in the form of double, twisted lengths of wire are embedded in the tread portion when the latter is cast. The grooves 13 provide a plurality of pyramidal projections 16 on the un25 der-face of the tread portion and, as shown in Fig. 6, one of the members 15 is disposed centrally of each pyramidal projection. As shown in the drawings, the eyes at the doubled ends of the anchor members are embedded in the tread 30 portion. The pattern for the tread portion may conveniently be slotted to receive the anchor members during the ramming of the mold. When the mold is completed and the pattern removed, the anchor members are supported with their 35 eyes exposed in the mold cavity whereby they are embedded in the finished casting.

As shown in Figs. 8 and 9, the eyes in the anchor members 15 are large enough to permit the molten metal to flow therethrough, thereby 40 forming a complete linkage which resists separation of the casting and the anchor member. Even in the absence of such complete linkage, however, the tapering outline of the eye resists such separation.

The wire from which the anchor members 15 are formed is of such size that there is practically no fusion, burning, nor crystallization thereof, by the heat of the molten iron during the casting of the tread portion. As a matter of ⁵⁰ fact, the anchor members have the effect of chilling the cast iron immediately adjacent thereto, thereby providing the latter with a close-grained surface and insuring a tight fit between the tread portion and the anchor members so that the latter are rigidly supported in

2,294,582 their own weight. In laying the blocks on the ties, the end joints need not be staggered.

The upward taper of the skirt 14 provides grooves between adjacent blocks which may be filled with sealing material 31 to prevent seepage of water through the joints. The downward taper on the body portion 12 facilitates the removal of any block, if desirable for any purpose, as well as the original setting of the blocks on the ties.

The plates 24 as shown in Fig. 2, bear on the spacer blocks 27 resting on alternate ties, and provide durable support-engaging surfaces.

The block of my invention is characterized by numerous advantages over anything known heretofore. In the first place, the blocks are provided with an all-metal tread surface having a uniformly high resistance to abrasion. The blocks are unitary, for all practical purposes.

Because of the firm anchorage of the members 15 in the tread portion 11 and their attachment to the reinforcing bars 23, the body and tread portions are firmly bound together. Since one of the members 15 is embedded in each of the projections 16, breakage of the tread portion along the lines of grooves 13 would not permit the chipping out of fragments of the tread portion. Any breakage would follow the lines of the grooves 13 and even if cracks appeared along all such grooves, each separate fragment of the tread portion would be securely anchored to the body portion. The holes 17 and 26 permit circulation of air through the ballast in which the ties are laid to assist in drying it out. They also provide air vents during the vibration of the entire track under the car wheels, thereby preventing the sucking-up of soil particles through the crevices between the ballast rock, and the resulting obstruction to drainage of the latter, as has been experienced with plastic materials laid in a continuous layer to provide a crossing floor or pavement. The blocks can easily be designed to have the desired strength when loaded as a beam supported at the ends of the 45 span between alternate ties and may also be designed to have the weight necessary to hold it in proper position. The blocks are of such character, furthermore, that they may be manufactured at relatively low cost. They are practi50 cally indestructible under ordinary conditions and their durability, therefore, is almost unlimited. Since each block rests on only two ties, it is not necessary that the three ties covered by the length of each block be accurately leveled.

Although I have illustrated and described but a preferred embodiment of the invention, it will be recognized that changes in the details of the construction disclosed may be made without departing from the spirit of the invention or the 60 scope of the appended claims.