# Patent

## Title
Certain 1,2,4-Oxa- and -thiadiazol-5-ylthioalkanoic acid derivatives

## Abstract

From the foregoing, it will be understood that the illustrative embodiments of the small diameter flexible plastic tubing mats, as shown above, are well suited to provide the advantages set forth. And since many possible embodiments may be made of various features of the invention and as the apparatus here described may be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter here and before set forth shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense in that certain features of these embodiments may be used without a corresponding use of other features without departing from the scope of the invention.

## Background
## Claims

1. A flexible portable plastic tubing mat adapted to be laid side-by-side with other similar mats for creating and maintaining an ice slab for skating and for preventing snow from melting on a ski slope and adapted to be laid end-to-end with other similar mats for creating an ice chute or trough for a toboggan slide or similar sliding purposes, a plurality of small diameter flexible plastic tubing members extending lengthwise of said mat adapted to have cooled anti-freeze liquid pumped therethrough, range from one-eighth to three-eighths of an inch, grid pattern in said mat, end of said mat with the ends of a plurality of said tubing members being connected respectively to said supply and return sub-headers with the direction of flow of the anti-freeze liquid being opposite in neighboring tubing members in the mat, transportation, and installation for interconnecting the plurality of said tubing members through the sub-headers to the main headers.

2. A flexible portable plastic tubing mat as claimed in claim 1 in which said small diameter plastic tubing members are co-extruded in pairs of such members and the ends of the tubing members are connected to said supply and return sub-headers to produce an opposite direction of the anti-freeze flow in the respective tubing members of each pair.

3. A flexible portable plastic tubing mat as claimed in claim 1 in which the mat is about 4 feet wide and at least 85 feet long.

4. A flexible portable plastic tubing mat as claimed in claim 1 in which supply and return sub-headers extend across both ends of said mat with the ends of a plurality of the tubing members connected respectively to supply and return sub-headers at opposite ends of the mat.

5. A flexible portable plastic tubing mat as claimed in claim 1 in which said small diameter plastic tubes are composed of ethylene vinyl acetate.

6. A flexible portable plastic tubing mat as claimed in claim 5 in which said securing means include tapes extending transversely along the mat at spaced positions along the length of said mat. .Iadd. 7. A flexible portable plastic tubing mat adapted to be laid side-by-side or end-to-end with other similar mats for creating and maintaining a frozen area, a plurality of small diameter flexible plastic tubing members extending lengthwise of said mat adapted to have cooled anti-freeze liquid pumped therethrough, range from one-eighth to three-eighth of an inch, grid pattern in said mat, end of said mat with the ends of a plurality of said tubing members being connected respectively to said supply and return sub-headers with the direction of flow of the anti-freeze liquid being opposite in neighboring tubing members in the mat, transportation, and installation for interconnecting the plurality of said tubing members through the sub-headers to the main headers. .Iaddend.