Expansion drain
United States Patent [I ll 3,876,322  
 Deason Apr. 8, 1975 [5 EXPANSION DRAIN 3.690.226 9/1972 Hein t. 404/68 76 l t 1 M W. D l W. 1 men or j g5 Pnce&#39; Primary Examiner-Nile C. Byers, Jr.  
  Auomey, Agent, or Firm-Cahill, Sutton &amp; Thomas [22] Filed: Feb. 21, 1974 211 App]. No.: 444.3% {57] ABSTRACT A drain is disclosed for separating or bordering sections of concrete and includes an elongated enclosed 2% 404/2; 404/65lE2l0/l63 channel having sidewalls with dove-tail shaped indenf g 9 tations or keyways therein to form a water barrier and l l 0 care 6 to anchor the drain in the concrete. The top of the 2 [OM63 drain includes a plurality ofopenings and also includes a pair of troughs extending longitudinally and borderlsl References cued ing said openings to catch water on the drain and pro- UNITED STATES PATENTS vide a path to the openings. The troughs also provide 469.U44 2/1892 Jungbluth 404/2 X a longitudinally extending area of flexure together 775.79] 1 H1904 Austin 404/2 with an inverted trough on the bottom of the drain to 3336113&#34; HV1945 wfefldclkfifl a g t a r 404/2 permit the drain to be compressed and expanded 2515-847 7/1950 wmklcr t t 404/3 X when adjacent sections of concrete expand and con- 3.387.544 6/l968 MacLellun 44444 404/68 X tract 3.605.574 NW7] Hall t t i 404/64 3.h2S.(HI 12/197] Stevenson 404/2 X 8 Claims, 2 Drawing Figures EXPANSION DRAIN The present application pertains to drains, and more particularly, to drains of the type suitable for separating adjacent sections of concrete such as may be found on pool decks.  
  It is important to provide for the expansion and contraction of concrete slabs or sections to prevent the occurrence of cracks and possibly disintegration of portions of the concrete sections. The appearance of cracks is of course especially undersirable when the appearance of the concrete section is important such as in pool decks. It is well known to provide expansion joints between adjacent sections of concrete to accommodate such expansion and contraction; however, it is also important to prevent water from seeping between the expansion joint and concrete to the soil beneath the concrete. If water is permitted to reach the soil beneath the concrete (the likelihood being substantially increased in the vicinity of a pool) certain types of soils known as expansive soils will expand and raise the concrete sections and even in some circumstances exert so much pressure that the concrete will break. Obviously, such occurrences are undesirable and in a pool environment can even be dangerous. It is therefore desirable to drain the water from the area of the expansion joint and carry it away to prevent its seepage to the soil beneath the concrete.  
  Expansion joints are well known; for example, U.S. Pat. No. 2.43 l ,3 86 to Fischer show a water stop expansion joint while the patent to Frederickson, U.S. Pat. No. 3,426.658. describes an expansion joint that is also intended to induce an expansion crack beneath the joint. Drains are also well known and have taken a variety of forms; however, it is important for the drain to be of such configuration that it can be economically produced, provide the functions of an expansion joint, be attractive in appearance (an important aspect when placed in a pool environment) and be effective in collecting water from the surface and carrying it away from the joint.  
  it is therefore an object of the present invention to provide a drain for separating shows bordering sections of concrete that will effectively collect water and carry the water off from the area of contact between the drain and the concrete.  
  lt is also an object of the present invention to provide a drain for separating or bordering sections of concrete that may be made attractive in appearance while nevertheless providing all the functions necessary of an expansion joint.  
  Still another object of the present invention is to provide a drain for separating and bordering sections of concrete wherein the drain performs the functions of an expansion joint while being readily manufacturable and effective in the collection of water from the surface thereof for transport from the joint with the adjacent section of concrete.  
  The present invention may be understood with more specificity andclarity with reference to the following figures, in which:  
  FIG. 1 is a perspective view ofa drain constructed in accordance with the teachings of the present invention; and  
  H6. 2 is a cross-section of FIG. 1 taken along line 2-2 and showing the cross section set in its intended environment.  
  Referring now to the drawings, a hollow elongated closed channel 10 includes a bottom wall 12 and a top wall 14. Sidewalls 16 and 17 extend substantially vertical and in parallel relation with each other from the bottom wall to the top wall. The sidewalls l6 and l7 include longitudinally extending dove-tail shaped indentations or keyways l8 and 19, respectively. The keyways 18 and 19 receive concrete when poured thereagainst to lock the drain in place and to anchor the drain to the adjacent sections of concrete to permit the sidewalls l6 and 17 to be pulled outwardly by the concrete when the concrete contracts. The concrete in the keyways l8 and 19 also provide a water barrier to prevent water from seeping downwardly along the sidewalls from the top of the concrete sections to the underlying ground therebeneath.  
  The top wall 14 includes a plurality of openings 20 which are formed of transverse slots extending through the top wall to provide communication from the exterior to the interior of the channel 10. The openings 20 do not extend the entire width of the wall 14 but rather terminate at either end thereof in a pair of longitudinally extending troughs 22 and 24. The troughs connect with the openings 20 so that water acumulating on the top wall of the channel 10 will travel into the troughs 22 and 24 and thereafter into the openings 20.  
  The drain may be formed from a suitable plastic ma terial that is semi-rigid in nature. That is, it is sufficiently rigid to hold its shape and support forces normally encountered with expansion joints or drains while nevertheless providing sufficient flexibility to permit yielding of the structure under the expansion and contraction forces of the adjacent sections of concrete. To assist the flexing. and to concentrate the flexure as much as possible in predesired areas. the troughs 22 and 24 are supported adjacent the bottom portions thereof by longitudinally extending webs 30 and 31 to thus provide a longitudinally extending area of flexure 26 and 28. Thus, as the adjacent sections of concrete expand and contract the forces exerted on the drain result in flexure concentrated at the areas 26 and 28 rather than significantly deforming the remaining portion of the top wall 14. Similarly. inverted trough 32 is positioned in the bottom wall 12 to accommodate flexure of the bottom wall resulting from the expansion and contraction of adjacent sections of concrete.  
  The structure of the present invention lends itself to manufacture through known extrusion techniques while the openings 20 may conveniently be formed after extrusion by rotary circular saws (not shown) which rotate in a plane perpendicular to the longitudinal axis ofthe channel 10 and are lowered into engagement with the top wall 14. Since the troughs 22 and 24 extend below the top surface of the wall 14 the saws will conveniently form the openings 20 making certain that the openings not only extend through the top wall 14 but also that they connect near the bottoms of the troughs 22 and 24.  
  In operation, the drain of the present invention is appropriately placed in position and concrete in plastic form is poured on one or both sides thereof. It may be noted here that the vertical sidewalls l6 and 17 permit the positioning of the drain against other vertical surfaces in the event that concrete is not to be placed on both sides thereof; it may also be noted that the symmetry of the cross-section of the channel 10 permits the efficient manufacture of angled drains without concern for the specific shape of the inside or outside walls. The keyways l8 and 19 lock&#34; the drain in position and permit the sidewalls l6 and 17 thereof to be pulled outwardly with the adjacent sections of concrete contracted. The contraction or expansion of the concrete is accommodated by the drain and is specifically provided for by the predetermined areas of flexure 26, 28 and 32. When water is present on the top of the concrete and drain, the water is prevented from seeping downwardly along the sidewalls l6 and 17 to the under&#39; lying soil by the existence of the concrete in the keyways 18 and I9. Water appearing at the top wall 14 is captured by the troughs 22 and 24 and travel from the lowest point thereof through the openings 20 into the interior of the channel to be carried off and disposed of.  
 I claim:  
 1. A drain for separating or bordering sections of concrete comprising:  
 a hollow elongated enclosed channel having a bottom wall top wall, and sidewalls extending from said bottom wall to said top wall;  
 at least one of said sidewalls including a longitudinally extending keyway therein to receive concrete when poured and thereby anchor said drain to ad jacent sections ofconcrete and to form a water barrier preventing water from travelling downwardly along said sidewall from said top wall to said bottom wall;  
 said top wall having a plurality of openings therein to admit water into said channel said top wall also including a longitudinally extending trough formed therein connecting with said openings to collect water on said top wall and deliver water to said openings; said trough forming a longitudinally extending area of flexure to permit said drain to be compressed and expanded when adjacent sections of concrete expand and contract, respectively.  
  2. The combination set forth in claim 1 wherein said sidewalls are parallel and wherein each said sidewall includes a longitudinally extending keyway.  
  3. The combination set forth in claim 1 wherein said bottom wall includes a longitudinally extending inverted trough to form a longitudinally extending area of flexure in the bottom wall.  
  4. The combination set forth in claim 1 wherein said top wall includes a pair of longitudinally extending troughs and wherein said openings extend from one trough to the other trough, said troughs each forming a longitudinally extending area of flexure.  
  5. The combination set forth in claim 4 including a pair of longitudinally extending webs positioned internally of said channel each extending from a sidewall to a bottom of a different one of said troughs.  
  6. The combination set forth in claim 2 wherein said bottom wall includes a longitudinally extending inverted trough to form a longitudinally extending area of flexure in the bottom wall.  
  7. The combination set forth in claim 6 wherein said top wall includes a pair of longitudinally extending troughs and wherein said openings extend from one trough to the other trough, said troughs each forming a longitudinally extending area of flexure; and  
  8. The combination set forth in claim 7 including a pair of longitudinally extending webs positioned inter nally of said channel each extending from a sidewall to a bottom of a different one of said troughs.