Abstract:
The invention relates to a friction reduced and ice resistant water control gate abutment plates that permit, without damage to the concrete, large relative thermal movement between the abutment plate assembly and the concrete abutment or pier to which the assembly is attached. Features that provide ease of maintenance, tight sealing and debris damage resistance are also disclosed.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
       [0001]    The present invention relates to abutment plates for water control gates specially adapted to controlling rivers and canals and especially wherein such gates are subject to freezing conditions. 
       2. Description of Related Art 
       [0002]    UHMW polyethylene may be used as an abutment plate for bottom hinged water control gates. In small sizes, for example 1 to 2 meters across, closely spaced bolts may be used to secure such (one piece) abutment plates with loosely fitting bolts. The close spacing of the bolts prevents thermal buckling of the abutment plates, while clearance between the bolts and the clearance holes in the UHMW abutment plates allows for limited thermal movement of the abutment plate relative to the underlying structure. Clearance at the bolts prevents undue stresses from being generated as a result of thermal size changes of the abutment plate. Alternatively, springs may be used to secure a UHMW abutment plate to a concrete abutment. The range of motion of the springs is necessarily limited and thus is the maximum size of abutment plate that can be constructed with the use of retention springs. In the case of damage to an abutment plate, retention by springs presents difficulty with respect to abutment plate replacement. For larger gates, the required large size abutment plates require accommodation of more thermal movement than can be accommodated with either bolts or springs. 
         [0003]    Unitary large abutment plates, as opposed to those comprised of strips in accordance with the present invention, are subject to thermally induced stresses as a result of spatial temperature variations. For example a portion of an abutment plate may be immersed in ice water while another portion of the same abutment plate may at the same time be exposed to direct sunlight. Carbon black is preferred filler and reinforcement for UHMW polyethylene used as abutment plates because it provides resistance to ultra-violet light (UV) degradation and also absorbs sunlight which aids in melting ice. The division of the abutment plate into strips, in accordance with the present invention mitigates the thermally induced stresses otherwise developed under the aforementioned conditions. 
         [0004]    Bottom hinged water control gates may be designed to seal to the abutments in all positions or only in the fully raised position. If clearance gaps exist when the gates are in intermediate positions water born debris may become lodged in the gap and may subsequently interfere with control of gate movement. It is therefore preferable to provide a seal in all gate positions. This may be accomplished by the provision of smooth abutment plates on the surfaces of the fixed abutments at each end of each span of the gate system in conjunction with flexible seals attached to the adjacent edges of the adjoining gate panels. The most commonly used abutment plates are stainless steel plates rigidly anchored to the underlying structure, usually a concrete abutment. In cold climates the stainless steel abutment plates, because of their relatively high thermal conductivity, conduct heat from the water behind the gate system to the cold air downstream and above the gate system and thus cause ice to form between the gate system and the abutment plates. This ice may adhere strongly to strongly to both stainless steel abutment plates and to the otherwise movable gate panels. This ice prevent a gate from moving as required. Stainless steel abutment plates have a coefficient of thermal expansion close to that of concrete and may be rigidly anchored to the concrete. In order to prevent the formation of ice in conjunction with stainless steel abutment plates, the plates may be heated, generally by means of electric heaters. Electricity for heat may not be available and is generally expensive in the quantities (kW-hours) needed to keep a gate system operable throughout the winter. 
         [0005]    Various air inflated water control gates have been disclosed by these inventors. Accordingly, the following patents and pending patents applications are hereby incorporated by reference:
   U.S. Pat. No. 7,422,392 Water Control Structure   U.S. Pat. No. 7,114,879 Water Control Gate and Actuator Therefore   U.S. Pat. No. 6,196,763 Connection System for Hoses, Expansion Joints and Actuators   U.S. Pat. No. 5,713,699 Spillway Crest Gate System and Inflatable Bladder Therefor   U.S. Pat. No. 5,709,502 Connection System for Reinforced Composite Structures   U.S. Pat. No. 5,642,963 Spillway Gate System   U.S. Pat. No. 5,538,360 Crest Gate Operating System   U.S. Pat. No. 5,092,707 Crest Gate Operating System   U.S. Pat. No. 4,780,024 Crest Gate   20090180835 Water Control Apparatus   20060072969 Water Control Apparatus   
 
       SUMMARY OF INVENTION 
       [0017]    Ultra high molecular weight polyethylene, (UHMW polyethylene) is particularly useful for the construction of water control gate abutment plates because it provides low thermal conductivity, exhibits low adhesion to ice, has excellent abrasion resistance, exhibits a low coefficient of friction to rubber gate seals, and in its most ultra violet light resistant form and color (black), it warms in response to solar illumination. The principal challenge to using it as an abutment plate is that it has a much higher coefficient of thermal expansion than concrete and also has a relatively high Young&#39;s modulus. If rigidly fixed to a concrete structure the differential expansion of UHMW polyethylene and concrete may cause the concrete to break in response to temperature extremes. The UHMW polyethylene is therefore, in accordance with this invention, attached to the concrete in a manner that allows it to slide relative to the concrete in the plane of the abutment surface in two degrees of freedom. For an installation temperature of 75 degrees Fahrenheit provision should be made for a summertime temperature with direct sun exposure of 140 degrees F. and a wintertime temperature of approximately negative 40 degrees F. This represents a total temperature change of approximately 100 degrees F. Based on a thermal expansion coefficient of 11×10 −5  in/in/deg F and an abutment plate height of 26.24 feet (8 meters) the height variation between summer and winter temperature extremes could be  4 . 85  inches. If the UHMW polyethylene abutment plate were divided into tiles, the dimension change in any one tile could be limited, but would require gaps that would result in water leakage and ice formation downstream of the gate where it could prevent needed lowering of the gate. It is very desirable that the abutment seals attached to the gate panels adjacent the abutments have continuous engagement and form a continuous seal with the abutment plates from bottom to top. 
         [0018]    In accordance with a preferred embodiment of the present invention the abutment plates are divided into strips parallel with the abutment seal in the fully raised gate position. In this configuration thermal expansion and contraction along the long axis of each strip may be accommodated by the use of tee-slots, that run parallel to the strips, in the back of the abutment plates. The strips may be of standard commercially available widths such as  4  feet, for example. Thermal expansion and contraction in the strip width direction may be accommodated by clearance in the tee slots. In a preferred embodiment a tee slot along the center of the strip is provided with minimal lateral clearance so as to fix the lateral position of the centerline of the strip relative to the concrete abutment while tee slots further from the strip centerline are provided with lateral clearance in proportion to their distance from the strip centerline. For example, 5 tee slots may be provided with the center tee slot is provided with minimal lateral clearance, the two tee slots nearest the center tee slot are provided with 3/16″ clearance and the outermost tee slots are provided with ⅜″ clearance. As a further example 3 tee slots might be provided in a 4 ft wide strip with the center slot having minimal lateral clearance, and the two outer tee slots having ⅜″ clearance. 
         [0019]    In accordance with a further aspect of the invention, the adjacent edges of adjacent abutment plate strips may be angled in order to help prevent water born debris from snagging the upstream edges of the abutment plate strips. 
         [0020]    In accordance with a further aspect of the invention, the lower edge of each strip may be fixed relative to the concrete. 
         [0021]    In accordance with a further aspect of the invention, the upstream edge of the furthest upstream strip of UHMW polyethylene may be clamped and sealed to the abutment in order to occlude water from upstream of the gate system from the interface between the concrete abutment and the UHMW polyethylene abutment plate. 
         [0022]    In accordance with a further aspect of this invention, the upper (thermally moving) edge of the abutment plate strips may be capped with a stainless steel bracket in order to prevent damage to the upper edge of the abutment plate strips during flood flows. 
         [0023]    In accordance with a further aspect of the invention, the aforementioned stainless steel bracket may be removable so as to allow replacement of any damaged abutment plate strips. 
         [0024]    In accordance with a further aspect of the invention, guide rails, of stainless steel for example, may be used to engage the tee slots and thereby secure the abutment plate strips. 
         [0025]    In accordance with a further aspect of the invention, the guide rails may be precisely spaced, prior to embedment in concrete, by spacer members connected thereto to form an assembly. The guide rails may be constructed by welding stainless steel flat bar to the edge of one leg of stainless steel angles. The spacer members may be similar stainless steel angles. The spacer members may extend past their respective abutment plate strip so as to overlap one or more guide rails of an adjoining abutment plate strip and thus provide a convenient means of establishing in the field a coplanar assembly that may be welded or bolted together prior to placement of concrete. 
         [0026]    In accordance with a further aspect of the invention, the assembly of guide rails and spacer members may be kept aligned during concrete placement by diagonal bracing members. 
         [0027]    In accordance with a further aspect of the invention, the lateral clearances provided between guide rails and abutment plate strips may be filled prior to concrete placement, preferably at the factory, with a low modulus filler such as RTV silicone caulk. In this manner concrete is prevented from entering the tee slots where it would impeded the intended free lateral thermal expansion and contraction of the abutment plate strips. 
         [0028]    In accordance with a further aspect of the invention, abutment plate strips may be provided in standard lengths such as 10 feet, for example, and fastened end-on-end prior to concrete placement in order to provide the required length. Such fastening may be by bolted joints, snap-together joints, or field welded joints, for example. 
         [0029]    In accordance with a further aspect of the invention, the guide rail assemblies may be provided in standard lengths such as 10 feet, for example, and fastened end-on-end prior to concrete placement in order to provide the required length. Such fastening may be by bolted joints, snap-together joints, or field welded joints, for example. 
         [0030]    In accordance with a further aspect of the invention, the rails may be comprised of rectangular stainless steel bar, for example, secured to the abutment concrete by Nelson studs, for example. Spacing of the guide rails may be established during concrete placement in such case with braces secured to the Nelson studs. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]      FIGS. 1  is a sectional elevation of a gate system and associated abutment plate. 
           [0032]      FIG. 2  is a cross section of an abutment plate and adjacent portion of water control gate and associated abutment seal. 
           [0033]      FIG. 3  is a cross section of an abutment plate upstream clamp and sealing means. 
           [0034]      FIG. 4  is a cross section of a non-sealing abutment plate clamp. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0035]    Referring to  FIG. 1 , Abutment plate  6   a ,  6   b ,  6   c ,  6   d , and  6   e  are attached to concrete abutment  19 . Inflated air bladder  17   b  actuates gate panel  28  to which is affixed abutment seal  2 . The upstream edges of abutment plate strip  6   a  are clamped to concrete abutment  19  by clamps  21  and  22 . The remaining edges of the abutment plate strips  6   a ,  6   b ,  6   c ,  6   d  and  6   e  are secured by clamps  23 ,  25 , and  25 . The abutment plate of this invention is applicable to a wide variety of water control gates in addition to the one illustrated. 
         [0036]    Referring now to  FIG. 2 , a cross section of an abutment plate assembly is shown. Guide rails  12   a ,  12   b ,  12   c ,  12   d  and  12   e  secure abutment plate  6   b  to concrete pier  19 . Clearances  7 ,  8 ,  9 , and  10  vary in proportion to distance from the center rail  12   c  where only minimal clearance need be provided. The rails are connected, by welding for example, to spacer member  13  which may in turn be connected to diagonal brace  14 . 
         [0037]    Referring now to  FIG. 3 , clamp  22  secures abutment plate strip  6   a  to embed  31 . O-ring  33  seals between abutment plate strip  6   a  and embed  31 . Abutment plat strip  6   a  may slide between embed  31  and clamp  22  in response to thermal strain. 
         [0038]    Referring now to  FIG. 4 , clamp  24  secures abutment plate  6  to abutment  19  and protects the edge of abutment plate  6  from damage by flowing debris or ice. 
         [0039]    As can be easily understood from the foregoing, the basic concepts of the present invention may be embodied in a variety of ways. It involves both abutment ice control techniques as well as devices to accomplish the appropriate method. In this application, the ice control techniques are disclosed as part of the results shown to be achieved by the various devices described and as steps which are inherent to utilization. They are simply the natural result of utilizing the devices as intended and described. In addition, while some devices are disclosed, it should be understood that these not only accomplish certain methods but also can be varied in a number of ways. Importantly, as to all of the foregoing, all of these facets should be understood to be encompassed by this disclosure. 
         [0040]    The discussion included in this PCT patent application is intended to serve as a basic description. The reader should be aware that the specific discussion may not explicitly describe all embodiments possible; many alternatives are implicit. It also may not fully explain the generic nature of the invention and may not explicitly show how each feature or element can actually be representative of a broader function or of a great variety of alternative or equivalent elements. Again, these are implicitly included in this disclosure. Where the invention is described in device-oriented terminology, each element of the device implicitly performs a function. Apparatus claims may not only be included for the device described, but also method or process claims may be included to address the functions the invention and each element performs. Neither the description nor the terminology is intended to limit the scope of the claims which will be included in a full patent application. 
         [0041]    It should also be understood that a variety of changes may be made without departing from the essence of the invention. Such changes are also implicitly included in the description. They still fall within the scope of this invention. A broad disclosure encompassing both the explicit embodiment(s) shown, the great variety of implicit alternative embodiments, and the broad methods or processes and the like are encompassed by this disclosure and may be relied upon when drafting the claims for the full patent application. It should be understood that such language changes and broad claiming will be accomplished when the applicant later (filed by the required deadline) seeks a patent filing based on this provisional filing. The subsequently filed, full patent application will seek examination of as broad a base of claims as deemed within the applicant&#39;s right and will be designed to yield a patent covering numerous aspects of the invention both independently and as an overall system. 
         [0042]    Further, each of the various elements of the invention and claims may also be achieved in a variety of manners. This disclosure should be understood to encompass each such variation, be it a variation of an embodiment of any apparatus embodiment, a method or process embodiment, or even merely a variation of any element of these. Particularly, it should be understood that as the disclosure relates to elements of the invention, the words for each element may be expressed by equivalent apparatus terms or method terms—even if only the function or result is the same. Such equivalent, broader, or even more generic terms should be considered to be encompassed in the description of each element or action. Such terms can be substituted where desired to make explicit the implicitly broad coverage to which this invention is entitled. As but one example, it should be understood that all actions may be expressed as a means for taking that action or as an element which causes that action. Similarly, each physical element disclosed should be understood to encompass a disclosure of the action which that physical element facilitates. Regarding this last aspect, as but one example, the disclosure of a “means for preventing ice adhesion” or a “ice preventer” should be understood to encompass disclosure of the act of “preventing”—whether explicitly discussed or not—and, conversely, were there effectively disclosure of the act of “preventing”, such a disclosure should be understood to encompass disclosure of a “preventer” and even a “means for preventing”. Such changes and alternative terms are to be understood to be explicitly included in the description. UHMW polyethylene is specified because it is readily available in North America at the time of the writing of this application. Other low thermal conductivity and low ice adhesion wear resistant materials may be substituted according to their availability, performance and price without deviating from this invention. 
         [0043]    Patents, publications, or other references mentioned in this application for patent are hereby incorporated by reference. In addition, as to each term used it should be understood that unless its utilization in this application is inconsistent with such interpretation, both traditional and common dictionary definitions should be understood as incorporated for each term and all definitions, alternative terms, and synonyms such as contained in the Random House Webster&#39;s Unabridged Dictionary, second edition are hereby incorporated by reference. Finally, all references listed in the list of References To Be Incorporated By Reference In Accordance With The Provisional Patent Application or other information statement filed with the application are hereby appended and hereby incorporated by reference, however, as to each of the above, to the extent that such information or statements incorporated by reference might be considered inconsistent with the patenting of this/these invention(s) such statements are expressly not to be considered as made by the applicant(s). 
         [0044]    Thus, the applicant(s) should be understood to claim at least: i) each of the input devices as herein disclosed and described, ii) the related methods disclosed and described, iii) similar, equivalent, and even implicit variations of each of these devices and methods, iv) those alternative designs which accomplish each of the functions shown as are disclosed and described, v) those alternative designs and methods which accomplish each of the functions shown as are implicit to accomplish that which is disclosed and described, vi) each feature, component, and step shown as separate and independent inventions, vii) the applications enhanced by the various systems or components disclosed, viii) the resulting products produced by such systems or components, ix) methods and apparatuses substantially as described hereinbefore and with reference to any of the accompanying examples, x) the various combinations and permutations of each of the elements disclosed, xi) each potentially dependent claim or concept as a dependency on each and every one of the independent claims or concepts presented, xii) processes performed with the aid of or on a computer as described throughout the above discussion, xiii) a programmable apparatus as described throughout the above discussion, xiv) a computer readable memory encoded with data to direct a computer comprising means or elements which function as described throughout the above discussion, xv) a computer configured as herein disclosed and described, xvi) individual or combined subroutines and programs as herein disclosed and described, xvii) the related methods disclosed and described, xviii) similar, equivalent, and even implicit variations of each of these systems and methods, xix) those alternative designs which accomplish each of the functions shown as are disclosed and described, xx) those alternative designs and methods which accomplish each of the functions shown as are implicit to accomplish that which is disclosed and described, xxi) each feature, component, and step shown as separate and independent inventions, and xxii) the various combinations and permutations of each of the above. 
         [0045]    It should also be understood that for practical reasons and so as to avoid adding potentially hundreds of claims, the applicant may eventually present claims with initial dependencies only. Support should be understood to exist to the degree required under new matter laws—including but not limited to European Patent Convention Article 123(2) and United States Patent Law 35 USC 132 or other such laws—to permit the addition of any of the various dependencies or other elements presented under one independent claim or concept as dependencies or elements under any other independent claim or concept. Further, if or when used, the use of the transitional phrase “comprising” is and will be used to maintain the “open-end” claims herein, according to traditional claim interpretation. Thus, unless the context requires otherwise, it should be understood that the term “comprise” or variations such as “comprises” or “comprising”, are intended to imply the inclusion of a stated element or step or group of elements or steps but not the exclusion of any other element or step or group of elements or steps. Such terms should be interpreted in their most expansive form so as to afford the applicant the broadest coverage legally permissible.