Abstract:
A gasket stop and gasket housing apparatus are provided. In one embodiment, the invention provides a gasket stop comprising: a body having: a first surface; and a second surface spaced from and substantially parallel to the first surface; an opening extending from the first surface to the second surface; at least one pillar extending at an acute angle from the first surface; and at least one retaining device having: an upright portion with at least one face; and a projecting portion extending outwardly from the body beyond the at least one face of the upright portion, whereby the at least one pillar and the at least one retaining device pass through a slot in a member such that the projecting portion secures the gasket stop against the member.

Description:
BACKGROUND OF THE INVENTION 
     Embodiments of the invention relate generally to gaskets and, more particularly, to a gasket stop for attachment to a bolt hole of a gasket frame, such as a filter house frame. 
     Various machines and devices, including gas and steam turbines, employ gaskets and gasket frames for sealing components of the machine or device. Typically, gaskets are housed within some manner of the gasket frame, which secures the gasket in place within the machine or device. A rail  20  of a conventional gasket frame is shown in  FIG. 1 . As can be seen, bolt holes  22 ,  24 ,  26  are located along rail  20 . A pair of rails will generally be placed along either side of a gasket and secured together by passing a bolt through each bolt hole  22 ,  24 ,  26 , thereby securing the gasket between the rails. The gasket frame itself may be of any shape and therefore include any number of rails of various sizes and shapes, as will be recognized by one skilled in the art. For ease of description, only a single elongate rail  20  is shown. 
     In order to avoid overcompression of a gasket secured between a pair of rails  20 , known gasket frames often employ gasket stops  10 ,  12  between bolt holes  22 ,  24 ,  26 . Typically, such gasket stops  10 ,  12  comprise metal discs welded along a surface of rail  20 . When a gasket is placed between a pair of rails  20 , which are then secured with bolts through bolt holes  22 ,  24 ,  26 , gasket stops  10 ,  12  prevent over-compression of the gasket as the bolts are tightened. Avoidance of compression of a gasket beyond its design compression limit is critical to obtaining and maintaining the desired seal. 
     However, the bolts securing the pair of rails  20  are often not tightened using a torque wrench or other device for applying a measured pressure. As a consequence, the bolts tend to be overtightened, resulting in bending or deflection of rail  20 , as shown in  FIG. 2 . Portions of rail  20  adjacent bolt holes  22 ,  24 ,  26  are deflected along path A, toward the second of the pair of rails (not shown), as the bolts are tightened. 
     Typically, gasket frames will include hundreds of bolt holes and gasket stops, resulting in extensive and uneven bowing of the frame&#39;s rails  20 . As a consequence, compression of the gasket is uneven along its length, resulting in a less efficient seal, an incomplete seal, or in some cases, a seal failure, any of which may damage or destroy the machine or device in which it is contained. 
     BRIEF DESCRIPTION OF THE INVENTION 
     A gasket stop and gasket housing apparatus are provided. 
     In one embodiment, the invention provides a gasket stop comprising: a body having: a first surface; and a second surface spaced from and substantially parallel to the first surface; an opening extending from the first surface to the second surface; at least one pillar extending at an acute angle from the first surface; and at least one retaining device having: an upright portion with at least one face; and a projecting portion extending outwardly from the body beyond the at least one face of the upright portion, whereby the at least one pillar and the at least one retaining device pass through a slot in a member such that the projecting portion secures the gasket stop against the member. 
     In another embodiment, the invention provides a gasket housing apparatus comprising: a first frame including at least one rail, the at least one rail having at least one bolt hole and at least one slot therethrough; a second frame including at least one rail, the at least one rail having at least one bolt hole therethrough; a gasket stop comprising: a body having: a first surface; and a second surface spaced from and substantially parallel to the first surface; an opening extending from the first surface to the second surface; at least one pillar extending at an acute angle from the first surface; and at least one retaining device having: an upright portion with at least one face; and a projecting portion extending outwardly from the body beyond the at least one face of the upright portion, wherein the at least one pillar and the at least one retaining device are adapted to pass through the at least one slot of the first frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features of this invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings that depict various embodiments of the invention, in which: 
         FIGS. 1 and 2  show perspective views of a known gasket frame rail. 
         FIGS. 3 and 4  show perspective views of a gasket stop according to an embodiment of the invention. 
         FIG. 5  shows a cross-sectional side view of the gasket stop of  FIGS. 3 and 4 . 
         FIGS. 6 and 7  show cross-sectional side views of the gasket stop of  FIG. 5  in conjunction with gasket frame rails. 
         FIGS. 8 and 9  show perspective views of the gasket stop of  FIGS. 3 and 4  in conjunction with a gasket frame rail. 
     
    
    
     It is noted that the drawings of the invention are not to scale. The drawings are intended to depict only typical aspects of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements between the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIGS. 3 and 4 , perspective views of a gasket stop  100  according to an embodiment of the invention are shown. Gasket stop  100  includes a body  110  having a first surface  112  and a second surface  114  spaced from and substantially parallel to first surface  112 . At least one edge  116  is disposed between first surface  112  and second surface  114 . The number of edges between first surface  112  and second surface  114  may vary, of course, depending on the shape of gasket stop  100 . In  FIGS. 3 and 4 , gasket stop  100  is shown with a first surface  112  having a substantially square periphery and a similarly shaped second surface  114  spaced from and extending substantially parallel thereto. As a consequence, gasket stop  100  includes four edges  115 ,  116 ,  117  (shown only in  FIG. 4 ),  118  (shown only in  FIG. 4 ) between first surface  112  and second surface  114 . Other arrangements are possible, of course, as will be recognized by one skilled in the art. 
     An opening  120  passes through body  110 , i.e., from first surface  112  through second surface  114 . As shown in  FIGS. 3 and 4 , opening  120  has a rounded oblong shape, having a length L and a width W, the length L being substantially perpendicular to and greater than the width W. Opening  120  forms a continuous surface  122  within body  110 . Opening  120  may have other shapes, however, as will be described in more detail below. 
     First surface  112  is shown having a pair of pillars  150 ,  160  extending at an acute angle therefrom. Pillars  150 ,  160  are shown adjacent opening  120 , although this is not essential. As will be described in greater detail below, pillars  150 ,  160  serve as a mating feature with an opening in a member, such as a gasket frame. That is, pillars  150 ,  160  are of a size and shape such that they may fit within an opening in the member. As such, pillars  150 ,  160  may have a different shape than that shown in  FIGS. 3 and 4 , as long as the shape permits entry into the opening in the member. Pillars  150 ,  160  include a face  154 ,  164 , respectively, substantially co-planar with at least a portion of continuous surface  122 . 
     First surface  112  also includes a pair of retaining devices  130 ,  140  adjacent pillars  150 ,  160 , but separated therefrom by voids  152 ,  162 , respectively. Retaining devices  130 ,  140  include an upright portion  132 ,  142  and a projecting portion  136 ,  146 . Upright portions  132 ,  142  each include a face  134  (shown only in  FIG. 4 ),  144  substantially co-planar with edges  118  (shown only in  FIG. 4) and 116 , respectively. Projecting portions  136 ,  146  extend outwardly from body  110  and beyond faces  134 ,  144  and edges  118 ,  116 . As shown in  FIGS. 3 and 4 , projecting portions  136 ,  146  have a substantially triangular shape in cross-section, although this is not essential. Other shapes are possible and both the sizes and shapes of projecting portions  136 ,  146  will vary depending on, for example, the size and shape of the opening in the member, into which it will be passed. 
     As will be described in greater detail below, insertion of retaining devices  130 ,  140  into a slot ( 233  in  FIG. 6 , infra) in a rail ( 230  in  FIG. 6 , infra) of a member, such as a gasket frame, will typically require, due to the extension of projecting portions  136 ,  146  beyond faces  134 ,  144  and edges  118 ,  116 , deflection of at least a portion of retaining devices  130 ,  140  along path B, i.e., away from edges  118 ,  116  and toward voids  152 ,  162 . As such, at least a portion of retaining devices  130 ,  140  are deformable along path B. Such deformation may be permanent or non-permanent. 
     Gasket stop  100  may comprise any number of materials or combinations of materials. Its use as a gasket stop requires some degree of rigidity, while deflection of some portion of retaining devices  130 ,  140  requires some degree of flexibility. Suitable materials include, for example, solid nylon (e.g., type 6,6, nylon 101, Nylon 6), other polyamides such as aramids, and polyethylenes. In some embodiments of the invention, gasket stop  100  comprises a single material. In other embodiments of the invention, gasket stop  100  comprises a combination of materials (e.g., retaining devices  130 ,  140  comprise a less rigid, more flexible material while the remainder of gasket stop  100  comprises a more rigid, less flexible material). 
       FIG. 5  shows a cross-sectional side view of gasket stop  100  along width W ( FIG. 3 ).  FIG. 6  shows the gasket stop  100  of  FIG. 5  between a pair of gasket frame rails  220 ,  230  and adjacent a gasket  300 . As can be seen in  FIG. 6 , pillars  150 ,  160  of gasket stop  100  sit below an inner surface  239  and within a slot  233  of bottom rail  230 . In the embodiment of  FIG. 6 , slot  233  is oblong, such that retaining devices  130 ,  140  and pillars  150 ,  160  pass through slot  233  to an extent that projecting portions  136 ,  146  reside along or below outer surface  238  of bottom rail  230 . Projecting portions  136 ,  146  thereby retain gasket stop  100  within bottom rail  230 . 
     Opening  120  of gasket stop  100  and bolt holes  222 ,  232  of top rail  220  and bottom rail  230 , respectively, form a path through which a bolt or similar fastening device may be passed, as shown in  FIG. 7 . Bolt  400 , nut  410 , and washers  420 ,  430  secure top rail  220  to bottom rail  230 , with gasket  300  and gasket stop  100  therebetween. Washer  430  is wider than a width but narrower than a length of oblong slot  233 , such that washer  430  may reside against outer surface  238  of bottom rail  230  without hindering passage of projecting portions  136 ,  146  through slot  233 . 
     The rigidity of gasket stop  100  prevents overtightening of bolt  400  and any consequent compression of gasket  300  beyond its design compression limit. The thickness T of gasket stop  100  may be varied based on the maximum compression of gasket  300  desired. 
       FIGS. 8 and 9  show perspective views of bottom rail  230  with gasket stop  100  in place. In  FIG. 8 , which shows outer surface  238  of bottom rail  230 , retaining devices  130 ,  140  and pillars  150 ,  160  of gasket stop  100  can be seen within slot  233 . A second bolt hole  242  and slot  243  are also shown, without a gasket stop in place, to better illustrate their structure in the depicted embodiment.  FIG. 9  shows inner surface  239  of bottom rail, with gasket stop  100  in place. As noted above, the size and shape of slot  233  may be different than that depicted. Various sizes and shapes may be employed, with the sizes and shapes of pillars  150 ,  160  and retaining devices  130 ,  140  varied in kind. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any related or incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.