Abstract:
A handheld tool is for facilitating installation of a resilient, elongate, generally rectangle-profiled gasket designed to tightly fit inside and along the partially obstructed perimetric channel of a watertight doorway onboard a marine vessel. As typically embodied, the inventive tool includes a straight handle (e.g., shaft or rod) and a head. The head includes a right-triangle profiled section and an L-shape-profiled section. The handle is perpendicularly connected to the hypotenuse surface of the right-triangle profiled section. The L-shape-profiled section has two interior surfaces forming an interior right angle that faces away from the hypotenuse surface. The bisector of the interior right angle is parallel to the handle and perpendicular to the hypotenuse surface. A user holds the inventive tool by the handle, controls the gasket so that a rectangular corner portion of the gasket fits inside the L-shape-profiled section&#39;s interior right angle, and forcefully manipulates the gasket into the channel.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to gaskets for effecting watertight sealing of doors and other closures, more particularly to methods and devices for installing such gaskets in such closures. 
     The United States Navy&#39;s surface ship fleet includes about about eighty thousand watertight closures such as doors, hatches, and scuttles. A common feature of shipboard watertight closures is an elastic (e.g., elastomeric) sealing body known as a “gasket.” The most prevalent watertight closure gasket in the U.S. Navy&#39;s fleet is an embodiment of the “Fluidtight Door Gasket” disclosed by Marline D. Rowe and Francis A. McMullin at U.S. Pat. No. 5,553,871, issue date 10 Sep. 1996, incorporated herein by reference. The gasket disclosed by Rowe and McMullin is typically embodied as being characterized along its length by two forty-five degree chamfers and a medial semicircular groove therebetween. 
     The Rowe-McMullin gasket and the vast majority of other gaskets are described herein as having a “generally rectangular” cross-section. The term “generally rectangular,” as used herein to describe the cross-sectional shape of a gasket or of a gasket channel, is intended herein to convey a rectangular form that is either a perfect rectangle or a quasi-rectangle, the latter being a rectangular form that departs from perfect geometric rectangularity in certain geometric respects. Historically speaking, most watertight closure gaskets, and most watertight closure channels to which they correspond, have been characterized by a three-dimensional shape that “generally” defines a rectangular prism or a rectangular parallelepiped. “Generally” conveys that a gasket or a gasket channel may be characterized by certain design geometric deviations from a pure rectangular prismatic geometry or pure rectangular parallelepiped geometry. 
     The Rowe-McMullin gasket embodiment in current Navy use, illustrated in  FIG. 1  and  FIG. 2 , is made of a Commercial Item Description A-A-59588 silicone rubber, grade 3B, class 30 composite, which is about a 30 durometer material. In terms of ease of installation, this silicone rubber material is superior to Mil-R-900 rubber (about 50 durometers), which used to be the Navy&#39;s material of choice for constituting watertight closure gaskets. 
     Generally speaking, the lower the durometer, the more pliable the material, and hence the easier it is for personnel to manipulate a gasket while installing it into a closure gasket channel. Nevertheless, installation of even a relatively pliable gasket requires strong hands and strong fingers to work the gasket into the entire channel perimeter; for instance, approximately seventeen linear feet of gasket is required for a typical watertight door onboard a Navy ship. 
     Personnel installing a gasket tend to longitudinally stretch (lengthen) the gasket, largely inadvertently, before and during insertion of the gasket into the channel. Lengthwise stretching of a gasket decreases the width of the gasket, thus making the gasket easier to install. Unfortunately, after the installation is complete, the gasket tends to relax back (shorten) to its original, pre-stretched length. This relaxation of the elastic gasket material often creates a gap between the two butt ends of the gasket, the watertight closure thereby being rendered “non-watertight.” The resultant defective gasket needs to be replaced, not due to any obvious material defect, but solely due to the gap between the two gasket ends. This gasket replacement cycle may repeat itself again and again. 
     The Navy&#39;s gasket is usually supplied on spools by vendors, each spool carrying a specific length (e.g., 160 feet) of the gasket. The Navy purchases enough gasket material through the stock system alone to replace every gasket on every watertight door on an annual basis. At about $3.50 per foot, this amounts to about $2,500,000 spent annually by the Navy for gasket material replacement, which is cost in addition to the time required by personnel to remove and install the gaskets. 
     The main reason for such high usage of the Navy&#39;s gasket is not ripping, tearing, or “permanent set” of the gasket, but rather is the elasticity of the gasket—in particular, the propensity of the gasket material to be stretched before and during installation, and to then relax back to its previous, installed length over a period of time, thereby creating a gap between the two gasket ends. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, it is an object of the present invention to provide method and apparatus for installing a gasket that is designed to be fit inside a channel included in or associated with a closure (such as may exist onboard a ship) so that the gasket imparts watertightness to the closure. 
     A further object of the present invention is to provide such method and apparatus that are facilitative of gasket installation. 
     Another object of the present invention is to provide such method and apparatus that, as compared with conventional approaches to gasket installation, reduce or minimize length-increasing elastic deformation of a gasket during gasket installation. 
     A typical embodiment of a gasket insertion device in accordance with the present invention includes a head and a handle. The head includes a right-trianguloid-profiled section and an L-profiled section. The right-trianguloid-profiled section has a hypotenuse surface. The handle is characterized by a geometric handle axis and is connected to the head at the hypotenuse surface. The handle axis is approximately perpendicular to the hypotenuse surface. The L-profiled section has a first interior surface and a second interior surface. A geometric first right angle is formed by the first interior surface and the second interior surface, and is characterized by a geometric first right angle bisector. The first bisector is approximately parallel to the handle axis and approximately perpendicular to the hypotenuse surface. 
     According to frequent inventive practice, the trianguloid-profiled section has, in addition to the hypotenuse surface, a first non-hypotenuse surface and a second non-hypotenuse surface. The L-profiled section has, in addition to the first interior surface and the second interior surface, a first exterior surface and a second exterior surface. A geometric second right angle is formed by the first exterior surface and the first non-hypotenuse surface, and is characterized by a geometric second right angle bisector, which is approximately perpendicular to the handle axis, approximately perpendicular to the first bisector, and approximately parallel to the hypotenuse surface. A geometric third right angle is formed by the second exterior surface and the second non-hypotenuse surface, and is characterized by a geometric third right angle bisector, which is approximately perpendicular to the handle axis, approximately perpendicular to the first bisector, approximately parallel to the hypotenuse surface, and approximately parallel to the second bisector. 
     The present invention&#39;s gasket insertion device, as typically embodied, is a handheld tool that enables personnel to insert gasket material into a watertight closure gasket channel without stretching the gasket. Elegant in its design and economical to fabricate, the inventive device eliminates the need for manual “muscling” of the gasket into the channel along the length of the channel, a forceful and labor-intensive activity that represents the primary causation for stretching of the gasket. The inventive device reduces the time required, and makes it easier, for personnel to install a gasket. 
     The cost-savings afforded by inventive practice can be significant, especially because of its mitigation or elimination of the gasket-stretching factor. For instance, inventive practice could save the Navy over a million dollars annually because of the alleviated need to procure and replenish gaskets for watertight closures. Moreover, fabrication of most embodiments of the present invention should be neither unduly difficult nor unduly expensive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the present invention may be clearly understood, it will now be described, by way of example, with reference to the accompanying drawings, wherein: 
         FIG. 1  is a cross-sectional view (or profile view) of the Rowe-McMullin gasket embodiment currently in use by the U.S. Navy. 
         FIG. 2  is a view, similar to the  FIG. 1  view of the Rowe-McMullin gasket, showing by way of example the Row-McMullin gasket installed in the gasket channel of a watertight closure onboard a ship. 
         FIG. 3  is a diagrammatic elevation view of a shipboard watertight door with a gasket installed in the door&#39;s perimetric channel. As shown in  FIG. 3 , the installed gasket&#39;s longitudinal ends meet each other. The installed gasket is elongated due to stretching associated with its installation. 
         FIG. 4  is a diagrammatic elevation view, similar to  FIG. 3 , of the same shipboard watertight door with the same gasket installed in the door&#39;s perimetric channel. As shown in  FIG. 4 , the installed gasket&#39;s longitudinal ends do not meet each other. The installed gasket has elastically relaxed to its original length, thereby leaving a gap between the gasket&#39;s longitudinal ends. 
         FIG. 5  is partial side longitudinal view of an embodiment of a gasket installation device in accordance with the present invention. 
         FIG. 6  is complete and smaller rendition of the view of the inventive embodiment shown in  FIG. 5 . 
         FIG. 7  is a top longitudinal view of the inventive embodiment shown in 
         FIG. 5 . 
         FIG. 8  is a view, of the head component of the inventive embodiment shown in  FIG. 5 , that is similar to the views of  FIG. 5  and  FIG. 6  and that includes dimensional and angular information. 
         FIG. 9  is a partial side longitudinal view of the inventive embodiment shown in  FIG. 5  and of a gasket channel of a watertight closure such as shown in  FIG. 2 .  FIG. 9  illustrates insertion, using the inventive embodiment shown in  FIG. 5 , of a gasket into a gasket channel. 
         FIG. 10  is a view, similar to the  FIG. 9  view, of the inventive embodiment shown in  FIG. 5  and of a gasket channel such as shown in  FIG. 2 .  FIG. 10  further illustrates insertion, using the inventive embodiment shown in  FIG. 5 , of a gasket into a gasket channel. 
         FIG. 11  is essentially the  FIG. 10  view, but reduced in size and amplified with dimensional and angular information, of the inventive embodiment shown in  FIG. 5  and of a gasket channel such as shown in  FIG. 2 . 
         FIG. 12  is a perspective view of another embodiment of a gasket installation device in accordance with the present invention. 
         FIG. 13  is a view, similar to the  FIG. 12  view, of the inventive embodiment shown in  FIG. 12  and of a gasket channel such as shown in  FIG. 2 .  FIG. 13  illustrates insertion, using the inventive embodiment shown in  FIG. 12 , of a gasket into a gasket channel. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIG. 1  and  FIG. 2 , Rowe-McMullin gasket  50  is characterized by a generally rectangular cross-section, two forty-five degree chamfers  51   a  and  51   b , and a medial semicircular groove  52 . Gasket  50  is a resilient body and is shaped and dimensioned compatibly with perimetric channel  61  of doorway  60 , thus permitting insertion of gasket  50  into channel  61  and tight situation therein. Installation of gasket  50  into a watertight closure channel such as channel  61  of doorway  60  has traditionally been accomplished through use of an installer&#39;s fingers to grasp and press gasket  50  along its length until completely situate inside channel  61 . 
     With reference to  FIG. 3  and  FIG. 4 , the person or persons who install a gasket need to know approximately how much gasket  50  is needed to go around the perimeter of the closure  60 . The installer “unwraps” the gasket  50  from a spool, and then makes a ninety-degree cut across the gasket  50 . The gasket  50  installation process, such as with respect to a door  60  as shown in  FIG. 3  and  FIG. 4 , starts at the top dead-center location  62  of the door  60 &#39;s perimetric gasket channel  61 . Installation of gasket  50  proceeds from starting location  62  all the way around the perimetric channel  61  in either a clockwise or counterclockwise direction, until returning to the starting location  62 , where the two ends  53  and  54  of gasket  50  nearly or imperfectly meet. At this point the installer makes another cut (a square cut) of the gasket  50 , the proper performance of which creates at location  62  a square butt joint  55  of the ends  53  and  54  of installed gasket  50 . The installer is careful to cut the gasket in a most suitable place to ensure that the resultant joint is a tight square butt joint of the two gasket  50  ends  53  and  54 , which meet each other at starting location  62 . 
     A problem arises over time after installation because the installer tends to stretch the elastic gasket  50 , especially in the lengthwise direction, during installation. As shown in  FIG. 2 , channel  61  has two protrusions (projections)  63  and  64 , which reduce the width of the opening  65  of channel  61 , as compared with the width of the interior  66  of channel  61 . Stretching the gasket  50  lengthwise decreases the width of gasket  50 , thus easing the pushing of gasket  50  past protrusions  63  and  64  until gasket  50  fits snugly within the interior  66  of channel  61 . However, subsequent to the installation, the gasket tends to “unstretch,” that is, shorten so as to return to its original length. The result of this relaxation of elastic gasket  50  is gap  56  in the area of starting location  62 . Gap  66 , the separation between the two butt ends  53  and  54  of gasket  50 , compromises the watertightness of closure  60 . Gasket  50  therefore is defective and requires replacement. 
     Reference now being made to  FIG. 5  through  FIG. 11 , the present invention is typically embodied as a device suitable for facilitating installation of a gasket (such as gasket  50 ) into a watertight closure channel (such as channel  61  of door  60 ). This example of a gasket insertion device  100  in accordance with the present invention includes a straight handle (e.g., a rod or a shaft)  200  and a specially shaped head  300 . Generally, the linear dimensions indicated in the drawings are expressed in inches. 
     Handle  200  has a geometric longitudinal axis a, an attached end  201 , and an unattached end  202 . Head  300  includes a trianguloid-profiled prismatic section  310  and an L-profiled prismatic section  320 . Trianguloid-profiled prismatic section  310  has a longitudinal planar attachment surface  311 , a longitudinal planar first non-attachment surface  312 , and a longitudinal planar second non-attachment surface  313 . Handle  200  is attached at its end  201  to trianguloid-profiled prismatic section  310  at the center of, and with its axis a perpendicular to, longitudinal attachment surface  311 . L-profiled prismatic section  320  includes two generally planar segments, viz., a first generally planar segment  321  and a second generally planar segment  322 . First generally planar segment  321  is significantly longer than (as shown in  FIG. 5  and other figures, roughly twice as long as) second generally planar segment  322 . Trianguloid-profiled prismatic section  310  and L-profiled prismatic section  320  are characterized by the same longitudinal expanse h L , and are joined along the same prismatic longitudinal direction h D . 
     First generally planar segment  321  has a longitudinal planar first L-interior segment surface  323  and a longitudinal planar first L-exterior segment surface  324 . Second generally planar segment  322  has a longitudinal planar second L-interior segment planar surface  325  and a longitudinal planar second L-exterior segment planar surface  326 . First L-interior segment surface  323  and second L-interior segment surface  325  form an L-interior right angle r IN  that faces generally opposite the attachment surface  311  and whose geometric bisector b is approximately parallel to the handle  200  axis a and approximately perpendicular to attachment surface  311 . First non-attachment surface  312  and first L-exterior segment surface  324  form a first L-exterior right angle r EX1 , which has geometric bisector b EX1 . Second non-attachment surface  313  and second L-exterior segment surface  326  form a second L-exterior right angle r EX2 , which has geometric bisector b EX2 . Geometric bisector b EX1  is approximately perpendicular to handle axis a, approximately perpendicular to geometric bisector b, and approximately parallel to attachment surface  311 . Geometric bisector b EX2  is approximately perpendicular to handle axis a, approximately perpendicular to geometric bisector b, approximately parallel to attachment surface  311 , and approximately parallel to geometric bisector b EX1 . 
     According to frequent practice and as exemplified by this inventive embodiment, second non-attachment surface  313  and first L-exterior segment surface  324  face in generally opposite directions and are approximately coplanar, each of the two surfaces lying in geometric plane p. Trianguloid-profiled prismatic section  310  and L-profiled prismatic section  320  hence are coupled, or can be conceived to be coupled, along a planar joint  330  (shown by dashed line segment in  FIG. 5 ), which also lies in geometric plane p. The two main components of head  300 , viz., trianguloid-profiled prismatic section  310  and L-profiled prismatic section  320 , are thus propitiously united so that manipulative force can be brought to bear upon L-profiled prismatic section  320  via humanly grasped handle  200 . Trianguloid-profiled prismatic section  310  serves to orient L-profiled prismatic section  320  (especially, L-interior right angle r IN ), and to bear much of the load during operation of inventive insertion device  100 . 
     The inventive device  100  embodiment shown in  FIG. 5  through  FIG. 11  has a quality of geometric elegance in various ways, among which are discussed hereinabove. Note further, as shown in  FIG. 5 , that handle axis a passes through the linear vertex of first L-exterior right angle r EX1 . Moreover, the linear vertex of second L-exterior right angle r EX2  lies in geometric bisector plane b of L-interior right angle r IN . The linear vertex of first L-exterior right angle r EX1  and the linear vertex of second L-exterior right angle r EX2  represent line segments that are coextensive and that lie in the same geometric plane, viz., bisector plane b, which is parallel to handle axis a. 
     Particularly with reference to  FIG. 9  through  FIG. 11 , the inventive device is typically embodied for purposes of facilitating insertion of an elongate generally rectangular-profiled gasket in a generally rectangular-profiled channel. As illustrated in  FIG. 9 , gasket  100  has two right-angled corner areas  103  that each match the L-interior right angle r IN  of L-profiled prismatic section  320 . Inventive device  100  is manually used to insert gasket  50  into channel  61 . A person grasps handle  200  and manipulatively applies pressure to gasket  50  via head  300  whereby a right-angled corner area  103  of gasket  50  fits inside L-interior right angle r IN . 
     Many closure gasket channels are characterized by two channel projections/protrusions that narrow the access opening into the channel. The projections/protrusions frequently are projecting/protruding lip-like formations separated from and pointing toward each other on opposite sides of and along the length of the channel, thereby partially closing the channel.  FIG. 2 ,  FIG. 9 ,  FIG. 10 ,  FIG. 11 , and  FIG. 13  are each illustrative, by way of example, of a channel  60  having two protrusions  63  and  64 . 
       FIG. 10  depicts use of inventive device  100  such as may follow the use of inventive device  100  that is depicted in  FIG. 9 . It can be conceived that gasket  50  is mostly but not entirely set in the interior  66  of gasket channel  61 . The user continues to grasp handle  200  and to manipulatively apply pressure to (e.g., tamp down) gasket  50  via head  300 , particularly via second generally planar segment  322  (which is shorter than first generally planar segment  321 ). As shown in  FIG. 10 , the user can avail himself/herself of, for leverage, either protrusion  63 , or protrusion  64 , or, consecutively and/or concurrently, both protrusion  63  and protrusion  64 . 
     Head  300  is shown in  FIG. 10  to be in contact, in the vicinity of either or both of said first L-exterior right angle r EX1  and said second L-exterior right angle r EX2 , with either or both of channel protrusion  63  and channel protrusion  64 ; more specifically, first L-exterior segment surface  324  is shown to be contiguous to protrusion  63 , and second L-exterior segment surface  326  is shown to be contiguous to protrusion  64 . A “rocking” motion can be performed by the user whereby the user moves handle  200  rotatively in a geometric plane in which handle  200  lies, primarily doing so bidirectionally perpendicular to prismatic longitudinal direction h D , or, equivalently expressed, bidirectionally perpendicular to the length of channel  60 . 
     Angular deviations from perpendicularity with respect to the length of channel  60  may be taken by the user in rotatively moving handle  200  back and forth so as to “finesse” gasket  50  into a fully set position inside channel  60 . Inventive manipulations same as or similar to those described herein and shown in  FIG. 9  through  FIG. 11  may be practiced throughout the entire length of channel  60 , that is, not only along the straight regions of channel  60 , but also along the curved regions (e.g., corners  67  shown in  FIG. 3  and  FIG. 4 ) of channel  60 . 
     Now referring to  FIG. 12  and  FIG. 13 , inventive insertion device  100 A includes straight handle (e.g., a rod or a shaft)  200  and head  300 A. Inventive device  100 A&#39;s head  300 A, shown in  FIG. 12  and  FIG. 13 , is characterized by a geometry that significantly differs from that of inventive device  100 &#39;s head  300 , shown in  FIG. 5  through  FIG. 11 . Handle  200  has a geometric longitudinal axis a, an attached end  201 , and an unattached end  202 . Head  300 A includes a trianguloid-profiled prismatic section  310 A and a T-profiled prismatic section  320 T. Handle  200  is perpendicularly and centrally attached at its end  201  to trianguloid-profiled prismatic section  310 A. 
     Note that T-profiled prismatic section  320 T of inventive device embodiment  100 A is analogous, in both structure and function, to L-profiled prismatic section  320  of inventive device embodiment  100 . Of particular note, inventive device  100 A&#39;s T-profiled prismatic section  320 T describes T-interior right angle r INA , similarly as inventive device  100 &#39;s L-profiled prismatic section  320  describes L-interior right angle r IN . Although the present inventors in their inventive testing found inventive device  100  to be preferable in general to inventive device  100 A, inventive device  100 A also offers beneficial usefulness, handheld implementation thereof being similar to that of inventive device  100 . In particular, a user of inventive device  100 A can utilize the interior right-angled surfaces of T-interior right angle r INA  to conformingly contain and control a gasket  50 , similarly as a user of inventive device  100  can utilize the interior right-angled surfaces of L-interior right angle r IN  to conformingly contain and control a gasket  50 . 
     The present invention, which is disclosed herein, is not to be limited by the embodiments described or illustrated herein, which are given by way of example and not of limitation. Other embodiments of the present invention will be apparent to those skilled in the art from consideration of the instant disclosure or from practice of the present invention. Various omissions, modifications, and changes to the principles disclosed herein may be made by one skilled in the art without departing from the true scope and spirit of the present invention, which is indicated by the following claims.