Abstract:
A sterilizable instrument supporting bracket that may be attached to a sterilization tray having spaced perforations. The apparatus includes a resilient body used to support medical instruments. A skeleton structure is located within the resilient body for providing support to the resilient body and includes resilient metal locking devices for attaching the bracket to the tray. The locking devices include two locking numbers having resilient shaft portions that are biased to given position. A head is located to each of the shaft portions with two of the head portions facing in opposite directions. Resilient ribs are attached to the resilient body and are compressed against the tray when the resilient body and related skeleton structure are attached to the tray. The bracket is attached to the tray by squeezing the head portions toward each other and passing them into perforations of the tray and then allowing them to resiliently move outwardly on the shafts to lock the bracket onto the tray. This locking is accomplished by the heads being located within the perforations and the resilient ribs acting to bias the resilient body and skeleton structure away from the tray to maintain engagement.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of my co-pending international application Ser. No. PCT/US97/06650 having an international filing date of Apr. 22, 1997 and entitled “INSTRUMENT BRACKET FOR USE WITH A STERILIZABLE TRAY”, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention comprises a bracket for supporting medical instruments in a sterilizable tray in which the bracket body is formed primarily from resilient silicone and is strengthened by a relatively rigid, spring tempered, metal interior skeleton. 
     2. Description of Related Art 
     It is common practice to put medical instruments on trays and place them into high temperature environments for the purposes of sterilization. Steam heated autoclaves are probably the most common device used for killing germs and other biohazards. The instruments to be sterilized are generally placed in trays which, in turn, are placed into the cleansing environment. In order to keep the instruments from moving, it is fairly common practice to separate and support them with brackets. 
     Instrument supporting brackets can take several different forms. Perhaps the most common form is a custom tray which includes custom made brackets laid out according to the specific request of the customer. An outline of the instrument to be supported is frequently printed on the bottom surface of the tray so that accurate instrument positioning is achieved. It is also common practice to place an English language legend, such as “Russian Tissue Forceps” adjacent to the outline of the desired instrument. The custom made brackets, which generally have an irregular shape, are then permanently attached to the tray with rivets. While such trays have advantages, they have several disadvantages too. First of all, they are expensive and time consuming to produce because each tray has to be individualized for each specific customer&#39;s request. Second, brackets are not removable and, therefore, there is no flexibility in the layout of the tray. Instrument holding trays, such as described are sold under the trademark MEDITRAY® by Case Medical, Inc., 65 Railroad Avenue, Ridgefield, N.J. 07657. 
     Another technique for attaching prior art brackets to a sterilizable tray is to have the brackets slide into a keyway that is provided for on the tray itself. 
     In an effort to further reduce costs, instrument holding brackets have recently become available which comprise stainless steel or aluminum bodies covered with a thin coat of nylon. The brackets typically have an L-shaped cross section. A pair of studs is attached to the bottom of the L-shaped bracket with nylon serving as the adhesive. The stainless steel or aluminum brackets just described can then be placed selectively or randomly on a tray having a plurality of regularly spaced perforations therein. 
     While the foregoing describe improvements in the art, they still do not present an optimal structure. What is desired is a bracket that will: withstand high temperatures; provide secure support for heavy instruments, yet light support for delicate instrumentation; provide for complete surrounding by steam; provide for the ability to grab and securely hold heavy and delicate instruments; provide flexibility and strong support at the same time; and, also, provide for the ability to place brackets at a wide variety of locations in order to accommodate a wide spectrum of instruments. 
     In addition to the foregoing, one of the problems with prior art instrument brackets is the difficulty of efficiently attaching them to a sterilizable tray. One of the most common forms of prior art attachment is to use rivets. Unfortunately, rivet attachments make it impossible to remove a bracket and/or move it around without destroying the tray. Other approaches have been tried, but most tend to be permanent or take a considerable amount of time to attach. The prior art, therefore, appears to be lacking in a simple and efficient mechanism for attaching instrument holders to a sterilizable tray in a secure manner yet, at the same time, permit the instrument holder to be rearranged to accommodate different types of instruments. 
     It was in the context of the foregoing prior art and the above identified needs that the present invention arose. 
     SUMMARY OF THE INVENTION 
     Briefly described, the invention comprises a bracket for supporting medical instruments in a sterilizable tray in which the bracket body is formed primarily from resilient silicone and is strengthened by a relatively rigid metal interior skeleton backbone. The resilient silicone bracket body includes a plurality of medical instrument receiving indentations or valleys separated by intervening peaks. Resilient ribs formed in the instrument receiving indentations gently support the medical instruments and optimally allow sterilizing steam to be exposed to the maximum surface area of the instrument. The spring tempered stainless steel skeleton backbone is encapsulated by the silicone body. The skeleton also includes peaks and valleys that mimic and align with the peaks and valleys of the silicone body and provide additional strength thereto. Flow-through holes or apertures in the skeleton backbone permit the silicone to optimally bond with the backbone. Threaded studs are mechanically attached to the skeleton backbone. Each stud includes a slotted head which attaches to the bottom edge of the stainless steel skeleton backbone, a widened, ring-like midsection, and a threaded end that is distal from the slotted end of the stud. The slotted end and most of the round midsection of the stud are also encapsulated in the silicone. The bracket is preferably attached to the tray by placing the threaded portions of the studs through the perforations in the tray and attaching them thereto with lock nuts. 
     According to alternative embodiments of the invention, the studs may be replaced by resilient prongs that snap into the vent perforations in the bottom of the tray. Each prong includes a shaft attached at one end to the stainless steel skeleton and includes at the distal end thereof an enlarged head section. According to a first alternative embodiment, the barbs on the head sections of the prongs face away from each other and are separated by a stabilizing foot. Each prong of a pair occupies its own individual perforation hole and is separated by the stabilizing foot which occupies a third hole between the two prongs. According to a second alternative embodiment of the invention, the barbs on the head sections of the prong pairs also face away from each other, but the prongs are located directly adjacent to each other in such a fashion that both prongs snap and lock into the same perforation hole. The two alternative embodiments also include a pair of resilient compressible ribs located on the resilient body of the bracket and on opposite sides of the locking prongs or means. The resilient ribs compress when the prongs are inserted into their respective vent perforation holes and help to provide sufficient pressure on the bracket and the locking prongs to keep the bracket stabile in the locked mode. 
     The invention may be more fully understood by reference to the following drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the preferred embodiment of the sterilizable instrument bracket. 
     FIG. 2 is a perspective view of the preferred embodiment of the invention illustrated in FIG. 1 shown in the process of being placed into a sterilizable tray and locked with respect thereto with lock nuts. 
     FIG. 3 is a partial, perspective cross sectional view of the bracket illustrated in FIG. 1 showing the manner in which the slotted head of the studs are attached to the relatively rigid spring tempered skeleton backbone. 
     FIG. 4 is a front, exploded view illustrating the manner in which the attachment studs are connected to the skeleton backbone. 
     FIG. 5 is a partial, front cross sectional view of the fully assembled bracket. 
     FIG. 6A is a front elevational view of a first alternative embodiment of the invention, intended to support only one medical instrument, and employing resilient locking means and further showing a pair of prongs, each having barbs on their head sections facing in opposite directions, separated by a stabilizing foot. 
     FIG. 6B is a cross-sectional view of the first alternative embodiment of the invention illustrated in FIG.  6 A. 
     FIG. 6C is a detail, cross-sectional view of the lower portion of the bracket illustrated in FIG. 6B showing the compressible ribs prior to compression. 
     FIG. 6D is another detail view of the lower portion of the first alternative embodiment of the invention illustrated in FIG. 6B showing the compressible ribs under compression after the locking means have locked into position in the vent perforations of a sterilizable tray. 
     FIG. 6E is a front elevational view of the stainless steel skeleton, or backbone, employed with the first alternative embodiment of the invention illustrated in FIG.  6 A. 
     FIG. 6F is a side elevational view of the stainless steel skeleton illustrated in FIG.  6 E. 
     FIG. 6G illustrates a detail of the stainless steel skeleton illustrated in FIG. 6E prior to the resilient locking means engaging the vent perforations in the base of a sterilizable tray. 
     FIG. 6H illustrates the stainless steel skeleton shown in FIG. 6G after the locking means have engaged the vent perforations in the base of a sterilizable tray. 
     FIG. 7A is a front elevational view of a second alternative embodiment of the invention, intended to support multiple medical instruments, in which the resilient locking means comprises a pair of prongs located adjacent to each other so that they can both be inserted into the same vent hole in the bottom of a sterilizable tray. 
     FIG. 7B is a cross-sectional view of the second alternative embodiment of the invention shown in FIG.  7 A. 
     FIG. 7C is a front elevational view of the stainless steel skeleton found inside of the second alternative embodiment of the invention illustrated in FIG.  7 A. 
     FIG. 7D is a side elevational view of the stainless steel skeleton shown in FIG.  7 C. 
     FIG. 7E illustrates the stainless steel skeleton of FIG. 7C prior to inserting the prong pair of locking means into the vent perforations in the base of a sterilizable tray. 
     FIG. 7F illustrates the prong pair of the locking means shown in FIG. 7E after they have passed through the same vent perforation in the base of a sterilizable tray. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     During the course of this description like numbers will be used to identify like elements according to the different views that illustrate the invention. 
     The preferred embodiment of the invention  10  is illustrated in a perspective view in FIG.  1 . The three major structural components of the preferred embodiment  10  are a resilient silicone body  12 , a skeleton backbone  14  encapsulated by the silicone body  12  and a plurality of threaded studs  16  partially encapsulated by the silicone body  12 . 
     Bracket  10  is preferably attached to a sterilizable tray  18  such as illustrated in FIG.  2 . Tray  18  includes a plurality of regularly spaced perforations or apertures  20  for receiving the threaded sections  50  of studs  16  of bracket  10 . The threaded section or end  50  of studs  16  pass through the perforations  20  and are locked with respect thereto by lock nuts  52  which threadably attach to the threaded portion  50  on the portion of stud  16  opposite from the silicone body  12 . Alternate methods could also be employed to attach studs  16  to tray  18 . For example, the threaded sections  50  of the studs  16  could be smooth or threaded and a push on clip could be used instead of lock nuts  52  to secure the bracket  10  to the apertures  20  in tray  18 . A plurality of different medical instruments  22  are supported by brackets  10  as shown in FIG.  2 . Threaded studs  16  are located at intervals identical to the spacing between perforations  20  in tray  18  so that the brackets  10  may be placed in any arrangement for supporting medical instruments  22 . Therefore, it is easy to rearrange the brackets to accommodate a wide variety of different medical instruments  22  which may vary substantially in size, weight and shape. 
     Details of the silicone body  12 , its related relatively rigid spring tempered skeleton backbone  14 , and threaded support studs  16  will be more fully appreciated by referring to FIGS. 3-5. 
     Medical instruments  22  are received in indentations or valleys  24  in the resilient silicone body  12 . The medical receiving indentations are separated by resilient peaks  26 . Ribs  28  located at regular intervals inside of the instrument receiving indentations  24  provide gentle yet firm support for the medical instruments  22 . More importantly, ribs  28  permit sterilizing steam to circulate in between so as to further assist in the killing of biohazardous germs and materials. There is a small gap between adjacent peaks  26  and the valleys  24  so as to further hold and secure an instrument  22  in the bracket  10 . 
     The profile of the relatively rigid spring tempered stainless steel skeleton backbone  14  generally mimics the profile of the peaks  26  and valleys  24  of the resilient silicone body  12 . Skeleton backbone  14 , therefore, includes valleys  30  separated by peaks  32 . Each skeleton backbone  14  also includes a top edge  40 , which incorporates peaks  32 , and valleys  30 , a bottom edge  42  which is attached to studs  16 , and a pair of side ends  34 . Flow through apertures  36  are located along the length of skeleton backbone  14 . Likewise a pair of flow through holes or apertures  38 , oriented perpendicularly to flow through apertures  36 , are located in the side ends  34  of skeleton backbone  14 . 
     Each stud  16  includes a head  44 , a ring shaped midsection  48  in the middle thereof, and a threaded end or section  50  distal from head  44 . A skeleton receiving slot  46  is located in stud head  44 . The slot  46  in stud head  44  is slightly smaller than the width of the skeleton backbone  14  so that it mechanically locks onto the bottom edge  42  of the skeleton backbone  14 . For additional security it may be desirable to weld the slotted head  44  to the bottom edge  42  of the skeleton backbone  14 . The ring shaped midsection  44  of stud  16  supports the bottom edge  42  of the skeleton backbone  14 . 
     The bracket  10 , according to its preferred embodiment, is constructed in the following manner. First, the bottom edge  42  of the backbone  14  is placed into the slot  46  in the head  44  of stud  16 . Three studs  16  are shown in FIGS. 1-5 but two studs  16  or four or more studs  16  could also be used according to the demands of the use. Studs  16  are preferably placed at regular intervals identical to the spacing between perforations  20  in tray  18  as previously described. Stud heads  44  are then mechanically attached to the bottom edge  42  of skeleton backbone  14  either by crimping or by welding, or both. Second, the skeleton backbone  14  with studs  16  attached is then placed into a mold in which silicone is injected to form resilient body  12 . The silicone completely encapsulates the skeleton backbone  14 . Flow through apertures  36  and  38  in skeleton backbone  14  further assist in mechanically anchoring the silicone body  12  to the skeleton backbone  14 . As previously described, the silicone also encapsulates the head  44  and most of the midsection  48  of stud  16 . The exposed portion of the midsection  48  of stud  16  also serves as a stop for the bracket  10  when it is placed in position on tray  18 . The resulting molded silicone bracket  10  includes sculpted indents  54  in the sides of the silicone bracket body  12 . Sculpted indents  54  help to conserve weight and space. 
     The invention described thus far has several significant, nonobvious advantages over the prior art. First, it provides for substantial versatility for permanent or semi-permanent fixturing of brackets  10  with respect to instruments. Second, it provides important structural support for heavy instruments  22 , yet protects delicate instruments  22 . Third, the encapsulated metal  14  cannot damage delicate instrumentation  22 . Fourth, the flexible silicone ribs  28  provide grip with minimal contact of the instrument  22  to the bracket surface, yet permits optimum sterilization. Presently existing prior art brackets do not allow for optimal sterilization, as they tend to be bulky and grip a large surface area of the instrument  22 . Fifth, the spring tempered metal skeleton  14  permits the bracket  10  to adjust slightly so that the threaded portion  50  of the studs  16  can align with perforations  20  in the tray  18  even if there isn&#39;t perfect spacing. 
     A first alternative embodiment  100  of the invention is illustrated in FIGS. 6A-6H. Embodiment  100  includes a silicone body  102  and a stainless steel skeleton or backbone  104  both similar to, but not identical to, the preferred embodiment  10 . The bottom portion of the silicone body  102  includes a pair of parallel, compressible ribs  106   a  and  106   b  shown in detail in FIGS. 6C and 6D. Compressible ribs  106   a  and  106   b  lie on opposite sides of a stabilizing tab or control foot  108  seen in FIG.  6 A. Stabilizing foot  108  is located between a pair of opposite facing resilient locking prongs  110   a  and  110   b.    
     Details of the resilient locking prongs  110   a  and  110   b  may be more easily understood by reference to FIGS. 6E,  6 G and  6 H. The resilient locking prongs  110   a  and  110   b  in combination with a stabilizer foot  108  comprise a resilient locking means which holds the first alternative embodiment of the bracket  100  in position with respect to the base  118  of the sterilizable tray. Each of the resilient prongs  110   a  and  110   b  include a shaft portion  112   a  and  112   b  attached at one end to the stainless steel backbone  104  and at the distal end thereof a bead  114   a  and  114   b . Each of the heads  114   a  and  114   b , respectively, include a barb portion  130   a  and  130   b  which face in opposite directions from each other. The stainless steel skeleton  104  includes a saddle portion  116  located half way between upper tips  126   a  and  126   b . A pair of downward directed, wing-like projections  124   a  and  124   b  are located on opposite sides of the stainless steel skeleton  104 . A flow through hole  126  permits the silicone material of the silicone body  102  to pass through the stainless steel skeleton  104  and reinforces its strength. Stainless steel skeleton  104  also includes a lower edge  128  that defines the bottom portion of the main body of the element. The first alternative embodiment  100  described in FIGS. 6A-6H is especially suited for use with a single medical instrument. The same technique could, however, be used for a larger bracket if desired. 
     The first alternative embodiment  100  is connected to the base  118  of a tray in the following manner. First, the resilient prongs  110   a  and  110   b  are squeezed towards each other so that they can pass through vent holes  120  in the base  118  of the tray (see FIGS.  6 C and  6 G). Second, the resilient prongs  110   a  and  110   b  are inserted into the holes  120  which causes the compressible silicone ribs  106   a  and  106   b  to begin to compress. Third, and last, the oppositely facing barbs  130   a  and  130   b  spring outwardly after they pass sufficiently far through the vent holes  120  so that the resilient prongs  110   a  and  110   b  lock into position. In the meantime, the stabilizing foot  108  also passes through an intermediate aperture  120  and fits snugly therein. Simultaneously, the compressible ribs  106   a  and  106   b  are at maximum compression as seen in FIGS.  6 D. The ridges or ribs  106   a  and  106   b  compress to account for use with different materials or different thicknesses of the tray base  118 . According to the preferred embodiment of the invention, the first alternative embodiment  100  has a height of H B  of 1.070 inches, a width W B  of 1.150 inches and a length measured from the top of the bracket  100  to the bottom portion of the silicone body adjacent to foot  108  of L BP  of 1.00 inches as seen in FIG.  6 A. As shown in FIG. 6B, the first alternative embodiment  100  has a maximum width of W B  max=0.350 inches and a minimum width W B  min of 0.225 inches. Similarly, the stainless steel skeleton  104  has a preferred width of W S  of 0.05 inches, and a height of H S  of 0.73 inches, as shown in FIG. 6E, and a width T S  of 0.05 inches, as shown in FIG.  6 F. 
     One of the major advantages of the first alternative embodiment  100  is that the resilient prongs  110   a  and  110   b  can snap into plastic trays 0.125 inches thick and metal trays as thin as 0.05 inches thick or any combination of materials from 0.040 inches to 0.150 inches thick. The single prong per hole structure of the first alternative embodiment  100  requires a stabilizing foot or tab  108  so that the locking prongs  110   a  and  110   b  will not bend beyond their yield strength. The stainless steel spine  104  is preferably formed from spring tempered stainless steel such as {fraction (3/4+L )} inch hard no. 301 or no. 400 spring tempered stainless steel. The silicone body  102  is preferably a material having a durometer in the range of 30-50. The foot or tab  108  has two purposes. The first is to assist in the location of the holes  120  in the tray bottom  118  and the second is to prevent the overstressing of the resilient prongs  110   a  and  110   b . In addition, the two compressible ribs  106   a  and  106   b  located on opposite sides of the stabilizer foot  108  provide spring tensioning to make up for the varying thicknesses of the tray base or bottom  118 . 
     In order to remove the bracket  104 , a pair of pliers can be employed, or a special tool can be used, which squeeze the barbs  130   a  and  130   b  inwardly, towards each other, so that the bracket  100  can be grasped and the prongs  110   a  and  110   b  pulled out of their respective apertures  120 . In this manner the bracket  100  can be reused or relocated. 
     A second alternative embodiment  200  employing resilient prong pairs  208  is illustrated in FIGS. 7A-7F. Second alternative embodiment  200  includes a silicone body  202  attached to a stainless steel skeleton  204 . A pair of resilient, compressible ribs  206   a  and  206   b  are located at the bottom of the silicone body  202  and on opposite sides of the resilient locking means  208 . Details of the skeleton or spine  204  can be more fully understood by reference to FIGS. 7C-7F. As seen in greater detail in FIG. 7E, the resilient locking means  208  comprises a pair of resilient prongs  210   a  and  210   b . Resilient prong  210   a  includes a shaft  212   a  and a head portion  214   a . Head portion  214   a  includes a barb  230   a  shown facing to the left. Similarly, resilient prong  210   b  includes a shaft portion  212   b  attached to the skeleton  204  and a head portion  214   b  attached to the opposite or distal end of shaft  212   b . Head portion  214   b  includes a right facing barb  230   b  which faces in the opposite direction from barb  230   a  previously described. Resilient prongs  210   a  and  210   b  are fairly long and extend a distance L P  from the base or bottom  224  of the skeleton  204  into the interior of the skeleton  204  as seen in detail in FIGS. 7E and 7F. In other words, the length of prongs  210  and  210   b  considerably exceeds the distance from skeleton base  224  to the tip of the head portions  214   a  and  214   b.    
     Each skeleton  204  preferably includes a plurality of circular, or oblong, flow-through holes  216  whose purpose is similar to that previously described with reference to flow-through holes  126  of the first alternative embodiment  100 . The bottom edge  224  of the stainless steel skeleton  204  is relatively flat except for the location of the dual locking means  208 . In contrast, the upper surface of skeleton  204  comprises a series of peaks  218  and valleys  220 . Peaks  218  permit the shafts  212   a  and  212   b  of prongs  210   a  and  210   b , respectively, to extend significantly into the body of the stainless steel skeleton  204  thereby providing substantially more resilience for the prongs  210   a  and  210   b . The foregoing structure creates a pair of small valleys  224   a  and  224   b  on the outsides of prongs  210   a  and  210   b  and a longer valley  226  between prongs  210   a  and  210   b.    
     The second alternative embodiment  200  is attached to the base  118  of a sterilizable tray in the following manner. First, the resilient locking means  208 , comprising a pair of prongs  210   a  and  210   b  as shown in FIG. 7E is positioned over the vent perforations  120  of the sterilizable tray  118 . Second, pressure is applied to the top of the second alternative embodiment  200  to insert the prongs  210   a  and  210   b  into vent aperture  120 . Because of the slanted face of the head portions  214   a  and  214   b  of barbs  230   a  and  230   b , the aperture  120  naturally cams or squeezes the prongs  210   a  and  210   b  so that they fit into aperture  120 . Third, continual pressure applied on the top of the second alternative embodiment bracket  200  causes the head portions  214   a  and  214   b  to pass through aperture  120  and snap into the locked position as shown in FIG.  7 F. In this position the barbs  230   a  and  230   b  resiliently move to a position beyond the outside periphery of the aperture  120  and are resistant to removal. When the prongs  210   a  and  210   b  are in the position shown in FIG. 7F, the second alternative embodiment  200  is firmly attached to the tray base  118  and cannot be removed of dislodged easily. In order to remove the second alternative embodiment bracket  200 , it is merely necessary to pinch or squeeze the two head portions  214   a  and  214   b  of each of the pairs  208  together and, at the same time, gently pull on the bracket  200  on the opposite side thereby permitting the barbs  230   a  and  230   b  to pass back through vent perforations  120  and release when they emerge on the opposite side of the apertures  120 . Prongs  210   a  and  210   b  may be squeezed together either manually or with the assistance of needle nose pliers or similar instruments. In this manner, the bracket  200  may be either removed or rearranged in a more suitable manner depending upon the type of instruments to be sterilized with the tray  118 . 
     The dual locking tab or prong embodiment  200  is especially useful for long brackets such as illustrated in FIG.  7 A. The bracket  200  shown in FIG. 7A has a preferred width W B  of 9.4 inches and a height H B  of 1.07 inches. As seen in FIG. 7B, the maximum width W B max  of the bracket  200  is 0.35 inches and the minimum width as measured to the interior of the silicone body  204  is W B min =0.225 inches. The stainless steel skeleton  204 , as shown in FIG. 7C, has a preferred width W S  of 9.087 inches and a height H S  of 0.482 inches. The distance from each end  234  of the spine  204  to the first pair of resilient locking means  208  is D PE  approximately 1.544 inches, and the distance between resilient locking pairs  208  D PP  is approximately 3.000 inches. Lastly, as shown in FIG. 7D, the preferred thickness T 5  of skeleton  204  is approximately 0.05 inches. The materials employed with respect to the dual locking tab, second alternative embodiment  200  are essentially the same as the materials employed with the single locking tab first embodiment  100 , previously described. The first alternative embodiment  100  includes flexible silicone fingers  132  for the purpose of grabbing a single instrument and, similarly, the second alternative embodiment  200  includes flexible silicone fingers  232  also. The silicone fingers  132  and  232  are appropriate for grabbing  10  mm instruments above fingers  132  and  232  and for containing 5 mm instruments below fingers  132  and  232 . As previously described single locking tab, first alternative embodiment  100  including the stabilizing foot  108 , is especially appropriate for small brackets. In contrast, the dual locking tab, second alternative embodiment  200 , where both resilient prongs  210   a  and  210   b  pass through the same aperture  120 , is especially appropriate for larger brackets. 
     While the invention has been described with reference to the preferred embodiment thereof, it will be appreciate by those of ordinary skill in the art that modifications can be made to the structure and form of the invention without departing from the spirit and scope thereof.