BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to mounting devices for the attachment of objects to expanded plastic foam articles of manufacture, and more particularly to a removable mounting bracket for engaging helmet fitting straps to expanded polystyrene (EPS) bicycle helmets. 
     2. Description of the Prior Art 
     The attachment of various articles, such as straps, to expanded plastic foam articles of manufacture, such as expanded polystyrene (EPS) bicycle helmets, has been accomplished in several ways. Openings can be molded into the EPS article such that straps or other objects can be looped through the openings and affixed thereto. Other types of engagement methods have included the placement of an anchor piece within an EPS mold for an article followed by the injection of EPS foam into the mold and the subsequent removal of the article from the mold, such that the anchor piece is molded in the hardened EPS article. Still other types of engagement methods have included the use of Velcro where one portion of the mating Velcro pieces is glued to the EPS article. 
     Each of these prior art methods has its drawbacks. Looped straps can be too loose fitting; molded in anchors can become difficult to orient in a repeatable manner during manufacture and adhesively bonded attachment devices such as Velcro can become detached where the adhesive fails. 
     The present invention solves these problems by providing a releasable anchor that is inserted within a cavity that is molded into the EPS article. As will be understood from the following disclosure, the anchor is easily inserted into the cavity and expands following insertion to resist pulling forces that act to remove it. It therefore provides a simple, strong yet releasable anchor for various articles such as a head fit strap for a bicycle helmet. 
     SUMMARY OF THE INVENTION 
     The mounting bracket of the present invention includes an integrally molded head portion and article attachment portion that are formed of a flexible plastic material. The head portion is shaped for insertion into a cavity that is molded into an EPS article of manufacture such as a bicycle helmet. The flexible plastic head portion expands upon insertion into the cavity, such that it engages sidewall portions of the cavity and resists pulling forces that tend to remove it from the cavity. 
     In the preferred embodiment, the head portion is generally shaped like a ladder, having two side rails and a plurality of rung members disposed therebetween. The cavity formed within the EPS foam is shaped to receive the head portion in a collapsed configuration. After the collapsed head portion is inserted within the cavity, it expands such that the outer surfaces of the side rails are pressed against sidewall surfaces of the cavity. A pulling force on one of the side rails tends to force the two side rails apart, increasing the lateral force of the side rails against the cavity walls, thus enhancing the engagement of the head within the cavity. An outwardly depending pull tab may be integrally formed with the other side rail to facilitate the release of the head from the cavity. 
     A bicycle helmet of the present invention includes the shaped cavity together with the mounting bracket that is formed for mating insertion within the cavity. 
     It is an advantage of the present invention that a mounting bracket is provided for the releasable attachment of an object with an EPS article of manufacture. 
     It is another advantage of the present invention that a mounting bracket is provided for the attachment of an object to an EPS article of manufacture wherein the mounting bracket is an integrally molded device. 
     It is a further advantage of the present invention that a mounting bracket is provided in which an increased pulling force generates an increased resistive force against the removal of the mounting bracket. 
     It is yet another advantage of the present invention that a reliable mounting bracket is provided that comprises a single integrally molded piece. 
     These and other features and advantages of the present invention will no doubt become apparent to those skilled in the art upon reading the following detailed description which makes reference to the several figures of the drawings. 
    
    
     IN THE DRAWINGS 
     FIG. 1 is a plan view of a bicycle helmet fit strap of the present invention including four EPS anchors of the present invention; 
     FIG. 2 is a front elevational view of an anchor of the present invention; 
     FIG. 3 is a side elevational view of the anchor depicted in FIG. 2; 
     FIG. 4 is a perspective view depicting an anchor cavity of the present invention formed within an EPS article of manufacture such as a bicycle helmet; 
     FIG. 5 is a front elevational view depicting a collapsed configuration of the anchor of FIG. 2 inserted within the cavity of FIG. 4; and 
     FIG. 6 is a front elevational view depicting the anchor engaged within the cavity of FIG.  4 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The anchor device of the present invention is designed to provide a secure yet releasable engagement of an object with an expanded plastic foam article of manufacture. A particular application of the present invention is the utilization of the anchor to attach a fit-strap to the inner portions of an expanded polystyrene (EPS) bicycle helmet, and FIG. 1 is a plan view of such a bicycle helmet fit-strap  14  which includes four anchors  10  of the present invention. As depicted in FIG. 1, the fit-strap  14  is comprised of a particularly shaped band of material, such as cloth or plastic, having a head engagement band portion  18  for engagement with a wearer&#39;s head, and helmet engagement band portions  22  to which the attachment anchors  10  of the present invention are engaged, and which serve to attach the fit-strap  14  to interior portions of an EPS helmet (not shown). Matingly engagable end portions  26  of the strap  14  are provided for engagement together, such that the fit-strap  14  forms a band around the wearer&#39;s head. Fit-straps are generally well known in the art, and the fit-strap of the present invention is unique in that it includes the anchors  10  of the present invention for releasable engagement with a bicycle helmet, as is described herebelow. 
     FIG. 2 is a front elevational view of a preferred embodiment of an anchor  10  of the present invention, and FIG. 3 is a side elevational view of the anchor  10  depicted in FIG.  2 . As depicted in FIGS. 2 and 3, the anchor  10  generally includes an anchor head portion  40  and an article attachment end portion  44 . The anchor head  40  is preferably integrally formed with the attachment end  44 , such that the anchor  10  is preferably formed as a single integrally molded piece and is composed of a flexible plastic material. The article attachment end portion  44  is depicted as a thin elongated end portion that projects from the head portion  40  and may be integrally molded with the engagement bands  22  of the fit strap  14 ; however, the attachment end  44  may take many forms and shapes as are generally required for the attachment of the anchor  10  to an object, such as the fit-strap depicted in FIG.  1 . In the attachment strap depicted in FIGS. 1 and 2, a thin flexible section  46  may be formed proximate the head  40  to provide further flexibility to the attachment strap  44  and facilitate the insertion of the head  40  into an anchor cavity  120  as is depicted in FIG.  4  and described in detail herebelow. However, where the anchor  10  is utilized to attach objects other than the fit-strap  14  of FIG. 1, the attachment end  44  may be formed in various shapes and sizes as are required to engage such objects. 
     The head  40  may be generally thought of as having a ladder shaped structure including a first side rail  50 , a second side rail  58  and a plurality of rungs  66  integrally formed between the side rails  50  and  58 . Each of the rungs  66  is formed with a wide, central body portion  74  and narrow end portions  82  formed at the juncture of the rung body portion  74  with the side rails  50  and  58 . The outer edges of the side rails  50  and  58  are preferably formed with a series of downwardly projecting serrations or teeth  92  which serve to aid in the engagement of the anchor  10  within a foam plastic article of manufacture such as an EPS bicycle helmet, as is described more fully herebelow. The first side rail  50  is preferably formed with a relatively wide base portion  100  that supports the engagement of the anchor head  40  with the attachment end  44  to provide a strong, reliable engagement of the head portion  40  with the attachment end  44 , where pulling forces are applied to the attachment end  44  during usage of the anchor  10 . The upper portion  104  of the attachment end  44  may be formed with an enlarged heel portion  108  that includes a flat angled surface  112 . The functional purpose of the heel portion  108  is described hereinbelow with the aid of FIG.  5 . 
     As indicated hereabove, the anchor  10  is designed for releasable engagement with an expanded plastic foam article of manufacture such as an EPS bicycle helmet, and without limiting the general application of the present invention, the following discussion refers to a bicycle helmet as the article of manufacture. To accomplish the releasable engagement of the anchor  10  to the EPS bicycle helmet, a shaped cavity  120 , as depicted in FIG. 4, is formed in the EPS helmet  121  at the desired attachment location of the anchor  10 . The cavity  120  is formed with two sidewalls  122  and two endwalls  124 , such that the cavity  120  has a generally rectangular cross-section. The sidewalls  122  have a length  128  that generally corresponds to the width  134  of the anchor head  40  depicted in FIG. 2, the endwalls  124  have a width  140  that generally corresponds to the thickness  144  of the anchor head  40  as depicted in FIG. 3, and the cavity  120  has a depth  152  that generally corresponds to the height  156  of the anchor head  140 , such that the anchor head  40  is insertable within the cavity  120 . To accomplish the releasable engagement of the anchor  10  within the cavity  120  the dimensions and tolerances of the anchor head  10  and the cavity  120  require further discussions, as is next provided with the aid of FIGS. 5 and 6. 
     FIG. 5 is a front elevational view of the anchor  10  depicted in a collapsed configuration and inserted within the cavity  120 , and FIG. 6 is an elevational view of the anchor engaged within the cavity  120 . The collapsed configuration of the anchor head  40  as depicted in FIG. 5 is best understood by comparison with the head configuration depicted in FIG.  2 . Specifically, owing to the flexible plastic material from which the anchor  10  is molded and the relatively thin rung end portions  82 , the second side rail  58  may be rotated downwardly (see arrow  180 ) relative to the first side rail  50 . The downward rotation  180  may be accomplished until the lower edge  188  of the thickened rung portion  74  of the lowest rung  196  makes contact with the upper surface  112  of the heel portion  108  of the anchor  10 . Owing to the generally parallelogram-like configuration of the ladder-like head design, each of the thicker central portions  74  of the rungs  66  are likewise collapsed into contact against each other when the head  40  is in its fully collapsed configuration as depicted in FIG.  5 . It can be seen in FIG. 5 that the length  128  of the cavity  120  is greater than the width of the collapsed head depicted in FIG. 5, such that the teeth  92  of the side rails  50  and  58  do not simultaneously contact both endwalls  124  of the cavity  120 . 
     FIG. 6 depicts the anchor head  40  in engagement within the cavity  120 . As depicted therein, the second side rail  58  has rotated upwardly (see arrow  210 ) such that the teeth  92  of side rail  50  as well as teeth  92  of side rail  58  simultaneously make contact with the endwalls  124  of the cavity  120 . In the preferred embodiment, the resilient nature of the flexible plastic of the anchor  10  naturally results in the upward rotation  210  of the second side rail  58 , where the anchor  10  is molded in the open configuration depicted in FIG.  2 . As will now be obvious to those skilled in the art, when a downward force  218  is applied to the attachment end  44  of the anchor  10 , the anchor head will become even more tightly engaged within the cavity  120 . This is because a downward motion of the attachment end  44  will cause a corresponding downward motion of the first side rail  50  owing to the integrally formed nature of the head. However, any downward motion of the first side rail  50  will create a lateral, outward force between the first side rail  50  and the second side rail  58  owing to the angular orientation of the rungs  66  between the side rails and the engagement of the teeth  92  of side rail  58  with the endwall  124  of the cavity. More specifically, the head  40  has a vertical central axis  230  and each rung  66  can be thought of as having a longitudinal central axis  238  that exists between the two narrow ends  82  of each rung  66 , such that an angle b is formed between the central head axis  230  and the rung axis  238  of each rung  66 . It will therefore be appreciated by those skilled in the art that general downward movement of the first side rail  50  relative to the second side rail  58  will cause angle b to increase and create a corresponding lateral outward movement of side rails  58  and  50  relative to each other until angle b could be approximately as much as 90°. Therefore, the dimensions of the cavity  120  and the anchor head  40  can conceivably be selected such that the engagement of the two side rails  50  and  58  with the endwalls  124  of the cavity  120  may occur anywhere from an angle b of about 90° down to a relatively steep angle b such as 25° (where the head is in a fully collapsed configuration). Significantly, however, as will be understood by those skilled in the art, a relatively weak head engagement within the cavity will occur where angle b is at its extreme of approaching 90° and at its minimum of approaching 25°, whereas a relatively strong engagement of the anchor head within the cavity  120  will occur where angle b is in a generally mid-range of approximately 35° to approximately 55° with a preferred angle of approximately 45°. Where angle b is less than approximately 35°, the anchor head  40  tends to pull out of the cavity  120  too easily and without significant opening of angle b, and where angle b is greater than approximately 60°, the anchor head  40  may be pulled out of the cavity  120  too easily because the lateral force generated between the two side rails  50  and  58  against the endwalls  124  of the cavity  120  does not increase sufficiently as the side rails  50  and  58  separate. Of course, these angles and angle ranges apply to the head embodiment depicted in FIGS. 1-3,  5  and  6 , and may not apply to other head rail/rung configurations that may be developed by those skilled in the art. 
     A significant feature of the present invention is that the side rails  50  and  58  apply a uniform outward force throughout the depth of the cavity endwalls  124 . That is, as is best seen in FIG. 6, each of the rungs  66  is disposed at a substantially identical angle relative to the central axis of the head  40 , and each rung  66  therefore applies an equal outward force between the side rails  50  and  58  at each rung location when a downward force  218  is applied to the attachment end  44 . Thus, the general parallelogram nature of the ladder configuration of the head  40  results in equal lateral force being applied throughout the length of each side rail  50  and  58  against the interior endwalls  124  of the cavity  120 , whereby a superior engagement of the head  40  within the cavity  120  is accomplished with the head configuration of the present invention. 
     It is typical though not necessary in forming molded cavities, such as cavity  120  that the sidewalls  122  and endwalls  124  are not exactly parallel, but rather are formed with a small angular draft, such that a mold cavity creating insert can be removed from the cavity  120  upon the opening of the mold, and such a cavity wall draft is typically on the order of 1° to 3° from the central axis of the cavity. To accomplish the generally uniform lateral force of the side rails  50  and  58  against cavity endwalls  124  having a draft angle such as 1° to 3°, the head  40  is preferably constructed such that the serrated outer edges of the side rails  50  and  58  diverge from the central axis  230  at a corresponding angle of 1° to 3°. Alternatively, the head can be constructed such that the first side rail  50  is tapered from its top region  280  to its base region  100  such that the right side rail&#39;s outer edge  292  diverges from the right side rail&#39;s inner edge  296  at an angle which is twice the draft angle, or approximately 2° to 6° where the draft angle of the cavity is 1° to 3°. In these configurations, the teethed outer edges of the side rails will be parallel to the corresponding endwalls  124  of the cavity  120  as the head  40  expands (arrow  210 ) within the cavity  120 . Uniform contact of the teeth  92  of the side rails  50  and  58  with the cavity endwalls  124  will occur when the head expansion occurs, as has been discussed hereabove. 
     It is to be noted that the thickened central portions  74  of the rungs  66  serves an important purpose of inhibiting a twisting collapse of the rungs  66  where a significant downward force  218  acts to pull the head  40  from the cavity  120 . That is, if the rungs  66  were as thin as end portions  82  throughout the length of each rung  66 , then a significant pulling force  218  could cause such thin rungs to bend or twist throughout their length, such that the lateral outward force of the side rails  50  and  58  against the cavity endwalls  124  could suddenly decrease, with a result that the head  40  would be pulled from the cavity  120 . The thickened central portions  74  of the rungs  66  act to prevent such bending and twisting of the rungs, and thereby serve to provide strength to the anchor head  40 . Where it is desired to provide an easily removable anchor, an anchor releasing pull tab  320  may be formed at the lower end of side rail  58 . Where the anchor head  40  is engaged within a cavity  120 , as depicted in FIG. 6, a downward force applied to the pull tab  320  will cause the head  40  to rotate towards the collapsed configuration depicted in FIG.  5 . When the head  40  is in the more collapsed configuration, the side rail  58  becomes released from the cavity endwall  124 , and the head  40  can thereupon be easily removed from the cavity  120 . 
     It will be understood by those skilled in the art that certain alterations and modifications of the anchor head  40  may be made without departing from the true spirit and scope of the present invention. A particularly significant feature of the present invention is the collapsible/expandable ladder-like configuration of the side rails and rungs of the head. This configuration provides a uniform outward force between the side rails as the head expands within the cavity. This results in a uniform engagement force of the anchor head side rails against the cavity side walls and thereby provide a strong engagement of the anchor head within the cavity. While a preferred rung shape, and preferred side rail shapes have been depicted herein, the present invention is not to be so limited. That is, other rung shapes and side rail shapes that nevertheless include the generalized ladder-like configuration of the head will become obvious to those skilled in the art upon reading this disclosure, and are deemed to be within the scope of the present invention and the claims that follow.
The mounting bracket of the present invention includes an integrally molded head portion and article attachment portion that are formed of a flexible plastic material. The head portion is shaped for insertion into a cavity that is molded into an EPS article of manufacture such as a bicycle helmet. The flexible plastic head portion expands upon insertion into the cavity, such that it engages sidewall portions of the cavity and resists pulling forces that tend to remove it from the cavity. In the preferred embodiment, the head portion is generally shaped like a ladder, having two side rails and a plurality of rung members disposed therebetween. The cavity formed within the EPS foam is shaped to receive the head portion in a collapsed configuration. After the collapsed head portion is inserted within the cavity, it expands such that the outer surfaces of the side rails are pressed against sidewall surfaces of the cavity.