in fig1 there is shown a conventional work shoe having installed therein a toe cap 10 of the present invention . in accordance with conventional shoe industry practice , the toe cap 10 is installed during manufacture of the shoe by placing the same over an inner liner and last ( neither shown ) and enclosing the toe cap in the shoe upper 11 which is subsequently attached to the shoe sole 12 in a conventional manner . whether formed of sheet steel , molded of plastic , or made of some other material , toe caps all have a generally similar shape , although a number of different styles are utilized to accommodate varying shoe toe styles . in any event , the toe cap 10 is of generally the same shape as the upper toe portion of the shoe for which it is made . referring also to fig2 - 5 , the toe cap 10 of the present invention comprises a unitary shoe toe - shaped body 13 , including an upper roof 14 which slopes forwardly and laterally in a smooth continuous surface to blend into a front wall 15 and opposite lateral side walls 16 . the toe cap body 13 is asymmetrical as is well known in the art . the front wall 15 and side walls 16 are generally vertical , however , they may be substantially curved over their entire extent , both vertically and horizontally , as shown . the side walls and front wall blend together to form a continuous outer wall and , in the embodiments shown , the continuous outer wall includes an integral inwardly turned narrow lip 17 along the entire lower edge of the body . the lip may be desirable to facilitate installation of the toe cap in the shoe , all in a manner well known in the art . in accordance with the preferred embodiment of the invention , the toe cap 10 is injection molded using a plastic resin material having a high loading of reinforcing fibers . the toe cap is molded in a manner to preferentially orient the reinforcing fibers in the resin material which forms the roof 14 in a generally lateral direction between the opposite side walls 16 . referring particularly to fig2 the preferred orientation of the reinforcing fibers f is shown schematically . it is believed that the preferred fiber orientation is uniquely attainable by proper sizing and location of the gate 18 ( shown relative to the toe cap body itself ) in the injection mold by which the toe caps are preferentially molded . by positioning the gate 18 on the rear edge 20 of the toe cap body , generally in the area of the curved transition between the roof 14 and one side wall 16 , and by further widening the gate to spread the entry point for the fiber filled resin in a lateral direction , the preferential orientation of fibers f in the roof 14 is attained . by comparison , injection of a fiber - filled resin material through a gate in the rear edge 20 at the bottom of the side wall 16 near the lip 17 results in a swirling of the fibers and a generally random directional orientation in the roof 14 . similarly , injecting the plastic at the lower edge on the center of the front wall 15 also results in a swirling and a more random directional orientation of the fibers . apart from the preferred orientation of the fibers f in the roof 14 , fiber orientation elsewhere in the toe cap is not believed to be particularly important . the preferential lateral orientation of the fibers f provides an optimally reinforced roof 14 in the toe cap which has been found to enhance substantially the resistance of the roof to failure under a vertical compressive or impact load and to further enhance the resilience of the structure , allowing it to bounce back after the imposition of a heavy vertical load . as shown in fig2 and in accordance with the ansi test standard identified above , a 50 pound ( 22 . 7 kg ) load is attached to a flat one inch ( 25 . 4 mm ) nose n which is dropped onto the roof 14 from a height of approximately 18 inches ( 45 . 7 cm ) or a height sufficient to provide an impact velocity of 118 inches per second ( approximately 3 m / sec ). toe caps 10 made in accordance with the present invention have been found to successfully pass two consecutive impact tests performed under the above standard . the preferred embodiment of the toe cap of the present invention includes a region of substantially reduced cross section in the front wall 15 specifically comprising an elongate generally horizontal slot 21 extending along the entire front wall 15 and rearwardly along and into portions of both side walls 16 . the slot 21 may be formed in any convenient manner , but is most conveniently formed in an injection molded part with a simple mold insert . it has been found that the reduced section 24 in the front end portions of the side walls provided by the slot 21 results in a controlled collapse of the toe cap under a vertically imposed load ( such as provided by impact of the nose n ), particularly when combined with the preferred orientation of the reinforcing fibers f . one fiber filled plastic resin material which has been found to work well is a glass - filled polyurethane supplied by polymer composites incorporated and carrying the designation pug60 . examination of test toe caps of the present invention , incorporated into actual shoe construction and tested in accordance with the above identified ansi standard , and the more rigorous canadian standard , shows a consistent performance characterized by a cracking of the roof 14 , along with a visible stressed area or cracking in and along the slot 21 , resulting in a temporary collapse of the roof under load , but a collapse which is within the range permitted by the respective test regimens , and a subsequent rebound of the plastic material to essentially its original shape . more specifically , the characteristic crack in the roof 14 typically forms generally along the longitudinal centerline of the roof directly under the point of impact and extends from the rear edge 20 forwardly and downwardly into the front wall 15 . thus , the crack is disposed generally perpendicular to the orientation of the fibers f in the roof 14 . simultaneously and dependent on the magnitude of the imposed load , either an area of visible stressing or a generally horizontal crack also typically occurs in the base 22 of the slot 21 at the point of thinnest cross section . the crack in the slot 21 may progress along its full length and even extend beyond the ends 23 of the slot and horizontally along the side walls 16 . although an obvious material failure is indicated when cracking occurs , the roof 14 of the toe cap will still bound back after impact and resume substantially its original shape . often , a subsequent test performed immediately on an initially cracked toe cap will also pass the test even though further cracking or fracturing of the roof and extended cracking of the side walls may occur . it is believed that the slot 21 in the front wall 15 results in a hinge - like effect that allows a downward tilting of the toe cap simultaneously with a generally vertical downward movement of the roof in a manner which controls the overall collapse of the toe cap to keep it within the range of movement permitted under the applicable test standard . in particular , it is important to prevent excessive downward movement and rearward tilting of the rear edge 20 to an extent which would result in the rear edge cutting into the toes of the wearer . the controlled collapse of the toe cap of the present invention obviates this problem . in addition , it has been found helpful to form the rear edge 20 of the toe cap at an angle to define a plane generally disposed to slope rearwardly and downwardly at an acute angle to the vertical , as best shown in fig2 and 4 . this angled rear edge 20 extends the base of the toe cap along the lower edges of side walls 16 to provide added stability against any tendency of the toe cap to tilt rearwardly . the actual angle at which the plane defining the rear edge 20 is disposed is not believed to be critical and as large an angle as possible , dictated primarily by requirements of the shoe manufacturing process , is desirable . in fig6 - 9 , there are shown two variations of another embodiment of the region of reduced cross section which helps provide the controlled collapse of the toe cap . in this embodiment , a toe cap 30 is of generally the same shape as the toe cap 10 of the preferred embodiment , but is made to accommodate a slightly different shoe style . the toe cap 30 has a unitary body 33 defined by a smooth blending of a roof 34 , a front wall 35 , and opposite side walls 36 . the walls 35 and 36 may define , at their lower edges , a continuous lip 37 . the fiber - filled plastic resin may be injected through a gate region 38 sized and positioned in a manner similar to the gate 18 of the preferred embodiment , resulting in the same preferred orientation of the fibers in the roof 34 . in lieu of the forwardly positioned slot 21 of the preferred embodiment , the alternate embodiment shown in fig6 and 9 includes a slot 41 in each of the side walls 36 extending forwardly from the rear edge 40 of the body 33 toward the front wall 35 . the slots 41 may be of any convenient shape to provide the regions of reduced cross section along the lower edges of the side walls 36 as shown . in the variation shown in fig8 only a single slot 41 is provided in one side wall 36 . under a vertically imposed compressive or impact load , the slot or slots 41 result in a similar collapse of the toe cap 30 as results from the slot 21 in the preferred embodiment of the toe cap 10 . the roof 34 collapses downwardly in the same manner and is characterized by the same generally centered longitudinal crack in the roof perpendicular to the laterally oriented fibers f . simultaneously , the slot or slots 41 allow the side wall or walls 36 to collapse about the reduced cross section 44 therein , also characterized by a horizontal crack running along the slot 41 in the base 42 of the slot . the crack may extend forwardly beyond the slot end 43 toward the front wall 35 . in other words , the reduced cross section 44 acts as a hinge allowing the slots 41 to close vertically under load . in fig1 - 12 , there is shown a variation in the slots 41 of the embodiments shown in fig6 - 9 . in the embodiment illustrated in fig1 - 12 , the regions of reduced cross section in the side walls 56 comprise a pair of slots 51 , each extending forwardly from the rear edge 50 of a side wall 56 . each slot 51 extends laterally through the full thickness of the side wall 56 . in the particular construction shown , each slot includes a generally horizontal bottom wall 52 and a sloping top wall 53 . the slots 51 allow the roof 54 of the toe cap to collapse vertically under a vertically imposed load in a manner similar to the embodiment in fig6 - 9 . a similarly sized and positioned gate 58 is also preferably provided to enhance the orientation of the fibers in the roof 54 . in fig1 and 14 , another embodiment of the toe cap of the present invention includes a body 63 having a shape similar to those shown in fig2 and 6 . however , the regions of reduced cross section in the side walls 66 and / or front wall 65 are provided by molding the side wall 66 and / or front wall 65 with substantially thinner cross sections than the thickness or cross section of the roof 64 . as may best be seen in fig1 , the relatively thick section of the roof 64 tapers laterally and downwardly in the regions of transition into substantially thinner side walls 66 . the side walls 66 terminate at their lower edges in a continuous lip 67 . the front wall 65 is preferably similarly thinned , as are the side walls 66 , to provide a region of continuous reduced cross section around the entire periphery of the toe cap . as in the previously described embodiments , a gate 68 is positioned in the rear edge 60 and sized to result in the preferred orientation of the reinforcing fibers f laterally across the roof 64 between the side walls 66 . under a vertically imposed load on the roof 64 , the reduced sections of the side walls 66 ( and front wall 65 of similarly reduced section ) result in the same controlled vertical collapse of the toe cap body 63 , as previously described . the presently preferred polyurethane base material identified above includes a glass fiber loading of about 60 % by weight of the total glass - filled plastic resin . the fibers have an average length of 1 / 2 inch ( 12 . 7 mm ), but fiber lengths as short as 1 / 4 inch ( 6 . 4 mm ) have been found to be satisfactory . glass fiber loadings in the range of 40 to 65 % by weight are believed to be suitable , depending on various additional factors such as toe cap wall thickness variations . in the toe caps shown and tested in accordance with the foregoing description , wall and roof thicknesses vary within a range of about 1 / 8 inch to about 1 / 4 inch ( 3 . 2 mm to 6 . 4 mm ). the unique gate 18 or 38 which permits the preferred lateral orientation of the fibers in the roof 14 or 34 , is also believed to prevent excessive fiber degradation by virtue of its laterally extended length . as shown , the gate 18 or 38 may be 1 / 2 inch ( 12 . 7 mm ) in length or longer which may be two or more times greater than the wall thickness at the point of injection . various modes of carrying out the present invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is required as the invention .
a toe cap for a protective shoe is injection molded utilizing a fiber - filled plastic resin having a high loading of relatively long fibers . the toe cap is constructed to provide a controlled vertical collapse of the body under a vertical load imposed on the roof by providing a roof section of relatively higher strength than the front and side walls of the toe cap . the front and / or side walls are provided with regions of substantially reduced cross section , as compared to the roof section , allowing the walls to close vertically and collapse in a hinge - like manner , while the relatively stronger roof substantially retains its original shape . a specially positioned and shaped gate allows the fiber - filled resin to be injected to form the toe cap in a manner resulting in the lateral orientation of the fibers across the roof to substantially enhance the strength thereof .