referring first to the embodiment illustrated in fig1 - 4 , the crossover unit has been denoted in its entirety by the reference numeral 10 . the unit 10 is comprised of an elongated elastomeric pad 12 , preferably of polyurethane , and an elastomeric insert or closure plug 14 , preferably of rubber . describing the pad 12 with greater particularity , it will be observed that it is formed with a top surface 16 composed of inclined ramp sections 16a , 16b and horizontal platform sections 16c , 16d . the ramp section 16a inclines upwardly from one side edge 18 and the ramp section 16b inclines upwardly from the opposite side edge 19 . the pad 12 has a flat bottom surface 20 . as best seen in fig3 the pad 12 has a longitudinally directed slot 22 formed therein . the slot 22 has what might be termed an inverted t appearance . thus , the slot 22 has a vertical leg portion 22a and laterally extending or horizontal leg portions 22b and 22c . in this way , a pair of overhanging integral lips 24 and 26 are formed , the lip 24 residing over the slot portion 22b and the lip portion 26 over the slot portion 22c . the lip 24 is provided with a sloping free edge 28 and the lip 26 with a sloping free edge 30 , the edges 28 , 30 having a degree of convergence that will shortly be referred to in greater detail . attention is now directed to a pair of parallel ribs 32 , 34 forming a flat portion 40 therebetween . the ribs 32 and 34 each have a sloping surface 36 and 38 , respectively , the convergence of the surfaces 36 , 38 corresponding to that imparted to the free edges 28 , 30 on the overhanging lips 24 and 26 . describing now the insert or closure plug 14 , it will be discerned that it has a wedge - shaped cross section which is very effective in assuring its retention in the slot 22 . more specifically , it has a flat upper surface 50 of a width just a trifle greater than the width of the entrance or upper end of the groove 22 , this being the distance between the free edges 28 , 30 . the bottom 52 is narrower than the top 50 , there being converging sides 54 and 56 . it will now be appreciated , it is believed , that the degree of convergence or angulation of the sides 54 , 56 corresponds to the degree of convergence imparted to the free edges 28 , 30 and also to the surfaces 36 , 38 . the insert or plug 14 is resilient and preferably or rubber , as hereinbefore stated . in this way , due to the compressibility of the rubber , assisted by the convergence of the sides 54 , 56 , the insert 14 can be readily placed within the slot 22 so as to close completely the entrance thereto between the free edges 28 , 30 . also , it will be appreciated that the sides 54 , 56 of the insert 14 block the horizontal or lateral slot portions 22b and 22c , respectively . in this way , voids are assured beneath the lip portions 24 , 26 . from fig4 it will be perceived that the insert 14 is formed with inclined ends 58 and 60 for a reason explained hereinafter . it is within the lateral or horizontal slot portions 22b and 22c that electric power cables 62 and 64 are contained , the cable 62 illustratively having a conductor 66 extending therethrough and the cable 64 having a similar conductor 68 contained therein . while only one conductor 66 has been shown for the cable 62 and one conductor 68 for the cable 64 , it will be appreciated that two conductors can be contained in each cable 62 , 64 . one of the attributes of the unit 10 is that two horizontal slot portions 22b , 22c are provided so that fairly sizable cables 62 and 64 can be accommodated . where heavy electrical currents are carried , the conductors 66 and 68 must have a sizable cross section , a cross section adequate for the current . although not forming a part of my invention , for the sake of completeness a pair of eye bolts 70 extend into the pad 12 from one end and a similar pair of eye bolts 72 extend into the pad from the other end , each eye bolt 70 , 72 having means thereon for anchoring the eye bolt . for the sake of simplicity the anchoring means has been shown as a washer 74 ( fig3 ) having a nut 76 on each side so that the washer 74 remains embedded in the polyurethane material constituting the pad 12 during the molding thereof . the eye bolts 70 , 72 permit the pad 12 to be pulled from one vantage point to another ; however , other means can be employed . having presented the foregoing description , the advantages to be derived from a practicing of my invention are believed to be fairly straightforward . however , it can be pointed out that the wedge - shaped insert or plug 14 engages each of the free edges 28 , 30 as well as the surface 40 at the bottom of the slot 22 . since loads of appreciable magnitudes will result from heavily loaded vehicles , such as those used in mining and construction operations , passing over the unit 10 , it can be pointed out that when the front wheels of the vehicle pass upwardly over the ramp section 16a onto the platform section 16c and over the upper surface 50 of the closure insert of plug 14 , the tendency for the lip 24 to flex downwardly will be resisted by the side 54 of the wedge - shaped insert 14 . in this regard , it should be understood that the wedge - shaped insert 14 not only engages both of the free edges 28 , 30 of the lips 24 , 26 , but also engages the bottom surface 40 . therefore , the vertical load applied to the top of the unit 10 is borne substantially by the wedge - shaped insert 14 , the insert being simply forced downwardly against the bottom surface 40 and not onto the cable 62 . the same thing can be said for the cable 64 , for the lip 26 resists downward deformation because its free edge 30 is in engagement with the side 56 of the insert 14 . of course , the resistance to flexing or deforming as far as the lips 24 , 26 are concerned , depends upon the resiliency or compressibility of the insert 14 , as well as the resiliency of the polyurethane . such resiliency factors can be readily taken into account when selecting the precise materials and their durometer factors for the pad 12 and the wedge - shaped insert 14 . it is also believed readily apparent that the cables 62 , 64 are placed into the horizontal slot portions 22b , 22c prior to the insertion of the insert or closure plug 14 . once in place , then the insert 14 is simply pressed into the vertical portion 22a of the groove 22 with the consequence that the engagement of its sides 54 , 56 with the surfaces 28 , 30 and 36 , 38 as well as the bottom surface 40 results and performs in the fashion already described . when the pad 12 is relatively short , say , on the order of eight or ten feet , it is planned that the insert 14 be somewhat longer so that the ends 58 and 60 project beyond the ends of the pad 12 to facilitate removal of the insert . when the pad 12 is longer than eight or ten feet , more than one insert 14 is contemplated and in such a situation the end 60 of one insert would overlie the end 58 of the next one to keep dirt out of the slot 22 . as already pointed out , the insert 14 resists inadvertent dislodgment , which has been one of the troubles experienced with prior art crossover devices . in some situations , only one cable or hose will require accommodation . of course , it is within the contemplation of the invention to accommodate two or more smaller cables in either slot portion 22b or 22c in lieu of a single larger cable . however , at this time attention is directed to fig5 is which a second embodiment 10a is depicted . the cross sectional view constituting fig5 is believed adequate to illustrate the modified version of the invention . fig5 corresponds to fig2 it might be pointed out . instead of two horizontal slot portions 22b and 22c , however , the unit 10a contemplates only one horizontal slot portion 22b . instead of the slot portion 22c , the pad 12a is formed with a sloping surface 38a which constitutes one side of the groove 22a . thus , instead of the inverted t - shaped configuration of the groove 22 , the groove 22a has what might be called an l - shaped configuration . at any rate , only a single cable 62a is shown having conductors 66a and 68a contained therein . the insert or closure plug 14 , being the same as in the unit 10 , resists deformation of the lip 24 , bearing against its free edge 28 . any tendency of the lip 24 to be flexed downwardly is resisted by the sloping side 54 of the insert 14 . actually , any reactive force is transmitted through the insert 14 to the bottom 40a and also the side 38a . in this way , collapsing of the lip 24 is resisted and the void or space provided by the horizontal slot portion therebeneath 22b is preserved so that for all intents and purposes none of the weight of a vehicle passing over the unit 10a is imposed on the cable 62a . as with the earlier embodiment denoted by the numeral 10 , it is particularly beneficial if the item contained within the crossover unit 10a is a flexible hose to prevent any collapsing of the hose , for any collapsing will throttle the fluid flowing therethrough .