referring to fig1 and 3 of the drawings , the slip - resistant sole according to the preferred embodiment of the present invention is illustrated . according to the preferred embodiment of the present invention , the slip - resistant sole comprises a bottom sole 1 and a plurality of protruded units 2 outwardly extended from and spacedly positioned on the bottom sole 1 . the protruded unit 2 is resilient and has a columnar structure . the protruded unit 2 has a bottom end 23 and a protruded unit cavity 22 provided at the middle portion of the protruded unit 2 in the bottom end 23 . a side wall of the protruded unit cavity 22 has a curved or inclined cross - section . the provision of the protruded unit cavity 22 not only facilitate the protruded unit to deform flexibly and easily , but also creating an adsorption force through a supporting and sucking relationship with a floor surface , thereby enhancing the slip - resistant ability . the position of the protruded unit cavity 22 with curved or inclined side wall 221 can be designed or arranged based on different needs of a user . for example , the edge of an opening of the protruded unit cavity 22 is overlapped with the edge of the bottom end 23 of the protruded unit 2 , or is at a distance from the edge of the bottom end 23 of the protruded unit 2 . a cross - section of the protruded unit 2 is trapezium in shape defining a long side and a short side . the protruded unit is extended from the bottom sole through the short side of the protruded unit 2 . an angle “ a ” is defined between an outer side of the protruded unit 2 and the bottom sole 1 , wherein the angle is between 60 ° and 90 °. because the cross - section of the protruded unit is trapezium in shape while the connecting portion between the protruded unit 2 and the bottom sole 1 has a surface area smaller than a surface area of the bottom end 23 of the protruded unit 2 , the protruded unit will be deformed outwardly when a force is acted onto the bottom sole and a height of the protruded unit 2 will be decreased . accordingly , a contacting area between the floor surface and the protruded unit 2 is increased , thereby increasing a friction between the bottom sole and the floor surface . in addition , a gap is provided between each of the protruded units 2 . accordingly , when the slip - resistant sole is used in wet smooth floor surface with water or oil , a weight of a user will cause the protruded units 2 on the bottom sole 1 to deform , thereby causing the water or the oil to be quickly removed through the gap between two adjacently positioned protruded units 2 , thereby further increasing the slip - resistant ability . referring to fig4 and 6 of the drawings , another structural construction is provided based on the above preferred embodiment of the present invention . in particular , at least one guiding groove 21 is provided on the bottom end 23 of the protruded unit 21 and the guiding groove 21 is positioned uniformly on the bottom end 23 . the guiding groove 21 is channeled to the protruded unit cavity 22 through a distal end of the guiding groove 21 . when the slip - resistant sole is used in wet smooth floor surface with water or oil , the guiding groove 21 can direct a small amount of water or oil to flow from the protruded unit cavity 22 to outside of the protruded unit 2 , thereby increasing a coefficient of friction between the bottom sole and the floor surface and increasing the slip - resistant ability of the slip - resistant sole of the present invention . on the other hand , the protruded unit 2 is pressed to deform , therefore creating a force at three different directions on the bottom end 23 of which the force at each direction is equal , thereby the protruded unit 2 is supported through the force at three different directions . at the same time , the protruded unit cavity 22 and the floor surface have created an absorption force through their supporting and sucking relationship , thereby a coefficient of friction between the bottom sole 1 and the floor surface is increased and the slip - resistant ability of the sole is further increased . the number of the guiding groove as mentioned above can be uniformly provided on the curved surface according to the design need . for example , the number of guiding groove can be 1 , 2 or more . when the number of guiding groove is two or more , the guiding grooves are spacedly provided on the bottom end 22 and a distal end of each guiding groove is channeled to the protruded unit cavity 22 respectively . according to the above embodiment , a junction groove 24 is further provided and is positioned at a connecting junction 30 between the protruded unit 2 and the bottom sole 1 . the connecting junction 30 is the junction at which the protruded unit 2 and the bottom sole 1 are connected . the junction groove 24 is not only capable of increasing a height of the protruded unit 2 , but also increasing the softness of the protruded unit 2 . in addition , when the bottom sole 1 is being acted by force from different directions , the resilient protruded unit 2 can absorb a portion of the energy and therefore the slip - resistant ability of the bottom sole 1 is enhanced . the protruded unit 2 can be made by resilient materials such as rubber and pu . the number of protruded unit 2 on the bottom sole 1 can also be adjusted according to the design need . when the number of protruded unit 2 is increased , the slip - resistant ability is increased . referring to fig7 and 9 of the drawings , the bottom end of the protruded unit 2 can be rectangular or square shape in which four guiding groove 21 is provided in the bottom end of the protruded unit 2 . the four guiding grooves 21 divide the bottom end into four sections . when the protruded unit is pressed to deform , equal forces are created through the bottom end 23 at four opposite directions . therefore the protruded unit 2 is supported by the force at four directions and hence the bottom sole 1 is provided with slip - resistant ability . when the number of guiding groove is one , the bottom end of the protruded unit 2 is divided into two symmetrical portions . when the bottom end is pressed to deform , two equal forces are created from the bottom end 23 at two opposite directions , therefore the protruded unit 2 is supported by the force at two different directions and hence the bottom sole 1 is provided with slip - resistant ability . the number of guiding groove can be 1 , 2 or more . when the number of guiding groove is two or more , the guiding grooves are spacedly provided on the bottom end 23 and a distal end of each guiding groove is channeled to the protruded unit cavity 22 respectively . one skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting . it will thus be seen that the objects of the present invention have been fully and effectively accomplished . it embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles . therefore , this invention includes all modifications encompassed within the spirit and scope of the following claims .
an antiskid - style sole includes a sole body and a number of projections disposed on the sole body . the projections are elastic columnar parts . a cavity is disposed in the middle of end surface of the projection , and the wall of the cavity is in the shape of cambered surface or inclined surface .