the present invention may be best exemplified by describing use of the preferred form of chock 10 in a chock assembly 12 for mountain climbing . as represented in fig1 and further shown in more detail in fig2 to 4 , the preferred form of chock 10 is defined by a main body portion in the form of a truncated pyramid having opposite ends 13 and 14 joined by sides 15 , 16 and 17 which taper from the base or end 14 upwardly toward the opposite end 13 . it will be readily apparent from a consideration of fig1 and 4 that the main body portion has a triangular cross section when taken in a plane transversely of the length or major axis of the pyramid , the sides each being of a width differing from the other two sides so that adjoining corners 18 , 19 and 20 are at unequal distances from each of their respective opposite sides . in order to provide for suspension of a climbing rope from the chock , a central cable - receiving opening or cavity 24 is formed in the chock for insertion of one end 25 of a cable or rope 26 , the opposite end of the cable terminating in a looped portion 28 which is fastened together as at 29 for connection of a ring 30 thereto . preferably the cable - receiving opening 24 includes a relatively small bore or groove 32 extending rearwardly from the smaller end 13 of the body to communicate with an enlarged area 34 so that the end of the cable 25 may be swaged or otherwise upset or enlarged as at 25 &# 39 ; to permanently anchor it within the body portion of the chock . fig1 illustrates the manner in which the chock is preferably wedged in a crack or crevice with one side surface 15 forming a flat bearing surface against one side of the crevice c and the opposite corner 19 forming a bearing edge against the opposite side of the crevice . the side selected to form a bearing surface will of course depend upon the width and configuration of the crack or crevice and utilization of that side which will most nearly conform to the angle or degree of taper of the crack or crevice . in this relation , the tapered configuration of the body will permit firm wedging engagement of the chock in the crack along a substantial surface of one side as well as along the opposed corner or edge . however , it has been found that the combination of the point or line bearing contact with the flat bearing contact offered by a triangular chock body construction establishes firm wedging engagement with the greatest variety of configurations and sizes of crevices . in addition , by placing the cable - receiving opening along the major axis of the chock , any load suspended from the chock assembly such as by attachment of a climbing rope to the ring 30 is applied more uniformly throughout the chock so as not to tend to loosen or displace the chock but instead to increase its wedging engagement . in the modified form of invention illustrated in fig5 to 7 , like elements are correspondingly enumerated with prime numbers wherein a body portion has external triangular sides 15 &# 39 ;, 16 &# 39 ; and 17 &# 39 ; with a central cavity or bore 34 &# 39 ; extending the length of the body , the bore having an inner circular wall surface in inner spaced concentric relations to the outer surfaces 15 &# 39 ;, 16 &# 39 ; and 17 &# 39 ;. in order to facilitate firm locking engagement of the end of the cable in the chock , the sides 15 &# 39 ;, 16 &# 39 ; and 17 &# 39 ; are initially of an outwardly bowed or convex configuration so as to enlarge the inner bore 34 &# 39 ; and permit insertion of the cable into the cavity . once in position , the side walls are squeezed or compressed inwardly by application of sufficient pressure to force them into a straight - sided configuration corresponding to that shown in fig1 to 4 and to firmly clamp the cable end in place . in the alternative the inner wall surface of the bore 34 &# 39 ; may be triangular so as to be in spaced relation to the external sides 15 &# 39 ;, 16 &# 39 ; and 17 &# 39 ; substantially in the manner shown with respect to fig8 to 10 as hereinafter described . in the modified form shown in fig8 to 10 , corresponding elements to the preferred form are once again correspondingly enumerated with double prime numbers . the distinguishing feature of the modified form shown in fig8 to 10 is to form the enlarged cavity 34 &# 34 ; with inner , curved side walls 35 &# 34 ;, 36 &# 34 ; and 37 &# 34 ;. in addition the cavity 34 &# 34 ; communicates with a pair of laterally spaced openings 32 &# 34 ; and 33 &# 34 ; so that one end of the cable may be looped through one opening and returned through the other opening and securely swaged together such as by a coupling sleeve in the same manner as illustrated at the lower looped end portion 28 in fig1 . once again the cable - receiving openings 32 &# 34 ; and 33 &# 34 ; are located symmetrically with respect to the longitudinal axis of the chock . in addition , the inner curved or convex side walls 35 &# 34 ; to 37 &# 34 ; serve to add additional thickness to the side walls of the chock . the modified forms of construction and arrangement as described with respect to fig8 to 10 is particularly useful in larger sized chocks ; whereas the form shown in fig5 to 7 has been found to be most useful in the smaller sized chocks , and that of fig1 to 4 has been found to be preferable for medium sized chocks . for the purpose of illustration and not limitation , the medium sized chocks may have sides ranging in size from 0 . 6132 inch , a second side of 0 . 6789 inch and a third side of 0 . 7614 inch with an overall length of the chock body on the order of 0 . 76 inch . the smaller sized chock as embodied by fig5 to 7 may have a narrow side of approximately 0 . 18 inch , a second side of 0 . 20 inch and a third side on the order of 0 . 22 inch with an overall length of 0 . 22 inch . the larger size chock as illustrated in fig8 to 10 may have a shorter side on the order of 4 . 0 inches , a second side on the order of 4 . 34 inch and a longer side on the order of 4 . 86 inch , the overall length of the chock also being on the order of 4 . 86 inch . in each form the degree of taper of each side is on the order of 05 ° to the longitudinal axis . it will be readily apparent that the relative width of the sides may vary as well as the degree of taper and overall length of the chock with respect to the width of the sides ; also the chock may be four - sided with unequal sides but the three - sided triangular configuration has been found to offer a much better opportunity to establish corner - to - side bearing contact in different sizes and shaped of crevices . similarly , the particular configuration of the central opening or cavity may vary although it is preferred to so design the central cavity and to permit affixation of the cable or rope end in such a way as to be substantially embedded within the outline of the chock body . in this relation it is further of particular advantage that the cable extend from the smaller end of the chock body so that the sides of the chock diverge away from the swage . it is therefore to be understood from the foregoing description of a preferred and modified forms of invention that various changes may be made in the construction , dimensioning and sizing of parts without departing from the spirit and scope of the present invention as defined by the appended claims .
a chock for mountain climbers is in the form of a truncated pyramid having sides of unequal width so that the chock is readily conformable for secure wedging engagement virtually in any type of crevice , the chock being manufactured in different sizes according to variations in size of cracks or crevices encountered in mountain climbing . the configuration permits central placement of one end of a carabiner , the opposite free end of which is provided with a hero loop to permit fastening of a ring for direct connection of the climbing rope thereby obviating connection of an additional carabiner .