as was noted above , it is an objective of the invention to overcome the disadvantages described above and to provide a binding apparatus for binding the front of a shoe or boot onto a ski . the binding is preferably for use in cross - country or mountaineer skiing wherein the skier lifts or raises his heel in the course of moving his legs . the binding is generally characterized by the fact that the front of the boot is connected to the ski by a flexible flexion element . a pivot means ia also provided which is journalled to pivot around a transverse axis . the pivot means may comprise an abutment shoulder or surface to block the pivoting thereof at the end of a certain extent of lifting of the heel . further lifting of the heel results in flexion of the flexible flexion element . according to one aspect of the invention , the first phase of the lifting of the heel occurs freely , and is accompanied by rotation around a transverse axis . however , rotation or pivoting beyond a certain extent is blocked by a shoulder , and further lifting of the heel results in flexion of the flexion element . it is another characteristic of the invention that the flexion and rotation occur beyond the front end of the boot . according to other aspects of the invention , the flexion element can be either journal - mounted on the ski or be attached to the ski in a rigid manner , in which case it is the boot which is journalled with respect to the flexion element . the first phase of the lifting of the boot occurs freely without consuming the energy of the skier ( the extent of lifting may be 0 - 2o ° with respect to angular lifting ). subsequently , lifting of the heel occurs against the elastic force of the flexion element which exerts a frontwardly directed moment on the ski , which is necessary for proper skiing . in this way , the ski is pressed against the snow as a result of the lifting of the heel , once the heel has been lifted beyond a predetermined extent . thus , the desired effect is achieved without tiring the skier by requiring him to work against flexional forces throughout his entire gate . fig1 - 6 illustrate a first embodiment of the invention . in this embodiment , binding apparatus 1 for connecting the front of the boot 2 to ski 3 comprises a binding 4 , shown as being mounted on a level surface of the ski , in cooperation with he front portion 5 of the boot . binding 4 comprises a movable and flexible flexion element 6 positioned in a base plate body 7 attached to the ski by virtue of screws 80 . flexion element 6 is substantially parallelpipedic and extends from the front to the rear of base plate body 7 . the base plate has two uprights , or lateral walls 70 and 71 extending vertically on both sides of the lateral edges of the flexion element . the flexion element is at least partially deformable and is mounted at its front portion to pivot around a transverse axis s . however , the pivoting of element 6 is angularly limited , as will be noted below . the front of the boot is secured onto element 6 by a retention apparatus 9 . the retention apparatus is described in french patent application no . 2 , 447 , 731 , the disclosure of which is hereby incorporated by reference , and need not be described in detail , particularly since this apparatus is given by way of example only . it need only be noted that element 6 extends rearwardly and comprises a support element 10 extending upwardly and that the front end 5 of boot 2 comprises a frontal support zone 11 as well as a latching element 12 which is spaced from the zone and extends in front of the boot . furthermore , a movable latch 13 is connected to element 6 by a stirrup 14 which may be journalled . the upper portion 15 of stirrup 14 is positioned in slot 16 comprising an elastic element 17 . slot 16 is formed in movable latch 13 which is pivotably mounted on stirrup 14 around upper portion 15 . insertion of the boot into the binding occurs by introduction of support element 10 between latching portion 12 and support zone 11 of the boot , and the retention is achieved by action of latch 13 on latching portion 12 , which thus forces support zone 11 against abutment zone 18 of support element 10 . fig1 illustrates the apparatus in the inactive position before insertion of the boot , and fig2 - 4 illustrate the apparatus in the active position with the boot inserted where the boot is to be retained . fig5 and 6 illustrate two phases of movement during lifting of the boot heel . the first phase involves a rotation around axis 8 , which is followed by a second phase which is accompanied by flexion of the flexion element . to pass from the first phase to the second phase , an abutment system is provided which blocks rotation beyond a certain extent . to achieve this , the front end of the flexion element comprises an abutment surface 19 which is inclined upwardly ( relative to the front of the binding ). fig5 illustrates the end of the first phase of movement during which the boot is lifted along direction f 1 by rotation around axis 8 until abutment surface 19 abuts against upper surface 20 of plate 21 of base plate body 7 . further pivoting of the flexion element is thus no longer possible , and any further lifting of the foot along direction f 1 results in flexion of the flexion element , as is shown in fig6 . movement along the direction f 1 thus occurs by pivoting of the flexion element around axis 8 , and subsequent movement along f 2 is accompanied by flexion of the flexion element . fig6 - 12 illustrate an alternative abutment system . in this embodiment , the same elements are against present ; namely , flexion element 6 &# 39 ; on which the boot is attached by virtue of the same apparatus as was previously described . flexion element 6 &# 39 ; is pivotably journalled around transverse axis 8 of base plate body 7 &# 39 ; which is attached to the ski . body 7 &# 39 ; comprises two lateral walls , 70 &# 39 ; and 71 &# 39 ;, which support pivot axis 8 and are connected at their upper portions by a horizontal wall member 72 . as may be seen from fig8 horizontal upper wall member 72 is upwardly spaced by a distance h from upper surface 60 of flexible element 60 &# 39 ;. this spacing allows for the free pivoting of element 6 &# 39 ; around axis 8 until upper surface 60 abuts against portion 73 of wall 72 ( see fig1 ). further pivoting is then blocked , and further movement of the boot occurs by flexion of flexion element 6 &# 39 ;. movement along f 1 thus occurs by pivoting of flexion element 6 &# 39 ; around axis 8 , and movement along direction f 2 occurs by flexion of flexion element 6 &# 39 ;. fig1 - 16 illustrate another embodiment in which it is not the flexion element which is journalled on the ski , but rather the end of the boot which pivots with respect to the flexion element . to achieve this , flexion element 6 &# 34 ; is attached to the ski at its front end by a body 7 &# 34 ; and a screw 8 . at its rear end , flexion element 7 &# 34 ; comprises a shaped element having a rounded slide surface 60 which is transverse and in the shape of a semi - circle of radius &# 34 ; r &# 34 ;. movable latch 61 is journalled around a transverse axis 62 . latch 61 is in the form of a stirrup which is configured and made of steel spring wire having a circular cross - section whose free ends 63 and 64 act as a journal axis for the upper portion 65 , which serves as a manipulation element . the free end of the boot comprises projection 30 , whose lower portion comprises a shaped slide member which has an arcuate surface extending in the transverse direction 31 , and has a shape which is complementary to the configuration of surface 60 and which cooperations therewith . the upper portion comprises a groove 32 which is adapted to receive horizontal arms 66 and 67 of latching element 61 . the lower frontal portion comprises an abutment surface 33 constituted by a surface which is inclined upwardly and frontwardly . fig1 illustrates the boot in the inserted position . movement along direction f 1 occurs by rotation of the boot with respect to the flexion element around the fictional transverse axis xx &# 39 ;, which passes through the center of the shaped projection having radius &# 34 ; r &# 34 ;. when surface 33 abuts against upper element 60 &# 39 ; of the flexible element , further rotation is no longer possible , and movement along direction f 2 occurs by flexion of the flexion element ( see fig1 ). fig1 illustrates an alternative embodiment in which flexion element 6 is definitively rendered integral with the boot , and remains permanently affixed thereto . it is thus possible , according to the invention , to provide for the flexion element to be either permanently or detachably secured to the boot with respect to each of the embodiments discussed above . the example set forth above illustates a number of ways of achieving such attachment although other techniques for accomplishing this aim are obviously possible . in all of the embodiments shown above , the binding is mounted on a level surface of the ski . also , the pivoting and flexional movements occur around real or virtual axes which are transverse and perpendicular to the longitudinal plane of symmetry . however , it is self - evident without going beyond the scope of the invention , that the journal axes . could also be skewed ( non - transverse angle ), as shown in french patent application no . 82 , o7758 , the disclosure of which is hereby incorporated by reference . thus , the invention is not limited to the transverse pivot axes disclosed and may be used with bindings having pivot axes which are other than transverse to the general logitudinal orientation of the ski , boot , and binding . it should also be noted that although an attempt has been made to include reference to all shoes and boots used in the manner of the invention , it is to be understood that the invention is not limited to any one particular shoe structure and extends to all equivalents within the scope of the claims . likewise , the application refers to &# 34 ; pivoting &# 34 ; and &# 34 ; flexion &# 34 ; as representing two different types of motion . it is to be understood , however , that what these terms intend to imply is that during &# 34 ; pivoting &# 34 ; there is a relatively free lifting of the heel , while during &# 34 ; flexion &# 34 ; the flexion element presents a resistance to further lifting which results in a moment forcing the front tips of the skis downwardly . finally , although the invention has been disclosed and described with reference to particular means , embodiments , and materials , it is to be understood that the invention is not limited to the particulars disclosed but extends to all equivalents within the scope of the claims .
a ski binding for securing a ski shoe or boot to a ski in a manner which permits the heel of the shoe or boot to be lifted away from the ski . the binding includes pivot means permitting the shoe or boot to pivot upwardly relative to the ski as the heel is lifted relative to the ski , and a flexion element which flexes as the heel of the boot is lifted beyond a predetermined extent .