Abstract:
A ski binding adapted to hold an end of a boot upon a ski. The binding includes a jaw and a body, in whyich the body of the binding further includes a lower part adapted to be affixed to the ski and having an upwardly facing surface extending upwardly and toward an end of the body, and an upper part which supports the jaw and having a downwardly facing surface for being positioned adjacent the upwardly facing surface of the lower part, wherein the upwardly facing surface of the lower part and the downwardly facing surface of the upper part are complementarily arcuately shaped having a common center of curvature, when the upwardly facing surface of the lower part is positioned adjacent the downwardly facing surface of the upper part, for enabling a generally pivotal movement of the upper part with respect to the lower part about the center of curvature.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a safety ski binding, preferably adapted to hold the front of a boot onto a ski. 
     2. Description of Background and Other Information 
     Safety ski bindings, specifically front abutments of the aforementioned type generally comprise a body fixed to the ski which supports, in a rear part, a movable jaw which is either of monoblock construction or comprises two independent lateral retention wings which are journalled, respectively, on the binding body by means of individual axes. 
     The binding body of a front abutment of the type mentioned is typically constituted by two parts nested in one another at the front, namely, a lower part or base which is affixed to the ski and an upper movable part which supports the jaw. The body likewise contains a mechanism for energization of the jaw, which is constituted by an energization spring and a force transmission device. The upper part of the body which supports the jaw is vertically upwardly movable during a rear fall which can cause, by means of a rear fall compensation device known per se, a lessening of the lateral release, i.e., a lowering of the lateral force threshold, exerted by the boot on one of the lateral retention wings, from which the binding releases. The upward movement of the upper part of the body can ultimately lead to the release of the boot when the upward angular clearance of the upper part of the body is sufficient. In front abutments of this type, the journalling between the upper part of the body, which is vertically movable, and the lower base affixed to the ski is achieved by means of a transverse horizontal journal axle which extends completely through these two elements, or even two transverse and coaxial half-axles which establish the linkage between the lateral adjacent surfaces of the upper part of the body and those of the base, respectively. 
     A front abutment of this type is described for example, in German Patent No. 3,612,697. In such a front abutment, the journal axle of the upper part of the body on the base has a relatively small diameter, whereas the forces that this axle transmit are relatively great. These forces are due to the thrust of the rear binding to which are added those which are due to the flexion of the ski, during skiing, the sum of these forces being able to reach 200 daN [decaNewton]. As a result, an axle of small diameter generates between its exterior surface and the surface of its support greatly elevated contact pressures which create a rapid wear-and-tear leading, in turn, to a certain amount of play and an inferior functioning of the binding. In addition, there can result a distortion of the axle or even a defect in alignment of the two opposed transverse half-axles, which is due to the elevated stresses during use of the binding. 
     SUMMARY OF THE INVENTION 
     The present invention aims to overcome the aforementioned disadvantages by providing a ski binding adapted to hold an end of a boot upon a ski, the binding comprising: 
     (a) a jaw; and 
     (b) a body comprising: 
     (i) a lower part adapted to be affixed to the ski and having a first end, a second end, and a longitudinal axis, the lower part further having an upwardly facing surface extending upwardly and toward the second end; and 
     (ii) an upper part for supporting the jaw and having a first end, a second end, and a longitudinal axis, the upper part having a downwardly facing surface for being positioned adjacent the upwardly facing surface of the lower part, wherein the upwardly facing surface of the lower part and the downwardly facing surface of the upper part are complementarily arcuately shaped having a common center of curvature, when the upwardly facing surface of the lower part is positioned adjacent the downwardly facing surface of the upper part, for enabling a generally pivotal movement of the upper part with respect to the lower part about the center of curvature. 
     In a specific aspect of the invention, the upwardly facing surface of the lower part terminates at a location spaced from the center of curvature in a direction toward the second end of the lower part. 
     More particularly, the lower part includes a generally vertical surface on either side of the longitudinal axis of the lower part, one of the generally vertical surfaces of the lower part having affixed thereto the upwardly facing surface, the other of the generally vertical surfaces of the lower part having affixed thereto another upwardly facing surface, wherein each of the generally vertical surfaces of the lower part further has affixed thereto a projection, wherein each of the projections is positioned above a respective one of the upwardly facing surface and the another upwardly facing surface to define a respective groove. 
     Still further, the upper part includes a generally vertical surface on either side of the longitudinal axis of the upper part, one of the generally vertical surfaces of the upper part having affixed thereto the downwardly facing surface, the other of the generally vertical surfaces of the upper part having affixed thereto another downwardly facing surface, wherein each of the generally vertical surfaces of the upper part further has a recess therein, wherein each of the recesses is positioned radially inwardly from a respective one of the downwardly facing surfaces toward the center of curvature to thereby define respective arc-shaped ribs for being slidingly receivable in a respective one of the grooves in the lower part. 
     Still further according to the invention, the generally vertical surfaces of the upper part include inner surfaces of respective parallel lateral arms, each of which is adapted to be positioned exteriorly of respective generally vertical surfaces of the lower part and to slide relative thereto during the general pivoting movement of the upper part with respect to the lower part. 
     Still further according to the invention, each of the projections and the recesses have complementarily shaped arcuate surfaces generally centered at the center of curvature. 
     Still further according to the invention, each of the projections extend transversely outwardly from a respective generally vertical surface and ends in a widened portion, and each of the recesses extend transversely inwardly from a respective generally vertical surface and ends in a widened portion for receiving a respective widened portion of a respective one of the projections. 
     Still further according to the invention, the upper part and the lower part of the body are further coupled by means of a height adjustment screw for selective adjustment of the height of the jaw relative to the ski. 
     It is a further object of the invention to provide a safety ski binding adapted to hold the front of a boot mounted on a ski, including: 
     (a) a jaw adapted to engage a portion of the boot and adapted to be biased to a predetermined position by means of a biasing mechanism comprised of a spring and an element for transmitting force from the spring to the jaw; and 
     (b) a body including: 
     (i) a lower part adapted to be affixed to the ski and having a front end and a rear end; and 
     (ii) an upper part, the upper part supporting the jaw and having a front end and a rear end, the upper part being movable with respect to the lower part about a generally horizontal transverse axis extending through the front end of the lower part and the front end of the upper part, wherein respective portions of the upper part and the lower part are nested with respect to one another by means of respective generally vertical surfaces of the upper part and the lower part laterally adjacent each other, wherein the respective vertical surfaces of the upper part and the lower part of the body support projecting elements and hollow elements having respective complementary shapes for respective engagement in one another. 
     According to a further aspect of the invention, the projecting elements and the hollow elements include, (1) on one of the upper part and the lower part of the body, (A) a projection in the form of a sector of a circle, generally centered on the axis, the sector thereby having a radius of curvature and an arc of the circle, the projection thereby having an arc-shaped edge, and (B) a first arc-shaped rib in the form of an annular segment having an average radius greater than the radius of the sector and generally centered on the axis, so as to define between the first arc-shaped rib and the projection a first groove in the form of an annular segment, generally centered on the axis, and, (2) on the other of the upper part and the lower part of the body, (A) a second arc-shaped rib in the form of an annular segment generally having the same width and radius as the first groove, the second arc-shaped rib being generally centered on the axis, and (B) an upper hollow in the form of a sector of a circle, complementary in shape to the projection, defined by the second arc-shaped rib and generally centered on the axis. 
     According to a specific feature of the invention, the first arc-shaped rib is positioned beneath the projection and the second arc-shaped rib is positioned beneath the hollow. 
     Further according to the invention, the projection and the hollow have upper surfaces which extend generally perpendicularly from the generally vertical surfaces of the upper part and the lower part of the body. 
     In a particular embodiment of the invention, the projection and the hollow have upper surfaces which extend at an angle less than 90° from the generally vertical surfaces of the upper part and the lower part of the body so as to constitute dovetailed assemblies. 
     More particularly according to the invention, the projection includes, in elevation, (1) an upper rectilinear side inclined upwardly and rearwardly with respect to the horizontal, (2) a lower side including the arc-shaped edge of the projection, the arc-shaped edge extending over an angle of approximately 120°, downwardly and frontwardly, and (3) a front side which is inclined upwardly and frontwardly, and forming an angle of approximately 20° with respect to the vertical. The first arc-shaped rib has an upper surface facing the upper projection, the upper surface of the first arc-shaped rib being constituted by an arc of a circle which is generally centered at the axis and which extends over an angle slightly less than 90°. The arc of the circle of the first arc-shaped rib has an upper extremity located substantially at a height substantially the same as the axis and offset rearwardly from the axis, and the arc of the circle of the first arc-shaped rib has a lower extremity located slightly rearwardly of a vertical plane passing through the axis. 
     Further, the hollow includes, in elevation, an upper rectilinear edge, a lower edge in the form of an arc of a circle having a center generally at the axis, the edge extending to a frontal surface of one of the upper part and the lower part of the body into which the hollow opens, the arc of the lower edge of the upper hollow having a radius of curvature generally equal to the radius of the arc of the sector of the circle of the projection, wherein the circle of the arc of the lower edge of the hollow has a center which is positioned so as to generally coincide with the center of the circle of the arc of the lower edge of the projection when the upper part and the lower part of the body are assembled, and wherein the second arc-shaped rib is defined by an upper edge merged with the lower arc-shaped edge of the hollow and by a lower arc-shaped edge having a center of curvature generally at the axis and having a radius of curvature generally equal to the radius of curvature of the arc constituting the upper edge of the first arc-shaped rib. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and additional objects, characteristics, and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments, with reference to the accompanying drawings, which are presented as a non-limiting example, in which: 
     FIG. 1 is a side elevation view, partially in section, of a front abutment according to the invention whose two parts are shown separated and presented in relative position in view of their assembly; 
     FIG. 2 is a transverse sectional view taken along line II--II of FIG. 1; 
     FIG. 3 is a transverse sectional view taken along line III--III of FIG. 1; 
     FIG. 4 is a front elevation view of the base of the body of the front abutment; 
     FIG. 5 is a plan view of the upper movable part of the body; 
     FIG. 6 is an elevation view of the front part of an internal lateral surface of the upper movable part of the body 
     FIGS. 7 and 8 are elevation views of the two parts of the body, at the beginning of the engagement of the upper part in the base and after rotation until the final assembly position, respectively; and 
     FIG. 9 is a transverse sectional view made along line IX--IX of FIG. 8. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention provides a journalling between the upper movable part of the body of the front abutment and the base, which is achieved by relatively simple means, ensuring a large contact surface and, consequently, a reduction in the contact pressure, without resorting to an axle having a small diameter. 
     To that end, the safety ski binding according to the present invention is preferably adapted to hold the front of a boot affixed to the ski, the binding comprising a body which supports, in its rear part, a movable jaw and which likewise contains an energization mechanism for the jaw, which is constituted by an energization spring and a device for transmission of force, the body being contributed by two parts which are movable with respect to one another about a generally horizontal and transverse axis located in the front of the body. The body of the binding includes a movable upper part, supporting the retention jaw, and a lower part or base which is affixed to the ski, the two upper and lower parts of the body being nested in one another in the front portion of the binding at lateral and vertical adjacent surfaces. According to the present invention, the lateral adjacent surfaces of the upper and lower parts of the body support the projecting and hollow elements, of complementary shapes, engaged respectively in one another while defining an imaginary horizontal and transverse journal axis between the two parts of the body. 
     With specific reference to the drawings, the front abutment shown in adapted to hold the front of a boot on a ski. This front abutment comprises a body constituted of two parts, namely an upper movable part 1, and a lower part or base 2 which is affixed to the ski by an appropriate means, for example, by screws. The upper movable part 1 is constituted by a molded piece supporting, at the rear, a retention jaw 3 which can be of monoblock construction, or have independent, movable, lateral retention wings. The jaw 3 is energized, when the front abutment is mounted in the position shown in FIG. 8, by means of an energization mechanism, not shown, lodged in base 2. The binding of the present invention, and the particular configuration of jaw and energization mechanism contemplated for the present invention is generally like that disclosed in copending, commonly assigned U.S. patent application Ser. No. 07/508,463, filed Apr. 13, 1990, the disclosure of which is hereby incorporated by reference thereto. 
     According to the invention, the movable upper part 1 is journalled, in the front, on the front of base 2, about an imaginary transverse axis A which is not constituted by a cylindrical rod of small diameter, as in the case of front abutments known in the art until now. The journal between the two parts 1 and 2 is in fact achieved by the mutual nesting of projecting and hollow elements provided on the adjacent lateral walls of the two parts 1, 2. As can be seen in FIG. 5, the upper movable part 1 of the body of the front abutment includes, in the front, a longitudinal opening 4 which opens into the anterior frontal surface 1a of the upper part 1 and which thus defines, in the molded piece constituting the upper part 1, two generally parallel lateral arms 5. Each of the lateral arms 5 is defined by an internal lateral surface 5a which constitutes a longitudinal surface of central opening 4. In the central opening 4 is tightly engaged, when the front abutment is mounted, the base 2 which is likewise constituted by a molded piece and which includes, in its anterior part, two generally vertical lateral walls 7. To ensure this tight nesting, the distance a between the external surfaces 7a of vertical lateral walls 7 of base 2, as shown in FIG. 4, is equal to the distance between the internal lateral surfaces 5a of arms 5 of the movable upper part 1, as shown in FIG. 5. 
     According to the invention, to achieve the journalling of the movable upper part 1 on base 2, on the external surface 7a of each lateral wall 7 of base 2, a projection 8 is provided in the form of a circle sector and an arc-shaped rib 9 which is located behind and beneath projection 8 The projection 8 in the form of a circle sector and the arc-shaped rib 9 are both centered on a single point A through which the imaginary transverse journal axis of the two parts 1, 2 of the body of the front abutment pass, once assembled. The projection 8 in the form of a circle sector includes, as shown in elevation in FIG. 1, an upper rectilinear side AB inclined from bottom to top and from front to rear with respect to the horizontal, a lower side BC in the form of an arc of a circle having center A, extending over an angle of approximately 120°, downwardly and frontwardly, and a front side AC which is inclined from top to bottom and from rear to front, while forming an angle of approximately 20° with respect to the vertical. Moreover, rib 9 has an upper surface, i.e. turned towards the projection 8, which is constituted by an arc of a circle DE which is centered at point A and which extends 
     over an angle slightly less than 90°. The center of curvature D of arc DE is located substantially at the same height as the imaginary journal axis A, while being offset towards the rear, while the end E of arc DE is located slightly rearwardly of the vertical plane passing through the imaginary journal axis A. Arc DE extends towards the front by a rectilinear part EF extending downwardly. Thus, it can be seen that the upper projection 8 and the lower rib 9 defining between them a groove 11 of width b, in the form of an annular segment centered on the imaginary journal axis A. 
     Each lateral arm 5 of the movable upper part 1 has, on the front part of its internal lateral surface 5a, hollow and projecting elements which have shapes complementary to those of the elements provided on the external surface 7a of lateral wall 7 of base 2. More particularly, as can best be seen in 
     FIG. 6, each internal lateral surface 5a has, near the anterior frontal surface 1a, an arc-shaped rib 12, in the form of an annular segment, which extends downwardly between an anterior and upper hollow part 13 and the remainder of the internal lateral surface 5a. The arc-shaped rib 12 is connected to an upper rectilinear rib 14 which follows the upper surface 15 of the movable part 1, which is inclined from top to bottom and from rear to front. The anterior hollow 13 has the shape of a circle sector and it is defined by an upper edge A&#39;B&#39;, a lower edge B&#39;C&#39; in the form of an arc of a circle centered on the point A&#39;, this edge extending frontwardly as far as the frontal surface la into which hollow 13 opens. The radius of arc B&#39;C&#39; is equal to that of arc BC of projection 8 provided on base 2 and the center A&#39; of circle sector A&#39;B&#39;C&#39; constituting the hollow 13 is placed so as to coincide with the center A of circle sector ABC which constitutes the projection 8, when the two parts 1, 2 of the front abutment are assembled as is shown in FIG. 8. The rib 12 in the form of an annular segment is defined by an upper edge merged with the lower arc-shaped edge B&#39;C&#39; of hollow 13 and by a lower arc-shaped edge D&#39;E&#39;  centered at point A&#39; and having a radius equal to the radius of arc DE constituting the upper edge of circular rib 9 of base 2. The width of the arc-shaped rib 12 is equal to the width b of groove 11 formed on base 2. 
     The extreme upper surfaces defining the projection 8 and hollow 13 and passing respectively through sides AB and A&#39;B&#39; can extend perpendicularly to the external surfaces 7a of lateral walls 7 of base 2 and to the internal surface 5a of the upper part 1 or, according to an alternative, as is shown in the drawing, they can be inclined with respect to these surfaces of an angle less than 90°, so as to constitute dovetailed assemblies. More particularly, projection 8 has, in transverse section, as is shown in FIG. 3, a rectangular trapezoid shape of height c, corresponding to the thickness of projection 8, and which is equal to the depth of hollow 13 of the upper part 1. Projection 8 has an upper surface 8a, originating from upper side AB, which is inclined downwardly and forms an acute angle with the external surface 7a of lateral wall 7. As a result, the width of projection 8 at the location where it is attached to the external surface 7a of lateral wall 7 is less than the width of its surface containing side AB. In the same way, hollow 13 in the form of a circle sector is defined by an upper surface 13a which is inclined downwardly so that the width of hollow 13 is greater in the bottom of the hollow than in the location of its opening defined between the two ribs 12 and 14. 
     By molding the upper and lower parts 1, 2 as mentioned above, the aforementioned projections, hollows, and associated surfaces can be conveniently formed unitarily with the remainder of the respective upper and lower parts. Further, by means of the aforementioned configuration, the lower part has upwardly facing surfaces and the upper has downwardly facing surfaces which, together, constitute at least a part of a means for journalling the upper part on the lower part, but which also comprises a means for vertically supporting the upper and lower parts. 
     To assemble the upper part 1 and lower part 2 of the body of the front abutment, upper part 1 is presented above base 2 as is shown in FIG. 1, so that its longitudinal axis is substantially perpendicular to that of base 2. Then upper part 1 is lowered so as to engage the front of the latter on the front of base 2 as is shown in FIG. 7. Projection 8 is then engaged in hollow 13, while the extreme lower part of rib 12 is engaged in the extreme upper part of groove 11 of base 2. Then, upper part 1 is pivoted with respect to base 2, in a clockwise direction, to bring it into its final assembly position shown in FIG. 8, in which the longitudinal axis of upper part 1 is substantially parallel to that of base 2. In the course of this movement, the upper part 1 turns around projection 8 constituting a sort of pivot and the rib 12 of the upper part 1 engages progressively in the circular groove 11 which has the same width and the same radius of curvature as rib 12. By this maneuver, latching is achieved between the projecting and hollow elements, of complementary shapes, provided on the two parts 1, 2. This maneuver makes it possible to likewise achieve the coupling between the movable element or elements of jaw 3 supported by the upper part 1 and the force transmission element forming part of the energization mechanism lodged in base 2. 
     To render the upper part 1 and base 2 of the body inseparable, their linkage is ensured by means of a height adjustment screw 15 vertically extending through a notch 16, open towards the front, formed in the upper part 1 of the body and screwed into a vertical tapped hole 17 formed in a vertical bushing 18 mounted in base 2. Screw 15 includes an upper head 15a and a lower collar 15b engaged, respectively, above and below a wall 16a in the lower portion of notch 16. As a result, screw 15, which is retained vertically and laterally as soon as it is screwed into hole 17, makes it possible, by screwing it more or less, to vary the inclination angle of the upper part 1 with respect to base 2 and, consequently, the height of the jaw 3 with respect to the base. 
     In final position, as is shown in FIG. 8, the two parts 1, 2 of the body are assembled between them in the front, because of the mutual latching of the hollow and projecting elements provided on the two parts 1, 2 and, at the rear, by the height adjustment screw 15. The only movement allowed then for the upper part 1 is a rotation movement about the imaginary horizontal and transverse axis passing through the merged centers A, A&#39; of projections 8 and hollows 13 in the form of a circle sector. For any other movements, there is a total interdependence between the two parts 1, 2 of the body. 
     The dismounting of the two parts 1, 2 is carried out by operations in the reverse direction, after removal of the height adjustment screw 15. 
     Although in the preceding description it has been indicated that each lateral wall 7 of the base supports, on its external lateral surface 7a, an upper projection 8 in the form of a circle sector and a lower arc-shaped rib 9 defining between them a groove 11, and that each lateral arm 5 of the movable upper part 1 has, on its internal surface 5a, an upper hollow 13 and a lower arc-shaped rib 12, the reverse arrangement could be adopted, i.e., there could be provided, on the front of each internal surface 5a of upper part 1 an upper projection in the form of a circle sector, similar to projection 8, and a lower arc-shaped rib, similar to rib 9, defining between them a groove in the form of an annular segment similar to the groove 11 and by providing correlatively on the external surface 7a facing base 2, a hollow similar to hollow 13 and an arc-shaped rib similar to arc-shaped rib 12. 
     In the same way, in the preceding description the lower part or base 2 engages, in front, between two arms 5 of the movable upper part 1. However, the invention could likewise apply to a front abutment mounted in the reverse, i.e., in which the movable upper part 1 would be engaged between two lateral and vertical arms of lower part 2. In this case, the projecting and hollow elements, whose mutual nesting ensures the actualization of imaginary journal axis A, would be provided on the external surfaces of the lateral walls of upper part 1 and on the internal surfaces of the lateral arms of lower part 2.