Binding for cross country skis

Abstract: Integrated attachment for cross country skis, which is suitable to connect ski boots (17) to the surface (35) of a cross country ski (34), the ski boot (17) comprising a main anchorage pin (20) clamped resiliently in a slot (25) included in the integrated attachment (10), with which (10) there cooperates a contrast thrust spring means (33), the attachment (10) comprising a support (11) with wings (36) that bear an oscillation pivot (12) positioned at a right angle to the ski (34) and supporting an oscillatory connector (26) with which the ski boot (17) can oscillate vertically, the oscillatory connector (26) extending before and behind the oscillatory pivot (12) and having an L-­ shaped form with its vertex on the axis of the oscillation pivot (12) situated in a part below the boot (17) and under the front part thereof (17),the contrast thrust spring means ((33) opposing the oscillation movement of the oscillatory connector (26) by acting on a first frontal side (127) of a frontal body (27).

Description: This invention concerns a binding for cross country skis. To be more exact, the invention concerns a binding to connect cross country ski boots to cross country skis, the binding enabling the boots to be guided lengthwise and laterally and to be continuously anchored to the skis during the lifting of the boots from the skis. Bindings are known which comprise coordinated systems consisting of a special conformation of the sole and/or heel of a cross country ski boot cooperating with an appropriate anchorage plate fitted to or installed in a cross country ski. Systems are known in particular which include in the soles of cross country ski boots one or more lengthwise and substantially parallel grooves which cooperate with relative ribs on the anchorage plates. These known types have developed side by side with the evolution of cross country ski-ing techniques and have become established together with modern cross country ski-ing steps. Among the cross country ski-ing steps which are of greater and greater interest to ski-ing fans and sportsmen is the so-called skater's step because of the advantages it confers. This step consists in alternating the directional action on one ski, whereas the thrust action is produced with the other ski, which diverges by a given angle from the direction of advance, with the vertex of the angle upstream, and is caused to run along a given distance towards the outside of the ski track. This step has the same name as the step performed mainly with a thrust in skating, as the movements are alike in both cases. However, the skater's step requires a lengthwise control of the ski and at the same time a suitable anchorage of the boot to the ski, so that the lateral thrust at an angle is transmitted fully to the ski and therefore leads to greater stability and speed. CH-C-619.147 discloses an embodiment which does not enable the thrust to be fully and properly transmitted nor the ski to be properly controlled. US-A-3,907,319, US-A-4,235,452 and DE-A-2.626.309 disclose a binding which, if used alone, is unsatisfactory for lateral control of the ski and is worthwhile substantially for the alternating step alone. US-A-4,082,312 discloses binding which makes lateral control of the ski possible only when the heel of the boot is rested on the ski itself and only provided that no snow has entered between the boot and the ski. DE-A-2.937.347 and FR-A-2.443.853 disclose a binding which provides a satisfactory lateral control of the ski but raises problems when snow enters between the boot and the ski and therefore does not allow the boot to be fully anchored to the ribs included on the ski. Italian patent application IT 83360 A/86 discloses an anchorage for the sole of cross country ski boots which consists of grooves cooperating with mating ribs included on the sole of the boot and on a plate included in, or forming part of, a cross country ski, whereby the grooves diverge towards the heel of the boot and the vertex of the groove is located in an area between the attachment of the bridge in the front part of the boot and the toes of the foot of the skier. This embodiment is satisfactory for a good lateral control of the skis only when the boot is rested on the ski, but not when the boot is lifted to carry out the step, since the guides remain fixed to the ski and the boot is guided only by a connecting point and is always subject to the risk of snow entering between the sole of the boot and the ski. Italian patent application IT 83374 A/86 discloses a frontal tip for cross country ski boots, whereby the sole is conformed as desired and a cavity is included in the front lower part of the boot and lodges an elongated replaceable element, which in anchored so as to be able to oscillate about a pivot within the cavity, the pivot being positioned at least below the toes of the foot of the user. This embodiment has brought about an improvement in the use of cross country skis since the binding is made resilient and can absorb and restore the thrust forces and at the same time can ensure a good lateral anchorage between the toe-cap and the boot. All the solutions acited above, however, are unsatisfactory for a plurality of reasons. They require the inclusion, on the upper face of the ski, of raised elements which cooperate with grooves included in the soles of the boots. These raised elements not only are the cause of installation and maintenance costs but also entail considerable problems of separation of the sole from the guides when there are strong lateral thrusts as in the skater's step, and become useless when the boot is lifted from the ski because, as is well known, these guides are fixed to the ski. In the case of IT 83374 A/86 too the lateral control has to be supplemented with other means as the solution proposed is, in fact, not adequate for prolonged use with the skater's step. Furthermore, the entry of snow creates problems of engagement and correct use. Moreover, the known proposals entail general and specific problems linked to the weight, dimensions and overall bulk and to the scanty facilities for fitting, maintenance and replacement of the bindings and adaptation thereof to the selected step. FR-A-2.537.010 includes an attachment for cross country ski boots which includes a hook element that is anchored to the point of the boot and oscillates therewith about a pivot; this oscillation is resisted by resilient means positioned in front of the hook element. This teaching of FR-A-2.537.010 enables the boot to be controlled properly only axially and not laterally; this prevents proper use of the attachment in the event of the use of the skater's step. Therefore in the current situation of cross country skiing there are various systems of boots and relative bindings, the special nature of which maximizes a perfect relationship between the athletic action and the efficiency of the equipment so as to improve performance in general. But the athletic technique has outclassed the performance of the equipment by introducing the skater's step. Improvements or revisions of the equipment have been applied in an attempt to adapt it to the new requirement, but the outcome has been substantially inadequate for the athletic innovations. The result is that a product is lacking on the market which has been conceived with new criteria able to meet the new requirements in a satisfactory manner. The greatest problem to be overcome is that of being able to guide the boot in each phase of performance of the athletic action, especially when the foot is separated from the ski. In all the existing bindings the boot is secured to the binding through a connection point located at the toe, and the boot is guided by means of some ribs fixed to the ski, which are inserted into corresponding grooves in the sole of the boot. These ribs provide an excellent guide only when the boot is pressed on the ski during sliding, but when the boot is lifted in thrusting or during the skater's step, there are strong lateral thrusts which may cause separation of the sole from the guide with twisting of the foot and heavy stresses on the binding and boot, causing strain and/or breakage of the latter. Moreover, with evolution of the materials there is a tendency to make lighter skis, which will therefore become much weaker, above all where the binding is fixed to the ski. It is well known that all the bindings are secured to the ski with three screws, the holes of which are of a standard size. When it is desired to replace the binding, the screws have to be unscrewed and screwed up again, with a resulting weakening of the ski, caused by enlargement of the holes for the screws, at the point of greatest stress. To regain a satisfactor fixture of the binding to the ski, it is necessary to make use of special adhesives. Another fact is that the special bindings are suitable for use only with their particular soles, thus creating the problem of non-interchangeability between the existing systems. A binding is therefore needed which, owing to its particular capability of miniaturization, performs the function of adapting the sole and the various systems to each other. Another factor which cannot be overlooked is the overall bulk. The existing bindings project to a smaller or greater extent from the toe of the boots and also laterally to the ski sometimes, thus causing problems of functioning, all the mechanisms being exposed to infiltration of snow and ice. The invention obviates to the mentioned problems by providing a binding having the features discolsed in claim 1, while the dependent claims describe variants of the invention. According to the invention the shortcomings described above are overcome with the oscillation of the binding on the upper part of the cross country ski by providing a support which extends frontally and below the sole of the boot. This support extends mainly below the sole of the boot and is contained in a hollow within the sole; it can be fixed to the ski or be extracted, for instance by dismantling a suitable clamping means. The support comprises below the boot two vertical wings, which are arranged along the boot and have the functions of a lateral guide and support. On these wings is fitted a support and oscillation pivot substantially parallel to the surface of the ski and at a right angle to the lengthwise axis of the ski. The lengthwise position of this oscillation pivot in relation to the front part of the boot determines the best arrangement for the skater's step or for the alternating step or for intermediate values between the these two extreme steps. A swinging element is fitted so as to be able to swing about a swinging pivot. This swinging element has a substantially L-shaped form and extends in front of the boot in a vertical direction and below the boot in a horizontal direction and can be lodged in a seating located in the sole. In front of the swinging pivot the swinging element includes a frontal body to support the front part of the boot. This frontal body rises above the upper surface of the ski and forms a support for the sole of the boot. A block is hinged on the frontal support body and, being resiliently resisted, serves to clamp between itself and the frontal support body the main anchorage pin included in front of the sole of the boot and forming one single body together with the sole. Resilient means cooperating with the surface of the ski or with the surface of the support and at least with the frontal support body are included to resiliently counteract the swing of the swinging element. The frontal support body is the front terminal part of the front body of the swinging element. At least one rear body forming part of the swinging element and hinged to the front body is included in a retracted postion in relation to the swinging pivot. The swing of this rear body is resiliently counteracted in relation to the frontal support body. The rear body includes an inclined slot with a terminal seat to house a secondary anchorage pin. This secondary anchorage pin is parallel to the main anchorage pin and solidly fixed to the sole and passes advantageously through the seat provided below the sole. The main anchorage pin and secondary anchorage pin may be connected to each other with a connection buried in the sole of the boot. The inclination of the slot is such that, as it approaches the surface of the ski, it becomes more distanced from the swinging pivot. Other frontal bodies anchored to the cited frontal body may also be included. When the sole causes the swinging element to rotate about the swinging pivot, the front body rotates on its own pivot and tends to thrust the secondary anchorage pin towards the main anchorage pin, thus improving the anchorage of the boot to the binding. The attached figures are given as a non-restrictive example and show the following: Fig.1 gives a side view of a binding according to the invention; Fig.2 gives a side view of the binding of Fig.1 with the boot and sole cut away lengthwise; Fig.3 shows the binding of Fig.1 cut away lengthwise; Fig.4 shows a section of the binding of Fig.1 along the line A-A of Fig.3; Fig.5 shows a lengthwise section of the beginning of the movement of lifting the boot in connection with the binding of Fig.1; Fig.6 shows a lengthwise section of the lifting of the boot in cooperation with the binding according to the invention; Fig.7 show diagrams of the idea of the solution. A binding 10 is fitted to a cross country ski 34 above the upper support surface 35 of that ski 34. The binding 10 comprises substantially a support 11 equipped with lateral wings 36 extending below the ski boot and positioned advantageously within a seat 19 included in the sole of the boot. The wings 36 comprise at their front end a swinging pivot 12, to which a swinging element 26 is anchored so as to be able to swing in a vertical plane along the ski. The wings 36 form also a lateral guide for the swinging element 26, which has a substantially L-shaped conformation with the vertex of the L coinciding with the axis of the swinging pivot 12. In the embodiment shown the swinging element 26 consists of at least two bodies, which are respectively a front body 27 anchored to and able to swing on the swinging pivot 12 and at least one rear body 29 anchored to and able to swing on the front body 27 by means of a second pivot 37. The front body 27 comprises a first front portion 127 extending vertically above the ski 34 and a second rear portion 227 extending substantially parallel to the ski 34. In the embodiment shown the rear body 29 is anchored terminally to the rear portion 227 of the front body 27. The rear body 29 includes an inclined slot 30, which becomes farther distanced from the swinging pivot 12 as it approaches the upper support surface 35 of the ski 34. A seat 39 is located at the inner end of the slot 30 and houses a secondary anchorage pin 21. Thrust spring means 31 are included between the front and rear bodies 27-29 and tend to keep those bodies 27-29 aligned and cooperating with the upper support surface 35 of the ski 34. A resilient extension of the front body 27 may be provided instead of the rear body 29 and will include the seat 39 for the secondary anchorage pin 21. As we said above, the front body 27 is supported on and can swing about the swinging pivot 12 and is guided laterally by the wings 36 of the support 11. The lengthwise position of the swinging pivot 12 in relation to the toe of the boot 17 conditions the type of preferred step to be carried out. Examples of positioning are shown in Figs.7a and 7b. The swinging pivot 12 may be positioned further forward or further backward, depending on the specific type of step which the specific installation of the binding is intended to assist. If the support 11 together with the relative swinging element 26 is replaced, or if only the swinging element 26 is replaced, it is possible to change the arrangement of the ski speedily. Thus the embodiment of Fig.7a, in which the swinging pivot 12 is positioned forwards, is advantageous for the alternate step, whereas the embodiment of Fig.7b, in which the swinging pivot 12 is positioned backwards and approximately under the boot 17, is advantageous for the skater's step. As we said above, the sole 18 in the example shown has at its front and below itself a seat 19 with which the main anchorage pin 20 and secondary anchorage pin 21 cooperate. In this example both the anchorage pins 20-21 pass through the seat 19 and secure the boot 17 to the binding 10. Rigid lateral connecting elements may be included between the main anchorage pin 20 and the secondary anchorage pin 21; if so they will be buried in the sole 18 and will reinforce the anchorage pins 20-21 and also the front part of the sole 18. The front body 27 rises at its front to provide a frontal support edge 28 on which the frontal part of the sole 18 rests with its seat 19. In a high portion of the first front portion 127 of the front body 27, where the frontal support edge 28 is located, there is a seat 25 which accommodates the main anchorage pin 20, whereas the secondary anchorage pin 21 is housed in the inclined slot 30 of the rear body 29 or, according to a variant, of the resilient extension of the second rear portion 227 of the front body 27. The seat 25 is provided partly in the frontal support edge 28 and partly in a block 22. The block 22 is thrust resiliently against the frontal support edge 28 by a thrust spring 32 and is supported by the first front porition 127 of the swinging element 26 in such a manner that it can swing on a pin 23. Thus, the block 22 is supported by the front body 27 by means of the pin 23. The block 22 comprises an actuation notch 24 suitable to apply the force that causes the block 22 to rotate about the pin 23, thus opening the seat 25 and releasing the main anchorage pin 20. Counteracting resilient means are included between the support 11 and the first front portion 127 and cooperate at least with the first front portion 127 on the front body 27. In the example shown the counteracting resilient means are constituted by a resilient block 33, made of a resilient material and which rests on the base of the support 11, acting in this case against the front body 27 and the block 22. The support 11 is secured at its front by a clamping cap 14, which serves also to oppose and house the counteracting resilient means 33. By removing the counteracting resilient means 33 it is possible to have access to a screw 15 which in this example secures the clamping cap 14. When the clamping cap 14 is removed, the support 11 can be withdrawn by being moved forwards along the binding 10. In fact, the support 11 comprises at its rear end a connection plate 16, which is inserted into a seat 38 formed by a positioner bracket 13, which is secured to the upper side 35 of the ski 34 by screws. The connection plate 16 may be buried in the ski 34 during construction of the latter and the seat 38 may be produced in this way. In the example shown the wings 36 of the support 11 cooperate with the upper surfaces of the positioner bracket 13 in clamping and stiffening the assembly. Accurate workmanship of the seat 38 and connection plate 16 makes possible very precise lateral anchorage, while lengthwise anchorage is provided by the frontal screw 15, which secures the clamping cap 14. The rear body 29, which can swing about a pivot 37, is included, as we said earlier, on the terminal part of the second rear portion 227 of the front body 27; a thrust spring means 31 operates between the front 27 and rear 29 bodies. When the boot 17 is positioned on the ski 34 and there is no action on a vertical plane (see Fig.3), the front body 27 rests on the support 11, whereas in this case the rear body 29 rests on the upper side 35 of the ski 34. The sole 18 with its own seat 19 rests on the frontal support edge 28 or else on the front body 27 and rear body 24, while in the situation of Fig.4 the sole rests laterally also on the ski 34. When the vertical movement of the boot 17 begins and before the swinging element 26 starts rotating about the swinging pivot 12 by overcoming the resistance of the counteracting resilient means 33, the rear body 29 (see Fig.5) rises slightly. By rising, the rear body 29 thrusts the secondary anchorage pin 21 further into the seat 39 in the slot 30 since the seat 39 tends to be displaced, thus reducing the distance between the seat 25 of the main anchorage pin 20 and the terminal seat 39 of the inclined slot 30. Thus, while the boot 17 is rotating vertically, the terminal seat 39 for the secondary anchorage pin 21 tends to approach the seat 25 that houses the main anchorage pin 20. In this way a better anchorage and stiffening of the boot 17 and a better frontal and lateral engagement of the same 17 are achieved. While the boot 17 continues rotating vertically (see Fig.6), the front body 27 starts rising, whereas the frontal support edge 28 is lowered since the resistance of the counteracting resilient means 33 is overcome. To dismantle the assembly it is enough to rest the sole 18 on the ski 34, act on the actuation notch 24 to open the slot 25 and extract the boot 17 vertically, so that the anchorage pins 20 and 21 leave their respective seat 25 and terminal seat 39. If the binding 10 has to be dismantled, it is enough in this case to remove the counteracting resilient means 33, unscrew the frontal screw 15, remove the clamping cap 14 and withdraw the support 11 with the swinging element 26 above it. In this way it is easy to replace the binding 10 with another binding in which the swinging pivot 12 is positioned geometrically further forward or backward than in the binding used previously. The fitting and dismantling of the counteracting resilient means 33 are very simple and easy. Variants are possible, for instance, by providing on the rear body 29 further rear bodies, each of which is anchored to the preceding rear body and comprises an inclined slot 30 cooperating with further secondary anchorage pins, the whole serving for a further control of the boot.

Claims: A combination of a binding (10) for cross country skis (34) which is suitable for connecting ski boots (17) to the surface (35) of the cross country skis (34), and the relative cross country ski boot (17), the ski boot (17) comprising a first anchorage pivot (20) which is integral to the toe of the boot (17) and is suitable for being clamped by means of a clamping element (22) in a first seat (25) included in the binding (10), the binding (10) being further provided with resilient means (33) suitable for exerting a progressive resistance to the movement of raising the ski boot (17), whereby the binding (10) comprises a support element (11) rigidly connected to the ski (34) and equipped with a pair of wings (36) able to form a guide so as to prevent transverse movements of the ski boot (17), the wings (36) supporting a second pivot (12) located, in operation, below the sole of the boot (17), the boot (17) being able to swing about the second pivot (12), and whereby the binding (10) comprises a swinging element (26) which can swing about the second pivot (12) and which includes a first front elongate body (127) extending forwards in relation to the second pivot (12) and forming a wall of the first seat (25) and which includes also a second rear elongate body (227) extending rearwards in relation to the second pivot (12) and contacting the sole of the boot (17), the resilient means (33) exerting a resilient force against the first elongate body (127), which opposes the swinging movement of the swinging element (26), the first front body (127) being substantially vertical to the ski (34) and the second rear body (227) being substantially parallel to the ski (34), the second swinging pivot (12) being located at the vertex which connects the first and second bodies (127-227), a frontal supporting edge (28) which supports advantageously the front part of the sole (18) being included in the first body (127). A combination as in Claim 1, in which the wings (36) of the support (11) extend lengthwise to form a lateral guide for the swinging element (26). A combination as in Claim 1 or 2, in which the wings (36) extend below the sole (18) of the boot (17) towards the heel of the same. A combination as in any claim hereinbefore, in which the angle at the vertex between the first front body (127) and the second rear body (227) is determined according to the predominant athletic action. A combination as in any claim hereinbefore, in which the clamping element (22) is anchored in such a way that it can swing, while being resiliently opposed, on a pivot (23) and is supported by the first front body (127). A combination as in any claim hereinbefore, in which at least one resiliently opposed third rear body (29) is fitted so as to be able to swing behind the second rear body (227). A combination as in Claim 6, in which the third rear body (29) with a controlled resilience is included behind the second rear body (227). A combination as in any claim hereinbefore, in which an inclined slot (30) having a terminal seat (39) to house a secondary pin (21) is included in the third rear body (29). A combination as in any claim hereinbefore, in which the inclined slot (30) is open at its upper end and becomes more distanced from the swinging pivot (12) as it approaches the ski (34). A combination as in any claim hereinbefore, in which the secondary anchorage pin (21) is an integral part of the sole (18) of the boot (17). A combination as in any claim hereinbefore, in which the sole (18) comprises a seat (19) to accommodate the binding (10). A combination as in any claim hereinbefore, in which the support (11) comprises at its front a removable clamping cap means (14). A combination as in any claim hereinbefore, in which the support (11) comprises at its rear end a connection plate (16) which can be withdrawn lengthwise to the ski (34) and which cooperates with a seat (38) formed by a positioner bracket (13).

Inventors: CALLEGARI MARIO, CALLEGARI, MARIO
Applicants: CANSTAR ITALIA SPA, CANSTAR ITALIA S.P.A.
Application year: 1989
Main classification: A63C9
IPC codes: A63C9