Patent Application
20240316438
This invention relates to the toe unit of release bindings used in alpine ski touring, also known as “AT bindings”. More particularly, this invention relates to such toe units which grasp the toe of the user's footwear and permit pivotal motion about the toe in upwardly forward and downwardly rearward directions generally parallel to a longitudinal axis of a snow travel aid, when the footwear heel is detached from the snow travel aid.
Alpine touring bindings allow the heel of the user's footwear (such as a ski boot) to be latched to a snow travel aid (such as a ski), for sliding downhill (the “downhill mode”) and allow the heel to be released for walking and climbing (the “touring mode”). Release bindings allow the footwear to release from the snow travel aid when in the downhill mode, in case of a fall. When in the touring mode, the user may climb or walk with a great degree of freedom since the footwear is pivotally engaged with the aid near the toe of the footwear while the heel of the footwear is free to move upward and downward relative to the aid. A historical collection of such bindings can be viewed in the “Virtual Museum of Backcountry Skiing Bindings” at www.wildsnow.com, authored by Louis Dawson.
Alpine touring bindings that take advantage of the fact that modem alpine touring boots have a rigid sole are called “pin bindings”. With pin bindings it is unnecessary to provide a bar, plate or other arrangement connecting the toe and heel units, as is the case with many other alpine touring bindings (see patent publications EP0199098, EP0519243, EP1559457, and AT402020). Unlike other release bindings, lateral release of pin bindings is provided at the heel, not the toe.
The pin binding system comprises a toe unit which has a set of laterally oriented jaws. Such jaws open and close in a direction generally perpendicular to the longitudinal axis of a ski or other snow travel aid so as to grasp opposite sides of the toe region of the user's footwear. The axis of rotation of each jaw in the pin binding system is oriented generally parallel to the longitudinal axis of the snow travel aid.
The toe unit is mounted at an appropriate location on the upper surface of the snow travel aid. A separate heel unit is mounted at a particular region on the upper surface of the snow travel aid rearward of the toe unit, the location of which is dictated by the length of the footwear sole. The heel unit typically comprises two protrusive shafts (e.g. embodied as respective legs of a singular U-shaped heel pin) which extend forward to engage opposite sides of a fitting placed over a cavity in the rear of the footwear heel. Under forward release conditions, the pin shafts are forced apart against spring pressure to disengage from the fitting.
Lateral release in pin binding systems is provided by the heel unit being rotatable on a generally vertical post, from which the aforementioned pin shafts extend forwardly to receive the footwear heel fitting. Adjustment of the lateral release is done by altering resistance to rotation of the heel unit. While the jaws of the toe unit open, they do so with a relatively high degree of force resistance in order to provide a constrained fulcrum that acts as the pivot point for the lateral release feature of the binding system. Thus, the toe unit of a pin binding is not considered a lateral release toe unit such as is employed in other binding systems. An example of a binding system in which the toe unit is a lateral release toe unit containing jaws for grasping the toe is described in EP1907078B1. The latter binding system operates differently from most pin binding systems because the toe unit rather than the heel unit provides lateral release.
There are biasing elements (typically coiled compression springs) in most pin bindings that are incorporated into the jaws, and thus rotate therewith about the pivot points of the jaws, to provide the grasping force exerted by the closure thereof onto the ski boot. There have been several attempts to minimize the number of biasing elements at the toe which traditionally, for example as seen in EP0199098, had four biasing elements. Recent bindings have reduced the number of biasing elements to two by several methods (U.S. Pat. No. 10,391,383B2, EP2815794B1), with the beneficial result of weight savings and assembly simplification. Minor adjustments needed to calibrate bindings often require the additions of shims, and such addition of shims on each side to maintain symmetry is a disadvantage of having biasing elements on both jaws.
One disadvantage of a jaw whose biasing element is integrated therein, and thus rotates therewith about the jaw's pivot axis, is that the moment arm distance from the centerline of the biasing element, along which the bias force is exerted, to the pivot axis of the jaw has a fixed length, which moment arm dictates the leverage that the biasing element provides to generate jaw torque, which translates directly into grasping force on the ski boot. If the grasping force versus the distance between the teeth of the jaws is plotted for these bindings, it is characterized by a steep spike of force in between the ski position (closed jaws) and the release position (open jaws), which means that the energy absorption is not optimised.
To switch between touring and downhill modes with pin binding systems, it is necessary to rotate the heel unit so that the heel pin either points forwardly to engage the footwear heel (downhill mode) or points rearwardly away from the footwear heel (touring mode). When the heel pin points away from the footwear heel, the footwear heel is free to move upward and downward relative to the toe of the footwear that is pivotally engaged to the toe unit. In order to switch from downhill mode to touring mode it is necessary to either forcibly release heel the pin from the fitting on the footwear heel (not recommended) or disengage the jaws of the toe unit from the footwear toe, so that the footwear can be lifted fully free from the entire binding system, whereupon the heel unit may be rotated to the touring mode position. Subsequent re-entry of the toe into the toe unit is then required. This process is time consuming and can be difficult to do in deep snow or on a steep slope, for the reasons discussed below.
The jaws of a pin binding system toe unit open by spreading outwardly away from a longitudinal midline axis of a snow travel aid. Each jaw has a lower arm that extends laterally inward towards the midline axis from a respective pivot point of that jaw, and an upper arm that stands upright from the lower arm at an outer end thereof. Each lower arm has an inner end that abuts the inner end of the other lower arm in an end-to-end manner, typically with a convexly rounded terminus of one lower arm engaged in a concavely rounded recess of the other lower arm to permit relative rotation of the jaws to one another about their respective pivots. In each of the open and closed positions, the inner ends of the jaw's lower arms are in a position of over-center relation to a lateral reference axis that intersects the pivot axes of the two jaws. The biasing elements are typically integrated into the lower arms of the two jaws and bias the inner ends of the two lower arms against one another, which in either over-center position, acts to bias the jaws toward the respective one of either the fully opened or the fully closed position. Each jaw, near an upper terminus of the upper arm thereof, has a generally conical “tooth” which laterally engages a corresponding concave fitting embedded on the side of the toe region of the footwear sole. When the jaws are closed and engage their respective teeth in these concave fittings, the toe is retained adjacent to the upper surface of the snow travel aid, but the footwear, when not also latched by the heel unit, is able to pivot upwardly forward and downwardly rearward about a pivot point at the tooth-engaged fittings to facilitate walking and climbing.
A catch is provided to prevent the jaws from inadvertently opening as a result of application of force sufficient to overcome the spring pressure, and is used when the toe unit is in the touring mode. The catch is usually disengaged in the downhill mode so as to not prevent release of the footwear during a fall. The user enters the toe unit by carefully positioning the footwear toe between the jaws so that the teeth will engage the toe fittings when the toe is depressed on a “trigger point” of a mode lever that, when depressed at said “trigger point”, drives movement of the jaws past their over-center position in a closure direction of the jaws. This process of entering the binding and achieving engagement therewith is generally called “step-in.” This step-in manoeuvre requires patience and practice, as the “trigger point” of the mode lever is typically around 10-12 mm wide, denoting a relatively narrow and unstable platform for supporting the footwear toe and ensuring that the concave fittings in the footwear are aligned with the jaw teeth during closure of the jaws. One design characterized by a wider than conventional trigger point is shown in EP3878528, which proposed a range width of 30-40 mm wide at the trigger point to provide a more stable platform for stepping into. U.S. Pat. No. 11,338,192 also has a trigger point slightly wider than traditional bindings.
In typical pin bindings, demonstrating another shortcoming among at least a majority of the prior art, all of the pivots for the jaws and the mode lever are of a riveted type to make them secure against possible unfastening. This renders the binding difficult or impossible to disassemble for service or recycling, the latter of which requires decoupling of parts of mismatched material composition.
Given the above summarized state of the art, one object of the present invention is to improve the assembly and construction of ski binding toe units.
Another object of the present invention is to make ski binding toe units easier to use by simplifying step-in for users.
Another object of the present invention is to make ski binding toe units absorb more energy between the closed position while skiing and the open position at release.
Another object of the present invention is to make ski binding toe units more sustainable by allowing easier disassembly for service or recycling at end of life.
Among preferred embodiments of this invention are novel design elements that, alone or in combination may denote, or contribute to, fulfillment of one or more of the foregoing objects of the invention, and in doing so, achieve an improved ski binding toe unit whose benefits or improvements may include simpler construction, easier step-in, more energy absorption and/or more sustainable manufacturability. In one particularly beneficial embodiment of the invention, a ski binding toe unit for a pin binding has a single central location for the biasing element that does not rotate with the jaws, but rather maintains a uniformly horizontal orientation throughout the full range of jaw movement, and houses the biasing element within the mode lever. This achieves several advantages relative to at least a bulk of the prior art, in that there is a reduction in the components needed, and it is possible to construct a ski binding toe unit with as little as a single biasing element. In addition to such reduction in componentry, fewer shims are needed for calibration, and a reduction in weight may be achieved, since biasing elements are generally made from heavier materials like steel. Additionally, the housing of the biasing element in the mode lever enables a wide step-in platform that allows the ski boot to be well supported rotationally under the toe to eliminate the potential for misalignments of the boot and the binding while trying to engage the two.
Since the biasing element remains in a consistent orientation independent of the jaw position, the moment arm distance from the line of bias force exerted by the biasing element to the centers of the two jaw pivots varies, meaning that the leverage that the biasing element applies to the jaws also varies advantageously between the open position and the closed position. Through this, a much flatter top profile can be achieved in the plotted curve of the grasping force versus distance between teeth between the closed and open position. Theoretically, to optimize energy absorption for a ski binding, the plotted force-distance curve would be completely flat between these two states, and this aspect of the invention provides more energy absorption due to the varying leverage length when compared to traditional pin bindings which have a fixed length for leverage, since the jaw and the biasing element rotate together about the jaw pivot in such conventional designs.
Preferred embodiments of the invention are assembled using threaded pivots, at least for the jaws, which threaded jaw pivots can be uniquely implemented to prevent unwanted loosening without, or in supplement to, conventional uncoupling prevention measures, like set screws and thread lock compound. By using threaded pivots of opposing left-hand and right-hand thread orientation to one another, or by inserting two threaded pivots of matching thread direction in oppositely pointing orientations, Applicant has found that the threaded pivots can self prevent loosening thereof in the loading conditions seen in typical use of pin bindings. In addition to this novel loosening/backout prevention, the use of threaded pivots allows the binding to be easily disassembled for service and for end of life recycling of all the individual components.
According to one aspect of the invention, there is provided an apparatus for holding a footwear toe to a snow travel aid having a longitudinal axis denoting a travel direction of said snow travel aid, the apparatus comprising:
According to another aspect of the invention, there is provided an apparatus for holding a footwear toe to a snow travel aid having a longitudinal axis denoting a travel direction of said snow travel aid, the apparatus comprising:
In embodiments comprising said pair of backout preventers, said backout preventers may be selected from a group comprising: respective deposits of thread lock compound on the respective threads of the threaded jaw pivots, respective nylock nuts engaged with the respective threads of the threaded jaw pivots, respective set screws engaged radially against the threaded jaw pivots, or respective blockers each positioned in at least partially overlapping relationship a head of a respective one of the jaw pivots to block axial displacement thereof in a backout direction corresponding to loosening of the jaw pivot threads.
According to yet another aspect of the invention, there is provided apparatus for holding a footwear toe to a snow travel aid having a longitudinal axis denoting a travel direction of said snow travel aid, the apparatus comprising:
The above and other objects, aspects, features and advantages of the invention will become apparent from a consideration of the subsequent detailed description presented in connection with the accompanying drawings.
The accompanying drawings, which are incorporated in and constitute part of this disclosure, illustrate exemplary aspects that, together with the written descriptions, serve to explain the principles of this disclosure. Numerous aspects are particularly described, pointed out, and taught in the written descriptions. Some structural and operational aspects may be even better understood by referencing the written portions together with the accompanying drawings, of which:
Aspects of the present disclosure are not limited to the exemplary structural details and component arrangements described in this description and shown in the accompanying drawings. Many aspects of this disclosure may be applicable to other aspects and/or capable of being practiced or carried out in various variants of use, including the examples described herein.
Throughout the written descriptions, specific details are set forth in order to provide a more thorough understanding to persons of ordinary skill in the art. For convenience and ease of description, some well-known elements may be described conceptually to avoid unnecessarily obscuring the focus of this disclosure. In this regard, the written descriptions and accompanying drawings should be interpreted as illustrative rather than restrictive, and enabling rather than limiting.
In the prior art toe unit 10 of
Here, the two spring plungers 8 rotate on one another during movement the jaws 14 via suitably rounded surfaces at which the two spring plungers interface with one another at a central location between the two upper arms of the jaws, where these spring plungers are captured by the mode lever 24 at a rear end thereof, and thus move up and down with the mode lever 24 during user manipulation thereof. Tour lever 30 is pivotably connected to the mode lever 24 at an opposing front end thereof, at a location residing across a pivot point of the mode lever 24 from the spring plungers 28. Accordingly, the tour lever 30 can be pressed down to rotate mode lever 6 in a direction lifting the spring plungers 8 to a raised over-center position in which the biasing elements force the jaws toward the open position in which the teeth 16 are spaced wide enough apart to allow the ski boot 20 to be positioned for engagement, as can be seen in
Having described the prior art of
In typical fashion, the inventive toe unit 110 comprises a chassis 134 for flush placement atop a ski 112 and fastening of the toe unit thereto via mounting screws 136 tightenable through suitably located fastening holes of the chassis 134. At each side of the chassis 134, a pair of jaw lugs 138 angle upwardly from the chassis 134 to accommodate pivotable support of a respective one of the jaws 14 between the two jaw lugs 138 on a respective threaded jaw pivot 140 that is inserted through aligned holes in the two jaw lugs 138 and the respective jaw 114. Referring to
The mode lever 124 is pivotably supported on the chassis 134 at a pair of mode lever lugs 144 that stand upright from the chassis 134 at or near a front end 146 thereof. A stem 148 of the mode lever 124 is received between these mode lever lugs 144, and projects forwardly therefrom and beyond the front end 146 of the chassis 134. A threaded mode lever pivot 150 is installed laterally through aligned holes in the mode lever lugs 144 and the mode lever stem 148 to enable pivotable movement of the mode lever 124 about a lateral axis situated in front of the jaws 14. Near a terminal front end of the mode lever 124, the tour lever 130 is pivotably coupled to the mode lever 124 by a threaded tour lever pivot 152 of parallel relation to the mode lever pivot 150, whereby relative pivoting between the mode lever 124 and the tour lever 130 is permitted. Given this layout of the jaws 114, jaw lugs 138, mode lever 124, mode lever lugs 144, and tour lever 130, it will be appreciated that the general opening and closing movement of the jaws 114, and control thereof via manipulation of the mode and touring levers 124, 130, is not inconsistent to those of the prior art described in the background above, and so the step-in procedure detailed above in the background need not be repeated here in its entirety, and can instead be deduced by reference to such background description. Given this, the detailed description now instead turns to the particularly distinctive and beneficial novelties embodied in the inventive toe unit 10.
As already mentioned, one of these novelties is the carrying of the biasing element 126 by the mode lever 124, rather than carrying of one or more biasing elements by one or more of the jaws. As best revealed in the cross-sections of
By relocating the biasing element 126 into the mode lever 124, and omitting integration of biasing elements into the lower arms 114B of the jaws themselves, the lower arms 114B of the jaws 114 can be made relatively short, and the mode lever 124 made notably wider at the rear region thereof that now both houses the biasing element 126 and, at the topside of the mode lever, also serves as a uniquely wide trigger 122 of the mode lever 124. This wide trigger 122 serves as a stable step-in platform for the footwear toe to depress in order to engage the footwear into the to unit 110. In the illustrated embodiment, the stem 148 of the mode lever 124 embodies a majority length of the overall mode lever 124, over which the stem 148 may have a uniform width, which is of lesser measure than the greater trigger width W at the comparably wide trigger 122. As used herein, the length of the mode lever 124 refers to the dimension thereof measured in the longitudinal direction, and width refers to the dimension thereof measured perpendicularly of the length in the lateral direction. In the illustrated example, the mode lever 124 is widest at its terminal rear end, and the trigger 122 gradually increases in width W from the front end of the stem 148 to the trigger's maximum width at the terminal rear end of the mode lever 124. As shown, this flared gradual increase in trigger width W may embodied in multiple stages, first flaring outward at an aggressive angle to the stem at a proximal region 122A of the trigger nearest the stem 138, and then continuing to flare outward, but at a softer angle at a distal regional 122B of the trigger furthest from the stem at which the cross-bore 132 and terminal rear end of the mode lever 124 are embodied.
In the illustrated example, the mode lever is Y-shaped rather than T-shaped, in that the distal region 122B of the trigger is bifurcated in top plan view, and thus characterized by a forwardly recessed center notch at the terminal rear end of the mode lever 124, where the cross-bore 132 is thus open over a partial axial length of the biasing element, whereby a central portion of the biasing element 126 is exposed, though this need not necessarily be the case in other embodiments. The Y-shaped mode lever was found to have superior strength to a T-shaped design, though both are encompassed within the scope of the present invention. In the illustrated example, using the laterally measured distance between the centers of the two jaw pivots 140 as a reference distance D (
Meanwhile, in further distinction over the bulk of the prior art, as few as one single biasing element 126 can be used rather than two or four biasing elements typically found among bindings of the type shown in
Because the biasing element 126 is carried by the mode lever 124, and not by either jaw 114, the moment arm distance from the centerline of the biasing element 126 to the center of each jaw pivot 140 (i.e. the perpendicular distance from the centerline of the biasing element 126 to the lateral reference axis 154) is not fixed like in the prior art, as can be visually appreciated from comparison of
In order to go ski touring with the toe unit 110 engaged on the toe of the ski boot 20 without the heel connected, the jaws 114 must be blocked from opening. If the ski boot 20 is torqued about a vertical axis, the jaws 114 are designed to open at a defined torque, overcoming the bias force of the biasing element 126, to provide a lateral release mechanism. In order to switch the toe unit 110 to touring mode while the toe is engaged, the user lifts the tour lever 130 upwards at the front of the mode lever 124, and via relative pivoting of the tour lever 130 about the tour lever pivot 152, brings a rounded rear end 130A of the tour lever 130 into interfering contact with an abutment 158 at the front of the chassis 134, which abutment 158 may protrude forwardly relative to a remainder of the front end 146 of the chassis 134. A user must then continue to lift the front end of the tour lever 130 to allow a bit of vertical flex of the mode lever 124 to occur, and to shift the tour lever's rounded rear end 130A forwardly past the first point of interference with the abutment 158 to ride over the abutment into contact with the ski 112, which provides a locking effect.
That said, an alternative solution for loosening/backout prevention of the two jaw pivots 140 was also uncovered in Applicant's development and experimentation of the novel toe unit 110, which is the use of one jaw pivot with a right-hand thread, and one jaw pivot with a left-hand thread. For example, referring to the exploded rear perspective view of
Without being limited to any particularly theory as to why this use of oppositely threaded jaw pivots was found to preventing loosening of either threaded pivot, it is posited that because user applied force is exerted on the mode lever 124 during the step-in process to drive closure of the jaws 114, the closing movement of the jaws 114 is believed to impart more friction on the jaw pivots 140 than the opening movement of the jaws 114, and so for every repetition of a jaw-closure and subsequent jaw-reopening (an open-close cycle, for short), there is more frictionally-induced rotational effect on each jaw pivot in the respective jaw's closing direction than in the opening direction. If a conventional right-hand thread were used on the forwardly inserted right jaw pivot of
While principles of the present disclosure are described herein with reference to illustrative aspects for particular applications, the disclosure is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, aspects, and substitution of equivalents all fall in the scope of the aspects described herein. Accordingly, the present disclosure is not to be considered as limited by the foregoing description.
This application claims benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application No. 63/454,407, filed Mar. 24, 2023, the entirety of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63454407 | Mar 2023 | US |
