US 3805603 A
This invention is directed to a device for manually applying forward bending forces to ski bindings and thus determining the proper release settings thereof through the use of simulated foot inserted into a ski boot which in turn is secured by the ski binding. A lever arm extends upwardly from the simulated foot for connection with a calibrated torque wrench through which forward bending forces may be applied. The same device can be used to determine torsion release settings of the ski bindings simply by changing the position of the torque wrench.
Description (OCR text may contain errors)
United States Patent [1 1 [111 3,805,603 Ettlinger 1 Apr. 23, 1974 DEVICE FOR MEASURING FORWARD BEND RESISTANCE OF SKI BINDINGS Primary ExaminerJames J. Gill Assistant Examiner-Anthony V. Ciarlante ABSTRACT This invention is directed to a device for manually applying forward bending forces to ski bindings and thus determining the proper release settings thereof through the use of simulated foot inserted into a ski boot which in turn is secured by the ski binding. A lever arm extends upwardly from the simulated foot for connection with a calibrated torque wrench through which forward bending forces may be applied. The same device can be used to determine torsion release settings of the ski bindings simply by changing the position of the torque wrench.
1 Claim, 5 Drawing Figures DEVICE FOR MEASURING FORWARD BEND RESISTANCE OF SKIBINDINGS THE INVENTION This invention relates generally to new and useful improvements in instruments for measuring torque forces that may be applied to torque resistant objects and particularly seeks to provide an instrument or device for determining the forward bending release resistances and settings or adjustments of ski boot bindings.
Apparently, one of the greater risks that a skier faces, almost regardless of expertise, is the possibility of a broken lower leg bone, such as the tibia, in the event that a binding releases prematurely under either or both torsion or forward bending forces during normal skiing, thus causing an unnecessary fall, or more likely when the binding fails to release quickly enough when either abnormally high torsion or forward bending forces are applied thereto, such as may occur during contact by a ski with an object that at least temporarily prevents the ski from following its normal track at its then existing speed.
Many modern ski bindings are mechanically designed to cope with both such problems, if properly adjusted, and instruments such as that disclosed in my copending patent application Ser. No. 265,529 filed June 23, 1972, now have been developed to measure the torque release settings of ski bindings and to enable such release settings to be adjusted to reflect the factors induced by the weight, tibia structure and expertise of each individual skier.
Such instruments, however, cannot measure or deter mine the forward bend release settings of the bindingssince the forward bend forces occur about a transverse axis as compared to the-vertical axis about which the torque forces are applied. So far little or no attention has been paid to the development of any instrument or device by which the forward bendingrelease settings of ski bindings can be either accurately measured or pre set for each ski of each individual skier.
However, a device constructed'in accordance with this invention is specifically adapted to measure the resistance of a ski binding to forward bending forces and to enable the ski binding to be adjusted for forward bending release at a given or predetermined setting.
Therefore, an object of this invention is to provide a simple portable device that can be manually operated to measure and determine the forward bending release settings or adjustments of ski bindings.
Another object of this invention is to provide a device of the character stated that includes a sole plate that may be either secured to a complementary plate on the ski binding for direct measurement of the forward bending release setting thereof or may be introduced into a ski boot fastened by the ski binding, thus measuring the forward bending release setting of the ski binding through the interposed ski boot.
Another object of this invention is to provide a device of the character stated that includes an upstanding lever arm rigidly affixed to the sole plate for applying forward bending forces thereto, the upper free end of the lever arm being fitted for connection to an adjustable torque wrench having its handle aligned with and serving as an extension of the lever arm.
Another object of this invention is to provide a device of the character stated that includes an adjustable sling extending between an upper position of the upstanding lever arm and the heel of the boot fastened to the ski binding or .to the heel portion of the complementary plate fastened to the ski binding whereby forward bending forces applied to the handle of the torque wrench will be translated into lifting forces at the heel portion of the ski binding with the toe portion of the sole plate acting as a pivot.
A further object of this invention is to provide a device of the character stated in which the torque wrench fitting at the upper free end of the lever arm is so constructed that the torque wrench also can be fitted thereto for force application to the lever arm in a horizontal plane normal to the axis thereof whereby to enable the same torque wrench to apply torsional forces to the sole plate of the device and thus also determine the torsion release setting of the ski binding by the same device.
A further object of this invention is to provide a device of the character stated in which the handle of the torque wrench is of so-called floating construction whereby to permit the handle to readily self-adjust to any slight misalignment caused by improper positioning of an operators hand, thus assuring properly directed force in the desired plane.
With these and other objects, the nature of which will be apparent, the invention will bemore fully understood by reference to the drawings, the accompanying detailed description and the appended claims.
In the drawings:
FIG. 1 is a side elevation of a ski binding forward bending release testing device constructed in accordance with this invention;
FIG. la is a detail side perspective of the torque wrench fitting; v
FIG. 2 is a rear elevationthereof; 7
HO. 3 is a view similar to HO. 1 but showing the device as fitted to a ski boot and ready for attachment to a ski binding; and
FIG. 4 is a perspective, partly in section, showing the preferred construction of the torque wrench and its handle.
Referring to the drawings in detail the invention, as illustrated, is embodied in a device primarily for testing and measuring the forward bending resistance of ski bindings and includes a simulated foot generally indicated 5 having a sole plate 6 configured in plan view to fit readily within a ski boot for support by the inner sole thereof, an upstanding socket 7 positioned adjacent the heel of the sole plate 6 and a forwardly extending reinforcing gusset 8. Qbviously, the simulated foot 5 may be fabricated either as a one piece plastic or metal molding or casting or formed from separate parts rigidly secured together; An upstanding lever arm 9, which simulates a human tibia, has its lower end fitted within the socket 7 and its upper end provided with a sleeve fitting generally indicated 10 for operative connection with a torque wrench as will'be hereinafter more fully described.
A pin or bolt 11 extends transversely through the lever arm 9 below the upper end thereof and pivotally carries at one end the fixed end of a flexible wire cable 12, the free end of which is provided with a plurality of spaced beads or other fixed abutments 13 for retention within the slot of a bifurcated clip 14 privotally mounted on the other end of the pin 11.
The torque wrench fitting at the top of the lever arm 9 is of generally tubular configuration and includes a lower sleeve portion adapted to fit snugly over the exposed end of the lever arm 9, a relatively thick intermediate transverse partition 16 provided with an axial wrench stud receiving aperture 17, and an upper longitudinally extending half shell 18 provided with a radial wrench stud receiving aperture 19 complementary to that of the aperture 17 so that either of the apertures 17 or 19 may receive the operational stud 20 of a given torque wrench 21, depending upon its horizontal or vertical disposition foruse with this device. The fitting '10 is affixed to the upper end of the lever arm 9 in'such a manner that the vertical edges of the upper half shell 18 lie in orclosely parallel to the vertical plane containing the axes of the sole plate 6, the socket 7 and the lever arm 9, so that the axis of the stud receiving aperture 19 will be normal thereto in a horizontal plane. The'axis of the stud receiving aperture 17, of course, is vertical In normal use the simulated foot 5 is inserted into a ski boot 22 as indicatedin FIG. 3 and the wire 12 of the sling is passed underthe heel of the ski boot so that one i of the abutment beads.13 of its free end may be engaged with the clip l4to hold the simulated foot in place. Then the ski boot is attached to a ski 23 through bindings schematically indicated 24in the usual manher, at which point the settings of the bindings may be measured and adjusted as necessary through the use of this device.
jFo'r forward bend testing, the torque wrench 21 is inserted axially intothefitting 10 at the top of the lever ar m 9 so that the wrench stud 20 becomes engaged within the aperture 19 and forwardly directed forcesthen can be applied to the handle of the torquewrench, thus applying a lifting force to the heel of the ski boot through the sling wire 12 with the toe of the sole plate together with the front binding 24, serving as a forwardor front pivot zone. y I
- Preferably, the handle of the. torque wrench 21 should be of the floating" type as shown in FlG. 4 so that forces applied to the handle will be transmitted to the lever arm of the torque wrench at a single position,
thus avoiding-any change in the effective length of the wrenchlever arm and also avoiding the-'inadvertant imposition of force vectors in undesired directions. For this purpose the lever arm of thetorque wrench 21 is provided with an axially extending stud 25 carrying a shoulder screw 26 at its free end. The handle 27 comprises an inner rigid sleeve 28 having a transverse washer 29 rigidly affixed therewithin intermediate its ends andvan outer grip 3,0. The washer 29 fits loosely over the shank of the shoulder screw 26, thus enabling the handle 27 to float and apply force to the torque wrench lever arm only throughthe washer 29 at its free connection with the shank of the shoulder screw 26. Obviously, in use, the handle 27 should never be cocked at such an angle that the inner open end of the sleeve 28 would bind against the stud 25.
' As mentioned'above, the device of this invention also,
can beused, without change, to determine the torsion release settings of the ski bindings. For this purpose it is only necessary to loosen or release the wire cable 12 and reposition the torque wrench 21 so that it is in the horizontal plane with its stud 20 engaged within the aperture 17 of the fitting 10 rather than in the aperture 19. Here, the operator holds the upper end of the lever It has been determined by observation that the relative breaking strengths of the average human tibia when subjeced to forward bending and torsion stresses is in the ratio of about 3:1 for such stresses. This observation has led to the development of a further unique feature of the device of this invention, namely by properly proportioning the relative lengths of the lever arm 9 and that of the'torque wrench 21, the same setting of the torque wrench can be used for both forward bend and torsion release testing; Thus, if the height of the lever'arm 9 to the torque wrench aperture 19 is always twice the effective length of the torque wrench from its stud 20 to the washer 29 of its floating handle 27, this 3:1 ratio becomes established and the same setting of v the torque wrench may be used for both types of testing. The slight theoretical error introduced by the spacing between the stud receiving apertures. 17 and 19 is too minor to be of anyfpractical importance, since'the whole purpose in properly adjusting ski bindings is to set them both for forward bending and torsion release well short of the empirically determined breaking points of the tibia-involved.
in. the practicaloperation of this device the calibrations of the torque wrench settings are .keyed to published numerically tabulated recommended release settings, the values of which are different for each weight and skill classification of the skier. Once the .proper recommended release setting has been selected from the table the torque wrench .is adjusted to and locked in that setting. The ski binding initially is set to a release known by experience to be higher than that desired and the ski boot with the testdevice attached is fitted to the binding-The torque wrench is attached to the lever arm fitting 10 in the orientation desired and a loading force is-applied tothe handle of the torque wrench until it clicks, thus indicating that the ski binding setting is too high. The appropriate binding release is then loosened slightly and force again. applied throughthe torque wrench. This procedure is repeated until the binding releases before the torque wrench*clicks', thus achieving the desired release setting. These operative principles are used both for the forward bendingto the ski boot. For testing and setting this plate" type of binding it is only necessary to fit an adapter (not shown) to the bottom of the sole plate 6' of. this device for direct connection to the binding plate, since the presence of the ski boot itself is not required in order to determine either of the desired release settings of the binding.
It also should be understood that even though a torque wrench has been described as the means by which to measure the force applied to the lever arm 9, any other type of calibratable friction drag or load resistant lever element could be used in its place so long as it is capable of functioning in the same or equivalent manner.
Similarly, while the sling-forming wire cable 12 appears to be the simplest and most convenient manner of providing an adjustable restraint between the heel of the ski boot (or heel end of a plate binding) and the upper portion of the lever arm 9, any other substantially non-extensible device capable of performing the same function is deemed to be the equivalent thereof for the purpose of using the device of this invention when performing forward bend test measurements.
It is of course to be understood that variations in arrangements and proportions of parts may be made within the scope of the appended claims.
1. In a device for measuring either the forward bend release settings or the torsion release settings of ski bindings; a simulated foot including a generally horizontal sole plate that is either insertable into a ski boot attachable directly to a ski binding or attachable to the sole plate of a plate type of ski binding to which the ski boot is attachable; a generally vertical first lever arm extending upwardly from the said sole plate of said simulated foot and rigidly affixed thereto adjacent the heel end thereof; adjustable releasable means extending between an upper location on said first lever arm and either the heel of said ski boot or the heel portion of said ski binding sole plate, whichever thereof is engaged by said ski binding, whereby to restrain said first lever arm against forward pivoting; means secured to the upper end of said first lever arm for connection with a second lever arm operable either in a vertical or horizontal plane; and a second lever arm comprising a torque wrench having its load-sensing end removably connectable with said connecting means; said adjustable releasable means being maintained in its restraining condition whenever said second lever arm is positioned for operation in vertical plane and being optionally releasable from its restraining condition whenever said second lever arm is positioned for operation in a horizontal plane, the relative length ratio between said first and second lever arms being such that the same release setting of the torque wrench comprising said second lever arm is used for the determination of both the forward bend and the torsional resistance of a given ski binding once the proper setting of the torque wrench has been determined for either purpose.