Ski suspension

A suspension for skis including a pair of vertically spaced plates, the lower plate being mounted to the ski and the upper plate having a boot attached thereon. Compression springs interposed between the suspension plates absorb shock and impact, and the suspension includes lateral alignment stabilizers and pivoted links interconnecting the plates which permit vertical movement but restrain the plates against lateral angular variations whereby the pressure applied to the ski edges is maintained during vibration absorbing. A foam material between the plates damps the suspension action and protects the interior components.

BACKGROUND OF THE INVENTION 
Downhill skiing imposes substantial shock, impact and vibration upon the 
skier's legs as terrain is traversed. Such impacts and vibration often 
injure the skier's leg and knee joints, and such injuries limit the 
duration of a skier's enjoyment of the sport. 
Various accessories and attachment for skis have been proposed which would 
absorb shocks and impact occurring during skiing and typical devices of 
this nature are shown in U.S. Pat. Nos. 2,330,731; 2,350,130; 3,917,298; 
and 4,139,214. However, prior art devices capable of absorbing vibration 
and impact during skiing do not provide the necessary stabilization and 
"feel" required by the skier during maneuvers, and ski suspension devices 
have not come into popular use. 
Known ski suspension devices have utilized springs and air cushions for 
absorbing shocks and vibration imposed on the ski, but existing ski 
suspensions have not been capable of effectively absorbing such forces 
while also providing effective ski control, particularly with respect to 
the regulating of the desired forces to the lateral edges of the skis 
during maneuvering. 
It is an object of the invention to provide a suspension for skis which is 
of concise configuration, capable of absorbing and damping vibration and 
impact imposed on the ski without transfer to the skier's legs, and which 
does not adversely interfere with the control of the ski. 
An additional object of the invention is to provide a ski suspension which 
is relatively economical to manufacture, stabilizes the ski and improves 
tracking during turns. 
An additional object of the invention is to provide a ski suspension which 
effectively absorbs and damps vibration and yet permits lateral forces 
applied to the suspension by the skier to be effectively transmitted to 
the ski edges. 
In the practice of the invention the ski suspension comprises an assembly 
which is attached to the upper surface of a conventional downhill snow ski 
at the center of the ski at the location at which the bindings are 
normally attached. The suspension assembly includes a pair of upper and 
lower plates normally maintained in spaced parallel relationship, the 
lower plate being affixed to the ski, and the upper plate having the 
binding attached thereto. 
The upper and lower plates have a plurality of compression springs 
interposed therebetween for absorbing the vibrations imposed on the ski 
and lower plate during use, the springs preventing the shock forces and 
vibrations from being transmitted to the upper plate. Posts are interposed 
between the plates to aid plate alignment and the posts and upper plate 
are relatively moveable to prevent the posts from interfering with the 
shock absorbing action. 
A plurality of links or hinges are interposed between the upper and lower 
plates which permit the plates to move relative to each other in a 
vertical direction, but maintain a predetermined lateral orientation 
whereby the skier's weight can be effectively transferred to the ski edges 
as is necessary during maneuvering. The links include a pivot operative 
about an axis fixed with respect to the lower plate, and an upper pivot 
axis adjacent the upper plate is relatively displaceable with respect to 
the upper plate in the direction of the length of the upper plate parallel 
to the lateral edges of the plates and ski. This mounting of the links 
prevents interference of the hinges with respect to the relative vertical 
movement of the plates while permitting lateral forces imposed upon the 
upper plate by the skier to be directly transferred to the lower plate and 
the ski edges. 
A compressible elastic foam material is also located between the plates 
having a plurality of voids or chambers defined therein. The chambers 
receive the compression springs, posts and hinges and the foam material 
functions as a gasket to protect these components from direct contact with 
snow and moisture, and simultaneously, the foam material functions as a 
shock absorber and damper between the plates which does not interfere with 
the shock absorbing aspects of the suspension, but provides improved 
"feel" and control during relative plate movement. 
The aforedescribed relationships of components results in a ski suspension 
capable of effectively reducing shock and vibration which would otherwise 
be directly imposed upon the skier's legs and joints, and the suspension 
reduces leg fatigue and joint and back strain. The ski suspension 
stabilizes the ski reducing the effort normally exerted by leg muscles for 
turning and maintaining balance, and a smoother and firmer ride results, 
tracking is improved during turning for improving maneuverability and 
speed, and as fewer vibrations and impacts are transmitted to the bindings 
fewer occurrences of inadvertent binding release result.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT 
A ski suspension constructed in accord with the inventive concepts for only 
a single ski is shown in the drawings, it being understood that both skis 
of a pair would be equipped with an identical suspension. While the 
suspension of the invention is particularly utilized in downhill skiing 
wherein maximum shock and vibrations occur, it is possible to use the 
suspension for other types of skis, such as of the cross country variety. 
In the drawings a single downhill ski 10 is illustrated having an upper 
surface 12 and parallel longitudinal edges 14, which are usually metal 
clad for forming a cutting edge for penetrating the snow during 
maneuvering, as is well known. 
The suspension assembly 16 includes an upper plate 18 and a lower plate 20. 
Each of the plates is generally planar in configuration and the lower 
plate 20 includes ends 22 and parallel lateral edges 24, while the upper 
plate includes ends 26 and parallel lateral edges 28. As is readily 
appreciated from the drawings, the longitudinal length and axis of the 
assembly 10 is parallel to the lateral edges 24 and 28. The plates 18 and 
20 are usually formed of metal, but may also be formed of a high strength 
epoxy with glass fiber reinforcement as such material is strong, rigid and 
light. 
Holes 30 are provided in the lower plate 20 to provide means for attaching 
the lower plate firmly to the ski upper surface 12 by bolts, screws or 
other conventional fasteners 32, FIG. 2. Holes 34 are defined in the upper 
plate 18 to receive the screws 36, FIG. 1, of the bindings for attaching 
the bindings to the upper surface of the plate 18. As best apparent from 
FIGS. 1 and 4, the bindings consist of the typical toe clamp 38 attached 
to the plate 18 by screws 36, and the heel clamp 40 is attached to the 
plate by screws 36'. The particular construction of the bindings 
constitutes no part of the present invention and the suspension disclosed 
may be utilized with all types of ski bindings. 
The plate 18 is superimposed above the plate 20 wherein the lateral edges 
24 are located directly below a lateral edge 28 as is apparent from FIGS. 
5 and 6. The plates 18 and 20 are in a spaced parallel relationship to 
each other, and a predetermined angular relationship is desired to be 
maintained between the plates 18 and 20 in a direction lateral to the 
longitudinal lengths of the plate and suspension assembly. Usually, this 
orientation is the maintaining of the plate 18 parallel to the plate 20 in 
both a longitudinal and lateral manner. However, it is foreseeable that it 
may be desirable to have a slight angular deviation between the plates 
laterally, to accommodate right and left feet, and such in instance the 
plates 18 and 20 would be generally parallel in the longitudinal 
direction, but the plates would have a slight angular orientation with 
respect to each other in the lateral direction. 
The spacing between the plates 18 and 20 is maintained by a plurality of 
coiled compression springs 42, eight of which are shown in the disclosed 
embodiment. The compression springs 42 are each provided with a 
positioning stud 44, FIG. 3, extending from the upper and lower plates 
into the spring coils in order to maintain the orientation of the springs, 
and the length of these studs is short so as not to engage when the 
suspension is under heavy compression. 
Alignment between the plates 18 and 20 is augmented by the use of four 
headed columns 46 each having a lower end which is attached to the lower 
plate 20. The columns 46 may be threaded into threaded holes defined in 
the plate 20 and the upper ends of the columns slidably extend through 
holes 48 defined in the upper plate 18, and enlarged hexagonal heads 50 
overlap the upper plate and limit the extent of the separation of the 
plates. A compression spring 52 surrounds each of the four columns 46 
bearing upon the plates 18 and 20 endeavoring to separate the plates, and 
the springs 52, in addition to the springs 42 tend to bias the plates away 
from each other. 
With a ski suspension it is important that the skier be able to control the 
application of weight to the ski edges 14, and such weight distribution is 
achieved by the lateral leaning of the body so as to vary the direction of 
the application of forces on the binding and to the ski. In order to 
transfer the desired ski edge loading through the bindings to the ski 
edges 14 the assembly suspension 16 utilizes a plurality of lateral load 
transfer links or hinges 54 interposed between the plates. In the 
disclosed embodiment three such links 54 are disclosed. 
The links or hinges 54 each consist of a flat plate 56 of a substantially 
rectangular configuration as will be appreciated from FIGS. 2 and 5 which 
forms a lever. A cylindrical pivot shaft 58 is affixed to the lower end of 
the plate 56, while a cylindrical pivot shaft 60 is attached to the upper 
end of the plate. The lower shaft includes end portions 62 which extend 
beyond the link plate end edges, and in a similar manner the upper pivot 
shaft includes end portions 64 which also extend beyond the plate ends. It 
is to be noted from the drawings that the end portions on each pivot shaft 
are spaced apart a distance substantially equal to the width of the 
assembly 10, and this spacing provides the optimum application of lateral 
forces. A bracket 66 is affixed to the lower plate 20 and includes holes 
68 for rotatably receiving the end portions 62 of the shaft 58, and in 
this manner the lower end of the link plates 56 is pivotally connected to 
the lower plate 20. 
A bracket 70 is attached to the underside of the upper plate 18, and the 
bracket 70 includes elongated slots 72 defined therein for receiving the 
ends 64 of the pivot shaft 60. The slots 72 extend in the longitudinal 
direction of the plate 18 and the suspension assembly and permits movement 
of the pivot shaft 60 in the direction of the suspension assembly length 
and also supports the shaft in a pivotal manner. As will be appreciated 
from the drawings, the axes of the pivot shafts 58 and 60 are 
substantially perpendicular to the length of the plates 18 and 20 and 
suspension assembly. Accordingly, as the distance separating the plates 18 
and 20 varies the links 54 hinge about the pivot shafts 58 and 60, but 
because the pivot shaft 60 is capable of sliding within the bracket slots 
72 the links do not interfere with the relative movement of the plates 18 
and 20 toward and away from each other. However, the links 54, prevent a 
twisting of the plates 18 and 20 in a lateral direction about the central 
longitudinal axis of the suspension, and the links 54 maintain a 
predetermined angular relationship between the plates 18 and 20 in the 
lateral direction. The links 54 permit the skier to transfer his weight to 
the ski edges 14 by lateral leaning and the links will maintain the 
desired predetermined angular orientation of the plates in the lateral 
direction regardless of the spacing between the plates. 
A resilient synthetic foam material 74 is interposed between the plates 18 
and 20 and functions as a gasket to protect the suspension components 
located between the plates from snow, water, and foreign matter and the 
foam material also serves to absorb and damp the transfer of vibration and 
forces between the plates and. As will apparent from FIG. 3, the foam 
material 74 extends fully between the plates, and a plurality of voids 76 
are defined in the foam material for receiving the springs 42, the voids 
78 receive the columns 46 and springs 52, and the larger rectangular voids 
receive the link hinges 54 and the associated brackets. As will be 
appreciated from FIG. 4, at its lateral edges the foam material is 
continuous and fully encloses the springs, columns and link hinges. 
In operation, a ski assembly 16 is mounted upon each ski 10 at the normal 
location of binding attachment, the lower plate 20 being attached to the 
ski while the bindings 38 and 40 are attached to the upper plate 18. The 
ski boot, not shown, is mounted in the bindings in the normal manner and 
the skier's weight is carried by the plate 18. As the plate 18 is 
supported by springs 42 and 52 the skier's weight is supported upon the 
springs and as the skier traverses the run vibrations imposed upon the ski 
will not be directly transmitted to the skier, but will be absorbed and 
damped by the springs 42 and 52. Additionally, the presence of the foam 
material 74, which will always be under a state of compression, damps 
movements of the springs and also helps to support the skier's weight. 
The ski suspension 10 does not affect the control imposed upon the skis by 
the skier as the presence of the link hinges 54 are very effective in 
permitting the skier to transfer lateral forces through the ski boot to 
the ski edges 14. The mounting of the link hinges 54 permits such lateral 
loading without adversely affecting the movement of the plates 18 and 20 
toward and away from each other, and the construction, location and 
utilization of the components permits a ski suspension to be provided 
which is of low profile, attractive, high strength and yet effective for 
its intended purpose. 
It is appreciated that various modifications to the inventive concepts may 
be apparent to those skilled in the art without departing from the spirit 
and scope of the invention. For instance, the slots 72 could be formed in 
lower brackets 66 rather than upper brackets 70, the spring location studs 
44 could be replaced by recesses in plates 18 and 20 for receiving springs 
42, and the springs 52 could be eliminated as their use is optional. Also, 
it is to be appreciated that the disclosed suspension could be 
incorporated into the sole of a ski boot with few modifications.