Ski brake with increased resiliency between brake actuator and brake blade

A ski brake has a main spring element mounted upon the upper surface of a ski and resiliently biased into an operative position when the ski is released from the ski boot to bring into play at least one brake element, e.g. a blade. In order to protect the brake against impact with stones or the like, an additional spring element is provided between the actuator, which includes a pivotal member received in a mounting plate on the upper surface of the ski, and the blade or brake element so that the latter can yield on impact while retaining its braking function to prevent free flight of the ski.

FIELD OF THE INVENTION 
The present invention relates to a device for braking the free flight of a 
ski upon release of the ski from a ski boot and, more particularly, to a 
brake of this type which remains functional upon impact of the brake 
element with a foreign body. 
BACKGROUND OF THE INVENTION 
As described more fully in the above-identified application, a ski which is 
released from a ski boot on a slope can engage in free flight and, at high 
speeds, poses a danger to other skiers. For this reason it has been 
proposed to provide a ski with an automatic brake which is retained in its 
inoperative position by an application of the ski boot against a ski, e.g. 
against a spring force tending to bias an actuator into an operative 
position. The actuator may be engaged by the toe or heel of the ski boot 
when the latter is properly received in the ski binding. 
The actuator is generally provided with one or two brake elements which are 
constituted as blades and swing from their inoperative positions in which 
they permit ordinary skiing into operative positions in which they engage 
the ground and prevent free flight of the ski when the actuator is 
released by the ski boot. 
Such devices are termed hereinafter generically as ski brakes and generally 
have an actuator which is biased under a primary spring force from the 
inoperative position toward the operative position, in a mounting plate 
which can be affixed to the upper surface of the ski. 
In one such ski brake, which is mounted behind the binding in a bearing or 
journal arrangement, the pivot axis includes an acute angle with the 
longitudinal axis of the ski and the basic spring force is generated by a 
torsion spring which acts upon a blade-like brake element. 
In another conventional construction, leaf springs are secured at their 
forward ends to the ski and at their rearward ends tend to bend upwardly 
when they are unloaded. Upon loading by the ski boot, these spring 
elements are urged toward the upper surface of the ski to swing the blades 
into positions generally parallel to the ski edges as described in 
Austrian Pat. No. 299,036. Other ski brakes are described in Austrian Pat. 
No. 280,867 and 210,804 although these devices are somewhat more remote 
from the present invention than the prior-art devices described above and 
hence require no detailed discussion. Austrian Pat. No. 305,844 describes 
a ski brake having a spring which, upon release of an actuator, rotates a 
shaft extending transverse to the ski, about the shaft axis to bring the 
blade into play. 
German published application (Offenlegungsschrift) No. 2,417,279 describes 
a ski brake which is mounted by a support plate on the upper surface of 
the ski. In one recess of this support plate, a round-cross-section wire 
is pivotally journaled and is formed as a pivot shaft. One end of the 
circular-cross-section wire forms a brake spur while another region of the 
wire is bent into a retaining hoop, the free end of the hoop being formed 
as a second shaft journaled in a further recess of the support plate. It 
is important in this construction that the two journaling recesses in the 
support plate be exactly parallel, a factor which increases the 
fabrication cost and causes differences with respect to mounting or 
operation if not fulfilled. These two journalling recesses impart an 
elastic prestress to the circular-section wire so that the braking spur 
automatically springs into the operative position when the wire is 
released by the ski boot. 
OBJECTS OF THE INVENTION 
It is the principal object of the present invention to provide a ski brake 
which extends the teachings of my above-identified copending application. 
It is another object of the invention to provide an improved ski brake 
whereby disadvantages of earlier systems may be avoided. 
Still another object of the invention is to protect a ski brake against 
impact with foreign objects. 
It is a further object of the invention to improve the transition between 
the brake element or blade of a ski brake and its spring-loaded actuator 
so that more effective braking is obtained obtained under a wide variety 
of environmental conditions and even in the presence of various hazards. 
SUMMARY OF THE INVENTION 
These objects and others which will become apparent hereinafter are 
attained in accordance with the present invention, in a ski brake which is 
preferably of the stirrup shape described in the above-identified 
copending application with a pair of brake elements or blades which 
straddle the opposite edges of the ski in the operative position and which 
consist of a wire bent into a U-shape and distorted upon depression 
against the surface of the ski by the ski boot so as to provide the 
primary prestress biasing the brake elements into their operative 
position, but which can use other types of actuators, wherein between the 
primary spring-biased actuator which is movably mounted on the ski and the 
brake element or blade, there is provided at least one further elastic 
element (preferably a spring) whose spring effect is superimposed upon the 
primary spring action and reduces the maximum spring force which is 
applied to the primary spring element. 
This arrangement ensures that, for example with a sudden impact of the 
brake element or blade against a foreign object, e.g. a stone or the like, 
that an overload will not be applied to the basic spring system so that 
the normal brake operation will be adversely affected. 
Assume a rigid connection between the actuator and the brake blade, i.e. a 
system in which a transition elastic system according to the invention is 
not provided. When the primary spring is in its fully stressed condition, 
an impact of this nature may increase the primary spring force and 
overload the brake, e.g. causing damage thereto or permanent deformation 
of the actuator or primary spring element. 
With the system of the present invention, however, such impacts are 
absorbed by yielding at the secondary spring element or elastic member. 
Consequently, the second elasticity enables the braking effect, because 
the brake element can be more responsive to environmental conditions, to 
be markedly improved.

SPECIFIC DESCRIPTION 
In all of the embodiments described below it should be noted that the point 
of the invention is the transition between the actuator and the blade 
element and that other aspects of the ski-brake construction, its mounting 
plate, the use of a toggle arrangement and even the blade construction are 
fully disclosed in the above-identified application which is hereby 
included by reference. Only the elements germane to the present 
improvement and the operation of such elements have been described here. 
In FIG. 1 I have shown a ski brake for a ski 5 which has, mounted upon the 
upper surface 5a thereof, a plate 6 formed with recesses 6a and 6b in 
which a pair of outwardly and downwardly diverging pivot portions 4 of a 
stirrup-shaped spring wire 4 are received. 
The spring wire 2 has an elongated loop-shaped bight 3 which lies in one 
plane, the offset portions 4 projecting from this plane. A tread plate 9 
is pivotal on the mounting plate 6 and bears upon the bight 3 of the 
stirrup-shaped member 2. When the bight 3 is depressed toward the surface 
5a of the ski, e.g. by stepping with the ski boot upon the tread plate 9, 
the offset portions 4 are rotated in the counterclockwise sense 
represented by the arrows 4a to swing a pair of blade-shaped brake 
elements 1 upwardly to lie along the longitudinal edges of the ski 
generally parallel to the surface 5a. 
Since the offset portions 4 are not coplanar with the bight 3, however, and 
are confined in the recesses 6a and 6b, the depression of the bight 
applies a primary spring force which tends to swing the bight upwardly and 
hence biases the offset portions 4 for rotation in the opposite sense, 
thereby swinging the brake elements 1 downwardly into their operative 
position from their inoperative position illustrated as described in the 
aforementioned copending application. 
In their operative position the brake elements or blades 1 straddle the ski 
and project downwardly below the snow-engaging surface of the ski to brake 
free flight of the latter. 
In FIG. 1 the transition between the actuator 3, 4 and the blade 1 is 
formed by an elongated loop 7 of the spring wire 2 which provides an 
additional elastic effect. As can be seen from FIG. 5, a similar elastic 
effect can be obtained when, instead of the loop 7, a spiral or 
like-shaped bend 8 is provided at the transition region. The loop extends 
into a wire portion 2a which can be embedded in the blade 1. The 
additional spring element in FIG. 1 is represented at 16 and in FIG. 5 at 
12. 
The systems of FIGS. 1 and 5 function similarly as described, it being 
noted that any impact upon the blade is cushioned by deformation of the 
additional spring element 16 or 12 to reduce the force applied to the 
primary spring element 3, 4 of the actuator 2, 9. 
A further embodiment is shown in FIG. 2 in which the additional spring 
element is formed by a continuation sleeve 11 securing the thin wire 
portion 2a embedded in the blade 1 to the stirrup-shaped member 2. Sleeve 
11 and thin wire 2a both contribute resiliency to the system and the 
sleeve 11 is preferably of an elastic material such as rubber. The portion 
2a and member 2 have different moduluses of elasticity. 
In the embodiment of FIG. 3 the thin wire 2a is formed at one of its free 
ends with a coil spring 17 which is fitted over one tightly hugs the free 
end of the thick spring wire 2. The spring 17 here provides a secondary 
spring action and may frictionally grip wire 2 or can be soldered, welded 
or otherwise fixed at the free end of the coil spring to the wire w. 
Another coil spring arrangement is shown in FIG. 4, in which the wire 2 is 
spaced from wire 2a', both being of the same thickness, by a gap 13 
bridged by the coil spring 17. The confronting ends 14 and 15 of the wires 
2 and 2a may here by formed with plates receivable between turns of the 
coil spring 17 so that the spacing between the ends of the wires may be 
varied. 
Of course, it is not essential that the spring-supported ends of the wires 
be embedded in the plates 1, since the blades may simply be fastened 
externally to these wires. Furthermore, other spring elements such as leaf 
springs can be substituted for the coil springs shown and described and 
can fasten the wire 2 to the blade 1.