Ski brake

This ski brake comprises two pivoting brake arms disposed symmetrically on either side of the ski and having each an operative portion movable between a lower braking position and a raised retracted inoperative position, the opposite ends of the brake arms carrying a control pedal hinged to bent extensions of the opposite ends of the brake arms. When the pivoting brake arms are in their retracted inoperative position above the ski top and the pedal is pressed against the ski top, the axes of the bent extensions form an obtuse angle having its vertex directed away from the brake shoes carried by the operative portions of the brake arms. These brake arms are on the other hand so shaped that when inoperative the brake shoes are retracted inwards of the ski edges, above the ski top. When the ski boot is lifted off the brake control pedal, the latter is urged by spring means to its raised position while both brake shoes are divaricated and lowered to their operative position clear of the ski edges.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a ski brake of which the braking shoes are 
retracted to a flush-fitting position so that they do not project from the 
side edges of the ski. 
2. The Prior Art 
The most popular ski brakes comprise a pair of pivoting brake arms disposed 
on either side of the ski and pivoted on top thereof about a transverse 
axis. These arms are interconnected at one end by a cross member acting as 
a control pedal, a return spring constantly urging said arms to pivot 
towards their positions in which their end opposite said one end is 
lowered with respect to the bottom surface of the ski, so as to penetrate 
into the underlying snow layer. Ski brakes of this character consist as a 
rule of metal wire and in this case the transverse pivot means may consist 
of a pair of elbows formed integrally with the pivot arms, respectively. 
When the ski boot is fitted to the ski, it exerts a pressure upon the 
control pedal, thus maintaining the operative portions of the brake arms 
in a raised or retracted position. However, in this case the operative 
portions of said arms project outwards in relation to the ski edges, and 
under certain circumstances this may prove particularly detrimental. 
Therefore, certain ski brakes have been so designed that the operative 
portions of their pivoting arms are moved towards each other above the ski 
top when they are in their raised and retracted position. Various means 
have been proposed for maintaining the pivoting arms in this retracted 
position. 
Thus, the French Patent No. 2,272,695 corresponding to U.S. Pat. No. 
3,989,271 issued Nov. 2, 1976 discloses a ski brake in which the brake 
arms are retracted by tensioning the metal wire constituting said arms, by 
using stretching means in the form of an overcenter device adapted to be 
flattened by the ski boot pressure. However, in operation this system is 
not fully reliable, for a considerable force is required for altering the 
configuration of the brake arm wire. In fact, the stiffness of this wire 
must on the other hand be sufficient to provide an efficient braking 
action and prevent the brake arms from being distorted in case of simple 
shocks. 
In another French Patent No. 2,308,389 (application No. 76 11752) the 
movement of the brake arms to their raised and retracted position is 
obtained by exerting a pressure on a deformable plate or hinged 
quadrilateral disposed under the boot location so as to be flattened by 
the boot when the latter is fitted in position. The arrangement is such 
that when flattened this plate or hinged quadrilateral causes the two 
brake arms to move towards each other after having been raised to their 
retracted position. 
However, if the control plate is a bent blade, the latter will exert an 
excessive pressure on the boot, and this is likely to interfere with the 
boot release when the safety ski binding is operated, for instance in case 
of fall. Besides, if the control plate consists of a hinged quadrilateral, 
the assembly contemplated appears to be particularly complicated and 
expensive. Moreover, this system is scarcely reliable because its 
operation is likely to be impaired in case of icing. 
In a further French Patent No. 2,330,419 (application No. 75 34137) the 
brake arms are retracted by means of one or a plurality of cam faces 
carried for example by an auxiliary pedal. But also in this case the 
solutions contemplated are not fully satisfactory. In fact, since the 
movement of retraction of the brake arms is obtained by altering the shape 
of the metal wire constituting said arms, a considerable effort must be 
exerted thereon to this end. Moreover, this system also develops 
additional stress interfering with the normal release of the ski boot by 
the ski binding. 
On the other hand, to avoid abnormal over-all dimensions, the height of the 
control cam faces must be limited, and this is attended by a detrimental 
limitation of the retraction movement of the brake arms. 
Finally, in another known proposal the brake arm retraction is obtained by 
causing the brake arm to pivot in a bearing having its axis disposed in a 
transverse plane in relation to the ski and inclined with respect to the 
ski top surface (cf. French Patent No. 2,228,506, FIG. 11, Application No. 
73 17074). The main advantage of this system is its extreme simplicity. 
Yet, it is objectionable in that the slightest change in the brake arm 
configuration may cause this arm to rub the ski edge and possibly be 
locked thereby, since the inward and upward movements of the ski arm are 
combined into a single movement. Another inconvenience of this arrangement 
lies in the fact that to obtain a sufficient inward or retraction movement 
the pivot bearing must be located at a relatively high level, a 
requirement that cannot be met if the brake is disposed under the ski 
boot. 
It is therefore clear that all the various systems proposed up to now for 
retracting the brake arms of ski brakes have serious drawbacks. Under 
these conditions, the present invention is directed to provide a ski brake 
wherein the brake arms are retracted by using particularly simple, 
reliable and economical means; besides, the system of the present 
invention is extremely simple to operate and exerts on the boot sole a 
substantially negligible thrust. 
SUMMARY OF THE INVENTION 
The ski brake according to the present invention, of the type comprising a 
control or brake pedal fulcrumed to bent extensions of the relevant ends 
of the pivoting brake arms, is characterized essentially in that it 
incorporates bearing means in which said extensions are adapted to be 
trunnioned, and that when said pivoting arms are in their retracted 
position and overlie the ski top, and when the brake pedal is pressed 
against this ski top, the axes of said bearing means and of course also 
the bent extensions of said pivoting arms form an obtuse angle having its 
vertex opposed to the operative portions of the pivoting arms. Besides, 
the configuration of these pivoting arms is such that their operative 
portions are disposed inwardly of the ski edges. 
It is another feature characterizing the ski brake of this invention to 
provide resilient return means constantly urging the brake pedal to its 
raised or braking position when the pressure exerted thereon by the ski 
boot is released. Possibly, the resilient return means may at the same 
time urge the brake arms to their operative position. 
With the arrangement of the present invention it is possible to obtain a 
variation in the relative spacing of the operative portions of the brake 
arms and consequently the drawing-in thereof to the retracted position, 
due to the pivotal movement of the control pedal with respect to said 
arms. Thus, when the brake arms are retracted and the brake pedal is 
pressed against the ski top, the operative portions of the brake arms 
remain recessed with respect to the ski edges. On the other hand, the 
upward movement of the brake pedal, as a consequence of the release 
thereof by the ski boot, is attended automatically by a divarication of 
the operative portions of said arms so that they can clear freely the ski 
edges during their downward travel. 
A more detailed description of the mode of operation of the ski brake 
according to the instant invention will now be given with reference to the 
accompanying drawings showing diagrammatically by way of illustration 
typical forms of embodiment thereof, it being understood however that 
various modifications and changes may be brought thereto without departing 
from the basic principles of the invention, as will readily occur to those 
conversant with the art.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The ski brake illustrated in FIGS. 1-6 of the drawings comprises a pair of 
pivoting arms 1 of rigid metal wire, adapted to be disposed on either side 
of the corresponding ski S. These arms 1 are pivoted in a pair of bearings 
2, respectively, carried by a mounting plate 3 adapted to be secured to 
the top surface of the ski in a position such that the axis X X' of said 
bearings extends at right angles to the ski axis. 
The pivoting arms 1 are disposed symmetrically and the pivot portion 4 of 
each arm consists of a bent or elbow section engaging the relevant bearing 
2. It will be seen that these bearings 2 are so arranged that the pivot 
portions 4 are relatively free therein. 
The pivot intermediate portion 4 of each arm 1 defines therein two main 
portions, namely an operative portion 5 adapted to penetrate into the snow 
in the braking position and a control portion 6 adapted to be actuated by 
the corresponding ski boot when the latter is fitted into the ski. Due to 
their pivotal movement possibility, these two arms 1 can assume two 
different end positions, namely a waiting position, in which the operative 
portions 5 thereof are retracted or recessed above the ski top, and an 
operative position, in which the same portions 5 project downwards, beyond 
the ski bottom surface (see FIG. 1). Preferably, the outer ends of the 
operative portions of the brake arms are provided with brake shoes adapted 
to penetrate into the snow to improve the braking efficiency. 
The control portions 6 of brake arms 1 carry a control or brake pedal 8 
constituting the only connecting member therebetween. This pedal 8 may 
consist of a relatively thick metal plate provided with a large aperture 9 
for the purpose of preventing snow from being trapped between the ski and 
the brake pedal 8 when the latter is folded down onto the ski. Adjacent 
its edge 10 opposite the brake shoes 7 the brake pedal is pivoted to bent 
extensions 11 of the relevant ends of the pair of brake arms. For this 
purpose, bores are formed in the thickness of the pedal 8 to constitute 
bearings in which the bent extensions 11 of the brake arms are trunnioned. 
According to an essential feature characterizing the ski brake of this 
invention, the axes of the pedal bearings, and those of the extensions 11 
of the pivoting arms, form with each other an obtuse angle .beta. when the 
pivoting arms are retracted or recessed above the ski top and the control 
or brake pedal itself is caused to bear flat on the ski top (see FIG. 5). 
The value of this angle may lie between 120.degree. to 170.degree., and a 
preferred value is 150.degree.. The vertex 0 of this angle is directed 
away from the brake shoes 7. Besides, the shape of the pivoting brake arms 
is such that in this fully retracted brake position the relative spacing 
e1 between the ends of brake shoes 7 has its minimum value, so that said 
ends are somewhat recessed in relation to the ski edges. 
Finally, a draw-spring 12 is provided which has one end pivotally mounted 
on base plate 3 and the opposite end attached to control pedal 8 at a 
central location 13 of the lower surface thereof adjacent the edge 9 
opposite the brake shoes 7. Thus, this spring 12 constantly urges the 
brake pedal 8 away from the ski top and when the ski boot is lifted off 
the ski it releases the pedal 8 which is thus allowed to pivot about the 
bent extensions 11 of brake arms 1. However, this spring 12 also urges the 
brake arms 1 to their operative position. 
In the example illustrated, the return spring 12 consists of resilient 
metal wire adapted to undergo an elastic deformation. However, any other 
suitable elastic return means could be substituted therefor. Possibly, two 
separate sets of resilient return means could be provided, one set acting 
upon the pivoting arms and the other upon the control pedal. 
With this arrangement, the upward movement of control pedal 8 permitted by 
the movement of the ski boot away from the ski top is attended by a 
specific movement of the two brake arms with respect to each other, and 
also by an increment in the relative spacing of the brake shoes 7. This 
spacing will thus reach a value e2 slightly greater than the ski width E 
(see FIG. 4), so that the brake shoes 7 can move freely on either side of 
the ski when the brake arms 1 move from their inoperative position to 
their operative position by pivoting in the corresponding bearings 2. 
When the ski boot is fitted in position, the reverse action takes place. In 
fact, the pressure exerted by the boot on the end portions 11 of brake 
arms 1 firstly causes these arms 1 to pivot in the direction of the arrow 
F1 (FIG. 1) to a position in which the brake shoes 7 are at a higher level 
than the ski top, which is an intermediate position corresponding simply 
to the raising of the brake shoes 7 as illustrated in FIGS. 2 and 4 of the 
drawings. 
In this intermediate position the relative spacing e2 of the brake shoes 7 
is slightly greater than the ski width E, and the brake pedal 8 is still 
raised with respect to the ski surface (see FIG. 2). However, when the ski 
boot is caused to bear again on the ski, the pedal 8 is folded down by 
pivoting as shown by the arrow F2 about the bent extensions 11 of brake 
arms 1, so that a specific movement which is the reverse of the specific 
movement described hereinabove is impressed to said brake arms. In fact, 
this reverse specific movement causes the brake shoes 7 to move towards 
each other, above the ski surface. As can be observed, during the 
retraction of the ski brake assembly the control pedal 8 is caused to 
pivot in a direction opposite the direction of the pivotal movement 
accomplished by the brake arms. 
Furthermore, when the brake pedal 8 is restored to its ski-engaging 
position shown in FIGS. 3 and 5, the relative spacing of brake shoes 7 is 
reduced to its minimum value e1 so that the shoe brakes are somewhat 
recessed in relation to the ski edges. 
The specific movement impressed to the brake arms by the pivotal movement 
of the control pedal in either direction is due of course to the oblique 
direction of the bent extensions 11 of brake arms 1 and also of the 
matching holes provided therefor in the pedal, which constitute the 
bearings for journaling said extensions. 
In fact, with this particular arrangement (i.e. the inclined position of 
extensions 11 and of the bore receiving them in the pedal) the brake shoes 
7 carried by the pivoting brake arms 1 have their minimum relative spacing 
in the position illustrated in FIG. 5. However, in the wholly theoretical 
hypothesis that the control pedal 8 might occupy the reverse position, in 
which it would again bear flat on the ski top, the brake arms would have 
their maximum relative spacing. Between these two extreme positions of the 
control pedal, the relative spacing of the brake shoes will thus vary 
continuously as a function of the value of the angle formed between the 
control pedal and the planes formed by the brake arms. 
In this respect, it will also be observed that it is only in one or the 
other of said end positions of the control pedal that the planes 
containing the two brake arms merge into each other and are parallel to 
the ski top. In fact, between these two end positions, the planes A B and 
B C containing these two arms are concurrent and constitute a dihedron 
having its aperture directed upwardly (see FIG. 6), while its edge extends 
parallel to the longitudinal center line of the ski. Now, the inner angle 
of the dihedron varies continuously as a function of the angular position 
of the brake pedal with respect to the brake arms. 
In fact, if this pedal were rotated fully about itself the bent extension 
11 of each brake arm would be shifted along the generatrices of a cone. 
But in the present instance only a limited portion of this movement is 
utilized for obtaining the desired change in the relative spacing of the 
brake shoes 7. 
It may also be pointed out that in the fully retracted brake position the 
return spring 12 is disposed very close to the ski top. Under these 
conditions, the extra force exerted on the ski boot is substantially zero. 
However, the main advantageous feature of the ski brake of the present 
invention lies in its extreme simplicity of construction and operation and 
also in its reliability under actual service conditions. Besides, due to 
its elementary simplicity, the cost of this brake is particularly low. 
Preferably, the ski brake according to the present invention is intended 
for mounting between the front and rear devices constituting the safety 
ski binding releasably retaining the ski boot on the ski. Certain 
component elements of the ski brake of this invention, notably the control 
pedal, may be lined with antifriction material such as 
polytetrafluoroethylene (Teflon) to facilitate the smooth sliding contact 
between the pedal and the ski boot during the release of the latter. 
However, the ski brake of this invention could also be incorporated in the 
safety ski binding. 
FIG. 7 illustrates a modified form of embodiment of the ski brake of this 
invention, in which the arrangement is such that the control pedal 28 is 
caused to pivot in the same direction as the brake arms 25 during the 
retraction of said arms. 
To this end, the position of the pivot means of this brake pedal is 
inverted with respect to the position contemplated in the preceding form 
of embodiment. In fact, the bores formed in the pedal for receiving the 
trunnion-like bent extensions 31 of the operative portions 26 of brake 
arms 25 are located near the pedal edge adjacent the brake shoes 27. 
Thus, when the ski boot is caused to bear on the brake assembly, the 
control pedal 28 is pivoted in the direction of the arrow F3, i.e. in the 
same direction as the brake arms. 
Otherwise, the other component elements of this modified version of the ski 
brake are arranged like those of the preceding example. In fact, the bent 
extensions 31 of the brake arms form an obtuse angle with each other, the 
vertex of this angle being directed away from the brake shoes 27. Thus, 
when the brake pedal 28 is caused to pivot towards the ski top the brake 
shoes 27 are moved towards each other above the upper ski surface as in 
the preceding form of embodiment, after the brake shoes have been raised 
to a level higher than said upper ski surface. 
Of course, when the brake pedal 28 is pivoted in the opposite direction by 
the corresponding return spring 32 attached at 33 to said pedal, the brake 
shoes 27 are divaricated and can thus clear freely the ski edges and move 
to their lower operative position. 
Of course, it will readily occur to those conversant with the art that 
other forms of embodiment, modifications and changes may be brought to 
this ski brake without departing from the basic principles thereof.