[0001] The present invention relates to a screw for mountain-climbing on ice faces.
[0002] Climbers that climb up ice faces use a plurality of safety devices in order to provide
protection against falls. Amongst such devices are safety ropes, which have the purpose
of keeping the climber hanging in the case where he loses his grip on the ice face,
thus preventing him from falling. One end of said rope is secured to the harness worn
by the climber whilst the other end is secured to bodies that are fixed to the base
of the ice face or else is held manually in tension by other climbers by means of
elements of friction. During the ascent and at regular intervals, the climber uses
particular screws, which are to be engaged in the ice and to which carabineres are
anchored. The climber runs the safety rope through each ring or carabiner. In this
way, in the event of a fall, the last ring or carabiner fixed to the ice face constitutes
the ring for return of the rope, and the climber will undergo a loss of height approximately
equal to twice the length of the rope comprised between his harness and the ring for
return of the rope. This system thus enables the fall of the climber to be arrested,
so guaranteeing his safety.
[0003] Traditional embodiments of ice screws are formed by a hollow cylindrical body, externally
threaded, provided with a head portion that has means for anchoring the carabineres
and means the function of which is to facilitate engagement of the threaded portion
in the ice.
[0004] For example, the U.S. patent No.
5,782,442 relates to an ice screw made up of two metal parts which can be fitted together:
an externally threaded hollow cylinder and a lever. In particular, the lever can be
fitted to the head portion of the cylinder through a slotting element having a shape
obtained by means of a restriction of the section of the cylinder itself. The lever
has a generally elongated shape and has a hole for insertion of a carabiner and a
tuck-away lever. By acting on the lever, the climber impresses a rotation on the lever,
which pivots on the head of the cylinder. Said rotation is transmitted to the cylinder
itself through the fit described above. The lever thus has the dual purpose of facilitating
engagement of the screw in the ice and of constituting the support for the carabineres.
[0005] The document No.
US 5,118,061 relates to an ice screw having characteristics similar to those of the screw previously
described in
US 5,782,442, but provided with a third element that can be fitted to the head of the
screw. Said element has the purpose of protecting the head of the screw and of transmitting
the force impressed by the climber through a hammer during the step of insertion of
the screw into the ice.
[0006] The ice screws described above and those according to the known art present various
drawbacks. In particular, the head of the screw has a through hole in communication
with the internal hole of the cylindrical portion of the screw for the purpose of
enabling extraction, through the head itself, of the core of ice that is created within
the cylindrical portion when it is engaged in the ice. The need to have said discharge
hole on the head of the screw causes the head itself not to offer a surface of adequate
extent and shape for being struck by a hammer.
[0007] In addition, ice screws according to the known art have a head that is in general
not ergonomic being difficult to manipulate. This aspect results in a further difficulty
for the climber, who in the step of insertion of the screw in the ice, before its
thread engages, must exert a discrete pressure on the head of the screw with his hand.
Consequently, traditional screws prove difficult to insert into the ice, and frequently
an ineffective initial insertion causes momentary loss of the screw, which slides
out of the ice and drops, forcing the climber to recover it by means of the rope that
secures the screw itself to the climber, with obvious expenditure of energy.
[0008] Another defect that can be encountered in screws according to traditional embodiments
is given by the fact that in order to be able to get the screw to make a complete
turn, by acting on the lever, the climber is forced to abandon his grip on the lever
and then resume it. This involves further risks of loss of the screw, which, if it
has not yet been engaged in the ice, at the moment when the climber detaches his hand
from the lever, may drop and even be lost altogether. In addition, the climber finds
himself having to expend a lot of energy given that he finds himself having to operate
on the lever while his balance is precarious.
[0009] The ice screw forming the subject of the invention solves the problems mentioned
above, since it is easy to insert manually into the ice with a single continuous,
i.e., non-interrupted, movement.
[0010] In addition, the ice screw according to the invention eliminates the possibility
of loss of the screw since it is possible to keep it anchored to a carabiner and a
rope for the entire duration of the step of positioning, inserting and screwing into
the ice, without any further hindrance.
[0011] The subject of the invention is an ice screw comprising: a hollow cylindrical shaft
in part externally threaded; a flange fitted to the non-threaded end of the shaft,
provided with a central through hole communicating with the internal channel of the
shaft; and a supporting ring, said flange being provided with extractable means designed
for turning the screw, said means being operable manually by means of just one hand,
and said ring being free to slide and rotate on the non-threaded portion of the hollow
cylindrical shaft, between the flange and the threaded portion of the shaft, said
ring being provided with means for anchorage of a carabiner.
[0012] In particular, the shaft is formed by a hollow metal cylinder having a first free
end, designed to be inserted into the ice, and a second end, which can be fitted to
the flange. The free end of the shaft has, along its edge, a toothed profile having
the purpose of facilitating engagement of the screw in the ice.
[0013] The teeth in fact are shaped in such a way as to penetrate into the ice during the
step of screwing of the screw, removing material (ice), which is guided towards the
internal cavity of the shaft.
[0014] According to the preferred embodiment, the toothing of the screw is obtained by making
appropriate flared portions along the edge of the free end of the shaft.
[0015] A portion of the outer surface of the shaft, in a position corresponding to the free
end, is threaded, whilst the remaining part, corresponding to the other end, is generally
smooth.
[0016] At its second end, the shaft is fixedly fitted to a flange, which is to constitute
the head of the screw. The fit can be chosen from among the different types of fit
traditionally used. For example, the flange can be fixed to the shaft by means of
a force fit that envisages the use of keys or metal catches. In general, said fit
envisages that the shaft will engage in the flange so as to project just from one
side of the flange itself.
[0017] The head of the screw (flange) has a generically cylindrical shape with an external
diameter greater than the length of its generatrix. The internal hole of the head
and the internal cavity of the shaft constitute a single passage open at the two ends
of the screw. The surface of the head that is on the opposite side of the shaft has
a convex profile. Provided on said surface is a groove of length equal to the external
diameter of the head of the screw, which at the external edge of the head is joined
to two diametrally opposite flared portions present on the lateral surface of the
head itself, said flared portions being parallel to the generatrix of the head.
[0018] The groove and the flared portions define a space designed to receive a lever having
an arched profile, characterized by the same radius of curvature as that of the convex
surface of the head of the screw. In particular, one end of the lever is hinged to
the head of the screw in a position corresponding to one of the two flared portions
in such a way that the lever itself may assume two configurations, corresponding to
two different positions thereof. In a first, closing, configuration, the lever is
received within the groove in such a way as to mate with the bottom and side surfaces
that define the groove itself. In this configuration, the top surface of the lever
and that of the head of the screw define a continuous surface, without any sharp edges,
and the lever intercepts the discharge hole of the screw. The lever can be rotated
manually about its hinge by an angle of approximately 180°, corresponding to its second
configuration, referred to as "opening" configuration. When it is in this position,
the lever projects in a radial direction from the head of the screw and does not intercept
the discharge hole. The free end of the lever can be fitted, for example by means
of a pin, to a bushing that is free to rotate about its own axis, which, when the
lever is in its closing position, is received in the corresponding flared portion
present on the head of the screw and can also project from the head towards the cylindrical
portion of the screw in a direction parallel thereto.
[0019] According to a further embodiment of the invention, the lever can be fitted to the
head of the screw along its outer circumference. According to this embodiment, the
lever has an arched profile and is extractable from the lateral surface of the head
of the screw.
[0020] According to a preferential embodiment of the invention, the head of the screw is
provided with a series of through holes set along a circumference and having the dual
purpose of lightening the head of the screw and of enabling insertion of a cord used
for performing the manoeuvre of recovery of the screw.
[0021] The openable lever thus constitutes a useful support for manual turning of the screw.
A climber, in fact, thanks to the convex profile of the head of the screw and with
the lever in the closing position, can push and rotate the screw in the ice without
ever detaching his hand from the grip, so preventing any accidental losses, and he
can then open the lever and, with a continuous movement of his hand, rotate the lever
by pivoting on the bushing present on the lever itself. This enables the climber to
engage the screw in the ice at a considerably greater speed as compared to the speed
made possible by traditional screws. This advantage results also in a saving of energy
for the climber, who is not forced to make slow and irregular movements whilst he
is in a precarious state of balance.
[0022] Provided between the head of the screw and the thread of the cylindrical surface
is a supporting ring of such a diameter as to enable its free sliding and its free
rotation on the cylindrical portion referred to above. The ring is provided with means
for anchorage of a carabiner, within which the safety rope passes. In particular,
the ring is provided with an eyelet, about which a tape is wound. The tape provides
a support for a carabiner and is made of a material designed to resist the tensile
stress caused by the weight of the climber, which, in the event of a fall, is loaded
on the screw and hence on the tape itself.
[0023] The ring offers the advantage of enabling free rotation of the screw and ease of
insertion thereof in the ice even when the safety rope is already inserted in the
carabiner. This considerably reduces the risks of dropping and loss of the screw,
which even in the event of detachment from the ice face (in the case where it has
it not been sufficiently inserted into the ice prior to engagement therein), remains
hanging on to the safety rope through the carabiner.
[0024] Further details will emerge more clearly evident from the detailed description of
preferred but non-exclusive embodiments of an ice screw according to the invention,
illustrated by way of indicative but non-limiting example in the attached drawings,
in which:
- Figure 1 is a side view of the ice screw, with the lever in the closing position;
- Figure 2 is a side view of the ice screw, with the lever in the opening position;
- Figure 3 is a front view of the screw, with the lever in the closing position;
- Figure 4 is a front view of the ice screw, with the lever in the opening position;
and
- Figure 5 is a side view of the toothing of the screw.
[0025] With reference to Figures 1-4, an ice screw 1 is illustrated, which comprises a hollow
cylindrical shaft 2, the outer surface of which has a threaded portion 3 and a smooth
portion 4, a flange 5, and a supporting ring 6.
[0026] The flange 5, which constitutes the head of the screw 1, is fixedly fitted to the
end of the shaft 2 on the side of the smooth portion 4. The outer surface 11 of the
flange 5 has a convex profile characterized by a radius of curvature that enables
the climber to insert the screw easily into the ice through the pressure and simultaneous
rotation of the flange 5 using the palm of his hand. The flange 5 has, in a position
corresponding to its axis, a through hole 9 having the same diameter as the internal
hole 10 of the cylindrical shaft 2 with which it is in communication. Present on the
surface 11 of the flange 5 is a transverse groove 12, the ends of which communicate
with two longitudinal flared portions 13 made in an area corresponding to the periphery
of the flange 5. The volume defined by the transverse groove 12 and by the longitudinal
flared portions 13 constitutes the housing for a tuck-away lever 14, fitted to the
flange 5 by means of a hinge 15 in a position corresponding to one of the flared portions
13. The lever 14 is provided with a bushing 16 pivoted thereto and which can turn
about its own axis. In addition, the lever 14 has a curved profile, characterized
by having the same radius of curvature as the outer surface 11 of the flange 5, so
that when the lever is in the closing position its outer surface is contiguous with
the surface 11 of the flange, without any generation of sharp edges. Once the climber
has inserted the screw 1 with a few turns into the ice face, he can open the lever
14 with a simple movement of just one hand, and, still using the same hand, he can
rotate the lever 14 in a circumferential direction by acting on the bushing 16, so
transmitting the rotation to the screw that engages in the ice.
[0027] In the embodiment illustrated, the flange 5 is provided with a series of through
holes 20 for insertion of a cord normally used by climbers for recovery of the screw.
[0028] The cylindrical shaft 2 of the screw 1 is equipped, at its free end 7, with a series
of teeth 8 that have the function of triturating and conveying the ice in the hole
10 of the shaft 2 when the screw is engaged. The core of ice that is thus being formed,
is expelled through the discharge channel formed by the hole of the flange 9 and by
the hole 10 of the shaft 2.
[0029] Figure 5 shows the preferred embodiment of the teeth 8, the profile of which is obtained
by making appropriate flared portions 21 along the edge of the shaft 2. The flared
portions 21 are inclined with respect to the axis of the shaft 2.
[0030] A supporting ring 6 is fitted to the smooth portion 4 of the screw 1. The internal
diameter of the ring 6 is slightly greater than the external diameter of the portion
4, so that the ring can slide freely between the flange 5 and the start of the threaded
portion 3. The ring 6 is provided with an eyelet 17, to which there is fixed a tape
18 that can be associated to a carabiner 19, in which the climber causes the safety
rope (not illustrated) to slide. The play existing between the supporting ring 6 and
the screw 1 enables the climber to turn the screw 1 even when the carabiner 19 is
in use, i.e., when it is engaged to the safety rope, thus eliminating the possibility
of the screw falling and getting lost. The tape 18 must be made of a material that
is able to resist the stresses that are loaded thereon, through the safety rope, in
the event of the climber falling.
1. An ice screw comprising: a hollow cylindrical shaft, which is in part externally threaded;
a flange fitted at the non-threaded end of the shaft, provided with a central through
hole communicating with the internal channel of the shaft; and a supporting ring;
said ice screw being
characterized in that:
- said flange is provided with extractable means designed to rotate the screw, said
means being operable manually by means of just one hand; and
- said ring is free to slide and rotate on the non-threaded portion of the hollow
cylindrical shaft, between the flange and the threaded portion of the shaft, and is
provided with means for anchorage of a carabiner.
2. An ice screw according to Claim 1, characterized in that said extractable means designed to rotate the screw consist of a tuck-away lever
fitted to the flange by means of a hinge, said lever being houseable in a suitable
compartment obtained in the flange and being actuatable by means of a bushing which
can turn about its own axis, fitted thereto through a pin present on the free end
of the lever.
3. An ice screw according to Claims 1 and 2, characterized in that said tuck-away lever may be opened in a direction orthogonal to the axis of the flange.
4. An ice screw according to Claims 1 and 2, characterized in that said tuck-away lever may be opened laterally from the perimetral surface of the flange.
5. An ice screw according to Claim 1, characterized in that said means for the anchorage of a carabiner consist of a tape made of fabric.
6. An ice screw according to any one of the preceding claims, characterized in that the end of the shaft opposite to the flange has a toothed profile.
7. An ice screw according to Claim 6, in which said toothed profile is obtained by means
of a series of oblique flared portions made along the edge of said end.