CROSS-REFERENCE TO RELATED APPLICATIONS
TECHNICAL FIELD
[0002] The present invention relates to an ice screw.
STATE OF THE PRIOR ART
[0003] Ice climbing is a very popular sport. Climbers climbing ice walls use a number of
safety systems to provide protection against falls. In particular, a number of ice
screws, each with an associated karabiner, and a safety rope passing through each
karabiner are used. In case the climber loses his/her grip, the rope ensures that
the climber's fall stops at the ice screws.
[0004] Ice screws consist of a hollow cylindrical body that is externally threaded like
a screw. The ice screw has a first grooved end that forms a toothed profile, generally
with a number of spikes along the circumference and adapted to be engaged on the ice
surface, and an end provided with a grip portion which protrudes from the screw itself,
integral with the screw and suitable to be gripped by the user to facilitate screwing.
Examples of known types of ice screws include Patents
US5782442,
US5118061.
[0005] The most common ice screws are made entirely of steel to ensure maximum grip in the
ice, which is why they are heavy and bulky.
[0006] For this reason, lighter aluminium screws were tested. However, aluminium does not
allow proper screwing into the ice, moreover, screws made of aluminium bend more easily
and therefore may not ensure the necessary safety features required for ice climbing.
[0007] Therefore, there is an ongoing search for alternative and better solutions for making
ice screws.
OBJECT OF THE INVENTION
[0008] The object of the present invention is to obtain an ice screw, which allows the above-mentioned
problem to be solved, is therefore easy to assemble, and has the qualities of a steel
screw and the lightness of an aluminium screw.
[0009] According to the present invention, this object is achieved by means of an ice screw
according to claim 1.
[0010] A further object of the present invention is to obtain an easier method for assembling
an ice screw.
[0011] According to the present invention, this object is achieved by means of a method
for assembling an ice screw according to claim 10.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a better understanding of the present invention, it will now also be described
with reference to the accompanying drawings, wherein:
- Figure 1 is a schematic side view of a preferred embodiment of an ice screw;
- Figure 2 is a schematic side view of a preferred embodiment of an enlarged terminal
portion of the ice screw in Figure 1;
- Figure 3 is an exploded schematic side view of a preferred embodiment of the ice screw
in Figure 1 broken down into its component parts; and
- Figure 4 is a bottom view of the terminal portion of the ice screw in Figure 3.
DESCRIPTION OF THE INVENTION
[0013] In Figure 1, the numeral 1 indicates, as a whole, an ice screw comprising a hollow
screw portion 2 having a preferably circular cross-section and provided with a threading
3 formed on a smooth, bottom outer surface 4, and a grip portion 5, which may have
any shape that is suitable to facilitate the gripping of the screw.
[0014] The screw portion 2, in use, is screwed into the ice, which is facilitated by the
grip portion 5 and the threading 3.
[0015] The grip portion 5 is used to grip the screw and facilitate the screwing into the
ice and is usually provided with a crank 6, in some models a foldable crank, merely
by way of example as shown in Figure 1.
[0016] As also shown in greater detail in Figure 2, the screw portion 2 of the ice screw
1 comprises a terminal portion 7, preferably made of a first metal, more preferably
made of steel, or with a Mohs hardness greater than 3.5, more preferably greater than
4 and even more preferably between 4 and 4.5, and a body portion 8, preferably made
of a metal lighter than the first metal, more preferably made of aluminium, or with
a Mohs hardness of less than 3.5, more preferably less than 3, even more preferably
between 2.5 and 3.
[0017] "Lighter" is therefore intended to mean a lower hardness index on the Mohs scale.
"Hardness" is used with its usual meaning, i.e., the metal's resistance to permanent
deformation.
[0018] The terminal portion 7 comprises a threading 9 connected to the threading 3 of the
body portion and formed on a smooth bottom surface 10, and an end portion 11 provided
with a toothed or saw-toothed profile 12. The toothed profile 12 is preferably formed
by a plurality of spikes 13.
[0019] Preferably, the toothed profile comprises a number of spikes 13 comprised between
2 and 8, more preferably 4 or 5.
[0020] Preferably, the spikes 13 have a triangular shape, more preferably the spikes 13
approximately have the shape of a right-angled triangle.
[0021] The threading 9 of the terminal portion 7 advantageously follows the threading 3
of the screw portion 2.
[0022] For this purpose, during the manufacturing of the ice screw 1, the terminal portion
7 and the body portion 8 are joined so that there are no discontinuities between the
threadings 3, 9 and neither between the respective bottom surfaces 4, 10, as schematically
shown in Figure 2.
[0023] As shown in Figure 3, the screw portion 2 is formed or assembled starting from three
distinct elements.
[0024] The terminal portion 7, the body portion 8 and an open ring 20.
[0025] The body portion 8 is formed by a first region 21 provided with a threading 3 and
having a first external diameter and by a second region 22, also called a male region
for coupling to the terminal portion 7 and having a second external diameter smaller
than the first diameter. In fact, the second region 22 allows a male-female coupling
to a corresponding region of the inner surface of the terminal portion 7.
[0026] The internal diameter of both regions 21 and 22 is such that once the screw portion
2 has been assembled it is substantially the same at both regions 21, 22, so as to
ensure that the inner surface of the screw portion 2 is coplanar, uniform and smooth
in order to facilitate the sliding of the ice inside the screw during the screwing
process.
[0027] The second region 22 therefore has an outer surface 23 having a shape suitable to
ensure coupling to an inner surface of the terminal portion 7.
[0028] For this purpose, the outer surface 23 of the second region 22 preferably has a surface
with a non-regular and therefore non-polygonal geometric shape. More preferably, it
has at least one flat portion 24, even more preferably at least two flat portions
24, 25. Even more preferably, the two flat portions 24, 25 have different sizes.
[0029] The flat portion(s) 24, 25 is/are formed externally on the outer surface and is/are
at respective flat portions having the same shape and size and formed on the inner
surface of the terminal portion 7, as shown in Figure 4.
[0030] As shown in Figure 4, the terminal portion 7 has, on the inside thereof, a smooth
region having an internal diameter equal to the internal diameter of the first region
21 of the body portion 8, and a coupling region 36 having an inner surface 37 having
a shape and size corresponding to the outer surface 23 of the second region 22 of
the body portion 8 so as to be able to provide a male-female coupling in one mandatory
configuration.
[0031] In fact, when the screw portion 2 is interference assembled by threading the second
region 22 into the terminal portion 7, there is only one assembly configuration or
position which ensures the continuity of the threading 3 of the body portion 8 with
the threading 9 of the terminal portion 7.
[0032] The one and only assembly position is ensured by the fact that the outer surface
of the second region 22 and the coupling region of the inner surface of the terminal
portion 7 do not have a regular shape, such as a polygonal shape, and therefore the
two portions cannot be coupled to each other in a different configuration from that
which makes the flat portions 24,25 on the outer surface of the second region 22 correspond
to those at the inner surface of the terminal portion 7.
[0033] In the preferred embodiment shown in Figures 3 and 4, the outer surface 23 of the
second region 22 has 4 flat portions designated by the reference numerals 24, 25,
26, 27, respectively, each one having a different size.
[0034] Preferably, the flat surfaces 24, 25, 26, 27 of the outer surface 23 of the second
region 22 are joined together by curved portions 28, 29, 30, 31, having a curved profile
corresponding to that of the screw portion 2.
[0035] The coupling region 36 of the terminal portion 7 comprises at least one, preferably
two, even more preferably, as shown in Figure 4, four flat portions 38, 39, 40, 41
on the inner surface of the coupling region, as also shown in the bottom section view
of the terminal portion 7 in Figure 4, also joined together by respective curved portions
42, 43, 44, 45.
[0036] The profile of the outer surface of the second region 2 therefore corresponds to
the profile of the inner surface of the coupling region 36 of the terminal portion
7.
[0037] More advantageously, the second coupling region 22 on the screw portion 2 further
comprises a groove 50 adapted to house an open ring 20.
[0038] According to a first preferred embodiment, the open ring 20 is made of magnetic material,
preferably a metallic material, and therefore can close or open elastically like a
spring.
[0039] According to a second preferred embodiment, the open ring 20 is made of polymeric
material, preferably a thermoplastic material, and therefore can close or open elastically
like a spring.
[0040] The method for assembling the screw portion 2 comprises a first step wherein the
open ring 20 is arranged into the groove 50, then the terminal portion 7 is assembled
onto, or in other words threaded into or coupled to the second region 22 of the body
portion 8.
[0041] The coupling takes place in such a way that the terminal portion 7 tightens the ring
on the groove in order to facilitate the coupling thereof. When the terminal portion
is in place, the open ring, as it is provided with elasticity due to the material
of which it is made, tends to open, abutting against the inner surface 37 of the coupling
region 36, eliminating the clearance and thus preventing, in use, the terminal portion
from unthreading.
[0042] The presence of the ring 20 also allows not only to ensure the tightness, in use,
of the coupling between the terminal portion 7 made of the first metal, in particular
of steel, and the body portion 8 made of the lighter metal, in particular of aluminium,
but also has the advantage of allowing the replacement of the terminal portion in
case of wear.
[0043] In fact, according to the first embodiment, by inserting into the screw portion 2
a magnetic element capable of attracting the magnetic material of which the open ring
20 is made, the ring itself tightens by completely entering the groove 50, thus allowing
the terminal portion 7 to be unthreaded from the body portion 8. Therefore, a new
terminal portion 7, for example with non-worn spikes, can be inserted by the same
method used for the first assembly of the ice screw.
[0044] The advantages enabled by the ice screw manufactured according to the present invention
will be apparent from an examination of the features thereof.
[0045] In particular, the ice screw combines the lightness of aluminium with the mechanical
characteristics of steel, which makes it easily screwable into the ice. At the same
time, in case of wear, the tip can be easily replaced, yet the coupling of the terminal
portion is ensured in an optimal way.
1. An ice screw (1) comprising a hollow screw portion (2) provided with a threading (3)
formed on an outer surface (4), said screw portion comprising a terminal portion (7)
made of a first metal and a body portion (8) made of a second metal lighter than said
first metal and an open ring (20) made of polymeric material or magnetic material.
2. The ice screw (1) according to claim 1, characterised in that said first metal is steel or has a Mohs hardness greater than 3.5.
3. The ice screw (1) according to claim 1, characterised in that said second metal is aluminium or has a Mohs hardness of less than 3.
4. The ice screw (1) according to any one of the preceding claims, characterised in that said terminal portion (7) comprises a threading (9) and an end portion (11) provided
with a toothed profile (12).
5. The ice screw (1) according to any one of the preceding claims, characterised in that said body portion (8) is formed by a first region (21) having a first external diameter
and by a second region (22) having a second external diameter smaller than the first
diameter.
6. The ice screw (1) according to any one of the preceding claims, characterised in that said second region (22) has an outer surface (23) and in that said terminal portion (7) has, on the inside thereof, a coupling region (36) having
an inner surface (37) having a shape and size corresponding to the outer surface (23)
of the second region (22) of the body portion (8) so as to be able to carry out a
coupling of the body portion (8) with the terminal portion (7).
7. The ice screw (1) according to any one of the preceding claims, characterised in that said outer surface comprises at least one flat portion (24).
8. The ice screw (1) according to any one of the preceding claims, characterised in that said open ring (20) is made of magnetic material or polymeric material.
9. The ice screw (1) according to any one of the preceding claims, characterised in that said second region (22) comprises a groove (50) adapted to house said open ring (20)
.
10. A method for assembling an ice screw according to claim 8 comprising a first step
wherein said open ring (20) is arranged into the groove (50) and a second step wherein
the terminal portion (7) is threaded into the second region (22) of the body portion
(8).