Abstract
A bicycle wheel, particularly for racing and mountain bicycle, comprising
a hub (3) that has two flanges (4,5) connected to a rim (2) by way
of wire spokes, said wire spokes forming a first plurality of radial
elements (6), which are mutually angularly equidistant by a preset
angle and connect said rim (2) to the first flange (4) of said hub
(3), and a second plurality of radial elements (6), which are mutually
angularly equidistant by said angle, are offset by half of said angle
with respect to said first plurality and connect said rim (2) to the
second flange (5) of said hub (3), each one of said radial elements
(6) being constituted by a first wire spoke (7) and a second wire
spoke (8) which are substantially parallel.
Claims
1. A bicycle wheel, particularly for racing and mountain bicycle,
comprising a hub that has two flanges connected to a rim by way of
wire spokes, characterized in that said wire spokes form a first plurality
of radial elements, which are mutually angularly equidistant by a
peset angle and connect said rim to the first flange of said hub,
and a second plurality of radial elements, which are mutually angularly
equidistant by said angle, are offset by half of said angle with respect
to said first plurality and connect said rim to the second flange
of said hub, each one of said radial elements being constituted by
a first wire spoke and a second wire spoke which are substantially
parallel.
2. The wheel according to claim 1, characterized in that said first
wire spoke and said second wire spoke of each one of said radial
elements are engaged on opposite sides with the respective flange
and in that said first wire spoke of one element is engaged with
said flange in a position that is intermediate with respect to the
engagement points of said first and second spokes of the contiguous
element.
3. The wheel according to claim 1, characterized in that said first
wire spoke and said second wire spoke of alternated of said radial
elements are engaged on a same side of said flange, the remaining
radial elements being engaged with the opposite side of said flange
4. The wheel according to claim 2, characterized in that said first
wire spoke and said second wire spoke have a proximal end that is
associated with said hub and a distal end that is proximate to said
rim, said proximal end being folded and inserted in a respective
peripheral engagement hole provided in said flange, said distal
end being screwed into a nipple that is rigidly coupled to said
rim, said first wire spoke and said second wire spoke forming, at
said proximal ends, larger portions for abutment respectively against
the inner face and the outer face of said flange.
5. The wheel according to claim 2, characterized in that said holes
are distributed, on each one of said flanges, in angularly equidistant
pairs, the first wire spoke of one element and the second wire spoke
of the contiguous element being engaged respectively in each one
of said pairs of holes, so as to cross without mutual contact.
6. The wheel according to claim 1, characterized in that each one
of said wire spokes has a circular transverse cross-section at said
distal end and said proximal end, and a substantially flat cross-section
in the central portion.
7. The wheel according to claim 2, characterized in that said nipples
are distributed, along said rim, in pairs that are angularly mutually
equidistant for fixing respectively said first wire spoke and said
second wire spoke of each one of said radial elements.
8. The wheel according to claim 2, characterized in that said rim
is internally hollow, has a peripheral groove for the application
of the tire and is affected by a plurality of radial openings for
accommodating said nipples.
Description
TECHNICAL FIELD
[0001] The present invention relates to a bicycle wheel particularly
for racing and mountain bicycle.
BACKGROUND ART
[0002] Racing bicycles and bicycles for excursions on rough or
mountainous terrain are currently provided with extremely lightweight
wheels by using new materials and modern manufacturing technologies.
[0003] At the same time, such wheels must have great mechanical
strength and a rigidity that is adapted for the characteristics
of the road surface. Wheels that have a particularly rigid behavior
when affected by the stresses encountered in use are those formed
monolithically by pressure die-casting, which however often are
too heavy and can be used only in particular conditions or situations.
[0004] A compromise between rigidity and low weight can be, achieved
with conventional wheels in which the rim is connected to the hub
by way of a distribution of wire spokes having various shapes and
dimensions. However, such wheels have drawbacks due to the fact
that the wire spokes, by crossing each other, are in mutual contact
in one or more points: this contact causes inward flexing of the
wire spokes after assembly, with a consequent concentration of abnormal
stresses and unacceptable instability in use.
DISCLOSURE OF THE INVENTION
[0005] The aim of the present invention is to obviate the drawbacks
cited above by providing a wheel that has high characteristics of
rigidity and stability in use combined with low weight and versatility
in use.
[0006] Within this aim, an object of the present invention is to
provide a wheel in which the wire spokes cross each other, connecting
the rim to the hub, without mutual contact points.
[0007] Another object of the present invention is provide a structure
that is simple, relatively easy to provide in practice, safe in
use, effective in operation, and relatively low in cost.
[0008] This aim and these and other objects are achieved by the
present bicycle wheel, particularly for racing and mountain bicycle,
which comprises a hub that has two flanges connected to a rim by
way of wire spokes, characterized in that said wire spokes form
a first plurality of radial elements, which are mutually angularly
equidistant by a preset angle and connect said rim to the first
flange of said hub, and a second plurality of radial elements, which
are mutually angularly equidistant by said angle, are offset by
half of said angle with respect to said first plurality and connect
said rim to the second flange of said hub, each one of said radial
elements being constituted by a first wire spoke and a second wire
spoke which are substantially parallel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Further characteristics and advantages will become better
apparent from is the detailed description of a preferred but not
exclusive embodiment of a bicycle wheel, particularly for racing
and mountain bicycle, according to the invention, illustrated only
by way of non-limitative example in the accompanying drawings, wherein:
[0010] FIG. 1 is a side elevation view of the wheel according to
the invention;
[0011] FIG. 2 is a side elevation view of a detail of the hub of
the wheel;
[0012] FIG. 3 is a detailed side elevation view of a sector of
the wheel:
[0013] FIG. 4 is a side elevation view of another embodiment of
the wheel according to the invention;
[0014] FIG. 5 is a side elevation view of a detail of the hub of
the wheel of FIG. 4;
[0015] FIG. 6 is a diametrical sectional view of the wheel, taken
along the line VI-VI of FIG. 4.
WAYS OF CARRYING OUT THE INVENTION
[0016] In the examples of embodiment that follow, individual features,
presented in relation to specific examples, may actually be interchanged
with other different features that exist in other examples of embodiment.
[0017] With reference to the figures, the reference numeral 1 generally
designates a bicycle wheel particularly for a racing and mountain
bicycle according to the invention.
[0018] The wheel comprises a rim 2 and a central hub 3, which are
mutually connected by a distribution of wire spokes: the hub 3 has
a first flange 4 and a second flange 5 which are lateral, are substantially
disk-like and have respective inner faces 4a, 5a and outer faces
4b, 5b.
[0019] According to the invention, the wire spokes form a first
plurality of radial elements 6, which connect the first flange 4
to the rim 2 and are mutually angularly equidistant by a preset
angle, and a second plurality of radial elements 6, which are mutually
angularly equidistant by the same angle and connect the second flange
5 to the rim 2.
[0020] The first and second pluralities of radial elements 6 are
mutually offset, preferably by half of such preset angle. In the
specific case, by way of example, for each of the two pluralities
there are six radial elements 6 that are mutually angularly spaced
by 60.degree.; accordingly, the first and second pluralities of
radial elements are mutually offset by 30.degree..
[0021] Each one of the radial elements 6 that connect the two flanges
4 and 5 of the hub 3 to the rim 2 is constituted by a first wire
spoke 7 and by a second wire spoke 8, which are substantially parallel
or, in a fully equivalent manner, converge slightly in a centripetal
direction.
[0022] The wire spokes 7 and 8 are of the type in which the proximal
end 9 is folded and engaged in a respective engagement hole 10 provided
peripherally in the flange 3 and 4; the spoke also forms, at the
proximal end 9, a larger portion 11 for retention in the hole 10.
Preferably, for each one of the radial elements 6 of the wheel,
the first wire spoke 7 is inserted in the respective hole 10 so
that the larger portion 11 is engaged against the inner face 4a,
5a of the respective flange 4 and 5, while the larger portion 11
of the second wire spoke 8 is engaged against the outer face 4b,
5b (see FIG. 6) of the same flange. The distal end 12 of each wire
spoke 7 and 8 is instead threaded and screwed into a respective
cylindrical nipple 13, which is rigidly coupled to the rim 2. The
distal end 12 and the proximal end 9 of the wire spokes 7 and 8
have a circular cross-section, while the central portion preferably
has a substantially flattened cross-section.
[0023] The nipples 13 are distributed along the rim 2 in pairs
that are mutually angularly equidistant, for fixing respectively
the first and second wire spokes 7 and 8 of each radial element
6. The nipples 13 of each pair are adjacent and are arranged at
a regular circumferential distance.
[0024] The rim 2 is internally hollow and has a peripheral groove
14 for accommodating the tire and a plurality of radial openings
15 for accommodating the respective nipples 13.
[0025] The engagement holes 10 for the wire spokes 7 and 8 are
uniformly distributed, on each one of the flanges 4 and 5, substantially
in mutually angularly equidistant pairs: the first wire spoke 7
of each one of the elements 6 and the second wire spoke 8 of the
directly contiguous element respectively engage in each hole 10
of those pairs. The wire spokes are fixed to the respective nipples
13 so as to cross each other proximate to the flange 4 and 5 without
mutual contact (reference should be made, in this regard, to FIGS.
2 and 3, which illustrate the radial elements 6 of only one of the
two pluralities).
[0026] FIGS. 4, 5 and 6 relate to a further embodiment of the wheel
according to the invention. In these figures, elements identical
or corresponding to elements of the previous figures are designated
by the same reference numerals. In this embodiment, a hub 3 is assembled
in which the holes 10 for engaging the wire spokes 7 and 8 are angularly
mutually equidistant in each one of the flanges 4 and 5.
[0027] In each one of the flanges 4 and 5, the radial elements
6 are engaged in the holes 10 so that the first wire spoke 7 of
each odd element 6 (the first, third and fifth elements) crosses,
without mutual contact, the second wire spoke 8 of the contiguous
odd elements; therefore, for example, the second wire spoke 8 of
the first element crosses the first wire spoke 7 of the third element.
In the same manner, the first wire spoke 7 of each even element
6 (the second, fourth and sixth elements) crosses, without mutual
contact, the second wire spoke 8 of the contiguous even element.
[0028] The distribution of the radial elements 6 in the holes 10
described above also allows the crossing, without mutual contact,
of the first wire spoke 7 of each radial element 6 and of the second
wire spoke 8 of the directly adjacent radial element, as shown in
particular in FIG. 6.
[0029] It is noted that the transverse cross-section of the spokes
7 and 8 can be of any kind, but must maintain the particular mechanical
behavior of each element 6 in use, which can be likened to that
of a solid spoke of a pressure die-cast wheel.
[0030] Moreover, the arrangement of the wire spokes 7 and 8 with
crossings without contact in one or more points ensures higher stability,
strength and rigidity of the wheel in any operating situation.
[0031] It has thus been shown that the invention achieves the intended
aim and objects.
[0032] The invention thus conceived is susceptible of numerous
modifications and variations, all of which are within the scope
of the appended claims.
[0033] All the details may further be replaced with other technically
equivalent ones.
[0034] In practice, the materials used, as well as the shapes and
the dimensions, may be any according to requirements without thereby
abandoning the scope of the protection of the appended claims.
[0035] The disclosures in Italian Utility Model No. BO2001U000092
from which this application claims priority are incorporated herein
by reference.
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