Equipment for a wheel of a bicycle and corresponding rim

Abstract

The invention relates to an equipment for a bicycle wheel. The equipment comprises at least one profiled wing-shaped projection adapted to be secured to the inner surface of the rim of the wheel.

Claims

1. Equipment for a wheel of a bicycle, comprising: at least one profiled wing-shaped projection positioned at an inner surface of a rim of the wheel, said rim having a first center and a first internal radius, (R1), wherein the at least one profiled wing-shaped projection has a profile and is positioned between first and second points along the inner surface of the rim, the profile shaped by and extending along an arc of a second circle having a second radius, (R2), and a second center, the second radius being such that (R2)=0.6*(R1) to 0.8*(R1); the second center of the arc of the second circle being placed at a distance, (H), from the first center, such that (H)=0.1*(R1) to 0.2*(R1); the profile of the at least one profiled wing-shaped projection having distal end shapes defined by a first angle (a) having a vertex at the first point and a second angle () having a vertex at the second point, the first angle () and second angle () each having a range between 20 to 45, inclusive.

2. The equipment, according to claim 1, wherein at least one through opening is provided on said at least one profiled wing-shaped projection.

3. The equipment, according to claim 1, wherein said at least one profiled wing-shaped projection is integral with said rim.

4. The equipment, according to claim 1, wherein the weight of said at least one profiled wing-shaped projection is comprised between 60 grams and 80 grams per wheel.

5. The equipment, according to claim 1, wherein the equipment comprises at least one passage on at least one profiled wing-shaped projection.

6. The equipment, according to claim 5, wherein said at least one passage has a three-dimensional inner profile designed as a portion of a wing-shaped profile of the NACA type.

7. The equipment, according to claim 6, wherein on each of two side faces of said rim, inlet sections of the portions of wing-shaped profiles are intercalated with outlet sections of the portions of the same wing-shaped profiles.

8. The equipment, according to claim 5, wherein said at least one passage has a three-dimensional inner profile designed as a Venturi tube.

9. The equipment, according to claim 8, wherein on each of two side faces of said rim, inlet sections of Venturi tubes are intercalated with outlet sections of Venturi tubes.

10. The rim for the wheel of the bicycle comprising: at least one of said equipment according to claim 1.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) For a better understanding of the present invention, a preferred embodiment is described below, purely as a non-limiting example and with reference to the accompanying drawings, wherein:

(2) FIG. 1 schematically shows a front view of a bicycle rim comprising a first embodiment of an equipment according to the present invention;

(3) FIG. 2 shows a three-dimensional view of a bicycle rim comprising a second embodiment of an equipment according to the present invention;

(4) FIG. 3 shows a front view of the rim of FIG. 2; and

(5) FIG. 4 shows a three-dimensional view of some enlarged details of a rim provided with at least a part of the equipment as shown in FIGS. 2 and 3.

BEST MODE FOR CARRYING OUT THE INVENTION

(6) In FIG. 1, a bicycle rim provided with an equipment 20 according to the teaching of the present invention has been indicated as a whole by the number 10.

(7) The rim 10 is part, as already known, of a wheel (WL) (not shown) including in turn also an inner tube covered by a tire (not shown). The wheel (WL) is also optionally provided with a plurality of spokes, of known type and not illustrated, which physically connect the rim 10 to a hub (not shown).

(8) In the first embodiment illustrated in FIG. 1, the equipment 20 comprises four profiled wing-shaped projections 25A, 25B, 25C and 25D, each of which occupies a respective quadrant I, II, III and IV of the rim 10.

(9) Each profiled wing-shaped projection 25A, 25B, 25C and 25D is flat and can be advantageously made by cutting a metal sheet.

(10) The inner profile of each profiled wing-shaped projection 25A, 25B, 25C and 25D can advantageously, but not necessarily, have the following geometrical characteristics with reference to the inner radius (R1) of the rim 10:

(11) (R2)=0.6*(R1) to 0.8*(R1);

(12) (H)=0.1*(R1) to 0.2*(R1);

(13) ()=20 to 45;

(14) ()=20 to 45.

(15) These optimal values have been obtained by means of a numerical modelling electronically processed by a computer and these first values were further confirmed by tests.

(16) Considering now the first quadrant I delimited by points (W1) and (Z1) that are drawn on the circumference of the rim 10.

(17) Now, by moving from the point (O), centre of the rim 10, along the perpendicular (pp) to a point (P) at a distance (H) of said point (O), it is possible to draw an arc (ARC1) of the radius (R2) (refer to the aforesaid directions).

(18) An angle () included advantageously, but not necessarily, between 20 and 45 (see the above directions) starts from the point (W1). In this way, a point (W2) is drawn on the arc (ARC1).

(19) Analogously, an angle (), also included advantageously, but not necessarily, between 20 and 45 (see the above directions) starts from the point (Z1). In this way, a point (Z2) is drawn on the arc (ARC1).

(20) It should incidentally be noted that the angles () and () may have identical or different values.

(21) Accordingly, the points (W1), (W2), (Z2) and (Z1) delimit the profiled wing-shaped projection 25A, whose area has been highlighted by hatching.

(22) The same operation can be performed on quadrants II, III and IV by drawing the respective arcs (ARC2) (ARC3) and (ARC4), which correspond to respective profiled wing-shaped projections 25B, 25C and 25D (FIG. 1).

(23) The profiled wing-shaped projections 25A, 25B, 25C and 25D can be integral with the rim 10 or may be attached thereto, for example by means of a dovetail coupling. These profiled wing-shaped projections 25A, 25B, 25C and 25D create a frill effect on the wheel (WL).

(24) In the second embodiment illustrated in FIGS. 2 and 3, the equipment 20* comprises three profiled wing-shaped projections 25A*, 25B* and 25C* (instead of four as in the first embodiment of FIG. 1) and are mutually offset by 120.

(25) Moreover, as shown in FIGS. 2 and 3, in this embodiment each profiled wing-shaped projection 25A* 25B* and 25C* may be provided with one or more openings (OP1), (OP2) and (OP3) to prevent said sailing effect due to the presence of strong side winds. These openings (OP1), (OP2) and (OP3) have a double function:

(26) a) they create a controlled and alternative bearing capacity to better contrast the effects of side winds; and

(27) b) by changing their size, it is possible to vary the inertia of the wheels to suit the different cycling races.

(28) In both embodiments, the weight of the profiled wing-shaped projections (25A, 25B, 25C, 25D; 25A*, 25B*, 25C*) is advantageously comprised between 60 g and 80 g per wheel.

(29) Furthermore, according to another embodiment of the present invention illustrated in FIGS. 2, 3 and 4, a certain number of passages (PS1) and (PS2) have been made on the body of the rim 10*.

(30) As illustrated more in detail in FIG. 4, each passage (PS1) and (PS2) has a three-dimensional inner profile designed according to the layer or contour of a portion of a wing-shaped profile, namely a wing-shaped profile commonly used for aircraft.

(31) Advantageously, but not necessarily, the wing-shaped profile is of the NACA type.

(32) Alternatively, on each of the two side faces (FC1) and (FC2) of the rim 10*, the inlet sections (SZ1) of the (PS1) passages are intercalated with the outlet sections (SZ2) of the (PS2) passages (FIG. 2).

(33) In other words, advantageously but not necessarily, the (PS1) passages and the (PS2) passages are shaped like a mould of the same wing-shaped profile having a tapered shape.

(34) Therefore, for (PS1) passages it is as if the wing-shaped profile came in through the side face (FC1) of the rim 10* and came out through the side face (FC2) arranged on the other side of this same rim 10*. On the contrary, for (PS2) passages it is as if the wing-shaped profile came in through the side face (FC2) of the rim 10* and came out through the side face (FC1) arranged on the other side of the same rim 10*.

(35) This advantageous alternation of (PS1) and (PS2) passages allows to remove the surplus wind that arrives from both the right and the left at 15, 20, 30 and 40.

(36) Moreover, by adequately designing the (PS1) and (PS2) passages as Venturi tubes, it is possible to create a natural acceleration of the wheel.

(37) Also in this case, the inlets and outlets of the Venturi tubes can be mutually intercalated as previously illustrated.

(38) The shape, number and length of (PS1) and (PS2) passages can be chosen so as to mitigate the negative effects of the above side winds.

(39) The main advantages of the equipment for a bicycle wheel, representing the main object of the present invention are:

(40) the passage through the (upper and lower) dead points is easily done and the cyclist uses less energy to keep pedalling;

(41) the wheel, according to the weight and/or the shape of the profiled wing-shaped projections, stiffens as desired by the project designer to adapt the bike to different races (on the plains, on the mountains, timed (called against the clock), etc. . . . ), and

(42) the wheel becomes much more stable in case of strong side winds.