A HANDLE-BAR MOTION UNIT, FOR AN EXERCISE BICYCLE

Abstract: A handle-bar motion unit for an exercise bicycle has a gear (1) provided with an eccentric boss (4) and is coupled to a toothed sprocket (2) rigidly connected for rotation with the pedal mechanism (3) of a bicycle. The eccentric boss (4) engages, in an eccentric hole in a bush (5) rotatably fitted within the big end (6) of a connecting rod (7) connected to the handle-bar column (34). The ratchet mechanism allows relative rotation of the bush (5) and the boss (4) in the opposite sense with respect to the sense of normal use in order to select an eccentricity position of the big end (6) with respect to the gear (1) to connect the exercise bicycle from one having fixed handle-bars, to one having a reciprocating movement applied to the handle-bars by rotation of the pedals, the conversion being effected simply by back-pedalling by half of one revolution.

Description: The present invention relates to a handle-bar motion unit for an exercise bicycle. Although many exercise bicycles (also known as static bicycles) provide only for exercising the legs by operating pedals against an adjustable resistance, some such machines are also provided with means for exercising the arms and upper part of the body. This movement is achieved by making the handle-bars perform a reciprocatory movement which, in practice, is directly driven from the motion of the pedals. In known such machines an eccentric mechanism is provided, which is connected to the pedals and is connectable, by means of a pin or similar element, to the lower end of the handle-bar support column in such a way as to cause a reciprocating motion of the handle-­ bars to take place in synchronism with the rotation of the pedals. If the utiliser does not wish to perform the exercises involved with the upper limbs and the trunk it is possible to disconnect the reciprocating motion drive to leave the handle-bars in a fixed position: this is achieved by uncoupling the eccentric connection, for example, by extraction of the pin which makes the connection. This conversion from one type of operation to the other is not, however, very easy to achieve and requires an operation, which whilst being simple, is rather inconvenient and is thus not always voluntarily effected by the utiliser. The present invention seeks therefore to overcome the above-explained limitation by providing a handle-bar motion unit for an exercise bicycle, which will allow the possibility of effecting the coupling or uncoupling of the reciprocating movement of the handle-bars simply by acting on the pedals without having to perform operations of other type. Embodiments of the invention may be so constructed that, in addition to the reciprocating motion towards and away from the saddle in the direction which the user is facing, the handle-bars may also be connected to perform an arcuate recipro­ cating motion about an upright axis generally parallel to the support column on which the handle-bars are mounted, thus permitting exercises beneficial for the twisting of the trunk. According to one aspect of the present invention, therefore, there is provided a handle-bar motion unit for an exercise bicycle, characterised in that it includes a gear provided with an eccentric boss connectable to a toothed sprocket connected for rotation with the pedal mechanism, the said eccentric body engaging rotatably within an eccentric bore in a bush rotatable within the big end of a connecting rod the little end of which is connectable to a pivoted handle-bar column, there being a ratchet mechanism between the eccentric boss of the gear and the bush so arranged that it transmits rotary motion from the eccentric boss to the bush when rotated in the forward direction and allows relative rotation of the boss and the bush when rotated in the reverse direction whereby to allow the unit to move from a first operating position in which the big end of the connecting rod is connected eccentrically to the gear to a second working position in which the eccentricity of the boss and that of the bush counteract one another and the big end of the connecting rod is effectively concentric to the gear. The present invention also comprehends an exercise bicycle provided with such a handle-bar motion unit. A particular advantage of the present invention is that it provides a handle-bar motion unit which is easily fitted to a static bicycle frame of any form and structure. Another advantage of the present invention is that it provides a handle-bar motion unit which, by its particular constructional characteristics is able to offer the widest guarantees of reliability and safety in use. A further advantage of the invention lies in the fact that it provides a handle-bar motion unit which is easily obtainable starting from elements and materials which are commonly available on the market and, moreover, which is competitive from an economic point of view. The big end of the connecting rod is preferably formed as a ring within which the bush is received. The ratchet mechanism may thus be caused to rotate with respect to the bush by rotation of the pedal mechanism in the opposite direction from the direction of normal use, that is by back-pedalling,to select a concentric position of the big end loop with respect to the gear, with a consequent fixed position of the handle-bars in use, or an eccentric position of the big end loop with respect to the gear, with the consequent transmission of reciprocating movement to the handle-bars themselves upon rotation of the pedal mechanism.. One embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a partially sectioned schematic plan view from above of a handle-bar motion mechanism shown in a first operating position; Figure 2 is a section taken on the line II-II of Figure 1; Figure 3 is a schematic plan view of a part of the unit shown in Figure 1, in a second operating position; Figure 4 is a schematic plan view similar to that of Figure 3, showing the unit in an intermediate position between the two end positions; Figure 5 represents the unit seen from above and partially in section, with the device for the recip­ rocating rotation of the handle-bar in evidence; Figure 6 represents, seen from above, the unit connected for reciprocating rotation of the handle-bars. Referring now to the drawings, and particularly to Figure 1, the exercise bicycle handle-bar motion unit of the invention can be fitted to an exercise bicycle of any shape, and includes a gear 1 which is rotatably supported by the frame (not shown) of the static bicycle. The gear 1 is coupled for rotation to a toothed sprocket 2 fitted to the axis of rotation of the pedal mecanism 3 in such a way as to drive the gear 1 to rotate when the pedal mechanism is caused to rotate. On one of its faces the gear 1 has an eccentric body or boss 4 which is housed within a bush 5 and connected for rotation therewith by a ratchet mechanism which will be described in more detail hereinbelow. The outer periphery of the bush 5 is rotatably coupled to a ring at the big end of a connecting rod 7 the little end of which is connected in a manner known per se to the handle-bars (not shown) whereby to obtain oscillation of the handle-bar about a substantially horizontal axis extending transversely of the longitudinal axis of the bicycle frame, that is the axis extending horizontally from front to back in the direction which the user faces when using the machine. The ratchet mechanism is provided in order to make it possible to effect conversion of the mechanism from an eccentric position to a non-eccentric or concentric position, or vice versa, simply by effecting rotation of the pedal mechanism in the opposite sense from the normal direction of operation. In the illustrated embodiment the ratchet mechanism is constituted by a pawl 10 housed in a radial bore 11 in the eccentric boss 4, and resiliently urged radially outwardly by a compression spring 12 which acts between the pawl 10 and the bottom of the bore 11. The radially outer end of the pawl 10 which projects from the eccentric boss has an asymmetric shape with a first face 10a lying approximately radially of the boss 4 and an inclined face 10b lying at a shallow angle to a tangent to the circumference. Correspondingly, in the eccentric bush 5 which surrounds the eccentric boss 4, there is provided, in diametrically opposite positions, detents 20 having a shape which matches that of the end of the pawl, in such a way as to define a rotary coupling surface 20a and an inclined surface 20b. The detents 20 are diametrically oppositely positioned on the axis of eccentricity of the bush 4 in such a way as to define two distinct positions, namely a first or eccentric position as illustrated in Figure 1, and a second or concentric position as illustrated in Figure 3. In the first position of the mechanism the gear 1 and the big end ring 6 of the connecting rod 7 are coupled eccentrically, and in the second position they are effectively connected concentrically by the compensating effects of the opposite eccentricity of the boss 4 and the bush 5. When the pedal mechanism 3 is turned in the normal or "forward" direction the rotation impressed on the gear and, consequently, on the eccentric body 4, is such that the coupling face 10a of the pawl 10 engages with the cooperating surface 20a of the detent 20 thereby forming a rotary coupling which also causes the bush to rotate. By reversing the direction of rotation of the pedal mechanism 3 the direction of rotation of the gear 1 and of the eccentric boss 4 is reversed, with the consequent result that relative rotation of the eccentric boss 4 takes place with respect to the eccentric bush 5 so that the inclined surfaces 10b of the pawl 10 and 20b of the detent 20 contact one another and when the resilient biasing of the spring 12 is overcome the pawl 10 is pressed into the bore 11. This allows the utiliser quickly and easily to change the mechanism over from an eccentric to a concentric coupling position or vice versa simply by back-pedalling for half of one revolution. When the eccentric coupling is made the handle-bar is caused to perform synchronous oscillation or angular reciprocation by the movement of the pedal mechanism, which as normal is continuously rotated in the forward direction during use. On the other hand, when a concentric coupling is made the connecting rod 7 does not transmit any motion to the handle-bars, which therefore, remain in a fixed upright position. As is clearly illustrated in Figures 5 and 6 the handle-bar motion unit forming the subject of the invention also offers the possibility of obtaining reciprocating rotation of the handle-bars about an upright or approximately vertical axis. This result is obtained by means of a rack section 30 which is coupled pivotally to the connecting rod 7 and which is slidably guided in a guide block 31 which defines a sliding seat 32 in which a toothed pinion 33 is provided. This latter is fitted to the handle-bar column in such a way that the reciprocating motion impressed on the rack 30 by an eccentric coupling of the bush 5 causes a reciprocating rotation of the handle-bars, thus contributing to torsional motion of the trunk of a user which is very beneficial. It will be appreciated that conversion from a fixed handle-bar position to a reciprocating motion position can be achieved simply by effecting a reverse rotation of the pedals because the ratchet mechanism described hereinabove permits the eccentricity of the coupling of the connecting rod which transmits the motion to the hendle-bars to be cancelled or reinstated at will. Furthermore a new function has been added to the classic functions of an exercise bicycle in that there is now provided the possibility of an angular reciprocating motion of the handle-bars about the axis of the handle-bar column.

Claims: 1. A handle-bar motion unit for an exercise bicycle, characterised in that it includes a gear (1) provided with an eccentric boss (4) connectable to a toothed sprocket (2) connected for rotation with the pedal mechanism (3), the said eccentric body (4) engaging rotatably within an eccentric bore in a bush (5) rotatable within the big end (6) of a connecting rod (7) the little end (8) of which is connectable to the handle-bar column, there being a ratchet mechanism (10a,10b,20a,20b) between the eccentric boss (4) of the gear (1) and the bush (5) so arranged that it transmits rotary motion from the eccentric boss (4) to the bush (5) when rotated in the forward direction and allows relative rotation of the boss (4) and the bush (5) when the boss (4) is rotated in the reverse direction whereby to allow the unit to move from a first operating position in which the big end (6) of the connecting rod (7) is connected eccentrically to the gear (1) to a second working position in which the eccentricity of the boss (4) and that of the bush (5) counteract one another and the big end (6) of the connecting rod is effectively concentric to the gear (1). 2. A handle-bar motion unit according to Claim 1, characterised in that the said gear (1) is rotatably supported by the static bicycle frame. 3. A handle-bar motion unit according to Claim 1 or Claim 2, characterised in that the ratchet mechanism is constituted by a pawl (10) lodged in a bore (11) within the eccentric boss (4), and resiliently urged outwardly by a spring (12) acting between the pawl (10) and the bottom of the bore (11). 4. A handle-bar motion unit according to any preceding Claim, characterised in that the radially outer end of the pawl (10) has a coupling face (10a) and an inclined face (10b), the surface of the bush (5) in contact with the said eccentric boss (4) having, in two diametrically opposite positions, detents (20) having a shape corresponding to that of the ends of the pawl (10) with the coupling surface (10a) of the pawl (10) being engageable cooperatively with an abutment surface (20a) of the detent (20) upon forward rotation of the pedal mechanism. 5. A handle-bar motion unit according to any preceding Claim, characterised in that it includes a rack (32) at the end of the connecting rod (7) slidably housed in a guide block (31) which defines a sliding seat for the rack (32), in which there is positioned a toothed pinion (33) fitted on the handle-bar column (34) for effecting reciprocating rotation of the handle-bar about a substantially upright axis. 6. An exercise bicycle having a frame, a pedal mechanism (3) and a handle-bar on a pivotal handle-bar column, characterised in that the pedal mechanism (3) is connected to the handle-bar columnm by a handle-bar motion unit according to any of the preceding Claims.

Inventors: CARNIELLI, TEODORO
Applicants: TEODORO CARNIELLI & C. S.P.A.
Application year: 1986
Main classification: A63B69
IPC codes: A63B22, A63B23, A63B69