A cycle

Abstract: A cycle is convertible between a standard cycle configuration for normal cycling and an exercise configuration in which the cycle is propelled forwards by alternate saddle strokes, and pedal strokes, the saddle stroke comprising putting the cyclist's weight on the saddle (5) which moves downwardly driving the crank shaft (6) and bringing the two in-phase pedals (4a, 4b) upwardly, the pedal stroke comprising pressing down on both pedals (4a, 4b) to bring the saddle up again. In the exercise configuration the cycle is prevented from stalling by an arrangement whereby when the pedals (4a, 4b) are at bottom dead centre the weight on the saddle (5) is applied to the crank (6c) at an angle to the vertical to maintain forward propulsion, and whereby when the saddle is at bottom dead centre the pedals (4a, 4b) are just forward of top dead centre so as to maintain forward propulsion. In the exercise configuration the pedals may be constrained to rotate in one direction only by means of a ratchet mechanism (12, 13, 14, 16) thereby preventing the pedals hitting the cyclist on the shins.

Description: This invention relates to cycles, and in particular, to cycles in which rotation of the drive wheel can be effected by the application of force alternately to pedals and to the saddle. My earlier United Kingdom Patent Specification No 2 111 924 describes a bicycle of the type mentioned above. The bicycle is in the nature of an exercise bicycle intended to allow the cyclist to exercise muscles and joints different to those which are exercised using a conventional bicycle, while at the same time experiencing the pleasures of outdoor cycling. My earlier bicycle is not suitable for use in exercising those muscles and joints which are exercised by using a conventional bicycle and for this reason a person interested in exercising both sets of muscles and joints would be obliged to purchase, store and maintain two different types of bicycle. My earlier bicycle suffers from stalling at low speed, for example when going up hill. The cyclist pushes downwardly on the pedals so that they rotate from the top dead centre position to the bottom dead centre position, bringing the saddle upwards towards the uppermost position. The momentum of the pedals should then cause the pedals to move past the bottom dead centre position. Often however the momentum does not do so, for example because the cyclist continues to push downwardly on the pedals for an instant too long, or because the cyclist while sitting on the saddle and putting almost his entire weight on the saddle, nevertheless leaves the weight of his feet on the pedals. Once the pedals lose their momentum the directly vertically downward weight of the cyclist on the saddle is insufficient to bring the pedals past the bottom dead centre position. My earlier cycle also suffers from the disadvantage that if a cyclist mounts a bicycle with the saddle near but to the rear of the top dead centre position and the pedals near but just forward of the bottom dead centre position the result may be that the weight of the cyclist drives the saddle downwardly, causing the pedals to counter rotate upwardly hitting the rider unexpectedly on the shins. Patent Specification US-A-4 561 668 discloses a cycle having the features of the pre-characterising part of appended claim 1. According to one aspect of the invention there is provided a cycle which is convertible between an exercise configuration in which the saddle and pedals are connected to a crank shaft in phase with one another with the saddle being connected to the crank shaft out of phase with the pedals so that the cycle may be propelled forwardly by the application of force alternately to the pedals and to the saddle, and a cruising configuration in which the saddle is connected to a cycle frame and the two pedals are connected to the crank shaft out of phase with one another so that the cycle may be pedalled by force applied alternately to each pedal in the conventional manner, characterised by a mechanism operative to limit rotation of the crank shaft with respect to the cycle frame to the rotational direction for forward travel of the cycle. A cyclist may use the cycle in the exercise configuration to take exercise, in the conventional configuration for transport purposes, or may set off on e.g. a day trip and convert from one mode to another as and when required. Thus there is provided a bicycle which is useful for both forms of exercise. A cycle dedicated to use in the exercise mode is known from DE-A- 3 137 317. According to a further aspect of the invention there is provided a cycle in which rotation of a drive wheel can be effected by the application of force alternately to pedals and to a saddle, in which the saddle and the pedals are connected to a crank shaft in a configuration such that when the saddle is at the bottom dead centre position pedal cranks and the pedals are just forward of the top dead centre position and a crank mechanism is provided to limit rotation of the crank shaft to the rotation for forward travel of the cycle. According to a still further aspect of the invention there is provided a cycle in which rotation of a drive wheel can be effected by the application of force alternately to pedals and to a saddle, in which a crank mechanism includes a mechanism for limiting rotation of a crank shaft to the forward direction of travel of the cycle only. Preferably the mechanism can be alternatively engaged or disengaged at the option of the cyclist, so that a cyclist who is very experienced at riding the cycle may disengage the mechanism allowing both rotation and counter rotation of the pedals, and may propel the cycle forwardly by pumping up and down on the saddle and on the pedals always on the same side of top and bottom dead centre without ever bringing the saddle and pedals through top or bottom dead centre, while a cyclist who is less experienced and risks being hit in the shins may leave the mechanism engaged so as to allow rotation in the forward direction. There now follows a description of a preferred embodiment of the invention, by way of example, with reference being made to the accompanying drawings in which: Figure I is a left hand side view of a cycle according to the invention in the exercise configuration; Figure 2 is a similar view but showing the cycle in the conventional configuration; Figure 3 is a right hand side view of a detail of the cycle on a larger scale showing the transmission from the saddle to the saddle crank; and Figures 4a, 4b and 4c show a left hand side view of a detail of the cycle illustrating one example of a mechanism for allowing or preventing counter rotation of the pedals. The cycle comprises a rigid cycle frame 1, a front wheel 2, rear drive wheel 3, right hand side pedal 4a and left hand side pedal 4b, a saddle 5, a crank shaft 6 and a drive transmission chain 7 which is on the right hand side of the bicycle. In the exercise configuration shown in Figure 1, the saddle support column 8a which forms part of a rigid triangular sub-frame 8a, 8b, 8c pivoted at a pivot mounting 9 on the cycle frame 1 is connected to a link 10 which in turn is connected to the crank shaft 6. The pedals 4a, 4b are mounted on cranks 6a, 6b configured in phase with one another (pedal 4a and crank 6a cannot be seen in Figure 1, as they are immediately behind pedal 4b and crank 6b) and out of phase with the saddle 5. As a result, the cycle may be propelled forward by a pedal stroke comprising applying downward foot pressure on pedals 4a, 4b causing rotation of the crank shaft 6, chain 7 and drive wheel 3 and also causing the saddle support column 8a and the saddle 5 to rise upwardly, followed by a saddle stroke comprising releasing the foot pressure so that the saddle 5 and saddle support column 8a descend under the weight of the cyclist, causing rotation of the crank shaft 6, 5 drive transmission chain 7 and rear wheel 3, and also causing the pedals 4a, 4b to rise again. Propelling the cycle in this way including the rising and falling motion of the cyclist's body is quite strenuous and exercises many different muscles. In the conventional configuration shown in Figure 2, left hand pedal 4b has been reset so that it is out of phase with pedal 4a. The link 10 has been disconnected from the saddle support column 8a and from the fixed mounting point 11 on the rigid frame 1, and has been removed from the bicycle. The saddle support column 8a has then been connected directly to the fixed mounting point 11. To assist in resetting the pedal 4b and in connecting and disconnecting the link 10, these components are mounted to the cycle by attachment means which can readily be secured or released using a spanner or other simple hand tool. The cycle is propelled forwardly in the conventional manner. Using the cycle according to the invention the cyclist may go on short or long trips as desired, and whenever using the cycle in the exercise configuration becomes too tiring, the cyclist can quickly convert the cycle to the conventional configuration and carry on cycling in a more leisurely manner. Referring to Figure 3, the pedal crank 6a and the pedal 4a are shown in the bottom dead centre position and with the saddle crank 6c lies along an the angle a between axis A and axis B, the weight on the saddle 5 is transmitted with mechanical advantage, ensuring that the saddle 5 moves downwardly, and the pedals 4a, 4b continue to rotate. Referring now to Figure 1, the dashed lines show the saddle 5 in the bottom dead centre position and show the position of the pedals 4a, 4b. It will be seen that the pedals 4a, 4b are just forward of the top dead centre position (in the drawing the distance forward has been exaggerated for purposes of illustration). This arrangement allows the cyclist to apply pressure to the pedals so as to create a definite forward propulsion and reduce the risk of stalling. Referring to Figure 4a, the pedal crank 6b and pedal 4b are shown in the top dead centre position. A ratchet lever 12 is pivotally moveable between a disengaged position as shown in the full lines and an engaged position as shown in the dashed lines. The lever 12 is retained in the appropriate position by means of a coil compression 5 spring 13 with a loop at one end which the cyclist may place over one or other of the two anchor posts 14a, 14b provided for that purpose. Figures 4b and 4c show the cover 13 of the crank mechanism removed, to reveal the ratchet 16 and the engagement and disengagement of the ratchet lever 12 with the ratchet. The ratchet mechanism 12, 13, 14, 16 is contained in a housing 17 located at the left hand end of the crank shaft 6. Instead of a ratchet mechanism any other desired mechanism may be used to releasably constrain pedal rotation to one direction only, for example a clutch mechanism may be used. In an alternative construction (not illustrated), the mechanism need not be releasable, instead pedal rotation is permanently constrained to one direction.

Claims: A cycle which is convertible between an exercise configuration in which the saddle (5) and pedals (4a, 4b) are connected to a crank shaft (6) in phase with one another with the saddle (5) being connected to the crank shaft (6) out of phase with the pedals (4a, 4b) so that the cycle may be propelled forwardly by the application of force alternately to the pedals (4a, 4b) and to the saddle (5), and a cruising configuration in which the saddle is connected to a cycle frame (1) and the two pedals (4a, 4b) are connected to the crank shaft (6) out of phase with one another so that the cycle may be pedalled by force applied alternately to each pedal (4a, 4b) in the conventional manner, characterised by a mechanism (12) operative to limit rotation of the crank shaft (6) with respect to the cycle frame (1) to the rotational direction for forward travel of the cycle. A cycle as claimed in claim 1, wherein said mechanism (12) is releasable. A cycle as claimed in claim 1 or 2, wherein said mechanism (12) is a ratchet mechanism. A cycle as claimed in claim 1 or 2, wherein said mechanism (12) is a clutch mechanism. A cycle as claimed in claim 3, wherein said ratchet mechanism comprises a lever (12) pivotal ly moveable between a disengaged position and an engaged position, two anchor posts (14a, 14b) respectively provided on either side of said lever (12), and a spring (13) selectively locatable between one of said anchor posts (14a, 14b) and said lever (12) to maintain said lever (12) in a desired engaged or disengaged position. A cycle in which rotation of a drive wheel (3) can be effected by the application of force alternately to pedals (4a, 4b) and to a saddle (5), in which the saddle (5) and the pedals (4a, 4b) are connected to a crank shaft (6) in a configuration such that when the saddle (5) is at the bottom dead centre position pedal cranks (6a, 6b) and the pedals (4a, 4b) are just forward of the top dead centre position and a crank mechanism (12 to 17) is provided to limit rotation of the crank shaft (6) to the rotation for forward travel of the cycle. A cycle in which rotation of a drive wheel (3) can be effected by the application of force alternately to pedals (4a, 4b) and to a saddle (5), in which a crank mechanism includes a mechanism (12 to 17) for limiting rotation of a crank shaft (6) to the forward direction of travel of the cycle only.

Inventors: HUNG GEORGE HON CHEUNG, HUNG, GEORGE HON CHEUNG
Applicants: HUNG GEORGE HON CHEUNG, HUNG, GEORGE HON CHEUNG
Application year: 1993
Main classification: B62M1
IPC codes: B62J1