AU2014202010B2 - Lever Driven Handcycle - Google Patents

Abstract

A handcycle 1 is disclosed, which supports a rider in a seated or kneeling position and is propelled by means of side-mounted crank levers 14 and 15, whereby the action of pushing either lever forward turns the rear driven wheel 5. One of the crank levers 15 also serves as a steering device, whereby it may be moved left or right to steer the front wheels 7L and 7R of the vehicle. The propulsion and steering functions of crank/steering lever 15 may be performed concurrently and are enhanced by the inclusion of a steering centring system, which biases the steered wheels to a generally centred position, in order to prevent unintended directional excursions caused by the action of cranking. The novel steering centring system described herein improves upon previous lever driven handcycle designs by assisting the rider to maintain more effective directional control whilst propelling the vehicle. f6 M 10 ), 7L 61-

Description

LEVER DRIVEN HANDCYCLE TECHNICAL FIELD

[0001] The present invention is in the field of handcycles, which are occupant propelled vehicles designed to be powered exclusively by hand. Handcycles provide individuals with lower-body disabilities with the means to engage in a form of cycling by using their arms and hands, rather than their legs and feet.

BACKGROUND ART

[0002] Most conventional, commercially available handcycles are propelled by means of a rotary crank system mounted in front of the rider and turning a single, driven front wheel. Franks US 6105986, and LofgrenUS 7722071B1, both disclosed vehicles propelled by such means. An alternative, and much less common concept, is the lever driven handcycle, which employs side-mounted cranking levers for propulsion. The levers, mounted either side of the rider, are moved in a back and forth motion to propel the vehicle, via a drive train system. The main benefit of lever cranking systems over rotary cranking systems is that they allow the rider to take more advantage of their upper body mass and leverage to apply greater power during cranking action. Spiess US 4460190, Stout US 4705284, Gramckow US 5536029, and Redman US 6352274B1 all disclosed hand powered vehicles propelled by lever means. SUMMARY OF INVENTION Steering Control Problem [0003] The steering of any handcycle poses a technical challenge, since the rider’s hands are primarily engaged in the task of propulsion, not steering. On conventional rotary crank handcycles, steering of the driven front wheel is facilitated by mounting the cranking system on a steering headset, which supports the forks and front wheel, such that rotation of the entire cranking assembly left or right effects turning of the front wheel. Thus, the cranking assembly on a conventional handcycle serves a secondary function as a form of steering wheel, which is held by both hands of the rider and provides a high degree of directional control over the vehicle.

[0004] Lever driven handcycles, however, do not benefit from a steering wheel type assembly. Instead, most examples have two freewheeling front wheels which are steered by means of crank levers, whereby one or both levers are moved left or right to facilitate steering of the front wheels, via a steering control system. Thus, the rider of a lever driven handcycle moves the crank levers forward and aft to propel the vehicle but must also concurrently move them left or right to steer the vehicle. The fore-aft movement of the levers is a gross motor skill involving large physical displacements, whilst the left right movement of the levers for steering is a fine motor skill involving small physical displacements. Since the two movements are combined in the one propulsion/steering action, it can be difficult for the rider to accurately control the fine motor steering movement whilst simultaneously applying the gross motor cranking movement. In practice this means that it can be difficult for the rider of a lever driven handcycle to maintain effective directional control of the vehicle whilst propelling it.

Solution to the Steering Control Problem [0005] In order to improve the directional control of lever driven handcycles there is a need for some means of assistance to the rider with the fine motor action of moving the crank levers left and right for steering, whilst simultaneously performing the gross motor action of cranking them forward and aft for propulsion. Since the generally preferred direction of travel of any vehicle is in a straight line, it would thus be of benefit to the rider if the natural tendency of a lever driven handcycle was to travel in a straight line, without impeding the ability to turn. That is, the vehicle’s steering system would ideally be biased to a generally neutral position, such that the wheels are centred in order to guide it in a generally straight line. This would thereby minimise the steering effort required of the rider to maintain a straight path, but at the same time permit steering. Thus, the objective of the present invention is to provide such a steering centring system for lever driven handcycles.

[0006] The present invention is based on a three or four wheeled design with at least one driven rear wheel, and two steerable front wheels. Propulsion is by means of two side-mounted ratchet-action crank levers which the rider moves in a back and forth motion to propel the vehicle. The crank levers turn a crankshaft, via interposed ratchet mechanisms, which is connected to a drive train. In the preferred embodiment the drive train consists of chain rings, chains and sprockets mounted beneath the rider and connected to the rear wheel.

[0007] The novel steering centring system of the present invention utilises dual, opposed elastic elements installed within the steering system such that they bias the system to a generally neutral position. This results in the front wheels of the handcycle remaining in a generally centred position, thus assisting the rider to maintain the desired direction of travel without unintended excursions due to the act of cranking the levers for propulsion. When a turn is required the rider simply applies lateral pressure to the crank lever in the desired direction of turn, thus turning the front wheels in the corresponding direction, away from the centre position bias. When the turn is complete the rider simply releases lateral pressure on the lever and the system returns to the neutral position, with the wheels being centred. In the preferred embodiment, said elastic elements comprise steel springs attached either side of a bell crank within the steering system and anchored to the frame with symmetrical tension such that the system is biased to a generally neutral position resulting in the steered front wheels being in a generally centred position.

BRIEF DESCRIPTION OF DRAWINGS

[0008] FIG. 1 is a perspective view, from the front left, of the preferred embodiment of the present invention.

[0009] FIG. 2 is a left view of the preferred embodiment, showing the drive train and seating arrangement in more detail.

[0010] FIG. 3 is a close up perspective view from the front right of the crank lever steering system of the present invention. The associated crank/steering lever, crank shaft, bell crank and tie-rods are shown.

[0011] FIG. 4 is a front view of the preferred embodiment of the present invention, illustrating the operation of the crank/steering lever during a left turn.

[0012] FIG. 5 is a close up perspective view from the front left of the front T-section portion of the frame, highlighting the novel steering centring system of the present invention, comprising dual, opposed elastic elements within the steering system.

[0013] FIG. 6 is a perspective view of a kneeling saddle, which can be used in lieu of a seat, in the preferred embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

[0015] The preferred embodiment of the present invention is illustrated in FIG. 1. Handcycle 1 carries a rider in an upright seated position. A frame constructed of tubular steel, aluminium, metal alloy or composite material is comprised of a longitudinal member 2 joined to a transverse front axle member 3, forming a T-section. The rear end of said longitudinal member is joined to a rear fork member 4, upon which is rotatably mounted a rear wheel 5. A pair of front wheels 7L and 7R are rotatably mounted upon kingpin/spindle assemblies 6L and 6R respectively, which are hingedly attached to the ends of front axle member 3. A seat mount 32 is attached to said frame via a plurality of support members attached to longitudinal member 2 and rear fork member 4. Seat mount 32 comprises a pair of spaced apart, parallel frame members, fixedly attached to one another. A seat 31 (shown in outline form only, for clarity) is attached to seat mount 32 to support a rider. Also shown in outline form in FIG. 1 is footrest pan 36, which is supported by longitudinal member 2, and front axle member 3.

[0016] Crankshaft 16 is mounted transversely and rotatably upon longitudinal member 2, beneath seat mount 32, and is operatively engaged with rear wheel 5, via a drive train means. Said drive train means comprises chain rings, sprockets, chains and gears, which are detailed in FIG. 2. Crank levers 14 and 15 are attached to crankshaft 16 via ratchet mechanisms 17L and 17R respectively. Said ratchet mechanisms allow their respective crank levers to be moved in a back and forth motion in order to rotate said crankshaft. Forward motion of said crank levers engages said ratchet mechanisms and thereby rotates said crankshaft forwards, whilst rearwards motion of said levers disengages their respective ratchet mechanisms and allows said levers to return to their start of stroke positions towards the rear. The reciprocating movement of the crank levers may be made in unison, or in an alternating fashion, since they operate independently. Said ratchet mechanisms are also reversible, in order to disengage the crank levers from the drive train, to enable freewheel operation. This facilitates ease of re-positioning said crank levers for the operating convenience of the rider, such as during commencement of cranking, or when reversing or manoeuvring the vehicle.

[0017] Steering of said vehicle is achieved by using crank lever 15 as a steering device. Said lever is pivotably attached to ratchet mechanism 17R, at the end of crankshaft 16, such that it may be moved laterally, whereby left or right movement of said lever is transmitted, via a steering linkage system, to said front wheels. Said steering linkage system comprises a tie-rod 13, which connects crank/steering lever 15 with one arm of bell crank 12, which is mounted upon said frame adjacent to said crankshaft. The other arm of bell crank 12 (not visible in this view but shown in FIG. 3) is connected to tie-rod 11, which runs to the front of said vehicle beneath longitudinal member 2, where it connects with one arm of a second bell crank, 10, attached to front axle member 3. The other arm of bell crank 10 is connected to the inboard ends of tie-rods 9L and 9R. The outboard ends of tie-rods 9L and 9R are connected to steering arms 8L and 8R respectively. Said steering arms are attached to kingpin/spindle assemblies 6L and 6R, which are attached to the ends of front axle member 3. Front wheels 7L and 7R are rotatably mounted upon kingpin/spindle assemblies 6L and 6R respectively. The tie-rods and bell cranks described herein comprise the steering linkage system of said vehicle, and permit the transmission of steering movement from crank/steering lever 15 to said kingpin/spindle assemblies of said front wheels, thus enabling steering of said vehicle.

[0018] FIG. 2 is a left view of the preferred embodiment. Chain ring 18 is attached to and driven by crankshaft 16 (not visible in this view, but shown in FIG. 1 and FIG. 3) and is operatively engaged with freewheel sprocket 20 via forward chain 19. Freewheel sprocket 20 is connected axially, via an internal crankshaft, to chain ring set 21, which is operatively engaged with geared hub 23, via rear chain 22. Geared hub 23 is affixed to, and turns, rear wheel 5 and rear chain 22 is kept taught by chain tensioner 27. Thus, power is transmitted from the crankshaft to the rear wheel via a drive train comprising chain rings, chains, a freewheel sprocket and a geared hub. Alternative embodiments may use any other suitable combination of drive train and gearing means, including but not limited to gear boxes, drive shafts, drive belts and sprocket clusters.

[0019] FIG. 2 also shows integrated handgrip and twist-type gear shifters 24 and 25 on crank levers 14 and 15 respectively. Gear shifter 24 controls forward derailleur 26 and gear shifter 25 controls geared hub 23. Any other type of gear shifting mechanisms, including but not limited to bar-end, trigger, integrated, or electronic, could also be used in lieu of the twist grip system shown.

[0020] Brake lever 28L, mounted next to handgrip/gear shifter 24, on crank lever 14, controls a brake unit 30L on left front wheel 7L, via a brake control cable. Similarly, brake lever 28R, mounted on crank/steering lever 15, controls the right-hand brake unit, via its brake control cable. The brake units may be disc brakes as shown, or drum brakes, for easier removal of the front wheels.

[0021] Seat 31 is fastened to seat mount 32 using seat attachment brackets 33 and bolts 35. Said bolts may be substituted with quick release pins for ease of seat removal. Fore-aft seat position can be adjusted for rider preference by moving seat 31 forward and aft along seat mount 32 using adjustment holes 34. Seat 31 may be substituted with a kneeling saddle, shown in FIG. 6, which may be attached to said seat mount in a similar fashion to said seat, but allowing the rider to assume a kneeling position instead of a seated position. Kneeling enables the rider to lean further forward, and thus achieve increased cranking leverage. Foot rest pan 36 is suspended from longitudinal frame member 2 and front axle member 3 (not visible, but shown in FIG. 1) in order to provide foot support means for the rider.

[0022] FIG. 3 is a perspective view of the crank/steering system of the present invention.

It shows crank/steering lever 15 connected via pivot pin 53 to ratchet mechanism 17R, which is attached to the end of crankshaft 16. It also shows crank lever 14 connected to said crankshaft via ratchet mechanism 17L. Crankshaft 16 is turned by the action of said crank levers and ratchet mechanisms about crankshaft axis 55 in direction of rotation 56. Said crankshaft is mounted transversely upon longitudinal member 2, and is supported by bearing assembly 48. Tie-rod 13 connects crank/steering lever 15 with bell crank 12. Bell crank 12 is comprised of longitudinal arm 12L and transverse arm 12T, which are rigidly attached to one another via connecting pin 12P. Bell crank 12 is mounted adjacent to crankshaft 16 upon U-bracket 49, which is attached to longitudinal member 2. The outboard end of tie-rod 13 is connected to crank/steering lever 15 via connection 51 and attachment bracket 50. The inboard end of tie-rod 13 is connected to longitudinal arm 12L, of bell crank 12, via connection 52. Transverse arm 12T, of bell crank 12, is connected to tie-rod 11, which runs to the front of the handcycle beneath longitudinal frame member 2, and connects with the remainder of the steering system.

[0023] Connection 51, between tie-rod 13 and crank/steering lever 15, is displaced sufficiently away from pivot pin 53 that substantial leverage may be applied by said lever upon longitudinal bell crank arm 12L, via tie-rod 13. (If connection 51 is located too close to pivot pin 53, then the available leverage is reduced to the point of being ineffective.) As a result, left/right movement of crank/steering lever 15, about pivot pin 53, produces a corresponding lateral displacement of bell crank arm 12L, via tie-rod 13. As longitudinal bell crank arm 12L moves laterally, so transverse bell crank arm 12T moves longitudinally, thereby moving tie-rod 11 forward or aft accordingly. This movement is transmitted via the remainder of the steering system to the front wheels. Thus, lateral displacement of crank/steering lever 15 results in steering movement of said front wheels.

[0024] Connection 52, between tie-rod 13 and longitudinal bell crank arm 12L, is located proximate to the axis of rotation 55 of crankshaft 16, immediately above said crankshaft, as shown. Such positioning of said connection close to said crankshaft axis allows crank/steering lever 15 to have freedom of movement both laterally and longitudinally (within the normal operating range of the levers’ arc of reciprocation 54). This means that said lever may be moved back and forth to propel said vehicle, whilst at the same time being able to move left and right to steer said vehicle. There is in practice a very small amount of induced lateral movement of said bell crank arm when said lever is moved back and forth, due to the fact that said connection cannot physically be located on said crankshaft axis. However, for practical purposes the degree of movement is negligible and has no noticeable impact upon the steering of said vehicle during cranking action.

[0025] In the preferred embodiment shown, tie-rod 13 and connections 51 and 52 are located above crankshaft 16. In an alternative embodiment, said tie-rod and connections could be located below said crankshaft. This would be achieved by lengthening crank/steering lever 15 downwards, beyond pivot pin 53, and re-locating bell crank arm 12L, tie rod 13 and connections 51 and 52 to below said crankshaft. This is a slightly more complex configuration, but the principle of operation remains the same.

[0026] FIG. 4 is a front view of the present invention and illustrates the steering operation of the front wheels. When crank/steering lever 15 is moved to the rider’s left as shown, front wheels 7L and 7R are turned to the left, via the steering system. Lever-rest brackets 37L and 37R are attached to the rear of rider’s seat 31, and provide stowage for crank levers 14 and 15 when not in use. Similar brackets may also be provided below the front of the seat to provide forward stowage positions. Also shown are brake/gear cable sets 38L and 38R, which control their respective brakes units, derailleur and geared hub.

[0027] FIG. 5 is a close-up perspective view of the T-section portion of said frame and associated front-end steering system components. It shows longitudinal frame member 2 joined to front axle member 3. Bell crank 10 rotates about mounting pin 47, and is actuated by fore-aft movement of tie-rod 11, which causes tie-rods 9L and 9R to move left or right accordingly, thereby turning their respective front wheels. Installed within the steering system are the novel dual, opposed elastic elements 45L and 45R. (Not shown in FIG. 1, for clarity of illustration) In the preferred embodiment said elastic elements comprise coil steel springs attached either side of bell crank 10, with their opposite ends being attached to frame lugs 46L and 46R. Said elastic elements are situated so as to bias the steering system to a generally centred position, such that the natural tendency of the vehicle is to proceed in a generally straight line.

[0028] Said elastic elements serve to assist the rider to steer the cycle, particularly during the act of moving the crank levers back and forth for propulsion, by counteracting any unintended lateral movement of said levers. Intentional steering commands, however, are simply applied against the elastic force as required, thereby providing effective steering control at all times. In alternative embodiments said elastic elements may be constructed of different elastic material, may be installed at different locations within the steering system, or may be integrated into a single assembly with only two connection points. Regardless of material or installation, the purpose of dual, opposed elastic elements is to bias the steering system to a generally centred position.

[0029] FIG. 6 is a perspective view of a representative kneeling saddle 41, which may be fitted in lieu of a seat, to seat mount 32, using the same attachment fittings. Kneeling saddle 41 provides support to the rider’s buttocks, via seat 42, and lower legs, via leg rests 43L and 43R, to achieve an upright kneeling position. Lever rest brackets 44L and 44R provide stowage for said crank levers when not in use. A kneeling position allows the rider to lean further forward and take greater advantage of their upper body mass to supplement arm strength. Said saddle may be further contoured and padded to provide optimum rider comfort and ergonomics.

Alternative Embodiments [0030] In an alternative embodiment of the hand-propelled vehicle described herein and shown in FIG. 1, said handcycle could be suitably adapted to accept a second rear wheel, via the substitution of rear fork member 4 with a wider rear fork member, or a transverse rear axle member, suitable for accommodating a pair of laterally spaced rear wheels.

[0031] Said handcycle frame could also be adapted to be collapsible, via the installation of a fastenable hinge or joint in the forward portion of longitudinal member 2, shown in FIG. 1. This would enable the folding or dismantling of said frame, once said wheels and seat were removed, in order to facilitate the compact transportation thereof. In a further embodiment, said frame may be constructed of heavier duty material to provide increased strength and durability for off-road applications. In addition, said durable frame may be fitted with suspension and shock-absorbtion means for the front and/or rear wheel/s in order to provide improved off-road handling and performance.

Claims (5)

1. CLAIMS The invention claimed is:

   1. A handcycle, being a land vehicle propelled by the hands of an occupant, comprising: a frame; two laterally spaced, steerable wheels, rotatably and hingedly mounted upon opposite sides of said frame, towards the front of said vehicle; at least one driven wheel rotatably mounted upon said frame towards the rear of said vehicle; occupant support means mounted upon said frame, for carrying a rider upon said vehicle; two lever means for propulsion, located either side of said occupant support means, comprising crank levers for translating a back and forth motion of the arms of the rider into a rotational motion of said rear driven wheel/s, so as to propel said vehicle forwards; a crankshaft, transversely and rotatably mounted upon said frame, beneath said occupant support means, and pivotably connected at either end to said crank levers, either fixedly or via interposing ratchet means; propulsion means, comprising said crank levers rotating said crankshaft and said crankshaft operatively engaging said rear driven wheel/s via a drive train means; crank/steering lever means, comprising at least one of said crank levers, pivotably connected to said crankshaft, such that said lever/s may be moved to the left or right in order to effect corresponding steering movement of said front wheels, so as to guide said vehicle; steering linkage system means, comprising tie-rods and bell cranks connecting said crank/steering lever/s with steering arm and kingpin/spindle assemblies associated with said front wheels; and steering centring means, comprising dual, opposed elastic elements installed within said steering system in order to bias said steering system to a generally centred position.
2. 2. The vehicle according to claim 1 which further includes: gearing means, associated with said drive train means, enabling variable mechanical advantage in the translation of the reciprocating action of said crank lever means into the rotation of said driven rear wheel/s, and operatively engaged with gear selection means co-located with handgrips on said crank lever means; and braking means, comprising at least one brake unit associated with at least one wheel, and operatively engaged with brake lever/s co-located with said handgrips on said crank lever means.
3. 3. The vehicle according to claim 2 which further includes: footrest means, attached to said frame such that the rider’s feet and legs are supported and do not hinder the operation of said vehicle when in use; lever rest means attached to said vehicle, such that said crank levers may be stowed in a forward and/or aft position when not in use; occupant support adjustment means, such that the position of said support means may be adjusted forward or aft upon said frame, according to rider preference; and occupant support adaption means, such that a kneeling saddle may be used in lieu of a seat, via common attachment means.
4. 4. The vehicle according to claim 3 which further includes: front and/or rear suspension and shock absorption means, for the purpose of off-road applications.
5. 5. The vehicle according to claim 3 which further includes: collapsible frame means, comprising a fastenable joint or hinge installed within said frame, such that, with wheels and seat removed, said frame may be dismantled or folded for the compact transportation thereof.