CA2556883A1 - Track drive suspension system for a rider propelled vehicle - Google Patents
Track drive suspension system for a rider propelled vehicle Download PDFInfo
- Publication number
- CA2556883A1 CA2556883A1 CA 2556883 CA2556883A CA2556883A1 CA 2556883 A1 CA2556883 A1 CA 2556883A1 CA 2556883 CA2556883 CA 2556883 CA 2556883 A CA2556883 A CA 2556883A CA 2556883 A1 CA2556883 A1 CA 2556883A1
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- Prior art keywords
- track
- link
- frame
- belt
- tension
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D55/00—Endless track vehicles
- B62D55/06—Endless track vehicles with tracks without ground wheels
- B62D55/07—Mono-track vehicles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62M—RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR SINGLE-TRACK CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES
- B62M27/00—Propulsion devices for sledges or the like
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62M—RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR SINGLE-TRACK CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES
- B62M27/00—Propulsion devices for sledges or the like
- B62M27/02—Propulsion devices for sledges or the like power driven
- B62M2027/021—Snow bikes resembling conventional motorcycles
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Axle Suspensions And Sidecars For Cycles (AREA)
Abstract
For a tracked cycle supported and driven by an endless track, the improvement including a track drive suspension system which engages and supports the endless track in a quadrilateral orientation. A guide wheel carriage operably supports multiple pairs of guide wheels, which in turn support the terrain engaging portion of the track. The guide wheel carriage is supported by upper and lower members, and a shock absorber is disposed between the frame and the lower member to absorb impact forces imposed on the track. A
first end of a tension member is pivotally mounted to the frame above the upper link, and the second end operatively supports an idle wheel adapted to guide and support the portion of the endless track above the ground engaging portion. A third point on the tension link is pivotally connected to a first end of a couple link, and the second end is attached to the upper member by a prismatic joint. A first end of a position link is connected coaxially with the second end of the couple link, and the second end of the position link is pivotally connected to the frame.
first end of a tension member is pivotally mounted to the frame above the upper link, and the second end operatively supports an idle wheel adapted to guide and support the portion of the endless track above the ground engaging portion. A third point on the tension link is pivotally connected to a first end of a couple link, and the second end is attached to the upper member by a prismatic joint. A first end of a position link is connected coaxially with the second end of the couple link, and the second end of the position link is pivotally connected to the frame.
Description
TITLE
Track Drive Suspension System for a Rider Propelled Vehicle TECHNICAL FIELD
The present invention concerns the design and construction of an articulating, endless loop track drive. More particularly, the present invention concerns a track drive as a propulsion means for a sledge type vehicle that is suitable for rider generated power.
Moreover, the present invention concerns the design for an articulated track drive system which minimizes operational energy losses involved with suspension feedback due to drive torque.
BACKGROUND OF THE INVENTION
The problem of traversing soft and irregular terrain by rider propelled means has been addressed by various devices over the past century, which seek to approach the efficiency and enjoyment to that provided by a typical bicycle. It is known that the conventional bicycle has traction and stability limitations when employed over snow covered or other soft terrain, mainly due to its relatively small amount of terrain contact area, or footprint, provided by the wheels. There exists a desire for a vehicle that can operate effectively on terrain beyond the limitations of these vehicles, either for transportation needs or for recreation.
To this end, a family of rider propelled vehicles have been developed which generally duplicate the conventional bicycle rider position and orientation, and are adapted for snow travel with a single or dual skis replacing the front wheel, and a track drive system replacing the rear wheel. These devices are most commonly provided as a convertible kit for an existing bicycle, although some designs are single-purpose, track-dedicated cycles.
Issued to Randall E. Rhode on April 7th, 1992, U.S. Patent Number 5,102,153 discloses a "Snow Cycle Attachment for a Bicycle Frame" as a conversion kit for a bicycle, which provides dual narrow tracks fixed to either side of the rear wheel, trained about a carriage and driven by frictional contact with the rear bicycle wheel. Also to Mr. Rhode, U.S. Patent Number 5,423,559 was issued on June 13th, 1995 for a "Snow Cycle" which presents a similar design to the '153 offering; however it has the track trained about the drive wheel. These designs may provide adequate and enjoyable performance over packed terrain, although track suspension is not provided for.
Canadian Patent Number 2,299,718 issued to Joshua Millstein on February 29th 2000, discloses a snow cycle with a track drive system that is rigidly mounted to the vehicle frame, and employs a chain link-style track belt that is indexed to an array of guide wheels that resemble conventional chain rings. This drive system provides no track suspension and allows bump forces to be transmitted to the rider; reducing both the stability of the vehicle and rider comfort.
As illustrated in Figure 1, U.S. Patent Number 6,164,670 issued on December 26th 2000 to Abarca et al. discloses a tracked cycle that provides a triangular track drive system which includes a suspension linkage in its design. While this solution improves on the '718 design by incorporating track suspension, the articulation is limited to the leading pair of guide wheels, and the portion of track contacting the terrain is only partially suspended.
Issued to Cheney et al. on December 16'h, 2003, U.S. Patent Number 6,663,117 discloses a "Tracked Bicycle" as a conversion kit for a conventional suspension bicycle. As with Patent Number 5,423,559, a single ski replaces the front wheel, and a narrow track is trained about a drive wheel similar in size to the original bicycle wheel. In addition to any suspension provided by the original bicycle frame; supporting the rear portion of the track is an idle wheel assembly that is mounted to a flexible spring frame to offer additional ground contact articulation.
Although the prior art mentioned may provide an enjoyable means of propulsion over difficult terrain and under difficult conditions, it is desirable to improve upon these means to produce a more efficient solution, where rider energy input to the vehicle propels it the greatest distance possible. Many of the prior art propulsive suspension systems provide impact absorbing articulation, however it is desirable to improve these systems to increase efficiency.
For vehicles intended to operate over rough or difficult terrain and under difficult conditions such as deep snow, mud, sand or tundra, it is known that a preferred means of propulsion and support is the endless loop track. In comparison to a wheel, the increased amount of ground-contacting surface area provides a reduced footprint pressure and hence, more 'float' (the resistance to the vehicle sinking) when used over soft terrain. Given the intended, irregular terrain, it is understood that ideally the track drive system incorporates some measure of articulation (or suspension) relative to the frame and rider. There are two main benefits of providing suspension support, namely improved rider comfort, and increased performance.
Increased rider comfort can be defined as attenuating the vibrations transmitted through the vehicle frame to the rider, which arise from any bump or impact forces acting on the ground contacting elements during travel over rough terrain. A reduction of these vibrations felt by the rider directly correlates to an increase of comfort, and greater enjoyment of use.
Secondly, a performance improvement provided by suspension is related to control, which is largely a function of maintaining track contact with the terrain [4].
When the track is not in contact with the terrain, rider control of vehicle acceleration, braking and steering are significantly diminished or absent. An unsuspended vehicle operating with forward velocity over rough terrain tends to intermittently lose contact with the surface, or 'hop', leading to intermittent control. Thus the performance advantage of track suspension is in reducing this hop, thereby minimizing the amount of time the track loses contact with the ground. An additional performance attribute of suspension is a reduced amount of rider fatigue arising from energy expended to maintain stability of the vehicle.
Incorporating the endless track drive to a rider propelled vehicle design has specific problems which require attention in order to produce an efficient and comfortable vehicle. The many well known snowmobile track systems designed for motorized propulsion are rendered virtually impractical for rider powered vehicle application, due to their inherent weight and friction components.
Analogous with common bicycle suspension designs, it is desirable to minimize any interaction between the suspension and the pedal forces transmitted through the drive system.
Canadian Patent Number 2,424,428 issued to Rocky Mountain Bicycles teaches that the ratio of the energy absorbed by the suspension system due to terrain irregularities, to the total energy absorbed by the suspension is termed the "efficiency" of the suspension system. Given the power output available from a typical person; it is desirable to maximize these efficiencies, because even small energy losses tend to be noticeable to the rider, as either less distance traveled, or more energy required by the system.
Additionally, the '428 patent discloses that if drive train forces are not isolated from suspension actuation, the rider feels feedback from the pedals as the suspension absorbs impacts. The teaching of patent '428 states that pedal feedback is reduced with a bicycle design that provides a chain-line that increases in length through the compression stroke of the shock absorber. Comparisons can be drawn between this teaching and the design of a track drive suspension system, such that by providing support for the track belt in a constant, or increasing length manner, pedal feedback is minimized.
With respect to prior art bicycle designs and preferred spring rate progression; U. S.
Patent Number 6,926,298 issued to Anthony Ellsworth of the United States teaches, like the '778 patent, that a rising rate spring progression is preferred for bicycle suspension to avoid bottoming of the compression stroke.
In considering prior art designs of snowmobile track suspension; Canadian Patent Number 2,453,778 issued to Kubota and Yoshihara of Japan on December 19, 2003, teaches that a track drive suspension system benefits from a rising spring rate. This prevents the suspension from bottoming its compression stroke, which is a known negative performance attribute.
SUMMARY OF THE INVENTION
It is, therefore, a feature of the present invention to provide an articulated track drive system for a tracked cycle which effectively isolates the rider from impacts and vibrations due to terrain irregularities encountered during operation, wherein the primary load bearing linkage is of the four-bar linkage format.
It is another feature of the present invention to provide an articulated track drive system which supports the track belt in a generally constant or increasing length manner at all points through the articulation range of the system. That is to say that the articulation of the track suspension system does not induce significant tension or slack on the track belt while functioning to isolate the rider from impacts or vibrations encountered during operation.
It is a further feature of the present invention to provide an articulating track drive system which isolates operation of the drive train from influencing track suspension position and vice-versa.
Therefore in accordance with the broader aspects of the present invention and in addressing the foregoing problems, there is provided an articulating track drive system for a tracked cycle having a frame, and a hub disposed on the frame connected operatively to a pedal-crank set for power generation. A track drive system is disposed below and rearward of the frame assembly, and is operatively connected to the crank set through a multispeed gearshift mechanism.
According to this embodiment of the present invention, the generally quadrilateral-shaped track drive system includes a track belt assembly trained about: a sprocket assembly mounted operatively to the frame, a track suspension linkage extending beneath and rearward from the frame, and an idle wheel linkage coupled to and above the suspension linkage, as well as the frame.
The track belt is formed from an endless flexible belt with multiple lugs mounted transverse to the belt, and spaced apart about the outer surface perimeter, and plural track alignment tabs mounted to the inner surface. The track belt of the present invention is formed as a composite composed of inner belts of aramid fibre and outer plies of rubber.
The track suspension linkage is comprised of a guide wheel carriage disposed beneath and rearward of the frame, and coupled to the frame by upper and lower suspension members to create a four bar linkage. The linkage is limited by a shock absorber that is operatively connected between the lower suspension member and the frame. The shock absorber serves to absorb impact forces imposed on the suspension during operation, and to restore the linkage to its extended position. The shock absorber and linkage are disposed to act at a specific rate at each point through the suspension travel.
The guide wheel frame supports a first pair of guide wheels mounted to the front end, a second pair of guide wheels operatively connected to the rear end, and four pairs of tertiary guide wheels operatively connected midway between the first and second pairs of guide wheels by a triangular bracket, that is pivotally mounted to the guide wheel frame.
The guide wheels are oriented to define a plane along their lower periphery to contact the inner surface of the track belt, and support the vehicle. The inside vertical surfaces of each wheel are aligned coplanar, to facilitate smooth intermittent contact with the track alignment surfaces.
In this embodiment, an idle (or tension) linkage assembly is connected above and in series with the suspension linkage and the frame, creating a one degree of freedom, seven-bar linkage with the frame as the ground link. Dual idle wheels are aligned coplanar with the inside vertical surface of the lower guide wheels, and are each pivotally mounted to an axle that is fixed to the distal ends of a tandem pair of triangular links with the proximal end of the links pivotally connected to the frame, and a pair of coupler links operatively connect the upper suspension member to the third point of the triangular link at the opposite ends. The linkage is arranged such that the idle wheels contact the inside surface of the track belt generally midway between the sprocket assembly and distal guide wheel, supporting the upper section of the track belt. The tension linkage is arranged to position the idle wheels such that a constant length perimeter of the suspension system is maintained throughout the range of suspension travel. Also, the geometry and orientation of the linkage defines a mechanical advantage and application rate between the idle wheel and the upper suspension member.
When torque is applied to the track drive system of the present invention, the terrain contacting portion of the track engages the ground. It is known that drive forces applied to a suspended track system tend to actuate its compression, and such actuation is undesirable as it removes energy from propulsive efforts and thus reduces system efficiency. The mechanical advantage of the tension linkage assembly is adapted to oppose the tendency The suspension system of the present invention advantageously places the shock absorber in an operational condition with a rising rate, such that most large impacts may be absorbed by the system without having the compression stroke thereof bottom out. This is desirable because it is known that a system prone to bottoming out tends to transmit large impacts to the rider, which is a negative performance attribute. The track suspension system of the present invention is shown to provide a rising rate shock progression, addressing this negative performance attribute.
Track Drive Suspension System for a Rider Propelled Vehicle TECHNICAL FIELD
The present invention concerns the design and construction of an articulating, endless loop track drive. More particularly, the present invention concerns a track drive as a propulsion means for a sledge type vehicle that is suitable for rider generated power.
Moreover, the present invention concerns the design for an articulated track drive system which minimizes operational energy losses involved with suspension feedback due to drive torque.
BACKGROUND OF THE INVENTION
The problem of traversing soft and irregular terrain by rider propelled means has been addressed by various devices over the past century, which seek to approach the efficiency and enjoyment to that provided by a typical bicycle. It is known that the conventional bicycle has traction and stability limitations when employed over snow covered or other soft terrain, mainly due to its relatively small amount of terrain contact area, or footprint, provided by the wheels. There exists a desire for a vehicle that can operate effectively on terrain beyond the limitations of these vehicles, either for transportation needs or for recreation.
To this end, a family of rider propelled vehicles have been developed which generally duplicate the conventional bicycle rider position and orientation, and are adapted for snow travel with a single or dual skis replacing the front wheel, and a track drive system replacing the rear wheel. These devices are most commonly provided as a convertible kit for an existing bicycle, although some designs are single-purpose, track-dedicated cycles.
Issued to Randall E. Rhode on April 7th, 1992, U.S. Patent Number 5,102,153 discloses a "Snow Cycle Attachment for a Bicycle Frame" as a conversion kit for a bicycle, which provides dual narrow tracks fixed to either side of the rear wheel, trained about a carriage and driven by frictional contact with the rear bicycle wheel. Also to Mr. Rhode, U.S. Patent Number 5,423,559 was issued on June 13th, 1995 for a "Snow Cycle" which presents a similar design to the '153 offering; however it has the track trained about the drive wheel. These designs may provide adequate and enjoyable performance over packed terrain, although track suspension is not provided for.
Canadian Patent Number 2,299,718 issued to Joshua Millstein on February 29th 2000, discloses a snow cycle with a track drive system that is rigidly mounted to the vehicle frame, and employs a chain link-style track belt that is indexed to an array of guide wheels that resemble conventional chain rings. This drive system provides no track suspension and allows bump forces to be transmitted to the rider; reducing both the stability of the vehicle and rider comfort.
As illustrated in Figure 1, U.S. Patent Number 6,164,670 issued on December 26th 2000 to Abarca et al. discloses a tracked cycle that provides a triangular track drive system which includes a suspension linkage in its design. While this solution improves on the '718 design by incorporating track suspension, the articulation is limited to the leading pair of guide wheels, and the portion of track contacting the terrain is only partially suspended.
Issued to Cheney et al. on December 16'h, 2003, U.S. Patent Number 6,663,117 discloses a "Tracked Bicycle" as a conversion kit for a conventional suspension bicycle. As with Patent Number 5,423,559, a single ski replaces the front wheel, and a narrow track is trained about a drive wheel similar in size to the original bicycle wheel. In addition to any suspension provided by the original bicycle frame; supporting the rear portion of the track is an idle wheel assembly that is mounted to a flexible spring frame to offer additional ground contact articulation.
Although the prior art mentioned may provide an enjoyable means of propulsion over difficult terrain and under difficult conditions, it is desirable to improve upon these means to produce a more efficient solution, where rider energy input to the vehicle propels it the greatest distance possible. Many of the prior art propulsive suspension systems provide impact absorbing articulation, however it is desirable to improve these systems to increase efficiency.
For vehicles intended to operate over rough or difficult terrain and under difficult conditions such as deep snow, mud, sand or tundra, it is known that a preferred means of propulsion and support is the endless loop track. In comparison to a wheel, the increased amount of ground-contacting surface area provides a reduced footprint pressure and hence, more 'float' (the resistance to the vehicle sinking) when used over soft terrain. Given the intended, irregular terrain, it is understood that ideally the track drive system incorporates some measure of articulation (or suspension) relative to the frame and rider. There are two main benefits of providing suspension support, namely improved rider comfort, and increased performance.
Increased rider comfort can be defined as attenuating the vibrations transmitted through the vehicle frame to the rider, which arise from any bump or impact forces acting on the ground contacting elements during travel over rough terrain. A reduction of these vibrations felt by the rider directly correlates to an increase of comfort, and greater enjoyment of use.
Secondly, a performance improvement provided by suspension is related to control, which is largely a function of maintaining track contact with the terrain [4].
When the track is not in contact with the terrain, rider control of vehicle acceleration, braking and steering are significantly diminished or absent. An unsuspended vehicle operating with forward velocity over rough terrain tends to intermittently lose contact with the surface, or 'hop', leading to intermittent control. Thus the performance advantage of track suspension is in reducing this hop, thereby minimizing the amount of time the track loses contact with the ground. An additional performance attribute of suspension is a reduced amount of rider fatigue arising from energy expended to maintain stability of the vehicle.
Incorporating the endless track drive to a rider propelled vehicle design has specific problems which require attention in order to produce an efficient and comfortable vehicle. The many well known snowmobile track systems designed for motorized propulsion are rendered virtually impractical for rider powered vehicle application, due to their inherent weight and friction components.
Analogous with common bicycle suspension designs, it is desirable to minimize any interaction between the suspension and the pedal forces transmitted through the drive system.
Canadian Patent Number 2,424,428 issued to Rocky Mountain Bicycles teaches that the ratio of the energy absorbed by the suspension system due to terrain irregularities, to the total energy absorbed by the suspension is termed the "efficiency" of the suspension system. Given the power output available from a typical person; it is desirable to maximize these efficiencies, because even small energy losses tend to be noticeable to the rider, as either less distance traveled, or more energy required by the system.
Additionally, the '428 patent discloses that if drive train forces are not isolated from suspension actuation, the rider feels feedback from the pedals as the suspension absorbs impacts. The teaching of patent '428 states that pedal feedback is reduced with a bicycle design that provides a chain-line that increases in length through the compression stroke of the shock absorber. Comparisons can be drawn between this teaching and the design of a track drive suspension system, such that by providing support for the track belt in a constant, or increasing length manner, pedal feedback is minimized.
With respect to prior art bicycle designs and preferred spring rate progression; U. S.
Patent Number 6,926,298 issued to Anthony Ellsworth of the United States teaches, like the '778 patent, that a rising rate spring progression is preferred for bicycle suspension to avoid bottoming of the compression stroke.
In considering prior art designs of snowmobile track suspension; Canadian Patent Number 2,453,778 issued to Kubota and Yoshihara of Japan on December 19, 2003, teaches that a track drive suspension system benefits from a rising spring rate. This prevents the suspension from bottoming its compression stroke, which is a known negative performance attribute.
SUMMARY OF THE INVENTION
It is, therefore, a feature of the present invention to provide an articulated track drive system for a tracked cycle which effectively isolates the rider from impacts and vibrations due to terrain irregularities encountered during operation, wherein the primary load bearing linkage is of the four-bar linkage format.
It is another feature of the present invention to provide an articulated track drive system which supports the track belt in a generally constant or increasing length manner at all points through the articulation range of the system. That is to say that the articulation of the track suspension system does not induce significant tension or slack on the track belt while functioning to isolate the rider from impacts or vibrations encountered during operation.
It is a further feature of the present invention to provide an articulating track drive system which isolates operation of the drive train from influencing track suspension position and vice-versa.
Therefore in accordance with the broader aspects of the present invention and in addressing the foregoing problems, there is provided an articulating track drive system for a tracked cycle having a frame, and a hub disposed on the frame connected operatively to a pedal-crank set for power generation. A track drive system is disposed below and rearward of the frame assembly, and is operatively connected to the crank set through a multispeed gearshift mechanism.
According to this embodiment of the present invention, the generally quadrilateral-shaped track drive system includes a track belt assembly trained about: a sprocket assembly mounted operatively to the frame, a track suspension linkage extending beneath and rearward from the frame, and an idle wheel linkage coupled to and above the suspension linkage, as well as the frame.
The track belt is formed from an endless flexible belt with multiple lugs mounted transverse to the belt, and spaced apart about the outer surface perimeter, and plural track alignment tabs mounted to the inner surface. The track belt of the present invention is formed as a composite composed of inner belts of aramid fibre and outer plies of rubber.
The track suspension linkage is comprised of a guide wheel carriage disposed beneath and rearward of the frame, and coupled to the frame by upper and lower suspension members to create a four bar linkage. The linkage is limited by a shock absorber that is operatively connected between the lower suspension member and the frame. The shock absorber serves to absorb impact forces imposed on the suspension during operation, and to restore the linkage to its extended position. The shock absorber and linkage are disposed to act at a specific rate at each point through the suspension travel.
The guide wheel frame supports a first pair of guide wheels mounted to the front end, a second pair of guide wheels operatively connected to the rear end, and four pairs of tertiary guide wheels operatively connected midway between the first and second pairs of guide wheels by a triangular bracket, that is pivotally mounted to the guide wheel frame.
The guide wheels are oriented to define a plane along their lower periphery to contact the inner surface of the track belt, and support the vehicle. The inside vertical surfaces of each wheel are aligned coplanar, to facilitate smooth intermittent contact with the track alignment surfaces.
In this embodiment, an idle (or tension) linkage assembly is connected above and in series with the suspension linkage and the frame, creating a one degree of freedom, seven-bar linkage with the frame as the ground link. Dual idle wheels are aligned coplanar with the inside vertical surface of the lower guide wheels, and are each pivotally mounted to an axle that is fixed to the distal ends of a tandem pair of triangular links with the proximal end of the links pivotally connected to the frame, and a pair of coupler links operatively connect the upper suspension member to the third point of the triangular link at the opposite ends. The linkage is arranged such that the idle wheels contact the inside surface of the track belt generally midway between the sprocket assembly and distal guide wheel, supporting the upper section of the track belt. The tension linkage is arranged to position the idle wheels such that a constant length perimeter of the suspension system is maintained throughout the range of suspension travel. Also, the geometry and orientation of the linkage defines a mechanical advantage and application rate between the idle wheel and the upper suspension member.
When torque is applied to the track drive system of the present invention, the terrain contacting portion of the track engages the ground. It is known that drive forces applied to a suspended track system tend to actuate its compression, and such actuation is undesirable as it removes energy from propulsive efforts and thus reduces system efficiency. The mechanical advantage of the tension linkage assembly is adapted to oppose the tendency The suspension system of the present invention advantageously places the shock absorber in an operational condition with a rising rate, such that most large impacts may be absorbed by the system without having the compression stroke thereof bottom out. This is desirable because it is known that a system prone to bottoming out tends to transmit large impacts to the rider, which is a negative performance attribute. The track suspension system of the present invention is shown to provide a rising rate shock progression, addressing this negative performance attribute.
Additionally, with respect to rider generated, cyclic driving forces applied to a suspension system; it is known that suspension actuation creates undesirable feedback through the drive train which the rider feels through the pedals.
BRIEF DESCRIPTION OF THE DRAWINGS
Having thus generally described the nature of the present invention, reference will now be made to the accompanying drawings, showing by way of illustration the preferred embodiments thereof, in which;
Figure 1 is an elevation view of a tracked cycle, showing prior art of the present invention.
Figure 2 is a side elevation view of a tracked cycle incorporating an embodiment of the present invention.
Figure 3 is a sectioned side view of a track drive system for a tracked cycle according to the embodiment of the present invention of Figure 2. The model is sectioned to show the locations of the linkage pivot points in greater detail, and includes Detail A, which displays the prismatic joint coupling the tension linkage to the upper suspension link.
Figure 4 is a diagram of a track drive suspension system according to the present invention of Figure 2 and Figure 3, showing the system in its extended, compressed and mid-travel states.
Figure 5 is a schematic side view of an embodiment of the present invention showing the system in its compressed state. The track belt is simplified for display.
Figure 6 is a graphical representation depicting the generally constant track belt support geometry of an embodiment of the present invention.
Figure 7 is a graphical representation depicting the generally increasing track belt support geometry through the compression cycle of an embodiment of the present invention, Figure 8 is a graphical representation depicting the generally increasing track suspension linkage rate of an embodiment of the present invention.
Figure 9 is a graphical representation displaying unit torque effects on the suspension linkage due to imposed drive train torque on an embodiment of the present invention. The torques are shown for the common link between the impact absorbing linkage and the tension linkage.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With respect to the representative figures presented above and the accompanying description, reference will be made to certain components of the vehicle that are readily known to persons skilled in the art, and a wide array of embodiments may be utilized to practice the invention. Accordingly, a detailed description of elements directly concerned with the function of the present invention is provided.
Referring to Figures 2 - 5, an embodiment of a tracked cycle 10 is shown which is intended primarily for traversing snow covered, or other low-density surfaces of varying incline and camber. In this embodiment, tracked cycle 10 (hereafter "cycle") includes a frame structure 12 having a front end 14 ("front") and rear end 16 ("rear") which are defined consistently with the forward travel direction of the vehicle. Throughout this specification, the terms 'proximal' and 'distal' reference the frame and structural elements.
Thus the proximal end is the end which is closest to the frame, and the distal end is the end that is furthest from the frame.
Frame 12 is supported and propelled by track drive assembly 18 in the rear 16.
Mounted to frame 12 is sprocket assembly 20, which transmits power to track belt 22 ("track") that is trained about the periphery of track suspension assembly 18, enabling propulsion of the cycle.
The sprocket assembly 20 is intended to transmit operator generated power to track 22 via pedal-crank assembly 24, or may transmit power from other sources such as an internal combustion engine or from an electro-mechanical source.
The generally quadrilateral shaped track drive assembly 18 comprises of a generally triangular (when viewed from the side) guide wheel carriage 26 that supports pairs of longitudinally spaced guide wheels 28 and 30 at opposite ends of its lower span, and four pairs of secondary guide wheels 32 supported in between by a secondary carriage 34.
The proximal end of lower link 36 is pivotally mounted to frame 12 at a lower mount point 38, while the distal end of lower link 36 is pivotally connected to the front of guide wheel carriage 26, coaxial with guide wheels 28. The proximal end of upper link 40 is pivotally mounted to frame 12 at an upper mount point 42, and the distal end is pivotally connected to the upper, third point 44 of guide wheel carriage 24, creating a four bar linkage. The range of motion of this linkage is limited by shock absorber 46 that is pinned at one end to frame 12 at mount point 48 and to lower link 36 at the opposite end.
The tension linkage assembly 50 is disposed generally above upper link 40 to provide a constant belt perimeter at all points of suspension travel, and to counteract input drive torque from affecting suspension performance. The proximal end of tension link 52 is pivotally connected to frame 12 at mount point 54, with a pair of idle wheel assemblies 56 rotatably mounted at the distal end. One end of couple link 58 is pinned at an intermediate point on tension link 52 with the opposite end operatively connected to prismatic joint 60 located on upper link 40, and also pinned coaxial with the distal end of position link 62. The proximal end of position link 62 is pivotally connected to frame 12 at mount point 64, which completes a seven-bar linkage comprising frame 12, lower link 36, carriage frame 26, upper link 40, couple link 58, tension link 52 and position link 62.
This arrangement of suspension components forms a quadrilateral track support profile;
with idle wheel assemblies 56 contacting the inside, upper section of track belt 22, generally midway between sprocket assembly 20 and the rear 16 pair of guide wheel assemblies 30. The lower contact points of guide wheels 28, 30 and 32 form a generally flat or slight downward convex curved plane, which carries the ground contacting portion of the track belt 22 to support the rear of the vehicle.
Referring now to Figure 4, in this embodiment sprocket assembly 20 comprises hub 66, which is a multispeed gear set of known configuration, (preferably US patent 6,258,005) having a chain ring 68 on one outer side of the transmission body, and a shift mechanism (not shown) connected to the other side. Hub 66 may be replaced with any similar device without detracting from the performance of the present invention and furthermore, hub 66 may be replaced by a standard rear bicycle hub and gear set (not shown), in combination with a standard bicycle rear derailleur. Sprocket rim 70 is connected coaxial to hub 66 by spokes (not shown) in a known manner. Trained about chain ring 68 and chain ring 72 of pedal crank assembly 24 is chain 74 which transmits operator generated torque to track belt 22.
Track belt 22 is mounted to the vehicle as an endless loop, trained around the outer perimeter of sprocket assembly 20, guide wheel assemblies 28, 30 and 32 and idle wheels 66.
Track belt 22 is engaged with and driven by sprocket teeth 76 disposed on sprocket rim 70.
Track belt 22 is a flexible loop, either formed as a loop or as a spliced length, and is of either solid or laminated structure, with the latter preferred according to this design. Preferably, track belt 22 contains a core of multiple belts of high modulus material such as aramid or steel fibre that are housed by outer lamina of rubber or other abrasion resistant material. The track lugs 78 ("lugs") are mounted to the exterior of the track belt by adhesive or mechanical means, and arranged equidistant from each other according to the dimensions of the outer diameter of the sprocket rim 70 and the number of sprocket teeth 76 disposed on sprocket rim 70. In this design, lugs 78 are mechanically fastened to the track belt, however the track belt 22 and lugs 78 may be molded as a single piece, in a known manner without compromising the teaching of the present invention. Composition of track belt 22 may vary without detracting from the performance of the present invention, given the overall elastic modulus is sufficient to prohibit significant length deformation.
Referring to Figure 5, the track suspension system is shown in its compressed state 80, extended state 82 and mid-travel state 84.
Referring to Figure 6, an embodiment of the present invention arranges the geometry and orientation of tension linkage assembly 50 such that idle wheel assemblies 56 are positioned to provide a generally constant length support perimeter for track belt 22 at all points through the suspension cycle. The graph shows a generally constant length throughout the stroke of the shock.
Referring to Figure 7, an alternative embodiment of the present invention arranges the geometry and orientation of tension linkage 50 such that idle wheel assemblies 56 are positioned to provide a generally increasing length support perimeter for track belt 22 at all points through the suspension cycle. The graph shows a generally increasing supported belt length throughout the stroke of the shock.
Referring to Figure 8, the position and orientation of shock absorber 46 is arranged in this embodiment such that under operation, it undergoes a rising rate spring progression through the compression cycle. The graph depicts the spring rate progression relative to the centre of the track footprint.
Referring now to Figure 9, the geometry and orientation of tension linkage assembly 50 also defines a mechanical advantage with a specific rate, between tension link 52 (input) and upper link 40 (output). As input torque is applied to sprocket assembly 20, the ground contacting portion of track belt 22 opposes the free rotation of the track about the system, and imposes a moment on the system which tends to compress the suspension. The mechanical advantage between tension linkage 50 and upper link 40 creates a feedback mechanism to oppose this compressive moment, and thus isolates drive forces from actuating the suspension.
Figure 9 shows the unit torque imposed on upper link 40 (the common link between the lower four-bar and tension linkage 50) due to unit input torque to the drive sprocket, and also the restorative unit torque arising from belt forces on tension linkage 50, at several points through the compression cycle. Also shown is the net unit torque imposed on the track drive system.
An example of ordinary use of the track drive system would involve incorporation of the track drive assembly 18 to a steerable sledge type vehicle, where the operator provides propulsive power by cycling the pedal crank assembly. When the vehicle encounters a bump or depression in the terrain, the system would compress or extend to maintain track contact with the terrain, and the specified suspension rate progression would prevent it from bottoming out.
When propulsive power is applied to the system, tension linkage assembly 50 maintains a constant belt perimeter minimizing belt slack, and also counteracts the compressive moments due to drive train torque.
BRIEF DESCRIPTION OF THE DRAWINGS
Having thus generally described the nature of the present invention, reference will now be made to the accompanying drawings, showing by way of illustration the preferred embodiments thereof, in which;
Figure 1 is an elevation view of a tracked cycle, showing prior art of the present invention.
Figure 2 is a side elevation view of a tracked cycle incorporating an embodiment of the present invention.
Figure 3 is a sectioned side view of a track drive system for a tracked cycle according to the embodiment of the present invention of Figure 2. The model is sectioned to show the locations of the linkage pivot points in greater detail, and includes Detail A, which displays the prismatic joint coupling the tension linkage to the upper suspension link.
Figure 4 is a diagram of a track drive suspension system according to the present invention of Figure 2 and Figure 3, showing the system in its extended, compressed and mid-travel states.
Figure 5 is a schematic side view of an embodiment of the present invention showing the system in its compressed state. The track belt is simplified for display.
Figure 6 is a graphical representation depicting the generally constant track belt support geometry of an embodiment of the present invention.
Figure 7 is a graphical representation depicting the generally increasing track belt support geometry through the compression cycle of an embodiment of the present invention, Figure 8 is a graphical representation depicting the generally increasing track suspension linkage rate of an embodiment of the present invention.
Figure 9 is a graphical representation displaying unit torque effects on the suspension linkage due to imposed drive train torque on an embodiment of the present invention. The torques are shown for the common link between the impact absorbing linkage and the tension linkage.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With respect to the representative figures presented above and the accompanying description, reference will be made to certain components of the vehicle that are readily known to persons skilled in the art, and a wide array of embodiments may be utilized to practice the invention. Accordingly, a detailed description of elements directly concerned with the function of the present invention is provided.
Referring to Figures 2 - 5, an embodiment of a tracked cycle 10 is shown which is intended primarily for traversing snow covered, or other low-density surfaces of varying incline and camber. In this embodiment, tracked cycle 10 (hereafter "cycle") includes a frame structure 12 having a front end 14 ("front") and rear end 16 ("rear") which are defined consistently with the forward travel direction of the vehicle. Throughout this specification, the terms 'proximal' and 'distal' reference the frame and structural elements.
Thus the proximal end is the end which is closest to the frame, and the distal end is the end that is furthest from the frame.
Frame 12 is supported and propelled by track drive assembly 18 in the rear 16.
Mounted to frame 12 is sprocket assembly 20, which transmits power to track belt 22 ("track") that is trained about the periphery of track suspension assembly 18, enabling propulsion of the cycle.
The sprocket assembly 20 is intended to transmit operator generated power to track 22 via pedal-crank assembly 24, or may transmit power from other sources such as an internal combustion engine or from an electro-mechanical source.
The generally quadrilateral shaped track drive assembly 18 comprises of a generally triangular (when viewed from the side) guide wheel carriage 26 that supports pairs of longitudinally spaced guide wheels 28 and 30 at opposite ends of its lower span, and four pairs of secondary guide wheels 32 supported in between by a secondary carriage 34.
The proximal end of lower link 36 is pivotally mounted to frame 12 at a lower mount point 38, while the distal end of lower link 36 is pivotally connected to the front of guide wheel carriage 26, coaxial with guide wheels 28. The proximal end of upper link 40 is pivotally mounted to frame 12 at an upper mount point 42, and the distal end is pivotally connected to the upper, third point 44 of guide wheel carriage 24, creating a four bar linkage. The range of motion of this linkage is limited by shock absorber 46 that is pinned at one end to frame 12 at mount point 48 and to lower link 36 at the opposite end.
The tension linkage assembly 50 is disposed generally above upper link 40 to provide a constant belt perimeter at all points of suspension travel, and to counteract input drive torque from affecting suspension performance. The proximal end of tension link 52 is pivotally connected to frame 12 at mount point 54, with a pair of idle wheel assemblies 56 rotatably mounted at the distal end. One end of couple link 58 is pinned at an intermediate point on tension link 52 with the opposite end operatively connected to prismatic joint 60 located on upper link 40, and also pinned coaxial with the distal end of position link 62. The proximal end of position link 62 is pivotally connected to frame 12 at mount point 64, which completes a seven-bar linkage comprising frame 12, lower link 36, carriage frame 26, upper link 40, couple link 58, tension link 52 and position link 62.
This arrangement of suspension components forms a quadrilateral track support profile;
with idle wheel assemblies 56 contacting the inside, upper section of track belt 22, generally midway between sprocket assembly 20 and the rear 16 pair of guide wheel assemblies 30. The lower contact points of guide wheels 28, 30 and 32 form a generally flat or slight downward convex curved plane, which carries the ground contacting portion of the track belt 22 to support the rear of the vehicle.
Referring now to Figure 4, in this embodiment sprocket assembly 20 comprises hub 66, which is a multispeed gear set of known configuration, (preferably US patent 6,258,005) having a chain ring 68 on one outer side of the transmission body, and a shift mechanism (not shown) connected to the other side. Hub 66 may be replaced with any similar device without detracting from the performance of the present invention and furthermore, hub 66 may be replaced by a standard rear bicycle hub and gear set (not shown), in combination with a standard bicycle rear derailleur. Sprocket rim 70 is connected coaxial to hub 66 by spokes (not shown) in a known manner. Trained about chain ring 68 and chain ring 72 of pedal crank assembly 24 is chain 74 which transmits operator generated torque to track belt 22.
Track belt 22 is mounted to the vehicle as an endless loop, trained around the outer perimeter of sprocket assembly 20, guide wheel assemblies 28, 30 and 32 and idle wheels 66.
Track belt 22 is engaged with and driven by sprocket teeth 76 disposed on sprocket rim 70.
Track belt 22 is a flexible loop, either formed as a loop or as a spliced length, and is of either solid or laminated structure, with the latter preferred according to this design. Preferably, track belt 22 contains a core of multiple belts of high modulus material such as aramid or steel fibre that are housed by outer lamina of rubber or other abrasion resistant material. The track lugs 78 ("lugs") are mounted to the exterior of the track belt by adhesive or mechanical means, and arranged equidistant from each other according to the dimensions of the outer diameter of the sprocket rim 70 and the number of sprocket teeth 76 disposed on sprocket rim 70. In this design, lugs 78 are mechanically fastened to the track belt, however the track belt 22 and lugs 78 may be molded as a single piece, in a known manner without compromising the teaching of the present invention. Composition of track belt 22 may vary without detracting from the performance of the present invention, given the overall elastic modulus is sufficient to prohibit significant length deformation.
Referring to Figure 5, the track suspension system is shown in its compressed state 80, extended state 82 and mid-travel state 84.
Referring to Figure 6, an embodiment of the present invention arranges the geometry and orientation of tension linkage assembly 50 such that idle wheel assemblies 56 are positioned to provide a generally constant length support perimeter for track belt 22 at all points through the suspension cycle. The graph shows a generally constant length throughout the stroke of the shock.
Referring to Figure 7, an alternative embodiment of the present invention arranges the geometry and orientation of tension linkage 50 such that idle wheel assemblies 56 are positioned to provide a generally increasing length support perimeter for track belt 22 at all points through the suspension cycle. The graph shows a generally increasing supported belt length throughout the stroke of the shock.
Referring to Figure 8, the position and orientation of shock absorber 46 is arranged in this embodiment such that under operation, it undergoes a rising rate spring progression through the compression cycle. The graph depicts the spring rate progression relative to the centre of the track footprint.
Referring now to Figure 9, the geometry and orientation of tension linkage assembly 50 also defines a mechanical advantage with a specific rate, between tension link 52 (input) and upper link 40 (output). As input torque is applied to sprocket assembly 20, the ground contacting portion of track belt 22 opposes the free rotation of the track about the system, and imposes a moment on the system which tends to compress the suspension. The mechanical advantage between tension linkage 50 and upper link 40 creates a feedback mechanism to oppose this compressive moment, and thus isolates drive forces from actuating the suspension.
Figure 9 shows the unit torque imposed on upper link 40 (the common link between the lower four-bar and tension linkage 50) due to unit input torque to the drive sprocket, and also the restorative unit torque arising from belt forces on tension linkage 50, at several points through the compression cycle. Also shown is the net unit torque imposed on the track drive system.
An example of ordinary use of the track drive system would involve incorporation of the track drive assembly 18 to a steerable sledge type vehicle, where the operator provides propulsive power by cycling the pedal crank assembly. When the vehicle encounters a bump or depression in the terrain, the system would compress or extend to maintain track contact with the terrain, and the specified suspension rate progression would prevent it from bottoming out.
When propulsive power is applied to the system, tension linkage assembly 50 maintains a constant belt perimeter minimizing belt slack, and also counteracts the compressive moments due to drive train torque.
Claims (7)
1. A track drive system for a vehicle with a frame, said frame having a front and rear, the system comprising:
a track belt having an outer surface, an inner surface, and a ground contacting portion;
a drive sprocket pivotally connected to said frame and indexed to said track belt;
a lower link and an upper link, each link having a first and second end, the first ends of the links rotatably mounted to the rear of said frame, the links adapted to extend downward and to the rear;
a track carriage frame operatively connected to the second ends of the links, the track carriage frame including first and second pairs of guide wheel assemblies rotatably mounted to and longitudinally spaced on said track carriage frame, the first guide wheel mounted to the proximal end of track carriage frame, the second guide wheel mounted to the distal end of the track carriage frame, the guide wheels being adapted to contact the inner surface of the ground contacting portion of the track belt;
a shock absorber operatively connected to the lower link for absorbing impact forces applied to the track carriage frame, the shock absorber oriented to function at a rate;
a tension link having first and second ends, first end pivotally connected to the frame, at least one idle wheel rotatably mounted to the second end, the idle wheel adapted to contact the inner surface of the track belt;
a coupling link having first and second ends, first end pivotally connected to the tension link, second end operatively connected to a prismatic joint on the upper link; and a position link having first and second ends, first end pivotally mounted to the frame, second end pivotally joined coaxial with the second end of the couple link;
said track drive system arranged to create a single degree of freedom, seven bar linkage for articulated support of a track belt, the continuous track extended around the drive sprocket, the idle wheel of the tension linkage, the second and first pairs of track guide wheels defining a quadrilateral, such that the lower side of the quadrilateral is supported by the first and second guide wheels, the portion of track between the drive sprocket and first pair of guide wheels is inclined toward the front of the vehicle, the first upper portion spanning between said drive sprocket and idle wheels, and the second upper portion extending between said idle wheels and said second pair of guide wheels.
a track belt having an outer surface, an inner surface, and a ground contacting portion;
a drive sprocket pivotally connected to said frame and indexed to said track belt;
a lower link and an upper link, each link having a first and second end, the first ends of the links rotatably mounted to the rear of said frame, the links adapted to extend downward and to the rear;
a track carriage frame operatively connected to the second ends of the links, the track carriage frame including first and second pairs of guide wheel assemblies rotatably mounted to and longitudinally spaced on said track carriage frame, the first guide wheel mounted to the proximal end of track carriage frame, the second guide wheel mounted to the distal end of the track carriage frame, the guide wheels being adapted to contact the inner surface of the ground contacting portion of the track belt;
a shock absorber operatively connected to the lower link for absorbing impact forces applied to the track carriage frame, the shock absorber oriented to function at a rate;
a tension link having first and second ends, first end pivotally connected to the frame, at least one idle wheel rotatably mounted to the second end, the idle wheel adapted to contact the inner surface of the track belt;
a coupling link having first and second ends, first end pivotally connected to the tension link, second end operatively connected to a prismatic joint on the upper link; and a position link having first and second ends, first end pivotally mounted to the frame, second end pivotally joined coaxial with the second end of the couple link;
said track drive system arranged to create a single degree of freedom, seven bar linkage for articulated support of a track belt, the continuous track extended around the drive sprocket, the idle wheel of the tension linkage, the second and first pairs of track guide wheels defining a quadrilateral, such that the lower side of the quadrilateral is supported by the first and second guide wheels, the portion of track between the drive sprocket and first pair of guide wheels is inclined toward the front of the vehicle, the first upper portion spanning between said drive sprocket and idle wheels, and the second upper portion extending between said idle wheels and said second pair of guide wheels.
2. The track drive system of claim 1, wherein the arrangement of the tension link, couple link and position link locates the idle wheel to provide a constant length support perimeter for the track belt as the suspension compresses.
3. The track drive system of claim 1, wherein the arrangement of the tension link, couple link and position link positions the idle wheel to provide an increasing length support perimeter for the track belt as the suspension compresses.
4. A track drive system for a vehicle with a frame, said frame having a front and rear, the system comprising:
a track belt having an outer surface, an inner surface, and a ground contacting portion;
a drive sprocket pivotally connected to said frame and indexed to said track belt;
a lower link and an upper link, each link having a first and second end, the first ends of the links rotatably mounted to the rear of said frame, the links adapted to extend downward and to the rear;
a track carriage frame operatively connected to the second ends of the links, the track carriage frame including plural guide wheel assemblies rotatably mounted to and longitudinally spaced on said track carriage frame, the guide wheels being adapted to contact the inner surface of the ground contacting portion of the track belt;
a shock absorber operatively connected to the lower link for absorbing impact forces applied to the track carriage frame, the shock absorber oriented to function at a rate; and a tension assembly pivotally connected to the frame and the upper link such that it is consistently actuated by motion of the track carriage frame, the tension assembly including at least one idle wheel adapted to contact the inner surface of the track belt;
said shock absorber is positioned to function at a progressively increasing rate through the compression stroke.
a track belt having an outer surface, an inner surface, and a ground contacting portion;
a drive sprocket pivotally connected to said frame and indexed to said track belt;
a lower link and an upper link, each link having a first and second end, the first ends of the links rotatably mounted to the rear of said frame, the links adapted to extend downward and to the rear;
a track carriage frame operatively connected to the second ends of the links, the track carriage frame including plural guide wheel assemblies rotatably mounted to and longitudinally spaced on said track carriage frame, the guide wheels being adapted to contact the inner surface of the ground contacting portion of the track belt;
a shock absorber operatively connected to the lower link for absorbing impact forces applied to the track carriage frame, the shock absorber oriented to function at a rate; and a tension assembly pivotally connected to the frame and the upper link such that it is consistently actuated by motion of the track carriage frame, the tension assembly including at least one idle wheel adapted to contact the inner surface of the track belt;
said shock absorber is positioned to function at a progressively increasing rate through the compression stroke.
5. The track drive system of claim 4, wherein the tension assembly provides support for the track belt in a substantially constant length manner throughout the suspension cycle.
6. The track drive system of claim 4, wherein the tension assembly provides an increasing length support perimeter for the track belt as the suspension compresses.
7. A track drive system for a vehicle with a frame, said frame having a front and rear, the system comprising:
a track belt having an outer surface, an inner surface, and a ground contacting portion;
a drive sprocket pivotally connected to said frame and indexed to said track belt;
a lower link and an upper link, each link having a first and second end, the first ends of the links rotatably mounted to the rear of said frame, the links adapted to extend downward and to the rear;
a track carriage frame operatively connected to the second ends of the links, the track carriage frame including plural guide wheel assemblies rotatably mounted to and longitudinally spaced on said track carriage frame, the guide wheels being adapted to contact the inner surface of the ground contacting portion of the track belt;
a shock absorber operatively connected to the lower link for absorbing impact forces applied to the track carriage frame, the shock absorber oriented to function at a rising rate spring progression; and a tension assembly pivotally connected to the frame and the upper link such that it is consistently actuated by motion of the track carriage frame, the tension assembly including at least one idle wheel adapted to contact the inner surface of the track belt;
said tension assembly connected and oriented to use track belt tension force to feedback to the upper link at a mechanical advantage, opposing drive induced compression of the suspension.
a track belt having an outer surface, an inner surface, and a ground contacting portion;
a drive sprocket pivotally connected to said frame and indexed to said track belt;
a lower link and an upper link, each link having a first and second end, the first ends of the links rotatably mounted to the rear of said frame, the links adapted to extend downward and to the rear;
a track carriage frame operatively connected to the second ends of the links, the track carriage frame including plural guide wheel assemblies rotatably mounted to and longitudinally spaced on said track carriage frame, the guide wheels being adapted to contact the inner surface of the ground contacting portion of the track belt;
a shock absorber operatively connected to the lower link for absorbing impact forces applied to the track carriage frame, the shock absorber oriented to function at a rising rate spring progression; and a tension assembly pivotally connected to the frame and the upper link such that it is consistently actuated by motion of the track carriage frame, the tension assembly including at least one idle wheel adapted to contact the inner surface of the track belt;
said tension assembly connected and oriented to use track belt tension force to feedback to the upper link at a mechanical advantage, opposing drive induced compression of the suspension.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2556883 CA2556883A1 (en) | 2006-08-16 | 2006-08-16 | Track drive suspension system for a rider propelled vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2556883 CA2556883A1 (en) | 2006-08-16 | 2006-08-16 | Track drive suspension system for a rider propelled vehicle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2556883A1 true CA2556883A1 (en) | 2008-02-16 |
Family
ID=39091917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2556883 Abandoned CA2556883A1 (en) | 2006-08-16 | 2006-08-16 | Track drive suspension system for a rider propelled vehicle |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2556883A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106585855A (en) * | 2016-12-30 | 2017-04-26 | 浙江华洋赛车股份有限公司 | Two-wheeled cross-country motorcycle snowfield modification suite |
| CN106741114A (en) * | 2016-11-16 | 2017-05-31 | 徐州科源液压股份有限公司 | For the Electric hand cart of delivery goods of going up a hill |
| CN108248711A (en) * | 2018-02-11 | 2018-07-06 | 吉林大学 | A kind of wearable crawler type snowfield mobile devices and its vibration-reducing control method |
| WO2023123588A1 (en) * | 2021-12-29 | 2023-07-06 | 苏州金韦尔机械有限公司 | Crawler-type conveying device for solar encapsulant films |
-
2006
- 2006-08-16 CA CA 2556883 patent/CA2556883A1/en not_active Abandoned
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106741114A (en) * | 2016-11-16 | 2017-05-31 | 徐州科源液压股份有限公司 | For the Electric hand cart of delivery goods of going up a hill |
| CN106741114B (en) * | 2016-11-16 | 2023-08-18 | 徐州科源液压股份有限公司 | Electric trolley for carrying goods on mountain and down mountain |
| CN106585855A (en) * | 2016-12-30 | 2017-04-26 | 浙江华洋赛车股份有限公司 | Two-wheeled cross-country motorcycle snowfield modification suite |
| CN108248711A (en) * | 2018-02-11 | 2018-07-06 | 吉林大学 | A kind of wearable crawler type snowfield mobile devices and its vibration-reducing control method |
| CN108248711B (en) * | 2018-02-11 | 2023-10-27 | 吉林大学 | Wearable crawler-type snowfield running device and vibration reduction control method thereof |
| WO2023123588A1 (en) * | 2021-12-29 | 2023-07-06 | 苏州金韦尔机械有限公司 | Crawler-type conveying device for solar encapsulant films |
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