CA1228884A - Snowmobile slide suspension - Google Patents
Snowmobile slide suspensionInfo
- Publication number
- CA1228884A CA1228884A CA000502719A CA502719A CA1228884A CA 1228884 A CA1228884 A CA 1228884A CA 000502719 A CA000502719 A CA 000502719A CA 502719 A CA502719 A CA 502719A CA 1228884 A CA1228884 A CA 1228884A
- Authority
- CA
- Canada
- Prior art keywords
- suspension
- slide
- assembly
- arm
- snowmobile
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Abstract
ABSTRACT
A slide suspension system for a snowmobile incorporates a system of suspension arms and levers positioned between the slide frame and the snowmobile body. The suspension incorporates hydraulic dampers and provides a progressive reaction system that includes four bell crank levers which can provide an adjustable leverage ratio to the dampers.
A slide suspension system for a snowmobile incorporates a system of suspension arms and levers positioned between the slide frame and the snowmobile body. The suspension incorporates hydraulic dampers and provides a progressive reaction system that includes four bell crank levers which can provide an adjustable leverage ratio to the dampers.
Description
2~3~84 Snowmobile Slide Suspension System Field of Invention This invention relates to snowmobiles, and in particular to a new or improved slide suspension system for a snowmobile.
Description of the Prior Art Over the years snowmobile suspensions have evolved from the earliest designs employing a series of bogies wheels running on the ground-engaging portion of the snowmobile track and employing torsion springs, to more refined arrangements employing slide rail frames in sliding contact with the track belt and incorporating systems of levers and hydraulic damper units. The performance requirements imposed upon snowmobile suspensions have increased continuously, and there is an ongoing need to improve the perform mange of snowmobile suspensions in terms owe comfort, dynamic response, and adjustability.
Summary of the Invention The invention provides, in a snowmobile comprising a slide frame assembly positioned in sliding contact with the ground-engag-in run of the track belt of the snowmobile, a slide suspension system comprising: a front suspension assembly and a rear suspension assembly forming attachments between the snowmobile frame and respect live forward and rearward portions of the slowed Erase assembly; one said suspension assembly comprising a corltrol arm having an upper end pivotal attached -to the snowmobile frame and a lower end pivotal attached to the slide frame assembly; the other said suspension asset-by comprising a generally upright first link having a lower end pivoted to the slide frame, a second link pivotal attached at one ~1.22~884 end to the upper end of the first link and extending angularly therefrom to a spaced pivotal mounting connected to the snowmobile frame on a fixed transverse horizontal axis, said second link come prosing one arm of a cranked lever which has a second arm extending at an angle to said first arm and having a distal end forming a pivotal mounting for one end of a telescopic damper and suspension spring unit that extends generally horizontally below the upper run of the track belt and has a second end pivoted on a second fixed transverse horizontal axis in said snowmobile frame.
Brief Description of the Drawings The invention will further be described, by way of example only, with reference to the accompanying drawings wherein:
Figure 1 is a perspective view of a snowmobile incorpor-cling a slide suspension in accordance with the invention;
Figure 2 is an enlarged somewhat schematic side view of the slide suspension, certain parts having been omitted for reasons of clarity;
Figure 3 is a top perspective view from the rear and one side showing the suspension and slide frame removed from the snow-mobile;
Figure 4 is a view similar to Figure 3 but showing the arrangement when viewed from the front and the opposite side;
Figure Skis an enlarged .Eragment~:ry view schematically illustrating the function of the rear portion of the assembly and Figure 6 is an enlarged side view schematically thus-treating the functioning of the front part of the suspension.
~8884 Description of the Preferred Em oddment A snowmobile 10 as shown in Figure 1 has a forward end supported upon a pair of steerable skis 11 and at the rear end has an inverted U frame channel structure 12 in which is received an endless track 13. As better seen in Figure 2, the track 13 extends in an endless loop over a forward drive sprocket 14 and a rearward arrangement of idler wheels 15, the track defining a lower ground-engaging run 16 and an upper return run 17. The drive sprocket 14 is driven in known manner through a transmission by the snowmobile engine (not shown) to rotate the track 13 and drive the snowmobile over the terrain.
The ground-engaging run 16 of the track is in sliding contact with a slide frame assembly 18 which has two spaced longitudinal rails curved upwardly at their front ends and carrying a low friction coating 19. The slide rails are interconnected in parallel by transversely arranged forward and rear tubes 20,21 which also carry smaller intermediate idler wheels 22 which extend slightly below the lower surface of the low friction coating 19 on the rails and further reduce the frictional resistance to movement of the track relative to the slide frame assembly.
As best seen in Figure 3, the rear idler wheels 15 are mounted on a transverse shaft 23 which is received in brackets 24 on the rails of the slide frame assembly, the shaft 23 being adjust-able in the longitudinal direction of the vehicle by adjustment means 25 to enable proper tensioning of the snowmobile track.
The slide suspension system comprises a front suspension system 26 and a rear suspension system 27 connected between the snowmobile frame 12 and the slide frame assembly 18. The slide suspension system presses the slide frame 18 downwardly into engage-mint with the track belt, but permits upwards deflection of the slide frame in response to ground induced loads applied thereto in operation.
As shown in Figures 2, 3, 4 and 6, the front suspension assembly 26 includes an inclined control arm 28 comprising a welded steel tube structure having an upper horizontal tube 29 pivoted in a bracket 30 on the snowmobile frame about a fixed axis 31, a lower tube 32 pivotal mounted in brackets 33 in the slide frame 18 on an axis 34 that is fixed relative thereto, the tubes 29 and 32 being interconnected by longitudinally extending side tubes 35 that diverge towards the top tube 29 and include on their upper sides steel loops 36.
At an intermediate location towards the lower end of the control arm 28, the side tubes 35 are spanned by a transverse shaft 37 on the center portion of which is fixed a cranked lever 38 having generally oppositely projecting upper and lower arms 39 and 40. The upper arm 39 forms a pivotal attachment 41 with one end of a strut 42 the other end of which has a pivotal attachment 43 with a radial arm 44 on the lower tube 32. The lower arm 40 of the crown lever 38 extends at an angle to the upper arm aloud forms a pivotal.
attachment 45 to one end of a combined hydraulic damper and come press ion spring assembly 46 the other end of which has a pivotal attachment 47 to a radial arm 48 on the top tube 29.
The cranked lever 38 includes a third arm in the form of a pair of radially projecting arms 49 projecting from the shaft on icily the opposite lateral sides of the arm ~10 and each having at its lower end a pivotal connection 50 to the upper end of a link 51 projecting radially upwardly from the forward tube 20.
The rear suspension 27 comprises a lower link 60 having a bottom tube pivotal attached on an axis 61 to the slide frame assembly 18 and extending generally upwardly therefrom, the upper end of the link 60 having a tube 62 pivoted on the central portion of a pin 63. A cranked lever assembly generally indicated at 64 has a transverse tube 65 pivotal mounted in bracket 66 in the snowmobile frame structure 12 on an axis 67 fixed with respect thereto. A pair of radial arms 68 projecting from the tube 65 carry at their ends bearing tubes 69 pivoted on the opposite ends of the pivot pin 63. Flanged brackets 70 on the radial arms 68 support an idler wheel pair 71 for engagement with the upper run of the snowmobile track as indicated in Figure 2.
On each outboard end of the tube 65 of the cranked lever is a fixed radial arm 72 the outer end of which forms a pivot connection 73 with one end of a respective damper unit 74. The opposite end of each damper unit 74 is in turn pivotal connected on a tube 75 that is attached by brackets 76 on a fixed axis 77 to the snowmobile frame 12.
In operation, the position assumed by tile slide frame suspension system when the vocal is at rest cJenerally corresponds to that shown in Figure 2. Issue position is referred to herein as "normal" or "neutral" position and it will be evident tilt the combined coil spring and hydraulic dampers referred to or con-lenience merely as "damper units") 46 and 74 act thrill the respective front and rear suspension assemblies to urge the slide frame assembly 18 downwardly into engagement with the track belt 13. Depending upon the static loading on the rear part of the snowmobile, the position of the side frame assembly 18 may be slightly higher or slightly lower than that shown. The suspension system can respond to the dynamic loadings encountered when the vehicle is in operation, the front suspension assembly 26 and the rear suspension assembly 27 yielding upwardly in unison or indepen-deftly depending upon the loading encountered.
Upwards deflection of the front suspension assembly 26 is discussed in reference to Figure 6. In this view various elements have been omitted for reasons of clarity, e.g. the damper unit 46 is merely represented by the broken line 46. Figure 6 shows in full lines the position of the various elements when the suspension is in the neutral position. It will be evident that the suspension spring acting through the pivot 45 urges the cranked lever 38 to pivot in the counterclockwise direction as shown urging the link 51 to turn in a clockwise direction about the forward tube 20 and thus pressing the front end of the slide frame assembly downwardly to support the vehicle loading thereon. When an excess upwards thrust is applied to the front of the slide frame assembly 18, as for example when traveling over rough terrain, the suspension assembly 26 yields upwardly. During such upwards deflection, the control arm 28 acts as a fixed length link and pivots about its upper end axis 31. As indicated in Figure 6, this constrains each Zoo 37 and 34 to move in an arcuate path. If it is assumed that the axis 37 is displaced upwardly to the location indicated at AYE, 38~34 then the axis 34 will be in the location given at AYE. The axis 20 likewise moves in an approximately arcuate path with respect to the fixed axis 31 and reaches the position indicated at AYE.
Accordingly, the pivot axis 50 joining the link 51 to the arm 49 is moved to the position AYE, this movement being accommodated by a slight pivoting of the link 51 and the cranked lever 38. The axis 45 at one end of the damper unit 46 is moved to position AYE
and the axis 47 at its other end to position AYE, the damper unit 46 being compressed axially during this movement against the force of its coiled spring.
The upwards deflection of the front suspension assembly 26 will vary in accordance with the magnitude of the imposed load.
In the maximum range of deflection the loops 36 on the side tubes 35 prevent the upper run 17 of the track belt from being contacted by any sharp edges associated with the cranked lever 38.
It will be evident that during this upwards deflection of the front suspension assembly 26 the damper unit 46 is compressed, and accordingly its coiled spring resists the suspension deflection and the hydraulic damper controls the deflection movement.
The rear suspension assembly 27 likewise acts to control upwards deflection of the rear end of the slide frame assembly 18.
Referring particularly to Figure 5, it will be evident that when the slide frame assembly 18 is deflected upwardly/ the link 60 will cause the cranked lever 64 to pivot in a clockwise direction because of the pivotal coupling 63. When the link 60 is deflected upwards to the position indicated by the broken lines AYE, the radial arms 72 will be pivoted to move the pivot axis 73 to the position indicated at AYE. Ike concurrent movement of the axis 63 ~Z'~81 34 to the position AYE will cause the idler wheel pair 71 to be pivoted upwardly raising the upper run 17 of the track belt to take up the slack created by upwards deflection of the ground engaging run 16 that is in contact with the slide frame assembly 18. It will be evident that movement of the pivotal axis 73 to the post-lion indicated at AYE will involve a compression of the damper unit indicated by the line 74, this compression increasing pro-gressively with further upwards deflection of the suspension.
The structure of the damper units 46 and 74 are best seen in Figures 3 and 4. In these views the coiled compression springs have been omitted for the sake of clarity. Each damper unit has a piston rod 81 extending from a cylinder 82, the distal end of the piston rod carrying an annular seat 83 to receive one end of the compression spring and the cylinder having an annular flanged collar 84 forming a seat for the opposite end of the come press ion spring. The collar 84 is rotatable on the cylinder and is adjustable axially with respect thereto. Specifically the collar 84 has a series of stepped teeth 85 angularly spaced and axially offset with respect to each other. Any of these teeth may be brought selectively into engagement with a detent 86 projecting from the wall of the cylinder 82. Thus the axial location of the collar 84 (and thus the preluding on the coiled compression spring) may be adjusted by rotating the collar 84 to bring selected teeth into engagement with the detent 86. This adjustment affects the preluding of the suspension springs, and thus pro-vises a means for selective variation of the stiffness character-fistic of the suspension.
12Z~884 The improved slide suspension system described above and illustrated in the drawings provides a "progressive rate" of spring suspension. In contrast to prior linear rate suspensions in which for each inch of compression the same amount of force was required, in a progressive rate system the force required for successive increments of compression increases. Thus the damper units 46 and 74, by virtue of the linkage arrangement mounting them, act as progressive rate springs. The slide suspension yields more easily initially and becomes progressively more difficult to deflect as its upwards displacement is increased.
The characteristics of the suspension can be varied by adjustment of the geometry of the linkages. For example the point of attachment of the lower end of the link 60 to the slide frame 18 is adjustable in the longitudinal direction by attaching it in holes 61' forward or to the rear of the attachment shown.
Description of the Prior Art Over the years snowmobile suspensions have evolved from the earliest designs employing a series of bogies wheels running on the ground-engaging portion of the snowmobile track and employing torsion springs, to more refined arrangements employing slide rail frames in sliding contact with the track belt and incorporating systems of levers and hydraulic damper units. The performance requirements imposed upon snowmobile suspensions have increased continuously, and there is an ongoing need to improve the perform mange of snowmobile suspensions in terms owe comfort, dynamic response, and adjustability.
Summary of the Invention The invention provides, in a snowmobile comprising a slide frame assembly positioned in sliding contact with the ground-engag-in run of the track belt of the snowmobile, a slide suspension system comprising: a front suspension assembly and a rear suspension assembly forming attachments between the snowmobile frame and respect live forward and rearward portions of the slowed Erase assembly; one said suspension assembly comprising a corltrol arm having an upper end pivotal attached -to the snowmobile frame and a lower end pivotal attached to the slide frame assembly; the other said suspension asset-by comprising a generally upright first link having a lower end pivoted to the slide frame, a second link pivotal attached at one ~1.22~884 end to the upper end of the first link and extending angularly therefrom to a spaced pivotal mounting connected to the snowmobile frame on a fixed transverse horizontal axis, said second link come prosing one arm of a cranked lever which has a second arm extending at an angle to said first arm and having a distal end forming a pivotal mounting for one end of a telescopic damper and suspension spring unit that extends generally horizontally below the upper run of the track belt and has a second end pivoted on a second fixed transverse horizontal axis in said snowmobile frame.
Brief Description of the Drawings The invention will further be described, by way of example only, with reference to the accompanying drawings wherein:
Figure 1 is a perspective view of a snowmobile incorpor-cling a slide suspension in accordance with the invention;
Figure 2 is an enlarged somewhat schematic side view of the slide suspension, certain parts having been omitted for reasons of clarity;
Figure 3 is a top perspective view from the rear and one side showing the suspension and slide frame removed from the snow-mobile;
Figure 4 is a view similar to Figure 3 but showing the arrangement when viewed from the front and the opposite side;
Figure Skis an enlarged .Eragment~:ry view schematically illustrating the function of the rear portion of the assembly and Figure 6 is an enlarged side view schematically thus-treating the functioning of the front part of the suspension.
~8884 Description of the Preferred Em oddment A snowmobile 10 as shown in Figure 1 has a forward end supported upon a pair of steerable skis 11 and at the rear end has an inverted U frame channel structure 12 in which is received an endless track 13. As better seen in Figure 2, the track 13 extends in an endless loop over a forward drive sprocket 14 and a rearward arrangement of idler wheels 15, the track defining a lower ground-engaging run 16 and an upper return run 17. The drive sprocket 14 is driven in known manner through a transmission by the snowmobile engine (not shown) to rotate the track 13 and drive the snowmobile over the terrain.
The ground-engaging run 16 of the track is in sliding contact with a slide frame assembly 18 which has two spaced longitudinal rails curved upwardly at their front ends and carrying a low friction coating 19. The slide rails are interconnected in parallel by transversely arranged forward and rear tubes 20,21 which also carry smaller intermediate idler wheels 22 which extend slightly below the lower surface of the low friction coating 19 on the rails and further reduce the frictional resistance to movement of the track relative to the slide frame assembly.
As best seen in Figure 3, the rear idler wheels 15 are mounted on a transverse shaft 23 which is received in brackets 24 on the rails of the slide frame assembly, the shaft 23 being adjust-able in the longitudinal direction of the vehicle by adjustment means 25 to enable proper tensioning of the snowmobile track.
The slide suspension system comprises a front suspension system 26 and a rear suspension system 27 connected between the snowmobile frame 12 and the slide frame assembly 18. The slide suspension system presses the slide frame 18 downwardly into engage-mint with the track belt, but permits upwards deflection of the slide frame in response to ground induced loads applied thereto in operation.
As shown in Figures 2, 3, 4 and 6, the front suspension assembly 26 includes an inclined control arm 28 comprising a welded steel tube structure having an upper horizontal tube 29 pivoted in a bracket 30 on the snowmobile frame about a fixed axis 31, a lower tube 32 pivotal mounted in brackets 33 in the slide frame 18 on an axis 34 that is fixed relative thereto, the tubes 29 and 32 being interconnected by longitudinally extending side tubes 35 that diverge towards the top tube 29 and include on their upper sides steel loops 36.
At an intermediate location towards the lower end of the control arm 28, the side tubes 35 are spanned by a transverse shaft 37 on the center portion of which is fixed a cranked lever 38 having generally oppositely projecting upper and lower arms 39 and 40. The upper arm 39 forms a pivotal attachment 41 with one end of a strut 42 the other end of which has a pivotal attachment 43 with a radial arm 44 on the lower tube 32. The lower arm 40 of the crown lever 38 extends at an angle to the upper arm aloud forms a pivotal.
attachment 45 to one end of a combined hydraulic damper and come press ion spring assembly 46 the other end of which has a pivotal attachment 47 to a radial arm 48 on the top tube 29.
The cranked lever 38 includes a third arm in the form of a pair of radially projecting arms 49 projecting from the shaft on icily the opposite lateral sides of the arm ~10 and each having at its lower end a pivotal connection 50 to the upper end of a link 51 projecting radially upwardly from the forward tube 20.
The rear suspension 27 comprises a lower link 60 having a bottom tube pivotal attached on an axis 61 to the slide frame assembly 18 and extending generally upwardly therefrom, the upper end of the link 60 having a tube 62 pivoted on the central portion of a pin 63. A cranked lever assembly generally indicated at 64 has a transverse tube 65 pivotal mounted in bracket 66 in the snowmobile frame structure 12 on an axis 67 fixed with respect thereto. A pair of radial arms 68 projecting from the tube 65 carry at their ends bearing tubes 69 pivoted on the opposite ends of the pivot pin 63. Flanged brackets 70 on the radial arms 68 support an idler wheel pair 71 for engagement with the upper run of the snowmobile track as indicated in Figure 2.
On each outboard end of the tube 65 of the cranked lever is a fixed radial arm 72 the outer end of which forms a pivot connection 73 with one end of a respective damper unit 74. The opposite end of each damper unit 74 is in turn pivotal connected on a tube 75 that is attached by brackets 76 on a fixed axis 77 to the snowmobile frame 12.
In operation, the position assumed by tile slide frame suspension system when the vocal is at rest cJenerally corresponds to that shown in Figure 2. Issue position is referred to herein as "normal" or "neutral" position and it will be evident tilt the combined coil spring and hydraulic dampers referred to or con-lenience merely as "damper units") 46 and 74 act thrill the respective front and rear suspension assemblies to urge the slide frame assembly 18 downwardly into engagement with the track belt 13. Depending upon the static loading on the rear part of the snowmobile, the position of the side frame assembly 18 may be slightly higher or slightly lower than that shown. The suspension system can respond to the dynamic loadings encountered when the vehicle is in operation, the front suspension assembly 26 and the rear suspension assembly 27 yielding upwardly in unison or indepen-deftly depending upon the loading encountered.
Upwards deflection of the front suspension assembly 26 is discussed in reference to Figure 6. In this view various elements have been omitted for reasons of clarity, e.g. the damper unit 46 is merely represented by the broken line 46. Figure 6 shows in full lines the position of the various elements when the suspension is in the neutral position. It will be evident that the suspension spring acting through the pivot 45 urges the cranked lever 38 to pivot in the counterclockwise direction as shown urging the link 51 to turn in a clockwise direction about the forward tube 20 and thus pressing the front end of the slide frame assembly downwardly to support the vehicle loading thereon. When an excess upwards thrust is applied to the front of the slide frame assembly 18, as for example when traveling over rough terrain, the suspension assembly 26 yields upwardly. During such upwards deflection, the control arm 28 acts as a fixed length link and pivots about its upper end axis 31. As indicated in Figure 6, this constrains each Zoo 37 and 34 to move in an arcuate path. If it is assumed that the axis 37 is displaced upwardly to the location indicated at AYE, 38~34 then the axis 34 will be in the location given at AYE. The axis 20 likewise moves in an approximately arcuate path with respect to the fixed axis 31 and reaches the position indicated at AYE.
Accordingly, the pivot axis 50 joining the link 51 to the arm 49 is moved to the position AYE, this movement being accommodated by a slight pivoting of the link 51 and the cranked lever 38. The axis 45 at one end of the damper unit 46 is moved to position AYE
and the axis 47 at its other end to position AYE, the damper unit 46 being compressed axially during this movement against the force of its coiled spring.
The upwards deflection of the front suspension assembly 26 will vary in accordance with the magnitude of the imposed load.
In the maximum range of deflection the loops 36 on the side tubes 35 prevent the upper run 17 of the track belt from being contacted by any sharp edges associated with the cranked lever 38.
It will be evident that during this upwards deflection of the front suspension assembly 26 the damper unit 46 is compressed, and accordingly its coiled spring resists the suspension deflection and the hydraulic damper controls the deflection movement.
The rear suspension assembly 27 likewise acts to control upwards deflection of the rear end of the slide frame assembly 18.
Referring particularly to Figure 5, it will be evident that when the slide frame assembly 18 is deflected upwardly/ the link 60 will cause the cranked lever 64 to pivot in a clockwise direction because of the pivotal coupling 63. When the link 60 is deflected upwards to the position indicated by the broken lines AYE, the radial arms 72 will be pivoted to move the pivot axis 73 to the position indicated at AYE. Ike concurrent movement of the axis 63 ~Z'~81 34 to the position AYE will cause the idler wheel pair 71 to be pivoted upwardly raising the upper run 17 of the track belt to take up the slack created by upwards deflection of the ground engaging run 16 that is in contact with the slide frame assembly 18. It will be evident that movement of the pivotal axis 73 to the post-lion indicated at AYE will involve a compression of the damper unit indicated by the line 74, this compression increasing pro-gressively with further upwards deflection of the suspension.
The structure of the damper units 46 and 74 are best seen in Figures 3 and 4. In these views the coiled compression springs have been omitted for the sake of clarity. Each damper unit has a piston rod 81 extending from a cylinder 82, the distal end of the piston rod carrying an annular seat 83 to receive one end of the compression spring and the cylinder having an annular flanged collar 84 forming a seat for the opposite end of the come press ion spring. The collar 84 is rotatable on the cylinder and is adjustable axially with respect thereto. Specifically the collar 84 has a series of stepped teeth 85 angularly spaced and axially offset with respect to each other. Any of these teeth may be brought selectively into engagement with a detent 86 projecting from the wall of the cylinder 82. Thus the axial location of the collar 84 (and thus the preluding on the coiled compression spring) may be adjusted by rotating the collar 84 to bring selected teeth into engagement with the detent 86. This adjustment affects the preluding of the suspension springs, and thus pro-vises a means for selective variation of the stiffness character-fistic of the suspension.
12Z~884 The improved slide suspension system described above and illustrated in the drawings provides a "progressive rate" of spring suspension. In contrast to prior linear rate suspensions in which for each inch of compression the same amount of force was required, in a progressive rate system the force required for successive increments of compression increases. Thus the damper units 46 and 74, by virtue of the linkage arrangement mounting them, act as progressive rate springs. The slide suspension yields more easily initially and becomes progressively more difficult to deflect as its upwards displacement is increased.
The characteristics of the suspension can be varied by adjustment of the geometry of the linkages. For example the point of attachment of the lower end of the link 60 to the slide frame 18 is adjustable in the longitudinal direction by attaching it in holes 61' forward or to the rear of the attachment shown.
Claims (8)
1. In a snowmobile comprising a slide frame assembly positioned in sliding contact with the ground-engaging run of the track belt of the snowmobile, a slide suspension system comprising:
a front suspension assembly and a rear suspension assembly forming attachments between the snowmobile frame and respective forward and rearward portions of the slide frame assembly;
one said suspension assembly comprising a control arm having an upper end pivotally attached to the snowmobile frame and a lower end pivotally attached to the slide frame assembly;
the other said suspension assembly comprising a generally upright first link having a lower end pivoted to the slide frame, a second link pivotally attached at one end to the upper end of the first link and extending angularly therefrom to a spaced pivotal mounting connected to the snowmobile frame on a fixed transverse horizontal axis, said second link comprising one arm of a cranked lever which has a second arm extending at an angle to said first arm and having a distal end forming a pivotal mounting for one end of a telescopic damper and suspension spring unit that extends generally horizontally below the upper run of the track belt and has a second end pivoted on a second fixed transverse horizontal axis in said snowmobile frame.
a front suspension assembly and a rear suspension assembly forming attachments between the snowmobile frame and respective forward and rearward portions of the slide frame assembly;
one said suspension assembly comprising a control arm having an upper end pivotally attached to the snowmobile frame and a lower end pivotally attached to the slide frame assembly;
the other said suspension assembly comprising a generally upright first link having a lower end pivoted to the slide frame, a second link pivotally attached at one end to the upper end of the first link and extending angularly therefrom to a spaced pivotal mounting connected to the snowmobile frame on a fixed transverse horizontal axis, said second link comprising one arm of a cranked lever which has a second arm extending at an angle to said first arm and having a distal end forming a pivotal mounting for one end of a telescopic damper and suspension spring unit that extends generally horizontally below the upper run of the track belt and has a second end pivoted on a second fixed transverse horizontal axis in said snowmobile frame.
2. A slide suspension system according to claim 1 wherein said one suspension assembly comprising a control arm is attached towards the front of the slide frame assembly, said control arm hav-ing at its upper end an integral radially projecting arm that forms a mounting for one end of a second telescopic damper and suspension spring unit that extends generally longitudinally of said control arm, the opposite end of said unit being connected to a linkage system coupled to said slide frame assembly and adapted to compress said second unit axially upon upwards displacement of said one suspension assembly.
3. A slide suspension system according to claim 2 wherein said linkage system comprises a second cranked lever pivotally mounted at an intermediate point in the length of the control arm on a transverse horizontal axis, said second cranked lever having a first arm that forms a pivotal attachment to said opposite end of said second damper unit, and a second arm angularly spaced with respect to said first arm and pivotal attached to the upper end of a control link which has a lower end pivotal attached to said slide frame assembly at a location spaced longitudinally to the point of attachment of the control arm thereon.
4. A slide suspension according to claim 2 wherein each of said first and second telescopic damper and suspension spring units comprises a hydraulic piston and cylinder assembly damper surrounded by a coiled compression spring and includes means for adjusting the compressive loading of said compression spring thereby to adjust the force with which each suspension assembly resists upwards deflection thereof.
5. A slide suspension system according to claim 4 wherein each said unit comprises a first annular seat associated with the piston rod of the damper receiving one end of the coiled compression spring and a second seat associated with the cylinder of the damper unit receiving the second end of the coiled compression spring, said second seat being in the form of an annular sleeve surrounding said cylinder and provided with a series of teeth at spaced axial locations thereon, said teeth being selectively engageable with a detent formed on said cylinder thereby to vary the location of said seat axially of said cylinder.
6. A slide suspension system according to claim 1 wherein said other suspension assembly is attached towards the rear of the slide frame assembly, said one arm of the cranked lever support-ing there above an arrangement of idler wheels engaging the upper run of the snowmobile track and adapted to displace this upper run upwardly upon upwards deflection of said other suspension assembly.
7. A slide suspension system according to claim 1 wherein said cranked lever comprises a horizontal tube that forms the pivotal mounting on said fixed transverse horizontal axis, there being two second arms, one extending from each end of the tube and being connected to one of a corresponding pair of telescopic damper and suspension spring units.
8. A slide suspension system according to claim 1 wherein means are provided for adjusting longitudinally of said slide frame assembly the location of the pivotal connection of the lower end of the first link thereon.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US70618785A | 1985-02-27 | 1985-02-27 | |
| US706,187 | 1985-02-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1228884A true CA1228884A (en) | 1987-11-03 |
Family
ID=24836562
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000502719A Expired CA1228884A (en) | 1985-02-27 | 1986-02-26 | Snowmobile slide suspension |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1228884A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6253867B1 (en) | 1998-04-24 | 2001-07-03 | Lillbacka Jetair Oy | Snowmobile suspension system |
-
1986
- 1986-02-26 CA CA000502719A patent/CA1228884A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6253867B1 (en) | 1998-04-24 | 2001-07-03 | Lillbacka Jetair Oy | Snowmobile suspension system |
| US6401852B2 (en) | 1998-04-24 | 2002-06-11 | Lillbacka Jetair Oy | Snowmobile suspension system |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |