Classifications

• • 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
• • 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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D55/00—Endless track vehicles
  • B62D55/08—Endless track units; Parts thereof
  • B62D55/18—Tracks
  • B62D55/20—Tracks of articulated type, e.g. chains
  • B62D55/202—Wheel engaging parts; Wheel guides on links
• • 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
  • B62M2027/027—Snow mobiles characterised by the tracks

Definitions

• the present invention relates to a device for vehicles driven by two substantially parallel endless tracks, said tracks being arranged at a mutual distance in the transversal direction of the vehicle, so that a space extending in the longitudinal direction of the vehicle is formed between the tracks, each track being associated with wheels rotatably arranged about a rear axle and arranged to bear against the track from inside and assure the rear diverting thereof, each rear axle being by at least one pivot lever extending forwardly pivotally arranged relative to the chassis of the vehicle about a virtual pivot axis being substantially parallel to the rear axle.
• Track vehicles in general and in particular snowmobiles are intended _o be driven on an irregular ground and often on a very rough ground. For this reason the surface of the tracks bearing upon the ground is often made adaptable to the ground, for instance by arranging the wheels guiding the tracks in resilient bogie couples.
• the rear diverting wheels are also generally, as in the device defined in the introduction, pivotally arranged by arms with respect to the chassis, so that the rear part of the track may be adapted to irregu ⁇ larities of the ground, such as cavities, elevations, brows and the like.
• the loading area of the vehicle if there is any, is located at the back of the vehicle, which results in the fact that a heavy load on this loading area will cause the rear part of the vehicle to sink because the rear diverting wheels may pivot upwardly towards the chassis of the vehicle.
• the object of the present invention is to provide a device of the type mentioned in the introduction, but which to a great extent reduces the drawbacks described above of the previously known devices on transportation of comparatively heavy loads on the vehicle or by trailing.
• This object is, according to the invention, obtained by arranging means in a device of the type defined in the introduction in said space in the region of said pivot axis for co-operating with said levers influencing the pressure exerted by the levers upon the rear axles downwardly towards the ground.
• the pressure upon the rear axles may, when loading a heavy load at the back of the track vehicle in question, be increased in advance, so that the heavy load will not weigh down the vehicle as much as would be the case otherwise.
• An excellent distribu ⁇ tion of the pressure of the tracks upon the ground over large track surfaces is thereby obtained, so that the steering problems described above are avoided.
• a particularly preferred embodiment of the invention is defined in the appended claim 8 and there are such arrangements made, that a tow hook for towing a trailed vehicle is arranged on the rear end of the rigid arm. Owing to this it is possible to increase the pressure exerted by the levers upon the rear axles downwardly towards the ground by application of forces from the trailed vehicle on the tow hook and thus on the rigid arm.
• Fig 1 is a side elevation of a twin track snowmobile provided with a preferred embodiment of the device according to the invention
• Fig 2 is a perspective view obliquely from behind of the device according to the invention of Fig 1 broken away from the snowmobile,
• Fig 3 is a side elevation of the snowmobile according to Fig 1 in a position in use with biasing of the diverting wheels
• Fig 4 is a view of the device according to the invention in the snowmobile utilized for carrying out towing work.
• Figs 1-3 show an advantageous embodiment of the invention.
• the invention is applied on a twin track snowmobile 1, which moves on the ground by means of two substantially parallel endless tracks 2, which are driven by driving wheels connected to an output shaft of an engine at the front diversion of the tracks. These driving wheels are hidden in the figures by a chassis sheet 3.
• the tracks 2 rest upon the ground through bearing pressure from wheels 4 of resiliently arranged bogie wheel couples.
• the rear diverting of the track is carried out by rear diverting wheels 5.
• Each track 2 has in this case diverting wheels 5 rotatably arranged on a rear axle 6.
• Each end of the respective rear axle 6 is secured on one end of rigid pivot levers 7 extending from the wheels 5 and forwardly.
• the wheels could of course also be secured to the rear axle 6 and the latter be rotatably arranged in bearings in the pivot levers 7.
• the other end of the pivot levers are by torsion spring-like elements 8 connected to a rigid axle 10 rotatably mounted on the chassis 9 of the vehicle by circular discs 9' (Fig 2).
• the rigid axle 9 is in this case divided into two axles, one for each track 2.
• the rigid axle 10 has a substantially square cross section, and the spring-like elements 8 consist of elements known from the trademark ROSTA, said elements consisting of a square cavity in one end 12 of each pivot lever 7, the internal corners of this cavity square being filled by rubber elements 13, which allow pivoting of the pivot levers about the axles 10, but constitute a resistance to such a pivoting and function as a type of torsion spring on the storage of potential energy.
• ROSTA the rigid axles
• the rigid axles are arranged on the chassis is shown at 14 in Fig 1, and they may be displaced by means of a screw 15 between and secured in different positions in the longitudinal directions with respect to the chassis 9 of the snowmobile.
• the rigid axle 10 of each track extends substantially in parallel to the rear axle 6 associated therewith and defines by means of the damping pivotability of the rigid pivot levers 7 therearound a pivot axis.
• the ends of the rigid axles turned to the interior of the snowmobile extend into the space 16 between the two tracks 2 and into a further torsion spring-like element (ROSTA-ele ent) 17 in the form of a short beam with a substan ⁇ tially square cross section and inner rubber elements in the corners.
• An elongated rigid arm 18 extending backwardly in the space 16 is connected to the element 17.
• a tow hook 19 is arranged on the outer end of the rigid arm.
• a member 20 pro ⁇ vided with bores is arranged on the chassis 9 of the vehicle by means of a locking pin 21 enabling locking of the arm 18 in certain fixed positions with respect to the chassis thanks to the penetration of the locking pin through a bore 22 arranged in the arm and into the member 20 provided with bores.
• the rigid levers 7 When the rigid arm 18 is unloaded the rigid levers 7 will be able to pivot freely about the pivot axis defined by the rigid axles 10 through the bearings of the circular discs 9' in the chassis, while the rigid arm 18 follows the rigid levers in this pivoting movement.
• the only exception occurs when the two tracks travel over irregularities extending differently in the transversal direction of the vehicle and the two rigid axles 10 turn with respect to each other.
• the torsion spring ⁇ like element 17 will cause a certain damping of these relative turnings.
• the rigid arm 18 is allowed to be movable with respect to the member 20 and in a plane substantially perpendicular to the rigid axles 10.
• the rigid arm 18 assures that the traction point is moved into the space under the snowmobile to the spring-like element 17 and through this and the spring-like elements 18 and the rigid pivot levers transmitted to the rear axle 6 of the wheels 5.
• the invention is for instance completely applicable to a vehicle having no loading area on the vehicle itself as well as a vehicle having such a loading area but not being adapted to tow any trailed vehicle. Thus, it is not necessary that the rigid arm has a tow hook.
• the tracks may be more than two in numbers and it would then be conceivable to arrange a rigid arm in each space between the tracks. These rigid arms could if desired be interconnected at their rear ends by a transversal element.
• the expression torsion spring-like element comprises all means allowing a turning of the part in question (rigid axle, pivot lever, rigid arm) , but in doing this store potential energy.
• More than two wheels could be arranged on each rear axle.
• One single roll would also be conceivable instead of the two rear diverting wheels.
• Locking means for the rigid arm could be designed in an arbi ⁇ trary way and it could also comprise a resilient locking with respect to the chassis instead of a rigid one.
• the circular discs could be torsion spring-like mounted in the chassis.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Vehicle Body Suspensions (AREA)
• Arrangement And Driving Of Transmission Devices (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20375997

Family Applications (1)

Country Status (4)

Cited By (1)

Citations (5)

• 1989
  • 1989-05-22 SE SE8901796A patent/SE462527B/sv not_active IP Right Cessation
• 1990
  • 1990-05-21 CA CA002058415A patent/CA2058415A1/en not_active Abandoned
  • 1990-05-21 WO PCT/SE1990/000327 patent/WO1990014263A1/en active Application Filing
• 1991
  • 1991-11-20 FI FI915465A patent/FI915465A0/fi not_active Application Discontinuation

Patent Citations (5)

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