Patent Publication Number: US-2004051357-A1

Title: Seat for snowmobile or other similar vehicle

Description:
FIELD OF THE INVENTION  
       [0001] The present invention relates to a seat for snowmobile or any other similar vehicle where the user is sat astride.  
       [0002] By way of examples of such similar vehicles, reference can be made to personal watercrafts, all terrain vehicles (ATV) and any other vehicles wherein the user is sat astride onto an horizontal seat of a given length usually filled with synthetic foam and mounted onto a rigid support.  
       BRIEF DESCRIPTION OF THE PRIOR ART  
       [0003] As indicated hereinabove, the seat of snowmobile or other similar vehicle of the above mentioned type comprises an horizontal seat that may be provided with the back rest. This seat is filled with synthetic foam and mounted onto a rigid support which is itself connected to the frame of the vehicle. The problem with this kind of seat is that the only suspension that is offered to the user is exclusively “restricted” to the synthetic foam that fills it up.  
       [0004] However, the density of the synthetic foam and its performance to absorb impacts are essentially related to the weight of the user.  
       [0005] In addition to this limitation, the density and performance of the foam may vary over the time if the user is very heavy and his weight deforms and scratches the foam.  
       [0006] Moreover, the density as well as the performance of the foam also depend on the external temperature. Indeed, the performance of the foam may vary in a substantial manner when the temperature varies within a large range of temperatures, as is the case in countries like Canada where the external temperature may vary from −30° to +30° C.  
       SUMMARY OF THE INVENTION  
       [0007] It has now been discovered that when an horizontal cavity is provided in at least one part of the length of the seat and this cavity is filled up with an inner tube inflated at a given pressure, one may obtain an additional suspension effect and thus may solve all the problems of losses of density and performance usually encountered when the seat is exclusively filled with synthetic foam.  
       [0008] Thus, with such an inner tube, it becomes possible for the seat to keep its shape and performance indefinitely, independently of the user&#39;s weight, the external temperature and/or the life time.  
       [0009] In fact, one may obtain even better performance than before, since the air in the inner tube is almost not affected by the cold, the heat or the presence of water and since its reaction to an impact when the vehicle moves, is different in synchronisation when the one of the suspension of the vehicle, thereby resulting in much higher shock absorption and much better comfort for the user.  
       [0010] Thus, the present invention provides a seat for snowmobile or other vehicle, which seat is of a given length and filled of synthetic foam and extends horizontally onto a rigid support. In accordance with the invention, this seat is provided with a cavity that extends horizontally over at least one part of its length and such a cavity is filled with an inflated inner tube so as to provide additional suspension for a user.  
       [0011] Preferably, the cavity provided in the seat has a length greater than the one of the inner tube so as to give extra space and thus allow the inner tube to expand in an horizontal plane in the case of an impact.  
       [0012] Preferably also, the inner tube is held in a sleeve having at least one open end. The sleeve only prevents the inner tube from dilating in a direction other than the longitudinal one in the case of an impact.  
       [0013] The invention and its various advantages will be better understood upon reading the following description of several preferred embodiments thereof, made reference to the accompanying drawings. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0014]FIG. 1 identified as “prior art”, is a side elevational view of a snowmobile, showing the seat of the same in cross-section;  
     [0015]FIG. 2 is a side elevational view in cross-section of a seat of snowmobile according to a preferred embodiment of the invention;  
     [0016]FIG. 3 is a view similar to FIG. 2, showing the seat when the same is deformed due to an impact;  
     [0017]FIG. 4 is a cross-sectional top view of an inner tube held within a sleeve, as used in the preferred embodiment shown in FIGS. 2 and 3;  
     [0018]FIGS. 5 and 6 are illustrations of possible variants of the inner tube; and  
     [0019]FIGS. 7 and 8 are cross-sectional top views of other type of inner tube possibly useful within sleeves. 
    
    
     DESCRIPTION OF SEVERAL PREFERRED EMBODIMENTS OF THE INVENTION  
     [0020] As mentioned in the “Brief Description of the Prior Art” given hereinabove, the seat  1  for snowmobile or other similar vehicle on which the user may seat astride comprises an horizontal body (also called seat  3 ) usually provided with a small backrest  5 . The seat  3  is fully filled with synthetic foam and mounted onto a rigid support  7  fixed to the frame of the vehicle.  
     [0021] Usually, this kind of seat also comprises a rear trunk  1   1  provided with a manually openable access door  13 .  
     [0022] This basic structure is very conventional and needs not be described in greater details.  
     [0023] As previously mentioned, the problem of this kind of seat is that it is exclusively made of foam, except of course for its covering. Therefore, the problem is that the density of the foam as well as its performance may vary as a function of the time, especially when the user of the vehicle is very heavy. In addition, the foam does not give a real suspension effect, and, more specifically, a real absorption effect when the vehicle moves over bumps and gives impacts to the user.  
     [0024] As shown in FIGS. 2 and 3, the present invention overcomes this problem that has been known for years and for which no solution has been found so far. More specifically, the invention consists in removing a portion of the foam forming the “heart” of the seat in order to form a cavity  15  that extends horizontally over at least one part of the length of the seat, and preferably over the full length thereof. This cavity  15  is filled with an inner tube that may be inflated in such a manner as to act as an additional suspension for the user.  
     [0025] As shown in FIGS. 2 and 3, the cavity  15  made in the seat preferably has a length greater than the one of the inner tube  17  to give some extra free space to the same and thus allows the inner tube  17  to expand in the horizontal direction in the case of an impact. The way the inlet tube can be deformed thanks to the free space left can be seen by comparing FIGS. 1 and 3.  
     [0026] It is worth noting that the free space  19  left to ensure an expansion of the inner tube may be left empty as shown, or may be filled up with another foam that is highly compressible. In all the cases, the only requirement is that the inner tube may be free to expand in an horizontal direction during an impact and thus to ensure better suspension.  
     [0027] For a practical standpoint, the inner tube may have any shape, provided that it may fill up the cavity and provide a good support for the user. Examples of possible shapes that may have the inner tube, are shown in FIGS.  4  to  8  of the drawings.  
     [0028] In the embodiments shown in FIG. 4, the inner tube is in the form of a ring where the central part may be filled up with a block made of foam  21 . This is also the case of the inner tube shown in FIG. 8.  
     [0029] In the other illustrated embodiment, the inlet tube consists of a single element that may be of oval shape as shown in FIG. 5, or of rectangular shape as shown in FIGS. 6 and 7.  
     [0030] In order to retain the inner tube and more especially to ensure that it expands in the right direction, namely the longitudinal direction, in order to avoid uncomfortable for the user seat astride onto the seat, the inner tube  17  is preferably held within a flexible sleeve  23  which must of course have at least one end opening at the place where is located the free space left within the cavity  15 . This sleeve avoids that the inner tube dilates in direction other than the longitudinal direction in the case of an impact.  
     [0031] To facilitate maintenance of the seat and/or adaptation of it as the function of the weight of the user, the inner tube  17  may be provided with an air inlet tube  25  which extends within the trunk  11 . This inlet tube  25  is preferably closed by a valve  27  which also extends within the trunk and to which can be connected a pump. Such permits to inflate the inlet tube at will depending on the user&#39;s needs.  
     [0032] In practice, tests made by the inventors have shown that a pressure as low as 0.75 to 2 psi is perfectly sufficient to obtain excellent comfort and suspension effects.  
     [0033] To facilitate maintenance of the vehicle, the pump that may be used for inflating the inner tube, may be fixed in a permanent manner to the valve. In this connection, one may refer to FIG. 4 which shows an embodiment of the invention wherein a pump  29  is fixed to the valve together with a pressure gauge  31  in order to check the pressure within the inner tube.  
     [0034] As mentioned hereinabove, tests were carried out by the inventors. These tests made with an inlet tube as shown in FIG. 4 at a pressure about 1 psi have proved to be very positive and have actually demonstrated the efficiency of the present invention.  
     [0035] Of course, numerous modifications could be made to the preferred embodiments disclosed hereinabove without departing from the scope of the present invention.