Abstract:
In a snowmobile or other vehicle, ventilation of ambient air to the engine compartment is necessary. However, from time to time when encountering deep snow or extremely cold temperatures, it may be necessary to restrict the inflow of ambient air into the engine compartment. An adjustable air vent having a sliding ventilation grill adjusts the air flow. The air vent has actuators for adjusting the air flow that are simple and easily manually operable by an operator even when wearing gloves or mittens without the need of any tools.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application is a continuation of U.S. application Ser. No. 09/689,788, filed Oct. 13, 2000 now U.S. Pat. No. 6,439,328, which claims priority to U.S. Application 60/178,776, filed Jan. 28, 2000 and U.S. Application 60/160,761, filed Oct. 21, 1999, the entire contents of all three applications hereby incorporated by reference. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to ventilation systems for vehicles, and in particular, to adjustable air vents for snowmobiles for adjusting an amount of ambient air permitted to flow into engine compartments of the snowmobiles. 
   2. Description of the Related Art 
   Recreational vehicles and more particularly snowmobiles, generally operate in cooler ambient temperatures. As such, air cooled engines (usually 2 cycle) are often used as a power source. In some newer models of snowmobiles, liquid cooled engines (either 2-cycle or 4 cycle) having heat exchangers are also used. It is generally necessary to have an inflow of air (called “ram air”) into the engine compartment to either cool the heat exchanger for the liquid cooled engine or to flow pass and remove heat from the cooling fins of the air cooled engine. 
   It has been found, however, that when the snowmobile operates at extremely cold temperatures, the engine can be so overcooled by the inflow of ram air, that its efficiency decreases. Furthermore, when operating in deep snow, snow may enter through the ventilation openings into the engine compartment and again overly cool the engine or adversely affect other mechanical systems. For instance, the snow can contact hot surfaces of the engine and melt or turn to steam. The melted snow or steam can then come into contact with cold surfaces and refreeze. The resulting buildup of ice can prevent proper operation of the vehicle systems, including, for example, the torque converter. 
   Thus, there is a need to have adjustable ventilation vents that can be quickly and easily opened and closed by an operator without tools and preferably, while wearing gloves or mittens, during different conditions of operation. 
   Sliding-type air vents are known in the prior art. See for instance, Hansen, U.S. Pat. No. 1,638,847, issued Aug. 16, 1927. Hansen discloses a shutter for an automobile radiator having a first plate  10  with a plurality of slots  14  and a second plate  18  having a like number of slots  19 . The two plates are slidably engaged with one another to allow plate  18  to be moved from a first position, where the slots  14  and the slots  19  are aligned and air can pass therethrough, to a second position, where the slots  14  and the slots  19  are not aligned and air does not flow therethrough. The sliding plate  18  is actuated via a remote pin  35  mounted to the automobile dashboard through actuating wires  31  and  32  positioned in tubes  33  and  34 . 
   Pratt, U.S. Pat. No. 4,706,461, issued Nov. 17, 1987, discloses a similar sliding air vent. Pratt uses a thermoelongating actuator  82  mounted to levers  74  and  76  mounted between the stationary and slidable grills to vertically move the slidable grill to an opened or closed position, as desired. 
   However, neither of these prior art devices is simple enough or easily manually operated by an operator wearing gloves or mittens so as to be applicable to use in a recreational vehicle, and especially a snowmobile. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a simple, inexpensive cooling air flow control device for a vehicle, and particularly a snowmobile, that is easily manually operable by an operator without tools, even when the operator is wearing gloves or mittens. 
   Therefore, this invention provides an adjustable air vent for a vehicle. The air vent includes a stationary grill adapted to be mounted to the vehicle, the stationary grill having at least one air aperture and an engaging surface. In addition, a movable grill is adapted to be movably mounted with respect to the stationary grill. The movable grill has at least one air aperture and an engaging surface adapted to engage the engaging surface of the stationary grill. The movable grill moves with respect to the stationary grill from an open position where the at least one aperture of the stationary grill is aligned with the at least one aperture of the movable grill to allow air to flow therethrough to a closed position where the at least one aperture of the stationary grill is not aligned with the at least one aperture of the movable grill to reduce the flow of air through the vent. 
   The stationary grill also includes a projecting closing actuator and a projecting opening actuator. The movable grill includes a projecting closing actuator positioned proximate the stationary grill projecting closing actuator such that squeezing the two together moves the movable grill to the closed position. The movable grill also includes a projecting opening actuator positioned proximate the stationary grill projecting opening actuator such that squeezing the two together moves the movable grill to the open position. 
   In a preferred embodiment of the present invention, a plurality of the adjustable air vents are fixed to an underside of a snowmobile hood. The provision of the actuators that can be easily manipulated by squeezing together to open and close the vents allows the operator of the snowmobile to easily adjust cooling air flow to the engine without having to remove mittens or gloves and without using tools. Thus, the simple, easily operated vents of the present invention increase both the efficiency in adjusting the air flow and the comfort of the operator so doing. 
   The foregoing and other objects, features, characteristics and advantages of the present invention as well as the methods of operation and functions of the related elements of structure, and the combination of parts and economies of manufacture, will be apparent from the following detailed description and the appended claims, taken in connection with the accompanying drawings, all of which form a part of the specification, wherein like reference numerals designate corresponding parts in the various figures. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a top perspective view of a front portion of a snowmobile with the hood closed; 
       FIG. 2  is a perspective view from a rear of the snowmobile wherein the hood is in the open position; 
       FIG. 3  is an underside view of a single sliding vent when the vent is in an open position; 
       FIG. 4  is a similar view to  FIG. 3  wherein the vent  5  is in a closed position; 
       FIG. 5  is an underside view of a double-sliding vent with the vents opened; 
       FIG. 6  is the same view of the vent shown in  FIG. 5  with the vents closed; 
       FIG. 7  is a partial view similar to  FIG. 4  showing a locking mechanism for maintaining the position of the movable grill; 
       FIG. 8  is a detail view of an actuator shown in  FIG. 7 ; 
       FIG. 9  is a partial view of an alternative embodiment single sliding actuator; 
       FIG. 10  is a partial view of a further alternative embodiment single sliding actuator; 
       FIG. 11  is a partial view of an alternative embodiment single sliding actuator controlled by a rotary knob; and 
       FIG. 12  a partial view of a further alternative embodiment controlled by a rotary knob. 
   

   DETAILED DESCRIPTION 
     FIG. 1  is a top perspective view of a front of a snowmobile generally shown as  100 . The snowmobile includes a hood  102  and windshield  103 . In  FIG. 2 , the same snowmobile  100  is shown, however, the view is taken from the rear left side of the vehicle. 
   In  FIG. 2 , the hood  102  is opened showing an underside of the hood  102  and a portion of an engine compartment  101 . A hinge  104  connected between the hood  102  and a body of the snowmobile allows the hood  102  to be raised and lowered. Both  FIGS. 1 and 2  show a large single adjustable air vent two large lateral double side vents  2 , and two smaller double lateral side vents  2 (A). 
   In  FIG. 3 , a single adjustable air vent  1  is shown. The bottom of the vent shown in  FIG. 3  is forward when placed under the hood  102 . The air vent  1  includes a stationary grill  3  on the outer side here) and a movable or sliding grill  4  (on the inner side here). The air vent  1 , and thus, the stationary grill  3  and sliding grill  4  can be shaped as necessary to conform to the contour of the hood in the desired placement location. 
   Stationary grill  3  is affixed to the underside of the hood  102 . It is affixed by means of a left lower lateral flange  5 , a right lower lateral flange  6 , an upper left lateral flange  7 , an upper right lateral flange  8  and an upper flange  9 . These flanges are adapted to receive the heads of bolts, screws or other types of fasteners that are fixed to the snowmobile hood  102 . 
   In  FIG. 3 , vent apertures  10  of the sliding grill and vent apertures  11  of the stationary grill are aligned and ambient air may pass therethrough. The sliding grill  4  is maintained in its position upon stationary grill  3  by lower slide bracket  12 , left upper slide bracket  13  and right upper slide bracket  14 . In addition, there are a number of guide posts, namely left lower guide post  15 , right lower guide post  16 , left upper guide post  17  and right upper guide post  18 . The lower guide posts  15  and  16  are equipped with lock washers  19  which extend over a portion of the sliding grill  4 . Alternatively, headed screws or other types of fasteners can be used to fasten to the guide posts so as to engage and secure the sliding grill to the stationary grill. 
   To activate the sliding grill  4 , actuator projections  20  are used. There is an inner sliding grill left actuator  20  which is a T-shaped perpendicular protrusion extending outward from sliding grill  4  and, in a preferred embodiment, integrally molded thereto. In addition, there is an inner sliding grill right actuator  21  which is also a T-shaped projection which extends perpendicularly outward from the sliding grill  4  and is integrally molded thereto. The T-shape of the actuators increases the strength of the actuators and reduces the risk of breakage of the actuators. 
   The sliding grill  4  is also equipped with a pair of T-shaped apertures shown as left T-shaped aperture  22  and right T-shaped aperture  23 . These permit perpendicular T-shaped stationary grill left actuator  24  and stationary grill right actuator  25  to extend outwardly through the inner grill, adjacent to left sliding grill actuator  20  and right sliding grill actuator  21 , respectively. Alternatively, the shape of the projecting actuators and apertures can also be varied and need not be T-shaped. 
   In operation, when the vent is in an open position, the apertures  10  and the apertures  11  are aligned as shown in  FIG. 3  to allow air to flow therethrough, and the sliding grill left actuator  20  and the stationary grill left actuator  24  have been pulled together and substantially abut one another. Aperture  22  appears to be quite open in this view. Also in the open position, the sliding grill right actuator  21  and stationary grill right actuator  25  are spaced some distance apart. 
   In order to place sliding grill  4  in the closed non aligned aperture position as shown in  FIG. 4 , the operator simply grasps the outer sides of actuators  21  and  25  and squeezes or presses them together. In that position, as shown in  FIG. 4 , with actuators  21  and  25  abutting each other, the vent is closed. A locking mechanism can be provided to maintain the vent in the closed and open positions. 
   As can be seen in  FIG. 7 , actuators  20 ,  21 ,  24  and  25  can be provided with locking projections  42 ,  44 ,  46  and  48 , respectively. As shown in  FIG. 7 , when actuators  21  and  25  are squeezed together, locking projection  44  will move past locking projection  48 , thereby providing a positive lock to maintain the vent in the closed position. The vent will remain in the closed position until sufficient force is applied to actuators  20  and  22  to open the vent and overcome the locking force of locking projections  44  and  48 . The locking projections can be molded onto the actuators. Alternatively, one or both of each corresponding pair of locking projections can be spring-loaded. See  FIG. 8  where it is shown how locking projection  48  of actuator  25  is provided on an extending semi-flexible finger  49  of actuator  2 S. In this way, the finger  49  provides a spring action to the locking projection  48 , thereby reducing the force necessary to move the locking projections  44  and  48  relative to one another while increasing the operating life of the projections. Other spring-loading mechanisms can also be used to spring-load the projections. Similarly, locking projections  42  and  46  interact to maintain the vent in the open position. Alternative locking mechanisms can also be used. 
   It should be noted that in the closed position, a lower projection  40  of sliding grill  4  between guide post  15  and guide post  16  is now abutting the guide post  15  as shown in FIG.  4 . This is opposed to the open position, where the lower projection  40  abuts the right hand guide post  16 . Thus, guide posts  15  and  16  also act as limiting stops. 
   To return the sliding grill to the open position with the apertures  10  and apertures  11  aligned, the operator simply grasps the outsides of actuators  20  and  24  and squeezes or presses them together. Slide brackets  12 ,  13  and  14  are molded in such a manner to provided a friction fit between themselves and sliding grill  4  to help maintain the sliding grill in the desired position once adjusted. This creates a snapping-together relationship that acts similar to a locking mechanism when the movable grill is moved from a closed position to an open position and vice-versa. Alternatively, a separate friction-type or other securing mechanism can be used to maintain the sliding grill  4  in the desired position. In such a case, the fit between the slide brackets and the sliding grill could be loosened, as desired. 
   A second embodiment of the invention is shown in  FIGS. 5 and 6 . The second embodiment is a double sliding adjustable air vent shown generally as  2 . The actuators  20 ,  21 ,  24  and  25  function in a similar manner as the embodiment shown in  FIGS. 3 and 4  with the exception that there are four pairs of such actuators. Two pairs function for each sliding grill  27  and  28 . The stationary grill  26  remains one integrally molded piece. 
   In the embodiment shown in  FIGS. 5 and 6 , one of the sliding vents such as left sliding grill  27  could be closed as shown in  FIG. 6 , while the other remains opened as shown in FIG.  5 . The stationary grill  26  shown in  FIGS. 5 and 6  is fastened to the underside of the hood  102  in positions lateral of either side of the stationary grill  1 . In order to fasten outer stationary grill  26  to the hood  102 , a lower fastening bracket  29  is used along with three upper fastening brackets  30 . 
   The left sliding grill  27  and right sliding grill  28  are guided for movement on stationary grill  26  by means of guide posts  31 . There are two guide posts which protrude upwardly from the stationary grill  26  through elongated slots  35  which are found in the left sliding grill  27  and right sliding grill  28 . Lock washers  32  secure the guide posts over the sliding grills. Springs can be placed between the lock washers and the sliding grills to provide friction for securing the sliding grills in the desired adjusted position. 
   Right and left sliding grills ( 28  and  27 ) are also  10  guided in place by lower slide brackets  33 . These slide brackets are integrally molded to stationary grill  26  and protrude upwardly through apertures  33 (A), one of which is found in the left sliding grill  27  and one in the right sliding grill  28 . The upper guide brackets  34  mark the upper limits for the sliding motion of the right sliding grill  28  and left sliding grill  27 . Slide brackets  33  and guide brackets  34  can be molded, as discussed above with respect to the first embodiment, to provide the desired frictional fit. 
   In operation, the apertures  10  and the apertures  11  are aligned in FIG.  5  and permit air to flow therethrough. In order to close the apertures, on either the right or left sides, the operator, as previously mentioned with regard to  FIGS. 3 and 4 , simply presses on the outsides of projecting actuators  20  and  24  on the right sliding grill  28  and left sliding grill  27  and the vents will move to the closed position or non-aligned aperture position as shown in FIG.  6 . In this case, it is the apertures  35  and  33 (A) in conjunction with guide posts  31  and lower slide brackets  33  that act as limiting stops. 
   To return the apertures of the stationary and movable grills to the open aligned position shown in  FIG. 5 , the operator grasps the outsides of actuators  21  and  25  and squeezes or presses them together. 
   Although in the preferred embodiments, the vent grills are molded from plastic, they can also be made of metal or other materials, as needs dictate. 
   In an alternative embodiment, one or more gaskets, liners or seals can be placed between the sliding and stationary grills and or between the grills and the snowmobile hood to provide better sealing against air flow when in the closed position and/or to reduce noise and/or wear caused by vibration between the grills. Additionally, the sliding vent need not be the inner vent but can be the outer vent. In an alternative embodiment, the vehicle hood or housing can serve as the stationary vent, with the sliding vent configured and shaped to conform to the hood/housing. In such an embodiment, a separate stationary grill need not be provided. Also, while the preferred embodiment positions one or more of the actuators in slots, such slots need not be provided, for instance, if the actuators are positioned adjacent an edge of one of the stationary and movable grills. 
   While the preferred embodiment uses a linear sliding motion between the sliding and stationary grills, it is also contemplated that other types of motion can be used. For instance, in one embodiment, the sliding motion can be rotary, with the sliding grill being rotatably slidable with respect to the stationary grill. In such an embodiment, the movable grill can rotate about an axis fixed with respect to the stationary grill. Two pairs of actuators can be provided at alternate positions around the axis, with one pair opening the vent when squeezed together and the other pair closing the vent when squeezed together, similarly to the operation of the preferred embodiment. 
   In another alternative embodiment, as shown in  FIG. 9 , the actuators  20 - 24  can be replaced by a single sliding actuator  50  sliding in a slot  52  with spaced apart stationary actuators  54  and  56  positioned either at opposite diagonal corners of the slot or adjacent one side of the slot at opposite ends of the slot (see FIG.  10 ). In this way, the vent can be placed in one of the open and closed position by squeezing the sliding actuator  50  and the first of the stationary actuators  54  and  56  to align the sliding actuator with the first stationary actuator. The vent can then be placed in the other of the open and closed position by squeezing the sliding actuator  50  and the second of the stationary actuators  54  and  56  to align the sliding actuator with the second stationary actuator. The open and closed positions of the sliding actuator are shown in phantom in  FIGS. 9 and 10 . 
   Alternatively, a manually grippable rotary knob control can be provided, interconnected between the sliding actuator and a stationary mount, to convert a rotating operating motion to the linear motion used for moving the sliding vent.  FIG. 11  shows a rotary knob  60  rotationally mounted on a stationary post  62 . A sliding actuator  64  is disposed in a slot  66 . A cylindrical projecting portion  66  is connected to and projects above sliding actuator  64  to engage a channel  68  disposed on the underside of knob  60 . By this arrangement, clockwise rotation of the knob imparts a driving force from the channel  68  to the projecting portion  66  to move the actuator  68  to the left in the slot  70 , Similarly, counterclockwise rotation of the knob  60  moves the actuator  68  to the right in the slot  70 . 
   Alternatively, a rack and pinion type arrangement can be used, as shown in FIG.  12 . An edge  80  of the movable grill is toothed to engage a pinion gear  82  rotationally mounted to the stationary grill. A rotary knob (not shown) can be attached to the pinion gear to convert rotary motion to the linear motion used to move the movable grill. 
   In applications where an intermediate air flow is desired, one or more further actuator pairs can be provided such that squeezing the sliding actuator and the stationary actuator of the respective further pair to align the two moves the sliding grill to a position where the vent is partially open. In addition, although the preferred embodiment has a closed position where the air flow is substantially blocked, in certain applications, it may be desirable to have the closed position be one that still flows a desired minimum amount of cooling air. This can be accomplished by limiting movement of the movable grill with respect to the stationary grill so that the corresponding air flow apertures always overlap to a desired minimum extent in the closed position. This can also be accomplished by providing a certain number of apertures that remain open even as the other apertures close when the movable grill is moved to the closed position. In situations where large quantities of air flow are required, additional ports can be provided that open to the outside of the vehicle. The ports can be covered by movable flaps that are rotatable between a closed position where the port is covered and an open position where the port is uncovered. 
   Further, the ventilation grill can be adapted for remote operation by the operator. In such an embodiment, the remote actuators can be configured similarly to the actuators  20 ,  24 ,  21  and  25  so that grasping and squeezing together one pair opens the vent and grasping and squeezing the other pair closes the vent. The remote actuator can be connected to the stationary and sliding grills by cable mechanisms. 
   In applications where more than one vent is provided, the plurality of vents can be independently operable so that each vent can be opened or closed independently of the other vents to provide the desired air flow, as conditions warrant. Alternatively, two or more of the vents can be interconnected, by cable mechanisms for instance, so that one set of actuators will operate the interconnected vents in tandem. Furthermore, in an alternative embodiment, the vent need not be attached to the vehicle hood or outer housing, but can also be used as long as it is positioned in the cooling air path. The vent can also be used to control cooling air flow by being positioned in the cooling air exit path. 
   It is contemplated that the various alternatives and modifications discussed above can be used together in different combinations as desired to provide a vent or vents most suitable for a specific application. 
   In summary, the adjustable air vents of the present invention are light and durable, non-rusting and easy to make and assemble. The placement of the actuators and the use of them by the operator without tools and while wearing gloves or mittens in frigid temperatures is a significant advance over the prior art. 
   While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that it is capable of further modifications and is not to be limited to the disclosed embodiment(s), and this application is intended to cover any variations, uses, equivalent arrangements or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains.