The present invention relates generally to devices for selectively admitting ventilation air into the interior of a vehicle, and more particularly, to devices of the type which are mounted in a wall of the vehicles and which are operable to selectively open and close the ventilating device.
Most conventional passenger automobiles include a standard ventilating system that is selectively operable to admit ventilating air that passes through the passenger automobile in a predetermined flow pattern that results in the fresh outside air adequately ventilating the entire interior passenger space within the vehicle. However, in larger vehicles that are designed to carry a relatively large number of passengers, such as a school buses, airport vans, and similar larger passenger vehicles, conventional ventilation systems may not be sufficient to properly ventilate the much larger passenger space within the vehicle. This problem can be exacerbated in special circumstances that further increase the need for more ventilating air, such as larger vehicles that may not include air conditioning and are often required to sit motionless in hot sunlight for prolonged periods of time so that the inside of the vehicle becomes uncomfortably hot.
To deal with this problem, it is known that school buses and the like may be provided with ventilating devices which are mounted in the roof of the vehicle, and which can be selectively opened and closed by the operator of the vehicle to admit ventilating air into the vehicle when desired.
In one form, such known ventilating devices are operable by an electric motor to tilt upwardly the front edge and/or the rear edge of a ventilating panel, depending upon the desired flow pattern of the ventilating air. If the front edge only is tilted upwardly, fresh air from the outside is forced into the interior of the vehicle by the forward motion of the vehicle. If the rear edge only is tilted upwardly, the forward motion of the vehicle will tend to draw air outwardly from the interior of the vehicle and set-up a flow of ventilating air through the interior of the vehicle. If both the front and rear edges are raised at the same time, the entire panel is moved upwardly to a position generally parallel to it initial position to provide the maximum opening for permitting ventilating air to flow inwardly and/or outwardly through such opening.
While these known ventilating devices generally provide an adequate flow of ventilating air through the vehicle, they have the disadvantage of being somewhat difficult and time consuming to operate. More specifically, the moveable ventilating panel is operated by a single electric motor, and the panel must be moved through a predetermined sequence of steps, normally including four steps, namely:
(1) tilting the front edge of the panel upwardly;
(2) then titling the back edge of the panel upwardly;
(3) then moving the front edge of the panel downwardly to its initial position;
(4) moving the back edge of the panel downwardly so that the panel is returned to its initial, fully-closed position.
Thus, to get to a particular position of the panel, (e.g. position (3) above, with just the rear edge of the panel tilted upwardly), it may be necessary for the vehicle operator to first move the panel through several positions in the sequence (e.g. positions (1) and (2) above), all of which is time consuming for the operator and which imposes unnecessary wear on the motor and the operating mechanism.
By contrast, the present invention provides a ventilating device which overcomes the disadvantages of known ventilating devices and offers significant versatility in the operation of the device.
In accordance with the present invention, a selectively openable ventilation device is provided for use in vehicles which includes a frame mountable in a wall of the vehicle and being formed with a ventilation opening therein, and a panel having a configuration corresponding generally to the ventilation opening and having two opposed sides. A first linkage assembly connects one side of the panel to the frame for permitting movement of the one side of the panel between a first closed position at which the one side is disposed within the frame to close the ventilation opening thereat and a second open position at which the one side is disposed in a raised position above the frame to open the ventilation opening thereat. A second linkage assembly connects the other the side of the panel to the frame for permitting movement of the other side of the panel between a first closed position at which the other side is disposed within the frame to close the ventilation opening thereat and a second open position at which the other side is disposed in a raised position above the frame to open the ventilation opening thereat. A first motor is operatively connected to the first linkage assembly to selectively move the one side edge of the panel between the first and second positions thereof, and a second motor is operatively connected to the second linkage assembly to selectively move the other side edge of the panel between the first and second positions thereof, the second motor being operable independently of the first motor whereby either or both of the sides of the panel can be selectively moved toward and way from the frame to permit ventilating air to flow through the ventilation opening at either or both of the sides of the panel.
In one preferred embodiment of the present invention, the first and second motors are electric motors, each operated by a control switch mountable within the vehicle and operable to selectively move the two sides of the panel between their open and closed positions and to selectively stop such movement at any desired intermediate position between the open and closed positions.
Also, it is preferable that the first and second linkage assemblies each include a pair of spaced mounting brackets having downwardly extending slots therein, with a crossbar positioned in the slots and connected to the motor to be moved in the slots by the motor. A pair of operating links are provided, each operating link being pivotally connected at one of its ends to the crossbar and at the other of its ends to the frame of the ventilation unit, whereby when the crossbar is moved downwardly in the slots by the motor the operating links cause the one panel side to be moved from the first closed position thereof to the second open position, and when the crossbar is moved upwardly in the slots by the motor the operating links cause the one panel side to be moved from the second open position thereof to the first closed position thereof.
This preferred operating arrangement may also provide at least one of the operating links with a pin extending outwardly therefrom, and provide a latching member mounted for movement between a first latching position at which it engages the pin to maintain the one panel at its first closed position and a second release position at which it disengages the pin to permit movement of the pin in the slot in the bracket.
The latching member is preferably mounted on the bracket for sliding movement relative thereto between the first latching position and the second release position, and it is formed with a hook shaped surface positioned to engage the pin during the last portion of the aforesaid upward movement of the crossbar in the slot. The crossbar may engage the latching member to move the latching member in a direction that will cause the hook shaped surface thereof to urge the pin upwardly when the latching member is in the first latching position and thereby maintain the panel securely pressed against the frame at the first closed position thereof to seal the ventilating opening thereat.