School bus escape door system

An escape door system is described which is useful on a school bus (e.g. as a rear escape door). The system includes a hinged door which is releasably attached along one side edge to a wall of the bus. A latch which is accessible on the outside of the bus enables the door to be separated or removed from the wall of the bus in an emergency.

FIELD OF THE INVENTION 
This invention relates to escape door systems in vehicles. More 
particularly, this invention relates to exit or escape doors for passenger 
buses such as school buses. 
BACKGROUND OF THE INVENTION 
School buses typically have a rear exit door. However, sometimes it is 
difficult to open the door to allow people to escape from the bus after an 
accident. This can be particularly difficult when the bus has been tipped 
over on its side and it is necessary to lift the weight of the rear door 
to open it. 
My prior patent (U.S. Pat. No. 5,011,215) describes an escape door system 
for a bus. That system involved an aperture in the rear wall, a tab member 
carried by one side edge of the door that projects through the aperture, 
and retention means inside the bus for retaining the tab member in the 
aperture. By releasing the tab member, the entire rear door can be 
removed. However, it is necessary to release the tab member from inside 
the bus. This is not always possible or convenient. 
There has not heretofore been provided an escape door system having the 
features and advantages provided by the present invention. 
SUMMARY OF THE PRESENT INVENTION 
In accordance with the present invention there is provided an escape door 
system for a passenger vehicle such as a school bus which can be easily 
and quickly opened after an accident to allow passengers to exit the bus. 
In one embodiment the escape door system comprises: 
(a) an escape door having a first side edge; wherein the door normally 
encloses an escape opening in the rear wall of the bus; 
(b) hinge means secured to the first side edge of the escape door which 
enables the escape door to pivot between open and closed positions; 
(c) attachment means for attaching the hinge means to the exterior of the 
rear wall of the bus; and 
(d) latch means on the exterior of the rear wall of the bus which is 
movable between open and closed positions. 
When the latch means is in the closed position, the attachment means is 
secured to the rear wall of the bus, and when the latch means is in the 
open position the attachment means is released from the rear wall. This 
enables the entire rear door to be removed or separated from the rear wall 
of the bus, thereby leaving a large opening for removing passengers from 
the bus in the case of an emergency. 
The escape door system of the invention is easy to operate and can be 
opened from the exterior (or, optionally, the interior) of the bus. In one 
embodiment the rear windows are hinged to the rear wall of the bus so that 
they can be easily opened to provide additional egress area.

DETAILED DESCRIPTION OF THE INVENTION 
In FIGS. 1 and 2 there is shown the rear of a bus 10 having a rear wall 10A 
and an access opening 10B which is normally closed by rear door 20. There 
are also windows 11 in the rear wall. 
The rear door 20 is hinged to the rear wall of the bus by means of bars 22 
secured at one of their end portions to the rear door and secured at their 
opposite ends to vertical bar 23. The lower end 23B of bar 23 is captured 
or supported in a recess in bracket 24 which is secured to the rear wall 
10A (e.g. with bolts). The upper end 23A of bar 23 is held against bracket 
25 (which also may be secured to the rear wall by means of bolts). 
Vertical bar 23 and bars 22 operate together as a hinge for the rear door, 
enabling the door to pivot or swing outwardly from the rear wall about the 
longitudinal axis of vertical bar 23 when handle 15 is manipulated to 
unlock the door. 
In an emergency, the entire rear door 20 can be easily separated or removed 
from the rear wall by first moving latch bar or lever 26 to a position 
where it no longer secures the upper end 23A of vertical bar 23 in the 
bracket 25. This is done by simply rotating lever 26 relative to pivot 
point or pin 27. Thus, by rotating lever 26 clockwise, the upper end 23A 
of bar 23 is released from bracket 25. The entire rear door can then be 
removed from the rear wall of the bus to leave an unobstructed opening for 
removing passengers from the bus. There may also be a lever inside the 
bus, mounted on the opposite end of pin 27, for operating lever 26 to 
release the rear door. 
Preferably, the rear door 20 also includes a vertical reinforcing member 21 
to protect the integrity of the door in the event of a rear end collision. 
Another vertical reinforcing bar 28 is positioned on the rear wall 10A 
adjacent to the vertical bar 23 to protect against rear end collisions. 
Preferably, the edges of the rear door 20 overlap the area around the 
opening in the rear wall to reduce the possible of the door being jammed 
in the event of a collision or rollover. Soft rubber insulation is used 
around the rear door. Caulking may also be used around the rear door to 
seal against dust and air currents. 
In FIGS. 3 and 4 there is shown another embodiment of escape door 40 in the 
rear wall 30A of bus 30. The rear wall also includes windows 13 on 
opposite sides of the rear door which are hinged at their outside edge to 
the rear wall with hinges 13A (e.g. piano-type hinges). Caulking may be 
used around the periphery of the windows to keep out dust, etc. The rear 
door may include a vertical reinforcing member 41 to protect against rear 
end collisions. Additional vertical reinforcing members 31 and 45 may also 
be included on the rear wall on opposite sides of the door 40. 
A hinge member 42 includes a portion 42A which is secured to the rear door 
40 and another portion 42B which is captured or retained at its lower end 
in a recess in bracket 44 and is retained at its upper end 43 in bracket 
47. Portion 42A can pivot relative to portion 42B along hinge line 42C. An 
arm or lever 46 (rotatably mounted on pin 49 in the rear wall 30A) holds 
the upper end 43 of the hinge portion 42B in bracket 47 when the lever 48 
is in its closed position. In this position, the rear door may be opened 
normally when the handle 15 is operated, and the door will pivot along 
vertical hinge line 42C. In the case of an emergency, lever 46 can be 
rotated clockwise relative to pin 49 to release the upper end 43 of hinge 
42. This enables the entire rear door to separate from the rear wall of 
the bus to provide an unobstructed opening in the rear wall. The rear 
windows 13 may then also be opened (by pivoting them outwardly on hinges 
13A) to enlarge the opening in the rear wall. 
The windows 13 may be held in closed position by means of magnets, for 
example, which enable the windows to be easily opened in the event of an 
emergency. When the rear door 40 is closed, the door prevents the windows 
from being opened. 
A lever 46A on the inside of the bus, mounted on the opposite end of pin 
49, also enables the rear door to be released and separated from the rear 
wall of the bus. Additional vertical reinforcing members 48 may be located 
on the interior side of the rear wall of the bus. These reinforcing 
members may be bolted to the frame of the bus. 
The brackets 24 and 25 (FIG. 1) and 44 and 47 (FIG. 3) may be bolted to the 
rear wall of the bus. This feature enables the escape door system to be 
used on any existing bus. 
Other variants are possible without departing from the scope of this 
invention. For example, a warning alarm may be included to signal movement 
of the latch release lever 26 (FIG. 1) or 46 (FIG. 3). 
It is also possible to include a canvas mounted at one edge to the top of 
the rear seat of the bus and at its opposite edge to the rear window sill. 
This canvas then spans the gap between the rear seat and the rear window 
in the event that it is necessary to crawl over the seat to exit through 
an open rear window.