Abstract:
An industrial truck cab is provided having a roof made at least partly of bulletproof glass. This roof combines a high degree of safety against falling objects with good sight lines.

Description:
The present application claims foreign priority to German application Ser. No. 198 15 126.8 filed Apr. 3, 1998. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to a cab of an industrial truck and, more particularly, to the cab of a fork lift truck. 
     2. Description of the Currently Available Technology 
     Industrial trucks with a driver workplace generally have a cab or roof that protects the driver from falling objects or falling parts of the load. In the prior art, the roof has been constructed both as a metal grid structure and also from sheet metal with an integrated window. These types of roofs represent a compromise between driver protection and a clear driver&#39;s view forward or diagonally upward. 
     It is therefore an object of the invention to provide a cab for an industrial truck that combines a high degree of safety with an improved field of vision for the driver. 
     SUMMARY OF THE INVENTION 
     The invention teaches that this object can be accomplished by a cab for an industrial truck having a roof made at least partly with substantially transparent bulletproof glass. The invention teaches that the roof is preferably substantially transparent for an improved field of vision and simultaneously provides the driver with optimal protection against falling objects. The bulletproof glass of the invention can be provided only in the roof area or, in a preferred embodiment, can also form a windshield and/or a rear window of the cab. For example, two or three separate bulletproof glass panels can be provided which protect the driver from the front, from the rear and overhead, which thereby allow the driver a good view in those directions. It is also possible that the glass panels can be constructed as one piece and can form the windshield and the roof, for example of the cab. In another embodiment, the one-piece glass panel runs continuously from the windshield, over the roof and to the rear window. The driver&#39;s field of vision is optimal in this embodiment. Only encircling metal frames that hold the glass panel and that form the frame for the doors or the side windows of the cab thus remain in the driver&#39;s field of vision. 
     In one preferred embodiment, the cab can be eggshaped or spherical. A spherical shape, for example, is inherently one of the most stable shapes possible, as is known from the use of this shape in conventional reactor vessels. The use of an egg-shaped cab makes it possible to have relatively thin walls while providing a high degree of safety and stability inherent in such an egg shape. 
     The driver&#39;s field of vision can be further improved if the side pieces that form the doors or the windows of the cab are also made of a transparent material, such as glass, e.g., bulletproof glass, or plastic. In this case, the driver has a clear view practically all the way around the cab. 
     Additional advantages, features and configurations of the invention are described in greater detail below, with reference to the exemplary embodiment illustrated in the accompanying drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The drawing FIGURE is a perspective view of an industrial truck having a cab of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As used herein, the term “bulletproof glass” is used in the conventional sense to refer to tempered or strengthened glass capable of withstanding the impact of a bullet or similar force. The thickness of the glass used in the invention may differ from one country to another depending upon the occupational safety requirements for industrial trucks in each country, e.g., how much weight an industrial truck roof must withstand, the particular work environment in which the truck will operate, etc. 
     The FIGURE shows one embodiment of a fork lift truck of the invention having a frame  2 , a cab  4 , a lifting frame  6  and a counterweight  8 . In this embodiment, the lifting frame  6  is equipped with a telescoping cylinder  10  to raise and/or lower a load. Inside the cab  4  there is a driver&#39;s seat  12  which, as is common in modern fork lift trucks, has a small steering wheel on the left armrest and a joystick for the fork lift functions as well as a selector for the direction of travel on the right armrest. In this embodiment, the cab  4  has a windshield  14  and two cameras  16 , e.g., conventional video cameras. The cameras  16  are directed toward the rear of the industrial truck. The cameras  16  are in electronic communication with a screen  18  located in front of the driver, i.e., between the driver&#39;s seat  12  and the lifting frame  6 . The screen  18  may be any type of conventional screen, e.g., a conventional video monitor, LCD display, “head&#39;s up display”, etc., to project for the driver an image on the screen  18  of what is behind the industrial truck. The screen  18  can be integrated into the windshield  14  in the area behind the fork lift on the lifting frame  6 . In this embodiment, the cab  4  can be elevated from the frame  2  by two elevating cylinders  20 , e.g., conventional pneumatic or hydraulic cylinders. 
     As shown in the FIGURE, the driver&#39;s seat  12  is enclosed by a substantially egg-shaped cab  4 . In this embodiment, the windshield  14  extends over the driver&#39;s seat  12  to form the roof  24  of the cab  4  and also extends behind the driver&#39;s seat  12  to thus also form the rear window  26  of the cab  4 . The driver therefore has an unimpeded view toward the front, overhead and toward the rear. In this embodiment, the sides of the cab  4  may be open. Alternatively, the sides of the cab  4  can be closed with doors  22  in the form of transparent side pieces  30  movably, e.g., attached by hinges  28 , to the cab  4 . Thus, the driver has an extraordinarily good view of his surroundings, which is restricted only by the curved metal frames that enclose the bulletproof glass panel forming the windshield  14 , roof  24  and rear window  26 . 
     It will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed in the foregoing description. Accordingly, the particular embodiments described in detail herein are illustrative only and are not limiting to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof.