Abstract:
A large vehicle entry door safety system which uses at least one fixed mark at a measured height and a position indicator attached to the door. By safely and clearly indicating the height of the large vehicle entry door by visual alignment of the position indicator with the fixed mark or marks, vehicle operators or door operators or both can be helped to avoid collisions with the door.

Description:
FIELD OF INVENTION 
     The present invention relates to a vehicle entrance door safety system and method which provides a position indicating means to prevent damage to vehicles and doors as well as injury to persons. 
     BACKGROUND AND OBJECT OF THE INVENTION 
     Damage to large vehicle entry doors has long been a problem for fleet operators and building owners. Often, large vehicle entry doors are not positioned in full open or full closed positions. Either to conserve energy or for convenience, doors are adjusted to various heights for differing vehicles as they pass through door openings. As a result, vehicles frequently collide with entry doors causing extensive damage to the door, door frame, vehicle or a combination thereof. Additional problems are encountered when a door or frame is damaged to such an extent as to prevent continued operation. If the door cannot be closed after being damaged, continued energy loss and increased security risks ar confronted. If the door cannot be opened, substantial interference with business traffic and increased safety risks are confronted. 
     Problems are also encountered when a vehicle is damaged extensively by a door collision. Damage to a truck&#39;s container can cause the truck to be removed from service for a substantial time period burdening its owner with repair costs and lost earnings. 
     Furthermore, personal injury can occur. People, passing through partially opened doors, can misjudge door clearances and incur injury. Such injuries are usually to the head and can be serious. 
     Damage to the door can occur even when a door is opened to its full height because operators of vehicles are not warned of the clearance available for entry. Additionally, doors might appear to be opened to their full height when in reality they are partially closed. 
     Two reasons for the problems as defined above are one, there is no way for a vehicle driver to determine the height position of the door opening or the door&#39;s maximum clearance and two, door operators are not able to accurately judge a door&#39;s opening clearance and are not instructed otherwise. 
     Existing height measuring systems are employed in other areas but do not address the problems as defined above. For example, various highway bridges usually display clearance heights for truck operators. There, the bridge clearance is fixed. There is no continuous adjustment to height as found with a large vehicle entry door. 
     In the marine environment, ruled marks are incorporated to indicate water an estimated depth or bridge clearance. There, variable depth or height is encountered but of a different nature. Variation in depth is encountered with the slow accumulation of sludge or other debris on the marine floor. The height variation in the marine environment is due to tidal changes which are slow and predictable. Marine operators who are concerned with depth or height clearances calculate ahead of time and need not be concerned with unknown clearances. That situation is not encountered with large vehicle entry doors. There, door heights are continuously adjusted for various vehicles without any pattern. Operators of doors and vehicles can control the height at which a door is to be adjusted and need to have clearance heights indicated to them at every adjustment. 
     Various attempts have heretofore been made to provide a satisfactory height indicating means. Early attempts involved attaching poles to the vehicles. An example of such a structure is shown in U.S. Pat. No. 3,137,267 issued to Hurt for a HEIGHT CLEARANCE INDICATOR. That invention involves a complex mechanism to indicate clearance by having a pole act as an antennae. Other related inventions use complex mechanisms to indicate side clearance. Examples of such mechanisms are shown in U.S. Pat. No. 3,493,925 issued to Brancale for a POSITION INDICATING SYSTEM, U.S. Pat. No. 2,706,462 issued to Evans for GARAGE DOOR GUIDES, and U.S. Pat. No. 2,569,529 issued to Kirk for a CLEARANCE INDICATOR. 
     None of those inventions disclose a simple height indicating system for large vehicle entry doors. It is therefore an object of the present invention to provide a safety system and method of indicating door clearance to door and vehicle operators to avoid entry door damage and risk of personal injury. 
     It is yet a further object of this invention to define the height of a door opening at all levels. 
     It is yet a further object of this invention to define safe clearance levels for specific entrance situations such as cars, people, vans or trucks. 
     It is yet a further object of this invention to inform an individual what a door&#39;s maximum height is and whether the door is opened to its maximum height. 
     It is yet a further object of this invention to allow a door to be positioned to correct heights to avoid unnecessary energy loss. 
     It is yet a further object of this invention to inform door operators as to the proper height to raise or lower a door. 
     It is yet a further object of this invention to inform vehicle operators to check door height clearance. 
     Objects and advantages of the present invention are set forth in part herein and part will be obvious here from, or may be learned in practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims. 
     The invention consists in the novel parts, constructions, arrangements, combinations, steps and improvements herein shown and described. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a safety system and method may be used for allowing an entry door operator or vehicle driver to determine, at a glance, the clearance available when an entry door is partially open or fully open. The invention uses a door and markings measured on an associated door frame or wall as a means to indicate door height. By using measured marks on a door frame or wall as a fixed reference and a door&#39;s bottom edge as a position indicating means a person can clearly discern available door clearance. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, referred to herein and constituting part hereof, illustrate preferred embodiments of the product of the present invention and together with the description serve to explain the principles of the invention, in which: 
     FIG. 1 is a perspective view of one embodiment of the safety system with two ruled edges in place; 
     FIG. 2 is a perspective view of another embodiment of the safety system with specific height markings; 
     FIG. 3 is a perspective view of another embodiment of the safety system with a single maximum clearance mark; 
     FIG. 4 is a perspective view of another embodiment with ruled markings positioned behind a door: 
     FIG. 5 is a front view of an embodiment of door panel instructions and warning labels. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now more particularly to FIGS. 1 of the accompanying drawings, there is illustrated a preferred embodiment of a vehicle door safety system in accordance with the present invention. As here embodied, entry door 1 is associated with a door frame 2. Attached to door frame 2 are two sets of ruled markings 4 &amp; 5. Ruled markings can be placed either against door frame 2, as shown with ruled markings 4, or on or near a facing wall, as shown with ruled markings 5. Additionally, a combination of frame and wall markings can be used as shown in FIG. 1. 
     A position indicating means, 3 or 7, is positioned at or near the door edge. A position indicating means can either be a mark 7 or an attached pointing device 3 or a combination of both as shown in FIG. 1. Pointing device 3, as shown in FIG. 1, is perpendicularly extended from door 1 and associated with ruled markings 4 to indicate door clearance. Additionally, Pointing device 3, as shown in FIG. 1, is bent at a right angle to a position parallel to ruled markings 5 and associated with same to indicate door clearance at a differing angle. 
     Also shown in FIG. 1 is a warning sign 6 which directs a viewer&#39;s attention to check the indicated door clearance. 
     Referring now to FIG. 2 of the accompanying drawings, another embodiment of the invention is illustrated. In this embodiment, the ruled markings of FIG. 1 have been replaced with specific vehicle clearance markings 8. Such markings, labeled to indicate a specific vehicle, are placed on the door frame or adjacent wall at various clearance heights for said vehicles. A mark, such as a picture of a car or the word &#34;CAR&#34;, is positioned at a height required for oar clearance. Additional markings, for example &#34;PERSON&#34;, &#34;VAN&#34; or &#34;DELIVERY TRUCK&#34;, are placed at the appropriate height for each vehicle. Position indicating means 3 &amp; 7 are used to indicate whether the door edge is aligned at or above the markings 8. Thus, a door operator, when needing to raise a door to allow a car to enter, can raise door 1 to a proper height by aligning the position indicating means 3 &amp; 7 at or above a car mark 8. 
     Referring now to FIG. 3 of the accompanying drawings another embodiment of the invention is illustrated. The embodiment of FIG. 3 is utilized when a door is usually found in a full open position. In such a situation, the need for indicating what a maximum door clearance is and whether a door is opened to said maximum clearance is required. 
     Mark 10 labeled with the maximum door clearance is attached to door frame 2 behind and parallel to door 1 so that when door 1 is opened to maximum clearance mark 10 becomes visible indicating that the door is opened to maximum clearance. Alternatively or additionally, mark 9, labeled with the maximum door clearance, can be placed against door frame 2 so that when position indicator 7 is aligned or above mark 9 the door is opened to its maximum clearance. 
     Referring now to FIG. 4 of the accompanying drawings, another embodiment of the invention is illustrated. Here, ruled markings 11 are placed parallel and behind door 1. As door 1 is opened ruled markings 11 become visible and indicated door clearance. Additionally, a door operator controlling the door 1 from a position inside the door can see the height clearance as indicated by the door edge and inner ruled markings not shown. Alternatively, the ruled markings 11 can function in the same manner when positioned in front of door 1. 
     Referring now to FIG. 5 of the accompanying drawings, instructions and warning labels are illustrated. Specifically, instructions 12 show a door operator how to use said safety system. Warning sign 13 can be placed on a vehicle to remind drivers and door operators to check the height indicated on the safety system. Also shown is warning signs 6 and 14 which can be placed in various areas to direct attention to the height indicated on the safety system.