1. Field of the Invention
The invention relates to a high-speed, constant-velocity conveyor for conveying individual transport modules containing either freight or passengers and to apparatus and techniques for loading and unloading the transport modules onto and off of the high-speed conveyors.
2. Description of the Prior Art
Many attempts have been made for speedy transportation of passengers and freight on constant-velocity, high-speed conveyors. The inherent problem of such systems is that the load-carrying element of the system must be stopped or greatly slowed down before freight and/or passengers can be safely loaded onto or off of the moving system.
For example, U.S. patents falling into U.S. Classes 104/25, 198/16, and 198/110 and into International Classes B65G17/06, B65G21/12, and related classes, described continuously-moving sidewalk or platform systems for conveying passengers and freight. The platforms of such systems are generally designed to expand or contract in the direction of travel to provide high-velocity sections and low-velocity sections. Freight is placed on and removed and passengers embark on and disembark from the moving platforms in the low-velocity sections.
U.S. Pat. No. 3580182, issued to G. Bouladon and U.S. Pat. No. 3793961, issued to R. Salvadorini, described variable-speed transportation systems for conveying passengers from a stationary surface to a belt moving at a constant velocity. The disadvantages of the Bouladon and Salvadorini systems are as follows:
a. Ingress onto and egress from a constant-velocity belt is provided by structurally-complex, variable-velocity, continuously-moving conveyors.
b. The systems can only handle mobile freight capable of moving under its own power from one moving conveyor system to another moving conveyor system.
c. Passenger transfer between the constant-velocity conveyor and the ingress and egress conveyors depends upon the agility and balance of the passengers.
d. Passengers and freight must be transferred between the constant-velocity conveyor and the ingress and egress conveyors in relatively short time intervals.
Specifically, assuming that a person embarking or debarking from the constant-velocity conveyor is moving at 44 feet per second (30 miles per hour) and the transfer zone is 440 feet long, the passenger has only ten seconds to move from one conveyor belt to the other conveyor belt. Ten-second transfer time is clearly impractical and even impossible for many passengers, particularly the old, the young, the infirm and those who drop their umbrellas. To provide a reasonable transfer time of, for example, three minutes, for a 30 m.p.h. constant-velocity conveyor, would require a transfer zone 1.5 miles long, clearly an impractical alternative.
Also, stationary structures located at the respective ends of the transfer zones of prior art constant-velocity conveyors pose severe safety hazards for passengers who do not successfully transfer from one conveyor to the other or who attempt to transfer within the last second.
For the foregoing reasons, the prior art transportation systems having a constant-velocity conveyor and a variable-velocity conveyor which require passengers to physically move from one part of the system to the other, are both impractical and unsafe.