LIFT GATES AND RELATED CONTROL SYSTEMS AND METHODS

Abstract

A gate system and related control systems and methods include a frame assembly and a tracking assembly coupled to the frame assembly. A door is in mechanical communication with the frame assembly. Related methods for operating a gate of a gate system, where the gate is set to manual mode to manually open or close the gate. Additionally, control systems include a fail-safe programmable logic controller (PLC) circuit for controlling the gate for opening and closing a gate that employs redundant fail-safe features. The control system includes a safety PLC circuit having a PLC including a first input terminal and a second input terminal, and a light curtain switch electrically coupled to the first and second input terminals.

Description

Claims

1. A gate system, comprising: a frame assembly;a tracking assembly coupled to the frame assembly; anda door in mechanical communication with the frame assembly via a pair of linear actuators and the tracking assembly via a guide rail engaging a track roller, the linear actuators and guide rail cooperating simultaneously with the door to rotate the door about an axis extending horizontally through the frame assembly.

2. The gate system of claim 1, wherein actuators are screw ball linear actuators.

3. The gate system of claim 1, wherein the frame assembly includes a pair of vertical posts spaced from each other, each of the posts containing one of the actuators.

4. The gate system of claim 1, wherein the door includes a first door panel and a second door panel each rotatable independently from each other about a vertical axis extending through the frame assembly.

5. The gate system of claim 4, wherein each of the door panels is independently rotatable from each other about the axis extending horizontally through the frame assembly.

6. The gate assembly of claim 2, wherein the guide rails are each formed from a dog-legged shaped track arm cooperating with a surface of the tracking assembly.

7. A method for operating a gate in a manual mode by a user, said method comprising: initiating the manual mode to manually open or close the gate;determining that the user has pressed a gate close input button;closing the gate in response to the gate close input button being pressed;periodically determining whether the gate has reached a fully closed position;determining whether the gate close input button is still being pressed if the gate has not reached the fully closed position; andstopping closing the gate if the gate close input button is not being pressed or the gate has reached the fully closed position.

8. The method for operating a gate in a manual mode by a user of claim 7, wherein the method further comprises: determining that the user has initiated an input signal by pressing a gate open input button;opening the gate in response to the input signal initiated by the gate open input button being pressed;periodically determining whether the gate has reached a fully open position;determining whether the gate open input signal is still being pressed if the gate has not reached the fully open position; andstopping opening the gate if the gate open input button is not being pressed or the gate has reached the fully open position.

9. The method for operating a gate in a manual mode by a user of claim 8, wherein a human-machine interface comprises the gate close input button and the gate open input button, the human machine interface being operatively connected to a programmable logic controller via an Ethernet connection.

10. A fail-safe programmable logic controller (PLC) circuit for controlling a gate, said PLC circuit comprising: a PLC including a first input terminal and a second input terminal;a light curtain switch electrically coupled to the first and second input terminals, said light curtain switch configured to be responsive to a signal from an optical light curtain device that is configured to detect an object in a light curtain, wherein the light curtain switch transmits a stop signal to stop movement of the gate in response to the signal from the optical light curtain device;a bump strip switch electrically coupled to the first and second input terminals, said bump strip switch being responsive to a signal from a bump strip on the gate that indicates that the gate has hit something to stop movement of the gate; anda laser camera switch electrically coupled to the first and second input terminals, said laser camera switch being responsive to a signal from a laser camera that indicates that an item is in a travel area of the gate to stop movement of the gate.

11. The fail-safe PLC circuit for controlling a gate of claim 10, wherein the light curtain device comprises self-monitoring circuitry, a transmitter, and a receiver, wherein the transmitter is aligned with the receiver and comprises one or more light emitting component configured to send a plurality of light pulses to the receiver according to a frequency pattern thereby forming the light curtain.

12. The fail-safe PLC circuit for controlling a gate of claim 10, wherein the stop signal is transmitted to at least one of the first input terminal and the second input terminal.

13. The fail-safe PLC circuit for controlling a gate of claim 12, wherein the stop signal is transmitted to both the first input terminal and the second input terminal.

14. The fail-safe PLC circuit for controlling a gate of claim 10, wherein the signal from the optical light curtain device is configured to be triggered based detecting the object in the light curtain and is further configured to close the light curtain switch thereby stopping movement of the gate.

15. The fail-safe PLC circuit for controlling a gate of claim 10, wherein the bump strip is positioned on a bottom edge of the gate.

16. The fail-safe PLC circuit for controlling a gate of claim 10, wherein the PLC circuit further comprises one or more additional safety devices to determine if two cars are tailgating.

17. The fail-safe PLC circuit for controlling a gate of claim 10, wherein the PLC circuit further comprises a sensor configured to detect whether an over-height vehicle is detected.

18. The fail-safe PLC circuit for controlling a gate of claim 10, the PLC circuit further comprising a down pressure switch, an up-pressure switch, and an emergency stop switch.

19. The fail-safe PLC circuit for controlling a gate of claim 10, wherein the PLC further includes an output terminal configured to transmit a safety signal to a motor configured to control movement of the gate.

20. The fail-safe PLC circuit for controlling a gate of claim 19, wherein the motor includes either a close motor to close the gate or an open motor to open the gate.