Patent ID: 8528459
Filing Date: 2013-09-10
Classification: E05F,E05Y,F15B,Y10T

Abstract:
1. A cushioning system for use with a pneumatic cylinder/differential engine door operator for driving a door between open and closed positions wherein said differential engine includes a large cylinder aligned with a small cylinder and large and small associated pistons having a rack and pinion assembly connected between and controlled by movement of said associated pistons, said cushioning system comprising: (a) a large cap for sealing said large cylinder; (b) a slider extending from said large cap and into said large cylinder, said slider being in fluid contact with an interior portion of said large cylinder; (c) at least a first port having a first diameter extending through a first wall portion of said slider; (d) at least a second port having a second diameter smaller than said first diameter and extending through a second wall portion of said slider, said second sidewall portion being at a remote location from said first sidewall portion; (e) a valve associate with said slider for applying fluid through said first and second ports into said large cylinder during a door closing cycle and exhausting fluid through said first and second ports from within said large cylinder during a door opening cycle; (f) a closing device for sealing said slider near the end of a door opening cycle, preventing the flow of exhaust through said first port so that the flow of exhaust occurs through the second port and slowing the forward movement of said pair of pistons, said closing device moveable relative to said large piston; (g) a biasing system for mounting said closing device with respect to said large cap and said slider, said biasing system adapted for linearly moving said closing device with respect to said large cap and said slider; and (h) an adjusting device for adjusting the linear extension of said slider into said large cylinder and adjusting the distance between said closing device and said slider for one of increasing and decreasing the amount of time before sealing of the slider occurs to adjust the time at which cushioning occurs during the door opening cycle.