Detection of obstruction of doors

• US 20030192252A1
• Filed: 04/10/2002
• Published: 10/16/2003
• Est. Priority Date: 10/05/1999
• Status: Active Grant

• Current Assignee: Door Systems Group Limited
• Original Assignee: Deans Systems Limited
• Inventors: Spencer, Peter Edward James, Harrison, Nicholas Charles
• Granted Patent: US 6,779,302 B2
• Time in Patent Office: Days
• US Class Current: 49/13
• CPC Class Codes: E05F 15/47 responsive to changes in fluid pressure
• CPC Class Codes: E05F 15/56 for horizontally-sliding wings
• CPC Class Codes: E05F 2015/487 Fault detection of safety edges
• CPC Class Codes: F15B 21/12 Fluid oscillators or pulse generators

Abstract

Pneumatic sensing elements are provided on the leading edges of power operated vehicle doors. If an obstruction is encountered on closing the doors, the sensing elements are compressed to cause a pressure increase which is sensed and is used to open the doors. Each time the doors are opened, operation of the system is tested by applying a gas pressure pulse to the system. The pressure pulse is gradually vented through a fixed orifice. The pressure in the system produced by the pressure pulse is sensed and is applied to a controller which compares the pressure pulse information with information for known pulses for a normally operating system and for system failures caused, for example, either by a leak or by a blockage in the system.

Claims

1. A method of testing the integrity of a sensing element for an obstruction detection system, said sensing element defining an interior space containing a fluid and being adapted to produce a detectable change in pressure in said fluid if an obstruction is encountered, said testing method comprising:

applying to the interior space of the sensing element a predetermined change in pressure of fluid;

providing for relief of said changed pressure in a predetermined manner;

and assessing a characteristic of the manner in which said change in pressure is actually relieved to provide, in comparison with said predetermined manner, an indication of said integrity.

2. A method according to claim 1 comprising introducing a small quantity of said fluid into the interior of said sensing element, to produce a predetermined pulse of increased pressure.

3. A method according to claim 2 wherein said relief of pressure in a predetermined manner is provided for by leakage of fluid from the sensing element by way of a bleed orifice connecting the interior of sensing element to external atmosphere, the size of said orifice being selected to provide a controlled rate of leakage of fluid from the sensing element.

4. A method of testing the integrity of a sensing element for an obstruction detection system, said sensing element defining an interior space containing a fluid and being adapted to produce a detectable change in pressure in said fluid if an obstruction is encountered, said testing method comprising:

introducing a small quantity of said fluid into the interior of the sensing element, to produce a predetermined pulse of increased pressure in said fluid;

providing for escape of fluid from the interior of said sensing element, to relieve said increased pressure in a predetermined manner;

measuring the rate at which pressure in the sensing element changes in response to said pressure pulse applied thereto; and

comparing said measured rate at which pressure changes with a predetermined rate of pressure change, to provide an indication of said integrity of the sensing element.

5. An obstruction detection system comprising a sensing element, said sensing element defining an interior space containing a fluid, said sensing element being adapted to cause a detectable pressure change in said fluid therein if an obstruction is encountered, and further comprising apparatus for testing the integrity of at least said sensing element, said testing apparatus comprising:

a device for applying a predetermined change in pressure to the interior of the sensing element, said changed pressure being arranged to be relieved in a predetermined manner; and

assessment apparatus for assessing the manner in which the pressure is actually relieved to provide, in comparison with said predetermined manner, an indication of said integrity.

6. A system according to claim 5 wherein said device for applying a predetermined change in pressure to the interior of the sensing element creates a pressure pulse in said sensing element by introducing a predetermined quantity of fluid into the sensing element, and a bleed orifice provides for relief of excess pressure in the sensing element in said predetermined manner.

7. A system according to claim 6 wherein said device comprises a piston movable within a cylinder and having cylinder spaces on opposite sides of the piston, the cylinder space on one side of the piston being arranged to have fluid pressure applied thereto and the cylinder space on the other side of the piston being connected to the interior of the sensing element.

8. A system according to claim 7 and wherein said device further comprising a one-way valve provided in a connection between the sensing element and said cylinder space which is connected to the sensing element.

9. A system according to claim 6 and further comprising a pressure sensor providing an electrical output signal for analysis to indicate the integrity of the system.

10. A system according to claim 9 and further comprising a timer for measuring the duration of the pressure pulse.

11. A door system for a vehicle including an obstruction detection system according to claim 5.

12. A pneumatically operated door system including an obstruction detection system according to claim 6.

13. A door system according to claim 12 wherein said obstruction detection system is caused to be operated each time the door is opened.

14. In combination with a pneumatically operated vehicle door system including an obstruction detecting system comprising a flexible sensing element forming a leading edge of a vehicle door and having a gas filled interior space connected through pipes to a gas pressure sensor which generates a signal in response to pressure changes in said interior space caused by said sensing element being compressed by an obstruction when said vehicle door is closing, a testing system for said obstruction detecting system including a manifold chamber connected between said pipes and said pressure sensor, an orifice providing a controlled vent to said manifold chamber, means for applying an increased pressure gas pulse to said manifold chamber when said vehicle door is opened, and means responsive to said pressure sensor when a gas pulse is applied to said manifold chamber for detecting gas leaks and blockages in said obstruction detecting system.

15. A testing system for a pneumatically operated vehicle door system including an obstruction detecting system, as set forth in claim 14, and wherein said means for applying an increased pressure gas pulse includes a piston mounted to move in a cylinder, means for moving said piston in said cylinder to displace a volume of gas in response to said vehicle door being opened, and means delivering said displaced gas to said manifold chamber.

16. A testing system for a pneumatically operated vehicle door system including an obstruction detecting system, as set forth in claim 15, and wherein said means delivering said displaced gas to said manifold chamber comprises a check valve.