Detection of obstruction of doors
First Claim
1. An obstruction detection system for an edge of a movable door, comprising a sensing element defining an interior space containing a fluid, said sensing element being deformable to cause an increase in pressure in said fluid in said interior space when an obstruction is encountered, improvement comprising testing apparatus for testing the integrity of at least said sensing element and wherein said testing apparatus comprises:
- a device introducing a predetermined quantity of said fluid into said interior space of the sensing element to raise the fluid pressure therein, said device further providing relief of the raised fluid pressure in said interior space of the sensing element over a predetermined time period; and
assessment apparatus measuring a time period in which the raised pressure in the interior space of the sensing element is relieved following said introduction therein of the predetermined quantity of fluid, and comparing said measured time period with said predetermined time period to provide an indication of the integrity of at least the sensing element.
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0 Petitions
Accused Products
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.
19 Citations
11 Claims
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1. An obstruction detection system for an edge of a movable door, comprising a sensing element defining an interior space containing a fluid, said sensing element being deformable to cause an increase in pressure in said fluid in said interior space when an obstruction is encountered, improvement comprising testing apparatus for testing the integrity of at least said sensing element and wherein said testing apparatus comprises:
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a device introducing a predetermined quantity of said fluid into said interior space of the sensing element to raise the fluid pressure therein, said device further providing relief of the raised fluid pressure in said interior space of the sensing element over a predetermined time period; and
assessment apparatus measuring a time period in which the raised pressure in the interior space of the sensing element is relieved following said introduction therein of the predetermined quantity of fluid, and comparing said measured time period with said predetermined time period to provide an indication of the integrity of at least the sensing element. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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- 9. 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.
Specification