Testing device and method for inflatable objects

• US 4,873,654 A
• Filed: 02/09/1987
• Issued: 10/10/1989
• Est. Priority Date: 06/11/1984
• Status: Expired due to Fees

• Current Assignee: Safe Text Ltd.
• Original Assignee: Safe Text Ltd.
• Inventors: Alexander, William B., Frenger, Paul
• Primary Examiner(s): Chin, Gary
• Application Number:
  US07/012,576
• Time in Patent Office: 974 Days
• Field of Search: 364/557, 364/558, 364/550, 364/551.01, 364/571.01, 73/708, 73/714, 73/753, 73/146.5, 73/146.8, 441/40-42
• US Class Current: 702/140
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for

Abstract

A testing device and method for inflatable objects comprising an arrangement of transducer sensors; connectors between the transducers and the inflatable object desired to be tested; processors electrically connected to the transducer sensors; a controller electrically connected to and interactive with the processors; and a display of the electrical output. The transducer sensors comprise a pressure transducer, a temperature transducer, and a load cell transducer. The temperature transducer is positioned generally adjacent to the valve nozzle of the inflatable object. The processors of the present invention comprise a multiplexer electrically connected to the transducer sensors, a differential amplifier electrically connected to the multiplexer, and a sample/hold amplifier electronically connected between the analog-to-digital converter and the differential amplifier. The controller comprises an input/output keyboard connected to the processors through an RS-232 communication line. The output display is a video display terminal and/or a serial type line printer.

Claims

1. A testing device for evaluating an inflatable object having expandible wall comprising:

transducer means for converting the physical inputs of temperature and pressure from said inflatable object into electrical impulses, said transducer means comprising;

a pressure transducer for evaluating the pressure of a gas within said inflatable object, said pressure transducer having a chamber connected thereto; and

a temperature transducer having a nozzle for connection to a valve of said inflatable object, said temperature transducer positioned adjacent said nozzle, said temperature transducer for measuring the temperature of said gas within said chamber of said pressure transducer;

connection means fastened to said transducer means for enabling said transducer means to be interactive with said physical inputs from said inflatable object, said connection means comprising a pressure transducer nozzle for connecting a valve of said inflatable object to said pressure transducer, said chamber of said pressure transducer being adjacent to and in air-tight connection with said pressure transducer nozzle, said chamber for allowing differential pressures within said chamber and said inflatable object to equalize upon connection of said pressure transducer nozzle to a valve of said inflatable object;

processing means electrically connected to said transducer means for selectively converting said electrical impulses of said transducer means into signals relative to said physical inputs of temperature and pressure, each of said pressure transducer and said temperature transducer having electrically conductive lines extending therefrom to said processing means, the signals from said transducer means being passed as separate inputs of temperature and pressure to said processing means, said processing means evaluating said inflatable object based on said signals; and

output means electrically connected to said processing means for producing a perceivable display of said signals from said processing means.

2. The testing device of claim 1, said transducer means further comprising:

a load cell transducer for weight measurement, said load cell transducer having electrically conductive lines extending therefrom to said processing means.

3. The testing device of claim 2, said load cell transducer comprising:

a load cell hook physically connected to said load cell transducer for receiving the weight to be measured, said load cell hook being interactive with said load cell transducer.

4. The testing device of claim 3, said load cell hook being adapted to support the weight of said inflatable object in mid-air.

5. The testing device of claim 1, said inflatable object being an aircraft emergency slide.

6. The testing device of claim 1, said processing means comprising:

differential amplifier means electrically connected to said transducer means for producing an analog signal relative to a selected one of said electrical impulses from said transducer means; and

analog-to-digital converter means electrically connected to said differential amplifier means for converting said analog signal to a digital output.

7. The testing device of claim 6, said processing means further comprising:

multiplexer means electrically connected to said transducer means, said multiplexer means receptive of the signals from said transducer means, said multiplexer means selectively passing a signal to said differential amplifier means.

8. The testing device of claim 7, said processing means further comprising:

sample/hold amplifier means electrically connected between said analog-to-digital converter means and said differential amplifier means, said sample/hold amplifier means for capturing the voltage output from said multiplexer means for a predetermined period of time.

9. The testing device of claim 1 further comprising:

an input/output keyboard connected to and interactive with said processing means through a RS-232 communication line.

10. The testing device of claim 1, said output means comprising a video display terminal connected to and interactive with said processing means.

11. The testing device of claim 10, said output means comprising a serial type line printer, said serial type line printer electrically connected to said processing means.

12. The testing device of claim 1, said output means comprising:

storage means electrically connected to said processing means, said storage means suitable for maintaining a database-type file relative to the signals as transmitted by said processing means.

13. The testing device of claim 1, further comprising:

a battery power supply connected to said processing means for providing electrical energy to said processing means.

14. A testing method for evaluating an inflatable object having expandible walls comprising the steps of:

inflating said inflatable object with a selected gas until said expandible walls expand to a desired tautness;

fastening a pressure transducer and a temperature transducer to a valve of the inflated object, said pressure transducer having a chamber adjacent said valve of said inflated object, said temperature transducer communicating with the interior of said chamber;

passing said selected gas from the interior of said inflated object into the chamber of said pressure transducer;

equalizing the pressure of said gas within said inflated object with the pressure in said chamber of said pressure transducer, said temperature transducer sensing the temperature of the equalized pressure within said chamber, said pressure transducer sensing the equalized pressure within said chamber;

converting the equalized pressure from said chamber of said pressure transducer and the sensed temperature of said equalized pressure into electrical signals indicative of the equalized pressure and the sensed temperature;

transmitting said electrical signals to a multiplexer;

converting said electrical analog signals from said multiplexer into digital signals, said digital signals corresponding to the equalized pressure from said chamber and to said sensed temperature;

processing said digital signals such that said signals are indicative of physical units of measurement of pressure and temperature;

transmitting said digital signals to a video display terminal having an input/output keyboard; and

displaying said physical units of measurement of pressure and temperature relative to said digital signals.

15. The testing method of claim 14, further comprising the step of:

adjusting the physical unit of pressure measurement as function of said sensed temperature in accordance with Boyle'"'"'s law.

16. The testing method of claim 14, further comprising the steps of:

fastening at least one load transducer to said inflatable object;

supporting said inflatable object in mid-air such that said load transducer detects the weight of said inflatable object;

transmitting the electrical impulse from said load transducer as an input to a terminal of said multiplexer, said multiplexer selectively passing said input as a signal to an analog-to-digital converter;

passing the selected input from said multiplexer to a differential amplifier;

converting the selected input into analog electrical signal relative to the physical input from said load transducer; and

passing the analog electrical signal to said analog-to-digital converter.