Elastomeric gage for borescope

• US 5,047,848 A
• Filed: 07/16/1990
• Issued: 09/10/1991
• Est. Priority Date: 07/16/1990
• Status: Expired due to Fees

• Current Assignee: Everest Visual Inspection Technologies, Inc. (GE Aerospace)
• Original Assignee: Welch Allyn Incorporated
• Inventors: Krauter, Allan I.
• Primary Examiner(s): Kostak, Victor R.
• Application Number:
  US07/552,574
• Time in Patent Office: 421 Days
• Field of Search: 358/100, 358/107, 358/98, 358/93, 358/139, 33/501
• US Class Current: 348/82
• CPC Class Codes: A61B 1/00097 Sensors
• CPC Class Codes: A61B 1/05 characterised by the image sensor, e.g. camera, being in the distal end portion
• CPC Class Codes: A61B 5/1076 for measuring dimensions inside body cavities, e.g. using catheters A61B3/1005 takes precedence
• CPC Class Codes: G01B 11/026 by measuring distance between sensor and object G01B11/0608 takes precedence

Abstract

An elastomeric distance gage is formed of a ring of elastomeric film to which is joined a vee-shaped ear of elastomeric film. The ring of this gage fits removably onto a video head or other imager at the distal tip of a borescope. The legs of the nose portion converge to a distal tip which is within the viewing field of the borescope imager. To determine the size of an object, the gage is brought into contact with the object. The gage nose will deflect and this is visible in the viewing screen of the borescope. The object can be measured by comparison to a known width of the flat apex of the gage. Also, at this contact point, the object is a predetermined known distance from the borescope tip, and the size of the object can be determined by counting the number of pixels in the displayed image from one edge of the object to an opposite edge.

Claims

1. Gage for measuring size and distance of a target object viewed in a borescope probe which has a viewing head at a distal tip of a tubular probe member, the gage comprising a ring fitting removably over said distal tip and a resiliently flexible ear projecting axially from said ring a predetermined distance distal of said viewing head.

2. Gage according to claim 1 wherein said ring and said ear are unitarily formed of an elastomeric material.

3. Gage according to claim 1 wherein said ear is generally triangular with an open window cut therethrough.

4. Gage according to claim 1 wherein said ear is in the form of a vee having a pair of legs that converge to an apex distal of the ring.

5. Gage according to claim 4 wherein said legs join said ring at a circumferential included angle of about 90 degrees.

6. Gage according to claim 1 wherein said apex has a flat transverse edge of a predetermined width.

7. Gage according to claim 2 wherein an inner non-elastomeric ring is contained within said elastomeric ring.

8. Gage according to claim 7 wherein said inner non-elastomeric ring is slit generally axially.

9. Gage according to claim 7 wherein both said elastomeric ring and said non-elastomeric ring are slit generally axially.

10. In combination, a borescope of the type which has an elongated insertion tube, and a viewing head at a distal tip of said insertion tube which obtains an image of an object in a viewing field distally of said tip and transmits same to a viewing device;

and a gage for measuring size and distance of said object;

said gage including a ring fitting removably over said distal tip and a flexible resilient ear projecting axially from said ring a predetermined distance distal of said viewing head.

11. The combination of claim 10 wherein said ring and said ear are unitarily formed of an elastomeric material.

12. The combination of claim 10 wherein said ear is in the form of a vee having a pair of legs that converge to an apex a predetermined distance distal of said viewing head.

13. The combination of claim 12 wherein said apex has a flat transverse edge of a predetermined width.

14. Method of measuring the size of an object that is within the viewing area of a video borescope of the type in which a viewing head is positioned at the distal tip of a probe insertion tube, the viewing head producing an image that is transmitted to a viewing device and presented as an array of picture elements and wherein a gage is removably fitted onto said distal tip, said gage including a ring fitting removably over said distal tip and a flexible resilient ear that extends distally to a distal edge a predetermined distance distal of said viewing head such that said ear appears in the image in the viewing device;

the method comprising;

a. positioning said insertion tube distal tip so that the distal edge of the ear contacts said object, while monitoring the image in said viewing device;

b. electronically capturing the image of said object in said viewing device when said ear is in contact with said object, so that said object is at substantially said predetermined distance from said viewing head;

c. electronically counting the picture elements from one edge of said object to an opposite edge in at least one direction; and

d. computing the size of said object based on the number of picture elements and the length of said predetermine distance.