Guage and method for measuring tapered internal and external threads
OwnerJames E. Roulstoneinventor
Life of this patent
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Abstract
A thread guage for indirectly determining the pitch diameter and taper of threads on casing and tubing is disclosed. In the preferred and illustrated embodiment, the thread guage includes a pair of adjustable thread engaging arm assemblies mounted on a bar member. The arm assemblies are selectively locked along the bar member, the distance between the arm assemblies being a fixed position corresponding to a specified thread size. At least two indicators are mounted on one of the arm assemblies providing a value of the measured thread dimensions relative to a standard, which value is used to determine pitch diameter and taper of the thread.
Claims18
A thread gauge, comprising;
- (a) a bar member having oppositely extending end portions;
- (b) protruding arm means adjustably mounted on said bar member;
- (c) means for locking said arm means at a selected location along said bar member;
- (d) thread engaging means connected to said arm means;
- (e) alignment for positioning said arm means relative to a thread form for engagement by said thread engaging means;
- (f) bias means supported by said arm means for urging said thread engaging means into engagement with the thread form;
- and
- (g) indicator means supported by said arm means cooperating with said thread engaging means for comparing thread form dimensions relative to a standard.
A thread guage, comprising:
- (a) a bar member having oppositely extending end portions;
- (b) an alignment bracket mounted on said bar member
- (c) a pair of arm assemblies adjustably mounted on said bar member;
- (d) means for locking each of said arm assemblies at a selected location along said bar member;
- (e) thread engaging means connected to each of said arm assemblies;
- (f) said locking means including a shoulder located thereon cooperating with said alignment bracket for positioning said arm assemblies relative to a thread form;
- (g) bias means supported by one of said arm assemblies for urging said thread engaging means into engagement with the thread form;
- and
- (h) indicator means connected to one of said arm assemblies cooperating with said thread engaging means for comparing thread form dimensions relative to a standard.
A method for determining the taper and pitch diameter of a thread formed on a tubular member, comprising the steps of:
- (a) calibrating a thread gauge with a standard for a specific thread form;
- (b) aligning the thread guage relative to the thread form;
- (c) contacting the thread form simultaneously at least at two separate points in axial alignment along said thread form;
- (d) determining at least two values of the thread form at the points of contact;
- and
- (e) calculating the taper and pitch diameter of the thread form as a function of the determined values at the points of contact.
Dependencies are inferred from the claim text.